Effect of frequency of static stretching on flexibility, hamstring tightness and electromyographic activity

We compared the effect of the number of weekly repetitions of a static stretching program on the flexibility, hamstring tightness and electromyographic activity of the hamstring and of the triceps surae muscles. Thirty-one healthy subjects with hamstring tightness, defined as the inability to perform total knee extension, and shortened triceps surae, defined by a tibiotarsal angle wider than 90° during trunk flexion, were divided into three groups: G1 performed the stretching exercises once a week; G2, three times a week, and G3, five times a week. The parameters were determined before and after the stretching program. Flexibility improved in all groups after intervention, from 7.65 ± 10.38 to 3.67 ± 12.08 in G1, from 10.73 ± 12.07 to 0.77 ± 10.45 in G2, and from 14.20 ± 10.75 to 6.85 ± 12.19 cm in G3 (P < 0.05 for all comparisons). The increase in flexibility was higher in G2 than in G1 (P = 0.018), while G2 and G3 showed no significant difference (G1: 4 ± 2.17, G2: 10 ± 5.27; G3: 7.5 ± 4.77 cm). Hamstring tightness improved in all groups, from 37.90 ± 6.44 to 29 ± 11.65 in G1, from 39.82 ± 9.63 to 21.91 ± 8.40 in G2, and from 37.20 ± 6.63 to 26.10 ± 5.72° in G3 (P < 0.05 for all comparisons). During stretching, a statistically significant difference was observed in electromyographic activity of biceps femoris muscle between G1 and G3 (P = 0.048) and G2 and G3 (P = 0.0009). No significant differences were found in electromyographic activity during maximal isometric contraction. Stretching exercises performed three times a week were sufficient to improve flexibility and range of motion compared to subjects exercising once a week, with results similar to those of subjects who exercised five times a week.

Frequency of 8 CFTR gene mutations in cystic fibrosis patients in Minas Gerais, Brazil, diagnosed by neonatal screening

The nature and frequency of cystic fibrosis mutations in Brazil is not uniform due to the highly varied ethnic composition of the population. The average frequency of the F508del mutation has been reported to be 48.6%. Other common mutations in Brazil are G542X, R1162X, and N1303K. The aim of this study was to analyze the frequency of 8 mutations (F508del, G542X, R1162X, N1303K, W1282X, G85E, 3120+1G>A, and 711+1G>T) in a sample of 111 newborn patients with cystic fibrosis diagnosed by the Cystic Fibrosis Neonatal Screening Program of Minas Gerais State. The mutations were tested by allele-specific oligonucleotide PCR with specially designed primers. An allele frequency of 48.2% was observed for the F508del mutation, and allele frequencies of 5.41, 4.50, 4.05, and 3.60% were found for the R1162X, G542X, 3120+1G>A, and G85E mutations, respectively. The genotypes obtained were in Hardy-Weinberg equilibrium. These data demonstrate that the 8-mutation panel studied here has extensive coverage (68%) for the cystic fibrosis mutations in Minas Gerais. These data improve our knowledge of cystic fibrosis in Brazil, particularly in this region. In addition, this investigation contributed to the establishment of a sensitive and population-specific mutation panel, which can be helpful for molecular diagnosis of cystic fibrosis.

Acute kidney injury in AIDS: frequency, RIFLE classification and outcome

The objective of the present study was to evaluate the characteristics of acute kidney injury (AKI) in AIDS patients and the value of RIFLE classification for predicting outcome. The study was conducted on AIDS patients admitted to an infectious diseases hospital inBrazil. The patients with AKI were classified according to the RIFLE classification: R (risk), I (injury), F (failure), L (loss), and E (end-stage renal disease). Univariate and multivariate analyses were used to evaluate the factors associated with AKI. A total of 532 patients with a mean age of 35 ± 8.5 years were included in this study. AKI was observed in 37% of the cases. Patients were classified as "R" (18%), "I" (7.7%) and "F" (11%). Independent risk factors for AKI were thrombocytopenia (OR = 2.9, 95%CI = 1.5-5.6, P < 0.001) and elevation of aspartate aminotransferase (AST) (OR = 3.5, 95%CI = 1.8-6.6, P < 0.001). General mortality was 25.7% and was higher among patients with AKI (40.2 vs17%, P < 0.001). AKI was associated with death and mortality increased according to RIFLE classification - "R" (OR 2.4), "I" (OR 3.0) and "F" (OR 5.1), P < 0.001. AKI is a frequent complication in AIDS patients, which is associated with increased mortality. RIFLE classification is an important indicator of poor outcome for AIDS patients.

