381 research outputs found
Towards an integrated understanding of how micro scale processes shape groundwater ecosystem functions
Micro scale processes are expected to have a fundamental role in shaping groundwater ecosystems and yet they
remain poorly understood and under-researched. In part, this is due to the fact that sampling is rarely carried out
at the scale atwhich microorganisms, and their grazers and predators, function and thus we lack essential information.
While set within a larger scale framework in terms of geochemical features, supply with energy and nutrients,
and exchange intensity and dynamics, the micro scale adds variability, by providing heterogeneous zones
at the micro scalewhich enable awider range of redox reactions. Here we outline howunderstanding micro scale
processes better may lead to improved appreciation of the range of ecosystemsfunctions taking place at all scales.
Such processes are relied upon in bioremediation and we demonstrate that ecosystem modelling as well as engineering
measures have to take into account, and use, understanding at the micro scale. We discuss the importance
of integrating faunal processes and computational appraisals in research, in order to continue to secure
sustainable water resources from groundwater
Collecting eco-evolutionary data in the dark : Impediments to subterranean research and how to overcome them
Caves and other subterranean habitats fulfill the requirements of experimental model systems to address general questions in ecology and evolution. Yet, the harsh working conditions of these environments and the uniqueness of the subterranean organisms have challenged most attempts to pursuit standardized research. Two main obstacles have synergistically hampered previous attempts. First, there is a habitat impediment related to the objective difficulties of exploring subterranean habitats and our inability to access the network of fissures that represents the elective habitat for the so-called "cave species." Second, there is a biological impediment illustrated by the rarity of most subterranean species and their low physiological tolerance, often limiting sample size and complicating laboratory experiments. We explore the advantages and disadvantages of four general experimental setups (in situ, quasi in situ, ex situ, and in silico) in the light of habitat and biological impediments. We also discuss the potential of indirect approaches to research. Furthermore, using bibliometric data, we provide a quantitative overview of the model organisms that scientists have exploited in the study of subterranean life. Our over-arching goal is to promote caves as model systems where one can perform standardized scientific research. This is important not only to achieve an in-depth understanding of the functioning of subterranean ecosystems but also to fully exploit their long-discussed potential in addressing general scientific questions with implications beyond the boundaries of this discipline.Peer reviewe
Paclitaxel-eluting balloon dilation of biliary anastomotic stricture after liver transplantation
AIM: To investigate the safety and effectiveness of endoscopic therapy with a paclitaxel-eluting balloon (PEB) for biliary anastomotic stricture (AS) after liver transplantation (LT). METHODS: This prospective pilot study enrolled 13 consecutive eligible patients treated for symptomatic AS after LT at the University Hospital of Münster between January 2011 and March 2014. The patients were treated by endoscopic therapy with a PEB and followed up every 8 wk by endoscopic retrograde cholangiopancreatography (ERCP). In cases of re-stenosis, further balloon dilation with a PEB was performed. Follow-up was continued until 24 mo after the last intervention. RESULTS: Initial technical feasibility, defined as successful balloon dilation with a PEB during the initial ERCP procedure, was achieved in 100% of cases. Long-term clinical success (LTCS), defined as no need for further endoscopic intervention for at least 24 mo, was achieved in 12 of the 13 patients (92.3%). The mean number of endoscopic interventions required to achieve LTCS was only 1.7 ± 1.1. Treatment failure, defined as the need for definitive alternative treatment, occurred in only one patient, who developed recurrent stenosis with increasing bile duct dilatation that required stent placement. CONCLUSION: Endoscopic therapy with a PEB is very effective for the treatment of AS after LT, and seems to significantly shorten the overall duration of endoscopic treatment by reducing the number of interventions needed to achieve LTCS
Long-Term Renal Function in Liver Transplant Recipients After Conversion From Calcineurin Inhibitors to mTOR Inhibitors
