351 research outputs found

    Transcriptomic analysis of the entomopathogenic nematode Heterorhabditis bacteriophora TTO1

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    Background: The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST) analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results: A total of 31,485 high quality ESTs were generated from cDNA libraries of the adult H. bacteriophora TTO1 strain. Cluster analysis revealed the presence of 3,051 contigs and 7,835 singletons, representing 10,886 distinct EST sequences. About 72% of the distinct EST sequences had significant matches (E value < 1e-5) to proteins in GenBank's non-redundant (nr) and Wormpep190 databases. We have identified 12 ESTs corresponding to 8 genes potentially involved in RNA interference, 22 ESTs corresponding to 14 genes potentially involved in dauer-related processes, and 51 ESTs corresponding to 27 genes potentially involved in defense and stress responses. Comparison to ESTs and proteins of free-living nematodes led to the identification of 554 parasitic nematode-specific ESTs in H. bacteriophora, among which are those encoding F-box-like/WD-repeat protein theromacin, Bax inhibitor-1-like protein, and PAZ domain containing protein. Gene Ontology terms were assigned to 6,685 of the 10,886 ESTs. A total of 168 microsatellite loci were identified with primers designable for 141 loci. Conclusion: A total of 10,886 distinct EST sequences were identified from adult H. bacteriophora cDNA libraries. BLAST searches revealed ESTs potentially involved in parasitism, RNA interference, defense responses, stress responses, and dauer-related processes. The putative microsatellite markers identified in H. bacteriophora ESTs will enable genetic mapping and population genetic studies. These genomic resources provide the material base necessary for genome annotation, microarray development, and in-depth gene functional analysis

    The Differential Impact of Unique Behavioral and Psychological Symptoms for the Dementia Caregiver: How and Why Do Patients' Individual Symptom Clusters Impact Caregiver Depressive Symptoms?

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    OBJECTIVE: The behavioral and psychological symptoms associated with dementia (BPSD) are highly burdensome to caregivers. While BPSD consist of a wide variety of patient behaviors including depression, physical aggression, and paranoid delusions, it remains unclear whether specific symptoms have a differential impact on caregivers. The aims of this study were 1) to assess how individual BPSD, categorized based on how they may affect caregivers, impact depressive symptoms for dementia patient caregivers and 2) to test the pathways by which BPSD clusters impact caregiver depressive symptoms. DESIGN: Cross-sectional analysis of data from a longitudinal study of patients with Alzheimer disease and dementia with Lewy bodies. SETTING: Multiple U.S. dementia clinics. PARTICIPANTS: One hundred sixty patient-caregiver dyads. METHODS: Using multivariate generalized estimating equation logistic models, we analyzed the relationship between four BPSD clusters (patient depressive symptoms, accusatory/aggressive behaviors, nonthreatening psychotic symptoms, and difficult to manage behaviors) and caregiver depressive symptoms and assessed mediators of these relationships. RESULTS: Only the presence of patient depressive symptoms was associated with caregiver depression (odds ratio: 1.55; 95% confidence interval: 1.14-2.1). This relationship was mediated by caregiver report of both the symptom's impact on the patient and perceived burden to caregivers. CONCLUSION: Patient depressive symptoms may be the most important driver of the relationship between BPSD and caregiver depression. Research in this field should further test the effects of individual BPSD and also consider how symptoms may negatively impact caregivers by increasing burden and evoking empathy for the patient

    Pennsylvania Folklife Vol. 37, No. 1

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    • Franklin in Fact and Fiction: The Double Perspective of Leland Baldwin • Jost Hite: From the Neckar to the Shenandoah • The Migration and Settlement of Pennsylvania Germans in Maryland, Virginia and North Carolina and Their Effects on the Landscape • Bethesda Evangelical Church in Farmers Mills: Fact and Folklore • The Tourist Bureau Shuns Me!https://digitalcommons.ursinus.edu/pafolklifemag/1117/thumbnail.jp

    Are There Sensitive Time Periods for Dementia Caregivers? The Occurrence of Behavioral and Psychological Symptoms in the Early Stages of Dementia

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    ABSTRACT Background: The behavioral and psychological symptoms associated with dementia (BPSD) can be burdensome to informal/family caregivers, negatively affecting mental health and expediting the institutionalization of patients. Because the dementia patient-caregiver relationship extends over long periods of time, it is useful to examine how BPSD impact caregiver depressive symptoms at varied stages of illness. The goal of this study was to assess the association of BPSD that occur during early stage dementia with subsequent caregiver depressive symptoms. Methods: Patients were followed from the early stages of dementia every six months for up to 12 years or until death (n = 160). Caregiver symptoms were assessed on average 4.5 years following patient's early dementia behaviors. A generalized estimating equation (GEE) extension of the logistic regression model was used to determine the association between informal caregiver depressive symptoms and BPSD symptoms that occurred at the earliest stages dementia, including those persistent during the first year of dementia diagnosis. Results: BPSD were common in early dementia. None of the individual symptoms observed during the first year of early stage dementia significantly impacted subsequent caregiver depressive symptoms. Only patient agitation/aggression was associated with subsequent caregiver depressive symptoms (OR = 1.76; 95% CI = 1.04-2.97) after controlling for concurrent BPSD, although not in fully adjusted models. Conclusions: Persistent agitation/aggression early in dementia diagnosis may be associated with subsequent depressive symptoms in caregivers. Future longitudinal analyses of the dementia caregiving relationship should continue to examine the negative impact of persistent agitation/aggression in the diagnosis of early stage dementia on caregivers

