1,138 research outputs found
Investigación pesquera: perspectiva actual, tensiones y aspectos emergentes. El futuro y su aproximación
[EN] The current development of fishery research can be considered as much a technical development as a scientific-conceptual one. In relation to the technical development we analyse the evolution of the concepts fishing effort and fishing power, as well as vulnerability, availability and accessibility. In the conceptual analysis of the basic parameters we consider new contributions with regards to recruitment and evolution of populations based on concepts such as the system’s carrying capacity and the effect of inverse density dependence. The impact of the available space is analysed as well as the effect of the prey-predator relationship in the context of the flows between the different levels in the trophic web. We point out that fishery analysis strategies need to consider that, from both the biological and socio-economic points of view, the system is never balanced but rather is at the very limit or even over the limit. On the whole, fishing (human action on the resource) can be understood within the context of the ecosystem. This situation implies introducing the concept of uncertainty. Aspects such as ecosystem elasticity are analysed in their broadest sense. In these terms, recovery of an ecosystem and of Large Marine Ecosystems (LME) is still possible, but the result can be different due to the appearance of opportunistic species. Some concepts such as fuzzy sets, and chaos and fractal analysis are important tools for analysing the evolution and management of ecosystems exploited by fisheries[ES] El desarrollo actual de la ciencia de las pesquerías es considerado tanto como desarrollo técnico como desarrollo científico-conceptual. En el primer aspecto se analiza la evolución de los conceptos: esfuerzo de pesca y poder de pesca. Así como la vulnerabilidad disponibilidad y accesibilidad. Se considera el análisis conceptual de los parámetros básicos con nuevas aportaciones sobre el reclutamiento y la evolución de las poblaciones a partir de conceptos como la capacidad de carga del sistema y el efecto de la densodependencia inversa. Se analiza el impacto del espacio disponible así como el efecto de la relación presa-depredador en el contexto de los flujos entre los diversos niveles de la relación trófica. La estrategia se sitúa considerando que tanto desde el punto de vista biológico como socieconómico el sistema no está nunca en equilibrio sino en el límite o fuera del mismo. En conjunto la pesca –acción del hombre sobre el recurso– se sitúa en el contexto del ecosistema. Esta situación implica introducir situaciones de incertidumbre. Se analizan aspectos como la elasticidad de los ecosistemas en su aspecto amplio. En estos términos la recomposición de un ecosistema y también de Large Marine Ecosystems (LME) es posible, pero el resultado puede ser diferente –aparición de especies oportunistas. Algunos conceptos como los conjuntos borrosos, el análisis caótico y la fractalidad son instrumentos importantes en el análisis de la evolución y el control de los ecosistemas depredados por la pescaPeer reviewe
Информационные интеллектуальные системы и семантический веб
В учебном пособии рассматриваются основные составляющие технологии семантического веба: XML, пространство имен, универсальный идентификатор ресурсов URI, XML Schema, XSL, RDF, RDF Schema и OWL. Особое внимание уделяется использованию DTD и XML Schema, а также модели DOM XML. Материал проиллюстрирован наглядными практическими примерами, разделы включают лабораторные работы. Предназначено для студентов специальностей "Прикладная лингвистика", "Прикладная информатика" и других информационных и компьютерных направлений
Asymmetric simple exclusion process in one-dimensional chains with long-range links
We study the boundary-driven asymmetric simple exclusion process (ASEP) in a
one-dimensional chain with long-range links. Shortcuts are added to a chain by
connecting different pairs of sites selected randomly where and
denote the chain length and the shortcut density, respectively. Particles flow
into a chain at one boundary at rate and out of a chain at the other
boundary at rate , while they hop inside a chain via nearest-neighbor
bonds and long-range shortcuts. Without shortcuts, the model reduces to the
boundary-driven ASEP in a one-dimensional chain which displays the low density,
high density, and maximal current phases. Shortcuts lead to a drastic change.
