Copper-dependent iron assimilation pathway in the model photosynthetic eukaryote chlamydomonas reinhardtii

The unicellular green alga Chlamydomonas reinhardtii is a valuable model for studying metal metabolism in a photosynthetic background. A search of the Chlamydomonas expressed sequence tag database led to the identification of several components that form a copper-dependent iron assimilation pathway related to the high-affinity iron uptake pathway defined originally for Saccharomyces cerevisiae. They include a multicopper ferroxidase (encoded by Fox1), an iron permease (encoded by Ftr1), a copper chaperone (encoded by Atx1), and a copper-transporting ATPase. A cDNA, Fer1, encoding ferritin for iron storage also was identified. Expression analysis demonstrated that Fox1 and Ftr1 were coordinately induced by iron deficiency, as were Atx1 and Fer1, although to lesser extents. In addition, Fox1 abundance was regulated at the posttranscriptional level by copper availability. Each component exhibited sequence relationship with its yeast, mammalian, or plant counterparts to various degrees; Atx1 of C. reinhardtii is also functionally related with respect to copper chaperone and antioxidant activities. Fox1 is most highly related to the mammalian homologues hephaestin and ceruloplasmin; its occurrence and pattern of expression in Chlamydomonas indicate, for the first time, a role for copper in iron assimilation in a photosynthetic species. Nevertheless, growth of C. reinhardtii under copper- and iron-limiting conditions showed that, unlike the situation in yeast and mammals, where copper deficiency results in a secondary iron deficiency, copper-deficient Chlamydomonas cells do not exhibit symptoms of iron deficiency. We propose the existence of a copper-independent iron assimilation pathway in this organism.

Using an IDMI methodology to make multi-criteria decisions

Multi-criteria decisions usually require measurement or evaluation of performance in different units and their mix by application of weighting factors. This approach leads to potential manipulation of the results as a direct consequence of the applied weightings. In this paper a mechanism has been proposed to overcome this problem. It is known as the : Interlink Decision Making Index (IDMI) and has all the desired features: simple, interlink (all criteria) and automatically and quantified influence of critical criteria (i.e. no human weighting needed). The IDMI is capable of reflecting the total merits of a particular option once the normal decision making criteria and (up to two) critical criteria (CC) have been chosen. Then, without arbitrarily weighting criteria, comparison and selection of the best possible option can be made. Simple software has been developed to do this numerical transfer and graphic presentation. Two hypothetical examples are presented in the paper to demonstrate the application of the IDMI concept and its advantages over the traditional "tabular and weighting method" in the decision making process.

Public transport and pedestrian access, the impact of suburban planning on adolescence

The following paper discusses the impact of suburban life for adolescents in relation to public transport and pedestrian access. The research compares the morphology and level of connectivity of two planning models, cul-de-sac and regular grid, with respect to two suburbs which share a similar socio-economic profile, Rowville and Caulfield. These are subsequently evaluated in terms of ABS statistics, in particular year 12 or equivalent levels of education, and transport statistics. The results of the investigation are discussed in reference to the four key tasks of adolescence (Carr-Greg & Shale 2002)', in order to establish the degree to which morphology and access levels of suburbs impact on adolescent development.

The importance of human FcyRI in mediating protection to malaria

The success of passive immunization suggests that antibody-based therapies will be effective at controlling malaria. We describe the development of fully human antibodies specific for Plasmodium falciparum by antibody repertoire cloning from phage display libraries generated from immune Gambian adults. Although these novel reagents bind with strong affinity to malaria parasites, it remains unclear if in vitro assays are predictive of functional immunity in humans, due to the lack of suitable animal models permissive for P. falciparum. A potentially useful solution described herein allows the antimalarial efficacy of human antibodies to be determined using rodent malaria parasites transgenic for P. falciparum antigens in mice also transgenic for human Fc-receptors. These human IgG1s cured animals of an otherwise lethal malaria infection, and protection was crucially dependent on human FcγRI. This important finding documents the capacity of FcγRI to mediate potent antimalaria immunity and supports the development of FcγRI-directed therapy for human malaria.

