861 resultados para group crowding effects


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Several techniques have been proposed in the literature to measure productivity. While allowing for inefficiency of the production unit, we provide a methodological comparison of alternative approaches to measure total factor productivity. This article evaluates the effects of unintended policy outcomes such as government subsidies and foreign trade. Empirically, we analyse the forest productivity of timber in Japan by using panel data on 46 regions. The results suggest substantial variation in productivity between these two techniques although average trends are similar. We find that subsidies impede competition since the government is ready to rescue a loss-making firm with subsidies rather than allow it to close. In contrast, trade is shown to have positive effects on productivity.

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This study focuses on weather effects on daily bus ridership in Brisbane, given bus’ dominance in this city. The weather pattern of Brisbane varies by season according to its sub-tropical climate characteristics. Bus is prone to inclement weather condition as it shares the road system with general traffic. Moreover, bus stops generally offer less or sometimes no protection from adverse weather. Hence, adverse weather conditions such as rain are conjectured to directly impact on daily travel behaviour patterns. There has been limited Australian research on the impact of weather on daily transit ridership. This study investigates the relationship between rainy day and daily bus ridership for the period of 2010 to 2012. Overall, rainfall affects negatively with varying impacts on different transit groups. However, this analysis confirmed a positive relationship between consecutive rainy days (rain continuing for 3 or more days). A possible explanation could be that people may switch their transport mode to bus to avoid high traffic congestion and higher accident potentiality on rainy days. Also, Brisbane’s segregated busway (BRT) corridor works favourably towards this mode choice. Our study findings enhance the fundamental understanding of traveller behaviour, particularly mode choice behaviour under adverse weather conditions.

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Resistance exercise triggers a subclinical inflammatory response that plays a pivotal role in skeletal muscle regeneration. Nuclear factor‐κB (NF‐κB) is a stress signalling transcription factor that regulates acute and chronic states of inflammation. The classical NF‐κB pathway regulates the early activation of post‐exercise inflammation; however there remains scope for this complex transcription factor to play a more detailed role in post‐exercise muscle recovery. Sixteen volunteers completed a bout of lower body resistance exercise with the ingestion of three 400 mg doses of ibuprofen or a placebo control. Muscle biopsy samples were obtained prior to exercise and at 0, 3 and 24 h post‐exercise and analysed for key markers of NF‐κB activity. Phosphorylated p65 protein expression and p65 inflammatory target genes were elevated immediately post‐exercise independent of the two treatments. These changes did not translate to an increase in p65 DNA binding activity. NF‐κB p50 protein expression and NF‐κB p50 binding activity were lower than pre‐exercise at 0 and 3 h post‐exercise, but were elevated at 24 h post‐exercise. These findings provide novel evidence that two distinct NF‐κB pathways are active in skeletal muscle after resistance exercise. The initial wave of activity involving p65 resembles the classical pathway and is associated with the onset of an acute inflammatory response. The second wave of NF‐κB activity comprises the p50 subunit, which has been previously shown to resolve an acute inflammatory program. The current study showed no effect of the ibuprofen treatment on markers of the NF‐κB pathway, however examination of the within group effects of the exercise protocol suggests that this pathway warrants further research.

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We investigated effects of roost loss due to clear-fell harvest on bat home range. The study took place in plantation forest, inhabited by the New Zealand long-tailed bat (Chalinolobus tuberculatus), in which trees are harvested between the ages 26-32 years. We determined home ranges by radiotracking different bats in areas that had and had not been recently clear-fell harvested. Home ranges were smaller in areas that had been harvested. Adult male bats selected 20-25 year old stands within home ranges before and after harvest. Males selected edges with open unplanted areas when harvest had not occurred but no longer selected these at proportions greater than their availability post harvest, probably because they were then readily available. This is the first radiotracking study to demonstrate a change in home range size and selection concomitant with felling of large areas of plantation forest, and thus quantify negative effects of forestry operations on this speciose group. The use of smaller home ranges post-harvest may reflect smaller colony sizes and lower roost availability, both of which may increase isolation of colonies and vulnerability to local extinction.

