167 research outputs found

    The History and Success of the Wood Duck Nest Box Program at Mackay Island National Wildlife Refuge

    Get PDF
    Coastal southeastern Virginia and northeastern North Carolina are considered to be within the primary breeding and wintering range of the Wood duck (Aix sponsa). To restore and expand the local Wood duck population, Mackay Island National Wildlife Refuge introduced 37 pairs of pen-reared Wood ducks in 1970. Concurrently, 34 nest boxes were erected on the refuge. The total number of nesting boxes has expanded at a moderate pace to where the number of boxes now totals 121. The nest box program during all or part of the 10 year period from 1980 - 1989 was evaluated to: (1) assess general nesting success, (2) determine the extent of nest parasitism by European starlings (Sturnus vulgaris), (3) measure habitat preference, and (4) identify whether nest box checks made during the spring versus the winter affected accuracy/reliability of nesting data. The accumulative mean rate of nesting success for 1980 - 1989 was estimated to be 81 percent, while the rate of box use or nest starts for the same period was 77 percent. Between 1983 and 1987, starling use of nest boxes grew from 18 to 54 boxes (200 percent). The corresponding mean rate of success for all nesting boxes with starling use declined from approximately 75 percent in 1983 to below 30 percent in 1989. The mean hatching rate parallelled this decline. Commencing in 1987, a modified nest box design that permitted greater light penetration into the cavity was utilized for all box replacements and additions. The rate of starling use in the modified nest box was 20 percent less overall than that for the standard nest box design. Generally, no distinguishable preference was evident between nest boxes placed in open marsh, wooded/semi-enclosed, and marsh-wood edge habitats. When nest box designs were segregated by habitat type, the proportionate rate of starling use was greatest for those standard boxes in open marsh habitats. Wood duck nest box inspections occurred during both spring/summer and winter seasons from 1980-1989. The relative reliability of winter checks was determined to be equivalent to spring/summer inspections when the spring/summer data of 1980-1982 were compared to the winter records from 1983-1989. Black rat snakes (Elaphe obsoleta) were determined to be the principal nest predator. It is unlikely that the season of inspection will influence the reliability of the production estimate unless nest box predator populations undergo significant fluctuation. The data confirms the growth and fidelity of the Wood duck population on the refuge. Despite an inhibition by Wood ducks to pioneer into new territory, the data suggests that the Back Bay, North Landing River, and Currituck Sound watersheds have the nucleus of a breeding population, at the very least. The judicious selection, placement, and maintenance of nesting boxes, within these integrated watersheds, affords an opportunity to expand the breeding population

    The influence of a serious game's narrative on students' attitudes and learning experiences regarding delirium:an interview study

    Get PDF
    Background: Delirium is a neuropsychiatric syndrome that affects patients' attention and awareness as a result of a physical condition. In recent years, persistent gaps in delirium education have led to suboptimal delirium care. Still, little is known about what are the most important aspects of effective delirium education. Serious games are both entertainment and an interactive, safe learning environment where players can experiment and create new knowledge. They have the potential to contribute to improved delirium education. We used a video-based serious games' narrative to explore aspects essential to enhance students' attitudes and learning experiences regarding delirium. Methods: We created a semi-structured interview guide and interviewed seven nursing and nine medical students about their attitudes and learning experiences, after they had played the game. A qualitative descriptive design and inductive content analysis with constant comparison were used. Results: The patient's and nurse's perspective, interactivity to experiment, realistic views on care options, and feedback on care actions were important for enhancing students' attitudes and learning experiences regarding delirium. Students felt these aspects encouraged them to get actively involved in and experiment with the study material, which in turn led to enhanced reflection on delirium care and education. Our findings highlight the importance of a more patient-oriented focus to delirium education to drive attitudinal change. Students' learning experiences were further enhanced through their affective responses provoked by the perspectives, interactivity, realism, and feedback. Conclusions: Students considered the characters' perspectives, interactivity, realism, and feedback important aspects of the game to enhance their attitudes towards delirious patients and enrich their learning experiences. A patient-oriented narrative provides a clinically relevant experience in which reflection plays an important role. The serious game also serves as medium to actively experiment with care solutions to create better understanding of how healthcare professionals can influence a delirious patient's experience.</p

    Transition of plasmodium sporozoites into liver stage-like forms is regulated by the RNA binding protein pumilio

    Get PDF
    Many eukaryotic developmental and cell fate decisions that are effected post-transcriptionally involve RNA binding proteins as regulators of translation of key mRNAs. In malaria parasites (Plasmodium spp.), the development of round, non-motile and replicating exo-erythrocytic liver stage forms from slender, motile and cell-cycle arrested sporozoites is believed to depend on environmental changes experienced during the transmission of the parasite from the mosquito vector to the vertebrate host. Here we identify a Plasmodium member of the RNA binding protein family PUF as a key regulator of this transformation. In the absence of Pumilio-2 (Puf2) sporozoites initiate EEF development inside mosquito salivary glands independently of the normal transmission-associated environmental cues. Puf2- sporozoites exhibit genome-wide transcriptional changes that result in loss of gliding motility, cell traversal ability and reduction in infectivity, and, moreover, trigger metamorphosis typical of early Plasmodium intra-hepatic development. These data demonstrate that Puf2 is a key player in regulating sporozoite developmental control, and imply that transformation of salivary gland-resident sporozoites into liver stage-like parasites is regulated by a post-transcriptional mechanism

