R.N. 70269/98 Postal Registration No.: DL-SW-1/4082/15-17 ISSN : 0972-169X Date of posting: 26-27 of advance month Date of publication: 24 of advance month
November 2017 Vol. 20 No. 2 Rs. 5.00 Nobel Prizes
Nobel Prize in Science 2017 in Science 2017
Editorial: Some priorities for 35 science communication management in India
Swarnakumari Devi: The 34 woman who led the scientific reawakening of India
Karl Schwarzschild and 31 his last gift
Nobel prizes in science 2017 29
Dead zones: An increasing concern 27
Irritable bowel syndrome — 24 Causes, triggers, red flags and more
Recent developments 21 in science and technology
36 Dream 2047, November 2017, Vol. 20 No. 2 36 Editorial Some priorities for science communication management in India
Dr. R. Gopichandran
A compendium of good is conspicuous by its absence. communication has always been an practices in science communication The role of communication integral aspect of citizen engagement must be developed at the earliest. barriers in translating the intents in India. The fourth element with This is to bring to light the good of communication into benefits crosscutting relevance that will work that is happening, especially at and integrated information, decide the success of communication the grassroots level with implications education, and communication strategies, i.e., about the interplay for changes in the quality of life. This strategies to overcome them will of regulations, market mechanisms implies communication regarding be essential component of the and institutional mechanisms that natural resources management, proposed theorisation framework. brings stakeholders together. The energy, health and sanitation, Most importantly, the agenda impacts of science communication crop protection and eco-system- behind communication has to be cannot be interpreted in isolation. specific bio-resources management interpreted to establish that there We might end up trivialising in particular. I have deliberately was no ulterior with respect to an science communication if these chosen the entry point as reflected idea/philosophy and therefore, the three parameters are not taken into in the topics stated above. Science centrality of transparency within the account. My final call is about the communication in this context communication framework. urgent need to not trivialise science means understanding the feasibility Collection of audio-visual, communication. It is probably the of using alternatives and enabling print and other knowledge products most robust unifying platform for the implementation of measures for developed by communicators knowledge centered engagement timely delivery of solutions; through will help understand the richness with citizens. robust knowledge management of such interventions. The three practices. priorities stated have to be addressed Theorisation of science simultaneously. The larger objective Email: r.gopichandran@vigyanprasar. gov.in n communication practices in India is to demonstrate the fact that science
Editor : R Gopichandran Vigyan Prasar is not responsible for the statements/opinions expressed and photographs used by the authors in their articles/write-ups published in Associate editor : Rintu Nath “Dream 2047” Production : Manish Mohan Gore and Pradeep Kumar Articles, excerpts from articles published in “Dream 2047” may be freely Expert member : Biman Basu reproduced with due acknowledgement/credit, provided periodicals in Address for Vigyan Prasar, C-24, which they are reproduced are distributed free. correspondence : Qutab Institutional Area, New Delhi-110 016 Published and Printed by Manish Mohan Gore on behalf of Vigyan Tel : 011-26967532; Fax : 0120-2404437 Prasar, C-24, Qutab Institutional Area, New Delhi - 110 016 and Printed e-mail : [email protected] at Aravali Printers & Publishers Pvt. Ltd., W-30, Okhla Industrial Area, website : http://www.vigyanprasar.gov.in Phase-II, New Delhi-110 020 Phone: 011-26388830-32.
35 Dream 2047, November 2017, Vol. 20 No. 2 History of Science Swarnakumari Devi: The woman who led the scientific reawakening of India
Dr Rakesh Kumar Dubey
In the annals of Indian society’s Swarnakumari Devi scientific reawakening, Swarnakumari Devi is a name written in golden letters. She was was the first Indian the first Indian woman to write effusively on subjects related to science. This was woman to write effusively in addition to Swarnakumari’s prowess as a prolific writer on social, political and on subjects related to cultural themes. She chose Bangla as the science. A perusal of language of her expression. This made her writings accessible to the common folks in her work makes it clear Bengal under the British Raj, including a large number of women. Swarnakumari that Swarnakumari not managed to usher in a new movement introducing masses to science, a significant only enriched common feat considering the odd circumstances of literature, but also the that era. The process of revitalisation of the Swarnakumari Devi scientific intelligentsia Indian society began from Bengal. The Renaissance originated in 14th century Swarnakumari Devi was born on 28 of her time. She was Europe, but it culminated in the land August 1855. She was the fourth amongst of Banga in 19th century India. The the daughters of Debendranath Tagore instrumental in bringing Bengali intelligentsia took up this baton (1817-1905) and Sharda Devi. Schools were the wonders of science to of knowledge and brought the cresset of still a taboo for girls in those days. However, modern scientific thought for the first time Debendranath Tagore appointed teachers at the masses, in a language to the sub-continent. The Bengalis had home. Swarnakumari learnt the polemics begun to take the lead in this respect from of Sanskrit, English, literature, painting, that they could relate to. the early 19th century. This part of India music, science, religion, political science had already taken early leads in religious and and academics. She made up for the lack Swarnakumari continues social reforms. Bengali was being enriched. of degrees through self-study and diligence. to hold her place as one Along with the idea of nationalism, scientific In 1868, Swarnakumari Devi was temper was also gaining ground. Among the married to Janakinath Ghoshal, a well- of the foremost reformers leading lights of this ushering change was educated landlord of Nadia district. The Swarnakumari Devi. Lack of high education couple had two daughters and a son. Sarala of the reawakening and formal training never stood in her way. Devi Chaudhurani, one of Swarnakumari’s Hard work and perseverance make her a daughters, matched her fame as author and period of India. distinguished leader of her era. editor. Janakinath Ghoshal was among the
Dr. Rakesh Kumar Dubey is Post-Doctoral Fellow, UGC, Department Of History, Benares Hindu University (BHU), Varanasi.Correspondence Address: H.No-168, Nehia, Varanasi, UP, India-221202.
