1,069 research outputs found
Pion parameters in nuclear medium from chiral perturbation theory and virial expansion
We consider two methods to find the effective parameters of the pion
traversing a nuclear medium. One is the first order chiral perturbation
theoretic evaluation of the pion pole contribution to the two-point function of
the axial-vector current. The other is the exact, first order virial expansion
of the pion self-energy. We find that, although the results of chiral
perturbation theory are not valid at normal nuclear density, those from the
virial expansion may be reliable at such density. The latter predicts both the
mass-shift and the in-medium decay width of the pion to be small, of about a
few MeV.Comment: 9 Pages RevTex, 3 eps figure
Geometrical quadrupolar frustration in DyB
Physical properties of DyB have been studied by magnetization, specific
heat, and ultrasonic measurements. The magnetic entropy change and the
ultrasonic properties in the intermediate phase II indicate that the degeneracy
of internal degrees of freedom is not fully lifted in spite of the formation of
magnetic order. The ultrasonic attenuation and the huge softening of
in phase II suggests existence of electric-quadrupolar (orbital) fluctuations
of the 4-electron. These unusual properties originate from the geometrical
quadrupolar frustration.Comment: 4 pages, 4 figures, accepted for publication in Journal of the
Physical Society of Japa
Could SARS-CoV-2 Have Bacteriophage Behavior or Induce the Activity of Other Bacteriophages?
SARS-CoV-2 has become one of the most studied viruses of the last century. It was assumed that the only possible host for these types of viruses was mammalian eukaryotic cells. Our recent studies show that microorganisms in the human gastrointestinal tract affect the severity of COVID-19 and for the first time provide indications that the virus might replicate in gut bacteria. In order to further support these findings, in the present work, cultures of bacteria from the human microbiome and SARS-CoV-2 were analyzed by electron and fluorescence microscopy. The images presented in this article, in association with the nitrogen (15N) isotope-labeled culture medium experiment, suggest that SARS-CoV-2 could also infect bacteria in the gut microbiota, indicating that SARS-CoV-2 could act as a bacteriophage. Our results add new knowledge to the understanding of the mechanisms of SARS-CoV-2 infection and fill gaps in the study of the interactions between SARS-CoV-2 and non-mammalian cells. These findings could be useful in suggesting specific new pharmacological solutions to support the vaccination campaign
Yoga respiratory training improves respiratory function and cardiac sympathovagal balance in elderly subjects: a randomised controlled trial
OBJECTIVES: Since ageing is associated with a decline in pulmonary function, heart rate variability and spontaneous baroreflex, and recent studies suggest that yoga respiratory exercises may improve respiratory and cardiovascular function, we hypothesised that yoga respiratory training may improve respiratory function and cardiac autonomic modulation in healthy elderly subjects.
DESIGN: 76 healthy elderly subjects were enrolled in a randomised control trial in Brazil and 29 completed the study (age 68 \ub1 6 years, 34% males, body mass index 25 \ub1 3 kg/m\ub2). Subjects were randomised into a 4-month training program (2 classes/week plus home exercises) of either stretching (control, n=14) or respiratory exercises (yoga, n=15). Yoga respiratory exercises (Bhastrika) consisted of rapid forced expirations followed by inspiration through the right nostril, inspiratory apnoea with generation of intrathoracic negative pressure, and expiration through the left nostril. Pulmonary function, maximum expiratory and inspiratory pressures (PE(max) and PI(max), respectively), heart rate variability and blood pressure variability for spontaneous baroreflex determination were determined at baseline and after 4 months.
RESULTS: Subjects in both groups had similar demographic parameters. Physiological variables did not change after 4 months in the control group. However, in the yoga group, there were significant increases in PE(max) (34%, p<0.0001) and PI(max) (26%, p<0.0001) and a significant decrease in the low frequency component (a marker of cardiac sympathetic modulation) and low frequency/high frequency ratio (marker of sympathovagal balance) of heart rate variability (40%, p<0.001). Spontaneous baroreflex did not change, and quality of life only marginally increased in the yoga group.
CONCLUSION: Respiratory yoga training may be beneficial for the elderly healthy population by improving respiratory function and sympathovagal balance. Trial Registration CinicalTrials.gov identifier: NCT00969345; trial registry name: Effects of respiratory yoga training (Bhastrika) on heart rate variability and baroreflex, and quality of life of healthy elderly subjects
Accounting students' IT applicaton skills over a 10-year period
This paper reports on the changing nature of a range of information technology (IT) application skills that students declare on entering an accounting degree over the period from 1996 to 2006. Accounting educators need to be aware of the IT skills students bring with them to university because of the implications this has for learning and teaching within the discipline and the importance of both general and specific IT skills within the practice and craft of accounting. Additionally, IT skills constitute a significant element within the portfolio of employability skills that are increasingly demanded by employers and emphasized within the overall Higher Education (HE) agenda. The analysis of students' reported IT application skills on entry to university, across a range of the most relevant areas of IT use in accounting, suggest that their skills have continued to improve over time. However, there are significant differential patterns of change through the years and within cohorts. The paper addresses the generalizability of these findings and discusses the implications of these factors for accounting educators, including the importance of recognising the differences that are potentially masked by the general increase in skills; the need for further research into the changing nature, and implications, of the gender gap in entrants' IT application skills; and the low levels of entrants' spreadsheet and database skills that are a cause for concern
Momentum-Resolved Charge Excitations in a Prototype One Dimensional Mott Insulator
We report momentum resolved charge excitations in a one dimensional (1-D)
Mott insulator studied using high resolution (~ 325 meV) inelastic x-ray
scattering over the entire Brillouin zone for the first time. Excitations at
the insulating gap edge are found to be highly dispersive (momentum
dependent)compared to excitations observed in two dimensional Mott insulators.
