975 resultados para ECOSYSTEM FUNCTIONING RELATIONSHIPS


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This naturalistic cross-sectional study explores how and to what extent cannabis dependence was associated with intrapersonal aspects (anxiety, coping styles) and interpersonal aspects of adolescent functioning (school status, family relationships, peer relationships, social life). A convenience sample of 110 adolescents (aged 12 to 19) was recruited and subdivided into two groups (38 with a cannabis dependence and 72 nondependent) according to DSM-IV-TR criteria for cannabis dependence. Participants completed the State-Trait Anxiety Inventory (STAI-Y), the Coping Across Situations Questionnaire (CASQ), and the Adolescent Drug Abuse Diagnosis (ADAD) interview investigating psychosocial and interpersonal problems in an adolescent's life. Factors associated with cannabis dependence were explored with logistic regression analyses. The results indicated that severity of problems in social life and peer relationships (OR = 1.68, 95% CI = 1.21 - 2.33) and avoidant coping (OR = 4.22, 95% CI = 1.01 - 17.73) were the only discriminatory factors for cannabis dependence. This model correctly classified 84.5% of the adolescents. These findings are partially consistent with the "self-medication hypothesis" and underlined the importance of peer relationships and dysfunctional coping strategies in cannabis dependence in adolescence. Limitations of the study and implications for clinical work with adolescents are discussed.

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The nuclear receptor PPAR alpha is a key regulatory transcription factor in lipid homeostasis, some liver detoxification processes and the control of inflammation. Recent findings suggest that many hypolipidemic drugs and anti-inflammatory agents can potentially act by binding to PPAR alpha and inducing its activity. Here, we identify some structure-function relationships in PPAR alpha, by using the species-specific responsiveness to the two hypolipidemic agents, Wy 14,643 and 5,8,11,14-eicosatetraynoic acid (ETYA). We first show that the species-specific differences are mediated primarily via the ligand binding domain of the receptor and that these two drugs are indeed ligands of PPAR alpha. By mutagenesis analyses we identify amino acid residues in the ligand binding domains of Xenopus, mouse and human PPAR alpha, that confer preferential responsiveness to ETYA and Wy 14,643. These findings will aid in the development of new synthetic PPAR alpha ligands as effective therapeutics for lipid-related diseases and inflammatory disorders.

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Background: Assertive community treatment (ACT) was reported to be an effective treatment to improve global functioning of ultra-high risk (UHR) adolescents. However, the infl uence of stressful life event (SLE) was not extensively studied which represent our objective. Method: The SLE (encompassing adoption, migration, family member's deceased, sexual or physical abuse, etc.) of 20 UHR adolescents, treated with an ACT model, were rated. 10 adolescents having 0 to 1 SLE (mainly parents' divorce; low SLE group) were compared 10 adolescents with 2 to 5 SLE (high SLE group). The adolescents were assessed at baseline and after treatment with the Health of Nation Outcome Scale for Children and Adolescents (HoNOSCA). The HoNOSCA allowed rating different diffi culties such as behavior, symptoms, disorders and social. Results: First, results on the whole sample indicated signifi cant improvement after ACT (compared to baseline) on the total (P = .04), symptoms (P = .025) and social (P = .009) scores of the HoNOSCA. Second, the improvement on the HoNOSCA's score of the high SLE group were signifi cantly higher for the total (P = .016), symptoms (P = .019) and behavior (P = .033) scores compared to the low SLE group. Discussion/Conclusion: Globally, ACT seems to be an appropriate treatment to enhance global functioning and more specifi cally the social and symptoms diffi culties of UHR adolescents. Additionally, UHR adolescents with a high numbers of SLE were observed to have a better benefi t of the ACT on global, symptoms and behavioral diffi culties.

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Impact of conduct disorder (CD) and substance use disorder (SUD) on constructive thinking skills and impulsivity was explored. 71 offending adolescents were assessed for CD and SUD. Furthermore, the constructive thinking inventory, the immediate and delayed memory tasks and the UPPS impulsive behaviour scale were administered. Results showed that youths with CD, independently from SUD, presented higher personality impulsivity (urgency) and altered constructive thinking skills (categorical thinking and personal superstitious thinking). Furthermore, trait-impulsivity explained variation in constructive thinking skills. The implications of these results were discussed.