BACKGROUND: Renal dysfunction often occurs in liver transplant (LT) recipients receiving calcineurin inhibitor (CNI)-based immunosuppressive regimens, increasing morbidity and mortality rates. Replacement of CNIs by mTOR inhibitor-based immunosuppressive protocols may prevent renal impairment in LT recipients. MATERIAL AND METHODS: Outcomes in patients who underwent LT between 1996 and 2010 at our center and who were switched from CNI-based to mTOR inhibitor-based immunosuppression were retrospectively analyzed. Renal course, hyperlipidemia, and graft rejection were assessed in patients maintained on this CNI-free regimen for at least 24 months. RESULTS: Of the 85 patients switched from CNI-based to mTOR inhibitor-based, CNI-free immunosuppression, 78 met the inclusion criteria. Within the first 6 weeks after switching, the covariable adjusted estimated glomerular filtration rate (eGFR) increased 5.6 mL/min [95% confidence interval 2.6–8.7 mL/min, p<0.001], but there were no further statistically noticeable changes in eGFR. Concentrations of cholesterol and triglycerides increased statistically, noticeable within the first 12 months after drug conversion. Histologically proven graft rejection was observed in 4 patients (5.1%) after conversion. CONCLUSIONS: Conversion from CNI-based to CNI-free, mTOR inhibitor-based immunosuppression after LT is safe and can result in significant renal recovery. CNI-free, mTOR inhibitor-based immunosuppression is a potential option for patients with contraindications for CNIs and for LT recipients with rapid reduction in kidney function due to CNIs
Elucidating the impact of micro-scale heterogeneous bacterial distribution on biodegradation
Groundwater microorganisms hardly ever cover the solid matrix uniformly–instead they form micro-scale colonies. To which extent such colony formation limits the bioavailability and biodegradation of a substrate is poorly understood. We used a high-resolution numerical model of a single pore channel inhabited by bacterial colonies to simulate the transport and biodegradation of organic substrates. These high-resolution 2D simulation results were compared to 1D simulations that were based on effective rate laws for bioavailability-limited biodegradation. We (i) quantified the observed bioavailability limitations and (ii) evaluated the applicability of previously established effective rate concepts if microorganisms are heterogeneously distributed. Effective bioavailability reductions of up to more than one order of magnitude were observed, showing that the micro-scale aggregation of bacterial cells into colonies can severely restrict the bioavailability of a substrate and reduce in situ degradation rates. Effective rate laws proved applicable for upscaling when using the introduced effective colony sizes
Analysis of Bile Colonization and Intestinal Flora may Improve Management in Liver Transplant Recipients Undergoing ERCP
Background: Immunosuppression, denervation of biliary tract, and presence of biliary strictures favor colonization of bile with microorganisms after liver transplantation. Little is known about spectrum and antibiotic susceptibility of this colonization. Material and Methods: Bile and feces were collected prospectively from 38 patients who underwent endoscopic retrograde cholangiopancreaticography after liver transplantation. Samples were analyzed for colonization and antibiotic susceptibility. Results: From the 38 tested bile samples, 86.6% tested positive. Of those, 26 (78.8%) were polymicrobial. Of isolated bile samples, 52 (64.2%) were gram-positive, 22.2% were gram-negative, and 13.6% revealed Candida albicans. Most detectable gram-positive bacteria were Enterococcus faecium. Most detectable gram-negative bacteria were E. coli and Klebsiella pneumonia. Our analyses revealed high resistance rates of the isolates. Only 55.6% of isolates were sensitive to ciprofloxacin, 54% were sensitive to piperacillin/tazobactam, and 60.3% were sensitive to imipenem. High susceptibility rates were found for linezolid and vancomycin (72.9% and 72.6%, respectively). We found a high correlation between microorganisms found in bile and those isolated from stool. Conclusions: Bile of liver transplant recipients is frequently colonized with microorganisms. The starting point of this colonization is usually the intestine. Systematic analysis of bile colonization during endoscopic interventions on biliary tracts of liver transplant recipients might help to select effective prophylactic antibiotic regimes as well as to facilitate the choice of suitable antimicrobial therapy in case of septic complications
Invertebrate traits, diversity and the vulnerability of groundwater ecosystems
Funding Information: This manuscript evolved from a workshop titled Trait‐based analyses in groundwater ecology and bioassessment held as part of the 24th International Conference on Subterranean Biology, 20–24th August 2018, University of Aveiro, Portugal. The workshop was supported by the conference organisers and the Macquarie University Species Spectrum Research Centre. Financial support was also provided to M.A.D. by the Portuguese government (Fundação para a Ciência e Tecnologia; FCT) through the research unit UIDB/04085/2020 (CENSE). A.S.P.S.R. was supported by the VILLUM FONDEN (research grant 15471) and by Portuguese National Funds through Fundação para a Ciência e a Tecnologia within the cE3c Unit funding UIDB/00329/2020. S.I.S. acknowledges funding through EU Operational Programme Research, Development and Education No. CZ.02.2.69/0.0/0.0/16_027/0008357, and by the Ministry of Education, Youth and Sports of the Czech Republic [grant number CZ.02.1.01/0.0/0.0/16 025/0007417]. K.L.K. was supported in part by Australian Research Council grant LP190100927. The comments of the Editor, Associate Editor and an anonymous reviewer greatly improved the MS. Open access publishing facilitated by Macquarie University, as part of the Wiley ‐ Macquarie University agreement via the Council of Australian University Librarians. Publisher Copyright: © 2022 The Authors. Functional Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.Groundwater