Satellite observations of circulation features associated with a bowhead whale feeding ‘hotspot’ near Barrow, Alaska

Satellite images, along with oceanographic, meteorological, and whale aerial survey data, are used to illustrate aspects of ocean circulation associated with a bowhead whale feeding ‘hotspot’ near Barrow, Alaska. In response to weak winds, a strong front forms near the shelf-break along the southern edge of Barrow Canyon when the Alaska Coastal Current flows adjacent to the southern flank of Barrow Canyon or intrudes onto the western Beaufort shelf. This front is of particular local interest because it is indicative of aggregation and retention of zooplankton on the western Beaufort shelf and, as a result, is a locus for bowhead whales pausing to feed during their westward fall migration. Groups (4 or more individuals) of bowhead whales are primarily seen on the western Beaufort shelf following wind conditions that promote the formation of this front.     

Predicting Improvement After First-Grade Reading Difficulties: The Effects of Oral Language, Emergent Literacy, and Behavior Skills.

This study investigated the role of early literacy and behavioral skills in predicting the improvement of children who have experienced reading difficulties in 1st grade. The progress of 146 low-income children whose reading scores in 1st grade were below the 30th percentile was examined to determine (a) how the poorest readers in 1st grade progressed in reading achievement through 4th grade and (b) which emergent literacy and behavioral skills measured in kindergarten predicted differential 4th grade outcomes. Results indicated that the divergence between children who improved and those who did not was established by the end of 2nd grade. Further, individual linguistic skills and behavioral attributes measured in kindergarten contributed substantively to this difference. Implications for intervention timing and educational policy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magnetic moment and reluctance network mixed method applied to transformer modeling

The aim of the study is to find a method to model electromagnetic devices which generate consequent magnetic leakage. Classical methods have proved to be efficient but time consuming. The method proposed in this paper is based on the magnetic moment method (MMM). An original methodology to obtain a simplified MMM model is described, adjusted with simple RNM model results. Besides the good accuracy, the simplicity of the model makes it possible to consider complicated studies with reasonable resolution times.     

Psychological impact of benign breast biopsy: A longitudinal, comparative study.

The impact of benign breast biopsy (BBB) on distress and perceptions of risk for breast cancer (BC) was examined. Interviews were conducted with 100 women shortly after notification of biopsy results and 4 and 8 months post-BBB. Compared with matched healthy comparison (HC) women without BBB, the BBB group evidenced greater BC-specific distress at baseline. BC-specific distress declined after BBB, remaining elevated relative to the HC group at the 8-month follow-up. Dispositional (optimism, informational coping style), demographic (education), clinical (family history of BC), and cognitive (BC risk perception) variables were associated with baseline levels of BC-specific distress or persistence of distress. Results support the monitoring process model (S. M. Miller, 1995) and the cognitive social health information processing model (S. M. Miller, Y. Shoda, & K. Hurley, 1996). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Graph structure in the Web

The study of the Web as a graph is not only fascinating in its own right, but also yields valuable insight into Web algorithms for crawling, searching and community discovery, and the sociological phenomena which characterize its evolution. We report on experiments on local and global properties of the Web graph using two AltaVista crawls each with over 200 million pages and 1.5 billion links. Our study indicates that the macroscopic structure of the Web is considerably more intricate than suggested by earlier experiments on a smaller scale.     

传输线电容参数提取中的奇异性处理方法

传输线电容参数提取过程中需要计算导体上的电量,而在电量计算过程中普遍存在着角点的奇异性问题.本文给出了角点附近区域电势分布的数学模型,通过采用有限级数逼近该数学模型的解析解提出了一种新的电量计算方法,并进行了级数逼近的误差分析.本文算法克服了邓肯矫正需要选择角点积分区域的不足,有效地校正了导体角点奇异性引起的电容参数提取的计算误差,最后给出了算法的数值实验与分析结果.     

Bioanalytical and chemical assessment of the disinfection by-product formation potential: Role of organic matter

Disinfection by-products (DBP) formed from natural organic matter and disinfectants like chlorine and chloramine may cause adverse health effects. Here, we evaluate how the quantity and quality of natural organic matter and other precursors influence the formation of DBPs during chlorination and chloramination using a comprehensive approach including chemical analysis of regulated and emerging DBPs, total organic halogen quantification, organic matter characterisation and bioanalytical tools. In vitro bioassays allow us to assess the hazard potential of DBPs early in the chain of cellular events, when the DBPs react with their molecular target(s) and activate stress response and defence mechanisms. Given the reactive properties of known DBPs, a suite of bioassays targeting reactive modes of toxic action including genotoxicity and sensitive early warning endpoints such as protein damage and oxidative stress were evaluated in addition to cytotoxicity. Coagulated surface water was collected from three different drinking water treatment plants, along with reverse osmosis permeate from a desalination plant, and DBP formation potential was assessed after chlorination and chloramination. While effects were low or below the limit of detection before disinfection, the observed effects and DBP levels increased after disinfection and were generally higher after chlorination than after chloramination, indicating that chlorination forms higher concentrations of DBPs or more potent DBPs in the studied waters. Bacterial cytotoxicity, assessed using the bioluminescence inhibition assay, and induction of the oxidative stress response were the most sensitive endpoints, followed by genotoxicity. Source waters with higher dissolved organic carbon levels induced increased DBP formation and caused greater effects in the endpoints related to DNA damage repair, glutathione conjugation/protein damage and the Nrf2 oxidative stress response pathway after disinfection. Fractionation studies indicated that all molecular weight fractions of organic carbon contributed to the DBP formation potential, with the humic rich fractions forming the greatest amount of DBPs, while the low molecular weight fractions formed more brominated DBPs due to the high bromide to organic carbon ratio. The presence of higher bromide concentrations also led to a higher fraction of brominated DBPs as well as proportionally higher effects. This study demonstrates how a suite of analytical and bioanalytical tools can be used to effectively characterise the precursors and formation potential of DBPs.     

Determination of Volatile and Semivolatile Contaminants in Meat by Supercritical Fluid Extraction/Gas Chromatography/Mass Spectrometry

Meat products that were exposed to a warehouse fire were collected and examined to identify contaminants present in the samples. An extraction method using supercritical carbon dioxide at 100 atm and 60°C was developed to analyse and characterise volatile and semi-volatile compounds from the samples. The major volatile compounds were lipid oxidation products, such as hexanal and nonanal. Volatiles concentrations from fire-exposed meat products were compared to control samples to determine compositional differences. Aromatic and polycyclic aromatic hydrocarbons were identified, and naphthalene was measured in suspected fire-damaged meat products. Direct supercritical extraction from the meat samples proved to be a rapid and reproducible method to assess contamination in commercial meat products.