Individual Specialization in the Hunting-wasp Trypoxylon (Trypargilum) agamemnon Richards (Hymenoptera: Crabronidae)

Renan B. Pitilin, Marcio S. Araujo, and Maria L.T. Buschini (2012) Individual specialization in the hunting-wasp Trypoxylon (Trypargilum) agamemnon Richards (Hymenoptera: Crabronidae). Zoological Studies 51(5): 655-662. Individuals of a population may differ with respect to resource use. This among-individual variation in resource utilization is called 'individual specialization' and may substantially impact the ecological and evolutionary dynamics of a population. The aim of this study was to evaluate whether females of 1 population of the hunting-wasp Trypoxylon agamemnon differed in their preferences for spider size and/or taxa. To observe the behavior of wasps, trap-nests were installed in an araucaria forest fragment in the Parque Municipal das Araucarias, Guarapuava (PR), southern Brazil. The indices within-individual component (WIC)/total niche width of a population (TNW) and average of values of the proportional similarity index (IS) were used to measure the degree of individual specialization. We found evidence of strong, significant individual specialization in T agamemnon in terms of both prey size (WIC/TNW = 0.43) and taxa (IS = 0.45). We hypothesized that individual specialization in this species resulted from cognitive tradeoffs that limit individuals to exploring a small subset of available resources. http://zoolstud.sinica.edu.tw/Journals/51.5/655.pdf

Processo markoviano de decisão para alocação dinâmica de recursos e controle de admissão de conexão em redes IEEE 802.16

Este trabalho apresenta uma solução para o problema de controle admissão de conexão e alocação dinâmica de recursos em redes IEEE 802.16 através da modelagem de um Processo Markoviano de Decisão (PMD) utilizando o conceito de degradação de largura de banda, o qual é baseado nos requisitos diferenciados de largura de banda das classes de serviço do IEEE 802.16. Para o critério de desempenho do PMD é feita a atribuição de diferentes retornos a cada classe de serviço, fazendo assim o tratamento diferenciado de cada fluxo. Nesse sentido, é possível avaliar a política ótima, obtida através de um algoritmo de iteração de valores, considerando aspectos como o nível de degradação médio das classes de serviço, utilização dos recursos e probabilidades de bloqueios de cada classe de serviço em relação à carga do sistema. Resultados obtidos mostram que o método de controle markoviano proposto é capaz de priorizar as classes de serviço consideradas mais relevantes para o sistema.

Resistir e fixar: a formação de negros territórios e suas manifestações na cidade de Rio Claro - SP

This paper presents some of the territories occupied by the black community in the city of Rio Claro in the course of its history and check through their interpretations of cultural, emergence, unfolding and current use. The identification of changes in those territories was through oral history, building on the views and stories of their own community, literature review, data collection 'in situ' through research and observation of participants and resource utilization of the global network of information. It is justified by the fundamental importance of recording information in the history of the land and built space in the black community of Rio Claro, since the most part, as well as throughout the Brazilian territory, has no documentation and remains alive in the memory and the stories within the past communities, so each time you die an old man also lost part of the history of our nation

Dynamic Routing in Translucent WDM Optical Networks: The Intradomain Case

Translucent wavelength-division multiplexing optical networks use sparse placement of regenerators to overcome physical impairments and wavelength contention introduced by fully transparent networks, and achieve a performance close to fully opaque networks at a much less cost. In previous studies, we addressed the placement of regenerators based on static schemes, allowing for only a limited number of regenerators at fixed locations. This paper furthers those studies by proposing a dynamic resource allocation and dynamic routing scheme to operate translucent networks. This scheme is realized through dynamically sharing regeneration resources, including transmitters, receivers, and electronic interfaces, between regeneration and access functions under a multidomain hierarchical translucent network model. An intradomain routing algorithm, which takes into consideration optical-layer constraints as well as dynamic allocation of regeneration resources, is developed to address the problem of translucent dynamic routing in a single routing domain. Network performance in terms of blocking probability, resource utilization, and running times under different resource allocation and routing schemes is measured through simulation experiments.

