1,302 research outputs found

    Functional Stomata of the Atmospheric Epiphyte Tillandsia Usneoides L.

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    This is the publisher's version, also available electronically from: http://www.jstor.org/stable/10.2307/2474260.Although stomatal opening in Tillandsia usneoides is not detectable by light microscopy, the guard cells swell in the dark and in the light in buffers known to stimulate stomatal opening. Abscisic acid or phenylmercuric acetate substantially reduced subsequent nocturnal C 0 2 uptake. Potassium ions were more concentrated in the guard cells in the dark than in the light. The stomata of this CAM epiphyte appear functional: open at night and closed throughout most of the day

    Antibiotic prophylaxis and reflux: Critical review and assessment

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    The use of continuous antibiotic prophylaxis (CAP) was critical in the evolution of vesicoureteral reflux (VUR) from a condition in which surgery was the standard of treatment to its becoming a medically managed condition. The efficacy of antibiotic prophylaxis in the management of VUR has been challenged in recent years, and significant confusion exists as to its clinical value. This review summarizes the critical factors in the history, use, and investigation of antibiotic prophylaxis in VUR. This review provides suggestions for assessing the potential clinical utility of prophylaxis

    Atypical presentation of obstructed hemivagina and ipsilateral renal anomaly

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    Herlyn-Werner-Wunderlich Syndrome, otherwise known as obstructed hemivagina and ipsilateral renal anomaly (OHVIRA), is a rare Müllerian anomalyconsisting of uterine didelphys, hemivaginal septum, and ipsilateral renal agenesis. Patients often present at the onset of menarche with abdominal pain and a pelvic mass from an obstructed hemivagina. We report a child who presented with a febrile urinary tract infection and upon further workup was found to have OHVIRA

    Managing vesicoureteral reflux in children: making sense of all the data [version 1; referees: 2 approved]

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    Current management of vesicoureteral reflux (VUR) in children is the result of a steady albeit controversial evolution of data and thinking related to the clinical impact of VUR and urinary tract infection (UTI) in children, the value of clinical screening, and the relative impact of testing and interventions for VUR. While controversy continues, there is consensus on the importance of bladder dysfunction on VUR outcomes, the likelihood of VUR resolution, and the fact that not all children with VUR require active treatment. Early efforts to define risk stratification hold the most promise to provide more patient-specific treatment of UTI and VUR in children

    Desert Research and Technology Studies Exposure of Lotus Coated Electrodynamic Shield Samples

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    The Lotus dust mitigation coating and the electrodynamic shield (EDS) are two new technologies currently being developed by NASA as countermeasures for addressing dust accumulation for long-duration human space exploration. These combined technologies were chosen by the Habitation Demonstration Unit (HDU) program for desert dust exposure at the Desert Research and Technologies Studies (D-RaTS) test site in Arizona. Characterization of these samples was performed prior to, during and post D-RaTS exposure

    Robotic Assisted Surgery in Pediatric Urology: Current Status and Future Directions

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    The evolution of robotic surgical technology and its application in Pediatric Urology have been rapid and essentially successful. Further development remains limited in three key areas: procedural inefficiencies, cost and integration of surgical and clinical information. By addressing these challenges through technology and novel surgical paradigms, the real potential of surgical robotics in pediatric, as well as adult applications, may ultimately be realized. With this evolution, a continued focus on patient-centered outcomes will be essential to provide optimal guidance to technical innovations

    Effects of Trophic Level and Metamorphosis on Discrimination of Hydrogen Isotopes in a Plant-Herbivore System

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    The use of stable isotopes in ecological studies requires that we know the magnitude of discrimination factors between consumer and element sources. The causes of variation in discrimination factors for carbon and nitrogen have been relatively well studied. In contrast, the discrimination factors for hydrogen have rarely been measured. We grew cabbage looper caterpillars (Trichoplusia ni) on cabbage (Brassica oleracea) plants irrigated with four treatments of deuterium-enriched water (δD = −131, −88, −48, and −2‰, respectively), allowing some of them to reach adulthood as moths. Tissue δD values of plants, caterpillars, and moths were linearly correlated with the isotopic composition of irrigation water. However, the slope of these relationships was less than 1, and hence, discrimination factors depended on the δD value of irrigation water. We hypothesize that this dependence is an artifact of growing plants in an environment with a common atmospheric δD value. Both caterpillars and moths were significantly enriched in deuterium relative to plants by ∼45‰ and 23‰ respectively, but the moths had lower tissue to plant discrimination factors than did the caterpillars. If the trophic enrichment documented here is universal, δD values must be accounted for in geographic assignment studies. The isotopic value of carbon was transferred more or less faithfully across trophic levels, but δ15N values increased from plants to insects and we observed significant non-trophic 15N enrichment in the metamorphosis from larvae to adult

    Isolation of Novel Trypanosomatid, Zelonia australiensis sp. nov. (Kinetoplastida: Trypanosomatidae) Provides Support for a Gondwanan Origin of Dixenous Parasitism in the Leishmaniinae

