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211.
Sinlan Poo Ana Karen Candia Kristina L. Cohen Francesca T. Erickson Sara A. Mason Bradley D. Nissen Adair F. McNear Jonathon J. Reinig Joseph S. Sherrock Ashley R. Aguiluz Letitia L. Jacques Hanna E. R. Jenkins Anne Devan-Song 《Biotropica》2023,55(4):806-815
Environmentally cued hatching has been well-documented in amphibians in response to a wide range of abiotic and biotic factors. The hatching of terrestrial amphibian eggs in response to flooding may be basal within the group, but amphibian lineages in tropical Asia and sub-Saharan Africa have not received as much attention as their Neotropical counterparts. We investigated submergence-induced hatching in Feihyla hansenae, a Rhacophorid tree frog with terrestrial eggs. We quantified natural rates of clutch submergence at our study site in Thailand. Using submergence experiments, we found that embryos are capable of hatching early to escape flooding, and that failure to hatch results in mortality. Among the embryos that were able to hatch early, only the earliest, youngest hatchlings experienced a trade-off in body size that persisted for 6 days, while later, older hatchlings were not significantly smaller than spontaneous hatchlings under control conditions. By incorporating our natural and experimental data into Monte Carlo methods to simulate and compare survival probabilities with and without hatching plasticity, we found an overall 3.1% increase in submergence survival due to hatching plasticity. Our findings support the idea that flooding-induced hatching is widespread across amphibians with terrestrial eggs and highlight the importance of researching understudied tropical regions. As climate change is projected to affect rainfall patterns, the ability of embryos to escape abiotic egg-stage threats may be an indicator of species' ability to flexibly navigate a changing environment. 相似文献
212.
Béatrice Drouet Luis Garcia Dominique Simon-Chazottes Marie Geneviève Mattei Jean-Louis Guénet Arnold Schwartz Gyula Varadi Martine Pinçon-Raymond 《Mammalian genome》1993,4(9):499-503
Using both chromosomal in situ hybridization and molecular techniques, we report the genetic localization of the gene coding for the alpha 1 subunit of the skeletal slow Ca2+ current channel/DHP receptor gene (Cchl1a3) on human Chromosome (Chr) 1 (1q31–1q32 region) and on mouse Chr 1 region (F-G). On the basis of single-strand conformation polymorphism (SSCP-PCR) analysis in an interspecific backcross, we have determined that the Cchl1a3=mdg (muscular dysgenesis) locus is very closely linked to the myogenin (Myog) locus. 相似文献
213.
María del Mar Rueda Sara Pasadas-del-Amo Beatriz Cobo Rodríguez Luis Castro-Martín Ramón Ferri-García 《Biometrical journal. Biometrische Zeitschrift》2023,65(2):2200035
Web surveys have replaced Face-to-Face and computer assisted telephone interviewing (CATI) as the main mode of data collection in most countries. This trend was reinforced as a consequence of COVID-19 pandemic-related restrictions. However, this mode still faces significant limitations in obtaining probability-based samples of the general population. For this reason, most web surveys rely on nonprobability survey designs. Whereas probability-based designs continue to be the gold standard in survey sampling, nonprobability web surveys may still prove useful in some situations. For instance, when small subpopulations are the group under study and probability sampling is unlikely to meet sample size requirements, complementing a small probability sample with a larger nonprobability one may improve the efficiency of the estimates. Nonprobability samples may also be designed as a mean for compensating for known biases in probability-based web survey samples by purposely targeting respondent profiles that tend to be underrepresented in these surveys. This is the case in the Survey on the impact of the COVID-19 pandemic in Spain (ESPACOV) that motivates this paper. In this paper, we propose a methodology for combining probability and nonprobability web-based survey samples with the help of machine-learning techniques. We then assess the efficiency of the resulting estimates by comparing them with other strategies that have been used before. Our simulation study and the application of the proposed estimation method to the second wave of the ESPACOV Survey allow us to conclude that this is the best option for reducing the biases observed in our data. 相似文献
214.
Kayleigh M. Hansford Sara L. Gandy Emma L. Gillingham Liz McGinley Benjamin Cull Colin Johnston Matthew Catton Jolyon M. Medlock 《Medical and veterinary entomology》2023,37(1):152-163
Tick-borne disease risk is intrinsically linked to the distribution of tick vector species. To assess risk and anticipate disease emergence, an understanding of tick distribution, host associations, and seasonality is needed. This can be achieved, to some extent, using passive surveillance supported by engagement with the public, animal health, and public health experts. The Tick Surveillance Scheme (TSS) collects data and maps tick distribution across the United Kingdom (UK). Between 2017 and 2020, 3720 tick records were received and 39 tick species were detected. Most records were acquired in the UK, with a subset associated with recent overseas travel. The dominant UK acquired species was Ixodes ricinus (Ixodida: Ixodidae, Linnaeus), the main vector of Lyme borreliosis. Records peaked during May and June, highlighting a key risk period for tick bites. Other key UK species were detected, including Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius) and Haemaphysalis punctata (Ixodida: Ixodidae, Canestrini & Fanzago) as well as several rarer species that may present novel tick-borne disease risk to humans and other animals. Updated tick distribution maps highlight areas in the UK where tick exposure has occurred. There is evidence of increasing human tick exposure over time, including during the COVID-19 pandemic, but seasonal patterns remain unchanged. 相似文献
215.
