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At least 1,333 records · Page 74Linked to original sources
PubMed2004

Value orientations of elementary and secondary physical education teachers in Flanders.

The purpose of this research was to examine and compare physical educators'value profiles. The Value Orientation Inventory was used to collect data from 528 elementary and 637 secondary physical education teachers in Flanders. Teacher characteristics, including gender and years of teaching experience revealed only minor differences in value orientations. Significant differences in teachers' value orientations were observed between teachers in elementary and secondary schools. The different value profiles of these two teacher groups are discussed in the perspective of the recently introduced conceptual innovations in physical education mandated by the Flemish government. The teachers at the elementary level placed a high priority on the disciplinary mastery and the self-actualization orientations; those at the secondary level scored high on the social responsibility and disciplinary mastery orientations. The findings from this study suggest that teaching level influences teachers' value orientation. Teachers appeared to adjust their curricular priorities to meet the demands and needs of students in elementary versus secondary schools.

Belgium↗
PubMed2004

A longitudinal perspective of the relationship between perceived motivational climate, goal orientations, and strategy use.

Achievement goal theory suggests that goal orientations and the perceived motivational climate may influence one another and other motivational variables over time. Therefore, the purpose of this study was threefold: (a) to examine the relationship between perceived motivational climate and goal orientations over time (b) to investigate how goal orientations may fluctuate when the climate was in opposition to the initial goal orientation, (c) to determine how the climate may impact practice strategies. A set of inventories was administered to 162 college students at preselected times throughout several 16-week physical activity classes. Changes occurred in students' goal orientations, particularly when the perceived motivational climate was in opposition to their goal orientation. Aspects of the task-involving climate positively predicted practice strategies.

Achievement↗
PubMed2005

Standard orientation of the pelvis: validation on a model and ten patients.

PURPOSE: To validate an image post-processing method for re-orienting the pelvis in CT volumes to a standardized orientation in a model and in 10 patients. MATERIAL AND METHODS: Twenty-four CT volumes of a pelvic model and 10 pairs of postoperative total hip arthroplasty (THA) patient CT scans were rotated to a defined pelvic standard orientation and the rotation was recorded. For precision, a test-retest procedure was used. For accuracy, three exactly represented coordinate points were used. For clinical application, the standard orientation was used for calculating the direction of acetabular cup migration from a previous model study. RESULTS: Precision of pelvic standard orientation, calculated as maximal directional error, was better than 1 degrees in the model study and better than 1.5 degrees in the patient study. Accuracy, expressed as angle between ideal and measured coordinate axes, was 0.1 degrees for x, y, z axes. No measurable systematic errors were found. When applied to acetabular cup migration in the model, standardization of pelvic orientation had no significant effect on the measurements. CONCLUSION: Reorienting the pelvis during image post-processing was shown to be accurate. It enables measurements relative to the pelvis and minimizes the dependency of patient positioning.

Adult↗
PubMed2004

Role of the electrostatic interactions in pre-orientation of subunits in the formation of protein-protein complexes.

Theoretical estimation of contribution of the electrostatic interactions to pre-orientation of ribonuclease subunits in process of complex formation was carried out. The subunit was considered as a multipole consisting of partial charges of all atoms of the molecule. The object of investigation was a system of two subunits with their centers of gravity fixed at some distance in vacuum. It was proposed that each subunit independently could rotate freely around its fixed center of gravity. The relative orientation states of the subunits in such system were searched at which the system has electrostatic energy minima (equilibrium states). In first approximation the equilibrium states were found using especially designed approximate method for electrostatic interaction energy calculation, which permitted to calculate and compare the energies of the system in 24(5) (approximately 8 10(6)) states with different mutual orientation of subunits. The angular coordinates of the found equilibrium states were further specified by calculation with gradient sliding method. Angular coordinates of the equilibrium states and the shapes of energy surface cuts along each coordinate angle were calculated also for the intersubunits distances diminished down to 50 angstroms. The dispersions of the angular coordinates of equilibrium states caused by heat movement (at T=300 degrees) and their changes with shortening the distance between centers of gravity of subunits were estimated. Mutual orientation of subunits in the equilibrium states of the system under consideration was found to be similar to their mutual orientations in complex. Also it was found that relaxation time of the system, caused by electrostatic interaction of subunits, after removing the system from an equilibrium state, is much less in vacuum than the mean time between their Brownian collisions at room temperature. It follows from these results that in the case of ribonuclease in vacuum the electrostatic interactions of its subunits must be strong enough to realize the effective pre-orientation of subunits during their Brownian approach from distances of the order 100 angstroms. Preliminary consideration taking into account the effect of surrounding water molecules on the electrostatic interactions of ribonuclease subunits showed that weakening of the interaction must be much less than in the case when one uses in its calculation the macroscopic dielectric permeability value equal to 80. So the results obtained for vacuum seem to be true for water solution also. More strict theoretical analysis of this problem will be carried out in the following publication.

