bluuebunny/crossref_metadata_2025 huggingface dataset:
The consequences of four land‐use scenarios for forest ecosystems and the services they provide
Authors: Thompson Jonathan R. , Lambert Kathleen F. , Foster David R. , Broadbent Eben N. , Blumstein Meghan , Almeyda Zambrano Angelica M. , Fan Yuanchao
Published: October 2016

Anticipating landscape‐ to regional‐scale impacts of land use on ecosystems and the services they provide is a central challenge for scientists, policymakers, and resource managers. Working with a panel of practitioners and regional experts, we developed and analyzed four plausible but divergent land‐use scenarios that depict the future of Massachusetts from 2010 to 2060 to address two questions: (1) “How do the magnitude and spatial distribution of ecosystem service provisioning vary under the different land‐use regimes?” and (2) “What are the synergies and trade‐offs among direct human uses, ecosystem services, and habitat quality?” Each scenario specifies the detailed prescriptions for the major uses of the forests, including conversion to residential and commercial development, clearing new farmland, shifting silvicultural practices, and designating forests protected from development. We simulated the land‐use scenarios and their interactions with anticipated climate change by coupling statistical models of land use to the LANDIS‐II landscape model and then evaluated the outcomes in terms of the magnitude and spatial distribution of (1) direct human uses of the landscape (residential and commercial development, agricultural, timber harvest), (2) ecosystem services (carbon storage, flood regulation, nutrient retention), and (3) habitat quality (forest tree species composition, interior forest habitat). Across all scenarios, conflicts occurred between dispersed residential development and the supply of ecosystem services and habitat quality. In all but the scenario that envisioned a significant agricultural expansion, forest growth resulted in net increases in aboveground carbon storage, despite the concomitant forest clearing and harvesting. One scenario, called Forests as Infrastructure, showed the potential for synergies between increased forest harvest volume through the sustainable practices that encouraged the maintenance of economically and ecologically important tree species, and carbon storage. This scenario also showed trade‐offs between development density and water quantity and quality at the watershed scale. The process of integrated scenario analysis led to important insights for land managers and policymakers in a populated forested region where there are tensions among development, forest harvesting, and land conservation. More broadly, the results emphasize the need to consider the consequences of contrasting land‐use regimes that result from the interactions between human decisions and spatially heterogeneous landscape dynamics.
Stage‐dependent effects of browsing by snowshoe hares on successional dynamics in a boreal forest ecosystem
Authors: Olnes Justin , Kielland Knut
Published: October 2016

Herbivores transform landscapes and affect succession via selective foraging that alters vegetation composition. In the boreal forest, mammalian herbivores, mainly moose, facilitate a shift toward the dominance of heavily defended species over time, such as white spruce. The effects of moose herbivory are intensified by the browsing of snowshoe hares. However, unlike moose, snowshoe hares also browse seedlings of white spruce. We quantified herbivory by snowshoe hares on white spruce along the Tanana River, interior Alaska, and assessed the effects on white spruce demography via two different herbivore exclosure experiments. We hypothesized that both experiments would show reduced plant density and height growth in the presence of hares. We found evidence of extensive browsing of white spruce seedlings by snowshoe hares, which negatively affected white spruce establishment along the Tanana River floodplain. Previous research has indicated that hares facilitate floodplain succession in the forward direction. However, hare herbivory can also retard succession by depressing white spruce establishment and increase the time individual trees spend in the understory. This stage‐dependent effect on successional dynamics via a unique temporal variation in snowshoe hare herbivory may contribute to alternative successional trajectories in the boreal forest.
Global associations between birds and vane‐dwelling feather mites
Authors: Doña Jorge , Proctor Heather , Mironov Sergey , Serrano David , Jovani Roger
Published: October 2016

Understanding host–symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo‐ and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird–feather‐mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used.
Cascading effects of predation risk determine how marine predators become terrestrial prey on an oceanic island
Authors: Thomsen Sarah K. , Green David J.
Published: October 2016

Apex predators can suppress the foraging activity of mesopredators, which may then result in cascading benefits for the prey of those mesopredators. We studied the interactions between a top predator, the Barn Owl (Tyto alba), and their primary prey, an island endemic deer mouse (Peromyscus maniculatus elusus), which in turn consumes the eggs of seabirds nesting on Santa Barbara Island in California. Scripps's Murrelets (Synthliboramphus scrippsi), a threatened nocturnal seabird, arrive annually to breed on this island, and whose first egg is particularly vulnerable to predation by mice. We took advantage of naturally occurring extreme variations in the density of mice and owls on the island over 3 years and predicted that (1) mouse foraging would decrease with increasing predation risk from owls and moonlight and (2) these decreases in foraging would reduce predation on murrelet eggs. We measured the giving up densities of mice with experimental foraging stations and found that mice were sensitive to predation risk and foraged less when owls were more abundant and less during the full moon compared to the new moon. We also monitored the fates of 151 murrelet eggs, and found that murrelet egg predation declined as owl abundance increased, and was lower during the full moon compared to the new moon. Moreover, high owl abundance suppressed egg predation even when mice were extremely abundant. We conclude that there is a behaviorally mediated cascade such that owls on the island had a positive indirect effect on murrelet egg survival. Our study adds to the wider recognition of the strength of risk effects to structure food webs, as well as highlighting the complex ways that marine and terrestrial food webs can intersect.
Cardiogenic shock in intensive care units: evolution of prevalence, patient profile, management and outcomes, 1997–2012
Authors: Puymirat Etienne , Fagon Jean Yves , Aegerter Philippe , Diehl Jean Luc , Monnier Alexandra , Hauw‐Berlemont Caroline , Boissier Florence , Chatellier Gilles , Guidet Bertrand , Danchin Nicolas , Aissaoui Nadia ,   on behalf of the Collège des Utilisateurs de Bases de données en Réanimation (CUB‐Réa Group [Intensive Care Database User Group])
Published: October 2016

Aim

To address the paucity of data on the characteristics, outcome and temporal trends in mortality of cardiogenic shock (CS) patients admitted to intensive care units (ICUs) we examined key features, variations in mortality from CS, and predictors of death in ICU patients over the past 15 years.

