974 resultados para new associations


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Neutral cues that predict emotional events (emotional harbingers) acquire emotional properties and attract attention. Given the importance of emotional harbingers for future survival, it is desirable to flexibly learn new facts about emotional harbingers when needed. However, recent research revealed that it is harder to learn new associations for emotional harbingers than cues that predict non-emotional events (neutral harbingers). In the current study, we addressed whether this impaired association learning for emotional harbingers is altered by one’s awareness of the contingencies between cues and emotional outcomes. Across 3 studies, we found that one’s awareness of the contingencies determines subsequent association learning of emotional harbingers. Emotional harbingers produced worse association learning than neutral harbingers when people were not aware of the contingencies between cues and emotional outcomes, but produced better association learning when people were aware of the contingencies. These results suggest that emotional harbingers do not always suffer from impaired association learning and can show facilitated learning depending on one’s contingency awareness.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The introduction of exotic species is one of the most important threats to biodiversity.This phenomenon may cause economic and environmental damage. To prevent these invasions there are institutions like EPPO. Nevertheless, the introduction of exotic pests is an increasing issue, difficult to control. Classic biological control, based on importation of natural enemies from the country of origin, has been successfully used for over 120 years, but it has also raised some criticism. My research work has focused on the study of the new associations occurring between indigenous parasitoids and three exotic pests introduced in Italy and Europe. The three target insects considered were: Cacyreus marshalli Butler (Lepidoptera: Lycaenidae), a pest of Geranium plants; Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), a plague of Castanea sp. and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). This ladybug has been introduced as a biological control agent, but since some years it considered as an invasive species. For C. marshalli I performed laboratory tests on acceptance and suitability of immature stages of this butterfly by Exorista larvarum (Diptera: Tachinidae) and Brachymeria tibialis (Hymenoptera: Chalcidicae). The experiments showed that these two parasitoids could be used to contain this pest. For D. kuriphilus I performed field samplings in an infested chestnut area, the samples were maintained in rearing chamber until gall wasp or parasitoids emergence. In the 3-year research many parasitoids of gall wasps were found; one of these, Torymus flavipes (Walker), was found in large number. For H. axyridis the research work included a first phase of field sampling, during which I searched indigenous parasitoids which had adapted to this new host; the only species found was Dinocampus coccinellae (Schrank) (Hymenoptera: Braconidae). Laboratory tests were performed on the wasp rearing, biology and capacity to contain H. axyridis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

PURPOSE: To describe novel underlying associations of classic acute macular neuroretinopathy (AMN). METHODS: Multimodal imaging case series evaluating patients with classic AMN lesions and previously unreported underlying aetiologies. RESULTS: Six patients were included (five women, one man, mean age 30±7 years). Mean distance best corrected visual acuity at initial presentation was 0.21±0.3 logMAR (mean Snellen acuity: 20/30, range 20/15-20/100) and at last follow-up visit 0.09±0.17 logMAR (Snellen acuity: 20/20, range 20/15-20/60). All cases but one had bilateral lesions and showed typical parafoveal hyporeflective lesions on infrared imaging, which corresponded to the hyper-reflectivity in the Henle's layer with attenuation of the external limiting membrane, the ellipsoid zone and interdigitation zone. Underlying diseases included thrombocytopenia and anaemia associated with dengue fever, acute lymphoblastic leukaemia, chronic kidney disease and ulcerative colitis, while Valsalva-like manoeuvre was found to be a potential trigger. Other novel associations included the use of lisdexamphetamine. CONCLUSIONS: Classic AMN may be associated with leukaemia, dengue fever, ulcerative colitis and chronic kidney disease, probably as a result of chorioretinal hypoxia in the setting of thrombocytopenia and anaemia. Adrenergic agonists such as lisdexamphetamine may also contribute to the manifestation of AMN.