Macroecology of methane-oxidizing bacteria: the β-diversity of pmoA genotypes in tropical and subtropical rice paddies

Studies addressing microbial biogeography have increased during the past decade, but research on microbial distribution patterns is still in its infancies, and many aspects are only poorly understood. Here, we compared the methanotroph community in paddy soils sampled in Indonesia, Vietnam, China and Italy, focusing on the distance-decay relationship. We used the pmoA gene as marker for methanotroph diversity in terminal restriction fragment length polymorphism, microarray and pyrosequencing approaches. We could observe a significant increase of -diversity with geographical distance across continents (12000km). Measured environmental parameters explained only a small amount of data variation, and we found no evidence for dispersal limitation. Thus, we propose historical contingencies being responsible for the observed patterns. Furthermore, we performed an in-depth analysis of type II methanotroph pmoA distribution at the sequence level. We used ordination analysis to project sequence dissimilarities into a three-dimensional space (multidimensional scaling). The ordination suggests that type II methanotrophs in paddy fields can be divided into five major groups. However, these groups were found to be distributed in all soils independent of the geographic origin. By including tropical field sites (Indonesia and Vietnam) into the analysis, we further observed the first paddy fields harbouring a methanotroph community depleted in type II methanotrophs

Ciliaten (Protozoa, Ciliophora) des Reisfeldbodens

Reisfeldböden sind die Bodenökosysteme, die während der letzten Dekade am intensivsten studiert wurden. Dabei haben sich Reisfeldböden in den letzten Jahren als geeignetes Modellökosystem zur Untersuchung von mikrobiellen Populationen und biogeochemischen Prozessen im Boden bewährt. Der Einfluß anderer wichtiger Bodenorganismen, wie der Protozoen, wurde bisher nicht studiert. Um den Einfluß dieser Organismen auf die mikrobielle Gemeinschaft (Bakteria und Archaea) und Biogeochemie von anoxischen Reisfeldböden abschätzen zu können, wurde stellvertretend das Taxon Ciliophora Doflein, 1904 als repräsentative und häufige Gruppe der Protozoa untersucht. In dem untersuchten italienischen Reisfeldboden wurden insgesamt 52 Taxa gefunden. Zusätzlich wurde Reisfeldboden anoxisch mit Wasser gesättigt (aber nicht geflutet), für ca. 160 Tage inkubiert. In diesen anoxischen Inkubationen wurden 23 Taxa entdeckt, wovon bisher nur 7 als obligat anaerob bekannt waren. Die anderen 16 Taxa sind als fakultativ anaerobe Taxa anzusehen. Dies zeigte, daß die Toleranz gegen anoxische Verhältnisse unter den Ciliaten des Bodens weiter verbreitet ist als bisher angenommen. Die Zellzahlen in den anoxischen Inkubationen lagen zwischen 34 und 190 Zellen gTG-1 Boden. Bezogen auf Zellzahlen und Biovolumenanteil dominierten in den anoxischen Inkubationen kontinuierlich Arten der obligat anaeroben Gattung Metopus. Weiterhin wurde der Einfluß der Ciliatenfauna auf die mikrobielle Gemeinschaft untersucht. Dabei unterschieden sich die Verteilungen der mikrobiellen Biovolumina an zwei Meßzeitpunkten (Tag 4 und Tag 80) deutlich voneinander. An Tag 4 wurden auch größte und kleinste Zellvolumina (Volumen von 0,25 – 2,25 µm3) gefunden. Eine solche Verteilung der Zellgrößen ist typisch für durch Protozoen beweidete Mikroorganismen. Nach 80 Tagen wurden nur mittlere Volumina gefunden (Volumen von 0,75 – 1,5 µm3). Bestätigt wird dieses Ergebnis durch einen in den ersten 4 Tagen beobachteten negativen Quotient der mikrobiellen und der Ciliatenvolumina. Mit Fluoreszenz in-situ Hybridisierung wurde eine bevorzugte Ingestion von Bakteria nachgewiesen. In einigen Fällen wurden jedoch auch Archaea in den Nahrungsvakuolen detektiert. Zusätzlich zu methanogenen Endosymbionten wurde in einigen Arten der Gattung Metopus ein weiterer den ?–Proteobacteria zugeordneter Endobiont identifiziert. Nähere Informationen zur Physiologie des Endobionten wurden bisher nicht gefunden. Die Bildung von Methan wurde in anoxischen Inkubationen bereits nach 24 h gemessen. Einige Details der frühen Methanogenese sind zur Zeit noch unklar. Eine mögliche Erklärung für die frühe Methanogenese sind methanogene Endosymbionten, wie sie in Ciliaten der Gattung Metopus gefunden wurden. Anhand von eigenen Zellzahlbestimmungen und Werten aus der Literatur (Fenchel T. und Finlay B.J. 1995: Ecology and evolution in anoxic worlds. Oxford University Press) wurden zwei Modelle zur potentiellen CH4-Produktion der methanogenen Endosymbionten berechnet. Diese Modelle erklärten 2 bzw. 59% des in den ersten zwei Wochen gebildeten CH4. Das erste Modell (2%) berücksichtigte am detailliertesten das untersuchte Habitat und wurde demnach bevorzugt. Eine Hemmung von Eukaryonten mit spezifischen Inhibitoren bewirkte in anoxischen Inkubationen eine deutliche Erhöhung der CH4-Produktion. Die Summe des zusätzlich gebildeten CH4 war weder über den vom Inhibitor eingebrachten Kohlenstoff noch über einen Abbau lysierter Ciliatenbiomasse zu erklären. Es wurde daher eine -durch Beweidung von Ciliaten induzierte- Unterdrückung der aktiven, freilebenden Methanogenen postuliert. Anhand der in dieser Arbeit gewonnenen Daten wurde gezeigt, daß Protozoen auch in Inkubationen anoxischen Reisfeldbodens einen deutlichen, aber zeitlich begrenzten Einfluß auf die mikrobielle Gemeinschaft und die Methanogenese haben. Berücksichtigt man, daß die Ciliaten nur eine der vier häufigsten Protozoengruppen darstellen, lassen diese Ergebnisse einen noch deutlicheren Einfluß der gesamten Protozoenfauna erwarten. Um die relative Abundanz und Diversität der gesamten Protozoenfauna abschätzen zu können, soll in einem kommenden Projekt eine molekulare Charakterisierung der Gemeinschaft auf Basis der 18S rDNS erfolgen

