196,660 research outputs found
Le comunita’ microbiche del suolo a supporto della degradazione biologica di idrocarburi in suoli contaminati da petrolio
No full textSCOPA and META-SCOPA: software for the analysis and aggregation of genome-wide association studies of multiple correlated phenotypes
No full textAbstract
Background
Genome-wide association studies (GWAS) of single nucleotide polymorphisms (SNPs) have been successful in identifying loci contributing genetic effects to a wide range of complex human diseases and quantitative traits. The traditional approach to GWAS analysis is to consider each phenotype separately, despite the fact that many diseases and quantitative traits are correlated with each other, and often measured in the same sample of individuals. Multivariate analyses of correlated phenotypes have been demonstrated, by simulation, to increase power to detect association with SNPs, and thus may enable improved detection of novel loci contributing to diseases and quantitative traits.
Results
We have developed the SCOPA software to enable GWAS analysis of multiple correlated phenotypes. The software implements \u201creverse regression\u201d methodology, which treats the genotype of an individual at a SNP as the outcome and the phenotypes as predictors in a general linear model. SCOPA can be applied to quantitative traits and categorical phenotypes, and can accommodate imputed genotypes under a dosage model. The accompanying META-SCOPA software enables meta-analysis of association summary statistics from SCOPA across GWAS. Application of SCOPA to two GWAS of high-and low-density lipoprotein cholesterol, triglycerides and body mass index, and subsequent meta-analysis with META-SCOPA, highlighted stronger association signals than univariate phenotype analysis at established lipid and obesity loci. The META-SCOPA meta-analysis also revealed a novel signal of association at genome-wide significance for triglycerides mapping to GPC5 (lead SNP rs71427535, p \u2009=\u20091.1x10
\u22128
), which has not been reported in previous large-scale GWAS of lipid traits.
Conclusions
The SCOPA and META-SCOPA software enable discovery and dissection of multiple phenotype association signals through implementation of a powerful reverse regression approach
Mimic Me While Playing! Social Tolerance and Rapid Facial Mimicry in Macaques (Macaca tonkeana and Macaca fuscata)
No full textSocial play and tolerance are positively correlated and playful signals are more freely expressed in egalitarian than in despotic species. Macaque species are organized along a continuum from intolerant to tolerant social systems and, for this reason, they are good models to test some hypotheses about the possible linkage between communication and tolerance. We compared facial playful communication in 2 macaque species at opposite ends of the continuum: despotic Japanese macaques, Macaca fuscata, and tolerant Tonkean macaques, Macaca tonkeana. We predicted that tolerance has favored larger facial display repertoires and playful cooperative tendency. Moreover, we evaluated if tolerance could also reflect in the selection for emotional sharing expressed through rapid facial mimicry (RFM). RFM is an automatic, unconscious, and fast (1 s) motor mirror response which favors emotional communication between subjects. Although M. fuscata and M. tonkeana performed play faces (PF) at comparable levels, only Tonkean macaques showed the phenomenon of RFM. The playful sessions characterized by RFM lasted longer than those characterized by the presence of playful signals perceived by a playmate but not followed by mimicry. Interestingly, the duration of playful sessions in Tonkean macaques overcame that of the sessions in Japanese macaques. It is likely that RFM improves communicative exchanges between the playmates and, at the same time, promotes behavioral coordination and cooperation in the sequence of actions. The tolerant nature of Tonkean macaques, also expressed in play, can foster RFM which, at the same time, positively enhances the propensity to cooperate in a sort of positive feedback
Melting behavior of hydrocarbon chain molecules with ionic end groups: prymary n-alchilammonium halides.
