57 resultados para singletons
Resumo:
Usually, vehicle applications require the use of artificial intelligent techniques to implement control methods, due to noise provided by sensors or the impossibility of full knowledge about dynamics of the vehicle (engine state, wheel pressure or occupiers weight). This work presents a method to on-line evolve a fuzzy controller for commanding vehicles? pedals at low speeds; in this scenario, the slightest alteration in the vehicle or road conditions can vary controller?s behavior in a non predictable way. The proposal adapts singletons positions in real time, and trapezoids used to codify the input variables are modified according with historical data. Experimentation in both simulated and real vehicles are provided to show how fast and precise the method is, even compared with a human driver or using different vehicles.
Resumo:
The specific-locus test (SLT) detects new mutants among mice heterozygous for seven recessive visible markers. Spontaneous mutations can be manifested not only as singleton whole-body mutants in controls (for which we report new data), but as mosaics—either visible (manifesting mottled coat color) in the scored generation (G2) or masked, among the wild-type parental generation (G1). Masked G1 mosaics reveal themselves by producing clusters of whole-body mutants in G2. We provide evidence that most, if not all, mosaics detected in the SLT (both radiation and control progenies) result from a single-strand spontaneous mutation subsequent to the last premeiotic mitosis and before the first postmeiotic one of a parental genome—the “perigametic interval.” Such events in the genomes of the G1 and G0 result, respectively, in visible and masked 50:50 mosaics. Per cell cycle, the spontaneous mutation rate in the perigametic interval is much higher than that in pregamete mitotic divisions. A clearly different locus spectrum further supports the hypothesis of different origin, and casts further doubt on the validity of the doubling-dose risk-estimation method. Because mosaics cannot have arisen in mitotic germ cells, and are not induced by radiation exposure in the perigametic interval, they should not be included in calculations of radiation-induced germ-line mutation rates. For per-generation calculations, inclusion of mosaics yields a spontaneous frequency 1.7 times that calculated from singletons alone for mutations contributed by males; including both sexes, the multiple is 2.2.
Resumo:
We report the construction of the mouse full-length cDNA encyclopedia, the most extensive view of a complex transcriptome, on the basis of preparing and sequencing 246 libraries. Before cloning, cDNAs were enriched in full-length by Cap-Trapper, and in most cases, aggressively subtracted/normalized. We have produced 1,442,236 successful 3'-end sequences clustered into 171,144 groups, from which 60,770 clones were fully sequenced cDNAs annotated in the FANTOM-2 annotation. We have also produced 547,149 5' end reads, which clustered into 124,258 groups. Altogether, these cDNAs were further grouped in 70,000 transcriptional units (TU), which represent the best coverage of a transcriptome so far. By monitoring the extent of normalization/subtraction, we define the tentative equivalent coverage (TEC), which was estimated to be equivalent to >12,000,000 ESTs derived from standard libraries. High coverage explains discrepancies between the very large. numbers of clusters (and TUs) of this project, which also include non-protein-coding RNAs, and the lower gene number estimation of genome annotations. Altogether, S'-end clusters identify regions that are potential promoters for 8637 known genes and S'-end clusters suggest the presence of almost 63,000 transcriptional starting points. An estimate of the frequency of polyadenylation signals suggests that at least half of the singletons in the EST set represent real mRNAs. Clones accounting for about half of the predicted TUs await further sequencing. The continued high-discovery rate suggests that the task of transcriptome discovery is not yet complete.
Resumo:
Because the determinants of anxiety and depression in late adolescence and early adulthood may differ from those in later life, we investigated the temporal stability and magnitude of genetic and environmental correlates of symptoms of anxiety and depression across the life span. Data were collected from a population-based Australian sample of 4364 complete twin pairs and 777 singletons aged 20 to 96 years who were followed-up over three studies between 1980 and 1996. Each study contained the 14-item self-report DSSI/sAD scale which was used to measure recently experienced symptoms of anxiety and depression. Symptom scores were then divided and assigned to age intervals according to each subject's age at time of participation. We fitted genetic simplex models to take into account the longitudinal nature of the data. For male anxiety and depression, the best fitting simplex models comprised a single genetic innovation at age 20 which was transmitted, and explained genetic variation in anxiety and depression at ages 30, 40, 50 and 60. Most of the lifetime genetic variation in female anxiety and depression could also be explained by innovations at age 20 which were transmitted to all other ages; however, there were also smaller age-dependent genetic innovations at 30 for anxiety and at 40 and 70 for depression. Although the genetic determinants of anxiety and depression appear relatively stable across the life-span for males and females, there is some evidence to support additional mid-life and late age gene action in females for depression. The fact that mid-life onset for anxiety occurs one decade before depression is also consistent with a causal relationship (anxiety leading to depression) between these conditions. These findings have significance for large scale depression prevention projects.
