6,806 research outputs found
The Effect of Pressure Gradient on the Aeroacoustics and WakDynamics of a Finite Wall-Mounted Square Cylinder
This paper reports an experimental investigation of the wake flow structures and noise production of a square finite-wall-mounted cylinder (FWMC) with an aspect ratio of 2.4. The cylinder was immersed in flows with favourable-, near-zero-and adverse-pressure gradients at a Reynolds number of 48000, based on cylinder width. Acoustic and particle image velocimetry measurements were taken simultaneously using the newly developed open-jet pressure gradient test rig in the UNSW Anechoic Wind Tunnel. An adverse pressure gradient was found to enhance the cylinder junction upwash, weaken the free-end downwash and suppress the primary tonal noise at a Strouhal number of approximately 0.1. Conversely, a favourable-pressure gradient promotes downwash over the free-end and leads to a higher tonal noise level. Wake flow structures that correlated with the far-field sound pressure were identified to understand noise generation or suppression mechanisms
Free radical scavenging activity of Pterogyne nitens Tul. (Fabaceae)
As part of our ongoing research on antioxidant agents from Brazilian flora, twenty extracts and fractions obtained from Pterogyne nitens Tulasne (Fabaceae) were screened for free radical scavenging activity by using ABTS [2,2’-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl-hydrate) radicals colorimetric assay and -carotene bleaching test. The strongest activity was found in ethyl acetate fraction from the stem barks, exhibiting IC50 values (inìg/ml) of 2.10 ± 0.1 and 10.2 ± 0.3 on ABTS•+ and DPPH•, respectively. Additionally, chromatographic fractionation of stem barks yielding myricetin, quercitrin and mirycetrin, three flavonols with remarkable antioxidant activity
Suicide first aid guidelines for Sri Lanka: a Delphi consensus study.
BACKGROUND: Sri Lanka has one of the highest suicide rates in the world. Gatekeeper programs aimed at specific target groups could be a promising suicide prevention strategy in the country. The aim of this study was to develop guidelines that help members of the public to provide first aid to persons in Sri Lanka who are at risk of suicide. METHODS: The Delphi method was used to elicit consensus on potential helping statements to include in the guidelines. These statements describe information members of the public should have and actions they can take to help a person who is experiencing suicidal thoughts. An expert panel, comprised of mental health and suicide experts in Sri Lanka, rated each statement. The panellists were encouraged to suggest any additional action that was not included in the original questionnaire and, in particular, to include items that were culturally appropriate or gender specific. Responses to open-ended questions were used to generate new items. These items were included in the subsequent Delphi rounds. Three Delphi rounds were carried out. Statements were accepted for inclusion in the guidelines if they were endorsed (rated as essential or important) by at least 80Â % of the panel. Statements endorsed by 70-79Â % of the panel were re-rated in the following round. Statements with less than 70Â % endorsement, or re-rated items that did not receive 80Â % or higher endorsement were rejected. RESULTS: The output from the Delphi process was a set of endorsed statements. In the first round questionnaire 473 statements were presented to the panel and 58 new items were generated from responses to the open-ended questions. Of the total 531 statements presented, 304 were endorsed. These statements were used to develop the suicide first aid guidelines for Sri Lanka. CONCLUSION: By engaging Sri Lankans who are experts in the field of mental health or suicide this research developed culturally appropriate guidelines for providing mental health first aid to a person at risk of suicide in Sri Lanka. The guidelines may serve as a basis for developing training for members of the public to provide mental health first aid to persons at risk of suicide as part of Sri Lanka's suicide prevention strategy