    Performance of the multiband imaging photometer for SIRTF

    Get PDF
    We describe the test approaches and results for the Multiband Imaging Photometer for SIRTF. To verify the performance within a `faster, better, cheaper' budget required innovations in the test plan, such as heavy reliance on measurements with optical photons to determine instrument alignment, and use of an integrating sphere rather than a telescope to feed the completed instrument at its operating temperature. The tests of the completed instrument were conducted in a cryostat of unique design that allowed us to achieve the ultra-low background levels the instrument will encounter in space. We controlled the instrument through simulators of the mission operations control system and the SIRTF spacecraft electronics, and used cabling virtually identical to that which will be used in SIRTF. This realistic environment led to confidence in the ultimate operability of the instrument. The test philosophy allowed complete verification of the instrument performance and showed it to be similar to pre-integration predictions and to meet the instrument requirements

    Six sequence variants on chromosome 9p21.3 are associated with a positive family history of myocardial infarction: a multicenter registry

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Recent genome-wide association studies have identified several genetic loci linked to coronary artery disease (CAD) and myocardial infarction (MI). The 9p21.3 locus was verified by numerous replication studies to be the first common locus for CAD and MI. In the present study, we investigated whether six single nucleotide polymorphisms (SNP) rs1333049, rs1333040, rs10757274, rs2383206, rs10757278, and rs2383207 representing the 9p21.3 locus were associated with the incidence of an acute MI in patients with the main focus on the familial aggregation of the disease.</p> <p>Methods</p> <p>The overall cohort consisted of 976 unrelated male patients presenting with an acute coronary syndrome (ACS) with ST-elevated (STEMI) as well as non-ST-elevated myocardial infarction (NSTEMI). Genotyping data of the investigated SNPs were generated and statistically analyzed in comparison to previously published findings of matchable control cohorts.</p> <p>Results</p> <p>Statistical evaluation confirmed a highly significant association of all analyzed SNP's with the occurrence of MI (p < 0.0001; OR: 1.621-2.039). When only MI patients with a positive family disposition were comprised in the analysis a much stronger association of the accordant risk alleles with incident disease was found with odds ratios up to 2.769.</p> <p>Conclusions</p> <p>The findings in the present study confirmed a strong association of the 9p21.3 locus with MI particularly in patients with a positive family history thereby, emphasizing the pathogenic relevance of this locus as a common genetic cardiovascular risk factor.</p

    A role for heparan sulfate proteoglycans in Plasmodium falciparum sporozoite invasion of anopheline mosquito salivary glands

    Get PDF
    HS (heparan sulfate) has been shown to be an important mediator of Plasmodium sporozoite homing and invasion of the liver, but the role of this glycosaminoglycan in mosquito vector host–sporozoite interactions is unknown. We have biochemically characterized the function of AgOXT1 (Anopheles gambiae peptide-O-xylosyltransferase 1) and confirmed that AgOXT1 can modify peptides representing model HS and chondroitin sulfate proteoglycans in vitro. Moreover, we also demonstrated that the mosquito salivary gland basal lamina proteoglycans are modified by HS. We used RNA interference-mediated knockdown of HS biosynthesis in A. gambiae salivary glands to determine whether Plasmodium falciparum sporozoites that are released from mosquito midgut oocysts use salivary gland HS as a receptor for tissue invasion. Our results suggest that salivary gland basal lamina HS glycosaminoglycans only partially mediate midgut sporozoite invasion of this tissue, and that in the absence of HS, the presence of other surface co-receptors is sufficient to facilitate parasite entry

    Force spectroscopy in studying infection

    Get PDF
    Biophysical force spectroscopy tools - for example optical tweezers, magnetic tweezers, atomic force microscopy, - have been used to study elastic, mechanical, conformational and dynamic properties of single biological specimens from single proteins to whole cells to reveal information not accessible by ensemble average methods such as X-ray crystallography, mass spectroscopy, gel electrophoresis and so on. Here we review the application of these tools on a range of infection-related questions from antibody-inhibited protein processivity to virus-cell adhesion. In each case we focus on how the instrumental design tailored to the biological system in question translates into the functionality suitable for that particular study. The unique insights that force spectroscopy has gained to complement knowledge learned through population averaging techniques in interrogating biomolecular details prove to be instrumental in therapeutic innovations such as those in structure-based drug design

    Comprehensive analysis of temporal alterations in cellular proteome of bacillus subtilis under curcumin treatment

    Get PDF
    Curcumin is a natural dietary compound with antimicrobial activity against various gram positive and negative bacteria. This study aims to investigate the proteome level alterations in Bacillus subtilis due to curcumin treatment and identification of its molecular/cellular targets to understand the mechanism of action. We have performed a comprehensive proteomic analysis of B. subtilis AH75 strain at different time intervals of curcumin treatment (20, 60 and 120 min after the drug exposure, three replicates) to compare the protein expression profiles using two complementary quantitative proteomic techniques, 2D-DIGE and iTRAQ. To the best of our knowledge, this is the first comprehensive longitudinal investigation describing the effect of curcumin treatment on B. subtilis proteome. The proteomics analysis revealed several interesting targets such UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1, putative septation protein SpoVG and ATP-dependent Clp protease proteolytic subunit. Further, in silico pathway analysis using DAVID and KOBAS has revealed modulation of pathways related to the fatty acid metabolism and cell wall synthesis, which are crucial for cell viability. Our findings revealed that curcumin treatment lead to inhibition of the cell wall and fatty acid synthesis in addition to differential expression of many crucial proteins involved in modulation of bacterial metabolism. Findings obtained from proteomics analysis were further validated using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) assay for respiratory activity, resazurin assay for metabolic activity and membrane integrity assay by potassium and inorganic phosphate leakage measurement. The gene expression analysis of selected cell wall biosynthesis enzymes has strengthened the proteomics findings and indicated the major effect of curcumin on cell division
    corecore