146 research outputs found

    Fast hashing with Strong Concentration Bounds

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    Previous work on tabulation hashing by Patrascu and Thorup from STOC'11 on simple tabulation and from SODA'13 on twisted tabulation offered Chernoff-style concentration bounds on hash based sums, e.g., the number of balls/keys hashing to a given bin, but under some quite severe restrictions on the expected values of these sums. The basic idea in tabulation hashing is to view a key as consisting of c=O(1)c=O(1) characters, e.g., a 64-bit key as c=8c=8 characters of 8-bits. The character domain Σ\Sigma should be small enough that character tables of size Σ|\Sigma| fit in fast cache. The schemes then use O(1)O(1) tables of this size, so the space of tabulation hashing is O(Σ)O(|\Sigma|). However, the concentration bounds by Patrascu and Thorup only apply if the expected sums are Σ\ll |\Sigma|. To see the problem, consider the very simple case where we use tabulation hashing to throw nn balls into mm bins and want to analyse the number of balls in a given bin. With their concentration bounds, we are fine if n=mn=m, for then the expected value is 11. However, if m=2m=2, as when tossing nn unbiased coins, the expected value n/2n/2 is Σ\gg |\Sigma| for large data sets, e.g., data sets that do not fit in fast cache. To handle expectations that go beyond the limits of our small space, we need a much more advanced analysis of simple tabulation, plus a new tabulation technique that we call \emph{tabulation-permutation} hashing which is at most twice as slow as simple tabulation. No other hashing scheme of comparable speed offers similar Chernoff-style concentration bounds.Comment: 54 pages, 3 figures. An extended abstract appeared at the 52nd Annual ACM Symposium on Theory of Computing (STOC20

    Preparation and in vitro characterization of non-effervescent floating drug delivery system of poorly soluble drug, carvedilol phosphate

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    The objective of the study was to enhance the solubility of carvedilol phosphate and to formulate it into non-effervescent floating tablets using swellable polymers. Solid dispersions (SD)of carvedilol were prepared with hydrophilic carriers such as polyvinylpyrrolidone and poloxamer to enhance solubility. Non-effervescent floating tablets were prepared with a combination of optimized solid dispersions and release retarding polymers/swellable polymers such as xanthan gum and polyethylene oxide. Tablets were evaluated for physicochemical properties such as hardness, thickness and buoyancy. SD prepared with the drug to poloxamer ratio of 1:4 by melt granulation showed higher dissolution rate than all other dispersions. Formulations containing 40 mg of polyethylene oxide (C-P40) and 50 mg xanthan gum (C-X50) were found to be best, with the drug retardation up to 12 hours. Optimized formulations were characterized using FTIR and DSC and no drug and excipient interactions were detected

    Patient Preferences for Diagnostic Testing in the Emergency Department: A Crossâ sectional Study

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    BackgroundDiagnostic testing is common during emergency department (ED) visits. Little is understood about patient preferences for such testing. We hypothesized that a patient’s willingness to undergo diagnostic testing is influenced by the potential benefit, risk, and personal cost.MethodsWe conducted a cross sectional survey among ED patients for diagnostic testing in two hypothetical scenarios: chest pain (CP) and mild traumatic brain injury (mTBI). Each scenario defined specific risks, benefits, and costs of testing. The odds of a participant desiring diagnostic testing were calculated using a series of nested multivariable logistic regression models.ResultsParticipants opted for diagnostic testing 68.2% of the time, including 69.7% of CP and 66.7% of all mTBI scenarios. In the CP scenario, 81% of participants desired free testing versus 59% when it was associated with a 100copay(differenceA^ =22100 copay (difference = 22%, 95% confidence interval [CI] = 16% to 28%). Similarly, in the mTBI scenario, 73% of adult participants desired free testing versus 56% when charged a 100 copayment (difference = 17%, 95% CI = 11% to 24%). Benefit and risk had mixed effects across the scenarios. In fully adjusted models, the association between cost and desire for testing persisted in the CP (odds ratio [OR] = 0.33, 95% CI = 0.23 to 0.47) and adult mTBI (OR = 0.47, 95% CI = 0.33 to 0.67) scenarios.ConclusionsIn this EDâ based study, patient preferences for diagnostic testing differed significantly across levels of risk, benefit, and cost of diagnostic testing. Cost was the strongest and most consistent factor associated with decreased desire for testing.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144652/1/acem13404.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144652/2/acem13404_am.pd

    Self-supervised Outdoor Scene Relighting

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    Outdoor scene relighting is a challenging problem that requires good understanding of the scene geometry, illumination and albedo. Current techniques are completely supervised, requiring high quality synthetic renderings to train a solution. Such renderings are synthesized using priors learned from limited data. In contrast, we propose a self-supervised approach for relighting. Our approach is trained only on corpora of images collected from the internet without any user-supervision. This virtually endless source of training data allows training a general relighting solution. Our approach first decomposes an image into its albedo, geometry and illumination. A novel relighting is then produced by modifying the illumination parameters. Our solution capture shadow using a dedicated shadow prediction map, and does not rely on accurate geometry estimation. We evaluate our technique subjectively and objectively using a new dataset with ground-truth relighting. Results show the ability of our technique to produce photo-realistic and physically plausible results, that generalizes to unseen scenes.Comment: Published in ECCV '20, http://gvv.mpi-inf.mpg.de/projects/SelfRelight

