14 research outputs found
A novel method to scale up fungal endophyte isolations
This record contains the Author’s Accepted Manuscript of an article published in Biocontrol Science and Technology 2015, available online at: http://www.tandfonline.com/ http://dx.doi.org/10.1080/09583157.2015.1033382. Manuscript will be openly accessible in March 2016
Origin, behaviour, and genetics of reproductive workers in an invasive ant
Background
Worker reproduction has an important influence on the social cohesion and efficiency of social insect colonies, but its role in the success of invasive ants has been neglected. We used observations of 233 captive colonies, laboratory experiments, and genetic analyses to investigate the conditions for worker reproduction in the invasive Anoplolepis gracilipes (yellow crazy ant) and its potential cost on interspecific defence. We determined the prevalence of worker production of males and whether it is triggered by queen absence; whether physogastric workers with enlarged abdomens are more likely to be reproductive, how normal workers and physogastric workers compare in their contributions to foraging and defence; and whether worker-produced males and males that could have been queen- or worker-produced differ in their size and heterozygosity.
Results
Sixty-six of our 233 captive colonies produced males, and in 25 of these, some males could only have been produced by workers. Colonies with more workers were more likely to produce males, especially for queenless colonies. The average number of days between the first appearance of eggs and adult males in our colonies was 54.1 ± 10.2 (mean ± SD, n = 20). In our laboratory experiment, queen removal triggered an increase in the proportion of physogastric workers. Physogastric workers were more likely to have yolky oocytes (37–54.9%) than normal workers (2–25.6%), which is an indicator of fertile or trophic egg production. Physogastric workers were less aggressive during interspecific aggression tests and foraged less than normal workers. The head width and wing length of worker-produced males were on average 4.0 and 4.3% greater respectively than those of males of undetermined source. Our microsatellite DNA analyses indicate that 5.5% of worker-produced males and 14.3% of males of undetermined source were heterozygous, which suggests the presence of diploid males and/or genetic mosaics in A. gracilipes.
Conclusions
Our experimental work provides crucial information on worker reproduction in A. gracilipes and its potential cost to colony defence. The ability of A. gracilipes workers to produce males in the absence of queens may also contribute to its success as an invasive species if intranidal mating can take place between virgin queens and worker-produced males
Beauveria bassiana and Metarhizium anisopliae endophytically colonize cassava roots following soil drench inoculation
AbstractWe investigated the fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae to determine if endophytic colonization could be achieved in cassava. An inoculation method based on drenching the soil around cassava stem cuttings using conidial suspensions resulted in endophytic colonization of cassava roots by both entomopathogens, though neither was found in the leaves or stems of the treated cassava plants. Both fungal entomopathogens were detected more often in the proximal end of the root than in the distal end. Colonization levels of B. bassiana were higher when plants were sampled at 7–9days post-inoculation (84%) compared to 47–49days post-inoculation (40%). In contrast, the colonization levels of M. anisopliae remained constant from 7–9days post-inoculation (80%) to 47–49days post-inoculation (80%), which suggests M. anisopliae is better able to persist in the soil, or as an endophyte in cassava roots over time. Differences in colonization success and plant growth were found among the fungal entomopathogen treatments
Recurrent Varicella in an Immunocompetent Woman
Varicella-zoster virus (VZV) infection causes 2 distinct disease processes. Primary VZV infection results in varicella (chickenpox), a common generalized eruption, and subsequent reactivation of VZV classically results in herpes zoster (shingles), which presents as a unilateral, dermatomal eruption. Although a single VZV infection typically confers protection against its reactivation, recurrent varicella rarely is reported, particularly in immunocompetent patients. We present the case of a 52-year-old black woman with an intact immune system who demonstrated 3 VZV infections
Consistent patterns of fungal communities within ant-plants across a large geographic range strongly suggest a multipartite mutualism
In recent decades, multipartite mutualisms involving microorganisms such as fungi have been discovered in associations traditionally thought of as bipartite. Ant-plant mutualisms were long thought to be bipartite despite fungi being noticed in an epiphytic ant-plant over 100 years ago. We sequenced fungal DNA from the three distinct domatium chambers of the epiphytic ant-plant Myrmecodia beccarii to establish if fungal communities differ by chamber type across five geographic locations spanning 675 km. The three chamber types serve different ant-associated functions including ‘waste’ chambers, where ant workers deposit waste; ‘nursery’ chambers, where the brood is kept; and ‘ventilation’ chambers, that allow air into the domatium. Overall, fungi from the order Chaetothyriales dominated the chambers in terms of the proportion of operational taxonomic units (OTUs; 13.4%) and sequence abundances of OTUs (28% of the total); however a large portion of OTUs (28%) were unidentified at the order level. Notably, the fungal community in the waste chambers differed consistently from the nursery and ventilation chambers across all five locations. We identified 13 fungal OTUs as 'common' in the waste chambers that were rare or in very low sequence abundance in the other two chambers. Fungal communities in the nursery and ventilation chambers overlapped more than either did with the waste chambers but were also distinct from each other. Differences in dominance of the common OTUs drove the observed patterns in the fungal communities for each of the chamber types. This suggests a multipartite mutualism involving fungi exists in this ant-plant and that the role of fungi differs among chamber types
Measuring Patients' Experiences with Individual Primary Care Physicians: Results of a Statewide Demonstration Project
BACKGROUND: Measuring and reporting patients' experiences with health plans has been routine for several years. There is now substantial interest in measuring patients' experiences with individual physicians, but numerous concerns remain. OBJECTIVE: The Massachusetts Ambulatory Care Experiences Survey Project was a statewide demonstration project designed to test the feasibility and value of measuring patients' experiences with individual primary care physicians and their practices. DESIGN: Cross-sectional survey administered to a statewide sample by mail and telephone (May–August 2002). PATIENTS: Adult patients from 5 commerical health plans and Medicaid sampled from the panels of 215 generalist physicians at 67 practice sites (n=9,625). MEASUREMENTS: Ambulatory Care Experiences Survey produces 11 summary measures of patients' experiences across 2 domains: quality of physician-patient interactions and organizational features of care. Physician-level reliability was computed for all measures, and variance components analysis was used to determine the influence of each level of the system (physician, site, network organization, plan) on each measure. Risk of misclassifying individual physicians was evaluated under varying reporting frameworks. RESULTS: All measures except 2 achieved physician-level reliability of at least 0.70 with samples of 45 patients per physician, and several exceeded 0.80. Physicians and sites accounted for the majority of system-related variance on all measures, with physicians accounting for the majority on all “interaction quality” measures (range: 61.7% to 83.9%) and sites accounting for the largest share on “organizational” measures (range: 44.8% to 81.1%). Health plans accounted for neglible variance (<3%) on all measures. Reporting frameworks and principles for assuring misclassification risk ≤2.5% were identified. CONCLUSIONS: With considerable national attention on the importance of patient-centered care, this project demonstrates the feasibility of obtaining highly reliable measures of patients' experiences with individual physicians and practices. The analytic findings underscore the validity and importance of looking beyond health plans to individual physicians and sites as we seek to improve health care quality