3,397 research outputs found
Study to investigate the effects of ionizing radiation on transistor surfaces Third quarterly report, period ending, 31 Mar. 1966
Ionizing radiation effects on transistor surface
Gynecologic conditions and bacterial vaginosis: implications for the non-pregnant patient.
Bacterial vaginosis is characterized by a shift from the predominant lactobacillus vaginal flora to an overgrowth of anaerobic bacteria. Bacterial vaginosis is associated with an increased risk of gynecologic complications, including pelvic inflammatory disease, postoperative infection, cervicitis, human immunodeficiency virus (HIV), and possibly cervical intraepithelial neoplasia (CIN). The obstetrical risks associated with bacterial vaginosis include premature rupture of membranes, preterm labor and delivery, chorioamnionitis and postpartum endometritis. Despite the health risks associated with bacterial vaginosis and its high prevalence in women of childbearing age, bacterial vaginosis continues to be largely ignored by clinicians, particularly in asymptomatic women
SEASAT: A satellite scatterometer illumination times of selected in situ sites
A list of times that the SEASAT A Satellite Scatterometer (SASS) illuminated from directly above or directly abeam, selected surface sites where in situ winds were measured is provided. The list is ordered by the Greenwich Mean Time (GMT) of the midpoint of the illumination period (hit time) for a given surface site. The site identification, the orbit number and the direction from the subtrack in which the truth lies are provided. The accuracy of these times depends in part upon the ascending node times, which are estimated to be within +.1 sec, and on the illumination time relative to the ascending node, which is estimated to be within +6 seconds. The uncertainties in the times provided were judged to be sufficiently small to allow efficient and accurate extraction of SASS and in situ data at the selected surface sites. The list contains approximately six thousand hit times from 61 geographically dispersed sites
Study to investigate the effects of ionizing radiation on transistor surfaces Fourth quarterly report, period ending Jun. 30, 1966
Ionizing radiation effects on transistor surfaces in vacuum or ambient nitrogen environmen
Database Search Strategies for Proteomic Data Sets Generated by Electron Capture Dissociation Mass Spectrometry
Large data sets of electron capture dissociation (ECD) mass spectra from proteomic experiments are rich in information; however, extracting that information in an optimal manner is not straightforward. Protein database search engines currently available are designed for low resolution CID data, from which Fourier transform ion cyclotron resonance (FT-ICR) ECD data differs significantly. ECD mass spectra contain both z-prime and z-dot fragment ions (and c-prime and c-dot); ECD mass spectra contain abundant peaks derived from neutral losses from charge-reduced precursor ions; FT-ICR ECD spectra are acquired with a larger precursor m/z isolation window than their low-resolution CID counterparts. Here, we consider three distinct stages of postacquisition analysis: (1) processing of ECD mass spectra prior to the database search; (2) the database search step itself and (3) postsearch processing of results. We demonstrate that each of these steps has an effect on the number of peptides identified, with the postsearch processing of results having the largest effect. We compare two commonly used search engines: Mascot and OMSSA. Using an ECD data set of modest size (3341 mass spectra) from a complex sample (mouse whole cell lysate), we demonstrate that search results can be improved from 630 identifications (19% identification success rate) to 1643 identifications (49% identification success rate). We focus in particular on improving identification rates for doubly charged precursors, which are typically low for ECD fragmentation. We compare our presearch processing algorithm with a similar algorithm recently developed for electron transfer dissociation (ETD) data
Design and fabrication of a long-life Stirling cycle cooler for space application. Phase 3: Prototype model
A second-generation, Stirling-cycle cryocooler (cryogenic refrigerator) for space applications, with a cooling capacity of 5 watts at 65 K, was recently completed. The refrigerator, called the Prototype Model, was designed with a goal of 5 year life with no degradation in cooling performance. The free displacer and free piston of the refrigerator are driven directly by moving-magnet linear motors with the moving elements supported by active magnetic bearings. The use of clearance seals and the absence of outgassing material in the working volume of the refrigerator enable long-life operation with no deterioration in performance. Fiber-optic sensors detect the radial position of the shafts and provide a control signal for the magnetic bearings. The frequency, phase, stroke, and offset of the compressor and expander are controlled by signals from precision linear position sensors (LVDTs). The vibration generated by the compressor and expander is cancelled by an active counter balance which also uses a moving-magnet linear motor and magnetic bearings. The driving signal for the counter balance is derived from the compressor and expander position sensors which have wide bandwidth for suppression of harmonic vibrations. The efficiency of the three active members, which operate in a resonant mode, is enhanced by a magnetic spring in the expander and by gas springs in the compressor and counterbalance. The cooling was achieved with a total motor input power of 139 watts. The magnetic-bearing stiffness was significantly increased from the first-generation cooler to accommodate shuttle launch vibrations
Magnetic Reconnection with Radiative Cooling. I. Optically-Thin Regime
Magnetic reconnection, a fundamental plasma process associated with a rapid
dissipation of magnetic energy, is believed to power many disruptive phenomena
in laboratory plasma devices, the Earth magnetosphere, and the solar corona.