A Load-Balancing Shared-Protection-Path Reconfiguration Approach in WDM Wavelength-Routed Networks

Wavelength-routed networks (WRN) are very promising candidates for next-generation Internet and telecommunication backbones. In such a network, optical-layer protection is of paramount importance due to the risk of losing large amounts of data under a failure. To protect the network against this risk, service providers usually provide a pair of risk-independent working and protection paths for each optical connection. However, the investment made for the optical-layer protection increases network cost. To reduce the capital expenditure, service providers need to efficiently utilize their network resources. Among all the existing approaches, shared-path protection has proven to be practical and cost-efficient [1]. In shared-path protection, several protection paths can share a wavelength on a fiber link if their working paths are risk-independent. In real-world networks, provisioning is usually implemented without the knowledge of future network resource utilization status. As the network changes with the addition and deletion of connections, the network utilization will become sub-optimal. Reconfiguration, which is referred to as the method of re-provisioning the existing connections, is an attractive solution to fill in the gap between the current network utilization and its optimal value [2]. In this paper, we propose a new shared-protection-path reconfiguration approach. Unlike some of previous reconfiguration approaches that alter the working paths, our approach only changes protection paths, and hence does not interfere with the ongoing services on the working paths, and is therefore risk-free. Previous studies have verified the benefits arising from the reconfiguration of existing connections [2] [3] [4]. Most of them are aimed at minimizing the total used wavelength-links or ports. However, this objective does not directly relate to cost saving because minimizing the total network resource consumption does not necessarily maximize the capability of accommodating future connections. As a result, service providers may still need to pay for early network upgrades. Alternatively, our proposed shared-protection-path reconfiguration approach is based on a load-balancing objective, which minimizes the network load distribution vector (LDV, see Section 2). This new objective is designed to postpone network upgrades, thus bringing extra cost savings to service providers. In other words, by using the new objective, service providers can establish as many connections as possible before network upgrades, resulting in increased revenue. We develop a heuristic load-balancing (LB) reconfiguration approach based on this new objective and compare its performance with an approach previously introduced in [2] and [4], whose objective is minimizing the total network resource consumption.

A Heuristic with Bounded Guarantee to Compute Diverse Paths under Shared Protection in WDM Mesh Networks

Establishing a fault-tolerant connection in a network involves computation of diverse working and protection paths. The Shared Risk Link Group (SRLG) [1] concept is used to model several types of failure conditions such as link, node, fiber conduit, etc. In this work we focus on the problem of computing optimal SRLG/link diverse paths under shared protection. Shared protection technique improves network resource utilization by allowing protection paths of multiple connections to share resources. In this work we propose an iterative heuristic for computing SRLG/link diverse paths. We present a method to calculate a quantitative measure that provides a bounded guarantee on the optimality of the diverse paths computed by the heuristic. The experimental results on computing link diverse paths show that our proposed heuristic is efficient in terms of number of iterations required (time taken) to compute diverse paths when compared to other previously proposed heuristics.

Cross-Layer Packet Size Optimization for Wireless Terrestrial, Underwater, and Underground Sensor Networks

In this paper, a cross-layer solution for packet size optimization in wireless sensor networks (WSN) is introduced such that the effects of multi-hop routing, the broadcast nature of the physical wireless channel, and the effects of error control techniques are captured. A key result of this paper is that contrary to the conventional wireless networks, in wireless sensor networks, longer packets reduce the collision probability. Consequently, an optimization solution is formalized by using three different objective functions, i.e., packet throughput, energy consumption, and resource utilization. Furthermore, the effects of end-to-end latency and reliability constraints are investigated that may be required by a particular application. As a result, a generic, cross-layer optimization framework is developed to determine the optimal packet size in WSN. This framework is further extended to determine the optimal packet size in underwater and underground sensor networks. From this framework, the optimal packet sizes under various network parameters are determined.

RHYTHM-AF: design of an international registry on cardioversion of atrial fibrillation and characteristics of participating centers

Background: Atrial fibrillation is a serious public health problem posing a considerable burden to not only patients, but the healthcare environment due to high rates of morbidity, mortality, and medical resource utilization. There are limited data on the variation in treatment practice patterns across different countries, healthcare settings and the associated health outcomes. Methods/design: RHYTHM-AF was a prospective observational multinational study of management of recent onset atrial fibrillation patients considered for cardioversion designed to collect data on international treatment patterns and short term outcomes related to cardioversion. We present data collected in 10 countries between May 2010 and June 2011. Enrollment was ongoing in Italy and Brazil at the time of data analysis. Data were collected at the time of atrial fibrillation episode in all countries (Australia, Brazil, France, Germany, Italy, Netherlands, Poland, Spain, Sweden, United Kingdom), and cumulative follow-up data were collected at day 60 (+/- 10) in all but Spain. Information on center characteristics, enrollment data, patient demographics, detail of atrial fibrillation episode, medical history, diagnostic procedures, acute treatment of atrial fibrillation, discharge information and the follow-up data on major events and rehospitalizations up to day 60 were collected. Discussion: A total of 3940 patients were enrolled from 175 acute care centers. 70.5% of the centers were either academic (44%) or teaching (26%) hospitals with an overall median capacity of 510 beds. The sites were mostly specialized with anticoagulation clinics (65.9%), heart failure (75.1%) and hypertension clinics (60.1%) available. The RHYTHM-AF registry will provide insight into regional variability of antiarrhythmic and antithrombotic treatment of atrial fibrillation, the appropriateness of such treatments with respect to outcomes, and their cost-efficacy. Observations will help inform strategies to improve cardiovascular outcomes in patients with atrial fibrillation.

