1,925 research outputs found
Life history of plesionika edwardsi (crustacea, decapoda, Pandalidae) around the Canary Islands, Eastern central Atlantic
The life history of Plesionika edwardsi (Brandt, 1851) around the Canary Islands in the Eastern Central Atlantic was investigated, based on a total of 11 434 shrimps ranging in length between 8 and 40 mm carapacelength (CL). The species carries out seasonal migrations; they concentrate in deep water during winter, move shallower in summer and return to deep water again in autumn. Ovigerous females occur throughout the year, but a spawning peak was determined between April and September. The size at maturity for females was approximately 26 mm CL. Shrimp size generally increased with increasing water depth. The growth parameters for males were L‡ = 25.75 mm CL and K = 0.55 year-1, and L‡ = 28.28 mm CL and K = 0.66.year-1 for females. The species displays the typical reproductive pattern of tropical pandalids and is dioecious
Double perovskite cathodes for proton-conducting ceramic fuel cells: are they triple mixed ionic electronic conductors?
Published by National Institute for Materials Science in partnership with Taylor & Francis. 18 O and 2 H diffusion has been investigated at a temperature of 300 °C in the double perovskite material PrBaCo 2 O 5+δ (PBCO) in flowing air containing 200 mbar of 2 H 2 16 O. Secondary ion mass spectrometry (SIMS) depth profiling of exchanged ceramics has shown PBCO still retains significant oxygen diffusivity (~1.3 × 10 −11 cm 2 s −1 ) at this temperature and that the presence of water ( 2 H 2 16 O), gives rise to an enhancement of the surface exchange rate over that in pure oxygen by a factor of ~3. The 2 H distribution, as inferred from the 2 H 2 16 O − SIMS signal, shows an apparent depth profile which could be interpreted as 2 H diffusion. However, examination of the 3-D distribution of the signal shows it to be nonhomogeneous and probably related to the presence of hydrated layers in the interior walls of pores and is not due to proton diffusion. This suggests that PBCO acts mainly as an oxygen ion mixed conductor when used in PCFC devices, although the presence of a small amount of protonic conductivity cannot be discounted in these materials
Evaluating machine-learning techniques for recruitment forecasting of seven North East Atlantic fish species
The effect of different factors (spawning biomass, environmental conditions) on recruitment is a subject of great importance in the management of fisheries, recovery plans and scenario exploration. In this study, recently proposed supervised classification techniques, tested by the machine-learning community, are applied to forecast the recruitment of seven fish species of North East Atlantic (anchovy, sardine, mackerel, horse mackerel, hake, blue whiting and albacore), using spawning, environmental and climatic data. In addition, the use of the probabilistic flexible naive Bayes classifier (FNBC) is proposed as modelling approach in order to reduce uncertainty for fisheries management purposes. Those improvements aim is to improve probability estimations of each possible outcome (low, medium and high recruitment) based in kernel density estimation, which is crucial for informed management decision making with high uncertainty. Finally, a comparison between goodness-of-fit and generalization power is provided, in order to assess the reliability of the final forecasting models. It is found that in most cases the proposed methodology provides useful information for management whereas the case of horse mackerel is an example of the limitations of the approach. The proposed improvements allow for a better probabilistic estimation of the different scenarios, i.e. to reduce the uncertainty in the provided forecasts
Etiology of Severe Non-malaria Febrile Illness in Northern Tanzania: A Prospective Cohort Study.
