704 research outputs found
Mild propofol sedation reduces frontal lobe and thalamic cerebral blood flow: An arterial spin labeling study
Mechanisms of anesthetic drug-induced sedation and unconsciousness are still incompletely understood. Functional neuroimaging modalities provide a window to study brain function changes during anesthesia allowing us to explore the sequence of neuro-physiological changes associated with anesthesia. Cerebral perfusion change under an assumption of intact neurovascular coupling is an indicator of change in large-scale neural activity. In this experiment, we have investigated resting state cerebral blood flow (CBF) changes in the human brain during mild sedation, with propofol. Arterial spin labeling (ASL) provides a non-invasive, reliable, and robust means of measuring cerebral blood flow (CBF) and can therefore be used to investigate central drug effects. Mild propofol sedation-related CBF changes were studied at rest (n = 15), in a 3 T MR scanner using a PICORE-QUIPSS II ASL technique. CBF was reduced in bilateral paracingulate cortex, premotor cortex, Broca’s areas, right superior frontal gyrus and also the thalamus. This cerebral perfusion study demonstrates that propofol induces suppression of key cortical (frontal lobe) and subcortical (thalamus) regions during mild sedation
Noninvasive assessment of arterial compliance of human cerebral arteries with short inversion time arterial spin labeling
A noninvasive method of assessing cerebral arterial compliance (AC) is introduced in which arterial spin labeling (ASL) is used to measure changes in arterial blood volume (aBV) occurring within the cardiac cycle. Short inversion time pulsed ASL (PASL) was performed in healthy volunteers with inversion times ranging from 250 to 850 ms. A model of the arterial input function was used to obtain the cerebral aBV. Results indicate that aBV depends on the cardiac phase of the arteries in the imaging volume. Cerebral AC, estimated from aBV and brachial blood pressure measured noninvasively in systole and diastole, was assessed in the flow territories of the basal cerebral arteries originating from the circle of Willis: right and left middle cerebral arteries (RMCA and LMCA), right and left posterior cerebral arteries (RPCA and LPCA), and the anterior cerebral artery (ACA). Group average AC values calculated for the RMCA, LMCA, ACA, RPCA, and LPCA were 0.56%±0.2%, 0.50%±0.3%, 0.4%±0.2%, 1.1%±0.5%, and 1.1%±0.3% per mm Hg, respectively. The current experiment has shown the feasibility of measuring AC of cerebral arteries with short inversion time PASL
Understanding pregnancy planning in a low-income country setting: validation of the London measure of unplanned pregnancy in Malawi
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: The London Measure of Unplanned Pregnancy (LMUP) is a new and psychometrically valid measure of pregnancy intention that was developed in the United Kingdom. An improved understanding of pregnancy intention in low-income countries, where unintended pregnancies are common and maternal and neonatal deaths are high, is necessary to inform policies to address the unmet need for family planning. To this end this research aimed to validate the LMUP for use in the Chichewa language in Malawi.Methods: Three Chichewa speakers translated the LMUP and one translation was agreed which was back-translated and pre-tested on five pregnant women using cognitive interviews. The measure was field tested with pregnant women who were recruited at antenatal clinics and data were analysed using classical test theory and hypothesis testing.Results: 125 women aged 15-43 (median 23), with parities of 1-8 (median 2) completed the Chichewa LMUP. There were no missing data. The full range of LMUP scores was captured. In terms of reliability, the scale was internally consistent (Cronbach's alpha = 0.78) and test-retest data from 70 women showed good stability (weighted Kappa 0.80). In terms of validity, hypothesis testing confirmed that unmarried women (p = 0.003), women who had four or more children alive (p = 0.0051) and women who were below 20 or over 29 (p = 0.0115) were all more likely to have unintended pregnancies. Principal component analysis showed that five of the six items loaded onto one factor, with a further item borderline. A sensitivity analysis to assess the effect of the removal of the weakest item of the scale showed slightly improved performance but as the LMUP was not significantly adversely affected by its inclusion we recommend retaining the six-item score.Conclusion: The Chichewa LMUP is a valid and reliable measure of pregnancy intention in Malawi and can now be used in research and/or surveillance. This is the first validation of this tool in a low-income country, helping to demonstrate that the concept of pregnancy planning is applicable in such a setting. Use of the Chichewa LMUP can enhance our understanding of pregnancy intention in Malawi, giving insight into the family planning services that are required to better meet women's needs and save lives. © 2013 Hall et al.; licensee BioMed Central Ltd.Dr Hall’s Wellcome Trust Research Training Fellowship, grant number 097268/Z/11/Z
Promoting Functional Literacy through Cooperative Learning
The Effects of Cooperative Learning Strategy Manipulations on the Enactment and Recall of a Medical Procedure Were Explored. One Hundred and Twenty-Three College Students Completed the Experiment. during Training, Participants Were Randomly Assigned to a Dyad in One of Four Conditions: (A) No-Strategy, (B) Baseline Strategy, (C) Prompting Strategy, and (D) Planning Strategy. during Testing, Participants Both Performed and Produced Written Recalls of the Procedure Instructions. Test Order Was Counterbalanced within Dyad. Training and Test Performances Were Videotaped. the Planning Group Produced the Best Recalls and Recalled More Conditions of the Procedure. the Prompting Group Performed Best. Recall of the Procedure in All Groups Was Enhanced by Prior Performance. However, Performance Was Enhanced by Prior Recall in Only Two Groups. the Groups Differed Also in the Nature of the Transition from Training to Testing. Theoretical and Applied Implications of These Findings Are Discussed. © 1988, SAGE Publications. All Rights Reserved
Depression and stages of change for smoking in psychiatric outpatients
Abstract This article reports on the relations between depression and stages of change for smoking cessation. A convenience sample of 205 psychiatric outpatients (68% female, mean age 41) completed measures of depression Primary Care Evaluation of Mental Disorders [PRIME-MD] and Beck Depression Inventory-II [BDI-II]), all transtheoretical model constructs related to smoking (stages and processes of change, pros and cons of smoking, and situational temptations), and thoughts about abstinence. As hypothesized, patients who had never smoked showed substantially lower rates of currently diagnosed major depressive disorder (MDD) than those who had ever smoked. Patients in early stages of change did not show more MDD or depressive symptoms but, as hypothesized, showed more negative thoughts about abstinence. Findings are consistent with the documented association between smoking and depression and suggest the appropriateness of building smoking cessation interventions based on the transtheoretical model of change for use with psychiatric populations.
