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Microplastics (MPs) are present across the global ocean and can be encountered by many species, including zooplankton. Although they fall within the size range of zooplankton prey, there are few studies on MPs ingestion carried out in situ. In this study, we analyzed MPs ingestion during two seasons (rainy and dry) of organisms from 5 taxonomic groups of zooplankton from two bays of the Mexican central Pacific: Manzanillo and Navidad. In total, 2643 individuals were analyzed, and of those 23 individuals contained MPs. The ingestion rate by taxonomic group was 1 MP/36 copepods (0.02), 1 MP/30 decapods-mysis (0.03), 1 MP/29 decapods-megalopa (0.03), and 1 MP/200 fish larvae (0.005). No plastics were found in chaetognaths, amphipods, or decapods-zoea. The average length of the ingested particles was 468.1 ± 113.8 μm, with a minimum of 15.6 and a maximum of 647.6 μm. All MPs300 μm were fibers, with diameters50 μm. Fragments were the most abundant MPs (54.2%), followed by fibers (34.2%) and spheres (11.4%). Statistical analyses showed no significant differences (p 0.05) between the bays or seasons. Using RAMAN spectroscopy, it was possible to identify 6 different types of polymers, with poly (ethylene:propylene) being the most abundant (42.8%). This polymer is commonly used to manufacture plastic bags, ropes and fishing nets. The results confirm that certain zooplankton groups are consuming MPs and suggest that omnivorous species are more likely to ingest MPs, possibly due to their capacity for foraging flexibility and opportunistic feeding strategies. However, the ingestion of MPs cannot be attributed to a single factor; it is necessary to consider variables such as the sampling area, feeding strategy, size, and seasonality to understand the dynamics of MPs ingestion by zooplankton groups.

The humpback whales which breed in the Mexican Pacific represent an important fraction (~38%) of the estimated population of the North Pacific. Despite the importance of Mexican waters for the reproductive habits of this species, little is known about the ecology of these whales, along the continental coast of Mexico. We analysed the temporal variation of abundance, group types, and inter- and intra-annual recapture rates in the waters adjacent to Isabel Island National Park as well as intra- and inter-seasonal movements with Banderas Bay breeding areas. Inter- and intra-annual recapture rates in Isabel Island National Park were low (1.8%); while 34% of 222 individuals photo-identified in Isabel Island National Park were also recaptured in Banderas Bay. Groups with calves were uncommon (9.5%), while pairs (33.5%) and competitive groups (29.5%) were more common. Intense singing activity was detected in the waters adjacent to Isabel Island. These waters seem to function as a reproductive corridor for the so-called ‘coastal stock’ of humpback whales in the waters adjacent to the continental coast of the Mexican Pacific. Therefore, mid- and long-term studies are needed to understand the dynamics of these displacements. Our findings suggest that Isabel Island National Park is an important area for the mating ecology of the humpback whales of the continental waters of the Mexican coast, and support the initiative to incorporate a Marine Protected Area within the Isabel Island National Park.

Background Chronological age (CA) is a predictor of adverse coronavirus disease 2019 (COVID-19) outcomes; however, CA alone does not capture individual responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we evaluated the influence of aging metrics PhenoAge and PhenoAgeAccel to predict adverse COVID-19 outcomes. Furthermore, we sought to model adaptive metabolic and inflammatory responses to severe SARS-CoV-2 infection using individual PhenoAge components. Method In this retrospective cohort study, we assessed cases admitted to a COVID-19 reference center in Mexico City. PhenoAge and PhenoAgeAccel were estimated using laboratory values at admission. Cox proportional hazards models were fitted to estimate risk for COVID-19 lethality and adverse outcomes (intensive care unit admission, intubation, or death). To explore reproducible patterns which model adaptive responses to SARS-CoV-2 infection, we used k-means clustering using PhenoAge components. Results We included 1068 subjects of whom 222 presented critical illness and 218 died. PhenoAge was a better predictor of adverse outcomes and lethality compared to CA and SpO2 and its predictive capacity was sustained for all age groups. Patients with responses associated to PhenoAgeAccel >0 had higher risk of death and critical illness compared to those with lower values (log-rank p < .001). Using unsupervised clustering, we identified 4 adaptive responses to SARS-CoV-2 infection: (i) inflammaging associated with CA, (ii) metabolic dysfunction associated with cardiometabolic comorbidities, (iii) unfavorable hematological response, and (iv) response associated with favorable outcomes. Conclusions Adaptive responses related to accelerated aging metrics are linked to adverse COVID-19 outcomes and have unique and distinguishable features. PhenoAge is a better predictor of adverse outcomes compared to CA.

