DNA repair deficiencies increase the resistance of Arabidopsis Thaliana to Hyaloperonospora Parasitica

We have found that UV-C treatment of Arabidopsis thaliana induces resistance to the biotrophic pathogen Hyaloperonospora parasitica, and our data suggest UV induced DNA photoproducts are involved (see accompanying abstract by K.G. McKenzie et al.). To address the potential role of DNA damage, we have examined the effect of mutations in nucleotide excision repair (uvr1-1), photoreactivation of cyclobutane pyrimidine dimers (uvr2-1) or flavonoid production (tt5) on the resistance of Arabidopsis to the pathogen with or without pre-inoculation treatment with UV-C. In the mutant backgrounds, UV-C induced pathogen resistance (as measured by decreased conidiophore formation) to the same degree as in the wildtype plants, but much lower UV doses were required (e.g., 100 Jm-2 in the mutant vs. 400 Jm-2 in the wildtype). This is the result expected if damage to DNA rather than a non DNA target is involved. Interestingly, in the absence of UV-C, the tt5 mutation alone resulted in a slight increase in resistance. However, when coupled with uvr1-1, resistance was enhanced to an even greater extent. Remarkably, the tt5 uvr1-1 uvr2-1 triple mutant was completely resistant to the pathogen. Since tt5 mutants are sensitive to reactive oxygen species, which can cause DNA damage susceptible to nucleotide excision repair, our results suggest that in addition to UV photoproducts, an accumulation of endogenous oxidative DNA damage may also trigger resistance to the pathogen. We are currently examining pathogen resistance in other DNA repair deficient mutants, and quantifying UV-C-induced DNA damage in Arabidopsis in order to assess the relationship between damage levels and the extent of resistance.

Human sarcopenia reveals an increase in SOCS-3 and myostatin and a reduced efficiency of Akt phosphorylation

Age-related skeletal muscle sarcopenia is linked with increases in falls, fractures, and death and therefore has important socioeconomic consequences. The molecular mechanisms controlling age-related muscle loss in humans are not well understood, but are likely to involve multiple signaling pathways. This study investigated the regulation of several genes and proteins involved in the activation of key signaling pathways promoting muscle hypertrophy, including GH/STAT5, IGF-1/Akt/GSK-3β/4E-BP1, and muscle atrophy, including TNFα/SOCS-3 and Akt/FKHR/atrogene, in muscle biopsies from 13 young (20 ± 0.2 years) and 16 older (70 ± 0.3 years) males. In the older males compared to the young subjects, muscle fiber cross-sectional area was reduced by 40–45% in the type II muscle fibers. TNFα and SOCS-3 were increased by 2.8 and 1.5 fold, respectively. Growth hormone receptor protein (GHR) and IGF-1 mRNA were decreased by 45%. Total Akt, but not phosphorylated Akt, was increased by 2.5 fold, which corresponded to a 30% reduction in the efficiency of Akt phosphorylation in the older subjects. Phosphorylated and total GSK-3β were increased by 1.5 and 1.8 fold, respectively, while 4E-BP1 levels were not changed. Nuclear FKHR and FKHRL1 were decreased by 73 and 50%, respectively, with no changes in their atrophy target genes, atrogin-1 and MuRF1. Myostatin mRNA and protein levels were significantly elevated by 2 and 1.4 fold. Human sarcopenia may be linked to a reduction in the activity or sensitivity of anabolic signaling proteins such as GHR, IGF-1, and Akt. TNFα, SOCS-3, and myostatin are potential candidates influencing this anabolic perturbation.

No limits : exploring the psychology of unsolicited credit card limit increase offers

The issue of credit card debt has become an increasing concern in recent years. In Australia, for example, there is currently $42.5 billion worth of outstanding debt on credit cards, with $30 billion (over 70 per cent) bearing interest. Further, in 2001, Visa reported that 32 per cent of consumers had not paid their card off in the previous 12 months, which suggests that interest-bearing debt in Australia is held by approximately only 113 of credit card borrowers. An important element of credit card marketing is the use of psychological manipulations to encourage consumers to take-up credit. In this article, we examine the use of language and imagery in unsolicited credit card limit increase offers, and how these might influence consumers' decisions to increase their credit card limit. The analysis found that the use of terms that focused on the benefits of credit card use, such as "choice", "freedom", and "peace of mind" were used consistently to convince consumers to increase their credit card limit, whereas the use the of terms that could be considered more pragmatic and with direct reference to the nature of the product, such as "debt", "repayment" and "loan", were rarely used. Similarly, the use of colour, text changes, and images, were used which may have an influence over a consumer's ability to rationally consider whether the increase is appropriate for them. The paper concludes by recommending that government and representative bodies need to take into account the psychological manipulations used by credit card providers when developing consumer policy and codes of ethics.

