240 research outputs found
Chiral Symmetry and N*(1440) -> N pi pi Decay
The N*(1440) -> N pi pi decay is studied by making use of the chiral
reduction formula. This formula suggests a scalar-isoscalar pion-baryon contact
interaction which is absent in the recent study of Hern{\'a}ndez et al. The
contact interaction is introduced into their model, and is found to be
necessary for the simultaneous description of g_{RN pi pi} and the pi-pi and
pi-N invariant mass distributions.Comment: 12 page
Master formula approach to broken chiral U(3)xU(3) symmetry
The master formula approach to chiral symmetry breaking proposed by Yamagishi
and Zahed is extended to the U_R(3)xU_L(3) group, in which effects of the
U_A(1) anomaly and the flavor symmetry breaking m_u \not= m_d \not= m_s are
properly contained. New identities for the gluon topological susceptibility and
pi^0, eta, eta' -> gamma^(*) gamma^(*) decays are derived, which exactly embody
the consequence from broken chiral symmetry in QCD without relying on any
unphysical limit.Comment: Version to appear in PRD, 25 page
Double and single pion photoproduction within a dynamical coupled-channels model
Within a dynamical coupled-channels model which has already been fixed from
analyzing the data of the pi N -> pi N and gamma N -> pi N reactions, we
present the predicted double pion photoproduction cross sections up to the
second resonance region, W< 1.7 GeV. The roles played by the different
mechanisms within our model in determining both the single and double pion
photoproduction reactions are analyzed, focusing on the effects due to the
direct gamma N -> pi pi N mechanism, the interplay between the resonant and
non-resonant amplitudes, and the coupled-channels effects. The model parameters
which can be determined most effectively in the combined studies of both the
single and double pion photoproduction data are identified for future studies.Comment: Version to appear in PRC. 16 pages, 13 figure
Study of excited nucleon states at EBAC: status and plans
We present an overview of a research program for the excited nucleon states
in Excited Baryon Analysis Center (EBAC) at Jefferson Lab. Current status of
our analysis of the meson production reactions based on the unitary dynamical
coupled-channels model is summarized, and the N* pole positions extracted from
the constructed scattering amplitudes are presented. Our plans for future
developments are also discussed.Comment: Plenary talk given at Workshop on the Physics of Excited Nucleon --
NSTAR2009, Beijing, April 19-22, 2009. 8 pages, 8 figure
Use and efficacy of low temperature plasma in foods: promising intervention on aflatoxin control in maize in Kenya – a review
Maize (Zea mays var. indentata L.) is the most important food security crop in Kenya and plays an important role in human nutrition. Mycotoxins (MTs) are fungal toxic metabolites which naturally contaminate food and feed. When ingested, inhaled or adsorbed through the skin, even in very small concentrations, are associated with various cancers, retarded growth, suppressed immunity and mutations among other complications. Aflatoxins especially aflatoxin B1, are considered the most lethal in the group of more than three hundred known mycotoxins. In Kenya, aflatoxin contamination in maize leads to huge losses in the country’s breadbasket and also in the grain reserves. One of the possible methods for control of the aflatoxin menace in maize would be through the use of plasma technology. Plasma, an electrically energized matter in form of a gas that is generated at different atmospheric pressures, has several uses. At low temperature, it makes the process of decontamination practical, inexpensive and suitable for products whereby use of heat is not desired. Non thermal plasma, a new discipline in food processing has been shown to destroy microorganisms including spores to undetectable levels. Over the years, there has been increased concern over the rising cases of aflatoxin poisoning in Kenya due to contaminated maize. The presence of aflatoxins is promoted by various factors, among them poor storage conditions, soil type, insect activity and drought conditions before harvest. Several measures including use of hermetic storage types such as pics (Purdue Improved Cowpea Storage) bags to store maize and proper drying of maize to the right moisture content to discourage mould growth have been suggested and used to tackle the aflatoxin menace. In Mexico and Caribbean countries, nixtamalization is widely practised and has been used to reduce aflatoxin in tortilla. Nixtamilization involves cooking the maize in an alkaline solution resulting in detoxification. The traditional nixtamalization and extrusion cooking processes have been combined in making of the dough (masa) for corn tortillas and have shown better success in elimination of aflatoxin. The main challenge with the use of this method of detoxification is acidification of aflatoxin extracts, which occurs during digestion and can lead to a rebuilding of the aflatoxin molecule leading to poisoning. The application of low temperature plasma technology can bring much needed reprieve in tackling the aflatoxin menace in maize and other foods both in Kenya and even worldwide