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Few studies have examined the effects of parental MS on children, and those that have suffered from numerous methodological weaknesses, some of which are addressed in this study. This study investigated the effects of parental MS on children by comparing youth of a parent with MS to youth who have no family member with a serious health condition on adjustment outcomes, caregiving, attachment and family functioning. A questionnaire survey methodology was used. Measures included youth somatisation, health, pro-social behaviour, behavioural-social difficulties, caregiving, attachment and family functioning. A total of 126 youth of a parent with MS were recruited from MS Societies in Australia and, were matched one-to-one with youth who had no family member with a health condition drawn from a large community sample. Comparisons showed that youth of a parent with MS did not differ on any of the outcomes except for peer relationship problems: adolescent youth of a parent with MS reported lower peer relationship problems than control adolescents. Overall, results did not support prior research findings suggesting adverse impacts of parental MS on youth.

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Isolated and purified organosolv eucalyptus wood lignin was depolymerized at different temperatures with and without mesostructured silica catalysts (i.e., SBA-15, MCM-41, ZrO2-SBA-15 and ZrO2-MCM-41). It was found that at 300 oC for 1 h with a solid/liquid ratio of 0.0175/1 (w/v), the SBA-15 catalyst with high acidity gave the highest syringol yield of 23.0% in a methanol/water mixture (50/50, wt/wt). Doping with ZrO2 over these catalysts did not increase syringol yield, but increased the total amount of solid residue. Gas chromatography-mass spectrometry (GC-MS) also identified other main phenolic compounds such as 1-(4-hydroxy-3,5-dimethoxyphenyl)-ethanone, 1,2-benzenediol, and 4-hydroxy-3,5-dimethoxy-benzaldehyde. Analysis of the lignin residues with Fourier transform-Infrared spectroscopy (FT-IR) indicated decreases in the absorption bands intensities of OH group, C-O stretching of syringyl ring and aromatic C-H deformation of syringol unit, and an increase in band intensities associated with the guaiacyl ring, confirming the type of products formed.

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How do celebrities like Gordon Ramsay appeal to consumers? This article examines one explanation. We study how celebrities appeal to consumers in the context of celebrity chefs. We examine how a consumer's self-concept clarity (SCC) interacts with their perception of the meaning that a celebrity endorser possesses. An experiment comparing fictional ads endorsed by different celebrity chefs yields the surprising result that consumers with a clear sense of who they are (high-SCC consumers) are more influenced by an ad featuring a celebrity high in meaning (Ramsay), whereas low-SCC consumers are influenced to slightly higher levels by a celebrity with lower levels of celebrity meaning.

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This thesis resolved the structural ambiguity surrounding ammonium and hydronium ions in the jarosite mineral group. The vibrational spectra of these two minerals were rationalised with their crystal structures for the first time. In doing so, a theory for dealing with orientational disorder in crystals was proposed.

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Enhancement of bone mineral acquisition during growth may be a useful preventive strategy against osteoporosis. The aim of this study was to explore the lean mass, strength, and bone mineral response to a 10-month, high-impact, strength-building exercise program in 71 premenarcheal girls, aged 9–10 years. Lean body mass, total body (TB), lumbar spine (LS), proximal femur (PF), and femoral neck (FN) bone mineral were measured using the Hologic QDR 2000+ bone densitometer. Strength was assessed using a grip dynamometer and the Cybex isokinetic dynamometer (Cybex II). At baseline, no significant difference in body composition, pubertal development, calcium intake, physical activity, strength, or bone mineral existed between groups. At completion, there were again no differences in height, total body mass, pubertal development, calcium intake, or external physical activity. In contrast, the exercise group gained significantly more lean mass, less body fat content, greater shoulder, knee and grip strength, and greater TB, LS, PF, and FN BMD (exercise: TB 3.5%, LS 4.8%, PF 4.5%, and FN 12.0%) compared with the controls (controls: TB 1.2%, LS 1.2%, PF 1.3%, and FN 1.7%). TB bone mineral content (BMC), LS BMC, PF BMC, FN BMC, LS bone mineral apparent density (BMAD), and FN bone area also increased at a significantly greater rate in the exercise group compared with the controls. In multiple regression analysis, change in lean mass was the primary determinant of TB, FN, PF, and LS BMD accrual. Although a large proportion of bone mineral accrual in the premenarcheal skeleton was related to growth, an osteogenic effect was associated with exercise. These results suggest that high-impact, strength building exercise is beneficial for premenarcheal strength, lean mass gains, and bone mineral acquisition.

