180 research outputs found

    Numerical simulation of tsunami runup in northern Chile based on non-uniform k −2 slip distributions

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    Artículo de publicación ISIA large seismic gap lies along northern Chile and could potentially trigger a M (w) similar to 8.8-9.0 megathrust earthquake as pointed out in several studies. The April 1, 2014, Pisagua earthquake broke the middle segment of the megathrust. Some slip models suggest that it ruptured mainly from a depth of 30 to 55 km along dip and over 180 km in length, reaching a magnitude M (w) 8.1-8.2. The northern and southern segments are still unbroken; thus, there is still a large area that could generate a M (w) > 8.5 earthquake with a strong tsunami. To better understand the effects of source parameters on the impact of a tsunami in the near field, as a case study, we characterize earthquake size for a hypothetical and great seismic event, M (w) 9.0, in northern Chile. On the basis of physical earthquake source models, we generate stochastic k (-2) finite fault slips taking into account the non-planar geometry of the megathrust in northern Chile. We analyze a series of random slip models and compute vertical co-seismic static displacements by adding up the displacement field from all point sources distributed over a regular grid mesh on the fault. Under the assumption of passive generation, the tsunami numerical model computes the runup along the shore. The numerical results show a maximum peak-runup of similar to 35-40 m in the case of some heterogeneous slip models. Instead, the minimum runup along the coast, from the heterogeneous slip models tested, almost coincides with the runup computed from the uniform slip model. This latter assumption underestimates the runup by a factor of similar to 6 at some places along the coast, showing agreement with near-field runups calculated by other authors using similar methodologies, but applied in a different seismotectonic context. The statistical estimate of empirical cumulative distribution functions conducted on two subsets of slips, and their respective runups, shows that slip models with large amount of slip near the trench are more probable to produce higher runups than the other subset. The simple separation criterion was to choose slip models that concentrate at least 60 % of the total seismic moment in the upper middle part of the non-planar rupture fault.Conicyt (Comision Nacional de Ciencia y Tecnologia) under Grant Fondecyt 113063

    Aβ43 aggregates exhibit enhanced prion-like seeding activity in mice.

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    When injected into genetically modified mice, aggregates of the amyloid-β (Aβ) peptide from the brains of Alzheimer's disease (AD) patients or transgenic AD mouse models seed cerebral Aβ deposition in a prion-like fashion. Within the brain, Aβ exists as a pool of distinct C-terminal variants with lengths ranging from 37 to 43 amino acids, yet the relative contribution of individual C-terminal Aβ variants to the seeding behavior of Aβ aggregates remains unknown. Here, we have investigated the relative seeding activities of Aβ aggregates composed exclusively of recombinant Aβ38, Aβ40, Aβ42, or Aβ43. Cerebral Aβ42 levels were not increased in AppNL-F knock-in mice injected with Aβ38 or Aβ40 aggregates and were only increased in a subset of mice injected with Aβ42 aggregates. In contrast, significant accumulation of Aβ42 was observed in the brains of all mice inoculated with Aβ43 aggregates, and the extent of Aβ42 induction was comparable to that in mice injected with brain-derived Aβ seeds. Mice inoculated with Aβ43 aggregates exhibited a distinct pattern of cerebral Aβ pathology compared to mice injected with brain-derived Aβ aggregates, suggesting that recombinant Aβ43 may polymerize into a unique strain. Our results indicate that aggregates containing longer Aβ C-terminal variants are more potent inducers of cerebral Aβ deposition and highlight the potential role of Aβ43 seeds as a crucial factor in the initial stages of Aβ pathology in AD

    A Study of Subgroup Discovery Approaches for Defect Prediction

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    Context: Although many papers have been published on software defect prediction techniques, machine learning approaches have yet to be fully explored. Objective: In this paper we suggest using a descriptive approach for defect prediction rather than the precise classification techniques that are usually adopted. This allows us to characterise defective modules with simple rules that can easily be applied by practitioners and deliver a practical (or engineering) approach rather than a highly accurate result. Method: We describe two well-known subgroup discovery algorithms, the SD algorithm and the CN2-SD algorithm to obtain rules that identify defect prone modules. The empirical work is performed with publicly available datasets from the Promise repository and object-oriented metrics from an Eclipse repository related to defect prediction. Subgroup discovery algorithms mitigate against characteristics of datasets that hinder the applicability of classification algorithms and so remove the need for preprocessing techniques

    Dihydrocapsiate does not increase energy expenditure nor fat oxidation during aerobic exercise in men with overweight/ obesity: a randomized, triple-blinded, placebo-controlled, crossover trial

