31 research outputs found

    Estimating viral prevalence with data fusion for adaptive two-phase pooled sampling.

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    The COVID-19 pandemic has highlighted the importance of efficient sampling strategies and statistical methods for monitoring infection prevalence, both in humans and in reservoir hosts. Pooled testing can be an efficient tool for learning pathogen prevalence in a population. Typically, pooled testing requires a second-phase retesting procedure to identify infected individuals, but when the goal is solely to learn prevalence in a population, such as a reservoir host, there are more efficient methods for allocating the second-phase samples.To estimate pathogen prevalence in a population, this manuscript presents an approach for data fusion with two-phased testing of pooled samples that allows more efficient estimation of prevalence with less samples than traditional methods. The first phase uses pooled samples to estimate the population prevalence and inform efficient strategies for the second phase. To combine information from both phases, we introduce a Bayesian data fusion procedure that combines pooled samples with individual samples for joint inferences about the population prevalence.Data fusion procedures result in more efficient estimation of prevalence than traditional procedures that only use individual samples or a single phase of pooled sampling.The manuscript presents guidance on implementing the first-phase and second-phase sampling plans using data fusion. Such methods can be used to assess the risk of pathogen spillover from reservoir hosts to humans, or to track pathogens such as SARS-CoV-2 in populations

    Lanthanide tetrazolate complexes combining single-molecule magnet and luminescence properties: the effect of the replacement of tetrazolate n3 by β-diketonate ligands on the anisotropy energy barrier

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    Three new sets of mononuclear LnIII complexes of general formulas [LnL3]⋅CH3OH [LnIII=Yb (1), Er (2), Dy (3), Gd (4), and Eu (5)], [LnL2(tmh)(CH3OH)]⋅n H2O⋅m CH3OH [LnIII=Yb (1 b), Er (2 b), Dy (3 b), Gd (4 b)], and [LnL2(tta)(CH3OH)]⋅CH3OH [LnIII=Yb (1 c), Er (2 c), Dy (3 c), Gd (4 c)] were prepared by the reaction of Ln(CF3SO3)⋅n H2O salts with the tridentate ligand 2-(tetrazol-5-yl)-1,10-phenanthroline (HL) and, for the last two sets, additionally with the β-diketonate ligands 2,2,6,6-tetramethylheptanoate (tmh) and 2-thenoyltrifluoroacetonate (tta), respectively. In the [LnL3]⋅CH3OH complexes the LnIII ions are coordinated to three phenanthroline tetrazolate ligands with an LnN9 coordination sphere. Dynamic ac magnetic measurements on 1–3 reveal that these complexes only exhibit single-molecule magnet (SMM) behavior when an external dc magnetic field is applied, with Ueff values of 11.7 K (1), 16.0 K (2), and 20.2 K (3). When the tridentate phenanthroline tetrazolate ligand is replaced by one molecule of methanol and the β-diketonate ligand tmh (1 b–3 b) or tta (1 c–3 c), a significant increase in Ueff occurs and, in the case of the DyIII complexes 3 b and 3 c, out-of-phase χ′′ signals below 15 and 10 K, respectively, are observed in zero dc magnetic field. CASSCF+RASSI ab initio calculations performed on the DyIII complexes support the experimental results. Thus, for 3 the ground Kramers’ doublet is far from being axial and the first excited state is found to be very close in energy to the ground state, so the relaxation barrier in this case is almost negligible. Conversely, for 3 b and 3 c, the ground Kramers’ doublet is axial with a small quantum tunneling of the magnetization, and the energy difference between the ground and first Kramers’ doublets is much higher, which allows these compounds to behave as SMMs at zero field. Moreover, these calculations support the larger Ueff observed for 3 b compared to 3 c. Additionally, the solid-state photophysical properties of 1, 2, 4, and 5 show that the phenanthroline tetrazolate ligand can act as an effective antenna to sensitize the characteristic YbIII, ErIII, and EuIII emissions through an energy-transfer process

