1,281 research outputs found
Evidence of fractal structures in hadrons
This study focuses on the presence of (multi)fractal structures in confined
hadronic matter through the momentum distributions of mesons produced in
proton-proton collisions between 23 GeV and 63 GeV. The analysis demonstrates
that the -exponential behaviour of the particle momentum distributions is
consistent with fractal characteristics, exhibiting fractal structures in
confined hadronic matter with features similar to those observed in the
deconfined quark-gluon plasma (QGP) regime. Furthermore, the systematic
analysis of meson production in hadronic collisions at energies below 1 TeV
suggests that specific fractal parameters are universal, independently of
confinement or deconfinement, while others may be influenced by the quark
content of the produced meson. These results pave the way for further research
exploring the implications of fractal structures on various physical
distributions and offer insights into the nature of the phase transition
between confined and deconfined regimes.Comment: 23 pages, 11 figures, supplementary materia
Ontologies and Unified Modeling Language: an approach to representation of domains of knowledge
This article emphasizes the use of Unified Modeling Language, UML in the specification of models based on ontologies in the representation of domains of knowledge, emphasizing the importance of semantic and of treatment of standardized language so the knowledge of the domain can be organized and shared. Finally, this article aims to establish a connection between the themes: the object oriented modeling and ontologies.Este artigo destaca o uso da Unified Modeling Language, UML na especificação de modelos baseados em ontologias na representação de domínios de conhecimento, enfatizando a importância da semântica e do tratamento da linguagem padronizada para que o conhecimento do domínio possa ser organizado e compartilhado. Finalmente, este artigo tem como objetivo estabelecer uma conexão entre as temáticas: modelagem orientada a objetos e ontologias
Eventos extremos de lluvia y riesgo hidroclimático en zona de La Mata - Pernambuco/Brasil
Intense rains are natural events associated with urban peculiarities that can become sources of danger, worsening the population's living conditions in the city. In Brazil, the scenarios of environmental degradation resulting from social inequalities and poor infrastructure, coupled with the occupation of inappropriate spaces highlight risks and vulnerabilities that often coincide with urban river environments. This article aims to analyze the occurrence of extreme events caused by rainfall in mesoregion Zona da Mata in Pernambuco, Brazil, specifically, the municipalities of Barreiros and Palmares. Furthermore, the risk conditions that led or may lead to disaster areas were studied. The analysis was carried out, firstly by analyzing the descriptive statistics of the time series of precipitation and later the Rain Anomaly Index (RAI) was calculated. Satellite image analysis was then utilized to characterize the pattern of rain and atmospheric dynamics associated with the period of occurrence of selected rainfall events; heavy rainfall concentrated in a short period of time. The main rainfall event of great magnitude for municipalities occurred in June 2010 caused by Eastern wave disturbance, which led to the flooding of rivers and flooding in several cities in the basin of Una and Mundau rivers.Las inundaciones son fenómenos naturales asociados con peculiaridades urbanas se convierten en fuentes de peligro, el empeoramiento de las condiciones de vida de la población en la ciudad. En Brasil, los escenarios de degradación del medio ambiente que resultan de las desigualdades sociales y la infraestructura deficiente, junto con la ocupación de los problemas de espacio de relieve los riesgos y las vulnerabilidades que suelen coincidir con los entornos de los ríos urbanos. Este artículo tiene como objetivo analizar la ocurrencia de eventos extremos causados por las lluvias en mesorregión Zona da Mata, en Pernambuco, Brasil, sobre la base, los municipios de Barreiros y Palmares, está tratando de comprender la dinámica de las lluvias asociadas con el período de ocurrencia de un evento. Además, se investigó las condiciones de riesgo que llevaron o puedan dar lugar a zonas de desastre en el estudiada. Se seleccionaron los datos de lluvia disponible en la Agencia de Pernambuco Agua y Clima y (sistema de monitoreo agrometeorológico. El análisis se llevó a cabo, en primer lugar, las estadísticas descriptivas de las series de tiempo de precipitación, se calculó la tarde del índice de anomalías de lluvia (IAC) y análisis de imágenes de satélite para caracterizar el modelo de la lluvia y la dinámica atmosférica asociados con el período de ocurrencia de eventos de lluvias fuertes lluvias seleccionados, se concentró en un corto período de tiempo. también se llevó a cabo el trabajo de campo para registrar el impacto del evento. el principal evento de gran magnitud para los municipios precipitaciones fue lo que sucedió en junio de 2010 causado por la interrupción de la onda del Este que dio lugar a la inundación de ríos e inundaciones en varias ciudades de la cuenca del río Una y Mundaú
