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https://www.readbyqxmd.com/read/28081528/rapid-decrease-in-populations-of-wild-ring-tailed-lemurs-lemur-catta-in-madagascar
#1
Marni LaFleur, Tara A Clarke, Kim Reuter, Toby Schaeffer
Lemurs are the most threatened group of mammals on earth. Lemur catta (ring-tailed lemur) represents one of the most iconic lemur species and faces numerous anthropogenic threats in the wild. In this study, we present population estimates from 32 sites across the range of L. catta, collected from primary and secondary data sources, to assess the number of ring-tailed lemurs left in the wild. We estimate that there are approximately 2,220 individual L. catta remaining in the 32 sites considered. We note local extinctions of populations of L...
January 13, 2017: Folia Primatologica; International Journal of Primatology
https://www.readbyqxmd.com/read/28081081/compact-broadband-polarization-beam-splitter-using-a-symmetric-directional-coupler-with-sinusoidal-bends
#2
Fan Zhang, Han Yun, Yun Wang, Zeqin Lu, Lukas Chrostowski, Nicolas A F Jaeger
We design and demonstrate a compact broadband polarization beam splitter (PBS) using a symmetric directional coupler with sinusoidal bends on a silicon-on-insulator platform. The sinusoidal bends in our PBS suppress the power exchange between two parallel symmetric strip waveguides for the transverse-electric (TE) mode, while allowing for the maximum power transfer to the adjacent waveguide for the transverse-magnetic (TM) mode. Our PBS has a nominal coupler length of 8.55 μm, and it has an average extinction ratio (ER) of 12...
January 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28081078/mid-wave-infrared-narrow-bandwidth-guided-mode-resonance-notch-filter
#3
Y Zhong, Z Goldenfeld, K Li, W Streyer, L Yu, L Nordin, N Murphy, D Wasserman
We have designed, fabricated, and characterized a guided mode resonance notch filter operating in the technologically vital mid-wave infrared (MWIR) region of the electromagnetic spectrum. The filter provides a bandstop at λ≈4.1  μm, with a 12 dB extinction on resonance. In addition, we demonstrate a high transmission background (>80%), less than 6% transmission on resonance, and an ultra-narrow bandwidth transmission notch (10  cm<sup>-1</sup>). Our filter is optically characterized using angle- and polarization-dependent Fourier transform infrared spectroscopy, and simulated using rigorous coupled-wave analysis (RCWA) with excellent agreement between simulations and our experimental results...
January 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28081068/plasmonic-wavelength-splitter-based-on-a-metal-insulator-metal-waveguide-with-a-graded-grating-coupler
#4
Yue Yu, Jiangnan Si, Yaying Ning, Minghai Sun, Xiaoxu Deng
A plasmonic wavelength splitter based on a sub-wavelength metal-insulator-metal (MIM) periodic rectangle wrinkle waveguide with a graded grating coupler is theoretically analyzed and experimentally demonstrated. The surface plasmon polaritons (SPPs), excited in the metal grating with wavelength selection, are deflected by the graded difference according to the aplanatic parametric principle. The wave vector of the deflected SPPs meets the phase-matching condition and couples into the periodic rectangle wrinkle waveguide with a plasmonic bandgap...
January 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28080997/tackling-emerging-fungal-threats-to-animal-health-food-security-and-ecosystem-resilience
#5
Matthew C Fisher, Neil A R Gow, Sarah J Gurr
Emerging infections caused by fungi have become a widely recognized global phenomenon. Their notoriety stems from their causing plagues and famines, driving species extinctions, and the difficulty in treating human mycoses alongside the increase of their resistance to antifungal drugs. This special issue comprises a collection of articles resulting from a Royal Society discussion meeting examining why pathogenic fungi are causing more disease now than they did in the past, and how we can tackle this rapidly emerging threat to the health of plants and animals worldwide...
December 5, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28080989/overview-of-chytrid-emergence-and-impacts-on-amphibians
#6
REVIEW
Karen R Lips
Chytridiomycosis is an emerging infectious disease of amphibians that affects over 700 species on all continents where amphibians occur. The amphibian-chytridiomycosis system is complex, and the response of any amphibian species to chytrid depends on many aspects of the ecology and evolutionary history of the amphibian, the genotype and phenotype of the fungus, and how the biological and physical environment can mediate that interaction. Impacts of chytridiomycosis on amphibians are varied; some species have been driven extinct, populations of others have declined severely, whereas still others have not obviously declined...
December 5, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28080982/drivers-of-variation-in-species-impacts-for-a-multi-host-fungal-disease-of-bats
#7
Kate E Langwig, Winifred F Frick, Joseph R Hoyt, Katy L Parise, Kevin P Drees, Thomas H Kunz, Jeffrey T Foster, A Marm Kilpatrick
Disease can play an important role in structuring species communities because the effects of disease vary among hosts; some species are driven towards extinction, while others suffer relatively little impact. Why disease impacts vary among host species remains poorly understood for most multi-host pathogens, and factors allowing less-susceptible species to persist could be useful in conserving highly affected species. White-nose syndrome (WNS), an emerging fungal disease of bats, has decimated some species while sympatric and closely related species have experienced little effect...
