1,424 research outputs found

    Vortex generation in stirred binary Bose-Einstein condensates

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    The dynamical vortex production, with a trap-confining time-dependent stirred potential, is studied by using mass-imbalanced cold-atom coupled Bose-Einstein condensates (BEC). The vortex formation is explored by considering that both coupled species are confined by a pancake-like harmonic trap, slightly modified elliptically by a time-dependent periodic potential, with the characteristic frequency enough larger than the transversal trap frequency. The approach is applied to the experimentally accessible binary mixtures 85^{85}Rb-133^{133}Cs and 85^{85}Rb-87^{87}Rb, which allow us to verify the effect of mass differences in the dynamics. For both species, the time evolutions of the respective energy contributions, together with associated velocities, are studied in order to distinguish turbulent from non-turbulent flows. By using the angular momentum and moment of inertia mean values, effective classical rotation frequencies are suggested, which are further considered within simulations in the rotating frame without the stirring potential. Spectral analysis is also provided for both species, with the main focus being the incompressible kinetic energies. In the transient turbulent regime, before stable vortex patterns are produced, the characteristic k−5/3k^{-5/3} Kolmogorov behavior is clearly identified for both species at intermediate momenta kk above the inverse Thomas-Fermi radial positions, further modified by the universal k−3k^{-3} scaling at momenta higher than the inverse of the respective healing lengths. Emerging from the mass-imbalanced comparison, relevant is to observe that, as larger is the mass difference, much faster is the dynamical production of stable vortices.Comment: 17 pages, 16 figure

    Conhecimento sobre câncer de mama e câncer de mama hereditário entre enfermeiros em um hospital público

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    OBJETIVO: avaliar os conhecimentos de enfermeiros envolvidos nos cuidados de pacientes oncológicos em um hospital público universitário, em relação ao câncer de mama e ao câncer de mama hereditário e verificar o uso de tais conhecimentos em sua prática diária. MÉTODOS: este é um estudo transversal. Os dados foram obtidos por meio de um questionário estruturado autoaplicado. De um total de 154 enfermeiros convidados a participar do estudo, 137 (88,9%) concordaram. Dois questionários foram excluídos, totalizando 135 analisados. RESULTADOS: a porcentagem global de respostas corretas não estava associada à idade (p = 0,173) ou à formação/especialização (p = 0,815). As perguntas foram classificadas em categorias. Nas categorias que abrangiam conhecimentos relacionados aos fatores de risco estabelecidos para o câncer de mama e aos indicadores do câncer de mama hereditário, a taxa de respostas corretas foi de 65,8% e 66,4%, respectivamente. Em relação à prática de aconselhamento genético, 40,7% dos entrevistados não tinham certeza sobre a definição de aconselhamento genético, e 78,5% relataram nunca ter identificado ou encaminhado um paciente com risco genético para uma avaliação de riscos especializada. A prática de ações educativas em relação a esse tema foi relatada por 48,5% dos entrevistados. CONCLUSÃO: este estudo reforça a necessidade de desenvolver ações qualificadoras para enfermeiros de modo que as estratégias para o controle do câncer tornem-se eficientes em suas prática de cuidados de saúde.OBJETIVO: evaluar los conocimientos del personal de enfermería involucrado en el cuidado de los pacientes de oncología de un hospital universitario público, en relación con el cáncer de mama y el cáncer de mama hereditario, y verificar el uso de esos conocimientos en su práctica diaria. MÉTODOS: estudio descriptivo de corte transversal; los datos se obtuvieron mediante un cuestionario estructurado autoadministrado. De un total de 154 enfermeros/as, 137 (88,9%) aceptaron participar en el estudio. Se excluyeron dos cuestionarios, totalizando 135 cuestionarios analizados. RESULTADOS: el porcentaje global de respuestas correctas no se asoció con la edad (p=0,173) o título/especialización (p=0,815). Las preguntas fueron clasificadas en categorías. En las categorías que implican el conocimiento de los factores de riesgo establecidos del cáncer de mama y los indicadores del cáncer de mama hereditario, la tasa de respuestas correctas fue de 65,8% y 66,4%, respectivamente. En relación con la práctica del consejo genético, el 40,7% de los entrevistados/as no estaban seguros/as acerca de la definición de consejo genético y el 78,5% informó que nunca habían identificado o derivado a un paciente en situación de riesgo genético para una evaluación de riesgos especializada. La práctica de acciones educativas con respecto a este tema se reportó en el 48,5% de los entrevistados/as. CONCLUSIÓN: este estudio refuerza la necesidad de desarrollar acciones de calificación para el personal de enfermería, para que las estrategias de control del cáncer de mama sean efectivas en su práctica asistencial.OBJECTIVE: To assess the knowledge of nurses involved in the care of oncology patients in a public university hospital, regarding breast cancer and hereditary breast cancer, and to verify the use of such knowledge in their daily practice. METHODS: This is a descriptive cross-sectional study. Data were obtained through a structured, self-administered questionnaire. Out of 154 nurses, 137 (88.9%) agreed to participate in the study. Two questionnaires were excluded such that 135 questionnaires were analyzed. RESULTS: The global percentage of correct answers was not associated with age (p=0.173) or degree/specialization (p=0.815). Questions were classified into categories. In categories involving knowledge of established breast cancer risk factors and indicators of hereditary breast cancer, the rate of correct answers was 65.8% and 66.4%, respectively. On the practice of genetic counseling, 40.7% of those interviewed were not sure about the definition of genetic counseling and 78.5% reported never having identified or referred a patient at genetic risk for specialized risk assessment. Practice of educational actions regarding this subject was reported by 48.5% of those interviewed. CONCLUSION: This study reinforces the need to develop qualifying actions for nurses, so that strategies to control breast cancer become effective in their health care practice

