Tomographic Simulations of Accretion Disks in Cataclysmic Variables - Flickering and Wind

Both continuum and emission line flickering are phenomena directly associated with the mass accretion process. In this work we simulate accretion disk Doppler maps including the effects of winds and flickering flares. Synthetic flickering Doppler maps are calculated and the effect of the flickering parameters on the maps is explored. Jets and winds occur in many astrophysical objects where accretion disks are present. Jets are generally absent among the cataclysmic variables (CVs), but there is evidence of mass loss by wind in many objects. CVs are ideal objects to study accretion disks and consequently to study the wind associated with these disks. We also present simulations of accretion disks including the presence of a wind with orbital phase resolution. Synthetic H-alpha line profiles in the optical region are obtained and their corresponding Doppler maps are calculated. The effect of the wind simulation parameters on the wind line profiles is also explored. From this study we verified that optically thick lines and/or emission by diffuse material into the primary Roche lobe are necessary to generate single peaked line profiles, often seen in CVs. The future accounting of these effects is suggested for interpreting Doppler tomography reconstructions.Comment: 9 pages, 9 figure

Monitorização de pragas associadas à amendoeira em Alfândega-da-Fé (Trás-os-Montes)

Trás-os-Montes é uma das principais regiões produtoras de amêndoa em Portugal. Esta cultura apresenta problemas fitossanitários associados a pragas que podem originar estragos significativos na produção da planta. A monitorização dessas pragas constitui um aspeto importante com vista a uma correta tomada de decisão no que diz respeito ao combate a efetuar contra cada espécie. O objetivo deste trabalho foi monitorizar as populações das principais pragas da amendoeira, nomeadamente Tetranychus urticae koch, Monosteira unicostata (Mulsant & Rey, 1852), Anarsia lineatella Zeller, Grapholita molesta (Busck), Cossus cossus L. e Zeuzera pyrina L. na zona de Alfândega-da-Fé, em Trás-os-Montes. Para a monitorização das populações de aranhiço-amarelo T. urticae e de M. unicostata realizaram-se observações entre meados de julho e meados de agosto de 2015 em um amendoal não regado através da colheita de 20 folhas em 20 árvores em cada uma das variedades "Giorieta" e "Masbovera" e, no laboratório, contaram-se ovos, ninfas e adultos de T. urticae e adultos de M. unicostata. Para a monitorização de A. lineatella, G. molesta, C. cossus e Z. pyrina instalaram-se, em dois amendoais (um regado e outro não regado), três armadilhas delta com feromona para captura das duas primeiras espécies e três armadilhas tipo funil com feromona para captura das duas segundas. Estas armadilhas permaneceram instaladas desde inícios de maio até finais de novembro de 2015. Não se verificaram diferenças significativas entre as populações de T. urticae e de M. unicostata capturadas nas duas variedades de amendoeira, nem entre as populações das restantes pragas capturadas nos dois amendoais. As populações de T. urticae registaram um pico de abundância em meados de julho e foi atingido o seu nível económico de ataque. As populações de A. lineatel/o e de G. molesta atingiram níveis populacionais relativamente elevados (com um pico médio de capturas de 74 e 9 indivíduos, respetivamente), mas apenas 1 indivíduo de C. cossus e 1 de Z. pyrina foram capturados. Estes resultados permitiram conhecer os níveis populacionais das pragas associadas à amendoeira e fazer recomendações, aos parceiro do projeto, sobre a melhor ocasião para efetuar o tratamento fitossanitário.Este trabalho foi realizado no âmbito do projeto PRODER 54610 - Estratégias integradas para o aumento da produtividade da amendoeira em Trás-osMontes, financiado pelo Programa de Desenvolvimento Rural (PRODER) no âmbito da medida 4.1 - Cooperação para a Inovação (Apoio à Inovação na Agricultura, Agroindústria e Floresta).info:eu-repo/semantics/publishedVersio

