192 research outputs found
Molecular phylogenetics reveals the evolutionary history of marine fishes (Actinopterygii) endemic to the subtropical islands of the Southwest Pacific
Remote oceanic islands of the Pacific host elevated levels of actinopterygian (ray-finned fishes) endemism. Characterizing the evolutionary histories of these endemics has provided insight into the generation and maintenance of marine biodiversity in many regions. The subtropical islands of Lord Howe, Norfolk, and Rangitāhua (Kermadec) in the Southwest Pacific are yet to be comprehensively studied. Here, we characterize the spatio-temporal diversification of marine fishes endemic to these Southwest Pacific islands by combining molecular phylogenies and the geographic distribution of species. We built Bayesian ultrametric trees based on open-access and newly generated sequences for five mitochondrial and ten nuclear loci, and using fossil data for time calibration. We present the most comprehensive phylogenies to date for marine ray-finned fish genera, comprising 34 species endemic to the islands, including the first phylogenetic placements for 11 endemics. Overall, our topologies confirm the species status of all endemics, including three undescribed taxa. Our phylogenies highlight the predominant affinity of these endemics with the Australian fish fauna (53%), followed by the East Pacific (15%), and individual cases where the closest sister taxon of our endemic is found in the Northwest Pacific and wider Indo-Pacific. Nonetheless, for a quarter of our focal endemics, their geographic affinity remains unresolved due to sampling gaps within their genera. Our divergence time estimates reveal that the majority of endemic lineages (67.6%) diverged after the emergence of Lord Howe (6.92 Ma), the oldest subtropical island in the Southwest Pacific, suggesting that these islands have promoted diversification. However, divergence ages of some endemics pre-date the emergence of the islands, suggesting they may have originated outside of these islands, or, in some cases, ages may be overestimated due to unsampled taxa. To fully understand the role of the Southwest Pacific subtropical islands as a 'cradle' for diversification, our study advocates for further regional surveys focused on tissue collection for DNA analysis.fals
Población anidante e impacto en la pesca artesanal del cormorán neotropical Phalacrocorax brasilianus Suliformes:Phalacrocoracidae), en el sitio Ramsar Cerrón Grande, El Salvador.
The neotropical cormorant (Phalacrocorax brasilianus) is a species of waterfowl abundant in the wetlands of El Salvador. Fish predation on aquatic ecosystems is generating a conflict with fishermen that associating declining fishing with predatory behavior of this bird. From April 2010 to February 2011, an investigation was conducted aimed at knowing the state of the population of P. brasilianus in the Ramsar wetland Cerron Grande, El Salvador. The study was conducted through counting and collecting of birds, to analyze the stomachic contents. The maximum recorded was 28.063 individuals and 3,000 breeding pairs. 266 birds were collected, on 207 it found fish in their stomachs, whose individual weight ranged from 2-307 g ± 52 g. A total of 1,078 fish specimens was found, from ten species, four of them obtained the highest values of abundance: bagre (Cathorops steindachneri) with 29%, followed by guapote (Parachromis managuensis) with 25%, tilapia (Oreochromis niloticus) with 22% and plateada (Astyanax aeneus, Roeboides bouchellei) with 31%
Collagen Prolyl 4-Hydroxylase 1 is Essential for HIF-1α Stabilization and TNBC Chemoresistance
Collagen prolyl 4-hydroxylase (P4H) expression and collagen hydroxylation in cancer cells are necessary for breast cancer progression. Here, we show that P4H alpha 1 subunit (P4HA1) protein expression is induced in triple-negative breast cancer (TNBC) and HER2 positive breast cancer. By modulating alpha ketoglutarate (α-KG) and succinate levels P4HA1 expression reduces proline hydroxylation on hypoxia-inducible factor (HIF) 1α, enhancing its stability in cancer cells. Activation of the P4HA/HIF-1 axis enhances cancer cell stemness, accompanied by decreased oxidative phosphorylation and reactive oxygen species (ROS) levels. Inhibition of P4HA1 sensitizes TNBC to the chemotherapeutic agent docetaxel and doxorubicin in xenografts and patient-derived models. We also show that increased P4HA1 expression correlates with short relapse-free survival in TNBC patients who received chemotherapy. These results suggest that P4HA1 promotes chemoresistance by modulating HIF-1-dependent cancer cell stemness. Targeting collagen P4H is a promising strategy to inhibit tumor progression and sensitize TNBC to chemotherapeutic agents
Should Histologic Grade Be Incorporated into the TNM Classification System for Small (T1, T2) Node-Negative Breast Adenocarcinomas?
