On the choice of posittioning and cluster size for fixed relay stations in a LTE network

The long term evolution (LTE) is one of the latest standards in the mobile communications market. To achieve its performance, LTE networks use several techniques, such as multi-carrier technique, multiple-input-multiple-output and cooperative communications. Inside cooperative communications, this paper focuses on the fixed relaying technique, presenting a way for determining the best position to deploy the relay station (RS), from a set of empirical good solutions, and also to quantify the associated performance gain using different cluster size configurations. The best RS position was obtained through realistic simulations, which set it as the middle of the cell's circumference arc. Additionally, it also confirmed that network's performance is improved when the number of RSs is increased. It was possible to conclude that, for each deployed RS, the percentage of area served by an RS increases about 10 %. Furthermore, the mean data rate in the cell has been increased by approximately 60 % through the use of RSs. Finally, a given scenario with a larger number of RSs, can experience the same performance as an equivalent scenario without RSs, but with higher reuse distance. This conduces to a compromise solution between RS installation and cluster size, in order to maximize capacity, as well as performance.

Índice de massa corporal e ganho ponderal gestacional como fator determinante do peso ao nascer do recém-nascido

RESUMO - Introdução: A literatura aponta que a gravidez é um período do ciclo reprodutivo associado com o excesso de peso, que se tem tornado um problema de saúde pública em ascensão. Na verdade, evidências sugerem que o excessivo peso pré-gestacional e o ganho ponderal excessivo estão associados a um peso elevado do RN. Objetivos: Relacionar o IMC antes da conceção e o ganho ponderal durante a gestação com o PN do RN. Métodos: Foi realizado um estudo epidemiológico, analítico, observacional e transversal, com uma amostra de cento e três mães e respetivos RNs, de termo, saudáveis e de gravidez única, da Unidade de Obstetrícia do Hospital Beatriz Ângelo. Estas foram recrutadas entre novembro de 2012 e março de 2013 inclusive. Para tal, foram recolhidos dados clínicos e outras informações relativas à gravidez e parto, nomeadamente o PN, através do sistema informático. Resultados: Após a análise dos resultados, constatou-se que mães com IMC superior a 25 antes da gravidez apresentam ganho ponderal durante a gravidez acima dos valores recomendados (47,2%). A prevalência de macrossomia e baixo peso ao nascer também foi maior em mães com excesso de peso (p=0,021), tal como de PIG e GIG (p=0,004). Observando a influência do ganho ponderal verificou-se que 9,5% (n=4) das mães com ganho ponderal excessivo tiveram RN com elevado peso ao nascer, enquanto 14,3% (n=4) das mães com ganho ponderal abaixo do recomendado tiveram RN com baixo peso ao nascer (p=0,018). Verificou-se também que o tempo de gestação é maior em mães com ganho ponderal acima do recomendado (p=0,024), e que este fator está positivamente associado com o PN (r=0,218; p=0,029), comprimento (r=0,221; p=0,027) e PC (r=0,249; p=0,012) do RN. No que se refere às correlações, encontrou-se uma correlação positiva moderada entre os fatores maternos (peso antes de engravidar; IMC pré-gestacional; e ganho ponderal) e o PN. Discussão/Conclusão: Desta forma, podemos concluir que tanto o excesso de peso pré-gestacional como o ganho de peso inadequado durante a gestação têm implicações diretas no peso do recém-nascido, nomeadamente aumentando o risco de macrossomia fetal.

