1,050 research outputs found
Variational Cumulant Expansions for Intractable Distributions
Intractable distributions present a common difficulty in inference within the
probabilistic knowledge representation framework and variational methods have
recently been popular in providing an approximate solution. In this article, we
describe a perturbational approach in the form of a cumulant expansion which,
to lowest order, recovers the standard Kullback-Leibler variational bound.
Higher-order terms describe corrections on the variational approach without
incurring much further computational cost. The relationship to other
perturbational approaches such as TAP is also elucidated. We demonstrate the
method on a particular class of undirected graphical models, Boltzmann
machines, for which our simulation results confirm improved accuracy and
enhanced stability during learning
Audiovisual cues to uncertainty
This paper presents research on the use of audiovisual prosody to signal a speaker’s level of uncertainty. The first study con-sists of an experiment, in which subjects are asked factual ques-tions in a conversational setting, while they are being filmed. Statistical analyses bring to light that the speakers ’ Feeling-of-Knowing (FOK) correlate significantly with a number of vi-sual and verbal properties. Interestingly, it appears that an-swers tend to have a higher number of marked feature settings (i.e., divergences of the neutral audiovisual expression) when the FOK score is low, while the reverse is true for non-answers. The second study is a perception experiment, in which a selec-tion of the utterances from the first study is presented to sub-jects in one of three conditions: vision only, sound only or vi-sion+sound. Results reveal that human observers can reliably distinguish HighFOK responses from LowFOK responses in all three conditions, be it that answers are easier than non-answers, and that a bimodal presentation of the stimuli is easier than their unimodal counterparts. Results of these two experiments are potentially relevant for improving the communication style in human-machine interaction. 1
Clinical outcomes with an aspheric monofocal and a new enhanced monofocal intraocular lens with modified optical profile
Purpose This study aimed to evaluate and compare the clinical outcomes obtained after cataract surgery with an aspheric monofocal intraocular lens (IOL) and an enhanced IOL with a modified optical profile. Methods Randomised clinical trial enrolling 70 patients (age, 52–87 years) undergoing cataract surgery. Two groups were created according to the type of IOL implanted: Vivinex iSert from Hoya Surgical Optics (Vivinex group, 35 patients) and Tecnis Eyhance ICB00 from Johnson & Johnson Vision (Eyhance group, 35 patients). Uncorrected (UDVA) and corrected distance visual acuity (CDVA), uncorrected (UIVA) and distance-corrected intermediate visual acuity (DCIVA), refraction, and self-perceived visual function (Catquest-9SF) were evaluated during a 3-month follow-up. Results No significant differences were found between IOL groups in UDVA and CDVA (p ≥ 0.093). In contrast, monocular and binocular UIVA and DCIVA were significantly better in the Eyhance group at 1 (p ≤ 0.015) and 3 months postoperatively (p ≤ 0.002). Postoperative DCIVA 20/25 or better was obtained in 71.4% and 20.0% of patients in Eyhance and Vivinex groups, respectively. Differences in postoperative Rasch calibrated Catquest scores between Eyhance and Vivinex groups did not reach statistical significance (p ≥ 0.102). However, significant correlations were only found between the change in UIVA and Catquest scores (0.364 ≤ r ≤ 0.444, p ≤ 0.041) in the Eyhance group. Conclusions The modified monofocal IOL evaluated provides better intermediate visual function in comparison with a standard aspheric monofocal IOL, but the impact of this benefit on the self-perceived level of vision achieved after surgery according to the patient seemed to be limited.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The author David P Piñero has been supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016–20471
Risk factors for septic arthritis in patients with joint disease: A prospective study
Objective. To quantify potential risk factors for septic arthritis, in order to identify a basis for prevention.
Methods. The occurrence of potential risk factors for septic arthritis in patients with joint diseases attending a rheumatic disease clinic was prospectively monitored at 3-m onth intervals over a period of 3 years. Potential risk factors investigated were type of joint disease, comorbidity, medication, joint prosthesis, infections, and invasive procedures. The frequencies of risk factors in patients with and those without septic arthritis were compared using multiple logistic regression analysis.
