The Morphological Basis of the Arm-To-Wing Transition
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Fuzzy Simplicial Networks: a Topology-Inspired Model to Improve Task Generalization in Few-Shot Learning
Fuzzy Simplicial Networks: A Topology-Inspired Model to Improve Task Generalization in Few-shot Learning Henry Kvinge∗, Zachary New∗, Nico Courts∗y, Jung H. Lee∗, Lauren A. Phillipsz, Courtney D. Corleyz, Aaron Tuor∗, Andrew Avilaz, Nathan O. Hodasz September 24, 2020 Abstract Deep learning has shown great success in settings with massive amounts of data but has struggled when data is limited. Few-shot learning algorithms, which seek to address this limitation, are designed to generalize well to new tasks with limited data. Typically, models are evaluated on unseen classes and datasets that are defined by the same fundamental task as they are trained for (e.g. category membership). One can also ask how well a model can generalize to fundamentally different tasks within a fixed dataset (for example: moving from category membership to tasks that involve detecting object orientation or quantity). To formalize this kind of shift we define a notion of independence of tasks and identify three new sets of labels for established computer vision datasets that test a model's ability to generalize to tasks which draw on orthogonal attributes in the data. We use these datasets to investigate the failure modes of metric-based few-shot models. Based on our findings, we introduce a new few-shot model called Fuzzy Simplicial Networks (FSN) which leverages a construction from topology to more flexibly represent each class from limited data. In particular, FSN models can not only form multiple representations for a given class but can also begin to capture the low-dimensional structure which characterizes class manifolds in the encoded space of deep networks. -
External Examination of Seabirds: Plumage & Morphometrics
External Examination of Seabirds: Plumage & Morphometrics Quantitative analysis of form, encompasses size and shape Seabird Topography ➢ Naming Conventions: • Parts of the body • Types of feathers (Harrison 1983) Types of Feathers Coverts: Rows bordering and overlaying the edges of the tail and wings on both the lower and upper sides of the body. Help streamline shape of the wings and tail and provide the bird with insulation. Feather Tracks ➢ Feathers are not attached randomly. • They occur in linear tracts called pterylae. • Spaces on bird's body without feather tracts are called apteria. • Densest area for feather tracks is head and neck. • Feathers arranged in distinct layers: contour feathers overlay down. Generic Pterylae Types of Feathers Contour feathers: outermost feathers. Define the color and shape of the bird. Contour feathers lie on top of each other, like shingles on a roof. Shed water, keeping body dry and insulated. Each contour feather controlled by specialized muscles which control their position, allowing the bird to keep the feathers in clean and neat condition. Specialized contour feathers used for flight: delineate outline of wings and tail. Types of Feathers Flight feathers – special contour feathers Define outline of wings and tail Long and stiff Asymmetrical those on wings are called remiges (singular remex) those on tail are called retrices (singular retrix) Types of Flight Feathers Remiges: Largest contour feathers (primaries / secondaries) Responsible for supporting bird during flight. Attached by ligaments or directly to the wing bone. Types of Flight Feathers Flight feathers – special contour feathers Rectrices: tail feathers provide flight stability and control. Connected to each other by ligaments, with only the inner- most feathers attached to bone. -
Beaks at the Bird Buffet
Beaks at the Bird Buffet Introduction A bird’s beak is a bony elongation of its skull that is covered in keratin, the same material that makes up your hair and fingernails. Birds use their beaks as tools. Beaks help birds gather food, groom their feathers, defend themselves, and build their nests. The shape of a bird’s beak gives us clues to figuring out its main source of food, as a bird’s beak is designed for eating a particular type of food. Raptors like owls, hawks, and vultures have grasping beaks. These beaks are hooked shaped which allows for tearing apart prey or carrion. Similar to a raptor’s beak, a cardinal’s beaks is a heavy thick beak that they use to crack seeds. Birds like a spoonbill have a long, flat, scooping beak that scoops up food like fish or insects in the water. Ducks also get their food from the water. Their flat shovel beaks allow them to scoop up fish or plants and then drain out water before swallowing. A hummingbird’s beak is long and thin, which allows it to reach into tight places for its food-like getting nectar out of a flower. For this activity, you will need a clothes pin, a spoon, chopsticks, and a craft stick - these are your beaks. A cup or bowl will serve as your bird’s stomach. Lay your “food” out on a table and select your first beak. See how much food you are able to pick up with your beak and move to your stomach in 30 seconds. -
A General Model for the Structure, Function, And