Evaluation of antihypertensive drugs in patients with obstructive sleep apnea and in rats submitted to chronic intermittent hypoxia

RESUMO: A hipertensão arterial (HA) é uma patologia altamente prevalente, embora claramente subdiagnosticada, em doentes com síndrome de apneia obstrutiva do sono (SAOS). Estas duas patologias apresentam uma estreita relação e a monitorização ambulatória da pressão arterial (MAPA), por um período de 24 horas, parece ser o método mais preciso para o diagnóstico de hipertensão em doentes com SAOS. No entanto, esta ferramenta de diagnóstico para além de ser dispendiosa e envolver um número acrescido de meios técnicos e humanos, é mais morosa e, por conseguinte, não é utilizada por rotina no contexto do diagnóstico da SAOS. Por outro lado, apesar da aplicação de pressão positiva contínua nas vias aéreas (CPAP – Continous Positive Airway Pressure) ser considerada a terapêutica de eleição para os doentes com SAOS, o seu efeito no abaixamento da pressão arterial (PA) parece ser modesto, exigindo, por conseguinte, a implementação concomitante de terapêutica anti-hipertensora. Acontece que são escassos os dados relativos aos regimes de fármacos anti-hipertensores utilizados em doentes com SAOS e, acresce ainda que, as guidelines terapêuticas para o tratamento farmacológico da HA, neste grupo particular de doentes, permanecem, até ao momento, inexistentes. A utilização de modelos animais de hipóxia crónica intermitente (CIH), que mimetizam a HA observada em doentes com SAOS, revela-se extremamente importante, uma vez que se torna imperativo identificar fármacos que promovam um controle adequado da PA neste grupo de doentes. No entanto, estudos concebidos com o intuito de investigar o efeito anti-hipertensor dos fármacos neste modelo animal revelam-se insuficientes e, por outro lado, os escassos estudos que testaram fármacos anti-hipertensores neste modelo não foram desenhados para responder a questões de natureza farmacológica. Acresce ainda que se torna imprescindível garantir a escolha de um método para administração destes fármacos que seja não invasivo e que minimize o stress do animal. Embora a gavagem seja uma técnica indiscutivelmente eficaz e amplamente utilizada para a administração diária de fármacos a animais de laboratório, ela compreende uma sequência de procedimentos geradores de stress para os animais e, que podem por conseguinte, constituir um viés na interpretação dos resultados obtidos. O objectivo global da presente investigação translacional foi contribuir para a identificação de fármacos anti-hipertensores mais efectivos para o tratamento da HT nos indivíduos com SAOS e investigar mecanismos subjacentes aos efeitos sistémicos associadas à SAOS bem como a sua modulação por fármacos anti-hipertensores. Os objectivos específicos foram: em primeiro lugar,encontrar novos critérios, baseados nas medidas antropométricas, que permitam a identificação de doentes com suspeita de SAOS, que erroneamente se auto-classifiquem como nãohipertensos, e desta forma promover um uso mais criterioso do MAPA; em segundo lugar, investigar a existência de uma hipotética associação entre os esquemas de fármacos antihipertensores e o controle da PA (antes e após a adaptação de CPAP) em doentes com SAOS em terceiro lugar, avaliar a eficácia do carvedilol (CVD), um fármaco bloqueador β-adrenérgico não selectivo com actividade antagonista α1 intrínseca e propriedades anti-oxidantes num modelo animal de hipertensão induzida pela CIH; em quarto lugar, explorar os efeitos da CIH sobre o perfil farmacocinético do CVD; e, em quinto lugar, investigar um método alternativo à gavagem para a administração crónica de fármacos anti-hipertensores a animais de laboratório. Com este intuito, na primeira fase deste projecto, fizemos uso de uma amostra com um número apreciável de doentes com SAOS (n=369), que acorreram, pela primeira vez, à consulta de Patologia do Sono do CHLN e que foram submetidos a um estudo polissonográfico do sono, à MAPA e que preencheram um questionário que contemplava a obtenção de informação relativa ao perfil da medicação anti-hipertensora em curso. Numa segunda fase, utilizámos um modelo experimental de HT no rato induzida por um paradigma de CIH. Do nosso trabalho resultaram os seguintes resultados principais: em primeiro lugar, o índice de massa corporal (IMC) e o perímetro do pescoço (PP) foram identificados como preditores independentes de “auto-classificação errónea” da HA em doentes com suspeita de SAOS; em segundo lugar, não encontramos qualquer associação com significado estatístico entre os vários esquemas de fármacos anti-hipertensores bem como o número de fármacos incluídos nesse esquemas, e o controle da PA (antes e depois da adaptação do CPAP); em terceiro lugar, apesar das doses de 10, 30 e 50 mg/kg de carvedilol terem promovido uma redução significativa da frequência cardíaca, não foi observado qualquer decréscimo na PA no nosso modelo animal; em quarto lugar, as razões S/(R+S) dos enantiómeros do CVD nos animais expostos à CIH e a condições de normóxia revelaram-se diferentes; e, em quinto lugar, a administração oral voluntária mostrou ser um método eficaz para a administração diária controlada de fármacos anti-hipertensores e que é independente da manipulação e contenção do animal. Em conclusão, os resultados obtidos através do estudo clínico revelaram que o controle da PA, antes e após a adaptação do CPAP, em doentes com SAOS é independente, quer do esquema de fármacos anti-hipertensores, quer do número de fármacos incluídos num determinado esquema. Os nossos resultados salientam ainda a falta de validade da chamada self-reported hypertension e sugerem que em todos os doentes com suspeita de SAOS, com HA não diagnosticada e com um IMC e um PP acima de 27 kg/m2 e 39 cm, respectivamente, a confirmação do diagnóstico de HA deverá ser realizada através da MAPA, ao invés de outros métodos que com maior frequência são utilizados com este propósito. Os resultados obtidos no modelo animal de HA induzida pela CIH sugerem que o bloqueio do sistema nervoso simpático, juntamente com os supostos efeitos pleiotrópicos do CVD, não parece ser a estratégia mais adequada para reverter este tipo particular de hipertensão e indicam que as alterações farmacocinéticas induzidas pela CIH no ratio S/(R+S) não justificam a falta de eficácia anti-hipertensora do CVD observada neste modelo animal. Por último, os resultados do presente trabalho suportam ainda a viabilidade da utilização da administração oral voluntária, em alternativa à gavagem, para a administração crónica de uma dose fixa de fármacos anti-hipertensores.