Mitochondrial genome acquisition restores respiratory function and tumorigenic potential of cancer cells without mitochondrial DNA

We report that tumor cells devoid of their mitochondrial genome (mtDNA) show delayed tumor growth and that tumor formation is associated with acquisition of mtDNA from host cells. This leads to partial recovery of mitochondrial function in cells derived from primary tumors grown from cells without mtDNA and a shorter lag in tumor growth. Cell lines from circulating tumor cells showed further recovery of mitochondrial respiration and an intermediate lag to tumor growth, while cells from lung metastases exhibited full restoration of respiratory function and no lag in tumor growth. Stepwise assembly of mitochondrial respiratory supercomplexes was correlated with acquisition of respiratory function. Our findings indicate horizontal transfer of mtDNA from host cells in the tumor microenvironment to tumor cells with compromised respiratory function to re-establish respiration and tumor-initiating efficacy. These results suggest a novel pathophysiological process for overcoming mtDNA damage and support the notion of high plasticity of malignant cells.

The respiratory health of urban Indigenous children aged less than 5 years: Study protocol for a prospective cohort study

Background Despite the burden of acute respiratory illnesses (ARI) among Aboriginal and Torres Strait Islander children being a substantial cause of childhood morbidity and associated costs to families, communities and the health system, data on disease burden in urban children are lacking. Consequently evidence-based decision-making, data management guidelines, health resourcing for primary health care services and prevention strategies are lacking. This study aims to comprehensively describe the epidemiology, impact and outcomes of ARI in urban Aboriginal and Torres Strait Islander children (hereafter referred to as Indigenous) in the greater Brisbane area. Methods/design A prospective cohort study of Indigenous children aged less than five years registered with a primary health care service in Northern Brisbane, Queensland, Australia. Children are recruited at time of presentation to the service for any reason. Demographic, epidemiological, risk factor, microbiological, economic and clinical data are collected at enrolment. Enrolled children are followed for 12 months during which time ARI events, changes in child characteristics over time and monthly nasal swabs are collected. Children who develop an ARI with cough as a symptom during the study period are more intensely followed-up for 28(±3) days including weekly nasal swabs and parent completed cough diary cards. Children with persistent cough at day 28 post-ARI are reviewed by a paediatrician. Discussion Our study will be one of the first to comprehensively evaluate the natural history, epidemiology, aetiology, economic impact and outcomes of ARIs in this population. The results will inform studies for the development of evidence-based guidelines to improve the early detection, prevention and management of chronic cough and setting of priorities in children during and after ARI.

Broadening the perspective on the airborne transmission of respiratory infection

Airborne bioaerosols are becoming increasingly recognized as a potential route of transmission for the spread of bacterial and viral respiratory tract infections.

Medically-attended respiratory illnesses amongst pregnant women in Brisbane, Australia

There are limited community-based data on the burden of influenza and influenza-like illnesses during pregnancy to inform disease surveillance and control. We aimed to determine the incidence of medically-attended respiratory illnesses (MARI) in pregnant women and the proportion of women who are tested for respiratory pathogens at these visits. We conducted a nested retrospective cohort study of a non-random sample of women aged ≥18 years who had a live birth in maternity units in Brisbane, Queensland, from March 2012 to October 2014. The primary outcomes were self-reported doctor visits for MARI and laboratory investigations for respiratory pathogens. Descriptive analyses were performed. Among 1202 participants, 222 (18.5%, 95%CI 16.3%-20.7%) self-reported MARI during their pregnancy. Of those with an MARI, 20.3% (45/222) self-reported a laboratory test was performed. We were able to confirm with health service providers that 46.7% (21/45) of tests were undertaken, responses from providers were not received for the remainder. Whilst one in five women in this population reported a MARI in pregnancy, only 3.7% (45/1202) reported a clinical specimen had been arranged at the consultation and the ability to validate that self-report was problematic. As the focus on maternal immunisation increases, ascertainment of the aetiological agent causing MARI in this population will be required and efficient and reliable methods for obtaining those data at the community level need to be established.

A factor 5 water saving with a cooling systems innovation

Melbourne-based manufacturer Muller Industries Australia’s new cooling system saves 80 per cent of the average water usage in commercial office buildings that use water-based cooling towers.

Interplay of MLC, gantry and respiratory motion during DCAT delivery

This study investigated the possible interplay effects arising from the treatment of moving targets using the dynamic conformal arc therapy (DCAT) technique. Dose from a modulated test beam was measured, with and without phantom motion and with and without a 30o arc rotation, using a diode array placed on a sinusoidally moving platform. Measurements were repeated at five different collimator angles (0, 22.5, 45, 67.5 and 90o), at two different dose rates (300 and 600 MU/min). Results showed that the effect of respiratory motion on the measured dose distribution increased slightly when the beams were delivered as arcs, rather than with a static gantry angle, and that this effect increased substantially as the collimator angle was increased from 0o (MLC motion perpendicular to respiratory motion) to 90o (MLC motion parallel to respiratory motion). The dose oscillations arising from interplay between phantom and MLC motion were found to increase in magnitude when the dose rate was increased. These results led to the development of simple recommendations for minimizing the negative effects of motion interplay on DCAT dose distributions