    Cancer-related worry and risk perception in Brazilian individuals seeking genetic counseling for hereditary breast cancer

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    In Brazil, the population in general has little knowledge about genetic risks, as well as regarding the role and importance of the Cancer Genetic Counseling (CGC). The goal of this study was to evaluate cancer-related worry and cancer risk perception during CGC sessions in Brazilian women at-risk for hereditary breast cancer. This study was performed in 264 individuals seeking CGC for hereditary breast cancer. Both cancer-affected and unaffected individuals were included. As results, individuals with and without cancer reported different motivations for seeking CGC and undergoing genetic testing. A correlation was observed between age at the first CGC session and age at which the closest relative was diagnosed with cancer. Multivariate analysis showed that educational level, cancer risk discussion within the family, and number of deaths by cancer among first-degree relatives influenced positively the cancer risk perception. In conclusion, the results of this study indicate that cancer-related worry and cancer risk perception are significant aspects of morbidity in individuals seeking CGC, whether they are cancer-affected or unaffected. CGC has an important role in health education and cancer prevention for its potential of promoting an accurate perception of the risk

    Quantifying habitat provisioning at macroalgal cultivation sites.

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    Macroalgal cultivation is expanding rapidly, and promises to contribute significantly towards future food and energy security, sustainable livelihoods, ecosystem services and habitat provisioning for a range of associated organisms globally. Habitat provisioning underpins biodiversity and ecosystem structure and functioning, supports many ecosystem services and has possible benefits to other marine industries, including enhancement of commercial fish stocks. In macroalgal cultivation, however, only recently has habitat provisioning started to be assessed at a local scale (within a farm's footprint) and with a range of different approaches. This review evaluates techniques used to quantify habitat provisioning in and around macroalgal cultivation sites, for species ranging from microorganisms to megafauna, and outlines recommendations to enable a more comprehensive ecological valuation of macroalgal cultivation in the future. The majority of information on biodiversity associated with macroalgal cultivation is associated with quantifying biofouling or pest organisms, rather than the contribution of colonising species to healthy ecosystem functioning. We suggest how better monitoring of macroalgal cultivation could enable an ecosystem approach to aquaculture (EAA) in the future. To achieve this, we highlight the need for standardised and robust methods for quantifying habitat provisioning that will enable assessment and monitoring of macroalgal cultivation sites of varying scales and within different regions and environmental settings. Increased evidence for the potential habitat value of macroalgal cultivation sites will help inform and shape marine legislation, licencing and certification for macroalgal farmers and potentially reduce marine user conflicts, helping the industry to continue to grow sustainably using EAA

    Ultra-high field imaging, plasma markers and autopsy data uncover a specific rostral locus coeruleus vulnerability to hyperphosphorylated tau