---------------------------- ABSTRACT: Hypertension (HT) is a highly prevalent condition, although under diagnosed, in patients with obstructive sleep apnea (OSA). These conditions are closely related and 24-hour ambulatory blood pressure monitoring (ABPM) seems to be the most accurate measurement for diagnosing hypertension in OSA. However, this diagnostic tool is expensive and time-consuming and, therefore, not routinely used. On the other hand, although continuous positive airway pressure (CPAP) is considered the gold standard treatment for symptomatic OSA, its lowering effect on blood pressure (BP) seems to be modest and, therefore, concomitant antihypertensive therapy is still required. Data on antihypertensive drug regimens in patients with OSA are scarce and specific therapeutic guidelines for the pharmacological treatment of hypertension in these patients remain absent. The use of animal models of CIH, which mimic the HT observed in patients with OSA, is extremely important since it is imperative to identify preferred compounds for an adequate BP control in this group of patients. However, studies aimed at investigating the antihypertensive effect of antihypertensive drugs in this animal model are insufficient, and most reports on CIH animal models in which drugs have been tested were not designed to respond to pharmacological issues. Moreover, when testing antihypertensive drugs (AHDs) it becomes crucial to ensure the selection of a non-invasive and stress-free method for drug delivery. Although gavage is effective and a widely performed technique for daily dosing in laboratory rodents, it comprises a sequence of potentially stressful procedures for laboratory animals that may constitute bias for the experimental results. The overall goal of the present translational research was to contribute to identify more effective AHDs for the treatment of hypertension in patients with OSA and investigate underlying mechanisms of systemic effects associated with OSA, as well as its modulation by AHDs. The specific aims were: first, to find new predictors based on anthropometric measures to identify patients that misclassify themselves as non-hypertensive, and thereby promote the selective use of ABPM; second, to investigate a hypothetical association between ongoing antihypertensive regimens and BP control rates in patients with OSA, before and after CPAP adaptation; third, to determine, in a rat model of CIH-induced hypertension, the efficacy of carvedilol (CVD), a nonselective beta-blocker with intrinsic anti-α1-adrenergic activity and antioxidant properties; fourth, to explore the effects of CIH on the pharmacokinetics profile of CVD and fifth, to investigate an alternative method to gavage, for chronic administration of AHDs to laboratory rats. For that, in the first phase of this project, we used a sizeable sample of patients with OSA (n=369), that attended a first visit at Centro Hospitalar Lisboa Norte, EPE Sleep Unit, and underwent overnight polysomnography, 24-h ABPM and filled a questionnaire that included ongoing antihypertensive medication profile registration. In the second phase, a rat experimental model of HT induced by a paradigm of CIH that simulates OSA was used. The main findings of this work were: first, body mass index (BMI) and neck circumference (NC) were identified as independent predictors of hypertension misclassification in patients suspected of OSA; second, in patients with OSA, BP control is independent of both the antihypertensive regimen and the number of antihypertensive drugs, either before or after CPAP adaptation; third, although the doses of 10, 30 and 50 mg/Kg of CVD promoted a significant reduction in heart rate, no decrease in mean arterial pressure was observed; fourth, the S/(R+S) ratios of CVD enantiomers, between rats exposed to CIH and normoxic conditions, were different and fifth, voluntary ingestion proved to be an effective method for a controlled daily dose administration, with a define timetable, that is independent of handling and restraint procedures. In conclusion, the clinical study showed that BP control in OSA patients is independent of both the antihypertensive regimen and the number of antihypertensive drugs. Additionally, our results highlight the lack of validity of self-reported hypertension and suggest that all patients suspected of OSA with undiagnosed hypertension and with a BMI and NC above 27 Kg/m2 and 39 cm should be screened for hypertension, through ABPM. The results attained in the rat model of HT related to CIH suggest that the blockade of the sympathetic nervous system together with the putative pleiotropic effects of carvedilol is not able to revert hypertension induced by CIH and point out that the pharmacokinetic changes induced by CIH on S/(R+S) ratio are not apparently responsible for the lack of efficacy of carvedilol in reversing this particular type of hypertension. Finally, the results here presented support the use of voluntary oral administration as a viable alternative to gavage for chronic administration of a fixed dose of AHDs.

