An investigation into the validation of formalised cognitive dimensions

The cognitive dimensions framework is a conceptual framework aimed at characterising features of interactive systems that are strongly influential upon their effective use. As such the framework facilitates the critical assessment and design of a wide variety of information artifacts. Although the framework has proved to be of considerable interest to researchers and practitioners, there has been little research examining how easily the dimensions used by it can be consistently applied. The work reported in this paper addresses this problem by examining an approach to the systematic application of dimensions and assessing its success empirically. The findings demonstrate a relatively successful approach to validating the systematic application of some concepts found in the cognitive dimensions framework.</p

ADAPT: a price-stabilizing compliance policy for renewable energy certificates: the case of SREC markets

Currently most Renewable Energy Certificate (REC) markets are defined based on targets which create an artificial step demand function resembling a cliff. This target policy produces volatile prices which can make investing in renewables a risky proposition. In this paper, we propose an alternative policy called Adjustable Dynamic Assignment of Penalties and Targets (ADAPT) which uses a sloped compliance penalty and a self-regulating requirement schedule, both designed to stabilize REC prices, helping to alleviate a common weakness of environmental markets. To capture market behavior, we model the market as a stochastic dynamic programming problem to understand how the market might balance the decision to use a REC now versus holding it for future periods (in the face of uncertain new supply). Then, we present and prove some of the properties of this market, and finally we show that this mechanism reduces the volatility of REC prices which should stabilize the market and encourage long-term investment in renewables

Rotation Symmetry Spontaneous Breaking of Edge States in Zigzag Carbon Nanotubes

Analytical solutions of the edge states were obtained for the (N, 0) type carbon nanotubes with distorted ending bonds. It was found that the edge states are mixed via the distortion. The total energies for N=5 and N>=7 are lower in the asymmetric configurations of ending bonds than those having axial rotation symmetry. Thereby the symmetry is breaking spontaneously. The results imply that the symmetry of electronic states at the apex depends on the occupation; the electron density pattern at the apex could change dramatically and could be controlled by applying an external field.Comment: 19 pages, 3 figure

Public Evidence from Secret Ballots

Elections seem simple---aren't they just counting? But they have a unique, challenging combination of security and privacy requirements. The stakes are high; the context is adversarial; the electorate needs to be convinced that the results are correct; and the secrecy of the ballot must be ensured. And they have practical constraints: time is of the essence, and voting systems need to be affordable and maintainable, and usable by voters, election officials, and pollworkers. It is thus not surprising that voting is a rich research area spanning theory, applied cryptography, practical systems analysis, usable security, and statistics. Election integrity involves two key concepts: convincing evidence that outcomes are correct and privacy, which amounts to convincing assurance that there is no evidence about how any given person voted. These are obviously in tension. We examine how current systems walk this tightrope.Comment: To appear in E-Vote-Id '1

Pan-PPAR Agonist, Bezafibrate, Restores Angiogenesis in Hindlimb Ischemia in Normal and Diabetic Rats

Introduction. The aim of this study was to investigate the effect of bezafibrate as a pan-PPAR agonist on angiogenesis and serum nitrite, the main metabolite of nitric oxide (NO), vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) concentrations in hindlimb ischemia model of normal and type I diabetic rats. Methods. 28 male Wistar rats were divided into control and diabetic groups. Then, all rats underwent unilateral hindlimb ischemia. After recovery, they were randomly assigned to one of the following experimental groups: (1) control; (2) control + bezafibrate (400 mg/kg/day); (3) diabetic; (4) diabetic + beztafibrate. After three weeks, blood samples were taken and capillary density was evaluated in the gasterocnemius muscle of ischemic limb. Results. Bezafibrate increased capillary density and capillary/fiber ratio in ischemic leg of diabetic and control rats (P < 0.05). Serum VEGF and VEGFR-2 concentrations did not alter after bezafibrate administration, however, serum nitrite concentration was significantly higher in bezafibrate-treated groups than non-treated groups (P < 0.05). Discussion. It seems that bezafibrate, as a pan PPAR agonist, restores angiogenesis in hindlimb ischemic diabetic animals and is useful for prevention and/or treatment of peripheral artery disease in diabetic subjects

SMART-SREC: a stochastic model of the New Jersey solar renewable energy certificate market

Markets for solar renewable energy certificates (SRECs) are gaining in promi- nence in many states, stimulating growth of the U.S. solar industry. However, SREC market prices have been extremely volatile, causing high risk to participants and potentially less investment in solar power generation. Such concerns necessitate the development of realis- tic, flexible and tractable models of SREC prices that capture the behavior of participants given the rules that govern the market. We propose an original stochastic model called SMART-SREC to fill this role, building on established ideas from the carbon pricing liter- ature, and including a feedback mechanism for generation response to prices. We calibrate the model to the New Jersey market and backtest it, analyzing parameter sensitivity and demonstrating its ability to reproduce historical dynamics. Finally, we run simulations to investigate the role and impact of regulatory parameters, thus providing insight into the crucial role played by market design

Degrees of tenant isolation for cloud-hosted software services : a cross-case analysis

