We studied the physiological basis of local adaptation to drought in Boechera holboellii, a perennial relative of Arabidopsis thaliana, and used cDNA-AFLPs to identify candidate genes showing differential expression in these populations. We compared two populations of B. holboellii from contrasting water environments in a reciprocal transplant experiment, as well as in a laboratory dry-down experiment. We continuously measured the water con tent of soils using time domain reflectometery (TDR). We compared populations for their water use efficiency (WUE), root/shoot ratios (R:S) and leaf mass per unit area (LMA) in the field and in the laboratory, and identified candidate genes that (i) responded plastically to water stress and (ii) were differentially expressed between the two populations. Genotypes from the drier site had higher WUE, which was attributable to a large reduction in transpi rational water loss. The xeric-adapted population also had increased investment in root bio mass and greater leaf mass per unit area. Reciprocal transplants in the field had significantly greater survival in their native habitat. In total, 450 cDNA-AFLP fragments showed significant changes between drought and control treatments. Furthermore, some genes showed genotype (population)-specific patterns of up-or down-regulation in response to drought. Three hundred cDNA-AFLP bands were sequenced leading to the identification of cDNAs coding for proteins involved in signal transduction, transcriptional regulation, redox regulation, oxidative stress and pathways involved in stress adaptation. Some of these proteins could contribute a physiological advantage under drought, making them potential targets for natural selection.
Background In 2013–2014, an outbreak of serogroup B meningococcal disease occurred among persons linked to a New Jersey university (University A). In the absence of a licensed serogroup B meningococcal (MenB) vaccine in the US, the Food and Drug Administration authorized use of an investigational MenB vaccine to control the outbreak. An investigation of the outbreak and response was undertaken to determine the population at risk and assess vaccination coverage. Methods The epidemiologic investigation relied on compilation and review of case and population data, laboratory typing of meningococcal isolates, and unstructured interviews with university staff. Vaccination coverage data were collected during the vaccination campaign held under an expanded access Investigational New Drug protocol. Results Between March 25, 2013 and March 10, 2014, 9 cases of serogroup B meningococcal disease occurred in persons linked to University A. Laboratory typing results were identical for all 8 isolates available. Through May 14, 2014, 89.1% coverage with the two-dose vaccination series was achieved in the target population. From the initiation of MenB vaccination through February 1, 2015, no additional cases of serogroup B meningococcal disease occurred in University A students. However, the 9th case occurred in March 2014 in an unvaccinated close contact of University A students. Conclusions No serogroup B meningococcal disease cases occurred in persons who received 1 or more doses of 4CMenB vaccine, suggesting 4CMenB may have protected vaccinated individuals from disease. However, the 9th case demonstrates that carriage of serogroup B Nesisseria meningitidis among vaccinated persons was not eliminated.
Wildland fires have a multitude of ecological effects in forests, woodlands, and savannas across the globe. A major focus of past research has been on tree mortality from fire, as trees provide a vast range of biological services. We assembled a database of individual-tree records from prescribed fires and wildfires in the United States. The Fire and Tree Mortality (FTM) database includes records from 164,293 individual trees with records of fire injury (crown scorch, bole char, etc.), tree diameter, and either mortality or top-kill up to ten years post-fire. Data span 142 species and 62 genera, from 409 fires occurring from 1981-2016. Additional variables such as insect attack are included when available. The FTM database can be used to evaluate individual fire-caused mortality models for pre-fire planning and post-fire decision support, to develop improved models, and to explore general patterns of individual fire-induced tree death. The database can also be used to identify knowledge gaps that could be addressed in future research.
The presence of heritable variation is a prerequisite for evolution, but natural selection typically reduces genetic variation. Variation can be maintained in traits under selection through spatial or temporal variation in fitness surfaces, frequency-dependent selection, or disruptive selection. We evaluated the maintenance of variation in the enantiomeric blend of pheromones employed by the bark beetle Ips pini (Say). In natural populations, we quantified fitness surfaces for mating success and progeny production. We investigated the effects of paternal pheromone blend on offspring survival by comparing the spatial scales at which pheromone blends and larval mortality agents vary. Males with extreme pheromone blends obtained up to 1.8 times as many mates who each laid equivalent numbers of eggs, producing strong disruptive selection on male pheromone blend. In combination with imperfect assortative mating that continually produces intermediate genotypes, this fitness surface is sufficient to maintain variation in a heritable trait that is strongly linked to fitness. The ultimate explanation for female preference is unknown but could be because of selection for reduced mortality from specialist predators that prefer common prey pheromone blends. Selection is most likely occurring at the scale of small resource patches within pine stands. Selection at coarser scales (pine stands) is unlikely because pheromone blends did not vary among pine stands. Selection at finer scales (within logs) is unlikely because males of similar enantiomeric blends were not aggregated on logs, and male pheromone blend did not affect the spacing to neighboring galleries. This study documents a rare case of diversifying selection in natural populations.
Objective This study examines differences in chronic health outcomes between coal, uranium, metal, and nonmetal miners. Methods In a cross-sectional study using data from a health screening program for current and former New Mexico miners, log-binomial logistic regression models were used to estimate relative risks of respiratory and heart disease, cancer, osteoarthritis, and back pain associated with mining in each sector as compared with coal, adjusting for other relevant risk factors. Results Differential risks in angina, pulmonary symptoms, asthma, cancer, osteoarthritis, and back pain between mining sectors were found. Conclusions New Mexico miners experience different chronic health challenges across sectors. These results demonstrate the importance of using comparable data to understand how health risks differ across mining sectors. Further investigation among a broader geographic population of miners will help identify the health priorities and needs in each sector.
On September 20, 2017, Hurricane Maria made landfall on Puerto Rico as a category 4 storm, resulting in serious widespread impact across the island, including communication and power outages, water systems impairment, and damage to life-saving infrastructure. In collaboration with the Puerto Rico Department of Health, the Public Health Branch (PHB), operating under the Department of Health and Human Services Incident Response Coordination Team, was tasked with completing assessments of health-care facilities in Puerto Rico to determine infrastructure capabilities and post-hurricane capacity. Additionally, in response to significant data entry and presentation needs, the PHB leadership worked with the Puerto Rico Planning Board to develop and test a new app-based infrastructure capacity assessment tool. Assessments of hospitals were initiated September 28, 2017, and completed November 10, 2017 (n = 64 hospitals, 97%). Assessments of health-care centers were initiated on October 7, 2017, with 186 health-care centers (87%) assessed through November 18, 2017. All hospitals had working communications; however, 9% (n = 17) of health-care centers reported no communication capabilities. For the health-care centers, 114 (61%) reported they were operational but had sustainment needs. In conclusion, health-care facility assessments indicated structural damage issues and operational capacity decreases, while health-care centers reported loss of communication capabilities post-Hurricane Maria.
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