2,471 research outputs found
Infinite stacking of alternating polyfluoroaryl rings and bromide anions
The crystal structure of 1-(4-bromo-2,3,5,6-tetrafluorophenyl)-3-benzylimidazolium bromide comprises columns of parallel bromotetrafluorophenyl rings with an interplanar distance of 6.936(6) Å separated by bromide anions
Model selection and prediction of outcomes in recent onset schizophrenia patients who undergo cognitive training.
Predicting treatment outcomes in psychiatric populations remains a challenge, but is increasingly important in the pursuit of personalized medicine. Patients with schizophrenia have deficits in cognition, and targeted cognitive training (TCT) of auditory processing and working memory has been shown to improve some of these impairments; but little is known about the baseline patient characteristics predictive of cognitive improvement. Here we use a model selection and regression approach called least absolute shrinkage and selection operator (LASSO) to examine predictors of cognitive improvement in response to TCT for patients with recent onset schizophrenia. Forty-three individuals with recent onset schizophrenia randomized to undergo TCT were assessed at baseline on measures of cognition, symptoms, functioning, illness duration, and demographic variables. We carried out 10-fold cross-validation of LASSO for model selection and regression. We followed up on these results using linear models for statistical inference. No individual variable was found to correlate with improvement in global cognition using a Pearson correlation approach, and a linear model including all variables was also found not to be significant. However, the LASSO model identified baseline global cognition, education, and gender in a model predictive of improvement on global cognition following TCT. These findings offer guidelines for personalized approaches to cognitive training for patients with schizophrenia
Self-report of difficult defecation is associated with overactive bladder symptoms
Aims The association of dysfunctional bowel elimination with lower urinary tract symptoms is well known in children, but not in adults. It was our objective to assess lower urinary tract symptoms (LUTS) in women who report difficult defecation (DD). Methods This is a secondary analysis of 2,812 women, aged 35–64, who participated in a telephone interview. All subjects were asked “When you move your bowels, does the stool come out easily?” DD was considered present in those answering “no.” All subjects were queried regarding LUTS, urinary infections in the past year, self-perceived health status, medical history, and demographics. Symptoms of stress incontinence (five items), urge incontinence (five items), and the impact of these symptoms on their quality of life were solicited from subjects reporting more than 12 episodes of incontinence in 1 year. Results DD was reported by 10.4% (290/2,790) of women. Women with DD had higher LUTS than those who did not: nocturia (mean 1.8 ± 0.1 vs. 1.3 ± 0.0), urgency (47.6% vs. 29.2%), increased daytime frequency (mean 8.2 ± 0.3 vs. 7.2 ± 0.1), dysuria (22.9% vs. 13.7%), and a sensation of incomplete bladder emptying (55.6% vs. 28.2%). DD women were more often menopausal, reported a fair or poor self-reported health status, and had a higher number of comorbidities, less formal education, and lower annual household income. Conclusions Women with symptoms of DD have an increased rate of LUTS, consistent with the diagnosis of overactive bladder without incontinence. The pathophysiology underlying this association is worthy of future research. Neurourol. Urodynam. 29:1290–1294, 2010. © 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78056/1/20839_ftp.pd
Functional network changes and cognitive control in schizophrenia
Cognitive control is a cognitive and neural mechanism that contributes to managing the complex demands of day-to-day life. Studies have suggested that functional impairments in cognitive control associated brain circuitry contribute to a broad range of higher cognitive deficits in schizophrenia. To examine this issue, we assessed functional connectivity networks in healthy adults and individuals with schizophrenia performing tasks from two distinct cognitive domains that varied in demands for cognitive control, the RiSE episodic memory task and DPX goal maintenance task. We characterized general and cognitive control-specific effects of schizophrenia on functional connectivity within an expanded frontal parietal network (FPN) and quantified network topology properties using graph analysis. Using the network based statistic (NBS), we observed greater network functional connectivity in cognitive control demanding conditions during both tasks in both groups in the FPN, and demonstrated cognitive control FPN specificity against a task independent auditory network. NBS analyses also revealed widespread connectivity deficits in schizophrenia patients across all tasks. Furthermore, quantitative changes in network topology associated with diagnostic status and task demand were observed. The present findings, in an analysis that was limited to correct trials only, ensuring that subjects are on task, provide critical insights into network connections crucial for cognitive control and the manner in which brain networks reorganize to support such control. Impairments in this mechanism are present in schizophrenia and these results highlight how cognitive control deficits contribute to the pathophysiology of this illness
Identifying an Experimental Two-State Hamiltonian to Arbitrary Accuracy
Precision control of a quantum system requires accurate determination of the
effective system Hamiltonian. We develop a method for estimating the
Hamiltonian parameters for some unknown two-state system and providing
uncertainty bounds on these parameters. This method requires only one
measurement basis and the ability to initialise the system in some arbitrary
state which is not an eigenstate of the Hamiltonian in question. The scaling of
the uncertainty is studied for large numbers of measurements and found to be
proportional to one on the square-root of the number of measurements.Comment: Minor corrections, Accepted for publication in Physical Review
Identifying a Two-State Hamiltonian in the Presence of Decoherence
Mapping the system evolution of a two-state system allows the determination
of the effective system Hamiltonian directly. We show how this can be achieved
even if the system is decohering appreciably over the observation time. A
method to include various decoherence models is given and the limits of this
technique are explored. This technique is applicable both to the problem of
calibrating a control Hamiltonian for quantum computing applications and for
precision experiments in two-state quantum systems. For simple models of
decoherence, this method can be applied even when the decoherence time is
comparable to the oscillation period of the system.Comment: 8 pages, 6 figures. Minor corrections, published versio
The Beta-Bernoulli process and algebraic effects
In this paper we use the framework of algebraic effects from programming language theory to analyze the Beta-Bernoulli process, a standard building block in Bayesian models. Our analysis reveals the importance of abstract data types, and two types of program equations, called commutativity and discardability. We develop an equational theory of terms that use the Beta-Bernoulli process, and show that the theory is complete with respect to the measure-theoretic semantics, and also in the syntactic sense of Post. Our analysis has a potential for being generalized to other stochastic processes relevant to Bayesian modelling, yielding new understanding of these processes from the perspective of programming
assessment of pain-related fear in individuals with chronic painful conditions
Background: Heightened fear and anxiety related to pain may result in emotional and behavioral avoidance responses causing disability, distress, and depression. Fear and anxiety associated with pain can potentially change the course of the pain experience. It is plausible that fear and anxiety related to pain affect the duration and frequency of pain experienced by the patient. Aim: The study aimed to examine the applicability of the Fear of Pain Questionnaire-III (FPQ-III) in identifying who are likely to report longer duration and greater frequency of pain experience. Methods: To test this hypothesis, a cross-sectional study was conducted with 579 individuals from a community-based sample living with chronic pain. The factor structure and validity of FPQ-III in the community-based sample were also tested.
Results: The findings suggest higher fear of severe pain but lower fear of medical pain, associ- ated with longer duration and more frequent pain experience. The analysis also confirmed the three-factor structure of FPQ-III, demonstrating good internal consistency for fear of severe pain (0.71) and fear of medical pain (0.73) and acceptable range for fear of minor pain (0.65). Conclusion: These findings suggest that the FPQ-III can be potentially applied to identify individuals at risk for prolonged continuous pain and as a screening tool to measure fear and anxiety related to pain
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