151 research outputs found

    Sustained Effects of Incredible Years as a Preventive Intervention in Preschool Children with Conduct Problems

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    The present study evaluated preventive effects of the Incredible Years program for parents of preschool children who were at risk for a chronic pattern of conduct problems, in the Netherlands. In a matched control design, 72 parents of children with conduct problems received the Incredible Years program. These families (intervention group) were compared with 72 families who received care as usual (control group). Two years after termination of the intervention, it appeared that observed and selfrated parenting skills were significantly improved in the intervention group. Likewise, in this group, observed child conduct problems showed sustained intervention effects. The decrease in observed critical parenting mediated the decrease in observed child conduct problems over time. In addition, it appeared that parental influence increased over time

    Tri-trophic effects of inter- and intra-population variation in defence chemistry of wild cabbage (Brassica oleracea)

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    The effect of direct chemical defences in plants on the performance of insect herbivores and their natural enemies has received increasing attention over the past 10Ā years. However, much less is known about the scale at which this variation is generated and maintained, both within and across populations of the same plant species. This study compares growth and development of the large cabbage butterfly, Pieris brassicae, and its gregarious pupal parasitoid, Pteromalus puparum, on three wild populations [Kimmeridge (KIM), Old Harry (OH) and Winspit (WIN)] and two cultivars [Stonehead (ST), and Cyrus (CYR)] of cabbage, Brassica oleracea. The wild populations originate from the coast of Dorset, UK, but grow in close proximity with one another. Insect performance and chemical profiles were made from every plant used in the experiment. Foliar glucosinolates (GS) concentrations were highest in the wild plants in rank order WINĀ >Ā OHĀ >Ā KIM, with lower levels found in the cultivars. Caterpillar-damaged leaves in the wild cabbages also had higher GS levels than undamaged leaves. Pupal mass in P. brassicae varied significantly among populations of B. oleracea. Moreover, development time in the host and parasitoid were correlated, even though these stages are temporally separated. Parasitoid adult dry mass closely approximated the development of its host. Multivariate statistics revealed a correlation between pupal mass and development time of P. brassicae and foliar GS chemistry, of which levels of neoglucobrassicin appeared to be the most important. Our results show that there is considerable variation in quantitative aspects of defensive chemistry in wild cabbage plants that is maintained at very small spatial scales in nature. Moreover, the performance of the herbivore and its parasitoid were both affected by differences in plant quality

    Estimating the delay between host infection and disease (incubation period) and assessing its significance to the epidemiology of plant diseases.

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    Knowledge of the incubation period of infectious diseases (time between host infection and expression of disease symptoms) is crucial to our epidemiological understanding and the design of appropriate prevention and control policies. Plant diseases cause substantial damage to agricultural and arboricultural systems, but there is still very little information about how the incubation period varies within host populations. In this paper, we focus on the incubation period of soilborne plant pathogens, which are difficult to detect as they spread and infect the hosts underground and above-ground symptoms occur considerably later. We conducted experiments on Rhizoctonia solani in sugar beet, as an example patho-system, and used modelling approaches to estimate the incubation period distribution and demonstrate the impact of differing estimations on our epidemiological understanding of plant diseases. We present measurements of the incubation period obtained in field conditions, fit alternative probability models to the data, and show that the incubation period distribution changes with host age. By simulating spatially-explicit epidemiological models with different incubation-period distributions, we study the conditions for a significant time lag between epidemics of cryptic infection and the associated epidemics of symptomatic disease. We examine the sensitivity of this lag to differing distributional assumptions about the incubation period (i.e. exponential versus Gamma). We demonstrate that accurate information about the incubation period distribution of a pathosystem can be critical in assessing the true scale of pathogen invasion behind early disease symptoms in the field; likewise, it can be central to model-based prediction of epidemic risk and evaluation of disease management strategies. Our results highlight that reliance on observation of disease symptoms can cause significant delay in detection of soil-borne pathogen epidemics and mislead practitioners and epidemiologists about the timing, extent, and viability of disease control measures for limiting economic loss.ML thanks the Institut Technique franƧais de la Betterave industrielle (ITB) for funding this project. CAG and JANF were funded by the UKā€™s Biotechnology and Biological Sciences Research Council (BBSRC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    A theoretical entropy score as a single value to express inhibitor selectivity

