The thermogenic center in social wasps

In the social wasps Vespa orientalis and Paravespula germanica (Hymenoptera, Vespinae), a thermogenic center has been found in the dorsal part of the first thoracic segment. The temperature in this region of the prothorax is higher by 6-9 degrees C than that at the tip of the abdomen, and this in actively flying hornets outside the nest (workers, males or queens) as well as in hornets inside the nest that attend to the brood in the combs. On viewing the region from the outside, one discerns a canal or rather a fissure in the cuticle, which commences at the center of the dorsal surface of the prothorax and extends till the mesothorax. Thus the length of this canal or fissure is approximately 5-7 mm and it is seen to contain numerous thin hairs whose shape varies from that of the hairs alongside the structure. Beneath the cuticle in this region there are dorsoventral as well as longitudinal muscles in abundance, much the same as the musculature in the remaining thoracic segments (i.e. the meso- and metathorax), which activate the two pairs of wings. The canal-bearing segment is of course devoid of wings, and its dorsoventral muscles are attached to the cuticle, which in this region resembles a bowl harboring several layers of epithelium that boasts numerous butterfly-shaped tracheal branches. Additionally there are layers that display lymph-filled spaces and also perforated layers and depressions, and beneath all these is a lace-like layer that also coats the cuticle's hollows. Underneath the cuticle proper, there are numerous large mitochondria and tracheae, which occupy a considerable part of the cuticular epithelium surface. These abundant mitochondria are, most probably, the main element of heat production in the thermogenic center.     

Wavefront sensor based on the Talbot effect with the precorrected holographic grating

A holographic wavefront sensor based on the Talbot effect is proposed. Optical wavefronts are measured by sampling the light amplitude distribution with a two-dimensional (2D) precorrected holographic grating. The factors that allow changing an angular measurement range and a spatial resolution of the sensor are discussed. A comparative analysis with the Shack-Hartmann sensor is illustrated with some experimental results.     

Child parent relationship training: Parents' perceptions of process and outcome.

Child Parent Relationship Training (CPRT) is a play-based parent consultation model designed for children (ages 3–10) who may be struggling emotionally or behaviorally. CPRT aims to help parents develop empathy and appreciation for their children, increase parenting ability and confidence, and strengthen parent–child relationships. To date, the majority of CPRT studies have been quantitative in nature. There has been limited research on the effectiveness of CPRT using qualitative methodologies, but existing qualitative studies show promising results. The current study utilized an ethnographic approach to examine the acceptability and perceived effectiveness of CPRT. Findings indicated that the parents perceived the CPRT model to be both acceptable and effective (e.g., increased knowledge and confidence in parenting, enhanced parent–child communication, strengthened parent–child relationships, and reduced behavioral problems among child participants). Limitations of the study and implications for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of child parent relationship therapy on child behavior and parent-child relationships: An examination of parental divorce.

The current study used a mixed methodological approach to examine the impact of Child-Parent-Relationship Therapy (CPRT) on divorced parents and their children. Specifically, in the present study, the authors investigated parents' perceptions of the impact of CPRT on the parent, the child, and the parent–child relationship. CPRT was found to be helpful in reducing parenting stress and child behavior problems. Parents also reported that CPRT helped them feel more connected to their children and provided them with new tools for parenting. The results of the current study add to the current literature on divorce, affirming that CPRT may be an effective intervention for children of divorce. Limitations of the study and implications for future research are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Metformin Influence on the Intestinal Microbiota and Organism of Rats with Metabolic Syndrome

Metformin is a first-line drug for DM2 treatment and prevention, but its complex effect on impaired glucose tolerance (IGT), including its influence on myocardial resistance to ischemia-reperfusion injury, is not completely studied. We aimed to evaluate the influence of metformin on the intestinal microbiota (IM), metabolism, and functional and morphological characteristics of myocardium in rats with IGT. IGT was modelled in SPF Wistar rats with a high-fat diet and streptozotocin and nicotinamide injection. Rats were divided into three groups: IGT (without treatment), IGT MET (metformin therapy), and CRL (without IGT induction and treatment). IGT group was characterized by: higher body weight, increased serum glucose and total cholesterol levels, atherogenic coefficient, impairment in the functional parameters of the isolated heart during perfusion, and larger myocardium infarction (MI) size in comparison with the CRL group. IM of IGT rats differed from that of CRL: an increase of Bacteroides, Acinetobacter, Akkermansia, Roseburia, and a decrease of Lactobacillus genera representation. Metformin therapy led to the diminishing of metabolic syndrome (MS) symptoms, which correlated with IM restoration, especially with the growth of Akkermansia spp. and decline of Roseburia populations and their influence on other members of IM. The obtained results allow us to consider from a new point of view the expediency of probiotic A. muciniphila use for MS treatment.     

