A steady supply of hosts at the susceptible stage for parasitism is a major component of mass rearing parasitoids for biological control programs. Here we describe the effects of storing 5th instar Plodia interpunctella larvae in dormancy on subsequent host development in the context of host colony maintenance and effects of the duration of host dormancy on the development of Habrobracon hebetor parasitoids reared from dormant hosts. We induced dormancy with a combination of short daylength (12L:12D) and lower temperature (15°C), conditions known to induce diapause in this species, and held 5th instar larvae of P. interpunctella for a series of dormancy durations ranging from 15 to 105 days. Extended storage of dormant 5th instar larvae had no significant impacts on survival, development, or reproductive potential of P. interpunctella, reinforcing that dormant hosts have a substantial shelf life. This ability to store hosts in dormancy for more than 3 months at a time without strong negative consequences reinforces the promise of using dormancy to maintain host colonies. The proportion of hosts parasitized by H. hebetor did not vary significantly between non-dormant host larvae and dormant host larvae stored for periods as long as 105 days. Concordant with a prior study, H. hebetor adult progeny production from dormant host larvae was higher than the number of progeny produced on non-dormant host larvae. There were no differences in size, sex ratio, or reproductive output of parasitoids reared on dormant hosts compared to non-dormant hosts stored for up to 105 days. Larval development times of H. hebetor were however longer when reared on dormant hosts compared to non-dormant hosts. Our results agree with other studies showing using dormant hosts can improve parasitoid mass rearing, and we show benefits for parasitoid rearing even after 3 months of host dormancy.

Malnutrition among adolescents is often associated with inadequate dietary diversity (DD). We aimed to explore the prevalence of inadequate DD and its socio-economic determinants among adolescent girls and boys in Bangladesh. A cross-sectional survey was conducted during the 2018–19 round of national nutrition surveillance in Bangladesh. Univariate and multivariable logistic regression was performed to identify the determinants of inadequate DD among adolescent girls and boys separately. This population-based survey covered eighty-two rural, non-slum urban and slum clusters from all divisions of Bangladesh. A total of 4865 adolescent girls and 4907 adolescent boys were interviewed. The overall prevalence of inadequate DD was higher among girls (55⋅4 %) than the boys (50⋅6 %). Moreover, compared to boys, the prevalence of inadequate DD was higher among the girls for almost all socio-economic categories. Poor educational attainment, poor maternal education, female-headed household, household food insecurity and poor household wealth were associated with increased chances of having inadequate DD in both sexes. In conclusion, more than half of the Bangladeshi adolescent girls and boys consumed an inadequately diversified diet. The socio-economic determinants of inadequate DD should be addressed through context-specific multisectoral interventions.

The World Health Organization set a target of a 15% relative reduction in the prevalence of insufficient physical activity (IPA) by 2025 among adolescents and adults globally. In Bangladesh, there are no national estimates of the prevalence of IPA among adolescents. The aim of this study was to estimate the prevalence of and risk factors associated with IPA among adolescent girls and boys. Data for 4865 adolescent girls and 4907 adolescent boys, collected as a part of a National Nutrition Surveillance in 2018–19, were analysed for this study. A modified version of the Global Physical Activity Questionnaire (GPAQ) was used to collect physical activity data. The World Health Organization recommended cut-off points were used to estimate the prevalence of IPA. Bivariate and multivariable logistic regression was performed to identify factors associated with IPA. Prevalences of IPA among adolescent girls and boys were 50.3% and 29.0%, respectively, and the prevalence was significantly higher among early adolescents (10–14 years) than late adolescents (15–19 years) among both boys and girls. The IPA prevalence was highest among adolescents living in non-slum urban areas (girls: 77.7%; boys: 64.1%). For both boys and girls, younger age, non-slum urban residence, higher paternal education and increased television viewing time were significantly associated with IPA. Additionally, residing in slums was significantly associated with IPA only among the boys. Higher maternal education was associated with IPA only among the girls. This study identified several modifiable risk factors associated with IPA among adolescent boys and girls in Bangladesh. These factors should be addressed through comprehensive public health interventions to promote physical activity among adolescent girls and boys.

We are reporting an approach to prepare bulk foils of α″-Fe16N2 that can be directly obtained from a melt spinning process. The diffraction peaks from α″-Fe16N2 phase were found in X-ray diffraction spectrum of the foil, for which a nitrogen composition of 8.7at% was found by Auger electron spectroscopy. The microstructure of this melt spun foil was analyzed. We found 600 nm subgrains inside 8 μm grains for this foil. The coercivity of the α″-Fe16N2 foil was found as 222 Oe with a saturation magnetization of 223 emu/g. We analyzed the coercivity based on the microstructure and proposed a model to explain how to further improve it in melt spun FeN foils.

The brain, a mixture of neural and glia cells, vasculature, and cerebrospinal fluid (CSF), is one of the most complex organs in the human body. To understand brain responses to traumatic injuries and diseases of the central nervous system it is necessary to develop accurate mathematical models and corresponding computer simulations which can predict brain biomechanics and help design better diagnostic and therapeutic protocols. So far brain tissue has been modeled as either a poroelastic mixture saturated by CSF or as a (visco)-elastic solid. However, it is not obvious which model is more appropriate when investigating brain mechanics under certain physiological and pathological conditions. In this paper we study brain’s mechanics by using a Kelvin-Voight (KV) model for a one-phase viscoelastic solid and a Kelvin-Voight-Maxwell-Biot (KVMB) model for a two-phase (solid and fluid) mixture, and explore the limit between these two models. To account for brain’s evolving microstructure, we replace in the equations of motion the classic integer order time derivatives by Caputo fractional order derivatives and thus introduce corresponding fractional KV and KVMB models. As in soil mechanics we use the displacements of the solid phase in the classic (fractional) KVMB model and respectively of the classic (fractional) KV model to define a poroelastic-viscoelastic limit. Our results show that when the CSF and brain tissue in the classic (fractional) KVMB model have similar speeds, then the model is indistinguishable from its equivalent classic (fractional) KV model.