1,141 research outputs found
Covariance, Dynamics and Symmetries, and Hadron Form Factors
We summarise applications of Dyson-Schwinger equations to the theory and
phenomenology of hadrons. Some exact results for pseudoscalar mesons are
highlighted with details relating to the U_A(1) problem. We describe inferences
from the gap equation relating to the radius of convergence for expansions of
observables in the current-quark mass. We recapitulate upon studies of nucleon
electromagnetic form factors, providing a comparison of the ln-weighted ratios
of Pauli and Dirac form factors for the neutron and proton.Comment: 9 pages, 2 figures. Contribution to proceedings of Workshop on
Exclusive Reactions at High Momentum Transfer, May 21-24, 2007, Jefferson
Lab, Newport News, V
The role of informal protected areas in maintaining biodiversity in the Western Ghats of India
Although it is widely believed that an important function of protected areas is to conserve species that are unable to survive elsewhere, there are very few empirical studies in which a comparison is made between biodiversity of protected areas and that of the cultivated landscape surrounding them. We examined the diversity of trees, birds, and macrofungi at 58 sites in three land-use types in a tree-covered landscape in Kodagu district in the Western Ghats of India. Ten forest reserve sites in the formal protected area, and 25 sacred groves and 23 coffee plantations in the neighboring cultivated landscape were sampled. A total of 215 tree, 86 bird, and 163 macrofungus species were recorded. The forest reserve had a large
number of trees that were restricted in their distribution, and the sacred groves had a large number of macrofungi. We observed that deciduous trees and non-forest-dwelling birds increased, and evergreen trees and forest-dwelling birds decreased with increasing intensity of land management. We found that trees having non-timber uses and macrofungi useful to the local people, as well as those with medicinal properties, were abundant in sacred groves. We found no significant differences in the distribution of endemic and threatened birds across the three land-use types. Although endemic trees were more abundant in the forest reserve than in sacred groves, threatened trees were more abundant in sacred groves than in the forest reserve. We attribute the high diversity in sacred groves to the native tree cover in shade coffee plantations. We conclude that informal protected areas are as important as formal ones for biodiversity conservation in Kodagu. We recommend that a conservation strategy that recognizes informal protection traditions is essential for successful biodiversity conservation in regions where formal reserves are surrounded by a matrix of cultivated land
Studying pion effects in the quark propagator
Within the framework of Schwinger-Dyson and Bethe-Salpeter equations we
investigate the importance of pions for the quark-gluon interaction. To this
end we choose a truncation for the quark-gluon vertex that includes
intermediate pion degrees of freedom and adjust the interaction such that
unquenched lattice results for various current quark masses are reproduced. The
corresponding Bethe-Salpeter kernel is constructed from constraints by chiral
symmetry. After extrapolation to the physical point we find a considerable
contribution of the pion back reaction to the quark mass function as well as to
the chiral condensate. The quark wave function is less affected.Comment: Talk given at 11th International Conference on Meson-Nucleon Physics
and the Structure of the Nucleon (MENU 2007), Julich, Germany, 10-14 Sep 200
Flavour symmetry breaking and meson masses
The axial-vector Ward-Takahashi identity is used to derive mass formulae for
neutral pseudoscalar mesons. Flavour symmetry breaking entails non-ideal
flavour content for these states. Adding that the \eta^\prime is not a
Goldstone mode, exact chiral-limit relations are developed from the identity.
They connect the dressed-quark propagator to the topological susceptibility. It
is confirmed that in the chiral limit the \eta^\prime mass is proportional to
the matrix element which connects this state to the vacuum via the topological
susceptibility. The implications of the mass formulae are illustrated using an
elementary dynamical model, which includes an Ansatz for that part of the
Bethe-Salpeter kernel related to the non-Abelian anomaly. In addition to the
current-quark masses, the model involves two parameters, one of which is a
mass-scale. It is employed in an analysis of pseudoscalar- and vector-meson
bound-states. While the effects of SU(N_f=2) and SU(N_f=3) flavour symmetry
breaking are emphasised, the five-flavour spectra are described. Despite its
simplicity, the model is elucidative and phenomenologically efficacious; e.g.,
it predicts \eta-\eta^\prime mixing angles of ~ (-15 degrees) and \pi^0-\eta
angles of ~ 1 degree.Comment: 11 pages, 2 figure
Virechana Karma in Eczema (Kshudra Kushtha) : A Case Study
Panchakarma therapy aims at the elimination of excessive Doshas from the body to maintain the state of health for a longer duration, while the Shamana therapy is for suppression of vitiated Doshas within the body. Virechana is one of the Panchakarma therapy. Virechana is the bio-purification procedure of Ayurveda when Doshas are expelled out from the body through the anal route then it is called Virechana. Normally, after Virechana Karma, patient does not complain of having any untoward like those present after diarrhea due to dehydration. Thus, Virechana Karma is one of the important bio-purificative method which is indicated for complete elimination of Doshas and thus result in eradication of diseases. Patient was treated with Shodhana in the form of Virechana Karma followed by oral medication. The patient reported symptomatic improvement
Vamana Karma in Tamaka Shwasa - A Case Study
Tamaka Shwasa is a very common disease in India. The prevalence of the disease is increasing day by day due to genetic susceptibility, Pollution, environmental factor, stressful life, abnormal Food style that all exposes the humans to suffer from Tamaka Shwasa. Ayurveda the science of life describes the management of lifestyle diseases. In the form of proper dietary, its behavioral management i.e., daily regimen and seasonal regimen, seasonal detoxification and rejuvenation therapies In Ayurveda Shodhana (Purification) Shamana (Pacification) and Nidana Parivarjana (avoiding causative factors) are the three folds of fundamental therapeutic management of the disease. Panchakarma is Ayurveda’s prime Shodhana procedures which is basically group of detoxification procedures. In Ayurveda text Tamaka Shwasa is a disease which Is Kapha Vata Dosha predominant and disease of Pranavaha Strotasa. Tamaka Shwasa is clinically much resembled with bronchial asthma. Here Panchakarma procedure is quite effective which is based on situation of patient. In present case study Panchakarma procedure i.e., Vasantik Vamana was given to the patient for management of Tamaka Shwasa
Solving the Bethe-Salpeter equation for a pseudoscalar meson in Minkowski space
A new method of solution of the Bethe-Salpeter equation for a pseudoscalar
quark-antiquark bound state is proposed. With the help of an integral
representation, the results are directly obtained in Minkowski space. Dressing
of Green's functions is naturally taken into account, thus providing the
possible inclusion of a running coupling constant as well as quark propagators.
First numerical results are presented for a simplified ladder approximation
Analysis of Media Agenda-Setting Effects on Consumer Confidence in the Safety of the U.S. Food System
Results from continuous tracking of consumer confidence and media coverage of food safety events over a 67 week period between May 2008 and August 2009 are reported. An ordered probit model is used to test the hypothesis that media coverage of food safety events affects consumer confidence in the safety of the U.S. food system. The results show that media coverage significantly and negatively affected consumer confidence in the safety of nation’s food supply during the sample period. Socioeconomic and demographic factors such as geographic region, use of media source, household size, age, ethnicity, education, and gender also had significant affects on consumer confidence in the safety of United States food supply.Food Safety, Consumer Confidence, Mass media, ordered probit, Food Consumption/Nutrition/Food Safety,
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