    Pennsylvania Folklife Vol. 31, No. 3

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    • Jamison City • Domestic Architecture in Lancaster County • Conversation with Marguerite de Angeli • Who Put the Turnip on the Grave? • Pennsylfawnisch Deitsch un Pfalzer: Dialect Comparisons Old and New • John Philip Boehm: Pioneer Pennsylvania Pastor • The Search for our German Ancestors • Aldes un Neieshttps://digitalcommons.ursinus.edu/pafolklifemag/1095/thumbnail.jp

    Health-Care Use and Cost in Dementia Caregivers: Longitudinal Results from the Predictors Caregiver Study

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    OBJECTIVE: To examine the effects of caregiver and patient characteristics on caregivers' medical care use and cost. METHODS: One hundred forty-seven caregiver/patient dyads were followed annually for 6 years in three academic Alzheimer's disease centers in the United States. Logistic, negative binomial, and generalized linear mixed models were used to examine overall effects of caregiver/patient characteristics on caregivers' hospitalizations, doctor visits, outpatient tests and procedures, and prescription and over-the-counter medications. RESULTS: Patients' comorbid conditions and dependence were associated with increased health-care use and costs of caregivers. Increases in caregiver depressive symptoms are associated with increases in multiple domains of caregivers' health-care use and costs. DISCUSSION: Findings suggest expanding our focus on dementia patients to include family caregivers to obtain a fuller picture of effects of caregiving. Primary care providers should integrate caregivers' needs in health-care planning and delivery. Clinical interventions that treat patients and caregivers as a whole will likely achieve the greatest beneficial effects

    Why fencers should bounce: a new method of movement to engage the stretch-shortening cycle

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    While teaching a heel first contact style of footwork in fencing (also referred to as toe contribution avoidance) is in keeping with long standing traditions, it is not conducive to today’s modern style of fast paced and explosive fencing. Equally, fencers towards the elite-end seem to be gradually adopting a more spring-based style, as their body progressively and organically transitions to “ball of the foot” based footwork, in order for them to fence competitively in the manner they have intuitively associated with success. Therefore, if from a young age fencers are taught to make full use of the stretch shortening cycle (SSC) via “bouncing” or simply by initiating movement via the ball of the foot, this will expedite the learning process. It will demonstrate to them how the SSC can be used to move at greater speed, cover greater distances when advancing, retreating and lunging, and conserve the much-needed energy required to compete over day long competitions. This paper details the mechanistic underpinnings of the SSC and its application to the modern day fencer

    Transcriptional profiling of trait deterioration in the insect pathogenic nematode Heterorhabditis bacteriophora

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    Background: The success of a biological control agent depends on key traits, particularly reproductive potential, environmental tolerance, and ability to be cultured. These traits can deteriorate rapidly when the biological control agent is reared in culture. Trait deterioration under laboratory conditions has been widely documented in the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora (Hb) but the specific mechanisms behind these genetic processes remain unclear. This research investigates the molecular mechanisms of trait deterioration of two experimental lines of Hb, an inbred line (L5M) and its original parental line (OHB). We generated transcriptional profiles of two experimental lines of Hb, identified the differentially expressed genes (DEGs) and validated their differential expression in the deteriorated line. Results: An expression profiling study was performed between experimental lines L5M and OHB of Hb with probes for 15,220 ESTs from the Hb transcriptome. Microarray analysis showed 1,185 DEGs comprising of 469 down- and 716 up-regulated genes in trait deteriorated nematodes. Analysis of the DEGs showed that trait deterioration involves massive changes of the transcripts encoding enzymes involved in metabolism, signal transduction, virulence and longevity. We observed a pattern of reduced expression of enzymes related to primary metabolic processes and induced secondary metabolism. Expression of sixteen DEGs in trait deteriorated nematodes was validated by quantitative reverse transcription-PCR (qRT-PCR) which revealed similar expression kinetics for all the genes tested as shown by microarray. Conclusion: As the most closely related major entomopathogen to C. elegans, Hb provides an attractive near-term application for using a model organism to better understand interspecies interactions and to enhance our understanding of the mechanisms underlying trait deterioration in biological control agents. This information could also be used to improve the beneficial traits of biological control agents and better understand fundamental aspects of nematode parasitism and mutualism
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