Fuzzy Load Balancing for IEEE 802.11 Wireless Networks

AbstractWireless networks (WNs) are today used in many areas thanks to several benefits deriving from the ease of installation and maintenance and the high scalability. However, in large areas, the increasing number of nodes implies that Access Points (APs) are the main responsible of clients' connection. An overloaded access point may compromise requirements in terms of timeliness of data exchanged among the clients. This paper proposes a load balancing technique for IEEE 802.11 networks based on fuzzy logic in order to ensure the achievement of typical constraints that characterize a wireless scenario. To validate the goodness of the proposed approach several real test-bed scenarios were implemented and load distribution was evaluated

Breaking the Cycle of "Flood-Rebuild-Repeat": Local and State Options to Improve Substantial Damage and Improvement Standards in the National Flood Insurance Program

Congress established the National Flood Insurance Program (NFIP) in 1968 to reduce flood damages nationwide and ease the Federal government’s financial burden for providing disaster recovery. Due largely to recent flood disasters, the NFIP is over $20.5 billion in debt. A proportionally small number of properties insured through the program, known as “severe repetitive loss” (SRL) properties, are repeatedly flooded, repaired, and rebuilt. These properties contribute disproportionally to the rising debts of the NFIP program. Climate change impacts, including sea level rise, more intense and frequent precipitation events, and increased storm surge, put these already vulnerable properties at even greater risk and will greatly increase the number of properties caught in this cycle of “flood-rebuild-repeat.” The NFIP contains an adaptive mechanism—the substantial improvement/damage (“SI/SD”) standard—which can break the cycle of “flood-rebuild-repeat.” The SI/SD standard requires property owners in the program who are making significant improvements or repairs to structures in areas most vulnerable to flooding to take certain measures to mitigate their risk. However, two critical shortcomings of the current FEMA SI/SD definition undermine the effectiveness of program: 1) the SI/SD standard is only triggered when damages or repair work are equal to or exceed 50 percent of the fair market value of the structure, and 2) the regulatory definitions of “substantial improvement” and “substantial damage” do not consider repetitive cumulative repair work or cumulative damage over time. This paper explains how reforming the SI/SD standard to calculate damages cumulatively over time and to be triggered for damages and repair work worth less than 50 percent of the fair market value of the structure can help the NFIP program better weather a changing climate, lessen the taxpayer burden, and increase the safety of homeowners. It analyzes the prevalence of heightened SI/SD standards among NFIP communities and in state model ordinances and discusses the benefits and challenges of implementing more rigorous SI/SD standards

Social Dynamics Modeling of Chrono-nutrition

Gut microbiota and human relationships are strictly connected to each other. What we eat reflects our body-mind connection and synchronizes with people around us. However, how this impacts on gut microbiota and, conversely, how gut bacteria influence our dietary behaviors has not been explored yet. To quantify the complex dynamics of this interplay between gut and human behaviors we explore the ``gut-human behavior axis'' and its evolutionary dynamics in a real-world scenario represented by the social multiplex network. We consider a dual type of similarity, homophily and gut similarity, other than psychological and unconscious biases. We analyze the dynamics of social and gut microbial communities, quantifying the impact of human behaviors on diets and gut microbial composition and, backwards, through a control mechanism. Meal timing mechanisms and ``chrono-nutrition'' play a crucial role in feeding behaviors, along with the quality and quantity of food intake. Considering a population of shift workers, we explore the dynamic interplay between their eating behaviors and gut microbiota, modeling the social dynamics of chrono-nutrition in a multiplex network. Our findings allow us to quantify the relation between human behaviors and gut microbiota through the methodological introduction of gut metabolic modeling and statistical estimators, able to capture their dynamic interplay. Moreover, we find that the timing of gut microbial communities is slower than social interactions and shift-working, and the impact of shift-working on the dynamics of chrono-nutrition is a fluctuation of strategies with a major propensity for defection (e.g. high-fat meals). A deeper understanding of the relation between gut microbiota and the dietary behavioral patterns, by embedding also the related social aspects, allows improving the overall knowledge about metabolic models and their implications for human health, opening the possibility to design promising social therapeutic dietary interventions

Massard-Vincent Josiane, Camelin Sylvaine et Jungen Christine (dir.), Portraits. Esquisses anthropographiques, Paris, Éditions PETRA, coll. Anthropologiques, 2011, 207 p.

