Factorial validity and measurement invariance of the Perceived Susceptibility to Sport Injury scale.

The Perceived Susceptibility to Sport Injury (PSSI) scale is a measure that has recently surfaced in the sport injury literature. The factor structure of the PSSI scale has not been subjected to a rigorous factor analysis; thus, the factorial validity of the measure in athlete populations is unknown. To establish the validity of the PSSI scale in sports medicine research, the purpose of this study was to examine the factor structure and measurement invariance across gender of the PSSI scale. Male and female intercollegiate athletes (N = 217) completed the PSSI scale during the off-season. The factor structure was analyzed using confirmatory factor analysis (CFA) procedures and maximum likelihood estimation. The measurement invariance analysis was conducted via comparisons of fit indices within a series of hierarchically constrained models. Results of the CFA yielded a very good fit of the measurement model: χ2 (2) = 4.535, P = 0.104; RMSEA = 0.076; SRMR = 0.018; CFI = 0.995; NNFI = 0.985. Results of the measurement invariance analysis demonstrated strict invariance across gender, and no significant latent mean differences emerged between men and women. Study results support the factorial validity of the PSSI scale for use in future sports medicine research.

Impact of healthy work environments on new graduate nurses' environmental reality shock.

Do healthy work environments (HWEs) facilitate new graduate transition into professional practice in hospitals? Are such environments related to a decrease in Environmental Reality Shock? Experienced nurses in 17 Magnet hospitals completed the Essentials of Magnetism II(©) (EOMII(©)) instrument that measures health of unit work environments. New graduates (N = 468) were then tracked with modified versions of the EOMII(©) from immediate post hire to 4, 8, and 12 months post hire to ascertain degree of Environmental Reality Shock. New graduate nurses have extremely high anticipations of unit work environments that would enable delivery of quality patient care. HWE is the most-significant variable in Environmental Reality Shock, number of related Issues and Concerns, and perceptions of quality of patient care. Suggestions of how to improve quality of unit work environments are offered.

Guided imagery to improve functional outcomes post-anterior cruciate ligament repair: randomized-controlled pilot trial.

Imagery can improve functional outcomes post-anterior cruciate ligament repair (ACLR). Research is needed to investigate potential mechanisms for this effect. The aim of this study was to (a) evaluate the effectiveness of an imagery intervention to improve functional outcomes post-ACLR, and (b) explore potential mechanisms. A randomized-controlled pilot trial was conducted. Participants were randomized to guided imagery and standard rehabilitation or standard rehabilitation alone (control). The primary outcome was knee strength 6-month post-operatively. Secondary outcomes were knee laxity at 6-months, and change in psychological (self-efficacy) and neurohormonal (adrenaline, noradrenaline, dopamine) variables. Participants (n=21; 62% male) were 34.86 (SD 8.84) years. Following the intervention, no statistical differences between groups for knee strength extension at 180°/s (t=-0.43, P=0.67), or at 60°/s (t=-0.72, P=0.48) were found. A statistically significant effect was found for knee laxity, F=4.67, P<0.05, mean difference of -3.02 (95% CI -4.44 to -1.60), favoring the intervention. No differences were found for self-efficacy; however, an overall effect was found for noradrenaline, F(1, 19) 19.65, P<0.001, η(2) =0.52, and dopamine, F(1, 19) 6.23, P=0.02, η(2) =0.29, favoring the intervention. This imagery intervention improved knee laxity and healing-related neurobiological factors.

Preliminary investigation of test-retest reliability of a robotic assessment for Parkinson's disease.

Several systems have been proposed to objectively quantify the motor signs of Parkinson's disease. While validity has been investigated for a subset of these systems, test-retest reliability of automated assessments has been more neglected. We have created a protocol that uses a robotic system to measure force and position as the user performs tracking tasks with and without a simultaneous cognitive or motor task. We present preliminary results for test-retest reliability with eight individuals with early to moderate PD. Based on this data, we identified variables with large, significant correlations between the test and retest data. A total of 21 reliable variables were identified with all portions of the assessment protocol producing reliable variables.

Feature selection for classification based on fine motor signs of Parkinson's disease.