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    <p>Abstract</p> <p>Background</p> <p>Designing maximally selective ligands that act on individual targets is the dominant paradigm in drug discovery. Poor selectivity can underlie toxicity and side effects in the clinic, and for this reason compound selectivity is increasingly monitored from very early on in the drug discovery process. To make sense of large amounts of profiling data, and to determine when a compound is sufficiently selective, there is a need for a proper quantitative measure of selectivity.</p> <p>Results</p> <p>Here we propose a new theoretical entropy score that can be calculated from a set of IC<sub>50 </sub>data. In contrast to previous measures such as the 'selectivity score', Gini score, or partition index, the entropy score is non-arbitary, fully exploits IC<sub>50 </sub>data, and is not dependent on a reference enzyme. In addition, the entropy score gives the most robust values with data from different sources, because it is less sensitive to errors. We apply the new score to kinase and nuclear receptor profiling data, and to high-throughput screening data. In addition, through analyzing profiles of clinical compounds, we show quantitatively that a more selective kinase inhibitor is not necessarily more drug-like.</p> <p>Conclusions</p> <p>For quantifying selectivity from panel profiling, a theoretical entropy score is the best method. It is valuable for studying the molecular mechanisms of selectivity, and to steer compound progression in drug discovery programs.</p

    Cancer stem cell metabolism: A potential target for cancer therapy

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    Ā© 2016 The Author(s). Cancer Stem cells (CSCs) are a unipotent cell population present within the tumour cell mass. CSCs are known to be highly chemo-resistant, and in recent years, they have gained intense interest as key tumour initiating cells that may also play an integral role in tumour recurrence following chemotherapy. Cancer cells have the ability to alter their metabolism in order to fulfil bio-energetic and biosynthetic requirements. They are largely dependent on aerobic glycolysis for their energy production and also are associated with increased fatty acid synthesis and increased rates of glutamine utilisation. Emerging evidence has shown that therapeutic resistance to cancer treatment may arise due to dysregulation in glucose metabolism, fatty acid synthesis, and glutaminolysis. To propagate their lethal effects and maintain survival, tumour cells alter their metabolic requirements to ensure optimal nutrient use for their survival, evasion from host immune attack, and proliferation. It is now evident that cancer cells metabolise glutamine to grow rapidly because it provides the metabolic stimulus for required energy and precursors for synthesis of proteins, lipids, and nucleic acids. It can also regulate the activities of some of the signalling pathways that control the proliferation of cancer cells. This review describes the key metabolic pathways required by CSCs to maintain a survival advantage and highlights how a combined approach of targeting cellular metabolism in conjunction with the use of chemotherapeutic drugs may provide a promising strategy to overcome therapeutic resistance and therefore aid in cancer therapy

    The direction of effects between perceived parental behavioral control and psychological control and adolescentsā€™ self-reported GAD and SAD symptoms

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    This study examined the direction of effects and age and sex differences between adolescentsā€™ perceptions of parental behavioral and psychological control and adolescentsā€™ self-reports of generalized anxiety disorder (GAD) and separation anxiety disorder (SAD) symptoms. The study focused on 1,313 Dutch adolescents (early-to-middle cohort nĀ =Ā 923, 70.3%; middle-to-late cohort nĀ =Ā 390, 29.7%) from the general population. A multi-group, structural equation model was employed to analyze the direction of the effects between behavioral control, psychological control and GAD and SAD symptoms for the adolescent cohorts. The current study demonstrated that a unidirectional child effect model of the adolescentsā€™ GAD and SAD symptoms predicting parental control best described the data. Additionally, adolescent GAD and SAD symptoms were stronger and more systematically related to psychological control than to behavioral control. With regard to ageā€“sex differences, anxiety symptoms almost systematically predicted parental control over time for the early adolescent boys, whereas no significant differences were found between the late adolescent boys and girls

    Carbon Dioxide Utilisation -The Formate Route

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    UIDB/50006/2020 CEEC-Individual 2017 Program Contract.The relentless rise of atmospheric CO2 is causing large and unpredictable impacts on the Earth climate, due to the CO2 significant greenhouse effect, besides being responsible for the ocean acidification, with consequent huge impacts in our daily lives and in all forms of life. To stop spiral of destruction, we must actively reduce the CO2 emissions and develop new and more efficient ā€œCO2 sinksā€. We should be focused on the opportunities provided by exploiting this novel and huge carbon feedstock to produce de novo fuels and added-value compounds. The conversion of CO2 into formate offers key advantages for carbon recycling, and formate dehydrogenase (FDH) enzymes are at the centre of intense research, due to the ā€œgreenā€ advantages the bioconversion can offer, namely substrate and product selectivity and specificity, in reactions run at ambient temperature and pressure and neutral pH. In this chapter, we describe the remarkable recent progress towards efficient and selective FDH-catalysed CO2 reduction to formate. We focus on the enzymes, discussing their structure and mechanism of action. Selected promising studies and successful proof of concepts of FDH-dependent CO2 reduction to formate and beyond are discussed, to highlight the power of FDHs and the challenges this CO2 bioconversion still faces.publishersversionpublishe
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