A field test of the diversity-openness moderator model in newly formed groups: openness to diversity affects group decision effectiveness and interaction patterns

Detrimental effects of diversity in workgroups has frequently been observed but research identifying the factors that lead to negative or positive effects in heterogeneous groups is lacking. The perceived dissimilarity openness moderator model provides one explanation of the process by which diversity influences group affective, behavioral, and cognitive outcomes. Specifically the model identifies individual, group, and organizational openness as moderating the effects of diversity in workgroups. In this paper evidence is provided from a field study that increased openness to perceived dissimilarity leads to better outcomes in newly formed groups. This study also constitutes a significant building block toward the development of theory concerning the moderating variables of the relationship between diversity and group processes, and outcomes of organizations.

Sperm environment affects offspring quality in broadcast spawning marine invertebrates

The provisioning of offspring can have far-reaching consequences for later life in a wide range of organisms and generally this provisioning is thought to be under maternal influence or control. In experiments with a broadcast-spawning ascidian, we found that the size of offspring was determined by egg size and the abundance of sperm present during fertilization. Larger eggs were fertilized at low sperm concentrations, whilst smaller eggs were successfully fertilized at high sperm concentrations. These differences in fertilized egg size resulted in differences in the development rate, hatching success and mean size of the subsequent larvae. Our results suggest that, in contrast to females that reproduce by other mating systems, free-spawning mothers lack some control over the provisioning of offspring. Furthermore, because males can alter the sperm environment, they can exert paternal (non-genetic) control over key offspring characteristics.

α2β1 integrin affects metastatic potential of ovarian carcinoma spheroids by supporting disaggregation and proteolysis

Background: Ovarian cancer is characterized by a wide-spread intra-abdominal metastases which represents a major clinical hurdle in the prognosis and management of the disease. A significant proportion of ovarian cancer cells in peritoneal ascites exist as multicellular aggregates or spheroids. We hypothesize that these cellular aggregates or spheroids are invasive with the capacity to survive and implant on the peritoneal surface. This study was designed to elucidate early inherent mechanism(s) of spheroid survival, growth and disaggregation required for peritoneal metastases.

Methods: In this study, we determined the growth pattern and adhesive capacity of ovarian cancer cell lines (HEY and OVHS1) grown as spheroids, using the well established liquid overlay technique, and compared them to a normal ovarian cell line (IOSE29) and cancer cells grown as a monolayer. The proteolytic capacity of these spheroids was compared with cells grown as a monolayer using a gelatin zymography assay to analyze secreted MMP-2/9 in conditioned serum-free medium. The disaggregation of cancer cell line spheroids was determined on extracellular matrices (ECM) such as laminin (LM), fibronectin (FN) and collagen (CI) and the expression of α2, α3, αv, α6 and β1 interin was determined by flow cytometric analysis. Neutralizing antibodies against α2, β1 subunits and α2β1 integrin was used to inhibit disaggregation as well as activation of MMPs in spheroids.

Results: We demonstrate that ovarian cancer cell lines grown as spheroids can sustain growth for 10 days while the normal ovarian cell line failed to grow beyond 2 days. Compared to cells grown as a monolayer, cancer cells grown as spheroids demonstrated no change in adhesion for up to 4 days, while IOSE29 cells had a 2–4-fold loss of adhesion within 2 days. Cancer cell spheroids disaggregated on extracellular matrices (ECM) and demonstrated enhanced expression of secreted pro-MMP2 as well as activated MMP2/MMP9 with no such activation of MMP's observed in monolayer cells. Flow cytometric analysis demonstrated enhanced expression of α2 and diminution of α6 integrin subunits in spheroids
versus monolayer cells. No change in the expression of α3, αv and β1 subunits was evident. Conversely, except for αv integrin, a 1.5–7.5-fold decrease in α2, α3, α6 and β1 integrin subunit expression was observed in IOSE29 cells within 2 days. Neutralizing antibodies against α2, β1 subunits and α2β1 integrin inhibited disaggregation as well as activation of
MMPs in spheroids.

Conclusion: Our results suggest that enhanced expression of α2β1 integrin may influence spheroid disaggregation and
proteolysis responsible for the peritoneal dissemination of ovarian carcinoma. This may indicate a new therapeutic target
for the suppression of the peritoneal metastasis associated with advanced ovarian carcinomas.

Bullying affects us too: parental responses to bullying at kindergarten

Preschool age children are often thought of as too young to be able to engage in bullying behaviours. However, when it does occur, there are ramifications not only for the child but also for parents and siblings. This article explores this issue by reporting on an exploratory study involving interviews with four parents whose child had experienced bullying in a Victorian kindergarten. Parents reported a range of responses, including anger, guilt for not protecting their child, and powerlessness in the face of denial from kindergarten staff that their child had been bullied. Being unable to access information about bullying among preschool children which might validate their experiences, reinforced the sense of isolation these parents experienced. Further research which explores the needs of family members of children bullied in the kindergarten (prior to school) setting is needed.

