Prolactin, body condition and the cost of good parenting: an interyear study in a long-lived seabird, Gould's Petrel (Pterodroma leucoptera)

1. The pituitary hormone prolactin is thought to play an important role in the promotion of parental care in birds and mammals. The level of care parents provide is, however, likely to be influenced by additional factors, such as their physiological condition at the time of breeding.

2. We examined relationships between parental body condition, plasma prolactin levels and reproductive performance in Gould's Petrels (Pterodroma leucoptera), a long-lived seabird. We predicted that parental body condition would correlate positively with both prolactin level and parenting intensity, as measured by the quality of the chick they produced. We also examined the effects of parenting intensity on parental body condition and reproductive success in the subsequent breeding season.

3. Body condition of male parents positively correlated with prolactin levels at the start of their second protracted incubation bout. The body condition of both parents correlated positively with the body condition of their chick at its peak mass. However, producing a good-quality chick did not negatively affect parental body condition or reproductive success the following year.

4. These results suggest that prolactin reinforces parental behaviour in parents in good body condition, which facilitates production of good-quality chicks. Moreover, good-quality parents consistently produce good-quality chicks with no apparent trade-off to their physical condition.

A novel zebrafish jak2a V581F model shared features of human JAK2 V617F polycythemia vera

Objective : The Janus kinase 2 (JAK2) is important for embryonic primitive hematopoiesis. A gain-of-function JAK2 (JAK2^V617F) mutation in human is pathogenetically linked to polycythemia vera (PV). In this study, we generated a zebrafish ortholog of human JAK2^V617F (referred herewith jak2a^V581F) by site-directed mutagenesis and examined its relevance as a model of human PV.

Materials and Methods : Zebrafish embryos at one-cell stage were injected with jak2a^V581F mRNA (200pg/embryo). In some experiments, the embryos were treated with a specific JAK2 inhibitor, TG101209. The effects of jak2a stimulation on hematopoiesis, jak/stat signaling, and erythropoietin signaling were evaluated at 18-somites.

Results : Injection with jak2a^V581F mRNA significantly increased erythropoiesis, as enumerated by flow cytometry based on gfp+ population in dissociated Tg(gata1:gfp) embryos. The response was reduced by stat5.1 morpholino coinjection (control: 4.37% ± 0.08%; jak2a^V581F injected: 5.71% ± 0.07%, coinjecting jak2a^V581F mRNA and stat5.1 morpholino: 4.66% ± 0.13%; p < 0.01). jak2a^V581F mRNA also upregulated gata1 (1.83 ± 0.08 fold; p = 0.005), embryonic α-hemoglobin (1.61 ± 0.12 fold; p = 0.049), and β-hemoglobin gene expression (1.65 ± 0.13–fold; p = 0.026) and increased stat5 phosphorylation. These responses were also ameliorated by stat5.1 morpholino coinjection or treatment with a specific JAK2 inhibitor, TG101209. jak2a^V581F mRNA significantly reduced erythropoietin gene (0.24 ± 0.03 fold; p = 0.006) and protein expression (control: 0.633 ± 0.11; jak2a^V581F mRNA: 0.222 ± 0.07 mIU/mL; p = 0.019).

Conclusion : The zebrafish jak2a^V581F model shared many features with human PV and might provide us with mechanistic insights of this disease.

Not the "other" mother : how language constructs lesbian co-parenting relationships

This paper presents findings from recent Australian qualitative research with lesbian co-parents where study participants' fluid narrative identities are  deconstructed in order to better understand how language constructs relationships within private and public domains. Language used to define, describe and give meaning to roles and relationships of lesbian co-parents within social and kinship networks and wider community is explored. Through claiming language and telling their stories lesbian co-parents give meaning to their lives; affirm their identity; and present their relationships as visible and valid.

Programmer friendly and efficient distributed shared memory integrated into a distributed operating system