Transmission potential, skin inflammatory response, and parasitism of symptomatic and asymptomatic dogs with visceral leishmaniasis
<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis in Brazil is caused by the protozoan <it>Leishmania (Leishmania) chagasi </it>and it is transmitted by sandfly of the genus <it>Lutzomyia</it>. Dogs are an important domestic reservoir, and control of the transmission of visceral leishmaniasis (VL) to humans includes the elimination of infected dogs. However, though dogs are considered to be an important element in the transmission cycle of <it>Leishmania</it>, the identification of infected dogs representing an immediate risk for transmission has not been properly evaluated. Since it is not possible to treat infected dogs, they are sacrificed when a diagnosis of VL is established, a measure that is difficult to accomplish in highly endemic areas. In such areas, parameters that allow for easy identification of reservoirs that represents an immediate risk for transmission is of great importance for the control of VL transmission. In this study we aimed to identify clinical parameters, reinforced by pathological parameters that characterize dogs with potential to transmit the parasite to the vector.</p> <p>Results</p> <p>The major clinical manifestations of visceral leishmaniasis in dogs from an endemic area were onicogriphosis, skin lesions, conjunctivitis, lymphadenopathy, and weight loss. The transmission potential of these dogs was assessed by xenodiagnosis using <it>Lutzomyia longipalpis</it>. Six of nine symptomatic dogs were infective to <it>Lutzomyia longipalpis </it>while none of the five asymptomatic dogs were infective to the sandfly. <it>Leishmania </it>amastigotes were present in the skin of all clinically symptomatic dogs, but absent in asymptomatic dogs. Higher parasite loads were observed in the ear and ungueal region, and lower in abdomen. The inflammatory infiltrate was more intense in the ears and ungueal regions of both symptomatic and asymptomatic dogs. In clinically affected dogs in which few or none <it>Leishmania </it>amastigotes were observed, the inflammatory infiltrate was constituted mainly of lymphocytes and macrophages. When many parasites were present, the infiltrate was also comprised of lymphocytes and macrophages, as well as a larger quantity of polymorphonuclear neutrophils (PMNs).</p> <p>Conclusion</p> <p>Dogs that represent an immediate risk for transmission of <it>Leishmania </it>in endemic areas present clinical manifestations that include onicogriphosis, skin lesions, conjunctivitis, lymphadenopathy, and weight loss. Lymphadenopathy in particular was a positive clinical hallmark since it was closely related to the positive xenodiagnosis.</p
Physiological and enzymatic changes in rice seeds stored at low temperatures
This study aimed to evaluate the effect of low temperatures on the physiological and enzymatic changes of rice seeds. The seeds were packed in airtight chambers and maintained at temperatures of 8 and -50°C for periods of 15, 30 , 45, 60, 75 and 90 days. The same procedure was adopted for the control treatment with the seeds kept at a temperature of 25°C. The seeds were evaluated regarding germination test; seedling emergency; emergency speed index; length and dry weight of radicle; and seedling of shoot. The activity of amylase and total protein content were also evaluated. The temperatures of 8 and -50°C significantly influenced the physiological quality and the enzyme amylase activity of rice seeds, resulting in higher germination, seedling emergence and enzyme activity. The temperature is a promising alternative for the maintenance of physiological quality and enzymatic activity of rice seeds during storage. Key words: Oryza sativa L., enzymatic activity, physiological quality, storage.Abbreviation: ESI, Emergence speed index; PVP, polyvinylpyrrolidone
Extensive Karyotype Reorganization in the Fish Gymnotus arapaima (Gymnotiformes, Gymnotidae) Highlighted by Zoo-FISH Analysis.