Dream 2047, November 2017, Vol. 20 No. 2 34 magazine was in some ways a family venture. Jyotirindranath Tagore started it in 1877. Dwijendranath Tagore edited the magazine for first seven years. It was the ace journal of its time in Bangla literary world. In 1884, Swarnakumari Devi took charge as Bharati’s editor. For the next 11 years, the magazine reached new heights and her efforts played a key part in this journey. The daughter Sarala Devi Chaudhurani took the responsibility in 1895 and carried forward the good work for the next 12 years. Thereafter, the job was back to Swarnakumari for eight years. Besides regular writings of Swarnakumari, the magazine boasted of contributions from many leading female Kadambini Ganguly contemporary intellectuals in Bengali arena Debendranath Tagore founders of the Indian National Congress. including Girindra Mohini, Sharat Kumari She joined the party in 1890 and took active Chaudhurani and Anurupa Devi. most women, Swarnakumari’s intellectual participation in its sixth session held under Swarnakumari Devi was as good a prowess and grasp over scientific topics were the presidentship of Pherozeshah Mehta. It poet, novelist and social activist as a beacon unrivalled. was the first conglomerate of the nascent of scientific ideas in the country. Her first Swarnakumari Devi was among the party that was marked by women’s presence. essay on popular science, ‘Bhugarbha’, was earliest proponents of the movement to Kadambini Ganguly (18 July 1861-3 serially published in four installments in bring scientific knowledge to the masses October 1923), India’s first female graduate Bharati (1880). After taking over the reins of in their own language. Several other and physician, addressed this conference. the magazine in 1884, she gave prominence Bengali journals of her time shared the Swarnakumari’s scientific aptitude to articles related to science as part of her same purpose. Most notable of them were was a family legacy. Debendranath Tagore editorial policy. It was to introduce such Kaumudi (1860), Vigyan Rahasya (1871), was an ardent supporter of Western rational women to the world of science who could Vigyan Vikas (1873), Vigyan Darpan (1876), values. He had announced an annual grant not understand English. Swarnakumari Sachitra Vigyan Darpan (1882), and Chikitsa of Rs. 1,000 to promote higher education wrote 17 scientific essays inBharati from Darshan (1887). Scientific research was in Bengal. Four Indian medical students 1880-1889. In addition, she penned similar still an alien concept during this period in were sent to England for higher education articles for Tatvabodhini Patrika magazine India. Therefore, these magazines could in 1845. Tagore bore the expenses of two on a regular basis. Swarnakumari authored only publish translations from the western of them. Out of these four, Bholanath Bose two dozen articles on scientific subjects scientific publications. All they reported became the first Indian to earn an MD during her career. Out of these, seven were were news and views from the western degree from the London University. related to geology and rest of them addressed scientific world. Besides, several popular Swarnakumari Devi began her contemporary trends in astronomy, natural Bengali magazines like Tatvabodhini Patrika, intellectual journey as a novelist and poet. sciences and physics. Her writings on these Somprakash, and SamvadPrabhakar also Her first novelDipnirban (The snuffing subjects were far ahead of her era. At a time covered happenings of the world of science out of the light) was published in 1876. It when even literacy was out-of-bounds for with an aim to instill a scientific temper was the first fiction to come out of the pen among the people. Swarnakumari played a of a woman in modern Indian literature. remarkable role in this endeavour through Among her other novels are Mibar Raj, Bharati and Tatvabodhini Patrika. Chhinna Mukul, Hughlir Imam Badi, In 1882, Prithibi, Swarnakumari Malati, Bidroha, Snehalata, Kahake, Phuler Devi’s collection of essays on science was Mala, Bichitra, Swapnabani, and Milanrati. published. It was a story of Earth’s journey. She is also credited with plays Koney Badal, The book was a tribute to her farther Pak Chakra, Rajkanya, and Rajkamal. Her Debendranath Tagore. The titles of these poetry collections Basanta Utsab, Gatha, essays themselves spoke for their progressive and Gitiguchchha were equally notable. approach. These were ‘Upakramanika- Swarnakumari also wrote an essay collection Bigyanshiksha’ (Preface-Science Education), titled Prithibi. ‘Sauroparibarborti Prithivi’ (Earth—a Apart from being a writer par Member of the Solar-Family), ‘Prithibir excellence, Swarnakumari was also an Gatipranali’ (Motions of the Earth), adroit editor with a special focus on the ‘Prithibir Utpatti’ (The Origins of the Earth), ‘Bhupanjar I-IV Prastab’ (The Earth’s Surface emancipation of women. Bharati, a monthly Sarala Devi Chaudhurani 33 Dream 2047, November 2017, Vol. 20 No. 2 — I-IV Propositions), ‘Bhugarbha’ (Earth’s and boycott movement that followed. She Interiors), and ‘Prithibir Parinam’ (The vouched for women’s education, Swadeshi Future of the Earth). In the introductory and popularisation of science. She believed essay ‘Science Education’, she defined the that if science is not improved then the true inductive and deductive attributes of science, National improvement is never possible. clearly distinguishing between the two. According to her, India lags behind the Swarnakumari’s expression was lucid even western world in development due to a lack while explaining the complexities of geology of practical training in science. She viewed and astronomy. She used hand-drawn poverty as the main obstacle to nation’s diagrams, commentaries and clear analysis progress and emphasised that it is solely by to explain for the layperson the intricacies of the power of science that this poverty can be the solar system, the Milky Way, the origin eradicated. In Swarnakumari’s opinion, the of the earth, nature and its formation. day science would bless us, that day we will Her presentation was free from make progress in all respects. science jargons, her words not burdened by A perusal of her work makes it clear the cumbersome theories. Swarnakumari’s that Swarnakumari not only enriched essays aimed at making inextricable common literature, but also the scientific scientific theories comprehensible to even intelligentsia of her time. She was the most ordinary mind. She took pains to instrumental in bringing the wonders of find corresponding words in Bengali as all Bharti Patrika, First Volume, April 1877 science to the masses, in a language that they Indian languages were still untouched by number of air atoms within this experimental could relate to. The way she contributed modern science. She also used diagrams tube to such an amount that wave paths to develop science in India despite her to complement her words. Following the could not only be recorded but also seen academic shortcomings makes her an evolutionary concept of ‘the survival of the with naked eyes. Such a state of matter, immortal name in the history of science. She fittest’, she believed in using the popular when atoms are sparsely distributed, is the was an embodiment of what women could language to make a place among readers. fourth state of the matter, better known as achieve and earned respect for their creative She was the first Indian woman to develop, the radiant matter. The word ‘radiant’ here capabilities. Analysing Swarnakumari’s use and popularise scientific terminology in does not refer to any rays. However, the work, Brajendranath Bandyopadhyay wrote the country; that too, without any formal fourth state matters give off light as they are in his essay ‘Sahitya-Sadhak-Charitmala’, education and training. governed by special natural laws. Sir Crookes “Swarnakumari, a self-taught woman who The versatile writer sought to has derived the term ‘radiant matter’ from lacked formal education and thus proper initiate and inspire scientific aptitude, not this glow discharge”. scientific training, is perhaps the first only in men but also the other half of the Another prominent work of Bengali woman to write scientific essays.” population. Formal studies in science were Swarnakumari Devi was a review of Deshbandhu Chitranjan Das has termed still out-of-bounds for women in those Ramendrasundar Trivedi’s work, Prakriti. her as “one of the great nation-builders.” days. This situation continued even post- Ramendrasundar Trivedi (1864-1919) was The University of Calcutta honoured her independence. No country has ever attained one of Bengal’s well-known writers in the with the Jagattarini Gold medal in 1927. prosperity without the welfare of its women. field of science. His body of work on popular Swarnakumari continues to hold her place Swarnakumari understood this fact earlier science and scientific philosophy was as one of the foremost reformers of the than the most people in modern India did. significant. He also worked incessantly for reawakening period of India. Swarnakumari’s scientific knowledge the growth of the Bangiya Sahitya Parishad, was bolstered by her voracious studying one of the oldest literary societies in Bengal. Reference habits. Delving on various states of matter in Trivedi wrote Jigmasa (Collected essays on 1. Hindi Pradeep Patrika, Volume-8, ‘The Fourth State of the Matter or Radiant science) and Prakriti (Collected essays on Number-2, October 1884, Light Matter’, she writes, “We experience matter philosophy). Swarnakumari’s critique of the Press, Varanasi only in solid, liquid and gaseous form. latter book was much appreciated among 2. Stri-Darpan Patrika, July 1910, Leader This was all scientists knew about matter the literary circles. To comment upon the Press, Prayag, Allahabad. till recently. However, English chemist and work of an intellectual of Trivedi’s repute 3. Dutta, Sunil K., The Raj & the physicist Sir William Crookes claim to have for a woman with no formal education was Bengali People, Firma KLM Ltd, discovered the fourth state of the matter.” astounding. Kolkata, 2002 Explaining Sir Crookes’ experiments on Swarnakumari held a distinguished 4. Tharu Susie and K Lalita, (Editors), cathode rays, she elaborates, “No machine stature among the Indians who understood Vol.-1, Women Writing in India, 600 could create a complete vacuum in a glass the importance of science in those days. BC to the Early 20th Century, Oxford tube till now, but, Sir Crookes has invented She was politically active during the University Press, New Delhi, 1991 the method to suck out more air from the catastrophic division of Bengal in 1905. She tube than ever before. He could reduce the ensured her participation in the swadeshi (Translation: Deepak Sharma)
Dream 2047, November 2017, Vol. 20 No. 2 32 History of Science Karl Schwarzschild and his last gift
Dr. Utpal Mukhopadhyay