Effective evaluation of potential neuroprotective interventions for Parkinson's disease (PD) requires precise quantification of the motor signs associated with this disease. We have created a protocol that uses force tracking in a simultaneous task paradigm to quantify the fine motor control deficits in individuals with PD. We have used this protocol to collect data from 30 individuals with early to moderate PD and 30 age-matched controls. Based on this data, we computed 60 variables. We generated all possible combinations of three of these variables, and we then computed the classification accuracy of a support vector machine (SVM) trained on each variable combination. We were able to correctly classify 85% of subjects as with or without PD. We found that root-mean-square error variables were the most important features for classification and that utilizing a simultaneous task paradigm improves classification accuracy.

Pain and negative mood during rehabilitation after anterior cruciate ligament reconstruction: a daily process analysis.

Daily diary methods were used to examine changes in pain and negative mood over the first 6 weeks of rehabilitation after surgical reconstruction of the anterior cruciate ligament (ACL). Participants (58 men and 33 women) completed measures of personal factors (i.e., age, athletic identity, neuroticism, optimism) before surgery and indices of daily pain, negative mood, and stress for 42 days after surgery. Multilevel modeling revealed that, as would be expected, daily pain ratings decreased significantly over the course of the study and that the rate of decline in pain ratings decreased over time. Age and daily negative mood were positively associated with daily pain ratings. Daily negative mood also decreased significantly over the course of the study and was positively associated with neuroticism, daily pain, and daily stress. Athletic identity and optimism interacted with time since surgery in predicting daily negative mood such that participants with high levels of athletic identity and low levels of optimism reported greater decreases in daily negative mood over time. Overall, the findings reveal a pattern of improved psychological functioning over the early stages of post-operative ACL rehabilitation.

Exercising caution: social physique anxiety and protective self-presentational behaviour.

This study examined relations among body mass index (BMI), social physique anxiety (SPA) and protective self-presentational exercise behaviours in a sample of 86 female participants in aerobics classes at a university fitness centre. Participants completed a questionnaire assessing demographic and exercise-related information, the 9-item version of the Social Physique Anxiety Scale, and measures of two forms of protective self-presentational exercise behaviour (i.e., preferring to stand away from the aerobics instructor and wearing concealing exercise attire). Consistent with previous research, SPA was positively associated with both preferred exercise studio floor position (r = .31, p < .05) and clothing concealingness (r = .25, p < .05). SPA did not mediate the relations between BMI and either of the two protective self-presentational behaviours. BMI was a better predictor of clothing concealingness than SPA, but the opposite was found for exercise studio floor position preferences (r = .31 with SPA versus r = .15 with BMI). The findings provide an enhanced understanding of factors associated with self-presentation in exercise.

Shaping synergistic pinching patterns with feedback distortion in a virtual rehabilitation environment.

Individuals with chronic disabilities often use compensatory coordination patterns learned during the recovery phase, even after their individual muscular control returns. Although these compensatory movements limit their ability to complete tasks, these individuals are not able to relearn the correct synergistic coordination patterns because doing so would temporarily compromise task performance. Following our previous work using feedback distortion in a virtual rehabilitation environment to increase the strength and range of motion of disabled individuals, we address the use of this same feedback distortion environment to alter movement coordination patterns. In this paper, we present the methodology and preliminary results showing that (1) able-bodied individuals could be trained to use a different coordination pattern to produce pinching movements, and (2) feedback distortion can alter movements for individual fingers separately during a coordinated movement. These results indicate that our distorted virtual environment may be a powerful rehabilitation tool to convert compensatory movements into movements that utilize all muscles in the normal synergistic patterns.

A normal rate of cellular cholesterol removal can be mediated by plasma from a patient with familial lecithin-cholesterol acyltransferase (LCAT) deficiency.

