151 research outputs found

    An analysis of Il Progresso Italo-Americo.

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    Thesis (M.S.)--Boston Universit

    The ILW hierarchy

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    In this paper, we present a new hierarchy which includes the intermediate long wave (ILW) equation at the lowest order. This hierarchy is thought to be a novel reduction of the 1st modified KP type hierarchy. The framework of our investigation is Sato theory.Comment: 8 pages, LaTeX2

    Remote monitoring and follow-up of pacemakers and implantable cardioverter defibrillators

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    In the era of communication technology, new options are now available for following-up patients implanted with pacemakers (PMs) and defibrillators (ICDs). Most major companies offer devices with wireless capabilities that communicate automatically with home transmitters, which then relay data to the physician, thereby allowing remote patient follow-up and monitoring. These systems are being widely used in the USA for remote follow-up, and have been more recently introduced in Europe, where their adoption is increasing. In this article, we describe the currently existing systems, review the available evidence in the literature regarding remote follow-up and monitoring of PMs and ICDs, and finally discuss some unresolved issues

    Global patterns and predictors of avian population density

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    Agencia de InnovaciĆ³n y Desarrollo de AndalucĆ­a, Grant/Award Number: EMERGIA20_00252; H2020 Marie Skłodowska- Curie Actions, Grant/ Award Number: 891052; Ministero dell'Istruzione, dell'UniversitĆ  e della Ricerca, Grant/Award Number: Rita Levi Montalcini programAim: How population density varies across animal species in the context of environ- mental gradients, and associated migratory strategies, remains poorly understood. The recent influx of avian trait data and population density estimates allows these patterns to be described and explored in unprecedented detail. This study aims to identify the main macroecological drivers of population density in birds. Location: Global. Time period: 1970ā€“2021. Major taxa studied: Birds (Aves). Methods: We collated a dataset of 5072 local population density estimates for 1853 species and modelled population density as a function of trait and environmental predictors in a Bayesian framework accounting for phylogenetic and spatial autocor- relation. We explored the influence of body mass, diet, primary lifestyle, mating sys- tem, nesting behaviour, territoriality, and migratory behaviour on population density, accounting for a range of environmental variables, including preferred habitat type, primary productivity, precipitation and temperature. Based on this empirical baseline, we then predicted the mean population density for 9089 species of birds and esti- mated global geographic patterns of bird population density. Results: Population density was lower in species with larger body mass and higher trophic levels, and also declined in territorial species, migratory species, brood para- sites and species inhabiting resource-poor habitat types (e.g., deserts). Conversely, population density increased in cooperative breeders. Environmental drivers were most influential for migratory birds, with precipitation and temperature both associ- ated with higher population density. Overall, bird population densities were higher at lower latitudes. Main conclusions: Our results support previous findings on the role of body mass, diet and environmental gradients, but also reveal novel species-specific drivers of avian densities related to reproduction, migration and resource- holding behaviour. Substantial fine-scale variation remains unexplained. We provide a global dataset of population density predictions for use in macroecological analyses and conservation assessments.Agencia de Innovacion y Desarrollo de Andalucia EMERGIA20_00252H2020 Marie Sklodowska-Curie Actions 891052Ministry of Education, Universities and Research (MIUR

    wmh_seg: Transformer based U-Net for Robust and Automatic White Matter Hyperintensity Segmentation across 1.5T, 3T and 7T

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    White matter hyperintensity (WMH) remains the top imaging biomarker for neurodegenerative diseases. Robust and accurate segmentation of WMH holds paramount significance for neuroimaging studies. The growing shift from 3T to 7T MRI necessitates robust tools for harmonized segmentation across field strengths and artifacts. Recent deep learning models exhibit promise in WMH segmentation but still face challenges, including diverse training data representation and limited analysis of MRI artifacts' impact. To address these, we introduce wmh_seg, a novel deep learning model leveraging a transformer-based encoder from SegFormer. wmh_seg is trained on an unmatched dataset, including 1.5T, 3T, and 7T FLAIR images from various sources, alongside with artificially added MR artifacts. Our approach bridges gaps in training diversity and artifact analysis. Our model demonstrated stable performance across magnetic field strengths, scanner manufacturers, and common MR imaging artifacts. Despite the unique inhomogeneity artifacts on ultra-high field MR images, our model still offers robust and stable segmentation on 7T FLAIR images. Our model, to date, is the first that offers quality white matter lesion segmentation on 7T FLAIR images

    Investigating white matter hyperintensities in a multicenter COVID-19 study using 7T MRI

