Showing papers by "Edith Cowan University published in 2009"

Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability

Abstract: Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios (delta(15)N), foliar N concentrations, mycorrhizal type and climate for over 11,000 plants worldwide. Arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal plants were depleted in foliar delta(15)N by 2 per thousand, 3.2 per thousand, 5.9 per thousand, respectively, relative to nonmycorrhizal plants. Foliar delta(15)N increased with decreasing mean annual precipitation and with increasing mean annual temperature (MAT) across sites with MAT >or= -0.5 degrees C, but was invariant with MAT across sites with MAT < -0.5 degrees C. In independent landscape-level to regional-level studies, foliar delta(15)N increased with increasing N availability; at the global scale, foliar delta(15)N increased with increasing foliar N concentrations and decreasing foliar phosphorus (P) concentrations. Together, these results suggest that warm, dry ecosystems have the highest N availability, while plants with high N concentrations, on average, occupy sites with higher N availability than plants with low N concentrations. Global-scale comparisons of other components of the N cycle are still required for better mechanistic understanding of the determinants of variation in foliar delta(15)N and ultimately global patterns in N cycling.

Cyberbullying Versus Face-to-Face Bullying A Theoretical and Conceptual Review

Abstract: Cyberbullying has been described as a type of electronic bullying and has recently been subjected to intense media scrutiny largely due to a number of high profile and tragic cases of teen suicide. Despite the media attention relatively little is known about the nature of cyberbullying. This is, at least in part, due to a lack of theoretical and conceptual clarity and an examination of the similarities and differences between cyberbullying and face-to-face bullying. This paper reviews the limited theoretical and empirical literature addressing both cyberbullying and face-to-face bullying, using some specific examples from a qualitative study for illustration. We compare and contrast individual factors common to cyber and face-to-face bullying. We then examine social information processing factors associated with face-to-face bullying and present a discussion of the similarities and differences that may characterize cyberbullying.

The Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging: Methodology and baseline characteristics of 1112 individuals recruited for a longitudinal study of Alzheimer's disease

Abstract: Background: The Australian Imaging, Biomarkers and Lifestyle (AIBL) flagship study of aging aimed to recruit 1000 individuals aged over 60 to assist with prospective research into Alzheimer's disease (AD). This paper describes the recruitment of the cohort and gives information about the study methodology, baseline demography, diagnoses, medical comorbidities, medication use, and cognitive function of the participants. Methods: Volunteers underwent a screening interview, had comprehensive cognitive testing, gave 80 ml of blood, and completed health and lifestyle questionnaires. One quarter of the sample also underwent amyloid PET brain imaging with Pittsburgh compound B (PiB PET) and MRI brain imaging, and a subgroup of 10% had ActiGraph activity monitoring and body composition scanning. Results: A total of 1166 volunteers were recruited, 54 of whom were excluded from further study due to comorbid disorders which could affect cognition or because of withdrawal of consent. Participants with AD (211) had neuropsychological profiles which were consistent with AD, and were more impaired than participants with mild cognitive impairment (133) or healthy controls (768), who performed within expected norms for age on neuropsychological testing. PiB PET scans were performed on 287 participants, 100 had DEXA scans and 91 participated in ActiGraph monitoring. Conclusion: The participants comprising the AIBL cohort represent a group of highly motivated and well- characterized individuals who represent a unique resource for the study of AD. They will be reassessed at 18-month intervals in order to determine the predictive utility of various biomarkers, cognitive parameters and lifestyle factors as indicators of AD, and as predictors of future cognitive decline.

Relationship between atrophy and beta-amyloid deposition in Alzheimer disease.

Abstract: OBJECTIVE: Elucidating the role of aggregated beta-amyloid in relation to gray matter atrophy is crucial to the understanding of the pathological mechanisms of Alzheimer disease and for the development of therapeutic trials. The present study aims to assess this relationship. METHODS: Brain magnetic resonance imaging and [(11)C]Pittsburgh compound B (PiB)-positron emission tomography scans were obtained from 94 healthy elderly subjects (49 with subjective cognitive impairment), 34 patients with mild cognitive impairment, and 35 patients with Alzheimer disease. The correlations between global and regional neocortical PiB retention and atrophy were analyzed in each clinical group. RESULTS: Global and regional atrophy were strongly related to beta-amyloid load in participants with subjective cognitive impairment but not in patients with mild cognitive impairment or Alzheimer disease. Global neocortical beta-amyloid deposition correlated to atrophy in a large brain network including the hippocampus, medial frontal and parietal areas, and lateral temporoparietal cortex, whereas regional beta-amyloid load was related to local atrophy in the areas of highest beta-amyloid load only, that is, medial orbitofrontal and anterior and posterior cingulate/precuneus areas. INTERPRETATION: There is a strong relationship between beta-amyloid deposition and atrophy very early in the disease process. As the disease progresses to mild cognitive impairment and Alzheimer disease clinical stages, pathological events other than, and probably downstream from, aggregated beta-amyloid deposition might be responsible for the ongoing atrophic process. These findings suggest that antiamyloid therapy should be administered very early in the disease evolution to minimize synaptic and neuronal loss.