Methods and results

From the 1997–2012 database of the Collège des Utilisateurs de Bases de données en Réanimation (CUB‐Réa) that prospectively collects data from ICUs in the greater Paris area, we determined temporal trends in the incidence of CS, patient outcomes [Crude and Simplified Acute Physiology Score (SAPS)‐II Standardized Mortality] and predictors of in‐ICU mortality. Of the 316 905 ICU admissions, 19 416 (6.1%) exhibited CS, with incidence increasing from 4.1% to 7.7% (P < 0.001). Over time, the age of admitted patients decreased by 2.7 years [95% confidence interval (CI), −2.0 to −3.4] and SAPS‐II increased by 5.8% (95% CI 4.8–6.8) from 58.7 ± 25.3 to 64.5 ± 23.3 (P < 0.001). Crude in‐ICU mortality declined from 50% to 45% (−5.6%; 95% CI −7.7 to −3.5) as SAPS‐II Standardized ICU mortality rates decreased from 56.5% to 44.2% (P < 0.001). A more recent time‐period was an independent correlate of decreased mortality in multivariate analyses. The decrease in mortality rate was more marked in patients with decompensated heart failure, cardiac arrest, or acute myocardial infarction.

Conclusions

Patients with CS represent a greater proportion of patients admitted to ICUs over the past 15 years, having become younger but more critically ill. Although their mortality has decreased, suggesting improved overall patient management, it remains particularly high, warranting further research specifically focused on this population.
Antigen presentation by B cells guides programing of memory CD4+ T‐cell responses to a TLR4‐agonist containing vaccine in mice
Authors: Dubois Cauwelaert Natasha , Baldwin Susan L. , Orr Mark T. , Desbien Anthony L. , Gage Emily , Hofmeyer Kimberly A. , Coler Rhea N.
Published: October 2016

The contribution of B cells to immunity against many infectious diseases is unquestionably important and well characterized. Here, we sought to determine the role of B cells in the induction of T‐helper 1 (TH1) CD4+ T cells upon vaccination with a tuberculosis (TB) antigen combined with a TLR4 agonist. We used B‐cell deficient mice (μMT−/−), tetramer‐positive CD4+ T cells, markers of memory “precursor” effector cells (MPECs), and T‐cell adoptive transfers and demonstrated that the early antigen‐specific cytokine‐producing TH1 responses are unaffected in the absence of B cells, however MPEC induction is strongly impaired resulting in a deficiency of the memory TH1 response in μMT−/− mice. We further show that antigen‐presentation by B cells is necessary for their role in MPEC generation using B‐cell adoptive transfers from wt or MHC class II knock‐out mice into μMT−/− mice. Our study challenges the view that B‐cell deficiency exclusively alters the TH1 response at memory time‐points. Collectively, our results provide new insights on the multifaceted roles of B cells that will have a high impact on vaccine development against several pathogens including those requiring TH1 cell‐mediated immunity.
Type I IFN signaling facilitates the development of IL‐10‐producing effector CD8+ T cells during murine influenza virus infection
Authors: Jiang Li , Yao Shuyu , Huang Su , Wright Jeffrey , Braciale Thomas J. , Sun Jie
Published: October 2016

Recent evidence has suggested that IL‐10‐producing effector CD8+ T cells play an important role in regulating excessive inflammation during acute viral infections. However, the cellular and molecular cues regulating the development of IL‐10‐producing effector CD8+ T cells are not completely defined. Here, we show that type I interferons (IFNs) are required for the development of IL‐10‐producing effector CD8+ T cells during influenza virus infection in mice. We find that type I IFNs can enhance IL‐27 production by lung APCs, thereby facilitating IL‐10‐producing CD8+ T‐cell development through a CD8+ T‐cell‐nonautonomous way. Surprisingly, we also demonstrate that direct type I IFN signaling in CD8+ T cells is required for the maximal generation of IL‐10‐producing CD8+ T cells. Type I IFN signaling in CD8+ T cells, in cooperation with IL‐27 and IL‐2 signaling, promotes and sustains the expression of IFN regulatory factor 4 (IRF4) and B‐lymphocyte‐induced maturation protein‐1 (Blimp‐1), two transcription factors required for the production of IL‐10 by effector CD8+ T cells. Our data reveal a critical role of the innate antiviral effector cytokines in regulating the production of a regulatory cytokine by effector CD8+ T cells during respiratory virus infection.
Catalytic Water‐Oxidation Activity of a Weakly Coupled Binuclear Ruthenium Polypyridyl Complex
Authors: Matias Tiago A. , Mangoni Ana P. , Toma Sergio H. , Rein Francisca N. , Rocha Reginaldo C. , Toma Henrique E. , Araki Koiti
Published: October 2016