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Background Cancer and its treatments produce lingering side-effects that undermine the quality of life (QOL) of survivors. Exercise and psycho-therapies increase QOL among survivors, however, research is needed to identify intervention characteristics most associated with such improvements. Objective This research aimed to assess the feasibility of a 9 week individual or group based exercise and counselling program, and to examine if a group based intervention is as effective at improving the QOL of breast cancer survivors as an individual-based intervention. Methods A three group design was implemented to compare the efficacy of a 9 week individual (IEC n = 12) and group based exercise and counselling (GEC n = 14) intervention to a usual care (UsC n = 10) group on QOL of thirty-six breast cancer survivors. Results Across all groups, 90% of participants completed the interventions, with no adverse effects documented. At the completion of the intervention, there was a significant difference between groups for change in global QOL across time (p < 0.023), with IEC improving significantly more (15.0 points) than the UsC group (1.8 points). The effect size was moderate (0.70). Although the GEC improved QOL by almost 10.0 points, this increase did not reach significance. Both increases were above the minimally important difference of 7–8 points. Conclusion These preliminary results suggest a combined exercise and psychological counseling program is both a feasible and acceptable intervention for breast cancer survivors. Whilst both the individual and group interventions improved QOL above the clinically important difference, only the individual based intervention was significant when compared to UsC.

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PURPOSE To review records of 330 patients who underwent surgery for femoral neck fractures with or without preoperative anticoagulation therapy. METHODS Medical records of 235 women and 95 men aged 48 to 103 years (mean, 81.6; standard deviation [SD], 13.1) who underwent surgery for femoral neck fractures with or without preoperative anticoagulation therapy were reviewed. 30 patients were on warfarin, 105 on aspirin, 28 on clopidogrel, and 167 were controls. The latter 3 groups were combined as the non-warfarin group and compared with the warfarin group. Hospital mortality, time from admission to surgery, length of hospital stay, return to theatre, and postoperative complications (wound infection, deep vein thrombosis, and pulmonary embolism) were assessed. RESULTS The warfarin and control groups were significantly younger than the clopidogrel and aspirin groups (80.8 vs. 80.0 vs. 84.2 vs. 83.7 years, respectively, p<0.05). 81% of the patients underwent surgery within 48 hours of admission. The overall mean time from admission to surgery was 1.8 days; it was longer in the warfarin than the aspirin, clopidogrel, and control groups (3.3 vs. 1.8 vs. 1.6 vs. 1.6 days, respectively, p<0.001). The mean length of hospital stay was 17.5 (SD, 9.6; range, 3-54) days. The overall hospital mortality was 3.9%; it was 6.7% in the warfarin group, 3.8% in the aspirin group, 3.6% in the clopidogrel group, and 3.6% in the control group (p=0.80). Four patients returned to theatre for surgery: one in the warfarin group for washout of a haematoma, 2 in the aspirin group for repositioning of a mal-fixation and for debridement of wound infection, and one in the control group for debridement of wound infection. The warfarin group did not differ significantly from non-warfarin group in terms of postoperative complication rate (6.7% vs. 2.7%, p=0.228) and the rate of return to theatre (3.3% vs. 1%, p=0.318). CONCLUSION It is safe to continue aspirin and clopidogrel prior to surgical treatment for femoral neck fracture. The risk of delaying surgery outweighs the peri-operative bleeding risk.