Distributed Shared Memory (DSM) provides programmers with a shared memory environment in systems where memory is not physically shared. Clusters of Workstations (COWs), an often untapped source of computing power, are characterised by a very low cost/performance ratio. The combination of Clusters of Workstations (COWs) with DSM provides an environment in which the programmer can use the well known approaches and methods of programming for physically shared memory systems and parallel processing can be carried out to make full use of the computing power and cost advantages of the COW. The aim of this research is to synthesise and develop a distributed shared memory system as an integral part of an operating system in order to provide application programmers with a convenient environment in which the development and execution of parallel applications can be done easily and efficiently, and which does this in a transparent manner. Furthermore, in order to satisfy our challenging design requirements we want to demonstrate that the operating system into which the DSM system is integrated should be a distributed operating system. In this thesis a study into the synthesis of a DSM system within a microkernel and client-server based distributed operating system which uses both strict and weak consistency models, with a write-invalidate and write-update based approach for consistency maintenance is reported. Furthermore a unique automatic initialisation system which allows the programmer to start the parallel execution of a group of processes with a single library call is reported. The number and location of these processes are determined by the operating system based on system load information. The DSM system proposed has a novel approach in that it provides programmers with a complete programming environment in which they are easily able to develop and run their code or indeed run existing shared memory code. A set of demanding DSM system design requirements are presented and the incentives for the placement of the DSM system with a distributed operating system and in particular in the memory management server have been reported. The new DSM system concentrated on an event-driven set of cooperating and distributed entities, and a detailed description of the events and reactions to these events that make up the operation of the DSM system is then presented. This is followed by a pseudocode form of the detailed design of the main modules and activities of the primitives used in the proposed DSM system. Quantitative results of performance tests and qualitative results showing the ease of programming and use of the RHODOS DSM system are reported. A study of five different application is given and the results of tests carried out on these applications together with a discussion of the results are given. A discussion of how RHODOS’ DSM allows programmers to write shared memory code in an easy to use and familiar environment and a comparative evaluation of RHODOS DSM with other DSM systems is presented. In particular, the ease of use and transparency of the DSM system have been demonstrated through the description of the ease with which a moderately inexperienced undergraduate programmer was able to convert, write and run applications for the testing of the DSM system. Furthermore, the description of the tests performed using physically shared memory shows that the latter is indistinguishable from distributed shared memory; this is further evidence that the DSM system is fully transparent. This study clearly demonstrates that the aim of the research has been achieved; it is possible to develop a programmer friendly and efficient DSM system fully integrated within a distributed operating system. It is clear from this research that client-server and microkernel based distributed operating system integrated DSM makes shared memory operations transparent and almost completely removes the involvement of the programmer beyond classical activities needed to deal with shared memory. The conclusion can be drawn that DSM, when implemented within a client-server and microkernel based distributed operating system, is one of the most encouraging approaches to parallel processing since it guarantees performance improvements with minimal programmer involvement.

Review essay : insiders, outsiders, and shared stories

The article reviews several books including "Being Australian: Narratives of National Identity," by Catriona Elder, "Australian Pastoral: The Making of a White Landscape," by Jeanette Hoorn, and "The Australians: Insiders and Outsiders on the National Character Since 1770," by John Hirst.

Applying socio-cultural lenses to childhood obesity prevention among African migrants to high-income western countries : the role of acculturation, parenting and family functioning

Migration from third-world and low-income countries to high-income Western countries presents significant challenges for individuals and families, and for health service providers in the receiving societies. Cultural conflicts related to preferred body size/shape and parenting practices, together with differential inter generational rates and styles of acculturation, can affect nutritional and lifestyle choices and be associated with high rates of childhood obesity. Using African cultures as an example, this paper examines these issues. It concludes that, in designing and implementating obesity prevention programmes, health service providers need to understand these factors and how they play out.

The role of evolution, bonding, and parenting style in understanding parental differences

This research demonstrates the influence of parental bonding and parental authority on the parent-child relationship and subsequent child development in both biological and step-families. Differential effects of parental behaviour on child attachment style development were found for biological children and stepchildren. The results provide guidance for intervention and future research.

Parenting, family functioning and lifestyle in a new culture : the case of African migrants in Melbourne, Victoria, Australia

This study documented the parenting styles among African migrants now living in Melbourne, Victoria, Australia, and assessed how intergenerational issues related to parenting in a new culture impact on family functioning and the modification of lifestyles. A total of 10 focus group discussions (five with parents and five with 13–17-year-old children; N = 85 participants) of 1.5–2 hours duration were conducted with Sudanese, Somali and Ethiopian migrant families. The analysis identified three discrete themes: (i) parenting-related issues; (ii) family functioning and family relations; and (iii) lifestyle changes and health. African migrant parents were restrictive in their parenting; controlled children's behaviours and social development through strict boundary-setting and close monitoring of interests, activities, and friends; and adopted a hierarchical approach to decision-making while discouraging autonomy among their offspring. Programmes seeking to improve the health and welfare of African migrants in their host countries need to accommodate the cultural and social dimensions that shape their lives. Such programmes may need to be so broad as to apply an acculturation lens to planning, and to assist young people, parents and families in addressing intergenerational issues related to raising children and growing up in a different social and cultural milieu.

Through the lens of hetero-normative assumptions : re-thinking attitudes towards gay parenting

In this study we explored the attitudes and beliefs of nine heterosexual adults towards gay male and female couples parenting children. We conceptualised participants' perceptions as one primary lens through which gay parenting is viewed. Based on the narratives provided, this lens comprised hetero-normative, homophobic or heterosexist assumptions and coloured the way in which participants perceived aspects of the concept of gay couples parenting children. At times, participants attempted to adjust their primary lens and adopt different views that initially suggested ambivalence and sometimes contradictory positions. Despite the range of attitudes and assumptions about same-sex parenting, consensus over the potential negative developmental impact on children raised by same-sex parents remained evident. Evidence suggests that same-sex parenting is already a reality in Westernised nations and has little or no bearing on the sexual orientation of children. However, concern that children be brought up with every opportunity to 'become' heterosexual, whether they are the product of same-sex or opposite-sex parents, remains evident.