Introduction Microvascular Dysfunction defined as a Myocardial Flow Reserve (MFR) Methods Retrospective cross-sectional study of patients with suspected CAD in which both PET/CT and CCTA were performed. Inclusion:CCTA with obstruction Results 335 patients included. MFR difference for each variable: female sex, hypertension (HT), Type 2 diabetes (T2D) and smoking – Appendix 1. Significant MFR difference for HT (p=0.024) and T2D (p=0.046). Severe ischemia had significant MFR reduction (p=0.006); patients with both HT and mild ischemia (p=0.018) – Appendix 2. Discussion Individuals with HT and T2D had a significantly lower MFR, consistent with previous studies (8,9). Absence of correlation with other risk factors, such as smoking (10) and female sex (11); latter may be caused by a significant lower number of women (108 vs 227). Further analysis in this subgroup ought to be done. When comparing MFR between level-of-ischemia groups, microvascular function was not reduced until severe ischemia. Remarkably, if we analyze the coexistence of HT with ischemia, MFR is reduced even in patients with mild ischemia. This finding highlights the importance of HT which alters function in early stages even in the absence of significant obstruction. This is one of the first studies correlating MFR with comorbidities in our population. Limitations the retrospective nature of the study. Conclusions MFR non-invasive assessment by PET/CT allows identifying very early stages of MVD, even in asymptomatic patients and when there's no evidence of ischemia or CAD. Therefore, timely recognition of this problem is mandatory to implement action strategies to stop the triggered events' cascade. Funding Acknowledgement Type of funding sources: None.

Analytical solutions of barotropic, quasi-geostrophic vortices over an axisymmetric bottom topography are presented. The solutions are based on independent azimuthal modes adapted to the shape of the topography. Modes 0 (circular monopoles) and 1 (asymmetric dipoles) are evaluated for different topographic profiles that represent either submarine mountains or valleys. The interior fields are matched with an exterior flow with streamlines enclosing the vortices, so the structures remain trapped over the topographic feature. The solutions are steady in a reference frame attached to the rotation of the vortices around the topography. The main features of trapped vortices as a function of the topographic parameters, such as the structure, strength and angular speed, are discussed through numerical simulations initialised with theoretical vorticity fields. The model results reproduce reasonably well the analytical solutions when the topographic effects are strong enough to inhibit the dipole self-propagation. In contrast, very intense dipolar modes may escape from the influence of the topography.

Literature indicates that mental health, time spent on mission, and reverse culture shock are all factors in Christian missionaries successful repatriation. The present study explored the effect of time since return, social support, and reverse culture shock on levels of depression, anxiety, and stress in long-term adult Christian missionaries during the repatriation process. I all, 31 Christian missionaries completed self-report measures of social support, reverse culture shock, depression, anxiety, and stress. Results showed that the longer an individual had been back in their passport country significantly correlated with lower levels of depression. In addition, higher levels of reverse culture shock correlated with higher levels of depression and stress. Although social support did not moderate the relationship between reentry shock and well-being, in open-ended questions, respondents indicated how valuable social support was to them in the repatriation process. Implications for sending agencies and clinicians working with repatriating adult Christian missionaries are discussed.

The dispersion of particles in two-dimensional vortices, two circular monopoles, and the Chaplygin–Lamb dipole is studied numerically with a Lagrangian stochastic model. The monopoles are the Rankine and the steady Oseen vortex, whose azimuthal velocity profile is irrotational at a long radial distance. The total velocity of each particle is divided into two parts: the deterministic field due to the vortex plus a stochastic velocity representing homogeneous turbulence. The experiments are carried out with thousands of particles to calculate the dispersion as a function of time. The dispersion in the monopoles grows rapidly and then increases at a lower rate as the particles transit toward the potential region. This transition occurs more quickly in the Rankine vortex, so the Oseen vortex has a wider time-lapse to generate a more significant dispersion. In the case of the Chaplygin–Lamb dipole, having an internal and external flow, the dispersion has different behavior depending on which region the particles depart. The dispersion curves describe the exchange of particles between the poles and the outer flow as the dipole drifts. We discuss the capacity of the dipole to transport particles through long distances.