The catalytic oxidation of water by the binuclear complex [Ru2(H2O)2(bpy)2(tpy2ph)](PF6)4 [bpy = 2,2′‐bipyridine; tpy2ph = 1,3‐bis(4′‐2,2′:6′,2′′‐terpyridin‐4‐yl)benzene] was investigated comparatively to its mononuclear counterpart [Ru(H2O)(bpy)(phtpy)](PF6)2 (phtpy = 4′‐phenyl‐2,2′:6′,2′′‐terpyridine). These catalysts were prepared from the synthesis of their precursor chloride complexes, which were also extensively characterized in this work. The H2O–RuII complexes were found to undergo proton‐coupled electron‐transfer processes to generate the redox species HO–RuIII, O=RuIV, and O=RuV. The catalytically active species, [RuV2(O)2(bpy)2(tpy2ph)]6+ and [RuV(O)(bpy)(phtpy)]3+, were generated electrochemically and by using cerium(IV) ammonium nitrate. In the presence of CeIV, the catalytic rates for O2 production by the binuclear and mononuclear species were 1.9 × 10–3 and 9.5 × 10–5 s–1, respectively. This superior catalytic performance of the binuclear complex suggests that, despite weak electronic coupling between the Ru centers, the second site could play an important mechanistic role in the formation of the activated species [(bpy)(OO)RuIV(tpy2ph)RuIII(OH)(bpy)]4+.
Effects of influent organic loading rates and electrode locations on the electrogenesis capacity of constructed wetland‐microbial fuel cell systems
Authors: Xu Dan , Xiao En‐Rong , Xu Peng , Zhou Yin , Zhou Qiao‐Hong , Xu Dong , Wu Zhen‐Bin
Published: October 2016

Three novel constructed wetland‐microbial fuel cells (CW‐MFCs), based on electrode location, were developed for wastewater treatment and sustainable electricity production by embedding a MFC into a CW system. In the three CW‐MFCs, electrodes were placed in different locations, including bottom anode‐rhizosphere cathode CW‐MFC (BA‐RC‐CW‐MFC), rhizosphere anode‐air cathode CW‐MFC (RA‐AC‐CW‐MFC), and bottom anode‐air cathode CW‐MFC (BA‐AC‐CW‐MFC), to investigate the combined effects of organic loading rates (OLRs) and reactor configurations on the electrogenesis capacity of the hybrid system. All the systems operated continuously to treat five types of synthetic wastewater with increasing OLRs: 9.2, 18.4, 27.6, 55.2, and 92.0 g chemical oxygen demand (COD) m−2 d−1. The BA‐RC‐CW‐MFC failed to produce electricity at any OLR, whereas the maximum power densities of 0.79 ± 0.01 and 10.77 ± 0.52 mW m−2 were achieved in the RA‐AC‐CW‐MFC with 18.4 g COD m−2 d−1 influent OLR and in the BA‐AC‐CW‐MFC with 27.6 g COD m−2 d−1 influent OLR, respectively. The coulombic efficiencies of the RA‐AC‐CW‐MFC and BA‐AC‐CW‐MFC decreased gradually with the increase in influent OLRs. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 435–441, 2017
Experimental study on the performance and emission characteristics of jojoba oil fueled DICI engine
Authors: Ramakrishnan C. , Devan P.K. , Karthikeyan R.
Published: October 2016

This work experimentally determines the maximum quantity of neat jojoba oil that can be applied in a CI engine. It uses a single cylinder diesel engine as a test rig and Jojoba ‐ diesel blends as a test fuel. Since the method uses a higher proportion of neat jojoba oil as test fuel, the regular operating parameters of the test engine have been modified. This work has considered injection pressure, injection timing, intake air temperature and compression ratio for the modification. Taguchi and gray relational analysis have been used for the optimization. The taguchi method has been used to minimize the number of experiments and Gray relational analysis is used for optimization. All parameter have varied in three levels and the range of parameter has chosen based on the previous experiment. An ANOVA is also conducted for the involved parameter to determine the percentage contribution of involved parameters. After the optimization a detailed engine experiment has been conducted using the test blends, to determine the performance, combustion and emission characteristics. From the obtained results, it is found that the application of neat jojoba oil upto 60% by volume is possible in CI engine with change in operating parameters. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 248–258, 2017
Numerical simulation of imbert biomass gasifier to select the feedstock available in remote areas
Authors: Murugan P.C. , Joseph Sekhar S.
Published: October 2016

The performance of a gasifier which is designed for a particular feedstock varies whenever the feedstock is changed. Moreover, to implement the biomass gasification technology in remote places, the performance of existing gasifier should be analysed for its dimensional suitability to work with different feedstock which are available in such locations. Even though, the species transport approach is more appropriate to model the gasification processes, it was not used to analyse all the zones of a gasifier. Hence, in this work, a numerical study was carried out with species transport model by considering all the four zones of a gasifier. This model uses gasification reactions with the corresponding pre‐exponential factor and activation energy to check the performance of a biomass gasifier. Different feedstocks such as coconut shell, rice husk, cow dung, rubber wood and rubber seed kernel shell that are commonly available in the selected region were used in this study. The influences of equivalence ratio on the composition and higher heating value of producer gas, and the temperature distribution inside the gasifier were been studied. Both the experimental and numerical studies demonstrate the best performance when the equivalence ratio is close to 0.25. Among the locally available biomasses, the producer gas from rubber seed kernel shell has the calorific value of 6.08 MJ/Nm3 and therefore it can be used as feedstock in gasifier which is designed for woody biomass. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 708–716, 2017
Evaluating the zebrafish embryo toxicity test for pesticide hazard screening
Authors: Glaberman Scott , Padilla Stephanie , Barron Mace G.
Published: October 2016

Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more resource-intensive, juvenile fish acute toxicity tests. However, there is also evidence that fish embryos are less sensitive than juvenile fish for certain types of chemicals, including neurotoxicants. The utility of fish embryos for pesticide hazard assessment was investigated by comparing published zebrafish embryo toxicity data from pesticides with median lethal concentration 50% (LC50) data for juveniles of 3 commonly tested fish species: rainbow trout, bluegill sunfish, and sheepshead minnow. A poor, albeit significant, relationship (r2 = 0.28; p < 0.05) was found between zebrafish embryo and juvenile fish toxicity when pesticides were considered as a single group, but a much better relationship (r2 = 0.64; p < 0.05) when pesticide mode of action was factored into an analysis of covariance. This discrepancy is partly explained by the large number of neurotoxic pesticides in the dataset, supporting previous findings that commonly used fish embryo toxicity test endpoints are particularly insensitive to neurotoxicants. These results indicate that it is still premature to replace juvenile fish toxicity tests with embryo-based tests such as the Organisation for Economic Co-operation and Development Fish Embryo Acute Toxicity Test for routine pesticide hazard assessment, although embryo testing could be used with other screening tools for testing prioritization. Environ Toxicol Chem 2017;36:1221–1226. © 2016 SETAC
Acute sensitivity of a broad range of freshwater mussels to chemicals with different modes of toxic action
Authors: Wang Ning , Ivey Christopher D. , Ingersoll Christopher G. , Brumbaugh William G. , Alvarez David , Hammer Edward J. , Bauer Candice R. , Augspurger Tom , Raimondo Sandy , Barnhart M. Christopher
Published: October 2016

Freshwater mussels, one of the most imperiled groups of animals in the world, are generally underrepresented in toxicity databases used for the development of ambient water quality criteria and other environmental guidance values. Acute 96-h toxicity tests were conducted to evaluate the sensitivity of 5 species of juvenile mussels from 2 families and 4 tribes to 10 chemicals (ammonia, metals, major ions, and organic compounds) and to screen 10 additional chemicals (mainly organic compounds) with a commonly tested mussel species, fatmucket (Lampsilis siliquoidea). In the multi-species study, median effect concentrations (EC50s) among the 5 species differed by a factor of ≤2 for chloride, potassium, sulfate, and zinc; a factor of ≤5 for ammonia, chromium, copper, and nickel; and factors of 6 and 12 for metolachlor and alachlor, respectively, indicating that mussels representing different families or tribes had similar sensitivity to most of the tested chemicals, regardless of modes of action. There was a strong linear relationship between EC50s for fatmucket and the other 4 mussel species across the 10 chemicals (r2 = 0.97, slope close to 1.0), indicating that fatmucket was similar to other mussel species; thus, this commonly tested species can be a good surrogate for protecting other mussels in acute exposures. The sensitivity of juvenile fatmucket among different populations or cultured from larvae of wild adults and captive-cultured adults was also similar in acute exposures to copper or chloride, indicating captive-cultured adult mussels can reliably be used to reproduce juveniles for toxicity testing. In compiled databases for all freshwater species, 1 or more mussel species were among the 4 most sensitive species for alachlor, ammonia, chloride, potassium, sulfate, copper, nickel, and zinc; therefore, the development of water quality criteria and other environmental guidance values for these chemicals should reflect the sensitivity of mussels. In contrast, the EC50s of fatmucket tested in the single-species study were in the high percentiles (>75th) of species sensitivity distributions for 6 of 7 organic chemicals, indicating mussels might be relatively insensitive to organic chemicals in acute exposures. Environ Toxicol Chem 2017;36:786–796. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Biomarkers of exposure to nanosilver and silver accumulation in yellow perch (Perca flavescens)
Authors: Martin Jonathan D. , Colson Tash-Lynn L. , Langlois Valerie S. , Metcalfe Chris D.
Published: October 2016

There is a risk of exposure of aquatic organisms to silver nanoparticles (AgNPs) from discharges of municipal and industrial wastewater. In the present study, yellow perch (Perca flavescens) were exposed to environmentally relevant concentrations (1 mg/L and 100 mg/L) of AgNPs and silver ions (Ag+) in static-renewal experiments conducted over 96 h and 10 d. The greatest accumulation of total Ag occurred in the liver of P. flavescens, and there was >10-fold more accumulation in the treatments with Ag+ relative to the AgNP treatments. Residues of total Ag increased with concentration and duration of exposure in liver, gill, and muscle. Both exposures caused a 2-fold induction of gene expression for metallothionein (mt) in liver tissue after 96 h of exposure and reductions in levels of oxidized glutathione (GSSG) in liver after 10 d of exposure. Both AgNPs and Ag+ decreased the expression of heat-shock proteins (hsp70). Exposure to the high concentration of AgNPs for 10 d significantly increased lipid peroxidation in gill tissue, as indicated by the thiobarbituric acid reactive substances (TBARS) assay. There was a negative correlation between mean levels of GSSG and TBARS for both gill and liver tissue when data for all treatments were combined. It is significant that these biological responses were observed in P. flavescens exposed to AgNPs, even though accumulation of total Ag was at least 10-fold lower relative to the treatments with Ag+. Environ Toxicol Chem 2017;36:1211–1220. © 2016 SETAC
Deltamethrin toxicity and impaired swimming behavior of two backswimmer species
Authors: Gutiérrez Yeisson , Tomé Hudson V.V. , Guedes Raul N.C. , Oliveira Eugênio E.
Published: October 2016