“I do not think of the misery, but I legendary talent very early when he wrote Schwarzschild has left think of the beauty that still remains” – these two research papers on the orbits of binary lines were written by teen-ager Anne Frank, stars while he was barely sixteen years of age. this world a century famous for his diary In this connection we written while sitting may recall that James ago. But his last gift under the spectre of Clerk Maxwell (1831- in terms of seminal death, hiding herself 1879), a towering from the Nazis in a figure of science, wrote scientific work during secret room, waiting for a research paper on the death which ultimately mechanical construction his illness has made came within a short of Cartesian oval when he period. Like Anne, Karl was fourteen years only. him immortal. Work Schwarzschild also, Anyway, while studying of Schwarzschild has daunting the pain of his in the Gymnasium, incurable disease, wrote Karl had an intimate produced many new ideas three research papers, friendship with Paul one of them being related Epstein (1871-1939), such as Schwarzschild to the solution of field who became a renowned equations of Einstein. mathematician coordinates, Those pioneering papers afterwards. This Schwarzschild radius, have not only enriched friendship had a lasting the scientific world but effect on Karl who Schwarzschild black also have paved the way for significant future learnt techniques of using a telescope as research works. well as some topics of higher mathematics hole etc. in the field of from Epstein. Karl also constructed a small A biographical sketch telescopeon his own when he was sixteen. astrophysics. Even today, After completing his studies in school, he a beginner in the field Karl Schwarzschild, son of Mojes studied in Strasbourgh University during Martin Schwarzschild and Henrietta Sabel, 1891-93. Here, as well as in Munich of general relativity will was born on 9 October 1873 in a wealthy University, Karl learnt theoretical and and cultured Jewish family of Frankfurt, practical astronomy. He obtained a doctorate have to know about Germany. Karl, the eldest among five degree from Munich University by working brothers and a sister, entered a primary on Poincare’s theory under the supervision Schwarzschild solution school for Jewish citizens at an age of of Hugo Von Seliger. The title of his thesis and its related topics. eleven. Then he entered the famous school was – An application of Poincare’s theory of Frankfurt Gymnasium. Karl showed his stable configuration of rotating bodies to tidal
Dr. Utpal Mukhopadhyay is with SatyabharatiVidyapith, P.O. Nabapally, Dist. North 24 Parganas, Kolkata – 700 126, West Bengal. Email: [email protected]
31 Dream 2047, November 2017, Vol. 20 No. 2 deformation of moons and to Laplace’s origin of had to return from the war front and in c2, where, G is the universal gravitational the solar system. spite of his illness he wrote three remarkable constant and c isthe velocity of light in Karl was deeply influenced by the research papers which can be considered as vacuum. beautiful technique of teaching of Seliger three jewels of the scientific world. It is clear from the above relation that which lasted throughout his life. After Schwarzschild radius of an object depends completing his research work, from October Three gems of Schwarzschild on its mass. For instance, the Schwarzschild 1896 to 1899,Karl worked as an assistant radius of the Sun is 3 kilometres. This means in Kufnar Observatory situated at Ottering Near the end of 1915, the basic that if, due to contraction, the radius of the in the outskirts of Vienna. During his stay equations of general theory of relativity Sun becomes 3 kilometres then it will reduce there, he worked on brightness of stars and of Einstein were published. Before that to a black hole. Consequently, it will be discovered two variable stars. He deduced a Schwarzschild had returned from the war invisible to an outside observer because its formula for measuring the optical brightness front due to his illness. However, in spite gravitational pull will be so strong that even of photographic material which was very of his illness, he derived exact solutions light will not be able to escape overcoming useful for determining the brightness of Einstein’s equations for a spherically this attraction. For our Earth, the value of the of deep-space celestial bodies.While he symmetric, non-rotating and uncharged Schwarzschild radius is only 1 centimetre. was in Kufnar, he wrote a thesis entitled body. Schwarzschildwas the first person After publication of the paper Bertridgezurphotographischephotometric der in the world to achieve that success. mentioned earlier, in anotherpaper(Karl Gestrine. After leaving Kufnar, he started Einstein himself could not imagine that Schwarzschild; Berliner Sitzungsber (1916), working as a ‘Privedozent’ in Munich his equations could be solved exactly page 414) Schwarzschild solved Einstein University. Around 1900, Karl pondered because while dealing with the problem of equation for a fluid of uniform density. This about the non-Euclidean character of the perihelion precession of Mercury, he could solution is called Schwarzschild interior universe. In a paper at that time, he showed find only approximate solution of his own solution. After these two seminal papers, that the lower limit of the radius of curvature equations. Einstein found approximate Schwarzschild did another important work of the universe will be 64 light years if the solution by using rectilinear coordinate on Stark effect−the splitting and displacement universe is hyperbolic in nature; on the other system. But Schwarzschild arrived at the of the spectral lines of atoms and molecules hand the same limit would be at least 1600 exact solution by judiciously employing due to influence of external electric field. For light years if it is of elliptical nature. Relying generalised polar coordinate system. For this discovery, Johannes Stark (1874-1957) on the assumption that the tail of a comet is this reason, when Schwarzschild sent received the Nobel Prize in physics in 1919. made of spherical particles, he calculated the his solution to Einstein, the latter, being Using Bohr-Sommerfeld quantum theory, diameter of those particle as between 0.07 to amazed at the success of Schwarzschild, in Schwarzschild derived linear and quadratic 1.5 microns. a letter in 1916 wrote to him – “I have read equations of Stark effect for hydrogen. During 1901 to 1909, Schwarzschild your paper with utmost interest. I had not This paper of Schwarzschild was published was in the post of an Extraordinary Professor expected that one could formulate the exact posthumously (Karl Schwarzschild; Berliner in Gottingen University. He also remained solution of the problem in such a simple Sitzungsber (1916), page548). Incidentally, in the post of Director of Gottingen way. I liked very much your mathematical Stark effect can be compared with Zeeman Observatory at that time. In Gottingen he treatment of the subject. Next Thursday Effect where the splitting of spectral lines of had the opportunity to work with world I shall present the work to the Academy atoms and molecules occur due to influence famous scientists like David Hilbert (1862- with a few words of explanation.” of external magnetic field. Undaunted byhis 1943), Felix Klein (1849-1925), Herman Einstein sent this paper of Schwarzschild painful disease, Schwarzschild presented Minkowski (1864-1909) and others. In 1909, to the Berlin Academy of Science on 13 the scientific world three remarkable papers he became the Director of Astrophysical January, 1916 (K. Schwarzschild; Berliner which can be considered as three jewels. Observatory in Potsdam,which was the Sitzungsber (1916), page 189). This paper Ultimately he succumbed to his ailment, most prestigious post for any astronomer of Schwarzschild helps us to understand leaving behind these three precious gifts. of Germany. On 22 October of that year, the gravitational field around a spherically After Schwarzschild’s demise, renowned Karl married Else Posenbach, daughter of a symmetric mass. This very solution of astrophysicist Sir Arthur Stanley Eddington Professor of Surgery of Gottingen. Karl and Schwarzschild is called ‘Schwarzschild wrote in 1916 in The Observatory – “The Else had three children− Agatha, Martin, and exterior solution’. The solution is of world loses an astronomer of exceptional genius, Alfred. Afterwards, Martin became Professor immense importance in later research who was one of the leaders in recent advances of Astronomy in Princeton University. work related to black holes. This solution both in observational methods and theoretical When First World War broke out in tells us that if the radius of a spherical researches.” Europe, Karl went to the battlefield as a body becomes less than a particular length, soldier of Germany. He had to go to both it is not possible to resist the gravitational eastern and western front and he became a collapse of that body and it will reduce to a Legacy of Schwarzschild lieutenant. In 1915, while in the Russian black hole. That particular radius is called It has been mentioned already front, he contracted a rare and painful Schwarzschild radius. that the idea of black hole can be found autoimmune skin disease pemphigus If the mass of a body is M and its vulgarisand consequently, at the end of 1915, Schwarzschild radius is Rs, thenRs = 2GM/ Continued on page 28
Dream 2047, November 2017, Vol. 20 No. 2 30 Nobel prizes in science 2017 Nobel prizes in science 2017
Biman Basu
Nine scientists, including seven from is about 9.5 trillion km. The Royal Swedish the United States, share the 2017 Nobel Academy of Sciences described the feat as Prizes in science. Two lareates are from “something completely new and different, Switzerland and the UK. opening up unseen worlds,” “A wealth of The Nobel Physics Prize will be shared discoveries awaits those who succeed in by astrophysicists Rainer Weiss of MIT, capturing the waves and interpreting their Cambridge, USA, and Barry C. Barish and message,” it added. Kip S. Thorne of California Institute of Technology, Pasadena, USA, “for decisive contributions to the LIGO detector and the observation of gravitational waves”. The Nobel Prize is a Weiss will receive one half annual international of the prize amount while the other half will be jointly received by Barry C. Barish awards bestowed Rainer Weiss Barry C. Barish Kip S. Thorne and Kip S. Thorne. in several categories Gravitational waves were predicted The Chemistry Nobel for 2017 has by Swedish and by Albert Einstein more than 100 years ago been awarded jointly to Jacques Dubochet in his general theory of relativity. In 1916, of the University of Lausanne, Switzerland, Norwegian institutions Einstein had predicted that rapid movement Joachim Frank of Columbia University, of massive objects would create ripples in the New York, USA, and Richard Henderson in recognition of fabric of space-time that would propagate at of MRC Laboratory of Molecular Biology, academic, cultural or the speed of light throughout the universe. Cambridge, UK, “for developing cryo-electron He also predicted that ripples caused by the microscopy for the high-resolution structure scientific advances. motion of large masses like binary neutron determination of biomolecules in solution”. stars or black holes should be large enough Cryo-electron microscopy is a technique that Nobel prize awarded for us to detect them across light years on makes it possible to portray biomolecules in 2017 in Physics, Earth. Scientists have been trying to detect after freezing them very quickly so their the elusive ripples for several decades but natural shape is preserved. “The method Chemistry and without success till they were first detected simplifies and improves the imaging of by the Advanced Laser Interferometer biomolecules and has moved biochemistry Physiology or Medicine Gravitational-wave Observatory, or LIGO, into a new era”, the Nobel committee said are mentioned in USA. in a statement. The prizewinning work The waves detected by the laureates may lead to what the prize committee said in this article. came from the collision of two black holes were “detailed images of life’s complex some 1.3 billion light years away. A light year machineries in atomic resolution.”
