Evolving NoSQL Databases Without Downtime

NoSQL databases like Redis, Cassandra, and MongoDB are increasingly popular because they are flexible, lightweight, and easy to work with. Applications that use these databases will evolve over time, sometimes necessitating (or preferring) a change to the format or organization of the data. The problem we address in this paper is: How can we support the evolution of high-availability applications and their NoSQL data online, without excessive delays or interruptions, even in the presence of backward-incompatible data format changes? We present KVolve, an extension to the popular Redis NoSQL database, as a solution to this problem. KVolve permits a developer to submit an upgrade specification that defines how to transform existing data to the newest version. This transformation is applied lazily as applications interact with the database, thus avoiding long pause times. We demonstrate that KVolve is expressive enough to support substantial practical updates, including format changes to RedisFS, a Redis-backed file system, while imposing essentially no overhead in general use and minimal pause times during updates.Comment: Update to writing/structur

Qualitative and quantitative analysis of mixtures of compounds containing both hydrogen and deuterium

Method allows qualitative and quantitative analysis of mixtures of partially deuterated compounds. Nuclear magnetic resonance spectroscopy determines location and amount of deuterium in organic compounds but not fully deuterated compounds. Mass spectroscopy can detect fully deuterated species but not the location

Effect of water deficit during flowering on growth and morpho-physiological responses in sesame (Sesamum indicum L.)

Sesame (Sesamum indicum L.) is an oil-seed and cash crop with high nutritional and added values. In semi-arid Senegal where drought often occurs during crop development, its cultivation is recent and its promotion is largely recommended by the government for fighting against the poverty considering the high interest for the rural populations. The purpose of this study is to characterize the agro-physiological responses and identify potential screening criteria for selection for drought tolerance. Soil moisture ( v), leaf area index (LAI), mid-day leaf water potential ( md), the difference between canopy and air temperature (Tc-Ta), net photosynthesis (Pn) and maximal yield of photochemistry (ratio of Fv : variable fluorescence to Fm : maximum fluorescence = ?P0) were measured during flowering-capsule production stage. Water consumption, considering RETcycle (real evapo-transpiration during the whole cycle), of 249 mm and 184 mm were recorded for well watered and stressed treatments respectively. After the with-holding of the irrigation, the decrease in md and Tc-Ta was noted earlier (18 Das) than in LAI (24 Das), Pn and ?P0 (28 Das). Low grain yield and number of capsule per plant were also induced by water deficit. Hence, md, Tc-Ta and chlorophyll a fluorescence considering ?P0 can be used as destructive ( md) and non-destructive (Tc-Ta, ?P0) tools respectively in screening for drought resistance in sesame. (Texte intégral

A Case of Henoch-Schonlein Purpura Associated with Rotavirus Infection in an Elderly Asian Male and Review of the Literature.

BACKGROUND Henoch-Schönlein purpura (HSP), a small vessel vasculitis mediated by deposition of immune-complexes containing IgA in the skin, gut, and glomeruli, often presents with abdominal pain, purpuric rash in the lower extremities and buttocks, joint pain, and hematuria. The disease most commonly targets children but can affect adults who tend to have a worse prognosis. CASE REPORT We discuss a case of HSP in an elderly Chinese male who presented with severe proximal bowel inflammation, vasculitic rash, and proteinuria; he was found to have positive stool rotavirus and giardia. He improved significantly with high dose steroids. We believe rotavirus may have been a triggering event in this patient. A brief review of the literature is also presented. CONCLUSIONS This is the first case report describing a classic presentation of HSP in an adult following a rotavirus infection. HSP can cause significant morbidity and mortality in adult patients predominantly from progressive renal failure; therefore careful management and monitoring is important. GI infections seem to be a common trigger for HSP and this case report suggests that rotavirus may be part of the spectrum

Resolving Conflicts in Highly Reactive Teams

In distributed cooperation frameworks for completely autonomous agents, conflicts between the involved agents can occur due to inconsistent data available to the agents. In highly dynamic domains, such as RoboCup, it is often neccessary to accept a certain level of conflicts in order to decrease reaction time of single agents, instead of relying on error-free, but extensive communication. However, this may lead to situations in which unresolved conflicts linger and cause cooperation to break down completely. In our cooperation framework, ALICA, we designed and implemented a simple but effective approach to detect these cases and resolve them quickly through a bully algorithm