Terahertz photoconductivity and plasmon modes in double-quantum-well field-effect transistors

Double-quantum-well field-effect transistors with a grating gate exhibit a sharply resonant, voltage tuned terahertz photoconductivity. The voltage tuned resonance is determined by the plasma oscillations of the composite structure. The resonant photoconductivity requires a double-quantum well but the mechanism whereby plasma oscillations produce changes in device conductance is not understood. The phenomenon is potentially important for fast, tunable terahertz detectors

Lessons Learned from Two Case Studies in Higher Education

As places where future citizens are educated, knowledge is (co-)produced and societal developments are critically reflected, higher education institutions (HEIs) can play a key role in addressing sustainability challenges. In order to accelerate mutual learning, shared problem understanding, and joint development of sustainable solutions, interinstitutional exchange and collaboration between HEIs is crucial. However, little research to date has focused on institutional HEI networks in the field of sustainability. More specifically, we still understand little about the concrete development, implementation, and adaptation of such networks. This article explores early-stage HEI networks for sustainability from a conceptual and empirical stance in order to develop a framework that facilitates structured descriptions of these networks, as well as to foster cross-HEI learning on their effective performance. It therefore combines insights from an explorative literature review, two case studies and an interactive workshop at the ISCN Conference 2018. As results, we first suggest an analytical framework to facilitate a systematic characterization of HEI networks. Second, by applying the framework to the two case studies, we present and discuss lessons learned on how a single HEI can contribute to establishing a network and how it can utilize its network membership effectively to strengthen its efforts for sustainability

Mitochondrial Dysregulation Secondary to Endoplasmic Reticulum Stress in Autosomal Dominant Tubulointerstitial Kidney Disease - UMOD (ADTKD-UMOD)

'Autosomal dominant tubulointerstitial kidney disease - UMOD' (ADTKD-UMOD) is caused by impaired maturation and secretion of mutant uromodulin (UMOD) in thick ascending limb of Henle loop (TAL) cells, resulting in endoplasmic reticulum (ER) stress and unfolded protein response (UPR). To gain insight into pathophysiology, we analysed proteome profiles of TAL-enriched outer renal medulla samples from ADTKD-UMOD and control mice by quantitative LC-MS/MS. In total, 212 differentially abundant proteins were identified. Numerous ER proteins, including BiP (HSPA5), phosphorylated eIF2 alpha (EIF2S1), ATF4, ATF6 and CHOP (DDIT3), were increased abundant, consistent with UPR. The abundance of hypoxia-inducible proteins with stress survival functions, i.e. HYOU1, TXNDC5 and ERO1L, was also increased. TAL cells in ADTKD-UMOD showed a decreased proportion of mitochondria and reduced abundance of multiple mitochondrial proteins, associated with disturbed post-translational processing and activation of the mitochondrial transcription factor NRF1. Impaired fission of organelles, as suggested by reduced abundance of FIS1, may be another reason for disturbed biogenesis of mitochondria and peroxisomes. Reduced amounts of numerous proteins of the OXPHOS and citrate cycle pathways, and activation of the LKB1-AMPK-pathway, a sensor pathway of cellular energy deficits, suggest impaired energy homeostasis. In conclusion, our study revealed secondary mitochondrial dysfunction in ADTKD-UMOD

Spatial analysis of fluoride concentrations in drinking water and population at risk in Namibia

© 2017, South African Water Research Commission. All rights reserved. Namibia, the driest country in sub-Saharan Africa, is largely reliant on groundwater for its potable water demand and groundwater is a major source of naturally-occurring fluoride. This study assessed the spatial distribution of fluoride in potable water and appraised the population at risk for high fluoride intake. Analysis of fluoride levels used existing databases that include 28 000 borehole locations across the country, while the population data were based on the 2011 Census. Spatial analysis and spatial statistics methods employed included Moran’s I, local indicators of spatial association (LISA), basic Euclidian distance, analysis of variance (ANOVA) and spatial overlay in a GIS environment. Fluoride concentrations above the recommended limit of 1.5 mg/L occur in a fifth of the boreholes and as much as 8% of the population across the country is at risk. Although the number of people in Namibia who are exposed to high fluoride is relatively small at a global scale, it is significant at a national level. Preventative measures against high fluoride intake are thus necessary in the country