The author is a former editor of the popular science monthly Science Reporter, published by CSIR, He is a winner of the 1994 ‘NCSTC National Award for Science Popularisation’. He is the author of more than 45 popular science books. Email: [email protected]
29 Dream 2047, November 2017, Vol. 20 No. 2 Medicine will be shared protein components of this machinery by three Americans – that revealed the mechanism governing the Jeffrey C. Hall of the self-sustaining clockwork inside the cell. University of Maine, It is now recognised that biological clocks Michael Rosbash of function by the same principles in cells of all Brandeis University in multicellular organisms, including humans. Waltham, and Michael Our body’s biological clock is involved W. Young of Rockefeller in many aspects of our complex physiology. University in New We now know that all multicellular York, USA, “for their organisms, including humans, utilise a Jacques Dubochet Joachim Frank Richard Henderson discoveries of molecular similar mechanism to control circadian Electron microscopes were long mechanisms controlling the circadian rhythm”. rhythms. A large proportion of our genes believed to only be suitable for imaging Circadian rhythms are 24-hour cycles are regulated by the biological clock and, dead matter, because the powerful electron driven by an organism’s internal biological consequently, a carefully calibrated circadian beam destroys biological material. But the clock, also known as laureates brought about modifications that the circadian clock. allowed the biomolecules to retain their The work of the three natural shape even in a vacuum, making laureates explains how it possible to image them using electron plants, animals and microscopy. humans adapt their Following the work of the three biological rhythm so laureates, it can be said that “every nut and that it is synchronised bolt of the electron microscope have been with the Earth’s optimised”. The desired atomic resolution revolutions. was reached in 2013, and researchers can The three Jeffrey C. Hall Michael Rosbash Michael W. Young now routinely produce three-dimensional laureates used fruit flies structures of biomolecules. In the past few as a model organism, and isolated a gene rhythm adapts our physiology to the years, scientific literature has been filled with that controls the normal daily biological different phases of the day. Since the seminal images of everything from proteins that rhythm. They showed that this gene encodes discoveries by the three laureates, circadian cause antibiotic resistance, to the surface of a protein that accumulates in the cell during biology has developed into a vast and highly the Zika virus. the night, and is then degraded during the dynamic research field, with implications for The 2017 Nobel Prize in Physiology or day. Subsequently, they identified additional our health and wellbeing.
Karl Schwarzschild and his last gift (Continued from page 30) from Schwarzschild solution. However, Edwin Salpeter (1924-2008) of Cornell all the three characteristics – mass, angular Schwarzschild himself didn’t believe in the University, USA,thought about possible momentum and charge. For this reason, existence of black hole and regarded his existence of super-massive black hole at the Kerr-Newman black hole is regarded as the own solution as meaningless so far as the centre of a quasar.Pulsar was discovered in most general form of black hole. real world is concerned. But, following 1967. Thomas Gold (1920-2004) proposed the line of Schwarzschild solution, that pulsar is a rapidly rotating neutron Last gift of Schwarzschild famous astrophysicist Subrahmanyan star. In 1968 John Wheeler (1911-2008) Chandrasekhar (1910-1995) showed in used the term ‘black hole’in his article Schwarzschild has left this world 1930 that if the mass of a star exceeds 1.5 Our Universe: the known and unknown. a century ago. But his last gift in terms of times the solar mass, then instead of ending Afterwards, many theoretical researches were seminal scientific work during his illness has its life as a white dwarf, it would contract done on the nature of black hole. A black made him immortal. Work of Schwarzschild further. In 1934, Walter Baade (1893-1960) hole is characterised by its three specialities, has produced many new ideas such as and Fritz Zwicky (1898-1974) gave the idea viz.,its mass, angular momentum and Schwarzschild coordinates, Schwarzschild of a neutron star. Then around 1939, Robert electric charge. Schwarzschild black hole is radius, Schwarzschild black hole etc. in the Oppenheimer (1904-1967) and George static and electrically neutral, i.e., its angular field of astrophysics.Even today, a beginner Volkoff (1914-2000) worked on the possible momentum and charge are both zero. Kerr in the field of general relativity will have structure of a neutron star. Many years after black hole has rotation, but it is neutral, i.e., to know about Schwarzschild solution that, Roy Kerr (born 1934) propounded the its charge is zero. On the other hand, Reisner- and its related topics. This is the greatest idea of a rotating black hole. Nordstroom black hole has no rotation, but achievement of a creative person. After the discovery of quasar in 1963, it is charged. Kerr-Newman black hole has
Dream 2047, November 2017, Vol. 20 No. 2 28 Environment Dead zones: An increasing concern
Susheela Srinivas
More than 70% of the Earth’s surface oxygen in water. This is found to be as low A number of factors is covered by water. Of this, 95% is oceanic as 1% and fluctuating slightly depending on contribute to formation water and a huge portion of this heavy saline the photosynthetic organisms and the depth waters remains in the deep sea − undiscovered of the sea. The part these life forms play of dead zones. Dead zones and mysterious. The oceanic water column is extremely essential and holds the key to extends from the surface to the presently maintain the delicate balance of the marine are formed naturally and life. intermittently along the Amidst all this the role of the humans is critical and vital to preserve the ecology coasts in many of the seas. and biodiversity. Sadly, this is not happening; rather there is growing concern as the marine These are seasonal and life is under potential threat due to various with change in the season, human activities on land which are in many ways affecting the seas. The past fifty years nature soon restores the has seen a drastic rise in the mass destruction of marine ecology which is detrimental to balance of marine life. marine life. Marine life, however, is Moray eel A look into the topology of oceans (Credit: Wikipedia) gives us a better picture of the different under potential threat known depths of around 11,000 m. This vast mechanisms that are interwoven to keep the expanse is host to a diverse and fascinating waters teeming with life. due to various human spectrum of life forms; depending on the activities on land which region the seas can be frigid, pulverising and deadly. In all, a staggering part of the are in many ways deep seas, however, hosts life forms which brave against these harsh environments affecting the seas. The to survive and procreate. Fascinatingly, past fifty years has seen the creatures have adapted themselves in unique ways − be it in the form of tentacular a drastic rise in the mass extensions, modified respiratory systems, jaws, calcareous shells or gelatinous (liquid destruction of marine like) muscles, and other adaptations. ecology and formation While the Earth’s atmosphere contains around 20% of oxygen to provide source of Deep sea giant Isopod of frequent dead zones life, the oceanic life depends on the dissolved (Credit: Flickr)
Susheela Srinivas is a Bengaluru based popular science writer, engineer and entrepreneur. Email: [email protected]