Results. There were 37 patients with and 4,870 without septic arthritis. Risk factors for developing septic arthritis were age ≥80 years (odds ratio [OR] = 3.5, 95% confidence interval [95% CI] 1.4–8.6), diabetes mellitus (OR = 3.3, 95% CI 1.1–10.1), rheumatoid arthritis (OR = 4.0, 95% CI 1.9–8.3), hip and/or knee prosthesis (OR = 15, 95% CI 4.1–54.3), joint surgery (OR = 5.1, 95% CI 2.2–11.9), and skin infection (OR = 27.2, 95% CI 7.6–97.1)
Conclusion. These findings indicate that preventive measures against septic arthritis in patients with joint diseases should mainly be directed at those with joint prostheses and/or skin infection
Milieueffecten van diervoeders
Life Cycle Analysis is used to calculate the greenhouse gas emissions, acidification, energy and land use of feed ingredients for cattle, pigs and poultry. Economic developments are explored and mitigation options are calculate
Monitoring recently acquired HIV infections in Amsterdam, The Netherlands:The attribution of test locations
Background: Surveillance of recent HIV infections (RHI) using an avidity assay has been implemented at Dutch sexual health centres (SHC) since 2014, but data on RHI diagnosed at other test locations is lacking. Setting: Implementation of the avidity assay in HIV treatment clinics for the purpose of studying RHI among HIV patients tested at different test locations. Methods: We retrospectively tested leftover specimens from newly diagnosed HIV patients in care in 2013–2015 in Amsterdam. Avidity Index (AI) values ≤0.80 indicated recent infection (acquired ≤6 months prior to diagnosis), and AI > 0.80 indicated established infection (acquired >6 months prior to diagnosis). An algorithm for RHI was applied to correct for false recency. Recency based on this algorithm was compared with recency based on epidemiological data only. Multivariable logistic regression analysis was used to identify factors associated with RHI among men who have sex with men (MSM).Results: We tested 447 specimens with avidity; 72% from MSM. Proportions of RHI were 20% among MSM and 10% among heterosexuals. SHC showed highest proportions of RHI (27%), followed by GPs (15%), hospitals (5%), and other/unknown locations (11%) (p < 0.001). Test location was the only factor associated with RHI among MSM. A higher proportion of RHI was found based on epidemiological data compared to avidity testing combined with the RHI algorithm. Conclusion: SHC identify more RHI infections compared to other test locations, as they serve high-risk populations and offer frequent HIV testing. Using avidity-testing for surveillance purposes may help targeting prevention programs, but the assay lacks robustness and its added value may decline with improved, repeat HIV testing and data collection
Comparative effectiveness of improvement in pain and physical function for baricitinib versus adalimumab, tocilizumab, and tofacitinib monotherapies in rheumatoid arthritis patients who are naïve to treatment with biologic or conventional synthetic disease-modifying antirheumatic drugs: a matching-adjusted indirect comparison
Objective To compare improvement in pain and physical function for patients treated with baricitinib, adalimumab, tocilizumab and tofacitinib monotherapy from randomised, methotrexate (MTX)-controlled trials in conventional synthetic disease-modifying antirheumatic drugs (csDMARDs)/biologic (bDMARD)-naïve RA patients using matching-adjusted indirect comparisons (MAICs).
Methods Data were from Phase III trials on patients receiving monotherapy baricitinib, tocilizumab, adalimumab, tofacitinib or MTX. Pain was assessed using a visual analogue scale (0–100 mm) and physical function using the Health Assessment Questionnaire-Disability Index (HAQ-DI). An MAIC based on treatment-arm matching, an MAIC with study-level matching and Bucher’s method without matching compared change in outcomes between therapies. Matching variables included age, gender, baseline disease activity and baseline value of outcome measure.
Results With all methods, greater improvements were observed in pain and HAQ-DI at 6 months for baricitinib compared with adalimumab and tocilizumab (p<0.05). Differences in treatment effects (TEs) favouring baricitinib for pain VAS for treatment-arm matching, study-level matching and Bucher’s method, respectively, were −12, −12 and −12 for baricitinib versus adalimumab and −7, −7 and −9 for baricitinib versus tocilizumab; the difference in TEs for HAQ-DI was −0.28, −0.28 and −0.30 for adalimumab and −0.23, −0.23 and −0.26 for tocilizumab. For baricitinib versus tofacitinib, no statistically significant differences for pain improvement were observed except with one of the three methods (Bucher method) and none for HAQ-DI.
Conclusions Results suggest greater pain reduction and improved physical function for baricitinib monotherapy compared with tocilizumab and adalimumab monotherapy. No statistically significant differences in pain reduction and improved physical function were observed between baricitinib and tofacitinib with the MAIC analyses
Female Sex and IL28B, a Synergism for Spontaneous Viral Clearance in Hepatitis C Virus (HCV) Seroconverters from a Community-Based Cohort
BACKGROUND & AIMS: Since acute hepatitis C virus (HCV) infection is often asymptomatic, it is difficult to examine the rate and determinants of spontaneous clearance. Consequently, these studies are subject to bias, which can potentially lead to biased rates of viral clearance and risk estimates. We evaluated determinants of spontaneous HCV clearance among HCV seroconverters identified in a unique community-based cohort. METHODS: Subjects were 106 drug users with documented dates of HCV seroconversion from the Amsterdam Cohort Study. Logistic regression was used to examine sociodemographic, behavioral, clinical, viral and host determinants, measured around acute infection, of HCV clearance. RESULTS: The spontaneous viral clearance rate was 33.0% (95% confidence interval (CI) 24.2-42.8). In univariate analyses female sex and fever were significantly associated with spontaneous clearance. The favorable genotypes for rs12979860 (CC) and rs8099917 (TT) were associated with spontaneous clearance, although borderline significant. In multivariate analysis, females with the favorable genotype for rs12979860 (CC) had an increased odds to spontaneously clear HCV infection (adjusted OR 6.62, 95% 2.69-26.13), whereas females with the unfavorable genotype were as likely as men with the favorable and unfavorable genotype to clear HCV. Chronic Hepatitis B infection and absence of HIV coinfection around HCV seroconversion also favor HCV clearance. CONCLUSIONS: This study shows that co-infection with HIV and HBV and genetic variation in the IL28B region play an important role in spontaneous clearance of HCV. Our findings suggest a possible synergistic interaction between female sex and IL28B in spontaneous clearance of HCV
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