61 research outputs found

    Observations of Coherent Turbulence Structures in the Near-Neutral Atmospheric Boundary Layer

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    Turbulence structures of high Reynolds number flow in the near-neutral atmospheric boundary layer (ABL) are investigated based on observations at Shionomisaki and Shigaraki, Japan. A Doppler sodar measured the vertical profiles of winds in the ABL. Using the integral wavelet transform for the time series of surface wind data, the pattern of a descending high-speed structure with large vertical extent (from the surface to more than 200-m level) is depicted from the Doppler sodar data. Essentially this structure is a specific type of coherent structure that has been previously shown in experiments on turbulent boundary-layer flows. Large-scale high-speed structures in the ABL are extracted using a long time scale (240 s) for the wavelet transform. The non-dimensional interval of time between structures is evaluated as 3.0–6.2 in most cases. These structures make a large contribution to downward momentum transfer in the surface layer. Quadrant analyses of the turbulent motion measured by the sonic anemometer (20-m height) suggest that the sweep motion (high-speed downward motion) plays a substantial role in the downward momentum transfer. In general, the contribution of sweep motions to the momentum flux is nearly equal to that of ejection motions (low-speed upward motions). This contribution of sweep motions is related to the large-scale high-speed structures

    Characteristics of Damages of Severe Local Storms Based on Field Surveys in Bangladesh

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    This paper presents field survey results on damage from severe local storms, such as tornadoes. Surveys were conducted in Bangladesh in August 2009 and August 2010 to clarify damage details, meteorological features, factors related to damage generation and spread, recovery problems experienced by local residents due to storm damage and storms prediction in local areas

    Temperature during pregnancy influences the fetal growth and birth size

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    BackgroundBirth weight and length have seasonal fluctuations. However, it is uncertain which meteorological element has an effect on birth outcomes and which timing of pregnancy would explain such effect. Therefore, the purpose of this study was to examine temperature effects during pregnancy and which timing of pregnancy has effects on size at birth.MethodsA large, randomized, controlled trial of food and micronutrient supplementation for pregnant women was conducted in Matlab, Bangladesh (MINIMat Study), where women were enrolled from November 2001 to October 2003. The fetal growth data which included the size at birth and information of their mothers were obtained (n = 3267). Meteorological data such as temperature, precipitation, relative humidity, and daily sunshine hours during pregnancy were observed at the nearest observatory site of Bangladesh Meteorological Department.ResultsInfants born in colder months (November–January) were shorter than those born in hot and dry, and monsoon months (mean (SD) of birth length was 47.5 cm (2.2) vs. 47.8 cm (2.1) vs. 47.9 cm (2.1) respectively; P < 0.001). Increased temperature during the last month of pregnancy was significantly related with increased birth length with adjustment for gestational weeks and the season at birth, and remained significant with further adjustments for precipitation, sex of infants, maternal early-pregnancy BMI, parity, and education status of the mother (P < 0.01). On the other hand, increased temperature at mid-gestation was associated with increased birth weight (P < 0.05).ConclusionsThese findings suggest that temperature affects both birth weight and length. The more temperature increased at the last month of pregnancy, birth length became longer. For birth weight, the temperature at mid-pregnancy affected in a positive way

    Cholera in Bangladesh: Climatic Components of Seasonal Variation

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    Background: The mechanisms underlying the seasonality of cholera are still not fully understood, despite long-standing recognition of clear bimodal seasonality in Bangladesh. We aimed to quantify the contribution of climatic factors to seasonal variations in cholera incidence. Methods: We investigated the association of seasonal and weather factors with the weekly number of cholera patients in Dhaka, Bangladesh, using Poisson regression models. The contribution of each weather factor (temperature and high and low rainfall) to seasonal variation was estimated as the mean over the study period (1983-2008) for each week of the year of each weather term. Fractions of the number of cholera patients attributed to each weather factor, assuming all values were constant at their minimum risk levels throughout the year, were estimated for spring and monsoon seasons separately. Results: Lower temperature predicted a lower incidence of cholera in the first 15 weeks of the year. Low rainfall predicted a peak in spring, and high rainfall predicted a peak at the end of the monsoon. The risk predicted from all the weather factors combined showed a broadly bi-modal pattern, as observed in the raw data. Low rainfall explained 18% of the spring peak, and high rainfall explained 25% of the peak at the end of the monsoon. Conclusions: Seasonal variation in temperature and rainfall contribute to cholera incidence in complex ways, presumably in interaction with unmeasured environmental or behavioral factors

    Effect of Ambient Temperature on Daily Nebulized Asthma Hospital Visits in a Tropical City of Dhaka, Bangladesh

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    The acute effect of temperature on asthma morbidity in Bangladesh is not well understood. As climate varies extensively in different parts of the world, the relation between temperature and asthma might also differ. We investigated the association between temperature and asthma-related hospital visits in the tropical city of Dhaka. We analyzed information from a total of 5989 asthma patients who received ambulatory care in the form of nebulized medication at the National Asthma Center in Mohakhali, Dhaka from February to November 2013. A time-stratified case-crossover study was conducted to estimate the effect of daily temperature, with consideration of delayed effects and possible confounders such as relative humidity and political strikes. An inverse association was observed between temperature and the number of hospital visits. The effect was delayed for approximately a week. A degree centigrade decrease in mean temperature (averaged across lags 0-6) was associated with an increase of approximately 4.5% (95% CI 1.5, 7.5) in all asthma visits. The association was evident in adult males but marginal in elderly males. A positive association (lag 0) was observed among adult females, whereas no association was observed among children. Strikes significantly modified the effect among the elderly. Findings suggest temperature declines affect asthma outcomes in a warm climate, and this effect can be delayed and vary by sex and age group

