Temperature modifies the health effects of particulate matter in Brisbane, Australia

A few epidemiological studies have examined whether there was an interactive effect between temperature and ambient particulate matter on cardiorespiratory morbidity and mortality, but the results were inconsistent. The present study used three time-series approaches to explore whether maximum temperature modified the impact of ambient particulate matter less than 10 μm in diameter (PM₁₀) on daily respiratory hospital admissions, cardiovascular hospital admissions, respiratory emergency visits, cardiovascular emergency visits, non-external cause mortality and cardiovascular mortality in Brisbane between 1996 and 2001. The analytical approaches included a bivariate response surface model, a non-stratification parametric model and a stratification parametric model. Results show that there existed a statistically significant interaction between PM₁₀ and temperature on most health outcomes at various lags. PM₁₀ exhibited more adverse health effects on warm days than cold days. The choice of the degree of freedom for smoothers to adjust for confounders and the selection of arbitrary cut-offs for temperature affected the interaction estimates to a certain extent, but did not change the overall conclusion. The results imply that it is important to control and reduce the emission of air particles in Brisbane, particularly when temperature increases.     

The health implications of birth by Caesarean section

Since the first mention of fetal programming of adult health and disease, a plethora of programming events in early life has been suggested. These have included intrauterine and postnatal events, but limited attention has been given to the potential contribution of the birth process to normal physiology and long‐term health. Over the last 30 years a growing number of studies have demonstrated that babies born at term by vaginal delivery (VD) have significantly different physiology at birth to those born by Caesarean section (CS), particularly when there has been no exposure to labour, i.e. pre‐labour CS (PLCS). This literature is reviewed here and the processes involved in VD that might programme post‐natal development are discussed. Some of the effects of CS are short term, but longer term problems are also apparent. We suggest that VD initiates important physiological trajectories and the absence of this stimulus in CS has implications for adult health. There are a number of factors that might plausibly contribute to this programming, one of which is the hormonal surge or “stress response” of VD. Given the increasing incidence of elective PLCS, an understanding of the effects of VD on normal development is crucial.     

How air pollution influences clinical management of respiratory diseases. A case-crossover study in Milan

Background

Environmental pollution is a known risk factor for multiple diseases and furthermore increases rate of hospitalisations. We investigated the correlation between emergency room admissions (ERAs) of the general population for respiratory diseases and the environmental pollutant levels in Milan, a metropolis in northern Italy.

Methods

We collected data from 45770 ERAs for respiratory diseases. A time-stratified case-crossover design was used to investigate the association between air pollution levels and ERAs for acute respiratory conditions. The effects of air pollutants were investigated at lag 0 to lag 5, lag 0–2 and lag 3–5 in both single and multi-pollutant models, adjusted for daily weather variables.

Results

An increase in ozone (O₃) levels at lag 3–5 was associated with a 78% increase in the number of ERAs for asthma, especially during the warm season. Exposure to carbon monoxide (CO) proved to be a risk factor for pneumonia at lag 0–2 and in the warm season increased the risk of ERA by 66%. A significant association was found between ERAs for COPD exacerbation and levels of sulphur dioxide (SO₂), CO, nitrate dioxide (NO₂), and particulate matter (PM₁₀ and PM_2.5). The multipollutant model that includes all pollutants showed a significant association between CO (26%) and ERA for upper respiratory tract diseases at lag 0–2. For chronic obstructive pulmonary disease (COPD) exacerbations, only CO (OR 1.19) showed a significant association.

Conclusions

Exposure to environmental pollution, even at typical low levels, can increase the risk of ERA for acute respiratory diseases and exacerbation of obstructive lung diseases in the general population.     

Resistance of the oil-oxidizing microorganism <Emphasis Type="Italic">Dietzia</Emphasis> sp. to hyperosmotic shock in reconstituted biofilms

A number of halotolerant and halophilic bacterial strains were isolated from the Romashkinskoe oil field (Tatarstan) stratal waters having a salinity of up to 100 g/l. The isolation of pure cultures involved biofilm reconstitution on M9 medium with paraffins. The associations obtained were dispersed and reinoculated onto solid media that contained either peptone and yeast extract (PY medium) or paraffins. It was shown that such associations included both oil-oxidizing bacteria and accompanying chemoheterotrophic bacteria incapable of oil oxidation. The pure cultures that were isolated were used for creating binary biofilms. In these biofilms, interactions between halophilic and nonhalophilic bacteria under hypo-and hyperosmotic shocks were investigated. We conducted a detailed study of a biofilm obtained from an oil-oxidizing halotolerant species (with an upper growth limit of 10–12% NaCl) identified as Dietzia sp. and an extremely halophilic gram-negative bacterium (growing within the 5–20% NaCl concentration range) of the genus Chromohalobacter that did not oxidize paraffins. If these microorganisms were grown in a mixed suspension (planktonic) culture that was not supplemented with an additional amount of NaCl, no viable cells of the halophilic microorganism were detected after reinoculation. In contrast, only halophilic cells were detected at a NaCl concentration of 15%. Thus, no mutual protective influence of the microorganisms manifested itself in suspension culture, either under hypoor under hyperosmotic shock. Neither could halophile cells be detected after reinoculating a biofilm obtained on a peptone medium without the addition of NaCl. However, biofilms produced at a NaCl concentration of 15% contained approximately equal numbers of cells of the halophilic and halotolerant organisms. Thus, the halophile in biofilms sustaining a hyperosmotic shock exerts a protective influence on the halotolerant microorganism. Preliminary data suggest that this effect is due to release by the halophile of osmoprotective substances (ectoine and glutamate), which are taken up by the halotolerant species. Such substances are diluted by a large medium volume in suspension cultures, whereas, in biofilms, their diffusion into the medium is apparently hampered by their interaction with the intercellular polymer matrix.     