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Ulcerative colitis is a common form of inflammatory bowel disease with a complex etiology. As part of the Wellcome Trust Case Control Consortium 2, we performed a genome-wide association scan for ulcerative colitis in 2,361 cases and 5,417 controls. Loci showing evidence of association at P 1 × 10 5 were followed up by genotyping in an independent set of 2,321 cases and 4,818 controls. We find genome-wide significant evidence of association at three new loci, each containing at least one biologically relevant candidate gene, on chromosomes 20q13 (HNF4A; P = 3.2 × 10 17), 16q22 (CDH1 and CDH3; P = 2.8 × 10 8) and 7q31 (LAMB1; P = 3.0 × 10 8). Of note, CDH1 has recently been associated with susceptibility to colorectal cancer, an established complication of longstanding ulcerative colitis. The new associations suggest that changes in the integrity of the intestinal epithelial barrier may contribute to the pathogenesis of ulcerative colitis. © 2009 Nature America, Inc. All rights reserved.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Esophageal adenocarcinoma is a cancer with rising incidence and poor survival. Most such cancers arise in a specialized intestinal metaplastic epithelium, which is diagnostic of Barrett's esophagus. In a genome-wide association study, we compared esophageal adenocarcinoma cases (n = 2,390) and individuals with precancerous Barrett's esophagus (n = 3,175) with 10,120 controls in 2 phases. For the combined case group, we identified three new associations. The first is at 19p13 (rs10419226: P = 3.6 × 10(-10)) in CRTC1 (encoding CREB-regulated transcription coactivator), whose aberrant activation has been associated with oncogenic activity. A second is at 9q22 (rs11789015: P = 1.0 × 10(-9)) in BARX1, which encodes a transcription factor important in esophageal specification. A third is at 3p14 (rs2687201: P = 5.5 × 10(-9)) near the transcription factor FOXP1, which regulates esophageal development. We also refine a previously reported association with Barrett's esophagus near the putative tumor suppressor gene FOXF1 at 16q24 and extend our findings to now include esophageal adenocarcinoma.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

In life, we must often learn new associations to people, places, or things we already know. The current fMRI study investigated the neural mechanisms underlying emotional memory updating. Nineteen participants first viewed negative and neutral pictures and learned associations between those pictures and other neutral stimuli, such as neutral objects and encoding tasks. This initial learning phase was followed by a memory updating phase, during which participants learned picture-location associations for old pictures (i.e., pictures previously associated with other neutral stimuli) and new pictures (i.e., pictures not seen in the first phase). There was greater frontopolar/orbito-frontal (OFC) activity when people learned picture–location associations for old negative pictures than for new negative pictures, but frontopolar OFC activity did not significantly differ during learning locations of old versus new neutral pictures. In addition, frontopolar activity was more negatively correlated with the amygdala when participants learned picture–location associations for old negative pictures than for new negative or old neutral pictures. Past studies revealed that the frontopolar OFC allows for updating the affective values of stimuli in reversal learning or extinction of conditioning [e.g., Izquierdo, A., & Murray, E. A. Opposing effects of amygdala and orbital PFC lesions on the extinction of instrumental responding in macaque monkeys. European Journal of Neuroscience, 22, 2341–2346, 2005]; our findings suggest that it plays a more general role in updating associations to emotional stimuli.