| 1. |
- Wallace, Bryan P., et al.
(author)
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Global Conservation Priorities for Marine Turtles
- 2011
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:9
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Journal article (peer-reviewed)abstract
- Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a "conservation priorities portfolio" system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world's 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and priority-setting for widespread, long-lived taxa.
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| 2. |
- Wallace, Bryan P., et al.
(author)
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Regional Management Units for Marine Turtles: A Novel Framework for Prioritizing Conservation and Research across Multiple Scales
- 2010
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:12
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Journal article (peer-reviewed)abstract
- Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques - including site-based monitoring, genetic analyses, mark-recapture studies and telemetry - can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings: To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine-to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally. Conclusions/Significance: The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework - including maps and supporting metadata - will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis.
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| 3. |
- Echtermeyer, T. J., et al.
(author)
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Graphene field-effect devices
- 2007
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In: The European Physical Journal Special Topics. - : Springer Science and Business Media LLC. - 1951-6355 .- 1951-6401. ; 148:1, s. 19-26
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Journal article (peer-reviewed)abstract
- In this article, graphene is investigated with respect to its electronic properties when introduced into field effect devices ( FED). With the exception of manual graphene deposition, conventional top-down CMOS-compatible processes are applied. Few and monolayer graphene sheets are characterized by scanning electron microscopy, atomic force microscopy and Raman spectroscopy. The electrical properties of monolayer graphene sandwiched between two silicon dioxide films are studied. Carrier mobilities in graphene pseudo-MOS structures are compared to those obtained from double-gated Graphene-FEDs and silicon metal-oxide-semiconductor field-effect-transistors ( MOSFETs).
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| 4. |
- Hahne, J., et al.
(author)
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Including gap junctions into distributed neuronal network simulations
- 2016
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In: 2nd International Workshop on Brain-Inspired Computing, BrainComp 2015. - Cham : Springer Publishing Company. - 9783319508610 ; , s. 43-57
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Conference paper (peer-reviewed)abstract
- Contemporary simulation technology for neuronal networks enables the simulation of brain-scale networks using neuron models with a single or a few compartments. However, distributed simulations at full cell density are still lacking the electrical coupling between cells via so called gap junctions. This is due to the absence of efficient algorithms to simulate gap junctions on large parallel computers. The difficulty is that gap junctions require an instantaneous interaction between the coupled neurons, whereas the efficiency of simulation codes for spiking neurons relies on delayed communication. In a recent paper [15] we describe a technology to overcome this obstacle. Here, we give an overview of the challenges to include gap junctions into a distributed simulation scheme for neuronal networks and present an implementation of the new technology available in the NEural Simulation Tool (NEST 2.10.0). Subsequently we introduce the usage of gap junctions in model scripts as well as benchmarks assessing the performance and overhead of the technology on the supercomputers JUQUEEN and K computer.
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| 5. |
- Lemme, Max C., 1970-, et al.
(author)
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Mobility in graphene double gate field effect transistors
- 2008
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In: Solid-State Electronics. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-1101 .- 1879-2405. ; 52:4, s. 514-518
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Journal article (peer-reviewed)abstract
- In this work, double-gated field effect transistors manufactured from monolayer graphene are investigated. Conventional top-down CMOS-compatible processes are applied except for graphene deposition by manual exfoliation. Carrier mobilities in single- and double-gated graphene field effect transistors are compared. Even in double-gated graphene FETs, the carrier mobility exceeds the universal mobility of silicon over nearly the entire measured range. At comparable dimensions, reported mobilities for ultra-thin body silicon-on-insulator MOSFETs cannot compete with graphene FET values. (c) 2007 Elsevier Ltd. All rights reserved.
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| 6. |
- Bolten, J., et al.
(author)
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Fabrication of Nanowires
- 2014
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In: Beyond CMOS Nanodevices 1. - Hoboken, NJ, USA : Wiley Blackwell. - 9781118984772 - 9781848216549 ; , s. 5-23
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Book chapter (other academic/artistic)abstract
- Several fabrication processes of silicon nanowires have been developed in the research community. They can be divided into bottom-up or top-down approaches. This chapter describes top-down fabrication of silicon nanowires using electron beam lithography (EBL), which combined with optical lithography can be a viable approach if not too many silicon nanowires need to be patterned on a wafer. It also describes the sidewall transfer lithography (STL) technique using I-line stepper lithography to pattern a vast amount of silicon nanowires on a silicon wafer. In addition the chapter examines how bottom-up Si nanowires synthesized by vapor-liquid-solid (VLS)-chemical vapor deposition (CVD) can be assembled at low cost in an efficient way for further use as a sensing material. Among the solution-based assembly methods for the nanostructured network (nanonet) fabrication, the vacuum filtration method is highly simple, versatile, low cost and scalable to large areas.
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| 7. |
- Chaloupka, Milani, et al.