Functional Characterization of a Novel Family of Acetylcholine-Gated Chloride Channels in Schistosoma mansoni

Acetylcholine is the canonical excitatory neurotransmitter of the mammalian neuromuscular system. However, in the trematode parasite Schistosoma mansoni, cholinergic stimulation leads to muscle relaxation and a flaccid paralysis, suggesting an inhibitory mode of action. Information about the pharmacological mechanism of this inhibition is lacking. Here, we used a combination of techniques to assess the role of cholinergic receptors in schistosome motor function. The neuromuscular effects of acetylcholine are typically mediated by gated cation channels of the nicotinic receptor (nAChR) family. Bioinformatics analyses identified numerous nAChR subunits in the S. mansoni genome but, interestingly, nearly half of these subunits carried a motif normally associated with chloride-selectivity. These putative schistosome acetylcholine-gated chloride channels (SmACCs) are evolutionarily divergent from those of nematodes and form a unique clade within the larger family of nAChRs. Pharmacological and RNA interference (RNAi) behavioral screens were used to assess the role of the SmACCs in larval motor function. Treatment with antagonists produced the same effect as RNAi suppression of SmACCs; both led to a hypermotile phenotype consistent with abrogation of an inhibitory neuromuscular mediator. Antibodies were then generated against two of the SmACCs for use in immunolocalization studies. SmACC-1 and SmACC-2 localize to regions of the peripheral nervous system that innervate the body wall muscles, yet neither appears to be expressed directly on the musculature. One gene, SmACC-1, was expressed in HEK-293 cells and characterized using an iodide flux assay. The results indicate that SmACC-1 formed a functional homomeric chloride channel and was activated selectively by a panel of cholinergic agonists. The results described in this study identify a novel clade of nicotinic chloride channels that act as inhibitory modulators of schistosome neuromuscular function. Additionally, the iodide flux assay used to characterize SmACC-1 represents a new high-throughput tool for drug screening against these unique parasite ion channels

Linear and nonlinear models in wind resource assessment and wind turbine micro-siting in complex terrain

The current trend of increasing the electricity production from wind energy has led to the installation of wind farms in areas of greater orographic complexity, raising doubts on the use of simple, linear, mathematical models of the fluid flow equations, so common in the wind energy engineering. The present study shows how conventional techniques, linear models and cup anemometers, can be combined with flow simulation by computational fluid dynamics techniques (nonlinear models) and measurements by sonic anemometers, and discuss their relative merits in the characterisation of the wind over a coastal region—a cliff over the sea. The computational fluid dynamic techniques were particularly useful, providing a global view of the wind flow over the cliff and enabling the identification of separated flow regions, clearly unsuitable for installation of wind turbines. These locations display a pulsating flow, with periods between 1 and 7min, in agreement with sonic anemometer measurements, and both a turbulence intensity and a gust factor well above the wind turbine design conditions.The authors acknowledge the support of the Portuguese Foundation for Science and Technology (FCT), under research Project TURBWIND (POCI/ENR/60965/2004). Data from the field experiment were kindly supplied by EEM-Empresa de Electricidade da Madeira, SA.info:eu-repo/semantics/publishedVersio

Increase in ghrelin levels after weight loss in obese Zucker rats is prevented by gastric banding.