December 5, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28079221/sizing-and-eddy-currents-in-magnetic-core-nanoparticles-an-optical-extinction-approach
#8
Luis J Mendoza Herrera, Ignacio J Bruvera, Lucía B Scaffardi, Daniel C Schinca
Optical extinction is a handy and ubiquitous technique that allows us to study colloidal nanoparticles in their native state. The typical analysis of the extinction spectrum can be extended in order to obtain structural information of the sample such as the size distribution of the cores and the thickness of the coating layers. In this work the extinction spectra of Fe3O4, Fe3O4@Au, and Fe3O4@SiO2@Au single and multilayer nanoparticles are obtained by solving full Mie theory with a frequency dependent susceptibility derived from the Gilbert equation and considering the effect of Eddy currents...
January 12, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28077774/tropical-ancient-dna-reveals-relationships-of-the-extinct-bahamian-giant-tortoise-chelonoidis-alburyorum
#9
Christian Kehlmaier, Axel Barlow, Alexander K Hastings, Melita Vamberger, Johanna L A Paijmans, David W Steadman, Nancy A Albury, Richard Franz, Michael Hofreiter, Uwe Fritz
Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island...
January 11, 2017: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/28077767/what-north-america-s-skeleton-crew-of-megafauna-tells-us-about-community-disassembly
#10
Matt Davis
Functional trait diversity is increasingly used to model future changes in community structure despite a poor understanding of community disassembly's effects on functional diversity. By tracking the functional diversity of the North American large mammal fauna through the End-Pleistocene megafaunal extinction and up to the present, I show that contrary to expectations, functionally unique species are no more likely to go extinct than functionally redundant species. This makes total functional richness loss no worse than expected given similar taxonomic richness declines...
January 11, 2017: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/28077688/pattern-process-inference-and-prediction-in-extinction-biology
#11
Barry W Brook, John Alroy
Extinction is a key feature of the evolutionary history of life, and assessments of extinction risk are essential for the effective protection of biodiversity. The goal in assembling this special issue of Biology Letters was to highlight problems and questions at the research frontier of extinction biology, with an emphasis on recent developments in the methodology of inferring the patterns and processes of extinction from a background of often noisy and sparse data. In selecting topics, we sought to illustrate how extinction is not simply a self-evident phenomenon, but the subject of a dynamic and quantitatively rigorous field of natural science, with practical applications to conservation...
January 2017: Biology Letters
https://www.readbyqxmd.com/read/28076517/standardization-of-the-face-hand-test-in-a-brazilian-multicultural-population-prevalence-of-sensory-extinction-and-implications-for-neurological-diagnosis
#12
Gustavo José Luvizutto, Marcelo Ortolani Fogaroli, Rodolfo Mazeto Theotonio, Hélio Rubens de Carvalho Nunes, Luiz Antônio de Lima Resende, Rodrigo Bazan
OBJECTIVE: The face-hand test is a simple, practical, and rapid test to detect neurological syndromes. However, it has not previously been assessed in a Brazilian sample; therefore, the objective of the present study was to standardize the face-hand test for use in the multi-cultural population of Brazil and identify the sociodemographic factors affecting the results. METHODS: This was a cross sectional study of 150 individuals. The sociodemographic variables that were collected included age, gender, race, body mass index and years of education...
December 1, 2016: Clinics
https://www.readbyqxmd.com/read/28076419/stability-of-a-coevolving-host-parasite-system-peaks-at-intermediate-productivity
#13
Xin-Feng Zhao, Yi-Qi Hao, Quan-Guo Zhang
Habitat productivity may affect the stability of consumer-resource systems, through both ecological and evolutionary mechanisms. We hypothesize that coevolving consumer-resource systems show more stable dynamics at intermediate resource availability, while very low-level resource supply cannot support sufficiently large populations of resource and consumer species to avoid stochastic extinction, and extremely resource-rich environments may promote escalatory arms-race-like coevolution that can cause strong fluctuations in species abundance and even extinction of one or both trophic levels...
2017: PloS One
https://www.readbyqxmd.com/read/28075134/dynamic-optical-switching-of-polymer-plasmonic-nanoparticle-hybrids-with-sparse-loading
#14
Zhaoxia Qian, Kathryn N Guye, David J Masiello, David S Ginger
Responsive plasmonic nanomaterials composed of gold nanoparticles (AuNPs) and temperature-responsive poly(N-isopropylacrylamide) (PNIPAM) hydrogels offer the promise of designing smart materials that can change color in response to varying thermal, or photothermal stimuli. Typical AuNP/PNIPAM hybrids are heavily loaded with AuNPs. Here we demonstrate that PNIPAM spheres with small number AuNP loadings exhibit significant extinction shifts and a broad range of color changes with varying temperature. Hybrids with an average loading of 3 to 5 AuNPs per PNIPAM sphere exhibit peak extinction shifts of over 150 nm and color change from red to purple to gray, with very large extinction changes in the NIR, as the temperature increases from 25oC to 50oC...