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    Background: Prior evidence suggests that capsinoids ingestion may increase resting energy expenditure (EE) and fat oxidation (FATox), yet whether they can modulate those parameters during exercise conditions remains poorly understood. We hypothesized that dihydrocapsiate (DHC) ingestion would increase EE and specifically FATox during an acute bout of aerobic exercise at FATmax intensity (the intensity that elicits maximal fat oxidation during exercise [MFO]) in men with overweight/ obesity. Since FATmax and MFO during aerobic exercise appear to be indicators of metabolic flexibility, whether DHC has an impact on FATox in this type of population is of clinical interest. Methods: A total of 24 sedentary men (age = 40.2 ± 9.2 years-old; body mass index = 31.6 ± 4.5 kg/m2 [n = 11 overweight, n = 13 obese]) participated in this randomized, triple-blinded, placebocontrolled, crossover trial (registered under ClinicalTrials.gov Identifier no. NCT05156697). On the first day, participants underwent a submaximal exercise test on a cycle ergometer to determine their MFO and FATmax intensity during exercise. After 72 hours had elapsed, the participants returned on 2 further days (≥ 72 hours apart) and performed a 60 min steady-state exercise bout (i.e. cycling at their FATmax, constant intensity) after ingesting either 12 mg of DHC or placebo; these conditions were randomized. Respiratory gas exchange was monitored by indirect calorimetry. Serum marker concentrations (i.e. glucose, triglycerides, non-esterified fatty acids (NEFAs), skin temperature, thermal perception, heart rate, and perceived fatigue) were assessed. Results: There were no significant differences (P > 0.05) between DHC and placebo conditions in the EE and FATox during exercise. Similarly, no significant changes were observed in glucose, triglycerides, or NEFAs serum levels, neither in the skin temperature nor thermal perception across conditions. Heart rate and perceived fatigue did not differ between conditions. Conclusions: DHC supplementation does not affect energy metabolism during exercise in men with overweight/obesity.Spanish Junta de Andalucia via Consejeria de Conocimiento, Investigacion y Universidades, Proyectos I+D+i del Programa Operativo del Fondo Europeo de Desarrollo Regional (FEDER 2018) B.CTS.377.UGR18Spanish Government PTA 12264-I FPU16/02828 FPU16/0515

    Factors structuring microbial communities in highly impacted coastal marine sediments (Mar Menor lagoon, SE Spain)

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    Coastal marine lagoons are environments highly vulnerable to anthropogenic pressures such as agriculture nutrient loading or runoff from metalliferous mining. Sediment microorganisms, which are key components in the biogeochemical cycles, can help attenuate these impacts by accumulating nutrients and pollutants. The Mar Menor, located in the southeast of Spain, is an example of a coastal lagoon strongly altered by anthropic pressures, but the microbial community inhabiting its sediments remains unknown. Here, we describe the sediment prokaryotic communities along a wide range of environmental conditions in the lagoon, revealing that microbial communities were highly heterogeneous among stations, although a core microbiome was detected. The microbiota was dominated by Delta- and Gammaproteobacteria and members of the Bacteroidia class. Additionally, several uncultured groups such as Asgardarchaeota were detected in relatively high proportions. Sediment texture, the presence of Caulerpa or Cymodocea, depth, and geographic location were among the most important factors structuring microbial assemblages. Furthermore, microbial communities in the stations with the highest concentrations of potentially toxic elements (Fe, Pb, As, Zn, and Cd) were less stable than those in the non-contaminated stations. This finding suggests that bacteria colonizing heavily contaminated stations are specialists sensitive to change

    The Proto-Magnetar Model for Gamma-Ray Bursts

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    Long duration Gamma-Ray Bursts (GRBs) originate from the core collapse of massive stars, but the identity of the central engine remains elusive. Previous work has shown that rapidly spinning, strongly magnetized proto-neutron stars (`millisecond proto-magnetars') produce outflows with energies, timescales, and magnetizations sigma_0 (maximum Lorentz factor) that are consistent with those required to produce long GRBs. Here we extend this work in order to construct a self-consistent model that directly connects the properties of the central engine to the observed prompt emission. Just after the launch of the supernova shock, a wind heated by neutrinos is driven from the proto-magnetar. The outflow is collimated into a bipolar jet by its interaction with the star. As the magnetar cools, the wind becomes ultra-relativistic and Poynting-flux dominated (sigma_0 >> 1) on a timescale comparable to that required for the jet to clear a cavity through the star. Although the site and mechanism of the prompt emission are debated, we calculate the emission predicted by two models: magnetic dissipation and internal shocks. Our results favor the magnetic dissipation model in part because it predicts a relatively constant `Band' spectral peak energy E_peak with time during the GRB. The jet baryon loading decreases abruptly when the neutron star becomes transparent to neutrinos at t ~ 10-100 seconds. Jets with ultra-high magnetization cannot effectively accelerate and dissipate their energy, suggesting this transition ends the prompt emission and may explain the steep decay phase that follows. We assess several phenomena potentially related to magnetar birth, including low luminosity GRBs, thermal-rich GRBs/X-ray Flashes, very luminous supernovae, and short duration GRBs with extended emission.Comment: 21 pages (plus 2 appendices), 21 figures, 1 table, now accepted to MNRA

    Integración de información en un entorno de entrenamiento para la gestión de proyectos software

