458 research outputs found

    Genetic variation during range expansion: effects of habitat novelty and hybridization

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    How species' ranges evolve remains an enduring problem in ecology and evolutionary biology. Species' range limits are potentially set by the inability of peripheral populations to adapt to range-edge habitat. Indeed, peripheral populations are often assumed to have reduced genetic diversity and population sizes, which limit evolvability. However, support for this assumption is mixed, possibly because the genetic effects of range expansion depend on two factors: the extent that habitat into which expansion occurs is novel and sources of gene flow. Here, we used spadefoot toads, Spea bombifrons, to contrast the population genetic effects of expansion into novel versus non-novel habitat. We further evaluated gene flow from conspecifics and from heterospecifics via hybridization with a resident species. We found that range expansion into novel habitat, relative to non-novel habitat, resulted in higher genetic differentiation, lower conspecific gene flow and bottlenecks. Moreover, we found that hybridizing with a resident species introduced genetic diversity in the novel habitat. Our results suggest the evolution of species' ranges can depend on the extent of differences in habitat between ancestral and newly occupied ranges. Furthermore, our results highlight the potential for hybridization with a resident species to enhance genetic diversity during expansions into novel habitat

    Seasonal and Spatial Patterns in Salinity, Nutrients, and Chlorophyll α in the Alvarado Lagoonal System, Veracruz, Mexico

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    Ten monthly collections, distributed among three seasons, were taken from July 2000 to June 2001 in the Alvarado lagoonal system, Veracruz, Mexico. Variables measured in situ included dissolved oxygen, salinity, and water temperature. Water samples were collected to determine concentrations of ammonium, nitrates, nitrites, orthophosphates, total phosphorus and chlorophyll α. Collections representing the rainy season were taken in September and October, those for the nortes season were taken in November, December, and January, and dry season collections were taken during February, March, May June, and July. There was seasonal and spatial variation in nutrient concentrations, and they were related to the discharge of the rivers; concentrations increased during the rainy and nortes seasons. Other factors affecting water quality included the constant discharge of organic materials into the system, resuspension of sediments during the nortes season and the biological activity within the system that assimilated the nutrients in the water. The Alvarado lagoonal system has three separate zones based on physicochemical characteristics; Camaronera Lagoon, Buen Pais Lagoon and the urban zone of Alvarado Lagoon, and the river zone in Alvarado Lagoon

    Electron transport through self-assembled monolayers of tripeptides

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    We report how the electron transport through a solid-state metal/Gly-Gly-His tripeptide (GGH) monolayer/metal junction and the metal/GGH work function are modified by the GGH complexation with Cu2+ ions. Conducting AFM is used to measure the current-voltage histograms. The work function is characterized by combining macroscopic Kelvin probe and Kelvin probe force microscopy at the nanoscale. We observe that the Cu2+ ions complexation with the GGH monolayer is highly dependent on the molecular surface density and results in opposite trends. In the case of a high density monolayer the conformational changes are hindered by the proximity of the neighboring peptides, hence forming an insulating layer in response to copper-complexation. Whereas the slightly lower density monolayers allow for the conformational change to a looped peptide wrapping the Cu-ion, which results in a more conductive monolayer. Copper-ion complexation to the high- and low-density monolayers systematically induces an increase of the work functions. Copper-ion complexation to the low-density monolayer induces an increase of electron transport efficiency, while the copper-ion complexation to the high-density monolayer results in a slight decrease of electron transport. Both of the observed trends are in agreement with first-principle calculations. Complexed copper to low density GGH-monolayer induces a new gap state slightly above the Au Fermi energy that is absent in the high density monolayer.Comment: Full paper with supporting informatio

    Valorizing fish processing waste: Production of protein hydrolysates from milkfish (Chanos chanos) by-products using acid hydrolysis