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    Background: Emerging evidence indicates that COVID-19 can negatively impact patientā€™s brain health (Douaud et al., 2022) (Cecchetti et al., 2022). Common clinical symptoms include brain fog, headaches, difficulty concentrating, and loss of sense of smell or taste. Some studies suggest that SARS-CoV-2 infection can damage the blood brain barrier either directly or through immune-inflammatory mechanisms (Zhang, et al. 2021). White matter hyperintensities (WMH) are imaging biomarkers of brain vascular or inflammatory injury. We investigated the association between severity of COVID-19 infection and burden of white matter hyperintensity volumes within a diverse multi-nation, multi-racial cohort using 7 Tesla (7T) MRI that can detect more subtle injury than conventional 1.5 or 3T MRI. Method: Participants were recruited at 4 sites: Pittsburgh, San Antonio and Houston, USA, and Nottingham, UK. To date, we have scanned and included the following participants in our analysis (Table 1). Detailed cognitive, neurological, mood and functional assessments and high-resolution MRI scans were collected. Subsequent WMH segmentation was performed using our in-house built deep learning based model (Figure 1). All segmentations were visually inspected and manually corrected before statistical analysis. Normalized WMH is calculated as a ratio of the WMH volume and the intracranial volume (WMH/ICV). Imaging data for an additional 36 age-matched controls were retrieved from the 7 Tesla Bioengineering Research Program (7TBRP) imaging bank at Pittsburgh. Result: Figure 1 shows the WMH segmentation outputs from our deep learning based model on images acquired at the 3 sites. Our Linear regression models along with our non-parametric Kruskal-Wallis test result suggests that compared to mild COVID cases and healthy control, COVID infected individuals that were ICU admitted show elevated WMH burden (Figure 2). Conclusion: Our results demonstrate that white matter hyperintensity volumes were higher among patients who had severe acute COVID infection that required ICU admission, compared to healthy age-matched controls. In contrast, no difference in white matter burden was observed in patients with mild COVID infection compared to healthy controls. Additional data (both cross-sectional and longitudinal), including more sensitive MRI measures is being collected to define the full spectrum of brain injury associated with sequelae of COVID infection

    Periodic ILW equation with discrete Laplacian

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    We study an integro-differential equation which generalizes the periodic intermediate long wave (ILW) equation. The kernel of the singular integral involved is an elliptic function written as a second order difference of the Weierstrass zeta-function. Using Sato's formulation, we show the integrability and construct some special solutions. An elliptic solution is also obtained. We present a conjecture based on a Poisson structure that it gives an alternative description of this integrable hierarchy. We note that this Poisson algebra in turn is related to a quantum algebra related with the family of Macdonald difference operators.Comment: 17 pages. To appear in J. Phys. A: Math. Theo

    User fees in private non-for-profit hospitals in Uganda: a survey and intervention for equity

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    BACKGROUND: In developing countries, user fees may represent an important source of revenues for private-non-for-profit hospitals, but they may also affect access, use and equity. METHODS: This survey was conducted in ten hospitals of the Uganda Catholic Medical Bureau to assess differences in user fees policies and to propose changes that would better fit with the social concern explicitly pursued by the Bureau. Through a review of relevant hospital documents and reports, and through interviews with key informants, health workers and users, hospital and non-hospital cost was calculated, as well as overall expenditure and revenues. Lower fees were applied in some pilot hospitals after the survey. RESULTS: The percentage of revenues from user fees varied between 6% and 89% (average 40%). Some hospitals were more successful than others in getting external aid and government subsidies. These hospitals were applying lower fees and flat rates, and were offering free essential services to encourage access, as opposed to the fee-for-service policies implemented in less successful hospitals. The wide variation in user fees among hospitals was not justified by differences in case mix. None of the hospitals had a policy for exemption of the poor; the few users that actually got exempted were not really poor. To pay hospital and non-hospital expenses, about one third of users had to borrow money or sell goods and property. The fee system applied after the survey, based on flat and lower rates, brought about an increase in access and use of hospital services. CONCLUSION: Our results confirm that user fees represent an unfair mechanism of financing for health services because they exclude the poor and the sick. To mitigate this effect, flat rates and lower fees for the most vulnerable users were introduced to replace the fee-for-service system in some hospitals after the survey. The results are encouraging: hospital use, especially for pregnancy, childbirth and childhood illness, increased immediately, with no detrimental effect on overall revenues. A more equitable user fees system is possible

    S. <i>mansoni</i> Schistosomula Antigens Induce Th1/Proinflammatory Cytokine Responses

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    Larvae of Schistosoma (schistosomula) are highly susceptible to host immune responses and are attractive prophylactic vaccine targets, although cellular immune responses against schistosomula antigens in endemic human populations are not well characterized. We collected blood and stool from 54 Schistosoma mansoni-infected Ugandans, isolated peripheral blood mononuclear cells and stimulated them for 24Ā hours with schistosome adult worm and soluble egg antigens (AWA and SEA), along with schistosomula recombinant proteins rSmKK7, Lymphocyte Antigen 6 isoforms (rSmLy6A and rSmLy6B), tetraspanin isoforms (rSmTSP6 and rSmTSP7). Cytokines, chemokines and growth factors were measured in the culture supernatants using a multiplex luminex assay, and infection intensity was determined before and at 1Ā year after praziquantel (PZQ) treatment using the Kato-Katz method. Cellular responses were grouped and the relationship between groups of correlated cellular responses and infection intensity before and after PZQ treatment was investigated. AWA and SEA induced mainly Th2 responses. In contrast, rSmLy6B, rSmTSP6 and rSmTSP7 induced Th1/pro-inflammatory responses. While recombinant antigens rSmKK7 and rSmLy6A did not induce a Th1/pro-inflammatory response, they had an association with pre-treatment infection intensity after adjusting for age and sex. Testing more schistosomula antigens using this approach could provide immune-epidemiology identifiers necessary for prioritizing next generation schistosomiasis vaccine candidates
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