27 Dream 2047, November 2017, Vol. 20 No. 2 tectonic plates and intense activity – under- oxygen is limited by the high salinity of the sea volcanoes. There are also hydrothermal waters. Since there is absence of biomass vents or chimneys which witness certain (plant life), the oxygen supply is limited chemical reactions. These vents spew with low concentrations; this amount is mineral-laden water up around which barely sufficient to support animal life. certain bacteria and microbes grow, feeding Many mobile animals migrate to oxygenated on the supply. The larger animals feed on waters in such a situation while the immobile these bacteria in the food chain. A vast organisms tend to perish. portion of this area still remains unexplored. Dead zones Challenges faced by Nitrogen and phosphorus are the deep sea creatures building blocks of many single-celled Phytoplankton (Credit: Wikimedia Commons) In the benthic region the life forms organisms like phyto- plankton. These meet many crushing challenges and phytoplankton or algae form the basis of the Different regions struggle to exist − the absence of sunlight, food chain in oceans since they are capable The oceanic water column is broadly no plant life in the food chain, pulverising of photosynthesis. This also ensures the divided into two major zones: the Pelagic pressures around 500- 1,000 atm., frigid oxygen replenishment to the waters. During and the Benthic zones. temperatures, polar currents, and very little daytime these algae photosynthesise to Pelagic zone: This is the open waters oxygen in the water. Along with these non- increase the dissolved oxygen in the water, where swimming and floating organisms biotic components, the organisms have to but respire during night time consuming live. The surface layers of this region, where contend with predators, competitors and some of the dissolved oxygen. the water and land meet, has slopes under also find potential mates. Due to these harsh The deep sea hosts unique bacteria water, access to the abundance of sunlight surroundings, the benthic creatures are which depend on the detritus − decay of seeping through the surface, and also found to be slow-moving or rooted to the plant and animals from upper regions which sufficient amounts of dissolved oxygen for seabed; many exhibit bio-luminescence, or naturally sink down − for nutrition. In this marine forms to exist. process they use up the oxygen for respiring. As the depth increases, the availability Sometimes seasonal changes bring of life sources reduces drastically. Marine about an increase in the nutrient content of biologists further divide this into regions the ocean waters near the coast. For example, depending on the depth from the surface, the spring months and rains feed the rivers namely and lakes with additional nutrients which Epipelagic (surface to 200 m, with are carried to the sea. This increase in the plenty of sunlight available and possibility of nutrients helps the algae to multiply rapidly. photosynthesis), Though they are not visible to the naked Mesopelagic or twilight zone (200 to eye, when large colonies of algae form, called 1,000 m, where sunlight is scanty and no algal bloom, they appear as blue-green to red photosynthesis), Algal bloom (La Jolla Red tide near layers on the water. This excessive growth Bathypelagic (1,000-4,000 m, or the California) caused due to Eutrophication on the surface blocks sunlight for the other midnight zone), hypoxia (Credit: Flickr) creatures below. Also, most of the oxygen is Abyssopelagic (4,000 – 6,000 m), and used up by the algae which lead to hypoxia Hadopelagic (6,000-11,000 m, made have unique body adaptations to combat the (little or no-oxygen content in a water body). up of mostly deep trenches in the ocean). intense water pressures and temperature. All This can suffocate other creatures leading to The last three regions get no sunlight these factors help them in sensing, feeding, mass kills. at all. procreating and surviving. When the algae die, the detritus from Benthic region: This is the seabed The major source of oxygen for the algal bloom increases the growth of which consists of sediments and other deep sea animals comes from thermohaline bacteria under sea which feed on them; this surfaces. Many life forms exist here too, currents. These are a part of the large-scale insurmountable bacterial growth depletes the which either swim slowly just above the ocean circulation that is driven by global oxygen in the deep sea as well as threatening seabed or are attached, rooted or burrowed density gradients created by surface heat and the survival of other organisms. Hence the to the seabed. Biologists divide this too into freshwater fluxes. They originate from the algal bloom becomes a cause for the creation zones. The base sediment is found to contain shallow polar seas which form the principal of a ‘dead zone’ in the sea. Under hypoxia a great amount of organic matter which is feeders of the cold, dense waters of the deep conditions natural life suffocates leading to composed of dead and decayed organisms sea. The thermohaline currents are found dead zones or biological deserts. from the upper pelagic regions. Rich in to travel all over the globe at these depths. Physical, chemical and biological nutrients, this is the main source of food to Since cold water dissolves more oxygen, it factors contribute to formation of dead many organisms. This zone is also home to sinks to the bottom. However, the dissolved zones. Dead zones are formed naturally and
Dream 2047, November 2017, Vol. 20 No. 2 26 Human contribution to communities which are capable of removing eutrophication is triggering more frequent nitrogen and convert it into a dead zone. algal blooms. Since the nutrient flow is However, currently this process is occurring continuous, the dead zones formed are rapid slowly and any day the situation may topple and persistent, permanently damaging the over. Moreover, the Bay of Bengal is a heavily ecological balance of the ocean. populated area with continuous maritime activities. A growing concern Effect of hypoxia Mass destruction in marine life due to Till recently, these types of dead zones hypoxia (Credit: Wikimedia Commons) were noticed all over the coasts of North What could be the outcome of and South Americas, the Mediterranean hypoxia in ocean waters? The larger and intermittently along the coasts in many of Sea, African coast, and the Arabian Sea. The mobile creatures like big fish, crabs, etc., try the seas. However, these are seasonal and waters of the Bay of Bengal were found to to migrate to other waters with more oxygen with change in the season, nature soon be free of such formations. An estimation content, while the immobile and benthic restores the balance of marine life. given in 2008 indicates that the oceans have creatures like sea grass, worms and clams are Spring season brings increased around 405 recorded dead zones – a figure hard hit and perish due to hypoxia. nutrient-rich water from rains, rivers and which has risen drastically in the past few But mass exodus of marine creatures other water bodies. This leads to sudden decades. will seriously damage the ecological balance spurt in algal growth forming a dead zone in In a recent discovery in 2016, scientists of the oceans. Even in the case of mobile the waters below. Sometimes a combination from Max Planck Institute and the National creatures, the migration is not always of algal bloom and absence of thermohaline Institute of Oceanography, Goa, observed successful as they soon become suffocated currents together can cause a natural dead an alarming situation in the Bay of Bengal. and unconscious, perishing in the waters. zone. However, the tropical storms of the Research also indicates that hypoxia following autumn season, breaks this dead leads to severe physiological changes in the zone restoring the balance of the ecosystem. animals. Their movement gets slower and the reproductive organs are found to shrink Human activity and the oceans drastically. Hormonal changes occur which are making them infertile. Mankind has depended on the sea and So a habitat which is teeming with life its resources for ages: for food, exploration, soon becomes a biological desert. trade and transport. As human populations Marine debris It is not far away that the impact increased around the coastlines, these (Credit: Wikipedia) will be felt on human survival too. Since activities have escalated. There is a huge Their study revealed a crazy situation where the oceans are the primary source of life on demand for agricultural activities, fishing the waters were poised to form a potential Earth and the principal suppliers in the water and other oceanic activities to meet his dead zone; this was developing in the area cycle. Excessive pollutants in air and on land growing demands. spreading around 60,000 sq km where are a precursor to global disruptions to the With the spike in human activities the waters were becoming hypoxic and water cycle. Ocean ports are also regions of and demands around the edge of seas, the the presence of bacteria had given rise to a additional activities like power harnessing, bay areas are bearing the brunt of seeping tipping condition where any moment a dead mining, drilling, and tourism − all causing chemicals, pollutants, excessive fishing, and zone can form. Their reports were published further damage. Other factors influencing air pollution and a host of other factors. in the journal Nature Geosciences. this massive destruction are marine debris While waste water and chemical effluents The lead scientists Laura Bristow and like plastic waste and other items that are from industries constitute the run-offs Wajih Naqvi say that the Bay of Bengal dumped on the shores causing pollution in developed countries, developing and hosts an enigmatic condition. Though there which is endangering many marine species. under-developed countries are diverting the is hypoxia in its waters, no known notable Excessive fishing activities in the sewage into the water bodies. In addition nitrogen loss has been observed unlike the deep sea can put human life in danger too. the air pollution too has contributed to the other dead zones around the world. Future changes in oxygen levels in water contamination of water bodies. Air pollution Explaining the situation they bodies could seriously impede the delicate alters the chemical composition of the air estimate that there were trace amounts of ecosystems in the oceans leading to mass and gets carried to the ocean through the oxygen present in the water here but the fish mortality; as a consequence the social water cycle. concentrations were undetectable by the and economic growth of humans may also Global warming and the use of standard techniques. They demonstrated get affected since we depend on the oceans nitrogen-based fertilisers for aggressive that the hypoxic waters had 10,000 times for goods and services. Hence, pertinent agricultural practises have led to the ocean lesser concentration of oxygen than the air- measures are needed immediately to preserve waters witnessing an increase in the levels of saturated surface waters. They also showed the ecological balance on Earth. nitrogen. This additional nutrient influx is that the Bay of Bengal contains microbial called eutrophication. 25 Dream 2047, November 2017, Vol. 20 No. 2 Mediscape Irritable bowel syndrome — Causes, triggers, red flags and more
