Voodoo - a vector algebra for portable database performance on modern hardware

In-memory databases require careful tuning and many engineering tricks to achieve good performance. Such database performance engineering is hard: a plethora of data and hardware-dependent optimization techniques form a design space that is difficult to navigate for a skilled engineer --- even more so for a query compiler. To facilitate performance-oriented design exploration and query plan compilation, we present Voodoo, a declarative intermediate algebra that abstracts the detailed architectural properties of the hardware, such as multi- or many-core architectures, caches and SIMD registers, without losing the ability to generate highly tuned code. Because it consists of a collection of declarative, vector-oriented operations, Voodoo is easier to reason about and tune than low-level C and related hardware-focused extensions (Intrinsics, OpenCL, CUDA, etc.). This enables our Voodoo compiler to produce (OpenCL) code that rivals and even outperforms the fastest state-of-the-art in memory databases for both GPUs and CPUs. In addition, Voodoo makes it possible to express techniques as diverse as cache-conscious processing, predication and vectorization (again on both GPUs and CPUs) with just a few lines of code. Central to our approach is a novel idea we termed control vectors, which allows a code generating frontend to expose parallelism to the Voodoo compiler in a abstract manner, enabling portable performance across hardware platforms. We used Voodoo to build an alternative backend for MonetDB, a popular open-source in-memory database. Our backend allows MonetDB to perform at the same level as highly tuned in-memory databases, including HyPeR and Ocelot. We also demonstrate Voodoo's usefulness when investigating hardware conscious tuning techniques, assessing their performance on different queries, devices and data

Computable bounds in fork-join queueing systems

In a Fork-Join (FJ) queueing system an upstream fork station splits incoming jobs into N tasks to be further processed by N parallel servers, each with its own queue; the response time of one job is determined, at a downstream join station, by the maximum of the corresponding tasks' response times. This queueing system is useful to the modelling of multi-service systems subject to synchronization constraints, such as MapReduce clusters or multipath routing. Despite their apparent simplicity, FJ systems are hard to analyze. This paper provides the first computable stochastic bounds on the waiting and response time distributions in FJ systems. We consider four practical scenarios by combining 1a) renewal and 1b) non-renewal arrivals, and 2a) non-blocking and 2b) blocking servers. In the case of non blocking servers we prove that delays scale as O(logN), a law which is known for first moments under renewal input only. In the case of blocking servers, we prove that the same factor of log N dictates the stability region of the system. Simulation results indicate that our bounds are tight, especially at high utilizations, in all four scenarios. A remarkable insight gained from our results is that, at moderate to high utilizations, multipath routing 'makes sense' from a queueing perspective for two paths only, i.e., response times drop the most when N = 2; the technical explanation is that the resequencing (delay) price starts to quickly dominate the tempting gain due to multipath transmissions

Conclave: secure multi-party computation on big data (extended TR)

Secure Multi-Party Computation (MPC) allows mutually distrusting parties to run joint computations without revealing private data. Current MPC algorithms scale poorly with data size, which makes MPC on "big data" prohibitively slow and inhibits its practical use. Many relational analytics queries can maintain MPC's end-to-end security guarantee without using cryptographic MPC techniques for all operations. Conclave is a query compiler that accelerates such queries by transforming them into a combination of data-parallel, local cleartext processing and small MPC steps. When parties trust others with specific subsets of the data, Conclave applies new hybrid MPC-cleartext protocols to run additional steps outside of MPC and improve scalability further. Our Conclave prototype generates code for cleartext processing in Python and Spark, and for secure MPC using the Sharemind and Obliv-C frameworks. Conclave scales to data sets between three and six orders of magnitude larger than state-of-the-art MPC frameworks support on their own. Thanks to its hybrid protocols, Conclave also substantially outperforms SMCQL, the most similar existing system.Comment: Extended technical report for EuroSys 2019 pape

Bacterial translocation in cirrhotics patients with splenomegaly and severe hypersplenism