Franco Alessandro Buoso Sara Zanin Laura Pinton Roberto Tomasi Nicola 《Journal of Plant Growth Regulation》2023,42(3):1567-1581
Journal of Plant Growth Regulation - The wide use of copper (Cu)-based fungicide has caused a stepwise accumulation of Cu in the environment increasing the occurrence of phytotoxicity in crops. To... 相似文献
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218.
Carbon : nitrogen : phosphorus (C : N : P) stoichiometry can underlie physiological and life history characteristics that shape ecological interactions. Despite its potential importance, there is much to learn about the causes and consequences of stoichiometric variation in terrestrial consumers. Here we show that treehoppers (Publilia modesta) tended by ants (Formica obscuripes) contained lower N concentrations than treehoppers on plants from which ants were excluded. Ant presence also affected nutrient concentrations in host plants: on plants with ants, leaves contained uniformly low concentrations of N; on plants without ants, N concentrations were low only in the few leaves fed upon by treehoppers at the time of collection. We suggest treehopper feeding reduces leaf nutrient levels and ants positively affect treehopper abundance, producing a top–down effect on plant quality. Determining the causes of these stoichiometric changes should help elucidate factors guiding the dynamics of conditional mutualisms between ants and homopterans. 相似文献
219.
Sara Divari Francesca Valetti Patrizia Caposio Enrica Pessione Maria Cavaletto Ersilia Griva Giorgio Gribaudo Gianfranco Gilardi Carlo Giunta 《European journal of biochemistry》2003,270(10):2244-2253
Phenol hydroxylase (PH) from Acinetobacter radioresistens S13 represents an example of multicomponent aromatic ring monooxygenase made up of three moieties: a reductase (PHR), an oxygenase (PHO) and a regulative component (PHI). The function of the oxygenase component (PHO), here characterized for the first time, is to bind molecular oxygen and catalyse the mono-hydroxylation of substrates (phenol, and with less efficiency, chloro- and methyl-phenol and naphthol). PHO was purified from extracts of A. radioresistens S13 cells and shown to be a dimer of 206 kDa. Each monomer is composed by three subunits: alpha (54 kDa), beta (38 kDa) and gamma (11 kDa). The gene encoding PHO alpha (named mopN) was cloned and sequenced and the corresponding amino acid sequence matched with that of functionally related oxygenases. By structural alignment with the catalytic subunits of methane monooxygenase (MMO) and alkene monooxygenase, we propose that PHO alpha contains the enzyme active site, harbouring a dinuclear iron centre Fe-O-Fe, as also suggested by spectral analysis. Conserved hydrophobic amino acids known to define the substrate recognition pocket, are also present in the alpha-subunit. The prevalence of alpha-helices (99.6%) as studied by CD confirmed the hypothized structural homologies between PHO and MMO. Three parameters (optimum ionic strength, temperature and pH) that affect kinetics of the overall phenol hydroxylase reaction were further analyzed with a fixed optimal PHR/PHI/PHO ratio of 2/1/1. The highest level of activity was evaluated between 0.075 and 0.1 m of ionic strength, the temperature dependence showed a maximum of activity at 24 degrees C and finally the pH for optimal activity was determined to be 7.5. 相似文献
220.
Zlatka Kostova Benjamin C Yan Saulius Vainauskas Roberta Schwartz Anant K Menon Peter Orlean 《European journal of biochemistry》2003,270(22):4507-4514
Saccharomyces cerevisiae Gpi3p is the UDP-GlcNAc-binding and presumed catalytic subunit of the enzyme that forms GlcNAc-phosphatidylinositol in glycosylphosphatidylinositol biosynthesis. It is an essential protein with an EX7E motif that is conserved in four families of retaining glycosyltransferases. All Gpi3ps contain a cysteine residue four residues C-terminal to EX7E. To test their importance for Gpi3p function in vivo, Glu289 and 297 in the EX7E motif of S. cerevisiae Gpi3p, as well as Cys301, were altered by site-specific mutagenesis, and the mutant proteins tested for their ability to complement nonviable GPI3-deleted haploids. Gpi3p-C301A supported growth but membranes from C301A-expressing cells had low in vitro N-acetylglucosaminylphosphatidylinositol (GlcNAc-PI) synthetic activity. Haploids harboring Gpi3p-E289A proved viable, although slow growing but Gpi3-E297A did not support growth. The E289D and E297D mutants both supported growth at 25 degrees C, but, whereas the E289D strain grew at 37 degrees C, the E297D mutant did not. Membranes from E289D mutants had severely reduced in vitro GlcNAc-PI synthetic activity and E297D membranes had none. The mutation of the first Glu in the EX7E motif of Schizosaccharomyces pombe Gpi3p (Glu277) to Asp complemented the lethal null mutation in gpi3+ and supported growth at 37 degrees C, but the E285D mutant was nonviable. Our results suggest that the second Glu residue of the EX7E motif in Gpi3p is of greater importance than the first for function in vivo. Further, our findings do not support previous suggestions that the first Glu of an EX7E protein is the nucleophile and that Cys301 has an important role in UDP-GlcNAc binding by Gpi3ps. 相似文献