Dengue is a mosquito-borne disease of global public health importance caused by four genetically and serologically related viruses (DENV-1 to DENV-4). Efforts to develop effective vaccines and therapeutics for dengue have been slowed by the paucity of preclinical models that mimic human disease. DENV-2 models in interferon receptor deficient AG129 mice were an important advance but only allowed testing against a single DENV serotype. We have developed complementary AG129 mouse models of severe disseminated dengue infection using strains of the other three DENV serotypes. Here we used the adenosine nucleoside inhibitor NITD-008 to show that these models provide the ability to perform comparative preclinical efficacy testing of candidate antivirals in vivo against the full-spectrum of DENV serotypes. Although NITD-008 was effective in modulating disease caused by all DENV serotypes, the variability in protection among DENV serotypes was greater than expected from differences in activity in in vitro testing studies emphasizing the need to undertake spectrum of activity testing to help in prioritization of candidate compounds for further development.

The Latin American Giant Observatory (LAGO) is an international network of water-Cherenkov detectors (WCD) set in different sites across Latin America. On top of the Sierra Negra volcano in Mexico at an altitude of 4530 m, LAGO has completed its first out of three instrumented detector. It consists of a cylindrical water tank with a diameter of 7.3 m and a height of 1 m and a total detection area of 40 m2 that is sectioned in four equal slices. In this work we present the full calibration procedure of this detector and the initial measurements of stability in rate. We also derive the effective area to gamma-ray bursts for the complete array using the LAGO simulation chain, based on CORSIKA and GEANT4.

The use of computational interfaces to automate cognitive memory test has allowed to improve the diagnosis of neurological diseases. The synchronization of these interfaces with EEG signals measurement, as well as their automation to obtain data specifically during the tasks defined by the test, have provided useful information in real time. This work aims to present the development of a Graphical User Interface (GUI) synchronized with EEG signals measurements in order to automate a specific intentional and incidental memory evaluation test.

The spreading of n particles simultaneously released is modeled numerically and analytically using a Langevin’s equation. In the numerical experiments, particles are dispersed utilizing the random walk technique plus advection caused by a vortex with rigid-body rotation (RV) or irrotational (IV). In each vortex, the dispersion is described analyzing the statistical behavior of the particles’ position as a function of time t. In the RV case, analytical expressions for the statistics indicate (like the numerical experiments) that the dispersion or variance is linear in t and the diffusion coefficient D depends on the angular speed Ω of the vortex. If the time scale of the random walk is much smaller than the rotation period (i.e., Δt ≪ 2π/Ω), then D decreases lightly if Ω increases relative to a pure two-dimensional (2D) random walk. In the experiments of the IV in which all particles start at the same point, we observe an asymmetric dispersion (the cloud becomes a comet and then a spiral), which leads to a...

Novel trisubstituted ethylenes, methyl and methoxy ring-disubstituted butyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C4H9 (where R is 2,4-dimethyl, 2,5-dimethyl, 2,6-dimethyl, 3,5-dimethyl, 2,3-dimethoxy, 2,4-dimethoxy, 2,5-dimethoxy, 2,6-dimethoxy, 3,4-dimethoxy, and 3,5-dimethoxy) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and butyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500oC range with residue (0.7-4.0% wt.), which then decomposed in the 500-800oC range.

Surface dispersion is measured in the Gulf of California by means of Argos drifters released along this semi-enclosed, elongated basin. First, basic one-particle statistics (Lagrangian scales, absolute dispersion and diffusion coefficients) are estimated along and across the Gulf. Absolute dispersion shows a nearly ballistic regime during the Lagrangian time scale ( t 2 , where t is time). During the subsequent 30 days, absolute dispersion enters a random-walk regime (∼ t ) along the Gulf, while being saturated across the basin due to the lateral boundaries. Secondly, the analysis is extended to two-particle statistics (relative dispersion between pairs of drifters and Finite Scale Lyapunov Exponents, FSLE). Relative dispersion is nearly exponential in both directions during the first few days, though evidence is not conclusive. During the subsequent 30 days, it grows as ∼ t 1.5 along the Gulf, while being saturated across the basin again. It is shown that relative dispersion along the Gulf is proportional to t 3 , where t represents a shifted time that depends on the initial separation of the particles. This form of the Richardson regime is consistently measured for particles that are sufficiently separated (30 km or more). The Richardson regime is verified with the FSLE for particle separations ranging from 30 to 140 km, approximately. The obtained dispersion properties are discussed in terms of the main circulation features within the basin, such as mesoscale vortices that occupy the width of the Gulf. These structures might retain buoys during days or weeks, thus preventing or delaying further displacements and therefore affecting the particle dispersion. The vortices are also an important mechanism to translate particles across the Gulf, between the Peninsula and the continent, thus promoting the saturation of dispersion along this direction.