    Frontispiece: Lanthanide tetrazolate complexes combining single-molecule magnet and luminescence properties: The effect of the replacement of tetrazolate N3 by β-Diketonate Ligands on the anisotropy energy barrier

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    Three new sets of mononuclear LnIII complexes of general formulas [LnL3]·CH3OH (LnIII = Yb (1), Er (2), Dy (3), Gd (4) and Eu (5)), [LnL2(tmh)(CH3OH)]·n H2O·m CH3OH (LnIII = Yb (1b), Er (2b), Dy (3b), Gd (4b)) and [LnL2(tta)(CH3OH)]·CH3OH (LnIII = Yb (1c), Er (2c), Dy (3c), Gd (4c) have been prepared from the reaction of Ln(CF3SO3)·nH2O salts with the tridentate ligand 2-(tetrazolate-5-yl)-1,10- phenanthroline (HL). For the two latter sets, additionally with the respective β- diketonate ligands 2,2,6,6-tetramethylheptanoate (tmh) or 2-thenoyltrifluoroacetonate (tta). In the [LnL3]·CH3OH complexes the LnIII ions are coordinated to three phenanthroline-tetrazolate ligands showing a LnN9 coordination sphere. Dynamic ac magnetic measurements for 1 – 3 reveal that these complexes only exhibit single molecule magnet (SMM) behaviour when an external dc magnetic field is applied, with Ueff values of 11.7 K (1), 16.0 K (2) and 20.2 K (3). When the tridentate phenanthrolinetetrazolate ligand is replaced by one molecule of methanol and the β-diketonate ligand tmh (1b – 3b) or tta (1c – 3c), a significant increase in Ueff occurs and, in the case of the DyIII derivates 3b and 3c, out-of-phase χ’’ signals below 15 K and 10 K, respectively, are observed under zero-dc magnetic field. CASSCF+RASSI ab initio calculations performed on the DyIII derivates support the experimental results. Thus, for 3 the ground Kramers’ doublet is far from being axial and the first excited state is found to be very close in energy to the ground state so the relaxation barrier in this case is almost negligible. Conversely, for 3b and 3c, the ground Kramers’ doublet is axial with a small quantum tunneling of the magnetization (QTM) and the energy difference between the ground and first Kramers’ doublets is much higher, which allows these compounds to behave as SMMs at zero-field. Moreover, these calculations support the larger Ueff observed for 3b compared to 3c. Additionally, the solid-state photophysical properties of 1, 2, 4 and 5 show that the phenanthroline tetrazolate ligand can act as an effective antenna to sensitize the characteristic YbIII, ErIII and EuIII emissions through an energy transfer process

    Impact of global warming at the range margins: Phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian

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    © 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. When dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. In this work, we evaluated whether there is physiological plasticity in the thermal performance curve (TPC) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population of the endemic frog Pleurodema thaul. Our results indicate that individuals acclimated to 20°C and 25°C increased the breath of their TPCs by shifting their upper limits with respect to when they were acclimated at 10°C. In addition, even when dispersal is not possible for this population, the landscape is heterogeneous enough to offer opportunities for behavioral thermoregulation. In particular, under current climatic conditions, behavioral thermoregulation is not compulsory as available operative temperatures are encompassed within the population TPC limits. However, for severe projected temperatures under climate change, behavioral thermoregulation will be required in the sunny patches. In overall, our results suggest that this population of Pleurodema thaul will be able to endure the worst projected scenario of climate warming as it has not only the physiological capacities but also the environmental opportunities to regulate its body temperature behaviorally.Link_to_subscribed_fulltex

    Human habitat modification, not apex scavenger decline, drives isotopic niche variation in a carnivore community