Power-time, force-time, and velocity-time curve analysis of the countermovement jump: Impact of training

Abstract: The purpose of this investigation was to examine the impact of training on the power-, force-, and velocity-time curves of the countermovement jump (CMJ) through both cross-sectional and longitudinal comparisons. The most novel aspect of this study was the analysis of these curves for the entire movement at a sampling frequency of 386-506 Hz averaged across 30 subjects. Thirty subjects, all men, participated in this investigation and included 12 athletes and 18 untrained men. Two major comparisons were conducted: 1) an acute, cross-sectional examination comparing experienced jumpers (jump height > 0.50 m; n = 12 men's athletes) with nonjumpers (jump height < 0.50 m; n = 14 untrained men), and 2) a longitudinal examination comparing performance before and after 12 weeks of power training (training group n = 10 untrained men; control group n = 8 untrained men). Data obtained from the baseline testing session of 14 subjects involved in the longitudinal study were used for the cross-sectional examination to represent the nonjumper group. The cross-sectional examination revealed significant (p

A Review of Interventions to Encourage SMEs to Make Environmental Improvements

Abstract: Small and medium-sized enterprises (SMEs) are an important part of the world economy but they are thought to be responsible for around 60% of all carbon dioxide emissions and 70% of all pollution. ...

Clearance mechanisms of Alzheimer's amyloid-|[beta]| peptide: implications for therapeutic design and diagnostic tests

Abstract: Currently, the 'amyloid hypothesis' is the most widely accepted explanation for the pathogenesis of Alzheimer's disease (AD). According to this hypothesis, altered metabolism of the amyloid-beta (Abeta) peptide is central to the pathological cascade involved in the pathogenesis of AD. Although Abeta is produced by almost every cell in the body, a physiological function for the peptide has not been determined, and the pathways by which Abeta leads to cognitive dysfunction and cell death are unclear. Numerous therapeutic approaches that target the production, toxicity and removal of Abeta are being developed worldwide. Although therapeutic treatment for AD may be imminent, the value and effectiveness of such treatment are largely dependent on early diagnosis of the disease. This review summarizes current knowledge of Abeta clearance, transport and degradation, and evaluates the use of such information in the development of diagnostic tools. The conflicting results of plasma Abeta ELISAs are discussed, as are the more promising results of Abeta imaging by positron emission tomography. Current knowledge of Abeta-binding proteins and Abeta-degrading enzymes is analysed in the context of a potential therapy for AD. Transport across the blood-brain barrier by the receptor for advanced glycation end products and efflux via the multi-ligand lipoprotein receptor LRP-1 is also reviewed. Enhancing clearance and degradation of Abeta remains an attractive therapeutic strategy, and improved understanding of Abeta clearance may lead to advances in diagnostics and interventions designed to prevent or delay the onset of AD.

Single-Leg Lateral, Horizontal, and Vertical Jump Assessment: Reliability, Interrelationships, and Ability to Predict Sprint and Change-of-Direction Performance

Abstract: The purposes of this study were to determine the reliability of unilateral vertical, horizontal, and lateral countermovement jump assessments, the interrelationship between these tests, and their usefulness as predictors of sprint (10 m) and change-of-direction (COD) performance for 80 men and women physical education students. Jump performance was assessed on a contact mat and sprint, and COD performances were assessed using timing lights. With regard to the reliability statistics, the largest coefficient of variation (CV) was observed for the vertical jump (CV = 6.7-7.2%) of both genders, whereas the sprint and COD assessments had smallest variability (CV = 0.8 to 2.8%). All intraclass correlation coefficients (ICC) were greater than 0.85, except for the men's COD assessment with the alternate leg. The shared variance between the single-leg vertical, horizontal, and lateral jumps for men and women was less than 50%, indicating that the jumps are relatively independent of one another and represent different leg strength/power qualities. The ability of the jumps to predict sprint and COD performance was limited (R2 < 43%). It would seem that the ability to change direction with 1 leg is relatively independent of a COD with the other leg, especially in the women (R < 30%) of this study. However, if 1 jump assessment were selected to predict sprint and COD performance in a test battery, the single-leg horizontal countermovement jump would seem the logical choice, given the results of this study. Many of the findings in this study have interesting diagnostic and training implications for the strength and conditioning coach.