Aerobic exercise acutely prevents the endothelial dysfunction induced by mental stress among subjects with metabolic syndrome: the role of shear rate
Mental stress induces transient endothelial dysfunction, which is an important finding for subjects at cardiometabolic risk. Thus, we tested whether aerobic exercise prevents this dysfunction among subjects with metabolic syndrome (MetS) and whether an increase in shear rate during exercise plays a role in this phenomenon. Subjects with MetS participated in two protocols. in protocol 1 (n = 16), endothelial function was assessed using brachial artery flow-mediated dilation (FMD). Subjects then underwent a mental stress test followed by either 40 min of leg cycling or rest across two randomized sessions. FMD was assessed again at 30 and 60 min after exercise or rest, with a second mental stress test in between. Mental stress reduced FMD at 30 and 60 min after the rest session (baseline: 7.7 +/- 0.4%, 30 min: 5.4 +/- 0.5%, and 60 min: 3.9 +/- 0.5%, P 0.05 vs. baseline). Protocol 2 (n = 5) was similar to protocol 1 except that the first period of mental stress was followed by either exercise in which the brachial artery shear rate was attenuated via forearm cuff inflation or exercise without a cuff. Noncuffed exercise prevented the reduction in FMD (baseline: 7.5 +/- 0.7%, 30 min: 7.0 +/- 0.7%, and 60 min: 8.7 +/- 0.8%, P > 0.05 vs. baseline), whereas cuffed exercise failed to prevent this reduction (baseline: 7.5 +/- 0.6%, 30 min: 5.4 +/- 0.8%, and 60 min: 4.1 +/- 0.9%, P < 0.05 vs. baseline). in conclusion, exercise prevented mental stress-induced endothelial dysfunction among subjects with MetS, and an increase in shear rate during exercise mediated this effect.Brazilian National Council of Scientific and Technological DevelopmentFoundation of Research Support of Rio de Janeiro StateCoordination for the Improvement of Higher Education PersonnelBrazilian Funding Agency for Studies and ProjectsUniv Fed Fluminense, Dept Physiol & Pharmacol, Lab Exercise Sci, BR-24210130 Niteroi, RJ, BrazilUniversidade Federal de São Paulo, Dept Physiol, Sect Exercise Physiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, Sect Exercise Physiol, São Paulo, BrazilWeb of Scienc
SIMULAÇÃO COMPUTACIONAL DO RESFRIAMENTO DA MANGA TOMMY ATKINS
Este trabalho tem como objetivo simular o resfriamento da manga Tommy Atkins através do software ANSYS Mechanical, evidenciando a capacidade dos processos de simulação computacional aplicada na agricultura como uma opção na predição do comportamento termofísico de produtos agrícolas. O método, de pequeno custo computacional, mostrou-se apropriado para a caracterização do processo de resfriamento, tendo como benefício a aplicabilidade para outros produtos agrícolas
On the use of organic semiconductors as handles for optical tweezers experiments: trapping and manipulating polyaniline (PANI) microparticles
Here we propose the use of the organic semiconductor polyaniline (PANI) for
the preparation of spherical-shaped microparticles to serve as handles in
optical tweezers (OT) experiments. The stable trapping and manipulation of PANI
beads was demonstrated for the first time, using a Gaussian () beam
optical tweezers. The trap stiffness was characterized for various different
parameters such as the bead radius, the laser power and the distance between
the bead and the coverslip of the sample chamber, attesting the viability of
using such material for optical manipulation. Since the effective optical
properties of PANI can be modulated by the synthesis process, new related
applications are also proposed. The results of the present work therefore open
the door for using semiconductor polymeric materials in OT applications.Comment: 10 pages and 5 figure
Structural changes in intestinal enteroendocrine cells after ileal interposition in normal rats
INTRODUCTION: No therapeutic approach has significantly impacted the progression of diabetes. As early improvement of glicaemic control is observed after bariatric surgeries, there is currently a search for surgical procedures that can promote euglycemia also in non-obese patients. Glicaemic control can be achieved by increasing the blood concentration of GLP-1, a hormone produced by L cells that are more densely concentrated in the terminal ileum. The interposition of ileal segment to a more anterior region (proximal jejunum) can promote a greater stimulation of the L cells by poorly digested food, increasing the production of GLP-1 and reflecting on glicaemic control.
AIMS: To investigate long-term histological modifications of intestinal mucosa of rats submitted to interposition of ileum segment to a proximal region (jejunum).
METHODS: Forty 8-week old male Wistar-EPM1 rats (Rattus norvegicus albinus) were randomly distributed into 3 groups: the Interposition Group (IG) was subjected to ileal interposition, the Sham Group (SG) was subjected to sham operations, and the Control Group (CG) was not subjected to surgery. All animals were followed until the 60th postoperative day (8 postoperative week) when they were euthanized. Segments of jejunum and ileum from all groups were collected and analyzed by optical microscopy and immunohistochemistry.