Parenting styles, family structure and adolescent dietary behaviour

Objective To examine associations between parenting styles, family structure and aspects of adolescent dietary behaviour.

Design Cross-sectional study.

Setting Secondary schools in the East Midlands, UK.

Subjects Adolescents aged 12–16 years (n 328, 57 % boys) completed an FFQ assessing their consumption of fruit, vegetables, unhealthy snacks and breakfast. Adolescents provided information on parental and sibling status and completed a seventeen-item instrument measuring the general parenting style dimensions of involvement and strictness, from which four styles were derived: indulgent, neglectful, authoritarian, authoritative.

Results After controlling for adolescent gender and age, analysis of covariance revealed no significant interactions between parenting style and family structure variables for any of the dietary behaviours assessed. Significant main effects for family structure were observed only for breakfast consumption, with adolescents from dual-parent families (P < 0·01) and those with no brothers (P < 0·05) eating breakfast on more days per week than those from single-parent families and those with one or more brother, respectively. Significant main effects for parenting style were observed for all dietary behaviours apart from vegetable consumption. Adolescents who described their parents as authoritative ate more fruit per day, fewer unhealthy snacks per day, and ate breakfast on more days per week than those who described their parents as neglectful.

Conclusions The positive associations between authoritative parenting style and adolescent dietary behaviour transcend family structure. Future research should be food-specific and assess the efficacy of strategies promoting the central attributes of an authoritative parenting style on the dietary behaviours of adolescents from a variety of family structures.

Health professionals' and dietetics practitioners' perceived effectiveness of fruit and vegetable parenting practices across six countries

Fruit and vegetable intake may reduce the risk of some chronic diseases. However, many children consume less-than-recommended amounts of fruit and vegetables. Because health professionals and dietetics practitioners often work with parents to increase children's fruit and vegetable intake, assessing their opinions about the effectiveness of parenting practices is an important step in understanding how to promote fruit and vegetable intake among preschool-aged children. Using a cross-sectional design, collaborators from six countries distributed an Internet survey to health and nutrition organization members. A self-selected sample reported their perceptions of the effectiveness of 39 parenting practices intended to promote fruit and vegetable consumption in preschool-aged children from May 18, 2008, to September 16, 2008. A total of 889 participants (55% United States, 22.6% Mexico, 10.9% Australia, 4.4% Spain, 3.3% Chile, 2.2% United Kingdom, and 1.6% other countries) completed the survey. The fruit and vegetable intake–related parenting practices items were categorized into three dimensions (structure, responsiveness, and control) based on a parenting theory conceptual framework and dichotomized as effective/ineffective based on professional perceptions. The theoretically derived factor structures for effective and ineffective parenting practices were evaluated using separate confirmatory factor analyses and demonstrated acceptable fit. Fruit and vegetable intake–related parenting practices that provide external control were perceived as ineffective or counterproductive, whereas fruit and vegetable intake–related parenting practices that provided structure, nondirective control, and were responsive were perceived as effective in getting preschool-aged children to consume fruit and vegetables. Future research needs to develop and validate a parent-reported measure of these fruit and vegetable intake–related parenting practices and to empirically evaluate the effect of parental use of the parenting practices on child fruit and vegetable consumption.

Parenting, family functioning and lifestyle in a new culture : the case of African migrants in Melbourne, Victoria, Australia

This study documented the parenting styles among African migrants now living in Melbourne, Victoria, Australia, and assessed how intergenerational issues related to parenting in a new culture impact on family functioning and the modification of lifestyles. A total of 10 focus group discussions (five with parents and five with 13–17-year-old children; N = 85 participants) of 1.5–2 hours duration were conducted with Sudanese, Somali and Ethiopian migrant families. The analysis identified three discrete themes: (i) parenting-related issues; (ii) family functioning and family relations; and (iii) lifestyle changes and health. African migrant parents were restrictive in their parenting; controlled children's behaviours and social development through strict boundary-setting and close monitoring of interests, activities, and friends; and adopted a hierarchical approach to decision-making while discouraging autonomy among their offspring. Programmes seeking to improve the health and welfare of African migrants in their host countries need to accommodate the cultural and social dimensions that shape their lives. Such programmes may need to be so broad as to apply an acculturation lens to planning, and to assist young people, parents and families in addressing intergenerational issues related to raising children and growing up in a different social and cultural milieu.