Backswimmers (Hemiptera: Heteroptera: Notonectidae) are insect predators in a wide variety of freshwater habitats. These insects are well known through their role as mosquito biocontrol agents, their ability to prey on immature fishes and frogs, and because they are often the first to colonize aquatic habitats. As a consequence, these predators may face intended or unintended insecticide exposures that may lead to death or to impairment of essential behaviors (e.g., swimming and position in the water column). The toxicity of deltamethrin (a type II pyrethroid insecticide stressor) and the swimming activity of the backswimmers Buenoa tarsalis and Martarega bentoi were evaluated. Concentration–mortality and survival bioassays were conducted with the insecticide, which were compared with controls without deltamethrin. Deltamethrin was 26-fold more toxic to B. tarsalis (median lethal concentration [LC50] = 4.0 ng a.i./L) than to M. bentoi (LC50 = 102.5 ng a.i./L). The pattern of occupation of B. tarsalis, but not of M. bentoi, in the water column was also disrupted, and B. tarsalis was forced to stay near the water surface longer with exposure to deltamethrin. Thus, based on the findings, B. tarsalis was less resilient to deltamethrin exposure compared with M. bentoi, and the efficacy of swimming-dependent processes might be negatively affected (e.g., prey catching, partner encounter, and antipredator behaviors) for B. tarsalis under deltamethrin exposure. Environ Toxicol Chem 2017;36:1235–1242. © 2016 SETAC
TBM drives at the Gotthard Base Tunnel – Design and experience from tunnelling in Faido / TBM‐Vortriebe am Gotthard Basistunnel – Projektierung und Erfahrung aus dem Vortrieb Faido
Authors: Jesel Thomas , Amberg Felix , Rohrer Thomas
Published: October 2016

In the course of designing the Gotthard Base Tunnel, extensive questions were considered about the tunnelling conditions to be expected and the resulting requirements for the TBM. Naturally this mainly concentrated on the achievable advance rates and the associated costs. The tunnelling works have now been completed and the essential assumptions and decisions from the design phase could be confirmed. Experience does however also show that the behaviour of the rock mass could not always be correctly predicted in its entireness and a corresponding flexibility in the use of support measures is unavoidable, which is only possible with suitable tunnelling equipment and machinery. The present article collects the essential data and facts from the TBM drives and described the areas where significant deviations arose. Particular attention is paid to the following subjects and the corresponding effects: wear to the cutterhead, heavy water ingress, rockburst, reciprocal influencing of the two tunnel drives under poor geological conditions and the collapse in the Tenelin Zone. The stated matters are described with a comparison against the assumptions made in the design phase and a complemented with few of the lessons learnt.

Im Zuge der Planung des Gotthard Basistunnels wurden umfangreiche Überlegungen angestellt, über die zu erwartenden Vortriebsverhältnisse und die sich daraus ergebenden Anforderungen an die TBM. Im Fokus standen dabei naturgemäß vor allem auch die erreichbaren Vortriebsleistungen und die damit verbundenen Kosten. Die Vortriebsarbeiten sind abgeschlossen, und die wesentlichen Annahmen und Entscheide aus der Planungsphase konnten bestätigt werden. Die Erfahrung zeigt aber auch, dass das Verhalten des Gebirges nicht immer vollumfänglich zutreffend vorausgesagt werden konnte und eine entsprechende Flexibilität beim Einsatz der Sicherungsmittel unumgänglich ist, was nur mit einer dafür geeigneten Vortriebsinstallation möglich ist. Der vorliegende Beitrag stellt die wesentlichen Daten und Fakten aus dem TBM‐ Vortrieb zusammen und zeigt auf, in welchen Bereichen sich deutliche Unterschiede ergeben haben. Ein besonderes Augenmerk wird auf folgende Themen und die entsprechenden Auswirkungen gelegt: Verschleiß am Bohrkopf, hoher Wasseranfall, Bergschlag, gegenseitige Beeinflussung der beiden Tunnelvortriebe bei schlechten geologischen Verhältnissen und Niederbruch in der Tenelin‐Zone. Die aufgeführten Punkte werden mit einem Vergleich der Annahmen aus der Projektierung und den effektiv angetroffenen Verhältnissen beleuchtet sowie mit einigen Hinweisen zu den Lessons learned abgerundet.
An innovative approach for optimising geothermal energy recovery / Tiefe geothermische Energiegewinnung – Innovative Wege zur Optimierung
Authors: Fruhwirth Rudolf K. , Hofstätter Herbert
Published: October 2016

The overall economics of a geothermal project are basically governed by the formation temperature gradient and the productivity of the reservoir. At the Chair of Petroleum and Geothermal Energy Recovery, a simulator has been developed considering different well geometries and casing strings or liner completions as well as total or partial cementation. In order to optimize heat transfer or to minimize losses, various tubing types like gas‐ or vacuum isolated pipes as well as relined or outside coated pipes can be simulated. The program also allows the simulation of transient states as well as the circulation of various media with various rates in closed systems. This enables the optimisation of energy recovery by simulating various materials and circulation rates over a long term, which is essential for the evaluation of the economical limits and energy efficiency of a geothermal project. The program can also be used for the simulation of oil and gas production since the conservation of energy results in less friction losses and higher flow velocities in gas wells which finally results in better deliquification behaviour.