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    © 2017 Barratt et al. The genus Leishmania includes approximately 53 species, 20 of which cause human leishmaniais; a significant albeit neglected tropical disease. Leishmaniasis has afflicted humans for millennia, but how ancient is Leishmania and where did it arise? These questions have been hotly debated for decades and several theories have been proposed. One theory suggests Leishmania originated in the Palearctic, and dispersed to the New World via the Bering land bridge. Others propose that Leishmania evolved in the Neotropics. The Multiple Origins theory suggests that separation of certain Old World and New World species occurred due to the opening of the Atlantic Ocean. Some suggest that the ancestor of the dixenous genera Leishmania, Endotrypanum and Porcisia evolved on Gondwana between 90 and 140 million years ago. In the present study a detailed molecular and morphological characterisation was performed on a novel Australian trypanosomatid following its isolation in Australia’s tropics from the native black fly, Simulium (Morops) dycei Colbo, 1976. Phylogenetic analyses were conducted and confirmed this parasite as a sibling to Zelonia costaricensis, a close relative of Leishmania previously isolated from a reduviid bug in Costa Rica. Consequently, this parasite was assigned the name Zelonia australiensis sp. nov. Assuming Z. costaricensis and Z. australiensis diverged when Australia and South America became completely separated, their divergence occurred between 36 and 41 million years ago at least. Using this vicariance event as a calibration point for a phylogenetic time tree, the common ancestor of the dixenous genera Leishmania, Endotrypanum and Porcisia appeared in Gondwana approximately 91 million years ago. Ultimately, this study contributes to our understanding of trypanosomatid diversity, and of Leishmania origins by providing support for a Gondwanan origin of dixenous parasitism in the Leishmaniinae

    Reporting of factorial trials of complex interventions in community settings: a systematic review

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    <p>Abstract</p> <p>Background</p> <p>Standards for the reporting of factorial randomised trials remain to be established. We aimed to review the quality of reporting of methodological aspects of published factorial trials of complex interventions in community settings.</p> <p>Methods</p> <p>We searched MEDLINE, EMBASE, PsychInfo and the Cochrane Controlled Trials Register to identify factorial randomised trials of complex interventions in community settings from January 2000 to August 2009. We also conducted a citation search of two review papers published in 2003. Data were extracted by two reviewers on 22 items relating to study design, analysis and presentation.</p> <p>Results</p> <p>We identified 5941 unique titles, from which 116 full papers were obtained and 76 were included in the review. The included trials reflected a broad range of target conditions and types of intervention. The median sample size was 400 (interquartile range 191-1001). Most (88%) trials employed a 2 × 2 factorial design. Few trials (21%) explicitly stated the rationale for using a factorial design. Reporting of aspects of design, analysis or presentation specific to factorial trials was variable, but there was no evidence that reporting of these aspects was different for trials published before or after 2003. However, for CONSORT items that apply generally to the reporting of all trials, there was some evidence that later studies were more likely to report employing an intention-to-treat (ITT) approach (78% vs 52%), present appropriate between-group estimates of effect (88% vs 63%), and present standard errors or 95% confidence intervals for such estimates (78% vs 56%). Interactions between interventions and some measure of the precision associated with such effects were reported in only 14 (18%) trials.</p> <p>Conclusions</p> <p>Reports of factorial trials of complex interventions in community settings vary in the amount of information they provide regarding important methodological aspects of design and analysis. This variability supports the extension of CONSORT guidelines to include the specific reporting of factorial trials.</p

    The Impact of Operation Bushmaster on Medical Student Decision-making in a High-Stress, Operational Environment.

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    INTRODUCTION: Operation Bushmaster is a high-fidelity military medical field practicum for fourth-year medical students at the Uniformed Services University. During Operation Bushmaster, students treat live-actor and mannequin-based simulated patients in wartime scenarios throughout the five-day practicum. This study explored the impact of participating in Operation Bushmaster on students\u27 decision-making in a high-stress, operational environment, a crucial aspect of their future role as military medical officers. MATERIALS AND METHODS: A panel of emergency medicine physician experts used a modified Delphi technique to develop a rubric to evaluate the participants\u27 decision-making abilities under stress. The participants\u27 decision-making was assessed before and after participating in either Operation Bushmaster (control group) or completing asynchronous coursework (experimental group). A paired-samples t-test was conducted to detect any differences between the means of the participants\u27 pre- and posttest scores. This study was approved by the Institutional Review Board at Uniformed Services University #21-13079. RESULTS: A significant difference was detected in the pre- and posttest scores of students who attended Operation Bushmaster (P \u3c .001), while there was no significant difference in the pre- and posttest scores of students who completed online, asynchronous coursework (P = .554). CONCLUSION: Participating in Operation Bushmaster significantly improved the control group participants\u27 medical decision-making under stress. The results of this study confirm the effectiveness of high-fidelity simulation-based education for teaching decision-making skills to military medical students
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