Development of a 1-Methylcyclopropene (1-MCP) Sachet Release System

ABSTRACT The partitioning of 1‐methylcyclopropene (1‐MCP) between the gas/polymer matrix was determined for 2 adsorbing agents and 4 sachet materials to estimate the adsorption potential of 1‐MCP at 23°C. The release study was performed using a closed system under 2 different environmental conditions, dry air (0% RH) and 90% RH. Sachets made from Tyvek®, paper, low‐density polyethylene (LDPE), and polyvinyl acetate (PVA) materials were fabricated to contain silica gel and activated carbon. Activated carbon sachets did not release 1‐MCP at either testing condition. Activated carbon had a very strong affinity for 1‐MCP. The permeability coefficients of 1‐MCP and water in polyethylene and polyvinyl acetate films were determined using a quasi‐isostatic method. LDPE sachets containing silica gel had similar 1‐MCP release rates at both 0% and 90% RH. PVA sachets containing silica gel had slow release of 1‐MCP. The amount of 1‐MCP released from PVA sachets containing silica gel at 90% RH was larger than the amount of 1‐MCP released at 0% RH. Release of 1‐MCP from paper and Tyvek sachets was largely dependent on the sorbate‐absorbing ability of the adsorbing agents.     

Relationship among fecal coliforms and <Emphasis Type="Italic"> Escherichia coli </Emphasis>in various foods

For much of the twentieth century, coliform bacteria and especially Escherichia coli have been used as indicators of possible post-processing contamination and the presence of E. coli as an indicator of fecal contamination in foods. In this study, 500 foods in 10 different groups, mainly dairy products, delicatessen products, salads, spices, cream cakes and fresh fruit and vegetable samples, were analyzed for the natural contamination of fecal coliforms and E. coli by the standard most probable number (MPN) method. The difference between weighted means of fecal coliforms and E. coli counts were only 0.246 log₁₀ MPN/g-ml (MPN/gram for solid samples, and MPN/milliliter for liquids). Enumeration results were also evaluated by Pearson's correlation coefficient ( r), Cronbach's alpha (f) and determination coefficient ( r ²) analysis. According to results, although 33 samples contained only non- E. coli fecal coliforms, the results of reliability analyses indicated that fecal coliform counts and E. coli counts may be used interchangeably ( P <0.0001). It can be said that fecal coliform or, preferably E. coli analysis is sufficient for rapid routine determination of fecal contamination, at least for those food groups analyzed in this research.     

"Factor structure of the BASC-2 Behavioral and Emotional Screening System Student Form": Correction to Dowdy et al. (2011).

Reports an error in "Factor structure of the BASC–2 Behavioral and Emotional Screening System Student Form" by E. Dowdy, et al. (Psychological Assessment. np). There was an omission in the author note. The author note should have included a disclosure as follows, “Randy W. Kamphaus wishes to disclose a potential conflict of interest in that he receives a portion of royalties on net sales of BESS.” (The following abstract of the original article appeared in record 2011-04578-001.) The BASC–2 Behavioral and Emotional Screening System (BESS) Student Form (Kamphaus & Reynolds, 2007) is a recently developed youth self-report rating scale designed to identify students at risk for behavioral and emotional problems. The BESS Student Form was derived from the Behavior Assessment System for Children—Second Edition Self-Report of Personality (BASC–2 SRP; Reynolds & Kamphaus, 2004) using principal component analytic procedures and theoretical considerations. Using 3 samples, the authors conducted exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) to understand the underlying factor structure of the BESS Student Form. The results of the EFA suggested that the SRP contained a 4-factor (i.e., Personal Adjustment, Inattention/Hyperactivity, Internalizing, School Problems) emergent structure, which was supported by CFA in 2 additional samples. Practical and research implications are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

SPQ editorial June 2008.