Animals↗
PubMed2003

Death anxiety as a predictor of future time orientation among individuals with spinal cord injuries.

PURPOSE: The purpose of this study was to examine the relationship between death anxiety and future time orientation among individuals who sustained spinal cord injuries (SCI). METHODS: Participants were 317 individuals with SCI, of whom 57.4% were US veterans. Data were obtained by means of mailed questionnaires and included responses to the Death Anxiety Scale (DAS), the Future Time Orientation (FTOS) measure, as well as information on participants' personal and disability-related characteristics. RESULTS: A hierarchical multiple regression analysis was conducted to examine the influence of a set of demographic variables, followed by a set of disability-related variables, and finally two factorially-derived measures of death anxiety (denial of death and distressed awareness of death) on future time orientation. Two disability-related variables (pain level and existence of pressure ulcers) and one of the two death anxiety measures (distressed awareness of death) significantly predicted future time orientation. A post-hoc analysis, adding depression as a predictor, was also significant, indicating that an increased level of depression uniquely contributed to a truncated future time orientation. CONCLUSIONS: Distressed anxiety and depression may be important factors affecting goals and plans of people with SCI. Future research should attempt to clarify the intricate relationships among negative affectivity, future time orientation, and psychosocial adaptation to SCI.

Adolescent↗
PubMed2001

Action-oriented support for occupational safety and health programs in some developing countries in Asia.

Action-oriented support programs have been increasingly playing vital roles in promoting safety and health in developing countries in Asia. This paper studied achievements of 3 action-oriented support programs: the WISE program for small enterprises, the WIND program for farmers, and the POSITIVE program for workers and trade unions. Special attention was paid to how the programs have strengthened local efforts for sustainable actions in safety and health improvements. The results showed that there were significant achievements in action-oriented support programs in the region, including a large number of improvement examples, integration into government policies, and network support through employers' and workers' organizations. Participatory, action-oriented training tools such as action-checklists, local good example photos, and group work methods played key roles in the effective implementation of the programs. It was of note that there were a number of local efforts to extend the coverage of action-oriented support even to hard-to-reach workers such as home-based workers, rural workers, and ethnic minorities. The efforts included the equal participation in the training by female and male farmers, shortened and weekend training programs, photo sheets showing local good examples, and reasonable fee collection for better sustainability. In conclusion, action-oriented support programs provided local people with concrete means to promote safety and health improvements. The successful programs commonly focused on local initiatives and were built on local wisdom and resources.

Asia↗
PubMed2000

Global-local orientation congruency effects in visual search.

In a visual search task, subjects had to decide which of 2 possible target letters was presented among 12 distractor letters. The 13 characters were arranged to form a global Navon-type letter. The global letter and the local letters (target and distractors) were independently presented in four different viewer-related orientations. When the global letter and the target were frequently congruently oriented, the response times increased with growing orientation disparity between them. This global-target congruency effect was independent from target identity (Experiment 1), and it diminished when global and target orientations were not correlated (Experiment 2). The results indicate that the orientation of the global letter can be deliberately used in order to facilitate the processing of congruently oriented local targets. The alignment of a spatial frame of reference is discussed as the most probable process underlying this facilitation.

Adult↗
PubMed2001

The effect of seed orientation deviations on the quality of 125I prostate implants.

We quantified the effect of seed orientation deviations on five prostate seed implant cases at our institution. While keeping their positions fixed, the iodine-125 seeds were assigned orientations sampled from a realistic probability distribution derived from the post-implant radiographs of ten patients. Dose distributions were calculated with both a model that explicitly includes anisotropy (TG43 anisotropy function) and a point source model (TG43 anisotropy factor). Orientation deviations had only a small influence on prostate dose-volume histograms: the 95% confidence intervals on the volumes receiving 100%, 150% and 200% dose were at most +/-0.8%, +/-1.1% and +/-0.6% of the prostate volume, respectively. The dose-volume histograms of anisotropic seed distributions were marginally better than those with isotropic point-source seeds. Anisotropy caused a displacement of cold spots (regions receiving <100% of the prescribed dose) in <1% of the prostate volume. Our results indicate no net benefit to prostate dosimetry in using more isotropic seeds. Furthermore, we propose a new 'weighted anisotropy function' to better account for the effects of anisotropy when seed orientation is unknown. Conceptually, the TG43 anisotropy factor described in AAPM TG43 averages the effect of anisotropy over all solid angles, with the implicit assumption that all seed orientations are equally probable. In prostate implants, however, seeds are preferentially oriented parallel to the needle axis. The proposed weighted anisotropy function incorporates this non-uniform probability.