Melatonin Prevents Early but Not Delayed Ventricular Fibrillation in the Experimental Porcine Model of Acute Ischemia

Antiarrhythmic effects of melatonin have been demonstrated ex vivo and in rodent models, but its action in a clinically relevant large mammalian model remains largely unknown. Objectives of the present study were to evaluate electrophysiological and antiarrhythmic effects of melatonin in a porcine model of acute myocardial infarction. Myocardial ischemia was induced by 40-min coronary occlusion in 25 anesthetized pigs. After ischemia onset, 12 animals received melatonin (4 mg/kg). 48 intramyocardial electrograms were recorded from left ventricular wall and interventricular septum (IVS). In each lead, activation time (AT) and repolarization time (RT) were determined. During ischemia, ATs and dispersion of repolarization (DOR = RTmax − RTmin) increased reaching maximal values by 3–5 and 20–25 min, respectively. Ventricular fibrillation (VF) incidence demonstrated no relations to redox state markers and was associated with increased DOR and delayed ATs (specifically, in an IVS base, an area adjacent to the ischemic zone) (p = 0.031). Melatonin prevented AT increase in the IVS base, (p < 0.001) precluding development of early VF (1–5 min, p = 0.016). VF occurrence in the delayed phase (17–40 min) where DOR was maximal was not modified by melatonin. Thus, melatonin-related enhancement of activation prevented development of early VF in the myocardial infarction model.     

Self-sealing property of concrete—Experimental evidence

Leak-tightness of concrete is often judged in terms of the D'Arcy coefficient determined by the flow of water through saturated concrete at a constant rate. In the case of flow through saturated concrete, this rate often reduces with time and reaching a constant value may take many days. The present experiments were designed to explore various models in order to account for this behaviour. The results obtained support the concept that the dissolution and redeposition of alkalis is the most significant mechanism in the time-dependent reduction of flow of water in saturated concrete. Permeability of saturated concrete and self-sealing may be used as measures of the “immune” systems and potential durability of different concretes.     

The molecular structure of anionic species of 2,4,5,7‐tetranitrofluorescein as studied by electrospray ionisation,nuclear magnetic resonance and X‐ray techniques

Among the fluorescein dyes, the behaviour of their nitro derivatives in solution is most unusual, and yet at the same time rarely studied. In this study, their ¹³C nuclear magnetic resonance and electrospray spectra are reported, which confirm, in concert with their ultraviolet‐visible spectra, the molecular structures of the neutral and ionic species of 2,4,5,7‐tetranitrofluorescein observed in different solvents and at various pH values. A peculiar property of this dye consists in its lactonisation of the double‐charged anion, contrary to the well‐known coloured and fluorescent dianions of fluorescein, eosin, etc. Also, this dianion‐lactone exhibits high ability for opening the pyran ring. This cleavage takes place at much lower pH values as compared with those for fluorescein and its halogen derivatives. The ruptured species can be formed as either lactone or carbinol; the latter appears as a result of the nucleophilic attack of a HO^? on the central carbon atom. The corresponding molecular structures are identified via the electrospray method and X‐ray analysis. The behaviour of some other nitrofluoresceins in alkaline media is also considered.     

Synthesis and corrosion inhibition mechanism of ammonium-based ionic liquids on API 5L X60 steel in sulfuric acid solution

A novel class of four new-free-halide-ionic liquids (ILs) derived from ammonium was synthesized and characterized via spectroscopic methods such as ¹H NMR and ¹³C NMR. The synthesized compounds were evaluated as corrosion inhibitors (CIs) of API 5L X60 steel in 1 M sulfuric acid by means of the potentiodynamic polarization and weight loss techniques. The results confirmed that the inhibition efficiency displayed by the four ILs is a function of their concentration and molecular structure. The obtained inhibition efficiency (η) ranged from 51 to 89%, confirming that the new class of ILs is good for corrosion inhibition purposes. The analysis of the potentiodynamic results showed that these compounds inhibit the corrosion of steel, classifying them as mixed-type CIs. The adsorption process of these new CIs on the API 5L X60 steel surface, which obeyed the Langmuir isotherm, was found to be physical and chemical. The SEM and EDX analyses confirmed the protection of steel in the corrosive medium.