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    Milkfish (Chanos chanos) by-products were used as raw material for the production of protein hydrolysates. Acid hydrolysis was performed at 121 °C for 90 min at 15 psi using various concentrations of hydrochloric acid (4, 6, and 8M). The protein hydrolysates were characterized for the degree of hydrolysis (DH), and antioxidant and other functional food properties. The yield obtained ranged from 5.14±0.42% to 6.08±1.53%. High DH was observed at a high acid concentration with 43.88±9.50% DH for 8M HCl. Regarding the functional food properties, solubility of over 80% over a wide range of pH (2-12) was observed, and emulsifying and foaming properties were found to depend on the pH (2-10). As for the antioxidant activity, 8M exhibited the highest antioxidant activity among the three treatments. The results showed that milkfish by-products have potential to serve as raw material for protein hydrolysates that can be used as ingredients for food formulations

    Improving Latin American soil information database for digital soil mapping enhances its usability and scalability

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    Spatial soil databases can help model complex phenomena in which soils are decisive, for example, evaluating agricultural potential or estimating carbon storage capacity. The Soil Information System for Latin America and the Caribbean, SISLAC, is a regional initiative promoted by the FAO's South American Soil Partnership to contribute to the sustainable management of soil. SISLAC includes data coming from 49,084 soil profiles distributed unevenly across the continent, making it the region's largest soil database. However, some problems hinder its usages, such as the quality of the data and its high dimensionality. The objective of this research is twofold. First, to evaluate the quality of SISLAC and its data values and generate a new, improved version that meets the minimum quality requirements to be used by different interests or practical applications. Second, to demonstrate the potential of improved soil profile databases to generate more accurate information on soil properties, by conducting a case study to estimate the spatial variability of the percentage of soil organic carbon using 192 profiles in a 1473 km2 region located in the department of Valle del Cauca, Colombia. The findings show that 15 percent of the existing soil profiles had an inaccurate description of the diagnostic horizons. Further correction of an 4.5 additional percent of existing inconsistencies improved overall data quality. The improved database consists of 41,691 profiles and is available for public use at ttps://doi.org/10.5281/zenodo.6540710 (DĂ­az-Guadarrama, S. & Guevara, M., 2022). The updated profiles were segmented using algorithms for quantitative pedology to estimate the spatial variability. We generated segments one centimeter thick along with each soil profile data, then the values of these segments were adjusted using a spline-type function to enhance vertical continuity and