Anisotropy↗
PubMed2004

Selection of beam orientations in intensity-modulated radiation therapy using single-beam indices and integer programming.

While the process of IMRT planning involves optimization of the dose distribution, the procedure for selecting the beam inputs for this process continues to be largely trial-and-error. We have developed an integer programming (IP) optimization method to optimize beam orientation using mean organ-at-risk (MOD) data from single-beam plans. Two test cases were selected in which one organ-at-risk (OAR) and four OARs were simulated, respectively, along with a PTV. Beam orientation space was discretized in 10 degrees increments. For each beam orientation, a single-beam plan without intensity modulation and without constraints on OAR dose was generated and normalized to yield a mean PTV dose of 2 Gy and the corresponding MOD was calculated. The degree of OAR sparing was related to the average OAR MODs resulting from the beam orientations utilized with improvements of up to 10% at some dose levels. On the other hand, OAR DVHs in the IMRT plans were insensitive to beam numbers (in the 6-9 range) for similar average single-beam MODs. These MOD data were input to an IP optimization process, which then selected specified numbers of beam angles as inputs to a treatment planning system. Our results show that sets of beam angles with lower average single-beam MODs produce IMRT plans with better OAR sparing than manually selected beam angles. To optimize beam orientations, weights were assigned to each OAR following MOD input to the IP which was subsequently solved using the branch-and-cut algorithm. Seven-beam orientations obtained from solving the IP were applied to the test case with four OARs and the resulting plan with a dose prescription of 63 Gy was compared with an equi-spaced beam plan. The IP selected beams produced dose-volume improvements of up to 40% for OARs proximal to the PTV. Further improvement in the DVH can be obtained by increasing the weights assigned to these OARs but at the expense of the remaining OARs.

Abdomen↗
PubMedDate not supplied

Sexual orientation and variation in physical and mental health status among women.

OBJECTIVE: To assess and compare the physical and mental health status of women of differing sexual orientation within a population-based sample. METHODS: We used a population-based telephone survey performed using random digit dialing techniques. Our study population was drawn from the 1999 Los Angeles County Health Survey and included women age 18-64 years who reported their sexual orientation (98%, n = 4135). These analyses include 4023 heterosexuals, 69 bisexuals, and 43 lesbians. RESULTS: We assessed the unique association of sexual orientation with physical and mental health status using bivariate and multivariate analyses. Both lesbians and bisexuals were more likely than heterosexual women to report a diagnosis of heart disease. Among women with a depressive disorder, lesbians were more likely than heterosexuals to be using an antidepressant medication. Compared with heterosexuals within the preceding 30 days, lesbians reported significantly more days of poor mental health, and bisexuals reported significantly more days of poor physical health. However, there were no significant differences by sexual orientation in impaired ability to perform daily activities due to physical or mental health. CONCLUSIONS: In this rare opportunity to use population-based data to study lesbian and bisexual health, we found that sexual orientation as a nonheterosexual woman was associated with increased rates of poor physical and mental health. We believe these findings support the need for the increased systematic study of the relationship between sexual orientation and health.

Adolescent↗
PubMed1980

Chi mutation in a transposon and the orientation-dependence of Chi phenotype.

Chi, an element that stimulates recombination via the E. coli RecBC pathway, can arise by spontaneous mutation in the transposon Tn5. When in phage lambda in one orientation, the mutant transposon confers Chi+ phenotype (large plaque and a high rate of exchange near the transposon). In the other orientation, however, the transposon does not confer Chi+ phenotype. The mobility of the transposon allows us to show that the Chi+ orientation of the mutant Tn5 is the same at different locations in lambda. These include a site near gene J, one in gam at 69, one to the right of gam at 73 and several to the right of R between 95.7 and 99.5. To the right of R, the mutant transposon could be found in only one orientation, that which confers Chi+ phenotype. We speculate that the other orientation of Tn5 in that locale is lethal to lambda. The orientation-dependence of Chi+ phenotype also revealed that Tn5 flip-flops in lambda.

Bacteriophage lambda↗
PubMed2002

The importance of policy orientation and environment on physical activity participation--a comparative analysis between Eastern Germany, Western Germany and Finland.