A challenge, when implementing multi-tenancy in a cloud-hosted software service, is how to ensure that the performance and resource consumption of one tenant does not adversely affect other tenants. Software designers and architects must achieve an optimal degree of tenant isolation for their chosen application requirements. The objective of this research is to reveal the trade-offs, commonalities, and differences to be considered when implementing the required degree of tenant isolation. This research uses a cross-case analysis of selected open source cloud-hosted software engineering tools to empirically evaluate varying degrees of isolation between tenants. Our research reveals five commonalities across the case studies: disk space reduction, use of locking, low cloud resource consumption, customization and use of plug-in architecture, and choice of multi-tenancy pattern. Two of these common factors compromise tenant isolation. The degree of isolation is reduced when there is no strategy to reduce disk space and customization and plug-in architecture is not adopted. In contrast, the degree of isolation improves when careful consideration is given to how to handle a high workload, locking of data and processes is used to prevent clashes between multiple tenants and selection of appropriate multi-tenancy pattern. The research also revealed five case study differences: size of generated data, cloud resource consumption, sensitivity to workload changes, the effect of the software process, client latency and bandwidth, and type of software process. The degree of isolation is impaired, in our results, by the large size of generated data, high resource consumption by certain software processes, high or fluctuating workload, low client latency, and bandwidth when transferring multiple files between repositories. Additionally, this research provides a novel explanatory framework for (i) mapping tenant isolation to different software development processes, cloud resources and layers of the cloud stack; and (ii) explaining the different trade-offs to consider affecting tenant isolation (i.e. resource sharing, the number of users/requests, customizability, the size of generated data, the scope of control of the cloud application stack and business constraints) when implementing multi-tenant cloud-hosted software services. This research suggests that software architects have to pay attention to the trade-offs, commonalities, and differences we identify to achieve their degree of tenant isolation requirements

Global prostate cancer incidence and mortality rates according to the human development index

Background: Prostate cancer (PC) is one of the leading causes of death, especially in developed countries. The human development index (HDI) and its dimensions seem correlated with incidence and mortality rates of PC. This study aimed to assess the association of the specific components of HDI (life expectancy at birth, education, gross national income per 1000 capita, health, and living standards) with burden indicators of PC worldwide. Materials and Methods: Information of the incidence and mortality rates of PC was obtained from the GLOBOCAN cancer project in year 2012 and data about the HDI 2013 were obtained from the World Bank database. The correlation between incidence, mortality rates, and the HDI parameters were assessed using STATA software. Results: A significant inequality of PC incidence rates was observed according to concentration indexes=0.25 with 95 CI (0.22, 0.34) and a negative mortality concentration index of -0.04 with 95 CI (-0.09, 0.01) was observed. Conclusions: A positive significant correlation was detected between the incidence rates of PC and the HDI and its dimensions including life expectancy at birth, education, income, urbanization level and obesity. However, there was a negative significant correlation between the standardized mortality rates and the life expectancy, income and HDI

Primary immunodeficiency disorders in Iran: Update and new insights from the third report of the national registry

Background: Primary immunodeficiency disorders (PID) are a group of heterogeneous disorders mainly characterized by severe and recurrent infections and increased susceptibility to malignancies, lymphoproliferative and autoimmune conditions. National registries of PID disorders provide epidemiological data and increase the awareness of medical personnel as well as health care providers. Methods: This study presents the demographic data and clinical manifestations of Iranian PID patients who were diagnosed from March 2006 till the March of 2013 and were registered in Iranian PID Registry (IPIDR) after its second report of 2006. Results: A total number of 731 new PID patients (455 male and 276 female) from 14 medical centers were enrolled in the current study. Predominantly antibody deficiencies were the most common subcategory of PID (32.3 %) and were followed by combined immunodeficiencies (22.3 %), congenital defects of phagocyte number, function, or both (17.4 %), well-defined syndromes with immunodeficiency (17.2 %), autoinflammatory disorders (5.2 %), diseases of immune dysregulation (2.6 %), defects in innate immunity (1.6 %), and complement deficiencies (1.4 %). Severe combined immunodeficiency was the most common disorder (21.1 %). Other prevalent disorders were common variable immunodeficiency (14.9 %), hyper IgE syndrome (7.7 %), and selective IgA deficiency (7.5 %). Conclusions: Registration of Iranian PID patients increased the awareness of medical community of Iran and developed diagnostic and therapeutic techniques across more parts of the country. Further efforts must be taken by increasing the coverage of IPIDR via electronically registration and gradual referral system in order to provide better estimation of PID in Iran and reduce the number of undiagnosed cases. © 2014 Springer Science+Business Media

Improving pulse crops as a source of protein, starch and micronutrients

Pulse crops have been known for a long time to have beneficial nutritional profiles for human diets but have been neglected in terms of cultivation, consumption and scientific research in many parts of the world. Broad dietary shifts will be required if anthropogenic climate change is to be mitigated in the future, and pulse crops should be an important component of this change by providing an environmentally sustainable source of protein, resistant starch and micronutrients. Further enhancement of the nutritional composition of pulse crops could benefit human health, helping to alleviate micronutrient deficiencies and reduce risk of chronic diseases such as type 2 diabetes. This paper reviews current knowledge regarding the nutritional content of pea (Pisum sativum L.) and faba bean (Vicia faba L.), two major UK pulse crops, and discusses the potential for their genetic improvement