Dynamic Graphs on the GPU

We present a fast dynamic graph data structure for the GPU. Our dynamic graph structure uses one hash table per vertex to store adjacency lists and achieves 3.4–14.8x faster insertion rates over the state of the art across a diverse set of large datasets, as well as deletion speedups up to 7.8x. The data structure supports queries and dynamic updates through both edge and vertex insertion and deletion. In addition, we define a comprehensive evaluation strategy based on operations, workloads, and applications that we believe better characterize and evaluate dynamic graph data structures

First Law, Counterterms and Kerr-AdS_5 Black Holes

We apply the counterterm subtraction technique to calculate the action and other quantities for the Kerr--AdS black hole in five dimensions using two boundary metrics; the Einstein universe and rotating Einstein universe with arbitrary angular velocity. In both cases, the resulting thermodynamic quantities satisfy the first law of thermodynamics. We point out that the reason for the violation of the first law in previous calculations is that the rotating Einstein universe, used as a boundary metric, was rotating with an angular velocity that depends on the black hole rotation parameter. Using a new coordinate system with a boundary metric that has an arbitrary angular velocity, one can show that the resulting physical quantities satisfy the first law.Comment: 19 pages, 1 figur

Novel signaling pathways in pulmonary arterial hypertension (2015 Grover Conference Series)

The proliferative endothelial and smooth muscle cell phenotype, inflammation, and pulmonary vascular remodeling are prominent features of pulmonary arterial hypertension (PAH). Mutations in bone morphogenetic protein type 2 receptor (BMPR2) have been identified as the most common genetic cause of PAH and females with BMPR2 mutations are 2.5 times as likely to develop heritable forms of PAH than males. Higher levels of estrogen have also been observed in males with PAH, implicating sex hormones in PAH pathogenesis. Recently, the estrogen metabolite 16α-OHE1 (hydroxyestrone) was implicated in the regulation of miR29, a microRNA involved in modulating energy metabolism. In females, decreased miR96 enhances serotonin’s effect by upregulating the 5-hydroxytryptamine 1B (5HT1B) receptor. Because PAH is characterized as a quasi-malignant disease, likely due to BMPR2 loss of function, altered signaling pathways that sustain this cancer-like phenotype are being explored. Extracellular signal–regulated kinases 1 and 2 and p38 mitogen-activated protein kinases (MAPKs) play a critical role in proliferation and cell motility, and dysregulated MAPK signaling is observed in various experimental models of PAH. Wnt signaling pathways preserve pulmonary vascular homeostasis, and dysregulation of this pathway could contribute to limited vascular regeneration in response to injury. In this review, we take a closer look at sex, sex hormones, and the interplay between sex hormones and microRNA regulation. We also focus on MAPK and Wnt signaling pathways in the emergence of a proproliferative, antiapoptotic endothelial phenotype, which then orchestrates an angioproliferative process of vascular remodeling, with the hope of developing novel therapies that could reverse the phenotype

Scale Invariance and the AdS/CFT Correspondence

Using the AdS/CFT correspondence, we show that the Anti-de Sitter (AdS) rotating (Kerr) black holes in five and seven dimensions provide us with examples of non-trivial field theories which are scale, but not conformally invariant. This is demonstrated by our computation of the actions and the stress-energy tensors of the four and six dimensional field theories residing on the boundary of these Kerr-AdS black holes spacetimes.Comment: 3 pages. LaTeX, IJMP style. Contribution to proceedings of DPF 2000, held at Ohio State

Higher Dimensional Taub-NUTs and Taub-Bolts in Einstein-Maxwell Gravity

We present a class of higher dimensional solutions to Einstein-Maxwell equations in d-dimensions. These solutions are asymptotically locally flat, de-Sitter, or anti-de Sitter space-times. The solutions we obtained depend on two extra parameters other than the mass and the nut charge. These two parameters are the electric charge, q and the electric potential at infinity, V, which has a non-trivial contribution. We Analyze the conditions one can impose to obtain Taub-Nut or Taub-Bolt space-times, including the four-dimensional case. We found that in the nut case these conditions coincide with that coming from the regularity of the one-form potential at the horizon. Furthermore, the mass parameter for the higher dimensional solutions depends on the nut charge and the electric charge or the potential at infinity.Comment: 11 pages, LaTe

Asymmetric contextual effects in age perception

How old we think someone is determines how we interact with them [1–3], and most people regularly make age judgements based on facial appearance. For example, when assessing the age of a suspect in crime scenes, or in daily tasks such as determining eligibility to buy alcohol or tobacco (for meta-analysis on age perception, see [3]). Given the importance of making accurate facial age estimations, and how frequently we make them, one might assume our perceptual system is precise in judging age. Indeed, early research claimed that people make reliable age estimates, with errors of ±3–4 years [4,5]. However, those studies were limited in the number and quality of their stimuli. Faces change as we grow older, and ageing of facial skin is driven by factors such as gender, genetics, lifestyle, diet, smoking, and consuming drugs and alcohol [6,7]. Therefore, given the large amount of variability in faces, using a small set of test faces potentially biases age estimates to the specific test identities used. More recent work has addressed this issue by using both a larger number of stimuli and a broader sample of participants. In this case, the authors find that estimating age is less reliable than originally proposed with a reported mean error magnitude between ±6 years [8,9] and ±8 years [10]. Taken together, this reveals that people make errors in age judgements even for single faces viewed individually