    Temperature during pregnancy influences the fetal growth and birth size

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    Background: Birth weight and length have seasonal fluctuations. However, it is uncertain which meteorological element has an effect on birth outcomes and which timing of pregnancy would explain such effect. Therefore, the purpose of this study was to examine temperature effects during pregnancy and which timing of pregnancy has effects on size at birth. Methods: A large, randomized, controlled trial of food and micronutrient supplementation for pregnant women was conducted in Matlab, Bangladesh (MINIMat Study), where women were enrolled from November 2001 to October 2003. The fetal growth data which included the size at birth and information of their mothers were obtained (n = 3267). Meteorological data such as temperature, precipitation, relative humidity, and daily sunshine hours during pregnancy were observed at the nearest observatory site of Bangladesh Meteorological Department. Results: Infants born in colder months (November–January) were shorter than those born in hot and dry, and monsoon months (mean (SD) of birth length was 47.5 cm (2.2) vs. 47.8 cm (2.1) vs. 47.9 cm (2.1) respectively; P < 0.001). Increased temperature during the last month of pregnancy was significantly related with increased birth length with adjustment for gestational weeks and the season at birth, and remained significant with further adjustments for precipitation, sex of infants, maternal early-pregnancy BMI, parity, and education status of the mother (P < 0.01). On the other hand, increased temperature at mid-gestation was associated with increased birth weight (P < 0.05). Conclusions: These findings suggest that temperature affects both birth weight and length. The more temperature increased at the last month of pregnancy, birth length became longer. For birth weight, the temperature at mid-pregnancy affected in a positive way

    Yokukansan Inhibits Neuronal Death during ER Stress by Regulating the Unfolded Protein Response

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    Recently, several studies have reported Yokukansan (Tsumura TJ-54), a traditional Japanese medicine, as a potential new drug for the treatment of Alzheimer's disease (AD). Endoplasmic reticulum (ER) stress is known to play an important role in the pathogenesis of AD, particularly in neuronal death. Therefore, we examined the effect of Yokukansan on ER stress-induced neurotoxicity and on familial AD-linked presenilin-1 mutation-associated cell death.We employed the WST-1 assay and monitored morphological changes to evaluate cell viability following Yokukansan treatment or treatment with its components. Western blotting and PCR were used to observe the expression levels of GRP78/BiP, caspase-4 and C/EBP homologous protein.Yokukansan inhibited neuronal death during ER stress, with Cnidii Rhizoma (Senkyu), a component of Yokukansan, being particularly effective. We also showed that Yokukansan and Senkyu affect the unfolded protein response following ER stress and that these drugs inhibit the activation of caspase-4, resulting in the inhibition of ER stress-induced neuronal death. Furthermore, we found that the protective effect of Yokukansan and Senkyu against ER stress could be attributed to the ferulic acid content of these two drugs.Our results indicate that Yokukansan, Senkyu and ferulic acid are protective against ER stress-induced neuronal cell death and may provide a possible new treatment for AD

    A Research on a New Science Curriculum Development Based on ‘Nature Of Science’ Ⅲ : Reconstruction of a Coherence Science Curriculum from Elementary School to Upper Secondary School

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    本研究は,新しい科学観を取り入れた小学校から高等学校までの理科カリキュラムを開発することを目的としており,今年度は3年次にあたる。これまでの成果と課題をもとに,初等・中等教育で一貫して「科学の本質」を学ぶためのフレームワーク構築に向け,小学校から高等学校を通じて系統的に取り扱うことが可能な内容について検討を行った。 中学校における実践からは,理科教師が,科学者コミュニティーによる知,政策決定者や教師たちによる教えるべき知,児童・生徒の発達段階や文脈などを考慮した教える知,について可能な限り熟知する必要があることが示唆された。また,論証活動を行う際の,教師の振る舞い方も重要であることも明らかとなった。 また,小学校における実践では,学年による差異はあるものの,見たことや考えたことの違いを次第に意識化させることによって,観察や実験等のレポートの書き方の指導にも繋がることが明らかとなった。 以上の実践より,科学の本質を初等・中等教育で一貫して教えるためには,これまでの実践の視点の変容に基づく教師による授業方略の在り方や投げ込み的教材を使用する教師の意図が,いかに重要であるかを示唆している。This study develops a new science curriculum for elementary to upper secondary schools which include the concept of the “Nature of Science”. We examined possible content to build a systematic framework for mentioned above science education. The practice at junior high school shows that teachers should be familiar with scholarly knowledge, knowledge to be taught by the policy makers and teachers, and taught knowledge which students understand through learning along with the students’ ages and contexts. The teacher’s behavior in argumentation by pupils is also important. The practice at elementary school shows that perceptions of the crucial distinction between inference and observation lead students to write good reports. These practices exemplify that teaching Nature of Science consistently to elementary and lower secondary students should largely depend on the teachers’ methods of instruction and what material they develop from a new viewpoint

    MEASUREMENTS OF TUBULENT FLUXES OVER A LAKE SURFACE

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    The results of measurements of the turbulent fluxes over Lake Biwa using a sonic anemometer and a fine thermocouple psychrometer are reported. The data are analyzed by an analog data processor. Mean values and standard deviations of the fluctuating quantities, and turbulent fluxes of momentum, sensible heat and latent heat are tabulated
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