Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila

Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila Free-living protozoa, which feed on bacteria, play an important role in the communities of microorganisms and invertebrates in drinking water supplies and in (warm) tap water installations. Several bacteria, including opportunistic human pathogens such as Legionella pneumophila, are able to survive and replicate within protozoan hosts, and certain free-living protozoa are opportunistic human pathogens as well. However, not much is known about the occurrence of these organisms in drinking water supplies in relation to water quality and other environmental conditions. This lack of knowledge may in part be attributed to the limitations of microscopic techniques and cultivation methods for detection and identification of protozoa. In the investigations described in this thesis, molecular methods were applied to identify communities of free-living protozoa in drinking water supplies and to elucidate the effects of environmental conditions on the growth of these organisms. Molecular methods were also used to detect and identify protozoan hosts, both known and yet-undescribed, for L. pneumophila. The eukaryotic communities were studied using terminal restriction fragment length polymorphism (T-RFLP), clone library analyses of partial 18S rRNA gene fragments, and qPCR assays for Acanthamoeba spp. and Hartmannella vermiformis. In two groundwater supplies in the Netherlands (T In one drinking water supply in the Caribbean, the concentration of H. vermiformis correlated with the concentration of Legionella spp., and clones related to Amoebozoa predominated the protozoan community. These observations, in combination with the low turbidity and the varying ATP concentrations, indicated that biofilms in this system promoted growth of amoebae and also Legionella spp. Ciliophora represented 25\\% of the protozoan OTUs in another Caribbean supply with elevated ATP concentrations and turbidity, related to corroding cast-iron pipes. Thus, sediments seem to favor growth of ciliates. Cercozoan types predominated in one of the Caribbean supplies with low ATP concentrations ( A biofilm batch test (BBT) was applied to amplify and subsequently identify protozoan hosts for L. pneumophila. In this test 21 freshwater samples, with added polyethylene cylinders to promote biofilm formation, were inoculated with L. pneumophila and subsequently incubated in duplicate at 37°C. Growth of L. pneumophila was observed in 16 of 18 water types when the host protozoan H. vermiformis had been added. Indigenous H. vermiformis was indicated as host in 12 of the 19 BBT flasks with growth of L. pneumophila. In none of the water samples incubated at 37°C in the BBT system, growth of Acanthamoeba spp. was observed. In several flasks with growth of L. pneumophila, the protozoa Diphylleia rotans, Echinamoeba thermarum and Neoparamoeba sp. were identified as candidate hosts. In vitro studies are needed to confirm their role as hosts for L. pneumophila. To assess the effects of water temperature on indigenous free-living protozoan communities, four water types were incubated in a BBT system at 20, 30, 37 and 42°C. Only two of the 53 OTUs related to free-living protozoa obtained from these freshwater types at day 0 were also detected after incubation. Multiplication of indigenous Acanthamoeba spp. was observed at 20 and 30°C, with only limited growth in one flask at 37°C. Indigenous H. vermiformis multiplied at 20, 30 and 37°C, but at 42°C proliferation was only observed in water collected from the river Rhine. Growth of organisms related to Amoebozoa and Stramenopiles was observed at all four temperatures, whereas Cercozoan and Euglenozoan types predominated in the BBT system incubated at 37 and 30°C, respectively. The Amoebozoan Arachnula sp. was identified as candidate host for L. pneumophila at 42°C, but in vitro studies with this organism are needed for confirmation. These observations indicate that H. vermiformis, the predominating protozoan host for Legionella spp., is ubiquitous in water supplies and other engineered water installations. This organism can grow at temperatures ranging from less than 20 to 42°C. Proliferation is limited at active biomass concentrations </p

A Course-Based Undergraduate Research Experience (CURE) in Soccer Analytics

The authors designed an honors seminar course entitled Sports Analytics: Soccer to provide students with a course-based undergraduate research experience (CURE) using cutting-edge GPS/accelerometer athlete-tracking devices. This paper offers details of the design and structure of the course, where a goal was for students to contribute to a longitudinal research project of performing a comprehensive performance and load analysis on Division III women\u27s soccer athletes

