141 resultados para 343.7


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Many genetic studies have demonstrated an association between the 7-repeat (7r) allele of a 48-base pair variable number of tandem repeats (VNTR) in exon 3 of the DRD4 gene and the phenotype of attention deficit hyperactivity disorder (ADHD). Previous studies have shown inconsistent associations between the 7r allele and neurocognitive performance in children with ADHD. We investigated the performance of 128 children with and without ADHD on the Fixed and Random versions of the Sustained Attention to Response Task (SART). We employed timeseries analyses of reaction-time data to allow a fine-grained analysis of reaction time variability, a candidate endophenotype for ADHD. Children were grouped into either the 7r-present group (possessing at least one copy of the 7r allele) or the 7r-absent group. The ADHD group made significantly more commission errors and was significantly more variable in RT in terms of fast moment-to-moment variability than the control group, but no effect of genotype was found on these measures. Children with ADHD without the 7r allele made significantly more omission errors, were significantly more variable in the slow frequency domain and showed less sensitivity to the signal (d') than those children with ADHD the 7r and control children with or without the 7r. These results highlight the utility of time-series analyses of reaction time data for delineating the neuropsychological deficits associated with ADHD and the DRD4 VNTR. Absence of the 7-repeat allele in children with ADHD is associated with a neurocognitive profile of drifting sustained attention that gives rise to variable and inconsistent performance. (c) 2008 Wiley-Liss, Inc.

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We report the discovery of a 7.3 M-J exoplanet WASP-14b, one of the most massive transiting exoplanets observed to date. The planet orbits the 10th-magnitude F5V star USNO-B1 11118-0262485 with a period of 2.243 752 d and orbital eccentricity e = 0.09. A simultaneous fit of the transit light curve and radial velocity measurements yields a planetary mass of 7.3 +/- 0.5 M-J and a radius of 1.28 +/- 0.08 R-J. This leads to a mean density of about 4.6 g cm(-3) making it the densest transiting exoplanets yet found at an orbital period less than 3 d. We estimate this system to be at a distance of 160 +/- 20 pc. Spectral analysis of the host star reveals a temperature of 6475 +/- 100 K, log g = 4.07 cm s(-2) and v sin i = 4.9 +/- 1.0 km s(-1), and also a high lithium abundance, log N(Li) = 2.84 +/- 0.05. The stellar density, effective temperature and rotation rate suggest an age for the system of about 0.5-1.0 Gyr.

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The arithmetical performance of typically achieving 5- to 7-year-olds (N = 29) was measured at four 6-month intervals. The same seven tasks were used at each time point: exact calculation, story problems, approximate arithmetic, place value, calculation principles, forced retrieval, and written problems. Although group analysis showed mostly linear growth over the 18-month period, analysis of individual differences revealed a much more complex picture. Some children exhibited marked variation in performance across the seven tasks, including evidence of difficulty in some cases. Individual growth patterns also showed differences in developmental trajectories between children on each task and within children across tasks. The findings support the idea of the componential nature of arithmetical ability and underscore the need for further longitudinal research on typically achieving children and of careful consideration of individual differences. (C) 2009 Elsevier Inc. All rights reserved.

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We report that a Jupiter-mass planet, WASP-7b, transits the V = 9.5 star HD 197286 every 4.95 d. This is the brightest discovery from the WASP-South transit survey so far and is currently the brightest transiting-exoplanet system in the southern hemisphere. WASP-7b is among the densest of the known Jupiter-mass planets, suggesting that it has a massive core. The planet mass is 0.96+0.12 -0.18 M Jup, the radius is 0.915+0.046 -0.040 R Jup, and the density is 1.26+0.25 -0.21 ?Jup (1.67+0.33 -0.28 g cm-3).

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The new ammonium iodomercurates(II), (NH4)(7)[HgI4](2)[Hg2I7](H2O) (1) and (NH4)(3)[Hg2I7] (2) contain isolated tetrahedra and vertex-sharing double tetrahedra as the anions. The crystal structures were determined from single-crystal X-ray diffraction data: 1: orthorhombic, Pnma (no. 62), a = 2175.9(2), b = 1781.8(2), c = 1256.2(2) pm, Z = 4. R-1 [I-0 > 2 sigma(I-0)] = 0.0520; 2: monoclinic, P2(1)/c (no. 14), a = 1259.0(2), b = 773.2(1), c = 2172.4(3) pm, beta = 101.18(2)degrees, Z = 4, R, [I-0 > 2 sigma(I-0)] = 0.0308.

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Objective: Interventions to reduce health inequalities for young children and their mothers are important: involving peers is recommended, but evidence of value for this approach is limited. The authors aimed to examine the effect of an innovative tailored peer-mentoring programme, based on perceived needs, for first-time mothers in socio-economically deprived communities. Design: Randomised controlled trial; parallel qualitative study with purposive samples using semistructured interviews. Setting: Socio-economically disadvantaged areas, Belfast. Participants: Primigravidae, aged 16-30 years, without significant co-morbidity. Intervention: Peer-mentoring by a lay-worker fortnightly during pregnancy and monthly for the following year, tailored to participants' wishes (home visits/telephone contacts), additional to usual care. Main outcome measures: Infant psychomotor and mental development (Bayley Scales of Infant Development (BSID-II)) at 1 year, assessed by an observer blinded to group allocation. Mothers' health at 1 year postnatal (SF-36). Results: Of 534 women invited, 343(64%) participated; 85%, with their children, completed outcome assessments (140 of 172 intervention; 152 of 171 controls). Intervention and control groups did not differ in BSID-II psychomotor (mean difference 1.64, 95% CI -0.94 to 4.21) or mental (-0.81, -2.78 to 1.16) scores, nor SF-36 physical functioning (-5.4, -11.6 to 0.7) or mental health (-1.8, -6.1 to 2.6). Women valued advice given in context of personal experience of child-rearing. Mentors gained health-related knowledge, personal skills and new employment opportunities. Conclusions: Despite possible longer-term social advantage, this peer-mentoring programme showed no benefit for infant development or maternal health at 1 year. Further rigorous evaluation of important outcomes of complex interventions promoting health for children in socially disadvantaged communities is warranted. Trial registration no: ISRCTN 55055030.