Frequency of primary glomerular disease in northeastern China

Most frequently reported Chinese renal biopsy data have originated from southeastern China. The present study analyzed the renal biopsy data from northeastern China. The records of 1550 consecutive native patients who were diagnosed with primary glomerular diseases (PGD) after renal biopsy at our hospital during 2005-2009 were used. These patients were divided into four age groups for stratified analysis: <15, 15-44, 45-59, and ≥60 years old. Among PGD, minimal change disease (MCD) was the most common histologically diagnosed disease (30.7%), followed by IgA nephropathy (IgAN), mesangial proliferative glomerulonephritis (MsPGN), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN), focal segmental glomerulosclerosis (FSGS), and endocapillary proliferative glomerulonephritis (EnPGN). MCD was the disease most frequently observed (43.7%) in the <15-year-old group. MsPGN was the most common disease in the elderly group (38.1%). MsPGN was more prevalent in females (27.8%), whereas MCD was more prevalent in males (35.3%). Primary glomerular diseases constituted the most commonly encountered group of diseases with a high prevalence of MCD, which predominantly affected males and young adults. The prevalence of MCD was high in northeastern China. Further study is necessary to expand the epidemiologic data available for renal disease in China.

High-frequency electroacupuncture versus carprofen in an incisional pain model in rats

The objective of the present study was to compare the effect of electroacupuncture (EA) and carprofen (CP) on postoperative incisional pain using the plantar incision (PI) model in rats. A 1-cm longitudinal incision was made through skin, fascia and muscles of a hind paw of male Wistar rats and the development of mechanical and thermal hypersensitivity was determined over 4 days using the von Frey and Hargreaves methods, respectively. Based on the experimental treatments received on the third postoperative day, the animals were divided into the following groups: PI+CP (CP, 2 mg/kg, po); PI+EAST36 (100-Hz EA applied bilaterally at the Zusanli point (ST36)); PI+EANP (EA applied to a non-acupoint region); PI+IMMO (immobilization only); PI (vehicle). In the von Frey test, the PI+EAST36 group had higher withdrawal force thresholds in response to mechanical stimuli than the PI, PI+IMMO and PI+EANP groups at several times studied. Furthermore, the PI+EAST36 group showed paw withdrawal thresholds in response to mechanical stimuli that were similar to those of the PI+CP group. In the Hargreaves test, all groups had latencies higher than those observed with PI. The PI+EAST36 group was similar to the PI+IMMO, PI+EANP and PI+CP groups. We conclude that 100-Hz EA at the ST36 point, but not at non-acupoints, can reduce mechanical nociception in the rat model of incisional pain, and its effectiveness is comparable to that of carprofen.

Determination of CYP2D6 *3, *4, and *10 frequency in women with breast cancer in São Luís, Brazil, and its association with prognostic factors and disease-free survival

The CYP2D6 enzyme is crucial for the metabolism of tamoxifen. The CYP2D6 gene is highly polymorphic, and individuals can be extensive, intermediate, or poor tamoxifen metabolizers. The aim of this study was to determine the frequencies of the CYP2D6 *3, *4, and *10 alleles in women with breast cancer who were treated with tamoxifen and analyze the association of enzyme activity with prognostic factors and disease-free survival. We observed a high frequency of CYP2D6 *10, with an allelic frequency of 0.14 (14.4%). The *3 allele was not present in the studied population, and *4 had an allelic frequency of 0.13 (13.8%). We conclude that patients with reduced CYP2D6 activity did not present worse tumor characteristics or decreased disease-free survival than women with normal enzyme activity, as the difference was not statistically significant. We also observed a high frequency of CYP2D6 *10, which had not been previously described in this specific population. This study is the first in north-northeastern Brazil that aimed to contribute to the knowledge of the Brazilian regional profile for CYP2D6 polymorphisms and their phenotypes. These findings add to the knowledge of the distribution of different polymorphic CYP2D6 alleles and the potential role of CYP2D6 genotyping in clinical practice prior to choosing therapeutic protocols.

