6,506 research outputs found

    Self-bound dense objects in holographic QCD

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    We study a self-bound dense object in the hard wall model. We consider a spherically symmetric dense object which is characterized by its radial density distribution and non-uniform but spherically symmetric chiral condensate. For this we analytically solve the partial differential equations in the hard wall model and read off the radial coordinate dependence of the density and chiral condensate according to the AdS/CFT correspondence. We then attempt to describe nucleon density profiles of a few nuclei within our framework and observe that the confinement scale changes from a free nucleon to a nucleus. We briefly discuss how to include the effect of higher dimensional operator into our study. We finally comment on possible extensions of our work.Comment: 17 pages, 5 figures, figures replaced, minor revision, to appear in JHE

    Candida esophageal perforation and esophagopleural fistula: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Esophageal perforation is a rare disease, which can lead to significant morbidity and mortality. Its clinical presentation can mimic other disease processes and, therefore, it can be easily misdiagnosed. <it>Candida </it>infection of the esophagus is an extremely rare cause of esophageal perforation.</p> <p>Case presentation</p> <p>We report the youngest pediatric case in the medical literature of spontaneous esophageal perforation and an esophagopleural fistula due to <it>Candida </it>infection.</p> <p>Conclusion</p> <p>A high index of suspicion, especially in the presence of <it>Candida </it>empyema and the absence of disseminated infection, should raise the possibility of esophageal perforation with esophagopleural fistula formation. This can lead to early diagnosis and surgical intervention, which would decrease the high mortality rate of this rare condition.</p

    Economic Impact of a Rotavirus Vaccine in Brazil

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    The study was done to evaluate the cost-effectiveness of a national rotavirus vaccination programme in Brazilian children from the healthcare system perspective. A hypothetical annual birth-cohort was followed for a five-year period. Published and national administrative data were incorporated into a model to quantify the consequences of vaccination versus no vaccination. Main outcome measures included the reduction in disease burden, lives saved, and disability-adjusted life-years (DALYs) averted. A rotavirus vaccination programme in Brazil would prevent an estimated 1,804 deaths associated with gastroenteritis due to rotavirus, 91,127 hospitalizations, and 550,198 outpatient visits. Vaccination is likely to reduce 76% of the overall healthcare burden of rotavirus-associated gastroenteritis in Brazil. At a vaccine price of US78perdose,thecosteffectivenessratiowouldbeUS 7-8 per dose, the cost-effectiveness ratio would be US 643 per DALY averted. Rotavirus vaccination can reduce the burden of gastroenteritis due to rotavirus at a reasonable cost-effectiveness ratio

    Prediction of tuberculosis clusters in the riverine municipalities of the Brazilian Amazon with machine learning

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    ABSTRACT Objective: Tuberculosis (TB) is the second most deadly infectious disease globally, posing a significant burden in Brazil and its Amazonian region. This study focused on the “riverine municipalities” and hypothesizes the presence of TB clusters in the area. We also aimed to train a machine learning model to differentiate municipalities classified as hot spots vs. non-hot spots using disease surveillance variables as predictors. Methods: Data regarding the incidence of TB from 2019 to 2022 in the riverine town was collected from the Brazilian Health Ministry Informatics Department. Moran’s I was used to assess global spatial autocorrelation, while the Getis-Ord GI* method was employed to detect high and low-incidence clusters. A Random Forest machine-learning model was trained using surveillance variables related to TB cases to predict hot spots among non-hot spot municipalities. Results: Our analysis revealed distinct geographical clusters with high and low TB incidence following a west-to-east distribution pattern. The Random Forest Classification model utilizes six surveillance variables to predict hot vs. non-hot spots. The machine learning model achieved an Area Under the Receiver Operator Curve (AUC-ROC) of 0.81. Conclusion: Municipalities with higher percentages of recurrent cases, deaths due to TB, antibiotic regimen changes, percentage of new cases, and cases with smoking history were the best predictors of hot spots. This prediction method can be leveraged to identify the municipalities at the highest risk of being hot spots for the disease, aiding policymakers with an evidenced-based tool to direct resource allocation for disease control in the riverine municipalities

    Short-Term Soil Organic Matter and Carbon Responses to Contrasting Grazing Intensities in Integrated Crop-Livestock Systems

