2,697 research outputs found
Distribution and morphological variation of Eleutherodactylus mercedesae Lynch & McDiarmid, 1987 (Amphibia, Anura, Leptodactylidae) with first record for Peru
Accepted by S. Carranza: 19 May 2006; published: 3 Aug. 2006 49[EN] We report new distributional information for Eleutherodactylus mercedesae in Bolivia, and provide the first record for Peru based on an adult female. This species, previously endemic to Bolivia, now ranges across about 1000 km in cloud forests on the Amazonian slopes of the Andes from southern Peru to central Bolivia. We provide the first morphological description of females based on two specimens, compare them with the male type and paratype, add some observations to the original description, and comment on variation in the species.[ES] Aportamos información novedosa sobre la distribución de Eleutherodactylus mercedesae en Bolivia y la primera cita para Perú, basada en una hembra adulta. Esta especie se consideraba hasta ahora endémica para Bolivia. Su rango conocido de distribución comprende actualmente unos 1000 km de los bosques nublados de las laderas amazónicas de los Andes, desde el sur de Perú al centro de Bolivia. Se describe por primera vez la hembra de esta especie en base a dos ejemplares, que son comparados con el holotipo y el paratipo. Añadimos algunas observaciones sobre la descripción original y la variación morfológica de la especie.This work was partially funded by projects REN/GLO 2001-1046 and CGL2005-03156 of the Spanish Ministry of Education and Science (I. De la Riva, Principal Investigator).Peer reviewe
A new species of arboreal toad (Anura: Bufonidae: Chaunus) from Madidi National Park, Bolivia
Accepted by M. Vences: 23 Jun 2006; published: 3 Aug. 2006A new arboreal species of the Chaunus veraguensis group is described for the humid montane forest of Madidi National Park, in northern Bolivia. The new species differs from other species in the group by the combination small size, long and slender extremities, webbed hands, conspicuous tympanic membrane, well developed parotoid glands, absence of large glands on dorsum and extremities, nuptial excrescences of males composed of pungent spines on dorsal surface of thumb, greenish-brown coloration on dorsum with red warts in life, and green iris. It is only known from two nearby localities in the Serranía Eslabón, Department La Paz. An operational key for species in the C. veraguensis group is provided.This work was partially funded by projects REN/GLO 2001-1046 and CGL2005-03156 of the Spanish Ministry of Education and Science (I. De la Riva, Principal Investigator) and by a project of the AECI (Spanish Agency of International Cooperation) (I. De la Riva, Principal Investigator) to inventory Madidi’s herpetofauna.Peer reviewe
Invariant indices of polarimetric purity. Generalized indices of purity for nxn covariance matrices
A proper set of indices characterizing the polarimetric purity of light and
material media is defined from the eigenvalues of the corresponding coherency
matrix. A simple and generalizable relation of these indices with the current
parameters characterizing the global purity is obtained. A general definition
for systems characterized by nxn positive semidefinite Hermitian matrices is
introduced in terms of the corresponding eigenvalues and diagonal Gell-Mann
matrices. The set of n-1 indices of purity has a nested structure and provide
complete information about the statistical purity of the system.Comment: 19 pages, 2 figure
Soluble ST2 levels and left ventricular structure and function in patients with metabolic syndrome
Background: A biomarker that is of great interest in relation to adverse cardiovascular events is soluble ST2 (sST2), a member of the interleukin family. Considering that metabolic syndrome (MetS) is accompanied by a proinflammatory state, we aimed to assess the relationship between sST2 and left ventricular (LV) structure and function in patients with MetS. Methods: A multicentric, cross-sectional study was conducted on180 MetS subjects with normal LV ejection fraction as determined by echocardiography. LV hypertrophy (LVH) was defined as an LV mass index greater than the gender-specific upper limit of normal as determined by echocardiography. LV diastolic dysfunction (DD) was assessed by pulse-wave and tissue Doppler imaging. sST2 was measured by using a quantitative monoclonal ELISA assay. Results: LV mass index (β=0.337, P<0 .001, linear regression) was independently associated with sST2 concentrations. Increased sST2 was associated with an increased likelihood of LVH [Exp (B)=2.20, P=0.048, logistic regression] and increased systolic blood pressure [Exp (B)=1.02, P=0.05, logistic regression]. Comparing mean sST2 concentrations (adjusted for age, body mass index, gender) between different LV remodeling patterns, we found the greatest sST2 level in the group with concentric hypertrophy. There were no differences in sST2 concentration between groups with and without LV DD. Conclusions: Increased sST2 concentration in patients with MetS was associated with a greater likelihood of exhibiting LVH. Our results suggest that inflammation could be one of the principal triggering mechanisms for LV remodeling in MetS
Block Copolymer–Nanorod Co-assembly in Thin Films: Effects of Rod–Rod Interaction and Confinement
Simulations and experiments of nanorods (NRs) show that co-assembly with block
copolymer (BCP) melts leads to the formation of a superstructure of side-to-side NRs
perpendicular to the lamellar axis. A mesoscopic model is validated against scan-
ning electron microscopy (SEM) images of CdSe NRs mixed with polystyrene-block-
poly(methyl methacrylate). It is then used to study the co-assembly of anisotropic
nanoparticles (NPs) with a length in the same order of magnitude as the lamellar spac-
ing. The phase diagram of BCP/NP is explored as well as the time evolution of the NR.