Contributions from the systematic review of economic evaluations: the case of childhood hepatitis A vaccination in Brazil

The aim of this study was to present the contributions of the systematic review of economic evaluations to the development of a national study on childhood hepatitis A vaccination. A literature review was performed in EMBASE, MEDLINE, WOPEC, HealthSTAR, SciELO and LILACS from 1995 to 2010. Most of the studies (8 of 10) showed favorable cost-effectiveness results. Sensitivity analysis indicated that the most important parameters for the results were cost of the vaccine, hepatitis A incidence, and medical costs of the disease. Variability was observed in methodological characteristics and estimates of key variables among the 10 studies reviewed. It is not possible to generalize results or transfer epidemiological estimates of resource utilization and costs associated with hepatitis A to the local context. Systematic review of economic evaluation studies of hepatitis A vaccine demonstrated the need for a national analysis and provided input for the development of a new decision-making model for Brazil.

A Mobile Ad Hoc Networking Competition: A Retrospective Look at the MANIAC Challenge

This article describes the Mobile Ad Hoc Networking Interoperability and Cooperation (MANIAC) Challenge, a competition in MANETs. The primary objective of the competition was to assess the trade-offs between network-wide connectivity and resource utilization in a MANET comprising autonomous self-interested nodes. The competition attracted participants from academic institutions in the United States, Europe, and Africa. The data collected provide a better understanding of link stability, route effectiveness, cooperation, and competition in an autonomously deployed MANET.

Webinar Training: an acceptable, feasible and effective approach for multi-site medical record abstraction: the BOWII experience

Background Abstractor training is a key element in creating valid and reliable data collection procedures. The choice between in-person vs. remote or simultaneous vs. sequential abstractor training has considerable consequences for time and resource utilization. We conducted a web-based (webinar) abstractor training session to standardize training across six individual Cancer Research Network (CRN) sites for a study of breast cancer treatment effects in older women (BOWII). The goals of this manuscript are to describe the training session, its participants and participants' evaluation of webinar technology for abstraction training. Findings A webinar was held for all six sites with the primary purpose of simultaneously training staff and ensuring consistent abstraction across sites. The training session involved sequential review of over 600 data elements outlined in the coding manual in conjunction with the display of data entry fields in the study's electronic data collection system. Post-training evaluation was conducted via Survey Monkey©. Inter-rater reliability measures for abstractors within each site were conducted three months after the commencement of data collection. Ten of the 16 people who participated in the training completed the online survey. Almost all (90%) of the 10 trainees had previous medical record abstraction experience and nearly two-thirds reported over 10 years of experience. Half of the respondents had previously participated in a webinar, among which three had participated in a webinar for training purposes. All rated the knowledge and information delivered through the webinar as useful and reported it adequately prepared them for data collection. Moreover, all participants would recommend this platform for multi-site abstraction training. Consistent with participant-reported training effectiveness, results of data collection inter-rater agreement within sites ranged from 89 to 98%, with a weighted average of 95% agreement across sites. Conclusions Conducting training via web-based technology was an acceptable and effective approach to standardizing medical record review across multiple sites for this group of experienced abstractors. Given the substantial time and cost savings achieved with the webinar, coupled with participants' positive evaluation of the training session, researchers should consider this instructional method as part of training efforts to ensure high quality data collection in multi-site studies.

