14 research outputs found

    Abundance, structure and function of zooplankton-associated bacterial communities within the York River, VA

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    Mesozooplankton function as microbial microhabitats and can support concentrations of bacteria orders of magnitude higher than in the surrounding water. These zooplankton-associated bacteria can have much higher production rates than their free-living counterparts. Portions of the zooplankton microhabitat may also be anoxic and provide refuge for anaerobic bacteria and their associated processes within the oxygenated water column. Despite their common presence in the marine environment, zooplankton-associated bacteria are largely ignored by microbial ecologists and zooplankton ecologists alike. Consequently, factors which influence zooplanktonassociated bacterial abundance, community composition and function, and how zooplankton-associated bacteria compare to free-living bacteria are not well known. The goal of my research was to investigate which environmental parameters and zooplanktonspecific characteristics influenced the zooplankton-associated bacterial abundance, community composition and function. During a year-long field study in the York River, VA, free-living bacteria concentration peaked in the summer, while zooplanktonassociated bacteria concentration peaked in both summer and winter. There were no relationships between number of bacteria per individual zooplankter and zooplankter size. Ambient ammonium concentration was the one environmental parameter that correlated with all zooplankton-associated bacterial concentrations. In laboratory experiments, copepods raised in high ammonium concentration had high concentrations of loosely attached bacteria, while copepods raised in low ammonium concentration supported fewer, firmly attached bacteria, suggesting greater exchange between free-living and zooplankton-associated bacterial communities in nutrient rich systems. Zooplankton-associated bacterial communities were genetically distinct from free-living bacterial communities and utilized a wider array of carbon substrates. Changes in ambient environmental conditions played a larger role than zooplankton-characteristics in shaping zooplankton-associated bacterial community composition and function. Additionally, the potential importance of zooplankton guts as anoxic microhabitats was evaluated by comparing carbon substrate usage by the total bacterial (epibiotic + gut) and gut bacterial communities of the calanoid copepod Acartia tonsa under aerobic and anaerobic conditions. Gut bacteria were responsible for a large portion of the microbial activity associated with the copepod under both aerobic and anaerobic conditions. A larger variety of substrate subsets were used by zooplankton-associated bacteria than free-living bacteria under anaerobic conditions, suggesting that each zooplankton group selects for a specific combination of bacteria. In fact, some zooplankton-associated bacteria were not detected in the surrounding water and utilized substrates not used by free-living bacteria. These results highlight that zooplankton act as micro bial hotspots and zooplankton-associated bacteria are an important part of the total bacterial abundance, diversity and functionality in aquatic systems

    Ciliate epibionts associated with crustacean zooplankton in German lakes: distribution, motility, and bacterivory

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    Ciliate epibionts associated with crustacean zooplankton are widespread in aquatic systems, but their ecological roles are little known. We studied the occurrence of ciliate epibionts on crustacean zooplankton in nine German lakes with different limnological features during the summer of 2011. We also measured the detachment and re-attachment rates of the ciliates, changes in their motility, and the feeding rates of attached vs. detached ciliate epibionts. Epibionts were found in all lakes sampled except an acidic lake with large humic inputs. Epibiont prevalence was as high as 80.96% on the cladoceran Daphnia cucullata, 67.17% on the cladoceran Diaphanosoma brachyurum, and 46.67% on the calanoid copepod Eudiaptomus gracilis. Both cladoceran groups typically had less than 10 epibionts per individual, while the epibiont load on E. gracilis ranged from 1 to \u3e30 epibionts per individual. After the death of the zooplankton host, the peritrich ciliate epibiont Epistylis sp. detached in an exponential fashion with a half-life of 5 min, and 98% detached within 30 min, leaving behind the stalks used for attachment. Immediately after detachment, the ciliates were immotile, but 62% became motile within 60 min. When a new host was present, only 27% reattached after 120 min. The average measured ingestion rate and clearance rate of Epistylis were 11,745 bacteria ciliate(-1) h(-1) and 24.33 mu l ciliate(-1) h(-1), respectively. Despite their high feeding rates, relatively low epibiont abundances were observed in the field, which suggests either diversion of energy to stalk formation, high metabolic loss by the epibionts, or high mortality among the epibiont populations

    The Probability of Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), Escape Differs Among Life Stages and Between Two Trapping Techniques Commonly Used By Landowners, Sticky Bands and Duct Tape.