Resumo:
In a first step toward understanding the molecular basis of pineapple fruit development, a sequencing project was initiated to survey a range of expressed sequences from green unripe and yellow ripe fruit tissue. A highly abundant metallothionein transcript was identified during library construction, and was estimated to account for up to 50% of all EST library clones. Library clones with metallothionein subtracted were sequenced, and 408 unripe green and 1140 ripe yellow edited EST clone sequences were retrieved. Clone redundancy was high, with the combined 1548 clone sequences clustering into just 634 contigs comprising 191 consensus sequences and 443 singletons. Half of the EST clone sequences clustered within 13.5% and 9.3% of contigs from green unripe and yellow ripe libraries, respectively, indicating that a small subset of genes dominate the majority of the transcriptome. Furthermore, sequence cluster analysis, northern analysis, and functional classification revealed major differences between genes expressed in the unripe green and ripe yellow fruit tissues. Abundant genes identified from the green fruit include a fruit bromelain and a bromelain inhibitor. Abundant genes identified in the yellow fruit library include a MADS box gene, and several genes normally associated with protein synthesis, including homologues of ribosomal L10 and the translation factors SUI1 and eIF5A. Both the green unripe and yellow ripe libraries contained high proportions of clones associated with oxidative stress responses and the detoxification of free radicals.
Resumo:
Recent large-scale analyses of mainly full-length cDNA libraries generated from a variety of mouse tissues indicated that almost half of all representative cloned sequences did flat contain ail apparent protein-coding sequence, and were putatively derived from non-protein-coding RNA (ncRNA) genes. However, many of these clones were singletons and the majority were unspliced, raising the possibility that they may be derived from genomic DNA or unprocessed pre-rnRNA contamination during library construction, or alternatively represent nonspecific transcriptional noise. Here we Show, using reverse transcriptase-dependent PCR, microarray, and Northern blot analyses, that many of these clones were derived from genuine transcripts Of unknown function whose expression appears to be regulated. The ncRNA transcripts have larger exons and fewer introns than protein-coding transcripts. Analysis of the genomic landscape around these sequences indicates that some cDNA clones were produced not from terminal poly(A) tracts but internal priming sites within longer transcripts, only a minority of which is encompassed by known genes. A significant proportion of these transcripts exhibit tissue-specific expression patterns, as well as dynamic changes in their expression in macrophages following lipopolysaccharide Stimulation. Taken together, the data provide strong support for the conclusion that ncRNAs are an important, regulated component of the mammalian transcriptome.
Resumo:
We have initiated an EST sequencing project to survey a range of expressed sequences from green fruit, yellow fruit, roots, and root-knot nematode infected root/gall tissues. In total, 5681 edited EST sequences were retrieved. Clone redundancy was high in the fruit libraries, with the combined fruit 1548 clone sequences clustering into just 634 contigs comprising 191 consensus sequences and 443 singletons. Half of all fruit EST clone sequences clustered within approximately 14 and 9% of contigs from green unripe and yellow ripe libraries respectively, indicating that a small subset of genes dominates the majority of the transcriptome. The root and root/gall libraries had lower levels of redundancy than the fruit libraries. Half of the root/gall ESTs clustered within approximately 40% of all contigs, indicating the roots possess a more complex transcriptome. Contig assembly and cluster analysis revealed major differences in the abundant gene sequences expressed between the unripe green and the ripe yellow fruit tissues, or gene sequences expressed between the weeks 1-4 and weeks 5-10 nematode infected gall vascular cylinder libraries.
Resumo:
We have developed a novel multilocus sequence typing (MLST) scheme and database (http://pubmlst.org/pacnes/) for Propionibacterium acnes based on the analysis of seven core housekeeping genes. The scheme, which was validated against previously described antibody, single locus and random amplification of polymorphic DNA typing methods, displayed excellent resolution and differentiated 123 isolates into 37 sequence types (STs). An overall clonal population structure was detected with six eBURST groups representing the major clades I, II and III, along with two singletons. Two highly successful and global clonal lineages, ST6 (type IA) and ST10 (type IB1), representing 64?% of this current MLST isolate collection were identified. The ST6 clone and closely related single locus variants, which comprise a large clonal complex CC6, dominated isolates from patients with acne, and were also significantly associated with ophthalmic infections. Our data therefore support an association between acne and P. acnes strains from the type IA cluster and highlight the role of a widely disseminated clonal genotype in this condition. Characterization of type I cell surface-associated antigens that are not detected in ST10 or strains of type II and III identified two dermatan-sulphate-binding proteins with putative phase/antigenic variation signatures. We propose that the expression of these proteins by type IA organisms contributes to their role in the pathophysiology of acne and helps explain the recurrent nature of the disease. The MLST scheme and database described in this study should provide a valuable platform for future epidemiological and evolutionary studies of P. acnes.
