2,900 research outputs found
Polarization observables in the longitudinal basis for pseudo-scalar meson photoproduction using a density matrix approach
The complete expression for the intensity in pseudo-scalar meson
photoproduction with a polarized beam, target, and recoil baryon is derived
using a density matrix approach that offers great economy of notation. A
Cartesian basis with spins for all particles quantized along a single
direction, the longitudinal beam direction, is used for consistency and clarity
in interpretation. A single spin-quantization axis for all particles enables
the amplitudes to be written in a manifestly covariant fashion with simple
relations to those of the well-known CGLN formalism. Possible sign
discrepancies between theoretical amplitude-level expressions and
experimentally measurable intensity profiles are dealt with carefully. Our
motivation is to provide a coherent framework for coupled-channel partial-wave
analysis of several meson photoproduction reactions, incorporating recently
published and forthcoming polarization data from Jefferson Lab.Comment: 11 pages, 2 figure
Total hemispherical emittance measured at high temperatures by the calorimetric method
A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements (plus or minus 5 percent). The probable error of the CVE measurements was typically less than 1 percent
Eligibility and enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)--27 states and New York City, 2007-2008.
The national Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides nutrition education, growth monitoring, breastfeeding promotion and support, and food to low-income pregnant or postpartum women, infants, and children aged <5 years. Several studies have linked WIC services with improved maternal and infant health outcomes. Most population-based studies have lacked information needed to identify eligible women who are not receiving WIC services and might be at risk for poor health outcomes. This report uses multistate, population-based 2007-2008 survey data from CDC's Pregnancy Risk Assessment Monitoring System (PRAMS) and California's Maternal and Infant Health Assessment (MIHA) to estimate how many women were eligible but not enrolled in WIC during pregnancy and to describe their characteristics and their prevalence of markers of risk for poor maternal or infant health outcomes. Approximately 17% of all women surveyed were eligible but not enrolled in WIC during pregnancy. The proportion of women eligible for WIC and WIC participation rates varied by state. WIC participants had higher prevalences of markers of risk for poor maternal or infant health outcomes than eligible nonparticipants, but both groups had higher prevalences of risk markers than ineligible women, suggesting that many eligible women and their children might benefit from WIC services. The results of this analysis can help identify the scope of WIC outreach needed to include more eligible nonparticipants in WIC and whom to target
Evolution of Preprofessional Pharmacy Curricula
Objectives. To examine changes in preprofessional pharmacy curricular requirements and trends, and determine rationales for and implications of modifications. Methods. Prerequisite curricular requirements compiled between 2006 and 2011 from all doctor of pharmacy (PharmD) programs approved by the Accreditation Council of Pharmacy Education were reviewed to ascertain trends over the past 5 years. An online survey was conducted of 20 programs that required either 3 years of prerequisite courses or a bachelor’s degree, and a random sample of 20 programs that required 2 years of prerequisites. Standardized telephone interviews were then conducted with representatives of 9 programs. Results. In 2006, 4 programs required 3 years of prerequisite courses and none required a bachelor’s degree; by 2011, these increased to 18 programs and 7 programs, respectively. Of 40 programs surveyed, responses were received from 28 (70%), 9 (32%) of which reported having increased the number of prerequisite courses since 2006. Reasons given for changes included desire to raise the level of academic achievement of students entering the PharmD program, desire to increase incoming student maturity, and desire to add clinical sciences and experiential coursework to the pharmacy curriculum. Some colleges and schools experienced a temporary decrease in applicants. Conclusions. The preprofessional curriculum continues to evolve, with many programs increasing the number of course prerequisites. The implications of increasing prerequisites were variable and included a perceived increase in maturity and quality of applicants and, for some schools, a temporary decrease in the number of applicants
EMPLOYING MARKOV MODELS TO FORECAST THE END STRENGTH OF THE US NAVY SUPPLY CORPS’ FINANCIAL MANAGEMENT (3111) COMMUNITY
The Navy Supply Corps has a wide array of Subspecialties (SSP) and Additional Qualification Designations (AQD) that define an officer’s skillset/experience and billet requirements. Current planning by the Supply Corps’ Office of Personnel (OP) assumes identical retention rates across all SSP/AQD combinations. This strategy may lead to unanticipated effects when changes to policy occur.