Pollutants increase song complexity and the volume of the brain area HVC in a songbird

Environmental pollutants which alter endocrine function are now known to decrease vertebrate reproductive success. There is considerable evidence for endocrine disruption from aquatic ecosystems, but knowledge is lacking with regard to the interface between terrestrial and aquatic ecosystems. Here, we show for the first time that birds foraging on invertebrates contaminated with environmental pollutants, show marked changes in both brain and behaviour. We found that male European starlings (Sturnus vulgaris) exposed to environmentally relevant levels of synthetic and natural estrogen mimics developed longer and more complex songs compared to control males, a sexually selected trait important in attracting females for reproduction. Moreover, females preferred the song of males which had higher pollutant exposure, despite the fact that experimentally dosed males showed reduced immune function. We also show that the key brain area controlling male song complexity (HVC) is significantly enlarged in the contaminated birds. This is the first evidence that environmental pollutants not only affect, but paradoxically enhance a signal of male quality such as song. Our data suggest that female starlings would bias their choice towards exposed males, with possible consequences at the population level. As the starling is a migratory species, our results suggest that transglobal effects of pollutants on terrestrial vertebrate physiology and reproduction could occur in birds.

Obesity and pronated foot type may increase the risk of chronic plantar heel pain : a matched case-control study

Background : Chronic plantar heel pain (CPHP) is one of the most common musculoskeletal disorders of the foot, yet its aetiology is poorly understood. The purpose of this study was to examine the association between CPHP and a number of commonly hypothesised causative factors.

Methods : Eighty participants with CPHP (33 males, 47 females, mean age 52.3 years, S.D. 11.7) were matched by age (± 2 years) and sex to 80 control participants (33 males, 47 females, mean age 51.9 years, S.D. 11.8). The two groups were then compared on body mass index (BMI), foot posture as measured by the Foot Posture Index (FPI), ankle dorsiflexion range of motion (ROM) as measured by the Dorsiflexion Lunge Test, occupational lower limb stress using the Occupational Rating Scale and calf endurance using the Standing Heel Rise Test.

Results : Univariate analysis demonstrated that the CPHP group had significantly greater BMI (29.8 ± 5.4 kg/m2 vs. 27.5 ± 4.9 kg/m2; P < 0.01), a more pronated foot posture (FPI score 2.4 ± 3.3 vs. 1.1 ± 2.3; P < 0.01) and greater ankle dorsiflexion ROM (45.1 ± 7.1° vs. 40.5 ± 6.6°; P < 0.01) than the control group. No difference was identified between the groups for calf endurance or time spent sitting, standing, walking on uneven ground, squatting, climbing or lifting. Multivariate logistic regression revealed that those with CPHP were more likely to be obese (BMI ≥ 30 kg/m2) (OR 2.9, 95% CI 1.4 – 6.1, P < 0.01) and to have a pronated foot posture (FPI ≥ 4) (OR 3.7, 95% CI 1.6 – 8.7, P < 0.01).

Conclusion : Obesity and pronated foot posture are associated with CPHP and may be risk factors for the development of the condition. Decreased ankle dorsiflexion, calf endurance and occupational lower limb stress may not play a role in CPHP.

What's needed to increase research capacity in rural primary health care

The aim of this study is to identify ways to build research capacity within primary health. A consultation was undertaken in late 2004 using a combination of a one-page survey and a guided meeting format, in a primary health setting in rural NSW. Most (81.3%) of the 134 individuals consulted were part of an Area Health Service, with 12.7% from non-government settings. Most (80.6%) were clinicians, with a third (31.5%) nurses, 8.3% in medicine, and the remainder from a range of allied health professions. Eleven organisations were represented. The main  outcome measures were identification of support needs, processes to enhance research engagement, and barriers and enablers to clinicians’ research  involvement. The results showed that popular delivery modes for research training and support were courses and “one-to- one” advice. Writing topics were generally more popular than others. Common barriers were time and technology issues. A key enabler was a discipline-specific focus. This is one of few rural Australian  consultations on research needs in primary health conducted with a diverse  range of clinicians at the clinician level. It will direct future research capacity  building efforts towards maximising face-to-face discipline specific options and  minimising technology use.

