3,435 research outputs found
A Search for New Physics with the BEACON Mission
The primary objective of the Beyond Einstein Advanced Coherent Optical
Network (BEACON) mission is a search for new physics beyond general relativity
by measuring the curvature of relativistic space-time around Earth. This
curvature is characterized by the Eddington parameter \gamma -- the most
fundamental relativistic gravity parameter and a direct measure for the
presence of new physical interactions. BEACON will achieve an accuracy of 1 x
10^{-9} in measuring the parameter \gamma, thereby going a factor of 30,000
beyond the present best result involving the Cassini spacecraft. Secondary
mission objectives include: (i) a direct measurement of the "frame-dragging"
and geodetic precessions in the Earth's rotational gravitomagnetic field, to
0.05% and 0.03% accuracy correspondingly, (ii) first measurement of gravity's
non-linear effects on light and corresponding 2nd order spatial metric's
effects to 0.01% accuracy. BEACON will lead to robust advances in tests of
fundamental physics -- this mission could discover a violation or extension of
general relativity and/or reveal the presence of an additional long range
interaction in physics. BEACON will provide crucial information to separate
modern scalar-tensor theories of gravity from general relativity, probe
possible ways for gravity quantization, and test modern theories of
cosmological evolution.Comment: 8 pages, 2 figures, 2 table
Appropriate Loads for Peak-Power During Resisted Sprinting on a Non-Motorized Treadmill
The purpose of this study was to determine the load which allows the highest peak power for resisted sprinting on a non-motorized treadmill and to determine if other variables are related to individual differences. Thirty college students were tested for vertical jump, vertical jump peak and mean power, 10 m sprint, 20 m sprint, leg press 1 RM, leg press 1 RM relative to body weight, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM. Participants performed eight resisted sprints on a non-motorized treadmill, with increasing relative loads expressed as percent of body weight. Sprint peak power was measured for each load. Pearson correlations were used to determine if relationships between the sprint peak power load and the other variables were significant. The sprint peak power load had a mode of 35% with 73% of all participants having a relative sprint peak power load between 25-35%. Significant correlations occurred between sprint peak power load and body weight, lean body mass, vertical jump peak and mean power, leg press 1 RM, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM (r = 0.44, 0.43, 0.39, 0.37, 0.47, 0.39, 0.46, and 0.47, respectively). Larger, stronger, more powerful athletes produced peak power at a higher relative load during resisted sprinting on a nonmotorized treadmill
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Accounting for Comorbidity in Assessing the Burden of Epilepsy Among US Adults: Results from the National Comorbidity Survey Replication (NCS-R)
Although epilepsy is associated with substantial role impairment, it is also highly comorbid with other physical and mental disorders, making unclear the extent to which impairments associated with epilepsy are actually due to comorbidities. This issue was explored in the National Comorbidity Survey Replication (NCS-R), a nationally representative household survey of 5,692 US adults. Medically-recognized epilepsy was ascertained with self-report, comorbid physical disorders with a chronic conditions checklist, and comorbid DSM-IV mental disorders with the Composite International Diagnostic Interview (CIDI). Lifetime epilepsy prevalence was estimated at 1.8%. Epilepsy was comorbid with numerous neurological and general medical conditions and with a sporadic cluster of mental comorbidities (panic, PTSD, conduct disorder, and substance use disorders). Although comorbid disorders explain part of the significant gross associations of epilepsy with impairment, epilepsy remains significantly associated with work disability, cognitive impairment, and days of role impairment after controlling comorbidities. The net association of epilepsy with days of role impairment after controlling for comorbidities is equivalent to an annualized 89.4 million excess role impairment days among US adults with epilepsy, arguing that role impairment is a major component of the societal costs of epilepsy per se rather than merely due to disorders comorbid with epilepsy. This estimated burden is likely conservative as some parts of the effects of epilepsy are presumably mediated by secondary comorbid disorders
