Pre-clinical evaluation of a whole-parasite vaccine to control human babesiosis

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Plasma plant sterols serve as poor markers of cholesterol absorption in man

The validation of the use of plasma plant sterols as a marker of cholesterol absorption is frail. Nevertheless, plant sterol concentrations are routinely used to describe treatment-induced changes in cholesterol absorption. Their use has also been advocated as a clinical tool to tailor cholesterol-lowering therapy. Prior to wider implementation, however, the validity of plant sterols as absorption markers needs solid evaluation. Therefore, we compared plasma plant sterol concentrations to gold-standard stable isotope-determined cholesterol absorption. Plasma campesterol/TC concentrations (camp/TC) were measured in a population of 175 mildly hypercholesterolemic individuals (age: 59.7 ± 5.6 years; BMI: 25.5 ± 2.9kg/m²; LDL-C: 4.01 ± 0.56 mmol/l). We compared cholesterol absorption according to the plasma dual-isotope method in subjects with the highest camp/TC concentrations (N = 41, camp/TC: 2.14 ± 0.68 μg/mg) and the lowest camp/TC concentrations (N = 39, camp/TC: 0.97 ± 0.22 μg/mg). Fractional cholesterol absorption did not differ between the groups (24 ± 12% versus 25 ± 16%, P = 0.60), nor was it associated with plasma camp/TC concentrations in the total population of 80 individuals (β = 0.13; P = 0.30, adjusted for BMI and plasma triglycerides). Our findings do not support a relation between plasma plant sterol concentrations and true cholesterol absorption and, therefore, do not favor the use of these sterols as markers of cholesterol absorption. This bears direct consequences for the interpretation of earlier studies, as well as for future studies targeting intestinal regulation of cholesterol metabolism.     

Synergy between parasitoids and pathogens for biological control of Helicoverpa armigera in chickpea

The chickpea pod borer, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), is an important pest of many legume crops, including chickpea, Cicer arietinum L. (Fabaceae). We field-tested the efficacy of two pathogens, Helicoverpa armigera nucleopolyhedrosis virus (HaNPV) and Bacillus thuringiensis Berliner subsp. kurstaki (Btk), both alone and in combination with the parasitoid Habrobracon hebetor Say (Hh) (Hymenoptera: Braconidae), for control of H. armigera larvae in chickpea fields. A randomized complete block design was used at two sites, so that wasp release treatments at one site would not contaminate pathogen-only treatments at the other. Pathogens were applied when most pest larvae were in the second instar, and wasp releases were made 2 days later. Number of H. armigera larvae per plant, number of damaged pods, yield (kg ha⁻¹), treatment cost (US$ ha⁻¹), and benefit:cost ratio were all determined. Treatments separated significantly at 14 days after treatment, with the HaNPV+Hh and Btk+Hh treatments providing the best control, suggesting a synergistic impact of the wasp and the pathogens when applied together. These treatments also produced the fewest damaged pods, the highest yields, and the greatest yield increments in comparison to untreated controls. However, costs were also highest for these combined treatments, which reduced their net benefit in comparison to use of Hh or Btk alone, although more efficient mass production of the pathogens might make combined applications feasible. We conclude that both HaNPV and Btk are suitable for integration with releases of H. hebetor against H. armigera in chickpea fields, provided parasitoid releases are delayed until 2 days after pathogen application.     

Characterization of Insecticidal Genes of Bacillus thuringiensis Strains Isolated from Arid Environments

This study aimed at characterizing the insecticidal genes of eight Bacillus thuringiensis isolates that were recovered from the local environment of western Saudi Arabia. The screening for the presence of lepidopteran-specific cry1A family and vip3A genes, dipteran-specific cry4 family and coleopteran-specific cry3A, vip1A and vip2A genes, was carried out by PCR. All eight isolates produced PCR products that confirmed the presence of cry1Aa, cry1Ab, cry1Ac, cry4A, cry4B genes, but not cry3A, vip1A and vip2A genes. However, three isolates only were found to carry vip3A genes as revealed by PCR. The observation of cry1 and cry4 genes suggests that these eight isolates may have dual activity against Lepidoptera and Diptera species, while three isolates possessed vip3 genes in addition to cry1 and cry4 which suggests that these three isolates have toxic crystals and vegetative proteins. The results of this study are interesting in the sense that they may help developing new strategies for controlling insects of economic and medical importance in Saudi Arabia, using B. thuringiensis strains that naturally exist in the local environment instead of the current control strategies that are based solely on chemical insecticides.     

