The histopathological spectrum of acute generalized exanthematous pustulosis (AGEP) and its differentiation from generalized pustular psoriasis

Background: Acute generalized exanthematous pustulosis (AGEP) represents a severe, acute, pustular skin reaction that is most often induced by drugs. AGEP can be difficult to differentiate from generalized pustular psoriasis (GPP) both clinically and histopathologically. We present a systematic description of the histopathological spectrum of AGEP and GPP with a focus on discriminating features. Materials and methods: A retrospective, descriptive, comparative histopathological study was completed utilizing step sections of 43 biopsies of 29 cases with a validated diagnosis of probable or definite AGEP and 24 biopsies of 19 cases with an established diagnosis of GPP. Results: In AGEP, biopsies from erythema and pustules showed minor differences, whereas histopathology of the acute stage of GPP showed major differences compared to the chronic stage. Comparing AGEP and GPP, the presence of eosinophils, necrotic keratinocytes, a mixed interstitial and mid-dermal perivascular infiltrate and absence of tortuous or dilated blood vessels were in favor of AGEP. Moreover, chronic GPP was characterized by prominent epidermal psoriatic changes. The frequency of a psoriatic background of AGEP patients in our study was higher than that of psoriasis in the general population. However, histopathology of a subgroup of AGEP patients with a personal history of psoriasis revealed no significant differences from the other AGEP patients. Conclusions: The spectrum of histopathological features of both AGEP and GPP is presented. Despite considerable overlap, subtle consistent histopathological differences and the grade of severity of specific features can help in differentiation. We could neither substantiate earlier reports that follicular pustules exclude AGEP nor did we see vasculitis as a specific feature in AGEP. Our study also supports the concept that AGEP is a separate entity that is distinct from GPP. Kardaun SH, Kuiper H, Fidler V, Jonkman MF. The histopathological spectrum of acute generalized exanthematous pustulosis (AGEP) and its differentiation from generalized pustular psoriasis

Load balancing and lifetime maximization in WSN

Workshop Univ Kyushu-INPTStrategies that balance the energy consumption of the nodes and ensure maximum network lifetime by balancing the load are proposed and analyzed. Multiple transmission power levels are used. We studied an optimal solution for calculating the hop-by-hop traffic proportions for the particular case of nodes having just two transmission power levels, and compared the results given by the heuristics with those from the optimal analytical case

Load Balancing Techniques for Lifetime Maximizing in Wireless Sensor Networks

International audienceEnergy consumption has been the focus of many studies on Wireless Sensor Networks (WSN). It is well recognized that energy is a strictly limited resource in WSNs. This limitation constrains the operation of the sensor nodes and somehow compromises the long term network performance as well as network activities. Indeed, the purpose of all application scenarios is to have sensor nodes deployed, unattended, for several months or years.This paper presents the lifetime maximization problem in “many-to-one” and “mostly-off” wireless sensor networks. In such network pattern, all sensor nodes generate and send packets to a single sink via multi-hop transmissions. We noticed, in our previous experimental studies, that since the entire sensor data has to be forwarded to a base station via multi-hop routing, the traffic pattern is highly non-uniform, putting a high burden on the sensor nodes close to the base station.In this paper, we propose some strategies that balance the energy consumption of these nodes and ensure maximum network lifetime by balancing the traffic load as equally as possible. First, we formalize the network lifetime maximization problem then we derive an optimal load balancing solution. Subsequently, we propose a heuristic to approximate the optimal solution and we compare both optimal and heuristic solutions with most common strategies such as shortest-path and equiproportional routing. We conclude that through the results of this work, combining load balancing with transmission power control outperforms the traditional routing schemes in terms of network lifetime maximization

Cross-Layer Extended Persistent Timeout Policy for SCTP and DSDV

International audienceCross layer techniques applied to various protocols stacks provide fair information sharing between OSI model layers. The performance gains have been demonstrated for many studied systems within protocols interactions. The example is illustrative of the reliable transport protocols that use retransmissions to achieve that reliability function. The performance gains of the persistent timeout policy for the management of the retransmission timeout have been produce in some recent works when applying that persistent timeout policy only to reliable transport protocol. The goal was to give an appropriate behavior in response to a bad state of the wireless channel that occurs and temporally blocks the transmission of data. The channel state is given by the 802.11 link layer through cross-layer mechanism. In this paper, the persistent policy is extended to the network layer and is applied to a stack that uses a reactive routing protocol, namely the Destination Sequenced Distance-Vector (DSDV) protocol that also generates additional periodic traffic regardless to the channel state. We are measuring the influence in terms of performance gains of the extended persistent policy because of the additional periodic signalization messages deriving from the used routing protocol. After the introduction in section I; Section II of this paper presents an overview of the Stream Control Transmission Protocol (SCTP). Section III describes the behavior of the DSDV protocol. Section IV presents the extended persistent timeout policy principle and Section V presents the simulation results used to compare the using of the traditional and the extended persistent timeout policies applied to the same protocol stack using SCTP and DSDV

