Breastfeeding mothers consume more vegetables and a greater variety of fruits and vegetables than non-breastfeeding peers : the influence of socioeconomic position

Aim:  This study compared the diets of breastfeeding and non-breastfeeding mothers from socioeconomically diverse regions of Melbourne to determine whether breastfeeding is a marker for healthier maternal dietary intakes.

Methods:  This cross-sectional study obtained information via self-reported questionnaire from 529 first-time Melbourne mothers. Breastfeeding status was determined when the children were 3.9 months. Diet information was obtained using a validated Food Frequency Questionnaire. Maternal diet was assessed by seven indicators: average daily intake of fruit, vegetables, non-core drinks, non-core sweet snacks, non-core savoury snacks, variety of fruit and variety of vegetables eaten in the preceding 12 months. Associations between breastfeeding status and each dietary variable were assessed using linear regression analyses. Socioeconomic position, maternal body mass index and the cluster-based sampling design were controlled for.

Results:  Of the 529 subjects, 70% were breastfeeding their child. Compared with non-breastfeeding mothers, breastfeeding mothers were found to consume more serves of vegetables (P= 0.001), a greater variety of fruit and vegetables (P= 0.001 and P≤ 0.001 respectively), and sweet snacks were consumed more frequently (P= 0.006). Differences were observed between low and high socioeconomic position mothers for fruit serves (P= 0.003), vegetable serves (P= 0.010) and fruit variety (P= 0.006). These associations persisted after controlling for socioeconomic position and maternal body mass index.

Conclusions:  The association between infant feeding (breastfeeding) and some aspects of maternal diet provides further evidence suggesting a link between maternal and child diets from a younger age than previously examined.

Role of position 627 of PB2 and the multibasic cleavage site of the hemagglutinin in the virulence of H5N1 avian influenza virus in chickens and ducks

Highly pathogenic H5N1 avian influenza viruses have caused major disease outbreaks in domestic and free-living birds with transmission to humans resulting in 59% mortality amongst 564 cases. The mutation of the amino acid at position 627 of the viral polymerase basic-2 protein (PB2) from glutamic acid (E) in avian isolates to lysine (K) in human isolates is frequently found, but it is not known if this change affects the fitness and pathogenicity of the virus in birds. We show here that horizontal transmission of A/Vietnam/1203/2004 H5N1 (VN/1203) virus in chickens and ducks was not affected by the change of K to E at PB2-627. All chickens died between 21 to 48 hours post infection (pi), while 70% of the ducks survived infection. Virus replication was detected in chickens within 12 hours pi and reached peak titers in spleen, lung and brain between 18 to 24 hours for both viruses. Viral antigen in chickens was predominantly in the endothelium, while in ducks it was present in multiple cell types, including neurons, myocardium, skeletal muscle and connective tissues. Virus replicated to a high titer in chicken thrombocytes and caused upregulation of TLR3 and several cell adhesion molecules, which may explain the rapid virus dissemination and location of viral antigen in endothelium. Virus replication in ducks reached peak values between 2 and 4 days pi in spleen, lung and brain tissues and in contrast to infection in chickens, thrombocytes were not involved. In addition, infection of chickens with low pathogenic VN/1203 caused neuropathology, with E at position PB2-627 causing significantly higher infection rates than K, indicating that it enhances virulence in chickens.

Alteration of the proline at position 7 of the HIV-1 spacer peptide p1 suppresses viral infectivity in a strain dependent manner

The HIV-1 spacer peptide p1 is located in the C-terminus of the Gag polyprotein and separates the nucleocapsid (NC) and p6(Gag). Research centered on p1 has been limited and as yet no function has been ascribed to this spacer peptide. We have previously found that the conserved p1 proline residues (position 7 and 13) are critical for replication in the HIV-1 strain HXB2-BH10. In this study we have focused on the proline rich p1-p6(Gag) C-terminus of HIV-1. We individually examined the role of p1 proline's in multiple strains of HIV-1 and investigated the role of three proline residues in p6(Gag) (P24, P25 and P30). Assessment of the HXB2-BH10 based mutants revealed that Gag-Pol incorporation relative to Gag decreased in the p1 mutant virions, with the double proline mutant the most impaired. Mutating both p1 proline residues was found to abolish infectivity in multiple strains of HIV-1. Independent mutation of the p1 proline at position 7 resulted in a strain-dependent suppression of viral infectivity. This defect correlates with the presence of a tyrosine residue at position 9 of p1 and occurs in the early phase of the HIV-1 replication cycle. The p1 proline residues were found to be functionally distinct from P24, P25 and P30 in p6(Gag). This work affords novel insights into our understanding of the role of p1 in HIV-1 replication.

Neighborhood disadvantage, individual-level socioeconomic position, and self-reported chronic arthritis : a cross-sectional multilevel study

Objective To examine the association between individual- and neighborhood-level disadvantage and self-reported arthritis.

Methods We used data from a population-based cross-sectional study conducted in 2007 among 10,757 men and women ages 40–65 years, selected from 200 neighborhoods in Brisbane, Queensland, Australia using a stratified 2-stage cluster design. Data were collected using a mail survey (68.5% response). Neighborhood disadvantage was measured using a census-based composite index, and individual disadvantage was measured using self-reported education, household income, and occupation. Arthritis was indicated by self-report. Data were analyzed using multilevel modeling.