Trans-disciplinary research in synthesis of grass pollen aerobiology and its importance for respiratory health in Australasia

Grass pollen is a major trigger for allergic rhinitis and asthma, yet little is known about the timing and levels of human exposure to airborne grass pollen across Australasian urban environments. The relationships between environmental aeroallergen exposure and allergic respiratory disease bridge the fields of ecology, aerobiology, geospatial science and public health. The Australian Aerobiology Working Group comprised of experts in botany, palynology, biogeography, climate change science, plant genetics, biostatistics, ecology, pollen allergy, public and environmental health, and medicine, was established to systematically source, collate and analyse atmospheric pollen concentration data from 11 Australian and six New Zealand sites. Following two week-long workshops, post-workshop evaluations were conducted to reflect upon the utility of this analysis and synthesis approach to address complex multidisciplinary questions. This Working Group described i) a biogeographically dependent variation in airborne pollen diversity, ii) a latitudinal gradient in the timing, duration and number of peaks of the grass pollen season, and iii) the emergence of new methodologies based on trans-disciplinary synthesis of aerobiology and remote sensing data. Challenges included resolving methodological variations between pollen monitoring sites and temporal variations in pollen datasets. Other challenges included “marrying” ecosystem and health sciences and reconciling divergent expert opinion. The Australian Aerobiology Working Group facilitated knowledge transfer between diverse scientific disciplines, mentored students and early career scientists, and provided an uninterrupted collaborative opportunity to focus on a unifying problem globally. The Working Group provided a platform to optimise the value of large existing ecological datasets that have importance for human respiratory health and ecosystems research. Compilation of current knowledge of Australasian pollen aerobiology is a critical first step towards the management of exposure to pollen in patients with allergic disease and provides a basis from which the future impacts of climate change on pollen distribution can be assessed and monitored.

Grass pollen allergens globally: The contribution of subtropical grasses to burden of allergic respiratory diseases

Grass pollens of the temperate (Pooideae) subfamily and subtropical subfamilies of grasses are major aeroallergen sources worldwide. The subtropical Chloridoideae (e.g. Cynodon dactylon; Bermuda grass) and Panicoideae (e.g. Paspalum notatum; Bahia grass) species are abundant in parts of Africa, India, Asia, Australia and the Americas, where a large and increasing proportion of the world's population abide. These grasses are phylogenetically and ecologically distinct from temperate grasses. With the advent of global warming, it is conceivable that the geographic distribution of subtropical grasses and the contribution of their pollen to the burden of allergic rhinitis and asthma will increase. This review aims to provide a comprehensive synthesis of the current global knowledge of (i) regional variation in allergic sensitivity to subtropical grass pollens, (ii) molecular allergenic components of subtropical grass pollens and (iii) allergic responses to subtropical grass pollen allergens in relevant populations. Patients from subtropical regions of the world show higher allergic sensitivity to grass pollens of Chloridoideae and Panicoideae grasses, than to temperate grass pollens. The group 1 allergens are amongst the allergen components of subtropical grass pollens, but the group 5 allergens, by which temperate grass pollen extracts are standardized for allergen content, appear to be absent from both subfamilies of subtropical grasses. Whilst there are shared allergenic components and antigenic determinants, there are additional clinically relevant subfamily-specific differences, at T- and B-cell levels, between pollen allergens of subtropical and temperate grasses. Differential immune recognition of subtropical grass pollens is likely to impact upon the efficacy of allergen immunotherapy of patients who are primarily sensitized to subtropical grass pollens. The literature reviewed herein highlights the clinical need to standardize allergen preparations for both types of subtropical grass pollens to achieve optimal diagnosis and treatment of patients with allergic respiratory disease in subtropical regions of the world. © 2014 John Wiley & Sons Ltd.

Respiratory Exacerbations in Indigenous Children From Two Countries With Non-Cystic Fibrosis Chronic Suppurative Lung Disease/Bronchiectasis

BACKGROUND: Acute respiratory exacerbations (AREs) cause morbidity and lung function decline in children with chronic suppurative lung disease (CSLD) and bronchiectasis. In a prospective longitudinal cohort study, we determined the patterns of AREs and factors related to increased risks for AREs in children with CSLD/bronchiectasis. METHODS: Ninety-three indigenous children aged 0.5 to 8 years with CSLD/bronchiectasis in Australia (n = 57) and Alaska (n = 36) during 2004 to 2009 were followed for > 3 years. Standardized parent interviews, physical examinations, and medical record reviews were undertaken at enrollment and every 3 to 6 months thereafter. RESULTS: Ninety-three children experienced 280 AREs (median = 2, range = 0-11 per child) during the 3-year period; 91 (32%) were associated with pneumonia, and 43 (15%) resulted in hospitalization. Of the 93 children, 69 (74%) experienced more than two AREs over the 3-year period, and 28 (30%) had more than one ARE in each study year. The frequency of AREs declined significantly over each year of follow-up. Factors associated with recurrent (two or more) AREs included age < 3 years, ARE-related hospitalization in the first year of life, and pneumonia or hospitalization for ARE in the year preceding enrollment. Factors associated with hospitalizations for AREs in the first year of study included age < 3 years, female caregiver education, and regular use of bronchodilators. CONCLUSIONS: AREs are common in children with CSLD/bronchiectasis, but with clinical care and time AREs occur less frequently. All children with CSLD/bronchiectasis require comprehensive care; however, treatment strategies may differ for these patients based on their changing risks for AREs during each year of care.