Os isotopes in SNC meteorites and their implications to the early evolution of Mars and Earth

A new development on the measurement of the Os isotopic composition by mass spectrometry using negative ions opened a new field of applications. The Re-Os systematic provides time information on the differentiation of the nobel metals. The nobel metals are strongly partitioned into metal and sulphide phases, but also the generation of silicate melts might fractionate the Re-Os system. Compared to the other isotopic systems which are mainly dating the fractionation of the alkalis and alkali-earth elements, the Re-Os system is expected to disclose entirely new information about the geochemistry. Especially the differentiation and early evolution of the planets such as the formation of the core will be elucidated with this method

NLC-2 graph recognition and isomorphism

NLC-width is a variant of clique-width with many application in graph algorithmic. This paper is devoted to graphs of NLC-width two. After giving new structural properties of the class, we propose a $O(n^2 m)$-time algorithm, improving Johansson's algorithm \cite{Johansson00}. Moreover, our alogrithm is simple to understand. The above properties and algorithm allow us to propose a robust $O(n^2 m)$-time isomorphism algorithm for NLC-2 graphs. As far as we know, it is the first polynomial-time algorithm.Comment: soumis \`{a} WG 2007; 12

Dating the Cryptococcus gattii Dispersal to the North American Pacific Northwest.

The emergence of Cryptococcus gattii, previously regarded as a predominantly tropical pathogen, in the temperate climate of the North American Pacific Northwest (PNW) in 1999 prompted several questions. The most prevalent among these was the timing of the introduction of this pathogen to this novel environment. Here, we infer tip-dated timing estimates for the three clonal C. gattii populations observed in the PNW, VGIIa, VGIIb, and VGIIc, based on whole-genome sequencing of 134 C. gattii isolates and using Bayesian evolutionary analysis by sampling trees (BEAST). We estimated the nucleotide substitution rate for each lineage (1.59 × 10-8, 1.59 × 10-8, and 2.70 × 10-8, respectively) to be an order of magnitude higher than common neutral fungal mutation rates (2.0 × 10-9), indicating a microevolutionary rate (e.g., successive clonal generations in a laboratory) in comparison to a species' slower, macroevolutionary rate (e.g., when using fossil records). The clonal nature of the PNW C. gattii emergence over a narrow number of years would therefore possibly explain our higher mutation rates. Our results suggest that the mean time to most recent common ancestor for all three sublineages occurred within the last 60 to 100 years. While the cause of C. gattii dispersal to the PNW is still unclear, our research estimates that the arrival is neither ancient nor very recent (i.e., <25 years ago), making a strong case for an anthropogenic introduction. IMPORTANCE The recent emergence of the pathogenic fungus Cryptococcus gattii in the Pacific Northwest (PNW) resulted in numerous investigations into the epidemiological and enzootic impacts, as well as multiple genomic explorations of the three primary molecular subtypes of the fungus that were discovered. These studies lead to the general conclusion that the subtypes identified likely emerged out of Brazil. Here, we conducted genomic dating analyses to determine the ages of the various lineages seen in the PNW and propose hypothetical causes for the dispersal events. Bayesian evolutionary analysis strongly suggests that these independent fungal populations in the PNW are all 60 to 100 years old, providing a timing that is subsequent to the opening of the Panama Canal, which allowed for more direct shipping between Brazil and the western North American coastline, a possible driving event for these fungal translocation events

Light Meson Dynamics Workshop. Mini proceedings

The mini-proceedings of the Light Meson Dynamics Workshop held in Mainz from February 10th to 12th, 2014, are presented. The web page of the conference, which contains all talks, can be found at https://indico.cern.ch/event/287442/overview .Comment: 46 pages, 17 contributions. Editors: W. Gradl, P. Masjuan, M. Ostrick, and S. Schere