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background: Dopamine D2 receptor (DRD2) is thought to be critical in regulating the dopaminergic pathway in the brain which is known to be important in the aetiology of schizophrenia. It is therefore not surprising that most antipsychotic medication acts on the Dopamine D2 receptor. DRD2 is widely expressed in brain, levels are reduced in brains of schizophrenia patients and DRD2 polymorphisms have been associated with reduced brain expression. We have previously identified a genetic variant in DRD2, rs6277 to be strongly implicated in schizophrenia susceptibility. Methods: To identity new associations in the DRD2 gene with disease status and clinical severity, we genotyped seven single nucleotide polymorphisms (SNPs) in DRD2 using a multiplex mass spectrometry method. SNPs were chosen using a haplotype block-based gene-tagging approach so the entire DRD2 gene was represented. Results: One polymorphism rs2734839 was found to be significantly associated with schizophrenia as well as late onset age. Individuals carrying the genetic variation were more than twice as likely to have schizophrenia compared to controls. Conclusions: Our results suggest that DRD2 genetic variation is a good indicator for schizophrenia risk and may also be used as a predictor age of onset.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objective: To replicate and refine the reported association of ankylosing spondylitis (AS) with two nonsynonymous single nucleotide polymorphisms (nsSNPs) on chromosome 16q22.1. Methods: Firstly, 730 independent UK patients with AS were genotyped for rs9939768 and rs6979 and allele frequencies were compared with 2879 previously typed historic disease controls. Secondly, the two data sets were combined in meta-analyses. Finally, 5 tagging SNPs, located between rs9939768 and rs6979, were analysed in 1604 cases and 1020 controls. Results: The association of rs6979 with AS was replicated, p=0.03, OR=1.14 (95% CI 1.01 to 1.28), and a trend for association with rs9939768 detected, p=0.06, OR=1.25 (95% CI 0.99 to 1.57). Meta-analyses revealed association of both SNPs with AS, p=0.0008, OR=1.31 (95% CI 1.12 to 1.54) and p=0.0009, OR=1.15 (95% CI 1.06 to 1.23) for rs9939768 and rs6979, respectively. New associations with rs9033 and rs868213 (p=0.00002, OR=1.23 (95% CI 1.12 to 1.36) and p=0.00002 OR=1.45 (95% CI 1.22 to 1.72), respectively, were identified. Conclusions: The region on chromosome 16 that has been replicated in the present work is interesting as the highly plausible candidate gene, tumour necrosis factor receptor type 1 (TNFR1)-associated death domain (TRADD), is located between rs9033 and rs868213. It will require additional work to identify the primary genetic association(s) with AS.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A strong association between ERAP1 and ankylosing spondylitis (AS) was recently identified by the Wellcome Trust Case Control Consortium and the Australo-Anglo-American Spondylitis Consortium (WTCCC-TASC) study. ERAP1 is highly polymorphic with strong linkage disequilibrium evident across the gene. We therefore conducted a series of experiments to try to identify the primary genetic association(s) with ERAP1. We replicated the original associations in an independent set of 730 patients and 1021 controls, resequenced ERAP1 to define the full extent of coding polymorphisms and tested all variants in additional association studies. The genetic association with ERAP1 was independently confirmed; the strongest association was with rs30187 in the replication set (P = 3.4 × 103). When the data were combined with the original WTCCC-TASC study the strongest association was with rs27044 (P = 1.1 × 10-9). We identified 33 sequence polymorphisms in ERAP1, including three novel and eight known non-synonymous polymorphisms. We report several new associations between AS and polymorphisms distributed across ERAP1 from the extended case-control study, the most significant of which was with rs27434 (P = 4.7 × 10-7). Regression analysis failed to identify a primary association clearly; we therefore used data from HapMap to impute genotypes for an additional 205 non-coding SNPs located within and adjacent to ERAP1. A number of highly significant associations (P < 5 × 10-9) were identified in regulatory sequences which are good candidates for causing susceptibility to AS, possibly by regulating ERAP1 expression. © 2009 The Author(s).

