Spectral averaging techniques for Jacobi matrices

Spectral averaging techniques for one-dimensional discrete Schroedinger operators are revisited and extended. In particular, simultaneous averaging over several parameters is discussed. Special focus is put on proving lower bounds on the density of the averaged spectral measures. These Wegner type estimates are used to analyze stability properties for the spectral types of Jacobi matrices under local perturbations

Smart home technologies in Europe: a critical review of concepts, benefits, risks and policies

Smart home technologies refer to devices that provide some degree of digitally connected, automated, or enhanced services to building occupants. Smart homes have become central in recent technology and policy discussions about energy efficiency, climate change, and the sustainability of buildings. Nevertheless, do they truly promote sustainability goals? In addition, what sorts of benefits, risks, and policies do they entail? Based on an extensive original dataset involving expert interviews, site visits to retailers, and a comprehensive review of the literature, this study critically examines the promise and peril of smart home technologies. Drawing on original data collected in the United Kingdom, which has access to European markets, the study first examines definitions of smart homes before offering a new classification involving 13 categories of smart technology covering 267 specific options commercially available from 113 companies. It situates these different technology classes alongside six degrees or levels of smartness, from the basic or traditional home to the fully automated and sentient home. It then elaborates on the 13 distinct benefits smart homes offer alongside 17 risks and barriers, before introducing seven policy recommendations from the material. It lastly suggests three areas of future research on the demographics and practices of actual smart home adopters, rethinking the duality of “control,” and looking beyond “homes” towards socio-technical systems, practices, and justice

Mirror matter searches with the J-PET detector

The positronium system — a bound state of an electron and a positron — is suitable for testing the predictions of quantum electrodynamics, since its properties can be perturbatively calculated to high accuracy and, unlike the hydrogen system, it is not affected by the finite size or quantum chromodynamics effects at the current level of experimental precision. Experiments searching for invisible decays of the positronium triplet state — the ortho-positronium — which mainly decays to three photons, are being conducted since they are sensitive to new physics scenarios, e.g., mirror matter, milli-charged particles, and extra space-time dimensions. The particular case of mirror matter and its search with the novel total-body positron emission tomography scanner at the Jagiellonian University is presented. This J-PET is a large, high precision medical imaging tool based on plastic scintillators

What is Localization?

We examine various issues relevant to localization in the Anderson model. We show there is more to localization than exponentially localized states by presenting an example with such states but where ⟨x(t)^2⟩/t^(2 − δ) is unbounded for any δ > 0. We show that the recently discovered instability of localization under rank one perturbations is only a weak instability

Renal function in Palestine sunbirds: elimination of excess water does not constrain energy intake

Copyright © 2004 Company of BiologistsAlthough the renal responses of birds to dehydration have received significant attention, the consequences of ingesting and processing large quantities of water have been less studied. Nectar-feeding birds must often deal with exceptionally high water intake rates in order to meet their high mass-specific energy demands. Birds that ingest large volumes of water may either eliminate excess water in the kidney or regulate the volume of water absorbed in the gastrointestinal tract. Because water absorption in the gastrointestinal tract of Palestine sunbirds (Nectarinia osea) decreases with increasing water ingestion rate, we predicted that glomerular filtration rate (GFR) in these birds would not be unusually high in spite of large ingested water loads. When feeding on dilute sucrose solutions, sunbirds ingested between 4 and 6 times their body mass in nectar per day, yet they were able to compensate for varying nectar energy density and increased thermoregulatory energy demands with no apparent difficulty. GFR was lower than predicted (1976.22±91.95 µl h-1), and was not exceptionally sensitive to water loading. Plasma glucose concentrations were high, and varied 1.8-fold between fasted (16.08± 0.75 mmol l-1) and fed (28.18±0.68 mmol l-1) sunbirds, but because GFR was low, glucose filtered load also remained relatively low. Essentially the entire glucose filtered load (98%) was recovered by the kidney. Renal fractional water reabsorption (FWR) decreased from 0.98 to 0.64 with increasing water intake. The ability of Palestine sunbirds to reduce the absorption of ingested water in the gastrointestinal tract may resolve the potential conflict between filtering a large excess of absorbed water in the kidney and simultaneously retaining filtered metabolites.Todd J. McWhorter, Carlos Martínez del Rio, Berry Pinshow and Lizanne Roxburg

