Large-Scale Land Development, Fugitive Dust, and Increased Coccidioidomycosis Incidence in the Antelope Valley of California, 1999-2014.

Ongoing large-scale land development for renewable energy projects in the Antelope Valley, located in the Western Mojave Desert, has been blamed for increased fugitive dust emissions and coccidioidomycosis incidence among the general public in recent years. Soil samples were collected at six sites that were destined for solar farm construction and were analyzed for the presence of the soil-borne fungal pathogen Coccidioides immitis which is endemic to many areas of central and southern California. We used a modified culture-independent nested PCR approach to identify the pathogen in all soil samples and also compared the sampling sites in regard to soil physical and chemical parameters, degree of disturbance, and vegetation. Our results indicated the presence of C. immitis at four of the six sites, predominantly in non-disturbed soils of the Pond-Oban complex, which are characterized by an elevated pH and salt bush communities, but also in grassland characterized by different soil parameters and covered with native and non-native annuals. Overall, we were able to detect the pathogen in 40% of the soil samples (n = 42). Incidence of coccidioidomycosis in the Antelope Valley was positively correlated with land use and particulate matter in the air (PM10) (Pearson correlation coefficient >0.5). With the predicted population growth and ongoing large-scale disturbance of soil in the Antelope Valley in coming years, incidence of coccidioidomycosis will likely further increase if policy makers and land developers continue to ignore the risk of grading land without implementing long-term dust mitigation plans in Environmental Impact Reports.

Risk of Exposure to Coccidioides spp. in the Temblor Special Recreation Management Area (SRMA), Kern County, CA.

The Temblor Mountain Special Recreation Area (SRMA) on the western flank of the San Joaquin Valley, CA, is located in the endemic area of Coccidioides, a fungal pathogen responsible for the increasing incidence of coccidioidomycosis (Valley fever). Recreationists in the SRMA, such as off-highway vehicle (OHV) drivers and mountain bikers who disturb the soils, are at risk of being exposed to airborne arthroconidia (asexual spores) of the pathogen. To reduce the risk of pathogen exposure for visitors, the Bureau of Land Management (BLM) plans to limit recreational activities to areas with a reduced pathogen presence. They envision an official OHV park in the future, by also restricting access to areas with ongoing restoration efforts and by limiting soil erosion in sensitive areas. To investigate which soils in the Temblor SRMA are most likely to support the growth of Coccidioides spp., soil samples were collected over a 3-year period from dominant soil types in a northern and a southern sampling area and analyzed for the pathogen using a culture-independent PCR-based method. In addition, soil pH and electrical conductivity were determined. The results of this study revealed slight genetic variance in the Coccidioides sequences obtained from the soils of the Temblor SRMA. An analysis of variance (ANOVA) could not confirm differences in soil pH and electrical conductivity (EC) between the different soil types investigated and between sites where the pathogen was detected compared to sites where it could not be found. However, the year of sampling appeared to have an influence on observed soil pH and EC, and the presence of the pathogen. Of all dominant soil types investigated, those belonging to the Littlesignal-Cochora association were the least likely to contain the pathogen, whereas soils of the Beam-Panoza-Hillbrick association appeared more supportive. In addition to pointing out OHV areas with lower pathogen exposure risk in the Temblor SRMA, recommendations were made to educate visitors and BLM workers about the risk of contracting Valley fever.

Valley Fever: Environmental Risk Factors and Exposure Pathways Deduced from Field Measurements in California.

Coccidioidomycosis, also known as Valley fever, has been reported among military personnel in Coccidioides-endemic areas of the southwestern United States since World War II. In this study, the prevalence of Coccidioides was confirmed in different soil and dust samples collected near three military bases in California using DNA extraction and Polymerase Chain Reaction (PCR) methods. Analyses of physical and chemical parameters revealed no significant differences between Coccidioides-positive and -negative sites. Soil samples collected in the Mojave Desert (near Twentynine Palms MCAGCC) showed the highest percentage of Coccidioides-positive soil and dust samples. Samples from the San Joaquin Valley (near NAS Lemoore) showed the lowest percentage of positive samples and were restricted to remnants of semi-natural areas between agricultural fields. Our results suggest that soil disturbance around all three military bases investigated poses a potential Coccidioides exposure risk for military personnel and the public. We conclude that once lands have been severely disturbed from their original state, they become less suitable for Coccidioides growth. We propose a conceptual framework for understanding exposure where disturbance of soils that exhibit natural or remnants of native vegetation (Creosote and Salt Bush) generate a high risk of exposure to the pathogen, likely during dry periods. In contrast, Coccidioides-positive sites, when undisturbed, will not pose a high risk of exposure.

A comparison of fluorescence in two sympatric scorpion species.

In order to test the feasibility of scorpion fluorescence as an indicator of gender and/or species identity, a comparison of the fluorescence spectra between genders across two sympatric species of scorpions (Vaejovis confusus Stahnke 1940 and Paruroctonus shulovi Williams 1970) was conducted. Each spectrum was represented in a simple multivariate analysis by its peak wavelength and width at 90% of peak intensity. No difference between genders was found, but a statistically significant difference between species was detected. The potential of fluorescence as a basis for species recognition based on this difference is discussed in the context of what is known about scorpion vision and discriminatory abilities.

Using a Concept Inventory to Assess the Reasoning Component of Citizen-Level Science Literacy: Results from a 17,000-Student Study.

After articulating 12 concepts for the reasoning component of citizen-level science literacy and restating these as assessable student learning outcomes (SLOs), we developed a valid and reliable assessment instrument for addressing the outcomes with a brief 25-item science literacy concept inventory (SLCI). In this paper, we report the results that we obtained from assessing the citizen-level science literacy of 17,382 undergraduate students, 149 graduate students, and 181 professors. We address only findings at or above the 99.9% confidence level. We found that general education (GE) science courses do not significantly advance understanding of science as a way of knowing. However, the understanding of science's way of knowing does increase through academic ranks, indicating that the extended overall academic experience better accounts for increasing such thinking capacity than do science courses alone. Higher mean institutional SLCI scores correlate closely with increased institutional selectivity, as measured by the institutions' higher mean SAT and ACT scores. Socioeconomic factors of a) first-generation student, b) English as a native language, and c) interest in commitment to a science major are unequally distributed across ethnic groups. These factors proved powerful in accounting for the variations in SLCI scores across ethnicities and genders.