Our research applies the Markov model to manpower data obtained from OP to analyze the current and forecasted end strength of the Supply Corps’ Financial Management (FM) community. This research addresses the following questions: 1) What are the forecasted end strengths for Navy Supply Corps Officers with FM experience and qualifications? 2) Does the FM community’s current billet structure create enough FM officers to achieve OP’s inventory goal of 2.5 times the number of qualified FM officers per FM billet at the O5-O6 level?
We find that if the Supply Corps’ FM community continues along its current manpower trajectory, OP will likely never achieve its inventory goal for the community. However, our models provide multiple ways through which OP can achieve its O5-O6 inventory goals over time.Lieutenant Commander, United States NavyLieutenant Commander, United States NavyLieutenant Commander, United States NavyApproved for public release. Distribution is unlimited
Ending Social Work\u27s Grudge Match: Problems Versus Strengths
Some in social work have called for a paradigm shift away from a focus on problems to a focus on strengths, empowerment, and capacity building. This call sets up an unnatural dichotomy, asking social workers to identify with one side or another. In this article, we review social work history to argue that the best social work practice has always maintained a dual focus on both problems and capacity building. Throughout our history, those who championed a problem-oriented practice also emphasized strengths and growing client capacity, and today\u27s strength-based, capacity-oriented practitioners typically advocate for the solving of consumer\u27s presenting problems
LptO (PG0027) is required for lipid A 1-phosphatase activity in Porphyromonas gingivalis W50
ABSTRACT
Porphyromonas gingivalis
produces outer membrane vesicles (OMVs) rich in virulence factors, including cysteine proteases and A-LPS, one of the two lipopolysaccharides (LPSs) produced by this organism. Previous studies had suggested that A-LPS and PG0027, an outer membrane (OM) protein, may be involved in OMV formation. Their roles in this process were examined by using W50 parent and the Δ
PG0027
mutant strains. Inactivation of
PG0027
caused a reduction in the yield of OMVs. Lipid A from cells and OMVs of
P. gingivalis
W50 and the Δ
PG0027
mutant strains were analyzed by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Lipid A from W50 cells contained bis-P-pentaacyl, mono-P-pentaacyl, mono-P-tetraacyl, non-P-pentaacyl, and non-P-tetraacyl species, whereas lipid A from Δ
PG0027
mutant cells contained only phosphorylated species; nonphosphorylated species were absent. MALDI-TOF/TOF tandem MS of mono-P-pentaacyl (
m
/
z
1,688) and mono-P-tetraacyl (
m
/
z
1,448) lipid A from Δ
PG0027
showed that both contained lipid A 1-phosphate, suggesting that the Δ
PG0027
mutant strain lacked lipid A 1-phosphatase activity. The total phosphatase activities in the W50 and the Δ
PG0027
mutant strains were similar, whereas the phosphatase activity in the periplasm of the Δ
PG0027
mutant was lower than that in W50, supporting a role for PG0027 in lipid A dephosphorylation. W50 OMVs were enriched in A-LPS, and its lipid A did not contain nonphosphorylated species, whereas lipid A from the Δ
PG0027
mutant (OMVs and cells) contained similar species. Thus, OMVs in
P. gingivalis
are apparently formed in regions of the OM enriched in A-LPS devoid of nonphosphorylated lipid A. Conversely, dephosphorylation of lipid A through a PG0027-dependent process is required for optimal formation of OMVs. Hence, the relative proportions of nonphosphorylated and phosphorylated lipid A appear to be crucial for OMV formation in this organism.
IMPORTANCE
Gram-negative bacteria produce outer membrane vesicles (OMVs) by “blebbing” of the outer membrane (OM). OMVs can be used offensively as delivery systems for virulence factors and defensively to aid in the colonization of a host and in the survival of the bacterium in hostile environments. Earlier studies using the oral anaerobe
Porphyromonas gingivalis
as a model organism to study the mechanism of OMV formation suggested that the OM protein PG0027 and one of the two lipopolysaccharides (LPSs) synthesized by this organism, namely, A-LPS, played important roles in OMV formation. We suggest a novel mechanism of OMV formation in
P. gingivalis
involving dephosphorylation of lipid A of A-LPS controlled/regulated by PG0027, which causes destabilization of the OM, resulting in blebbing and generation of OMVs.
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