Lecithin-cholesterol acyltransferase (LCAT) is the major enzyme involved in the esterification of cholesterol in circulating plasma lipoproteins. In the present study, we describe the molecular defects in the LCAT gene and in lipoprotein metabolism of a 34-year-old patient presenting with features of classic familial LCAT deficiency. DNA sequencing revealed two separate point mutations in exon 3 of the patient's LCAT gene: a C to A substitution converting Tyr(83) to a Stop and a C to T transition converting an Arg(99) to a Cys. Digestion of patient PCR-amplified DNA with the restriction enzymes AccI and AciI established that the patient was a compound heterozygote for both mutations. In vitro expression of LCAT (Arg(99)-->Cys) in human embryonic kidney-293 cells demonstrated reduced expression, as well as reduced secretion and/or increased intracellular degradation of the mutant enzyme with significantly decreased alpha-LCAT specific activity, thus, establishing the functional significance of the LCAT (Arg(99)-->Cys) mutation. The plasma cholesterol esterification rate (CER, 2+/-0.3 nmol/ml/h), alpha-LCAT activity (2.9+/-0.1 nmol/ml/h) and LCAT concentration (0.3+/-0.1 microg/ml) were 2.9%, 2.3% and 6.1% that of normal subjects, respectively. Analysis of the patient's plasma lipid profile revealed reduced plasma concentrations of total cholesterol (111+/-0.5 mg/dl), HDL cholesterol (1.6+/-0.2 mg/dl), apolipoprotein (apo) A-I (52+/-4 mg/dl) and apo A-II (11+/-0.5 mg/dl). Nevertheless, for the first time, we demonstrate that the LCAT-deficient plasma is as efficient as control plasma in cholesterol efflux experiments performed with [(3)H]-cholesterol loaded fibroblasts. This result could explain the absence of premature atherosclerosis in this LCAT-deficient patient.

Replication dynamics of the yeast genome.

Oligonucleotide microarrays were used to map the detailed topography of chromosome replication in the budding yeast Saccharomyces cerevisiae. The times of replication of thousands of sites across the genome were determined by hybridizing replicated and unreplicated DNAs, isolated at different times in S phase, to the microarrays. Origin activations take place continuously throughout S phase but with most firings near mid-S phase. Rates of replication fork movement vary greatly from region to region in the genome. The two ends of each of the 16 chromosomes are highly correlated in their times of replication. This microarray approach is readily applicable to other organisms, including humans.

An ATP-binding cassette gene (ABCG5) from the ABCG (White) gene subfamily maps to human chromosome 2p21 in the region of the Sitosterolemia locus.

We characterized a new human ATP-binding cassette (ABC) transporter gene that is highly expressed in the liver. The gene, ABCG5, contains 13 exons and encodes a 651 amino acid protein. The predicted protein is closely related to the Drosophila white gene and a human gene, ABCG1, which is induced by cholesterol. This subfamily of genes all have a single ATP-binding domain at the N-terminus and a single C-terminal set of transmembrane segments. ABCG5 maps to human chromosome 2p21, between the markers D2S117 and D2S119. The abundant expression of this gene in the liver suggests that the protein product has an important role in transport of specific molecule(s) into or out of this tissue.

The Elder Image Scale: a method for indexing history and emotion in family caregiving.

Although caregiving has been studied extensively, most studies have focused on the activities performed by caregivers, problems encountered and caregivers' reactions. Less attention has been paid to measuring historical and interpersonal factors that may shape the situation and affect outcomes, but are not necessarily embedded in the role itself. The objective of this article is to report on the development and testing of the Elder Image Scale (EIS) which indexes the personal identity of the elder, the mental image the caregiver has of the elder derived from past associations, present observations, and the reconciliation of the past with present impressions. This scale was based on the Family Caregiving Dynamics Model and the personal image of the elder is predicted to be shaped by certain structural factors and to impact both the perceptions of caregivers and the outcomes of caregiving. This article reports on four separate investigations; six-hundred-and-fifty-six caregivers participated. The EIS is in the semantic differential format. Internal consistency ranged from .92 to .98 over four studies. Stability after two weeks was .93 for both subscales. All correlations with criteria were in the direction predicted and most were significant. Known group comparisons showed all group differences were statistically significant as predicted. The EIS is internally consistent, stable and evidences construct validity. In addition, measuring this concept appears to have great relevance for explaining both perceptions of caregivers and outcomes of caregiving.

An origin-deficient yeast artificial chromosome triggers a cell cycle checkpoint.

Checkpoint controls coordinate entry into mitosis with the completion of DNA replication. Depletion of nucleotide precursors by treatment with the drug hydroxyurea triggers such a checkpoint response. However, it is not clear whether the signal for this hydroxyurea-induced checkpoint pathway is the presence of unreplicated DNA, or rather the persistence of single-stranded or damaged DNA. In a yeast artificial chromosome (YAC) we have engineered an approximately 170 kb region lacking efficient replication origins that allows us to explore the specific effects of unreplicated DNA on cell cycle progression. Replication of this YAC extends the length of S phase and causes cells to engage an S/M checkpoint. In the absence of Rad9 the YAC becomes unstable, undergoing deletions within the origin-free region.

Fine mapping of a gene responsible for regulating dietary cholesterol absorption; founder effects underlie cases of phytosterolaemia in multiple communities.