Clinica 2 chirurgie “Constantin Tîbîrnă”, Catedra Chirurgie nr. 2, Catedra Morfopatologie, USMF „N. Testemiţanu”, Chişinău, Republica Moldova, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere. Translocaţia bacteriană reprezintă fenomenul tranzitării microorganismelor tractului gastrointestinal în spaţiile extraluminale sterile. Scopul: estimarea semnificaţiei clinice a translocării bacteriene în nodulii limfatici mezenterici la bolnavii cirotici. Material şi metode. 21 pacienţi cirotici cu splenomegalie şi hipersplenism sever au fost trataţi prin splenectomie cu deconectare azygo-portală şi 19 bolnavi cu litiază biliară cu excizia şi cercetarea bacteriologică a nodulilor limfatici mesenterici. Nodulii limfatici mezenterici s-au prelevat nemijlocit după laparotomie, înainte de intervenţia decongestivă sau colecistectomie. Toţi pacienţii au fost monitorizaţi în decurs de 30 zile postoperatorii în ce priveşte complicaţiile infecţioase. Protocolul tratamentului antibacterial postoperator a fost analogic în ambele loturi de studiu şi a inclus administrarea cefalosporinelor de ultimă generaţie. Rezultate. Translocarea bacteriană s-a depistat la 5 pacienţi cu ciroză hepatică, ce au constituit 23,8 % şi la 1 bolnav (5,3%) din lotul de control. Culturile pozitive obţinute au fost determinate de E.Coli. Nu am remarcat conexiune între scorul Child şi creşterea florei microbiene în nodurile limfatice cu o tendinţă de evoluţie mai frecventă a translocării bacteriene pe măsura reducerii rezervelor hepatice funcţionale. Toţi bolnavii cirotici cu translocare bacteriană au prezentat ascită tranzitorie, în absenţa translocării ascita evoluînd doar la 3 (18,75%) pacienţi. Totodată în subrgupa bolnavilor cu translocaţie bacteriană s-a atestat o incidenţă înaltă a trombozei portale parţiale (80% cazuri) cu diminuarea fluxului portal. Nu am remarcat complicaţii de ordin septic. Concluzii. Translocarea bacteriană poate evolua şi în cazul unui statut hepatic compensat. Probabil, că imunosupresia condiţionată de hipersplenismul cirogen progresant reprezintă factor predispozant către translocarea bacteriană. Semnificaţia clinică a translocării bacteriene la bolnavul cirotic poate fi exteriorizată printr-o rată mai înaltă de evoluţie a trombozei portale.Introduction. Bacterial translocation is defined by wich microorganisms escape from the gastrointestinal tract to extraluminal sterile sites. Aim: evaluation of the signification of bacterial translocation to the mesenteric lymph node in cirrhotic patients. Material and methods. 21 cirrhotic patients with splenomegaly & hypersplenism were treated using splenectomy with azygo-portal disconnection and 19 patients with gallbladder stone which excised and microbiologically investigated mesenteric lymph nodes. Mesenteric lymph nodes were taken directly after laparotomy, before decongestive surgery or cholecystectomy. All patients were followed up within 30 days postoperative in the infectious complications. Postoperative antibacterial treatment protocol was analog in both groups of study and included the latest generation cephalosporin administration. Results. Bacterial translocation was found in 5 patients with liver cirrhosis, which accounted for 23.8% and 1 patient (5.3%) in the control group. Positive cultures were caused by E.Coli.I noticed connection between Child score and microbial growth in lymph nodes with a trend of more frequent development of bacterial translocation to measure liver function reserve reduction.All cirrhotic patients with bacterial translocation showed tranzitory ascites, in the absence of translocation ascites evolving only in 3 (18.75%) patients. Also in bacterial translocation subrgupa was registered patients with a high incidence of partial portal thrombosis (80% cases) with decrease of portal flow. I noticed septic complications of order.Conclusions. The bacterial translocation may evolve if compensated liver status. Perhaps that immunosuppression is conditional on progress of the cirogen hypersplenism its a factor predisposing to bacterial translocation in this patients. The clinical significance of bacterial translocation in cirrhotic patient may be externalized by a higher rate of evolution of portal thrombosis

The impact of behavioural skills training on the knowledge, skills and well-being of front line staff in the intellectual disability sector: a clustered randomised control trial