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    Top carnivores can influence the structure of ecological communities, primarily through competition and predation; however, communities are also influenced by bottom-up forces such as anthropogenic habitat disturbance. Top carnivore declines will likely alter competitive dynamics within and amongst sympatric carnivore species. Increasing intraspecific competition is generally predicted to drive niche expansion and/or individual specialisation, while interspecific competition tends to constrain niches. Using stable isotope analysis of whiskers, we studied the effects of Tasmanian devil Sarcophilus harrisii declines upon the population- and individual-level isotopic niches of Tasmanian devils and sympatric spotted-tailed quolls Dasyurus maculatus subsp. maculatus. We investigated whether time since the onset of devil decline (a proxy for severity of decline) and landscape characteristics affected the isotopic niche breadth and overlap of devil and quoll populations. We quantified individual isotopic niche breadth for a subset of Tasmanian devils and spotted-tailed quolls and assessed whether between-site population niche variation was driven by individual-level specialisation. Tasmanian devils and spotted-tailed quolls demonstrated smaller population-level isotopic niche breadths with increasing human-modified habitat, while time since the onset of devil decline had no effect on population-level niche breadth or interspecific niche overlap. Individual isotopic niche breadths of Tasmanian devils and spotted-tailed quolls were narrower in human-modified landscapes, likely driving population isotopic niche contraction, however, the degree of individuals’ specialisation relative to one another remained constant. Our results suggest that across varied landscapes, mammalian carnivore niches can be more sensitive to the bottom-up forces of anthropogenic habitat disturbance than to the top-down effects of top carnivore decline

    An ALMA survey of submillimetre galaxies in the COSMOS field: The extent of the radio-emitting region revealed by 3 GHz imaging with the Very Large Array

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    We determine the radio size distribution of a large sample of 152 SMGs in COSMOS that were detected with ALMA at 1.3 mm. For this purpose, we used the observations taken by the VLA-COSMOS 3 GHz Large Project. One hundred and fifteen of the 152 target SMGs were found to have a 3 GHz counterpart. The median value of the major axis FWHM at 3 GHz is derived to be 4.6±0.44.6\pm0.4 kpc. The radio sizes show no evolutionary trend with redshift, or difference between different galaxy morphologies. We also derived the spectral indices between 1.4 and 3 GHz, and 3 GHz brightness temperatures for the sources, and the median values were found to be α=0.67\alpha=-0.67 and TB=12.6±2T_{\rm B}=12.6\pm2 K. Three of the target SMGs, which are also detected with the VLBA, show clearly higher brightness temperatures than the typical values. Although the observed radio emission appears to be predominantly powered by star formation and supernova activity, our results provide a strong indication of the presence of an AGN in the VLBA and X-ray-detected SMG AzTEC/C61. The median radio-emitting size we have derived is 1.5-3 times larger than the typical FIR dust-emitting sizes of SMGs, but similar to that of the SMGs' molecular gas component traced through mid-JJ line emission of CO. The physical conditions of SMGs probably render the diffusion of cosmic-ray electrons inefficient, and hence an unlikely process to lead to the observed extended radio sizes. Instead, our results point towards a scenario where SMGs are driven by galaxy interactions and mergers. Besides triggering vigorous starbursts, galaxy collisions can also pull out the magnetised fluids from the interacting disks, and give rise to a taffy-like synchrotron-emitting bridge. This provides an explanation for the spatially extended radio emission of SMGs, and can also cause a deviation from the well-known IR-radio correlation.Comment: 32 pages (incl. 5 appendices), 17 figures, 7 tables; accepted for publication in A&A; abstract abridged for arXi

    Cathelicidin-3 associated with serum extracellular vesicles enables early diagnosis of a transmissible cancer