•• A GENERAL MODEL FOR THE STRUCTURE, FUNCTION, AND ALLOMETRY OF PLANT VASCULAR SYSTEMS Geoffrey B. West', James H. Brown!, Brian J. Enquist I G. B. West, Theoretical Division, T-8, MS B285, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. G. B. West, J. H. Bmwn and B. J. Enquist, The Santa Fe Institute, 1399 Hyde Par'k Road, Santa Fe, NM 87501, USA. J. H. Brown and B. J. Enquist, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA . •email: [email protected] !To whom correspondence should be addressed; email: [email protected] lemail: [email protected] 1 , Abstract Vascular plants vary over 12 orders of magnitude in body mass and exhibit complex branching. We provide an integrated explanation for anatomical and physiological scaling relationships by developing a general model for the ge ometry and hydrodynamics of resource distribution with specific reference to plant vascular network systems. The model predicts: (i) a fractal-like branching architecture with specific scaling exponents; (ii) allometric expo nents which are simple multiples of 1/4; and (iii) values of several invariant quantities. It invokes biomechanical constraints to predict the proportion of conducting to non-conducting tissue. It shows how tapering of vascular tubes· permits resistance to be independent of tube length, thereby regulating re source distribution within a plant and allowing the evolution of diverse sizes and architectures, but limiting the maximum height for trees. .. 2 ,, I. INTRODUCTION Variation in body size is a major component of biological diversity. Among all organisms, size varies by more than 21 orders ofmagnitude from 1O-13g microbes to 108g whales. -
Screaming Biplane Dromaeosaurs of the Air. June/July
5c.r~i~ ~l'tp.,ne pr~tl\USp.,urs 1tke.A-ir Written & illustrated by Gregory s. Paul It is questionable whether anyone even speculated that some dinosaurs were feathered until Ostrom detailed the evidence that birds descended from predatory avepod theropods a third of a century ago. The first illustration of a feathered dinosaur was a nice little study of a well ensconced Syntarsus dashing down a dune slope in pursuit of a gliding lizard in Robert Bakker's classic "Dinosaur Renaissance" article in the April 1975 Scientific American by Sarah Landry (can also be seen in the Scientific American Book of the Dinosaur I edited). My first feathered dinosaur was executed shortly after, an inappropriately shaggy Allosaurus attacking a herd of Diplodocus. I was soon doing a host of small theropods in feathers. Despite the logic of feath- / er insulation on the group ancestral birds and showing evidence of a high level energetics, images of feathered avepods were often harshly and unsci- Above: Proposed relationships based on flight adaptations of entifically criticized as unscientific in view of the lack of evidence for their preserved skeletons and feathers of Archaeopteryx, a generalized presence, ignoring the equal fact that no one had found scales on the little Sinornithosaurus, and Confuciusornis, with arrows indicating dinosaurs either. derived adaptations not present in Archaeopteryx as described in In the 1980s I further proposed that the most bird-like, avepectoran text. Not to scale. dinosaurs - dromaeosaurs, troodonts, oviraptorosaurs, and later ther- izinosaurs _were not just close to birds and the origin of flight, but were see- appear to represent the remnants of wings converted to display devices. -
Multivariate Allometry
MULTIVARIATE ALLOMETRY Christian Peter Klingenberg Department of Biological Sciences University of Alberta Edmonton, Alberta T6G 2E9, Canada ABSTRACT The subject of allometry is variation in morphometric variables or other features of organisms associated with variation in size. Such variation can be produced by several biological phenomena, and three different levels of allometry are therefore distinguished: static allometry reflects individual variation within a population and age class, ontogenetic allometry is due to growth processes, and evolutionary allomctry is thc rcsult of phylogcnctic variation among taxa. Most multivariate studies of allometry have used principal component analysis. I review the traditional technique, which can be interpreted as a least-squares fit of a straight line to the scatter of data points in a multidimensional space spanned by the morphometric variables. I also summarize some recent developments extending principal component analysis to multiple groups. "Size correction" for comparisons between groups of organisms is an important application of allometry in morphometrics. I recommend use of Bumaby's technique for "size correction" and compare it with some similar approaches. The procedures described herein are applied to a data set on geographic variation in the waterstrider Gerris costae (Insecta: Heteroptera: Gcrridac). In this cxamplc, I use the bootstrap technique to compute standard errors and perform statistical tcsts. Finally, I contrast this approach to the study ofallometry with some alternatives, such as factor analytic and geometric approaches, and briefly analyze the different notions of allometry upon which these approaches are based. INTRODUCTION Variation in sizc of organisms usually is associated with variation in shape, and most mctric charactcrs arc highly corrclatcd among one another. -
The Oldest Record of Ornithuromorpha from the Early Cretaceous of China
