Influence of different resistance exercise loading schemes on mechanical power output in work to rest ratio - equated and - nonequated conditions

Paulo CA, Roschel H, Ugrinowitsch C, Kobal R and Tricoli V. Influence of different resistance exercise loading schemes on mechanical power output in work to rest ratio-equated and -nonequated conditions. J Strength Cond Res 26(5): 1308-1312, 2012-It is well known that most sports are characterized by the performance of intermittent high-intensity actions, requiring high muscle power production within different intervals. In fact, the manipulation of the exercise to rest ratio in muscle power training programs may constitute an interesting strategy when considering the specific performance demand of a given sport modality. Thus, the aim of this study was to evaluate the influence of different schemes of rest intervals and number of repetitions per set on muscle power production in the squat exercise between exercise to rest ratio-equated and -nonequated conditions. Nineteen young males (age: 25.7 +/- 4.4 years; weight: 81.3 +/- 13.7 kg; height: 178.1 +/- 5.5 cm) were randomly submitted to 3 different resistance exercise loading schemes, as follows: short-set short-interval condition (SSSI; 12 sets of 3 repetitions with a 27.3-second interval between sets); short-set long-interval condition (SSLI; 12 sets of 3 repetitions with a 60-second interval between sets); long-set long-interval (LSLI; 6 sets of 6 repetitions with a 60-second rest interval between sets). The main finding of the present study is that the lower exercise to rest ratio protocol (SSLI) resulted in greater average power production (601.88 +/- 142.48 W) when compared with both SSSI and LSLI (581.86 +/- 113.18 W; 578 +/- 138.78 W, respectively). Additionally, both the exercise to rest ratio-equated conditions presented similar performance and metabolic results. In summary, these findings suggest that shorter rest intervals may fully restore the individual's ability to produce muscle power if a smaller exercise volume per set is performed and that lower exercise to rest ratio protocols result in greater average power production when compared with higher ratio ones.

Simultaneous optical signal-to-noise ratio and differential group delay monitoring based on degree of polarization measurements in optical communications systems

We present a simultaneous optical signal-to-noise ratio (OSNR) and differential group delay (DGD) monitoring method based on degree of polarization (DOP) measurements in optical communications systems. For the first time in the literature (to our best knowledge), the proposed scheme is demonstrated to be able to independently and simultaneously extract OSNR and DGD values from the DOP measurements. This is possible because the OSNR is related to maximum DOP, while DGD is related to the ratio between the maximum and minimum values of DOP. We experimentally measured OSNR and DGD in the ranges from 10 to 30 dB and 0 to 90 ps for a 10 Gb/s non-return-to-zero signal. A theoretical analysis of DOP accuracy needed to measure low values of DGD and high OSNRs is carried out, showing that current polarimeter technology is capable of yielding an OSNR measurement within 1 dB accuracy, for OSNR values up to 34 dB, while DGD error is limited to 1.5% for DGD values above 10 ps. For the first time to our knowledge, the technique was demonstrated to accurately measure first-order polarization mode dispersion (PMD) in the presence of a high value of second-order PMD (as high as 2071 ps(2)). (C) 2012 Optical Society of America

Is waist-to-height ratio a useful indicator of cardio-metabolic risk in 6-10-year-old children?

Background: Childhood obesity is a public health problem worldwide. Visceral obesity, particularly associated with cardio-metabolic risk, has been assessed by body mass index (BMI) and waist circumference, but both methods use sex-and age-specific percentile tables and are influenced by sexual maturity. Waist-to-height ratio (WHtR) is easier to obtain, does not involve tables and can be used to diagnose visceral obesity, even in normal-weight individuals. This study aims to compare the WHtR to the 2007 World Health Organization (WHO) reference for BMI in screening for the presence of cardio-metabolic and inflammatory risk factors in 6–10-year-old children. Methods: A cross-sectional study was undertaken with 175 subjects selected from the Reference Center for the Treatment of Children and Adolescents in Campos, Rio de Janeiro, Brazil. The subjects were classified according to the 2007 WHO standard as normal-weight (BMI z score > −1 and < 1) or overweight/obese (BMI z score ≥ 1). Systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glycemia, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), Homeostatic Model Assessment – Insulin Resistance (HOMA-IR), leukocyte count and ultrasensitive C-reactive protein (CRP) were also analyzed. Results: There were significant correlations between WHtR and BMI z score (r = 0.88, p < 0.0001), SBP (r = 0.51, p < 0.0001), DBP (r = 0.49, p < 0.0001), LDL (r = 0.25, p < 0.0008, HDL (r = −0.28, p < 0.0002), TG (r = 0.26, p < 0.0006), HOMA-IR (r = 0.83, p < 0.0001) and CRP (r = 0.51, p < 0.0001). WHtR and BMI areas under the curve were similar for all the cardio-metabolic parameters. A WHtR cut-off value of > 0.47 was sensitive for screening insulin resistance and any one of the cardio-metabolic parameters. Conclusions: The WHtR was as sensitive as the 2007 WHO BMI in screening for metabolic risk factors in 6-10-year-old children. The public health message “keep your waist to less than half your height” can be effective in reducing cardio-metabolic risk because most of these risk factors are already present at a cut point of WHtR ≥ 0.5. However, as this is the first study to correlate the WHtR with inflammatory markers, we recommend further exploration of the use of WHtR in this age group and other population-based samples.

