Proposal for a formal foundation of RM-ODP concepts

This paper presents an approach for formalizing the RM-ODP (Reference Model for Open Distributed Processing), an ISO and ITU standard. The goal of this formalization is to clarify the RM-ODP modeling framework to make it more accessible to modelers such as system architects, designers and implementers, while opening the way for the formal verification of RM-ODP models, either within an ODP viewpoint or across multiple ODP viewpoints. Our formalization is based on set theory and the usual predicate logic, and is ex-pressed in the Alloy language

Tambora 1815 as a test case for high impact volcanic eruptions: Earth system effects

The eruption of Tambora (Indonesia) in April 1815 had substantial effects on global climate and led to the ‘Year Without a Summer’ of 1816 in Europe and North America. Although a tragic event—tens of thousands of people lost their lives—the eruption also was an ‘experiment of nature’ from which science has learned until today. The aim of this study is to summarize our current understanding of the Tambora eruption and its effects on climate as expressed in early instrumental observations, climate proxies and geological evidence, climate reconstructions, and model simulations. Progress has been made with respect to our understanding of the eruption process and estimated amount of SO2 injected into the atmosphere, although large uncertainties still exist with respect to altitude and hemispheric distribution of Tambora aerosols. With respect to climate effects, the global and Northern Hemispheric cooling are well constrained by proxies whereas there is no strong signal in Southern Hemisphere proxies. Newly recovered early instrumental information for Western Europe and parts of North America, regions with particularly strong climate effects, allow Tambora's effect on the weather systems to be addressed. Climate models respond to prescribed Tambora-like forcing with a strengthening of the wintertime stratospheric polar vortex, global cooling and a slowdown of the water cycle, weakening of the summer monsoon circulations, a strengthening of the Atlantic Meridional Overturning Circulation, and a decrease of atmospheric CO2. Combining observations, climate proxies, and model simulations for the case of Tambora, a better understanding of climate processes has emerged

Modelling the regulative role of business processes with use and misuse cases

Business processes contain value-added and abuse prevention activities. Most modelling techniques do not provide a rationale for abuse prevention activities. Such a rationale is needed when redesigning business processes. In this paper we propose to consider business processes as the main regulatory mechanism that an organization uses to survive and flourish in its environment. We propose a theoretical framework based on the concept of Homeostasis, the maintenance of identity in a changing world. The framework classifies business processes into three levels and explains the interconnections between processes at different levels and the organization’s environment. Based on this framework, we extend the “Use and Misuse Cases” technique to support modelling of value-added and abuse prevention activities and their interconnections with the organization’s environment. We thus provide the needed rationale for business process redesign

Plasmonic nanorods for enhanced absorption in mid-wavelength infrared detectors

The absorption properties of HgCdTe-based infrared detectors can be greatly increased in the mid-infrared band, by incorporating nanostructured plasmonic arrays on the illuminated detector face. The array periodicity, combined with the excitation of surface plasmon-polariton stationary modes, enhances the absorption efficiency by a substantial amount, allowing to reduce in turn the HgCdTe absorption thickness

Will Remote Sensing Shape the Next Generation of Species Distribution Models?

Two prominent limitations of species distribution models (SDMs) are spatial biases in existing occurrence data and a lack of spatially explicit predictor variables to fully capture habitat characteristics of species. Can existing and emerging remote sensing technologies meet these challenges and improve future SDMs? We believe so. Novel products derived from multispectral and hyperspectral sensors, as well as future Light Detection and Ranging (LiDAR) and RADAR missions, may play a key role in improving model performance. In this perspective piece, we demonstrate how modern sensors onboard satellites, planes and unmanned aerial vehicles are revolutionizing the way we can detect and monitor both plant and animal species in terrestrial and aquatic ecosystems as well as allowing the emergence of novel predictor variables appropriate for species distribution modeling. We hope this interdisciplinary perspective will motivate ecologists, remote sensing experts and modelers to work together for developing a more refined SDM framework in the near future

Paleo-denudation rates suggest variations in runoff drove aggradation during last glacial cycle, Crete, Greece

Fluvial aggradation and incision are often linked to Quaternary climate cycles, but it usually remains unclear whether variations in runoff or sediment supply or both drive channel response to climate variability. Here we quantify sediment supply with paleo-denudation rates and provide geochronological constraints on aggradation and incision from the Sfakia and Elafonisi alluvial-fan sequences in Crete, Greece. We report seven optically stimulated luminescence and ten radiocarbon ages, eight 10Be and eight 36Cl denudation rates from modern channel and terrace sediments. For five samples, 10Be and 36Cl were measured on the same sample by measuring 10Be on chert and 36Cl on calcite. Results indicate relatively steady denudation rates throughout the past 80 kyr, but the aggradation and incision history indicates a link with climate shifts. At the Elafonisi fan, we identify four periods of aggradation coinciding with Marine Isotope Stages (MIS) 2, 4, 5a/b, and likely 6, and three periods of incision coinciding with MIS 1, 3, and likely 5e. At the Sfakia fan, rapid aggradation occurred during MIS 2 and 4, followed by incision during MIS 1. Nearby climate and vegetation records show that MIS 2, 4, and 6 stadials were characterized by cold and dry climates with sparse vegetation, whereas forest cover and more humid conditions prevailed during MIS 1, 3, and 5. Our data thus suggest that past changes in climate had little effect on landscape-wide denudation rates but exerted a strong control on the aggradation–incision behaviour of alluvial channels on Crete. During glacial stages, we attribute aggradation to hillslope sediment release promoted by reduced vegetation cover and decreased runoff; conversely, incision occurred during relatively warm and wet stages due to increased runoff. In this landscape, past hydroclimate variations outcompeted changes in sediment supply as the primary driver of alluvial deposition and incision

Circular RNAs in urine of kidney transplant patients with acute T Cell-mediated allograft rejection

BACKGROUND: Circular RNAs (circRNAs) have recently been described as novel noncoding regulators of gene expression. They are detectable in the blood of patients with acute kidney injury. We tested whether circRNAs were present in urine and could serve as new predictors of outcome in renal transplant patients with acute rejection. METHODS: A global circRNA expression analysis using RNA from urine of patients with acute T cell-mediated renal allograft rejection and control transplant patients was performed. Dysregulated circRNAs were confirmed in a cohort of 62 patients with acute rejection, 10 patients after successful antirejection therapy, 18 control transplant patients without rejection, and 13 stable transplant patients with urinary tract infection. RESULTS: A global screen revealed several circRNAs to be altered in urine of patients with acute rejection. Concentrations of 2 circRNAs including hsa_circ_0001334 and hsa_circ_0071475 were significantly increased. These were validated in the whole cohort of patients. hsa_circ_0001334 was upregulated in patients with acute rejection compared with controls. Concentrations of hsa_circ_0001334 normalized in patients with acute rejection following successful antirejection therapy. hsa_circ_0001334 was associated with higher decline in glomerular filtration rate 1 year after transplantation. CONCLUSIONS: CircRNA concentrations are significantly dysregulated in patients with acute rejection at subclinical time points. Urinary hsa_circ_0001334 is a novel biomarker of acute kidney rejection, identifying patients with acute rejection and predicting loss of kidney function