Purpose: To compare the performance (covariate balance, effective sample size [ESS]) of stable balancing weights (SBW) versus propensity score weighting (PSW). Two applied cases were used to compare performance: (Case 1) extreme imbalance in baseline covariates between groups and (Case 2) substantial discrepancy in sample size between groups.
Methods: Using the Premier Healthcare Database, we selected patients who (Case 1) underwent a surgical procedure with one of two different bipolar forceps between January 2000 and June 2020, or (Case 2) a neurological procedure using one of two different nonabsorbable surgical sutures between January 2000 and March 2020.
Several but not all MRI studies have reported volume reductions in the hippocampus and dorsolateral prefrontal cortex (DLPFC) in patients with schizophrenia. Given the high prevalence of smoking among schizophrenia patients and the fact that smoking has also been associated with alterations in brain morphology, this study evaluated whether a proportion of the known gray matter reductions in key brain regions may be attributed to smoking rather than to schizophrenia alone. We examined structural MRI data of 112 schizophrenia patients (53 smokers and 59 non-smokers) and 77 healthy non-smoker controls collected by the MCIC study of schizophrenia.
View Article and Find Full Text PDFBackground: Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a bacterial disease of fish, which is both geographically widespread and difficult to control. Previously, application of various molecular typing methods has failed to reliably discriminate between R. salmoninarum isolates originating from different host species and geographic areas.
View Article and Find Full Text PDFThe majority of patients with schizophrenia smoke cigarettes. Both nicotine use and schizophrenia have been associated with alterations in brain white matter microstructure as measured by diffusion tensor imaging (DTI). The purpose of this study was to examine fractional anisotropy (FA) in smoking and non-smoking patients with schizophrenia and in healthy volunteers.
View Article and Find Full Text PDFDisease is a major constraint on animal production and welfare in agriculture and aquaculture. Movement of animals between farms is one of the most significant routes of disease transmission and is particularly hard to control for pathogens with subclinical infection. Renibacterium salmoninarum causes bacterial kidney disease (BKD) in salmonid fish, but infection is often sub-clinical and may go undetected with major potential implications for disease control programmes.
View Article and Find Full Text PDFA method was developed to quantify the effect of scanner instability on functional MRI data by comparing the instability noise to endogenous noise present when scanning a human. The instability noise was computed from agar phantom data collected with two flip angles, allowing for a separation of the instability from the background noise. This method was used on human data collected at four 3 T scanners, allowing the physiological noise level to be extracted from the data.
View Article and Find Full Text PDFInfectious salmon anaemia (ISA) is an orthomyxoviral disease, primarily affecting marine-phase farmed Atlantic salmon, which can result in high levels of mortality. ISA first emerged in Norway in the 1980s and subsequently has occurred in Canada, the USA, the Faeroe Islands and Chile. An outbreak occurred in Scotland in 1998-1999, but was eradicated at a cost of over pounds sterling 20M.
View Article and Find Full Text PDFCreatine monohydrate (creatine) has potential neuroprotective properties and is a commonly used supplement in amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Minimum therapeutic and maximum tolerated dosages of creatine are not yet known, nor is it known what systemic plasma concentrations result from specific dosage regimens. The objectives of this study were to establish steady-state plasma pharmacokinetics of creatine at several dosages, and to evaluate the effects of creatine on brain metabolites using proton magnetic resonance spectroscopy ((1)H-MRS).
View Article and Find Full Text PDFNeuroimaging studies are facilitated significantly when it is possible to recruit subjects and acquire data at multiple sites. However, the use of different scanners and acquisition protocols is a potential source of variability in multi-site data. In this work we present a multi-site study of the reliability of fMRI activation indices, where 10 healthy volunteers were scanned at 4 different sites while performing a working memory paradigm.
View Article and Find Full Text PDFSimultaneous reports were received between June and July 2007 of wild Atlantic salmon Salmo salar with red, swollen, bloody vents returning to geographically diverse rivers in Scotland. By the end of September the condition, colloquially known as 'red vent syndrome' (RVS), was reported from >50 rivers across Scotland. Fish were generally in good overall condition but the vent area showed mild to severe lesions.
View Article and Find Full Text PDFContext: The term temperament refers to a biologically based predilection for a distinctive pattern of emotions, cognitions, and behaviors first observed in infancy or early childhood. High-reactive infants are characterized at age 4 months by vigorous motor activity and crying in response to unfamiliar visual, auditory, and olfactory stimuli, whereas low-reactive infants show low motor activity and low vocal distress to the same stimuli. High-reactive infants are biased to become behaviorally inhibited in the second year of life, defined by timidity with unfamiliar people, objects, and situations.
View Article and Find Full Text PDFAbnormalities of the medial temporal lobe have been consistently demonstrated in schizophrenia. A common functional polymorphism, Val108/158Met, in the putative schizophrenia susceptibility gene, catechol-O-methyltransferase (COMT), has been shown to influence medial temporal lobe function. However, the effects of this polymorphism on volumes of medial temporal lobe structures, particularly in patients with schizophrenia, are less clear.
View Article and Find Full Text PDFBackground: Emerging evidence implicates white matter (WM) abnormalities in the pathophysiology of schizophrenia. However, there is considerable heterogeneity in the presentation of WM abnormalities in the existing studies. The object of this study was to evaluate WM integrity in a large sample of patients with first-episode (FE) and chronic schizophrenia in comparison to matched control groups.
View Article and Find Full Text PDFBackground: Intravenous cannulation is a very common procedure. Venous aneurysm secondary to peripheral intravenous cannulation is extremely rare. Moreover, venous aneurysm can mimic other conditions and may confuse the issue.
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