Modelling age‐ and density‐structured reproductive biology and seasonal survival of Apanteles galleriae Wilkinson (Hym., Braconidae)

Abstract: The biology of Apanteles galleriae Wilkinson, an important biological control agent of wax moths, is well described in the literature. We developed models simulating the functional response of fecundity and female progeny proportion of adult females as a function of age, host and/or parasitoid density to integrate current knowledge. Daily pattern of age‐related fecundity and female progeny proportion of different parasitoids was also examined. We investigated the effect of sex, mating status and seasonal time on adult longevity. We derived survival data of females in two different seasonal periods. We found that 50% of adult life span is important for an efficient fecundity. The patterns of host and/or parasitoid density‐dependent fecundity and sex ratio varied considerably. The highest fecundity and female progeny proportion occurred with one parasitoid and one female equivalent host. Longevity of adults was affected by sex and month periods, but mating status did not affect their longevity. Female survival was greater between December and May relative to June and November. Our results indicated that age, host and parasitoid density, and the timing of rearing influenced the life processes of parasitoids.     

Alchemilla boluensis (Rosaceae), a new species from the west Black Sea region (Bolu, Turkey)

Alchemilla boluensis from the west Black Sea region of Turkey is described as a species new to science and illustrated. It belongs to the section Alchemilla , subsection Calycanthum and series Elatae , and is closely related to A. amoena , from which it mainly differs in its stem and leaf features.     

The chromate-inducible chrBACF operon from the transposable element TnOtChr confers resistance to chromium(VI) and superoxide

Large-scale industrial use of chromium(VI) has resulted in widespread contamination with carcinogenic chromium(VI). The abilities of microorganisms to survive in these environments and to detoxify chromate require the presence of specific resistance systems. Here we report identification of the transposon-located (TnOtChr) chromate resistance genes from the highly tolerant strain Ochrobactrum tritici 5bvl1 surviving chromate concentrations of >50 mM. The 7,189-bp-long TnOtChr of the mixed Tn21/Tn3 transposon subfamily contains a group of chrB, chrA, chrC, and chrF genes situated between divergently transcribed resolvase and transposase genes. The chrB and chrA genes, but not chrF or chrC, were essential for establishment of high resistance in chromium-sensitive O. tritici. The chr promoter was strongly induced by chromate or dichromate, but it was completely unresponsive to Cr(III), oxidants, sulfate, or other oxyanions. Plasmid reporter experiments identified ChrB as a chromate-sensing regulator of chr expression. Induction of the chr operon suppressed accumulation of cellular Cr through the activity of a chromate efflux pump encoded by chrA. Expression of chrB, chrC, or chrF in an Escherichia coli sodA sodB double mutant restored its aerobic growth in minimal medium and conferred resistance to superoxide-generating agents menadione and paraquat. Nitroblue tetrazolium staining on native gels showed that ChrC protein had superoxide dismutase activity. TnOtChr appears to represent a mobile genetic system for the distribution of the chromate-regulated resistance operon. The presence of three genes protecting against superoxide toxicity should provide an additional survival advantage to TnOtChr-containing cells in the environments with multiple redox-active contaminants.     

A retrospective controlled study of thiol disulfide homeostasis as a novel marker in Crimean Congo hemorrhagic fever

Objectives: Crimean Congo hemorrhagic fever (CCHF) is the second most common hemorrhagic fever worldwide. This study aimed to evaluate the oxidant–antioxidant balance of patients with CCHF by detecting dynamic thiol disulfide homeostasis (TDH), which is a novel oxidative stress marker, and other molecules, including paraoxonase (PON), arylesterase (ARES), ceruloplasmin (CLP), myeloperoxidase (MPO), and catalase.

Methods: This retrospective, cross-sectional, controlled study, which involved patients with CCHF and healthy volunteers, measured dynamic TDH using a novel automated method developed by Erel.

Results: We recruited 69 adult patients with CCHF (31 females, 38 males, median age 46 years). The case fatality rate was 1.49% (1/69). Increased disulfide/native thiol and disulfide/total thiol ratios, decreased total antioxidant status (TAS), and increased total oxidant status (TOS) were found in patients with CCHF. TAS, PON, and ARES values were found to be positively correlated with both native and total thiol levels, whereas TOS and CLP were negatively correlated with both, at a significant level. MPO activity was similar in both groups.

Discussion: This is the first study in the literature to evaluate dynamic TDH in CCHF. TDH shifts to the oxidative side in patients with CCHF, leading to an increase in TOS.     

Polymersomes Containing Iron Sulfide (FeS) as Primordial Cell Model

According to Wächtershäuser??s ??Iron-Sulfur-World?? one major requirement for the development of life on the prebiotic Earth is compartmentalization. Vesicles spontaneously formed from amphiphilic components containing a specific set of molecules including sulfide minerals may have lead to the first autotrophic prebiotic units. The iron sulfide minerals may have been formed by geological conversions in the environment of deep-sea volcanos (black smokers), which can be observed even today. Wächtershäuser postulated the evolution of chemical pathways as fundamentals of the origin of life on earth. In contrast to the classical Miller-Urey experiment, depending on external energy sources, the ??Iron-Sulfur-World?? is based on the catalytic and energy reproducing redox system $ FeS + {H_2}S \to FeS{}_2 + {H_2} $ . The energy release out of this redox reaction (?_RG°?=??38 kJ/mol, pH 0) could be the cause for the subsequent synthesis of complex organic molecules and the precondition for the development of more complex units similar to cells known today. Here we show the possibility for precipitating iron sulfide inside vesicles composed of amphiphilic block-copolymers as a model system for a first prebiotic unit. Our findings could be an indication for a chemoautotrophic FeS based origin of life.