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    Autopsy data indicate that the locus coeruleus (LC) is one of the first sites in the brain to accumulate hyperphosphorylated tau pathology, with the rostral part possibly being more vulnerable in the earlier stages of the disease. Taking advantage of recent developments in ultra-high field (7 T) imaging, we investigated whether imaging measures of the LC also reveal a specific anatomic correlation with tau using novel plasma biomarkers of different species of hyperphosphorylated tau, how early in adulthood these associations can be detected and if are associated with worse cognitive performance. To validate the anatomic correlations, we tested if a rostro-caudal gradient in tau pathology is also detected at autopsy in data from the Rush Memory and Aging Project (MAP). We found that higher plasma measures of phosphorylated tau, in particular ptau231, correlated negatively with dorso-rostral LC integrity, whereas correlations for neurodegenerative plasma markers (neurofilament light, total tau) were scattered throughout the LC including middle to caudal sections. In contrast, the plasma Aβ42/40 ratio, associated with brain amyloidosis, did not correlate with LC integrity. These findings were specific to the rostral LC and not observed when using the entire LC or the hippocampus. Furthermore, in the MAP data, we observed higher rostral than caudal tangle density in the LC, independent of the disease stage. The in vivo LC-phosphorylated tau correlations became significant from midlife, with the earliest effect for ptau231, starting at about age 55. Finally, interactions between lower rostral LC integrity and higher ptau231 concentrations predicted lower cognitive performance. Together, these findings demonstrate a specific rostral vulnerability to early phosphorylated tau species that can be detected with dedicated magnetic resonance imaging measures, highlighting the promise of LC imaging as an early marker of AD-related processes

    Retinoblastoma in a pediatric oncology reference center in southern brazil

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    Background: Retinoblastoma (Rb) is the most common intraocular tumor diagnosed in children in Brazil. However, detailed information is lacking regarding patient clinical demographics. This study aimed to determine the clinical profile of patients with Rb who were treated in a public university hospital in southern Brazil from 1983 to 2012. Methods: Patients’ medical records were reviewed to retrospectively identify patients with a principal diagnosis of Rb. Rb was classified as hereditary or non-hereditary. Clinical staging was reviewed by an ophthalmologist. Statistical analysis was performed using SPSS. Results: Of 165 patients with a diagnosis of Rb during this period, 140 were included in the study. Disease was unilateral in 65.0 % of patients, bilateral in 32.9 %, and trilateral in 2.1 %. The mean age at onset of the first sign/ symptom was 18.1 month, and 35.7 % of patients were diagnosed during the first year of life. The most common presenting signs were leukocoria (73.6 %) and strabismus (20.7 %). The mean age at diagnosis was 23.5 months, and time to diagnosis was 5.4 months. In patients with clinical features of hereditary Rb, both onset of the first sign/symptom and diagnosis were at an earlier age than in patients without these features (12.3 vs 21.6 months [P = 0.001] and 15.9 vs 28.0 months [P < 0.001], respectively). However, there was no significant difference in overall survival between the two groups. Ocular stage at diagnosis was advanced in 76.5 % (Reese V) and 78.1 % (International Classification D or E). Of patients with unilateral and bilateral disease, 35.2 % and 34.8 %, respectively, had extraocular disease at diagnosis; 10.7 % had metastatic disease at diagnosis. Enucleation was observed in 88.1 % and exenteration in 11.9 % of patients; 93.6 % patients were followed until 2012, and 22.9 % relapsed. Overall survival was 86.4 %. Conclusions: Most Rb diagnoses are still diagnosed in advanced stages of the disease, considerably reducing overall survival time and the rate of eye and vision preservation

    Increased oxidative damage in carriers of the germline TP53 p.R337H mutation

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    Germline mutations in TP53 are the underlying defect of Li-Fraumeni Syndrome (LFS) and Li-Fraumeni-like (LFL) Syndrome, autosomal dominant disorders characterized by predisposition to multiple early onset cancers. In Brazil, a variant form of LFS/LFL is commonly detected because of the high prevalence of a founder mutation at codon 337 in TP53 (p.R337H). The p53 protein exerts multiple roles in the regulation of oxidative metabolism and cellular anti-oxidant defense systems. Herein, we analyzed the redox parameters in blood samples from p.R337H mutation carriers (C, n = 17) and non-carriers (NC, n = 17). We identified a significant increase in erythrocyte GPx activity and in plasma carbonyl content,an indicator of protein oxidative damage, in mutation carriers compared to non-carriers (P = 0.048 and P = 0.035, respectively). Mutation carriers also showed a four-fold increase in plasma malondialdehyde levels, indicating increased lipid peroxidation (NC = 40.2060.71, C = 160.560.88, P,0.0001). Finally, carriers showed increased total antioxidant status but a decrease in plasma ascorbic acid content. The observed imbalance could be associated with deregulated cell bioenergetics and/or with increased inflammatory stress, two effects that may result from loss of wild-type p53 function. These findings provide the first evidence that oxidative damage occurs in carriers of a germline TP53 mutation, and these may have important implications regarding our understanding of the mechanisms responsible for germline TP53 p.R337H mutation-associated carcinogenesis
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