3,333 research outputs found
In-situ measurements of total reactive nitrogen, total water vapor, and aerosols in polar stratospheric clouds in the Antarctic stratosphere
Measurements of total reactive nitrogen, NOy, total water vapor, and aerosols were made as part of the Airborne Antarctic Ozone Experiment. The measurements were made using instruments located onboard the NASA ER-2 aircrafts which conducted twelve flights over the Antarctic continent reaching altitudes of 18 km at 72 S latitude. Each instrument utilized an ambient air sample and provided a measurement up to 1 Hz or every 200 m of flight path. The data presented focus on the flights of Aug. 17th and 18th during which Polar Stratospheric Clouds (PSCs) were encountered containing concentrations of 0.5 to 1.0 micron diameter aerosols greater than 1 cm/cu. The temperature pressure during these events ranged as low as 184 K near 75 mb pressure, with water values near 3.5 ppm by volume (ppmv). With the exception of two short periods, the PSC activity was observed at temperatures above the frost point of water over ice. The data gathered during these flights are analyzed and presented
TRAVEL MOBILITY AND PHYSICAL ACTIVITY IN THE DAILY LIVES OF COLLEGE STUDENTS
poster abstractTyson (2010) conducted research on 100 students using the Hospital Anxiety and Depression Scale (HADS) and the Physical Activity Question-naire (PAQ). He concluded that students who engaged in more exercise had better mental health. Other studies have confirmed his findings, and have demonstrated how a student’s well-being is related to their success in build-ing relationships and maintaining academic studies. On the other hand, stu-dents that do not engage in physical activity often experience negative well-being, including difficulty concentrating, fatigue, and psychological disorders. The objectives of this study are to determine if the strength of association between daily emotion and activity participation is similar across college stu-dents, and how physical activity and travel mobility relate to well-being. The Experience Sampling Method (ESM), developed by Csikszentmihalyi, Larson, and Prescott (1977) will be used in conjunction with an accelerometer and global positioning system (GPS) to collect data from a sample of (n=24) full-time students over a period of seven days from 9:00am-9:00pm. Subjects will be randomly signaled seven times a day, at which time they will com-plete several Likert-type statements and semantic deferential items in order to measure their perceptions of well-being. To date, the combined methodo-logical use of ESM, GPS and accelerometry has not been conducted on col-lege students. Travel mobility and physical activity will be recorded using the Garmin Forerunner 410 GPS and the Actigraph accelerometer. Data collec-tion phase is incomplete. It is expected that the strength of association be-tween daily emotion and activity participation will be consistent across col-lege students, and physical activity and travel mobility will contribute to stu-dent’s well-being. It is also expected that students with high levels of physi-cal activity and travel mobility will report an overall sense of happiness and increased well-being as compared to those with low levels of physical activity and travel mobility
Inhibition of the mitochondrial pyruvate carrier protects from excitotoxic neuronal death.
Glutamate is the dominant excitatory neurotransmitter in the brain, but under conditions of metabolic stress it can accumulate to excitotoxic levels. Although pharmacologic modulation of excitatory amino acid receptors is well studied, minimal consideration has been given to targeting mitochondrial glutamate metabolism to control neurotransmitter levels. Here we demonstrate that chemical inhibition of the mitochondrial pyruvate carrier (MPC) protects primary cortical neurons from excitotoxic death. Reductions in mitochondrial pyruvate uptake do not compromise cellular energy metabolism, suggesting neuronal metabolic flexibility. Rather, MPC inhibition rewires mitochondrial substrate metabolism to preferentially increase reliance on glutamate to fuel energetics and anaplerosis. Mobilizing the neuronal glutamate pool for oxidation decreases the quantity of glutamate released upon depolarization and, in turn, limits the positive-feedback cascade of excitotoxic neuronal injury. The finding links mitochondrial pyruvate metabolism to glutamatergic neurotransmission and establishes the MPC as a therapeutic target to treat neurodegenerative diseases characterized by excitotoxicity
Computational and Experimental Unsteady Pressures for Alternate SLS Booster Nose Shapes
Delayed Detached Eddy Simulation (DDES) predictions of the unsteady transonic flow about a Space Launch System (SLS) configuration were made with the Fully UNstructured Three-Dimensional (FUN3D) flow solver. The computational predictions were validated against results from a 2.5% model tested in the NASA Ames 11-Foot Transonic Unitary Plan Facility. The peak C(sub p,rms) value was under-predicted for the baseline, Mach 0.9 case, but the general trends of high C(sub p,rms) levels behind the forward attach hardware, reducing as one moves away both streamwise and circumferentially, were captured. Frequency of the peak power in power spectral density estimates was consistently under-predicted. Five alternate booster nose shapes were assessed, and several were shown to reduce the surface pressure fluctuations, both as predicted by the computations and verified by the wind tunnel results
Effects of Alcohol and Saccharin Deprivations on Concurrent Ethanol and Saccharin Operant Self-Administration by Alcohol-Preferring (P) Rats
Consumption of sweet solutions has been associated with a reduction in withdrawal symptoms and
alcohol craving in humans. The objective of the present study was to determine the effects of
EtOH and saccharin (SACC) deprivations on operant oral self-administration. P rats were allowed
to lever press concurrently self-administer EtOH (15% v/v) and SACC (0.0125% g/v) for 8 weeks.
