Dynamic, self consistent electro-thermal simulation of power microwave devices including the effect of surface metallizations

We present an efficient simulation technique to account for the thermal spreading effects of surface metallizations in the self-consistent dynamic electro-thermal analysis of power microwave devices. Electro-thermal self-consistency is achieved by solving the coupled nonlinear system made of a temperature dependent device electrical model, and of an approximate description of the device thermal behavior through a thermal impedance matrix. The numerical solution is pursued in the frequency domain by the Harmonic Balance technique. The approach is applied to the thermal stability analysis of power AlGaAs/GaAs HBTs and the results show that metallizations have a significant impact on the occurrence of the device thermal collapse

Experimental measurements of thermal-hydraulic performance of aluminum-foam water-to-air heat exchangers for a HVAC application

In this paper, thermal and hydraulic performance of in-house made prototypes of water-to-air heat exchangers are experimentally investigated and compared to those of a compact heat exchanger, used in a commercial fan coil. The prototypes are built replacing the fins with aluminum foam surfaces characterized by a large porosity, higher than 96%. In order to evaluate the performance of the foam-based heat exchangers in a real-scale application, the geometry of the prototypes was based on that of the reference model and, moreover, experimental tests were performed placing the heat exchangers within the commercial cabinet, under the same fan power. Different bonding techniques were also tested to couple metal foams to copper tubes. Results show that similar hydraulic performance can be obtained with the foam-based heat exchangers, if compared to the commercial device. However, the large foam porosity accounts for a lower value of the surface-to-volume ratio of the aluminum foam media, thus yielding a strong penalty, up to 60%, of the heat transfer rate with respect to that of the conventional finned surface. Moreover, experimental results highlight how the bonding technique and the foam packaging have a strong influence on the contact thermal resistance and, consequently, on the overall heat transfer coefficient. Epoxy bonding allows to increase the thermal performance of the heat exchanger, if compared to press fitting, between 15% and 110%. In conclusion, results presented in this paper suggest that metal foams can be considered as a potential alternative to fins in water-to-air heat exchangers only if the foam tube bonding is obtained by welding or brazing

New radio observations of anomalous microwave emission in the HII region RCW175

We have observed the HII region RCW175 with the 64m Parkes telescope at 8.4GHz and 13.5GHz in total intensity, and at 21.5GHz in both total intensity and polarization. High angular resolution, high sensitivity, and polarization capability enable us to perform a detailed study of the different constituents of the HII region. For the first time, we resolve three distinct regions at microwave frequencies, two of which are part of the same annular diffuse structure. Our observations enable us to confirm the presence of anomalous microwave emission (AME) from RCW175. Fitting the integrated flux density across the entire region with the currently available spinning dust models, using physically motivated assumptions, indicates the presence of at least two spinning dust components: a warm component with a relatively large hydrogen number density n_H=26.3/cm^3 and a cold component with a hydrogen number density of n_H=150/cm^3. The present study is an example highlighting the potential of using high angular-resolution microwave data to break model parameter degeneracies. Thanks to our spectral coverage and angular resolution, we have been able to derive one of the first AME maps, at 13.5GHz, showing clear evidence that the bulk of the AME arises in particular from one of the source components, with some additional contribution from the diffuse structure. A cross-correlation analysis with thermal dust emission has shown a high degree of correlation with one of the regions within RCW175. In the center of RCW175, we find an average polarized emission at 21.5GHz of 2.2\pm0.2(rand.)\pm0.3(sys.)% of the total emission, where we have included both systematic and statistical uncertainties at 68% CL. This polarized emission could be due to sub-dominant synchrotron emission from the region and is thus consistent with very faint or non-polarized emission associated with AME.Comment: Accepted for publication in the Astrophysical Journa

Understanding Cerebellum Granular Layer Network Computations through Mathematical Reconstructions of Evoked Local Field Potentials