ARTICLE Received 6 Jan 2015 | Accepted 20 Mar 2015 | Published 5 May 2015 DOI: 10.1038/ncomms7987 OPEN The oldest record of ornithuromorpha from the early cretaceous of China Min Wang1, Xiaoting Zheng2,3, Jingmai K. O’Connor1, Graeme T. Lloyd4, Xiaoli Wang2,3, Yan Wang2,3, Xiaomei Zhang2,3 & Zhonghe Zhou1 Ornithuromorpha is the most inclusive clade containing extant birds but not the Mesozoic Enantiornithes. The early evolutionary history of this avian clade has been advanced with recent discoveries from Cretaceous deposits, indicating that Ornithuromorpha and Enantiornithes are the two major avian groups in Mesozoic. Here we report on a new ornithuromorph bird, Archaeornithura meemannae gen. et sp. nov., from the second oldest avian-bearing deposits (130.7 Ma) in the world. The new taxon is referable to the Hongshanornithidae and constitutes the oldest record of the Ornithuromorpha. However, A. meemannae shows few primitive features relative to younger hongshanornithids and is deeply nested within the Hongshanornithidae, suggesting that this clade is already well established. The new discovery extends the record of Ornithuromorpha by five to six million years, which in turn pushes back the divergence times of early avian lingeages into the Early Cretaceous. 1 Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China. 2 Institue of Geology and Paleontology, Linyi University, Linyi, Shandong 276000, China. 3 Tianyu Natural History Museum of Shandong, Pingyi, Shandong 273300, China. 4 Department of Biological Sciences, Faculty of Science, Macquarie University, Sydney, New South Wales 2019, Australia. -
Alula Characteristics As Indicators of Golden-Cheeked Warbler Age
Alula Characteristics as Indicators of Golden-cheeked Warbler Age Rebecca G. Peak and Daniel J. Lusk (SY) birds from older age classes. Dwight (1900) P.O. Box 5190 first illustrated the utility of molt limits in ageing Fort Hood, TX 76544 passerines. More recent literature on the use of molt [email protected] limits to age North American passerines provide detailed descriptions ofhow to distinguish different feather generations from each other for a variety of ABSTRACT species (Yunick 1984, Pyle et al. 1987, Mulvihill 1993, Pyle 1997a, Pyle 1997b ). We assessed the alula ofGolden-cheeked Warblers (Dendroica chrysoparia) to determine its usefulness Dendroica warblers retain greater primary coverts as a criterion for age determination. We compared (hereafter "primary coverts") from the juvenal the alula to the greater secondary coverts for color plumage but replace greater secondary coverts contrast and examined it for presence of white. (hereafter "greater coverts") during the first Overall, 98.2% ofsecond-year birds had an alula/ prebasic molt (Pyle et al. 1987). Hence, greater secondary covert contrast; whereas, I 00% comparison of color and extent of wear between of after-second-year birds did not have a contrast these feather groups is useful for ageing members between these feather groups. All after-second of this genus. The contrast between primary and year birds had white on the alula. Our data greater coverts can be challenging for inexperi demonstrate that these characteristics are reliable enced banders to recognize. These feather groups indicators of age for Golden-cheeked Warblers. are small, the color difference is often difficult for Still, we advocate using them in combination with the untrained eye to discern, and some of these existing ageing criteria to enhance the confidence species replace the inner greater coverts during of banders' age determinations, especially during prealternate molts. -
Metabolic Allometric Scaling Model: Combining Cellular Transportation and Heat Dissipation Constraints Yuri K
© 2016. Published by The Company of Biologists Ltd | Journal of Experimental Biology (2016) 219, 2481-2489 doi:10.1242/jeb.138305 RESEARCH ARTICLE Metabolic allometric scaling model: combining cellular transportation and heat dissipation constraints Yuri K. Shestopaloff* ABSTRACT body mass M is mathematically usually presented in the following Living organisms need energy to be ‘alive’. Energy is produced form: by the biochemical processing of nutrients, and the rate of B / M b; energy production is called the metabolic rate. Metabolism is ð1Þ very important from evolutionary and ecological perspectives, where the exponent b is the allometric scaling coefficient of and for organismal development and functioning. It depends on metabolic rate (also allometric scaling, allometric exponent). Or, if different parameters, of which organism mass is considered to we rewrite this expression as an equality, it is as follows: be one of the most important. Simple relationships between the b mass of organisms and their metabolic rates were empirically B ¼ aM : ð2Þ discovered by M. Kleiber in 1932. Such dependence is described by a power function, whose exponent is referred to as the Here, a is assumed to be a constant. allometric scaling coefficient. With the increase of mass, the Presently, there are several theories explaining the phenomenon metabolic rate usually increases more slowly; if mass increases of metabolic allometric scaling. The resource transport network by two times, the metabolic rate increases less than two times. (RTN) theory assigns the effect to a single foundational mechanism This fact has far-reaching implications for the organization of life. related to transportation costs for moving nutrients and waste The fundamental biological and biophysical mechanisms products over the internal organismal networks, such as vascular underlying this phenomenon are still not well understood. -