Measuring the success of intervention programmes designed to increase the participation rate by women in computing

Many intervention programmes to encourage greater female participation in computer education and careers have been conducted in the last twenty years. These intervention programmes take considerable time, effort and money to design and implement. If success were to be measured by an increase in the percentage of female students undertaking computing courses then these programmes would have to be considered a failure. This paper describes a research project which examined fourteen intervention programmes in detail. From the perspective of the programme champions each of the intervention programmes was considered successful, even when this success was restricted to specific areas or limited to small groups of individuals. Formal evaluation appeared to have been an afterthought rather than a priority of many of the programme champions. Some programmes appeared to be less effective due to the lack of targeted and clear goals or predetermined evaluation criteria. It is recommended that during the initial planning phase for intervention programmes a clear objective is to consider what a successful programme would look like and what the evaluation criteria would be. Further work is needed to understand how intervention programmes can be better designed and evaluated so that their impact and success can be expanded.

a7-Nicotinic acetylcholine receptors mediate an A71-42-induced increase in the level of acetylcholinesterase in primary cortical neurones

The β-amyloid protein (Aβ) is the major protein component of amyloid plaques found in the Alzheimer brain. Although there is a loss of acetylcholinesterase (AChE) from both cholinergic and non-cholinergic neurones in the brain of Alzheimer patients, the level of AChE is increased around amyloid plaques. Previous studies using P19 cells in culture and transgenic mice which overexpress human Aβ have suggested that this increase may be due to a direct action of Aβ on AChE expression in cells adjacent to amyloid plaques. The aim of the present study was to examine the mechanism by which Aβ increases levels of AChE in primary cortical neurones. Aβ₁₋₄₂ was more potent than Aβ₁₋₄₀ in its ability to increase AChE in primary cortical neurones. The increase in AChE was unrelated to the toxic effects of the Aβ peptides. The effect of Aβ₁₋₄₂ on AChE was blocked by inhibitors of α7 nicotinic acetylcholine receptors (α7 nAChRs) as well as by inhibitors of L- or N-type voltage-dependent calcium channels (VDCCs), whereas agonists of α7 nAChRs (choline, nicotine) increased the level of AChE. The results demonstrate that the effect of Aβ₁₋₄₂ on AChE is due to an agonist effect of Aβ₁₋₄₂ on the α7 nAChR.

The plan to increase Fiji's rice production - is it worthwhile?

In a recent initiative, the Fiji government has established a revitalisation program for the rice industry, with assistance expected from the Republic of China, India and Indonesia. Using the computable general equilibrium model of the Fijian economy, the economy-wide impact of a 40 per cent increase in rice production is simulated. This analysis finds that even such a large increase in production would have an insignificant impact on Fiji's economic growth.

Risk of prostate cancer associated with a family history in an era of rapid increase in prostate cancer diagnosis (Australia)

OBJECTIVE: We conducted a case-control study of prostate cancer and familial risk of the disease in Australia between 1994 and 1998, a period during which the incidence of prostate cancer increased dramatically with widespread use of prostate-specific antigen (PSA) testing. METHODS: 1475 cases and 1405 controls were asked about prostate cancer in their first-degree relatives. Odds ratios (OR) were calculated using logistic regression. RESULTS: Cases were more likely to report a family history of prostate cancer than controls (OR 3.0; 95% confidence interval (CI) 2.3-3.9) and cases reporting an affected relative were younger (58.8 versus 60.9 years, p < 0.0001). The OR for an affected first-degree relative increased with increasing number of affected relatives and decreased with increasing age of the case. The OR for more than one affected first-degree relative was 6.9 (95% CI 2.7-18). The OR for an affected brother was 3.9 (95% CI 2.5-6.1) and for an affected father was 2.9 (95% CI 2.1-3.9) but these were not significantly different (p = 0.2). When analyses were repeated including only diagnoses made in relatives prior to 1992, the risks were generally similar except that the OR for an affected brother decreased to 3.1 (95% CI 1.2-3.9). When only relatives' diagnoses made after 1991 were included results were again similar to those for all relatives, although the effect for brothers was greater and the attenuation with age at diagnosis dissipated. CONCLUSIONS: The recent introduction of PSA testing that has resulted in a greater prevalence of apparent prostate cancer, does not appear to have substantially altered familial risks of disease, although effects associated with brothers may be inflated.