Summer
ABSTRACT: In two experiments, interpersonal status was experimentally manipulated by assigning one dyad member to be the owner of a mock art gallery and the other to be the owner's assistant. Without forewarning, participants were asked immediately following the interaction to recall their partner's hand gestures, selftouch, gazing, smiling, and nodding. Accuracy of recall was determined by comparing these ratings to their partners' behavior as coded from the videotape. In both experiments, assistants were more accurate at recalling the amount of owners' selftouch than vice versa, but there was little evidence of an accuracy difference in recall of the other nonverbal cues. When accuracy was defined as the correlation between a participant's ratings of the partner's behaviors and the partner's actual behaviors, there was evidence that assistants were more accurate than owners when a combined p-value was calculated across both studies. KEY WORDS: nonverbal sensitivity; recall accuracy; status; power. Social psychologists have hypothesized that people with weak or subordinate status display enhanced interpersonal sensitivity, either as a general skill or vis-à-vis superiors (e.
Caltech Faint Galaxy Redshift Survey. XI. The Merger Rate to Redshift 1 from Kinematic Pairs
The rate of mass accumulation due to galaxy merging depends on the mass, density, and velocity distribution of galaxies in the near neighborhood of a host galaxy. The fractional luminosity in kinematic pairs combines all of these effects in a single estimator that is relatively insensitive to population evolution. Here we use a k-corrected and evolution-compensated volume-limited sample having an R-band absolute magnitude of M^(k,e)_R ≤ -19.8 + 5 log h mag drawing about 300 redshifts from the Caltech Faint Galaxy Redshift Survey and 3000 from the Canadian Network for Observational Cosmology field galaxy survey to measure the rate and redshift evolution of merging. The combined sample has an approximately constant comoving number and luminosity density from redshift 0.1 to 1.1 (Ω_M = 0.2, Ω_Λ = 0.8); hence, any merger evolution will be dominated by correlation and velocity evolution, not density evolution. We identify kinematic pairs with projected separations less than either 50 or 100 h^(-1) kpc and rest-frame velocity differences of less than 1000 km s^(-1). The fractional luminosity in pairs is modeled as f_L(Δv, r_p, M^(k,e)_τ)(1 + z)^(m,L), where [f_L, m_L] are [0.14 ± 0.07, 0 ± 1.4] and [0.37 ± 0.7, 0.1 ± 0.5] for r_p ≤ 50 and 100 h^(-1) kpc, respectively (Ω_M = 0.2, Ω_Λ = 0.8). The value of mL is about 0.6 larger if Λ = 0. To convert these redshift-space statistics to a merger rate, we use the data to derive a conversion factor to a physical space pair density, a merger probability, and a mean in-spiral time. The resulting mass accretion rate per galaxy (M_1, M_2 ≥ 0.2M*) is 0.02 ± 0.01(1 + z)^(0.1±0.5)M* Gyr^(-1). Present-day high-luminosity galaxies therefore have accreted approximately 0.15M* of their mass over the approximately 7 Gyr to redshift 1. Since merging is likely only weakly dependent on the host mass, the fractional effect, δM/M 0.15M*/M, is dramatic for lower mass galaxies but is, on the average, effectively perturbative for galaxies above 1M*
Pregnancy outcomes in women with cardiovascular disease: evolving trends over 10 years in the ESC Registry Of Pregnancy And Cardiac disease (ROPAC)
Aims Reducing maternal mortality is a World Health Organization (WHO) global health goal. Although maternal deaths due to haemorrhage and infection are declining, those related to heart disease are increasing and are now the most important cause in western countries. The aim is to define contemporary diagnosis-specific outcomes in pregnant women with heart disease. Methods and results From 2007 to 2018, pregnant women with heart disease were prospectively enrolled in the Registry Of Pregnancy And Cardiac disease (ROPAC). Primary outcome was maternal mortality or heart failure, secondary outcomes were other cardiac, obstetric, and foetal complications. We enrolled 5739 pregnancies; the mean age was 29.5. Prevalent diagnoses were congenital (57%) and valvular heart disease (29%). Mortality (overall 0.6%) was highest in the pulmonary arterial hypertension (PAH) group (9%). Heart failure occurred in 11%, arrhythmias in 2%. Delivery was by Caesarean section in 44%. Obstetric and foetal complications occurred in 17% and 21%, respectively. The number of high-risk pregnancies (mWHO Class IV) increased from 0.7% in 2007–2010 to 10.9% in 2015–2018. Determinants for maternal complications were pre-pregnancy heart failure or New York Heart Association >II, systemic ejection fraction <40%, mWHO Class 4, and anticoagulants use. After an increase from 2007 to 2009, complication rates fell from 13.2% in 2010 to 9.3% in 2017. Conclusion Rates of maternal mortality or heart failure were high in women with heart disease. However, from 2010, these rates declined despite the inclusion of more high-risk pregnancies. Highest complication rates occurred in women with PAH
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