Crowding induces behavioral and lasting morphological and chromatic changes in insects. This study examined how larval rearing density of Propylea dissecta (Mulsant 1850) affected food choice and ...development duration, hypothesizing that larvae under stress will opt for lower quality food as larval density increases. Larvae were reared at various densities under three crowding treatments: direct physical, indirect physical, and chemical tracks. In each treatment, larvae experienced crowding at densities of 0, 2, 4, 6, 8, 10 and 12 individuals per arena. Fourth stage larvae were provided with food choice of aphids, heterospecific eggs and conspecific eggs. Significant effect of crowding on total development duration, first consumption time and first food consumption were observed. Decrease in development duration at densities of 4 and 6 and increase in development duration at low and high densities were observed in direct physical crowding. Indirect physical and chemical crowding yield the shortest development duration at densities of 8, 10, and 12, when compared to low and moderate crowding. First encounter time increased with increasing chemical tracks concentration, while first consumption time decreases with crowding across all groups. First consumed food was also significantly influenced by crowding, suggesting a negative impact on larval food choice. Our results indicate that crowding among larvae leads to a longer development duration and show less selectivity in their food choices.
Here, in the present report, an attempt has been made to explore a quantitative correlation between the Urbach energy (E U) and the dielectric constant (ε) by using a Bohr-like model for ...Cr-substituted PrFeO3. In order to quantify the E U and ε values, optical absorption spectroscopy, Raman scattering, and dielectric measurements have been carried out. The dielectric experiments suggest a decrease in ε values, whereas a systematic increase in the values of EU has been observed with Cr doping. It is shown that E U exhibits inverse square dependence with ε (E U ∼ 1/ε2) up to a certain fraction of Cr (<20%), which is found to be consistent with the quantitative relation obtained by the Bohr-like model. The present investigation explores quantitatively the relationship between ε and E U, which has significant importance for improving the dielectric and optical properties in strongly correlated systems.
The variation of dielectric constant (εr) in the low-frequency region (∼106 Hz) in Hf-substituted BaTiO3 has been modelled considering the electronic disorder in the form of Urbach energy (E U) with ...the help of a Bohr-like model. Optical absorption spectroscopy has been employed in order to estimate E U and also the band gap (E g), which are found to scale systematically with Hf incorporation, whereas dielectric measurements reveal a decrease in the value of εr observed in the frequency range up to 106 Hz with Hf substitution in these prepared samples. The model predicts E U ∝ 1/εr 2 and E g ∝ 1/εr 2, which agrees with the variation of the corresponding experimental values. Thus, the present work contributes to understanding the interconnection between the optical and dielectric properties of such materials and successfully demonstrates the decrease in dielectric constant with increasing disorder.
▶ Identified the relevant pore structure features of pervious concretes, provided methodologies to extract those, and quantified the influence of these features on compressive response. ▶ A model for ...stress–strain relationship of pervious concretes, and relationship between model parameters and parameters of the stress–strain relationship developed. ▶ Statistical model for compressive strength as a function of pore structure features; and a stochastic model for the sensitivity of pore structure features in strength prediction.
Properties of a random porous material such as pervious concrete are strongly dependent on its pore structure features, porosity being an important one among them. This study deals with developing an understanding of the material structure–compressive response relationships in pervious concretes. Several pervious concrete mixtures with different pore structure features are proportioned and subjected to static compression tests. The pore structure features such as pore area fractions, pore sizes, mean free spacing of the pores, specific surface area, and the three-dimensional pore distribution density are extracted using image analysis methods. The compressive stress–strain response of pervious concretes, a model to predict the stress–strain response, and its relationship to several of the pore structure features are outlined. Larger aggregate sizes and increase in paste volume fractions are observed to result in increased compressive strengths. The compressive response is found to be influenced by the pore sizes, their distributions and spacing. A statistical model is used to relate the compressive strength to the relevant pore structure features, which is then used as a base model in a Monte-Carlo simulation to evaluate the sensitivity of the predicted compressive strength to the model terms.
Adoptive T cell transfer (ACT) is a new area of transfusion medicine involving the infusion of lymphocytes to mediate antitumor, antiviral, or anti-inflammatory effects. The field has rapidly ...advanced from a promising form of immuno-oncology in preclinical models to the recent commercial approvals of chimeric antigen receptor (CAR) T cells to treat leukemia and lymphoma. This Review describes opportunities and challenges for entering mainstream oncology that presently face the CAR T field, with a focus on the challenges that have emerged over the past several years.
Developmental and growth rates are known to vary in response to genetic, developmental, physiological and environmental factors. However, developmental variations that exist within a cohort under any ...constant rearing condition are not so well investigated. A few such prominent polymorphisms have been studied, but not the subtle ones. The current study investigates the presence of such varying rates of development, slow and fast, in a cohort reared under constant conditions in two ladybirds, Cheilomenes sexmaculata and Propylea dissecta. Our results reveal slow and fast developers in the cohorts of each species and the ratio of slow and fast developers was similar. Slow developers showed a female biased sex ratio. The two developmental variants differed significantly in juvenile duration only in the first instar and the pupal stage, though variations in developmental time were observed in all stages. Fecundity was higher in slow developers, but developmental rates did not affect egg viability. The similar ratio in both ladybirds indicates it to be a result of either presence of a constant ratio across species or an effect of the similar rearing environment.
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