Traditional reconnection research, geared towards these rather tenuous
environments, has justifiably ignored the effects of radiation on the
reconnection process. However, in many reconnecting systems in high-energy
astrophysics (e.g., accretion-disk coronae, relativistic jets, magnetar flares)
and, potentially, in powerful laser plasma and z-pinch experiments, the energy
density is so high that radiation, in particular radiative cooling, may start
to play an important role. This observation motivates the development of a
theory of high-energy-density radiative magnetic reconnection. As a first step
towards this goal, we present in this paper a simple Sweet--Parker-like theory
of non-relativistic resistive-MHD reconnection with strong radiative cooling.
First, we show how, in the absence of a guide magnetic field, intense cooling
leads to a strong compression of the plasma in the reconnection layer,
resulting in a higher reconnection rate. The compression ratio and the layer
temperature are determined by the balance between ohmic heating and radiative
cooling. The lower temperature in the radiatively-cooled layer leads to a
higher Spitzer resistivity and hence to an extra enhancement of the
reconnection rate. We then apply our general theory to several specific
astrophysically important radiative processes (bremsstrahlung, cyclotron, and
inverse-Compton) in the optically thin regime, for both the zero- and
strong-guide-field cases. We derive specific expressions for key reconnection
parameters, including the reconnection rate. We also discuss the limitations
and conditions for applicability of our theory.Comment: 31 pages, 1 figur
Preventing Illness in the Public Schools
Since I started working in the public school system in the fall of 2003, the place I call work sometimes feels like a big box infested with germs. I had never washed my hands so much in my life. Bacteria is crawling everywhere with these little people coughing, sneezing, picking their nose, and using the bathroom and not washing their hands. They touch everything – from their desk, pencils, crayons, papers, books, other students, doorknobs, and the staff. It's understandable why parents have concerns when H1N1 enters their child's school and they respond by keeping their perfectly healthy child home when they're not sick. Many parents have concerns about their children attending school and possibly contracting H1N1 or some other disease. It is interesting to think that some of these parents send their children to school with a cold, or worse, when they had vomited the night before and then they themselves may go to work when they are sick with a cold or a minor case of the flu. It's not only important for the adults to know how to protect themselves from getting sick, but their children and the people who work with them and support them daily in the schools. Besides the simple information that anyone can use to stay healthy, programs that can be implemented into the schools, like any program, need staff and money. Whether the challenges can be addressed may be too broad to be answered in a paper, but we can still educate everyone in the importance of disease prevention by simply washing your hands and following the recommended vaccination schedule to help prevent keeping healthy children home from school or having school systems close schools because of illness.Master of Public Healt
Effective dynamics using conditional expectations
The question of coarse-graining is ubiquitous in molecular dynamics. In this
article, we are interested in deriving effective properties for the dynamics of
a coarse-grained variable , where describes the configuration of
the system in a high-dimensional space , and is a smooth function
with value in (typically a reaction coordinate). It is well known that,
given a Boltzmann-Gibbs distribution on , the equilibrium
properties on are completely determined by the free energy. On the
other hand, the question of the effective dynamics on is much more
difficult to address. Starting from an overdamped Langevin equation on , we propose an effective dynamics for using conditional
expectations. Using entropy methods, we give sufficient conditions for the time
marginals of the effective dynamics to be close to the original ones. We check
numerically on some toy examples that these sufficient conditions yield an
effective dynamics which accurately reproduces the residence times in the
potential energy wells. We also discuss the accuracy of the effective dynamics
in a pathwise sense, and the relevance of the free energy to build a
coarse-grained dynamics
Targeted online liquid chromatography electron capture dissociation mass spectrometry for the localization of sites of in vivo phosphorylation in human Sprouty2
We demonstrate a strategy employing collision-induced dissociation for phosphopeptide discovery, followed by targeted electron capture dissociation (ECD) for site localization. The high mass accuracy and low background noise of the ECD mass spectra allow facile sequencing of coeluting isobaric phosphopeptides, with up to two isobaric phosphopeptides sequenced from a single mass spectrum. In contrast to the previously described neutral loss of dependent ECD method, targeted ECD allows analysis of both phosphotyrosine peptides and lower abundance phosphopeptides. The approach was applied to phosphorylation analysis of human Sprouty2, a regulator of receptor tyrosine kinase signaling. Fifteen sites of phosphorylation were identified, 11 of which are novel
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