46 research outputs found
The first occurrence records of Kukulcania hibernalis (Hentz, 1842) from Ascension Island and Saint Barthélemy (Araneae: Filistatidae)
The Southern House Spider Kukulcania hibernalis (Hentz, 1842), native to coastal eastern Mexico and the eastern United States, is widely distributed in Central and South America, the Caribbean, and has been recorded from Liberia and the
Canary Islands. Recent examination of material from Ascension Island and Saint Barthélemy newly confirm its presence as a non-native species on these islands. Kukulcania hibernalis is synanthropic, which has presumably allowed it to colonise many non-indigenous countries. In addition to reporting the new localities, we map the updated global distribution of K. hibernalis
Testing for hybridisation of the Critically Endangered Iguana delicatissima on Anguilla to inform conservation efforts
The Caribbean Island of Anguilla in the north-eastern Lesser Antilles is home to one of the last populations of the Critically Endangered Lesser Antillean iguana Iguana delicatissima. This population is highly threatened primarily because of hybridisation with non-native Iguana iguana. This study assesses the degree of hybridisation between Anguillaâs Iguana species firstly using morphological characteristics and then genetic analysis to validate the genetic integrity of morphologically identified I. delicatissima. We also examined the genetic diversity of Anguillaâs I. delicatissima population, and that of a population on the nearby island of Ălet Fourchue, St BarthĂ©lemy. Forty-five iguanas were captured in Anguilla and 10 in St BarthĂ©lemy, and sequences from 3 nuclear and 1 mtDNA genes were obtained for each. Of the 45 iguanas captured in Anguilla, 22 were morphologically identified as I. delicatissima, 12 as I. iguana and the remainder were identified as hybrids. Morphological assignments were all confirmed by genetic analyses except for one I. iguana and one hybrid individual. These two individuals appeared likely to have originated following ancestral hybridisation events several generations ago. A significant paucity of genetic diversity was found within Anguillan and St BarthĂ©lemy I. delicatissima populations, with a single haplotype being identified for each of the three nuclear genes and the mtDNA sequence. This study highlights the urgency for immediate action to conserve Anguillaâs remnant I. delicatissima population. Protection from hybridisation will require translocation to I. iguana-free offshore cays, with supplementary individuals being sourced from neighbouring islands to enhance the genetic diversity of the population
Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations
North America's Eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programs often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response (rate of tongue-flick [RTF]). RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating predation and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is a potential low-cost alternative trap lure for the control of invasive corn snake populations
Postglacial expansion of the arctic keystone copepod calanus glacialis
Calanus glacialis, a major contributor to zooplankton biomass in the Arctic shelf seas, is a key link between primary production and higher trophic levels that may be sensitive to climate warming. The aim of this study was to explore genetic variation in contemporary populations of this species to infer possible changes during the Quaternary period, and to assess its population structure in both space and time. Calanus glacialis was sampled in the fjords of Spitsbergen (Hornsund and Kongsfjorden) in 2003, 2004, 2006, 2009 and 2012. The sequence of a mitochondrial marker, belonging to the ND5 gene, selected for the study was 1249 base pairs long and distinguished 75 unique haplotypes among 140 individuals that formed three main clades. There was no detectable pattern in the distribution of haplotypes by geographic distance or over time. Interestingly, a Bayesian skyline plot suggested that a 1000-fold increase in population size occurred approximately 10,000 years before present, suggesting a species expansion after the Last Glacial Maximum.GAME from the National Science Centre, the Polish Ministry of Science and Higher Education Iuventus Plus [IP2014 050573]; FCT-PT [CCMAR/Multi/04326/2013]; [2011/03/B/NZ8/02876
PDBe: Protein Data Bank in Europe