Numerical simulation studies suggest that there emerge three phases; an empty
phase with , a jammed phase with , and a shock phase
with where is the mean particle density. The shock phase is
characterized with a phase separation between an empty region and a jammed
region with a localized shock between them. The mechanism for the shock
formation and the non-equilibrium phase transition is explained by an analytic
theory based on a mean-field approximation and an annealed approximation.Comment: revised version (16 pages and 6 eps figures
Skin-impedance in Fabry Disease: A prospective, controlled, non-randomized clinical study
<p>Abstract</p> <p>Background</p> <p>We previously demonstrated improved sweating after enzyme replacement therapy (ERT) in Fabry disease using the thermo-regularity sweat and quantitative sudomotor axon reflex tests. Skin-impedance, a measure skin-moisture (sweating), has been used in the clinical evaluation of burns and pressure ulcers using the portable dynamic dermal impedance monitor (DDIM) system.</p> <p>Methods</p> <p>We compared skin impedance measurements in hemizygous patients with Fabry disease (22 post 3-years of bi-weekly ERT and 5 ERT naive) and 22 healthy controls. Force compensated skin-moisture values were used for statistical analysis. Outcome measures included 1) moisture reading of the 100<sup>th </sup>repetitive reading, 2) rate of change, 3) average of 60–110<sup>th </sup>reading and 4) overall average of all readings.</p> <p>Results</p> <p>All outcome measures showed a significant difference in skin-moisture between Fabry patients and control subjects (p < 0.0001). There was no difference between Fabry patients on ERT and patients naïve to ERT. Increased skin-impedance values for the four skin-impedance outcome measures were found in a small number of dermatome test-sites two days post-enzyme infusions.</p> <p>Conclusion</p> <p>The instrument portability, ease of its use, a relatively short time required for the assessment, and the fact that DDIM system was able to detect the difference in skin-moisture renders the instrument a useful clinical tool.</p
Particle interactions and lattice dynamics: Scenarios for efficient bidirectional stochastic transport?
Intracellular transport processes driven by molecular motors can be described
by stochastic lattice models of self-driven particles. Here we focus on
bidirectional transport models excluding the exchange of particles on the same
track. We explore the possibility to have efficient transport in these systems.
One possibility would be to have appropriate interactions between the various
motors' species, so as to form lanes. However, we show that the lane formation
mechanism based on modified attachment/detachment rates as it was proposed
previously is not necessarily connected to an efficient transport state and is
suppressed when the diffusivity of unbound particles is finite. We propose
another interaction mechanism based on obstacle avoidance that allows to have
lane formation for limited diffusion. Besides, we had shown in a separate paper
that the dynamics of the lattice itself could be a key ingredient for the
efficiency of bidirectional transport. Here we show that lattice dynamics and
interactions can both contribute in a cooperative way to the efficiency of
transport. In particular, lattice dynamics can decrease the interaction
threshold beyond which lanes form. Lattice dynamics may also enhance the
transport capacity of the system even when lane formation is suppressed.Comment: 25 pages, 17 figures, 2 table
Long-term follow-up of renal function in patients treated with migalastat for Fabry disease
The effect of migalastat on long-term renal outcomes in enzyme replacement therapy (ERT)–naive and ERT-experienced patients with Fabry disease is not well defined. An integrated posthoc analysis of the phase 3 clinical trials and open-label extension studies was conducted to evaluate long-term changes in renal function in patients with Fabry disease and amenable GLA variants who were treated with migalastat for ≥2 years during these studies. The analysis included ERT-naive (n = 36 [23 females]; mean age 45 years; mean baseline estimated glomerular filtration rate (eGFR), 91.4 mL/min/mL/1.73 m2) and ERT-experienced (n = 42 [24 females]; mean age, 50 years; mean baseline eGFR, 89.2 mL/min/1.73m2) patients with amenable