RCL : A new Method for Cross-Layer Network Modelling and Simulation

International audienceThe evolution from wired network systems to wireless environments such as Ad-hoc networks enables the emerging of cross-layer systems to improve the wireless network performance. Efficient methods, that may either produce or update cross-layer conceptual models have to be considered. Those models allow an efficient organisation of the wireless systems. In our approach, a cross-layer conceptual model is composed of : cross- layer interaction models and interactions description arrays, produced by the Reverse Cross-Layer (RCL) method that we proposed. The method has been applied to a chosen protocol stack

Cross layer Interaction Models for SCTP and OLSR

International audienceThe evolution from wired system to the wireless environment opens a set of challenge for the improvement of the wireless system performances because of many of their weakness compared to wired networks. To achieve this goal, cross layer techniques are used to facilitate the sharing of information between the layers of the OSI model. In some precedent works, the Reverse Cross Layer (RCL) method has been proposed to facilitate the design of cross layer conceptual models. The method has the advantage to highlight the impact of each cross layer interaction on each protocol in order to update its source code and to describe the intuitive gains that can be achieve. The method may be applied to a given protocol stack or to an existent cross layer model to integrate new interactions. In this paper, we are applying the RCL method on the stack that uses the Stream Control Transport Protocol (SCTP) at the transport layer and the Optimized Link State Routing (OLSR) at the network layer. Cross layer conceptual models are produced based on new cross layer interactions that are proposed to populate the environment subsystem built with the application of the RCL method. The improvement of the environment subsystem is specified through the performance gains provide by the new interactions. The implementation of the interactions that impact the SCTP protocol is described in the Interaction Description Array. After the introduction, Section II of this paper presents an overview of the SCTP protocol. Section III is related to the overview of the OLSR protocol. Section IV is used for the application of the RCL method and the different interaction arrays it generates. Section V presents the improvement of the environment subsystem and the definition of the performance gain of each Cross Layer Atomic Action (CLAA)

The effects of changes in consumption composition and growth in recycling on decoupling household consumption from its waste footprint

Worldwide, household consumption has significantly increased in the last decades while its composition has significantly changed. In France, economic growth (and therefore consumption growth) is a political objective. On the contrary, waste policies rather target reduction, in particular as to waste generation and waste disposal. Accordingly, decoupling household consumption growth from its waste footprint is a requirement to simultaneously achieve economic and waste policy targets. In this context, this study aims at assessing the effects of both changes in the composition of consumption and growth in recycling rates on the waste footprint of French households. Three models are combined. Firstly, the macro-econometric model “NEMESIS” is used to elaborate prospective economic scenarios by 2020. Three scenarios of economic trajectories for France are built, exclusively modifying the total volume of household consumption. In the meantime, three scenarios of consumption patterns are built, respectively assuming that i) composition remains constant from 2008 to 2020, ii) trends in consumption observed from 1980 to 2010 apply to the period 2008-2020, iii) some final consumption expenditures increase at arbitrarily chosen rates. Moreover, two models are specifically designed in order to calculate the waste footprint of French household consumption in these cases of economic scenarios by 2020. In the first place, an Input-Output model extended to waste is built in order to quantify waste from economic activities induced by household consumption. Quantities of waste to treatments are also differentiated in the model, so that scenarios of recycling can be implemented together with economic scenarios. Secondly a complementary coefficient-based model is built to compute waste generation and treatment (in ktonnes of waste) as a function of household consumption (in Meuros). The results highlight that if consumption trends observed over the last 30 years continue over the period 2008-2020, then they would favor “relative” decoupling between consumption and waste footprint in terms of dry recyclables, mixed wastes and organic wastes, and “absolute” decoupling in terms of mineral wastes. Three scenarios of recycling are additionally assessed in the framework of the economic scenarios, respectively considering the increase in recycling of source-sorted waste fractions, the increase in recovery at sorting centers and the increase in source-segregation. This assessment highlights that the increase in recycling rates would globally limit the effects of consumption growth on the demand for non-mineral waste disposal induced by French households over the period 2008-2020. However, changes in production structures would be additionally required in order to significantly decouple household consumption from its “waste disposal footprint” over the period 2008-2020. Please click Additional Files below to see the full abstract

Origines de la localisation en Ethiopie du Royaume du Prêtre-Jean

 Miscellaneous Article