36 research outputs found
A new MONERIS in-stream retention module to account nutrient budget of a temporary river in Cyprus
The nature of the nutrient budget for temporary rivers differs from that for permanent rivers because of the restricted nature of flow, the lack of adequate dilution, and weather conditions which are conducive to the development of algal blooms. We analyse the nutrient budget of three tributaries of a temporary river in Cyprus, the Kouris, with the aid of the MONERIS model. MONERIS in-stream retention module was modified to account for a 1-dimensional advection - dispersion pollutants transport rather than the general mass balance equation for mixed reactors. TRS plot classified Kryos stream as an Intermittent flow – Dry (I-D) stream (hydrologically altered) and Kouris and Limnatis as Intermittent – Pool (I-P) streams that need different lumped parameterization in MONERIS simulation. Point sources are important for nitrogen (64 %) and phosphorous emissions (22 %), and diffuse sources for nitrogen via erosion (15 %) and free grazing (12 %) and for phosphorous via free grazing (8 %). We estimate that around 40 % of N and 88 % of P entering streams is retained in the stream. An analysis of the model uncertainty and sensitivity to input data indicates that MONERIS model, even in semi-arid areas, may be used for the purpose of managing river basins
Resource-efficient dynamic partial reconfiguration on FPGAs for space instruments
Field-Programmable Gate Arrays (FPGAs) provide highly flexible platforms to implement sophisticated data processing for scientific space instruments. The dynamic partial reconfiguration (DPR) capability of FPGAs allows it to schedule HW tasks. While this feature adds another dimension of processing power that can be exploited without significantly increasing system complexity and power consumption, there are still several challenges for an efficient DPR use. State-of-the-art concepts concentrate either on resource-efficient implementations at design time or flexible HW task scheduling at runtime. In this paper we propose a balanced algorithm that considers both optimization goals and is well suited for resource-limited space applications
Hardware and Software Task Scheduling for ARM-FPGA Platforms
ARM-FPGA coupled platforms allow accelerating the computation of specific algorithms by executing them in the FPGA fabric. Several computation steps of our case study for a stereo vision application have been accelerated by hardware implementations. Dynamic Partial Reconfiguration places these hardware tasks in the programmable logic at appropriate times. For an efficient scheduling, it needs to be decided when and where to execute a task. Although there already exist hardware/software scheduling strategies and algorithms, none exploit all possible optimization techniques: re-use, prefetching, parallelization, and pipelining of hardware tasks. The scheduling algorithm proposed in this paper takes this into account and optimizes for the objectives latency/throughput and power/energy
Transmembrane protein PERP is a component of tessellate junctions and of other junctional and non-junctional plasma membrane regions in diverse epithelial and epithelium-derived cells
Protein PERP (p53 apoptosis effector related to PMP-22) is a small (21.4 kDa) transmembrane polypeptide with an amino acid sequence indicative of a tetraspanin character. It is enriched in the plasma membrane and apparently contributes to cell-cell contacts. Hitherto, it has been reported to be exclusively a component of desmosomes of some stratified epithelia. However, by using a series of newly generated mono- and polyclonal antibodies, we show that protein PERP is not only present in all kinds of stratified epithelia but also occurs in simple, columnar, complex and transitional epithelia, in various types of squamous metaplasia and epithelium-derived tumors, in diverse epithelium-derived cell cultures and in myocardial tissue. Immunofluorescence and immunoelectron microscopy allow us to localize PERP predominantly in small intradesmosomal locations and in variously sized, junction-like peri- and interdesmosomal regions (“tessellate junctions”), mostly in mosaic or amalgamated combinations with other molecules believed, to date, to be exclusive components of tight and adherens junctions. In the heart, PERP is a major component of the composite junctions of the intercalated disks connecting cardiomyocytes. Finally, protein PERP is a cobblestone-like general component of special plasma membrane regions such as the bile canaliculi of liver and subapical-to-lateral zones of diverse columnar epithelia and upper urothelial cell layers. We discuss possible organizational and architectonic functions of protein PERP and its potential value as an immunohistochemical diagnostic marker
Predicting Solar Cell Performance from Terahertz and Microwave Spectroscopy