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    Combining integrated crop-livestock systems under no-till management may improve soil organic matter (SOM) build up and improve soil C sequestration. Grazing cover crops appears as a possibility to combine crops and livestock in a farm system. Further SOM and soil C increase can be achieved by adding perennial grasses into crop rotations. However, the effect of grazing intensity in such systems are not fully understood. This 2-yr study investigated short-term effects of cropping system [winter cover crops-summer cotton (Gossypium hirsutum L.) and winter cover crops-summer bahiagrass (Paspalum notatum Flüggé) rotations], grazing intensity (no grazing, heavy, moderate, and light grazing), and N fertilization (34 and 90 kg N ha-1 ), on OM and soil C of the soil-surface (0-15 cm) and deep-soil (0-90 cm) under no-till. Preliminary results indicate that treatments containing bahiagrass improved SOM in 1.5 g kg-1 compared to winter grazing on cover crops-cotton systems (P = 0.017). There were no differences among treatments for soil total C stock (15.4 Mg ha-1) and particulate OM-C (4.8 Mg ha-1) at the 15-cm depth (P \u3e 0.1). Carbon concentration increased from 8.0 to 12.6 g kg-1 as aggregate fraction decreased from 250 – 2000 to \u3c 53 µm (P \u3c 0.001). Nonetheless, C stock was not affected by aggregate fraction, with each fraction containing 3.8 Mg C ha-1, on average. Carbon stocks from 0-15, 15-30, 30-60, and 60-90-cm depths did not differ among treatments (P = 0.743), totalizing 30.4 Mg C ha-1 in the soil profile. Long-term studies are necessary to better understand the role of cropping system and grazing intensities on soil OM and C responses on surface and deep soil

    The effect of music on discomfort during lumbar spine SPECT scintigraphy

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    Single-photon emission computed tomography (SPECT) imaging forms part of the bone scintigraphy examination to significantly improve the detection of skeletal lesions. It has been observed that patients undergoing lumbar spine SPECT scintigraphy frequently complain of general discomfort in the shoulder girdle. Music has been used as an intervention during medical procedures or imaging examinations in an attempt to relieve discomfort and anxiety. The aim of this study was to determine the effect of music, as an intervention, on the perceived discomfort in the shoulder girdle during lumbar spine SPECT scintigraphy. A pretest-posttest quasi-experimental design with two groups was used to conduct this study. Ninety-six consecutive patients routinely referred for lumbar spine SPECT scintigraphy were recruited from two private nuclear medicine practices in Gauteng. Patients were systematically assigned to the control or experimental group. Patients were asked to rate their discomfort at various time points. The results indicate that the group exposed to music as an intervention more frequently reported a decrease in discomfort as compared with the control group. The experimental group also reported less percentage increase in discomfort. There were statistically significant differences in discomfort scores 10 min into the SPECT and after the SPECT between the control and intervention groups. Discomfort scores of the control group had a noticeable increase after the SPECT had started. Music as an intervention during SPECT imaging is more of a distraction than an analgesic and can be used to increase patient comfort and the patients’ experience.http://www.sciencedirect.com/journal/journal-of-radiology-nursing2021-09-02hj2020Radiograph

    Impact of a program of diagnostic imaging quality control in mammography centers of the Federal District, Brazil

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    OBJETIVO: Esta pesquisa visou a avaliar a qualidade dos serviços de mamografia do Distrito Federal e o impacto de uma intervenção de inspeção e capacitação. MATERIAIS E MÉTODOS: Foram estudados 41 serviços de mamografia no Distrito Federal no período de 2000 a 2002. A intervenção consistiu na inspeção inicial seguida de um treinamento e notificação oficial da Vigilância Sanitária. Os resultados de qualidade da imagem foram comparados "antes" e "depois" da intervenção. RESULTADOS: O estudo demonstrou que dos 36 serviços que completaram a pesquisa, nenhum estava acima de 90% de conformidade antes da intervenção. Após a intervenção, dez unidades atingiram mais de 90%. As principais melhorias foram em relação aos chassis, compressão da mama e visualização de microcalcificações. CONCLUSÃO: Apesar de o Distrito Federal dispor de muitos serviços, na sua maioria não eram de qualidade. A intervenção foi eficaz para a melhoria da qualidade, porém, torna–se necessária uma ação continuada para resolver os problemas restantes e aumentar o impacto. _________________________________________________________________________________ ABSTRACTOBJECTIVE: The present study was aimed at evaluating the quality and the impact of an intervention involving inspection and education in mammography centers of the Federal District, Brazil. MATERIALS AND METHODS: Forty one mammography centers in the Federal District were studied in the period between 2000 and 2002. The intervention involved an initial inspection followed by a training activity and notification of mammography centers by the Federal District Sanitary Vigilance authority. The imaging quality was compared before and after the intervention. RESULTS: None of the 36 centers which completed the study reached more than 90% compliance with the standard imaging quality prior to the interventions, whereas ten were above 90% afterwards. Major improvements were observed in chassis maintenance, breast compression and visualization of microcalcifications. CONCLUSION: Despite the availability of a great number of mammography centers in the Federal District, most of them did not meet the required quality standards. The intervention has shown to be effective for improving the imaging quality, however a continued action is required to solve the remaining problems and increase the impact of the program

