Direct current electric potential in an anisotropic half-space with vertical contact containing a conductive 3D body

Detailed studies of anomalous conductors in otherwise homogeneous media have been modelled. Vertical contacts form common geometries in galvanic studies when describing geological formations with different electrical conductivities on either side. However, previous studies of vertical discontinuities have been mainly concerned with isotropic environments. In this paper, we deal with the effect on the electric potentials, such as mise-`a-la-masse anomalies, due to a conductor near a vertical contact between two anisotropic regions. We also demonstrate the interactive effects when the conductive body is placed across the vertical contact. This problem is normally very difficult to solve by the traditional numerical methods. The integral equations for the electric potential in anisotropic half-spaces are established. Green’s function is obtained using the reflection and transmission image method in which five images are needed to fit the boundary conditions on the vertical interface and the air-earth surface. The effects of the anisotropy of the environments and the conductive body on the electric potential are illustrated with the aid of several numerical examples.

The core of the global warming problem: energy

From the thermodynamic point of view, the global warming problem is an ''energy balance'' problem. The heat (energy) accumulation in the earth and its atmosphere is the cause of the global warming. This accumulation is mainly due to the imbalance of (solar) energy reaching and the energy leaving the earth, caused by ''greenhouse effect'' in which the CO₂ and other greenhouse gases play a critical role; so that balance of the energy entering and leaving the earth should be the key to solve the problem. Currently in the battle of tackling the global warming, we mainly focus on the development of CO₂-related measures, i.e., emission reduction, CO₂ sequestration, and CO₂ recycle technologies. It is right in technical aspect, because they are attempting thinner the CO₂ ''blanket'' around the earth. However, ''Energy'' that is the core of the problem has been overlooked, at least in management/policy aspect. This paper is proposing an ''Energy Credit'' i.e., the energy measure concept as an alternative to the ''CO₂ credit'' that is currently in place in the proposed emission trading scheme. The proposed energy credit concept has the advantages such as covering broad activities related to the global warming and not just direct emissions. Three examples are given in the paper to demonstrate the concept of the energy measure and its advantages over the CO₂ credit concept.

The influence of demographic, behavioural and treatments characteristics on problem gambling counselling outcomes

The paper considers the influence of client characteristics and gambling behaviour as well as treatment modality on the resolution of gambling behaviour for 591 clients who sought help from the publicly funded BreakEven counselling services in the state of Victoria between 1 July 1996 and 30 June 1997. Statistical data about clients and their consultations was collected in the form of a Minimum Data Set. On their own, client demographics accounting for 12% of the variance were identified as discriminating between problem gamblers who achieved some resolution of their gambling behaviour and those whose behaviour did not change. Variables associated with gambling behaviour accounted for 10% of variance and treatment variables for 12% of variance in treatment outcomes. Collectively, the three types of data could explain 26% of the variance in problem resolution. Importantly, these findings demonstrate that the resolution of problematic gambling behaviour is affected by a complex interplay of client characteristics, their gambling behaviour and the treatment they receive. It is argued that the evaluation of treatment programs for problem gambling, and potentially all counselling programs in the primary health arena, needs to include measures from each of these domains.

The relationship between quality of life and perceived body weight an dieting history in Dutch men and women

OBJECTIVES: (1) To study the relationship between quality of life (QoL) and measured and perceived weight and dieting history in Dutch men and women; (2) to assess the effect of weight loss over a 5 y period on QoL.

DESIGN: A cross-sectional study, in a sub-sample longitudinal over 5 y.

SUBJECTS: A total of 2155 men and 2446 women, aged 20-59 and recruited from the general population from three towns in The Netherlands.

MEASUREMENTS: Body weight, height, self-administered questionnaire including questions concerning demographic variables and weight loss practices as part of the Dutch Monitoring project on Risk Factors for Chronic Disease (MORGEN). The Rand-36 questionnaire was used as the QoL measure.

RESULTS: In men, measured overweight (body mass index, BMI>25 kg=m2) was not associated with any dimension of QoL after adjustment for age, educational level and perceived overweight. Perceived overweight was related to reduced scores for general health and vitality. This relationship was independent of measured obesity. A history of repeated weight loss was associated with reduced scores for role functioning due to both physical and emotional problems. In women, measured overweight was significantly associated with lower scores for five out of eight QoL dimensions and perceived overweight with three: general health, vitality and physical functioning. A history of frequent weight loss was related to significantly reduced scores in six dimensions. However, only with history of frequent weight loss, and uniquely in women, was there a significant reduction in
scores on mental health and limited emotional role functioning. Measured and perceived overweight and frequent weight loss were all related to reduced scores for physical functioning. Longitudinal data indicate that in older women weight gain of 10% body weight or more was associated with a significant deterioration in QoL.

