How to stay together? Habitat use by three sympatric sharks in the western coast of Baja California Sur, Mexico

Sharks are top predators and play an important role in the regulation of marine ecosystems at lower trophic position. Mustelus californicus, Sphyrna zygaena, and Isurus oxyrinchus prove to be important fishery resources along the western coast of Baja California Sur and cohabit the same coastal areas, probably sharing resources. However, our knowledge about ecological dynamics of multiple species coexisting and sharing similar habitat resources is still limited, particularly for predators such as sharks. Therefore, this study focuses on the analysis of trophic ecology of the sharks species, using carbon (C) and nitrogen (N) stable isotope values in muscle tissues coupled with trace element concentration (Hg, Se, and Cd) in muscle and hepatic tissues of sharks. The values of δC (M. californicus −17.3 ± 1.1‰, S. zygaena −17.9 ± 0.5‰, and I. oxyrinchus −18.3 ± 0.3‰) and δN (M. californicus 18.2 ± 1.1‰, S. zygaena 18.4 ± 0.9‰, and I. oxyrinchus 17.8 ± 1.1‰) indicated that these species feed in the Gulf of Ulloa all throughout the year, and for extended periods with similar habitat use and trophic niche. The above-mentioned statement is also a conclusion supported by the significant correlation between isotopic and trace element concentrations in the muscular tissues in all studied species. Thus, the results of the present study emphasize the habitat and niche characteristics of three sympatric sharks off the coast of Baja California Sur, Mexico.The Instituto Politecnico Nacional (COFFA, EDI), CONA-CYT project 25370, Instituto Politecnico Nacional grants 20181417 and 20196736 and SIP20211002 and SIP2152 provided the fellowships to support this study

Towards the improvement of methane production in CO2 photoreduction using Bi2WO6/TiO2 heterostructures

Russelite bismuth tungstate (Bi2WO6) has been widely reported for the photocatalytic degradation and mineralization of a myriad of pollutants as well as organic compounds. These materials present perovskite-like structure with hierarchical morphologies, which confers excellent optoelectronic properties as potentials candidates for photocatalytic solar fuels production. Here, we propose the development of Bi2WO6/TiO2 heterojunctions for CO2 photoreduction, as a promising solution to produce fuels, alleviate global warming and tackle fossil fuel shortage. Our results show an improvement of the photocatalytic activity of the heterojunctions compared to the pristine semiconductors. Near Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) experiments reveals a preferential CO2 adsorption over TiO2. On the other hand, transient absorption spectroscopy measurements show that the charge transfer pathway in Bi2WO6/TiO2 hybrids leads to longer-lived photogenerated carriers in spatially separated redox active sites, which favor the reduction of CO2 into highly electron demanding fuels and chemicals, such as CH4 and C2H6Financial support has been received from the European Research Council (ERC), through HYMAP project (grant agreement No. 648319), under the European Union's Horizon 2020 research and innovation program, as well as from the Marie Sklodowska-Curie grant agreement No. 754382. L.C. acknowledges funding from the project ARMONIA (PID2020–119125RJ-I00) funded by MCIN/AEI/10.13039/ 501100011033. Financial support has also been received from AEIMINECO/FEDER (Nympha Project, PID2019–106315RB-I00), "Comunidad de Madrid" regional government, and the European Structural Funds (FotoArt-CM project, S2018/NMT-4367). Authors also acknowledge financial support from the grant PLEC2021–007906 funded by MCIN/AEI/10.13039/501100011033 and the "European Union NextGenerationEU/PRTR"

Mapping the structure of mixed seagrass meadows in the Mexican Caribbean

The physical and ecological importance of seagrass meadows in coastal processes is widely recognized, and the development of tools facilitating characterization of their structure and distribution is important for improving our understanding of these processes. Mixed (multi-specific) meadows in a Mexican Caribbean reef lagoon were mapped employing a multiparameter approach, using PlanetScope remote sensing images, and supervised classification based on parameters related to the structure of the seagrasses meadows, including the cover percentages of seagrass/algae/sediment, algae thalli and seagrass shoot densities, canopy heights and estimated leaf area index (LAI). The cover, seagrass and algae densities, and seagrass canopy heights were obtained using ground truth sampling, while the LAI was estimated using data obtained from long-term monitoring programs. The maps do not show the differentiation of seagrass species, but ground truthing contemplated characterization of the density of Thalassia testudinum, Syringodium filiforme and Halodule wrightii and their respective LAIs. S. filiforme was the dominant species in terms of shoot density, and T. testudinum was dominant in terms of LAI. In the multiparameter-based map four classes were defined, based on the cover and structural characteristics, and its overall accuracy was very high (~90%). Maps based on sediment cover and LAI alone also had 4 classes, but they were less accurate than the multiparameter-based map (~70% and ~80%, respectively). The multiparameter-based seagrass map provided spatially-explicit data on the abundance and structure of seagrasses, useful for future monitoring of the changes in the meadows, and also for studies of that require data of large-scale meadow structure, such as inventories of associated biota, blue carbon storage, or modelling of the local hydrodynamics