Resumo:
OBJECTIVE: To determine risk of Down syndrome (DS) in multiple relative to singleton pregnancies, and compare prenatal diagnosis rates and pregnancy outcome.
DESIGN: Population-based prevalence study based on EUROCAT congenital anomaly registries.
SETTING: Eight European countries.
POPULATION: 14.8 million births 1990-2009; 2.89% multiple births.
METHODS: DS cases included livebirths, fetal deaths from 20 weeks, and terminations of pregnancy for fetal anomaly (TOPFA). Zygosity is inferred from like/unlike sex for birth denominators, and from concordance for DS cases.
MAIN OUTCOME MEASURES: Relative risk (RR) of DS per fetus/baby from multiple versus singleton pregnancies and per pregnancy in monozygotic/dizygotic versus singleton pregnancies. Proportion of prenatally diagnosed and pregnancy outcome.
STATISTICAL ANALYSIS: Poisson and logistic regression stratified for maternal age, country and time.
RESULTS: Overall, the adjusted (adj) RR of DS for fetus/babies from multiple versus singleton pregnancies was 0.58 (95% CI 0.53-0.62), similar for all maternal ages except for mothers over 44, for whom it was considerably lower. In 8.7% of twin pairs affected by DS, both co-twins were diagnosed with the condition. The adjRR of DS for monozygotic versus singleton pregnancies was 0.34 (95% CI 0.25-0.44) and for dizygotic versus singleton pregnancies 1.34 (95% CI 1.23-1.46). DS fetuses from multiple births were less likely to be prenatally diagnosed than singletons (adjOR 0.62 [95% CI 0.50-0.78]) and following diagnosis less likely to be TOPFA (adjOR 0.40 [95% CI 0.27-0.59]).
CONCLUSIONS: The risk of DS per fetus/baby is lower in multiple than singleton pregnancies. These estimates can be used for genetic counselling and prenatal screening.
Resumo:
SOUSA,M.B.C. et al. Reproductive Patterns and Birth Seasonality in a South-American Breeding Colony of Common Marmosets, Callithrix jacchus. Primates, v.40, n.2, p. 327-336, Apr. 1999.
Resumo:
SOUSA,M.B.C. et al. Reproductive Patterns and Birth Seasonality in a South-American Breeding Colony of Common Marmosets, Callithrix jacchus. Primates, v.40, n.2, p. 327-336, Apr. 1999.
Resumo:
Brackish water ecosystems are often exposed to wide variations in environmental variables, including temperature and salinity, which may cause strong selective pressures on organisms modifying the genetic patterns of species. The aim of this work was to test whether there is a ‘divergence-with-gene flow’ in coastal lagoon populations of white seabream (Diplodus sargus) (Ria Formosa, S Portugal and Mar Menor, SE Spain) respect to four marine populations, by using partial sequences of cyt b mitochondrial gene and information from nine microsatellite loci. Genetic diversity was highest in both coastal lagoons (Mar Menor and Ria Formosa) considering mitochondrial and nuclear markers. Although some of FST population pairwise comparisons were not significant, analyses of molecular variance (AMOVAs) detected differences between groups (coastal lagoon and marine) close to significance. Also, only two haplotypes (Cytb-17 and Cytb-18) were detected in both coastal lagoon sampling sites and these localities (Mar Menor and Ria Formosa) showed the highest number of singletons, some of them with a high number of mutations, as has been already described for other Mar Menor populations (Pomatochistus marmoratus and Holothuria polii). Also, several tests detected significant positive and balancing selection considering mtDNA and microsatellite data. These data support the hypothesis of selection as one of the drivers of the genetic differences found between coastal lagoon and marine populations. The life strategy adopted by Diplodus sargus in coastal lagoons allows it to decrease its mortality rate and improve the heritability of its genes. Also, the increase time spent in coastal lagoons with different temperatures and salinities favours the fitness selection and the maintenance of exclusive haplotypes and genotypes in coastal lagoon inhabitants favouring the ‘divergence-with-gene-flow’.