A set of general allometric scaling laws is derived for different systems represented by tree networks. The formulation postulates self-similar networks with an arbitrary number of branches developed in each generation, and with an inhomogeneous structure given by a fractal relation between successive generations. Three idealized examples are considered: networks of masses, electric resistors, and elastic springs, which obey a specific recurrence relation between generations. The results can be generalized to networks made with different elements obeying equivalent relations. The equivalent values of the networks (total mass, resistance and elastic coefficient) are compared with their corresponding spatial scales (length, cross-section and volume) in order to derive allometric scaling laws. Under appropriate fractal-like approximations of the length and cross-section of the branches, some allometric exponents reported in the literature are recovered (for instance, the 3/4-law of metabolism in biological organisms or the hydraulic conductivity scaling in porous networks). The formulation allows different choices of the fractal parameters, thus enabling the derivation of new power-laws not reported before., 10 pages, 2 figures. Full version of a preliminary study presented in the Int. J. Complex Systems in Science

A characterization of the LtrR regulator, an S. Typhi protein belonging to the LysR family is presented. Proteomics, outer membrane protein profiles and transcriptional analyses demonstrated that LtrR is required for the synthesis of OmpR, OmpC and OmpF. DNA-protein interaction analysis showed that LtrR binds to the regulatory region of ompR and then OmpR interacts with the ompC and ompF promoters inducing porin synthesis. LtrR-dependent and independent ompR promoters were identified, and both promoters are involved in the synthesis of OmpR for OmpC and OmpF production. To define the functional role of the ltrR-ompR-ompC-ompF genetic network, mutants in each gene were obtained. We found that ltrR, ompR, ompC and ompF were involved in the control of bacterial transformation, while the two regulators and ompC are necessary for the optimal growth of S. Typhi in the presence of one of the major bile salts found in the gut, sodium deoxycholate. The data presented establish the pivotal role of LtrR in the regulatory network of porin synthesis and reveal new genetic strategies of survival and cellular adaptation to the environment used by Salmonella.

LAGO is an extended cosmic ray observatory composed of water-Cherenkov detectors (WCD) placed throughout Latin America. It is dedicated to the study of various issues related to astrophysics, space weather and atmospheric physics at the regional scale. In this paper we present the design and implementation of the front-end electronics and the data acquisition system for readout of the WCDs of LAGO. The system consists of preamplifiers and a digital board sending data to a computer via an USB interface. The analog signals are acquired from three independent channels at a maximum rate of 1:2 105 pulses per second and a samplingrate of 40 MHz. To avoid false triggers due to baseline fluctuations, we present in this work a baseline correction algorithm that makes it possible to use WCDs to study variations of the environmental radiation. A data logging software has been designed to format the received data. It also enables an easy access to the data for an o-line analysis, together with the operational conditions and environmental information. The system is currently used at dierent sites of LAGO. Fil: Sofo Haro, Miguel Francisco. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Arnaldi, Luis Horacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Alvarez, W.. Universidad de San carlos; Guatemala Fil: Alvarez, C.. Universidad de Chiapas; México Fil: Araujo, C.. Universidad San Antonio Abad del Cusco; Perú Fil: Areso, Omar Antonio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Asorey, Hernán Gonzalo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Audelo, M.. Escuela Superior Politécnica de Chimborazo; Ecuador Fil: Barros, H.. Universidad Simón Bolivar; Venezuela Fil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Bonnett, M.. Universidad San Antonio Abad del Cusco; Perú Fil: Calderon, R.. Universidad de San Carlos; Guatemala Fil: Calderon, M.. Escuela Politécnica Nacional; Ecuador Fil: Campos Fauth, A.. Universidade Estadual de Campinas; Brasil Fil: Carramiñana, A.. Instituto Nacional de Astrofísica, Óptica y Electrónica; México Fil: Carrasco, E.. Instituto Nacional de Astrofísica, Óptica y Electrónica; México Fil: Carrera, E.. Universidad San Francisco de Quito; Ecuador Fil: Cazar, D.. Universidad San Francisco de Quito; Ecuador Fil: Cifuentes, E.. Universidad de San Carlos; Guatemala Fil: Cogollo, D.. Universidade Estadual de Campinas; Brasil Fil: Conde, R.. Benemérita Universidad Autónoma de Puebla; México Fil: Cotzomi, J.. Benemérita Universidad Autónoma de Puebla; México Fil: Dasso, Sergio Ricardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: De castro, A.. Universidad Industrial de Santander; Colombia Fil: Gomez Berisso, Mariano. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Gonzalez, M.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Gulisano, Adriana Maria. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Martin, R.. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina Fil: Masías Meza, Jimmy Joel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: The LAGO Collaboration.