Prévalence de la dénutrition chez 143 adultes en bilan prétransplantation hépatique. Experience lausannoise de 1997 a 2005 [Prevalence of undernutrition in 143 patients before liver transplantation. The Lausanne experience between 1997 and 2005]

The prevalence of undernutrition was prospectively studied in 143 patients before liver transplantation between 1997 and 2005. Nutritional assessment is a particularly tricky problem in cirrhosis and mid-arm muscle circumference is considered as the best reliable anthropometric tool. In this prospective study, prevalence rate is very high (61%) and undernutrition is more frequent in alcoholic cirrhotic patients. In conclusion, these patients should benefit from an early dietician intervention before liver transplantation.

Novel loci for adiponectin levels and their influence on type 2 diabetes and metabolic traits: a multi-ethnic meta-analysis of 45,891 individuals.

Circulating levels of adiponectin, a hormone produced predominantly by adipocytes, are highly heritable and are inversely associated with type 2 diabetes mellitus (T2D) and other metabolic traits. We conducted a meta-analysis of genome-wide association studies in 39,883 individuals of European ancestry to identify genes associated with metabolic disease. We identified 8 novel loci associated with adiponectin levels and confirmed 2 previously reported loci (P = 4.5×10(-8)-1.2×10(-43)). Using a novel method to combine data across ethnicities (N = 4,232 African Americans, N = 1,776 Asians, and N = 29,347 Europeans), we identified two additional novel loci. Expression analyses of 436 human adipocyte samples revealed that mRNA levels of 18 genes at candidate regions were associated with adiponectin concentrations after accounting for multiple testing (p<3×10(-4)). We next developed a multi-SNP genotypic risk score to test the association of adiponectin decreasing risk alleles on metabolic traits and diseases using consortia-level meta-analytic data. This risk score was associated with increased risk of T2D (p = 4.3×10(-3), n = 22,044), increased triglycerides (p = 2.6×10(-14), n = 93,440), increased waist-to-hip ratio (p = 1.8×10(-5), n = 77,167), increased glucose two hours post oral glucose tolerance testing (p = 4.4×10(-3), n = 15,234), increased fasting insulin (p = 0.015, n = 48,238), but with lower in HDL-cholesterol concentrations (p = 4.5×10(-13), n = 96,748) and decreased BMI (p = 1.4×10(-4), n = 121,335). These findings identify novel genetic determinants of adiponectin levels, which, taken together, influence risk of T2D and markers of insulin resistance.

