2,036 research outputs found

    Bird assemblages from Carilauquen Marshes (Llancanelo Lagoon, Mendoza, Argentina): considerations for their conservation

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    Analizamos los cambios estacionales en la riqueza, composición, abundancia y uso de hábitat de las especies de aves de los ambientes acuáticos y terrestres del sistema de bañados de Carilauquen. Identificamos cinco hábitats de importancia para las aves: el bañado, las playas y aguas costeras de la laguna, el salitral costero, el pichanal y el matorral arbustivo. Registramos 100 especies distribuidas en forma heterogénea en el mosaico ambiental; cada hábitat aportó especies exclusivas al conjunto total de especies. La similitud entre hábitats fue baja; la mayoría de las especies ocuparon solo uno o dos hábitats. La abundancia y riqueza de especies fueron mayores en primavera y verano, lo que coincide con la estación reproductiva de la mayoría de las especies. Varias especies endémicas de zonas áridas y semiáridas de Argentina nidifican en los ambientes terrestres de Carilauquen. Analizamos el valor para la conservación de los cinco tipos de hábitat considerando el uso de hábitat, la exclusividad taxonómica y la distribución de las especies de cada ensamble. El bañado es el hábitat prioritario para el mantenimiento de la diversidad de aves de Carilauquen, ya que alberga muchas especies con distribuciones particula- res y con marcadas preferencias de hábitat. El matorral arbustivo, pese a su menor riqueza, también posee interés especial por la composición del ensamble. Una estrategia de conservación efectiva debe contemplar la complementariedad de ambos tipos de hábitat para la conservación regional de la avifauna.We analyzed seasonal changes in species richness, composition, abundance and habitat use of birds in wetlands and terrestrial environ- ments from the Carilauquen marsh system. We identified five important habitats for birds: marsh, coast of the lagoon, coastal salt-land, pichanal and shrubland. During the study we recorded 100 bird species that showed a heterogeneous distribution on the environmental mosaic; each habi- tat contributed with exclusive species to the overall species pool. The Carilauquen marsh system showed low between-habitat similarity; most of the bird species used only one or two habitats. Bird abundance and species richness were higher during spring and summer, likely due to the nest season of most of the species. Several endemic species of arid lands from Argentina nested in the terrestrial environments of Carilauquen. We analyzed the conservation value of the five habitats considering habitat preferences, distribution and taxonomic exclusivity of each bird- species assemblage. The conservation of the marsh guarantees the maintenance of high bird diversity, because this habitat harbours many species with restricted ranges and with narrow habitat preferences. The shrubland, in despite of its lower species richness in comparison to wetlands, is a habitat of special interest for bird conservation due to the species composition of the assemblage. An effective conservation strategy has to consider the complementarity of both habitats for the conservation of the regional avifauna

    Vacuum Energy Cancellation in a Non-supersymmetric String

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    We present a nonsupersymmetric orbifold of type II string theory and show that it has vanishing cosmological constant at the one and two loop level. We argue heuristically that the cancellation persists at higher loops.Comment: 31 pages harvmac big, 6 figures. New version includes the 2-loop analysis of hep-th/9810129 and elimination of one of the two heuristic arguments for higher loop cancellatio

    Potential role of new molecular plasma signatures on cardiovascular risk stratification in asymptomatic individuals

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    The evaluation of cardiovascular (CV) risk is based on equations derived from epidemiological data in individuals beyond the limits of middle age such as the Framingham and SCORE risk assessments. Lifetime Risk calculator (QRisk®), estimates CV risk throughout a subjects' lifetime, allowing those. A more aggressive and earlier intervention to be identified and offered protection from the consequences of CV and renal disease. The search for molecular profiles in young people that allow a correct stratification of CV risk would be of great interest to adopt preventive therapeutic measures in individuals at high CV risk. To improve the selection of subjects susceptible to intervention with aged between 30-50 years, we have employed a multiple proteomic strategy to search for new markers of early CV disease or reported CV events and to evaluate their relationship with Lifetime Risk. Blood samples from 71 patients were classified into 3 groups according to their CV risk (healthy, with CV risk factors and with a previously reported CV event subjects) and they were analyzed using a high through quantitative proteomics approach. This strategy allowed three different proteomic signatures to be defined, two of which were related to CV stratification and the third one involved markers of organ damage.This work was supported by grants from the Instituto de Salud Carlos III (PI070537, IF08/3667-1, PI11-02239, PI 14/01917, PI11/01401, PI11/02432, PI13/01873, PI13/01746, PI13/01581, PI14/01650, PI14/01841), PT13/0001/0013, PIE13/00051, PIE13/00045, CP09/00229, CP15/00129, IDC Salud (3371/002), the MutuaMadrileña Foundation, the SENEFRO Foundation and FONDOS FEDER (RD06/0014/1015, RD12/0042/0071). Sociedad Española de cardiología para la Investigación Básica 2017. Grant PRB3 (IPT17/0019 - ISCIII-SGEFI / ERDF. These results are in line with the Spanish initiative on the Human Proteome Project.S