The Latin American Giant Observatory (LAGO) is an extended cosmic ray observatory composed by a network of water-Cherenkov detectors spanning over different sites located at significantly different altitudes (from sea level up to more than 5000\,m a.s.l.) and latitudes across Latin America, covering a huge range of geomagnetic rigidity cut-offs and atmospheric absorption/reaction levels. This detection network is designed to measure the temporal evolution of the radiation flux at ground level with extreme detail. The LAGO project is mainly oriented to perform basic research in three branches: high energy phenomena, space weather and atmospheric radiation at ground level. LAGO is built and operated by the LAGO Collaboration, a non-centralized collaborative union of more than 30 institutions from ten countries. These are the contributions of the LAGO Collaboration to the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.

Solutions of barotropic coastal-trapped waves in the shallow-water context are discussed for different shapes of the bottom topography. In particular, an infinite family of topographic waves over continental shelves characterized by a shape parameter is considered. The fluid depth is proportional to xs, where x is the offshore coordinate and s is a real, positive number. The model assumes the rigid-lid approximation and a semi-infinite domain 0 ≤ x ≤ ∞. The wave structure and the dispersion relation depend explicitly on the shape parameter s. Essentially, waves over steeper shelves possess higher frequencies and phase speeds. In addition, the wave frequency is independent of the alongshore wavenumber k, implying a zero group velocity component along the coast. The advantages and limitations of this formulation, as well as some comparisons with other models, are discussed in light of numerical simulations for waves over arbitrary topography within a finite domain. The numerical calculations show that the frequency of the waves present a nondispersive regime at small wavenumbers (observed by several authors), followed by a constant value predicted by the analytical solutions for larger k. It is concluded that these frequencies can be considered as an upper limit reached by barotropic coastal-trapped waves over the infinite family of xs-bottom profiles, regardless of the horizontal and vertical scales of the system. The modification of the dispersion curves in a stratified ocean is briefly discussed.

The evolution of barotropic vortices over a topographic, axisymmetric mountain in a homogeneous rotating fluid is studied experimentally. The aim is to identify the main physical processes observed in (i) a horizontal plane of motion, perpendicular to the rotation axis of the system, and (ii) a vertical plane across the diameter of the mountain. The vortices are monopolar cyclones initially generated near or over the topography. Initially, the vortices drift towards the mountain due to the $\ensuremath{\beta} $-effect associated with the topographic slope. On arriving, they turn around the obstacle in an anticyclonic direction, whilst anticyclonic vorticity is generated over the summit. The long-term vorticity distribution is dominated by the original cyclone elongated around the topographic contours and the generated anticyclone over the tip of the topography. In the vertical plane an oscillatory uphill–downhill flow is generated, which is directly related to the drift of the cyclone around the mountain. Depending on the vortex characteristics, the period of the oscillation ranges from 4 to 10 times the rotation period of the system. The horizontal and vertical flow fields are reproduced numerically by using a shallow-water formulation, which allows a detailed view of the vertical motions, hence facilitating the interpretation of the experimental results. In addition, the cyclone–anticyclone pair over the mountain is compared with analytical solutions of topographically trapped waves. A general conclusion is that vertical motions persist for several days (or rotation periods), which implies that this mechanism might be potentially important for the vertical transport over seamounts.