The Swiss cohort of elderly patients with venous thromboembolism (SWITCO65+): rationale and methodology

Venous thromboembolism (VTE) is common and has a high impact on morbidity, mortality, and costs of care. Although most of the patients with VTE are aged ≥65 years, there is little data about the medical outcomes in the elderly with VTE. The Swiss Cohort of Elderly Patients with VTE (SWITCO65+) is a prospective multicenter cohort study of in- and outpatients aged ≥65 years with acute VTE from all five Swiss university and four high-volume non-university hospitals. The goal is to examine which clinical and biological factors and processes of care drive short- and long-term medical outcomes, health-related quality of life, and medical resource utilization in elderly patients with acute VTE. The cohort also includes a large biobank with biological material from each participant. From September 2009 to March 2012, 1,863 elderly patients with VTE were screened and 1003 (53.8 %) were enrolled in the cohort. Overall, 51.7 % of patients were aged ≥75 years and 52.7 % were men. By October 16, 2012, after an average follow-up time of 512 days, 799 (79.7 %) patients were still actively participating. SWITCO65+ is a unique opportunity to study short- and long-term outcomes in elderly patients with VTE. The Steering Committee encourages national and international collaborative research projects related to SWITCO65+, including sharing anonymized data and biological samples.

Speciation leads to divergent methylmercury accumulation in sympatric whitefish

Central European lake whitefish (Coregonus spp.) colonized Swiss lakes following the last glacial retreat and have undergone rapid speciation and adaptive radiation. Up to six species have been shown to coexist in some lakes, and individual species occupy specific ecological niches and have distinct feeding and reproductive ecologies. We studied methylmercury (MeHg) accumulation in sympatric whitefish species from seven Swiss lakes to determine if ecological divergence has led to different rates of MeHg bioaccumulation. In four of seven lakes, sympatric species had distinctly different MeHg levels, which varied by up to a factor of two between species. Generally, species with greater MeHg levels were smaller in body size and planktivorous, and species with lower MeHg were larger and benthivorous. While modest disparities in trophic position between species might be expected a priori to explain the divergence in MeHg, δ15N of bulk tissue did not correlate with fish MeHg in five of seven lakes. Results of a nested ANCOVA analysis across all lakes indicated that only two factors (species, lake) explained substantial portions of the variance, with species accounting for more variance (52 %) than inter-lake differences (32 %). We suggest that differences in MeHg accumulation were likely caused by diverging metabolic traits between species, such as differences in energy partitioning between anabolism and catabolism, potentially interacting with species-specific prey resource utilization. These results indicate substantial variability in MeHg accumulation between closely related fish species, illustrating that ecological speciation in fish can lead to divergent MeHg accumulation patterns.

Prospective surveillance of varicella-zoster virus infections in an out-patient setting in Switzerland

Limited data are available on the clinical impact of varicella in the ambulatory setting. Our goal was to determine real-life data on the clinical outcomes, medical management, and resource utilization in patients with varicella in Switzerland, a country without a universal immunization program against varicella. A total of 236 patients (222 = 94% primarily healthy individuals) with a clinical diagnosis of varicella were recruited by pediatricians and general practitioners. Age range of patients was 0-47 years with a median of 5 years. The great majority of patients (179 = 76%) were

Economic evaluation of varicella vaccination in Swiss children and adolescents

This study explores the effects of three different 2-dose varicella zoster virus (VZV) vaccination strategies in Switzerland. The EVITA model was used to assess clinical benefits and costs of strategies (1) vaccination of 11-15 year old adolescents with a negative or uncertain history for chickenpox, (2) universal vaccination of toddlers at age 1 to 2 years, and (3) strategy 2 plus catch-up vaccination of 11-15 year old susceptible adolescents. The cost-effectiveness analysis compares strategies 2 and 3 versus strategy 1 (current vaccination policy in Switzerland). Probabilities for clinical outcomes and medical resource utilization were derived from a real-world survey among Swiss pediatricians and general practitioners including 236 individuals with VZV infection, published information on varicella complications, and expert opinion. Costs of medical resource utilization represent official Swiss medical tariffs. The model predicts both universal childhood vaccination strategies to be more effective in reducing varicella disease burden compared to strategy 1. Economically, both universal childhood vaccination strategies with or without catch-up result in net savings from the societal perspective reflected by a benefit cost ratio (BCR) of 1.22 or 1.29, respectively. In contrast, the model predicts net costs from the payer perspective (BCR of 0.27 and 0.30, respectively). These economic findings are comparable to those reported from other similar evaluations. However, due to the recent recommendation for using a 2-dose varicella vaccination schedule, our economic results for Switzerland are somewhat less favorable than those for other country analyses in which a less expensive 1-dose vaccination regimen for toddlers has been studied.