224 research outputs found

    The microbial ecology and colonisation of surfaces in selected hot springs - a molecular-and culture-based approach

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    Traditionally, culture-based approaches have been used to investigate the microbial ecology of thermal habitats. The emergence of alternate molecular approaches based on DNA sequences has shown that terrestrial thermal environments have a rich diversity of uncultured prokaryotes. To the best of our knowledge these latter approaches have not previously been applied to New Zealand thermal environments and this became the central aim of this study. The major objective of the study was to target the metabolically active members of the hot pool community by applying a suite of molecular and microscopical techniques to those species colonising surfaces incubated in situ in the hot pools. Two neutral pH pools were investigated in some detail; pool KP1 at 75°C and pool AQ1 at 95°C. Surfaces in pool KP1 were colonised by a high diversity of bacteria (archaea were not detected), as evidenced by complex denaturing gradient gel electrophoresis (DGGE) profiles, and many different species were obtained in enrichment culture. Although colonisation rates were greater in pool AQ1, this was entirely due to only two observed morphotypes and was reflected in DGGE profiles that reflected only two dominant archaeal species. A 16S rDNA clone library of the AQ1 pool water and DGGE profiles of both pool water and colonised slides were dominated by rods of the species Pyrobaculum. Slides incubated deep within AQ1 were also colonised by cocci, the closest cultured relative being Aeropyrum pernix, a marine hyperthermophile. Two pure cultures were obtained from pool AQ1, Pyrobaculum sp. (AQ1.S2) and a novel crenarchaeaotal coccus, (AQ1.S1T). Isolations of the latter organism were also obtained from two other pools in New Zealand. These were obtained as obligate co-cultures with Pyrobaculum rods and could not be isolated into pure culture. A full description of this novel genus of organisms has been accepted for publication in the International Journal of Systematic and Evolutionary Microbiology, with the isolate from pool AQ1 named as the type strain lgnisphaera aggregans AQl .S1T. The techniques used to follow colonisation were then applied to a survey of high-temperature pools of New Zealand (>80°C, pH 5.5-9.7), White Island (72-94°C, pH 1.5-3.8) and Yellowstone National Park (75-92.5°C, pH 5.0-8.0). For New Zealand, bacteria were detected by DGGE on colonised slides in pools below 88°C, and archaea, only in pools above 83°C. Bacterial colonisers with dominant signatures included those of Thermodesulfobacteria and Aquificales species, though interestingly, isolations of these organisms were not obtained. The archaeal colonisers were pH dependent: pools with a pH of 6.0-7.0 had a dominant Thermofilum signature; pools above pH 7.0 had both a Pyrobaculum sp. and a relative of the Desulfurococcales; and the acidic pools (including White Island) were dominated by Sulfolobus sp. Pool water DGGE profiles of the New Zealand pools differed from slide colonisation profiles in some respects, e.g. Thermococcus sp. were only detected in pool water. In contrast to the New Zealand results, the Yellowstone National Park slides were dominated by bacteria, with bacterial signatures detected in high-temperature pools (87-92.5°C); representative DGGE bands were sequenced and found to be related to the Aquificales. Nanoarchaeal l 6S rDNA PCR amplicons were also obtained from pool water for most of the New Zealand pools (closest relative of AQ1 amplicon being a nanoarchaeal clone from the Uzon Caldera), including the Pyrobaculum sp. AQl .S2 culture. Attempts were also made to isolate marine nanoarchaea from nascent hydrothermal vents situated on the East Pacific Rise; however, these were unsuccessful

    Die Schule von Salamanca: eine digitale Quellensammlung und ein Wörterbuch ihrer juristischpolitischen Sprache : zu Grundanliegen und Struktur eines Forschungsvorhabens

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    Das im Jahr 2013 begonnene und für einen Zeitraum von 18 Jahren konzipierte Forschungsvorhaben zielt auf die Erstellung eines historisch-semantischen Wörterbuchs zum Denken der Schule von Salamanca und ihrer Bedeutung für politische Theorie und Recht in der Moderne. Als Grundlage dieses Wörterbuchs wird ein digitales Corpus von zentralen Texten der Schule von Salamanca aufgebaut, das mit der elektronischen Version des Wörterbuchs verknüpft ist und der internationalen und interdisziplinären Forschergemeinschaft direkten Zugriff auf die einschlägigen Quellentexte ermöglicht. Durch die Volltexterschließung der digitalen Quellen wird zugleich ein in seiner Funktionalität neuartiges elektronisches Arbeitsinstrument geschaffen, das einen wichtigen Fortschritt gegenüber allen bisherigen Digitalisierungsprojekten in diesem Bereich darstellt. Dieses Arbeitsinstrument wird auch über seine Funktionalität für das zu erstellende Wörterbuch hinaus qualitativ neue Forschungsmöglichkeiten eröffnen. Beides – Wörterbuch und Quellencorpus – werden in einem repository erfasst und über eine Webseite als Forschungsinstrument der internationalen scientific community zur Verfügung gestellt. Das Wörterbuch wird zum Schluss der letzten Arbeitsphase zusätzlich in Buchform publiziert. Die weltweite Forschung zur Schule von Salamanca und zu ihrer Wirkungsgeschichte wird damit zum ersten Mal Zugriff auf ein gemeinsames Textcorpus haben und über einen intellektuellen Referenzrahmen für dessen historische Unter-suchung und interdisziplinäre Diskussion verfügen. Dieser Beitrag soll Ausgangslage und Zielsetzung des Vorhabens zusammenfassen (1.), das geplante Quellencorpus (2.), das Wörterbuch (3.) und den Arbeitsplan (4.) vorstellen.The article introduces a research project financed by the Academy of Sciences and Literature Mainz which has taken up work in 2013 and is conceived for a term of 18 years. It aims at producing a historical-semantic dictionary elucidating central terms of the School of Salamanca’s discourses and their significance for modern political theory and jurisprudence. The project’s fundament will be a digital corpus of important texts from the School of Salamanca which will be linked up with the dictionary’s online version. By making the source corpus accessible in searchable full text (as well as in high quality digital images), the project is creating a new research tool with exciting possibilities for further investigations. The dictionary will be a valuable source of information for the interdisciplinary research carried out in this field

