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https://www.readbyqxmd.com/read/29791087/sexual-and-somatic-development-of-wood-frog-tadpoles-along-a-thermal-gradient
#1
Max R Lambert, Meredith S Smylie, Amber J Roman, L Kealoha Freidenburg, David K Skelly
All amphibian species are known to have genetic sex determination. However, a variety of environmental conditions can moderate sexual differentiation, in some cases leading to sex reversal and skewed sex ratios. While there has been a recent focus on chemically-induced sex reversal in amphibians, temperature can also influence sexual differentiation. Building upon a classic 1929 study by Emil Witschi, we assessed temperature-mediated sex reversal. Witschi found that the wood frog sex ratio is 100% male at a high temperature (32°C) compared to a 50:50 sex ratio at 20°C...
May 23, 2018: Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology
https://www.readbyqxmd.com/read/29786147/timing-and-frequency-of-sublethal-exposure-modifies-the-induction-and-retention-of-increased-insecticide-tolerance-in-wood-frogs-lithobates-sylvaticus
#2
Devin K Jones, Erika K Yates, Brian M Mattes, William D Hintz, Matthew S Schuler, Rick A Relyea
While the paradigm for increased tolerance to pesticides has been by selection on constitutive (naïve) traits, recent research has shown it can also occur through phenotypic plasticity. However, the time period in which induction can occur, the duration of induced tolerance, and the influence of multiple induction events remain unknown. We hypothesized that the induction of increased pesticide tolerance is limited to early sensitive periods, the magnitude of induced tolerance depends on the number of exposures, and the retention of induced tolerance depends on the time elapsed after an exposure and the number of exposures...
May 22, 2018: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/29785337/modelling-the-growth-of-the-brown-frog-rana-dybowskii
#3
Qing Tong, Xiao-Peng Du, Zong-Fu Hu, Li-Yong Cui, Hong-Bin Wang
Well-controlled development leads to uniform body size and a better growth rate; therefore, the ability to determine the growth rate of frogs and their period of sexual maturity is essential for producing healthy, high-quality descendant frogs. To establish a working model that can best predict the growth performance of frogs, the present study examined the growth of one-year-old and two-year-old brown frogs ( Rana dybowskii ) from metamorphosis to hibernation (18 weeks) and out-hibernation to hibernation (20 weeks) under the same environmental conditions...
2018: PeerJ
https://www.readbyqxmd.com/read/29780268/filling-the-bins-of-life-report-of-an-amphibian-and-reptile-survey-of-the-tanintharyi-tenasserim-region-of-myanmar-with-dna-barcode-data
#4
Daniel G Mulcahy, Justin L Lee, Aryeh H Miller, Mia Chand, Myint Kyaw Thura, George R Zug
Despite threats of species extinctions, taxonomic crises, and technological advances in genomics and natural history database informatics, we are still distant from cataloguing all of the species of life on earth. Amphibians and reptiles are no exceptions; in fact new species are described nearly every day and many species face possible extinction. The number of described species continues to climb as new areas of the world are explored and as species complexes are examined more thoroughly. The use of DNA barcoding provides a mechanism for rapidly estimating the number of species at a given site and has the potential to record all of the species of life on Earth...
2018: ZooKeys
https://www.readbyqxmd.com/read/29778442/developmental-profiles-of-progesterone-receptor-transcripts-and-molecular-responses-to-gestagen-exposure-during-silurana-tropicalis-early-development
#5
Paisley Thomson, Valerie S Langlois
Environmental gestagens are an emerging class of contaminants that have been recently measured in surface water and can interfere with reproduction in aquatic vertebrates. Gestagens include endogenous progestogens, such as progesterone (P4), which bind P4-receptors and have critically important roles in vertebrate physiology and reproduction. Gestagens also include synthetic progestins, which are components of human and veterinary drugs, such as melengestrol acetate (MGA). Endogenous progestogens are essential in the regulation of reproduction in mammalian species, but the role of P4 in amphibian larval development remains unclear...