RESULTS: No structural nor histological changes in intestinal L cells in the interposed intestinal segment and other intestinal segments were noted after ileal interposition surgery. 
CONCLUSION: As L cells endocrine characteristics were likely maintained, the use of metabolic surgical techniques for the treatment of metabolic diseases, especially diabetes, seems to be justified
Will an ancient refuge become a modern one? A critical review on the conservation and research priorities for the red squirrel (Sciurus vulgaris) in the Iberian peninsula
Mediterranean peninsulas are well-known glacial refugia for several mammal species. For Eurasian red squirrel ( Sciurus vulgaris ), a forest-dwelling rodent, there is some evidence that population diversification was influenced by these refugia. Here, we review the poorly known history of the red squirrel in the Iberian Peninsula, and discuss current threats to this species, suggesting conservation guidelines and exploring several research lines for forthcoming studies. Red squirrel populations suffered several bottlenecks in Iberia, but recently, after four centuries of absence, this species is expanding throughout the Portuguese territory. Although S. vulgaris taxonomic and genetic status needs further investigation, molecular data support the occurrence of a possible distinct cluster in the Iberian Peninsula. Additionally, a distinct and endemic population was recorded to the Sierra de Espuña, in Spain, which was probably the result of Quaternary climatic and vegetation fluctuations. Two major threats for red squirrels in Europe were identified: (i) habitat deterioration; and (ii) competition with the invasive Eastern grey squirrel ( S. carolinensis ). Conservation actions should focus on the conservation, restoration and appropriate management of suitable forested habitats. Although to date no grey squirrels occur in the wild in the Iberia, the trade and release of this invasive sciurid species is already forbidden by national conservation agencies in both Iberian countries and awareness campaigns are suggested. An integrated research approach using both molecular and ecological data, and a large dataset containing samples from the entire Iberian Peninsula, should be followed to better understand historical, contemporary and future factors that may affect squirrel distribution
Eccentric Exercise Leads To Glial Activation But Not Apoptosis In Mice Spinal Cords.
The aim of this investigation was to evaluate the effects of 3 overtraining (OT) protocols on the glial activation and apoptosis in the spinal cords of mice. Rodents were divided into control (C; sedentary mice), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR). The incremental load test, ambulation test, exhaustive test and functional behavioural assessment were used as performance evaluation parameters. 36 h after the exhaustive test, the dorsal and ventral parts of the lumbar spinal cord (L4-L6) were dissected for subsequent protein analysis by immunoblotting. The OT protocols led to similar responses of some performance parameters. The ventral glial fibrillary acidic protein (GFAP) protein levels were diminished in the OTR/up and OTR compared to CT and OTR/down groups. The ventral ionized calcium binding adaptor molecule 1 (Iba-1), and the dorsal GFAP and Iba-1 protein levels were increased in the OTR/down compared to the other groups. The ratio between the cleaved capase-3/caspase-3 and cleaved caspase-9/caspase-9 measured in the spinal cord were not sensitive to the OT protocols. In summary, the OTR/down activated the glial cells in the motor (i. e. Iba-1) and sensory (i. e. GFAP and Iba-1) neurons without leading to apoptosis
Continuous Electrical Current and Zinc Sulphate Administered by Transdermal Iontophoresis Improves Skin Healing in Diabetic Rats Induced by Alloxan: Morphological and Ultrastructural Analysis
Purpose. Evaluated the effects of continuous electrical current (CEC) or zinc administrated by transdermal iontophoresis (Zn+TDI). Methods. 120 male Wistar rats were submitted to an incision surgery at the anterior region of abdomen and distributed into 6 experimental groups with 40 animals: 3 diabetic groups and 3 normal groups, untreated and treated with CEC alone or with Zn + TDI. Each group was further divided into 4 subgroups with 10 rats each to be evaluated on the 4th, 7th, 14th, and 21st day after surgery. In each period, clinical and laboratory parameters from the animals were analyzed. Results. The analysis by optical and scanning electron microscopy showed a delay in the phases of wound healing in diabetic rats without treatment in all periods of the experiment; breaking strength (BS) was significantly reduced in skin scars of untreated diabetic rats when compared to other groups. In contrast, BS in skin scars of nondiabetic groups and diabetic rats treated with Zn + TDI showed significant increase in those, besides not presenting delayed healing. Conclusion. Electrical stimulation of surgical wounds used alone or in association with zinc by TDI is able to consistently improve the morphological and ultrastructural changes observed in the healing of diabetic animals
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