The effects of tin (Sn) additions on the growth of spinach plants

An increase in bioavailable tin in the environment could result in bioaccumulation thereof in agricultural crops, and therefore, have adverse health consequences on humans that eat these crops. The aims of the current study were thus to assess the uptake of Sn by spinach plants, and the subsequent effects this will have on the uptake of Na, Zn, K, Ca, and Mg as well as the growth of spinach plants. Spinach plants were grown in sand culture and received tin at concentrations of 0.02, 0.2, 2 and 20 mg/L along with a nutrient solution. The uptake of tin at detectible concentrations only occurred at the highest concentrations (2 and 20 mg/L), and it was mostly retained in the roots of the plants. Tin additions also resulted in no visual toxicity symptoms, and might be beneficial to biomass production. Further field trials are needed to ensure that these experimental results remain true under field conditions.     

A tetravalent dengue nanoparticle stimulates antibody production in mice

Background

Dengue is a major public health problem worldwide, especially in the tropical and subtropical regions of the world. Infection with a single Dengue virus (DENV) serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients experiencing secondary infection with a different serotype progresses to the severe form of the disease, dengue hemorrhagic fever/dengue shock syndrome. Currently, there are no licensed vaccines or antiviral drugs to prevent or treat dengue infections. Biodegradable nanoparticles coated with proteins represent a promising method for in vivo delivery of vaccines.

Findings

Here, we used a murine model to evaluate the IgG production after administration of inactivated DENV corresponding to all four serotypes adsorbed to bovine serum albumin nanoparticles. This formulation induced a production of anti-DENV IgG antibodies (p < 0.001). However, plaque reduction neutralization assays with the four DENV serotypes revealed that these antibodies have no neutralizing activity in the dilutions tested.

Conclusions

Our results show that while the nanoparticle system induces humoral responses against DENV, further investigation with different DENV antigens will be required to improve immunogenicity, epitope specicity, and functional activity to make this platform a viable option for DENV vaccines.     

Time‐shifted reproductive behaviours among fall armyworm (Noctuidae: Spodoptera frugiperda) host strains: evidence for differing modes of inheritance

The noctuid moth Spodoptera frugiperda consists of two strains associated with different larval host plants (most notably corn and rice). These strains exhibit differential temporal patterns of female calling and copulation during scotophase, with the corn strain more active earlier in the night. We investigated strain‐specific constraints in reproductive timing, mating interactions between the two strains, and the mode of inheritance of timing of female calling, male calling, copulation and oviposition. We observed an allochronic shift of all reproductive behaviours by approximately 3 h and a parallel shift of nonreproductive locomotor activity, suggesting involvement of the circadian clock. The corn strain was more variable in the timing of calling and copulation than the rice strain. Rice strain females were more restricted in the timing of copulation than rice strain males, while such differences between the sexes were not apparent in the corn strain. There were significant interactions between the strains affecting onset times of copulation and male calling. The four investigated reproductive traits differed in their modes of inheritance: timing of female and male calling exhibited strong maternal effects, timing of copulation was controlled by a combination of maternal effects and corn strain dominant autosomal factors, and timing of oviposition was inherited in a corn strain dominant fashion. We conclude that the allochronic separation of reproduction between fall armyworm strains is asymmetric, less pronounced than previously thought, and under complex genetic control.