171 research outputs found
Projected Carbon Dioxide to Increase Grass Pollen and Allergen Exposure Despite Higher Ozone Levels
One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10–30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change
Metal worker’s lung: spatial association with Mycobacterium avium
Background Outbreaks of hypersensitivity pneumonitis (HP) are not uncommon in workplaces where metal working fluid (MWF) is used to facilitate metal turning. Inhalation of microbe-contaminated MWF has been assumed to be the cause, but previous investigations have failed to establish a spatial relationship between a contaminated source and an outbreak.
Objectives After an outbreak of five cases of HP in a UK factory, we carried out blinded, molecular-based microbiological investigation of MWF samples in order to identify potential links between specific microbial taxa and machines in the outbreak zone.
Methods Custom-quantitative PCR assays, microscopy and phylogenetic analyses were performed on blinded MWF samples to quantify microbial burden and identify potential aetiological agents of HP in metal workers.
Measurements and main results MWF from machines fed by a central sump, but not those with an isolated supply, was contaminated by mycobacteria. The factory sump and a single linked machine at the centre of the outbreak zone, known to be the workstation of the index cases, had very high levels of detectable organisms. Phylogenetic placement of mycobacterial taxonomic marker genes generated from these samples indicated that the contaminating organisms were closely related to Mycobacterium avium.
Conclusions We describe, for the first time, a close spatial relationship between the abundance of a mycobacterium-like organism, most probably M. avium, and a localised outbreak of MWF-associated HP. The further development of sequence-based analytic techniques should assist in the prevention of this important occupational disease
De-Icing Impacts on the Danforth Campus, Spring 2021
De-Icing Impacts on the Danforth Campus, Sustainability Exchange, Washington University in St. Louis, Spring 2021
Mentalizing, Personal Prayer, the Presence of God, and Evil
People who believe in a relational, personal deity, conceptualize god(s) as intentional agents with mental states. Hence it follows that mentalizing or theory of mind may be one of the cognitive foundations of religious belief and behavior. This study examined this relationship as it corresponds to reported prayer experiences, intimacy with god, and experience of agentic evil
Understanding sustainable professional learning communities by considering school leaders’ interpretations and educational beliefs
The way in which school leaders implement professional learning communities (PLCs) is important for realizing sustainable school improvement. The assumption is that school leaders act based on their interpretation of the PLC, which is based on their underlying educational beliefs. In this study, we explored these latter aspects by interviewing six formal and informal school leaders, discussing the sustainability of PLCs in two secondary schools that had each worked with PLCs for seven years. The results of this in-depth qualitative study show that the schools differed in the degree of sustainability they achieved: one still used the PLC as intended; the other now omitted one step of the original format. This can be explained by the leaders’ interpretations of the PLC and their educational beliefs. Furthermore, we found that student- and col-laboration-oriented beliefs are critical for continuing the work of a PLC. Finally, we found that the organizational context mediates-whether leaders act upon their beliefs. Tensions between leaders’ beliefs and the organizational context, such as fear of colleagues’ resistance, appeared to influence their choice to act or not concern-ing specific aspects of the PLC. These findings can give school leaders insights into conditions for sustainable school improvement with PLCs. <br/
Interaction of the Onset of Spring and Elevated Atmospheric CO(2) on Ragweed (Ambrosia artemisiifolia L.) Pollen Production
Increasing atmospheric carbon dioxide is responsible for climate changes that are having widespread effects on biological systems. One of the clearest changes is earlier onset of spring and lengthening of the growing season. We designed the present study to examine the interactive effects of timing of dormancy release of seeds with low and high atmospheric CO(2) on biomass, reproduction, and phenology in ragweed plants (Ambrosia artemisiifolia L.), which produce highly allergenic pollen. We released ragweed seeds from dormancy at three 15-day intervals and grew plants in climate-controlled glasshouses at either ambient or 700-ppm CO(2) concentrations, placing open-top bags over inflorescences to capture pollen. Measurements of plant height and weight; inflorescence number, weight, and length; and days to anthesis and anthesis date were made on each plant, and whole-plant pollen productivity was estimated from an allometric-based model. Timing and CO(2) interacted to influence pollen production. At ambient CO(2) levels, the earlier cohort acquired a greater biomass, a higher average weight per inflorescence, and a larger number of inflorescences; flowered earlier; and had 54.8% greater pollen production than did the latest cohort. At high CO(2) levels, plants showed greater biomass and reproductive effort compared with those in ambient CO(2) but only for later cohorts. In the early cohort, pollen production was similar under ambient and high CO(2), but in the middle and late cohorts, high CO(2) increased pollen production by 32% and 55%, respectively, compared with ambient CO(2) levels. Overall, ragweed pollen production can be expected to increase significantly under predicted future climate conditions
Nano-Immunodetection and Quantification of Mycobacteria in Metalworking Fluids
The accurate detection and enumeration of mycobacteria in metalworking fluids (MWFs) is imperative from an environmental protection and occupational health perspective. We report here on a comparison of the labeling efficiency of nano-immunomagnetic particles (NIMP) and free antibody (FAb) to detect mycobacteria in semisynthetic MWF by using both traditional visualization analysis and cluster analysis aided visualization analysis (CAAVA). The NIMP labeling method involved coating nanometer-scale magnetic particles with Protein A, and oriented conjugation of polyclonal antibodies specific to Mycobacterium spp. The FAb labeling method is modified from the traditional immunofluorescence (IF) method for more efficient detection of mycobacteria in a model MWF. The labeling efficiency of NIMP and FAb were 7.2 ± 4.6 and 16.3 ± 5.5%, and the specificity 85.0 ± 6.1 and 88.1 ± 10.5%, respectively, based on traditional visualization analysis. Based on CAAVA analysis, the labeling efficiency of NIMP and FAb increased to 12.4 ± 1.6 and 20.5 ± 3.9%, and the specificity to 97.8 ± 3.2 and 98.5 ± 2.5%, respectively. A linear relationship of FCM counts and seeded concentrations was observed over four orders of magnitude (R 2 ≤ 0.99) in pure and ternary cultures. The results strongly support the applicability of either FAb or NIMP coupled with CAAVA and flow cytometry for rapid detection and enumeration of mycobacteria in complex matrices.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63114/1/ees.2007.24.58.pd
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