Dr. Yatish Agarwal
A common bowel disorder that affects What causes irritable the large intestine known as irritable bowel bowel syndrome? syndrome is a long-lasting problem that can change the way how people live their life. It is not known exactly what causes Known more popularly by its acronym IBS, irritable bowel syndrome, but a variety its signs and symptoms can be gut wrenching, of factors play a role. The walls of the making a person severely uncomfortable. intestines are lined with layers of muscle However, the good news is: it is not life- that contract and relax in a coordinated threatening, and unlike some of the other rhythm as they move food from the stomach large bowel conditions like ulcerative colitis, through the intestinal tract to the rectum. Although many adults it does not cause changes in bowel tissue or In a person with irritable bowel syndrome, increase the risk of colorectal these contractions may be experience signs and cancer. stronger and last longer Millions of people than normal, causing gas, symptoms of irritable suffer from irritable bowel bloating and diarrhoea. syndrome. Most of them Or the opposite may bowel syndrome, fewer are women. People are most occur, with weak intestinal than 1 in 5 who have likely to get the condition in contractions slowing food their late teens to early 40s. It passage and leading to symptoms seek medical commonly presents with belly hard, dry stools. discomfort, abdominal cramps Abnormalities in the help. If a person has or tummy pain, bloating, gas, gastrointestinal nervous and trouble with bowel habits producing system also may play a a persistent change in either diarrhoea or constipation and having a role, causing a person to experience greater bowel habits or some thin, hard, or soft and liquid stool. than normal discomfort when the abdomen A chronic condition, only a small bloats with gas or stool. Poorly coordinated other unexplained number of people with irritable bowel signals between the brain and the intestines syndrome have severe signs and symptoms. can make the body overreact to the changes signs or symptoms, it is Some people can control their symptoms that normally occur in the digestive process. simply by managing diet, lifestyle and This overreaction can cause pain, cramps, important that s/he sees stress. Still, in others, it can be life-altering. distension, and diarrhoea or constipation. a doctor because these They may miss work or school more often, and may feel less able to take part in daily Triggers symptoms may indicate activities. Some people may need to change Stimuli that do not bother other their work setting: shifting to working at people can trigger symptoms in people with a more serious condition, home, changing hours, or even not working irritable bowel syndrome - but not all people at all. Some will need medication and with the condition react to the same stimuli. such as colon cancer. counselling. The common triggers include:
The author is physician and teacher at New Delhi’s Safdarjung Hospital. He has authored 47 popular health-books. E-mail: [email protected]
Dream 2047, November 2017, Vol. 20 No. 2 24 Stress abuse are risk factors. For women, domestic they’re not living life to the fullest, leading to Most people with irritable bowel abuse may be a risk factor as well. discouragement or depression. syndrome find that their signs and symptoms are worse or more frequent during periods Recognising the signs When to see a doctor of increased stress, such as finals week or and symptoms Although many adults experience the first weeks on a new job. However, The signs and symptoms of irritable signs and symptoms of irritable bowel while stress may aggravate symptoms, it is bowel syndrome can vary widely between syndrome, fewer than 1 in 5 who have probably not the key trigger. people and may resemble those of other symptoms seek medical help. Still, if a person Hormones diseases. Among the most common are: has a persistent change in bowel habits or Since a large number of sufferers are l Diarrhoea (often some other unexplained signs or women, medical researchers believe that described as violent symptoms, it is important that hormonal changes potentially may play episodes of diarrhoea) s/he sees a doctor because these a significant role in this condition. Many l Constipation symptoms may indicate a more women find that signs and symptoms are l Constipation alternating serious condition, such as colon worse during or around their menstrual with diarrhoea, but this is cancer. periods. a sign that may represent If the doctor is able to rule a more serious condition out the more serious conditions Bacteria and gut infections and must stimulate a and can confirm the diagnosis Sometimes another illness, such as person to immediately seek of irritable bowel syndrome, an acute episode of infectious diarrhoea a medical consultation he could help you find recipes to relieve (gastroenteritis) or a bacterial overgrowth l Belly pains or cramps, usually in the symptoms as well as advise treatments that in the intestine, can trigger irritable bowel lower half of the belly, that get worse can avoid possible complications which may syndrome. after meals and feel better after a bowel have arisen due to chronic diarrhoea. Foods movement The role of food allergy or intolerance l A lot of gas or bloating The red flags Some signs and symptoms may point in irritable bowel syndrome is not yet clearly l Harder or looser stools than normal to a more serious condition. If you have any understood, but many people have more (pellets or flat ribbon stools) of these red flag symptoms, you must not severe symptoms when they eat certain l Mucus in the stool delay going to a doctor. These symptoms things. A wide range of foods has been l Worsening of haemorrhoids: Diarrhoea implicated - beans, cabbage, cauliflower, and constipation, both signs of include: l broccoli, spices, fats, fruits, milk, carbonated irritable bowel syndrome, can also New onset after age 50 l beverages, chocolate and alcohol to name a aggravate haemorrhoids. Weight loss few. l Stress can make symptoms worse. l Rectal bleeding l Some people also have urinary l Fever Who’s at risk? symptoms or sexual problems. l Nausea or recurrent vomiting Many people have occasional signs and There are typically four types of the l Abdominal pain, especially if it is symptoms of irritable bowel, but irritable condition. There is IBS with constipation not completely relieved by a bowel bowel syndrome is more likely to take root (IBS-C) and IBS with diarrhoea (IBS-D). movement, or occurs at night in the following people: Some people have an alternating pattern l Diarrhoea that is persistent or awakens you from sleep Young adults of constipation and diarrhoea. This is l Anaemia related to low iron Irritable bowel syndrome tends to called mixed IBS (IBS-M). Other people occur in people under age 45. don’t fit into these categories easily, called unsubtyped IBS, or IBS-U. Which doctor to see? Fair gender If you have symptoms of irritable Women are about twice as likely as Outcome bowel syndrome, you could make an For most people, irritable bowel men to develop irritable bowel syndrome. appointment with your family doctor syndrome is a chronic condition, although or an internist. Subsequent to an initial Family history there will likely be times when the signs and evaluation, the family doctor may refer you Studies suggest that people who symptoms are worse and times when they to a gastroenterologist. A gastroenterologist have a family member with irritable bowel improve or even disappear completely. syndrome may be at increased risk of the is a specialist who is well versed in treating However, the condition’s impact on condition. The influence of family history digestive disorders. a person’s overall quality of life may be the on the risk may be related to genes, shared most significant complication. If a person factors in a family’s environment or both. Preparing for an appointment begins to avoid certain foods due to IBS, Before going for your appointment, Psychological issues they may not get enough of the nutrients it is best to write down any symptoms Anxiety, depression, a personality they need, leading to malnourishment. you’re experiencing, and for how long, and disorder and a history of childhood sexual These effects of IBS may cause them to feel if you have found any specific factor that