Background: The cerebellar granular layer input stage of cerebellum receives information from tactile and sensory re- gions of the body. The somatosensory activity in the cerebellar granular layer corresponds to sensory and tactile input has been observed by recording Local Field Potential (LFP) from the Crus-IIa regions of cerebellum in brain slices and in anesthetized animals. Purpose: In this paper, a detailed biophysical model of Wistar rat cerebellum granular layer net- work model and LFP modelling schemas were used to simulate circuit\u2019s evoked response. Methods: Point Source Ap- proximation and Line Source Approximation were used to reconstruct the network LFP. The LFP mechanism in in vitro was validated in network model and generated the in vivo LFP using the same mechanism. Results: The network simulations distinctly displayed the Trigeminal and Cortical (TC) wave components generated by 2 independent bursts implicating the generation of TC waves by 2 independent granule neuron populations. Induced plasticity was simulated to estimate granule neuron activation related population responses. As a prediction, cerebellar dysfunction (ataxia) was also studied using the model. Dysfunction at individual neurons in the network was affected by the population response. Conclusion: Our present study utilizes available knowledge on known mechanisms in a single cell and associates network function to population responses

Evolutionary optimization of service times in interactive voice response systems

A call center is a system used by companies to provide a number of services to customers, which may vary from providing simple information to gathering and dealing with complaints or more complex transactions. The design of this kind of system is an important task, since the trend is that companies and institutions choose call centers as the primary option for customer relationship management. This paper presents an evolutionary algorithm based on Dandelion encoding to obtain near-optimal service trees which represent the structure of the desired call center. We introduce several modifications to the original Dandelion encoding in order to adapt it to the specific problem of service tree design. Two search space size reduction procedures improve the performance of the algorithm. Systematic experiments have been tackled in order to show the performance of our approach: first, we tackle different synthetic instances, where we discuss and analyze several aspects of the proposed evolutionary algorithm, and second, we tackle a real application, the design of the call center of an Italian telecommunications company. In all the experiments carried out we compare our approach with a lower bound for the problem based on information theory, and also with the results of a Huffman algorithm we have used for reference

Injuries in Medium to Long-Distance Triathlon: A Retrospective Analysis of Medical Conditions Treated in Three Editions of the Ironman Competition

Triathlon's popularity is rapidly increasing, and epidemiological data relating to its related medical conditions is crucial to the development of proper medical plans and safety guidelines for it. This study examined the data from the medical reports collected during three consecutive editions of Ironman Italy, from 2017 to 2019. Out of 10,653 race-starters, 3.3% required medical attention sustaining 472 medical conditions. A significantly higher injury risk was found for females versus males (χ2 = 9.78, p = 0.02) and in long-distance (IR: 4.09/1,000hours) rather than in Olympic/middle distance races (IR: 1.75/1,000hours). Most (68.4%) conditions (including muscular exhaustion, hypothermia, and dehydration) were systemic, whilst only 10.2% were acute traumatic injuries. Of a total of 357 triathletes requiring medical assistance, 8.1% were a candidate for hospitalisation. The equipment and personnel that are required for the medical assistance in future triathlon events were estimated based on Maurer's algorithm, and ten practical recommendations for triathlon medical support were formulated

Climate change effects on bread wheat phenology and grain quality: A case study in the north of Italy

Increasing temperatures, heat waves, and reduction of annual precipitation are all the expressions of climate change (CC), strongly affecting bread wheat (Triticum aestivum L.) grain yield in Southern Europe. Being temperature the major driving force of plants' phenological development, these variations also have effects on wheat phenology, with possible consequences on grain quality, and gluten protein accumulation. Here, through a case study in the Bolognese Plain (North of Italy), we assessed the effects of CC in the area, the impacts on bread wheat phenological development, and the consequences on grain gluten quality. The increasing trend in mean annual air temperature in the area since 1952 was significant, with a breakpoint identified in 1989, rising from 12.7 to 14.1°C, accompanied by the signals of increasing aridity, i.e., increase in water table depth. Bread wheat phenological development was compared in two 15-year periods before and after the breakpoint, i.e., 1952-1966 (past period), and 2006-2020 (present period), the latest characterized by aridity and increased temperatures. A significant shortening of the chronological time necessary to reach the main phenological phases was observed for the present period compared to the past period, finally shortening the whole life cycle. This reduction, as well as the higher temperature regime, affected gluten accumulation during the grain-filling process, as emerged analyzing gluten composition in grain samples of the same variety harvested in the area both before and after the breakpoint in temperature. In particular, the proportion of gluten polymers (i.e., gliadins, high and low molecular weight glutenins, and their ratio) showed a strong and significant correlation with cumulative growing degree days (CGDDs) accumulated during the grain filling. Higher CGDD values during the period, typical of CC in Southern Europe, accounting for higher temperature and faster grain filling, correlated with gliadins, high molecular weight glutenins, and their proportion with low molecular weight glutenins. In summary, herein reported, data might contribute to assessing the effects of CC on wheat phenology and quality, representing a tool for both predictive purposes and decision supporting systems for farmers, as well as can guide future breeding choices for varietal innovation

