A framework for SLA management in cloud computing for informed decision making

In cloud computing, service providers offer cost-effective and on-demand IT services to service users on the basis of Service Level Agreements (SLAs). However the effective management of SLAs in cloud computing is essential for the service users to ensure that they achieve the desired outcomes from the formed service. In this paper, we introduce a SLA management framework that will enable service users to select the best available service provider on the basis of its reputation and then monitor the run time performance of the service provider to determine whether or not it will fulfill its promise defined in the SLA. Such analysis will assist the service user to make an informed decision about the continuation of service with the service provider.     

Reciprocal insurance among Kenyan pastoralists

In large areas of low and locally variable rainfall in East Africa, pastoralism is the only viable activity, and cattle are at risk of reduced milk output and even death in dry periods. The herders were nomadic, but following the Kenyan government’s scheme of giving titles to group ranches, they are evolving reciprocity arrangements where a group suffering a dry period can send some of its cattle to graze on lands of another group that has better weather. We model such institutions using a repeated game framework. As these contracts are informal, we characterize schemes that are optimal subject to a self-enforcement or dynamic incentive compatibility condition. Where the actual arrangements differ from the predicted optima, we discuss possible reasons for the discrepancy and suggest avenues for further research.     

Asymmetry of the gramicidin channel in bilayers of asymmetric lipid composition: II. Voltage dependence of dimerization

Summary The asymmetric current-voltage relationship of gramicidin-doped asymmetric bilayers made by the Montal-Mueller technique was investigated in current relaxation experiments. It was shown that, in addition to the contribution of the asymmetric single channel conductance to the asymmetry of the steady-state current-voltage relationship, there is an asymmetric voltage dependence of the step which leads to the formation of the conducting channel. This asymmetric voltage dependence could be simulated in a model assuming a membrane-internal electrical potential drop or an equivalent potential, called asymmetry potential, which could be compensated by externally applying an offset potential. Significant asymmetry potentials were found in asymmetric bilayers made of charged lipids or only of neutral lipids. The asymmetry potential, was dependent on the salt composition in the aqueous phase.The factors responsible for the asymmetry potential do not appear to be of electrostatic origin. Several lines of evidence suggest that the dimerization step which leads to the conducting ion channel may be a complex series of reactions which are influenced by one or more membrane structural properties not yet characterized, in addition to the effects of the externally applied electric field.     

The logic of asymmetric contests

A theoretical analysis is made of the evolution of behavioural strategies in contest situations. It is assumed that behaviour will evolve so as to maximize individual fitness. If so, a population will evolve an ‘evolutionarily stable strategy’, or ESS, which can be defined as a strategy such that, if all members of a population adopt it, no ‘mutant’ strategy can do better. A number of simple models of contest situations are analysed from this point of view. It is concluded that in ‘symmetric’ contests the ESS is likely to be a ‘mixed’ strategy; that is, either the population will be genetically polymorphic or individuals will be behaviourally variable. Most real contests are probably asymmetric, either in pay-off to the contestants, or in size or weapons, or in some ‘uncorrelated’ fashion; i.e. in a fashion which does not substantially bias either the pay-offs or the likely outcome of an escalated contest. An example of an uncorrelated asymmetry is that between the ‘discoverer’ of a resource and a ‘late-comer’. It is shown that the ESS in asymmetric contests will usually be to permit the asymmetric cue to settle the contest without escalation. Escalated contests will, however, occur if information to the contestants about the asymmetry is imperfect.     

Influence of asymmetric stiffness on the structural and aerodynamic response of synthetic vocal fold models

The influence of asymmetric vocal fold stiffness on voice production was evaluated using life-sized, self-oscillating vocal fold models with an idealized geometry based on the human vocal folds. The models were fabricated using flexible, materially-linear silicone compounds with Young's modulus values comparable to that of vocal fold tissue. The models included a two-layer design to simulate the vocal fold layered structure. The respective Young's moduli of elasticity of the “left” and “right” vocal fold models were varied to create asymmetric conditions. High-speed videokymography was used to measure maximum vocal fold excursion, vibration frequency, and left–right phase shift, all of which were significantly influenced by asymmetry. Onset pressure, a measure of vocal effort, increased with asymmetry. Particle image velocimetry (PIV) analysis showed significantly greater skewing of the glottal jet in the direction of the stiffer vocal fold model. Potential applications to various clinical conditions are mentioned, and suggestions for future related studies are presented.     