23 Dream 2047, November 2017, Vol. 20 No. 2 particularly triggers the symptoms. You must Rome criteria people who have had bowel surgery or who also write down key personal information, The Rome criteria factor in a number have diabetes or some other disease that including any recent changes or stressors in of specific signs and symptoms for a doctor slows down digestion. your life. These factors can play a key role in to diagnose irritable bowel syndrome. The the frequency and severity of irritable bowel most important of these are abdominal Blood tests Celiac disease is sensitivity to wheat, syndrome symptoms. You should also think pain and discomfort lasting at least three barley and rye protein that may cause signs out and write down questions to ask your days a month and bothering the patient and symptoms like those of irritable bowel doctor. Creating your list of questions in recurrently for at least last three months. syndrome. Blood tests can help rule out advance can help you make the most of Such symptoms must be associated with this disorder. Children with IBS have a far your time with your doctor. In addition to two or more of following: improvement greater risk of celiac disease than do children these questions, do not hesitate to ask any with defecation, altered frequency of stool or who don’t have IBS. If your doctor suspects other questions that may come to your mind altered consistency of stool. that you have celiac disease, he or she may during your appointment. Manning criteria perform an upper endoscopy to obtain a Your doctor is likely to ask you a The Manning criteria focus on biopsy of your small intestine. number of questions. Being ready to answer the following symptoms: pain relieved them may reserve time to go over any points by defecation, having incomplete bowel Stool tests you want to spend more time on. You will movements, mucus in the stool, and changes If you have chronic diarrhoea, doctors be asked about your symptoms, and their in stool consistency. The more symptoms may want to examine your stool for bacteria duration and severity; if the symptoms come present, the greater the likelihood of irritable or parasites. and go or stay about the same; if you have bowel syndrome. The doctor may also ask for the noticed anything that seems to trigger your The doctor you consult will likely assess following imaging tests: symptoms, including certain foods, stress how you fit these criteria, as well as whether or - in women - your menstrual period; if Flexible sigmoidoscopy you have any other signs or symptoms that This test examines the lower part of you have lost weight without trying; if you might suggest a more serious condition. If have noticed any blood in your stools; if you the colon (sigmoid) with a flexible, lighted you fit the IBS criteria and do not have any tube, called the sigmoidoscope. have such signs and symptoms as vomiting, red flag signs or symptoms, your doctor may or fever; if you have recently experienced suggest a course of treatment without doing Colonoscopy significant stress, emotional difficulty or loss; additional testing. However, if you do not In some cases, especially if you are what is your typical daily diet; if you have any respond to treatment, or the doctor feels age 50 or older or have other signs of a family history of bowel disorders or colon uncertain, you’ll likely require more tests. potentially more serious condition, your cancer; and if you been diagnosed with any doctor may perform this diagnostic test other medical conditions. These questions Diagnostic tests in which a small, flexible tube is used to The treating doctor may recommend can help the doctor in reaching the correct examine the entire length of the colon. diagnosis and ordering tests which would several tests, including stool studies to be appropriate to your condition. check for infection or problems with your Computerised tomography intestine’s ability to take in the nutrients (CT) scan Making of a diagnosis from food, a condition that goes by the CT scans produce cross-sectional name of malabsorption. X-ray images of internal organs. CT scans The diagnosis of irritable bowel of your abdomen and pelvis may help syndrome largely depends upon a detailed Lactose intolerance test your doctor rule out other causes of your Lactase is an enzyme you need to digest medical history, clinical examination in a symptoms, especially if you have abdominal the sugar found in dairy products. If you doctor’s office and a battery of diagnostic pain. tests that serve to rule out other conditions do not produce this enzyme, you may have which may mimic irritable bowel syndrome problems similar to those caused by irritable Lower GI barium series and still be of more serious nature. bowel syndrome, including abdominal pain, In this test, doctors fill your large gas and diarrhoea. To find out if this is the intestine with a liquid (barium solution) to Diagnostic criteria cause of your symptoms, your doctor may make it easier to see any problems on the based on symptoms order a breath test or ask you to remove milk X-ray. and milk products from your diet for several The idea behind conducting these tests Since there are no confirmatory weeks. is simply to rule out a more nature of disease. physical signs to diagnose irritable Once that’s been done, the treatment focuses bowel syndrome and other functional Breath test on the relief of symptoms so that you can gastrointestinal disorders with perfection, Your doctor may perform a breath live as normally as possible. medical researchers have developed two test to look for a condition called bacterial sets of extensive diagnostic criteria which overgrowth, in which bacteria from the are primarily based on symptoms a person colon grow up into the small intestine, (Next month: Winning over has, with a caveat that other more serious leading to bloating, abdominal discomfort irritable bowel syndrome: conditions have been ruled out. and diarrhoea. This is more common among the way forward)
Dream 2047, November 2017, Vol. 20 No. 2 22 New horizons Recent developments in science and technology
Biman Basu
Silk mats developed tissue substitute to repair the damaged to treat arthritis tissue in osteoarthritis patients, the scientists looked into the natural bone-cartilage Osteoarthritis, commonly known as interface and tried to mimic it synthetically wear-and-tear arthritis, is the most common in lab conditions. Mandal said they used silk, type of arthritis. It is a condition in which the a natural protein, to fabricate electrospun natural cushioning between joints – cartilage mats to mimic the cartilage portion and bio- – wears away and makes the bones of the active glass to develop a composite material joints rub more closely against one another with less of the shock- absorbing benefits of cartilage. The rubbing results in pain, swelling, Ultraviolet (UV) stiffness, and decreased ability to move. If left untreated, it can radiation is harmful for result in severe swelling, pain, and living beings. Despite ultimately restrict the range of movement. Knee osteoarthritis is UV radiation being the most common bone and joint dangerous, life survives disease in India. Current clinical treatment on Earth mainly because methods are limited by lack of viable tissue substitutes to aid the of a protective layer of Scanning electron micrograph of a cross-section of repair process. Replacement of mats formed by electrospun bioactive glass layer the damaged knees with artificial ozone gas in Earth’s (left arrow), followed by silk layer (right arrow), knees is another option, but exhibiting coherent well-integrated interface. upper atmosphere. But is quite expensive. Recently a a new study suggests team of researchers from Indian Institute similar to the natural tissue. For the mat, of Technology Guwahati (IITG) and the scientists used Muga silk easily available that UV radiation may University College London, UK, led by in North-east India which they said is have played a critical Biman B. Mandal of IITG have developed “endowed with properties that enhance the a unique material based on Muga silk and healing process”. role in the emergence of bioactive glass fibres to treat osteoarthritis. The researchers adopted a clean According to the researchers, the synthesised fabrication approach called electrospinning life on Earth, and could mats can assist the growth of bone cells for developing the silk composite mats. be a key for where to and repair worn-out joints in osteoarthritis Electrospinning is a fibre production arthritis patients (ACS Applied Materials & method which uses electric force to draw look for life elsewhere Interfaces, 9 February 2017 | DOI: 10.1021/ charged threads of polymer solutions or in the universe. acsami.6b16590). polymer melts up to fibre diameters of In their effort to develop a suitable the order of some hundred nanometres.