Introduction. Angiotensin II (AngII) regulates blood pressure and water and electrolyte metabolism through the stimulation of NAD(P)H oxidase and production of reactive oxygen species (ROS) such as O2—, which is metabolised by superoxide dismutase, catalase and glutathione peroxidase. We assessed the role of AT1 and AT2 receptors, NAD(P)H oxidase and protein kinase C (PKC) in Ang II-induced sodium and water excretion and their capacity to stimulate antioxidant enzymes in the rat hypothalamus, a brain structure known to express a high density of AngII receptors. Materials and methods. Male Sprague—Dawley rats were intracerebroventricularly (ICV) injected with AngII and urinary sodium and water excretion was assessed. Urine sodium concentration was determined using flame photometry. After decapitation the hypothalamus was microdissected under stereomicroscopic control. Superoxide dismutase, catalase and glutathione peroxidase activity were determined spectrophotometrically and extracellular signal-regulated kinase (ERK1/2) activation was analysed by Western blot. Results. AngII-ICV resulted in antidiuresis and natriuresis. ICV administration of losartan, PD123319, apocynin and chelerythrine blunted natriuresis. In hypothalamus, AngII increased catalase, superoxide dismutase and glutation peroxidase activity and ERK1/2 phosphorylation. These actions were prevented by losartan, apocynin and chelerythrine, and increased by PD123319. Conclusions. AT 1 and AT2 receptors, NAD(P)H oxidase and PKC pathway are involved in the regulation of hydromineral metabolism and antioxidant enzyme activity induced by AngII.

Two-dimensional shear flows continuously forced in the presence of dissipative effects are studied by means of numerical simulations. In contrast with most previous studies, the forcing is confined in a finite region, so the behavior of the system is characterized by the long-term evolution of the global kinetic energy. We consider regimes with 1 36, in which the energy maintains a regular oscillation around a reference value. The flow configuration is an elliptica...

The evolution and decay of a homogeneous flow over random topography in a rotating system is studied by means of numerical simulations and theoretical considerations. The analysis is based on a quasi-two-dimensional shallow-water approximation, in which the horizontal divergence is explicitly different from zero, and topographic variations are not restricted to be much smaller than the mean depth, as in quasi-geostrophic dynamics. The results are examined by comparing the evolution of a turbulent flow over different random bottom topographies characterized by a specific horizontal scale, or equivalently, a given mean slope. As in two-dimensional turbulence, the energy of the flow is transferred towards larger scales of motion; after some rotation periods, however, the process is halted as the flow pattern becomes aligned along the topographic contours with shallow water to the right. The quasi-steady state reached by the flow is characterized by a nearly linear relationship between potential vorticity and transport function in most parts of the domain, which is justified in terms of minimum-enstrophy arguments. It is found that global energy decays faster for topographies with shorter horizontal length scales due to more effective viscous dissipation. In addition, some comparisons between simulations based on the shallow-water and quasi-geostrophic formulations are carried out. The role of solid boundaries is also examined: it is shown that vorticity production at no-slip walls contributes for a slight disorganization of the flow.

The evolution of decaying two-dimensional turbulent flows in a bounded domain is considered. It is shown that the global enstrophy is always equal to the total squared strain field, when integrated over a domain with no-slip boundaries, despite the complex evolution of the flow and strong vortex-wall interactions. This property is also valid for a square domain with stress-free walls, and in general for any polygonal boundary. In contrast, the enstrophy is always greater than the squared strain field in a stress-free circular domain, and in general for any closed domain with negatively-signed curvature at all points of the boundary.

The long-time decay of rotating, homogeneous flows over variable topography is analyzed by means of laboratory experiments and numerical simulations. The influence of the topography on the flow evolution is associated with stretching and squeezing effects on fluid columns as they experience changes in depth, and with viscous effects produced by the boundary condition at the solid bottom of the tank. In particular, experiments with a sine-shaped topography in one of the horizontal directions are analyzed by using two different basic flows. First, the evolution of dipolar vortices drifting across the topography while slowly decaying, is examined. The second set of experiments considers the evolution and decay of an initially circular vortex transforming into a tripolar structure. The experiments are well represented by numerical simulations based on a quasi-two-dimensional formulation with variable topography. The main result is that the long-term evolution of the flow (one or two Ekman periods, which are much longer than the rotation period of the system) is characterized by the alignment of the flow along the topographic contours. It is shown that the key process that leads to this phenomenon takes place as cyclonic (anticyclonic) structures are cleaved in two parts over crests (troughs) of the topography. As a result, positive relative vorticity is distributed on deep regions, while anticyclonic vorticity spreads over shallow parts of the domain. In addition, it is numerically found that the dipole speed is somewhat slower than for the flat bottom case, due to a more effective Ekman decay over variable topography. For circular, unstable vortices where the horizontal length scale of the topography is comparable with the vortex diameter, the formation of tripolar structures might be inhibited. © 2007 Elsevier B.V. All rights reserved.