An adoption model for mobile banking in Ghana

Abstract: The impact of social and cultural factors on the adoption of technology still requires much research. To investigate it more fully, we examine the reasons for the adoption and non-adoption of mobile banking in Ghana. Through a survey of 271 people in Ghana, it has been found that social and cultural factors in the form of perceived credibility, facilitating conditions, perceived elitisation and demographic factors do play a significant role in adoption decisions. It has been found that elitisation of technology and services can be a positive influence for adopters whilst being a negative influence for non-adopters. In addition, perceived credibility and facilitating conditions also influence attitudes towards the technology. When these factors are added to a range of demographic factors, the impact of the social and cultural features of the context of studies can be seen as significant.

Cholesterol metabolism and transport in the pathogenesis of Alzheimer’s disease

Abstract: Alzheimer's disease (AD) is the most common neurodegenerative disorder, affecting millions of people worldwide. Apart from age, the major risk factor identified so far for the sporadic form of AD is possession of the epsilon4 allele of apolipoprotein E (APOE), which is also a risk factor for coronary artery disease (CAD). Other apolipoproteins known to play an important role in CAD such as apolipoprotein B are now gaining attention for their role in AD as well. AD and CAD share other risk factors, such as altered cholesterol levels, particularly high levels of low density lipoproteins together with low levels of high density lipoproteins. Statins--drugs that have been used to lower cholesterol levels in CAD, have been shown to protect against AD, although the protective mechanism(s) involved are still under debate. Enzymatic production of the beta amyloid peptide, the peptide thought to play a major role in AD pathogenesis, is affected by membrane cholesterol levels. In addition, polymorphisms in several proteins and enzymes involved in cholesterol and lipoprotein transport and metabolism have been linked to risk of AD. Taken together, these findings provide strong evidence that changes in cholesterol metabolism are intimately involved in AD pathogenic processes. This paper reviews cholesterol metabolism and transport, as well as those aspects of cholesterol metabolism that have been linked with AD.

Social and Ecological Structures Supporting Adolescent Connectedness to School: A Theoretical Model

Abstract: BACKGROUND: Adolescence is a time of great change. For most young people, this is a healthy and happy experience; however, for some it is characterized by many health, social, and academic challenges. A student's feeling of connectedness to school helps meet these challenges. Little is known, however, about the school characteristics that promote this connection and, more importantly, how this connection occurs. This article reviews the connectedness literature and integrates health promotion, adolescent development, and ecological frameworks to describe how a school context fosters this connection. METHOD: A systematic search and review process was used to retrieve scholarly articles pertaining to the research topic. RESULTS: Each retrieved article was summarized, and a subsequent model was developed to define a school ecology and describe how this ecology influences a student's need to feel connected to school and the positive influence this connection has on adolescent health and well-being. CONCLUSIONS: Integrating developmental, ecological, and health promotion intervention theories and frameworks assists in the identification of interpersonal and organizational aspects of a school environment, which satisfy an individual's needs to feel autonomous, competent, and connected, and to improve health and well-being outcomes for adolescents.

Reliability of performance measurements derived from ground reaction force data during countermovement jump and the influence of sampling frequency.