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    The identification of practical early diagnostic biomarkers is a cornerstone of improved prevention and treatment of cancers. Such a case is devil facial tumor disease (DFTD), a highly lethal transmissible cancer afflicting virtually an entire species, the Tasmanian devil (Sarcophilus harrisii). Despite a latent period that can exceed one year, to date DFTD diagnosis requires visual identification of tumor lesions. To enable earlier diagnosis, which is essential for the implementation of effective conservation strategies, we analyzed the extracellular vesicle (EV) proteome of 87 Tasmanian devil serum samples using data-independent acquisition mass spectrometry approaches. The antimicrobial peptide cathelicidin-3 (CATH3), released by innate immune cells, was enriched in serum EV samples of both devils with clinical DFTD (87.9% sensitivity and 94.1% specificity) and devils with latent infection (i.e., collected while overtly healthy, but 3-6 months before subsequent DFTD diagnosis; 93.8% sensitivity and 94.1% specificity). Although high expression of antimicrobial peptides has been mostly related to inflammatory diseases, our results suggest that they can be also used as accurate cancer biomarkers, suggesting a mechanistic role in tumorous processes. This EV-based approach to biomarker discovery is directly applicable to improving understanding and diagnosis of a broad range of diseases in other species, and these findings directly enhance the capacity of conservation strategies to ensure the viability of the imperiled Tasmanian devil population

    Author Correction: Ecology, evolution and spillover of coronaviruses from bats.

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    In the past two decades, three coronaviruses with ancestral origins in bats have emerged and caused widespread outbreaks in humans, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first SARS epidemic in 2002–2003, the appreciation of bats as key hosts of zoonotic coronaviruses has advanced rapidly. More than 4,000 coronavirus sequences from 14 bat families have been identified, yet the true diversity of bat coronaviruses is probably much greater. Given that bats are the likely evolutionary source for several human coronaviruses, including strains that cause mild upper respiratory tract disease, their role in historic and future pandemics requires ongoing investigation. We review and integrate information on bat–coronavirus interactions at the molecular, tissue, host and population levels. We identify critical gaps in knowledge of bat coronaviruses, which relate to spillover and pandemic risk, including the pathways to zoonotic spillover, the infection dynamics within bat reservoir hosts, the role of prior adaptation in intermediate hosts for zoonotic transmission and the viral genotypes or traits that predict zoonotic capacity and pandemic potential. Filling these knowledge gaps may help prevent the next pandemic

    VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad

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    Acta de congresoLa conmemoración de los cien años de la Reforma Universitaria de 1918 se presentó como una ocasión propicia para debatir el rol de la historia, la teoría y la crítica en la formación y en la práctica profesional de diseñadores, arquitectos y urbanistas. En ese marco el VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad constituyó un espacio de intercambio y reflexión cuya realización ha sido posible gracias a la colaboración entre Facultades de Arquitectura, Urbanismo y Diseño de la Universidad Nacional y la Facultad de Arquitectura de la Universidad Católica de Córdoba, contando además con la activa participación de mayoría de las Facultades, Centros e Institutos de Historia de la Arquitectura del país y la región. Orientado en su convocatoria tanto a docentes como a estudiantes de Arquitectura y Diseño Industrial de todos los niveles de la FAUD-UNC promovió el debate de ideas a partir de experiencias concretas en instancias tales como mesas temáticas de carácter interdisciplinario, que adoptaron la modalidad de presentación de ponencias, entre otras actividades. En el ámbito de VIII Encuentro, desarrollado en la sede Ciudad Universitaria de Córdoba, se desplegaron numerosas posiciones sobre la enseñanza, la investigación y la formación en historia, teoría y crítica del diseño, la arquitectura y la ciudad; sumándose el aporte realizado a través de sus respectivas conferencias de Ana Clarisa Agüero, Bibiana Cicutti, Fernando Aliata y Alberto Petrina. El conjunto de ponencias que se publican en este Repositorio de la UNC son el resultado de dos intensas jornadas de exposiciones, cuyos contenidos han posibilitado actualizar viejos dilemas y promover nuevos debates. El evento recibió el apoyo de las autoridades de la FAUD-UNC, en especial de la Secretaría de Investigación y de la Biblioteca de nuestra casa, como así también de la Facultad de Arquitectura de la UCC; va para todos ellos un especial agradecimiento
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