106 research outputs found

    Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae), a parasite of the intertidal bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae) on the Oregon coast

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    This is the publisher’s final pdf. The published article is copyrighted by BioMed Central and can be found at: http://www.biomedcentral.com/.Background: It is rare to find terrestrial nematode lineages parasitizing arthropods inhabiting the intertidal or\ud littoral zone of the oceans. During an ecological study along the Oregon dunes, an allantonematid nematode\ud (Tylenchomorpha: Allantonematidae) was discovered parasitizing the intertidal shore bug, Saldula laticollis (Reuter)\ud (Hemiptera: Saldidae). This shore bug is adapted to an intertidal environment and can survive short periods of\ud submergence during high tides. The present study describes the nematode parasite and discusses aspects of its\ud development, ecology and evolution.\ud Methods: Adults and last instar nymphs of S. laticollis (Hemiptera: Saldidae) were collected from the high intertidal\ud zone among clumps of Juncus L. (Juncaceae) plants at Waldport, Oregon on October 3, 2011. The bugs were\ud dissected in 1% saline solution and the nematodes killed in 1% Ringers solution and immediately fixed in 5%\ud formalin (at 20°C). Third stage juveniles removed from infected hosts were maintained in 1% saline solution until\ud they matured to the adult stage, molted and mated.\ud Results: Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae) is described from last instar nymphs\ud and adults of the intertidal bug, Saldula laticollis on the Oregon coast. The new genus can be distinguished from\ud other genera in the Allantonematidae by a stylet lacking basal knobs in both sexes, an excretory pore located\ud behind the nerve ring, ribbed spicules, a gubernaculum, the absence of a bursa and the elongate-tubular shape of\ud the ovoviviparous parasitic females. Studies of the organogenesis of Halophilanema showed development to third\ud stage juveniles in the uterus of parasitic females. Maturation to the free-living adults and mating occurred in the\ud environment. The incidence of infection of S. laticollis ranged from 0% to 85% depending on the microhabitat in\ud the intertidal zone.\ud Conclusions: Based on the habitat and morphological characters, it is proposed that Halophilanema adapted a\ud parasitic existence fairly recently, evolutionarily speaking. It was probably a free-living intertidal or shore nematode\ud that fed on microorganisms, especially fungi, in the intertidal habitat and became parasitic after saldids entered the\ud environment. Halophilanema represents the first described nematode parasite of an intertidal insect

    Interim Report for Phase I Clean Lakes Study: Lake Blackshear

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    Proceedings of the 1993 Georgia Water Resources Conference, April 20-21, 1993, Athens, Georgia.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Natural Resources, The University of Georgia, Athens, Georgia 30602 with partial funding provided by the U.S. Department of Interior, Geological Survey, through the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1984 (P.L. 98-242). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors

    The Origin Recognition Complex Interacts with a Subset of Metabolic Genes Tightly Linked to Origins of Replication

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    The origin recognition complex (ORC) marks chromosomal sites as replication origins and is essential for replication initiation. In yeast, ORC also binds to DNA elements called silencers, where its primary function is to recruit silent information regulator (SIR) proteins to establish transcriptional silencing. Indeed, silencers function poorly as chromosomal origins. Several genetic, molecular, and biochemical studies of HMR-E have led to a model proposing that when ORC becomes limiting in the cell (such as in the orc2-1 mutant) only sites that bind ORC tightly (such as HMR-E) remain fully occupied by ORC, while lower affinity sites, including many origins, lose ORC occupancy. Since HMR-E possessed a unique non-replication function, we reasoned that other tight sites might reveal novel functions for ORC on chromosomes. Therefore, we comprehensively determined ORC “affinity” genome-wide by performing an ORC ChIP–on–chip in ORC2 and orc2-1 strains. Here we describe a novel group of orc2-1–resistant ORC–interacting chromosomal sites (ORF–ORC sites) that did not function as replication origins or silencers. Instead, ORF–ORC sites were comprised of protein-coding regions of highly transcribed metabolic genes. In contrast to the ORC–silencer paradigm, transcriptional activation promoted ORC association with these genes. Remarkably, ORF–ORC genes were enriched in proximity to origins of replication and, in several instances, were transcriptionally regulated by these origins. Taken together, these results suggest a surprising connection among ORC, replication origins, and cellular metabolism