The identification of critical facilities from the position of cybersecurity violation by the example of energy

The article describes methods for identification of critical facilities, being a significant trend in researching critical infrastructures, particularly in the energy sector. The proposed methods are focused on the investigation of the energy object state in relation to the violation of cybersecurity of its information infrastructure. The cyber threats are believed to be important contemporary threats to energy security in Russia. The proposed methods formed the basis of development information-analytical system used for monitoring of cybersecurity violations in energy sector

Mental Health Prevalence in NCAA Division III Collegiate Athletes

Stressors related to academic requisites, sport participation and pressure to perform may increase college athlete risk for mental health symptoms (Cox, Ross-Stewart, & Foltz, 2017; Sudano & Miles, 2017; Yang et al., 2007). The purpose of this study was to identify the level of clinically relevant self-reported mental health symptoms in National Collegiate Athletic Association (NCAA) Division III athletes and variations based on sport participation (i.e., men’s or women’s athletics; team or individual sports) over a two-year period. A nonexperimental, trend study design was used. Data analysis included descriptive statistics, chi square test, and multivariate analysis of variance (MANOVA) which used one-way analysis of variance (ANOVA) for follow-up procedures. A MANOVA revealed a significant interaction of gender and sport type for general symptoms [F(1, 564) = 9.583, p = .002] and depression [F(1, 564) = 6.945, p = .009] but not anxiety [F(1, 564) = 3.332, p = .068, ƞ2 = .006]. The project was able to describe mental health symptoms in a population that is not often included in the literature. Knowledge of collegiate athlete mental health prevalence is important because prevention and early intervention is a key component of community-based health programming

ISO-1 Binding to the Tautomerase Active Site of MIF Inhibits Its Pro-inflammatory Activity and Increases Survival in Severe Sepsis

MIF is a proinflammatory cytokine that has been implicated in the pathogenesis of sepsis, arthritis, and other inflammatory diseases. Antibodies against MIF are effective in experimental models of inflammation, and there is interest in strategies to inhibit its deleterious cytokine activities. Here we identify a mechanism of inhibiting MIF pro-inflammatory activities by targeting MIF tautomerase activity. We designed small molecules to inhibit this tautomerase activity; a lead molecule, "ISO-1 ((S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester)," significantly inhibits the cytokine activity in vitro. Moreover, ISO-1 inhibits tumor necrosis factor release from macrophages isolated from LPStreated wild type mice but has no effect on cytokine release from MIFdeficient macrophages. The therapeutic importance of the MIF inhibition by ISO-1 is demonstrated by the significant protection from sepsis, induced by cecal ligation and puncture in a clinically relevant time frame. These results identify ISO-1 as the first small molecule inhibitor of MIF proinflammatory activities with therapeutic implications and indicate the potential of the MIF active site as a novel target for therapeutic interventions in human sepsis

Why do people use portable air purifiers? Evidence from occupant surveys and air quality monitoring in homes in three European cities

One of the most widely available technologies to clean the air in homes of particulate matter of less than 2.5 µm in diameter (PM2.5), known to have negative health impacts, are portable home air purifiers (HAPs). This paper presents research which (1) explored the effectiveness of HAPs in real-world conditions in 57 homes in three European cities; (2) examined if HAPs affect users’ perceptions of the indoor air quality (IAQ) at home; and (3) considered the motivations for occupants’ operation of HAPs. Results from this study found that PM2.5 concentrations in bedrooms were reduced by 45% to 69%; perceptions of IAQ were not correlated with measured high PM2.5 levels; occupants reported the HAPs to have a ‘cooling’ effect, which may explain why the predominant driver of HAP use was thermal comfort, rather than IAQ, in all three cities. The latter finding was supported by a statistically significant increase in the probability of HAP use with increasing indoor temperatures. If the operation of HAPs can be managed, or fully automated, to reflect indoor air pollution levels rather than thermal conditions, better pollutant reduction would be feasible and their use to reduce PM2.5 may help mitigate the negative health effects of exposure whilst at home