May 17, 2018: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/29777142/the-programmed-dna-elimination-and-formation-of-micronuclei-in-germ-line-cells-of-the-natural-hybridogenetic-water-frog-pelophylax-esculentus
#6
Magdalena Chmielewska, Dmitry Dedukh, Katarzyna Haczkiewicz, Beata Rozenblut-Kościsty, Mikołaj Kaźmierczak, Krzysztof Kolenda, Ewa Serwa, Agnieszka Pietras-Lebioda, Alla Krasikova, Maria Ogielska
DNA elimination is a radical form of gene silencing and occurs both in somatic and germ cells. The programmed DNA elimination occurs during gametogenesis in interspecies hybrids that reproduce by hybridogenesis (stick insects, fishes, and amphibians) and concerns removal of whole genomes of one of the parental species and production of clonal gametes propagating the genome of the other species. The cellular mechanisms differ considerably in hybridogenetic insects and fishes but remains unknown in edible frogs Pelophylax esculentus, natural hybrids between Pelophylax lessonae and Pelophylax ridibundus...
May 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29776453/dye-residue-analysis-in-raw-and-processed-aquaculture-products-matrix-extension-of-aoac-international-official-method-%C3%A2-2012-25
#7
Wendy C Andersen, Christine R Casey, Tara J Nickel, Susan L Young, Sherri B Turnipseed
Background : Triphenylmethane dyes and metabolites are known or suspected mutagens and areprohibited in animals intended for human consumption. Despite toxicity, triphenylmethane dyes are used illegally as inexpensive treatments for fungal and parasite infections in aquatic animals. Objective: AOAC INTERNTIONAL Official Method ℠ 2012.25 for the LC-MS/MS determination of malachite green, crystal violet, brilliant green, and metabolites leucomalachite green and leucocrystal violet in seafood products was previously validated for finfish (trout, salmon, catfish, and tilapia) and shrimp, but had not been fully validated for other types of aquacultured products such as eel, molluscan shellfish, or frog or for processed seafoods...
May 18, 2018: Journal of AOAC International
https://www.readbyqxmd.com/read/29775850/electrical-resistivity-imaging-inversion-an-isfla-trained-kernel-principal-component-wavelet-neural-network-approach
#8
Feibo Jiang, Li Dong, Qianwei Dai
The traditional artificial neural network (ANN) inversion of electrical resistivity imaging (ERI) based on gradient descent algorithm is known to be inept for its low computation efficiency and does not ensure global convergence. In order to solve above problems, a kernel principal component wavelet neural network (KPCWNN) trained by an improved shuffled frog leaping algorithm (ISFLA) method is proposed in this study. An additional kernel principal component (KPC) layer is applied to reduce the dimensionality of apparent resistivity data and increase the computational efficiency of wavelet neural network (WNN)...
April 24, 2018: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/29775775/knowledge-and-learning-of-verb-biases-in-amnesia
#9
Rachel Ryskin, Zhenghan Qi, Natalie V Covington, Melissa Duff, Sarah Brown-Schmidt
Verb bias-the co-occurrence frequencies between a verb and the syntactic structures it may appear with-is a critical and reliable linguistic cue for online sentence processing. In particular, listeners use this information to disambiguate sentences with multiple potential syntactic parses (e.g., Feel the frog with the feather.). Further, listeners dynamically update their representations of specific verbs in the face of new evidence about verb-structure co-occurrence. Yet, little is known about the biological memory systems that support the use and dynamic updating of verb bias...
May 15, 2018: Brain and Language
https://www.readbyqxmd.com/read/29774810/procedural-module-flexible-cystoscopy
#10
Shoaib Safiullah, Daniel J Lama, Roshan Patel, Ralph V Clayman
INTRODUCTION: Cystoscopy is a basic urologic skill necessary for the endoscopic evaluation of the urethra and bladder. Presented is a step-by-step guide for flexible cystoscopy of the male and female patient. MATERIALS/METHODS: Routine flexible cystoscopy was performed on a male patient with a history of upper tract urothelial carcinoma and a female patient as part of a hematuria evaluation. The male patient was positioned supine, and the female patient frog-leg supine...