Developing Autonomy and Transitional Paternalism

Adolescents, in many jurisdictions, have the power to consent to life saving treatment but not necessarily the power to refuse it. A recent defence of this asymmetry is Neil Manson's theory of ‘transitional paternalism’. Transitional paternalism holds that such asymmetries are by‐products of sharing normative powers. However, sharing normative powers by itself does not entail an asymmetry because transitional paternalism can be implemented in two ways. Manson defends the asymmetry‐generating version of transitional paternalism in the clinical context, arguing that it maximizes respect for adolescent autonomy. This article offers an alternative argument in favour of the asymmetry‐generating form of transitional paternalism, one that makes appeal to obligations that individuals have to develop self‐governance in others. We should share normative powers asymmetrically in the clinical context for three reasons. First, the asymmetric version of transitional paternalism takes seriously duties to support adolescents’ developing autonomy, alongside other duties that adults have to young people. It does so by enabling young people to be involved in important decisions that they would otherwise be excluded from. This is of value because participation of this sort is central to the cultivation of their self‐governance. Second, only the asymmetric version gives young people a voice in respect of all clinical actions, and only the asymmetric version leaves open the possibility that the coarse lines of legislation might be ‘fine‐tuned’ in individual cases. Third, the asymmetric sharing of normative powers is consistent with the kind of social arrangements that best support autonomy.     

Development of fluctuating asymmetry in tail feathers of the barn swallow Hirundo rustica

Fluctuating asymmetry represents usually small, random deviations from symmetry in bilateral morphological characters. The ontogeny of asymmetry in morphological characters may reveal information about developmental processes in a general sense. I studied the development of fluctuating asymmetry in feather characters of the barn swallow Hirundo rustica, that are developed repeatedly during the single annual moult, with the following results. First, the side developing a larger feather was found to be partially biased, as demonstrated by one side consistently developing a larger feather under natural and experimentally induced growth episode events. Second, asymmetric feathers were found to consist of asymmetric daily growth increments, and the size of the increments developing under different environmental conditions were positively correlated. Third, fluctuating asymmetries of feathers developing under different environmental conditions were positively correlated, although the level of asymmetry was larger under adverse environmental conditions. Fourth, individual asymmetries in tail length and growth bar length were unrelated to the duration of the developmental period, although late growth increments were smaller and more symmetric than early increments. These observations suggest that fluctuating asymmetry partially arises as a consequence of a random bias in the feather follicles and differences in environmental conditions during ontogeny of feathers.     

Asymmetry in Orb-Webs: An Adaptation to Web Building Costs?

Orb-web spiders build vertically asymmetric webs, in which the lower part is larger than the upper part. One hypothesis explaining this asymmetry suggests that the spider’s mass imposes higher building costs in the upper part of the web, causing the spider to reduce this part of the web. We tested this hypothesis by assessing building costs of different parts of the web. We found that the specific time-cost of building (i.e. the time required to build a certain length of silk) differed between the two parts of the web and that the difference in time-costs influenced web asymmetry. Contrary to predictions, however, building costs were larger in the lower part of the web, suggesting that additional factors affect the spider’s decisions while building the web, which are likely to be prey-capture considerations.     

Risk Analysis,Uncertainty Factors,and the Susceptibilities of Children

This article examines the use of uncertainty factors (UFs) by the Agency for Toxic Substances and Disease Registry (ATSDR) when developing health guidance values known as minimal risk levels (MRLs) in environmental risk analysis as it applies to children. Improvements in the chemical-specific databases often reveal new information and thereby reduce uncertainty or alternatively raise new concerns. As a result, MRLs can and will change. Children, in particular, are not “small adults” and in some instances demonstrate greater risks of exposure to environmental toxicants and greater susceptibility for adverse health effects once exposed. Recent experience with risk analysis for three toxicants (organic mercury, dioxin, and manganese) is recounted to demonstrate how ATSDR has revised MRLs as the emerging science generates greater knowledge and awareness of children's special vulnerabilities to toxic substances in the environment.     

Effect of management on natural capital stocks underlying ecosystem service provision: a ‘provider group’ approach

Land management practices directly impact on the occurrence and condition of natural capital stocks, which can be measured using species diversity and abundance metrics. Species identity and abundance drive ecosystem service supply, either through effects of local diversity and/or through the presence of service providing species. However, the influence of management practices on the provision of ecosystem services is not adequately understood. We grouped grassland plant species into six groups according to desirable attributes (palatability and nutritional value to livestock; medicinal or aromatic compounds; nectar production; pollen production; nitrogen fixation; and endemic and red listed species), which we recognise as ecosystem service ‘provider groups’, and tested the influence of three land management practices (abandonment of mowing, grazing, and mowing) on diversity and abundance within these groups in upland temperate grasslands of Transylvania (Romania). All three management practices favoured at least one provider group, but hay making in upland grasslands favoured more provider groups than abandonment of mowing or grazing. The effects of management on diversity and abundance within several provider groups diverged from the effects on overall species diversity and abundance. Management, through changes in species composition, favours certain provider groups, and hence ecosystem services, over others. The provider group approach is more useful than overall species diversity metrics for assessing the provision of ecosystem services from landscapes and can be used to inform the development of agri-environment schemes and conservation policies aimed at meeting priorities for ecosystem service provision.     