Inflammation induced by increased frequency of intermittent hypoxia is attenuated by tempol administration

The levels of serum inflammatory cytokines and the activation of nuclear factor kappa B (NF-κB) and hypoxia inducible factor-1α (HIF-1α) in heart tissues in response to different frequencies of intermittent hypoxia (IH) and the antioxidant tempol were evaluated. Wistar rats (64 males, 200-220 g) were randomly divided into 6 experimental groups and 2 control groups. Four groups were exposed to IH 10, 20, 30, or 40 times/h. The other 2 experimental groups were challenged with IH (30 times/h) plus tempol, either beginning on day 0 (IH30T0) or on day 29 (IH30T29). After 6 weeks of challenge, serum levels of tumor necrosis factor (TNF)-α, intracellular adhesion molecule (ICAM)-1, and interleukin-10 were measured, and western blot analysis was used to detect NF-κB p65 and HIF-1α in myocardial tissues. Serum levels of TNF-α and ICAM-1 and myocardial expression of NF-κB p65 and HIF-1α were all significantly higher in IH rats than in controls (P<0.001). Increased IH frequency resulted in more significant changes. Administration of tempol in IH rats significantly reduced levels of TNF-α, ICAM-1, NF-κB and HIF-1α compared with the non-tempol-treated group (F=16.936, P<0.001). IH induced an inflammatory response in a frequency-dependent manner. Additionally, HIF-1α and NF-κB were increased following IH administration. Importantly, tempol treatment attenuated this effect.

Comparison of Model-Based Flow Rate Estimation Methods in Frequency-Converter-Driven Pumps and Fans

Fluid handling systems such as pump and fan systems are found to have a significant potential for energy efficiency improvements. To deliver the energy saving potential, there is a need for easily implementable methods to monitor the system output. This is because information is needed to identify inefficient operation of the fluid handling system and to control the output of the pumping system according to process needs. Model-based pump or fan monitoring methods implemented in variable speed drives have proven to be able to give information on the system output without additional metering; however, the current model-based methods may not be usable or sufficiently accurate in the whole operation range of the fluid handling device. To apply model-based system monitoring in a wider selection of systems and to improve the accuracy of the monitoring, this paper proposes a new method for pump and fan output monitoring with variable-speed drives. The method uses a combination of already known operating point estimation methods. Laboratory measurements are used to verify the benefits and applicability of the improved estimation method, and the new method is compared with five previously introduced model-based estimation methods. According to the laboratory measurements, the new estimation method is the most accurate and reliable of the model-based estimation methods.

On site measurements of DC link electrolytic capacitor bank of frequency converter using constant DC magnetization of the motor

Preventive maintenance of frequency converters has been based on pre-planned replace-ment of wearing or ageing components. Exchange intervals follow component life-time expectations which are based on empirical knowledge or schedules defined by manufac-turer. However, the lifetime of a component can vary significantly, because drives are used in very different operating environments and applications. The main objective of the research was to provide information on methods, i.e. how in-verter's operating condition can be measured reliably under field conditions. At first, the research focused on critical components such as current transducers, IGBTs and DC link capacitor bank, because these aging have already been identified. Of these, the DC link capacitor measurement method was selected for closer examination. With this method, the total capacitance and its total series resistance can be measured. The suitability of the measuring procedure was estimated on the basis of practical measurements. The research was made by using so called triangulation method, including a literature review, simulations and practical measurements. Based on the results, the new measu-rement method seems suitable with some reservations to practical measurements. How-ever, the measuring method should be further developed in order to improve its reliability.