    Risk factors for surgical site infections after caesarean section at Yaounde, Cameroon

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    Background: Surgical site infection is the invasion by microorganisms of the tissue layers affected by the surgical procedure. Maternal morbidity from infections has been shown to be higher after caesarean section compared to the vaginal delivery. Objective of the research was to analyze the risk factors associated with surgical site infections after caesarean section.Methods: This was a cross sectional (affected/non affected) study approved by the institutional committee for ethics and research of the faculty of medicine and biomedical sciences. A total of 310 medical files were assessed, 62 files from patients with surgical site infections and 248 files from patients without any complications. The data was collected using a pretested questionnaire and analyzed using the statistical package for the social sciences (SPSS) software version 22.0. The Chi squared and the Fisher exact tests were used to assess homogeneity between the 2 groups. Odd ratio 95% confidence interval was used to assess the association between the variables.Results: The proportion of surgical site infections during the study was 1.81%. Factors associated with surgical site infections were premature rupture of membranes (OR: 2.065; 95% CI 1.051-4.05; p=0.035); the vertical midline incision (OR=5.26; 95% CI; 1.41-19.57; p=0.013) and a operation by a resident physician doctor (OR=1.98; 95% CI 1.09-3.59; p=0.02).Conclusions: A factors associated with surgical site infections after caesarean section are a premature rupture of membranes, vertical midline incision and the qualification of the practitioner

    Retrospective analysis and modern spatiotemporal characteristics of tularemia in the territory of the West Kazakhstan and North Kazakhstan regions

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    Rationale. An important task is to monitor the incidence of tularemia among the population of Kazakhstan. Natural foci of this infection occupy large areas. In some regions with large numbers of rodents and ectoparasites and low vaccination coverage, human cases of tularemia have been reported.The aim of the study. To carry out retrospective analysis and to study modern spatiotemporal characteristics of tularemia in the West Kazakhstan and North Kazakhstan regions in order to improve the effectiveness of preventive measures.Materials and methods. In our work, we used public records, the results of an epizootological survey of tularemia natural foci and the official data from the Departments of Sanitary and Epidemiological Control of two regions on the human cases of tularemia in 2000–2021. We used descriptive statistics methods, relative and absolute indicators of the tularemia incidence in the population for the analysis. The phenotypic and genetic properties of the strains isolated in 2000–2021 were studied according to the guidelines.Results. A retrospective analysis of the tularemia incidence among the population of the North Kazakhstan and West Kazakhstan regions showed an improvement in the epidemic situation. Over the past 20 years, 4 human cases of tularemia have been registered in the West Kazakhstan region, while the epizootic potential was quite high; more than 300 strains of the tularemia microbe were isolated during the studied period. In the North Kazakhstan region from 2000 to 2021, 11 human cases of tularemia were registered; when studying rodents, mammals and environmental objects, single positive samples for specific tularemia antibodies and antigens were detected; no strains of tularemia microbe were isolated.Conclusion. An analysis of long-term data on the epizootic and epidemic activity of tularemia natural foci, processed using descriptive statistics and GIS technology, made it possible to identify places of long-term persistence of the tularemia agent in the natural focus of the North Kazakhstan and West Kazakhstan regions and to create an electronic map of the territories endemic for tularemia to determine the scope of preventive measures

    Elevated Toll-Like Receptor 4 Expression and Signaling in Muscle From Insulin-Resistant Subjects

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    OBJECTIVE— Tall-like receptor (TLR)4 has been implicated in the pathogenesis of free fatty acid (FFA)-induced insulin resistance by activating inflammatory pathways, including inhibitor of κB (IκB)/nuclear factor κB (NFκB). However, it is not known whether insulin-resistant subjects have abnormal TLR4 signaling. We examined whether insulin-resistant subjects have abnormal TLR4 expression and TLR4-driven (IκB/NFκB) signaling in skeletal muscle

    Role of Androgen Receptor CAG Repeat Polymorphism and X-Inactivation in the Manifestation of Recurrent Spontaneous Abortions in Indian Women

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    The aim of the present study was to investigate the role of CAG repeat polymorphism and X-chromosome Inactivation (XCI) pattern in Recurrent Spontaneous Abortions among Indian women which has not been hitherto explored. 117 RSA cases and 224 Controls were included in the study. Cases were recruited from two different hospitals - Lakshmi Fertility Clinic, Nellore and Fernandez Maternity Hospital, Hyderabad. Controls were roughly matched for age, ethnicity and socioeconomic status. The CAG repeats of the Androgen Receptor gene were genotyped using a PCR-based assay and were analysed using the GeneMapper software to determine the CAG repeat length. XCI analysis was also carried out to assess the inactivation percentages. RSA cases had a significantly greater frequency of allele sizes in the polymorphic range above 19 repeats (p = 0.006), which is the median value of the controls, and in the biallelic mean range above 21 repeats (p = 0.002). We found no evidence of abnormal incidence of skewed X-inactivation. We conclude that longer CAG repeat lengths are associated with increased odds for RSA with statistical power estimated to be ∼90%
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