End-to-end informed VM selection in compute clouds

The selection of resources, particularly VMs, in current public IaaS clouds is usually done in a blind fashion, as cloud users do not have much information about resource consumption by co-tenant third-party tasks. In particular, communication patterns can play a significant part in cloud application performance and responsiveness, specially in the case of novel latencysensitive applications, increasingly common in today’s clouds. Thus, herein we propose an end-to-end approach to the VM allocation problem using policies based uniquely on round-trip time measurements between VMs. Those become part of a userlevel ‘Recommender Service’ that receives VM allocation requests with certain network-related demands and matches them to a suitable subset of VMs available to the user within the cloud. We propose and implement end-to-end algorithms for VM selection that cover desirable profiles of communications between VMs in distributed applications in a cloud setting, such as profiles with prevailing pair-wise, hub-and-spokes, or clustered communication patterns between constituent VMs. We quantify the expected benefits from deploying our Recommender Service by comparing our informed VM allocation approaches to conventional, random allocation methods, based on real measurements of latencies between Amazon EC2 instances. We also show that our approach is completely independent from cloud architecture details, is adaptable to different types of applications and workloads, and is lightweight and transparent to cloud providers.This work is supported in part by the National Science Foundation under grant CNS-0963974

Valuing nested names in the Portuguese olive oil market: An exploratory study

The Portuguese olive oil market had a remarkable development in recent years. Production is rising steadily is response to a EU program supporting a renewal of olive groves. Moreover there is a proliferation of national brands and private labels. These are often associated to regional collective labels or to organic production. The aim of our research is to determine how consumers value these nested names or co-brands. We conducted a pilot survey on a convenience sample of 103 consumers in the Oporto and Lisbon metropolitan areas as well in a rural area. Our results reveal some contradictions, for instance while origin is an important purchasing criteria, few PDO olive oils are recognized. Moreover, only 25% of respondents identify organic olive oils sold in the market and this attribute is one of the last purchasing criteria, but organic olive oils have the highest willingness to pay. Finally we find that associating a PDO to private labels increases willingness to pay by 33.3%, but doesn’t affect valuation of national brands. While we can’t take definite conclusions our findings give us interesting cues for future research. Therefore we aim to investigate whether regional identity, alternative usage and health or environmental conscience determine of affect valuation and choices of different olive oils brands and labels.olive oil, nested names, valuation., Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Food Consumption/Nutrition/Food Safety, Labor and Human Capital,

“Only People Who Know It Here Speak Well of It...”: The Location of Social Housing in Brazilian Cities and Effects of Territorial Stigmatization

In Brazil, social housing estates have acquired a reputation as substandard housing and places of the poor. Throughout the second half of the 20th century, housing policies that were designed on a national and local level focused on the fight against the growth of favelas in Brazilian cities. Often, the inhabitants of favelas were resettled to public housing estates (conjuntos habitacionais) in the urban peripheries where they did not have access to infrastructures and public services. This has contributed much to the bad image of social housing. In their daily life, the residents are subjected to a multilayered process of stigmatization. This article considers a conjunto that was established in the central area of Belo Horizonte in the 1940s. Even though its location brought important advantages, the inhabitants suffer from the stigma of being dwellers of a housing complex (“moradores de conjunto”). By analyzing contemporary sources and oral history interviews, this article aims to contribute to the discussion about the location of social housing in Brazilian cities and the effects of territorial stigmatization. Furthermore, the focus is on recent developments which show that there are several ways how stigma can be reduced or even reversed

Les traitements non médicamenteux de la constipation pour augmenter la qualité de vie en EMS: revue de littérature

La constipation touche la majorité des résidents vivant en établissement médico-social. Le traitement principal pour cette affection est l’administration de laxatif. Pourtant ce traitement ne présente pas le résultat escompté. D’autres moyens alternatifs doivent être mis en place pour traiter la constipation fonctionnelle et ainsi améliorer la qualité de vie et le bien-être

Heat conduction in a chain of harmonic and anharmonic oscillators under the presence of an energy conserving noise

Reproducing Fourier's law of heat conduction from a microscopic stochastic model is a long standing challenge in statistical physics. As was shown by Rieder, Lebowitz and Lieb many years ago, a chain of harmonically coupled oscillators connected to two heat baths at different temperatures does not reproduce the diffusive behaviour of Fourier's law, but instead a ballistic one with an infinite thermal conductivity. Since then, there has been a substantial effort from the scientific community in identifying the key mechanism necessary to reproduce such diffusivity, which usually revolved around anharmonicity and the effect of impurities. Recently, it was shown by Dhar, Venkateshan and Lebowitz that Fourier's law can be recovered by introducing an energy conserving noise, whose role is to simulate the elastic collisions between the atoms and other microscopic degrees of freedom, which one would expect to be present in a real solid. For a one-dimensional chain this is accomplished numerically by randomly flipping - under the framework of a Poisson process with a variable “rate of collisions" - the sign of the velocity of an oscillator. In this poster we present Langevin simulations of a one-dimensional chain of oscillators coupled to two heat baths at different temperatures. We consider both harmonic and anharmonic (quartic) interactions, which are studied with and without the energy conserving noise. With these results we are able to map in detail how the heat conductivity k is influenced by both anharmonicity and the energy conserving noise. We also present a detailed analysis of the behaviour of k as a function of the size of the system and the rate of collisions, which includes a finite-size scaling method that enables us to extract the relevant critical exponents. Finally, we show that for harmonic chains, k is independent of temperature, both with and without the noise. Conversely, for anharmonic chains we find that k increases roughly linearly with the temperature of a given reservoir, while keeping the temperature difference fixed

Bond strength of different endodontic sealers to dentin: push-out test

OBJECTIVE: The aim of this in vitro study was to evaluate the bond strength of different root canal sealers to dentin. MATERIAL AND METHODS: Forty extracted single-rooted human teeth were examined and the coronal and middle thirds of the canals were prepared with a 1.50 mm post drill (FibreKor Post System, Pentron). The teeth were allocated in two experimental groups, irrigated with 2.5% NaOCl+17% EDTA or saline solution (control group) and instrumented using Race rotary files (FKG) to a size #40 at the working length. Then, the groups were divided into four subgroups and filled with Epiphany sealer (Group 1), EndoREZ (Group 2), AH26 (Group 3) and Grossman's Sealer (Group 4). After 2 weeks of storage in 100% humidity at 37ºC, all teeth were sectioned transversally into 2-mm-thick discs. Push-out tests were performed at a cross-head speed of 1 mm/min using a universal testing machine. The maximum load at failure was recorded and expressed in MPa. RESULTS: Means (±SD) in root canals irrigated with 2.5% NaOCl and 17% EDTA were: G1 (21.6±6.0), G2 (15.2±3.7), G3 (14.6±4.5) and G4 (11.7±4.1).Two-way ANOVA and Tukey's test showed the highest bond strength for the Epiphany's group (p< 0.01) when compared to the other tested sealers. Saline solution decreased the values of bond-strength (