Dynamical coupled-channels analysis of 1H(e,e'pi)N reactions
We have performed a dynamical coupled-channels analysis of available
p(e,e'pi)N data in the region of W < 1.6 GeV and Q^2 < 1.45 (GeV/c)^2. The
channels included are gamma^* N, pi N, eta N, and pi pi N which has pi Delta,
rho N, and sigma N components. With the hadronic parameters of the model
determined in our previous investigations of pi N --> pi N, pi pi N reactions,
we have found that the available data in the considered W < 1.6 GeV region can
be fitted well by only adjusting the bare gamma^* N --> N^* helicity amplitudes
for the lowest N^* states in P33, P11, S11 and D13 partial waves. The
sensitivity of the resulting parameters to the amount of data included in the
analysis is investigated. The importance of coupled-channels effect on the
p(e,e' pi)N cross sections is demonstrated. The meson cloud effects, as
required by the unitarity conditions, on the gamma^* N --> N^* form factors are
also examined. Necessary future developments, both experimentally and
theoretically, are discussed.Comment: 14 pages, 11 figures. Version to appear in PR
Prevalence of Gestational Diabetes in Hospitals in the City of Lubumbashi in the Democratic Republic of Congo: Case of the Jason Sendwe General Reference Hospital in 2015 to 2019
Gestational diabetes is defined as a carbohydrate tolerance disorder leading to hyperglycaemia of varying severity, occurring or first diagnosed during pregnancy, regardless of the treatment required and the course of the postpartum period. Its prevalence has been estimated at between 2.2% and 8.8% of pregnancies, depending on the populations studied and the screening criteria used. We determined the prevalence of gestational diabetes at the Jason Sendwe General Referral Hospital. A descriptive cross-sectional study was carried out from January 2015 to December 2019 at Sendwe Hospital. It concerned 48 pregnant women from 24 weeks of pregnancy. The diagnosis of gestational diabetes was made by blood glucose obtained with the O'Sullivan test or by fasting blood glucose. The prevalence of gestational diabetes was 2.15%. Modifiable and non-modifiable factors associated with gestational diabetes in this study are age ≥ 35 years, parity, history of macrosomia, and history of type 2 diabetes in the surrogates of the pregnancies. The prevalence rate remains high and shows that gestational diabetes is a public health problem in the city of Lubumbashi. The O'Sullivan test is a valid alternative for its good detection. We found that age, especially after 35 years is the major determinant of gestational diabetes in the population living in Lubumbashi
Symptoms of depression among patients attending a diabetes care clinic in rural western Kenya
Objective: The prevalence of diabetes in sub-Saharan Africa is rising, but its relationship to depression is not well-characterized. This report describes depressive symptom prevalence and associations with adherence and outcomes among patients with diabetes in a rural, resource-constrained setting.
Methods: In the Webuye, Kenya diabetes clinic, we conducted a chart review, analyzing data including medication adherence, hemoglobin A1c (HbA1c), clinic attendance, and PHQ-2 depression screening results.
Results: Among 253 patients, 20.9% screened positive for depression. Prevalence in females was higher than in males; 27% vs 15% (p = 0.023). Glycemic control trends were better in those screening negative; at 24 months post-enrollment mean HbA1c was 7.5 for those screening negative and 9.5 for those screening positive (p = 0.0025). There was a nonsignificant (p = 0.269) trend toward loss to follow-up among those screening positive.
Conclusions: These findings suggest that depression is common among people with diabetes in rural western Kenya, which may profoundly impact diabetes control and treatment adherence
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