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Taxonomic assessment of two pygopodoid gecko subspecies from Western Australia
Abstract
Subspecies designations for herpetofauna in Western Australia were largely coined in the 20th century where rigorous evolutionary concepts to species were not consistently applied. Rather, subspecies tended to designate geographic populations of similar-looking taxa to nominate forms, usually differing in size, pattern or colour and, at best, a few scalation differences. Here we re-evaluate two pygopodoid taxa from Western Australia using a combination of published and original genetic data coupled with a reassessment of morphology. We review these differences in light of an integrative taxonomic approach that looks to find multiple independent lines of evidence to establish the evolutionary independence of populations. For the pygopod species Pletholax gracilis, we found consistent diagnostic characters (e.g. body size, visibility of ear opening, scalation) and a deep genetic divergence between the two subspecies. We therefore raise each subspecies to full species: P. gracilis and P. edelensis. The two subspecies of the carphodactylid gecko Nephrurus wheeleri were also assessed, and we found strong genetic and morphological evidence (e.g. body size, scalation, pattern) to raise these to full species: N. wheeleri and N. cinctus. By revisiting Storr’s morphological insights and newly acquired genetic evidence, in addition to a thorough re-examination of morphological traits, our study provides a robust foundation to raise Storr’s morphological subspecies into full species based upon multiple lines of evidence. Such an approach applied to other subspecies in the Australian herpetofauna also may result in revised taxonomies
Machigonne : March, Two-Step
https://digitalcommons.library.umaine.edu/mmb-ps/2000/thumbnail.jp
Acadian Exiles: a Chronicle of the Land of Evangeline
Volume of Canadian history dealing with the Acadians and Acadia
Day2Dark: Pseudo-Supervised Activity Recognition beyond Silent Daylight
This paper strives to recognize activities in the dark, as well as in the
day. As our first contribution, we establish that state-of-the-art activity
recognizers are effective during the day, but not trustworthy in the dark. The
main causes are the limited availability of labeled dark videos as well as the
distribution shift from the lower color contrast. To compensate for the lack of
labeled dark videos, our second contribution is to introduce a
pseudo-supervised learning scheme, which utilizes unlabeled and task-irrelevant
dark videos to improve an activity recognizer in low light. As the lower color
contrast results in visual information loss, we propose to incorporate the
complementary activity information within audio, which is invariant to
illumination. Since the usefulness of audio and visual features differs
depending on the amount of illumination, we introduce our `darkness-adaptive'
audio-visual recognizer as the third contribution. Experiments on
EPIC-Kitchens, Kinetics-Sound, and Charades demonstrate our proposals are
superior to image enhancement, domain adaptation and alternative audio-visual
fusion methods, and can even improve robustness to occlusions.Comment: Under revie
Learning Unseen Modality Interaction
Multimodal learning assumes all modality combinations of interest are
available during training to learn cross-modal correspondences. In this paper,
we challenge this modality-complete assumption for multimodal learning and
instead strive for generalization to unseen modality combinations during
inference. We pose the problem of unseen modality interaction and introduce a
first solution. It exploits a feature projection module to project the
multidimensional features of different modalities into a common space with rich
information reserved. This allows the information to be accumulated with a
simple summation operation across available modalities. To reduce overfitting
to unreliable modality combinations during training, we further improve the
model learning with pseudo-supervision indicating the reliability of a
modality's prediction. We demonstrate that our approach is effective for
diverse tasks and modalities by evaluating it for multimodal video
classification, robot state regression, and multimedia retrieval.Comment: Under revie
Performance assessment of low pressure nuclear thermal propulsion
A low pressure nuclear thermal propulsion (LPNTP) system, which takes advantage of hydrogen dissociation/recombination, was proposed as a means of increasing engine specific impulse (Isp). The effect of hydrogen dissociation/recombination on LPNTP Isp is examined. A two-dimensional computer model was used to show that the optimum chamber pressure is approximately 100 psia (at a chamber temperature of 3,000 K), with an Isp approximately 15 s higher than at 1,000 psia. At high chamber temperatures and low chamber pressures, the increase in Isp is due to both lower average molecular weights caused by dissociation and added kinetic energy from monatomic hydrogen recombination. Monatomic hydrogen recombination increases the Isp more then hydrogen dissociation. Variations in the mole fraction of monatomic hydrogen are similar to variations in static pressure along the axial nozzle position. Most recombination occurs close to the nozzle throat. Practical variations in nozzle geometry have minimal impact on recombination. Other models which can simulate a wider range of nozzle designs should be used in the future. The uncertainty of the hydrogen kinetic reaction rates at high temperatures (approximately 3,000 K) affects the accuracy of the analysis and should be verified with simple bench tests
Audio-Adaptive Activity Recognition Across Video Domains
This paper strives for activity recognition under domain shift, for example
caused by change of scenery or camera viewpoint. The leading approaches reduce
the shift in activity appearance by adversarial training and self-supervised
learning. Different from these vision-focused works we leverage activity sounds
for domain adaptation as they have less variance across domains and can
reliably indicate which activities are not happening. We propose an
audio-adaptive encoder and associated learning methods that discriminatively
adjust the visual feature representation as well as addressing shifts in the
semantic distribution. To further eliminate domain-specific features and
include domain-invariant activity sounds for recognition, an audio-infused
recognizer is proposed, which effectively models the cross-modal interaction
across domains. We also introduce the new task of actor shift, with a
corresponding audio-visual dataset, to challenge our method with situations
where the activity appearance changes dramatically. Experiments on this
dataset, EPIC-Kitchens and CharadesEgo show the effectiveness of our approach.Comment: Accepted at CVPR 202
Polyploidy breaks speciation barriers in Australian burrowing frogs Neobatrachus
Polyploidy has played an important role in evolution across the tree of life but it is still unclear how polyploid lineages may persist after their initial formation. While both common and well-studied in plants, polyploidy is rare in animals and generally less understood. The Australian burrowing frog genus Neobatrachus is comprised of six diploid and three polyploid species and offers a powerful animal polyploid model system. We generated exome-capture sequence data from 87 individuals representing all nine species of Neobatrachus to investigate species-level relationships, the origin and inheritance mode of polyploid species, and the population genomic effects of polyploidy on genus-wide demography. We describe rapid speciation of diploid Neobatrachus species and show that the three independently originated polyploid species have tetrasomic or mixed inheritance. We document higher genetic diversity in tetraploids, resulting from widespread gene flow between the tetraploids, asymmetric inter-ploidy gene flow directed from sympatric diploids to tetraploids, and isolation of diploid species from each other. We also constructed models of ecologically suitable areas for each species to investigate the impact of climate on differing ploidy levels. These models suggest substantial change in suitable areas compared to past climate, which correspond to population genomic estimates of demographic histories. We propose that Neobatrachus diploids may be suffering the early genomic impacts of climate-induced habitat loss, while tetraploids appear to be avoiding this fate, possibly due to widespread gene flow. Finally, we demonstrate that Neobatrachus is an attractive model to study the effects of ploidy on the evolution of adaptation in animals
Effect of smoke on subcanopy shaded light, canopy temperature, and carbon dioxide uptake in an Amazon rainforest
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95278/1/gbc1694.pd
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