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The dissertation discusses the conceptions of place and landscape amongst Nenets living on the island of Kolguyev or being of Kolguyev descent. The conceptions are examined through the everyday life of the community, oral recollections and narration that unfold meanings related to the island. The research material has been collected in ethnographic fieldwork in 2000 2005. The duration of individual fieldworks varies from two weeks to three months and their total duration is nearly six months. The fieldwork has been conducted both on the island and in the city of Nar yan-Mar. The main methods have been participant observation and recorded and unrecorded informal interviews. In addition to the field work data, archive materials, travel accounts, and other historical texts by outsiders about Kolguyev or the Nenets living in the European side of Russia have been used as a research material. The analysis is based on the idea of the place as a meeting point of the physical features, experiences in them and collective narration about them. The concept sense of place is used to describe the interaction of these three. Lived space manifests individual s or collective sense of place. The places form different kinds of networks of meanings which are called landscapes. Hot spots are places where different meanings accumulate. Furthermore, the material is analysed using the concepts of Tale World and Story Realm by Katherine Young. The Tale World is a realm created during the Story Realm, i.e. the event of narrations. The Tale Worlds are true as such but become evaluated in the Story Realm. The Tale Worlds are seen to arise both from the physical features of a place and from oral tradition, but at the same time these worlds give meanings to the place. The Tale Worlds are one of the central ingredients for the sense of place. One of the most central hot spots in Kolguyev is the arok harbour, where most of the themes of the pre-Soviet Tale Worlds are placed: trade and interaction with the Russians, rituals of the popular religion and arrival of the first Nenets to the island. arok is also part of the landscape of the coast where the meetings of Nenets and the other(s) are generally connected. Furthermore, arok is connected to the network of amans graves but also more generally to the landscape of collective sacred and sacrificial places. Another hot spot is the population centre of Bugrino which unfolds through the evaluations of the Tale Worlds. It also is the centre of the everyday life of the community studied. The Tale Worlds of the radiant past fastens on the population centre which is described through the negative models within the genre of litany. Sacred places, that represent the possibility to meet the Otherworld or mark places were encounters with the Otherworld have taken place, generate many kinds of landscapes in the island. They fasten on the graves of the amans, sirtya tradition, and to collective sacred places with their associations. The networks are not closed systems but are given meanings and new associations continuously in narration and recollection. They form multi-level and significant landscapes which reflect the fastening of the Kolguyev Nenets in the tundra of the island. In the research material the holy places and the popular religiousness are emphasised which is one of the most significant research results. It can be seen to reflect collective resistance and the questioning of the atheistic propaganda of the Soviet years. The narration and the recollection often refer also to the discourse of the anti-religious propaganda or use its strategies. The centrality of the holy places is also based on the tenacity of the religious Tale Worlds and sense of place and to the collective significance of the religion in general.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

By now, there are still many unsolved questions about associative priming. This study used process dissociation paradigm, perceptual identification task and speeded naming task,together with near infrared spectroscopy, to investigate priming for new associations and its brain mechanisms systematically. The results showed there was interaction between level of processing and unitization in affecting associative priming. When comparing with shallow encoding unrelated word pairs, the activation of both sides of prefrontal lobe was stronger, which suggested prefrontal lobe had relations with memory for new associations. Medial temporal lobe and frontal lobe lesioned patients were tested respectively using methods of perceptual identification task and speeded naming task. Both brain regions participated in associative priming. Medial temporal lobe mediated unitization between unrelated items. Frontal lobe contributed to priming for new associations by elaborative processing, inhibiting irrelevant information, selective attending to tasks, and establishing some effective strategies. In addition, normal subjects needed to aware the relationship between study and test to form associative priming and densely memory deficit patients could not form memory for new associations. In conclusion, the results further demonstrated that perceptual representation system could not support priming for new associations alone. Medial temporal lobe and frontal lobe played roles in priming for new associations, and there was some relation between associative priming and conscious retrieval processing.