The interaction of a barotropic, dipolar vortex with a step-like topography is studied by means of laboratory experiments in a rotating tank and by numerical simulations based on a quasi-two-dimensional model. Two main configurations are analyzed: when the dipole approaches a “low” or a “high” step with respect to the maximum water depth. For relatively low steps, the vortex crosses the topography with a deflected trajectory, while maintaining its dipolar structure. The sense of this deflection depends on whether the dipole reaches a step-up or a step-down. For high steps, in contrast, the dipole is not able to cross the topography, and the reflection of one of the dipole structures is observed. In both cases, one observes a weak flow along the topography with shallow water on its right. The essential features of the flow evolution for low and high steps can be explained by using arguments of potential vorticity conservation due to the weakness of viscous effects. In order to determine whether a barotropic dipole is able to cross the step or is reflected, qualitative criteria based on the step height and dipole strength are derived using inviscid arguments. © 2006 American Institute of Physics. DOI: 10.1063/1.2204070

The evolution of a barotropic coastal current in the presence of a bottom ramp-shaped topography is studied by means of laboratory experiments and numerical simulations. The experiments are performed in a rectangular rotating tank filled with freshwater. The fluid depth is shallow at one side of the domain and deeper at the other side, and both regions are divided by a narrow slope, whose depth contours are perpendicular to the long sides of the tank. A current approaching the slope is produced along one of the vertical walls, having the boundary at its right. Two configurations are analyzed: when the current flows from shallow to deep water and when flowing in the opposite direction. In the first scenario, the current is divided in two parts, one of them following the coastline. The other part of the current pairs with a cell of negative relative vorticity generated at the slope due to squeezing effects, forming a dipolar structure moving offshore, back toward the shallow side. In addition, a weak current moving inshore along the slope is clearly formed. In the second configuration, when the flow goes from deep to shallow water, a part of or even the whole current might be forced to move along the contours of the topography, away from the coast. In this case there is no dipole formation. The experiments are well reproduced by means of quasigeostrophic numerical simulations, which allow a more detailed systematic study of the influence of flow parameters such as the topography height and the width of the slope.

The dispersion of surface drifters released over a 7-year period from five locations in the southern Gulf of Mexico is described. It is shown that the drifter dispersion is strongly affected by the main mesoscale circulations features frequently observed in this area. Some of them are the anticyclonic eddies shed by the Loop Current at the eastern side of the Gulf of Mexico, and a semi-permanent cyclonic gyre at the Bay of Campeche. The results are examined further in terms of two dominant and contrasting dispersion scenarios: (i) an intense northward advection of drifters, preferentially along the western margin, and (ii) the retention of drifters in the southernmost part of the Gulf of Mexico. The results are discussed from an environmental point of view, by considering particle dispersion from point sources as an approach to study marine pollution problems.

A characterization of the LtrR regulator, an S. Typhi protein belonging to the LysR family is presented. Proteomics, outer membrane protein profiles and transcriptional analyses demonstrated that LtrR is required for the synthesis of OmpR, OmpC and OmpF. DNA-protein interaction analysis showed that LtrR binds to the regulatory region of ompR and then OmpR interacts with the ompC and ompF promoters inducing porin synthesis. LtrR-dependent and independent ompR promoters were identified, and both promoters are involved in the synthesis of OmpR for OmpC and OmpF production. To define the functional role of the ltrR-ompR-ompC-ompF genetic network, mutants in each gene were obtained. We found that ltrR, ompR, ompC and ompF were involved in the control of bacterial transformation, while the two regulators and ompC are necessary for the optimal growth of S. Typhi in the presence of one of the major bile salts found in the gut, sodium deoxycholate. The data presented establish the pivotal role of LtrR in the regulatory network of porin synthesis and reveal new genetic strategies of survival and cellular adaptation to the environment used by Salmonella.