Obes Surg. 2007 Dec;17(12):1599-607. Epub 2007 Nov 30. Increase in ghrelin levels after weight loss in obese Zucker rats is prevented by gastric banding. Monteiro MP, Ribeiro AH, Nunes AF, Sousa MM, Monteiro JD, Aguas AP, Cardoso MH. Department of Anatomy and UMIB (Unit for Multidisciplinary Biomedical Research) of ICBAS (Abel Salazar Institute for the Biomedical Sciences), University of Porto, 4099-003 Porto, Portugal. [email protected] Abstract BACKGROUND: Gastric banding is thought to decrease appetite in addition to the mechanical effects of food restriction, although this has been difficult to demonstrate in human studies. Our aim was to investigate the changes in orexigenic signals in the obese Zucker rat after gastric banding. METHODS: Obese Zucker rats (fa/fa) were submitted to gastric banding (GBP), sham gastric banding fed ad libitum (sham), or sham operation with food restriction, pair-fed to the gastric banding group (sham-PF). Lean Zucker rats (fa/+) were used as additional controls. Body weight and food intake were daily recorded for 21 days after surgery when epididymal fat was weighed and fasting ghrelin and hypothalamic NPY mRNA expression were measured. RESULTS: Gastric banding in obese Zucker rats resulted in a significant decrease of cumulative body weight gain and food intake. Furthermore, gastric banded rats were leaner than Sham-PF, as expressed by a significantly lower epididymal fat weight. Ghrelin levels of gastric banded rats were not increased when compared to sham-operated animals fed ad libitum and were significantly lower than the levels of weight matched sham-PF rats (1116.9 +/- 103.3 g GBP vs 963.2 +/- 54.3 g sham, 3,079.5 +/- 221.6 sham-PF and 2,969.9 +/- 150.9 g lean rats, p < 0.001); hypothalamic NPY mRNA expression was not increased in GBP when compared to sham-operated rats. CONCLUSION: In obese Zucker rats, GBP prevents the increase in orexigenic signals that occur during caloric deprivation. Our data support the hypothesis that sustained weight loss observed after gastric banding does not depend solely on food restriction

Diversity and bioactive potential of actinobacteria isolated from a coastal marine sediment in Northern Portugal

Natural compounds have had increasing applications in the biotechnological sector, with a large fraction of these substances being channeled to the pharmaceutical industry due to their important pharmacological properties. The discovery of new bioactive molecules with novel mechanisms of action constitutes a promising solution for the design of alternative therapeutic solutions. Actinobacteria are a large group of morphologically and physiologically diverse bacteria well known for their production of biotechnologically relevant compounds. The Portuguese coast is scantly explored in terms of Actinobacteria diversity and respective bioactive potential, offering a good opportunity to find new Actinobacteria taxa and bioactive natural products. In this study, we investigated the Actinobacteria diversity associated with a sediment sample collected from the intertidal zone of a beach in northern Portugal, through a cultivation-dependent approach, and screened its antimicrobial and cytotoxic potential. A total of 52 Actinobacteria strains were recovered from the marine sediment, with the largest fraction of the isolates belonging to the genus Micromonospora. Bioactivity screening assays identified crude extracts of six Streptomyces strains active against C. albicans, exhibiting minimum inhibition concentration (MIC) values in the range of 3.90–125 μg mL−1. Twenty-five Actinobacteria crude extracts (obtained from strains of the genera Micromonospora, Streptomyces and Actinomadura) exhibited significant effects on the viability of at least one tested cancer cell line (breast ductal carcinoma T-47D and liver hepatocellular carcinoma HepG2). The Actinobacteria extracts demonstrating activity in the antimicrobial and/or cytotoxic assays were subjected to metabolomic analysis (Mass spectrometry (MS)-based dereplication and molecular networking analyses), indicating the presence of four clusters that may represent new natural products. The results obtained demonstrate the importance of bioprospecting underexplored environments, like the Portuguese coast, for enhancing the discovery of new natural products, and call attention to the relevance of preserving the natural genetic diversity of coastal environments.This work was funded by the structured program of R&D&I ATLANTIDA - Platform for the monitoring of the North Atlantic Ocean and tools for the sustainable exploitation of the marine resources (reference NORTE-01-0145-FEDER-000040), supported by the North Portugal Regional Operational Programme (NORTE2020), through the European Regional Development Fund (ERDF). It was also supported by the strategic funding UIDB/04423/2020 and UIDP/04423/2020 through national funds provided by FCT

