Spin content of constituent quarks and one-spin asymmetries in inclusive processes

We consider mechanism for one-spin asymmetries observed in inclusive hadron production. The main role belongs to the orbital angular momentum of the quark-antiquark cloud in the internal structure of constituent quarks. We argue that the origin of the asymmetries in pion production is a result of retaining of this internal angular orbital momentum by the perturbative phase of QCD under transition from the non-perturbative phase. The non-perturbative hadron structure is based on the results of chiral quark models. PACS number(s): 11.30.Qc, 12.40.Pp, 13.75.Ni, 13.88.+eComment: 21 pages LaTeX + 8 figures (not included

Hyperon Polarization in the Constituent Quark Model

We consider mechanism for hyperon polarization in inclusive production. The main role belongs to the orbital angular momentum and polarization of the strange quark-antiquark pairs in the internal structure of the constituent quarks. We consider a nucleon as a core consisting of the constituent quarks embedded into quark condensate. The nonperturbative hadron structure is based on the results of chiral quark models.Comment: 14 pages, LaTeX, 2 Figures, References adde

Effectiveness of a High School Alcohol Misuse Prevention Program

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65153/1/j.1530-0277.1996.tb05253.x.pd

Polarization in Hadronic \Lambda Hyperon Production and Chiral-Odd Twist-3 Distribution

Polarization of the \Lambda hyperon produced with a large transverse momentum in the unpolarized nucleon-nucleon collision is analyzed in the framework of QCD factorization. We focus on the mechanism in which the soft-gluon component of the chiral-odd spin-independent twist-3 quark distribution E_F(x,x) becomes a source of the polarized quark fragmenting into the polarized \Lambda. Our simple model estimate for this contribution indicates that it gives rise to a significant \Lambda polarization at large x_F. This is in parallel with the observation that the soft gluon pole mechanism gives rise to a large single transverse spin asymmetry in the pion production at x_F\to 1.Comment: 10 pages in LaTex + 5 figures in PS files. Phys. Rev. D in press. Title changed and some discussions adde

Nectar Yeasts in the Tall Larkspur Delphinium barbeyi (Ranunculaceae) and Effects on Components of Pollinator Foraging Behavior

Microorganisms frequently colonize the nectar of angiosperm species. Though capable of altering a suite of traits important for pollinator attraction, few studies exist that test the degree to which they mediate pollinator foraging behavior. The objective of our study was to fill this gap by assessing the abundance and diversity of yeasts associated with the perennial larkspur Delphinium barbeyi (Ranunculaceae) and testing whether their presence affected components of pollinator foraging behavior. Yeasts frequently colonized D. barbeyi nectar, populating 54–77% of flowers examined depending on site. Though common, the yeast community was species-poor, represented by a single species, Metschnikowia reukaufii. Female-phase flowers of D. barbeyi were more likely to have higher densities of yeasts in comparison to male-phase flowers. Pollinators were likely vectors of yeasts, as virgin (unvisited) flowers rarely contained yeasts compared to flowers open to pollinator visitation, which were frequently colonized. Finally, pollinators responded positively to the presence of yeasts. Bombus foragers both visited and probed more flowers inoculated with yeasts in comparison to uninoculated controls. Taken together, our results suggest that variation in the occurrence and density of nectar-inhabiting yeasts have the potential to alter components of pollinator foraging behavior linked to pollen transfer and plant fitness

The Feasibility of Utilizing the Open Dynamic Interaction Network (ODIN) app to assess rEMA data across 30 days among those Recovering from Alcoholism

About ~4 million people with an alcohol use disorder receive treatment annually, and frequent relapse has produced a rapid revolving door between recovery and use. This paper presents preliminary data from a prospective micro-longitudinal study (30 days) that examines co-evolution of relapse risk processes of people with alcohol use disorders who entered a short-term residential substance use treatment. The primary goal of the current data was to assess the feasibility of using the open dynamic interaction network (ODIN) responsive ecological momentary assessment (rEMA). rEMA collected daily estimates on affect, urges, sober-support engagement, and use. The ODIN app administered twelve questions at established EMA times each day. GPS identified engagement in sober support activities and alcohol cue exposure (e.g., gas stations, grocery stores, bars) prompted additional questions. Of the eight hundred questions asked over 31 days, the mode for questions answered was 500. Five-day estimates showed that 80% of the participants answered between 80-100 questions (10-30 questions/day). Also, the ODIN app acquired 95% of GPS readings across 30 days (~288 GPS readings/day). Most were satisfied with stability (84%), look/feel (82.4%), and ease of use (92.2%) of the ODIN app. Participants also reported interest in longer assessments (100%) using the app if it prompted them to call sponsor (85%) or to use relapse prevention skills (72%). Preliminary findings show that the ODIN platform accurately and efficiently collects data amongst this population. There was a high rate of acceptability, satisfaction, and interest in using ODIN to help them engage in sober support/relapse prevention

Incident hand OA is strongly associated with reduced peripheral blood leukocyte telomere length