Managing international development: (Re)positioning critique in the post-2008 conjuncture

Despite earlier neglect, International Development (ID) has begun to receive some attention from the Critical Management Studies (CMS) community over the last two decades. This paper reviews existing CMS work that engages with ID and outlines directions for future research. Building on extant research and scholarship that has focussed on linkages between managerialism and ID, we identify and discuss in some depth three emerging areas within ID – financialization, evaluation and projectification–that, we argue, merit further critical scrutiny from CMS scholars. We call for a programme of theoretical and grounded empirical research into these three areas in the hope of reinvigorating CMS’ engagement with ID; a programme that would seek to expose the fallacy of the universalizing managerialism that increasingly informs ID projects and organizational practices. In operationalizing this research programme, we draw attention to problems of positionality, drawing on methodological and epistemological debates in Anthropology to inform our argument. We thus highlight the need for grounding CMS research practices in reflective trans-disciplinarity

Jejunal obstruction due to rare internal hernia between skeletonized external iliac artery and vein as late complication of laparoscopic hysterectomy with pelvic lymphadenectomy-case report and review of literature

Background Internal herniation of small intestine in the lesser pelvis alongside iliac vasculature is a rare occurrence. Skeletonization of iliac vessels during pelvic lymph node dissection (LND), as part of surgical staging or treatment of patients with uterine, ovarian or urogenital cancer, is a strict prerequisite for orifce formation. Case presentation A 68-year-old woman presented at the emergency department with complaints of constipation for the last 3 days and acute-onset abdominal pain, nausea and vomiting since few hours. She had a history of laparoscopic hysterectomy, bilateral salpingo-oophorectomy and para-aortic and pelvic LND 7 years ago. A distended abdomen with difuse tenderness on palpation was noted. A CT scan demonstrated bowel obstruction secondary to an incarcerated hernia underneath an elongated right external iliac artery. During an emergency exploratory laparotomy, the incarcerated bowel was reduced and the hernial orifce closed with a running suture. The patient had an uneventful postoperative period and was discharged on the ffth postoperative day. Discussion This rare internal hernia can manifest with non-specifc symptoms of small bowel obstruction at any given point after index surgery, sometimes even after several years free of complaints. Contrast-enhanced computed tomography is the method of choice for fast and reliable diagnosis and helps in planning the necessary emergency laparotomy. Conclusion This life-threatening complication adds to the current controversy of pelvic and para-aortic lymphadenectomy in patients with endometrial cancer. Primary closure of peritoneal defects should be considered to potentially prevent internal hernias, especially when elongated iliac vessels are present

Safety of Catheter Embolization of Pulmonary Arteriovenous Malformations—Evaluation of Possible Cerebrovascular Embolism after Catheter Embolization of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia/Osler Disease by Pre- and Post-Interventional DWI