The genus Gymnotus (Gymnotiformes) contains over 40 species of freshwater electric fishes exhibiting a wide distribution throughout Central and South America, and being particularly prevalent in the Amazon basin. Cytogenetics has been an important tool in the cytotaxonomy and elucidation of evolutionary processes in this genus, including the unraveling the variety of diploid chromosome number (2n = from 34 to 54), the high karyotype diversity among species with a shared diploid number, different sex chromosome systems, and variation in the distribution of several Repetitive DNAs and colocation and association between those sequences. Recently whole chromosome painting (WCP) has been used for tracking the chromosomal evolution of the genus, showing highly reorganized karyotypes and the conserved synteny of the NOR bearing par within the clade G. carapo. In this study, painting probes derived from the chromosomes of G. carapo (GCA, 2n = 42, 30 m/sm + 12 st/a) were hybridized to the mitotic metaphases of G. arapaima (GAR, 2n = 44, 24 m/sm + 20 st/a). Our results uncovered chromosomal rearrangements and a high number of repetitive DNA regions. From the 12 chromosome pairs of G. carapo that can be individually differentiated (GCA1-3, 6, 7, 9, 14, 16, and 18-21), six pairs (GCA 1, 9, 14, 18, 20, 21) show conserved homology with GAR, five pairs (GCA 1, 9, 14, 20, 21) are also shared with cryptic species G. carapo 2n = 40 (34 m/sm + 6 st/a) and only the NOR bearing pair (GCA 20) is shared with G. capanema (GCP 2n = 34, 20 m/sm + 14 st/a). The remaining chromosomes are reorganized in the karyotype of GAR. Despite the close phylogenetic relationships of these species, our chromosome painting studies demonstrate an extensive reorganization of their karyotypes
Danos materiais causados à Saúde Pública e à sociedade decorrentes de inundações e enxurradas no Brasil, 2010-2014: dados originados dos sistemas de informação global e nacional
The Effects of Dasatinib in Experimental Acute Respiratory Distress Syndrome Depend on Dose and Etiology
Background/Aims: Evidence suggests that tyrosine-kinase inhibitors may attenuate lung inflammation and fibrosis in experimental acute respiratory distress syndrome (ARDS). We hypothesized that dasatinib, a tyrosine-kinase inhibitor, might act differently depending on the ARDS etiology and the dose. Methods: C57/BL6 mice were divided to be pre-treated with dasatinib (1mg/kg or 10mg/kg) or vehicle (1% dimethyl-sulfoxide) by oral gavage. Thirty-minutes after pre-treatment, mice were subdivided into control (C) or ARDS groups. ARDS animals received Escherichia coli lipopolysaccharide intratracheally (ARDSp) or intraperitoneally (ARDSexp). A new dose of dasatinib or vehicle was administered at 6 and 24h. Results: Forty-eight hours after ARDS induction, dasatinib 1mg/kg yielded: improved lung morphofunction and reduced cells expressing toll-like receptor (TLR)-4 in lung, independent of ARDS etiology; reduced neutrophil and levels of interleukin (IL)-6, IL-10 and transforming growth factor (TGF)-β in ARDSp. The higher dose of dasatinib caused no changes in lung mechanics, diffuse alveolar damage, neutrophil, or cells expressing TLR4, but increased IL-6, vascular endothelial growth factor (VEGF), and cells expressing Fas receptor in lung in ARDSp. In ARDSexp, it improved lung morphofunction, increased VEGF, and reduced cells expressing TLR4. Conclusion: Dasatinib may have therapeutic potential in ARDS independent of etiology, but careful dose monitoring is required. © 2015 S. Karger AG, Basel
Environmental enrichment for collared peccaries Dicotyles tajacu, Tayassuidae in managed care: Different items provoke different behavioural responses
Being in human care often modifies the behaviour of animals, mainly because of the lack of environmental stimuli, and the ease of finding food and reproductive partners. Animals in human care may have a poorer behavioural repertoire and lower welfare than their wild conspecifics. Environmental enrichment is a technique that introduces stimuli into enclosures, thereby enhancing the welfare of the animals. In the present study, the effect of different environmental-enrichment items on the behaviour of collared peccary Dicotyles tajacu was investigated. Basins with food, cardboard boxes filled with paper and food items, scent trails and piles of straw mixed with food items were provided to the peccaries. Behavioural recordings were made during the three phases of the experiment: baseline, enrichment and post-enrichment. The environmental enrichment items—especially the straw pile and cardboard boxes—increased exploratory behaviours, decreased inactivity and increased behavioural diversity in the collared peccaries. Enrichment items associated with food rewards resulted in the most significant positive changes in behaviour and should be used for collared peccaries in human care. An increased behavioural repertoire, with less inactivity and greater exploration of the environment, are important for animals that are under human-managed care and indicate an increase in animal welfare
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Chromosomal evolution and phylogenetic considerations in cuckoos (Aves, Cuculiformes, Cuculidae).
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