Prognosis of invasive ductal carcinoma (IDC) strongly correlates with tumor grade as determined by Nottingham combined histologic grade. While reporting grade as low grade/favorable (G1), intermediate grade/moderately favorable (G2), and high grade/unfavorable (G3) is recommended by American Joint Committee on Cancer (AJCC) staging system, existing TNM (Primary Tumor/Regional Lymph Nodes/Distant Metastasis) classification does not directly incorporate these data. For large tumors (T3, T4), significance of histologic grade may be clinically moot as those are nearly always candidates for adjuvant therapy. However, for small (T1, T2) node-negative (N0) tumors, grade may be clinically relevant in influencing treatment decisions, but data on outcomes are sparse and controversial. This retrospective study analyzes clinical outcome in patients with small N0 IDC on the basis of tumor grade. Our results suggest that the grade does not impact clinical outcome in T1N0 tumors. In T2N0 tumors, however, it might be prognostically significant and relevant in influencing decisions regarding the need for additional adjuvant therapy and optimal management
Remote Laboratory for E-Learning of Systems on Chip and Their Applications to Nuclear and Scientific Instrumentation
Configuring and setting up a remote access laboratory for an advanced online school on fully programmable System-on-Chip (SoC) proved to be an outstanding challenge. The school, jointly organized by the International Centre for Theoretical Physics (ICTP) and the International Atomic Energy Agency (IAEA), focused on SoC and its applications to nuclear and scientific instrumentation and was mainly addressed to physicists, computer scientists and engineers from developing countries. The use of e-learning tools, which some of them adopted and others developed, allowed the school participants to directly access both integrated development environment software and programmable SoC platforms. This facilitated the follow-up of all proposed exercises and the final project. During the four weeks of the training activity, we faced and overcame different technology and communication challenges, whose solutions we describe in detail together with dedicated tools and design methodology. We finally present a summary of the gained experience and an assessment of the results we achieved, addressed to those who foresee to organize similar initiatives using e-learning for advanced training with remote access to SoC platforms
A novel bocavirus in canine liver
Background: Bocaviruses are classified as a genus within the Parvoviridae family of single-stranded DNA viruses and are pathogenic in some mammalian species. Two species have been previously reported in dogs, minute virus of canines (MVC), associated with neonatal diseases and fertility disorders; and Canine bocavirus (CBoV), associated with respiratory disease.
Findings: In this study using deep sequencing of enriched viral particles from the liver of a dog with severe hemorrhagic gastroenteritis, necrotizing vasculitis, granulomatous lymphadenitis and anuric renal failure, we identified and characterized a novel bocavirus we named Canine bocavirus 3 (CnBoV3). The three major ORFs of CnBoV3 (NS1, NP1 and VP1) shared less than 60% aa identity with those of other bocaviruses qualifying it as a novel species based on ICTV criteria. Inverse PCR showed the presence of concatemerized or circular forms of the genome in liver.
Conclusions: We genetically characterized a bocavirus in a dog liver that is highly distinct from prior canine bocaviruses found in respiratory and fecal samples. Its role in this animal’s complex disease remains to be determined.
Keywords: Canine bocavirus 3; Episome; Coinfectio
The fight against HIV-associated disseminated histoplasmosis in the Americas: Unfolding the different stories of four centers
Disseminated histoplasmosis is a major opportunistic infection of HIV-infected patients, killing thousands in Latin America each year. Yet, it remains a neglected disease that is often confused with tuberculosis, for lack of simple, affordable, and rapid diagnostic tools. There is great heterogeneity in the level of histoplasmosis awareness. The purpose of this report was to describe how the historical “awakening” to the threat of histoplasmosis came to be in four different centers that have actively described this disease: In Brazil, the Sao José hospital in Fortaleza; in Colombia, the Corporación para Investigaciones Biológicas inMedellin; in French Guiana, Cayenne Hospital; and in Guatemala, the Association de Salud Integral in Guatemala city. In Brazil and French Guiana, the search for leishmaniasis on the buffy coat or skin smears, respectively, led to the rapid realization that HIV patients were suffering from disseminated histoplasmosis. With time and progress in fungal culture, the magnitude of this problem turned it into a local priority. In Colombia and Guatemala, the story is different because for these mycology centers, it was no surprise to find histoplasmosis in HIV patients. In addition, collaborations with the CDC to evaluate antigen-detection tests resulted in researchers and clinicians developing the capacity to rapidly screen most patients and to demonstrate the very high burden of disease in these countries. While the lack of awareness is still a major problem, it is instructive to review the ways through which different centers became histoplasmosis-aware. Nevertheless, as new rapid diagnostic tools are becoming available, their implementation throughout Latin America should rapidly raise the level of awareness in order to reduce the burden of histoplasmosis deaths. © 2019 by the authors
Power law scaling of lateral deformations with universal Poissons index for randomly folded thin sheets
We study the lateral deformations of randomly folded elastoplastic and
predominantly plastic thin sheets under the uniaxial and radial compressions.
We found that the lateral deformations of cylinders folded from elastoplastic
sheets of paper obey a power law behavior with the universal Poissons index nu
= 0.17 pm 0.01, which does not depend neither the paper kind and sheet sizes,
nor the folding confinement ratio. In contrast to this, the lateral
deformations of randomly folded predominantly plastic aluminum foils display
the linear dependence on the axial compression with the universal Poissons
ratio nu_e = 0.33 pm 0.01. This difference is consistent with the difference in
fractal topology of randomly folded elastoplastic and predominantly plastic
sheets, which is found to belong to different universality classes. The general
form of constitutive stress-deformation relations for randomly folded
elastoplastic sheets is suggested
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