Vertical mixing and coherent anticyclones in the ocean: the role of stratification

The role played by wind-forced anticyclones in the vertical transport and mixing at the ocean mesoscale is investigated with a primitive-equation numerical model in an idealized configuration. The focus of this work is to determine how the stratification impacts such transport. <br><br> The flows, forced only at the surface by an idealized wind forcing, are predominantly horizontal and, on average, quasigeostrophic. Inside vortex cores and intense filaments, however, the dynamics is strongly ageostrophic. <br><br> Mesoscale anticyclones appear as "islands" of increased penetration of wind energy into the ocean interior and they represent the maxima of available potential energy. The amount of available potential energy is directly correlated with the degree of stratification. <br><br> The wind energy injected at the surface is transferred at depth through the generation and subsequent straining effect of Vortex Rossby Waves (VRWs), and through near-inertial internal oscillations trapped inside anticyclonic vortices. Both these mechanisms are affected by stratification. Stronger transfer but larger confinement close to the surface is found when the stratification is stronger. For weaker stratification, vertical mixing close to the surface is less intense but below about 150 m attains substantially higher values due to an increased contribution of both VRWs, whose time scale is on the order of few days, and of near-inertial motions, with a time scale of few hours

Cognitive resilience in Emergency Room operations: A theoretical framework.

System resilience implies practitioners\u2019 capacity to cope with unexpected events, i.e. cognitive resilience. To address it, we outline a framework based on the Skill-Rule-Knowledge model grounding it in the operators\u2019 sensitivity to the variety that normally occurs in complex systems activities. This variety can hide information enabling the organization to be proactive and to manage unexpected events. Each situation can be described with a SRK profile, according to the cognitive processes necessary to control it. Operators\u2019 reliability can therefore be analyzed by evaluating the match between their cognitive SRK profile and that demanded by the current situation. System resilience is ensured by the capacity of operators to: (i) choose the most suitable cognitive level; (ii) freely move along these levels according to the situation; (iii) be mindful towards variety; (iv) transfer their personal mindfulness into group dynamic adaptation. The outcome of these behaviors is a balance of mindfulness (constant attention to anomalous signals) and dynamic adaptation (organizational adjustment of existing rules according to the new information). This continuous equilibrium between chaos and order is the strategy followed by adaptive complex systems in order to evolve and can be successfully applied to high-risk organizations to enhance the emergence of resilient behaviors

The B_{s0} meson and the B_{s0}B K coupling from QCD sum rules

We evaluate the mass of the $B_{s0}$ scalar meson and the coupling constant in the $B_{s0} B K$ vertex in the framework of QCD sum rules. We consider the $B_{s0}$ as a tetraquark state to evaluate its mass. We get m_{B_s0}=(6.04\pm 0.08) \GeV, which is bigger than predictions supposing it as a $b\bar{s}$ state or a $B\bar{K}$ bound state with $J^{P}=0^+$. To evaluate the $g_{B_{s0}B K}$ coupling we use the three point correlation functions of the vertex, considering $B_{s0}$ as a normal $b\bar{s}$ state. The obtained coupling constant is: g_{B_{s0} B K} =(16.3 \pm 3.2) \GeV. This number is in agreement with light-cone QCD sum rules calculation. We have also compared the decay width of the \BS\to BK process considering the \BS to be a $b\bar{s}$ state and a $BK$ molecular state. The width obtained for the $BK$ molecular state is twice as big as the width obtained for the $b\bar{s}$ state. Therefore, we conclude that with the knowledge of the mass and the decay width of the \BS meson, one can discriminate between the different theoretical proposals for its structure.Comment: revised version to appear in Phys. Rev.

AFS Pool Account Users - GSSKLOG and LCMAPS extension to support AFS users as EGEE pool account users

This paper describes the extensions to the gssklog and lcmaps packages that make possible the utilization of AFS users as LCMAPS/VOMS pool account users. This work has been performed in the framework of the integration of ENEA-GRID and EGEE infrastructure

Synthetic curved DNA sequences can act as transcriptional activators in Escherichia coli.

Can a transcriptional activator known to bend DNA be functionally replaced by a sequence-directed bend in Escherichia coli? To investigate this question, a partially truncated promoter was used, deleted of its -35 region and of its CRP binding site, leaving only two Pribnow boxes as functional elements. Synthetic and naturally occurring curved DNA sequences introduced upstream from these elements could restore transcription at either one of the two natural starts. Some of these hybrid promoters turned out to be more efficient than the CRP activated wild-type gal promoter in vivo. Control experiments performed with very similar sequences devoid of any curvature produced weak promoters only. Minimal changes in the location of the centre of curvature or perturbation in the amount of curvature strongly affected the level of expression. No significant stimulation of transcription could be detected in vitro. Furthermore, both gal P1 and P2 starts could be activated in vivo but also in vitro via a properly positioned CRP binding site. This partial analogy suggests that bending induced by the cAMP-CRP complex upon binding to its site may be biologically relevant to the mechanism of transcriptional activation