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    The invasive Lycorma delicatula (White) was first identified in Pennsylvania, U.S.A. in 2014, and has since increased its range to several Eastern states. Lycorma delicatula pose a serious threat to many native species, including hardwoods and grapes, and land owners are continually seeking effective traps to control populations. Both commercially-produced Web-Cote brand sticky bands and less expensive duct tape are often used by land owners to trap L. delicatula. However, the probability of escape from these adhesives has not been formally assessed, and almost certainly differs as a function of life stage and type of adhesive used. The purpose of this work was to determine if the effect of adhesive type (Web-Cote sticky bands vs. duct tape) on the probability of escape differs based on life stage. Additionally, we wanted to know how escape probability differs among life stages when individuals were exposed to each adhesive type, separately. In all life stages, the probability of escape from duct tape was greater than from Web-Cote sticky bands, indicating that sticky bands are a more effective tool in L. delicatula population control. In trials using only Web-Cote sticky bands, the probability of escape was low in second (21.1%), third (32.6%), and fourth (38.5%) instars relative to adults (84.1%). In trials using only duct tape, the probability of escape remained high among all life stages, with approximately 72% of second instars and 100% of adults escaping. Recent studies indicate that alternate trapping techniques, including circle trunk traps, are even more effective at capturing L. delicatula than sticky bands, though they are costlier. We propose a hybrid approach to L. delicatula trapping which utilizes relatively inexpensive sticky bands early in the season, and fewer, more effective circle trunk traps later in the season

    Correction to The Probability of Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), Escape Differs Among Life Stages and Between Two Trapping Techniques Commonly Used by Landowners, Sticky Bands and Duct Tape. The Great Lakes Entomologist 53(3-4): 170-177.

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    This is a manuscript correction in reference to: Desko M, Schiebel C, Silverman S, Bickel J, Felton K, and Chandler JL. (2020) The Probability of spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), escape differs among life stages and between two trapping techniques commonly used by landowners, sticky bands and duct tape. The Great Lakes Entomologist 53(3-4): 170-177

    Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.

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    To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC

    Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science

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    It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations

    Knowledge and Perceptions of Family Leave Policies Among Female Faculty in Academic Medicine

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    OBJECTIVE: The purpose of this research was to examine the knowledge and perceptions of family leave policies and practices among senior leaders including American Association of Medical College members of the Group on Women in Medicine and Science (GWIMS) to identify perceived barriers to career success and satisfaction among female faculty. METHODS: In 2011–2012 GWIMS representatives and senior leaders at 24 medical schools were invited to participate in an interview about faculty perceptions of gender equity and overall institutional climate. An inductive thematic analysis of the qualitative data was conducted to identify themes represented in participant responses. The research team read and reviewed institutional family leave policies for concordance with key informant descriptions. FINDINGS: 22 GWIMS representatives and senior leaders comprised the final sample. Participants were female, 18 (82%) were full professors with the remainder being associate professors. Compared with publicly available policies at each institution, the knowledge of nine participants was consistent with policies, was discrepant for six, with the remaining seven acknowledging a lack of knowledge of policies. Four major themes were identified from the interview data: 1) Framing family leave as a personal issue undermines its effect on female faculty success; 2) Poor communication of policies impairs access and affects organizational climate; 3) Discrepancies in leave implementation disadvantage certain faculty in terms of time and pay; 4) Leave policies are valued and directly related to academic productivity. CONCLUSIONS: Family leave policies are an important aspect of faculty satisfaction and academic success, yet policy awareness by senior leaders is lacking. Further organizational support is needed to promote equitable policy creation and implementation to support women in medical academia

    Zooplankton-associated and free-living bacteria in the York River, Chesapeake Bay: comparison of seasonal variations and controlling factors

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    Trace caches deliver a high number of instructions per cycle to wide-issue superscalar processors. To overcome complex control flow, multiple branch predictors have to predict up to 3 conditional branches per cycle. These multiple branch predictors sometimes predict completely wrong paths of execution, degrading the average fetch bandwidth. This paper shows that such mispredictions can be detected by monitoring trace cache misses. Based on this observation, a new technique called trace substitution is introduced. On a trace cache miss, trace substitution overrides the predicted trace with a cached trace. If the substitution is correct, the fetch bandwidth increases. We show that trace substitution consistently improves the fetch bandwidth with 0.2 instructions per access. For inaccurate predictors, trace substitution can increase the fetch bandwidth with up to 2 instructions per access
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