363 research outputs found

    Nitrogen and phosphorus limitation of oceanic microbial growth during spring in the Gulf of Aqaba

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    Bioassay experiments were performed to identify how growth of key groups within the microbial community was simultaneously limited by nutrient (nitrogen and phosphorus) availability during spring in the Gulf of Aqaba's oceanic waters. Measurements of chlorophyll a (chl a) concentration and fast repetition rate (FRR) fluorescence generally demonstrated that growth of obligate phototrophic phytoplankton was co-limited by N and P and growth of facultative aerobic anoxygenic photoheterotropic (AAP) bacteria was limited by N. Phytoplankton exhibited an increase in chl a biomass over 24 to 48 h upon relief of nutrient limitation. This response coincided with an increase in photosystem II (PSII) photochemical efficiency (F v /F m), but was preceded (within 24 h) by a decrease in effective absorption crosssection (σPSII) and electron turnover time (τ). A similar response for τ and bacterio-chl a was observed for the AAPs. Consistent with the up-regulation of PSII activity with FRR fluorescence were observations of newly synthesized PSII reaction centers via low temperature (77K) fluorescence spectroscopy for addition of N (and N + P). Flow cytometry revealed that the chl a and thus FRR fluorescence responses were partly driven by the picophytoplankton (æ10 μm) community, and in particular Synechococcus. Productivity of obligate heterotrophic bacteria exhibited the greatest increase in response to a natural (deep water) treatment, but only a small increase in response to N and P addition, demonstrating the importance of additional substrates (most likely dissolved organic carbon) in moderating the heterotrophs. These data support previous observations that the microbial community response (autotrophy relative to heterotrophy) is critically dependent upon the nature of transient nutrient enrichment. © Inter-Research 2009

    Mechanical Percussion Devices: A Survey of Practice Patterns Among Healthcare Professionals

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    # Background Mechanical percussion devices have become popular among sports medicine professionals. These devices provide a similar effect as manual percussion or tapotement used in therapeutic massage. To date, there are few published studies or evidence-based guidelines for these devices. There is a need to understand what professionals believe about this technology and how they use these devices in clinical practice. # Purpose To survey and document the knowledge, clinical application methods, and use of mechanical percussion devices among healthcare professionals in the United States. # Design Cross-sectional survey study. # Methods A 25 question online survey was emailed to members of the National Athletic Trainers Association, Academy of Orthopedic Physical Therapy, and American Academy of Sports Physical Therapy. # Results Four hundred twenty-five professionals completed the survey. Most professionals (92%, n=391) used devices from two manufacturers: Hyperice® and Theragun®. Seventy-seven percent directed clients to manufacturer and generic websites (n=329) to purchase devices. Most respondents used a medium and low device speed setting for pre- and post-exercise (62%, n=185), pain modulation (59%, n=253), and myofascial mobility (52%, n=222). A large proportion of respondents preferred a total treatment time between 30 seconds and three minutes (36-48%, n=153-204) or three to five minutes (18-22%, n=76-93). Most respondents (54-69%, n=229-293) believed that mechanical percussion increases local blood flow, modulates pain, enhances myofascial mobility, and reduces myofascial restrictions. Most respondents (72%, n=305) were influenced by other colleagues to use these devices. Sixty-six percent used patient reported outcomes (n=280) to document treatment efficacy. Live instruction was the most common mode of education (79%, n=334). # Conclusion These results are a starting point for future research and provide insight into how professionals use mechanical percussion devices. This survey also highlights the existing gap between research and practice. Future research should examine the efficacy of this technology and determine consensus-based guidelines. # Level of Evidence

    Short-term variability in euphotic zone biogeochemistry and primary productivity at Station ALOHA : a case study of summer 2012