Mobilities and lifetimes of photogenerated charge carriers are core properties of photovoltaic materials and can both be characterized by contactless terahertz or microwave measurements. Here, the expertise from fifteen laboratories is combined to quantitatively model the current voltage characteristics of a solar cell from such measurements. To this end, the impact of measurement conditions, alternate interpretations, and experimental inter laboratory variations are discussed using a Cs,FA,MA Pb I,Br 3 halide perovskite thin film as a case study. At 1 sun equivalent excitation, neither transport nor recombination is significantly affected by exciton formation or trapping. Terahertz, microwave, and photoluminescence transients for the neat material yield consistent effective lifetimes implying a resistance free JV curve with a potential power conversion efficiency of 24.6 . For grainsizes above amp; 8776;20 nm, intra grain charge transport is characterized by terahertz sum mobilities of amp; 8776;32 cm2 V amp; 8722;1 s amp; 8722;1. Drift diffusion simulations indicate that these intra grain mobilities can slightly reduce the fill factor of perovskite solar cells to 0.82, in accordance with the best realized devices in the literature. Beyond perovskites, this work can guide a highly predictive characterization of any emerging semiconductor for photovoltaic or photoelectrochemical energy conversion. A best practice for the interpretation of terahertz and microwave measurements on photovoltaic materials is presente
Horizon scanning for invasive alien species with the potential to threaten biodiversity and human health on a Mediterranean island
© 2019, The Author(s). Invasive alien species (IAS) are one of the major drivers of change that can negatively affect biodiversity, ecosystem functions and services and human health; islands are particularly vulnerable to biological invasions. Horizon scanning can lead to prioritisation of IAS to inform decision-making and action; its scale and scope can vary depending on the need. We focussed on IAS likely to arrive, establish and affect biodiversity and human health on the Mediterranean island of Cyprus. The scope of the horizon scanning was the entire island of Cyprus. We used a two-step consensus-building process in which experts reviewed and scored lists of alien species on their likelihood of arrival, establishment and potential to affect biodiversity, ecosystems and/or human health in the next 10 years. We reviewed 225 alien species, considered to be currently absent on Cyprus, across taxa and environments. We agreed upon 100 species that constituted very high, high or medium biodiversity risk, often arriving through multiple pathways of introduction. The remaining 125 species were ranked as low risk. The potential impacts on human health were documented for all 225 species; 82 species were considered to have a potentially negative impact on human health ranging from nuisance to disease transmission. The scope of the horizon scanning was the entire island of Cyprus, but the thematic groups also considered the relevance of the top 100 species to the Sovereign Base Areas of Cyprus, given their differing governance. This horizon scan provides the first systematic exercise to identify invasive alien species of potential concern to biodiversity and ecosystems but also human health within the Mediterranean region. The process and outcomes should provide other islands in the region and beyond with baseline data to improve IAS prioritisation and management
A new MONERIS in-Stream Retention Module to Account Nutrient Budget of a Temporary River in Cyprus
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The recovery of European freshwater biodiversity has come to a halt
Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity. Here, using 1,816 time series of freshwater invertebrate communities collected across 22 European countries between 1968 and 2020, we quantified temporal trends in taxonomic and functional diversity and their responses to environmental pressures and gradients. We observed overall increases in taxon richness (0.73% per year), functional richness (2.4% per year) and abundance (1.17% per year). However, these increases primarily occurred before the 2010s, and have since plateaued. Freshwater communities downstream of dams, urban areas and cropland were less likely to experience recovery. Communities at sites with faster rates of warming had fewer gains in taxon richness, functional richness and abundance. Although biodiversity gains in the 1990s and 2000s probably reflect the effectiveness of water-quality improvements and restoration projects, the decelerating trajectory in the 2010s suggests that the current measures offer diminishing returns. Given new and persistent pressures on freshwater ecosystems, including emerging pollutants, climate change and the spread of invasive species, we call for additional mitigation to revive the recovery of freshwater biodiversity