Abstract: Force platforms are used extensively to measure force and power output during countermovement jump (CMJ). The purpose of this study was to examine measurement reliability and validity of commonly used performance measurements derived from ground reaction force (GRF)-time data during CMJ and the influence of sampling at different frequencies. Twenty-four men performed 2 trials of CMJ on a force platform, and GRF-time data were sampled at a rate of 500 Hz. Data obtained at 500 Hz were considered as the reference, and then data were resampled at 400, 250, 200, 100, 50, and 25 Hz, using interpolation. Commonly used power, force, and velocity performance measures were obtained from GRF-time data. Reliability was assessed by intraclass correlation coefficient (ICC) and coefficient of variation (CV) between the 2 trials within the session. Peak power, peak force, and peak velocity were highly reliable across all sampling frequencies (ICC = 0.92-0.98, CV = 1.3-4.1). Percentage differences from 500-Hz reference values ranged from -0.85 to 0.20% at 400 Hz, -1.88 to 0.89% at 250 Hz, -1.80 to 1.31% at 200 Hz, -3.63 to 3.34% at 100 Hz, -11.37 to 6.51% at 50 Hz, and -13.17 to 9.03% at 25 Hz. In conclusion, peak power, force, and velocity measurements derived from GRF to assess leg extensor capabilities are reliable within a test session except for peak rate of force development and time to peak power. With regard to sampling frequency, scientists and practitioners may consider sampling as low as 200 Hz, depending on the purpose of measurement, because the percentage difference is not markedly enlarged until the frequency is 100 Hz or lower.

Major conservation policy issues for biodiversity in Oceania.

Abstract: Oceania is a diverse region encompassing Australia, Melanesia, Micronesia, New Zealand, and Polynesia, and it contains six of the world's 39 hotspots of diversity. It has a poor record for extinctions, particularly for birds on islands and mammals. Major causes include habitat loss and degradation, invasive species, and overexploitation. We identified six major threatening processes (habitat loss and degradation, invasive species, climate change, overexploitation, pollution, and disease) based on a comprehensive review of the literature and for each developed a set of conservation policies. Many policies reflect the urgent need to deal with the effects of burgeoning human populations (expected to increase significantly in the region) on biodiversity. There is considerable difference in resources for conservation, including people and available scientific information, which are heavily biased toward more developed countries in Oceania. Most scientific publications analyzed for four threats (habitat loss, invasive species, overexploitation, and pollution) are from developed countries: 88.6% of Web of Science publications were from Australia (53.7%), New Zealand (24.3%), and Hawaiian Islands (10.5%). Many island states have limited resources or expertise. Even countries that do (e.g., Australia, New Zealand) have ongoing and emerging significant challenges, particularly with the interactive effects of climate change. Oceania will require the implementation of effective policies for conservation if the region's poor record on extinctions is not to continue.

Reduced muscle strength and functional performance in men with prostate cancer undergoing androgen suppression: A comprehensive cross-sectional investigation

Abstract: This study examined the effects of androgen suppression therapy (AST) on upper and lower body muscle strength and a range of direct measures of physical performance using a cross-sectional design with 118 men (48 men undertaking AST for prostate cancer and 70 healthy aged-matched controls) from a single tertiary center. Primary end points included muscle strength for the upper- and lower-body; functional performance--repeated chair rise, usual and fast 6-m walk, 6-m backwards walk and 400-m walk time; and dual-energy X-ray absorptiometry assessment--whole body, regional soft tissue composition and bone mineral density (BMD). Men on AST had significantly reduced muscle strength for the upper- and lower-body and impaired functional performance compared to controls (P<0.05). As expected, AST patients had significantly lower whole-body and hip BMD and higher percent of body fat than controls (P<0.05), and tended to have lower whole-body lean mass (-2.3 kg, P=0.077). Appendicular skeletal muscle was positively associated with upper-body (r=0.400-0.606, P<0.001) and lower-body (r=0.549-0.588, P<0.001) muscle strength, and strength was related to functional performance. Men undertaking AST were consistently impaired across a broad range of physical and functional musculoskeletal performance assessments compared with their age-matched normal controls. These findings are relevant for those patients considering AST for subclinical disease management, but whose physical reserve is marginal. Strategies to counter these adverse effects of AST need to be initiated so that independent living and quality of life can be maintained.

Anthropometric, physiological and performance characteristics of elite team-handball players

Abstract: The objective of this study was to provide anthropometric, physiological, and performance characteristics of an elite international handball team. Twenty-one elite handball players were tested and categorized according to their playing positions (goalkeepers, backs, pivots, and wings). Testing consisted of anthropometric and physiological measures of height, body mass, percentage body fat and endurance ([Vdot]O2max), performance measures of speed (5, 10, and 30 m), strength (bench press and squat), unilateral and bilateral horizontal jumping ability, and a 5-jump horizontal test. Significant differences were found between player positions for some anthropometric characteristics (height and percentage body fat) but not for the physiological or performance characteristics. Strong correlations were noted between single leg horizontal jumping distances with 5-, 10-, and 30-m sprint times (r = 0.51–0.80; P < 0.01). The best predictors of sprint times were single leg horizontal jumping with the dominan...