Environmental and policy interventions are seen as boosting physical activity because they are designed to influence large groups. However, they have not been much researched and the evidence on their role is still quite limited. The purpose of this study was to investigate differences in and relationships between policy orientation, the objective and perceived physical environment, and physical activity between Finland, Eastern Germany and Western Germany. The data are taken from a public telephone survey carried out as part of the international MAREPS project (Methodology for the Analysis of Rationality and Effectiveness of Prevention and Health Promotion Strategies; Eastern Germany, n = 913; Western Germany, n = 489; Finland, n = 400), statistics of sports facilities and policy documents. Results from the survey showed that Finns are more active than Germans and that they differ in their way of practising physical activity from Germans. Finns were more satisfied with their opportunities for physical activity and were better informed about physical programmes and measures. Finland also has the best opportunities in indoor sports facilities and outdoor sports grounds per number of inhabitants (excluding indoor swimming pools). Analysis of policy orientations showed that Finland had the most extensive 'Sport for All' policy, although West Germany's policy orientation did not differ that much from Finland's. East Germany's policy orientation was characterized by competitive sports. A policy orientation that places emphasis on the physical activity of the whole population seems to be related to better opportunities and a better infrastructure for sports and physical activity. This study suggests that there is a relationship between policy orientation, physical environment and physical activity participation.

Attitude to Health↗
PubMed2006

Cellulose orientation determines mechanical anisotropy in onion epidermis cell walls.

The role of cellulose microfibril orientation in determining cell wall mechanical anisotropy and in the control of the wall plastic versus elastic properties was studied in the adaxial epidermis of onion bulb scales using the constant-load (creep) test. The mean or net cellulose orientation in the outer periclinal wall of the epidermis was parallel to the long axis of the cells. In vitro cell wall extensibility was 30-90% higher in the direction perpendicular to the net microfibril orientation than parallel to it. This was the case for the size of the initial deformation occurring just after the load application and for the rate of time-dependent creep. Loading/unloading experiments confirmed the presence of a real irreversible component in cell wall extension. The plastic component of the time-dependent deformation was higher perpendicular to the net cellulose orientation than parallel to it. An acid buffer (pH 4.5) increased the creep rate by 25-30% but this response was not related to cellulose orientation. The present data provide direct evidence that the net orientation of cellulose microfibrils confers mechanical anisotropy to the walls of seed plants, a characteristic that may be relevant to understanding anisotropic cell growth.

Anisotropy↗
PubMed1987

Transient orientation of linear DNA molecules during pulsed-field gel electrophoresis.

The transient orientation of lambda DNA and lambda-DNA oligomers has been measured during pulsed field gel electrophoresis. The DNA becomes substantially aligned parallel to the electric field E. In response to a single rectangular pulse, orientation shows an overshoot with a peak at 1 second, then a small undershoot, and finally a plateau. When the field is turned off, the orientation dissipates in two distinct exponential phases. Field inversion leads to periods of orientation with intervening periods of reduced orientation as the chains reverse direction. Field inversion pulses applied to linear oligomers of lambda-DNA show that orientation responses slow down but increase in amplitude as molecular weight increases, for a given field. Because DNA stretching and alignment parallel to E are expected to correlate with DNA velocity, the velocity in response to a pulsed field is also expected to exhibit an overshoot.

DNA↗
PubMed1998

The yeast FBP1 poly(A) signal functions in both orientations and overlaps with a gene promoter.

This report provides an analysis of a region of chromosome XII in which the FBP1 and YLR376c genes transcribe in the same direction. Our investigation indicates that the Saccharomyces cerevisiae FBP1 gene contains strong signals for polyadenylation and transcription termination in both orientations in vivo . A (TA)14 element plays a major role in directing polyadenylation in both orientations. While this region has four nonoverlapping copies of a TATATA hexanucleotide, which is a very potent polyadenylation efficiency element in yeast, it alone is not sufficient for full activation in the reverse orientation of a cluster of downstream poly(A) sites, and an additional upstream sequence is required. The putative RNA hairpin formed from the (TA)14 element is not involved in 3'-end formation. Surprisingly, deletion of the entire (TA)14 stretch affects transcription termination in the reverse orientation, in contrast to our previous results with the forward orientation, indicating that the transcription termination element operating in the reverse orientation has very different sequence requirements. Promoter elements for the YLR376c gene overlap with the signal for FBP1 3'-end formation. To our knowledge, this is the first time that overlapping of both types of regulatory signals has been found in two adjacent yeast genes.

