The effects of Bodymax high-repetition resistance training on measures of body composition and muscular strength in active adult women

This is the author's PDF version of an article published in Journal of strenght and conditioning research in 2003. The definitive version is available at http://www.nsca-jscr.orgThe purpose of this study was to investigate the effects of a light, high-repetition resistance-training program on skinfold thicknesses and muscular strength in women. Thirty-nine active women (mean age 38.64 +/- 4.97 years) were randomly placed into a resistance-training group (RT; n = 20) or a control group (CG; n = 19). The RT group performed a resistance-training program called Bodymax for 1 hour, 3 d.wk(-1), which incorporated the use of variable free weights and high repetitions in a group setting. The CG group continued its customary aerobic training for 1 hour 3 d.wk(-1). Five skinfold and 7 muscular strength measures were determined pretraining and after 12 weeks of training. Sum of skinfolds decreased (-17 mm; p < 0.004) and muscular strength increased (+57.4 kg; p < 0.004) in the RT group. Effect sizes for individual skinfold sites and strength measures were "medium" and "high," respectively. Bodymax is an effective resistance-training program for reducing skinfold thickness and increasing muscular strength in active women. Therefore, women with a similar or lower-activity status should consider incorporating such training into their regular fitness programs

Estimated daily phthalate exposures in a population of mothers of male infants exhibiting reduced anogenital distance.

Phthalate diesters have been shown to be developmental and reproductive toxicants in animal studies. A recent epidemiologic study showed certain phthalates to be significantly associated with reduced anogenital distance in human male infants, the first evidence of subtle developmental effects in human male infants exposed prenatally to phthalates. We used two previously published methods to estimate the daily phthalate exposures for the four phthalates whose urinary metabolites were statistically significantly associated with developmental effects in the 214 mother-infant pairs [di-n-butyl phthalate (DnBP) , diethyl phthalate (DEP) , butylbenzyl phthalate (BBzP) , diisobutyl phthalate (DiBP) ] and for another important phthalate [di-2-ethylhexyl phthalate (DEHP) ]. We estimated the median and 95th percentile of daily exposures to DBP to be 0.99 and 2.68 microg/kg/day, respectively ; for DEP, 6.64 and 112.3 microg/kg/day ; for BBzP, 0.50 and 2.47 microg/kg/day ; and for DEHP, 1.32 and 9.32 microg/kg/day. The U.S. Environmental Protection Agency (EPA) reference doses for these chemicals are 100 (DBP) , 800 (DEP) , 200 (BBzP) , and 20 (DEHP) microg/kg/day. The median and 95th percentile exposure estimates for the phthalates associated with reduced anogenital distance in the study population are substantially lower than current U.S. EPA reference doses for these chemicals and could be informative to any updates of the hazard assessments and risk assessments for these chemicals

Evaluation of Activated Carbon as a Reactive Cap Sorbent for Sequestration of PCBs in Presence of Humic Acid

This study investigated the interferences caused by high humic acid concentrations on the adsorption of coplanar and noncoplanar polychlorinated biphenyls (PCBs) on coconut shell activated carbon. In particular, the research focuses on the application of activated carbon as a reactive cap for contaminated sediment sites, a possible intervention to reduce contaminant flux through pore water, and to organisms in aquatic environments. Kinetic and equilibrium studies were conducted using activated carbon as a sorbent for individual PCB congeners including BZ 1, 52, 77, 153, and 169, respectively, in the presence and absence of humic acid. Results showed that preloading of activated carbon with humic acid significantly reduced the adsorption affinity for all selected PCB congeners. Experiments conducted without preloading of activated carbon demonstrated that desorption upon subsequent spiking with humic acid (simulating long-term exposure to pore water that contains high humic acid concentrations) was not found to be statistically significant, and varied with coplanarity of PCBs. Results provide important information for the design of reactive caps in sediments where high concentrations of dissolved organic carbon are found, and highlight the importance of considering site conditions when designing effective reactive caps

