Spacing behaviour of juvenile corn mice, Calomys musculinus, at the beginning of the breeding period, in absence of adult males

This research was carried out to examine the hypothesis that the absence of fathers promotes a different spacing behaviour in juveniles Calomys musculinus at the beginning of the breeding period. The study was carried out in four 0.25-ha enclosures (two control and two experimental), in a natural pasture, between November 2003 and February 2004. In this study the fathers were removed from the experimental enclosures after juveniles were born. Home-range size depended on sex of juveniles and treatment (father removal). In control and experimental enclosures, female home-range sizes were always smaller than male home-ranges. Male home-ranges were always larger in experimental enclosures than in control enclosures. Treatment and overlap type (intra- and inter-sexual) were not independent. The overlap proportions of male home-ranges were greatest in experimental enclosures than in control enclosures, in both the overlap types (male/male, males/females). The intra- (females/females) and inter-sexual (females/males) overlap proportions of female home-ranges were independent of treatment. In C. musculinus, at the beginning of the breeding period and in absence of adult males, juvenile males increase their home-range size and therefore the degree of inter- and intra-sexual home-range overlap as a mechanism for enlarging the number of receptive females that they encounter.     

The combined luminol/isoluminol chemiluminescence method for differentiating between extracellular and intracellular oxidant production by neutrophils

To address the question why isoluminol, but not luminol, failed to detect oxidants produced intracellularly, differences between these luminophores were investigated with respect to physicochemical parameters and the character of chemiluminescence signal. Our results showed the isoluminol molecule to be more polar, more hydrophilic and possessing lower ability to form intramolecular bonds than the luminol molecule. Therefore, isoluminol: (i) only slightly pervaded biological membranes; (ii) depended essentially on extracellular peroxidase; (iii) did not produce chemiluminescence in the presence of extracellular scavengers; and (iv) it could be considered a specific detector of extracellular radicals. On the other hand, the physicochemical parameters of luminol and partial resistance of its chemiluminescence to the effect of extracellular inhibitors proved the lipo/hydrophilic character of this luminophore and thus its ability to interact with radicals both outside and inside of cells. The luminol chemiluminescence measured in the presence of extracellular scavengers and the isoluminol chemiluminescence were used with the intention to differentiate the effects of two antihistamine drugs on intra- and extracellular radical formation. In activated human neutrophils, brompheniramine inhibited the extracellular and potentiated the intracellular part of chemiluminescence signal, whereas a reducing effect of loratadine was observed in both compartments.     

Feeding ecology and niche segregation of the spider crab Libinia ferreirae (Decapoda,Brachyura, Majoidea), a symbiont of Lychnorhiza lucerna (Cnidaria,Scyphozoa, Rhizostomeae)

Hydrobiologia - Feeding strategies provide essential information to help understand symbiotic relationships and resource competition as well as environmental integrity. This study examined the...     

A Glimpse into the Microbiota of Marketed Ready-to-Eat Crickets ( Acheta domesticus )

The present study was aimed to get an insight into the bacterial biota of ready-to-eat small crickets (Acheta domesticus) already marketed in the European Union. 16S rRNA gene of the DNAs extracted from thirty-two samples of ready-to-eat crickets commercialized by 4 European Union producers located in Austria, Belgium, France and the Netherlands (2 batches per producer) was analyzed by Polymerase Chain Reaction–Denaturing Gradient Gel Electrophoresis (PCR–DGGE). The species belonging to the genera Hespellia, Ruminococcus and Clostridium were detected in samples from Austria, while those from genera Lysobacter, Staphylococcus and Clostridium were detected in samples from Belgium. Moreover, samples from France were characterized by Staphylococcus, Pseudomonas, and Hydrogenophilus genera. Finally, the genera Staphylococcus, Hydrogenophilus, Clostridium and Ruminococcus were identified in the samples produced in the Netherlands. When insects are intended for commercialization, rearing, processing and handling could affect the presence of the occurring microbial species. Hence, to assure a safe product, the need for a full standardization of production technologies, including feed supply as well as rearing and processing practices, is recommended.     

Natural variation of photosynthetic efficiency in Arabidopsis thaliana accessions under low temperature conditions

Low, but non-freezing, temperatures have negative effects on plant growth and development. Despite some molecular signalling pathways being known, the mechanisms causing different responses among genotypes are still poorly understood. Photosynthesis is one of the processes that are affected by low temperatures. Using an automated phenotyping platform for chlorophyll fluorescence imaging the steady state quantum yield of photosystem II (PSII) electron transport (Φ_PSII) was measured and used to quantify the effect of moderately low temperature on a population of Arabidopsis thaliana natural accessions. Observations were made over the course of several weeks in standard and low temperature conditions and a strong decrease in Φ_PSII upon the cold treatment was found. A genome wide association study identified several quantitative trait loci (QTLs) that are associated with changes in Φ_PSII in low temperature. One candidate for a cold specific QTL was validated with a mutant analysis to be one of the genes that is likely involved in the PSII response to the cold treatment. The gene encodes the PSII associated protein PSB27 which has already been implicated in the adaptation to fluctuating light.     

Mitochondrial biogenesis: An update

In response to the energy demand triggered by developmental signals and environmental stressors, the cells launch the mitochondrial biogenesis process. This is a self‐renewal route, by which new mitochondria are generated from the ones already existing. Recently, considerable progress has been made in deciphering mitochondrial biogenesis‐related proteins and genes that function in health and in pathology‐related circumstances. However, an outlook on the intracellular mechanisms shared by the main players that drive mitochondrial biogenesis machinery is still missing. Here, we provide such a view by focusing on the following issues: (a) the role of mitochondrial biogenesis in homeostasis of the mitochondrial mass and function, (b) the signalling pathways beyond the induction/promotion, stimulation and inhibition of mitochondrial biogenesis and (c) the therapeutic applications aiming the repair and regeneration of defective mitochondrial biogenesis (in ageing, metabolic diseases, neurodegeneration and cancer). The review is concluded by the perspectives of mitochondrial medicine and research.     

Life cycle assessment and circularity indicators

The International Journal of Life Cycle Assessment - In a context where the transition to a circular economy is increasingly required, it is necessary to clarify the relationship between...     

Genetic sexing strains for the population suppression of the mosquito vector Aedes aegypti

Aedes aegypti is the primary vector of arthropod-borne viruses including dengue, chikungunya and Zika. Vector population control methods are reviving to impede disease transmission. An efficient sex separation for male-only releases is crucial for area-wide mosquito population suppression strategies. Here, we report on the construction of two genetic sexing strains using red- and white-eye colour mutations as selectable markers. Quality control analysis showed that the Red-eye genetic sexing strains (GSS) is better and more genetically stable than the White-eye GSS. The introduction of an irradiation-induced inversion (Inv35) increases genetic stability and reduces the probability of female contamination of the male release batches. Bi-weekly releases of irradiated males of both the Red-eye GSS and the Red-eye GSS/Inv35 fully suppressed target laboratory cage populations within six and nine weeks, respectively. An image analysis algorithm allowing sex determination based on eye colour identification at the pupal stage was developed. The next step is to automate the Red-eye-based genetic sexing and validate it in pilot trials prior to its integration in large-scale population suppression programmes.This article is part of the theme issue ‘Novel control strategies for mosquito-borne diseases’.