Background. This paper aimed to prospectively evaluate the safety of embolization therapy of pulmonary arteriovenous malformations (PAVMs) for the detection of cerebral infarctions by preand post-interventional MRI. Method One hundred and five patients (male/female = 44/61; mean age 48.6+/−15.8; range 5–86) with pre-diagnosed PAVMs on contrast-enhanced MRA underwent embolization therapy. The number of PAVMs treated in each patient ranged from 1–8 PAVMs. Depending on the size and localization of the feeding arteries, either Nester-Coils or Amplatzer vascular plugs were used for embolization therapy. cMRI was performed immediately before, and at the 4 h and 3-month post-embolization therapy. Detection of peri-interventional cerebral emboli was performed via T2w and DWI sequences using three different b-values, with calculation of ADC maps. Results Embolization did not show any post-/peri-interventional, newly developed ischemic lesions in the brain. Only one patient who underwent re-embolization and was previously treated with tungsten coils that corroded over time showed newly developed, small, diffuse emboli in the post-interventional DWI sequence. This patient already had several episodes of brain emboli before re-treatment due to the corroded coils, and during treatment, when passing the corroded coils, experienced additional small, clinically inconspicuous brain emboli. However, this complication was anticipated but accepted, since the vessel had to be occluded distally. Conclusion Catheter-based embolization of PAVMs is a safe method for treatment and does not result in clinically inconspicuous cerebral ischemia, which was not demonstrated previously

Diagnostic Performance of a Lower-dose Contrast-Enhanced 4D Dynamic MR Angiography of the Lower Extremities at 3 T Using Multisegmental Time-Resolved Maximum Intensity Projections

Background For peripheral artery disease (PAD), MR angiography (MRA) is a well-established diagnostic modality providing morphologic and dynamic information comparable to digital subtraction angiography (DSA). However, relatively large amounts of contrast agents are necessary to achieve this. Purpose To evaluate the diagnostic accuracy of time-resolved 4D MR-angiography with interleaved stochastic trajectories (TWIST-MRA) by using maximum intensity projections (MIPs) of dynamic images acquired with reduced doses of contrast agent. Study Type Retrospective. Population Forty adult PAD patients yielding 1088 artery segments. Field Strength/Sequence A 3.0 T, time-resolved 4D MR-angiography with TWIST-MRA and MIP of dynamic images. Assessment DSA was available in 14 patients (256 artery segments) and used as reference standard. Three-segmental MIP reconstructions of TWIST-images after administration of 3 mL of gadolinium-based contrast agent (Gadoteridol/Prohance®, 0.5 M) per anatomical level (pelvis, thighs, and lower legs) yielded 256 artery segments for correlation between MRA and DSA. Three independent observers rated image quality (scale: 1 [nondiagnostic] to 4 [excellent]) and the degree of venous overlay (scale: 0 [none] to 2 [significant]) for all segments. Diagnostic accuracy for the detection of >50% stenosis and artery occlusion was calculated for all observers. Statistical Tests Binary classification test (sensitivity, specificity, positive/negative predictive values, diagnostic accuracy). Intraclass correlation coefficients (ICCs), logistic regression analysis with comparison of areas under the receiver-operating-characteristics (ROC) curves (AUCs) with the DeLong method. Bland–Altman-comparison. Results High diagnostic performance was achieved for the detection of >50% stenosis (sensitivity 92.9% [84.3–99.9% (95%-CI)] and specificity 98.5% [95.7–99.8% (95%-CI)]) and artery occlusion (sensitivity 93.1% [77.2–99.2% (95%-CI)] and specificity 99.1% [96.9–99.9% (95%-CI)]). Inter-reader agreement was excellent with ICC values ranging from 0.95 to 1.0 for >50% artery stenosis and occlusion. Image quality was good to excellent for both readers (3.41 ± 0.72, 3.33 ± 0.65, and 3.38 ± 0.61 [mean ± SD]) with good correlation between observer ratings (ICC 0.71–0.81). No significant venous overlay was observed (0.06 ± 0.24, 0.23 ± 0.43 and 0.11 ± 0.45 [mean ± SD]). Data Conclusion MIPs of dynamic TWIST-MRA offer a promising diagnostic alternative necessitating only reduced amounts (50%) of gadolinium-based contrast agents for the entire runoff vasculature. Evidence Level 3 Technical Efficacy Stage