Obesity markers and blood pressure in a sample of Portuguese children and adolescents.

Little information exists regarding the effect of several obesity markers on blood pressure (BP) levels in youth. Transverse study including 2494 boys and 2589 girls. Height, weight and waist were measured according to the international criteria and body fat (BF) by bioimpedance. BP was measured by an automated device. Hypertension was defined using sex-specific, age-specific and height-specific observation-points. Body mass index (BMI) and waist were positively related with systolic blood pressure (SBP) and diastolic blood pressure (DBP) and heart rate in both sexes, whereas the relationships with BF were less consistent. Stepwise linear regression analysis showed that BMI was positively related with SBP and DBP in both sexes, whereas BF was negatively related with SBP in both sexes and with heart rate in boys only; finally, waist was positively related with SBP in boys and heart rate in girls. Age and heart rate-adjusted values of SBP and DBP increased with BMI: for SBP, 117+/-1, 123+/-1 and 124+/-1 mmHg in normal, overweight and obese boys, respectively; corresponding values for girls were 111+/-1, 114+/-1 and 116+/-2 mmHg (mean+/-SE, P<0.001). Overweight and obese boys had an odds ratio for being hypertensive of 2.26 (95% confidence interval: 1.79-2.86) and 3.36 (2.32-4.87), respectively; corresponding values for girls were 1.58 (confidence interval 1.25-1.99) and 2.31 (1.53-3.50). BMI, not BF or waist, is consistently and independently related to BP levels in children; overweight and obesity considerably increase the risk of hypertension.

Is thinness more prevalent than obesity in Portuguese adolescents?

There is little information regarding the prevalence of thinness in European adolescents. This was assessed in a convenience sample of children and adolescents from the Lisbon area (Portugal). Cross-sectional study including 2494 boys and 2519 girls aged 10-18 years. Body mass index (BMI), waist and hip were measured using standardized methods; thinness was defined using international criteria. Body fat was assessed by bioelectrical impedance. In girls, prevalence of thinness, overweight and obesity were 5.6%, 19.7% and 4.7%, respectively, whereas the corresponding numbers in boys were 3.9%, 17.4% and 5.3%. Prevalence of thinness increased whereas obesity decreased with age: from 1.5% to 7.6% for thinness and from 9.2% to 3.8% for obesity in girls aged 10 and 18, respectively. In boys, the corresponding trends were from 0% to 7.3% for thinness and from 10.6% to 3% for obesity. After adjusting for age, differences were found between BMI groups for weight, body fat percentage, fat mass, lean mass, waist and hip, while no differences regarding height were found between thin and normal weight participants. The prevalence of thinness is more frequent than obesity after age 14 in girls and 16 years in boys. Thinness is associated with a decreased body weight and body fat, whereas no consistent effect on height was noted.

Mirror extreme BMI phenotypes associated with gene dosage at the chromosome 16p11.2 locus.