Geographical Analysis of US Green Sector Industry Concentration
This paper analyzes the geographic distribution of “green energy” sector clustering in the lower 48 United States using recent developments in industry concentration analysis. Evidence suggests that the ten green energy subsectors and the aggregate of the firms comprising the green energy sector are regionally concentrated. Positive changes in industry concentration from 2002 to 2006 tended to be greatest in non-metropolitan counties, suggesting comparative advantage with respect to site location for the composite of firms making up these sectors.Agglomeration, Location Quotient, Renewable Energy, Community/Rural/Urban Development, Industrial Organization, Research and Development/Tech Change/Emerging Technologies,
The Importance of Winter Dinoflagellate Blooms in Chesapeake Bay—a Missing Link in Bay Productivity
It is widely assumed that phytoplankton abundance and productivity decline during temperate winters because of low irradiance and temperatures. However, winter phytoplankton blooms commonly occur in temperate estuaries, but they are often undocumented because of reduced water quality monitoring in winter. The small body of in situ work that has been done on winter blooms suggests they can be of enormous consequence to ecosystems. However, because monitoring is often reduced or stopped altogether during winter, it is unclear how widespread these blooms are or how long they can last. We analyzed an over 30-year record of monthly phytoplankton monitoring samples along with ad hoc sampling throughout Chesapeake Bay to assess the distributions of two common winter bloom species, Heterocapsa rotundata and Heterocapsa steinii, and the environmental conditions associated with these blooms. The long-term monitoring data revealed that H. rotundata blooms occur within a narrow salinity range (7–12) and potentially have different triggers depending upon the nutrient status of waters affected. The ad hoc sampling confirmed the occurrence of H. steinii blooms in the lower Chesapeake Bay, despite the lack of evidence for them from monthly monitoring data. Together, our findings demonstrate that winter blooms routinely occur in numerous locations throughout Chesapeake Bay and can last up to a month. Our findings suggest that while winter blooms are a staple of the Bay’s annual phytoplankton community, there are major data gaps reporting their occurrence highlighting the need for more frequent monitoring to understand factors promoting these blooms and their consequences on ecosystem productivity
Endocrine responses and acute mTOR pathway phosphorylation to resistance exercise with leucine and whey
Leucine ingestion reportedly activates the mTOR pathway in skeletal muscle, contributing to a hypertrophy response. The purpose of the study was to compare the post-resistance exercise effects of leucine and whey protein supplementation on endocrine responses and muscle mTOR pathway phosphorylation. On visit 1, subjects (X±SD; n=20; age=27.8±2.8yrs) provided baseline blood samples for analysis of cortisol, glucose and insulin; a muscle biopsy of the vastus lateralis muscle to assess mTOR signaling pathway phosphorylation; and were tested for maximum strength on the leg press and leg extension exercises. For visits 2 and 3, subjects were randomized in a double-blind crossover design to ingest either leucine and whey protein (10g+10g; supplement) or a non-caloric placebo. During these visits, 5 sets of 10 repetitions were performed on both exercises, immediately followed by ingestion of the supplement or placebo. Blood was sampled 30 min post-, and a muscle biopsy 45 min post-exercise. Western blots quantified total and phosphorylated proteins. Insulin increased (α<.05) with supplementation with no change in glucose compared to placebo. Relative phosphorylation of AKT and rpS6 were greater with leucine and whey supplementation compared to placebo. Supplementation of leucine and whey protein immediately after heavy resistance exercise increases anabolic signaling in human skeletal muscle
Perspectives of United States–based infectious diseases physicians on outpatient parenteral antimicrobial therapy practice
Matrix Metalloproteinase-9 Increases the Ligand Sensitivity of CNG Channels: Evidence for Sequential Subunit Modification
Core excitations across the neutron shell gap in ²⁰⁷Tl
The single closed-neutron-shell, one proton-hole nucleus 207Tl was populated in deep-inelastic collisions of a 208Pb beam with a 208Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupol
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