CONCLUSIONS: When looking at measures of QoL in relation to overweight it is important to separate the effects of perception of weight status and history of weight loss. We observed that the latter two factors were associated with reduced scores on several dimensions of QoL, particularly in women. These associations were observed to be independent of body weight. International Journal of Obesity (2001) 25, 1386 – 1392

Understanding problem solving in requirements engineering : debating creativity with IS practitioners

RE is well-recognised as a creative problem solving activity by the systems development community. However, while substantial research has been conducted and knowledge gained about creativity in the general psychology of problem solving, creativity as it applies to RE remains a relatively unexplored area - one that has neither been comprehensively studied, nor highly recognised, as a research topic of importance. This paper attempts to address the above mentioned gap by presenting findings from a recent focus group study of creativity in RE as perceived by a group of RE practitioners. We provide a conceptual framework for understanding creativity in RE, which may be of use to requirements engineers attempting to enable more creative approaches and results, as well as adding to the existing, limited body of research in this area.

A performance comparison of three wireless multi hop ad-hoc network routing protocols when streaming MPEG4 traffic

Mobile ad-hoc networks are characterised by constant topology changes, the absence of fixed infrastructure and lack of any centralised control. Traditional routing algorithms prove to be inefficient in such a changing environment. Ad-hoc routing protocols such as dynamic source routing (DSR), ad-hoc on-demand distance vector routing (AODV) and destination-sequence distance vector (DSDV) have been proposed to solve the multi hop routing problem in ad-hoc networks. Performance studies of these routing protocols have assumed constant bit rate (CBR) traffic. Real-time multimedia traffic generated by video-on demand and teleconferencing services are mostly variable bit rate (VBR) traffic. Most of these multimedia traffic is encoded using the MPEG standard. (ISO moving picture expert group). When video traffic is transferred over MANETs a series of performance issues arise. In this paper we present a performance comparison of three ad-hoc routing protocols - DSR, AODV and DSDV when streaming MPEG4 traffic. Simulation studies show that DSDV performs better than AODV and DSR. However all three protocols fail to provide good performance in large, highly mobile network environments. Further study is required to improve the performance of these protocols in mobile ad-hoc networks offering VBR services.

Problem of precision missile guidance: LQR and H‡ control frameworks

Addressed here is the precision missile guidance problem where the successful intercept criterion has been defined in terms of both minimizing the miss distance and controlling the missile body attitude with respect to the target at the terminal point. We show that the H∞ control theory, when suitably modified, provides an effective framework for the precision missile guidance problem. The existence of feedback controllers (guidance laws) is investigated for the case of finite horizon and non-zero initial conditions. Both state feedback and output feedback implementations are explored.

Emotional reactions following exposure to idealized bodies predict unhealthy body change attitudes and behaviors in women and men

Objective: We explored the extent to which changes in emotional states following exposure to images of idealized bodies predict unhealthy body change attitudes and behaviors in women and men, and whether particular psychological traits mediate these effects. Method: One hundred thirty-three women and 93 men were assessed for unhealthy attitudes and behaviors related to body weight and muscles using the Eating Disorder Inventory-2 (EDI-2), the Obligatory Exercise Questionnaire, and the strategies to increase muscles subscale of the Body Change Inventory. Psychological traits assessed included body dissatisfaction (EDI-2), internalization of the thin/athletic ideal (Sociocultural Attitudes Towards Appearance Questionnaire-3), body comparison (Body Comparison Scale), self-esteem (Rosenberg Self-Esteem Inventory), depression (Beck Depression Inventory-II), and identity confusion (Self-Concept Clarity Scale). Participants were then exposed to photographs of thin female models and muscular male models, and visual analogue scales were used to measure changes in postexposure state body dissatisfaction, anger, anxiety, and depression.
Results: Postexposure increases in state anger, anxiety, depression, and body dissatisfaction correlated with drive for thinness and disordered eating symptomatology in women, while postexposure increases in state body dissatisfaction correlated with muscle development in men. Analyses revealed that internalization and body comparison mediated these relationships, with trait body dissatisfaction, trait depression, self-esteem, and self-concept/identity confusion serving as mediators for women only. Conclusion: These results are indicative of gender differences in: (a) reactions to idealized bodies; (b) psychological traits that predispose individuals to experience these reactions; and (c) types of body change behavior that are associated with these reactions.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background
While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).
Methods
This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.
Results
Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion
Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

The problem of obesity : is there a role for antagonists of the renin-angiotensin system?

Obesity is a major health problem worldwide; it is associated with more than 30 medical conditions and is a leading cause of unnecessary deaths. Adipose tissue not only acts as an energy store, but also behaves like an endocrine organ, synthesising and secreting numerous hormones and cytokines. Angiotensin II (ANG II) is the biologically active component of the renin-angiotensin system (RAS). The RAS is present in adipose tissue and evidence suggests that ANG II is intimately linked to obesity. Indeed, ANG II increases fat cell growth and differentiation, increases synthesis, uptake and storage of fatty acids and triglycerides and possibly inhibits lipolysis. Evidence obtained using genetically modified animals has shown that the amount of body fat is directly related to the amount of ANG II, i.e., animals with low levels of ANG II have reduced fat stores while animals with excessive ANG II have increased fat stores. In humans, epidemiological evidence has shown that body fat is correlated with angiotensinogen, a precursor of ANG II, or other components of the RAS. Furthermore, blocking the production and/or actions of ANG II with drugs or natural substances decreases body fat. The decrease in body fat caused by such treatments predominantly occurs in abdominal fat depots and appears to be independent of energy intake and digestibility. Clearly, ANG II has an important role in the accumulation of body fat and the possibility exists that treatment of obesity will be enhanced by the use of natural or synthetic substances that interfere with ANG II.