The Protein Data Bank in Europe (PDBe) (http://www.ebi.ac.uk/pdbe/) is actively working with its Worldwide Protein Data Bank partners to enhance the quality and consistency of the international archive of bio-macromolecular structure data, the Protein Data Bank (PDB). PDBe also works closely with its collaborators at the European Bioinformatics Institute and the scientific community around the world to enhance its databases and services by adding curated and actively maintained derived data to the existing structural data in the PDB. We have developed a new database infrastructure based on the remediated PDB archive data and a specially designed database for storing information on interactions between proteins and bound molecules. The group has developed new services that allow users to carry out simple textual queries or more complex 3D structure-based queries. The newly designed âPDBeView Atlas pagesâ provide an overview of an individual PDB entry in a user-friendly layout and serve as a starting point to further explore the information available in the PDBe database. PDBeâs active involvement with the X-ray crystallography, Nuclear Magnetic Resonance spectroscopy and cryo-Electron Microscopy communities have resulted in improved tools for structure deposition and analysis
Population genomics of marine zooplankton
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Bucklin, Ann et al. "Population Genomics of Marine Zooplankton." Population Genomics: Marine Organisms. Ed. Om P. Rajora and Marjorie Oleksiak. Springer, 2018. doi:10.1007/13836_2017_9.The exceptionally large population size and cosmopolitan biogeographic distribution that
distinguish many â but not all â marine zooplankton species generate similarly exceptional patterns of
population genetic and genomic diversity and structure. The phylogenetic diversity of zooplankton has
slowed the application of population genomic approaches, due to lack of genomic resources for closelyrelated
species and diversity of genomic architecture, including highly-replicated genomes of many
crustaceans. Use of numerous genomic markers, especially single nucleotide polymorphisms (SNPs), is
transforming our ability to analyze population genetics and connectivity of marine zooplankton, and
providing new understanding and different answers than earlier analyses, which typically used
mitochondrial DNA and microsatellite markers. Population genomic approaches have confirmed that,
despite high dispersal potential, many zooplankton species exhibit genetic structuring among geographic
populations, especially at large ocean-basin scales, and have revealed patterns and pathways of population
connectivity that do not always track ocean circulation. Genomic and transcriptomic resources are
critically needed to allow further examination of micro-evolution and local adaptation, including
identification of genes that show evidence of selection. These new tools will also enable further
examination of the significance of small-scale genetic heterogeneity of marine zooplankton, to
discriminate genetic ânoiseâ in large and patchy populations from local adaptation to environmental
conditions and change.Support was provided by the
US National Science Foundation to AB and RJO (PLR-1044982) and to RJO (MCB-1613856); support to
IS and MC was provided by Nord University (Norway)
Orientational Effects and Random Mixing in 1âAlkanol + Nitrile Mixtures
1-Alkanol + alkanenitrile or + benzonitrile systems have been investigated by means of the molar excess
functionsenthalpies (Hm E ), isobaric heat capacities (Cp,m
E ), volumes (Vm E ), and entropiesand using the Flory model and the
concentrationâconcentration structure factor (SCC(0)) formalism. From the analysis of the experimental data available in the
literature, it is concluded that interactions are mainly of dipolar type. In addition, large Hm E values contrast with rather low Vm E
values, indicating the existence of strong structural effects. Hm E measurements have been used to evaluate the enthalpy of the
hydroxylânitrile interactions (ÎHOHâCN). They are stronger in methanol systems and become weaker when the alcohol size
increases. In solutions with a given short chain 1-alkanol (up to 1-butanol), the replacement of ethanenitrile by butanenitrile
weakens the mentioned interactions. Application of the Flory model shows that orientational effects exist in methanol or 1-
nonanol, or 1-decanol + ethanenitrile mixtures. In the former solution, this is due to the existence of interactions between unlike
molecules. For mixtures including 1-nonanol or 1-decanol, the systems at 298.15 K are close to their UCST (upper critical
solution temperature), and interactions between like molecules are dominant. Orientational effects also are encountered in
methanol or ethanol + butanenitrile mixtures because self-association of the alcohol plays a more important role. Aromaticity
effect seems to enhance orientational effects. For the remainder of the systems under consideration, the random mixing
hypothesis is attained to a rather large extent. Results from the application of the SCC(0) formalism show that homocoordination
is the dominant trend in the investigated solutions, and are consistent with those obtained from the Flory model