[Abstract] Objective: To evaluate the relationship of telomere length to the prevalence and incidence of hand osteoarthritis in a longitudinal cohort. Design: We conducted a cross-sectional and longitudinal analysis of data from a subset of participants in the Osteoarthritis Initiative (OAI) recruited between February 2004 and May 2006. 274 individuals were eligible for the study based on availability of both baseline and 48-month hand radiographs and peripheral blood leucocyte telomere length data. Mean telomere length of peripheral blood leukocytes (PBL)s from the DNA samples was determined using a validated quantitative polymerase chain reaction (PCR)-based assay, and hand radiographs were analyzed and graded using the Kellgren-Lawrence scale. Results: In joint -level analyses, prevalent Interphalangeal Joint Osteoarthritis (IPJOA) was significantly associated with PBL telomere length in the baseline sample in unadjusted analyses (RR = 2.84; 95% CI:0.87-9.29) or in models adjusted for age, sex, and body mass index (aRR = 1.10; 95% CI: 0.96-1.27). The association in crude and adjusted analyses appeared slightly stronger with incident IPJOA, especially in the subset with normal hands at baseline (aRR = 1.62; 95% CI: 1.02-2.57). PBL telomere length was also associated with prevalent HOA at baseline (significant in unadjusted analysis: RR = 1.22; 95% CI 1.06-1.42), but not after adjusting for covariates: aRR = 1.12; 95% CI: 0.96-1.30). The magnitude of association was stronger for incident HOA, especially incident symptomatic HOA (aRR = 1.53; 95% CI: 1.09-2.15). Conclusions: In summary, the results of this exploratory analysis are confirmatory of previous work showing a cross-sectional relationship between telomere length and HOA and add to the field by demonstrating an even stronger association with incident IPJOA, both radiographic and symptomatic.info:eu-repo/grantAgreement/MINECO/Programa Estatal de I+D+I Orientada a los Retos de la Sociedad/PI16%2F02124/ES/Determinación de índices predictivos de diagnóstico y pronóstico de artrosis de rodilla mediante la validación de biomarcadores proteicosinfo:eu-repo/grantAgreement/ISCIII/Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia/PI17%2F01987/ES/ANALISIS DINAMICO DE PARAMETROS DE FISIOLOGIA TELOMERICA, COMO MARCADORES DE INCIDENCIA Y/O PROGRESION DE OSTEOARTITI

Strength Training for Arthritis Trial (START): design and rationale

Background Muscle loss and fat gain contribute to the disability, pain, and morbidity associated with knee osteoarthritis (OA), and thigh muscle weakness is an independent and modifiable risk factor for it. However, while all published treatment guidelines recommend muscle strengthening exercise to combat loss of muscle mass and strength in knee OA patients, previous strength training studies either used intensities or loads below recommended levels for healthy adults or were generally short, lasting only 6 to 24 weeks. The efficacy of high-intensity strength training in improving OA symptoms, slowing progression, and affecting the underlying mechanisms has not been examined due to the unsubstantiated belief that it might exacerbate symptoms. We hypothesize that in addition to short-term clinical benefits, combining greater duration with high-intensity strength training will alter thigh composition sufficiently to attain long-term reductions in knee-joint forces, lower pain levels, decrease inflammatory cytokines, and slow OA progression. Methods/Design This is an assessor-blind, randomized controlled trial. The study population consists of 372 older (age ≥ 55 yrs) ambulatory, community-dwelling persons with: (1) mild-to-moderate medial tibiofemoral OA (Kellgren-Lawrence (KL) = 2 or 3); (2) knee neutral or varus aligned knee ( -2° valgus ≤ angle ≤ 10° varus); (3) 20 kg.m-2 ≥ BMI ≤ 45 kg.m-2; and (3) no participation in a formal strength-training program for more than 30 minutes per week within the past 6 months. Participants are randomized to one of 3 groups: high-intensity strength training (75-90% 1Repetition Maximum (1RM)); low-intensity strength training (30-40%1RM); or healthy living education. The primary clinical aim is to compare the interventions’ effects on knee pain, and the primary mechanistic aim is to compare their effects on knee-joint compressive forces during walking, a mechanism that affects the OA disease pathway. Secondary aims will compare the interventions’ effects on additional clinical measures of disease severity (e.g., function, mobility); disease progression measured by x-ray; thigh muscle and fat volume, measured by computed tomography (CT); components of thigh muscle function, including hip abductor strength and quadriceps strength, and power; additional measures of knee-joint loading; inflammatory and OA biomarkers; and health-related quality of life. Discussion Test-retest reliability for the thigh CT scan was: total thigh volume, intra-class correlation coefficients (ICC) = 0.99; total fat volume, ICC = 0.99, and total muscle volume, ICC = 0.99. ICC for both isokinetic concentric knee flexion and extension strength was 0.93, and for hip-abductor concentric strength was 0.99. The reliability of our 1RM testing was: leg press, ICC = 0.95; leg curl, ICC = 0.99; and leg extension, ICC = 0.98. Results of this trial will provide critically needed guidance for clinicians in a variety of health professions who prescribe and oversee treatment and prevention of OA-related complications. Given the prevalence and impact of OA and the widespread availability of this intervention, assessing the efficacy of optimal strength training has the potential for immediate and vital clinical impact