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The authors propose a new phyiosociologic interpretation of Juniperas comniunis subsp. hemisphaerica and Juniperus sabina shrublands in the Djurdjura. They make up two new associations: the Cynosuro balansae-Juniperetun, hemisphaericae and the Daphno oleoidis-Juniperetum sabinae, belonging to the new alliance Lonicero kabylicae-Juniperion hemisphaericae included in the order Querco Cedretalia atlanticae. The ecologic and biogeograpbic value of these communities is analized in a Westem-mediterrancan context as well as their dynamic importance. On this mountain, they correspond to ihe preforested level of cedar forests. For this reason, an attempt to inlerprel Kabylian cedar forests as a whole was made they belong to the new association Senecio perralderlani-Cedretum atlanticae. A diachronic evaluation of changes in native plant communities over a 30 year period is made, in particular as related to the creation of several local structures to protect natural resources.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Latent inhibition (LI) is a behavioural paradigm in which repeated exposure to a stimulus without consequence inhibits the formation of any new associations with that stimulus. To the extent that LI reflects a process of learning to ignore irrelevant stimuli, disrupted LI has been suggested as an animal model for the attentional deficits observed in schizophrenia. The antipsychotic potential of cholecystokinin (CCK) stems from its colocalization with dopamine (DA) in the mesolimbic pathway, where it demonstrates both excitatory and inhibitory effects on dopaminergic activity. This may be explained by mediation through different receptor subtypes. A variety of hypotheses has emerged regarding the potential clinical application of subtype-selective CCK-based drugs. The present experiments examined the effects on LI of two selective CCKA ligands: PD-140,548 (a CCKA antagonist, Experiment 1: 0.001, 0.01, and 0.1 mg/kg) and A-71623 (a CCKA agonist, Experiment 2: 0.02, 0.05, and 0.1 mg/kg). In both experiments, the effects of haloperidol (0.1 mg/kg) were also investigated. Animals receiving 0.1 mg/kg of haloperidol or 0.001 or 0.1 mg/kg (but not 0.01 mg/kg) of PD-140,548 treated the preexposed stimulus as irrelevant after a low number of preexposures. In contrast, no facilitatory effect on LI was detectable at any of the A-71623 doses. The finding that A-71623 failed to enhance LI indicates that it is unlikely that this compound would have any antipsychotic effect within the clinical setting. Considering the facilitatory effect exerted by PD-140,548 on LI, it is probable that the inhibition of CCK activity might prove a more promising strategy for the pharmacological treatment of schizophrenia.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

RESUMO - Objetivos: Anualmente morrem cerca de 1,3 milhões de pessoas, a nível mundial, devido aos acidentes de viação. Também mais de 20 milhões de pessoas sofrem ferimentos ligeiros ou graves devido aos acidentes de viação que resultam em incapacidade temporária ou permanente. Desta forma, consideram-se os acidentes de viação, um grave problema de saúde pública, com custos elevados para as sociedades afetando a saúde das populações e economias de cada país. Este estudo pretendeu descrever e caracterizar os condutores de veículos ligeiros, residentes em Portugal Continental, abrangendo características sociodemográficas, experiência de condução e questões relativas a atitudes, opiniões e comportamentos. Por outro lado procurou-se analisar a associação entre as opiniões, atitudes e comportamentos, auto reportados e a ocorrência de um acidente de viação nos últimos três anos a fim de construir um modelo final preditivo do risco de sofrer um acidente de viação. Método: Foi realizado um estudo observacional analítico transversal baseado num questionário traduzido para a língua portuguesa e com origem no projeto europeu SARTRE 4. A população-alvo foram todos os condutores de veículos ligeiros possuidores de uma licença de condução e residentes