Distributions of caregiving tasks among family members: the place of gender and availability.

To extend family-oriented approaches to caregiving, participants in 2 studies were asked to distribute tasks among a set of adult children, first with information only about gender and then with systematically varied information about commitments to paid work, marriage, and/or parenting. Making the distributions, using a computer-based program, were 2 groups of older adults (ages 60 to 90 years). In Study 1, gender composition was kept constant (2 sons and 2 daughters). In Study 2, it was varied. The results showed several ways in which people combine attention to gender and to availability. The results also pointed to the need to consider both the number and type of tasks allocated. The results are discussed in terms of implications for the way caregiving is regarded, the development of multiple-factor models for variations among family members, and the possible replications and extensions to other circumstances and populations.

Extending studies of collaborative cognition by way of care giving situations

Care giving situations contain several features that offer opportunities for expanding the way that collaborative cognition is conceptualised and explored. These features are the presence of several possible contributors, more than one kind of change in participation, distinctions drawn among parts of a task, and differences in understanding based on interests. All represent departures from the traditional focus on dyads, tasks that emphasise one kind of change only, single problems, and differences in competence or expertise. All are also features likely to be found in everyday problem solving. Study 1 focuses on family contributions, based on reports by care givers about their current situation and their preferences for the involvement of other family members. Study 2 presents a standard family scenario and focuses on the views held by care givers, older adults, and community nurses about the reasonableness of various changes in participation. Results are discussed in terms of the ways situations such as care giving can help build a richer picture of collaborative cognition, one that is applicable to a variety of tasks and to all parts of the life span.

Frequency, severity and effect of life of physical symptoms experienced during pregnancy

This study aimed to: 1) describe the number, frequency, severity of discomfort and effect of symptoms on life of 29 physical symptoms women experienced at 15 to 25 weeks of gestation; 2) explore whether experiencing this group of physical symptoms more frequently and intensely was associated with a higher score of depressive symptoms and lower self-esteem; (3) examine whether discomfort and effect ratings aided prediction of well being over and above symptom frequency; and (4) investigate which individual physical symptoms contributed most to predicting depressive symptoms and self-esteem. Pregnant women (n = 215) completed the Beck Depression Inventory, Rosenberg Self-Esteem Scale, and a physical symptoms questionnaire. Frequency, discomfort, and the effect of physical symptoms all consistently correlated with higher scores for depressive symptoms, but less consistently with lower self-esteem. Discomfort and the effect of symptoms predicted variance in depressive symptoms after accounting for symptom frequency. Higher frequency, more discomfort, and the effect of fatigue and effect of flatulence were related to depressive symptoms. Relationships between pregnancy-related physical symptoms, depressive symptoms, and low self-esteem suggest that when women report any of these constellation of factors, further screening is indicated. A comprehensive assessment of physical symptoms includes frequency, discomfort, and effect on life.

My baby body : a qualitative insight into women's body-related experiences and mood during pregnancy and the postpartum

An inductive qualitative approach was employed to explore women's experiences of their body and mood during pregnancy and the postpartum. In-depth interviews were conducted with 20 perinatal women (n at late pregnancy=10; n in the early postpartum period=10). While most of the sample reported adapting positively to body changes experienced during pregnancy, the postpartum period was often associated with body dissatisfaction. Women reported several events unique to pregnancy which helped them cope positively with bodily changes (e.g. increased perceived body functionality, new sense of meaning in life thus placing well-being of developing foetus above body aesthetics, perceptual experiences such as feeling baby kick, increased sense of social connectedness due to pregnancy body shape, and positive social commentary); however, these events no longer protected against body dissatisfaction post-birth. While women reported mood lability throughout the perinatal period, the postpartum was also a time of increased positive affect for most women, and overall most women did not associate body changes with their mood. Clinical implications of these findings included the need for education about normal postpartum body changes and their timing, and the development of more accurate measures of perinatal body image.