D-luokan audiovahvistimen särö ja kohina

Tämän kandidaatintyön aiheena on D-luokan audiovahvistimen särö ja kohina. Tarkoituksena on selvittää vahvistinluokan merkittävin särö- ja kohinamekanismi, sekä arvioida, voidaanko häiriöitä vähentää lähdön suodattimella. Tutkimusmenetelminä on kirjallisuus ja simulointi. Aineistona on käytetty IEEE:ssä julkaistuja tieteelisiä artikkeleita, eri valmistajien laatimia ohjeita, sekä aihetta käsitteleviä kirjoja. Keskeisimmät tulokset olivat, että merkittävin särömekanismi on transistoreiden suoja-ajan aiheuttama vääristymä, sekä että merkittävin kohina syntyy modulaatiossa käytetystä kantoaallosta. Kantoaallon näkyvyyteen kuormassa voidaan vaikuttaa ulostulon alipäästösuodattimella. Suoja-ajan aiheuttama harmoninen kokonaissärö asettuu musiikin kaistanleveydelle, joten sitä ei voida poistaa suodattamalla.

Case: Kitaravahvistimen AB-luokan tehovahvistimen päivittäminen D-luokkaan

D-luokan vahvistimien etu perinteisiin A- tai AB-luokan vahvistimiin nähden on niitten korkea hyötysuhde ja pieni koko. Lisäksi ne ovat edullisia ja niihin voidaan asentaa pienemmät jäähdytyslevyt kuin perinteisiin vahvistimiin korkean hyötysuhteen ansiosta. Tässä tutkimuksessa asennetaan Peavey Solo –kitaravahvistimen pääteasteena toimivan AB-luokan päätevahvistimen tilalle tehokkaampi ja uudempaa vahvistinluokkaa edustava D-luokan vahvistin. Tutkimuksessa selvitetään, miten D-luokan vahvistimella toteutettu kytkentä toimii verrattuna alkuperäiseen kytkentään tutkimalla kitaravahvistimelle tyypillisiä sähköisiä ominaisuuksia. Työ toteutetaan mittauksin. Koska työssä olevissa kytkennöissä on jännitteisiä osia, on siinä perehdyttävä sähköturvallisuuteen. D-luokan vahvistin asettaa tietyt sähkötekniset kestävyysvaatimukset kytkennän teholähteelle ja kaiutinelementille, jolloin työssä paneudutaan myös niiden valintaan. D-luokan vahvistimeen päivitetyn kytkennän tuottamat äänenpainetasot olivat valtaosassa mittauksia suuremmat kuin alkuperäisellä kytkennällä. Äänenpainetasojen mittaustilanteissa myös kuormalle syötetyt tehot olivat suuremmat päivitetyllä kytkennällä verrattuna alkuperäiseen. Suurin päivitetyn kytkennän kuorman teho 72,72 W saavutettiin, kun kaiutinelementin yli oli 24,12 V:n jännitteen tehollisarvo ja kuorman teho oli noin 36 kertaa suurempi kuin alkuperäisellä kytkennällä. D-luokan vahvistimen mitatut harmonisen särön arvot ovat huomattavasti pienempiä kuin alkuperäisellä vahvistimella. Muokkaamattoman vahvistimen mitatusta sähköisestä taajuusvasteeesta nähdään, että alkuperäinen vahvistin korostaa tiettyjä taajuuksia, kun D-luokan vahvistimen taajuusvaste on sen sijaan likimain tasainen. Akustinen taajuusvaste ei ole niin tasainen D-luokan vahvistimeen päivitetyllä kytkennällä kuin alkuperäisellä kytkennällä ja sillä on myös kapeampi taajuusalue. Jos päivitetyn kytkennän sointia haluttaisiin parantaa, pitäisi tutkia lisää akustiseen taajuusvasteeseen vaikuttavia asioita.