Rats were then maintained on daily operant access (non-deprived), deprived of both fluids (2
weeks), deprived of SACC and given 2 ml of EtOH daily, or deprived of EtOH and given 2 ml of
SACC daily. All groups were then given two weeks of daily operant access to EtOH and SACC,
followed by an identical second deprivation period. P rats responded more for EtOH than SACC.
All deprived groups increased responding on the EtOH lever, but not on the SACC lever. Daily
consumption of 2 ml EtOH decreased the duration of the ADE. Home cage access to 2 ml SACC
also decreased the ADE but to a lesser extent than access to EtOH. A second deprivation period
further increased and prolonged the expression of an ADE. These results show EtOH is a more
salient reinforcer than SACC. With concurrent access to EtOH and SACC, P rats do not display a
saccharin deprivation effect. Depriving P rats of both EtOH and SACC had the most pronounced
effect on the magnitude and duration of the ADE, suggesting that there may be some interactions
between EtOH and SACC in their CNS reinforcing effects
Adjunctive intraocular and peri-ocular steroid (triamcinolone acetonide) versus standard treatment in eyes undergoing vitreoretinal surgery for open globe trauma (ASCOT): study protocol for a phase III, multi-centre, double-masked randomised controlled trial
BACKGROUND: Eyes sustaining open globe trauma are at high risk of severe visual impairment. Ocular injuries which result in visual loss invariably affect the posterior segment of the eye, and prevention of visual loss involves posterior segment (vitreoretinal) surgery. Despite improvements in vitreoretinal surgical techniques, outcomes in these patients remain unsatisfactory, and development of the intraocular scarring response proliferative vitreoretinopathy is the leading cause. Proliferative vitreoretinopathy is the most common cause of recurrent retinal detachment in these eyes; it is reported to occur in up to 45 % of cases. METHODS/DESIGN: The Adjunctive Steroid Combination in Ocular Trauma (ASCOT) trial is a multi-centre, double-masked, parallel-arm randomised controlled trial with an internal pilot designed to investigate the effectiveness and cost-effectiveness of using intravitreal and sub-Tenon's triamcinolone acetonide peri-operatively in patients undergoing vitrectomy following open globe trauma. In total, 300 eyes of 300 patients will be recruited and randomly allocated to one of two treatment groups. Both groups will receive standard surgical treatment and routine pre-operative and post-operative treatment and care. The treatment group will receive an adjunctive peri-operative steroid combination (triamcinolone acetonide) consisting of 4 mg/0.1 ml into the vitreous cavity and 40 mg/1 ml into the sub-Tenon's space. The trial incorporates a two-stage internal pilot to examine projected recruitment and retention rates. Progression criteria from the internal pilot study will enable us to determine whether to undertake the main trial. Patients and primary outcome assessors will be masked to treatment allocation. The primary outcome will be an improvement from baseline to 6 months of at least 10 on the corrected visual acuity as measured by ETDRS letter score. Secondary outcomes will be development of scarring, retinal detachment, intraocular pressure abnormalities, quality of life and public sector service use. DISCUSSION: This is the first powered, controlled clinical trial to investigate the use of adjunctive triamcinolone in patients undergoing vitrectomy following open globe trauma. TRIAL REGISTRATION: EudraCT2014-002193-37 . Registered on 5 September 2014. ISRCTN30012492 . Registered on 5 September 2014
Orion Crew Module Aerodynamic Testing