NRs that are slightly larger than the lamellar spacing are found to rotate and organise
side-to-side with a tilted orientation with respect to the interface. Strongly interacting
NPs are found to dominate the co-assembly while weakly interacting nanoparticles are
less prone to form aggregates and tend to form well-ordered configurations
Extensive conservation of ancient microsynteny across metazoans due to cis-regulatory constraints
This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date; after six months, it is available under a Creative Commons License.-- et al.The order of genes in eukaryotic genomes has generally been assumed to be neutral, since gene order is largely scrambled over evolutionary time. Only a handful of exceptional examples are known, typically involving deeply conserved clusters of tandemly duplicated genes (e.g., Hox genes and histones). Here we report the first systematic survey of microsynteny conservation across metazoans, utilizing 17 genome sequences. We identified nearly 600 pairs of unrelated genes that have remained tightly physically linked in diverse lineages across over 600 million years of evolution. Integrating sequence conservation, gene expression data, gene function, epigenetic marks, and other genomic features, we provide extensive evidence that many conserved ancient linkages involve (1) the coordinated transcription of neighboring genes, or (2) genomic regulatory blocks (GRBs) in which transcriptional enhancers controlling developmental genes are contained within nearby bystander genes. In addition, we generated ChIP-seq data for key histone modifications in zebrafish embryos, which provided further evidence of putative GRBs in embryonic development. Finally, using chromosome conformation capture (3C) assays and stable transgenic experiments, we demonstrate that enhancers within bystander genes drive the expression of genes such as Otx and Islet, critical regulators of central nervous system development across bilaterians. These results suggest that ancient genomic functional associations are far more common than previously thought—involving ∼12% of the ancestral bilaterian genome—and that cis-regulatory constraints are crucial in determining metazoan genome architecture.M.I., M.S.A., S.W.R., and H.B.F. were funded by NIH grant 1R21HG005240-01A1. H.B.F. is an Alfred P. Sloan Fellow and Pew Scholar in the Biomedical Sciences. J.J.T., A.F-M., O.B., E.C-M., and J.L.G-S. were funded by grants BFU2010-14839, CSD2007-00008, and Proyecto de Excelencia CVI-3488.Peer reviewe
Hypervitaminosis D has no positive effects on goat tuberculosis and may cause chronic renal lesions
[Background]: There is evidence for a link between vitamin D deficiency and active tuberculosis (TB). In human beings, several trials have evaluated the role of vitamin D supplementation in TB treatment with conflicting results. However, the role of vitamin D supplementation in animal TB control has received less attention. The authors evaluated the benefit of vitamin D supplementation for preventing mycobacterial infection or reducing TB lesions (TBL) in a controlled trial with goats naturally exposed to Mycobacterium caprae.
[Methods]: Two groups of goats, a vitamin D-supplemented group and a non-supplemented control group, were housed for 10 months in direct contact with M caprae-infected adult goats. Upon contact with the infected adult goats, all animals were TB-tested every two months.
[Results]: No experimental evidence of a protective effect of vitamin D supplementation based on M caprae culture prevalence, TBL prevalence, median TBL score or the proportion of single versus multiple organs presenting TBL was observed.
[Conclusion]: The results indicate that, in the conditions used in this study, vitamin D supplementation in goats does not reduce TB infection risk nor the diffusion and severity of TBL. In addition, vitamin D-supplemented goats presented hyperphosphataemia and renal injury with calcifications suggestive of vitamin D intoxication.This work was supported by the Ministerio de Economía, Industria y Competitividad of Spain (RTC-2016-4746-2) and the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria of Spain (RTA2015-00043-C02-02). AR is the recipient of an Industrial Doctorate contract (DI-15-08110) and JB holds a ‘Juan de la Cierva program’ contract (IJCI-2015-24805), both funded by the Spanish Ministry of Science, Innovation and Universities
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