Collaborative learning in a Japanese as a foreign language classroom /

This study examined the influence of training on Asian learners' beliefs, interaction, and attitudes during collaborative learning (CL) and explored the processes of their CL in pairs. The literature contains few studies on the effect of collaborative training in language learning. In addition, it shows gaps between SLA theory and practice resulting from learners' cultural differences. Although second/subsequent language acquisition (SLA) theory assumes that CL contributes to language learning, implementing CL in a multicultural classroom is often considered to be unsuccessful by teachers. The research questions designed to address this gap explore: (a) the extent to which tra~ng affects Asian learners' attitudes towards and interaction during CL; (b) how Asian learners accomplish collaborative tasks in pairs. In the quasi-experimental research design, the learners in the treatment group received special training in CL for 5 weeks while the learners in the comparison group did not receive similar training. Data were collected from 45 McMaster University students through pre- and posttests, pre- and postintervention questionnaires, student information, and informal classroom observations. To detennine the influence of training, the frequency of communication units (c-units), Language Related Episodes (LREs), Collaborative Dialogue (CD) from audio-taped data, and the fmal draft scores were compared between pre- and posttests. The learners' pre- and postintervention questionnaires were also compared. Transcripts from audio-taped data, students' information, their responses and comments from questionnaires, and informal observations served to investigate the processes of Asian learners' CL. Overall, this study found that training had significant influence on the frequency of c-units and CD, and considerable impact on the draft scores, although little influence on the frequency of LREs was observed. The results from the questionnaires in the treatment group showed positive changes in the learners' beliefs on pair work after training. On the other hand, analyses of the transcription data showed that the learners did not conduct enough discussion for a resolution of problems with peers. In conclusion, results suggested the need for teacher intervention, a longer period of collaborative training, and an implementation of self-evaluation into the course grade to encourage the learners to succeed in collaborative learning.

The effect of social condition and diet on the frequency of male-male agonistic displays in the field cricket, gryllus bimaculatus /

The frequency and type of agonistic displays involved in male-male encounters should be significantly influenced by the presence of females. Discrete agonistic displays vary in energy expenditure and risk, and therefore should be dependent on available resources. The influence of live females and the scent of females, on the frequency of male agonistic displays was observed in a laboratory terrarium using the field cricket Gryllus bimaculatus. The effect of energy constraints on display frequency was also determined. Half the males were fed a diet high in protein and fet; the other males were fed a lower quality diet, for a 7-11 day period. The frequency of five individual displays and mating frequency were recorded using an Event Recorder and notebook. Each group of males was presented with three experimental conditions, over three days, involving the presence or absence of live females and female scent. The presence of females elicited an increase in all displays except antennation; female scent increased the frequency of antennations, mandible flares and grapples, but to a lesser extent than did live females. The frequency of grapples significantly increased for males fed the high quality diet; however diet did not influence the other displays. The combined influence of diet and condition was significant for mandible flare only. Mating frequency was not influenced by diet. However, the frequency ofthe displays were positively correlated with mating frequency for high quality fed males. Escalated displays involving high costs, such as grapple and mandible flare, increased in frequency when the benefits of winning contests were high in G.bimaculatus. Escalation to grapple behaviour was less evident for males fed the lower quality diet as this imposed energy constraints on high cost displays.

Low frequency Raman scattering in amorphous materials: fused quartz, "pyrex" boro-silicate glass and soda-lime silicate glass

Raman scattering in the region 20 to 100 cm -1 for fused quartz, "pyrex" boro-silicate glass, and soft soda-lime silicate glass was investigated. The Raman spectra for the fused quartz and the pyrex glass were obtained at room temperature using the 488 nm exciting line of a Coherent Radiation argon-ion laser at powers up to 550 mW. For the soft soda-lime glass the 514.5 nm exciting line at powers up to 660 mW was used because of a weak fluorescence which masked the Stokes Raman spectrum. In addition it is demonstrated that the low-frequency Raman coupling constant can be described by a model proposed by Martin and Brenig (MB). By fitting the predicted spectra based on the model with a Gaussian, Poisson, and Lorentzian forms of the correlation function, the structural correlation radius (SCR) was determined for each glass. It was found that to achieve the best possible fit· from each of the three correlation functions a value of the SCR between 0.80 and 0.90 nm was required for both quartz and pyrex glass but for the soft soda-lime silicate glass the required value of the SCR. was between 0.50 and 0.60 nm .. Our results support the claim of Malinovsky and Sokolov (1986) that the MB model based on a Poisson correlation function provides a universal fit to the experimental VH (vertical and horizontal polarizations) spectrum for any glass regardless of its chemical composition. The only deficiency of the MB model is its failure to fit the experimental depolarization spectra.