Sitosterolaemia (also known as phytosterolaemia, MIM 210250) is a rare recessive autosomal inherited disorder, characterised by the presence of tendon and tuberous xanthomas, accelerated atherosclerosis and premature coronary artery disease. The defective gene is hypothesised to play an important role in regulating dietary sterol absorption and biliary secretion, thus defining a molecular mechanism whereby this physiological process is carried out. The disease locus was localised previously to chromosome 2p21, in a 15 cM interval between microsatellite markers D2S1788 and D2S1352 (based upon 10 families, maximum lodscore 4.49). In this study, we have extended these studies to include 30 families assembled from around the world. A maximum multipoint lodscore of 11.49 was obtained for marker D2S2998. Homozygosity and haplotype sharing was identified in probands from non-consanguineous marriages from a number of families, strongly supporting the existence of a founder effect among various populations. Additionally, based upon both genealogies, as well as genotyping, two Amish/Mennonite families, that were previously thought not to be related, appear to indicate a founder effect in this population as well. Using both homozygosity mapping, as well as informative recombination events, the sitosterolaemia gene is located at a region defined by markers D2S2294 and Afm210xe9, a distance of less than 2 cM.

Sport psychology service delivery: staying ethical while keeping loose.

Although the parent discipline of sport psychology is psychology, the delivery of sport psychology services has its main roots in physical education and sports science (motor learning and control, skill acquisition). Thus, sport psychologists may look more like coaches than they look like clinicians or counselors. In this article, the authors trace the evolution of sport psychology services and contrast the temporal, spatial, and delivery issues of applied sport psychology with more mainstream counseling and clinical psychology. The looser boundaries of sport psychologist practice have both benefits and dangers, and the authors offer some examples to professional psychologists who are thinking of expanding their delivery of service to athletes and coaches.

Clinical, echocardiographic, and neurohormonal effects of a sodium-restricted diet in dogs with heart failure.

The use of low-sodium diets in dogs with heart failure is common practice, but randomized, double-blind studies have not been conducted to examine the benefits or problems with this approach. The purpose of this study was to determine the effects of a low-sodium diet on clinical, echocardiographic, and neurohormonal parameters in dogs with heart failure. Dogs with stable chronic heart failure were fed exclusively a low-sodium (LS) and a moderate-sodium (MS) diet for 4 weeks each in a randomized, double-blind, crossover design. At days 0, 28, and 56, echocardiography and thoracic radiography were performed, and blood was analyzed for electrolytes and neurohormones. Fourteen dogs completed the study (9 with chronic valvular disease and 5 with dilated cardiomyopathy). Electrolyte abnormalities were common during the study, and serum sodium and chloride concentrations decreased significantly on the LS diet. Neurohormones did not change significantly between diet groups. Maximum left atrial (P = .05) and standard left atrial (P = .09) size decreased on the LS diet. For dogs with chronic valvular disease, vertebral heart score (P = .05), left ventricular internal dimension in diastole (P = .006) and systole (P = .02), standard left atrial dimension (P = .03), maximum left atrial dimension (P = .02), end-diastolic volume index (P = .02), and end-systolic volume index (P = .04) decreased significantly on the LS diet compared to the MS diet. Although analysis of these data suggests some benefits of a low-sodium diet, future studies with improved study design are needed to further evaluate the advantages and disadvantages of sodium restriction in dogs with heart failure.

Ribosomal DNA replication fork barrier and HOT1 recombination hot spot: shared sequences but independent activities.

In the ribosomal DNA of Saccharomyces cerevisiae, sequences in the nontranscribed spacer 3' of the 35S ribosomal RNA gene are important to the polar arrest of replication forks at a site called the replication fork barrier (RFB) and also to the cis-acting, mitotic hyperrecombination site called HOT1. We have found that the RFB and HOT1 activity share some but not all of their essential sequences. Many of the mutations that reduce HOT1 recombination also decrease or eliminate fork arrest at one of two closely spaced RFB sites, RFB1 and RFB2. A simple model for the juxtaposition of RFB and HOT1 sequences is that the breakage of strands in replication forks arrested at RFB stimulates recombination. Contrary to this model, we show here that HOT1-stimulated recombination does not require the arrest of forks at the RFB. Therefore, while HOT1 activity is independent of replication fork arrest, HOT1 and RFB require some common sequences, suggesting the existence of a common trans-acting factor(s).