Die Wirtschaftlichkeit eines geothermischen Projekts wird im Wesentlichen durch den Temperaturgradienten und die Produktivität der Lagerstätte bestimmt. Am Chair of Petroleum and Geothermal Energy Recovery der Montanuniversität Leoben wurde in den vergangenen Jahren ein Simulator entwickelt, der die Modellierung geothermischer Vorgänge im Bohrloch erlaubt. Ziel dieser Arbeit ist die Simulation der Wärmeverluste auf dem Weg von der Lagerstätte nach Obertage unter Berücksichtigung verschiedener Bohrlochgeometrien als auch Tagesrohrtouren oder Linerkomplettierungen samt deren vollständigen oder partiellen Zementation.

Um den Wärmetransport zu optimieren bzw. die Verluste zu minimieren, werden verschiedene Materialien der Steigrohre, wie gas‐ oder vakuumisolierte Rohre, aber auch innen und/oder außen isolierte Tübbinge behandelt. Das Programm ist für transiente Simulation sowie die Zirkulation verschiedener Medien mit variabler Zirkulationsrate in einem geschlossenen System ausgelegt. So kann die optimale Energieausbeute unter Verwendung verschiedenster Materialien und Zirkulationsraten über einen langen Beobachtungszeitraum simuliert werden, was wiederum die Basis für die Wirtschaftlichkeit und Energieeffizienz geothermaler Projekte darstellt. Das Programm wird aber auch für die Simulation von Erdöl‐ und Erdgasförderung herangezogen, zumal durch die Energiekonservierung die Reibungsdruckverluste wesentlich geringer sind, bei Gassonden die Fließgeschwindigkeit höher ist und somit die Austragfähigkeit von Flüssigkeiten aus der Sonde verbessert werden kann.
Semmering Base Tunnel Contract SBT2.1 Tunnel Fröschnitzgraben – Creative solutions for complex shafts / Semmering‐Basistunnel Baulos SBT2.1 Tunnel Fröschnitzgraben – Kreative Lösungen für komplexe Schachtbauwerke
Authors: Pacher Wolfgang , Putz Georg C.J.
Published: October 2016

Contract SBT2.1 “Tunnel Fröschnitzgraben” has a value of about EUR 623 million, the largest contract for the Semmering Base Tunnel. The construction contract was awarded in autumn 2013 to the joint venture Tunnel Fröschnitzgraben Implenia – Swietelsky Tunnelbau. The contract includes altogether about 26 km of running tunnels to be driven by two mechanised drives and two conventional drives, with the works being undertaken at all four faces almost simultaneously. The particular challenge is that the entire supply to the underground activities and the clearance of excavated material has to pass through two shafts about 400 m deep. The construction of these two shafts with excavated diameters of about 12.4 and 9.9 m respectively and the selection of the shaft logistics are of decisive significance for the success of the project. These special requirements of the project faced a limited availability of flexible complete contractors for the construction and operation of shafts. Considering this situation, the joint venture partner Swietelsky Tunnelbau decided to solve the problem in‐house and follow new routes with innovative concepts.

Das Baulos SBT2.1 “Tunnel Fröschnitzgraben” ist mit einem Auftragswert von etwa 623 Mio. EUR das größte Baulos des Semmering‐Basistunnels. Im Herbst 2013 erhielt die Arbeitsgemeinschaft Tunnel Fröschnitzgraben Implenia – Swietelsky Tunnelbau den Bauauftrag. Für die im Baulos insgesamt aufzufahrenden ca. 26 km Streckenröhren sind zwei maschinelle Vortriebe (TVM) und zwei konventionelle Vortriebe vorgesehen. Die Arbeiten werden an allen vier Vortriebsästen großteils zeitgleich abgewickelt. Die besondere Herausforderung liegt darin, dass die gesamte Versorgung der untertägigen Aktivitäten sowie der Abtransport des Ausbruchmaterials über zwei jeweils ca. 400 m tiefe Schächte erfolgen müssen. Die Herstellung der beiden Schächte mit einem Ausbruchdurchmesser von rd. 12,4 bzw. 9,9 m und die Auswahl der Schachtlogistik sind für das Gelingen des Projekts von entscheidender Bedeutung. Den speziellen Anforderungen des Projekts stand ein begrenztes Angebot an flexiblen Komplettanbietern für den Bau und den Betrieb von Schächten gegenüber. Angesichts dieser Situation hat sich der Arge‐Partner Swietelsky Tunnelbau dazu entschieden, die Problemstellungen in Eigenregie zu lösen und mit innovativen Konzepten neue Wege zu beschreiten.
Excavation of the Perschling Tunnels by TBM – expectations and reality – lessons learned / TBM‐Vortrieb Tunnelkette Perschling – Erwartung und Wirklichkeit – Erfahrungen und Erkenntnisse
Authors: Benedikt Johannes , Lemmerer Johann , Köpf Manfred , Obermeier Oskar
Published: October 2016

In the course of constructing the new Vienna – St. Pölten high‐speed railway line, three TBM tunnels with an excavated diameter of approx. 13 m were driven between 2005 and 2010. The total length of these three tunnels including portal structures, cut‐and‐cover and top‐down sections was approx. 7.4 km, of which 6.2 km were excavated by TBM‐S. The tunnels were constructed with drainage systems and two‐pass linings in the tunnel arch. During the feasibility study, the permit application design and the tender design phase, detailed risk analyses were performed for excavation method (TBM or NATM), machine type (TBM‐S or SM‐EPB) and lining type (single‐ or two‐pass). The expectations of the client during the design phase and those of the contractor during the bidding phase are compared and discussed, taking into account construction time considerations, geotechnical risk assessments, lining design, machine type and construction sequence as well as the allocation of risks between client and contractor. The reality of the project, i.e. the construction time actually needed, the challenges encountered, the problems solved and the joint approach adopted to implement the project as well as the lessons learned (experiences and findings) are all described.