May 2018: Journal of Endourology
https://www.readbyqxmd.com/read/29771993/correction-effects-of-traffic-noise-on-the-calling-behavior-of-two-neotropical-hylid-frogs
#11
Valentina Zaffaroni Caorsi, Camila Both, Sonia Cechin, Rógger Antunes, Márcio Borges-Martins
[This corrects the article DOI: 10.1371/journal.pone.0183342.].
2018: PloS One
https://www.readbyqxmd.com/read/29769395/methods-for-investigating-the-larval-period-and-metamorphosis-in-xenopus
#12
Daniel R Buchholz, Yun-Bo Shi
Anuran metamorphosis resembles postembryonic development in mammals, a period around birth when many organs/tissues mature into their adult form as circulating thyroid and stress hormone levels are high. Unlike uterus-enclosed mammalian embryos, tadpoles develop externally and undergo the dramatic changes of hormone-dependent development totally independent of maternal influence, making them a valuable model in which to study vertebrate postembryonic organ development and maturation. Various protocols have been developed and/or adapted for studying metamorphosis in Xenopus laevis and X...
May 16, 2018: Cold Spring Harbor Protocols
https://www.readbyqxmd.com/read/29769389/extracts-for-analysis-of-dna-replication-in-a-nucleus-free-system
#13
Justin Sparks, Johannes C Walter
Frog egg extracts represent a powerful approach with which to dissect molecular mechanisms of vertebrate DNA replication and repair. In the classical approach, sperm chromatin is added to a crude egg lysate to form replication-competent nuclei. We subsequently described a procedure that bypasses the requirement for nuclear assembly in DNA replication. In this method, DNA is first added to a high-speed supernatant (HSS) of egg lysate, which mimics the G1 phase of the cell cycle in that it supports replication licensing...
May 16, 2018: Cold Spring Harbor Protocols
https://www.readbyqxmd.com/read/29768082/mary-jane-hogue-1883-1962-a-pioneer-in-human-brain-tissue-culture
#14
Steven J Zottoli, Ernst-August Seyfarth
The ability to maintain human brain explants in tissue culture was a critical step in the use of these cells for the study of central nervous system disorders. Ross G. Harrison (1870-1959) was the first to successfully maintain frog medullary tissue in culture in 1907, but it took another 38 years before successful culture of human brain tissue was accomplished. One of the pioneers in this achievement was Mary Jane Hogue (1883-1962). Hogue was born into a Quaker family in 1883 in West Chester, Pennsylvania, and received her undergraduate degree from Goucher College in Baltimore, Maryland...
May 16, 2018: Journal of the History of the Neurosciences
https://www.readbyqxmd.com/read/29766216/impact-of-angiotensin-converting-enzyme-inhibitors-or-receptor-blockers-on-post-icu-discharge-outcome-in-patients-with-acute-kidney-injury
#15
Etienne Gayat, Alexa Hollinger, Alain Cariou, Nicolas Deye, Antoine Vieillard-Baron, Samir Jaber, Benjamin G Chousterman, Qin Lu, Pierre François Laterre, Xavier Monnet, Michael Darmon, Marc Leone, Bertrand Guidet, Romain Sonneville, Jean-Yves Lefrant, Marie-Céline Fournier, Matthieu Resche-Rigon, Alexandre Mebazaa, Matthieu Legrand
PURPOSE: Acute kidney injury (AKI) is associated with the activation of the renin-angiotensin system. Whether angiotensin-converting enzyme inhibitors (ACEi) or angiotensin-receptor blockers (ARB) improve outcome in patients recovering from AKI remains unexplored. The purpose was to investigate the association between prescription of ACEi/ARB at intensive care unit (ICU) discharge and 1-year outcome in patients recovering from AKI. METHODS: Association between ACEi/ARB and 1-year mortality rate was explored in 1551 patients discharged from 21 European ICUs in an observational cohort...