The observed dispersion in 1-D is consistent with charge excitations involving
holons which is unique to spin-1/2 quantum chain systems. These results point
to the potential utility of inelastic x-ray scattering in providing valuable
information about electronic structure of strongly correlated insulators.Comment: 3 pages, 2 figures, Revised with minor change
A North American Expert Opinion Statement on Sarcopenia in Liver Transplantation
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151960/1/hep30828_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151960/2/hep30828.pd
The effectiveness and cost-effectiveness of assistive technology and telecare for independent living in dementia: a randomised controlled trial
OBJECTIVES: The use of assistive technology and telecare (ATT) has been promoted to manage risks associated with independent living in people with dementia but with little evidence for effectiveness. METHODS: Participants were randomly assigned to receive an ATT assessment followed by installation of all appropriate ATT devices or limited control of appropriate ATT. The primary outcomes were time to institutionalisation and cost-effectiveness. Key secondary outcomes were number of incidents involving risks to safety, burden and stress in family caregivers and quality of life. RESULTS: Participants were assigned to receive full ATT (248 participants) or the limited control (247 participants). After adjusting for baseline imbalance of activities of daily living score, HR for median pre-institutionalisation survival was 0.84; 95% CI, 0.63 to 1.12; P = 0.20. There were no significant differences between arms in health and social care (mean -£909; 95% CI, -£5,336 to £3,345, P = 0.678) and societal costs (mean -£3,545; 95% CI, -£13,914 to £6,581, P = 0.499). ATT group members had reduced participant-rated quality-adjusted life years (QALYs) at 104 weeks (mean - 0.105; 95% CI, -0.204 to -0.007, P = 0.037) but did not differ in QALYs derived from proxy-reported EQ-5D. DISCUSSION: Fidelity of the intervention was low in terms of matching ATT assessment, recommendations and installation. This, however, reflects current practice within adult social care in England. CONCLUSIONS: Time living independently outside a care home was not significantly longer in participants who received full ATT and ATT was not cost-effective. Participants with full ATT attained fewer QALYs based on participant-reported EQ-5D than controls at 104 weeks
Mild Systemic Oxidative Stress in the Subclinical Stage of Alzheimer's Disease
Alzheimer's disease (AD) is a late-onset, progressive degenerative disorder that affects mainly the judgment, emotional stability, and memory domains. AD is the outcome of a complex interaction among several factors which are not fully understood yet; nevertheless, it is clear that oxidative stress and inflammatory pathways are among these factors. 65 elderly subjects (42 cognitively intact and 23 with probable Alzheimer's disease) were selected for this study. We evaluated erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase as well as plasma levels of total glutathione, alpha-tocopherol, beta-carotene, lycopene, and coenzyme Q10. These antioxidant parameters were confronted with plasmatic levels of protein and lipid oxidation products. Additionally, we measured basal expression of monocyte HLA-DR and CD-11b, as well as monocyte production of cytokines IL1-alpha, IL-6, and TNF-alpha. AD patients presented lower plasmatic levels of alpha-tocopherol when compared to control ones and also higher basal monocyte HLA-DR expression associated with higher IL-1 alpha production when stimulated by LPS. These findings support the inflammatory theory of AD and point out that this disease is associated with a higher basal activation of circulating monocytes that may be a result of alpha-tocopherol stock depletion.Univ São Paulo, Inst Quim, BR-05508900 São Paulo, BrazilUNIFESP, Inst Ciencias Ambientais Quim Farmaceut, BR-09972270 Diadema, SP, BrazilFMABC, Dept Hematol & Oncol, BR-09060650 Santo Andre, SP, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04021001 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med Prevent, BR-04021001 São Paulo, BrazilUNIFESP, Inst Ciencias Ambientais Quim Farmaceut, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04021001 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med Prevent, BR-04021001 São Paulo, BrazilWeb of Scienc
Pair Interaction Potentials of Colloids by Extrapolation of Confocal Microscopy Measurements of Collective Structure
A method for measuring the pair interaction potential between colloidal
particles by extrapolation measurement of collective structure to infinite
dilution is presented and explored using simulation and experiment. The method
is particularly well suited to systems in which the colloid is fluorescent and
refractive index matched with the solvent. The method involves characterizing
the potential of mean force between colloidal particles in suspension by
measurement of the radial distribution function using 3D direct visualization.
The potentials of mean force are extrapolated to infinite dilution to yield an
estimate of the pair interaction potential, . We use Monte Carlo (MC)
simulation to test and establish our methodology as well as to explore the
effects of polydispersity on the accuracy. We use poly-12-hydroxystearic
acid-stabilized poly(methyl methacrylate) (PHSA-PMMA) particles dispersed in
the solvent dioctyl phthalate (DOP) to test the method and assess its accuracy
for three different repulsive systems for which the range has been manipulated
by addition of electrolyte.Comment: 35 pages, 14 figure
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