The syndrome of fever is a commonly presenting complaint among persons seeking healthcare in low-resource areas, yet the public health community has not approached fever in a comprehensive manner. In many areas, malaria is over-diagnosed, and patients without malaria have poor outcomes. We prospectively studied a cohort of 870 pediatric and adult febrile admissions to two hospitals in northern Tanzania over the period of one year using conventional standard diagnostic tests to establish fever etiology. Malaria was the clinical diagnosis for 528 (60.7%), but was the actual cause of fever in only 14 (1.6%). By contrast, bacterial, mycobacterial, and fungal bloodstream infections accounted for 85 (9.8%), 14 (1.6%), and 25 (2.9%) febrile admissions, respectively. Acute bacterial zoonoses were identified among 118 (26.2%) of febrile admissions; 16 (13.6%) had brucellosis, 40 (33.9%) leptospirosis, 24 (20.3%) had Q fever, 36 (30.5%) had spotted fever group rickettsioses, and 2 (1.8%) had typhus group rickettsioses. In addition, 55 (7.9%) participants had a confirmed acute arbovirus infection, all due to chikungunya. No patient had a bacterial zoonosis or an arbovirus infection included in the admission differential diagnosis. Malaria was uncommon and over-diagnosed, whereas invasive infections were underappreciated. Bacterial zoonoses and arbovirus infections were highly prevalent yet overlooked. An integrated approach to the syndrome of fever in resource-limited areas is needed to improve patient outcomes and to rationally target disease control efforts
Contribution of microscopy for understanding the mechanism of action against trypanosomatids
Transmission electron microscopy (TEM) has proved to be a useful tool to study the ultrastructural alterations and the target organelles of new antitrypanosomatid drugs. Thus, it has been observed that sesquiterpene lactones induce diverse ultrastructural alterations in both T. cruzi and Leishmania spp., such as cytoplasmic vacuolization, appearance of multilamellar structures, condensation of nuclear DNA, and, in some cases, an important accumulation of lipid vacuoles. This accumulation could be related to apoptotic events. Some of the sesquiterpene lactones (e.g., psilostachyin) have also been demonstrated to cause an intense mitochondrial swelling accompanied by a visible kinetoplast deformation as well as the appearance of multivesicular bodies. This mitochondrial swelling could be related to the generation of oxidative stress and associated to alterations in the ergosterol metabolism. The appearance of multilamellar structures and multiple kinetoplasts and flagella induced by the sesquiterpene lactone psilostachyin C indicates that this compound would act at the parasite cell cycle level, in an intermediate stage between kinetoplast segregation and nuclear division. In turn, the diterpene lactone icetexane has proved to induce the external membrane budding on T. cruzi together with an apparent disorganization of the pericellar cytoskeleton. Thus, ultrastructural TEM studies allow elucidating the possible mechanisms and the subsequent identification of molecular targets for the action of natural compounds on trypanosomatids.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Spina Zapata, Renata María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Tonn, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Sosa Escudero, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin
Efectos sobre la autopercepción en personas mayores de 60 años de un programa de actividad física en el agua
Introduction: the incidence of the aging process is observed on the physical, mental and social capacities and their relationship with the quality of life, hence the importance of the practice of physical activity in the elderly. The aquatic environment is an ally in physical activity with adults for applying a low joint impact. Objective: to check the evolution of the mood of the participants in a program of aquatic physical activity. Method: 98 adults (69,08 ±7,39years) performed a program of aquatic physical activity with two sessions (60 min) per week for 20 weeks. There were three evaluations: pre-intervention, during and post-intervention, using the POMS scale and the SF-36 scale. Results: significant differences were found, with increased vigor, reduction of tension, fatigue, depression and hostility, perceiving an improvement in health. Conclusion: aquatic physical activity improves the perception of the mood of the participants, both in the physical component and in the mental.Introducción: se observa la incidencia del proceso de envejecimiento sobre las capacidades físicas, mentales y sociales y su relación con la calidad de vida, de ahí la importancia de la práctica de actividad física en mayores. El medio acuático es un aliado en la actividad física con mayores por aplicar un bajo impacto articular. Objetivo: comprobar la evolución del estado de ánimo de los participantes en un programa de actividad física acuática. Método: 98 adultos (69,08 ± 7,39 años) realizaron un programa de actividad física acuática con dos sesiones (60 min) semanales durante 20 semanas. Hubo tres evaluaciones: pre-intervención, durante y post-intervención, mediante la escala POMS y el cuestionario SF-36. Resultados: se encontraron diferencias significativas, con aumento del vigor, reducción de la tensión, fatiga, depresión y hostilidad, percibiendo una mejora de salud. Conclusión: la actividad física acuática mejora la percepción del estado de ánimo de los participantes, tanto en el componente físico como en el mental