L’ouvrage collectif coordonné par Josiane Massard-Vincent, Sylvaine Camelin et Christine Jungen est issu d’une réflexion menée, de 2005 à 2009, au sein du Laboratoire d’anthropologie urbaine (CNRS) et dans le cadre de l’atelier « Portraits arrêtés, portraits en mouvement ». Le projet qui sous-tend l’ouvrage s’annonce à partir des titre et sous-titre : « Portraits. Esquisses anthropographiques ». L’anthropographie, comme l’explique l’introduction, est « une manière de décrire, et surtout d’écr..

The role of the fibroblast growth factor receptor in skeletal myogenesis

Skeletal muscle development can be modeled using primary myocytes or established myocyte lines. These in vitro models have been used to study regulatory events of myogenesis. Early studies demonstrated that fibroblast growth factors promote proliferation and prevent differentiation of skeletal myocytes. FGFs and FGF receptors are both downregulated with myocyte differentiation. Studies have demonstrated that endogenous FGFs regulate myogenesis. The influence of FGFs was believed to be mediated through high affinity receptor tyrosine kinases. However, some studies demonstrating a role for nuclear localized FGF, challenged this belief. Furthermore, the two best characterized FGFs lack signal sequences making unclear whether they needed to exit the cell in order to exert their effects. In order to determine whether endogenous FGFs exit the cell to regulate myogenesis and, if so, whether high affinity tyrosine kinase receptors mediate the myogenic response of FGFs, two approaches were used. The first approach, stably expressing a dominant negative FGFR-1 in skeletal myocytes, was used to determine if decreasing receptor availability decreases proliferation and/or promotes differentiation. The second approach was to make myocyte lines that constitutively express the wild type FGF receptor-1. These cells were used to determine whether increasing signaling through the FGF receptor increases proliferation and/or delays differentiation. The ability of these cells to proliferate was measured by cell counting and enzymatic activity of muscle specific creatine kinase was measured as a marker of differentiation. Myocytes expressing the dominant negative receptor proliferated more slowly and differentiated more quickly than control cells. Conversely, the myocytes constitutively expressing the wild type receptor proliferated more quickly and differentiated more slowly than control cells. These results demonstrate that endogenously produced FGFs use a transmembrane mediated signaling pathway to exert their effects and that the FGFR plays a regulatory role in myogenesis

Breaking the Cycle of Flood-Rebuild-Repeat : Local and State Options to Improve Substantial Damage and Improvement Standards in the National Flood Insurance Program

Congress established the National Flood Insurance Program (NFIP) in 1968 to reduce flood damages nationwide and ease the Federal government’s financial burden for providing disaster recovery. Today, approximately 22,000 communities in all 50 states and U.S. territories participate in the NFIP. The program has 5.1 million flood insurance policies providing $1.3 trillion in coverage. Due largely to recent flood disasters, the NFIP is over$20.5 billion in debt. A proportionally small number of properties insured through the program are repeatedly flooded, repaired, and rebuilt. These properties, known as “severe repetitive loss” (SRL) properties, contribute disproportionally to the rising debts of the NFIP program. SRL properties represent just 0.6 percent of the roughly 5.1 million properties insured through the NFIP, but they account for 9.6 percent of all damages paid, as of 2015. Climate change impacts, including sea level rise, more intense and frequent precipitation events, and increased storm surge, put these already vulnerable properties at even greater risk and will greatly increase the number of properties caught in this cycle of “flood-rebuild-repeat.

Changing the National Flood Insurance Program for a Changing Climate

Congress established the National Flood Insurance Program (NFIP) in 1968 to reduce flood damages nationwide and ease the federal government’s financial burden for providing disaster recovery.1 To achieve this goal, the program was designed to perform three primary functions. First, the program provides federally backed insurance to property owners and renters. Second, the program established minimum requirements for building, land use, and floodplain management practices that local communities must adopt in order for their residents to be eligible to purchase NFIP insurance coverage. Third, the program is responsible for mapping high floodrisk areas. These maps inform local land use decisions as well as the pricing of flood insurance premiums. Theoretically, the NFIP should have deterred development in flood-prone areas, ensured that any new development in the floodplain was designed to minimize the risk of flood damage, and reduced federal expenditures on disaster recovery costs. In practice, the rising debts of the program and growing severity and frequency of flood disasters imply the opposite is true. One significant factor contributing to this shortcoming is that the NFIP is predicated on the assumption that flood risks are static and change little over time. Climate change is proving that assumption to be extremely dangerous and costly. This Comment will assess the current state of the NFIP and the threats to it from climate change (Part I). In addition, it explores several strategies to change the NFIP for a changing climate