High-School Students' Informal Reasoning and Argumentation about Biotechnology: An Indicator of Scientific Literacy?.

Abstract: The aim of this research was to explore Australian high‐school students’ argumentation and informal reasoning about biotechnology. Data were obtained from semi‐structured interviews with 10 Year‐8 students (12–13 years old), 14 Year‐10 students (14–15 years old) and 6 Year‐12 students (16–17 years old) from six metropolitan high schools in Perth, Western Australia. The transcripts were analysed using both Toulmin’s argumentation pattern and informal reasoning patterns (rational, emotive, and intuitive) as frameworks. The notion of scientific literacy was used as the basis of the theoretical framework to examine the data. Most students used no data or only simple data to justify their claims. Students of all year groups used intuitive and emotive informal reasoning more frequently than rational. Rational informal reasoning was associated with more sophisticated arguments.

A Turing Test for Computer Game Bots

Abstract: In this paper, a version of the Turing Test is proposed, to test the ability of computer game playing agents (ldquobotsrdquo) to imitate human game players. The proposed test has been implemented as a bot design and programming competition, the 2K BotPrize Contest. The results of the 2008 competition are presented and analyzed. We find that the Test is challenging, but that current techniques show promise. We also suggest probable future directions for developing improved bots.

Ending the ‘dialogue of the deaf’: evidence and policing policies and practices. An Australian case study

Abstract: In this paper two current police research traditions are examined, the critical police research and policy police research, as they have evolved in the USA, the UK, and in Australia. Each tradition has developed a typical pattern of relationship between researchers and police practitioners, but both suffered from what we call the ‘dialogue of the deaf.’ While acknowledging the continuing importance of each approach to police research, we suggest the need for a third new approach to be developed in which academics and police work in close and continuous collaborative relationships.

Exercise for the primary, secondary and tertiary prevention of low back pain in the workplace: a systematic review.

Abstract: Introduction Low back pain (LBP) is one of the most costly conditions to manage in occupational health. Individuals with chronic or recurring LBP experience difficulties returning to work due to disability. Given the personal and financial cost of LBP, there is a need for effective interventions aimed at preventing LBP in the workplace. The aim of this systematic review was to examine the effectiveness of exercises in decreasing LBP incidence, LBP intensity and the impact of LBP and disability. Methods A comprehensive literature search of controlled trials published between 1978 and 2007 was conducted and a total of 15 studies were subsequently reviewed and analyzed. Results There was strong evidence that exercise was effective in reducing the severity and activity interference from LBP. However, due to the poor methodological quality of studies and conflicting results, there was only limited evidence supporting the use of exercise to prevent LBP episodes in the workplace. Other methodological limitations such as differing combinations of exercise, study populations, participant presentation, workloads and outcome measures; levels of exercise adherence and a lack of reporting on effect sizes, adverse effects, and types of sub-groups, make it difficult to draw definitive conclusions on the efficacy of workplace exercise in preventing LBP. Conclusions Only two out of the 15 studies reviewed were high in methodological quality and showed significant reductions in LBP intensity with exercise. Future research is needed to clarify which exercises are effective and the dose-response relationships regarding exercise and outcomes.

Antenatal depression and suicidal ideation among rural Bangladeshi women: a community-based study.

Abstract: Depression during pregnancy is a significant public health problem because of its negative effects on the health of both mother and infant. Data on its prevalence and determinants are lacking in Bangladesh. To estimate the prevalence of depression during pregnancy and to identify potential contributory factors among rural Bangladeshi women, a community-based study was conducted during 2005 in Matlab sub-district, a rural area of eastern Bangladesh. Three hundred and sixty-one pregnant women were identified through an existing health and demographic surveillance system covering a population of 110,000 people. The women were interviewed at home at 34-35 weeks of pregnancy. Information on risk factors was collected through structured questionnaires, with the Bangla version of the Edinburgh Postnatal Depression Scale (EPDS-B) used to measure their psychological status. Both univariate analysis and multivariate logistic regression were applied using the SPSS 15.0 statistical software. The prevalence of depression at 34-35 weeks pregnancy was 33% (95% CI, 27.6-37.5). After adjustment in a multivariate logistic regression model, a history of being beaten by her husband either during or before the current pregnancy had the highest association with depression followed by having an unhelpful or unsupportive mother-in-law or husband, and family preference for a male child. Of the antenatally depressed women, 17 (14%) admitted to thoughts of self-harm during the pregnancy. This paper further explores the reasons why women have considered some form of self-harm during pregnancy. Depression during pregnancy is common among Bangladeshi women, with about a third being affected. The study highlights the need to allocate resources and develop strategies to address depression in pregnancy.