A dandelion-encoded evolutionary algorithm for the delay-constrained capacitated minimum spanning tree problem

This paper proposes an evolutionary algorithm with Dandelion-encoding to tackle the Delay-Constrained Capacitated Minimum Spanning Tree (DC-CMST) problem. This problem has been recently proposed, and consists of finding several broadcast trees from a source node, jointly considering traffic and delay constraints in trees. A version of the problem in which the source node is also included in the optimization process is considered as well in the paper. The Dandelion code used in the proposed evolutionary algorithm has been recently proposed as an effective way of encoding trees in evolutionary algorithms. Good properties of locality has been reported on this encoding, which makes it very effective to solve problems in which the solutions can be expressed in form of trees. In the paper we describe the main characteristics of the algorithm, the implementation of the Dandelion-encoding to tackled the DC-CMST problem and a modification needed to include the source node in the optimization. In the experimental section of this article we compare the results obtained by our evolutionary with that of a recently proposed heuristic for the DC-CMST. the Least Cost (LC) algorithm. We show that our Dandelion-encoded evolutionary algorithm is able to obtain better results that the LC in all the instances tackled. (C) 2008 Elsevier B.V. All rights reserved

From combinations to single-molecule polypharmacology—cromolyn-ibuprofen conjugates for alzheimer’s disease

Despite Alzheimer’s disease (AD) incidence being projected to increase worldwide, the drugs currently on the market can only mitigate symptoms. Considering the failures of the classical paradigm “one target-one drug-one disease” in delivering effective medications for AD, polypharmacology appears to be a most viable therapeutic strategy. Polypharmacology can involve combinations of multiple drugs and/or single chemical entities modulating multiple targets. Taking inspiration from an ongoing clinical trial, this work aims to convert a promising cromolyn–ibuprofen drug combination into single-molecule “codrugs.” Such codrugs should be able to similarly modulate neuroinflammatory and amyloid pathways, while showing peculiar pros and cons. By exploiting a linking strategy, we designed and synthesized a small set of cromolyn–ibuprofen conjugates (4–6). Preliminary plasma stability and neurotoxicity assays allowed us to select diamide 5 and ethanolamide 6 as promising compounds for further studies. We investigated their immunomodulatory profile in immortalized microglia cells, in vitro anti-aggregating activity towards Aβ42-amyloid self-aggregation, and their cellular neuroprotective effect against Aβ42-induced neurotoxicity. The fact that 6 effectively reduced Aβ-induced neuronal death, prompted its investigation into an in vivo model. Notably, 6 was demonstrated to significantly increase the longevity of Aβ42-expressing Drosophila and to improve fly locomotor performance

Hidradenitis suppurativa: guidelines of the Italian Society of Dermatology and Venereology (SIDeMaST) for the use of anti-TNF-α agents.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by nodules, abscesses and sinus tracts, primarily affecting the intertriginous areas. The occlusion of the upper part of the folliculopilosebaceous unit, leading to rupture of the sebofollicular canal with the consequent development of perifollicular lympho-histiocytic inflammation, is believed to be the initial pathogenic event in HS. Giving the chronic nature of HS, its destructive impact on social, working and daily life of patients, its management is often frustrating both for patients and physicians. The HS treatment choices are influenced by disease severity and its individual subjective impact. In this article, the Board of the Italian Society of Dermatology and Venereology (SIDeMaST) on HS has prepared a document focusing on the role of biologic drugs (anti-TNF-α) in HS management, providing also a flow-chart for HS handling and the inclusion and exclusion criteria for HS treatment with anti-TNF-α