A strengthening plan for enterprise information security based on cloud computing

Cloud computing environment came about in order to effectively manage and use enormous amount of data that have become available with the development of the Internet. Cloud computing service is widely used not only to manage the users’ IT resources, but also to use enterprise IT resources in an effective manner. Various security threats have occurred while using cloud computing and plans for reaction are much needed, since they will eventually elevate to security threats to enterprise information. Plans to strengthen the security of enterprise information by using cloud security will be proposed in this research. These cloud computing security measures must be supported by the governmental policies. Publications on guidelines to information protection will raise awareness among the users and service providers. System of reaction must be created in order to constantly monitor and to promptly respond to any security accident. Therefore, both technical countermeasures and governmental policy must be supported at the same time. Cloud computing service is expanding more than ever, thus active research on cloud computing security is expected.     

Asymmetry of the os pubis: Implications for the Suchey‐Brooks method

Studies of skeletal development frequently document populational incidences of bilateral asymmetry. Degenerative morphological skeletal changes, attributed to age related and irregular ossification, may also progress asymmetrically, either as the result of asymmetric biomechanical factors expressed over the lifespan, asymmetric expression of physiological processes, or progressive magnification of asymmetry acquired previously during development. This study illustrates the effects of bilateral asymmetry on age at death estimates obtained from human skeletal remains. The Suchey‐Brooks method, which uses the pubic symphyseal face for age estimation (Katz and Suchey, Am J Phys Anthropol 69 1986 427–435), was selected for the study based on its widespread use. Asymmetry in the Suchey‐Brooks symphyseal age phases was found in over 60% of a sample composed of 20th century White male individuals from 18 to 86 years of age (N = 130). However, results suggest that the presence of asymmetry does not compromise the accuracy of the Suchey‐Brooks method if the morphologically older symphyseal face of an asymmetric individual is used to estimate age at death. In addition, weak directional asymmetry and a correlation between age and asymmetry were found. This suggests that a comparison of asymmetry in this area with that in other skeletal areas, where the factors originating and influencing asymmetry are better understood, may be useful in better understanding the biological processes which underlie the age markers used in the Suchey‐Brooks method. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.     

Stairway to Asymmetry: Five Steps to Lipid-Asymmetric Proteoliposomes

Membrane proteins are embedded in a complex lipid environment that influences their structure and function. One key feature of nearly all biological membranes is a distinct lipid asymmetry. However, the influence of membrane asymmetry on proteins is poorly understood, and novel asymmetric proteoliposome systems are beneficial. To our knowledge, we present the first study on a multispanning protein incorporated in large unilamellar liposomes showing a stable lipid asymmetry. These asymmetric proteoliposomes contain the Na⁺/H⁺ antiporter NhaA from Salmonella Typhimurium. Asymmetry was introduced by partial, outside-only exchange of anionic phosphatidylglycerol (PG), mimicking this key asymmetry of bacterial membranes. Outer-leaflet and total fractions of PG were determined via ζ-potential (ζ) measurements after lipid exchange and after scrambling of asymmetry. ζ-Values were in good agreement with exclusive outside localization of PG. The electrogenic Na⁺/H⁺ antiporter was active in asymmetric liposomes, and it can be concluded that reconstitution and generation of asymmetry were successful. Lipid asymmetry was stable for more than 7 days at 23°C and thus enabled characterization of the Na⁺/H⁺ antiporter in an asymmetric lipid environment. We present and validate a simple five-step protocol that addresses key steps to be taken and pitfalls to be avoided for the preparation of asymmetric proteoliposomes: 1) optimization of desired lipid composition, 2) detergent-mediated protein reconstitution with subsequent detergent removal, 3) generation of lipid asymmetry by partial exchange of outer-leaflet lipid, 4) verification of lipid asymmetry and stability, and 5) determination of protein activity in the asymmetric lipid environment. This work offers guidance in designing asymmetric proteoliposomes that will enable researchers to compare functional and structural properties of membrane proteins in symmetric and asymmetric lipid environments.     

Making the internal market work: a case for managed change.

The internal market in the NHS is meant to ensure that provider units compete on the basis of price and quality and that money follows patients into efficient units. But the example of what happened to one local ophthalmology unit suggests what may go wrong when entrepreneurial activity is applied in a market that does not work perfectly. In 1991-2 the unit had a high workload but also comparatively high prices (because of crude pricing in the local hospital); because of pressure of work the waiting times lengthened and general practitioners increasingly complained about the service. The staff in the unit reopened a longstanding debate about the need for a third consultant ophthalmologist, but neither the purchasers (including fundholders) nor the provider unit were able to fund the post. Fundholders in a neighbouring district, however, together with that district health authority, decided to place their contracts elsewhere for the following year. Although the withdrawal of contracts jeopardised the clinical and financial viability of the ophthalmic unit, patients continued to use the service. When general practitioners in the district realised that their local service might collapse they pressed to keep the service open. The fundholders and the host purchaser finally agreed to fund a third consultant and drew up standards for the service. As a result the waiting times fell and the service is now described as "excellent." Short term market decisions may have unforseen long term implications for services to patients. This needs to be addressed as part of the evolution of the reformed NHS.     