Effect of antioxidant supplementation of cryopreservation medium on post-thaw integrity of human spermatozoa.

Abstract: This study examined whether the addition of an antioxidant to cryopreservation medium could improve the post-thaw integrity of cryopreserved human spermatozoa, particularly from men with abnormal semen parameters. Semen samples were collected by masturbation and assessed following WHO standards. Normal (n = 23) and abnormal (n = 20) samples were divided into three aliquots prior to cryopreservation. The first aliquot remained untreated and was mixed with cryopreservation medium (in-house 1:1). The second and third aliquots were mixed with cryopreservation medium containing either 100 micromol or 200 micromol vitamin E analogue. Samples were frozen at -10 degrees C per minute to -80 degrees C, then plunged into liquid nitrogen. Thawed samples were assessed for motility, vitality and DNA integrity. Split-plot repeated-measures ANOVA was used to assess within-subject (dose) and between-group (normal/abnormal) differences in post-thaw motility index, vitality staining and DNA fragmentation. Vitamin E dose was significantly associated with post-thaw motility (P = 0.041) and the pattern of response across doses was similar for normal and abnormal groups. Post-thaw motility was significantly improved by the addition of 200 micromol vitamin E (P = 0.006), but neither vitality nor sperm DNA fragmentation were altered. These results suggest that the addition of vitamin E to cryopreservation medium improves post-thaw motility.

Body image and self-esteem in older adulthood

Abstract: Given global population ageing and the fact that Australia is experiencing a significant increase in the proportion of older adults in its population, research into ageing issues has become a national priority. Whilst body image and self-esteem have been empirically linked, the relationship among older adults has been neglected. This study investigated several body-image variables and their relationship to self-esteem in a sample of 148 men and women aged 65–85 years who were living independently in the Perth Metropolitan Area of Western Australia. They completed the ‘Rosenberg Self-Esteem Scale’ and the ‘Multidimensional Body-Self Relations Questionnaire’. The results indicated, contrary to a common misconception, that body-image concerns are significant to self-esteem in older adulthood, but that these vary by age and gender. Whilst women appear to develop various strategies to counter the effects of ageing, men seem to be more negatively affected, particularly in relation to body functioning. The findings shed light on the meaning of body image in older adulthood. A better understanding of the meaning of body image, of the factors that influence the meaning, and of how these relate to older adults' self-esteem may help older adults develop a positive body image that will contribute to psycho-social strengths and enhance their quality of life.

Eight weeks of resistance training can significantly alter body composition in children who are overweight or obese.

Abstract: The purpose of this study was to investigate the effect of an 8-week resistance training program on children who were overweight or obese. Forty-eight children (n = 26 girls and 22 boys; mean age = 9.7 years) participated in an 8-week undulating periodized resistance training program for 3 d x wk-1. Measures of body composition via dual-energy X-ray absorptiometry, anthropometry, strength, and power were made before and after the training intervention. There was a significant decrease in absolute percent body fat of 2.6%(p = 0.003) and a significant increase in lean body mass of 5.3% (p = 0.07). There were no significant changes in height, weight, body mass index, total fat mass, or bone mineral content. There were significant increases in 1-repetition maximum squat (74%), number of push-ups (85%), countermovement jump height (8%), static jump height (4%), and power (16%). These results demonstrate that the resistance training program implemented produces significant changes in body composition and strength and power measures, as well as being well tolerated by the participants. An undulating periodized program provides variation and significantly increases lean body mass, decreases percent body fat, and increases strength and power in children who are overweight and obese.