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Variation in body iron is associated with or causes diseases, including anaemia and iron overload. Here, we analyse genetic association data on biochemical markers of iron status from 11 European-population studies, with replication in eight additional cohorts (total up to 48,972 subjects). We find 11 genome-wide-significant (P<5 × 10−8) loci, some including known iron-related genes (​HFE, ​SLC40A1, ​TF, ​TFR2, ​TFRC, ​TMPRSS6) and others novel (​ABO, ​ARNTL, ​FADS2, ​NAT2, ​TEX14). SNPs at ​ARNTL, ​TF, and ​TFR2 affect iron markers in ​HFE C282Y homozygotes at risk for hemochromatosis. There is substantial overlap between our iron loci and loci affecting erythrocyte and lipid phenotypes. These results will facilitate investigation of the roles of iron in disease.

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Background This study addresses limitations of prior research that have used group comparison designs to test the effects of parental illness on youth. Purpose This study examined differences in adjustment between children of a parent with illness and peers from ‘healthy’ families controlling for the effects of whether a parent or non-parent family member is ill, illness type, demographics and caregiving. Methods Based on questionnaire data, groups were derived from a community sample of 2,474 youth (‘healthy’ family, n = 1768; parental illness, n = 336; other family member illness, n = 254; both parental and other family illness, n = 116). Results The presence of any family member with an illness is associated with greater risk of mental health difficulties for youth relative to peers from healthy families. This risk is elevated if the ill family member is a parent and has mental illness or substance misuse. Conclusions Serious health problems within a household adversely impact youth adjustment.

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Objective The aim of this systematic review and meta-analysis was to determine the overall effect of resistance training (RT) on measures of muscular strength in people with Parkinson’s disease (PD). Methods Controlled trials with parallel-group-design were identified from computerized literature searching and citation tracking performed until August 2014. Two reviewers independently screened for eligibility and assessed the quality of the studies using the Cochrane risk-of-bias-tool. For each study, mean differences (MD) or standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for continuous outcomes based on between-group comparisons using post-intervention data. Subgroup analysis was conducted based on differences in study design. Results Nine studies met the inclusion criteria; all had a moderate to high risk of bias. Pooled data showed that knee extension, knee flexion and leg press strength were significantly greater in PD patients who undertook RT compared to control groups with or without interventions. Subgroups were: RT vs. control-without-intervention, RT vs. control-with-intervention, RT-with-other-form-of-exercise vs. control-without-intervention, RT-with-other-form-of-exercise vs. control-with-intervention. Pooled subgroup analysis showed that RT combined with aerobic/balance/stretching exercise resulted in significantly greater knee extension, knee flexion and leg press strength compared with no-intervention. Compared to treadmill or balance exercise it resulted in greater knee flexion, but not knee extension or leg press strength. RT alone resulted in greater knee extension and flexion strength compared to stretching, but not in greater leg press strength compared to no-intervention. Discussion Overall, the current evidence suggests that exercise interventions that contain RT may be effective in improving muscular strength in people with PD compared with no exercise. However, depending on muscle group and/or training dose, RT may not be superior to other exercise types. Interventions which combine RT with other exercise may be most effective. Findings should be interpreted with caution due to the relatively high risk of bias of most studies.

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Meta-analyses estimate a statistical effect size for a test or an analysis by combining results from multiple studies without necessarily having access to each individual study's raw data. Multi-site meta-analysis is crucial for imaging genetics, as single sites rarely have a sample size large enough to pick up effects of single genetic variants associated with brain measures. However, if raw data can be shared, combining data in a "mega-analysis" is thought to improve power and precision in estimating global effects. As part of an ENIGMA-DTI investigation, we use fractional anisotropy (FA) maps from 5 studies (total N=2, 203 subjects, aged 9-85) to estimate heritability. We combine the studies through meta-and mega-analyses as well as a mixture of the two - combining some cohorts with mega-analysis and meta-analyzing the results with those of the remaining sites. A combination of mega-and meta-approaches may boost power compared to meta-analysis alone.