Regional and seasonal variation in airborne grass pollen levels between cities of Australia and New Zealand

Although grass pollen is widely regarded as the major outdoor aeroallergen source in Australia and New Zealand (NZ), no assemblage of airborne pollen data for the region has been previously compiled. Grass pollen count data collected at 14 urban sites in Australia and NZ over periods ranging from 1 to 17 years were acquired, assembled and compared, revealing considerable spatiotemporal variability. Although direct comparison between these data is problematic due to methodological differences between monitoring sites, the following patterns are apparent. Grass pollen seasons tended to have more than one peak from tropics to latitudes of 37°S and single peaks at sites south of this latitude. A longer grass pollen season was therefore found at sites below 37°S, driven by later seasonal end dates for grass growth and flowering. Daily pollen counts increased with latitude; subtropical regions had seasons of both high intensity and long duration. At higher latitude sites, the single springtime grass pollen peak is potentially due to a cooler growing season and a predominance of pollen from C₃ grasses. The multiple peaks at lower latitude sites may be due to a warmer season and the predominance of pollen from C₄ grasses. Prevalence and duration of seasonal allergies may reflect the differing pollen seasons across Australia and NZ. It must be emphasized that these findings are tentative due to limitations in the available data, reinforcing the need to implement standardized pollen-monitoring methods across Australasia. Furthermore, spatiotemporal differences in grass pollen counts indicate that local, current, standardized pollen monitoring would assist with the management of pollen allergen exposure for patients at risk of allergic rhinitis and asthma.     

Trypanosoma cruzi: acute and long-term infection in the vertebrate host can modify the response to benznidazole

We analyzed the influence of Trypanosoma cruzi maintenance in different hosts (dog and mouse) on its susceptibility to benznidazole treatment. Five T. cruzi stocks were isolated from dogs inoculated with Be-62 or Be-78 strain (both sensitive to benznidazole) 2-10 years ago, and the benznidazole sensitivity was then determined using the mouse as experimental model. The different T. cruzi stocks obtained from long-term infected dogs showed 50-90% drug resistance right after isolation. However, maintenance of these T. cruzi stocks in mice, by successive blood passages (2.5 years), led to either a decrease or stability of the drug resistance pattern and an increase in parasite virulence. We also demonstrated the effectiveness of the induction of parasitemia reactivation by cyclophosphamide immunosuppression in the evaluation of the response to the specific drug treatment.     

A note on species richness and the variance of epidemic severity

Journal of Mathematical Biology - The commonly observed negative correlation between the number of species in an ecological community and disease risk, typically referred to as “the dilution...     

Risk factors for cardiovascular disease in rural area of Croatia

Rural areas, where 47.6% of the Croatian population lives are not generally the focus of research; yet there are challenges which affect the rural population that often go unreported. These communities often exhibit disadvantages in many areas of health. The aim of this study is to examine the specific health needs and related determinants of rural populations influenced by transition that were affected by the consequences of war. The focus of the research is rural lifestyle, behaviour and cardiovascular risk factors in three villages of Sisacko-moslavacka County. Results show that participants generally understand that their own lifestyles influence their health, but they often neglect to change their behaviour to improve their health. This can be explained through complex socio-economic conditions and traditional values of their heritage. These results suggest a need for further research on health status, attitude, and behaviour of Croatia's rural population. Specific public health intervention and services for rural populations must be promoted.     

Enzymatic coating of lignocellulosic surfaces with polyphenols

Upgrading of the surface characteristics could enhance the bulk properties of naturally abundant fiber-forming materials for better performance or create new value-added products. Laccase can induce cross-linkage and covalent coupling of low molecular weight compounds onto lignocellulosic surfaces. For this purpose the 38-kDa laccase from Trametes hirsuta was purified and characterized. The best conditions for laccase-induced coating of flax fibers were determined. This evaluation was based on the obtained coloration and color depth. A screening was carried out with different phenols for their potential as monomers for enzyme-catalyzed polymerization resulting in a coating with antibacterial performance. While all the methoxyphenols showed different coloration with weak fastness properties, bacterial growth of Bacillus subtilis and Staphylococcus aureus was reduced significantly using ferulic acid and hydroquinone. Using laccase-induced coupling and polymerization, multi-functionality of the lignocellulosic surface, such as coloration and antimicrobial performance, was achieved, which depended on the nature of the applied phenolic monomer.     

Voltametric monitoring of enzyme-mediated indigo reduction in the presence of various fibre materials

A comparative study of enzyme-mediated indigo reduction is presented as an environmentally-friendly alternative to alkaline sodium dithionite reduction. The effect of the mediator 1,8-dihydroxy-9,10-anthraquinone in enzymatic reduction was studied by means of voltammetry, both in the presence and absence of different textile materials (polyamide 6, polyamide 6,6 and cotton), and compared to chemically reduced indigo. It was observed that bio-catalytic formation of leuco indigo and its exhaustion on substrates is inversely proportional to the pH within the range of 7–11. Additionally, substrate coloration was strongly influenced by the mediator, resulting in in situ formation of leuco indigo. This effect was most pronounced for polyamide substrates. The reuse of an enzyme-mediated reduction bath for dyeing was assessed showing that the levelness of the obtained shade was either excellent or good at pH 9 and 11, respectively. The wash, perspiration, and light color fastness properties of all textile materials dyed with enzymatically-reduced indigo were comparable or even better than those obtained with chemically reduced indigo. The use of enzyme-mediated reduction of indigo combined with potential reuse of the reduction bath represents a cost effective and environmentally-friendly dyeing process that can be applied for the dyeing of natural cellulosic and synthetic polyamide fibres.     

Historic fuel wood use in the Galápagos Islands: identification of charred remains

Charcoal fragments from five historic campsite locations in the Galápagos Islands were identified and radiocarbon dated to investigate postulated early human presence in the archipelago, historic fuel wood collection patterns and the resultant impact on native vegetation. A variety of taxa and fuel types were revealed to be present in the charcoal assemblages, indicating geographically driven rather than species-specific methods of collection. Historic anthropogenic impact was therefore spread amongst woody taxa in the lowland plant communities, with severity dependent on proximity to campsite location. All charred remains were found to date from within the historic period, supporting the preponderance of archaeological evidence indicating that human presence did not begin in Galápagos until after European discovery.