The author is a former editor of the popular science monthly Science Reporter, published by CSIR, He is a winner of the 1994 ‘NCSTC National Award for Science Popularisation’. He is the author of more than 45 popular science books. Email: [email protected]
21 Dream 2047, November 2017, Vol. 20 No. 2 The process does not require the use of deletions in both copies of the DFR-B gene, coagulation chemistry or high temperatures butthe DFR-A and DFR-C genes remained to produce solid threads from solution. This unaltered, demonstrating the extreme method makes the process clean by ensuring precision of the technique (Scientific Reports, that no solvent can be carried over into the 30 August 2017 |. DOI: 10.1038/s41598- final product. According to Mandal, “It is 017-10715-1). similar to knitting, except that it utilises According to the researchers, the electric high voltage force to draw ultra-fine CRISPR/Cas9 system they described is the fibres.” He said, a layer-by-layer approach ‘reverse’ genetic approach, used to find out was followed, where the bone layer was first what an organism looks like after a known formed, on top of which the cartilage layer Researchers used cutting-edge gene-editing gene is disrupted, and confirms that the was developed. technology to turn Japanese morning glories DFR-B gene is the main gene responsible The resulting composite mat white. (Photo: University of Tsukuba) for colour in Japanese morning glory plants. resembled the architecture of the natural They hope this research will greatly facilitate bone-cartilage interface. The mats were to change the colour of a Japanese morning those interested in the modification of flower tested under laboratory conditions, where glory, a popular garden flower, from violet to colours and shapes using the CRISPR/Cas9 artificial tissue formed efficiently during the white, by disrupting a single gene. system in ornamental flowers or vegetables. two weeks of the study.When cultured with Last year, Japanese researchers had specific animal-derived immune cells, the successfully decoded the entire Japanese UV radiation key to life’s origin mats did not induce any adverse immune morning glory (Ipomoea nil)genome. responses, indicating biocompatibility. Subsequently, the researchers identified We know that life on Earth would not According to the researchers, the mats need a single gene called dihydroflavonol-4- be possible without the Sun. Our nearest to be tested in suitable animal models like reductase-B, or DFR-B, which encodes an star not only provides light and heat but rabbits and pigs, and finally in human trials, anthocyanin biosynthesis enzyme responsible also causes the seasons, which make life before they become available to patients. for the colour of the plant’s stems, leaves and thrive. But sunlight also has a dangerous To assist the regenerative process flowers. Incidentally, two other, very closely component – ultraviolet (UV) radiation – in osteoarthritis patients, the mats would related genes (DFR-A and DRF-C) are that is extremely harmful for living beings. be grafted in the damaged joint with cells also found next to DFR-B. Therefore, the In fact, ultraviolet radiation is widely used harvested from the patient. “The mats challenge was to specifically and accurately to kill bacteria in water and for disinfecting would bond with the native tissue and act target the DFR-B gene without altering materials and objects. Despite UV radiation as an artificial tissue construct. Eventually the other genes. The CRISPR/Cas9 system being dangerous, however, life survives on the mats would degrade with time and was used as it is currently the most precise Earth mainly because of a protective layer new tissue formed in its place, repairing method of gene editing. of ozone gas in Earth’s upper atmosphere the damaged cartilage,” Mandal said.“The For the present study, the researchers that cuts off the most dangerous ultraviolet composite mats are a potential candidate as used a short DNA sequence in the Japanese radiation from the Sun. green materials to repair bone defects caused morning glory DFR-B gene as the target for Given this background, it may come by osteoarthritis,” he added. the CRISPR/Cas9 system. This sequence as a surprise that the appearance of life on contains the active site of the enzyme Earth was in fact triggered by UV radiation, produced by the DFR-B gene. The disruption as a new study shows. It was earlier believed Flower colour changed that intense UV rays from a young Sun by gene editing of this sequence was expected to de-activate the enzyme, resulting in an absence of the bombarded the early Earth and were thought Flowers come in many colours colour pigment, anthocyanin, which indeed although there are many that are fragrant turned out to be true. When the CRISPR/ and bloom at night, which are mostly white. Cas9 system was inserted into tissue-cultured It has been known that flower colours are embryos of Japanese morning glory plants decided by genes and floriculturists have using the DNA-transferring capabilities of developed techniques to breed flowers of the plant bacterium Rhizobium, the DFR-B different colours through hybridisation. enzyme was indeed found to be inactivated, But no attempt has hitherto been made resulting in approximately 75% of the to change colour of a flower by tinkering transgenic plants having green stems and with its gene. Now, in a worldfirst, white flowers instead of the characteristic researchers from the University of Tsukuba, violet. In contrast, non-transformed plants the National Agriculture and Food with an active enzyme had violet stems Planets of red dwarf stars like Research Organisation, and Yokohama and flowers. Subsequent genetic analyses TRAPPIST-1 are unlikely to harbour City University in Japan, have used the confirmed that, as expected, the DNA target life because it might not emit enough revolutionary CRISPR gene-editing tool, sequence had been altered in the transgenic UV radiation to kick-start the biological sometimes referred to as a molecular scissor, plants, with either DNA insertions or processes most familiar to our planet.
Dream 2047, November 2017, Vol. 20 No. 2 20 likely to destroy any exposed organic Using computer models and the have combined ground and satellite molecules. But a new study by SukritRanjan known properties of red dwarfs, the authors measurements of tropical Asia, Africa and of the Harvard-Smithsonian Center for estimate that the surface of rocky planets in the Americas and arrived at the surprising Astrophysics (CfA) in Cambridge, Mass. the potentially habitable zones around red conclusion that tropical forests may be USA, and colleagues suggests that UV dwarfs would experience 100 to 1,000 times actually a net source of heat-trapping carbon radiation may have played a critical role in less of the UV radiation than the young emissions, rather than a carbon sink – they the emergence of life on Earth, and could Earth would have billions of years ago. contribute more carbon dioxide to the be a key for where to look for life elsewhere Chemistry that depends on UV radiation atmosphere than they remove. in the universe. They contend that certain might shut down at such low levels, and The researchers led by Alessandro levels of UV might be necessary for the even if it does proceed, it could operate at a Baccini, a forest ecologist and remote formation of ribonucleic acid (RNA), a much slower rate than on the young Earth, sensing specialist at the Woods Hole molecule necessary for all forms of known possibly delaying the advent of life. Research Centre in Falmouth, Mass., USA, life. The new study suggests that red dwarf However, the study does not entirely suggest that this may be due to the fact stars – by far the most common sort of stars, rule out the possibility of life even if the that tropical forests are drying out or being and thought by some to be the best star UV output of a steady-state M-dwarf star is cleared, burned and logged so fast that they systems in which to search for life – might not sufficient to spark life, because transient now spew out a lot more carbon than they not emit enough UV radiation to kick- elevated UV irradiation due to flares may be trap by photosynthesis. According to them start the biological processes most familiar sufficient to trigger the process. Only further human activities such as starting fires and to our planet (The Astrophysical Journal, 11 laboratory studies could establish whether natural factors including droughts have July 2017 | doi.org/10.3847/1538-4357/ such a possibility exists. dealt a severe blow to forests’ ability to store aa773e). carbon. The study went further than any of According to the researchers, before Tropical forests become net the earlier studies in measuring the impact of life began, radiation from the Sun was the emitters of carbon dioxide disturbance and degradation, the thinning primary source of energy on our planet, of tree density and the culling of biodiversity just as it is today. In the oxygen-poor, For ages it had been assumed that below an apparently protected canopy – prebiotic world, solar UV radiation may tropical forests act as an enormous sink of usually as a result of selective logging, fire have provided the jolt to transform simple carbon, removing substantial amounts of and drought (Science, 28 September 2017 | organic molecules into more complex ones, carbon dioxide during photosynthesis thus doi: 10.1126/science.aam5962). which were used as the building blocks of The researchers based their finding biology and life. on 12 years (2003-2014) of data and images The earliest life on Earth is widely from satellites including NASA’s Ice, Cloud, thought to have been based on RNA, the and Land Elevation Satellite (ICESat), a chemical cousin of DNA in which the sugar laser-equipped satellite that gathered data on deoxyribose is replaced by ribose. RNA is forest height and vegetation layers around made of subunits called nucleotides, which the globe, and NASA’s Terra and Aqua link together to form long polymer chains. satellites. They also made use of laser remote According to the scientists, certain levels of sensing technology and field measurements. UV might be necessary for the formation of Most of the carbon emissions from ribonucleic acid, a molecule necessary for all forests – making up nearly 70 percent in the forms of known life. Wanton destruction and degradation tropics of the Americas, Asia and Africa – the “It would be like having a pile of wood of tropical forests have made them emit study found are linked to forest degradation. and kindling and wanting to light a fire, but more carbon dioxide than they soak up. In total, the researchers found, tropical not having a match,” says Ranjan. “Our forests emit 861 million tons of carbon to research shows that the right amount of UV preventing uncontrolled rise in carbon the atmosphere annually and absorb only light might be one of the matches that gets dioxide level in the atmosphere. That is 436 million tons of carbon each year, thus life as we know it to ignite.” why conservation of forests has been given leading to a net contribution of 425 million The CfA study was focussed on the top priority to control global warming and tons to Earth’s atmosphere each year, which study of red dwarf stars, which are smaller climate change. Of course, forests absorb is more than the emissions from all vehicular and less massive than the Sun, and the carbon dioxide only during the day; at night traffic in the United States. planets that orbit them. Recently, several they release carbon dioxide. It has been According to the researchers, much planetary systems with potential habitable estimated that every moment, the world’s of the carbon contribution is due to forest zones, where liquid water could exist, have roughly 3 trillion trees either suck up carbon degradation, namely deforestation and the been discovered around red dwarfs including dioxide from the air or release it into the conversion of forests to urban spaces such Proxima Centauri, TRAPPIST-1, and LHS atmosphere. Scientists have been trying as farms or roads. But more than two-thirds 1140, raising hopes of finding life there. But to quantify these carbon flows accurately comes from a less visible source, namely a the recent study rules out such a possibility in order to understand how forests help to decline in the number and diversity of trees in view of insufficient UV intensity. regulate Earth’s climate. Now, researchers in remaining forests
19 Dream 2047, November 2017, Vol. 20 No. 2