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Approximately 5% of pigs slaughtered in the UK have been tail-bitten, leading to welfare and production issues. Tail biting is sporadic and not all pigs tail bite. The aim of this study was to identify factors that are common in pigs that perform tail-biting behaviour, and that might be used in a predictive way to identify such animals.

The behaviour of 159 pigs was observed in the post-weaning period. Pigs were weaned at 4 weeks of age. In the week prior to weaning and at 6 weeks of age each pig was individually tested in a tail chew test (tail chew test 1 and 2, respectively). The tail chew test involved recording the pig's behaviour directed towards two ropes, one of which had been soaked in saline solution and the other not. The production performance of the pigs was recorded from birth to 7 weeks of age. Time spent performing tail-biting behaviour correlated positively with time in contact with the rope in tail chew test 2 (r = 0.224, P 1.5% tail biting 8.96 kg, = 1.5% tail biting 15-75 kg, = or = 1.5% tail biting 260 g/day, = 1.5% tail biting 343 g/day, 0.05).

The results suggest that pigs that tail bite have some nutritional deficiency that results in performance of foraging behaviour that is expressed in intensive housing as ear/tail biting.

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The mammalian nervous system exerts essential control on many physiological processes in the organism and is itself controlled extensively by a variety of genetic regulatory mechanisms. microRNA (miR), an abundant class of small non-coding RNA, are emerging as important post-transcriptional regulators of gene expression in the brain. Increasing evidence indicates that miR regulate both the development and function of the nervous system. Moreover, deficiency in miR function has also been implicated in a number of neurological disorders. Expression profile analysis of miR is necessary to understand their complex role in the regulation of gene expression during the development and differentiation of cells. Here we present a comparative study of miR expression profiles in neuroblastoma, in cortical development, and in neuronal differentiation of embryonic stem (ES) cells. By microarray profiling in combination with real time PCR we show that miR-7 and miR-214 are modulated in neuronal differentiation (as compared to miR-1, -16 and -133a), and control neurite outgrowth in vitro. These findings provide an important step toward further elucidation of miR function and miR-related gene regulatory networks in the mammalian central nervous system. (C) 2010 Elsevier Inc. All rights reserved.

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N-(3-Halogenopropyl)-4-phenylazetidin-2-ones undergo amination in liquid ammonia followed by transamidative ring expansion to give the eight-membered 4-phenyl -1,5-diazacyclooctan-2-one in excellent yield. Ring expansion of the amines in liquid ammonia is found to be much more effective than in hydrocarbon solvents. Formation of 7-, 8-, and 9-membered azalactams from the requisite -halogenoalkyl--lactams is an excellent synthetic process, though it is not applicable to 10membered rings. In the cases of rings of 13-, 15- and 17-members, although amination and apparent expansion takes place, the large rings appear not to be stable to ammonia and the final products are acyclic amides. N-[4-Halogenobut-2(Z)-enyl]-4-phenylazetidin-2-one satisfactorily forms a 9-membered (Z)-olefinic azalactam, but the (E)-isomer gives an acyclic amino amide. By using alkyl-substituted -lactam side-chains, C-substituted medium rings can be obtained; the relative instability of N-acyl -lactams to ammonia, however, leads to acylamino amides rather than expanded rings.Employing ethylamine in place of ammonia, it is shown that N-ethylated azalactams are formed satisfactorily, and using allylamine, N-allyl medium rings capable of further elaboration are obtained. The chemistry of these systems is discussed. Using transamidation in liquid ammonia, a short synthesis of the 9-membered spermidine alkaloid (±)-dihydroperiphylline is reported. Synthesis of key intermediates, whose transformation into the 13-membered alkaloids of the celabenzine group has already been effected, has been carried out.X-Ray single-crystal structure determinations for 4-phenyl-1,5-diazacyclononan-2-one, trans-4-phenyl-8-methyl-1,5-diazacyclooctan-2-one and (Z)-4-phenyl-1,5-diazacyclonon-7-en-2-one are reported, and comment is made on certain conformational features.

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Psychotic symptoms are common in Alzheimer's disease (AD) and have a negative impact oil quality of life. It is suggested that psychotic symptoms may be attributed to genetic risk factors which are revealed during neurodegeneration. CHRNA7, the gene for the alpha 7 nicotinic acetylcholine receptor, has been associated with schizophrenia in linkage and association Studies. Hence we investigated single SNPs and haplotypes in CHRNA7 in relation to AD with psychosis in a large, well-characterised and previously described cohort within the Northern Ireland population. A significant association between delusions and the T allele of rs6494223 (P = 0.014, OR = 1.63, Cl 1.22-2.17) was found. This suggests that the alpha 7 receptor may be a suitable target for the treatment of AD with psychosis.