No full textStepwise melting behavior for a series of primary long chain n-alkylammonium chlorides was pointed out. A plastic phase, a smectic mesophase and a “clear” liquid possibly unisotropic were observed. The same trend seems to be common to other hydrocarbon molecules with ionic endgroups, including alkali metal n-alkanoates
SCOPA-Cognition Cutoff Value for Detection of Parkinson's Disease Dementia
No full textThe SCOPA-Cognition is a reliable and valid test to evaluate cognitive functioning in Parkinson's disease and is widely used in clinical and research settings. Recently, the Movement Disorder Society introduced criteria for Parkinson's disease dementia. The objective of the present study was to use these criteria to determine SCOPA-Cognition cutoffs for maximum accuracy, screening, and diagnosing of Parkinson's disease dementia. A total of 282 patients with Parkinson's disease were assessed with the SCOPA-Cognition and the Movement Disorder Society's Parkinson's disease dementia criteria. From the 275 patients with a complete assessment of the dementia criteria, 12% (n = 32) fulfilled the criteria. Data from 268 patients with complete assessments of both the dementia criteria and the SCOPA-Cognition were used to determine cutoffs for maximum accuracy, screening, and diagnosing of Parkinson's disease dementia. The area under the curve was 0.91 (95% confidence interval, 0.85-0.97), showing a strong association between the dementia criteria and the SCOPA-Cognition. The cutoff for maximum accuracy was 22/23, based on the highest sum of sensitivity (0.80) and specificity (0.87), with positive and negative predictive values of 0.43 and 0.97, respectively. The optimal screening cutoff was 24/25, and the optimal diagnostic cutoff was 17/18. Using the recently published Parkinson's disease dementia criteria as a reference, the current study presents SCOPA-Cognition cutoffs for maximum accuracy, screening, and diagnosing of Parkinson's disease dementia. The availability of SCOPA-Cognition cutoffs for Parkinson's disease dementia may contribute to the scale's usefulness and promote its further use in both clinical and research settings. (C)2011 Movement Disorder Societ
Trophic importance of subtidal metazoan meiofauna: evidence from in situ exclusion experiments on soft and rocky substrates
No full textIn coastal marine ecosystems, predation might affect spatial distribution and population dynamics of benthic assemblages. Here, by means of experimental exclusion of potential predators, we compared the effects of epibenthic predation on metazoan meiofaunal assemblages on soft and rocky substrates. Different patterns of abundance were observed in uncaged versus caged plots, across habitats. In caged soft substrates, the abundance of Nematodes, Copepods and Polychaetes increased by 56, 45, 57%, respectively, in the first 3 months. An increase in the number of meiofaunal taxa was also observed. The exclusion of predators from rocky substrates showed less clear patterns. It did not affect the number of taxa while a decrease in meiofaunal abundance was observed. Our results suggest that the exclusion of epibenthic predators had clear effect on total metazoan meiofaunal abundance and on the number of taxa, only in soft bottoms. The different impact of predation across habitats can be potentially explained by differences in terms of spatial variability and substrate complexity. We estimated that, coarsely, more than 75% of total metazoan meiofaunal production can be channeled to higher trophic levels through predation on soft-bottoms. Among meiofaunal taxa, Polychaetes and Nematodes provided the major contribution to benthic energy transfers. These results suggest the trophic relevance of metazoan meiofauna in coastal food webs and claim for the refinement of further experiments for the quantification of its role in different ecological systems
Psychometric properties of the Italian version of the Scales for Outcomes in Parkinson’s disease-Cognition (SCOPA-Cog)
No full textThe Scales for Outcomes in Parkinson’s disease-Cognition (SCOPA-Cog) has been shown to be a clinimetrically rigorous and valid instrument for a disease-oriented neuropsychological assessment of Parkinson’s disease (PD) patients. In the present study we evaluated the psychometric properties of the Italian version of the SCOPA-Cog in 121 PD patients. The scale explores memory, attention, and executive and visuospatial functions and takes approximately 20 minutes to administer. Data
distribution (skewness= -0.23) and internal consistency
(Cronbach’s alpha= 0.78) were satisfactory. Standard error of measurement was 3.42. The outcome was significantly worse in patients with an abnormal Psychometric properties of the Italian version of the Scales for Outcomes in Parkinson’s disease-Cognition (SCOPA-Cog) score on the Dementia Rating Scale (DRS) (SCOPA-Cog mean score 14.6±5.1 out of a total of 43) with respect to cognitively intact subjects (24.2±4.3)(p<0.0001). The DRS showed good convergent validity (Spearman rho= 0.77, p<0.0001), and a high coefficient of variation (= 0.34). These findings support the goodness of the Italian SCOPA-Cog in terms of metrics and validity
Different root growth patterns in tomato seedlings grown hydroponically under an electric field
No full textElectric fields can determine changes at morphological and physiological levels in plants. In this study, seedlings of Solanum lycopersicum L., grown hydroponically in a floating system, were exposed to a DC 12.0 V m–1 electric field (EF). Root morphology was strongly affected by the electric field applied and a significant variation in root growth rate was observed along the gradient. The tomato plants grown on the hand of the positive electrode showed a pronounced length, root hairs’ development and root branching, compared to the plants grown at the central area of the container and on the hand of the negative electrode. Root growth of the control plants not exposed to the EF resembled that of EF-exposed plants taken in the central area. Hypotheses according to which the different growth patterns observed could be related to a chemiosmotic-induced activity and/or the distribution of plasma membrane carriers are discussed. In conclusion, the root growth was affected by the positions under application of EF. The results point to a possibility of applying electric fields for controlling tomato root growth
Simulation of the oil storage process in the scopa of specialized bees
No full textS.115-130Several species of specialized bees possess special structures to store and transport floral oils. By using closely spaced hairs at their back legs, the so called scopa, these bees can absorb and release oil droplets without loss. The high efficiency of this process is a matter of ongoing research. Based on recent X-ray microtomography scans from a bee's scopa, we build a three-dimensional geometric computer model. Then, using NaSt3DGPF, a two-phase flow solver developed at the Institute for Numerical Simulation, we compute the micro flow in the scopa model. Our calculations reveal the laminar to turbulent air flow in the scopa during flight. Furthermore, we simulate the deformation of an oil droplet in the scopa due to surface tension effects on a microscopic length scale. Our results are in good agreement with measurements for an oil-wetted scopa at steady state which are obtained from X-ray scans. Both simulations are relevant for the understanding of the process of oil absorption and transportation in the real scopa of a bee. Due to the large computational complexity of the problem, massively parallel computations are essential for our simulations.11
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