RESUMO
This study investigated the relations between parent-child interactions and infant brain activity in the context of a frustration eliciting task. Specifically, electroencephalography (EEG) data were recorded and processed to provide alpha frontal asymmetry indicators linked with approach/avoidance emotions and motivation. These data were collected from 53 mother-infant dyads during baseline and a toy retraction task, with play interactions coded for caregiving quality indicators. Hierarchical multiple linear regression analyses indicated that infants of more sensitive/responsive mothers and those engaging in more fast-paced/active play exchanges with caregivers demonstrated a relative left frontal activation response during toy retraction. Reciprocity/synchrony and directedness (parent vs. child directed) did not account for significant amounts of toy retraction EEG asymmetry response variance. It may be that infants experience greater frustration in the context of an attractive toy being removed when their typical play exchanges with caregivers are marked by sensitivity to their needs and are physically/verbally engaging. The findings are discussed in the context of the capability model of EEG asymmetry with regard to infant EEG.
Assuntos
Lobo Frontal , Neurofisiologia , Eletroencefalografia , Feminino , Lobo Frontal/fisiologia , Humanos , Lactente , Relações Mãe-Filho/psicologia , Relações Pais-FilhoRESUMO
The INTERPRET project was a multicentre European collaboration, carried out from 2000 to 2002, which developed a decision-support system (DSS) for helping neuroradiologists with no experience of MRS to utilize spectroscopic data for the diagnosis and grading of human brain tumours. INTERPRET gathered a large collection of MR spectra of brain tumours and pseudo-tumoural lesions from seven centres. Consensus acquisition protocols, a standard processing pipeline and strict methods for quality control of the aquired data were put in place. Particular emphasis was placed on ensuring the diagnostic certainty of each case, for which all cases were evaluated by a clinical data validation committee. One outcome of the project is a database of 304 fully validated spectra from brain tumours, pseudotumoural lesions and normal brains, along with their associated images and clinical data, which remains available to the scientific and medical community. The second is the INTERPRET DSS, which has continued to be developed and clinically evaluated since the project ended. We also review here the results of the post-INTERPRET period. We evaluate the results of the studies with the INTERPRET database by other consortia or research groups. A summary of the clinical evaluations that have been performed on the post-INTERPRET DSS versions is also presented. Several have shown that diagnostic certainty can be improved for certain tumour types when the INTERPRET DSS is used in conjunction with conventional radiological image interpretation. About 30 papers concerned with the INTERPRET single-voxel dataset have so far been published. We discuss stengths and weaknesses of the DSS and the lessons learned. Finally we speculate on how the INTERPRET concept might be carried into the future.
Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Proteínas de Neoplasias/metabolismo , Neoplasias Encefálicas/classificação , Europa (Continente) , Perfilação da Expressão Gênica/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Imagem Molecular/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Heat stress exerts a profound impact on the resistance of plants to parasites. In this research, we investigated the impact of an acute transient heat stress on the resistance of the wheat line 'Molly,' which contains the R gene H13, to an avirulent Hessian fly (Mayetiola destructor (Say)) population. We found that a significant portion of Molly seedlings stressed at 40 degrees C for 6 h during or after the initial Hessian fly larval attack became susceptible to otherwise avirulent insects, whereas unstressed control plants remained 100% resistant. Specifically, 77.8, 73.3, 83.3, and 46.7% of plants heat stressed at 0, 6,12, and 24 h, respectively, after the initial larval attack became susceptible. Biochemical analysis revealed that heat stress caused a transient decrease in 12-oxo-phytodienoic acid, but an increase in salicylic acid accumulation in Molly plants. The change in phytohormones after heat stress and Hessian fly infestation was not observed in 'Newton,' a near-isogenic but Hessian fly susceptible wheat line. Instead, heat stress caused a relatively prolonged reduction in palmitoleic acid. The role of phytohormones in heat-induced loss of wheat resistance was discussed.
Assuntos
Dípteros , Temperatura Alta , Triticum/fisiologia , Animais , Ácidos Graxos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plântula/fisiologia , Estresse FisiológicoRESUMO
Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA), play important roles in plant defense against parasite attacks. Here, we studied the impact of a combination of heat stress and exogenous SA on the resistance of wheat (Triticum aestivum L.) plants to the Hessian fly [Mayetiola destructor (Say)]. We found that the wheat cultivar 'Molly', which contains the resistance gene H13, lost resistance to Hessian fly under heat stress (40°C for 3 and 6 h), and that exogenous application of SA on Molly seedlings right before heat stress can partially prevent the loss of resistance of Molly plants under heat conditions. Our findings have significant implications for understanding the dynamics of plant-insect interactions in the context of heat stress.
Assuntos
Antibiose , Dípteros/fisiologia , Temperatura Alta/efeitos adversos , Reguladores de Crescimento de Plantas/farmacologia , Ácido Salicílico/farmacologia , Triticum/fisiologia , Animais , Dípteros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Estresse Fisiológico , Triticum/crescimento & desenvolvimentoRESUMO
A computer-based decision support system to assist radiologists in diagnosing and grading brain tumours has been developed by the multi-centre INTERPRET project. Spectra from a database of 1H single-voxel spectra of different types of brain tumours, acquired in vivo from 334 patients at four different centres, are clustered according to their pathology, using automated pattern recognition techniques and the results are presented as a two-dimensional scatterplot using an intuitive graphical user interface (GUI). Formal quality control procedures were performed to standardize the performance of the instruments and check each spectrum, and teams of expert neuroradiologists, neurosurgeons, neurologists and neuropathologists clinically validated each case. The prototype decision support system (DSS) successfully classified 89% of the cases in an independent test set of 91 cases of the most frequent tumour types (meningiomas, low-grade gliomas and high-grade malignant tumours--glioblastomas and metastases). It also helps to resolve diagnostic difficulty in borderline cases. When the prototype was tested by radiologists and other clinicians it was favourably received. Results of the preliminary clinical analysis of the added value of using the DSS for brain tumour diagnosis with MRS showed a small but significant improvement over MRI used alone. In the comparison of individual pathologies, PNETs were significantly better diagnosed with the DSS than with MRI alone.