Memòria de recerca: paral·lelització dels diccionaris de la Standard Template Library de C++

Estudi elaborat a partir d’una estada a la Universität Karlsruhe entre gener i maig del 2007. Les biblioteques d’estructures de dades defineixen interfícies i implementen algorismes i estructures de dades fonamentals. Un exemple n’és la Satandard Template Library (STL ), que forma part del llenguatge de programació C++. En el marc d’una tesi, s’està treballant per obtenir implementacions més eficients i/o versàtils d’alguns components de la STL. Per a fer-ho s’utilitzen tècniques de la enginyeria d’algorismes. En particular, s’integra el coneixement de la comunitat algorítmica i es té en consideració la tecnologia existent. L’acció durant l’estada s’ha emmarcat en el desenvolupament la Multi Core STL (MCSTL ). La MCSTL és una implementació paral•lela de la STL per a màquines multi-core. Les màquines multi-core són actualment l’únic tipus de màquina disponible al mercat. Per tant, tot i que el paral•lelisme obtingut no sigui òptim, és preferible a tenir els processadors esperant, ja que , la tendència és que el nombre de processadors per computador augmenti.

Associations between alcohol consumption and selected cytokines in a Swiss population-based sample (CoLaus study).

To assess the associations between alcohol consumption and cytokine levels (interleukin-1beta - IL-1β; interleukin-6 - IL-6 and tumor necrosis factor-α - TNF-α) in a Caucasian population. Population sample of 2884 men and 3201 women aged 35-75. Alcohol consumption was categorized as nondrinkers, low (1-6 drinks/week), moderate (7-13/week) and high (14+/week). No difference in IL-1β levels was found between alcohol consumption categories. Low and moderate alcohol consumption led to lower IL-6 levels: median (interquartile range) 1.47 (0.70-3.51), 1.41 (0.70-3.32), 1.42 (0.66-3.19) and 1.70 (0.83-4.39) pg/ml for nondrinkers, low, moderate and high drinkers, respectively, p<0.01, but this association was no longer significant after multivariate adjustment. Compared to nondrinkers, moderate drinkers had the lowest odds (Odds ratio=0.86 (0.71-1.03)) of being in the highest quartile of IL-6, with a significant (p<0.05) quadratic trend. Low and moderate alcohol consumption led to lower TNF-α levels: 2.92 (1.79-4.63), 2.83 (1.84-4.48), 2.82 (1.76-4.34) and 3.15 (1.91-4.73) pg/ml for nondrinkers, low, moderate and high drinkers, respectively, p<0.02, and this difference remained borderline significant (p=0.06) after multivariate adjustment. Moderate drinkers had a lower odds (0.81 [0.68-0.98]) of being in the highest quartile of TNF-α. No specific alcoholic beverage (wine, beer or spirits) effect was found. Moderate alcohol consumption is associated with lower levels of IL-6 and (to a lesser degree) of TNF-α, irrespective of the type of alcohol consumed. No association was found between IL-1β levels and alcohol consumption.

Implicit attitudes and self-concepts towards transgression and aggression: Differences between male community and offender adolescents, and associations with psychopathic traits.

Research suggests that implicit attitudes play a key role in the occurrence of antisocial behaviours. This study assessed implicit attitudes and self-concepts related to aggression and transgression in community and offender adolescents, using a new set of Implicit Association Tests (IATs), and examined their association with of psychopathic traits. Thirty-six offenders and 66 community adolescents performed 4 IATs assessing 1) implicit attitudes about a) aggression and b) transgression as good, and 2) implicit self-concepts about a) aggression and b) transgression as self-descriptive. They filled in self-report questionnaires: the Youth Psychopathic Traits Inventory, the Child Behaviour Checklist, and explicit measures of their attitudes and self-concepts towards transgression and aggression. Results showed few differences between community and offender adolescents on implicit attitudes and self-concepts, and unexpected negative associations between some implicit attitudes and psychopathic traits, while the association was positive for the corresponding explicit attitudes. Possible explanations of these findings are discussed.