reliability. Vertical variability was estimated up to 150 cm in-depth, while ordinary kriging predicts horizontal variability at three depth intervals, 0 to 5, 5 to 15, and 15 to 30 cm, at 250 m-spatial resolution, following the standards of the GlobalSoilMap project. Finally, the leave-one-out cross validation provides information for evaluating the kriging model performance, obtaining values for the RMSE index between 1.77% and 1.79% and the R2 index greater than 0.5. The results show the usability of SISLAC database to generate spatial information on soil properties and suggest further efforts to collect a more significant amount of data to guide sustainable soil management.Fil: Diaz Guadamarra, Sergio. Universidad Nacional de Colombia. Facultad de Ciencias Agrarias. Departamento de AgronomĂ­a; ColombiaFil: Lizarazo, IvĂĄn. Universidad Nacional de Colombia. Facultad de Ciencias Agrarias. Departamento de AgronomĂ­a; ColombiaFil: Guevara, Mario. Universidad Nacional AutĂłnoma de MĂ©xico. Campus Juriquilla. Centro de Geociencias; MĂ©xicoFil: Guevara, Mario. Universidad Nacional AutĂłnoma de MĂ©xico.Campus Juriquilla. Centro de Geociencias; MĂ©xico. United States Department of Agriculture. Soil Salinity National Laboratory, Estados UnidosFil: Angelini, Marcos Esteban. Instituto Nacional de TecnologĂ­a Agropecuaria (INTA). Instituto de Suelos; Argentina. Wageningen University. Soil Geography and Landscape Group; PaĂ­ses Bajos. International Soil Reference and Information Centre. World Soil Information; PaĂ­ses BajosFil: Araujo Carrillo, Gustavo A. CorporaciĂłn Colombiana de InvestigaciĂłn Agropecuaria AGROSAVIA; ColombiaFil: Argeñal, Jainer. Universidad Nacional AutĂłnoma de Honduras. Facultad de Ciencias; Honduras.Fil: Armas, Daphne. Universidad de AlmerĂ­a. Departamento de AgronomĂ­a, Edif. CITEIIB, España.Fil: Balsa, Rafael A. Ministerio de Desarrollo Agrario y Riego. DirecciĂłn General de Asuntos Ambientales Agrarios, PerĂș.Fil: Bolivar, Adriana. Instituto GeogrĂĄfico AgustĂ­n Codazzi. SubdirecciĂłn AgrologĂ­a; ColombiaFil: Bustamante, Nelson. Servicio AgrĂ­cola y Ganadero; Chile.Fil: Dart, Ricardo O. Embrapa Solos; BrasilFil: Dell Acqua, MartĂ­n. Ministerio de GanaderĂ­a, Agricultura y Pesca. DirecciĂłn General de Recursos Naturales; UruguayFil: Lencina, Arnulfo. Universidad Nacional de AsunciĂłn. Facultad de Ciencias Agrarias; ParaguayFil: Figueredo, HernĂĄn. Sociedad Boliviana de la Ciencia del Suelo; Bolivia.Fil: Fontes, Fernando. Ministerio de GanaderĂ­a, Agricultura y Pesca. DirecciĂłn General de Recursos Naturales; UruguayFil: Gutierrez Diaz, Joan S. Aarhus University. Faculty of Science and Technology,.Department of Agroecology; DinamarcaFil: JimĂ©nez, Wilmer. Ministerio de Agricultura y GanaderĂ­a; Ecuador.Fil: Rodriguez, Dario Martin. Instituto Nacional de TecnologĂ­a Agropecuaria (INTA). Instituto de Suelos; ArgentinaFil: Schulz, Guillermo. Instituto Nacional de TecnologĂ­a Agropecuaria (INTA). Instituto de Suelos; ArgentinaFil: Tenti Vuegen, Leonardo Mauricio. Instituto Nacional de TecnologĂ­a Agropecuaria (INTA). Instituto de Suelos; Argentin