Promoter Genotyping and mRNA Expression – Based Analysis of the PTGDR Gene in Allergy
[EN]Background: Prostaglandin D2 receptors are acquiring a relevant role as potential therapeutic targets in allergy. PTGDR has been described as a candidate gene in allergic disease, although functional studies on this gene are lacking. Objective: The objective of this case-control study was to investigate the potential role of PTGDR in allergy. Methods: The study population comprised 195 allergic patients and 112 healthy controls. The PTGDR promoter polymorphisms –1289G>A, –1122T>C, –881C>T, –834C>T, –613C>T, –549T>C, –441C>T, –197T>C, and-95G>T were amplified by polymerase chain reaction (PCR) and sequenced. PTGDR expression levels were analyzed using quantitative PCR and normalized to GAPDH and TBP mRNA levels. All procedures were performed following the Minimum Information for Publication of Quantitative Real-Time PCR Experiment guidelines. Results: [EN]PTGDR expression levels were significantly higher in allergic patients than in controls (PA and –1122T>C were found in allergic patients (P=.009). Conclusions: The results indicate that PTGDR overexpression is associated with allergy. The polymorphisms –1289G>A and –1122T>C partly explain the variation in expression we observed. PTGDR expression could have a potential role as a biomarker and pharmacogenetic factor in allergy
Financing essential HIV services: a new economic agenda.
Anna Vassall and colleagues discuss the need for, and challenges facing, innovative and sustainable financing of the HIV response. Please see later in the article for the Editors' Summary
Human-carnivore relations: conflicts, tolerance and coexistence in the American West
Carnivore and humans live in proximity due to carnivore recovery efforts and ongoing human encroachment into carnivore habitats globally. The American West is a region that uniquely exemplifies these human-carnivore dynamics, however, it is unclear how the research community here integrates social and ecological factors to examine human-carnivore relations. Therefore, strategies promoting human-carnivore coexistence are urgently needed. We conducted a systematic review on human-carnivore relations in the American West covering studies between 2000 and 2018. We first characterized human-carnivore relations across states of the American West. Second, we analyzed similarities and dissimilarities across states in terms of coexistence, tolerance, number of ecosystem services and conflicts mentioned in literature. Third, we used Bayesian modeling to quantify the effect of social and ecological factors influencing the scientific interest on coexistence, tolerance, ecosystem services and conflicts. Results revealed some underlying biases in human-carnivore relations research. Colorado and Montana were the states where the highest proportion of studies were conducted with bears and wolves the most studied species. Non-lethal management was the most common strategy to mitigate conflicts. Overall, conflicts with carnivores were much more frequently mentioned than benefits. We found similarities among Arizona, California, Utah, and New Mexico according to how coexistence, tolerance, services and conflicts are addressed in literature. We identified percentage of federal/private land, carnivore family, social actors, and management actions, as factors explaining how coexistence, tolerance, conflicts and services are addressed in literature. We provide a roadmap to foster tolerance towards carnivores and successful coexistence strategies in the American West based on four main domains, (1) the dual role of carnivores as providers of both beneficial and detrimental contributions to people, (2) social-ecological factors underpinning the provision of beneficial and detrimental contributions, (3) the inclusion of diverse actors, and (4) cross-state collaborative management
Вимоги видавничого відділу ІМФЕ ім. М. Т. Рильського до оформлення авторами рукописів
Industrial parts are manufactured to tolerances as no production process is capable of delivering perfectly identical parts. It is unacceptable that a plan for a manipulation task that was determined on the basis of a CAD model of a part fails on some manufactured instance of that part, and therefore it is crucial that the admitted shape variations are systematically taken into account during the planning of the task. We study the problem of orienting a part with given admitted shape variations by means of pushing with a single frictionless jaw. We use a very general model for admitted shape variations that only requires that any valid instance must contain a given convex polygon PI while it must be contained in another convex polygon PE. The problem that we solve is to determine, for a given h, the sequence of h push actions that puts all valid instances of a part with given shape variation into the smallest possible interval of final orientations. The resulting algorithm runs in O(hn) time, where n=|PI|+|PE|
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