May 15, 2018: Intensive Care Medicine
https://www.readbyqxmd.com/read/29760492/dna-points-to-a-frog-killer-s-birthplace
#16
(no author information available yet)
No abstract text is available yet for this article.
May 2018: Nature
https://www.readbyqxmd.com/read/29760079/selection-and-environmental-adaptation-along-a-path-to-speciation-in-the-tibetan-frog-nanorana-parkeri
#17
Guo-Dong Wang, Bao-Lin Zhang, Wei-Wei Zhou, Yong-Xin Li, Jie-Qiong Jin, Yong Shao, He-Chuan Yang, Yan-Hu Liu, Fang Yan, Hong-Man Chen, Li Jin, Feng Gao, Yaoguang Zhang, Haipeng Li, Bingyu Mao, Robert W Murphy, David B Wake, Ya-Ping Zhang, Jing Che
Tibetan frogs, Nanorana parkeri , are differentiated genetically but not morphologically along geographical and elevational gradients in a challenging environment, presenting a unique opportunity to investigate processes leading to speciation. Analyses of whole genomes of 63 frogs reveal population structuring and historical demography, characterized by highly restricted gene flow in a narrow geographic zone lying between matrilines West (W) and East (E). A population found only along a single tributary of the Yalu Zangbu River has the mitogenome only of E, whereas nuclear genes of W comprise 89-95% of the nuclear genome...
May 14, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29760058/amazonia-is-the-primary-source-of-neotropical-biodiversity
#18
Alexandre Antonelli, Alexander Zizka, Fernanda Antunes Carvalho, Ruud Scharn, Christine D Bacon, Daniele Silvestro, Fabien L Condamine
The American tropics (the Neotropics) are the most species-rich realm on Earth, and for centuries, scientists have attempted to understand the origins and evolution of their biodiversity. It is now clear that different regions and taxonomic groups have responded differently to geological and climatic changes. However, we still lack a basic understanding of how Neotropical biodiversity was assembled over evolutionary timescales. Here we infer the timing and origin of the living biota in all major Neotropical regions by performing a cross-taxonomic biogeographic analysis based on 4,450 species from six major clades across the tree of life (angiosperms, birds, ferns, frogs, mammals, and squamates), and integrate >1...
May 14, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29752415/a-pathogenic-skin-fungus-and-sloughing-exacerbate-cutaneous-water-loss-in-amphibians
#19
Catherine J M Russo, Michel E B Ohmer, Rebecca L Cramp, Craig E Franklin
Batrachochytrium dendrobatidis ( Bd ) is a pathogenic fungus that causes the cutaneous, infectious disease chytridiomycosis and has been implicated in population declines of numerous anuran species worldwide. Proximate cause of death by chytridiomycosis is asystolic cardiac arrest as a consequence of severe disruption to electrolyte balance. Animals heavily infected with Bd also experience a disruption to their skin sloughing regime, indicating that core functions of the skin, such as water retention, may be severely impacted...
May 11, 2018: Journal of Experimental Biology
https://www.readbyqxmd.com/read/29751398/tadpoles-of-the-horned-frog-ceratophrys-ornata-exhibit-high-sensitivity-to-chlorpyrifos-for-conventional-ecotoxicological-and-novel-bioacoustic-variables
#20
C Salgado Costa, A E Ronco, V L Trudeau, D Marino, G S Natale
Previous studies reported that some species of the family Ceratophryidae are able to produce sounds during premetamorphic tadpole stages. We have now determined the effects of the cholinesterase-inhibiting insecticide chlorpyrifos (CPF) on sounds emitted by tadpoles of Ceratophrys ornata. Tadpoles were exposed individually in order to evaluate the progression of effects. Effects on sound production were complemented with common ecotoxicological endpoints (mortality, behavior, abnormalities and growth inhibition)...
April 2018: Environmental Pollution
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