    The brain decade in debate: I. Neurobiology of learning and memory

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    This article is a transcription of an electronic symposium in which some active researchers were invited by the Brazilian Society for Neuroscience and Behavior (SBNeC) to discuss the last decade's advances in neurobiology of learning and memory. The way different parts of the brain are recruited during the storage of different kinds of memory (e.g., short-term vs long-term memory, declarative vs procedural memory) and even the property of these divisions were discussed. It was pointed out that the brain does not really store memories, but stores traces of information that are later used to create memories, not always expressing a completely veridical picture of the past experienced reality. To perform this process different parts of the brain act as important nodes of the neural network that encode, store and retrieve the information that will be used to create memories. Some of the brain regions are recognizably active during the activation of short-term working memory (e.g., prefrontal cortex), or the storage of information retrieved as long-term explicit memories (e.g., hippocampus and related cortical areas) or the modulation of the storage of memories related to emotional events (e.g., amygdala). This does not mean that there is a separate neural structure completely supporting the storage of each kind of memory but means that these memories critically depend on the functioning of these neural structures. The current view is that there is no sense in talking about hippocampus-based or amygdala-based memory since this implies that there is a one-to-one correspondence. The present question to be solved is how systems interact in memory. The pertinence of attributing a critical role to cellular processes like synaptic tagging and protein kinase A activation to explain the memory storage processes at the cellular level was also discussed.University of Bristol Department of PsychologyUniversidade Federal de São Paulo (UNIFESP) Departamento de PsicobiologiaUniversity of California Center for Neurobiology of Learning and Memory Department of Neurobiology and BehaviorUniversity of California Neuropsychiatric InstituteUniversidade Federal do Rio Grande do Sul Instituto de Biociências Departamento de BioquímicaUniversity of Edinburgh Department of NeuroscienceUniversity of Arizona Department of PsychologyNorthwestern UniversityUniversidade de São Paulo Instituto de Biociências Departamento de FisiologiaUniversidade Federal do Paraná Departamento de Farmacologia Laboratório de Fisiologia e Farmacologia do Sistema Nervoso CentralUNIFESP, Depto. de PsicobiologiaSciEL

    Remoção de nitratos de águas em biorreatores com suporte de sabugo de milho e espuma de poliuretano

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    A presença de nitrato em corpos d’água pode causar danos ambientais e, se consumido, ao ser humano. Estudos mostram que biorreatores preenchidos com suportes orgânicos são eficientes na remoção de nitratos de águas de drenagem agrícola, que são ricas em nutrientes. Este trabalho teve como objetivo avaliar a remoção de nitratos em biorreator de leito fixo preenchido com dois tipos de meio suporte: R1 (Reator 1), com pedaços de sabugo de milho, e R2 (Reator 2), com pedaços de sabugo de milho e Mini Biobobs®. Os reatores foram alimentados com água de drenagem agrícola enriquecida com 20 mg.L-1 de N-NO3 e operados com tempos de detenção hidráulica (TDH) de 96, 48, 24 e 16 horas. Observou-se que, com exceção dos ensaios com TDH = 16 h, todos os demais apresentaram efluente com concentração de N-NO3 abaixo de 10 mg.L-1, que atende aos padrões exigidos pela legislação brasileiras para potabilidade de água para consumo humano. Através da técnica de NMP constatou-se a presença de bactérias desnitrificantes em ambos os reatores, comprovando a remoção do nitrato pelo processo de desnitrificação heterotrófica. Pode-se concluir que os reatores estudados são eficientes na remoção de nitratos de águas.
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