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    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 29 (2015): 1145–1164, doi:10.1002/2015GB005141.Time-series observations are critical to understand the structure, function, and dynamics of marine ecosystems. The Hawaii Ocean Time-series program has maintained near-monthly sampling at Station ALOHA (22°45′N, 158°00′W) in the oligotrophic North Pacific Subtropical Gyre (NPSG) since 1988 and has identified ecosystem variability over seasonal to interannual timescales. To further extend the temporal resolution of these near-monthly time-series observations, an extensive field campaign was conducted during July–September 2012 at Station ALOHA with near-daily sampling of upper water-column biogeochemistry, phytoplankton abundance, and activity. The resulting data set provided biogeochemical measurements at high temporal resolution and documents two important events at Station ALOHA: (1) a prolonged period of low productivity when net community production in the mixed layer shifted to a net heterotrophic state and (2) detection of a distinct sea-surface salinity minimum feature which was prominent in the upper water column (0–50 m) for a period of approximately 30 days. The shipboard observations during July–September 2012 were supplemented with in situ measurements provided by Seagliders, profiling floats, and remote satellite observations that together revealed the extent of the low productivity and the sea-surface salinity minimum feature in the NPSG.NOAA Climate Observation Division; National Science Foundation (NSF) Center for Microbial Oceanography: Research and Education (C-MORE) Grant Numbers: EF0424599, OCE-1153656, OCE-1260164; Gordon and Betty Moore Foundation Marine Microbiology Investigator2016-02-1

    PENGARUH TEKANAN KETAATAN DAN KOMPLEKSITAS TUGAS TERHADAP AUDIT JUDGMENT (Survey Terhadap Lima Kantor AkuntanPublik di Kota Bandung)

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    ABSTRAK Seperti yang kita ketahui bahwa seorang auditor dalam melakukan tugasnya membuat audit judgment dipengaruhi banyak faktor, baik bersifat teknis dan non teknis. Salah satu faktor non teknis adalah aspek perilaku individual. Aspek perilaku individu, sebagai salah satu faktor yang banyak mempengaruhi pembuatan audit judgment. Pada penelitian ini ada beberapa faktor yang mempengaruhi audit judgment yaitu tekanan ketaatan dan kompleksitas tugas. Dalam penelitian ini penullis ingin mengetahui sejauh mana “tekanan ketaatan dan kompleksitas tugas terhadap audit judgment”. Sedangkan tujuan dari penelitian ini adalah untuk mengetahui dan mempelajari tekanan ketaatan dan kompleksitas tugas terhadap audit judgment. Hipotesis yang diuji dalam penelitian ini adalah “ jika tekanan ketaatan dan kompleksitas tugas baik, maka audit judgment akan meningkat ( baik pula)”. Hipotesis ini berdasarkan asumsi bahwa tekanan ketaatan dan kompleksitas tugas berpengaruh terhadap audit judgment.dalam penelitian ini penulis menggunakan metode deskriptif asosiatif dengan pendekatan survey dan tes statistik. Penelitian ini terdiri dari atas variabel X1 dan X2 dan audit judgment sebagai veriabel Y atau variabel independen. Uji statistik dilakukan dengan mengolah data dari hasil jawaban kuesioner. Dalam penelitian ini, peulis menyebarkan angket kepada 5 Kantor Akuntan Publik di Kota Bandung khusunya untuk para auditor. Pengumpulan data dilakukan dengan cara penyebaran kuesioner yang telah diuji validitasnya dan reabilitasnya. Penelitian ini dilakukan di 5 KAP di Kota Bandung. Pengambilan sampel ini menggunakan purposive sampling berukuran 28 orang responden. Untuk uji hipotesis penelitian, penulis melakukannya dengan uji t untuk masing-masing variabel X1,X2, dan Y. Dari hasil uji tHitung tekanan ketaatan terhadap audit judgment tHitung =4,178>ttabel = 1.705 kompleksitas tugas terhadap audit judgment 5 tHitung = 3.364 > ttabel = 1,705. Maka, dari hasil uji hipotesis tersebut penulis menyimpulkan bahwa hipotesis penelitian diterima (Ho ditolak, Ha diterima) artinya terdapat pengaruh antara terkanan ketaatan terhadap audit judgment dan kompleksitas tugas terhadap audit judgment Untuk mencari besarnya pengaruh Tekanan ketaatan dan Kompleksitas Tugas terhadap Audit Judgment secara simultan penulis melakukannya dengan uji f dengan koefisien determinasi (KD). Dari hasil uji fhitung dan > f table yaitu 16,182>3,370. Kata kunci : Tekanan Ketaatan dan Kompleksitas tugas Terhadap Audit Judgmen

    Effect of manipulation of primary tumour vascularity on metastasis in an adenocarcinoma model