comprises the largest freshwater ecosystem on the planet. It has a distinct regime of extreme, yet stable environmental conditions that have favoured the development of similar morphological and functional traits in the resident invertebrate fauna (stygofauna). The analysis of community traits is increasingly used as an alternative to taxonomy-based assessments of biodiversity, especially for monitoring ecosystem status and linking the functions of organisms to ecological processes, yet it has been rarely applied to stygofauna and groundwater ecosystems. In this paper, we review the variation in functional traits among the invertebrate fauna of this important ecosystem. We focus on the stygofauna and processes of alluvium and fractured rock aquifers that are typified by small voids and fissures that constrain the habitats and environmental conditions. As a first step, we compare trait variability between groundwater and surface water invertebrate communities and then examine the significance of the ranges of these traits to the vulnerability of the ecosystem to change. Fifteen potentially useful functional traits are recognised. Eight of these have narrower ranges (i.e. exhibit fewer states, or attributes, of a particular trait) in groundwater than they do in surface water. Two traits have wider ranges. Our synthesis suggests that the relative stability of groundwater environments has led to low trait variability. The low biomass and low reproductive rate of stygofauna suggest that recovery potential following disturbance is likely to be low. For the purposes of both improved understanding and effective management, further work is needed to document additional functional traits and their states in groundwater fauna, enabling a better understanding of the relationship between response and effect traits in these ecosystems. Read the free Plain Language Summary for this article on the Journal blog.publishersversionpublishe
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High density lipoprotein mediates anti-inflammatory transcriptional reprogramming of macrophages via the transcriptional repressor ATF3
High Density Lipoprotein (HDL) mediates reverse cholesterol transport and it is known to be protective against atherosclerosis. In addition, HDL has potent anti-inflammatory properties that may be critical for protection against other inflammatory diseases. The molecular mechanisms of how HDL can modulate inflammation, particularly in immune cells such as macrophages, remain poorly understood. Here we identify the transcriptional repressor ATF3, as an HDL-inducible target gene in macrophages that down-regulates the expression of Toll-like receptor (TLR)-induced pro-inflammatory cytokines. The protective effects of HDL against TLR-induced inflammation were fully dependent on ATF3 in vitro and in vivo. Our findings may explain the broad anti-inflammatory and metabolic actions of HDL and provide the basis for predicting the success of novel HDL-based therapies
The psychopathological and psychosocial outcome of early-onset schizophrenia: Preliminary data of a 13-year follow-up
<p>Abstract</p> <p>Background</p> <p>Relatively little is known about the long-term psychopathological and psychosocial outcome of early-onset schizophrenia. The existing literature describes more severe courses of illness in these patients compared with adult-onset schizophrenia. This article reports preliminary data of a study exploring the outcome of early-onset schizophrenia 13.4 years (mean) after first admission. Predictors for interindividual outcomes were investigated.</p> <p>Methods</p> <p>We retrospectively assessed 27 former patients (mean age at first admission 15.5 years, SD = 2.0) that were consecutively admitted to the Department of Child and Adolescent Psychiatry at the University of Wuerzburg between 1990 and 2000. A multidimensional approach was chosen to assess the outcome consisting of a mail survey including different questions about psychopathological symptoms, psychosocial parameters, and standardized self-reports (ESI and ADS).</p> <p>Results</p> <p>Concerning the psychopathological outcome, 22.2% reported having acute schizophrenic symptoms. Almost one third (30.8%) described symptoms of depression and 37.0% reported having tried to commit suicide or seriously thought about it. 77.8% of the former patients were still in outpatient treatment. Compared to the general population, the number of patients without a school graduation was relatively high (18.5%). Almost half of participants still live with their parents (48.1%) or in assisted or semi-assisted living conditions (33.3%). Only 18.5% were working in the open market.</p> <p>Conclusion</p> <p>Schizophrenia with an early onset has an unfavourable prognosis. Our retrospective study of the psychopathological and psychosocial outcome concludes with a generally poor rating.</p
Ways to Develop Specialists in Engineering Activities: Professional Development and Retraining
This article discusses ways to develop an engineer in the form of professional development and retraining courses. The relevance of this topic is due to the lack of students' and professionals' awareness of the importance of further engineering education, the lack of interest in getting additional paid education, and the bad quality of additional education in Russia
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