Character of interactions of saprophytic soil microflora via gaseous metabolites

The character of interaction between saprophytic soil bacteria via gaseous metabolites was studied. It was established that, at the metabolic level, a diverse character of interspecies interrelationships between bacteria exist, directly influencing their reproduction and preservation in soil. Volatile compounds produced by bacteria are able to act as both intra-and interspecies regulators of microbial communities. The soil microbiocenosis composition may be therefore regulated by volatile products of metabolism of saprophytic soil bacteria. Methanol released by bacteria into the environment plays an important role in this process.     

灵芝孢子粉对重症急性胰腺炎大鼠肠道微生态失调的调整作用

目的探讨灵芝孢子粉对重症急性胰腺炎（SAP）导致的肠道微生态失调的调整作用。方法采用胆胰管逆行注射5％牛磺胆酸钠法造成SAP模型;SD大鼠随机分为假手术组、模型组、奥曲肽治疗组、灵芝孢子粉治疗组及灵芝孢子粉奥曲肽联合治疗组;于给药7d后处死大鼠,进行肠道菌群、肝脏及胰腺细菌易位检测。结果SAP时出现明显的肠道菌群紊乱,细菌易位。经治疗后发现,灵芝孢子粉能够扶植双歧杆菌、乳酸杆菌的生长,使肠杆菌的数量减少,并可控制细菌易位。将灵芝孢子粉与奥曲肽合用作用更佳,与其他治疗组相比差异有显著性（P〈0．05）。结论灵芝孢子粉可调整SAP时出现的肠道微生态失调,其与奥曲肽联合应用治疗SAP可降低感染率,取得较好的疗效。     

Simulated climate change impacts on fluxes of carbon in Norway spruce ecosystems along a climatic transect in Sweden

A simulation study based on recent regional climate scenarios for Sweden investigated possible changes in carbon (C) dynamics and net ecosystem exchange (NEE) of Swedish Norway spruce forest ecosystems. Four sites, representative of well-drained soils in four regions, were included. Stand development was simulated for a 100-year rotation period using a coupled model describing abiotic and biotic processes in the soil-plant-atmosphere system. Two IPCC climate change scenarios, corresponding to a mean annual temperature increase of about 2°C (A2) or 3°C (B2) from the reference period 1961–1990 to a new period 2061–2090, were considered. Annual maximum snow depth decreased with the increase in air temperature, whereas maximum soil frost depth and mean annual soil temperature showed only small changes, especially for the sites in northern Sweden. Simulations suggested that in the warmer climate, gross primary production (GPP) increased by 24–32% in northern Sweden and by 32–43% in the south. In the north, the increase was related to the combined effect of air and soil temperature extending the growing season, whereas in the south it was mainly governed by increased N availability due to increased soil temperature. NEE increased by about 20% (A2) or 25% (B2) at all sites, more or less solely due to increased accumulation of C in the tree biomass (including harvest residues), since changes in soil C were small compared with the current climate. Both light use efficiency and water use efficiency were improved in the future climate scenarios, despite increases in atmospheric CO₂ not being considered.     

Repeated batch process for biological treatment of black liquor using brown-rot basidiomycete <Emphasis Type="Italic">Fomitopsis</Emphasis> sp. IMER2

A repeated batch operation is developed for the treatment of alkaline pulp black liquor, through a process of biological acidification precipitation of lignin using brown rot fungus Fomitopsis sp. IMER2. The results showed that COD and color removal of black liquor was dependent on the biomass concentration, pH decrease and initial COD. Based on these results, the repeated batch process was successfully carried out 12 times over 36 days in an air bubble column bioreactor. The average reduction of COD and color was approximately 40% and 70%, respectively.     

Relative contributions of organ shape and receptor arrangement to the design of cricket’s cercal system

Understanding the relative contributions of the shape of a sensory organ and the arrangement of receptors to the overall performance of the organ has long been a challenge for sensory biologists. We tackled this issue using the wind-sensing system of crickets, the cerci, two conical abdominal appendages covered with arrays of filiform hairs. Scanning electron microscopy coupled with 3D reconstruction methods were used for mapping of all cercal filiform hairs. The hairs are arranged according to their diameter in a way that avoids collisions with neighbours during hair deflection: long hairs are regularly spaced, whereas short hairs are both randomly and densely distributed. Particle image velocimetry showed that the variation in diameter of the cercus along its length modifies the pattern of fluid velocities. Hairs are subject to higher air flow amplitudes at the base than at the apex of the cercus. The relative importance of interactions between receptors and the air flow around the organ may explain the performance of the cricket's cercal system: it is characterised by a high density of statistically non-interacting short hairs located at the base of the cercus where sensitivity to air currents is the highest.