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    One explanation for the clinical association between tumour vascularity and probability of metastasis is that increased primary tumour vascularity enhances haematogenous dissemination by offering greater opportunity for tumour cell invasion into the circulation (intravasation). We devised an experimental tumour metastasis model that allowed manipulation of primary tumour vascularity with differential exposure of the primary and metastatic tumour site to angiogenic agents. We used this model to assess the effects of local and systemic increases in the level of the angiogenic agent basic fibroblast growth factor on metastasis. BDIX rats with implanted hind limb K12/TR adenocarcinoma tumours received either intratumoural or systemic, basic fibroblast growth factor or saline infusion. Both intratumoural and systemic basic fibroblast growth factor infusion resulted in significant increases in tumour vascularity, blood flow and growth, but not lung metastasis, compared with saline-infused controls. Raised basic fibroblast growth factor levels and increase in primary tumour vascularity did not increase metastasis. The clinical association between tumour vascularity and metastasis is most likely to arise from a metastatic tumour genotype that links increased tumour vascularity with greater metastatic potential

    Surplus Photosynthetic Antennae Complexes Underlie Diagnostics of Iron Limitation in a Cyanobacterium

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    Chlorophyll fluorescence from phytoplankton provides a tool to assess iron limitation in the oceans, but the physiological mechanism underlying the fluorescence response is not understood. We examined fluorescence properties of the model cyanobacterium Synechocystis PCC6803 and a ΔisiA knock-out mutant of the same species grown under three culture conditions which simulate nutrient conditions found in the open ocean: (1) nitrate and iron replete, (2) limiting-iron and high-nitrate, representative of natural high-nitrate, low-chlorophyll regions, and (3) iron and nitrogen co-limiting. We show that low variable fluorescence, a key diagnostic of iron limitation, results from synthesis of antennae complexes far in excess of what can be accommodated by the iron-restricted pool of photosynthetic reaction centers. Under iron and nitrogen co-limiting conditions, there are no excess antennae complexes and variable fluorescence is high. These results help to explain the well-established fluorescence characteristics of phytoplankton in high-nutrient, low-chlorophyll ocean regions, while also accounting for the lack of these properties in low-iron, low-nitrogen regions. Importantly, our results complete the link between unique molecular consequences of iron stress in phytoplankton and global detection of iron stress in natural populations from space

    The Photosynthetic Apparatus and Its Regulation in the Aerobic Gammaproteobacterium Congregibacter litoralis gen. nov., sp. nov

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    BACKGROUND: There is accumulating evidence that in some marine environments aerobic bacteriochlorophyll a-producing bacteria represent a significant part of the microbial population. The interaction of photosynthesis and carbon metabolism in these interesting bacteria is still largely unknown and requires further investigation in order to estimate their contribution to the marine carbon cycle. METHODOLOGY/PRINCIPAL FINDINGS: Here, we analyzed the structure, composition and regulation of the photosynthetic apparatus in the obligately aerobic marine gammaproteobacterium KT71(T). Photoheterotrophically grown cells were characterized by a poorly developed lamellar intracytoplasmic membrane system, a type 1 light-harvesting antenna complex and a photosynthetic reaction center associated with a tetraheme cytochrome c. The only photosynthetic pigments produced were bacteriochlorophyll a and spirilloxanthin. Under semiaerobic conditions KT71(T) cells expressing a photosynthetic apparatus showed a light-dependent increase of growth yield in the range of 1.3-2.5 fold. The expression level of the photosynthetic apparatus depended largely on the utilized substrate, the intermediary carbon metabolism and oxygen tension. In addition, pigment synthesis was strongly influenced by light, with blue light exerting the most significant effect, implicating that proteins containing a BLUF domain may be involved in regulation of the photosynthetic apparatus. Several phenotypic traits in KT71(T) could be identified that correlated with the assumed redox state of growing cells and thus could be used to monitor the cellular redox state under various incubation conditions. CONCLUSIONS/SIGNIFICANCE: In a hypothetical model that explains the regulation of the photosynthetic apparatus in strain KT71(T) we propose that the expression of photosynthesis genes depends on the cellular redox state and is maximal under conditions that allow a balanced membrane redox state. So far, bacteria capable of an obligately aerobic, photosynthetic metabolism constitute a unique phenotype within the class Gammaproteobacteria, so that it is justified to propose a new genus and species, Congregibacter litoralis gen. nov, sp. nov., represented by the type strain KT71(T) ( = DSM 17192(T) = NBRC 104960(T))