The use of TFBGF method with a 3D transient analytical solution to solve an inverse heat conduction problem in the presence of a moving heat source

Moving heat source are present in numerous problem pratical in ingeenring. For example, machining process as the Gas tungsten arc welding (GTAW) , laser welding, friction stirwleing process or milding problem. Moving heat source are also present in biological heating as the metabolism or in heat thermal treatment. All this case, the heat input identification is a complex task and represents an important factor in the optimization of the process. The aim of this work is to investigate both the temperature field as the heat flux delivered to a piece during a process with moving heat source. The temperature measurements are obtained using thermocouples at accessible regions of the workpiece surface while the theoretical temperatures are calculated from a 3D transient heat conduction thermal model with a moving heat source. The thermal model solution is obtained analytically (direct problem). The inverse problem, it means, the estimation of the moving heat source, uses the Transfer Function Based on Green’s Function (TFBGF) method. This method is based on Green’s function and in the equivalence between thermal and dynamic systems. The technique is a simple approach without iterative processes, and therefore extremely fast. From the knowledge of both the temperature profile (hypothetical or experimental temperature far from the heat source) and of the transfer function it is possible to estimate the heat flux by an inverse procedure of the Fast Fourier Transform (IFFT) . The TFBGF is, then, adapted to solve an inverse heat conduction problem with a moving heat source. Simulated and experimental test are used for estimating the heat source delivered to the piece. The estimation of the moving heat source without use of minimization least square, or optimization technique is the great advantages of the technique proposed here. The moving heat source can, then, be obtained directly from the temperature measured since the 3D transient analytical solution is obtained and the TFBGF can be applied in that solution.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

CARACTERIZAÇÃO GRANULOMÉTRICA E HIDRODINÂMICA DOS SEDIMENTOS DEPOSITADOS NA LAGOA DO PONTAL, PIRAPORA-MG.

O trabalho apresenta a caracterização granulométrica dos sedimentos depositados na Lagoa do Pontal e sua relação com a hidrodinâmica do Rio São Francisco. Foram coletados testemunhos e identificadas 28 camadas sedimentares cujas frações granulométricas foram determinadas em Analisador de Partículas por difratometria. Os resultados indicam a predominância de sedimentos finos, depositados em ambiente de baixa energia intercalados por camadas arenosas associadas a eventos de mais alta energia

Inclusion of shrimp waste meal in diet of free-range chickens

Shrimp waste meal (SWM) is a by-product from the processing of shrimp for human consumption. The value of SMW in feeding poultry is not well documented. The objective of this study was to determine the energy value and optimal inclusion level of SWM in the diet of growing chickens. A total of 180 one-day-old broilers were randomly assigned to five treatments with 0, 50, 100, 150 and 200 g/kg of SWM included in their diet. There were six replicates of six birds for each treatment. Dry matter intake (DMI) was not affected by the level of SWM that was fed. Retained dry matter varied from 72.39% in the diet that did not contain SWM to 66.97% in the diet with 200 g/kg of SWM. Nitrogen retention (NR) ranged from 54.70% to 70.10%; N ingested was between 18.71% and 24.03%. Energy intake ranged from 73.57% to 69.33% for the control and the diet with 200 g/kg of SWM, respectively. NR improved with increasing SWM inclusion levels. The apparent metabolizable energy (AME) and corrected apparent energy metabolizable (AMEn) ranged from 2928 to 2527 kcal/kg and 2774 to 2329 kcal/kg, respectively, relative to the control and 200 g/kg SWM diets. The energy consumption, in kcal/kg, of SWM consumed was AME = 2332-6.971 x SWM and AMEn = 2113-8.128 x SWM. High levels of SWM reduce the dry matter metabolization coefficient and metabolizable energy values in broilers during the growing phase, so it is recommended that up to 100 g/kg should be included, which would provide an AMEn of 1300.2 kcal/kg for free-range chickens in dry matter