    Effect of Colchicine vs Usual Care Alone on Intubation and 28-Day Mortality in Patients Hospitalized with COVID-19: A Randomized Clinical Trial

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    Importance Hospitalized patients with COVID-19 pneumonia have high rates of morbidity and mortality. Objective To assess the efficacy of colchicine in hospitalized patients with COVID-19 pneumonia. Design, Setting, and Participants The Estudios ClĂ­nicos Latino AmĂ©rica (ECLA) Population Health Research Institute (PHRI) COLCOVID trial was a multicenter, open-label, randomized clinical trial performed from April 17, 2020, to March 28, 2021, in adults with confirmed or suspected SARS-CoV-2 infection followed for up to 28 days. Participants received colchicine vs usual care if they were hospitalized with COVID-19 symptoms and had severe acute respiratory syndrome or oxygen desaturation. The main exclusion criteria were clear indications or contraindications for colchicine, chronic kidney disease, and negative results on a reverse transcription–polymerase chain reaction test for SARS-CoV-2 before randomization. Data were analyzed from June 20 to July 25, 2021. Interventions Patients were assigned in a 1:1 ratio to usual care or usual care plus colchicine. Colchicine was administered orally in a loading dose of 1.5 mg immediately after randomization, followed by 0.5 mg orally within 2 hours of the initial dose and 0.5 mg orally twice a day for 14 days or discharge, whichever occurred first. Main Outcomes and Measures The first coprimary outcome was the composite of a new requirement for mechanical ventilation or death evaluated at 28 days. The second coprimary outcome was death at 28 days. Results A total of 1279 hospitalized patients (mean [SD] age, 61.8 [14.6] years; 449 [35.1%] women and 830 [64.9%] men) were randomized, including 639 patients in the usual care group and 640 patients in the colchicine group. Corticosteroids were used in 1171 patients (91.5%). The coprimary outcome of mechanical ventilation or 28-day death occurred in 160 patients (25.0%) in the colchicine group and 184 patients (28.8%) in the usual care group (hazard ratio [HR], 0.83; 95% CI, 0.67-1.02; P = .08). The second coprimary outcome, 28-day death, occurred in 131 patients (20.5%) in the colchicine group and 142 patients (22.2%) in the usual care group (HR, 0.88; 95% CI, 0.70-1.12). Diarrhea was the most frequent adverse effect of colchicine, reported in 68 patients (11.3%). Conclusions and Relevance This randomized clinical trial found that compared with usual care, colchicine did not significantly reduce mechanical ventilation or 28-day mortality in patients hospitalized with COVID-19 pneumonia.Fil: Diaz, Rafael. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Instituto Cardiovascular de Rosario; ArgentinaFil: Orlandini, AndrĂ©s. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Instituto Cardiovascular de Rosario; ArgentinaFil: Castellana, Noelia. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Universidad Nacional de Rosario; ArgentinaFil: Caccavo, Alberto. Provincia de Buenos Aires. DirecciĂłn General de Cultura y EducaciĂłn. Universidad Provincial del Sudoeste; ArgentinaFil: Corral, Pablo. Universidad FASTA "Santo Tomas de Aquino"; ArgentinaFil: Corral, Gonzalo. InfectologĂ­a ClĂ­nica de Mayo; ArgentinaFil: ChacĂłn, Carolina. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Universidad Abierta Interamericana; Argentina. Unidad Coronaria de Sanatorio Delta de Rosario; Argentina. Comite de Epidemiologia y PrevenciĂłn Cardiovascular de la FederaciĂłn Argentina de Cardiologia; ArgentinaFil: Lamelas, Pablo. McMaster University; CanadĂĄ. Instituto Cardiovascular de Buenos Aires; ArgentinaFil: Botto, Fernando. Instituto Cardiovascular de Buenos Aires; ArgentinaFil: DĂ­az, MarĂ­a Luz. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Instituto Cardiovascular de Rosario; ArgentinaFil: DomĂ­nguez, Juan Manuel. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Instituto Cardiovascular de Rosario; ArgentinaFil: Pascual, Andrea. Estudios ClĂ­nicos Latino AmĂ©rica; ArgentinaFil: Rovito, Carla. Estudios ClĂ­nicos Latino AmĂ©rica; ArgentinaFil: Galatte, Agustina. Estudios ClĂ­nicos Latino AmĂ©rica; ArgentinaFil: Scarafia, Franco. Estudios ClĂ­nicos Latino AmĂ©rica; Argentina. Universidad Nacional de Rosario; ArgentinaFil: Sued, Omar. FundaciĂłn HuĂ©sped; ArgentinaFil: Gutierrez, Omar. Ministerio de Salud de Jujuy; ArgentinaFil: Jolly, Sanjit S.. McMaster University; CanadĂĄFil: MirĂł, JosĂ© M.. Universidad de Barcelona; EspañaFil: Eikelboom, John. McMaster University; CanadĂĄFil: Loeb, Mark. McMaster University; CanadĂĄFil: Maggioni, Aldo Pietro. Associazione Nazionale Medici Cardiologi Ospedalieri Research Center; ItaliaFil: Bhatt, Deepak L.. Brigham and Women’s Hospital; Estados Unidos. Harvard Medical School; Estados UnidosFil: Yusuf, Salim. McMaster University; CanadĂĄFil: Lopez, Lorena. No especifĂ­ca;Fil: Leon de la Fuente, Ricardo Alfonso. Gobierno de la Provincia de Salta. Ministerio de Salud PĂșblica. Hospital Papa Francisco; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Forciniti, Cristian C. G.. No especifĂ­ca;Fil: Colombo, Hugo. No especifĂ­ca;Fil: Sabas, Nicolas. No especifĂ­ca;Fil: PilĂłn, Leonardo. No especifĂ­ca;Fil: Steren, Adriana P.. No especifĂ­ca

    Activation of c-Jun N-Terminal Kinase (JNK) during Mitosis in Retinal Progenitor Cells