Platform optimization and cost analysis in a floating offshore wind farm

Floating offshore wind represents a new frontier of renewable energies. The absence of a fixed structure allows exploiting wind potential in deep seas, like the Atlantic Ocean and Mediterranean Sea, characterized by high availability and wind potential. However, a floating offshore wind system, which includes an offshore turbine, floating platform, moorings, anchors, and electrical system, requires very high capital investments: One of the most relevant cost items is the floating substructure. This work focuses on the choice of a floating platform that minimizes the global weight, in order to reduce the material cost, but ensuring buoyancy and static stability. Subsequently, the optimized platform is used to define a wind farm located near the island of Pantelleria, Italy in order to meet the island’s electricity needs. A sensitivity analysis to estimate the Levelized Cost Of Energy is presented, analyzing the parameters that influence it most, like Capacity Factor, Weighted Average Capital Cost (WACC) and number of wind turbines

Performance of the EQ-5D in Patients with Irritable Bowel Syndrome

ABSTRACTObjectiveThe EQ-5D is a standardized, nondisease-specific instrument for evaluating patients' preference-based valuations of health-related quality of life (HRQoL). This study's purpose was to determine the psychometric properties of EQ-5D in patients with irritable bowel syndrome (IBS).MethodsData from four European IBS studies were assessed: UK (n = 161 and n = 297), Spain (n = 503), and Germany (n = 100). The EQ-5D is a five-item health state descriptive system used to develop health states (EQ-5DINDEX) and a visual analog scale (VAS) (0–100 from worst to best imaginable health state, EQ-5DVAS). Measures used with the EQ-5D included the SF-36, Irritable Bowel Syndrome—Quality of Life (IBS-QOL), and both subjective and clinical global assessments of IBS. Convergent validity was assessed using SF-36 and IBS-QOL data, discriminant validity using global ratings of IBS severity, and responsiveness by subjective and physician assessment of condition.ResultsModerate-to-high associations (r ≥ 0.33) were seen between the EQ-5DVAS and the SF-36 and IBS-QOL subscales. Mean response scores to EQ-5DINDEX dimensions and the EQ-5DVAS score were significantly better for control patients than for patients with IBS (all P < 0.01). The EQ-5DVAS was able to discriminate between levels of pain severity (quartiles, P < 0.001; mild/moderate/severe, P < 0.05) and general health severity (mild/moderate/severe, P < 0.001). The EQ-5DVAS and the EQ-5DINDEX were responsive in patients using both a self-perceived (Subject's Global Assessment) and physician-rated (Clinic Global Assessment) improvement.ConclusionsThe EQ-5D performs well in comparison to general and disease-specific outcomes. It is a valid and responsive measure that can be used to generate preference-based valuations of HRQoL in patients with IBS and useful for comparisons in clinical and cost-effectiveness studies

Propiedades fotofísicas y reactividad fotoquímica de especies poliméricas derivatizadas con grupos cromóforos del tipo -Re(CO)3L (L= Azina)

El objetivo de este trabajo de tesis es el estudio fotofísico y fotoquímico de nuevos complejos del tipo -ReI(CO)3L2 que penden de un esqueleto de polivinilpiridina. En la Parte I se describe en primer lugar la configuración electrónica de complejos d6 en un entorno octaédrico, familia a la que pertenecen los complejos tricarbonílicos de Re1. Luego se describe la generalidad de los procesos fotofísicos y fotoquímicos. Por último se realiza una descripción de los métodos experimentales utilizados para el estudio de estos procesos, como espectroscopia de emisión y absorción estacionaria y resuelta en el tiempo, y radiólisis de pulso. En la Parte II, se detalla la síntesis y caracterización de polímero. Se muestran los resultados de espectroscopia de absorción y emisión estacionaria y resuelta en el tiempo, y se describe el proceso de transferencia de energía observado en los polímeros mixto. Se presentan los resultados de reducción fotoinducida de Citocromo c por el estado excitado del polímero {(vpy)2vpyRe(CO)3(tmephen)+}m-200. Y por último se estudia el proceso de desactivación (quenching) del estado excitado de transferencia de carga metal-ligando, TCML, del monómero PyRe(CO)3(2,2'Bpy) y del polímero {(vpy)2vpyRe(CO)3(2,2'Bpy)+}m~200, donde Py: Piridina y 2,2'Bpy; 2,2'Bipiridina; con una serie de aminas alifáticas y aromáticas. Este proceso como se verá mas adelante es un proceso redox en donde ocurre la oxidación de la amina y la reducción del estado excitado de TCML. Esta serie de aminas se eligió de modo de disponer de un amplio rango de potenciales de oxidación. De esta manera se varía ampliamente el AG de la reacción. El trabajo apunta a establecer las diferencias entre el comportamiento del monómero y el polímero frente al proceso de desactivación reductiva.Tesis digitalizada en SEDICI gracias a la Biblioteca Central de la Facultad de Ciencias Exactas (UNLP).Facultad de Ciencias Exacta