Dielectrophoretic sample preparation for environmental monitoring of microorganisms: Soil particle removal

Detection of pathogens from environmental samples is often hampered by sensors interacting with environmental particles such as soot, pollen, or environmental dust such as soil or clay. These particles may be of similar size to the target bacterium, preventing removal by filtration, but may non-specifically bind to sensor surfaces, fouling them and causing artefactual results. In this paper, we report the selective manipulation of soil particles using an AC electrokinetic microfluidic system. Four heterogeneous soil samples (smectic clay, kaolinitic clay, peaty loam, and sandy loam) were characterised using dielectrophoresis to identify the electrical difference to a target organism. A flow-cell device was then constructed to evaluate dielectrophoretic separation of bacteria and clay in a continous flow through mode. The average separation efficiency of the system across all soil types was found to be 68.7% with a maximal separation efficiency for kaolinitic clay at 87.6%. This represents the first attempt to separate soil particles from bacteria using dielectrophoresis and indicate that the technique shows significant promise; with appropriate system optimisation, we believe that this preliminary study represents an opportunity to develop a simple yet highly effective sample processing system.     

Genetics of muscle strength and power: polygenic profile similarity limits skeletal muscle performance

Environmental and genetic factors influence muscle function, resulting in large variations in phenotype between individuals. Multiple genetic variants (polygenic in nature) are thought to influence exercise-related phenotypes, yet how the relevant polymorphisms combine to influence muscular strength in individuals and populations is unclear. In this analysis, 22 genetic polymorphisms were identified in the literature that have been associated with muscular strength and power phenotypes. Using typical genotype frequencies, the probability of any given individual possessing an "optimal" polygenic profile was calculated as 0.0003% for the world population. Future identification of additional polymorphisms associated with muscular strength phenotypes would most likely reduce that probability even further. To examine the genetic potential for muscular strength within a human population, a "total genotype score" was generated for each individual within a hypothetical population of one million. The population expressed high similarity in polygenic profile with no individual differing by more than seven genotypes from a typical profile. Therefore, skeletal muscle strength potential within humans appears to be limited by polygenic profile similarity. Future research should aim to replicate more genotype-phenotype associations for muscular strength, because only five common genetic polymorphisms identified to date have positive replicated findings.     

The effects of age and body weight on anthropometric estimations of minimal wrestling weight in high school wrestlers

The purpose of this study was to determine the effects of age and body weight on anthropometric estimations of minimal wrestling weight (MWW) in high school wrestlers. Five hundred and twenty-two high school wrestlers (M age +/- SD = 16.45 +/- 1.03 years) volunteered as subjects for this study. The total sample (N = 522) was dichotomized by age (less than 16 years, n = 171; greater than or equal to 16 years, n = 351) and body weight (less than or equal to 62.60 kg, n = 252; greater than 62.60 kg, n = 270). Cross-validation analyses included examination of the constant error (CE), standard error of estimate (SEE), r, and total error (TE). The results indicated that the quadratic skinfold equation of Lohman (EQ1; Table 2) most accurately estimated MWW in each group. Furthermore, it was recommended that MWW be calculated from EQ1 using the conversion constants of Lohman ([(5.03/BD)-4.59] x 100) to estimate relative fat from body density.     

Issues for the Asia-Pacific region

The Asia-Pacific region has made substantial but uneven advances in education, particularly over the past two decades. The region’s countries must share information on successful and unsuccessful approaches to solving educational problems and join forces to explore topics about which educators and policy-makers know little or nothing. On the basis of a history of successful co-operation and a commitment to respecting cultural difference, they can and must collaborate both to improve their own education systems and to contribute to the development of secondary education around the world.     

初秋

When Bill was very young, they had been in love. Many nights they had spent walking, talking together. Then something not very important had come between them, and they didn' t speak. Impulsively, she had married a man she thought she loved. Bill went away,     

Can performance management work in Australian universities?

Performance appraisal and performance management are much discussed topics at the moment and are widely promoted as tools for maximising the effectiveness of an institution's human resources. This paper will consider the lessons to be learnt from consideration of the private sector experience, and discuss the issues raised in a recent review of a performance management program implemented for general staff at the University of New South Wales (UNSW). The matters highlighted by the review appear to be common to most Australian universities, and we argue that until these issues are addressed performance management, including appraisal, is unlikely to work effectively in the university context for either general or academic staff.     

Teacher-student relationships as compensatory resources for aggressive children

This 2-year prospective investigation examined the association between the quality of teacher-student relationships and children's levels of aggression in a sample of 140 second- and third-grade aggressive children (M age = 8.18). Consistent with the proposed dual-risk compensatory hypothesis, positive teacher-student relationships were more beneficial for aggressive African American and Hispanic children than for aggressive Caucasian children. Data did not support a moderating effect of negative parent-child relationship quality on the association between supportive teacher-student relationships and aggression. Findings underscore the importance of recruiting and preparing teachers capable of establishing supportive relationships with aggressive African American and Hispanic children. Results also suggest the need for multiple reporters of relationship quality in future research.     

Patterns of maternal behavior among neglectful families: implications for research and intervention

OBJECTIVE: The heterogeneity within neglecting caregivers has not been explored in an empirical fashion. The current study sought to address this limitation by utilizing archival data in order to explore variability of maternal behavior among neglectful families. METHOD: The current study utilized archival data containing caseworker and self-report information on 100 mothers for whom neglect had been substantiated and was the primary referral concern. Cluster analysis was used to describe patterns of maternal behavior. Subsequent analysis was used to determine differences between the clusters on degree of neglect, maternal depression, perceived social support, and other demographic characteristics (income, education). RESULTS: Five distinct patterns of maternal behavior emerged, each with different ratings of maternal confidence, relatedness, impulse control, and willingness to engage in verbal interactions. The clusters differed on ratings of neglect, life stressors, resource problems and adult problems. The clusters were similar in terms of maternal education, number of children in the home, and monthly income. Additionally, women in all clusters reported similar levels of depression, similar number of children, and a comparable amount of social support. CONCLUSIONS: The five clusters are described and implications for intervention approaches are discussed.     

Assessing the Practicum

The practicum appears in many different forms in professional education — as field placement, cooperative education, sandwich programs, internship and clinical placement. This review of current literature reveals many different conceptions of the kinds of learning outcomes that can be achieved through learning in the workplace and the contribution that the practicum can make to professional education. In consequence, assessment philosophies and methods are equally varied. Five distinct approaches to assessment of the practicum are identified and the strengths and weaknesses of each are evaluated. While assessment of the practicum in some programs has been very limited, in the best examples cited, integration of the practicum with the educational program has provided opportunities for students to bring together a range of knowledge and skills in a complex natural environment. Well‐designed assessment requirements can make a significant contribution to learning in the practicum by putting pressure on supervisors to structure the opportunities available and by requiring students to identify and reflect on what they have learned.