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    Most studies of c-Jun N-terminal Kinase (JNK) activation in retinal tissue were done in the context of neurodegeneration. In this study, we investigated the behavior of JNK during mitosis of progenitor cells in the retina of newborn rats. Retinal explants from newborn rats were kept in vitro for 3 hours and under distinct treatments. Sections of retinal explants or freshly fixed retinal tissue were used to detect JNK phosphorylation by immunohistochemistry, and were examined through both fluorescence and confocal microscopy. Mitotic cells were identified by chromatin morphology, histone-H3 phosphorylation, and location in the retinal tissue. The subcellular localization of proteins was analyzed by double staining with both a DNA marker and an antibody to each protein. Phosphorylation of JNK was also examined by western blot. The results showed that in the retina of newborn rats (P1), JNK is phosphorylated during mitosis of progenitor cells, mainly during the early stages of mitosis. JNK1 and/or JNK2 were preferentially phosphorylated in mitotic cells. Inhibition of JNK induced cell cycle arrest, specifically in mitosis. Treatment with the JNK inhibitor decreased the number of cells in anaphase, but did not alter the number of cells in either prophase/prometaphase or metaphase. Moreover, cells with aberrant chromatin morphology were found after treatment with the JNK inhibitor. The data show, for the first time, that JNK is activated in mitotic progenitor cells of developing retinal tissue, suggesting a new role of JNK in the control of progenitor cell proliferation in the retina

    Non-Gaussianity in the Very Small Array CMB maps with Smooth-Goodness-of-fit tests

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    (Abridged) We have used the Rayner & Best (1989) smooth tests of goodness-of-fit to study the Gaussianity of the Very Small Array (VSA) data. Out of the 41 published VSA individual pointings dedicated to cosmological observations, 37 are found to be consistent with Gaussianity, whereas four pointings show deviations from Gaussianity. In two of them, these deviations can be explained as residual systematic effects of a few visibility points which, when corrected, have a negligible impact on the angular power spectrum. The non-Gaussianity found in the other two (adjacent) pointings seems to be associated to a local deviation of the power spectrum of these fields with respect to the common power spectrum of the complete data set, at angular scales of the third acoustic peak (l = 700-900). No evidence of residual systematics is found in this case, and unsubstracted point sources are not a plausible explanation either. If those visibilities are removed, a cosmological analysis based on this new VSA power spectrum alone shows no differences in the parameter constraints with respect to our published results, except for the physical baryon density, which decreases by 10 percent. Finally, the method has been also used to analyse the VSA observations in the Corona Borealis supercluster region (Genova-Santos et al. 2005), which show a strong decrement which cannot be explained as primordial CMB. Our method finds a clear deviation (99.82%) with respect to Gaussianity in the second-order moment of the distribution, and which can not be explained as systematic effects. A detailed study shows that the non-Gaussianity is produced in scales of l~500, and that this deviation is intrinsic to the data (in the sense that can not be explained in terms of a Gaussian field with a different power spectrum).Comment: 14 pages, 7 figures. Accepted for publication in MNRA

    A Chirality-Based Quantum Leap

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    There is increasing interest in the study of chiral degrees of freedom occurring in matter and in electromagnetic fields. Opportunities in quantum sciences will likely exploit two main areas that are the focus of this Review: (1) recent observations of the chiral-induced spin selectivity (CISS) effect in chiral molecules and engineered nanomaterials and (2) rapidly evolving nanophotonic strategies designed to amplify chiral light-matter interactions. On the one hand, the CISS effect underpins the observation that charge transport through nanoscopic chiral structures favors a particular electronic spin orientation, resulting in large room-temperature spin polarizations. Observations of the CISS effect suggest opportunities for spin control and for the design and fabrication of room-temperature quantum devices from the bottom up, with atomic-scale precision and molecular modularity. On the other hand, chiral-optical effects that depend on both spin- and orbital-angular momentum of photons could offer key advantages in all-optical and quantum information technologies. In particular, amplification of these chiral light-matter interactions using rationally designed plasmonic and dielectric nanomaterials provide approaches to manipulate light intensity, polarization, and phase in confined nanoscale geometries. Any technology that relies on optimal charge transport, or optical control and readout, including quantum devices for logic, sensing, and storage, may benefit from chiral quantum properties. These properties can be theoretically and experimentally investigated from a quantum information perspective, which has not yet been fully developed. There are uncharted implications for the quantum sciences once chiral couplings can be engineered to control the storage, transduction, and manipulation of quantum information. This forward-looking Review provides a survey of the experimental and theoretical fundamentals of chiral-influenced quantum effects and presents a vision for their possible future roles in enabling room-temperature quantum technologies.ISSN:1936-0851ISSN:1936-086
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