Finite volume effects in a quenched lattice-QCD quark propagator

We investigate finite volume effects in the pattern of chiral symmetry breaking. To this end we employ a formulation of the Schwinger-Dyson equations on a torus which reproduces results from the corresponding lattice simulations of staggered quarks and from the overlap action. Studying the volume dependence of the quark propagator we find quantitative differences with the infinite volume result at small momenta and small quark masses. We estimate the minimal box length L below which chiral perturbation theory cannot be applied to be L \simeq 1.6 fm. In the infinite volume limit we find a chiral condensate of ||_{\bar{MS}}^{2 GeV} = (253 \pm 5.0 MeV)^3, an up/down quark mass of m_{\bar{MS}}^{2 GeV} = 4.1 \pm 0.3 MeV and a pion decay constant which is only ten percent smaller than the experimental value.Comment: 19 pages, 8 figures. v2: minor clarifications added, version published in PR

Quark Condensates: Flavour Dependence

We determine the q-bar q condensate for quark masses from zero up to that of the strange quark within a phenomenologically successful modelling of continuum QCD by solving the quark Schwinger-Dyson equation. The existence of multiple solutions to this equation is the key to an accurate and reliable extraction of this condensate using the operator product expansion. We explain why alternative definitions fail to give the physical condensate.Comment: 9 pages, 7 figures, uses appolb.cls, LaTeX. Talk presented by R. Williams at the EURIDICE Final Meeting, August 24-27th, 2006, Kazimierz, Polan

Response of Fishes to Revetment Placement

Routine fish sampling with hoop nets was conducted monthly from April through December 1978 along natural and revetted riverbanks on the lower Mississippi River near Eudora, Arkansas, to monitor changes in fish populations affected by placement of new revetment for bank protection. Eighteen species of fish were collected with four species comprising over 75% of the total catch. During the months prior to revetment placement, freshwater drum, Aplodinotus grunniens, was the most abundant (32.7% of the catch) species collected. Following in abundance were the flathead catfish, Pylodictis olivaris, (9.8%), common carp, Cyprinus carpio, (7.8%), and blue catfish, Ictalurus furcatus, (3.3%). After revetment placement in August 1978, the freshwater drum was again the most abundant component, comprising 9.7% of the catch. Gizzard shad, Dorosoma cepedianum, flathead catfish, and blue catfish followed in abundance and comprised 8.9, 4.1, and 3.4% of the total catch, respectively. Catch per effort data indicated that fish were generally more abundant at natural bank stations than revetted bank stations but the difference was not significant. The study suggests that fish inhabiting natural riverbank habitat recover quite rapidly from bank perturbation caused by the placement of revetment

Evaluation of Word Processing for ESL Writers

This paper offers an assessment of the promise and problems for ESL of computerassisted writing using word processing. Both positive and negative effects reported in the published literature in ESL and native-speaker composition are reviewed, and the attempt is made to find explanations for the differing results of individual studies. In addition to the inherent properties of the medium, methodological and context effects are identified which help to account for the differential findings. These effects are attributable to variation across studies in one or more of the following variables: (a) the nature of the subjects, (b) the abilities and attitudes of teachers, (c) the setting for computer use, (d) the time-span of the research, (e) the type and amount of training for use of the software, (f) the instructional format for computer use, (g) the biases introduced by particular word processing software, and (h) the effectiveness measures applied to evaluate results. Considering the needs of ESL students in the area of writing and the results that can be predicted for word processing based on the nature of the computer medium, it is concluded that use of word processing seems justified as a medium for enhancing the creative revision process of ESL students, and recommendations are offered for pedagogy and research in ESL contexts

The Difference in Academic Achievement for Students in the Healthy Fitness Zone Compared to the High Risk Zone for BMI and Aerobic Capacity

Childhood obesity rates have climbed significantly over the past 40 years. With that, there has also been an increase in the number of associated health concerns, such as diabetes, heart disease, and asthma, of many. Quite independently, there has also been an increase in the accountability placed on schools to improve their reading and math test scores. This has resulted in a decrease in physical activity times in schools in order to provide more class time for reading and math. This study’s purpose has been to identify whether a difference exists in academic outcomes for students in the HFZ compared to those in the HRZ in order to support better decision-making for school leaders in regards to reducing physical activity opportunities, like PE and recess. Using matched data for 666 fifth grade students from a southeastern Georgia community, this researcher measured student BMI and aerobic capacity scores comparing FITNESSGRAM® with results for these children on the MAP reading and math assessments. When accounting for SES, students in the HFZ for BMI and aerobic capacity had higher mean scores on the MAP math test. Students who were in the HRZ for BMI and not economically disadvantaged had a higher mean score in reading than students in the HFZ. Likewise, students who were in the HRZ for aerobic capacity and economically disadvantaged had a higher mean score in reading than students in the HFZ. None of the results were statistically significant, and, therefore, no difference between physical fitness and academic achievement for students in the HFZ compared to HRZ could be identified

THE INDUSTRY HAS CHANGED, HAVE YOU? THE AGCO STORY

AGCO Corporation is a success story in the agricultural machinery sector. Utilizing marketing strategies of out-sourcing, cross-over selling, and a full line of products, AGCO markets its own way. In 7 years, AGCO has 18 brands sold through 7,000 dealerships in 140 countries. Acquisition and consolidation powered the growth of AGCO using nontraditional buyout financing. Herein lies its real success.Agribusiness, Industrial Organization,

Brain GABA and Glutamate Concentrations Following Chronic Gabapentin Administration: A Convenience Sample Studied During Early Abstinence From Alcohol.

Gabapentin (GBP), a GABA analog that may also affect glutamate (Glu) production, can normalize GABA and Glu tone during early abstinence from alcohol, effectively treating withdrawal symptoms and facilitating recovery. Using in vivo magnetic resonance spectroscopy, we tested the degree to which daily GBP alters regional brain GABA and Glu levels in short-term abstinent alcohol-dependent individuals. Regional metabolite levels were compared between 13 recently abstinent alcohol-dependent individuals who had received daily GBP for at least 1 week (GBP+) and 25 matched alcohol-dependent individuals who had not received GBP (GBP-). Magnetic resonance spectra from up to five different brain regions were analyzed to yield absolute GABA and Glu concentrations. GABA and Glu concentrations in the parieto-occipital cortex were not different between GBP- and GBP+. Glu levels in anterior cingulate cortex, dorsolateral prefrontal cortex, and basal ganglia did not differ between GBP- and GBP+. However, in a subgroup of individuals matched on age, sex, and abstinence duration, GBP+ had markedly lower Glu in the frontal white matter (WM) than GBP-, comparable to concentrations found in light/non-drinking controls. Furthermore, lower frontal WM Glu in GBP+ correlated with a higher daily GBP dose. Daily GBP treatment at an average of 1,600 mg/day for at least 1 week was not associated with altered cortical GABA and Glu concentrations during short-term abstinence from alcohol, but with lower Glu in frontal WM. GBP for the treatment of alcohol dependence may work through reducing Glu in WM rather than increasing cortical GABA