Background: Antimicrobial resistance is an increasing concern in ICUs worldwide. Infection with an antibiotic resistant (ABR) strain of an organism is associated with greater mortality than infection with the non-resistant strain, but there are few data assessing whether being admitted to an intensive care unit (ICU) with high levels of antimicrobial resistance is associated with a worse outcome than being admitted to an ICU with low rates of resistance. The aim of this study was, therefore, to compare the characteristics of infections and antibiotic treatments and patient outcomes in patients admitted to ICUs in countries considered as having high levels of antibiotic resistance and those admitted to ICUs in countries considered as having low levels of antibiotic resistance.Methods: Data from the large, international EPIC II one-day point prevalence study on infections in patients hospitalized in ICUs were used. For the current study, we compared the data obtained from patients from two groups of countries: countries with reported MRSA rates of ≥ 25% (highABR: Greece, Israel, Italy, Malta, Portugal, Spain, and Turkey) and countries with MRSA rates of < 5% (lowABR: Denmark, Finland, Netherlands, Norway, and Sweden).Results: On the study day, 1187/2204 (53.9%) patients in the HighABR ICUs were infected and 255/558 (45.7%) in the LowABR ICUs (P < 0.01). Patients in the HighABR ICUs were more severely ill than those in the LowABR ICUs, as reflected by a higher SAPS II score (35.6 vs 32.7, P < 0.05) and had longer median ICU (12 days vs 5 days) and hospital (24 days vs 16 days) lengths of stay. They also had higher crude ICU (20.0% vs 15.4%) and hospital (27.0% vs 21.5%) mortality rates (both P < 0.05). However, after multivariable adjustment and matched pair analysis there were no differences in ICU or hospital mortality rates between High or LowABR ICU patients overall or among those with infections.Conclusions: Being hospitalized in an ICU in a region with high levels of antimicrobial resistance is not associated per se with a worse outcome. © 2014 Hanberger et al.; licensee BioMed Central Ltd.

The evolution of quasi-two-dimensional (2D) dipolar vortices over a flat bottom in a rotating fluid system is studied numerically, and the main results are experimentally verified. Our aim is to examine the dipole decay due to bottom friction effects. The numerical simulations are based on the 2D physical model derived by Zavala Sansón and van Heijst [J. Fluid Mech. 412, 75 (2000)], which contains nonlinear Ekman terms, associated with bottom friction, in the vorticity equation. In contrast, the conventional 2D model with bottom friction only retains a linear stretching term in the same equation. It is shown that the dipole trajectory is deflected towards the right (i.e., in the anticyclonic direction) when nonlinear Ekman terms are included. This effect is not observed in simulations based on the conventional model, where the dipole trajectory is a straight line. The basic reason for this behavior is the slower decay of the anticyclonic part of the dipole, with respect to the cyclonic one, due to nonlinear Ekman effects. Another important result is the exchange of fluid between the cyclonic part and the ambient, leaving a tail behind the dipole. By means of laboratory experiments in a rotating tank, these results are qualitatively verified.

The interaction of a barotropic cyclonic vortex on a 13 plane with a strong topographic slope is studied by means of laboratory experiments and numerical simulations. In the laboratory, the vortex is produced in a rectangular rotating tank with a weak uniformly sloping bottom (slope angle 3.5°) in order to simulate the 13 effect. The cyclonic vortex moves in the northwestward direction and interacts with an additional, pronounced linear topography (slope angle 35°) along the western boundary of the tank. The laboratory experiments revealed that the original northwestward trajectory changes to the south until the vortex is dissipated by viscous effects and bottom friction. As it moves upslope, the exterior ring of the vortex forms a strong current to the northeast From this current a new cyclonic vortex is created, repeating approximately the behavior of the original one. Later, two more vortices are formed in the same way A finite difference numerical model is used to solve the nondivergent barotropic equation. Despite the presence of the strong slope, agreement between laboratory results and numerical runs suggests that conservation of potential vorticity is indeed the basic mechanism involved in the southward motion of the vortex and the northeastward meandering current.

The collision of anticyclonic, lens-like eddies with a meridional western boundary is investigated as a function of two independent, nondimensional numbers: ß = ß0 R/f o and e = ¿/f o, where f 0 and ß0 are the Coriolis parameter and its rate of change with latitude, respectively, both evaluated at the reference latitude. R is the eddy's radius, and ¿ is its angular frequency. The numerical experiments show that in all cases there is a southward expulsion of mass proportional to both ß and e. which is estimated during the eddy-boundary interaction. The eddies are invariably deformed with the initial collision, but afterward, they reacquire a new circular shape. There is a meridional translation of the eddy along the boundary which depends exclusively on the initial ratio r = e/ß. If r > 1, the eddy goes southward, but if r