A Voting-Based System for Ethical Decision Making

We present a general approach to automating ethical decisions, drawing on machine learning and computational social choice. In a nutshell, we propose to learn a model of societal preferences, and, when faced with a specific ethical dilemma at runtime, efficiently aggregate those preferences to identify a desirable choice. We provide a concrete algorithm that instantiates our approach; some of its crucial steps are informed by a new theory of swap-dominance efficient voting rules. Finally, we implement and evaluate a system for ethical decision making in the autonomous vehicle domain, using preference data collected from 1.3 million people through the Moral Machine website.Comment: 25 pages; paper has been reorganized, related work and discussion sections have been expande

Effect of pre-harvest calcium chloride and ethanol spray on quality of 'El-Bayadi' table grapes during storage

Grapes (Vitis vinifera L.) are highly perishable due to postharvest fungal decay and softening. The effects of pre-harvest calcium chloride (CC) (at 1 or 2 %) and ethanol (at 10 or 20 %) spray at 30 and 7 days before harvest on quality of 'El-Bayadi' table grapes during cold storage at 0 °C ± 1 plus 1 day of shelf life at 20 °C were evaluated. Pre-harvest spray of CC and ethanol at both low and high concentrations significantly decreased berry decay percentage during storage compared to control. The combination between CC and ethanol also decreased decay compared to control but was less effective than each one alone. In this respect, there were no significant differences between low and high concentration of CC and ethanol. In all treatments, decay was recorded after 30 days of storage and significantly increased to reach 26.3 % after 50 days. CC spray alone, at both concentrations, increased weight loss percentage compared to control and most other treatments. However ethanol spray especially at 20 % decreased weight loss compared to other treatments except for 10 % ethanol spray. The combination between CC and ethanol, however, increased weight loss compared to control except for, 1 % CC plus 20 % ethanol and 2 % CC plus 10 % ethanol. Weight loss percentage increased during storage to reach 2.30 % after 50 days of storage. However, the overall quality characteristics of berries as firmness, TSS, acidity, TSS/acid ratio, pH, vitamin C, total phenols and soluble tannins were not negatively affected by both CC and ethanol spray treatments. Also, both CC and ethanol spray caused neither foliar damage on the vines nor significant changes in berry quality. It is concluded that pre-harvest spray of 1 % CC or 20 % ethanol could be suggested as practical alternatives to synthetic fungicides and SO2 to decrease postharvest decay and improve quality of 'El-Bayadi' table grapes.

Factors affecting the performance of small-scale construction firms in Nigeria

Small-Scale Construction Firms (SSCFs) in Nigeria are confronted with several problems that tend to limits their contributions to the country’s GDP, employment generation as well as infrastructural development. Although the prospect for improved contribution towards development still exists, there is the need for implementation of good management practices and support measures. Therefore, this study uses focus group to explore factors affecting the performance of small-scale construction firms and possible remedial measures. The study identified 113 factors that negatively affect performance. The interview further helped in grouping the variables into seven (7) groups. The focus group participants helped to identify and classify eighty-two (82) measures into internal and external measures. Internal measures are to be implemented by the construction firms towards solving internal constraints and external measures to be implemented by government and other stakeholders towards minimizing problems that are outside the control of the small-scale construction firms. Results revealed critical factors affecting performance such as financial indiscipline by contractors, lack of experience and track records, poor policy by commercial banks on SMEs, corruption, effects of globalisation, multiple taxation, stringent prequalification criteria, poor design and specifications, lack of entrepreneurship skills and delay in payment for work done. The study recommends the implementation of remedial measures by management of small-scale construction firms and governments with other stakeholders that could improve performance. Keywords: small-scale constructions firms, focus group, problems, remedial measures and performance.&nbsp

Thermal energy storage enhancement of a binary molten salt via in-situ produced nanoparticles

Thermal energy storage (TES) system is an essential component of any concentrating solar thermal power (CSP) plant to ensure a reliable plant operation even at night or cloudy weather. To enhance the TES capacity, a one-step method was proposed to synthesize nano-salts by in-situ production of CuO nanoparticles, via a high temperature decomposition of copper oxalate, in a binary salt used as a phase change material (PCM). The specific heat of the nano-salt both for solid and liquid phases were measured by differential scanning calorimetry (DSC) with the weight fraction of CuO nanoparticles varied from 0.1 to 3.0 wt%. The maximum specific heat increment of 7.96% in solid phase and 11.48% in liquid phase, were achieved at a CuO nanoparticle concentration of 0.5 wt%. A forming of intermediate layers composing of needle-like structures between nanoparticles and the salt was observed. The mixing model considering such an intermediate layer can be used to explain the observed specific heat enhancement at low particle concentrations. Both latent heat and onset temperature were decreased with increasing concentrations of CuO nanoparticles, while the melting temperature range was increased. When considering both latent heat and sensible heat contributions, the maximum increment of TES was achieved as 4.71% at 0.5 wt% CuO concentration in the temperature range from 160 °C to 300 °C