2,796 research outputs found
Response Dynamics of Entorhinal Cortex in Awake, Anesthetized, and Bulbotomized Rats. <i>Brain Research</i> <b>911</b>(2)
The generation of oscillatory activity may be crucial to brain function. The coordination of individual neurons into rhythmic and coherently active populations is thought to result from interactions between excitatory and inhibitory cells mediated by local feedback connections. By using extracellular recording wires and silicon microprobes to measure electrically evoked damped oscillatory responses at the level of neural populations in the entorhinal cortex, and by using current-source density analysis to determine the spatial pattern of evoked responses, we show that the propagation of activity through the cortical circuit and consequent oscillations in the local field potential are dependent upon background neural activity. Pharmacological manipulations as well as surgical disconnection of the olfactory bulb serve to quell the background excitatory input incident to entorhinal cortex, resulting in evoked responses without characteristic oscillations and showing no signs of polysynaptic feedback. Electrical stimulation at 200 Hz applied to the lateral olfactory tract provides a substitute for the normal background activity emanating from the bulb and enables the generation of oscillatory responses once again. We conclude that a nonzero background level of activity is necessary and sufficient to sustain normal oscillatory responses and polysynaptic transmission through the entorhinal cortex
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Process of forming crosslinked copolymer film, crosslinked copolymer film formed thereby, and water purification membrane
Azidoaryl-substituted cyclooctene monomers and synthesized and used in the preparation of various copolymers. Among these copolymers are those prepared from ring-opening metathesis polymerization of cyclooctene, polyethylene glycol-substituted cyclooctene, and azidoaryl-substituted cyclooctene. These copolymers are useful in the formation of crosslinked films that reduce fouling of water purification membranes.Board of Regents, University of Texas Syste
The Prevalence of Physical Inactivity and Low Back Pain in Sedentary Office Employees: A Survey Analysis
Low back pain (LBP) is an increasingly common chronic condition and self-perceived disability that full-time sedentary employees are at risk of being exposed to. Sedentary employees are paid workers who fulfill all or most of their occupational duties seated. Currently, there is very little research available that discusses how physical inactivity affects LBP in sedentary office employees. PURPOSE: The purpose of this study is to: (1) determine the prevalence of LBP pain among sedentary office employees, (2) identify the number of sedentary employees who meet the current physical activity guidelines outlined by the American College of Sports Medicine (ACSM) and mirroring Physical Activity Guidelines for Americans, and (3) to determine the prevalence of LBP amongst physical activity habits in the surveyed population. METHODS: One hundred sixty-four participants completed the 36-question survey. Survey questions assessed past injuries, working history, chair type, exercise history and training frequency, sedentary habits, and pain prevalence and management. RESULTS: The survey found 73.7% of participants experience some level of LBP when seated at work. Additionally, 32.3% of participants were inactive, 57.9% of participants were insufficiently active, 7.9% of participants were active and 1.8% of participants were highly active in accordance with the Physical Activity Guidelines for Americans. Sixty-six participants reported engaging in resistance training with 63.6% reporting LBP. Ninety-five participants reported engaging in aerobic activity with 75.7% reporting LBP. Eighty-nine participants reported engaging in core training with 70.7% reporting LBP. CONCLUSION: The majority of sedentary office employees reported LBP. Additionally, only ~10% of survey respondents met or exceeded ACSM’s Physical Activity Guidelines and LBP was still prevalent in most participants despite their engagement in physical activity
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Stable isotope metabolomics of pulmonary artery smooth muscle and endothelial cells in pulmonary hypertension and with TGF-beta treatment.
Altered metabolism in pulmonary artery smooth muscle cells (PASMCs) and endothelial cells (PAECs) contributes to the pathology of pulmonary hypertension (PH), but changes in substrate uptake and how substrates are utilized have not been fully characterized. We hypothesized stable isotope metabolomics would identify increased glucose, glutamine and fatty acid uptake and utilization in human PASMCs and PAECs from PH versus control specimens, and that TGF-β treatment would phenocopy these metabolic changes. We used 13C-labeled glucose, glutamine or a long-chain fatty acid mixture added to cell culture media, and mass spectrometry-based metabolomics to detect and quantify 13C-labeled metabolites. We found PH PASMCs had increased glucose uptake and utilization by glycolysis and the pentose shunt, but no changes in glutamine or fatty acid uptake or utilization. Diseased PAECs had increased proximate glycolysis pathway intermediates, less pentose shunt flux, increased anaplerosis from glutamine, and decreased fatty acid β-oxidation. TGF-β treatment increased glycolysis in PASMCs, but did not recapitulate the PAEC disease phenotype. In TGF-β-treated PASMCs, glucose, glutamine and fatty acids all contributed carbons to the TCA cycle. In conclusion, PASMCs and PAECs collected from PH subjects have significant changes in metabolite uptake and utilization, partially recapitulated by TGF-β treatment
Optical and magneto-optical properties of ferromagnetic full-Heusler films: experiments and first-principles calculations
We report a joint theoretical and experimental study focused on understanding
the optical and magneto-optical properties of Co-based full-Heusler compounds.
We show that magneto-optical spectra calculated within ab-initio density
functional theory are able to uniquely identify the features of the
experimental spectra in terms of spin resolved electronic transitions. As
expected for 3d-based magnets, we find that the largest Kerr rotation for these
alloys is of the order of 0.3o in polar geometry. In addition, we demonstrate
that (i) multilayered structures have to be carefully handled in the
theoretical calculations in order to improve the agreement with experiments,
and (ii) combined theoretical and experimental investigations constitute a
powerful approach to designing new materials for magneto-optical and
spin-related applicationsComment: 20 pages, including 6 figures and 1 table. 40 refs. To be published
in Phys. Rev.