Both obesity and being underweight have been associated with increased mortality. Underweight, defined as a body mass index (BMI) ≤ 18.5 kg per m(2) in adults and ≤ -2 standard deviations from the mean in children, is the main sign of a series of heterogeneous clinical conditions including failure to thrive, feeding and eating disorder and/or anorexia nervosa. In contrast to obesity, few genetic variants underlying these clinical conditions have been reported. We previously showed that hemizygosity of a ∼600-kilobase (kb) region on the short arm of chromosome 16 causes a highly penetrant form of obesity that is often associated with hyperphagia and intellectual disabilities. Here we show that the corresponding reciprocal duplication is associated with being underweight. We identified 138 duplication carriers (including 132 novel cases and 108 unrelated carriers) from individuals clinically referred for developmental or intellectual disabilities (DD/ID) or psychiatric disorders, or recruited from population-based cohorts. These carriers show significantly reduced postnatal weight and BMI. Half of the boys younger than five years are underweight with a probable diagnosis of failure to thrive, whereas adult duplication carriers have an 8.3-fold increased risk of being clinically underweight. We observe a trend towards increased severity in males, as well as a depletion of male carriers among non-medically ascertained cases. These features are associated with an unusually high frequency of selective and restrictive eating behaviours and a significant reduction in head circumference. Each of the observed phenotypes is the converse of one reported in carriers of deletions at this locus. The phenotypes correlate with changes in transcript levels for genes mapping within the duplication but not in flanking regions. The reciprocal impact of these 16p11.2 copy-number variants indicates that severe obesity and being underweight could have mirror aetiologies, possibly through contrasting effects on energy balance.

Prevalence, awareness and treatment of type 2 diabetes mellitus in Switzerland: the CoLaus study.

ABSTRACT: Aims To assess the prevalence, awareness and treatment levels of Type 2 diabetes in a Swiss city. Methods Population-based cross-sectional study of 6181 subjects (3246 women) aged 35-75 years living in Lausanne, Switzerland. Type 2 diabetes was defined as fasting plasma glucose >/= 7 mmol/l and/or oral hypoglycaemic treatment and/or insulin. Results Total prevalence of Type 2 diabetes was 6.3% (95% confidence interval: 5.7-7.0%), higher in men (9.1%) than in women (3.8%, P < 0.001) and increased with age. Two-thirds (65.3%; 60.4-70.0%) of participants with Type 2 diabetes were aware of their status and among those aware 86.0% (81.5-90.3%) were treated. Treatment was more frequent in men (91.3%) than in women (75.9%, P < 0.001). Two-thirds of those treated for Type 2 diabetes were on monotherapy. Biguanides were prescribed in 65.0% of Type 2 diabetes patients and represented 48% of all antidiabetic drugs. Multivariable analysis showed male gender, increasing age, waist or BMI to be positively associated with prevalence of Type 2 diabetes, while leisure-time physical activity and alcohol consumption were negatively associated. Among participants presenting with Type 2 diabetes, increasing age was positively associated with awareness of Type 2 diabetes. Among subjects diagnosed with Type 2 diabetes, male gender and increasing age were positively associated with treatment. Conclusion Prevalence of Type 2 diabetes in Switzerland is estimated to be between 5.7% and 7.0%. Two-thirds of patients with Type 2 diabetes are aware of their status, and over three quarters of those aware are treated.

Prevalence and Diagnostic Approach to Sleep Apnea in Hemodialysis Patients: A Population Study.

BACKGROUND: Previous observations found a high prevalence of obstructive sleep apnea (OSA) in the hemodialysis population, but the best diagnostic approach remains undefined. We assessed OSA prevalence and performance of available screening tools to propose a specific diagnostic algorithm. METHODS: 104 patients from 6 Swiss hemodialysis centers underwent polygraphy and completed 3 OSA screening scores: STOP-BANG, Berlin's Questionnaire, and Adjusted Neck Circumference. The OSA predictors were identified on a derivation population and used to develop the diagnostic algorithm, which was validated on an independent population. RESULTS: We found 56% OSA prevalence (AHI ≥ 15/h), which was largely underdiagnosed. Screening scores showed poor performance for OSA screening (ROC areas 0.538 [SE 0.093] to 0.655 [SE 0.083]). Age, neck circumference, and time on renal replacement therapy were the best predictors of OSA and were used to develop a screening algorithm, with higher discriminatory performance than classical screening tools (ROC area 0.831 [0.066]). CONCLUSIONS: Our study confirms the high OSA prevalence and highlights the low diagnosis rate of this treatable cardiovascular risk factor in the hemodialysis population. Considering the poor performance of OSA screening tools, we propose and validate a specific algorithm to identify hemodialysis patients at risk for OSA for whom further sleep investigations should be considered.