Effect of Humic Acid on Adsorption of Polychlorinated Biphenyls onto Organoclay

Mitigation of risks stemming from contaminated sediments in freshwater and estuarine environments remains an important challenge to the field of environmental science and engineering. Capping sediments with reactive materials is one approach that has recently been the subject of research and development. This research evaluated the use of organoclay as a sorbent in a reactive cap for in situ remediation of contaminated sediments, and provides an original contribution by presenting the sorption characteristics of individual polychlorinated biphenyls (PCB) congeners in the presence of high concentrations of humic acids typical of sediment porewater environments. Sorption of coplanar and noncoplanar PCBs on three commercially available organoclays was studied in this work. Studies were conducted to evaluate the kinetics of adsorption of PCBs on organoclay and to determine the effect of humic acid on the kinetics of adsorption. Isotherm studies were conducted to determine the adsorption affinity of PCBs for organoclays in the presence and absence of humic acid. Studies showed a 45 to 96% reduction in the sorption affinity for organoclays after preloading with high concentrations of humic acid, depending both on the congener and the composition of organoclay. Desorption of PCBs upon addition of humic acid after PCBs were equilibrated with organoclay was statistically significant, although the magnitude of the effect was much smaller than that observed from preloading of humic acid

Nutrient management on intensive dairy farms in the southwest of Ireland

End of Project ReportIntensive grass-based dairy farming relies on high inputs of nutrients that are now regulated under SI 378, 2006 (Good Agricultural Practice for Protection of Waters). This project studied nutrient management practices on twenty-one intensive dairy farms in the south-west of Ireland between 2003 and 2006. Mean stocking rate was 202 kg organic-N/ha deposited by grazing livestock. Overall fertiliser-N use on the farms decreased from 266 to 223 kg N/ha/yr during the study, with the rate of fertiliser-N in the first application each year decreasing from 49 to 33 kg N/ha, while the rate of fertiliser-N applied for first cut silage production also fell from 106 to 96 kg N/ha. These decreases were partly achieved by applying more slurry in springtime and by the introduction of white clover on five of the farms. While the limits on fertiliser-N use under SI 378 were exceeded on ten farms in 2003, the limits were exceeded on only two farms in 2006. Fertiliser-P usage declined from 12.0 to 10.2 kg P/ha/yr, and complied with the limits of SI 378 on thirteen of the farms in 2006. Mean Morgan’s extractable soil P concentration (STP) exceeded 10 mg/l on five farms, while the mean concentration exceeded 8 mg/l on ten farms. Phosphorus management, therefore, was close to that required by SI 378 on most farms. Slurry storage capacity met or exceeded the minimum requirements of SI 378 on eight farms; substantial investment in slurry storage facilities was necessary on thirteen farms. The mean N surplus on the farms declined from 277 to 232 kg N/ha/yr during the study due to a decline in total N input from 335 to 288 kg N/ha/yr over the same period. The mean efficiency of N-use increased from 17.9 to 20.2 %. The large variation in rates of fertiliser-N applied on farms with similar stocking rates suggests potential for further improvements in N use efficiency on some farms. Decreases in nutrient input levels can be partly attributed to increased farmer awareness, due to advice and record keeping from this study and the introduction of SI 378, and the increasing cost of nutrient inputs relative to output prices. In terms of fertiliser N and P use and soil P concentrations, complying with the limits in SI 378 does not require major changes in nutrient management practices on the majority of these intensive dairy farms

The Neurology of the Immune System: Neural Reflexes Regulate Immunity

Parallel advances in neuroscience and immunology established the anatomical and cellular basis for bidirectional interactions between the nervous and immune systems. Like other physiological systems, the immune system—and the development of immunity—is modulated by neural reflexes. A prototypical example is the inflammatory reflex, comprised of an afferent arm that senses inflammation and an efferent arm, the cholinergic anti-inflammatory pathway, that inhibits innate immune responses. This mechanism is dependent on the α7 subunit of the nicotinic acetylcholine receptor, which inhibits NF-κB nuclear translocation and suppresses cytokine release by monocytes and macrophages. Here we summarize evidence showing that innate immunity is reflexive. Future advances will come from applying an integrative physiology approach that utilizes methods adapted from neuroscience and immunology

Dobutamine stress MRI in pulmonary hypertension: relationships between stress pulmonary artery relative area change, RV performance, and 10-year survival