Low temperature solar cooling system with absorption chiller and desiccant wheel

Nowadays Solar Cooling systems are becoming popular to reduce the carbon footprint of air conditioning. The use of an absorption chiller connected to solar thermal panels is increasing, but little study has been carried out to assess the advantage of join together an absorption chiller and a desiccant wheel to remove the sensible heat and the latent heat in different ways than the current design adopted in the industry. In this work I assess the possibility of implement a desiccant wheel in a conventional solar cooling system and the possibility of recovering the heat rejected by the absorption chiller which is then used for the regeneration of the desiccant wheel. The implementation of a desiccant wheel and the recovery of the heat rejected could provide a significant energy saving when compared to traditional solar cooling system. The results assist in the practical development of a solar cooling system which simultaneously uses absorption and adsorption technology.

Evaluating the potential use of direct evaporative cooling in Australia

Greenhouse gas emissions and associated global climate change are a significant and growing concern for the world community. In order to improve building energy efficiency, the use of evaporative cooling systems is attracting growing attention. Using a climate assessment tool, the potential use of direct evaporative coolers over different Australian climates is evaluated. It is found that overall, the potential use of direct evaporative cooling is very significant in Australian climates. Among all the eight capital cities across Australia, except for Darwin, the need of hybrid cooling for other cities is found to be insignificant,and is less than 5% if appropriate air circulation is provided on hot/warm days. It is also found that the potential use of evaporative cooling can be significantly influenced by a change in the applications or design parameters. In Brisbane, it is estimated that with an increase of sensible cooling load from 30 W/m2 to 40 W/m2 in the conditioned space, the requirement in hours of hybrid cooling can increase significantly, from 4.06% to 14.89%.

Performance analysis of solar desiccant-evaporative cooling for a commercial building under different Australian climates

This paper evaluates and compares the system performance of a solar desiccant-evaporative cooling (SDEC) system with a referenced conventional variable air volume (VAV) system for a typical office building in all 8 Australian capital cities. A simulation model of the building is developed using the whole building simulation software EnergyPlus. The performance indicators for the comparison are system coefficient of performance (COP), annual primary energy consumption, annual energy savings, and annual CO2 emissions reduction. The simulation results show that Darwin has the most apparent advantages for SDEC system applications with an annual energy savings of 557 GJ and CO2 emission reduction of 121 tonnes. The maximum system COP is 7. For other climate zones such as Canberra, Hobart and Melbourne, the SDEC system is not as energy efficient as the conventional VAV system.

Comparative genomic analysis of human Chlamydia pneumoniae isolates from respiratory, brain and cardiac tissues

Chlamydia pneumoniae is an obligate intracellular bacterium implicated in a wide range of human diseases including atherosclerosis and Alzheimer's disease. Efforts to understand the relationships between C. pneumoniae detected in these diseases have been hindered by the availability of sequence data for non-respiratory strains. In this study, we sequenced the whole genomes for C. pneumoniae isolates from atherosclerosis and Alzheimer's disease, and compared these to previously published C. pneumoniae genomes. Phylogenetic analyses of these new C. pneumoniae strains indicate two sub-groups within human C. pneumoniae, and suggest that both recombination and mutation events have driven the evolution of human C. pneumoniae. Further fine-detailed analyses of these new C. pneumoniae sequences show several genetically variable loci. This suggests that similar strains of C. pneumoniae are found in the brain, lungs and cardiovascular system and that only minor genetic differences may contribute to the adaptation of particular strains in human disease.

The sputtering temperature of a cooling cylindrical rod with an insulated core

By a standard application of Jones's method associated with the Wiener-Hopf technique an explicit solution is obtained for the temperature distribution inside a cylindrical rod with an insulated inner core when the rod is allowed to enter into a fluid of large extent with a uniform speed, and a simple integral expression is derived for the value of the sputtering temperature of the rod at the points of entry. Numerical results under certain special circumstances are also obtained and presented in the form of a table.

The sputtering temperature of a cooling cylindrical rod with an insulated core

By a standard application of Jones's method associated with the Wiener-Hopf technique an explicit solution is obtained for the temperature distribution inside a cylindrical rod with an insulated inner core when the rod is allowed to enter into a fluid of large extent with a uniform speed, and a simple integral expression is derived for the value of the sputtering temperature of the rod at the points of entry. Numerical results under certain special circumstances are also obtained and presented in the form of a table.