Psychosocial Quality-of-Life, Lifestyle and Adiposity: A Longitudinal Study in Pre-schoolers (Ballabeina Study).

PURPOSE: In obesity prevention, understanding psychosocial influences in early life is pivotal. Reviews reported contradictory results and a lack of longitudinal studies focusing on underlying lifestyle factors. This study tested whether psychosocial Quality-Of-Life (QOL) was associated with pre-schoolers' lifestyle and adiposity changes over one school year and whether lifestyle moderated the latter. It was hypothesised that QOL might not impact adiposity in everybody but that this might depend on preceding lifestyle. METHOD: Longitudinal data from 291 Swiss pre-schoolers (initially 3.9-6.3 years) was available. The following measures were used in longitudinal regressions: psychosocial QOL by PedsQL, adiposity (BMI z-score, waist, fat%), diet (food frequency), sedentary time and accelerometer-based activity. RESULTS: Concerning lifestyle, low psychosocial QOL was only related to unfavourable changes in diet (less fruit β = 0.21 and more fat intake β = -0.28) and lower physical activity (β = 0.21). Longitudinal QOL-adiposity relations appeared only after moderation by lifestyle factors (beta-range 0.13-0.67). Low psychosocial QOL was associated with increased adiposity in children with an unhealthy diet intake or high sedentary time. By contrast, low psychosocial QOL was associated with decreasing adiposity in high fruit consumers or more physically active pre-schoolers. CONCLUSION: Results emphasise the need for testing moderation in the QOL-adiposity relation. An unhealthy diet can be a vulnerability factor and high physical activity a protective factor in QOL-related adiposity. Consequently, QOL and lifestyle should be targeted concurrently in multi-factorial obesity prevention. The environment should be an 'activity encouraging, healthy food zone' that minimises opportunities for stress-induced eating. In addition, appropriate stress coping skills should be acquired.

Individual difference factors and men's attraction to female body features /

Existing research on attraction to body features has suggested that men show general preferences for women with lower waist-to-hip ratios (WHR), larger breasts, and slender body weights. The present study intended to expand on this research by investigating several individual difference factors and their potential contribution to variation in what men find attractive in female body features. Two hundred and seventy-three men were assessed for sex-role identity, 2D:4D digit ratios (a possible marker of prenatal exposure to androgens, and thus masculinization), physical attractiveness, early sexual experiences (as indices of early sexual conditioning), and early family attitudes toward body features, as well as their current preferences for WHR, breast size, weight, and height in women. For WHR, as predicted, physical attractiveness, early sexual experiences, and lower (more masculine) right-hand 2D:4D ratios significantly predicted current preferences for more feminine (lower) WHR. Early sexual experiences significantly predicted later preferences for breast size; in addition, more masculine occupational preferences and lower (more masculine) left-hand 2D:4D ratios predicted preferences for larger breasts. Participants' height, education level, Unmitigated Agency (masculinity) scores, and early sexual experiences significantly predicted current preferences for height. Finally, early sexual experiences significantly predicted current preferences for weight. The results suggest that variation in preferences for women's bodily features can be uniquely accounted for by a number of individual difference factors. Strengths and weaknesses of the study, along with implications for future research, are discussed.

The association between body composition and arterial stiffness in peri-pubescent children