Predictors of hepatitis C treatment failure after using direct-acting antivirals in people living with human immunodeficiency virus

[Abstract] Background. Little is known about the influence of ongoing barriers to care in the persistence of hepatitis C virus (HCV) viremia after treatment with direct-acting antivirals (DAAs) among people living with human immunodeficiency virus (PLWH). Methods. We conducted a retrospective cohort analysis of PLWH treated through the standard of care in 3 Western countries, to investigate the predictors of HCV treatment failure (clinical or virologic), defined as having a detectable serum HCV ribonucleic acid within 12 weeks after DAA discontinuation. In addition to HCV and liver-related predictors, we collected data on ongoing illicit drug use, alcohol abuse, mental illness, and unstable housing. Logistic regression analyses were used to identify predictors of HCV treatment failure. Results. Between January 2014 and December 2017, 784 PLWH were treated with DAA, 7% (n = 55) of whom failed HCV therapy: 50.9% (n = 28) had a clinical failure (discontinued DAA therapy prematurely, died, or were lost to follow-up), 47.3% (n = 26) had an HCV virologic failure, and 1 (1.8%) was reinfected with HCV. Ongoing drug use (odds ratio [OR] = 2.60) and mental illness (OR = 2.85) were independent predictors of any HCV treatment failure. Having both present explained 20% of the risk of any HCV treatment failure due to their interaction (OR = 7.47; P < .0001). Predictors of HCV virologic failure were ongoing illicit drug use (OR = 2.75) and advanced liver fibrosis (OR = 2.29). Conclusions. People living with human immunodeficiency virus with ongoing illicit drug use, mental illness, and advanced liver fibrosis might benefit from enhanced DAA treatment strategies to reduce the risk of HCV treatment failure.University of California (USA); P30 AI03621

The HRA2pl fusion peptide exerts in vitro antiviral activity against human respiratory paramyxoviruses and pneumoviruses

Acute respiratory infections are a group of diseases caused by viruses, bacteria, and parasites that mainly affect children until the age of 5 and immunocompromised senior adults. In Mexico, these infections are the main cause of morbidity in children, with more than 26 million cases of respiratory infections reported by the Secretariat of Health, in 2019. The human respiratory syncytial virus (hRSV), the human metapneumovirus (hMPV), and the human parainfluenza-2 (hPIV-2) are responsible for many respiratory infections. Currently, palivizumab, a monoclonal antibody against the fusion protein F, is the treatment of choice against hRSV infections. This protein is being studied for the design of antiviral peptides that act by inhibiting the fusion of the virus and the host cell. Therefore, we examined the antiviral activity of the HRA2pl peptide, which competes the heptad repeat A domain of the F protein of hMPV. The recombinant peptide was obtained using a viral transient expression system. The effect of the fusion peptide was evaluated with an in vitro entry assay. Moreover, the effectiveness of HRA2pl was examined in viral isolates from clinical samples obtained from patients with infections caused by hRSV, hMPV, or hPIV-2, by evaluating the viral titer and the syncytium size. The HRA2pl peptide affected the viruses’ capacity of entry, resulting in a 4-log decrease in the viral titer compared to the untreated viral strains. Additionally, a 50% reduction in the size of the syncytium was found. These results demonstrate the antiviral potential of HRA2pl in clinical samples, paving the way toward clinical trials

Overexpression of wild type RRAS2, without oncogenic mutations, drives chronic lymphocytic leukemia