em Portugal Continental, baseado numa amostra de igual dimensão à definida no estudo europeu SARTRE 4 (600 condutores de veículos ligeiros). Das 52 perguntas existentes, selecionaram-se pela análise de componentes principais (ACP) variáveis potencialmente independentes e complementares para as componentes opiniões, atitudes e comportamentos. Para além das medidas descritivas usuais, recorreu-se à regressão logística binária para analisar associações e obter um modelo que permitisse estimar a probabilidade de sofrer um acidente rodoviário em função das variáveis selecionadas referentes às opiniões, atitudes e comportamentos auto reportados. Resultados: Dos 612 condutores inquiridos, 62,7% (383) responderam não ter sofrido nenhum acidente de viação nos últimos três anos enquanto 37,3% (228) respondeu ter estado envolvido em pelo menos um acidente de viação com danos materiais ou feridos, no mesmo período. De uma forma geral, o típico condutor que referiu ter sofrido um acidente nos últimos três anos é homem com mais de 65 anos de idade, com o 1º ensino básico, viúvo e sem filhos, não empregado e reside numa área urbana. Os condutores residentes numa área suburbana apresentaram um risco 5,368 mais elevado de sofrer um acidente de viação em relação aos condutores que habitam numa zona rural (IC 95%: 2,344-12,297; p<0,001). Os condutores que foram apenas submetidos uma vez a um controlo de álcool, nos últimos três anos, durante o exercício da condução apresentaram um risco 3,009 superior de sofrer um acidente de viação em relação aos condutores que nunca foram fiscalizados pela polícia (IC 95%: 1,949-4,647, p<0,001). Os condutores que referiram muito frequentemente parar para dormir quando se sentem cansados a conduzir têm uma probabilidade inferior de 81% de sofrer um acidente de viação em relação aos condutores que nunca o fazem (IC 95%: 0,058-0,620; p=0,006). Os condutores que quando cansados raramente bebem um café/bebida energética têm um risco de 4,829 superior de sofrer um acidente de viação do que os condutores que sempre o referiram fazer (IC 95%:1,807-12,903; p=0,002). Conclusões: Os resultados obtidos em relação aos fatores comportamentais vão ao encontro da maioria dos fatores de risco associados aos acidentes de viação referidos na literatura. Ainda assim, foram identificadas novas associações entre o risco de sofrer um acidente e as opiniões e as atitudes auto reportadas que através de estudos de maiores dimensões populacionais poderão vir a ser mais exploradas. Este trabalho vem reforçar a necessidade urgente de novas estratégias de intervenção, principalmente na componente comportamental, direcionadas aos grupos de risco, mantendo as existentes.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

La présente thèse examine les liens entre le sommeil, la mémoire épisodique et les rêves. Dans une première étude, nous utilisons les technologies de la réalité virtuelle (RV) en liaison avec un paradigme de privation de sommeil paradoxal et de collecte de rêve en vue d'examiner l'hypothèse que le sommeil paradoxal et le rêve sont impliqués dans la consolidation de la mémoire épisodique. Le sommeil paradoxal a été associé au rappel des aspects spatiaux des éléments émotionnels de la tâche RV. De la même façon, l'incorporation de la tâche RV dans les rêves a été associée au rappel des aspects spatiaux de la tâche. De plus, le rappel des aspects factuels et perceptuels de la mémoire épisodique, formé lors de la tâche VR, a été associé au sommeil aux ondes lentes. Une deuxième étude examine l'hypothèse selon laquelle une fonction possible du rêve pourrait être de créer de nouvelles associations entre les éléments de divers souvenirs épisodiques. Un participant a été réveillé 43 fois lors de l'endormissement pour fournir des rapports détaillés de rêves. Les résultats suggèrent qu'un seul rêve peut comporter, dans un même contexte spatiotemporel, divers éléments appartenant aux multiples souvenirs épisodiques. Une troisième étude aborde la question de la cognition lors du sommeil paradoxal, notamment comment les aspects bizarres des rêves, qui sont formés grâce aux nouvelles combinaisons d'éléments de la mémoire épisodique, sont perçus par le rêveur. Les résultats démontrent une dissociation dans les capacités cognitives en sommeil paradoxal caractérisée par un déficit sélectif dans l'appréciation des éléments bizarres des rêves. Les résultats des quatre études suggèrent que le sommeil aux ondes lentes et le sommeil paradoxal sont différemment impliqués dans le traitement de la mémoire épisodique. Le sommeil aux ondes lentes pourrait être implique dans la consolidation de la mémoire épisodique, et le sommeil paradoxal, par l'entremise du rêve, pourrais avoir le rôle d'introduire de la flexibilité dans ce système mnémonique.