In pulmonary hypertension (PH), right ventricular (RV) performance determines survival. Pulmonary artery (PA) stiffening is an important biomechanical event in PH and also predicts survival based on the PA relative area change (RAC) measured at rest using magnetic resonance imaging (MRI). In this exploratory study, we sought to generate novel hypotheses regarding the influence of stress RAC on PH prognosis and the interaction between PA stiffening, RV performance and survival. Fifteen PH patients underwent dobutamine stress-MRI (ds-MRI) and right heart catheterization. RACREST, RACSTRESS, and ΔRAC (RAC STRESS – RAC REST) were correlated against resting invasive hemodynamics and ds-MRI data regarding RV performance and RV-PA coupling efficiency (n’vv [RV stroke volume/RV end-systolic volume]). The impact of RAC, RV data, and n’vv on ten-year survival were determined using Kaplan–Meier analysis. PH patients with a low ΔRAC (&lt;−2.6%) had a worse long-term survival (log-rank P = 0.045, HR for death = 4.46 [95% CI = 1.08–24.5]) than those with ΔRAC ≥ −2.6%. Given the small sample, these data should be interpreted with caution; however, low ΔRAC was associated with an increase in stress diastolic PA area indicating proximal PA stiffening. Associations of borderline significance were observed between low RACSTRESS and low n’vvSTRESS, Δη’VV, and ΔRVEF. Further studies are required to validate the potential prognostic impact of ΔRAC and the biomechanics potentially connecting low ΔRAC to shorter survival. Such studies may facilitate development of novel PH therapies targeted to the proximal PA

New Jobs, New Workers? Organizational Restructuring and Management Hiring Decisions

Tout comme les lieux de travail, les organisations connaissent actuellement des changements drastiques. Au cours des dernières années, les petites et grandes entreprises ont procédé à des restructurations: redéfinition des postes de travail, modifications à l'interne et changement des attentes au plan de l'emploi. Cet article a pour objectif de vérifier dans quelle mesure des changements récents de la philosophie de gestion au plan de l'organisation du travail ont incité la direction de ces entreprises à modifier leurs attentes à l'endroit des travailleurs: est-ce que le nouveau travail fait appel à de nouveaux travailleurs?Pour répondre à cette question, nous avons puisé dans des rapports d'entrevues avec des directeurs de ressources humaines de trois types d'industries de l'Ouest de l'Ontario (les équipements de transport, les produits chimiques et les services de santé). Nous avons ainsi cherché à évaluer l'ampleur des restructurations qui ont cours dans ces secteurs et la perception que les dirigeants se font de la nature des habiletés et des caractéristiques des travailleurs maintenant exigées par ces restructurations. Les dirigeants dans ces trois secteurs décrivent la nature des changements en cours en termes d'aplatissement des structures organisationnelles, de redéfinition des postes et de l'insertion de ces derniers dans une nouvelle structure. De plus, ces mêmes dirigeants nous révèlent que ces changements ont modifier leur vision de ce qu'est un bon travailleur. Ils ont donc changé la nature des caractéristiques recherchées chez un travailleur. En premier lieu, ces dirigeants souhaitent un niveau de scolarité plus élevé, une formation préalable plus accentuée et de l'expérience différente de celle exigée dans le passé. Ils croient que le rythme récent des changements technologiques, associé à une tendance vers un agrandissement des tâches, fait appel à une main-d’œuvre plus scolarisée et mieux formée. De plus, dans plusieurs cas, ils veulent de moins en moins assumer les coûts inhérents à un relèvement des niveaux de scolarité et de formation.En deuxième lieu, ces directeurs de ressources humaines souhaitent une plus grande flexibilité chez les travailleurs, flexibilité qui reçoit diverses significations: des travailleurs plus polyvalents, mieux adaptés à des emplois de plus d'envergure qu'on retrouve maintenant dans les entreprises allégées. Cette flexibilité peut aussi revêtir des caractéristiques personnelles de l'ordre d'une réponse aux besoins de l'entreprise et d'une volonté de travailler au moment et à l'endroit où cette dernière l'exige. Les entreprises valorisent aussi une flexibilité qui implique des changements de lieux de travail d'un établissement à l'autre à l'intérieur d'une province, d'un pays et dans le monde entier. Ces entreprises recherchent des personnes qui sont prêtes à travailler selon différents horaires et aussi à accepter de faire du surtemps.En troisième lieu, ces directions de ressources humaines souhaitent l'arrivée de travailleurs qui peuvent se servir des nouvelles technologies plus que dans le passé. Elles manifestent également un plus grand besoin de salariés qui peuvent faire l'entretien et la programmation de ces technologies et de salariés sans spécialité qui peuvent utiliser des ordinateurs ou d'autres équipements informatiques dans l'exécution de leur travail.Quatrièmement, ces directions mettent l'accent sur certaines habiletés douces (d'ordre relationnel), telles que la capacité de communiquer et de travailler en équipe. Les entreprises font appel au travail d'équipe beaucoup plus que dans le passé, de sorte que la communication interpersonnelle devient de plus en plus importante. Les directions recherchent aussi des travailleurs capables d'accomplir des tâches multiples et d'assumer un élargissement de leurs responsabilités. La capacité d'apprendre est aussi une préoccupation de ces directions et elle est associée à une croyance que l'entraînement et la formation bonifiés sont nécessaires pour se tenir à jour face au changement continuel de la technologie et des lieux de travail. Des changements au niveau des attitudes des directions ont des effets sur l'emploi et les travailleurs. Au fur et à mesure que le niveau de formation exigé par les entreprises s'accroît, les travailleurs possédant peu de scolarité sont poussés hors du marché du travail. Par conséquent, les travailleurs susceptibles d'obtenir et de conserver un emploi sont ceux qui sont mieux formés, qui possèdent une bonne connaissance de la technologie nouvelle et les habiletés relationnelles alors exigées. De plus, la demande de main-d’œuvre plus flexible semble en opposition avec l'accroissement du nombre de familles à double revenu et de familles monoparentales. L'obligation pour ces familles de satisfaire aux exigences de deux carrières et aux responsabilités inhérentes à l'éducation des enfants vient de façon évidente limiter la flexibilité des travailleurs.Sans égard à la nature exacte des changements en cours dans les organisations, la reconnaissance chez les dirigeants d'un besoin de repenser le travail vient changer de façon significative la perception qu'ils se font des qualifications exigées chez les salariés. Ces changements auront donc des conséquences largement diffusées tant chez les travailleurs que dans les organisations au cours des années qui viennent.Recent studies of work have argued that organizational restructuring and the introduction of technology are altering the nature and experience of work. In this paper, we examine whether recent change has affected managerial perceptions of the characteristics and abilities required of workers. Drawing on interviews with human resource managers in three industries (chemicals production, transportation equipment manufacturing, health services) in Southwestern Ontario, we conclude that management across these industries is indeed seeking a "new" kind of worker, and is placing new demands on their workers. Implications of these changes for employment and for workers are discussed.Los estudios recientes sobre el trabajo argumentan que la restructuracion organizacional y la introducciòn de tecnologfa estàn alterando la naturaleza y la experiencia concreta de trabajo. En estas paginas, nosotros examinamos si los recientes cambios han afectado las percepciones de los directivos respecto a las caracteristicas y habilidades exigidas a los trabajadores. A partir de entrevistas con responsables de recursos humanos en très industrias (producciòn quìmica, equipo de transporte, servicios de salud) ubicadas al sur de Ontario, nosotros llegamos a la conclusion que los directivos de estas industrias buscan verdaderamente un nuevo tipo de trabajador y que estàn planteando nuevas exigencias a sus trabajadores. Se discute también las implicaciones de estos cambios para los trabajadores y respecto al empleo

