Laboratórios virtuais: Um estudo comparativo entre plataformas de aprendizagem para o ensino da química

Como proposta para o presente estudo, analisamos os contributos e as limitações dos laboratórios virtuais para o ensino da química, com base em um estudo comparativo. O trabalho qualitativo e empírico descritivo foi desenvolvido no Departamento de Estatística e Informática da Universidade Federal Rural de Pernambuco, e foi desenvolvido no período de maio de 2016 a maio de 2017.

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Efeito do treinamento resistido sobre a atividade enzimática da MMP-2 e antioxidantes no ventrículo esquerdo de ratos obesos

Obesity is associated with increased lipid peroxidation in the myocardium and an increased susceptibility to oxidative damage, which can lead to several cardiovascular risk factors including heart failure, insulin resistance, hypertension and dyslipidemia. The ONOOin conjunction with normal intracellular levels of reduced glutathione (GSH), are responsible, among other factors, to activate the matrix metalloproteinases (MMPs) that are important in mediating the deleterious effects of cardiovascular diseases. The unregulated activity of MMPs, such as MMP-2, may promote the development of heart disease. Resistance training (RT) can mitigate or even reverse the obesity, prevent against lipid peroxidation, increasing the levels of antioxidant enzymes, improved lipid profile, reduced cardiovascular risk and reduce the concentration of fibrosis and dysregulation of MMP-2. Purpose: To analyze the effects of RT high intensity on ladder associated with high fat diet on the activity of MMP-2 and antioxidant enzymes (SOD Total, Mn-SOD, CAT, GPx), GSH and lipid peroxidation, related to left ventricle remodeling in rats. Methods: 60 rats Wistar were used in this study, which was divided into three phases: 1) three week period of obesity induction, control group fed with standard diet (CT-S n = 30) and control group fed with high fat diet (CT-H n = 30); 2) effect of fat diet for eight weeks, sedentary standard diet group (SED-S n = 10) and high fat diet sedentary (SED-H n = 10), 3) effect of high-intensity RT on ladder for eight weeks associated with high-fat diet, RT standard diet (RT-S n = 10) and RT high-fat diet RT (RT-H n = 10). Results: The three-week obesity induction was effective in promoting the group CTH increased body mass (p <0.05), LV mass (p <0.05) and activity of MMP-2 (p <.001), TBRs (p <0.03) and decrease the citrate synthase activity (p <0.05). After eight weeks of high fat diet, the SED-H group had a higher body mass (p <0.02) compared to SED-S. The volume LV for SED-H group was higher compared to that of CT-H (p <0.001), but did not change when compared to SED-S. There was a lower activity of MMP-2 (p <0.05) in SED-S compared to CT-H. Lipid accumulation was observed (p <0.007) in the LV of SED-H group compared to CT-H. The longer life associated with high-fat diet promoted suppression in the enzymatic activity of SOD Total (p <0.01) and Mn-SOD (p <0.002) (SED-H), and increased activity of GSH (p <0.004). The RT was effective in attenuating the gain body mass in RT-H group compared to SED-H, even though higher compared to RT-S (p <0.005). In the group RT-H of MMP-2 activity was higher (p <0.03) compared to RT-S, but lower (p <0.04) compared to SED-H. The RT promoted greater citrate synthase activity (p <0.03), SOD Total (p <0.001) and Mn-SOD (p <0.03) and lower activity of GSH (p <0.01) in RT-H. There was no significant increase in TBARs level in the VE of the RT-H group. However, we observed increased lipid content (p <0.04). Conclusion: We conclude that high intensity RT, in obese rats, could be a pharmacological tool able to positively modulate the activity of MMP-2 and some antioxidant enzymes