January 11, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28075073/resolving-the-relationships-of-paleocene-placental-mammals
#15
Thomas J D Halliday, Paul Upchurch, Anjali Goswami
The 'Age of Mammals' began in the Paleocene epoch, the 10 million year interval immediately following the Cretaceous-Palaeogene mass extinction. The apparently rapid shift in mammalian ecomorphs from small, largely insectivorous forms to many small-to-large-bodied, diverse taxa has driven a hypothesis that the end-Cretaceous heralded an adaptive radiation in placental mammal evolution. However, the affinities of most Paleocene mammals have remained unresolved, despite significant advances in understanding the relationships of the extant orders, hindering efforts to reconstruct robustly the origin and early evolution of placental mammals...
February 2017: Biological Reviews of the Cambridge Philosophical Society
https://www.readbyqxmd.com/read/28075029/does-cortical-bone-thickness-in-the-last-sacral-vertebra-differ-among-tail-types-in-primates
#16
Abigail C Nishimura, Gabrielle A Russo
OBJECTIVES: The external morphology of the sacrum is demonstrably informative regarding tail type (i.e., tail presence/absence, length, and prehensility) in living and extinct primates. However, little research has focused on the relationship between tail type and internal sacral morphology, a potentially important source of functional information when fossil sacra are incomplete. Here, we determine if cortical bone cross-sectional thickness of the last sacral vertebral body differs among tail types in extant primates and can be used to reconstruct tail types in extinct primates...
January 11, 2017: American Journal of Physical Anthropology
https://www.readbyqxmd.com/read/28074853/plasmonic-plano-semi-cylindrical-nanocavities-with-high-efficiency-local-field-confinement
#17
Feifei Liu, Xinping Zhang, Xiaohui Fang
Plasmonic nanocavity arrays were achieved by producing isolated silver semi-cylindrical nanoshells periodically on a continuous planar gold film. Hybridization between localized surface plasmon resonance (LSPR) in the Ag semi-cylindrical nanoshells (SCNS) and surface plasmon polaritons (SPP) in the gold film was observed as split bonding and anti-bonding resonance modes located at different spectral positions. This led to strong local field enhancement and confinement in the plano-concave nanocavites. Narrow-band optical extinction with an amplitude as high as 1...
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28074851/corrigendum-dynamics-and-genetics-of-a-disease-driven-species-decline-to-near-extinction-lessons-for-conservation
#18
M A Hudson, R P Young, J D'Urban Jackson, P Orozco-terWengel, L Martin, A James, M Sulton, G Garcia, R A Griffiths, R Thomas, C Magin, M W Bruford, A A Cunningham
No abstract text is available yet for this article.
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28074844/no-signs-of-inbreeding-despite-long-term-isolation-and-habitat-fragmentation-in-the-critically-endangered-montseny-brook-newt-calotriton-arnoldi
#19
E Valbuena-Ureña, A Soler-Membrives, S Steinfartz, P Orozco-terWengel, S Carranza
Endemic species with restricted geographic ranges potentially suffer the highest risk of extinction. If these species are further fragmented into genetically isolated subpopulations, the risk of extinction is elevated. Habitat fragmentation is generally considered to have negative effects on species survival, despite some evidence for neutral or even positive effects. Typically, non-negative effects are ignored by conservation biology. The Montseny brook newt (Calotriton arnoldi) has one of the smallest distribution ranges of any European amphibian (8 km(2)) and is considered critically endangered by the International Union for Conservation of Nature...
January 11, 2017: Heredity
https://www.readbyqxmd.com/read/28073165/description-of-a-new-species-of-hoolock-gibbon-primates-hylobatidae-based-on-integrative-taxonomy
#20
Peng-Fei Fan, Kai He, Xing Chen, Alejandra Ortiz, Bin Zhang, Chao Zhao, Yun-Qiao Li, Hai-Bo Zhang, Clare Kimock, Wen-Zhi Wang, Colin Groves, Samuel T Turvey, Christian Roos, Kristofer M Helgen, Xue-Long Jiang
We describe a species of Hoolock gibbon (Primates: Hylobatidae) that is new to science from eastern Myanmar and southwestern China. The genus of hoolock gibbons comprises two previously described living species, the western (Hoolock hoolock) and eastern hoolock (H. leuconedys) gibbons, geographically isolated by the Chindwin River. We assessed the morphological and genetic characteristics of wild animals and museum specimens, and conducted multi-disciplinary analyses using mitochondrial genomic sequences, external morphology, and craniodental characters to evaluate the taxonomic status of the hoolock population in China...
January 10, 2017: American Journal of Primatology
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