Fenitrothion, an organophosphate, affects running endurance but not aerobic capacity in fat-tailed dunnarts (Sminthopsis crassicaudata)

We measured aerobic metabolism during cold exposure and exercise performance (run duration and oxygen consumption while running at 1 m s⁻¹) in the fat-tailed dunnart Sminthopsis crassicaudata, a dasyurid marsupial, before and after ingestion of 30 mg kg⁻¹ of fenitrothion, an organophosphate (OP) pesticide. Running endurance of OP-exposed animals was less than half that of control animals over the first 3 days after dosing and 55% of control animal endurance on day 5 post-dose. Despite these declines, peak metabolic rate at this running speed (9.3 times basal metabolic rate; BMR) was unaffected by OP exposure. Peak metabolic rate (PMR) and cumulative oxygen consumption during a 1-h exposure to conditions equivalent to −20 °C did not differ between OP-treated and control dunnarts, with PMR averaging 11 times BMR. We conclude that fenitrothion-induced exercise fatigue is not due to limitations in oxygen or substrate delivery to muscle or in their uptake per se, but more likely relates to decreased ability to sustain high-frequency neuromuscular function. The persistence of locomotor impairment following OP exposure in otherwise asymptomatic animals emphasizes the importance of using performance-based measures when characterising sublethal effects of pesticide exposure in an ecological context.

Developmental stress selectively affects the song control nucleus HVC in the zebra finch brain

Songbirds sing complex songs as a result of evolution through sexual selection. The evolution of such sexually selected traits requires genetic control, as well as selection on their expression. Song is controlled by a discrete neural pathway in the brain, and song complexity has been shown to correlate with the volume of specific song control nuclei. As such, the development of these nuclei, in particular the high vocal centre (HVC), is thought to be the mechanism controlling signal expression indicating male quality. We tested the hypothesis that early developmental stress selectively affects adult HVC size, compared with other brain nuclei. We did this by raising cross–fostered zebra finches (Taeniopygia guttata) under stressed and controlled conditions and determining the effect on adult HVC size. Our results confirm the strong influence of environmental conditions, particularly on HVC development, and therefore on the expression of complex songs. The results also show that both environmental and genetic factors affect the development of several brain nuclei, highlighting the developmental plasticity of the songbird brain. In all, these results explain how the complex song repertoires of songbirds can evolve as honest indicators of male quality.

Developmental stress affects the attractiveness of male song and female choice in the zebra finch (Taeniopygia guttata)

Developmental stress has recently been shown to have adverse effects upon adult male song structure in birds, which may well act as an honest signal of male quality to discriminating females. However, it still remains to be shown if females can discriminate between the songs of stressed and non-stressed males. Here we use a novel experimental design using an active choice paradigm to investigate preferences in captive female zebra finches (Taeniopygia guttata). Nine females were exposed to ten pairs of songs by previously stressed and non-stressed birds that had learned their song from the same tutor. Song pairs differed significantly in terms of song complexity, with songs of stressed males exhibiting lower numbers of syllables and fewer different syllables in a phrase. Song rate and peak frequency did not differ between stressed and non-stressed males. Females showed a significant preference for non-stressed songs in terms of directed perching activity and time spent on perches. Our results therefore indicate that developmental stress affects not only the structure of male song, but that such structural differences are biologically relevant to female mate choice decisions.

How deinstitutionalisation and the current public mental health system affects individuals with schizophrenia : four case reports

The professional component of this thesis focuses on how deinstitutionalisation and the current public mental health system have affected individuals with schizophrenia. Chapter one discusses the process of deinstitutionalisation and the research that has examined the impact of this initiative. Chapter two concentrates on schizophrenia, specifically the symptoms, course, etiological theories and treatments of this illness. Four case studies are then provided in order to explore how deinstitutionalisation and the current mental health system have affected individuals with schizophrenia. The names and identifying characteristics of these clients and their families have been modified to ensure anonymity. Chapter three describes a 47 year old woman, AA, who was referred for a neuro-psychological assessment. Chapter four outlines the second case study, a 23 year old male, BB, who was referred for a psychological assessment regarding diagnosis and treatment recommendations. Chapter five describes the third case study, a 54 year old woman, CC, who was referred for therapy and consultation regarding future treatment recommendations. Chapter six discusses the fourth case study, a 21 year old male, DD, who was seen for crisis intervention and treated in the community. Each of these case studies outlines the background history, formulation and treatment approaches. These case reports are used to illustrate how deinstitutionalisation and the present public mental health system affect individuals with schizophrenia. Chapter seven provides an overall discussion and conclusion to these case studies.

Actual/ideal body images of high school girls and how it affects their self-esteem : implications for educational and clinical institutions

Given that adolescence is a critical period for the development of a positive self-concept and body image, it is imperative that educators have an understanding of adolescent students' body image and their dieting practises and behaviours. Negative body image is an issue that is rife within the adolescent student population in Australia and around the world, and is a factor that is commonly associated with and linked to disturbed eating behaviours and chronic eating disorders like Anorexia Nervosa (AN). Despite the intuitive appeal and importance of investigating adolescents' body image in terms of what adolescents would like to look like and what they think that they look like now, very little research has investigated these concepts. Furthermore, very little research has explored whether there is a difference between these two constructs how this may affect adolescents' self-esteem. This study therefore aimed to explore the actual and ideal body images of adolescent high school girls aged between 12 and 18 years in two samples of adolescents, one with eating disorders (n=76, clinical sample) and one without (n=823 high school sample). Additionally, this study investigates these constructs in relation to self-esteem levels. The results of this study have important implications for educators and clinicians within educational and clinical settings.