533 research outputs found

    Assessment of culture and environment in the Adolescent Brain and Cognitive Development Study: Rationale, description of measures, and early data.

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    Neurodevelopmental maturation takes place in a social environment in addition to a neurobiological one. Characterization of social environmental factors that influence this process is therefore an essential component in developing an accurate model of adolescent brain and neurocognitive development, as well as susceptibility to change with the use of marijuana and other drugs. The creation of the Culture and Environment (CE) measurement component of the ABCD protocol was guided by this understanding. Three areas were identified by the CE Work Group as central to this process: influences relating to CE Group membership, influences created by the proximal social environment, influences stemming from social interactions. Eleven measures assess these influences, and by time of publication, will have been administered to well over 7,000 9-10 year-old children and one of their parents. Our report presents baseline data on psychometric characteristics (mean, standard deviation, range, skewness, coefficient alpha) of all measures within the battery. Effectiveness of the battery in differentiating 9-10 year olds who were classified as at higher and lower risk for marijuana use in adolescence was also evaluated. Psychometric characteristics on all measures were good to excellent; higher vs. lower risk contrasts were significant in areas where risk differentiation would be anticipated

    Direct regional microvascular monitoring and assessment of blood brain barrier function following cerebral ischemia-reperfusion injury

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    Evans Blue (EB) is often used to evaluate Blood-Brain Barrier Damage (BBB) in cerebral ischemia, frequently by dye extraction. Herein we present a method that allows assessing regional brain microvasculature, distribution of EB and Fluorescent Isothiocyanate-Labeled Red Blood Cells (FITC-RBCs) in a rat model of acute cerebral Ischemia-Reperfusion (I-R). Wistar rats were subjected to 3 h of middle cerebral artery occlusion and then reperfused. At ~2.5 h of reperfusion, BBB opening was assessed by contrast enhanced magnetic resonance imaging. It was followed by injections of EB and FITC-RBCs that circulated for either 5 or 20 min. Regional microvasculature and tracer distributions were assessed by laser scanning confocal microscopy. Microvascular networks in stroke-affected regions networks were partially damaged with apparent EB extravasation. Brain regions were affected in the following order: preoptic area (PoA)\u3estriatum (Str)\u3ecortex (Ctx). EB leakage increased with circulation time in Str. Cells around the leakage sites sequestered EB. An inverse correlation was observed between low CBF rates recorded during MCA occlusion and post-reperfusion EB extravasation patterns. Accordingly, this approach provided data on brain regional microvascular status, extravascular tracer distribution and its cellular uptake. It may be useful to evaluate model-dependent variations in vascular injury and efficacy of putative vascular protective drugs in stroke

    Isotopic signals in an agricultural watershed suggest denitrification is locally intensive in riparian areas but extensive in upland soils