    Management of medication overuse (MO) and medication overuse headache (MOH) S1 guideline.

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    INTRODUCTION Chronic headache due to the overuse of medication for the treatment of migraine attacks has a prevalence of 0.5-2.0%. This guideline provides guidance for the management of medication overuse (MO) and medication overuse headache (MOH). RECOMMENDATIONS Treatment of headache due to overuse of analgesics or specific migraine medications involves several stages. Patients with medication overuse (MO) or medication overuse headache (MOH) should be educated about the relationship between frequent use of symptomatic headache medication and the transition from episodic to chronic migraine (chronification), with the aim of reducing and limiting the use of acute medication. In a second step, migraine prophylaxis should be initiated in patients with migraine and overuse of analgesics or specific migraine drugs. Topiramate, onabotulinumtoxinA and the monoclonal antibodies against CGRP or the CGRP-receptor are effective in patients with chronic migraine and medication overuse. In patients with tension-type headache, prophylaxis is performed with amitriptyline. Drug prophylaxis should be supplemented by non-drug interventions. For patients in whom education and prophylactic medication are not effective, pausing acute medication is recommended. This treatment can be performed in an outpatient, day hospital or inpatient setting. Patients with headache due to overuse of opioids should undergo inpatient withdrawal. The success rate of the stepped treatment approach is 50-70% after 6 to 12 months. A high relapse rate is observed in patients with opioid overuse. Tricyclic antidepressants, neuroleptics (antiemetics) and the administration of steroids are recommended for the treatment of withdrawal symptoms or headaches during the medication pause. Consistent patient education and further close monitoring reduce the risk of relapse

    Carbon-fixation rates and associated microbial communities residing in arid and ephemerally wet Antarctic Dry Valley soils

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    Carbon-fixation is a critical process in severely oligotrophic Antarctic Dry Valley (DV) soils and may represent the major source of carbon in these arid environments. However, rates of C-fixation in DVs are currently unknown and the microorganisms responsible for these activities unidentified. In this study, C-fixation rates measured in the bulk arid soils (<5% moisture) ranged from below detection limits to ∼12 nmol C/cc/h. Rates in ephemerally wet soils ranged from ∼20 to 750 nmol C/cc/h, equating to turnover rates of ∼7–140 days, with lower rates in stream-associated soils as compared to lake-associated soils. Sequencing of the large subunit of RuBisCO (cbbL) in these soils identified green-type sequences dominated by the 1B cyanobacterial phylotype in both arid and wet soils including the RNA fraction of the wet soil. Red-type cbbL genes were dominated by 1C actinobacterial phylotypes in arid soils, with wetted soils containing nearly equal proportions of 1C (actinobacterial and proteobacterial signatures) and 1D (algal) phylotypes. Complementary 16S rRNA and 18S rRNA gene sequencing also revealed distinct differences in community structure between biotopes. This study is the first of its kind to examine C-fixation rates in DV soils and the microorganisms potentially responsible for these activities

    Follow-up strategies after trimodal treatment for muscle-invasive bladder cancer: a systematic review