Family average income and body mass index above the healthy weight range among urban and rural resicents in regional Mainland China

Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.

Implications of accuracy, sensitivity, and variability of body size estimations to disordered eating

The current study was conducted to investigate the relationships between body size estimations and disordered eating symptomatology. The method of constant stimuli was used to derive three measures of self-perceived body size in 93 women: (1) accuracy of body size estimations (body image distortion); (2) sensitivity in discriminating body size within blocks of trials (body image sensitivity); and (3) variability in making body size estimations between blocks of trials (body image variability). Participants also completed measures of disordered eating. Although body image distortion correlated with dietary restraint and eating concern, body image variability accounted for additional variance in these variables, as well as variance in binge eating. The relationships involving body image variability were found to be mediated by body dissatisfaction and internalization of the thin ideal. Together, these results are consistent with the proposition that body image variability is a significant factor in disordered eating.

The effect of active support training on engagement, opportunities for choice, challenging behaviour and support needs

Background: The aim of this study was to evaluate active support (AS) training and to investigate changes to perceived engagement in domestic tasks, opportunities for choice, frequency of challenging behaviour, and level of support needs.

Method: Participants were 12 adults with ID aged 27–57 years (M = 37 years) residing in three group homes, and their support workers. The support workers completed assessments on three occasions (at baseline, post-training, and at follow-up).

Results: Residents' engagement in domestic tasks increased over time, and overall choice increased, although perceived choice in two life domains initially increased, but decreased to baseline levels at follow-up. Residents exhibited an overall decrease in anxiety, self-absorbed behaviour, disruptive behaviour, and problem behaviour in general. There was also an overall decrease in perceived support needs for five activity domains, with no change for one domain.

Conclusions: The results contribute to a growing body of evidence demonstrating favourable outcomes of AS in terms of engagement and challenging behaviour in people with ID. Surprising results are presented for choice and perceived support needs, warranting further investigation.

Prevalence and correlates of three types of pelvic pain in a nationally representative sample of Australian men

Introduction: Recent international prevalence studies of pelvic pain in men have estimates ranging between 2% and 10%. These studies conclude that it is an important international health problem.

Aims: The aims of this study were to establish the first population-based study of pelvic pain in Australian men, and identify correlates with men's sexual and reproductive histories and other health conditions.

Methods: A representative household sample of 4,290 Australian men aged 16–64 years completed a computer-assisted telephone interview. They were asked about their experiences of pain in the pelvic region during the past 12 months.

Main Outcome Measures: Prevalence of correlates of pain associated with sexual intercourse, pain associated with urination, and pelvic pain not associated with intercourse or urination.

Results: Five percent of men reported pain during urination, 5% reported pain related to sexual intercourse, and 12% of men reported other chronic pelvic pain. There was little overlap in reporting any of the three types of pelvic pain, with 18% of men reporting some form of pelvic pain. Men reporting any of the pain conditions were significantly more likely than other men to report a sexual experience when they had felt forced or frightened. Men reporting pain during intercourse and/or chronic pelvic pain were significantly more likely than other men to report same sex experience. All three groups of men with pelvic pain were more likely than other men to report some form of sexual difficulties. A report of ever receiving a diagnosis of depression or a report of anxiety was significantly associated with all forms of pelvic pain.

Conclusions: More than one man in six report having some form of pelvic pain in the past 12 months. It is likely that men would benefit from a discussion about possible symptoms during consultations with their physicians.

Predictors of body mass index change in Australian primary school children

Objective. To assess associations between multiple potential predictors and change in child body mass index (BMI). Methods.In the 1997 Health of Young Victorians Study, children in Grades preparatory to three (aged 510 years) had their height and weight measured. Parents provided information on potential predictors of childhood overweight across six domains (children’s diet, children’s activity level, family composition, sociodemographic factors, prenatal factors and parental adiposity). Measures were repeated three years later in 2000/1. BMI was transformed to standardised (z) scores using the US 2000 Growth Chart data and children were classified as non-overweight or overweight according to international cutpoints.Regression analyses, including baseline BMI z-score as a covariate, assessed the contribution of each potential predictor to change in BMI z-score, development of overweight and spontaneous resolution of overweight in 1 373 children.Results. BMI z-score change was positively associated with frequency of take-away food, food quantity, total weekly screen time, non-Australian paternal country of birth, maternal smoking during pregnancy, and maternal and paternal BMI.Inverse associations were noted for the presence of siblings and rural residence (all pB0.05). Predictors of categorical change (development and resolution of overweight) were less clearly identified, apart from an association between maternal BMI and overweight development (p0.02). Multivariable models suggested individual determinants have a cumulative effect on BMI change. Conclusions. Strong short-term tracking of BMI makes it difficult to identify predictors of change. Nonetheless, putative determinants across all domains assessed were independently associated with adiposity change. Multi-faceted solutions are likely to be required to successfully deal with the complexities of childhood overweight.