Protein-DNA associations in a gender-specific gene of Schistosoma mansoni: characterization by UV cross-linking, DNase I footprinting and band shift assays

Protein extracts obtained from male and female shistosomes were incubated with a gender-specific gene, F-10, transcribed only in adult females and encoding a major egg-shell protein. The protein/DNA interaction was measured using the band shift, DNase-I-footprinting and UV cross-linking techniques. The results showed a clear band shift when a 302 bp restriction fragment containing the 3'end of the gene was incubated with either female or male proteins. This fragment also contained a putative steroid hormone regulatory element (HRE). In contrast, only the male proteins produced a shift with the 495 bp fragment corresponding to the middle region of the gene. DNase I footprinting showed that proteins from males and females interacted with the F-10 gene by binding to multiple adjacent sites along the DNA, thus generatingrelatively long protected fragments of approximately 100 bp. This result suggested that the adjacent binding of several moles of proteins occured at the 5'end of the gene. UV cross-linking between schistosome proteins and a 21 bp synthetic oligonucleotide the F-10 HRE, evidence proteins having MWS of 30,45 and 65 kDNA. These proteins are presumably involved in the regulation of transcription of the F-10 gene.

Sequencing and identification of expressed Schistosoma mansoni genes by random selection of cDNA clones from a directional library

We have initiated a gene discovery program in Schistosoma mansoni based on the technique of Expressed Sequence Tags (ESTs), i.e. partial sequences of cDNAs obtained from single passes in automatic DNA sequencers. ESTs can be used to identify genese onf the basis of their homology whith sequences from other species deposited in DNA or protein databases. Trasncripts with sequences without matches in teh databases may represent novel parasite-specific genes. This approach has shown to be very efficient and in less than two years a broad range of novel genes has already been ascertained, more than doubling the number of known S. mansoni genes.

Three-year-olds' attachment play narratives and their associations with internalizing problems

Representational strategies of emotion regulation during play are believed to protect children against behaviour problems. Yet, before the age of 4, it appears that children rely more on their attachment figure than on representational strategies to assuage distress. The study was aimed at testing whether 3-year-olds' narrative features during the Attachment Story Completion Task (ASCT) could predict concurrent internalizing problems assessed by the mothers' and fathers' ratings of the child, using the Child Behaviour Checklist Regression analyses including gender, IQ, socio-economic status and ASCT dimensions revealed that representations of supportive caregiving predicted mother-reported internalizing problems (negative association), whereas positive resolution and attachment strategies (security, deactivation, hyperactivation, disorganization) did not. Results were interpreted with reference to Bowlby's hypotheses regarding the aetiology of depression and anxiety disorders. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

Concurrent and simultaneous polydrug use among young Swiss males: use patterns and associations of number of substances used with health issues.

Background: Simultaneous polydrug use (SPU) may represent a greater incremental risk factor for human health than concurrent polydrug use (CPU). However, few studies have examined these patterns of use in relation to health issues, particularly with regard to the number of drugs used. Methods: In the present study, we have analyzed data from a representative sample of 5734 young Swiss males from the Cohort Study on Substance Use Risk Factors. Exposure to drugs (i.e., alcohol, tobacco, cannabis, and 15 other illicit drugs), as well as mental, social and physical factors, were studied through regression analysis. Results: We found that individuals engaging in CPU and SPU followed the known stages of drug use, involving initial experiences with licit drugs (e.g., alcohol and tobacco), followed by use of cannabis and then other illicit drugs. In this regard, two classes of illicit drugs were identified, including first uppers, hallucinogens and sniffed drugs; and then "harder" drugs (ketamine, heroin, and crystal meth), which were only consumed by polydrug users who were already taking numerous drugs. Moreover, we observed an association between the number of drugs used simultaneously and social issues (i.e., social consequences and aggressiveness). In fact, the more often the participants simultaneously used substances, the more likely they were to experience social problems. In contrast, we did not find any relationship between SPU and depression, anxiety, health consequences, or health. Conclusions: We identified some associations with SPU that were independent of CPU. Moreover, we found that the number of concurrently used drugs can be a strong factor associated with mental and physical health, although their simultaneous use may not significantly contribute to this association. Finally, the negative effects related to the use of one substance might be counteracted by the use of an additional substance.

Forensic examination of ink by high-performance thin layer chromatography - The United States Secret Service Digital Ink Library

Forensic examinations of ink have been performed since the beginning of the 20th century. Since the 1960s, the International Ink Library, maintained by the United States Secret Service, has supported those analyses. Until 2009, the search and identification of inks were essentially performed manually. This paper describes the results of a project designed to improve ink samples' analytical and search processes. The project focused on the development of improved standardization procedures to ensure the best possible reproducibility between analyses run on different HPTLC plates. The successful implementation of this new calibration method enabled the development of mathematical algorithms and of a software package to complement the existing ink library.