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    PURPOSE: Optimal follow-up strategies following trimodal treatment for muscle invasive bladder cancer play a crucial role in detecting and managing relapse and side-effects. This article provides a comprehensive summary of the patterns and risk factors of relapse, functional outcomes, and follow-up protocols. METHODS: A systematic literature search on PubMed and review of current guidelines and institutional follow-up protocols after trimodal therapy were conducted. RESULTS: Out of 200 identified publications, 43 studies (28 retrospective, 15 prospective) were selected, encompassing 7447 patients (study sizes from 24 to 728 patients). Recurrence rates in the urinary bladder varied between 14-52%; 3-16% were muscle-invasive while 11-36% were non-muscle invasive. Nodal recurrence occurred at 13-16% and distant metastases at 15-35%. After 5 and 10 years of follow-up, around 60-85% and 45-75% of patients could preserve their bladder, respectively. Various prognostic risk factors associated with relapse and inferior survival were proposed, including higher disease stage (> c/pT2), presence of extensive/multifocal carcinoma in situ (CIS), hydronephrosis, multifocality, histological subtypes, incomplete transurethral resection of bladder tumor (TURBT) and incomplete response to radio-chemotherapy. The analyzed follow-up guidelines varied slightly in terms of the number, timing, and types of investigations, but overall, the recommendations were similar. CONCLUSION: Randomized prospective studies should focus on evaluating the impact of specific follow-up protocols on oncological and functional outcomes following trimodal treatment for muscle-invasive bladder cancer. It is crucial to evaluate personalized adaption of follow-up protocols based on established risk factors, as there is potential for improved patient outcomes and resource allocation

    Effect of shunted piezoelectric control for tuning piezoelectric power harvesting system responses – Analytical techniques

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    This paper presents new analytical modelling of shunt circuit control responses for tuning electromechanical piezoelectric vibration power harvesting structures with proof mass offset. For this combination, the dynamic closed-form boundary value equations reduced from strong form variational principles were developed using the extended Hamiltonian principle to formulate the new coupled orthonormalised electromechanical power harvesting equations showing combinations of the mechanical system (dynamical behaviour of piezoelectric structure), electromechanical system (electrical piezoelectric response) and electrical system (tuning and harvesting circuits). The reduced equations can be further formulated to give the complete forms of new electromechanical multi-mode FRFs and time waveform of the standard AC-DC circuit interface. The proposed technique can demonstrate self-adaptive harvesting response capabilities for tuning the frequency band and the power amplitude of the harvesting devices. The self-adaptive tuning strategies are demonstrated by modelling the shunt circuit behaviour of the piezoelectric control layer in order to optimise the harvesting piezoelectric layer during operation under input base excitation. In such situations, with proper tuning parameters the system performance can be substantially improved. Moreover, the validation of the closed-form technique is also provided by developing the Ritz method-based weak form analytical approach giving similar results. Finally, the parametric analytical studies have been explored to identify direct and relevant contributions for vibration power harvesting behaviours

    Novel sulfur-oxidizing streamers thriving in a perennial cold saline springs of the Canadian high Arctic

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    The perennial springs at Gypsum Hill (GH) and Colour Peak (CP), situated at nearly 80\ub0N on Axel Heiberg Island in the Canadian high Arctic, are one of the few known examples of cold springs in thick permafrost on Earth. The springs emanate from deep saline aquifers and discharge cold anoxic brines rich in both sulfide and sulfate. Grey-coloured microbial streamers form during the winter months in snow-covered regions of the GH spring run-off channels (-1.3\ub0C to 6.9\ub0C, ~7.5% NaCl, 0\u201320 p.p.m. dissolved sulfide, 1 p.p.m. dissolved oxygen) but disappear during the Arctic summer. Culture- and molecular-based analyses of the 16S rRNA gene (FISH, DGGE and clone libraries) indicated that the streamers were uniquely dominated by chemolithoautotrophic sulfur-oxidizing Thiomicrospira species. The streamers oxidized both sulfide and thiosulfate and fixed CO2 under in situ conditions and a Thiomicrospira strain isolated from the streamers also actively oxidized sulfide and thiosulfate and fixed CO2 under cold, saline conditions. Overall, the snow-covered spring channels appear to represent a unique polar saline microhabitat that protects and allows Thiomicrospira streamers to form and flourish via chemolithoautrophic, phototrophicindependent metabolism in a high Arctic winter environment characterized by air temperatures commonly below -40\ub0C and with an annual average air temperature of -15\ub0C. These results broaden our knowledge of the physical and chemical boundaries that define life on Earth and have astrobiological implications for the possibility of life existing under similar Martian conditions.NRC publication: Ye

    Rapid microbial dynamics in response to an induced wetting event in Antarctic Dry Valley Soils

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    The cold deserts of the McMurdo Dry Valleys (MDV), Antarctica, host a high level of microbial diversity. Microbial composition and biomass in arid vs. ephemerally wetted regions are distinctly different, with wetted communities representing hot spots of microbial activity that are important zones for biogeochemical cycling. While climatic change is likely to cause wetting in areas not historically subject to wetting events, the responses of microorganisms inhabiting arid soils to water addition is unknown. The purpose of this study was to observe how an associated, yet non-wetted microbial community responds to an extended addition of water. Water from a stream was diverted to an adjacent area of arid soil with changes in microbial composition and activities monitored via molecular and biochemical methods over 7 weeks. The frequency of genetic signatures related to both prokaryotic and eukaryotic organisms adapted to MDV aquatic conditions increased during the limited 7 week period, indicating that the soil community was transitioning into a typical “high-productivity” MDV community. This work is consistent with current predictions that MDV microbial communities in arid regions are highly sensitive to climate change, and further supports the notion that changes in community structure and associated biogeochemical cycling may occur much more rapidly than predicted
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