    Benign Ancient Schwannoma of the abdominal wall: An unwanted birthday present

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    <p>Abstract</p> <p>Background</p> <p>There has been a recent growth in the use of whole body Computerised Tomography (CT) scans in the private sector as a screening test for asymptomatic disease. This is despite scant evidence to show any positive effect on morbidity or mortality. There has been concern raised over the possible harms of the test in terms of radiation exposure as well as the risk and anxiety of further investigation and treatment for the large numbers of benign lesions identified.</p> <p>Case Presentation</p> <p>A healthy 64 year old lady received a privately funded whole body CT scan for her birthday which revealed an incidental mass in the right iliac fossa. This was investigated with further imaging and colonoscopy and as confident diagnosis could not be made, eventually excised. Histology demonstrated this to be a benign ancient schwannoma and we believe this to be the first reported case of an abdominal wall schwannoma in the English literature</p> <p>Conclusions</p> <p>Ancient schwannomas are rare tumours of the peripheral nerve sheaths more usually found in the head, neck and flexor surfaces of extremities. They are a subtype of classical schwannomas with a predominance of degenerative changes. Our case highlights the pitfalls of such screening tests in demonstrating benign disease and subjecting patients to what turns out to be unnecessary invasive investigation and treatment. It provides evidence as to the consequences of the large number of false positive results that are created by blind CT scanning of asymptomatic patients i.e. its tendency to detect pseudodiesease rather than affect survival rates. Should the number of scans increase there may be an unnecessary burden on NHS resources due to the large numbers of benign lesions picked up, that are then referred for further investigation.</p

    Development of a 3D workspace Shoulder Assessment Tool Incorporating Electromyography and an Inertial Measurement Unit - A preliminary study

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    Traditional shoulder Range of Movement (ROM) measurement tools suffer from inaccuracy or from long experimental set-up times. Recently, it has been demonstrated that relatively low-cost wearable inertial measurement unit (IMU) sensors can overcome many of the limitations of traditional motion tracking systems. The aim of this study is to develop and evaluate a single IMU combined with an Electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. Six volunteer subjects with healthy shoulders and one participant with a ‘frozen’ shoulder were recruited to the study. Arm movement in 3D space was plotted in spherical coordinates while the relative EMG intensity of any arm position is presented graphically. The results showed that there was an average ROM surface area of 27291±538 deg2 among all six healthy individuals and a ROM surface area of 13571±308 deg2 for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace

    Improving hypertension management through pharmacist prescribing; the rural alberta clinical trial in optimizing hypertension (Rural RxACTION): trial design and methods

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    <p>Abstract</p> <p>Background</p> <p>Patients with hypertension continue to have less than optimal blood pressure control, with nearly one in five Canadian adults having hypertension. Pharmacist prescribing is gaining favor as a potential clinically efficacious and cost-effective means to improve both access and quality of care. With Alberta being the first province in Canada to have independent prescribing by pharmacists, it offers a unique opportunity to evaluate outcomes in patients who are prescribed antihypertensive therapy by pharmacists.</p> <p>Methods</p> <p>The study is a randomized controlled trial of enhanced pharmacist care, with the unit of randomization being the patient. Participants will be randomized to enhanced pharmacist care (patient identification, assessment, education, close follow-up, and prescribing/titration of antihypertensive medications) or usual care. Participants are patients in rural Alberta with undiagnosed/uncontrolled blood pressure, as defined by the Canadian Hypertension Education Program. The primary outcome is the change in systolic blood pressure between baseline and 24 weeks in the enhanced-care versus usual-care arms. There are also three substudies running in conjunction with the project examining different remuneration models, investigating patient knowledge, and assessing health-resource utilization amongst patients in each group.</p> <p>Discussion</p> <p>To date, one-third of the required sample size has been recruited. There are 15 communities and 17 pharmacists actively screening, recruiting, and following patients. This study will provide high-level evidence regarding pharmacist prescribing.</p> <p>Trial Registration</p> <p>Clinicaltrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00878566">NCT00878566</a>.</p
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