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When a promising natural enemy of a key pest exists locally, it is a common practice in biological control (BC) to rear and release it for supplementary control in the targeted agroecosystem even though significant knowledge gaps concerning pre/post release may still exist. Incorporating genetic information into BC research fills some of these gaps. Habrobracon hebetor, a parasitoid of many economically important moths that infest stored and field crops worldwide is commonly used, particularly against the millet head miner (MHM), a key pest of millet in Sahelian countries. To advance our knowledge on how H. hebetor that occurs naturally in open-field cropping systems and grain stores as well as being mass-produced and released for MHM control, performs in millet agroecosystems in Niger we evaluated its population genetics using two mitochondrial and 21 microsatellite markers. The field samples were genetically more diverse and displayed heterozygote excess. Very few field samples had faced significant recent demographic bottlenecks. The mating system (i.e. nonrandom mating with complementary sex determination) of this species may be the major driver of these findings rather than bottlenecks caused by the small number of individuals released and the scarcity of hosts during the longlasting dry season in Niger. H. hebetor population structure was represented by several small patches and genetically distinct individuals. Gene flow occurred at local and regional scales through human-mediated and natural short-distance dispersal. These findings highlight the importance of the mating system in the genetic diversity and structure of H. hebetor populations, and contribute to our understanding of its reported efficacy against MHM in pearl millet fields.
Determining interventions to address food insecurity and poverty, as well as setting targets to be achieved in a specific time period have been a persistent challenge for development practitioners and decision makers. The present study aimed to assess the changes in food access and consumption at the household level after one-year implementation of an integrated food security intervention in three rural districts of Rwanda.
A before-and-after intervention study comparing Household Food Insecurity Access Scale (HFIAS) scores and household Food Consumption Scores (FCS) at baseline and after one year of programme implementation.
Three rural districts of Rwanda (Kayonza, Kirehe and Burera) where the Partners In Health Food Security and Livelihoods Program (FSLP) has been implemented since July 2013.
All 600 households enrolled in the FSLP were included in the study.
There were significant improvements (P<0·001) in HFIAS and FCS. The median decrease in HFIAS was 8 units (interquartile range (IQR) −13·0, −3·0) and the median increase for FCS was 4·5 units (IQR −6·0, 18·0). Severe food insecurity decreased from 78 % to 49 %, while acceptable food consumption improved from 48 % to 64 %. The change in HFIAS was significantly higher (P=0·019) for the poorest households.
Our study demonstrated that an integrated programme, implemented in a setting of extreme poverty, was associated with considerable improvements towards household food security. Other government and non-government organizations’ projects should consider a similar holistic approach when designing structural interventions to address food insecurity and extreme poverty.
The dopamine D3 receptor gene (DRD3) is a meaningful candidate gene because it unifies the dopamine and the limbic hypotheses for schizophrenia. We tested for an allelic association between schizophrenia and the DRD3 Mscl alleles, hypothesising heterogeneity between childhood/early adolescence-onset schizophrenia (CO-SZ) and adult-onset schizophrenia (A-SZ).
The frequencies of the DRD3 alleles were compared between 70 DSM-III-R schizophrenics (35 CO-SZ and 35 A-SZ) and 79 controls.
Compared with the controls, the subsample of A-SZ, but not CO-SZ, showed an over-proportion (P = 0.025) of allele 1. The association was not found in the total sample, combining the two subsamples.
Consistently with former studies, our data suggest an aetiological heterogeneity between CO-SZ and A-SZ and a possible specificity of the excess of allele 1 to the familial form of schizophrenia and to schizophrenia with a better outcome.
The aim of this study was to verify the presence and stability across life of the positive/negative distinction in early-onset schizophrenia (EO-SZ) through a longitudinal factor analysis of the schizophrenic dimensions, and to identify the factors predicting several indices of long-term outcome for EO-SZ.
Forty children consecutively referred for DSM–III–R schizophrenia (SZ) in a specific catchment area comprised the sample.
Across a 14.8-year follow-up, longitudinal factor analysis identified two separate factors corresponding to the positive and negative symptom dimensions. We also observed that: the GAS rated over the last three years of adult illness and the severity of negative symptoms during the stabilised interepisode intervals in adulthood were the indices of adult outcome that were most easily predicted; and the best childhood predictors of adult outcome were premorbid functioning and severity of positive and negative symptoms during acute episodes.
The presence of premorbid non-psychotic behaviour disturbances (NPBD) and premorbid developmental problems was not related to severity of outcome, in contrast to the former variables.
Little is known about the long-term outcome of schizophrenia that has its onset during childhood and early adolescence (early-onset schizophrenia, or EO-SZ). Whether or not EO-SZ is an aetiologically separate form of schizophrenia (SZ) is unresolved.
The study was a 14.8-year follow-up, using methods such as systematic sampling, evaluation of possible non-respondent bias, consensus best-estimate diagnoses (DSM–III–R) made independently in childhood and adulthood, measures of positive and negative dimensions, of non-psychotic behaviour disturbances (NPBD) and of developmental problems before the appearance of SZ.
There was high stability of EO-SZ (n=40) diagnoses (mean onset at 14.0 years) until adulthood (mean age at follow-up 28.8 years) but a lower stability of positive and negative schizophrenic dimensions. There was a poor outcome of EO-SZ, a strong over-representation of males but few gender differences, and no effect of age of onset on clinical features and outcome.
EO-SZ taken as a whole shows no qualitative differences to adult-onset SZ. However, a distinction through the onset of preschizophrenic developmental problems or NPBD might be a way to investigate heterogeneity within EO-SZ.