A NEW METHOD TO QUANTIFY X-RAY SUBSTRUCTURES IN CLUSTERS OF GALAXIES

We present a new method to quantify substructures in clusters of galaxies, based on the analysis of the intensity of structures. This analysis is done in a residual image that is the result of the subtraction of a surface brightness model, obtained by fitting a two-dimensional analytical model (beta-model or Sersic profile) with elliptical symmetry, from the X-ray image. Our method is applied to 34 clusters observed by the Chandra Space Telescope that are in the redshift range z is an element of [0.02, 0.2] and have a signal-to-noise ratio (S/N) greater than 100. We present the calibration of the method and the relations between the substructure level with physical quantities, such as the mass, X-ray luminosity, temperature, and cluster redshift. We use our method to separate the clusters in two sub-samples of high-and low-substructure levels. We conclude, using Monte Carlo simulations, that the method recuperates very well the true amount of substructure for small angular core radii clusters (with respect to the whole image size) and good S/N observations. We find no evidence of correlation between the substructure level and physical properties of the clusters such as gas temperature, X-ray luminosity, and redshift; however, analysis suggest a trend between the substructure level and cluster mass. The scaling relations for the two sub-samples (high-and low-substructure level clusters) are different (they present an offset, i. e., given a fixed mass or temperature, low-substructure clusters tend to be more X-ray luminous), which is an important result for cosmological tests using the mass-luminosity relation to obtain the cluster mass function, since they rely on the assumption that clusters do not present different scaling relations according to their dynamical state.

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm(2)). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m(2)), waist-hip ratio and the support base (cm 2). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

Osteoporotic hip fractures in non-elderly patients: relevance of associated co-morbidities

Osteoporotic hip fractures (OHF) are not limited to elderly; however, studies in non-elderly are scarce. Thus, the aim of this study was to evaluate co-morbidities in non-elderly patients with OHF in a Community Teaching Hospital. All hospitalizations due to OHF during a 3-year period in a Community Teaching Hospital were retrospectively evaluated for co-morbidities, and patients 18-64 years old were compared with those a parts per thousand yen65 years old. Of all hospitalizations, 232 (0.73%) were due to hip fractures, and 120/232 (51.7%) patients had OHF. The comparison of the 13 (10.8%) OHF patients < 65 years old (47.3 +/- A 9.7 years) with 107 (89.2%) a parts per thousand yen65 years old (80.4 +/- A 7.7 years) revealed a male predominance (61.5 vs. 27.1%, P = 0.022) and a distinct ethnic distribution with a lower proportion of Caucasians in the former (61.5 vs. 86.9%, P = 0.033). Moreover, non-elderly OHF patients had higher frequencies of insulin-dependent DM (38.5 vs. 3.7%, P = 0.001) and alcoholism (38.5 vs. 4.7%, P = 0.001) than aged patients. In contrast, rates of age-related co-morbidities such as stroke (7.7 vs. 18.7%, P = 0.461), heart failure (23.1 vs. 14.0%, P = 0.411), and dementia (7.7 vs. 15.9%, P = 0.689) were comparable in both groups. Logistic regression analysis demonstrated that insulin-dependent DM (OR = 25.4, 95% CI = 4.7-136.8, P < 0.001) and alcoholism (OR = 20.3, 95% CI = 3.9-103.3, P < 0.001) remained as independent risk factors for OHF in non-elderly patients. Osteoporosis is an important cause of HF in Community Hospital. Non-elderly patients with OHF have a peculiar demographic profile and associated co-morbidities. These findings reinforce the need of early osteoporosis diagnosis and rigorous fracture prevention in patients with DM and alcoholism.

Does Adjunctive Chemotherapy Reduce Remission Rates Compared to Cortisone Alone in Unifocal or Multifocal Histiocytosis of Bone?