Automatic Target Recognition in Synthetic Aperture Sonar Images Based on Geometrical Feature Extraction

This paper presents a new supervised classification approach for automated target recognition (ATR) in SAS images. The recognition procedure starts with a novel segmentation stage based on the Hilbert transform. A number of geometrical features are then extracted and used to classify observed objects against a previously compiled database of target and non-target features. The proposed approach has been tested on a set of 1528 simulated images created by the NURC SIGMAS sonar model, achieving up to 95% classification accuracy

ATRA mechanically reprograms pancreatic stellate cells to suppress matrix remodelling and inhibit cancer cell invasion

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a dismal survival rate. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homoeostasis of the tumour microenvironment to favour cancer cell invasion. Here we report that ATRA, an active metabolite of vitamin A, restores mechanical quiescence in PSCs via a mechanism involving a retinoic acid receptor beta (RAR-β)-dependent downregulation of actomyosin (MLC-2) contractility. We show that ATRA reduces the ability of PSCs to generate high traction forces and adapt to extracellular mechanical cues (mechanosensing), as well as suppresses force-mediated extracellular matrix remodelling to inhibit local cancer cell invasion in 3D organotypic models. Our findings implicate a RAR-β/MLC-2 pathway in peritumoural stromal remodelling and mechanosensory-driven activation of PSCs, and further suggest that mechanical reprogramming of PSCs with retinoic acid derivatives might be a viable alternative to stromal ablation strategies for the treatment of PDAC

First insights on Lake General Carrera/Buenos Aires/Chelenko water balance

Lago General Carrera (Chile) also called Lago Buenos Aires (Argentina) or originally Chelenko by the native habitants of the region is located in Patagonia on the Chilean-Argentinean border. It is the largest lake in Chile with a surface area of 1850 km<sup>2</sup>. The lake is of glacial/tectonic origin and surrounded by the Andes mountain range. The lake drains primarily to the Pacific Ocean to the west, through the Baker River (one of Chile's largest rivers), and intermittently eastward to the Atlantic Ocean. We report ongoing results from an investigation of the seasonal hydrological cycle of the lake basin. The contribution by river input through snowmelt from the Andes is of primary importance, though the lack of water input by ungaged rivers is also critical. We present the main variables involved in the water balance of Lake General Carrera/Buenos Aires/Chelenko, such as influent and effluent river flows, precipitation, and evaporation, all this based mostly in in-situ information

Inundaciones y cambio climático

Las inundaciones de los ríos han sucedido de forma tradicional en numerosos ríos de la Península Ibérica, aportando grandes beneficios en la agricultura y en la disponibilidad de recursos hídricos, pero en la historia más reciente han originado graves daños en personas y bienes haciendo que hoy día predomine una percepción de las inundaciones como “catástrofes”. En el origen del incremento de la frecuencia de las inundaciones hay que mencionar la intensificación del uso del territorio, sellando y compactando los suelos haciendo que aumenten las escorrentías rápidas, y la alteración hidromorfológica de los ríos, concentrando las aguas y favoreciendo la ocurrencia de avenidas y desbordamientos. En el incremento exponencial de las pérdidas que las inundaciones han originado en los últimos años hay que referirse a la intensa ocupación de las riberas de los ríos y sus llanuras de inundación por personas y actividades económicas, con un desarrollo en dichas zonas no compatible con la dinámica fluvial. El cambio climático es considerado un factor de riesgo adicional muy variable según las regiones, y la estimación de sus efectos sobre las inundaciones presenta todavía numerosas incertidumbres. Atendiendo a ello se revisan algunos estudios e informes relacionados con el fenómeno de las inundaciones y su posible relación con el cambio climático, y se propone la restauración de los sistemas fluviales y la restricción de usos en las zonas inundables como estrategias más acertadas para hacer frente a la mencionada problemática de las inundaciones y a la incertidumbre creada con el cambio climático. El análisis de los sucesivos paradigmas históricos planteados por el hombre frente a las inundaciones de los ríos pone en evidencia el interés de cambiar unas estrategias de “defensa” en contra de ellas, tratando de evitar que ocurran, por otras de “convivencia” con las mismas gestionando de la forma más apropiada el riesgo de los daños que pueden generar, atendiendo al espíritu de las Directivas europeas Marco del Agua y de evaluación y gestión del riesgo de la inundación