Aquatic and terrestrial proxy evidence for Middle Pleistocene palaeolake and lake‐shore development at two Lower Palaeolithic sites of Schöningen, Germany

The archaeological sites in the open‐cast mine of Schöningen, Germany, represent outstanding archives for understanding Middle Pleistocene interglacial–glacial transitions and human adaption. Aquatic microfossil and pollen assemblages from the ‘Reinsdorf sequence’, likely correlated to Marine Isotope Stage 9, document environmental changes from a thermal maximum to succeeding glacial conditions recorded in two sequences of excavation sites 12 II and 13 II. Multi‐proxy analyses enable detailed reconstruction of lake‐shore and landscape developments despite variable microfossil preservation in changing carbonate‐ and organic‐rich deposits. Rich aquatic vegetation with abundant charophytes suggests repeated phases with water depths of 0.5–2 m at site 13 II, while even greater temporary depths are deduced for 12 II DB. Mesorheophilic and mesotitanophilic ostracod species indicate stream inflows with medium–low calcium contents of >18 mg Ca L –1 originating from nearby springs. Diatoms point to meso‐eutrophic conditions and an alkaline pH of the lake water. Interglacial conditions with thermophile forests but no aquatic microfossils preserved, suggesting a dry or only temporarily flooded site, mark the beginning of the sequence. Continuous presence of aquatic organisms and overall dominance of small tychoplanktonic diatoms during a subsequent cool steppe phase provide evidence for increased water depths and unstable habitats characterized by erosion and probably prolonged periods of lake ice cover. During the succeeding boreal forest‐steppe phase, surface runoff into the productive, shallow lake decreased due to a more extensive vegetation cover. Concurrently, intensified groundwater input in contact with the nearby salt wall caused elevated salinities. Following a lake level drop, stream inflows and lake levels increased again towards the end of the Reinsdorf sequence and promoted development of a diverse fauna and flora at the lake shore; thereby maintaining an attractive living and hunting environment for early humans during a phase of generally cooler temperatures and landscape instability at the transition into a glacial period

Iatrogenic arterio-biliary fistula and peripheral hepatic artery pseudoaneurysm after transjugular liver biopsy: complication management using a microvascular plug

This study aimed to report on complication management in a 58-year-old woman referred for transjugular biopsy for the evaluation of unknown liver disease. After an initial uneventful biopsy procedure, the patient complained of severe upper abdominal pain. Laboratory tests revealed increasing liver enzymes. Imaging studies depicted an iatrogenic pseudoaneurysm associated with an arterio-biliary fistula originating from the right peripheral hepatic artery. Angiography and percutaneous transarterial superselective embolotherapy was performed by means of a microcatheter and microvascular plug. Precise device positioning allowed for successful closure of the bleeding site without compromising the hepatic vasculature