Langerhans cell histiocytosis (LCH) is a rare disorder that can affect almost any organ, including bone. Treatment options include local corticosteroid infiltration in isolated bone lesions and oral corticosteroids and chemotherapy in multifocal bone lesions. Several studies show local corticosteroid injection in unifocal bone lesions heal in more than 75% of patients with minimal side effects. Therefore, it is unclear whether chemotherapy adds materially to the healing rate. We therefore compared overall survival, remission rate, and recurrence rate in patients with bone LCH treated with chemotherapy and corticosteroids or corticosteroids alone. We retrospectively reviewed the records of 198 patients with LCH since 1950. Median age at diagnosis was 5 years, male-to-female ratio was 1.33, and the most frequent symptom was local pain (95%). We recorded the disease presentation, demographics, treatment, and clinical evolution of each patient. Minimum followup was 4 months (median, 24 months; range, 4-360 months). The survival rate of the systemic disease group was 76.5% (65 of 85) while the survival rate in the unifocal and multifocal bone involvement groups was 100% at a median 5-year followup. All patients with unifocal bone involvement and 40 of 43 (93%) with multifocal bone involvement had complete remission. One of 30 patients with multifocal bone involvement treated with chemotherapy and oral corticosteroids did not achieve remission whereas two of six receiving only corticosteroids did not achieve remission. Our observations suggest intralesional corticosteroid injection without adjunctive chemotherapy achieves remission in unifocal bone LCH but may not do so in multifocal single-system bone involvement. Larger series would be required to confirm this observation. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Suicide rates and trends in Sao Paulo, Brazil, according to gender, age and demographic aspects: a joinpoint regression analysis

Objective: To evaluate suicide rates and trends in Sao Paulo by sex, age-strata, and methods. Methods: Data was collected from State registry from 1996 to 2009. Population was estimated using the National Census. We utilized joinpoint regression analysis to explore temporal trends. We also evaluated marital status, ethnicity, birthplace and methods for suicide. Results: In the period analyzed, 6,002 suicides were accrued with a rate of 4.6 per 100,000 (7.5 in men and 2.0 in women); the male-to-female ratio was around 3.7. Trends for men presented a significant decline of 5.3% per year from 1996 to 2002, and a significant increase of 2.5% from 2002 onwards. Women did not present significant changes. For men, the elderly (> 65 years) had a significant reduction of 2.3% per year, while younger men (25-44 years) presented a significant increase of 8.6% from 2004 onwards. Women did not present significant trend changes according to age. Leading suicide methods were hanging and poisoning for men and women, respectively. Other analyses showed an increased suicide risk ratio for singles and foreigners. Conclusions: Specific epidemiological trends for suicide in the city of Sao Paulo that warrant further investigation were identified. High-risk groups - such as immigrants - could benefit from targeted strategies of suicide prevention.

Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility

Abstract Background In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. Results Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as well as by changes in the inner cell wall structure, such as damaging, hole formation and loss of mechanical resistance, facilitating liquid and enzyme access to crystalline cellulose. Conclusions The results presented herewith show the efficiency of the proposed method for improving the enzymatic digestibility of sugarcane bagasse and provide understanding of the pretreatment action mechanism. Combining the different techniques applied in this work warranted thorough information about the undergoing morphological and chemical changes and was an efficient approach to understand the morphological effects resulting from sample delignification and its influence on the enhanced hydrolysis results.

Suicide rates and trends in São Paulo, Brazil, according to gender, age and demographic aspects: a joinpoint regression analysis

OBJECTIVE: To evaluate suicide rates and trends in São Paulo by sex, age-strata, and methods. METHODS: Data was collected from State registry from 1996 to 2009. Population was estimated using the National Census. We utilized joinpoint regression analysis to explore temporal trends. We also evaluated marital status, ethnicity, birthplace and methods for suicide. RESULTS: In the period analyzed, 6,002 suicides were accrued with a rate of 4.6 per 100,000 (7.5 in men and 2.0 in women); the male-to-female ratio was around 3.7. Trends for men presented a significant decline of 5.3% per year from 1996 to 2002, and a significant increase of 2.5% from 2002 onwards. Women did not present significant changes. For men, the elderly (> 65 years) had a significant reduction of 2.3% per year, while younger men (25-44 years) presented a significant increase of 8.6% from 2004 onwards. Women did not present significant trend changes according to age. Leading suicide methods were hanging and poisoning for men and women, respectively. Other analyses showed an increased suicide risk ratio for singles and foreigners. CONCLUSIONS: Specific epidemiological trends for suicide in the city of São Paulo that warrant further investigation were identified. High-risk groups - such as immigrants - could benefit from targeted strategies of suicide prevention.