The objective of this study was to examine the association between body composition and arterial stiffuess in peri-pubescent boys and girls. Differences in arterial distensibility were measured in 68 children (45 normal weight, 12 overweight, and 11 obese) between the ages of9 to 12 years. Weight classification was based on age and gender-specific body mass index cut-offs, while pubertal maturation was self-reported using Tanner staging. Distensibility was determined using two-dimensional, B-Mode echo Doppler ultrasound to measure changes at the right common carotid artery (CCA) diameter changes, while carotid pulse pressure (cPP) was measured at the left CCA by applanation tonometry. One-way ANOV A analysis revealed significant differences (p<0.001) in all anthropometric measures between the normal weight and overweight children, as well as the normal weight and obese children. Body stature was only higher in obese children compared to normal weight children (p<0.01). No significant differences were found between groups regarding age or Tanner stage. Common carotid artery distensibility showed a significant difference (p<0.01) between normal weight children (0.008 ± 0.002 mmHg-1 ) compared to obese children (0.005 ± 0.002 mmHg-1 ), with a borderline significant difference between the normal and overweight subjects (p=0.06). There was no significant effect for gender between males and females across all independent variables. The strongest determinants of distensibility in children were cPP (r= -0.52, pwaist-to-hip ratio explained 94% of the variance among peri-pubescent children. This study greatly underscores the need for weight management for long-term prevention of cardiovascular disease in overweight and obese children.

Some electrical properties of semi-conductor crystals / |nPhyu Phyu Khin. -- 260 St. Catharines, Ont. : [s. n.],

SiC and AtB 12 have been prepared and their resistivities and Hall voltages measured. The resistivities and Hall voltages were measured by the Van der Pauw's method, using spring loaded tungsten contacts. In this method, the major requirement is to have samples of plane parallel surfaces of arbitrary shape with four small contacts at the circumference. Similar measurements were made with a number of SiC crystals obtained from the Norton Research Corporation (Canada)-Ltd., Carolina Aluminum Co., Exolon Co. and Carborundum Co. It was found that resistivity, carrier concentration and mobility of ions depend on the type of impurity. AtB 12 was prepared from the melt containing At and B in the ratio of 4:1. They formed amber-colour pseudo tetragonal crystals. As the crystals obtained were small for electrical measurements, hot pressed lumps have been used to measure their resistivity.

The influence of physical activity behaviour on the relationship between motor proficiency and body composition in children

There is an emerging awareness that children with poor motor abilities are at particular risk for overweight. This cross-sectional study examined the influence of physical activity behaviour on the relationship between motor proficiency and body composition. Participants were 1287 (646 males, 641 females) Grade 6 students in the Physical Health Activity Study project. Height, weight, waist girth, and motor proficiency (Bruininks-Oseretsky Test of Motor Performance BOTMP-SF) were assessed. Physical activity behaviours were also evaluated with a multifaceted approach and reported for school-based, non-school based physical activity, free-time play, and sedentary activities (Participation Questionnaire), and leisure time exercise (Godin-Shephard Leisure Time Exercise Questionnaire GS). Overweight was defined by BMI scores: boys :::20.6-21.2 and <25.1-26.0; girls: ::: 20.7-21.7and <25.4-26.7 and obesity was defined as: boys:::: 25.1-26.0; girls: :::25.4-26.7. Children were classified as case group (CG,::; 10% on BOTMP-SF), borderline case group (BC, > 10% to ::; 20% on BOTMP-SF) or non-case group. Analyses of variance (ANOVAs) uncovered a significant difference in overweight and obesity between the case group and non-case group. Normal-weight children reported higher participation in organized school-sports (intra-mural and inter-school teams). The CG reported significantly lower participation in school sports teams and lower GS results, with a trend towards lower participation in all active pursuits. They also reported a significantly higher duration of television watching and book reading. There were no significant differences between motor proficiency groups by gender, age, nonschool sports, or free-time activity. Multivariate ordinal logistic regression analysis showed that the case group was 10.9 times more likely to be overweight/obese than their peers. No single aspect of physical activity was able to explain the difference in odds ratios for the motor proficiency groups. However, for the entire cohort, children who participated in more organized school sports were less likely to be overweight/obese. These findings confirm that children with low motor proficiency are at significant risk of developing overweight. It is evident that these children have generally attenuated activity levels and heightened levels of sedentary pursuits. School-based activities appear particularly limited, and are the one area where children have near autonomy in their decision to pursue active opportunities. The promotion of school-based programs, specifically intramural sports may be an important aspect in increasing children's overall activity levels. It is also essential to consider the needs of those children with low motor proficiency when designing activity promotion programs. Future research should further explore motor proficiency and overweight/obesity.