such as SOD Total, Mn-SOD and GSH. These effects are important for the maintenance of heart health, relieving the deleterious effects on obesityrelated of the left ventricle remodeling, so experiment.Universidade Federal de Sao CarlosA obesidade está associada com aumento da peroxidação lipídica no miocárdio e com uma maior suscetibilidade ao dano oxidativo, o que pode levar a vários fatores de risco cardiovascular incluindo insuficiência cardíaca, resistência à insulina, hipertensão e dislipidemia. O ONOO- em conjunto com níveis normais intracelular de glutationa reduzida (GSH), são responsáveis, dentre outros fatores, por ativar as metaloproteinases de matriz (MMPs), que são importantes na mediação dos efeitos deletérios de doenças cardiovasculares. A atividade desregulada das MMPs, como a MMP-2, pode favorecer o desenvolvimento de doenças cardíacas. O treinamento resistido (TR) pode amenizar ou mesmo reverter o quadro de obesidade, prevenir contra a peroxidação lipídica, aumentando os níveis das enzimas antioxidantes, melhora do perfil lipídico, diminui os riscos á doenças cardiovasculares, além de reduzir a concentração de fibrose e a desregulação da MMP-2. Objetivo: Analisar os efeitos do TR de alta intensidade em escada associado à dieta hiperlipídica na atividade da MMP-2 e enzimas antioxidantes (SOD Total, Mn-SOD, CAT, GPx), GSH e peroxidação lipídica, relacionadas ao remodelamento do ventrículo esquerdo, em ratos. Metodologia: 60 ratos Wistar foram utilizados neste estudo, sendo este divido em três fases: 1) período de três semanas de indução à obesidade, grupo controle alimentado com dieta padrão (CT-P n= 30) e controle alimentado com dieta hiperlipídica (CT-H n= 30); 2) efeito da dieta hiperlipídica por mais oito semanas, grupo sedentário dieta padrão (SED-P n= 10) e sedentário dieta hiperlipídica (SED-H n= 10); 3) efeito do TR em escada por oito semanas associado a dieta hiperlipídica, grupo TR dieta padrão (TR-P n= 10) e TR dieta hiperlipídica (TR-H n= 10). Resultados: As três semanas de indução à obesidade foi eficaz em promover aumento da massa corporal (p < 0,05), massa do VE (p < 0,05) e da atividade da MMP-2 (p < 0,001), do TBRs (p < 0,03) e de diminuir a atividade da citrato sintase (p < 0,05) no grupo CT-H. Após mais oito semanas de dieta hiperlipídica, o grupo SED-H teve a massa corporal maior (p < 0,02) comparado ao SED-P. Já a massa do VE para o grupo SED-H foi maior em comparação ao do CT-H (p < 0,001), porém não se modificou quando comparado ao SEP-P. Houve uma menor atividade da MMP-2 (p < 0,05) no grupo SED-H comparado ao CT-H. Foi observado acúmulo de lipídios totais (p < 0,007) no VE do grupo SD-H comparado ao CT-H. O maior tempo de vida associado à dieta hiperlipídica promoveu inibição da SOD Total (p < 0,01) e Mn-SOD (p < 0,002) (SED-H), e aumento da GSH (p < 0,004). O TR foi eficaz em atenuar o ganho de massa corporal no grupo TR-H comparado ao SED-H, mesmo sendo maior comparado ao TR-P (p < 0,005). No grupo TR-H a atividade da MMP-2 foi maior (p < 0,03) comparado ao TR-P, porém menor (p < 0,04) comparado ao SED-H. O TR promoveu maior atividade das enzimas citrato sintase (p < 0,03), SOD Total (p < 0,001) e Mn-SOD (p < 0,03) menor atividade da GSH (p < 0,01) no grupo TR-H. Não foi observado aumento significativo do TBARS no VE do TR-H. Contudo, foi observado aumento do conteúdo lipídico (p < 0,04). Conclusão: Concluímos que o TR de alta intensidade, em ratos obesos, pode ser uma ferramenta não farmacológica capaz de modular de forma positiva a atividade da MMP-2 e de algumas enzimas antioxidantes como a SOD Total, Mn-SOD e a GSH. Efeitos esses que são importantes para a manutenção da saúde cardíaca, amenizando os efeitos deletérios relacionados à obesidade sobre o remodelamento do ventrículo esquerdo, de forma experimental