Option to cooperate increases women's competitiveness and closes the gender gap

We advance the hypothesis that women are as competitive as men once the incentive for winning includes factors that matter to women. Allowing winners an opportunity to share some of their winnings with the low performers has gendered consequences for competitive behavior. We ground our work in an evolutionary framework in which winning competitions brings asymmetric benefits and costs to men and women. In the new environment, the potential to share some of the rewards from competition with others may afford women the benefit of reaping competitive gains without incurring some of its potential costs. An experiment (N = 438 in an online convenience sample of U.S. adults) supports our hypothesis: a 26% gender gap in performance vanishes once a sharing option is included to an otherwise identical winner-take-all incentive scheme. Besides providing a novel experiment that challenges the paradigm that women are not as motivated to compete as men, our work proposes some suggestions for policy: including socially-oriented rewards to contracts may offer a novel tool to close the persistent labor market gender gap.     

Using EEG Frontal Asymmetry to Predict IT User’s Perceptions Regarding Usefulness,Ease of Use and Playfulness

Information systems (IS) community is increasingly interested in employing neuroscience tools and methods in order to develop new theories concerning Human–computer interaction (HCI) and further understand IS acceptance models. The new field of NeuroIS has been introduced to address these issues. NeuroIS researchers have proposed encephalography (EEG), among other neuroscience instruments, as a valuable usability metric, when used effectively in appropriately designed experiments. Moreover, numerous researchers have suggested that EEG frontal asymmetry may serve as an important metric of user experience. Based on the aforementioned evidence, this study aims to integrate frontal asymmetry with Technology acceptance model (TAM). Particularly, we assumed that frontal asymmetry might predict users’ perceptions regarding Usefulness and Ease of Use. Furthermore, we hypothesized that frontal asymmetry might also affect (influence) users’ Perceived Playfulness. Specifically, 82 (43 females and 39 males) undergraduate students were chosen to use a Computer-Based Assessment (while being connected to the EEG) in the context of an introductory informatics course. Results confirmed our hypothesis as well as points of theory about Information technology (IT) acceptance variables. This is one of the first studies to suggest that frontal asymmetry could serve as a valuable tool for examining IT acceptance constructs and better understanding HCI.     

Negatively-Biased Credulity and the Cultural Evolution of Beliefs

The functions of cultural beliefs are often opaque to those who hold them. Accordingly, to benefit from cultural evolution’s ability to solve complex adaptive problems, learners must be credulous. However, credulity entails costs, including susceptibility to exploitation, and effort wasted due to false beliefs. One determinant of the optimal level of credulity is the ratio between the costs of two types of errors: erroneous incredulity (failing to believe information that is true) and erroneous credulity (believing information that is false). This ratio can be expected to be asymmetric when information concerns hazards, as the costs of erroneous incredulity will, on average, exceed the costs of erroneous credulity; no equivalent asymmetry characterizes information concerning benefits. Natural selection can therefore be expected to have crafted learners’ minds so as to be more credulous toward information concerning hazards. This negatively-biased credulity extends general negativity bias, the adaptive tendency for negative events to be more salient than positive events. Together, these biases constitute attractors that should shape cultural evolution via the aggregated effects of learners’ differential retention and transmission of information. In two studies in the U.S., we demonstrate the existence of negatively-biased credulity, and show that it is most pronounced in those who believe the world to be dangerous, individuals who may constitute important nodes in cultural transmission networks. We then document the predicted imbalance in cultural content using a sample of urban legends collected from the Internet and a sample of supernatural beliefs obtained from ethnographies of a representative collection of the world’s cultures, showing that beliefs about hazards predominate in both.     

Connecting domination contracts

In Black Rights/White Wrongs, Charles Mills continues his critique of contemporary American political philosophy for ignoring issues of racial oppression, and in particular for ignoring the way that liberal social contracts rest on underlying domination contracts. In this commentary, I will discuss some of the new research inspired by Mills’ account of domination contracts, including recent accounts of the “capability contract” and the “species contract”, and explore how they relate to Mills’ own work on the “racial contract”. While this new research on diverse domination contracts confirms the richness of Mills’ analysis of the social contract tradition, it may also require some revisions to his own preferred vision of how we theorize racial justice.