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Cospeciation between host-parasite species is generally thought to result in mirror-image congruent phylogenies. Incongruence can be explained by mechanisms such as host switching, duplication, failure to speciate and sorting events. To investigate the level of association in the host-parasite relationship between Spinturnicid mites and their bat hosts, we constructed the phylogenetic tree of the genus Spinturnix (Acari, Mesostigmata) and compared it to the host phylogeny. We sequenced 938bp of the mitochondrial 16S rDNA and Cytochrome Oxydase subunit I (COI) genes among eleven morphospecies of Spinturnix collected on 20 European Vespertilionid and Rhinolophid bat species. Phylogenetic reconstruction of hosts and parasites showed statistical evidence for cospeciation and suggested that their evolutionary history involved also failure to speciate events and host switches. The latter seem to be mainly promoted by similar roosting habits of the host. As currently understood, host associations of Spinturnicid mites likely results from a complex interaction between the phylogenetic history of the host and the behaviour and the ecology of both parasite and host.

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Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem.

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• Grasses rank among the world's most ecologically and economically important plants. Repeated evolution of the C(4) syndrome has made photosynthesis highly efficient in many grasses, inspiring intensive efforts to engineer the pathway into C(3) crops. However, comparative biology has been of limited use to this endeavor because of uncertainty in the number and phylogenetic placement of C(4) origins. • We built the most comprehensive and robust molecular phylogeny for grasses to date, expanding sampling efforts of a previous working group from 62 to 531 taxa, emphasizing the C(4)-rich PACMAD (Panicoideae, Arundinoideae, Chloridoideae, Micrairoideae, Aristidoideae and Danthonioideae) clade. Our final matrix comprises c. 5700 bp and is > 93% complete. • For the first time, we present strong support for relationships among all the major grass lineages. Several new C(4) lineages are identified, and previously inferred origins confirmed. C(3)/C(4) evolutionary transitions have been highly asymmetrical, with 22-24 inferred origins of the C(4) pathway and only one potential reversal. • Our backbone tree clarifies major outstanding systematic questions and highlights C(3) and C(4) sister taxa for comparative studies. Two lineages have emerged as hotbeds of C(4) evolution. Future work in these lineages will be instrumental in understanding the evolution of this complex trait.

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The relationship between electrophysiological and functional magnetic resonance imaging (fMRI) signals remains poorly understood. To date, studies have required invasive methods and have been limited to single functional regions and thus cannot account for possible variations across brain regions. Here we present a method that uses fMRI data and singe-trial electroencephalography (EEG) analyses to assess the spatial and spectral dependencies between the blood-oxygenation-level-dependent (BOLD) responses and the noninvasively estimated local field potentials (eLFPs) over a wide range of frequencies (0-256 Hz) throughout the entire brain volume. This method was applied in a study where human subjects completed separate fMRI and EEG sessions while performing a passive visual task. Intracranial LFPs were estimated from the scalp-recorded data using the ELECTRA source model. We compared statistical images from BOLD signals with statistical images of each frequency of the eLFPs. In agreement with previous studies in animals, we found a significant correspondence between LFP and BOLD statistical images in the gamma band (44-78 Hz) within primary visual cortices. In addition, significant correspondence was observed at low frequencies (<14 Hz) and also at very high frequencies (>100 Hz). Effects within extrastriate visual areas showed a different correspondence that not only included those frequency ranges observed in primary cortices but also additional frequencies. Results therefore suggest that the relationship between electrophysiological and hemodynamic signals thus might vary both as a function of frequency and anatomical region.