variants who received migalastat 123 mg every other day for ≥2 years. The annualized rate of change from baseline to last observation in estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration equation (eGFRCKD-EPI) was calculated by both simple linear regression and a random coefficient model. In ERT-naive patients, mean annualized rates of change from baseline in eGFRCKD-EPI were − 1.6 mL/min/1.73 m2 overall and − 1.8 mL/min/1.73 m2 and − 1.4 mL/min/1.73 m2 in male and female patients, respectively, as estimated by simple linear regression. In ERT-experienced patients, mean annualized rates of change from baseline in eGFRCKD-EPI were − 1.6 mL/min/1.73 m2 overall and − 2.6 mL/min/1.73 m2 and − 0.8 mL/min/1.73 m2 in male and female patients, respectively. Mean annualized rate of change in eGFRCKD-EPI in ERT-naive patients with the classic phenotype (defined by white blood cell alpha galactosidase A [α-Gal A] activity of <3% of normal and multiorgan system involvement) was −1.7 mL/min/1.73 m2. When calculated using the random coefficient model, which adjusted for sex, age, and baseline renal function, the annualized eGFRCKD-EPI change was minimal (mean: −0.1 and 0.1 mL/min/1.73 m2 in ERT-naive and ERT-experienced patients, respectively). In conclusion, patients with Fabry disease and amenable GLA variants receiving long-term migalastat treatment (≤8.6 years) maintained renal function irrespective of treatment status, sex, or phenotype
Treatment of Fabry Disease: Outcome of a Comparative Trial with Agalsidase Alfa or Beta at a Dose of 0.2 mg/kg
Two different enzyme preparations, agalsidase alfa (Replagal(TM), Shire) and beta (Fabrazyme(TM), Genzyme), are registered for treatment of Fabry disease. We compared the efficacy of and tolerability towards the two agalsidase preparations administered at identical protein dose in a randomized controlled open label trial.Thirty-four Fabry disease patients were treated with either agalsidase alfa or agalsidase beta at equal dose of 0.2 mg/kg biweekly. Primary endpoint was reduction in left ventricular mass after 12 and 24 months of treatment. Other endpoints included occurrence of treatment failure (defined as progression of cardiac, renal or cerebral disease), glomerular filtration rate, pain, anti-agalsidase antibodies, and globotriaosylceramide levels in plasma and urine. After 12 and 24 months of treatment no reduction in left ventricular mass was seen, which was not different between the two treatment groups. Also, no differences in glomerular filtration rate, pain and decline in globotriaosylceramide levels were found. Antibodies developed only in males (4/8 in the agalsidase alfa group and 6/8 in the agalsidase beta group). Treatment failure within 24 months of therapy was seen in 8/34 patients: 6 male patients (3 in each treatment group) and 2 female patients (both agalsidase alfa). The occurrence of treatment failures did not differ between the two treatment groups; chi(2) = 0.38 p = 0.54.Our study revealed no difference in reduction of left ventricular mass or other disease parameters after 12 and 24 months of treatment with either agalsidase alfa or beta at a dose of 0.2 mg/kg biweekly. Treatment failure occurred frequently in both groups and seems related to age and severe pre-treatment disease.International Standard Randomized Clinical Trial ISRCTN45178534 [http://www.controlled-trials.com/ISRCTN45178534]
Phase diagram of two-lane driven diffusive systems
We consider a large class of two-lane driven diffusive systems in contact
with reservoirs at their boundaries and develop a stability analysis as a
method to derive the phase diagrams of such systems. We illustrate the method
by deriving phase diagrams for the asymmetric exclusion process coupled to
various second lanes: a diffusive lane; an asymmetric exclusion process with
advection in the same direction as the first lane, and an asymmetric exclusion
process with advection in the opposite direction. The competing currents on the
two lanes naturally lead to a very rich phenomenology and we find a variety of
phase diagrams. It is shown that the stability analysis is equivalent to an
`extremal current principle' for the total current in the two lanes. We also
point to classes of models where both the stability analysis and the extremal
current principle fail
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