This issue features the first research article (Bradshaw, Buckley & Ialongo, 2008) accepted by our new editorial team; a group of individuals with unusual methodological talent. Also in this issue you will find a special section on neurodevelopmental disorders of childhood, the adaptation of children with such problems to schooling, and implications for the practice of psychology with these children in schools. Our fall issue will premier our first contribution to the Evidence for Practice section, which represents an attempt to directly link accumulated scientific knowledge to the everyday work of psychological practitioners. I am happy to receive any inquiries from prospective contributors to SPQ. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

军用无源器件的发展趋势

军工/航天和商用电子元器件市场常常被认为是两个不同的市场,但实际上,二者之间的共同之处正在不断增加。由于高可靠性业务的数量显著较少,该领域的采购商似乎把目光放在商业客户的对应型号上,当然前提是满足起码的性能要求。这些采购商开始仿照商用标准产品的客户，越来越多地通过分销商来采购所需的元器件。那些军工和航天领域的巨头不再局限于原有的垂直集成业务模式，开始象那些商业OEM厂商一样，考虑将电路板组装业务通过离岸合同制造的方式外包出去，以降低他们的成本。     

A vision-based collision avoidance technique for micro air vehicles using local-level frame mapping and path planning

This paper presents a vision-based collision avoidance technique for small and miniature air vehicles (MAVs) using local-level frame mapping and path planning. Using computer vision algorithms, a depth map that represents the range and bearing to obstacles is obtained. Based on the depth map, we estimate the range, azimuth to, and height of obstacles using an extended Kalman filter that takes into account the correlations between obstacles. We then construct maps in the local-level frame using cylindrical coordinates for three dimensional path planning and plan Dubins paths using the rapidly-exploring random tree algorithm. The behavior of our approach is analyzed and the characteristics of the environments where the local path planning technique guarantees collision-free paths and maneuvers the MAV to a specific goal region are described. Numerical results show the proposed technique is successful in solving path planning and multiple obstacle avoidance problems for fixed wing MAVs.     

Jane Loevinger (1918-2008).

Jane Loevinger died unexpectedly on January 4, 2008. She was well-known for her work in psychometrics, her theory of ego development, and her widely used assessment instrument, the Washington University Sentence Completion Test. Among the first to focus on women as a demographic, Loevinger obtained funding from the National Institute of Mental Health. She developed measures of women's attitudes and formed a research group of her own that focused on the problems facing mothers and women in general. Loevinger was a perennial iconoclast and skeptic within her fields of interest. Despite her wry wit, or perhaps because of it, her opinions and contributions came to be greatly valued by her colleagues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in entrainment of mood to the weekly calendar.

This study addressed two questions: Do daily fluctuations in mood exhibit a 7-day (circaseptum) cycle, and are there reliable individual differences in how entrained peoples' moods are to such a weekly cycle? Spectral analysis of daily mood over 84 occasions revealed a strong weekly rhythm in the temporal organization of mood in a sample of 74 undergraduates. A sine wave with a period of 7 days accounted for 40% of the variance in the daily mood data. Individual differences were also found in how entrained subjects' moods were to this weekly rhythm. We predicted that extraverts (compared with introverts) should be less entrained to a weekly cycle. Results suggest that the novelty- and sensation-seeking behavior of extraverts most likely serves to lessen the cyclical predictability of their day-to-day moods. The origin and psychological meaning of the 7-day week are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Large scale production of indium antimonide film for position sensors in automobile engines

We use low pressure MOVPE to grow indium antimonide films on groups of eight 3 inch GaAs wafers per run. The films are used for the production of magnetoresistive position sensors for the car industry. To meet the narrow specifications for automotive components, the standard deviation of the sheet resistivity, and the thickness of the films have been reduced below 1.5%. This uniformity is the result of an optimization process encompassing the determination of the best susceptor temperature and the optimum flow. The gas velocity was found to have a large impact on the uniformity of the layers. Rotation of the wafers and the use of an optimum gas velocity results in extremely uniform layers.     

Diameter-Controlled Synthesis of Polyaniline Nanofibers

Summary  Various diameters of polyaniline (PANI) nanofibers were easily made by varying the sweep rate in the electrochemical polymerization of the aniline monomer. At a sweep rate of 5 mV/s, the PANI nanofibers have an average diameter of 450 nm with a median of 440 nm. The fibers are short, on the order of a few microns in length, and exhibit a branched geometry. Increasing the sweep rate to 50 mV/s produced longer nanofibers with a smaller average diameter of 200 nm. Nanofibers synthesized at 100 mV/s were noted to be smaller with an average and median diameter of 100 nm. These results illustrate the ease in which the morphology of nanostructured PANI can be altered and indicate that the method has the potential to create multi-diameter fibers or mixed-morphology materials.