What Drives the Expansion of Giant HII Regions?: A Study of Stellar Feedback in 30 Doradus
Observations show that star formation is an inefficient and slow process.
This result can be attributed to the injection of energy and momentum by stars
that prevents free-fall collapse of molecular clouds. The mechanism of this
stellar feedback is debated theoretically: possible sources of pressure include
the classical warm HII gas, the hot gas generated by shock-heating from stellar
winds and supernovae, direct radiation of stars, and the dust-processed
radiation field trapped inside the HII shell. In this paper, we measure
observationally the pressures associated with each component listed above
across the giant HII region 30 Doradus in the Large Magellanic Cloud. We
exploit high-resolution, multi-wavelengh images (radio, infrared, optical, and
X-ray) to map these pressures as a function of position. We find that radiation
pressure dominates within 75 pc of the central star cluster, R136, while the
HII gas pressure dominates at larger radii. By contrast, the dust-processed
radiation pressure and hot gas pressure are generally weak and not dynamically
important, although the hot gas pressure may have played a more significant
role at early times. Based on the low X-ray gas pressures, we demonstrate that
the hot gas is only partially confined and must be leaking out the HII shell.
Additionally, we consider the implications of a dominant radiation pressure on
the early dynamics of 30 Doradus.Comment: 14 pages, 17 figures; ApJ in pres
SLAPex Freeze/Thaw 2015: The First Dedicated Soil Freeze/Thaw Airborne Campaign
Soil freezing and thawing is an important process in the terrestrial water, energy, and carbon cycles, marking the change between two very different hydraulic, thermal, and biological regimes. NASA's Soil Moisture Active/Passive (SMAP) mission includes a binary freeze/thaw data product. While there have been ground-based remote sensing field measurements observing soil freeze/thaw at the point scale, and airborne campaigns that observed some frozen soil areas (e.g., BOREAS), the recently-completed SLAPex Freeze/Thaw (F/T) campaign is the first airborne campaign dedicated solely to observing frozen/thawed soil with both passive and active microwave sensors and dedicated ground truth, in order to enable detailed process-level exploration of the remote sensing signatures and in situ soil conditions. SLAPex F/T utilized the Scanning L-band Active/Passive (SLAP) instrument, an airborne simulator of SMAP developed at NASA's Goddard Space Flight Center, and was conducted near Winnipeg, Manitoba, Canada, in October/November, 2015. Future soil moisture missions are also expected to include soil freeze/thaw products, and the loss of the radar on SMAP means that airborne radar-radiometer observations like those that SLAP provides are unique assets for freeze/thaw algorithm development. This paper will present an overview of SLAPex F/T, including descriptions of the site, airborne and ground-based remote sensing, ground truth, as well as preliminary results
A systematic review of clinic and community intervention to increase fecal testing for colorectal cancer in rural and low-income populations in the United States – How, what and when?
Abstract Background Interventions to improve fecal testing for colorectal cancer (CRC) exist, but are not yet routine practice. We conducted this systematic review to determine how implementation strategies and contextual factors influenced the uptake of interventions to increase Fecal Immunochemical Tests (FIT) and Fecal Occult Blood Testing (FOBT) for CRC in rural and low-income populations in the United States. Methods We searched Medline and the Cochrane Library from January 1998 through July 2016, and Scopus and clinicaltrials.gov through March 2015, for original articles of interventions to increase fecal testing for CRC. Two reviewers independently screened abstracts, reviewed full-text articles, extracted data and performed quality assessments. A qualitative synthesis described the relationship between changes in fecal testing rates for CRC, intervention components, implementation strategies, and contextual factors. A technical expert panel of primary care professionals, health system leaders, and academicians guided this work. Results Of 4218 citations initially identified, 27 unique studies reported in 29 publications met inclusion criteria. Studies were conducted in primary care (n = 20, 74.1%), community (n = 5, 18.5%), or both (n = 2, 7.4%) settings. All studies (n = 27, 100.0%) described multicomponent interventions. In clinic based studies, components that occurred most frequently among the highly effective/effective study arms were provision of kits by direct mail, use of a pre-addressed stamped envelope, client reminders, and provider ordered in-clinic distribution. Interventions were delivered by clinic staff/community members (n = 10, 37.0%), research staff (n = 6, 22.2%), both (n = 10, 37.0%), or it was unclear (n = 1, 3.7%). Over half of the studies lacked information on training or monitoring intervention fidelity (n = 15, 55.6%). Conclusions Studies to improve FIT/FOBT in rural and low-income populations utilized multicomponent interventions. The provision of kits through the mail, use of pre-addressed stamped envelopes, client reminders and in-clinic distribution appeared most frequently in the highly effective/effective clinic-based study arms. Few studies described contextual factors or implementation strategies. More robust application of guidelines to support reporting on methods to select, adapt and implement interventions can help end users determine not just which interventions work to improve CRC screening, but which interventions would work best in their setting given specific patient populations, clinical settings, and community characteristics. Trial registration In accordance with PRISMA guidelines, our systematic review protocol was registered with PROSPERO, the international prospective register of systematic reviews, on April 16, 2015 (registration number CRD42015019557 )
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