Base Sequence↗
PubMed2005

Differential activation of DNA-PK based on DNA strand orientation and sequence bias.

DNA-PKcs and Ku are essential components of the complex that catalyzes non-homologous end joining (NHEJ) of DNA double-strand breaks (DSBs). Ku, a heterodimeric protein, binds to DNA ends and facilitates recruitment of the catalytic subunit, DNA-PKcs. We have investigated the effect of DNA strand orientation and sequence bias on the activation of DNA-PK. In addition, we assessed the effect of the position and strand orientation of cisplatin adducts on kinase activation. A series of duplex DNA substrates with site-specific cisplatin-DNA adducts placed in three different orientations on the duplex DNA were prepared. Terminal biotin modification and streptavidin (SA) blocking was employed to direct DNA-PK binding to the unblocked termini with a specific DNA strand orientation and cisplatin-DNA adduct position. DNA-PK kinase activity was measured and the results reveal that DNA strand orientation and sequence bias dramatically influence kinase activation, only a portion of which could be attributed to Ku-DNA binding activity. In addition, cisplatin-DNA adduct position resulted in differing degrees of inhibition depending on distance from the terminus as well as strand orientation. These results highlight the importance of how local variations in DNA structure, chemistry and sequence influence DNA-PK activation and potentially NHEJ.

Base Sequence↗
PubMed1987

The locations and amounts of endogenous ions and elements in the cap and elongating zone of horizontally oriented roots of Zea mays L.: an electron-probe EDS study.

We used quantitative electron-probe energy-dispersive x-ray microanalysis to localize endogenous Na, Cl, K, P, S, Mg and Ca in cryofixed and freeze-dried cryosections of the cap (i.e. the putative site of graviperception) and elongating zone (i.e. site of gravicurvature) of horizontally oriented roots of Zea mays. Ca, Na, Cl, K and Mg accumulate along the lower side of caps of horizontally oriented roots. The most dramatic asymmetries of these ions occur in the apoplast, especially the mucilage. We could not detect any significant differences in the concentrations of these ions in the central cytoplasm of columella cells along the upper and lower sides of caps of horizontally-oriented roots. However, the increased amounts of Na, Cl, K and Mg in the longitudinal walls of columella cells along the lower side of the cap suggest that these ions may move down through the columella tissue of horizontally-oriented roots. Ca also accumulates (largely in the mucilage) along the lower side of the elongating zone of horizontally-oriented roots, while Na, P, Cl and K tend to accumulate along the upper side of the elongating zone. Of these ions, only K increases in concentration in the cytoplasm and longitudinal walls of cortical cells in the upper vs lower sides of the elongating zone. These results indicate that (1) gravity-induced asymmetries of ions differ significantly in the cap and elongating zone of graviresponding roots, (2) Ca accumulates along the lower side of the cap and elongating zone of graviresponding roots, (3) increased growth of the upper side of the elongating zone of horizontally-oriented roots correlates positively with increased amounts of K in the cytoplasm and longitudinal walls of cortical cells, and (4) the apoplast (especially the mucilage) may be an important component of the pathway via which ions move in graviresponding rots of Zea mays. These results are discussed relative to mechanisms for graviperception and gravicurvature of roots.

Calcium↗
PubMedDate not supplied

Two-dimensional orientational response of smooth muscle cells to cyclic stretching.

It was hypothesized that an orientated cellular tissue for incorporation into vital, functioning hybrid artificial organs can be prepared by periodically applying mechanical stresses on a hybrid tissue. Therefore, the effect of cyclic stretching on the two-dimensional (2-D) orientation response of arterial smooth muscle cells (SMCs) was studied. Smooth muscle cells derived from bovine aortas were seeded onto transparent elastomeric membranes made of polyurethane, and subjected to periodical stretching with various amplitudes from 5-20% at frequencies of 15 to 120 RPM for up to 24 hours. Phase-contrast microscopic views of SMCs were time-lapse video recorded. The orientation angle to the direction of stretching (OA) and cellular longitudinal length (CLL) of individual cells were analyzed by a computerized image processor. After several hours, SMCs subjected to the stress exhibited orientation responses perpendicular to the direction of stretching, evidenced by a significant increase in OA. The responses were more rapid under operating conditions with higher amplitudes and frequencies of stretching. Meanwhile, little significant change in CLL was observed. These findings indicate that an applied mechanical stress induces a significant orientation response, without morphologic alteration of SMCs. The mechanically induced orientation response provides a fundamental basis for more structured hybrid organs and tissue engineering.

Animals↗