© 2019 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd Background: Staff with varying backgrounds and educational qualifications can be effectively trained to implement procedures in line with evidence-based practice. Behavioural skills training (BST) is a competency-based training model used to effectively educate a broad selection of professionals, including front line staff, in a range of work-related skills. However, BST has yet to be evaluated in a large group-based experiment. Methods: This study involved a parallel cluster randomised control trial. Six service sites, with a total of 54 participants, were randomised to the intervention condition using the ‘coin toss’ method. The intervention condition used BST to coach intellectual disability staff in reinforcement, systematic prompting, functional communication training and task analysis. Six service sites, with a total of 50 participants, were also randomised to a control condition in which generalised training in behavioural interventions was restricted. Recruited service sites were randomly assigned to the intervention condition (N = 6, n = 54) or the control condition (N = 6, n = 50) at one point in time, immediately after recruitment and before baseline testing took place. Allocations were stratified by service type (residential or day) and geographical region. One member of the research team allocated service sites using the ‘coin toss’ method, and another member, blind to the allocations, decided which experimental arm would receive the intervention and which would be designated as control. It was not possible to mask the intervention from participants, but they were recruited prior to randomisation. Results: Participants in the intervention condition demonstrated statistically significant improvements in their knowledge scores over the study period. Participants in the control condition showed no change or a statistically significant decrease in their knowledge scores. No statistically significant changes to well-being were observed for either group. There was clear evidence of knowledge maintenance, as well as skill acquisition and subsequent generalisation to the workplace environment, among participants in the intervention condition. Participants also evaluated the BST intervention positively. Conclusions: Results support BST as a method for disseminating evidence-based practice to front line staff working with adults with intellectual and developmental disabilities

Hidden Markov Model Analysis of Maternal Behavior Patterns in Inbred and Reciprocal Hybrid Mice

Individual variation in maternal care in mammals shows a significant heritable component, with the maternal behavior of daughters resembling that of their mothers. In laboratory mice, genetically distinct inbred strains show stable differences in maternal care during the first postnatal week. Moreover, cross fostering and reciprocal breeding studies demonstrate that differences in maternal care between inbred strains persist in the absence of genetic differences, demonstrating a non-genetic or epigenetic contribution to maternal behavior. In this study we applied a mathematical tool, called hidden Markov model (HMM), to analyze the behavior of female mice in the presence of their young. The frequency of several maternal behaviors in mice has been previously described, including nursing/grooming pups and tending to the nest. However, the ordering, clustering, and transitions between these behaviors have not been systematically described and thus a global description of maternal behavior is lacking. Here we used HMM to describe maternal behavior patterns in two genetically distinct mouse strains, C57BL/6 and BALB/c, and their genetically identical reciprocal hybrid female offspring. HMM analysis is a powerful tool to identify patterns of events that cluster in time and to determine transitions between these clusters, or hidden states. For the HMM analysis we defined seven states: arched-backed nursing, blanket nursing, licking/grooming pups, grooming, activity, eating, and sleeping. By quantifying the frequency, duration, composition, and transition probabilities of these states we were able to describe the pattern of maternal behavior in mouse and identify aspects of these patterns that are under genetic and nongenetic inheritance. Differences in these patterns observed in the experimental groups (inbred and hybrid females) were detected only after the application of HMM analysis whereas classical statistical methods and analyses were not able to highlight them

The relationship between subtypes of depression and cardiovascular disease: a systematic review of biological models

A compelling association has been observed between cardiovascular disease (CVD) and depression, suggesting individuals with depression to be at significantly higher risk for CVD and CVD-related mortality. Systemic immune activation, hypothalamic–pituitary–adrenal (HPA) axis hyperactivity, arterial stiffness and endothelial dysfunction have been frequently implicated in this relationship. Although a differential epidemiological association between CVD and depression subtypes is evident, it has not been determined if this indicates subtype specific biological mechanisms. A comprehensive systematic literature search was conducted using PubMed and PsycINFO databases yielding 147 articles for this review. A complex pattern of systemic immune activation, endothelial dysfunction and HPA axis hyperactivity is suggestive of the biological relationship between CVD and depression subtypes. The findings of this review suggest that diagnostic subtypes rather than a unifying model of depression should be considered when investigating the bidirectional biological relationship between CVD and depression. The suggested model of a subtype-specific biological relationship between depression and CVDs has implications for future research and possibly for diagnostic and therapeutic processes

Automatic target recognition based on cross-plot

Automatic target recognition that relies on rapid feature extraction of real-time target from photo-realistic imaging will enable efficient identification of target patterns. To achieve this objective, Cross-plots of binary patterns are explored as potential signatures for the observed target by high-speed capture of the crucial spatial features using minimal computational resources. Target recognition was implemented based on the proposed pattern recognition concept and tested rigorously for its precision and recall performance. We conclude that Cross-plotting is able to produce a digital fingerprint of a target that correlates efficiently and effectively to signatures of patterns having its identity in a target repository.Kelvin Kian Loong Wong and Derek Abbot