Aβ aggregation and possible implications in Alzheimer's disease pathogenesis

Abstract: Amyloid β protein (Aβ) has been associated with Alzheimer's disease (AD) because it is a major component of the extracellular plaque found in AD brains. Increased Aβ levels correlate with the cognitive decline observed in AD. Sporadic AD cases are thought to be chiefly associated with lack of Aβ clearance from the brain, unlike familial AD which shows increased Aβ production. Aβ aggregation leading to deposition is an essential event in AD. However, the factors involved in Aβ aggregation and accumulation in sporadic AD have not been completely characterized. This review summarizes studies that have examined the factors that affect Aβ aggregation and toxicity. By necessity these are studies that are performed with recombinant-derived or chemically synthesized Aβ. The studies therefore are not done in animals but in cell culture, which includes neuronal cells, other mammalian cells and, in some cases, non-mammalian cells that also appear susceptible to Aβ toxicity. An understanding of Aβ oligomerization may lead to better strategies to prevent AD.

Evidence for impacts of nonindigenous macroalgae: a meta-analysis of experimental field studies

Abstract: Invasions by nonindigenous macroalgal species (NIMS) potentially cause severe impacts on native species. We conducted a meta-analysis of 18 field-based manipulative experiments to quantify the direction and magnitude of impacts (Hedges effect size d, hereafter ES). We found significant small-to-medium negative effects on "macrophyte abundance" (cover, biomass of native taxa; EScumulative = -0.30) and medium-to-large negative effects on "macrophyte assemblages" (richness, diversity, total abundance; EScumulative = -0.70). In contrast, EScumulative were not significant for "macrophyte processes" (growth, mortality; EScumulative = -0.39), "animal abundance" (densities; EScumulative = -0.13), or "animal assemblages" (richness, diversity; EScumulative = 0.75). The nonsignificant effect sizes were characterized by low sample sizes and should be interpreted with caution. Three study-specific effect sizes were particularly large (<-2.0), showing that, in specific cases, impacts can be highly negative. From a conservation perspective, focus could be on such worst-case scenarios. Still, the reported EScumulative are likely biased toward larger effects because only the most conspicuous NIMS have been tested and because nonsignificant results are less likely to be published. To better understand the impacts of NIMS, more manipulative experiments are needed, testing more species and under contrasting environmental conditions. Future studies should include procedural control treatments and report the abundance of the NIMS to avoid ambiguous interpretations. In conclusion, current experimental evidence shows that NIMS have, on average, small-to-large negative impacts on native plant species and assemblages. It is possible that these effects can result in severe consequences when accumulated over long time periods and large spatial scales.

Effect of bench press exercise intensity on muscle soreness and inflammatory mediators

Abstract: This study compared four different intensities of a bench press exercise for muscle soreness, creatine kinase activity, interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) concentrations in the blood. Thirty-five male Brazilian Army soldiers were randomly assigned to one of five groups: 50% one-repetition maximum (1-RM), 75% 1-RM, 90% 1-RM, 110% 1-RM, and a control group that did not perform the exercise. The total volume (sets × repetitions × load) of the exercise was matched among the exercise groups. Muscle soreness and plasma creatine kinase activity increased markedly (P < 0.05) after exercise, with no significant differences among the groups. Serum PGE2 concentration also increased markedly (P < 0.05) after exercise, with a significantly (P < 0.05) greater increase in the 110% 1-RM group compared with the other groups. A weak but significant (P < 0.05) correlation was found between peak muscle soreness and peak PGE2 concentration, but no significant corre...

A 5-Year Cohort Study of the Effects of High Protein Intake on Lean Mass and BMC in Elderly Postmenopausal Women

Abstract: Long-term effects of high dietary protein intake on muscle and bone structure in the elderly are not clear. The aim of this study was to investigate the relationship between baseline protein intake and lean mass and BMC 5 yr later in a cohort of elderly postmenopausal women. A total of 862 community-dwelling women 75 +/- 3 yr of age provided baseline data including nutrient intake assessed by a food frequency questionnaire. At 5 yr, upper arm muscle area (UAMA) and body composition using DXA were measured. Baseline protein intake was 81 +/- 28 g/d (1.2 +/- 0.4 g/kg/d), contributing 19 +/- 3% of total energy intake. There were positive correlations between baseline protein intake and whole body and appendicular bone-free lean mass and BMC (r = 0.14-0.18, p 87 g/d) had 5.4-6.0% higher whole body and appendicular lean mass and UAMA and 5.3-6.0% higher whole body and appendicular BMC. These effects remained after adjusting for potential confounders. However, the effect on BMC disappeared after further adjustment for lean mass. This study shows that high protein intake is associated with long-term beneficial effects on muscle mass and size and bone mass in elderly women. The protein effect on bone may be partly mediated by its effects on muscle.