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We examined phylogenetic relationships among six species representing three subfamilies, Glirinae, Graphiurinae and Leithiinae with sequences from three nuclear protein-coding genes (apolipoprotein B, APOB; interphotoreceptor retinoid-binding protein, IRBP; recombination-activating gene 1, RAG1). Phylogenetic trees reconstructed from maximum-parsimony (MP), maximum-likelihood (ML) and Bayesian-inference (BI) analyses showed the monophyly of Glirinae (Glis and Glirulus) and Leithiinae (Dryomys, Eliomys and Muscardinus) with strong support, although the branch length maintaining this relationship was very short, implying rapid diversification among the three subfamilies. Divergence time estimates were calculated from ML (local clock model) and Bayesian-dating method using a calibration point of 25 Myr (million years) ago for the divergence between Glis and Glirulus, and 55 Myr ago for the split between lineages of Gliridae and Sciuridae on the basis of fossil records. The results showed that each lineage of Graphiuros, Glis, Glirulus and Muscardinus dates from the Late Oligocene to the Early Miocene period, which is mostly in agreement with fossil records. Taking into account that warm climate harbouring a glirid-favoured forest dominated from Europe to Asia during this period, it is considered that this warm environment triggered the prosperity of the glirid species through the rapid diversification. Glirulus japonicas is suggested to be a relict of this ancient diversification during the warm period.

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OBJECTIVE: Pituitary incidentalomas (PIs) constitute an increasingly clinical problem. While the therapeutic management is well defined for symptomatic non-functioning PIs (NFPIs), a controversy still exists for asymptomatic macro-NFPIs between surgery and a "wait and see" approach. The aim of this study is to compare surgical results between symptomatic and asymptomatic macro-NFPIs. METHODS: We conducted a retrospective study on 76 patients with newly diagnosed symptomatic and asymptomatic macro-NFPIs operated on between 2001 and 2010. We compared age, tumor size and surgical results between these two patient groups. RESULTS: After the initial evaluation, 48 patients were found to be symptomatic. Gross total removal (GTR) rate was significantly higher in asymptomatic (82%) than in symptomatic patients (58%; p=0.03). Gross total removal was strongly associated with Knosp's classification (p=0.01). Postoperative endocrinological impairment was significantly associated with the existence of preoperative symptoms (p=0.03). It was 10 times less frequent in the asymptomatic group. In symptomatic patients, postoperative visual and endocrinological impairment were present in 49% and 78% versus 0% and 14% in asymptomatic patients respectively. CONCLUSIONS: The endocrinological and visual outcome was better in those patients who underwent surgery for asymptomatic tumors. The extent of tumor resection was also significantly greater in smaller tumors. It would therefore be appropriate to offer surgery to patients with asymptomatic macro-NFPIs.

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Arbuscular mycorrhizal symbioses occur between fungi and the majority of plant species. They are important for plant nutrition, plant growth, protection from pathogens, plant diversity, nutrient cycling, and ecosystem processes. A key goal in research is to understand the molecular basis of the establishment, regulation, and functioning of the symbiosis. However, lack of knowledge on the genetics of the fungal side of this association has hindered progress. Here, we show how several key, recently discovered processes concerning the genetics of arbuscular mycorrhizal fungi could be essential for ultimately understanding the molecular genetics of this important symbiosis with plants.

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The interrelation of curing time, curing temperature, strength, and reactions in lime-bentonite-water mixtures was examined. Samples were molded at constant density and moisture content and then cured for periods of from 1 to 56 days at constant temperatures that ranged from 5C to 60C. After the appropriate curing time the samples were tested for unconfined compressive strength. The broken samples were then analyzed by x-ray diffractometer and spectrophotometer to determine the identity of the reaction products present after each curing period. It was found that the strength gain of lime-clay mixtures cured at different temperatures is due to different phases of the complex reaction, lime & clay to CSH(gel) to CSH(II) to CSH(I) to tobermorite. The farther the reaction proceeds, the higher the strength. There was also evidence of lattice substitutions in the structure of the calcium silicate hydrates at curing temperatures of 50C and higher. No consistent relationship between time, temperature, strength, and the S/A ration of reaction products existed, but in order to achieve high strengths the apparent C/S ration had to be less than two. The curing temperature had an effect on the strength developed by a given amount of reacted silica in the cured lime-clay mixture, but at a given curing temperature the cured sample that had the largest amount of reacted silica gave the highest strength. Evidence was found to indicate that during the clay reaction some calcium is indeed adsorbed onto the clay structure rather than entering into a pozzolanic reaction. Finally, it was determined that it is possible to determine the amount of silica and alumina in lime-clay reaction products by spectrophotometric analysis with sufficient accuracy for comparison purposes. The spectrophotometric analysis techniques used during the investigation were simple and were not time consuming.