    Urinary exosomes reveal protein signatures in hypertensive patients with albuminuria

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    Albuminuria is an indicator of cardiovascular risk and renal damage in hypertensive individuals. Chronic renin-angiotensin system (RAS) suppression facilitates blood pressure control and prevents development of new-onset-albuminuria. A significant number of patients, however, develop albuminuria despite chronic RAS blockade, and the physiopathological mechanisms are underexplored. Urinary exosomes reflect pathological changes taking place in the kidney. The objective of this work was to examine exosomal protein alterations in hypertensive patients with albuminuria in the presence of chronic RAS suppression, to find novel clues underlying its development. Patients were followed-up for three years and were classified as: a) patients with persistent normoalbuminuria; b) patients developing de novo albuminuria; and c) patients with maintained albuminuria. Exosomal protein alterations between groups were identified by isobaric tag quantitation (iTRAQ). Confirmation was approached by target analysis (SRM). In total, 487 proteins were identified with high confidence. Specifically, 48 proteins showed an altered pattern in response to hypertension and/or albuminuria. Out of them, 21 proteins interact together in three main functional clusters: glycosaminoglycan degradation, coagulation and complement system, and oxidative stress. The identified proteins constitute potential targets for drug development and may help to define therapeutic strategies to evade albuminuria progression in hypertensive patients chronically treated.Instituto de Salud Carlos III, fondos FEDER/FSE (PI11/01401, PI13/01873, PI14/01841, IF08/3667-1, PI11-02239, PI 14/0917, PI11/02432, PI13/01746, PI14/01650, PI16/01334, PT13/0001/0013, CP09/00229, CP15/00129, CPII15/00027), Fundacion SENEFRO, Fundacion Conchita Rabago de Jimenez Diaz, and Redes Tematicas de Investigacion Cooperativa (fondos FEDER/FSE, RD12/0021/0001, RD12/0042/0071). These results are lined up with the Spanish initiative on the Human Proteome Project (SpHPP).S

    Topo-Iberia Project: CGPS crustal velocity field in the Iberian Peninsula and Morocco

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    A new continuous GPS network was installed under the umbrella of a research project called 'Geociencias en Iberia: Estudios integrados de topografı´a y evolución 4D (Topo-Iberia)', to improve understanding of kinematic behavior of the Iberian Peninsula region. Here we present a velocity field based on the analysis of the 4 years of data from 25 stations constituting the network, which were analyzed by three different analysis groups contributing to the project. Different geodetic software packages (GIPSY-OASIS, Bernese and GAMIT) as well as different approaches were used to estimate rates of present day crustal deformation in the Iberian Peninsula and Morocco. In order to ensure the consistency of the velocity fields determined by the three groups, the velocities obtained by each analysis center were transformed into a common Eurasia Reference Frame. After that, the strain rate field was calculated. The results put in evidence more prominent residual motions in Morocco and southernmost part of the Iberian Peninsula. In particular, the dilatation and shear strain rates reach their maximum values in the Central Betics and northern Alboran Sea. A small region of high shear strain rate is observed in the east-central part of the peninsula and another deformation focus is located around the Strait of Gibraltar and the Gulf of Cadiz

    Analysis of metastases rates during follow-up after endoscopic resection of early "high-risk" esophageal adenocarcinoma

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    BACKGROUND AND AIMS: After endoscopic resection (ER) of early esophageal adenocarcinoma (EAC), the optimal management of patients with high-risk histological features for lymph node metastases (LNM) (i.e., submucosal invasion, poor differentiation grade, or lymphovascular invasion (LVI)), remains unclear. We aimed to evaluate outcomes of endoscopic follow-up after ER for high-risk EAC. METHODS: For this retrospective cohort study, data was collected from all Dutch patients managed with endoscopic follow-up (endoscopy, endoscopic ultrasound) after ER for high-risk EAC between 2008 and 2019. We distinguished 3 groups: intramucosal cancers with high-risk features, submucosal cancers with low-risk features, and submucosal cancers with high-risk features. Primary outcome was the annual risk for metastases during follow-up, stratified for baseline histology. RESULTS: A total of 120 patients met the selection criteria. Median FU was 29 months (IQR 15-48). Metastases were observed in 5/25 (annual risk 6.9%; 95% CI 3.0-15), 1/55 (annual risk 0.7%; 95% CI 0-4.0) and 3/40 (annual risk 3.0%; 95% CI 0-7.0) in high-risk intramucosal, low-risk submucosal, and high-risk submucosal cancers, respectively. CONCLUSIONS: Whereas the annual metastasis rate for high-risk submucosal EAC (3.0%) was somewhat lower than expected in comparison with previous reported percentages, the annual metastasis rate of 6.9% for high-risk intramucosal EAC is new and worrisome. This calls for further prospective studies and suggests that strict follow-up of this small subgroup is warranted until prospective data are available

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file
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