Tropical Tree Height and Crown Allometries for the Barro Colorado
Biogeosciences, 16, 847–862, 2019 https://doi.org/10.5194/bg-16-847-2019 © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License. Tropical tree height and crown allometries for the Barro Colorado Nature Monument, Panama: a comparison of alternative hierarchical models incorporating interspecific variation in relation to life history traits Isabel Martínez Cano1, Helene C. Muller-Landau2, S. Joseph Wright2, Stephanie A. Bohlman2,3, and Stephen W. Pacala1 1Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA 2Smithsonian Tropical Research Institute, 0843-03092, Balboa, Ancón, Panama 3School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611, USA Correspondence: Isabel Martínez Cano ([email protected]) Received: 30 June 2018 – Discussion started: 12 July 2018 Revised: 8 January 2019 – Accepted: 21 January 2019 – Published: 20 February 2019 Abstract. Tree allometric relationships are widely employed incorporation of functional traits in tree allometric models for estimating forest biomass and production and are basic is a promising approach for improving estimates of forest building blocks of dynamic vegetation models. In tropical biomass and productivity. Our results provide an improved forests, allometric relationships are often modeled by fitting basis for parameterizing tropical plant functional types in scale-invariant power functions to pooled data from multiple vegetation models. species, an approach that fails to capture changes in scaling during ontogeny and physical limits to maximum tree size and that ignores interspecific differences in allometry. Here, we analyzed allometric relationships of tree height (9884 in- 1 Introduction dividuals) and crown area (2425) with trunk diameter for 162 species from the Barro Colorado Nature Monument, Panama. -
Allometry – Page 1.01 – RR Lew Isometric Example
Allometry – page 1.01 – RR Lew isometric example The word Allometry has two roots. Allo means ‘other’ and metric refers to measure- ment. The Oxford American Dictionary defines Allometry as “the growth of body parts at different rates, resulting in a change of body proportions.”. It is different from either isometry (where iso means ‘same’) or anisometry (where aniso means ‘not the same’). The emphasis is on a difference in shape or proportions. Allometry may be a term unique to biology, since it is biological organisms that must change their shape (and thus their relative proportions) when their size is changed. To give an example of the differences (and similarities) of allometry and isometry, here is a relatively simple example of isometry that gives insight into why biological organisms tend to be allo- metric. A cube has a surface area of 6 • L2. Its volume is L3. As long as the shape is constant, the ratio of suraface area L to volume will always be (6 • L2) / L3, or 6/L. For a sphere, the surface area is 4 • • r2, and the volume is • r3; the corresponding ratio of surface area to volume is 4/r. 2•r area and volume ratio 240000 1 The ratio of area to volume scales as the volume inverse of L with an increase in size. The 0.8 graph (left) shows the area, volume and ratio 180000 area as a function of the size of the cube (as a multiple of L). 0.6 120000 0.4 Nota bene: The decrease in the surface area to volume ratio has an extraordinary impact on 60000 biological organisms. -
On the Role of the Alula in the Steady Flight of Birds
Ardeola 48(2), 2001, 161-173 ON THE ROLE OF THE ALULA IN THE STEADY FLIGHT OF BIRDS J. C. ÁLVAREZ*1, J. MESEGUER*, E. MESEGUER* & A. PÉREZ** SUMMARY.—On the role of the alula on the steady flight of birds. The alula is a high lift device located at the leading edge of the birds wings that allows these animals to fly at larger angles of attack and lower speeds without wing stalling. The influence of the alula in the wing aerodynamics is similar, to some extent, to that of leading edge slats in aircraft wings, which are only operative during take-off and landing operations. In this paper, representative parameters of the wing geometry including alula position and size of forty species of birds, are reported. The analysis of the reported data reveals that both alula size and position depend on the ae- rodynamic characteristics (wing load and aspect ratio) of the wing. In addition, aiming to clarify if the alula is deflected voluntarily by birds or if the deflection is caused by pressure forces, basic experimental results on the influence of the wing aerodynamics on the mechanism of alula deflection at low velocities are presented. Experimental results seem to indicate that the alula is deflected by pressure forces and not voluntarily. Key words: Alula, high lift devices, steady flight, wing load. RESUMEN.—El papel del álula en el vuelo estacionario de las aves. El álula es un dispositivo hipersus- tentador situado en el borde de ataque de las alas de los pájaros que permite que estos animales vuelen a altos ángulos de ataque y bajas velocidades sin que se produzca la entrada en pérdida del ala (el ala deja de sus- tentar si el ángulo de ataque es muy grande).