[Background]: Chronic lymphocytic leukemia (CLL) is the most frequent, and still incurable, form of leukemia in the Western World. It is widely accepted that cancer results from an evolutionary process shaped by the acquisition of driver mutations which confer selective growth advantage to cells that harbor them. Clear examples are missense mutations in classic RAS genes (KRAS, HRAS and NRAS) that underlie the development of approximately 13% of human cancers. Although autonomous B cell antigen receptor (BCR) signaling is involved and mutations in many tumor suppressor genes and oncogenes have been identified, an oncogenic driver gene has not still been identified for CLL. [Methods]: Conditional knock-in mice were generated to overexpress wild type RRAS2 and prove its driver role. RT-qPCR analysis of a human CLL sample cohort was carried out to measure RRAS2 transcriptional expression. Sanger DNA sequencing was used to identify a SNP in the 3’UTR region of RRAS2 in human CLL samples. RNAseq of murine CLL was carried out to identify activated pathways, molecular mechanisms and to pinpoint somatic mutations accompanying RRAS2 overexpression. Flow cytometry was used for phenotypic characterization and shRNA techniques to knockdown RRAS2 expression in human CLL. [Results]: RRAS2 mRNA is found overexpressed in its wild type form in 82% of the human CLL samples analyzed (n = 178, mean and median = 5-fold) as well as in the explored metadata. A single nucleotide polymorphism (rs8570) in the 3’UTR of the RRAS2 mRNA has been identified in CLL patients, linking higher expression of RRAS2 with more aggressive disease. Deliberate overexpression of wild type RRAS2 in mice, but not an oncogenic Q72L mutation in the coding sequence, provokes the development of CLL. Overexpression of wild type RRAS2 in mice is accompanied by a strong convergent selection of somatic mutations in genes that have been identified in human CLL. R-RAS2 protein is physically bound to the BCR and mediates BCR signals in CLL. [Conclusions]: The results indicate that overexpression of wild type RRAS2 is behind the development of CLL.This work was supported by grants from the Spanish Association against Cancer (GC16173472GARC), PID2019-104935RB-I00 from the ‘Comision Interministerial de Ciencia y Tecnología’, the ‘Fundación Ramón Areces’, and by the European Research Council ERC 2013-Advanced Grant 334763 “NOVARIPP”, Instituto de Salud Carlos III (ISCIII) (CIBERONC – groups CB16/12/00233, CB16/12/00351), the Health Council of the Junta de Castilla y León (GRS 2036/A/19) and private Gilead (GLD15/00348). Juan de la Cierva (FJCI-2016-28756)

Analysis of changes in the association of income and the utilization of curative health services in Mexico between 2000 and 2006

<p>Abstract</p> <p>Background</p> <p>A common characteristic of health systems in most developing countries is unequal access to health services. As a result, members of the poorest population groups often do not receive formal attention for health services, because they cannot afford it. In 2001 in Mexico, to address income-related differences in the use of health services, the government launched a major healthcare reform, which includes a health insurance program called <it>Seguro Popular</it>, aimed at improving healthcare access among poor, uninsured residents. This paper analyzes the before and after changes in the demand for curative ambulatory health services focusing on the association of income-related characteristics and the utilization of formal healthcare providers vs. no healthcare service utilization.</p> <p>Methods</p> <p>By using two nationally representative health surveys (ENSA-2000 and ENSANUT-2006), we modeled an individual's decision when experiencing an illness to use services provided by the (1) Ministry of Health (MoH), (2) social security, (3) private entities, or (4) to not use formal services (no healthcare service utilization).</p> <p>Results</p> <p>Poorer individuals were more likely in 2006 than in 2000 to respond to an illness by using formal healthcare providers. Trends in provider selection differed, however. The probability of using public services from the MoH increased among the poorest population, while the findings indicated an increase in utilization of private health services among members of low- and middle-income groups. No significant change was seen among formal workers -covered by social security services-, regardless of socioeconomic status.</p> <p>Conclusions</p> <p>Overall, for 2006 the Mexican population appears less differentiated in using healthcare across economic groups than in 2000. This may be related, in part, to the implementation of <it>Seguro Popular</it>, which seems to be stimulating healthcare demand among the poorest and previously uninsured segment of the population. Still, public health authorities need to address the remaining income-related healthcare utilization differences, the differences in quality between public and private health services, and the general perception that MoH facilities offer inferior services.</p

HLA B*5701-positive long-term nonprogressors/elite controllers are not distinguished from progressors by the clonal composition of HIV-specific CD8+ T cells

To better understand the qualitative features of effective human immunodeficiency virus (HIV)-specific immunity, we examined the TCR clonal composition of CD8+ T cells recognizing conserved HIV p24-derived epitopes in HLA-B*5701-positive long-term nonprogressors/elite controllers (LTNP/EC) and HLA-matched progressors. Both groups displayed oligoclonal HLA-B5701-restricted p24-specific CD8+ T-cell responses with similar levels of diversity and few public clonotypes. Thus, HIV-specific CD8+ T-cell responses in LTNP/EC are not differentiated from those of progressors on the basis of clonal diversity or TCR sharing

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011