External morphology of the freshwater prawn Caridina africana collected from Egypt

Abstract

The present paper deals with the external morphology of the freshwater prawn Caridina africana collected from al-Fayum oasis, Egypt. The study includes some morphometric and meristic characters.     

Further observations on immunization of sheep against Schistosoma mansoni and S. bovis using irradiation-attenuated schistosomula of homologous and heterologous species.

This paper describes further characteristics of the immunization of sheep against schistosomes using live, irradiation schistosomula. Sheep immunized with a non-virulent strain of Schistosoma mattheei were protected against a more virulent strain of the same species for over a year. As there was no evidence that the irradiated parasites were able to persist this long, it was concluded that the vaccine had induced a sterile resistance. Heterologous vaccination, using irradiated S. mattheei schistosomula to immunize against S. bovis or irradiated S. mansoni schistosomula to immunize against S. mattheei, failed to induce any protection.     

Is body size a good indicator of fecundity in the genus Thaumetopoea? A story told by two intrageneric Mediterranean forest defoliators

1. Body size correlates with several factors such as reproductive fitness, environmental changes, the quality and quantity of food during critical development stages, and the feeding season. For the Palearctic moths of the genus Thaumetopoea (Lepidoptera; Notodontidae), the larval development is crucial and differs between species according to their feeding season; larvae of the pine processionary moth Thaumetopoea pityocampa (Denis & Schiffermüller 1775) feed during winter while larvae of its congeneric cedar processionary moth Thaumetopoea bonjeani (Powell 1922) develop during summer in North Africa.
2. This discrepancy in lifecycles leads to different reproductive traits such as egg batch length, number of eggs per batch, eggs protection mechanisms and female body size.
3. According to Darwin's fecundity advantage hypothesis (1871), female body size should have a positive influence on reproductive fitness, since larger females supposedly have higher fecundity. The universal allometric scaling phenomenon rule proposed by Rensch (1950) predicts that the degree of sexual size dimorphism tends to decrease with the increase of female body size.
4. Here, two morphometrical parameters that is, body size and scale size, estimated from body measurements of individuals of both species, feeding on the same host Atlantic cedar Cedrus atlantica (Manetti & Carrière 1855) (Pinales; Pinaceae) in Algeria were proposed. The aim was to find out traits that might rule the competition for food and space, in particularly fecundity and body size.
5. Results of the present study highlight a female-biased sexual size dimorphism in both species. The positive correlation between female body size and fecundity shown in this study weakly supports Darwin's hypothesis. Finally, the intrageneric test performed leads to conclude that Rensch's rule does not hold in the considered species.

     

Fabrication,characterization and application of laccase–nylon 6,6/Fe3+ composite nanofibrous membrane for 3,3′-dimethoxybenzidine detoxification

Bioprocess and Biosystems Engineering - In this study, laccase was immobilized on nylon 6,6/Fe3+ composite (NFC) nanofibrous membrane and used for the detoxification of...     

Bayesian Analysis of Composite Quantile Regression

This paper introduces a Bayesian approach for composite quantile regression employing the skewed Laplace distribution for the error distribution. We use a two-level hierarchical Bayesian model for coefficient estimation and future selection which assumes a prior distribution that favors sparseness. An efficient Gibbs sampling algorithm is developed to update the unknown quantities from the posteriors. The proposed approach is illustrated via simulation studies and two real datasets. Results indicate that the proposed approach performs quite good in comparison to the other approaches.