(author)
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Encouraging outlook for recovery of a once severely exploited marine megaherbivore
- 2008
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In: Global Ecology and Biogeography. - : Wiley. - 1466-8238 .- 1466-822X. ; 17:2, s. 297-304
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Journal article (peer-reviewed)abstract
- Aim To critically review the status of the green sea turtle (Chelonia mydas) using the best available scientific studies as there is a prevailing view that this species is globally endangered and its marine ecosystem functions compromised. Location Ogasawara (Japan), Hawaii (USA), Great Barrier Reef (Australia), Florida (USA), Tortuguero (Costa Rica). Methods We compiled seasonal nesting activity data from all reliable continuous long-term studies (> 25 years), which comprised data series for six of the world's major green turtle rookeries. We estimated the underlying time-specific trend in these six rookery-specific nester or nest abundance series using a generalized smoothing spline regression approach. Results Estimated rates of nesting population increase ranged from c. 4-14% per annum over the past two to three decades. These rates varied considerably among the rookeries, reflecting the level of historical exploitation. Similar increases in nesting population were also evident for many other green turtle stocks that have been monitored for shorter durations than the long-term studies presented here. Main conclusions We show that six of the major green turtle nesting populations in the world have been increasing over the past two to three decades following protection from human hazards such as exploitation of eggs and turtles. This population recovery or rebound capacity is encouraging and suggests that the green turtle is not on the brink of global extinction even though some stocks have been seriously depleted and are still below historical abundance levels. This demonstrates that relatively simple conservation strategies can have a profound effect on the recovery of once-depleted green turtle stocks and presumably the restoration of their ecological function as major marine consumers.
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| 8. |
- Hawkey, Christopher J, et al.
(author)
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Less small-bowel injury with lumiracoxib compared with naproxen plus omeprazole
- 2008
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In: Clinical Gastroenterology and Hepatology. - : Elsevier BV. - 1542-7714 .- 1542-3565. ; 6:5, s. 536-544
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Journal article (peer-reviewed)abstract
- Background & Aims: The selective cyclooxygenase-2 inhibitor lumiracoxib has been shown to reduce endoscopically detected ulcers and ulcer complications in the upper gastrointestinal tract compared with nonselective nonsteroidal anti-inflammatory drugs. We investigated whether lumiracoxib would reduce small-bowel injury compared with naproxen plus omeprazole. Methods: Healthy volunteers were randomized to receive lumiracoxib, 100 mg once daily, naproxen 500 mg twice daily plus omeprazole 20 mg once daily, or placebo in a 16-day double-blind, parallel-group study. Small-bowel mucosal injury and inflammation were assessed by video capsule endoscopy, the lactulose:L-rhamnose permeability assessment, and the fecal calprotectin test. Results: Of 152 randomized subjects, 139 completed the study with valid video capsule endoscopies (lumiracoxib, n = 47; naproxen plus omeprazole, n = 45; placebo, n = 47). Compared with placebo, an increased number of subjects on naproxen plus omeprazole had small-bowel mucosal breaks (77.8% vs 40.4%, P < .001), with increased permeability (P = .023) and increased fecal calprotectin (increase, 96.8 vs 14.5 mg/kg for placebo; P < .001). With lumiracoxib, 27.7% of subjects had small-bowel mucosal breaks (P = .196 vs placebo; P < .001 vs naproxen), there was no increase in permeability (P = .157 vs placebo; P = .364 vs naproxen), and no increase in fecal calprotectin (-5.7 mg/kg; P = .377 vs placebo; P < .001 vs naproxen). Conclusions: As assessed by 3 different measures, acute small-bowel injury on lumiracoxib treatment is less frequent than with naproxen plus omeprazole and similar to placebo.
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| 9. |
- Kupper, D, et al.
(author)
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Impact of supercritical CO(2) drying on roughness of hydrogen silsesquioxane e-beam resist
- 2006
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In: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 24:2, s. 570-574
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Journal article (peer-reviewed)abstract
- Surface roughness (SR) and, especially, the closely related line-edge roughness (LER) of nanostructures are important issues in advanced lithography. In this study, the origin of surface roughness in the negative tone electron resist hydrogen silsesquioxane is shown to be associated with polymer aggregate extraction not only during resist development but also during resist drying. In addition, the impact of exposure dose and resist development time on SR is clarified. Possibilities to reduce SR and LER of nanostructures by optimizing resist rinsing and drying are evaluated. A process of supercritical CO(2) resist drying that delivers remarkable reduction of roughness is presented. (c) 2006 American Vacuum Society.
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| 10. |
- Wahlbrink, T., et al.
(author)
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Supercritical drying for high aspect-ratio HSQ nano-structures
- 2007
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In: Microelectronic Engineering. - : Elsevier BV. - 0167-9317 .- 1873-5568. ; 84:5-8, s. 1045-1048
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Journal article (peer-reviewed)abstract
- The benefits of supercritical resist drying (SRD) technique using carbon dioxide (CO2) are investigated with respect to the resolution of dense patterns and the aspect ratio (AR) of nano-structures in rather thick HSQ layers. For double lines separated by a distance of 50 nm the maximum achievable AR is trebled using SRD processes compared to conventional nitrogen blow. The mechanical stability of resist structures is significantly improved by using SRI).
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