3,312 research outputs found
The PN Technique of Ranging as Applied in the Ranging Subsystem Mark I
Pseudo-Noise /PN/ technique of ranging as applied in Ranging Subsystem Mark I - ranging code
School Boards - A Mandate for Enlightenment Unfulfilled
Boards of education, whose members are elected to their public office; whose members are, collectively, the employers of educators; and whose members are, collectively, the governing authority responsible for the educational policies in their school district, have a duty far greater than merely serving as a vehicle for the purpose of carrying out the affairs of state. Because school activity constitutes the first sustained contact of governmental authority with our youthful citizens, school boards have the highest degree of responsibility to represent the sov- ereign and majestic power of government in the most enlightened manner possible
HIV/STI Risk Factors Among African-American Students Attending Predominantly White Universities
Introduction: The majority of African American college students in the U.S. attend predominantly white institutions (PWIs). However, there is minimal research examining this population’s HIV/STI risk behaviors. The purpose of this investigation was to assess HIV/STI behavioral risk factors among African American college students (aged 18 – 24years) attending PWIs. (n = 2,568)
Methods: Backwards step-wise logistic regression analyses were conducted to determine factors associated with a positive HIV/STI diagnosis (past year) among sexually active African American college students who participated in the Spring, 2006 National College Health Assessment.
Findings: Nine factors were significantly associated with an HIV/STI diagnosis among African American college students attending PWIs. Different risk factors were associated with having a HIV/STI diagnosis among African American male and female college students. These results may be useful to HIV/STIs prevention programs targeting African American college students attending PWIs
Statistical multi-moment bifurcations in random delay coupled swarms
We study the effects of discrete, randomly distributed time delays on the
dynamics of a coupled system of self-propelling particles. Bifurcation analysis
on a mean field approximation of the system reveals that the system possesses
patterns with certain universal characteristics that depend on distinguished
moments of the time delay distribution. Specifically, we show both
theoretically and numerically that although bifurcations of simple patterns,
such as translations, change stability only as a function of the first moment
of the time delay distribution, more complex patterns arising from Hopf
bifurcations depend on all of the moments
APPLICABILITY OF FOUR LOCALIZED-CALIBRATION METHODS IN UNDERWATER MOTION ANALYSIS
Four different localized-calibration methods were developed based on the DLT (direct linear transformation) algorithm in an effort to reduce the error due to refraction in underwater motion analysis. Their applicability in underwater motion analysis was assessed based on a simulated 3D calibration trial with 2 cameras and a hexahedral calibration frame. It was concluded from the analysis of the calibration results that (a) all methods substantially reduced the maximum reconstruction error and demonstrated the potential to minimize object space deformation, (b) localization methods based on overlapped control volumes/areas revealed superior performance than those based on distinct volumes/areas, and (c) the 2D DLT-based localization algorithm provided more accurate object space reconstruction than the 3D DLT-based algorithm
Climatic determinants of the reproductive timing in the Asian house gecko, Hemidactylus frenatus Duméril and Bibron (Gekkonidae)
Small ectotherms are strongly affected by their immediate environment and so respond sensitively to climate. The climatic determinants of reproductive timing in a reptile species may, ultimately, determine the geographic range of that species, and these determinants are, thus, of particular interest when the species is invasive. Here we examine climatic correlates of reproductive timing in the invasive asian house gecko, Hemidactylus frenatus, across two sites representing its long-established and recently-introduced range. We collected data on the proportion of gravid females in Darwin, Australia (its introduced range) over two years, and compared that with previously published data from the gecko's long-established range (in Bandung, Java, Indonesia). Our analysis suggests strong site differences in the response of this species' reproductive timing to climate. In both sites, high minimum monthly temperatures were strongly associated with increased numbers of gravid females, but the effects of other variables (maximum temperature and moisture availability) were more site dependent. These site differences may be due to many factors, including plasticity, and evolution, which we are unable to elucidate here. The differences between sites in the response to climatic variables, however, suggests it may be difficult to determine the climatic limits to this species' range based on a simple analysis of climate
Management of Fluid Status in Haemodialysis Patients: The Roles of Technology and Dietary Advice, Technical Problems in Patients on Hemodialysis
The kidneys play a vital role in maintaining normal tissue hydration and serum sodium level. In haemodialysis patients, with impaired or absent kidney function, fluid status is managed by removing excess fluid using ultrafiltration and by restricting dietary sodium intake. Ideally, haemodialysis patients should remain close to normal hydration throughout the interdialytic period, with minimal periods of excessive dehydration or fluid overload and with no fluid–related co-morbidity. Optimal fluid management is achieved by adjusting the post-dialysis ‘target’ weight and, where necessary, limiting the fluid gained between dialysis sessions. While clinical history and examination remain the basis for prescribing the target weight, technology can provide useful objective information especially where the clinical indications are ambiguous. A simple non-invasive test can now be carried out when a patient attends for dialysis enabling staff to pick up changes in body composition so that their target weight can be adjusted to maintain optimal fluid status. In most patients, interdialytic fluid gain (IDFG) is directly related to sodium intake. Acceptable fluid gains can usually be achieved by limiting salt intake to the recommended daily allowance for the general population and avoiding unnecessary sodium loading during dialysis. Low pre-dialysis serum sodium levels can help identify patients with other causes of high IDFG, such as high blood sugar or social drinking, who need additional counselling. For the patients, lowering sodium intake may also improve blood pressure control and reduce requirements for antihypertensive medication. Staff education, and preferably participation, is vital when implementing salt restriction in a haemodialysis unit
A SEARCH FOR ELECTRON ANTINEUTRINOS ASSOCIATED WITH GRAVITATIONAL-WAVE EVENTS GW150914 AND GW151226 USING KAMLAND
We present a search, using KamLAND, a kiloton-scale anti-neutrino detector, for low-energy anti-neutrino events that were coincident with the gravitational-wave (GW) events GW150914 and GW151226, and the candidate event LVT151012. We find no inverse beta-decay neutrino events within ±500 s of either GW signal. This non-detection is used to constrain the electron anti-neutrino fluence and the total integrated luminosity of the astrophysical sources.United States. Department of Energy (Grant DE-FG03-00ER41138)United States. Department of Energy (Grant DE-AC02- 05CH11231)United States. Department of Energy (Grant DE-FG02-01ER41166
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