An agent-based movement model to assess the impact of landscape fragmentation on disease transmission

Landscape changes can result in habitat fragmentation and reduced landscape connectivity, limiting the ability of animals to move across space and altering infectious disease dynamics in wildlife. In this study, we develop and implement an agent-based model to assess the impacts of animal movement behavior and landscape structure on disease dynamics. We model a susceptible/infective disease state system applicable to the transmission of feline immunodeficiency virus in bobcats in the urbanized landscape of coastal southern California. Our agent-based model incorporates animal movement behavior, pathogen prevalence, transmission probability, and habitat fragmentation to evaluate how these variables influence disease spread in urbanizing landscapes. We performed a sensitivity analysis by simulating the system under 4200 different combinations of model parameters and evaluating disease transmission outcomes. Our model reveals that host movement behavior and response to landscape features play a pivotal role in determining how habitat fragmentation influences disease dynamics. Importantly, interactions among habitat fragmentation and movement had non-linear and counter-intuitive effects on disease transmission. For example, the model predicts that an intermediate level of non-habitat permeability and directionality will result in the highest rates of between-patch disease transmission. Agent-based models serve as computational laboratories that provide a powerful approach for quantitatively and visually exploring the role of animal behavior and anthropogenic landscape change on contacts among agents and the spread of disease. Such questions are challenging to study empirically given that it is difficult or impossible to experimentally manipulate actual landscapes and the animals and pathogens that move through them. Modeling the relationship between habitat fragmentation, animal movement behavior, and disease spread will improve understanding of the spread of potentially destructive pathogens through wildlife populations, as well as domestic animals and humans