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sigler, W. A., Ewing, S. A., Wankel, S. D., Jones, C. A., Leuthold, S., Brookshire, E. N. J., & Payn, R. A. Isotopic signals in an agricultural watershed suggest denitrification is locally intensive in riparian areas but extensive in upland soils. Biogeochemistry, 158, (2022): 251–268, https://doi.org/10.1007/s10533-022-00898-9.Nitrogen loss from cultivated soils threatens the economic and environmental sustainability of agriculture. Nitrate (NO3−) derived from nitrification of nitrogen fertilizer and ammonified soil organic nitrogen may be lost from soils via denitrification, producing dinitrogen gas (N2) or the greenhouse gas nitrous oxide (N2O). Nitrate that accumulates in soils is also subject to leaching loss, which can degrade water quality and make NO3− available for downstream denitrification. Here we use patterns in the isotopic composition of NO3− observed from 2012 to 2017 to characterize N loss to denitrification within soils, groundwater, and stream riparian corridors of a non-irrigated agroecosystem in the northern Great Plains (Judith River Watershed, Montana, USA). We find evidence for denitrification across these domains, expressed as a positive linear relationship between δ15N and δ18O values of NO3−, as well as increasing δ15N values with decreasing NO3− concentration. In soils, isotopic evidence of denitrification was present during fallow periods (no crop growing), despite net accumulation of NO3− from the nitrification of ammonified soil organic nitrogen. We combine previous results for soil NO3− mass balance with δ15N mass balance to estimate denitrification rates in soil relative to groundwater and streams. Substantial denitrification from soils during fallow periods may be masked by nitrification of ammonified soil organic nitrogen, representing a hidden loss of soil organic nitrogen and an under-quantified flux of N to the atmosphere. Globally, cultivated land spends ca. 50% of time in a fallow condition; denitrification in fallow soils may be an overlooked but globally significant source of agricultural N2O emissions, which must be reduced along-side other emissions to meet Paris Agreement goals for slowing global temperature increase.National Institute of Food and Agriculture, 2011–51130-31121, S. A. Ewing, 2011, S. A. Ewing, 2016–67026-25067, S. A. Ewing, Montana State University Extension, Montana Fertilizer Advisory Committee, Montana Agricultural Experiment Station, Montana State University Vice President of Research, Montana State University College of Agriculture, Montana Institute on Ecosystems, NSF EPSCoR, OIA-1757351, S. A. Ewing, OIA-1443108, S. A. Ewing, EPS-110134, S. A. Ewing

    Elastic waves push organic fluids from reservoir rock

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    Elastic waves have been observed to increase productivity of oil wells, although the reason for the vibratory mobilization of the residual organic fluids has remained unclear. Residual oil is entrapped as ganglia in pore constrictions because of resisting capillary forces. An external pressure gradient exceeding an ‘‘unplugging’’ threshold is needed to carry the ganglia through. The vibrations help overcome this resistance by adding an oscillatory inertial forcing to the external gradient; when the vibratory forcing acts along the gradient and the threshold is exceeded, instant ‘‘unplugging’’ occurs. The mobilization effect is proportional to the amplitude and inversely proportional to the frequency of vibrations. We observe this dependence in a laboratory experiment, in which residual saturation is created in a glass micromodel, and mobilization of the dyed organic ganglia is monitored using digital photography.We also directly demonstrate the release of an entrapped ganglion by vibrations in a computational fluid-dynamics simulation

    A Randomized Controlled Trial: Attachment-Based Family and Nondirective Supportive Treatments for Youth Who Are Suicidal

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    Objective: To evaluate the efficacy of attachment-based family therapy (ABFT) compared with a family-enhanced nondirective supportive therapy (FE-NST) for decreasing adolescents’ suicide ideation and depressive symptoms. Method: A randomized controlled trial of 129 adolescents who are suicidal ages 12- to 18-years-old (49% were African American) were randomized to ABFT (n ¼ 66) or FE-NST (n ¼ 63) for 16 weeks of treatment. Assessments occurred at baseline and 4, 8, 12, and 16 weeks. Trajectory of change and clinical recovery were calculated for suicidal ideation and depressive symptoms. Results: There was no significant between-group difference in the rate of change in self-reported ideation (Suicidal Ideation Questionnaire-Jr; F1,127 ¼ 181, p ¼ .18). Similar results were found for depressive symptoms. However, adolescents receiving ABFT showed a significant decrease in suicide ideation (t127 ¼ 12.61, p \u3c .0001; effect size, d ¼ 2.24). Adolescents receiving FE-NST showed a similar significant decrease (t127 ¼ 10.88, p \u3c .0001; effect size, d ¼ 1.93). Response rates (ie, 50% decrease in suicide ideation symptoms from baseline) at post-treatment were 69.1% for ABFT versus 62.3% for FE-NST. Conclusion: Contrary to expectations, ABFT did not perform better than FE-NST. The 2 treatments produced substantial decreases in suicidal ideation and depressive symptoms that were comparable to or better than those reported in other more intensive, multicomponent treatments. The equivalent outcomes could be attributed to common treatment elements, different active mechanisms, or regression to the mean. Future studies will explore long-term follow up, secondary outcomes, and potential moderators and mediators
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