Im Zuge der Errichtung der Neubaustrecke Wien – St. Pölten wurden in den Jahren 2005 bis 2010 drei Tunnel mittels einer Tunnelbohrmaschine mit einem Ausbruchsdurchmesser von rund 13 m aufgefahren. Die Gesamtlänge der drei Tunnelbauwerke, inklusive der Portalbauwerke, offenen Bauweisen und Deckelbauweisen, betrug rund 7,4 km, wobei rund 6,2 km mit einer TBM‐S aufgefahren wurden. Die Tunnel wurden druckwasserentlastet mit einem zweischaligen Ausbau im Gewölbe hergestellt. Für die Tunnel wurden in den Phasen der Grundsatzprüfung, der Behördenverfahren und der Ausschreibungsplanung vertiefte Risikoanalysen zur Vortriebsmethode (TVM oder NÖT), zur Wahl des Maschinentyps (TBM‐S oder SM‐EPB) und des Ausbaus (einschalig oder zweischalig) erstellt. Die Erwartungen des Auftraggebers (AG) in der Planungsphase und des Auftragnehmers (AN) in der Angebotsphase werden anhand von Bauzeitüberlegungen, Risikobetrachtungen zu Geotechnik, Ausbau, Maschine und Bauablauf sowie der Sphärenzuordnung AG und AN gegenübergestellt und erläutert. Die Wirklichkeit, also die reale Bauzeit, die aufgetretenen Schwierigkeiten, die gelösten Probleme und die partnerschaftliche Projektabwicklung sowie die gewonnenen Erfahrungen und Erkenntnisse werden dargelegt.
The St. Kanzian Chain of Tunnels – Tunnelling under very varied and extremely difficult conditions / Tunnelkette St. Kanzian – Tunnelbau unter sehr unterschiedlichen und extrem schwierigen Bedingungen
Authors: Benedikt Johannes , Wagner Hanns , Herzeg Thomas
Published: October 2016

In the course of the building of the new Koralmbahn railway line between Graz and Klagenfurt in Austria, six tunnels have to be built in a sensitive landscape on the Carithian side. The tunnels have lengths of between 230 and 2,100 m. All the tunnels are designed to resist water under pressure and have a two‐track standard cross‐section. Except for the 495 m long Kühnsdorf Green Tunnel, which has already been completed, all the tunnels are currently under construction. The Srejach and Untersammelsdorf Tunnels with lengths of 620 and 665 m respectively are being driven in very challenging ground conditions consisting of silty to fine sandy lacustrine sediments, and extensive specialised civil engineering works had to be carried out in advance of both these tunnels. The performance of extensive tests and investigations during the tendering phase turned out to be very valuable for the planning of the project. The longest tunnel, the Stein Tunnel with a length of 2,100 m, is characterised by its location in soft ground with shallow overburden and the sensitive hydrogeological and ecological conditions. The driving of the Lind Tunnel in phyllite required special measures due to the lacustrine sediments above the tunnel, which reached down to the tunnel crown.

Im Zuge der Errichtung der Koralmbahn zwischen Graz und Klagenfurt sind auf Kärntner Seite in einem sensiblen Landschaftsraum sechs Tunnelbauwerke zu errichten. Die Tunnellängen liegen zwischen 230 und 2.100 m. Sämtliche Tunnelbauwerke werden druckwasserhaltend mit einem zweigleisigen Regelquerschnitt ausgeführt. Bis auf den 495 m langen Grüntunnel Kühnsdorf, der bereits fertig gestellt ist, befinden sich derzeit alle Tunnelbauwerke in der Ausführungsphase. Die Tunnel Srejach und Untersammelsdorf mit einer Länge von 620 und 665 m sind in extrem herausfordernden Untergrundbedingungen, bestehend aus schluffigen bis feinsandigen Stillwassersedimenten, herzustellen. Für diese beiden Tunnelbauwerke werden vorab Spezialtiefbaumaßnahmen in großem Umfang durchgeführt. Für die Planung dieser Arbeiten war die Durchführung von umfangreichen Versuchen und Untersuchungen in der Ausschreibungsphase sehr wertvoll. Der Tunnel Stein, mit 2.100 m der längste Tunnel in der Kette, ist durch seine Lage im Lockermaterial mit geringer Überlagerung und durch sensible hydrogeologische und ökologische Verhältnisse gekennzeichnet. Der Vortrieb des Tunnels Lind im Phyllit erfordert infolge der darüber liegenden Stillwassersedimente, die bis in die Tunnelfirste reichen, besondere Maßnahmen.
Design considerations for pillar systems in deep mines
Authors: Wagner Horst , Ladinig Tobias , Blaha Hannes
Published: October 2016

Pillar systems in mines are statically indeterminate systems. The paper presents the results of numerical investigations to evaluate the effects of panel dimensions on pillar loads. It is shown that pillar load in deep mines is strongly influenced by the lateral and vertical extent of extraction panels. The commonly applied tributary area concept does not account for these effects and is an oversimplification that has to be applied with caution. The effects of local pillar failures on stability of pillar workings are examined using simple models. It is shown that limiting panel dimensions by substantial barrier pillars can reduce the danger of regional pillar collapses and enhance overall mine stability.
Metro Doha Green Line – EPB TBM tunnelling under very special circumstances / Metro Doha Green Line – EPB‐Vortriebe unter Berücksichtigung sehr spezieller Randbedingungen
Authors: Köhler Hans , Rengshausen Rainer
Published: October 2016

As part of the Qatar National Vision 2030, the capital of Qatar – Doha – is being expanded into a modern centre for economy, trade and sport. A main part of this plan is the establishment of an efficient infrastructure with modern means of transportation.