The Apollo-derived Orion Crew Exploration Vehicle (CEV), part of NASA s now-cancelled Constellation Program, has become the reference design for the new Multi-Purpose Crew Vehicle (MPCV). The MPCV will serve as the exploration vehicle for all near-term human space missions. A strategic wind-tunnel test program has been executed at numerous facilities throughout the country to support several phases of aerodynamic database development for the Orion spacecraft. This paper presents a summary of the experimental static aerodynamic data collected to-date for the Orion Crew Module (CM) capsule. The test program described herein involved personnel and resources from NASA Langley Research Center, NASA Ames Research Center, NASA Johnson Space Flight Center, Arnold Engineering and Development Center, Lockheed Martin Space Sciences, and Orbital Sciences. Data has been compiled from eight different wind tunnel tests in the CEV Aerosciences Program. Comparisons are made as appropriate to highlight effects of angle of attack, Mach number, Reynolds number, and model support system effects
High Pressure Processing of Dairy Foods
End of Project ReportThe term High Pressure Processing (HPP) is used to describe the technology whereby
products are exposed to very high pressures in the region of 50 - 800 MPa (500 - 8000
Atmospheres). The potential application of HPP in the food industry has gained popularity
in recent years, due to developments in the construction of HPP equipment which makes
the technology more affordable. Applying HPP to food products results in modifications to
interactions between individual components, rates of enzymatic reactions and inactivation
of micro-organisms.
The first commercial HPP products appeared on the market in 1991 in Japan, where HPP
is now being used commercially for products such as jams, sauces, fruit juices, rice cakes
and desserts. The pioneering research into the application of HPP to milk dates back to the
end of the 19th century. Application of HPP to milk has been shown to modify its gel
forming characteristics as well as reducing its microbial load. HPP offers the potential to
induce similar effects to those generated by heat on milk protein.
Recent reports have also indicated that HPP could accelerate the ripening of cheese. Much
of the Irish cheese industry is based on the production of Cheddar cheese, the ripening time
for which can vary from 4 - 12 months or more, depending on grade. A substantial portion
of the cost associated with Cheddar manufacture is therefore attributed to storage under
controlled conditions during ripening. Thus, any technology which may accelerate the
ripening of Cheddar cheese while maintaining a balanced flavour and texture is of major
economic significance.
While food safety is a dominant concern, consumers are increasingly demanding foods that
maintain their natural appearance and flavour, while free of chemical preservatives. HPP
offers the food industry the possibility of achieving these twin goals as this technology can
lead to reduced microbial loads without detrimentally effecting the nutritional or sensory
qualities of the product.
The development of food ingredients with novel functional properties offers the dairy
industry an opportunity to revitalise existing markets and develop new ones. HPP can lead
to modifications in the structure of milk components, in particular protein, which may
provide interesting possibilities for the development of high value nutritional and functional
ingredients.
Hence these projects set out to investigate the potential of HPP in the dairy industry and
to identify products and processes to which it could be applied.Department of Agriculture, Food and the Marin
Neural Network Parameterizations of Electromagnetic Nucleon Form Factors
The electromagnetic nucleon form-factors data are studied with artificial
feed forward neural networks. As a result the unbiased model-independent
form-factor parametrizations are evaluated together with uncertainties. The
Bayesian approach for the neural networks is adapted for chi2 error-like
function and applied to the data analysis. The sequence of the feed forward
neural networks with one hidden layer of units is considered. The given neural
network represents a particular form-factor parametrization. The so-called
evidence (the measure of how much the data favor given statistical model) is
computed with the Bayesian framework and it is used to determine the best form
factor parametrization.Comment: The revised version is divided into 4 sections. The discussion of the
prior assumptions is added. The manuscript contains 4 new figures and 2 new
tables (32 pages, 15 figures, 2 tables
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