Results The overall rate of self-reported arthritis was 23% (95% confidence interval [95% CI] 22–24). After adjustment for sociodemographic factors, arthritis prevalence was greatest for women (odds ratio [OR] 1.5, 95% CI 1.4–1.7) and in those ages 60–65 years (OR 4.4, 95% CI 3.7–5.2), those with a diploma/associate diploma (OR 1.3, 95% CI 1.1–1.6), those who were permanently unable to work (OR 4.0, 95% CI 3.1–5.3), and those with a household income <$25,999 (OR 2.1, 95% CI 1.7–2.6). Independent of individual-level factors, residents of the most disadvantaged neighborhoods were 42% (OR 1.4, 95% CI 1.2–1.7) more likely than those in the least disadvantaged neighborhoods to self-report arthritis. Cross-level interactions between neighborhood disadvantage and education, occupation, and household income were not significant.

Conclusion Arthritis prevalence is greater in more socially disadvantaged neighborhoods. These are the first multilevel data to examine the relationship between individual- and neighborhood-level disadvantage upon arthritis and have important implications for policy, health promotion, and other intervention strategies designed to reduce the rates of arthritis, indicating that intervention efforts may need to focus on both people and places.

Locating frames of reference for information systems : a position paper

Frame analysis has been applied in Information Systems (IS) research to generate understanding of such issues as organisational change and IS implementation. Frames are the unconscious interpretive schemas that people, or groups of people, use to interpret their surroundings, determine what is important, and guide their actions. While framing has been used as a theoretical lens in IS research into organisations, there has been no analysis to date of how frames may play a role in the IS field itself. This paper argues that is relevant and insightful to examine the IS discourse from a framing perspective. In order to demonstrate the potential value of such an approach, a subset of a collection of articles from six journals in the senior scholars’ basket of journals was analysed in an exploratory attempt to locate the frames of reference that predominate in the IS discourse. Three levels of framing were identified and a provisional schema is proposed. We suggest that further investigation of the schema, the frames and their application will provide opportunity for critical reflection on the nature of Information Systems as an academic discipline. Such critical self-examination may even foster purposive frame breaking, in support of recent calls for transformation in the IS field.

Controlled synthesis of TiO2 hierarchical nanofibre structures via electrospinning and solvothermal processes : photocatalytic activity for degradation of methylene blue

The present article describes a new titanium oxide‐based (TiO2) photocatalyst that shows promise for acceleration of dye degradation. A hierarchical TiO2 nanostructure comprising nanorods on‐nanofibres has been prepared using a sol–gel route and electrospinning. Calcination of electrospun nanobre mats was performed in air at 500 °C. The TiO2 nanofibre surface was then exploited as a ‘seeding ground’ to grow TiO2 nanorods by a solvothermal process in NaOH. The nanofibres had a diameter of approximately 100 nm while the nanorods were evenly distributed on the nanofibre surface with a mean diameter of around 50–80 nm. The hierarchical nanostructure showed enhanced photocatalytic activity when compared to pure TiO2 nanofibres. This improved efficiency in degrading methylene blue through the photocatalytic process was attributed to the larger specific surface area of the TiO2 nanostructures, as well as high surface‐to‐volume ratio and higher reactive surface resulting in enhanced surface adsorption and interfacial redox reaction.

DSP-based sliding-mode control for electromagnetic-levitation precise position system

This paper investigates the robust tracking control problem for a bipolar electromagnetic-levitation precise-position system. The dynamic model of the precise-position device is derived by conducting a thorough analysis on the nonlinear electromagnetic forces. Conventional sliding-mode control and terminal sliding-mode control strategies are developed to guarantee asymptotic and finite-time tracking capabilities of the closed-loop system. A lumped uncertainty estimator is proposed to estimate the system uncertainties. The estimated information is then used to construct a smooth uniformly ultimately bounded sliding-mode control. An exact estimator is also proposed to exactly estimate the unknown uncertainties in finite time. The output of the exact estimator is used to design a continuous chattering free terminal sliding-mode control. The time taken for the closed-loop system to reach zero tracking error is proven to be finite. Experiment results are presented, using a real time digital-signal-processor (DSP) based electromagnetic-levitation system to validate the analysis.

Hierarchical workflow management in wireless sensor network

To build the service-oriented applications in a wireless sensor network (WSN), the workflow can be utilized to compose a set of atomic services and execute the corresponding pre-designed processes. In general, WSN applications rely closely on the sensor data which are usually inaccurate or even incomplete in the resource-constrained WSN. Then, the erroneous sensor data will affect the execution of atomic services and furthermore the workflows, which form an important part in the bottom-to-up dynamics of WSN applications. In order to alleviate this issue, it is necessary to manage the workflow hierarchically. However, the hierarchical workflow management remains an open and challenging problem. In this paper, by adopting the Bloom filter as an effective connection between the sensor node layer and the upper application layer, a hierarchical workflow management approach is proposed to ensure the QoS of workflow-based WSN application . The case study and experimental evaluations demonstrate the capability of the proposed approach.