The Design & Build – Project Green Line Underground was awarded to a Joint Venture (JV) composed of PORR (lead), the Saudi BinLadin Group and the local construction company HBK in summer 2013. It contains the turnkey construction of the underground part of the Green Line with a total length of 2 × 17 km tunnel, six stations, switching areas as well as cross passages and emergency exit shafts. The 34 km of tunnelling, bored by six EPB machines simultaneously, has now been completed. The expectations for the project, especially concerning the TBM tunnelling, are compared to the knowledge gained.

The following topics are highlighted:

– climate and culture,

– personnel of different origins/education,

– working with unskilled/semiskilled workers,

– TBM/logistic concepts,

– performance, wear and tear,

– geological conditions,

– segment design,

– health and safety.

The tunnel drives were completed in 18 months despite all challenges.

Im Rahmen der Qatar National Vision 2030 wird die Hauptstadt Katars – Doha – zu einem modernen Zentrum für Wirtschaft, Handel und Sport ausgebaut. Ein wesentlicher Bestandteil zur Realisierung dieses Ziels ist die Errichtung einer leistungsfähigen Infrastruktur mit modernen Massentransportmitteln.

Das Design & Build‐Projekt Green Line Underground wurde im Sommer 2013 an ein Joint Venture (JV) aus Porr (Federführung), der Saudi BinLadin Group und dem lokalen Bauunternehmen HBK vergeben und beinhaltet die schlüsselfertige Errichtung des unterirdischen Abschnitts der Green Line mit einer Tunnellänge von 2 × 17 km, sechs Stationen, Spurwechsel‐ und Weichenanlagen sowie Querschlägen und Notausstiegsschächten. Die Vortriebe der ca. 34 km langen Tunnel, die mit sechs EPB‐Maschinen hergestellt wurden, sind mittlerweile abgeschlossen. In einem Rückblick werden die Erwartungen an das Projekt, insbesondere an den TVM‐Vortrieb, mit den gemachten Erfahrungen verglichen.

Hier werden speziell folgende Themen beleuchtet:

– klimatisches und kulturelles Umfeld,

– Personal unterschiedlichster Herkunft und Bildung,

– Arbeiten mit ungelerntem/angelerntem Personal,

– Vortriebs‐ und Logistikkonzepte,

– Leistungen, Verschleiß, Schäden,

– geologische Verhältnisse, Vorauserkundung,

– technische Ausführung der Tübbinge, inkl. Dichtung,

– Arbeitssicherheit, Gesundheitsschutz.

Trotz aller Herausforderungen konnten die Vortriebsarbeiten in ca. 18 Monaten abgeschlossen werden.
Two different mechanosensitive calcium responses in Müller glial cells of the guinea pig retina: Differential dependence on purinergic receptor signaling
Authors: Agte Silke , Pannicke Thomas , Ulbricht Elke , Reichenbach Andreas , Bringmann Andreas
Published: October 2016

Tractional forces or mechanical stimulation are known to induce calcium responses in retinal glial cells. The aim of the study was to determine the characteristics of calcium responses in Müller glial cells of the avascular guinea pig retina induced by focal mechanical stimulation. Freshly isolated retinal wholemounts were loaded with Mitotracker Deep Red (to fill Müller cells) and the calcium‐sensitive dye Fluo‐4/AM. The inner retinal surface was mechanically stimulated with a micropipette tip for 10 ms. Stimulation induced two different cytosolic calcium responses in Müller cells with different kinetics in dependence on the distance from the stimulation site. Müller cells near the stimulation site displayed an immediate and long‐lasting calcium response with high amplitude. This response was mediated by calcium influx from the extracellular space likely triggered by activation of ATP‐insensitive P2 receptors. More distant Müller cells displayed, with a delay of 2.4 s, transient calcium responses which propagated laterally in a wave‐like fashion. Propagating calcium waves were induced by a calcium‐independent release of ATP from Müller cells near the stimulation site, and were mediated by a release of calcium from internal stores triggered by ATP, acting in part at P2Y1 receptors. The data suggest that mechanically stimulated Müller cells of the guinea pig retina release ATP which induces a propagating calcium wave in surrounding Müller cells. Propagating calcium waves may be implicated in the spatial regulation of the neuronal activity and homeostatic glial functions, and may transmit gliosis‐inducing signals across the retina. Mechanical stimulation of guinea pig Müller cells induces two calcium responses: an immediate response around the stimulation site and propagating calcium waves. Both responses are differentially mediated by activation of purinergic receptors. GLIA 2016 GLIA 2017;65:62–74
Personality and behavioural changes do not precede memory problems as possible signs of dementia in ageing people with Down syndrome
Authors: Blok J. B. , Scheirs J. G. M. , Thijm N. S.
Published: October 2016

Objective

The objective was to find out whether changes in personality and adaptive functioning or memory processes decline first in ageing people with Down syndrome.

Methods

We measured these variables cross‐sectionally in a Dutch sample (22 to 62 years of age) of 68 institutionalised people with Down syndrome.

Results

The scores on all the variables except one of the temperament scales were found to decline gradually with increasing age, but deterioration of episodic memory started earlier.

Conclusions

We argued that a subset of our sample suffered from dementia. Furthermore, the data suggested that immediate memory impairment is one of the earliest signs of the disease in people with Down syndrome, just as it is in the general population. Copyright © 2016 John Wiley & Sons, Ltd.