    Anxiety disorders in headache patients in a specialised clinic: prevalence and symptoms in comparison to patients in a general neurological clinic

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    Data from several studies indicate an association of headache with anxiety disorders. In this study, we assessed and differentiated anxiety disorders in 100 headache patients by using the PSWQ (Penn State Worry Questionnaire) screening tool for generalised anxiety disorder (GAD) and the ACQ (Agoraphobic Cognitions Questionnaire) and BSQ (Body Sensation Questionnaire) for panic disorder (PD). Control groups were constructed: (1) on the basis of epidemiological studies on PD and GAD in the general population and (2) by including neurological patients. 37.0% of headache patients had a GAD. 27% of headache patients met the score for PD in the BSQ, 4.0% in the ACQ. Significant results were obtained in comparison to the general population (p < 0.001) and with regard to GAD in comparison with a sample of neurological patients (p < 0.005). The BSQ significantly correlated with the number of medication days (p < 0.005). The results confirm the increased prevalence of GAD in headache patients. PD seems to increase the risk of medication overuse

    An Investigation of a Role for U2 snRNP Spliceosomal Components in Regulating Transcription

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    There is mounting evidence to suggest that the synthesis of pre-mRNA transcripts and their subsequent splicing are coordinated events. Previous studies have implicated the mammalian spliceosomal U2 snRNP as having a novel role in stimulating transcriptional elongation in vitro through interactions with the elongation factors P-TEFb and Tat-SF1; however, the mechanism remains unknown [1]. These factors are conserved in Saccharomyces cerevisiae, a fact that suggests that a similar interaction may occur in yeast to stimulate transcriptional elongation in vivo. To address this possibility we have looked for evidence of a role for the yeast Tat-SF1 homolog, Cus2, and the U2 snRNA in regulating transcription. Specifically, we have performed a genetic analysis to look for functional interactions between Cus2 or U2 snRNA and the P-TEFb yeast homologs, the Bur1/2 and Ctk1/2/3 complexes. In addition, we have analyzed Cus2-deleted or -overexpressing cells and U2 snRNA mutant cells to determine if they show transcription-related phenotypes similar to those displayed by the P-TEFb homolog mutants. In no case have we been able to observe phenotypes consistent with a role for either spliceosomal factor in transcription elongation. Furthermore, we did not find evidence for physical interactions between the yeast U2 snRNP factors and the P-TEFb homologs. These results suggest that in vivo, S. cerevisiae do not exhibit functional or physical interactions similar to those exhibited by their mammalian counterparts in vitro. The significance of the difference between our in vivo findings and the previously published in vitro results remains unclear; however, we discuss the potential importance of other factors, including viral proteins, in mediating the mammalian interactions

    Double jeopardy:subordinates' worldviews and poor performance as predictors of abusive supervision

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    Purpose - To test a moderated mediation model where a positive relationship between subordinates’ perceptions of a dangerous world—the extent to which an individual views the world as a dangerous place—and supervisory abuse is mediated by their submission to authority figures, and that this relationship is heightened for more poorly performing employees. Design/Methodology/Approach - Data were obtained from 173 subordinates and 45 supervisors working in different private sector organizations in Pakistan. Findings - Our model was supported. It appears that subordinates’ dangerous worldviews are positively associated with their perceptions of abusive supervision and that this is because such views are likely to lead to greater submission to authority figures. But this is only for those employees who are performing more poorly. Implications - We highlight the possibility that individual differences (worldviews, attitudes to authority figures, and performance levels) may lead employees to become victims of abusive supervision. As such, our research informs organizations on how they may better support supervisors in managing effectively their subordinate relationships and, in particular, subordinate poor performance. Originality/Value - We add to recent work exploring subordinate-focused antecedents of abusive supervision, finding support for the salience of the previously untested constructs of individual worldviews, authoritarian submission, and individual job performance. In so doing we also extend research on dangerous worldviews into a new organizational setting. Finally, our research takes place within a new Pakistani context, adding to the burgeoning non-US based body of empirical work into the antecedents and consequences of abusive supervision
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