Relação entre frequência cardíaca e percepção subjetiva de esforço em indivíduos entre 10 e 15 anos na natação

A natação é um exercício físico completo por trabalhar o corpo todo e sua prática regular promove adaptações fisiológicas no organismo. Essas adaptações ocorrem com a manipulação e quantificação das cargas de treinamento, como a intensidade. Para mensurar essa variável diversos métodos são utilizados tanto no meio terrestre quanto no meio aquático como a frequência cardíaca (FC) e a percepção subjetiva de esforço (PSE). A PSE aumenta linearmente com a intensidade e se correlaciona com a FC e o consumo de oxigênio (VO2), mas ainda não se sabe se há correlação entre FC e PSE em indivíduos adolescentes praticantes de natação. O objetivo desta pesquisa foi analisar se existe correlação entre a FC e a PSE utilizando a Escala de Borg (15 pontos) em aulas de natação para indivíduos entre 10 a 15 anos de idade. Foram selecionados 8 voluntários de ambos os sexos com idade 12,62 ± 1,84 anos aparentemente saudáveis. Todos voluntários nadaram a 90% da FC máxima na água (56 m), a 70% (112 m) e a 50% (196 m) respectivamente e ao final de cada metragem foi identificado a PSE na Escala de Borg. As correlações entre a FC e PSE em relação a intensidade possui uma correlação positiva muito forte (r > 0,90) para 90% e para 70% e uma correlação positiva forte (r = 0,70 a 0,89) para 50%. Concluímos que existe correlação entre FC e PSE na natação, em indivíduos entre 10 e 15 anos de idade. ABSTRACT Relationship between heart rate and subjective perception of exertion in practitioners of swimming with 10-15 years oldSwimming is a complete physical exercise by working the whole body and its regular practice promotes physiological adaptations in the body. These adaptations occur with the manipulation and quantification of training loads, such as intensity. To measure this variable, several methods are used both in the terrestrial environment and in the aquatic environment such as heart rate (HR) and subjective perception of effort (PSE). PSE increases linearly with intensity and correlates with HR and oxygen consumption (VO2), but it is not yet known if there is a correlation between HR and PSE in swimming adolescents. The objective of this research was to analyze whether there is a correlation between the heart rate and the subjective perception of effort using the Borg Scale (15 points) in swimming lessons for individuals between 10 and 15 years of age. Eight volunteers of both sexes with 12.62 ± 1.84 years of age were apparently healthy. All volunteers swam to 90% of the maximum HR in water (56 m), 70% (112 m) and 50% (196 m) respectively and at the end of each film PSE was identified on the Borg scale. The correlation between HR and PSE in relation to intensity has a very strong positive correlation (r> 0.90) to 90% and 70% and a strong positive correlation (r = 0.70 to 0.89) to 50%. We conclude that there is a correlation between HR and PSE in swimming, particularly between 10 and 15 years of age

Resistance training improves body composition and increases matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles of diet-induced obese rats

OBJECTIVE: We investigated the influence of resistance training on body composition and matrix metalloproteinase 2 activity in skeletal muscles of rats fed a high-fat diet. METHODS: Thirty-two Wistar rats were divided into four experimental groups (n&#8202;=&#8202;8/each) according to diet and exercise status: Control (standard diet), Obese Control (high-fat diet), Resistance Training (standard diet) and Obese Resistance Training (high-fat diet) groups. Animals were fed a high-fat diet for 12 weeks to promote excessive weight gain. Resistance Training groups performed 12 weeks of training periods after this period in a vertical ladder three times/week. Fat percentage, fat-free mass and fat mass were assessed using dual-energy X-ray absorptiometry, and matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles was analyzed using zymography. RESULTS: Resistance training significantly reduced body and fat masses and fat percentages in both trained groups (p<0.05). The maximal carrying load between trained groups was not different, but relative force was higher in the Resistance Training group (p<0.05). Of note, increased matrix metalloproteinase 2 activity was noted in the tested muscles of both trained groups (p<0.05). CONCLUSION: In conclusion, altered body composition and muscle matrix metalloproteinase 2 activity promoted by excessive weight gain were positively modified by resistance training

Käytännön kosteikkosuunnittelu

Maatalouden vesiensuojelua edistetään monin tavoin. Ravinteita ja eroosioainesta sisältäviä valumavesiä pyritään puhdistamaan erilaisissa kosteikoissa. Tämä opas on kirjoitettu avuksi pienimuotoisten kosteikkojen perustamiseen. Oppaassa esitetään käytännönläheisesti kosteikon toteuttamisen eri vaiheet paikan valinnasta suunnitteluun ja rakentamiseen. Vuonna 2010 julkaistun painoksen tiedot on saatettu ajantasalle. Julkaisu on toteutettu osana Tehoa maatalouden vesiensuojeluun (TEHO) -hanketta ja päivitetty TEHO Plus -hankkeen toimesta. Oppaan toivotaan lisäävän kiinnostusta kosteikkojen suunnitteluun ja edelleen niiden rakentamiseen