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    La gestión de proyectos se puede considerar todavía como un arte en el cual el uso de la información cuantitativa tiende a fomentar un enfoque más riguroso de la gestión. En este trabajo presentamos la estructura y los elementos principales de un entorno de entrenamiento para jefes de proyectos. El objetivo del sistema es proporcionar una estructura uniforme para que se puedan incorporar nuevas técnicas en la estructura de forma gradual. El sistema reúne y almacena los datos del proyecto real y del simulado e implementa diferentes técnicas basadas en aprendizaje automático, modelado dinámico, monitorización de proyectos, etc. El propósito básico de este trabajo es hacer que la toma de decisiones esté apoyada por la integración de diferentes fuentes de información.Ministerio de Ciencia y Tecnología TIC 99-035

    SEGESOFT: un entorno de entrenamiento para la gestión de proyectos software

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    La gestión de proyectos se puede considerar todavía como un arte en el cual el uso de la información cuantitativa tiende a fomentar un enfoque más riguroso de la gestión. En este trabajo presentamos la estructura y los elementos principales de un entorno de entrenamiento para directores de proyectos. El objetivo del sistema es proporcionar una estructura uniforme para que se puedan incorporar nuevas técnicas en la estructura de forma gradual. El sistema reúne y almacena los datos del proyecto real y del simulado e implementa diferentes técnicas basadas en aprendizaje automático, modelado dinámico, monitorización de proyectos, etc. El propósito básico de este trabajo es el de presentar un entorno que facilite la toma de decisiones integrando diferentes técnicas y líneas de investigación.Comisión Interministerial de Ciencia y Tecnología TIC 99-035

    Integrated treatment of first episode psychosis with online training (e-learning): study protocol for a randomised controlled trial

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    BackgroundThe integrated treatment of first episode psychosis has been shown to improve functionality and negative symptoms in previous studies. In this paper, we describe a study of integrated treatment (individual psychoeducation complementary to pharmacotherapy) versus treatment as usual, comparing results at baseline with those at 6-month re-assessment (at the end of the study) for these patients, and online training of professionals to provide this complementary treatment, with the following objectives: 1) to compare the efficacy of individual psychoeducation as add-on treatment versus treatment as usual in improving psychotic and mood symptoms; 2) to compare adherence to medication, functioning, insight, social response, quality of life, and brain-derived neurotrophic factor, between both groups; and 3) to analyse the efficacy of online training of psychotherapists.Methods/designThis is a single-blind randomised clinical trial including patients with first episode psychosis from hospitals across Spain, randomly assigned to either a control group with pharmacotherapy and regular sessions with their psychiatrist (treatment as usual) or an intervention group with integrated care including treatment as usual plus a psychoeducational intervention (14 sessions). Training for professionals involved at each participating centre was provided by the coordinating centre (University Hospital of Álava) through video conferences. Patients are evaluated with an extensive battery of tests assessing clinical and sociodemographic characteristics (Positive and Negative Syndrome Scale, State-Trait Anxiety Inventory, Liebowitz Social Anxiety Scale, Hamilton Rating Scale for Depression, Scale to Assess Unawareness of Mental Disorders, Strauss and Carpenter Prognostic Scale, Global Assessment of Functioning Scale, Morisky Green Adherence Scale, Functioning Assessment Short Test, World Health Organization Quality of Life instrument WHOQOL-BREF (an abbreviated version of the WHOQOL-100), and EuroQoL questionnaire), and brain-derived neurotrophic factor levels are measured in peripheral blood at baseline and at 6 months. The statistical analysis, including bivariate analysis, linear and logistic regression models, will be performed using SPSS.DiscussionThis is an innovative study that includes the assessment of an integrated intervention for patients with first episode psychosis provided by professionals who are trained online, potentially making it possible to offer the intervention to more patients.Trial registrationNCT01783457 clinical trials.gov. Date of registration in primary registry 23 January 2013

    Earliest Known Use of Marine Resources by Neanderthals

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    Numerous studies along the northern Mediterranean borderland have documented the use of shellfish by Neanderthals but none of these finds are prior to Marine Isotopic Stage 3 (MIS 3). In this paper we present evidence that gathering and consumption of mollusks can now be traced back to the lowest level of the archaeological sequence at Bajondillo Cave (Málaga, Spain), dated during the MIS 6. The paper describes the taxonomical and taphonomical features of the mollusk assemblages from this level Bj19 and briefly touches upon those retrieved in levels Bj18 (MIS 5) and Bj17 (MIS 4), evidencing a continuity of the shellfishing activity that reaches to MIS 3. This evidence is substantiated on 29 datings through radiocarbon, thermoluminescence and U series methods. Obtained dates and paleoenvironmental records from the cave include isotopic, pollen, lithostratigraphic and sedimentological analyses and they are fully coherent with paleoclimate conditions expected for the different stages. We conclude that described use of shellfish resources by Neanderthals (H. neanderthalensis) in Southern Spain started ∼150 ka and were almost contemporaneous to Pinnacle Point (South Africa), when shellfishing is first documented in archaic modern humans
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