Seasonal Signal of Photosynthesis in the Forests of North Eurasia

Russian Journal of Plant Physiology - The seasonal course of the water potential in branch xylem reflects the dynamics of photosynthetic СО2/Н2О exchange in the forest...     

Association between level of intelligence and heart rate variability

Earlier we discovered that heart rate variability was associated with the level of intelligence. The purpose of this study is to confirm this association using more reliable method and to define more precisely the frequency band within which the amplitude of the heart rate modulations is related to intelligence. 13 males (aged 14 to 17) were the study subjects. The total score of the computer game Tetris was taken as a general measure of the intelligence level. Heart rate was recorded electrocardiographically both at rest and during playing Tetris. Frequency analysis of heart rate was carried out with digital Fourier transformation. Correlation analysis showed that there was positive association between the level of intelligence and the amplitude of heart rate modulation at the frequencies 0.30 and 0.15 modulations per RR interval. This association is closer for the heart rate at rest than for the heart rate during mental work and for the frequency 0.30 than for the 0.15 modulations per RR interval.     

Association of heart rate variability and frontal cortex activation

Literature data and results of our own research suggest that amplitude of periodic modulations of heart rate may be related to the cerebral cortex activity. Verification of this assumption was accomplished by searching for correlation between the heart rate periodogram (as a measure of amplitude of periodic modulations of heart rate at different frequencies), and electroencephalographic evaluation of the level of different cortical areas activation. Positive association between levels of activation of the frontal cortex and amplitude of heart rate modulation with the period of 3 modulations per heart rate interval was discovered.     

Phenogenetics of offspring and their ancestors

By the help of questionnaire of young peoples (18-25 years) was received an information about their psycobiological likeness to mother, father, grandmother, grandfather. From 788 girls likeness to mother marked in 50.51%, father--37.06%, grandmother--9.77%, grandfather--2.66%. Boys (416 answers) marked likeness in 34.13% with mother, in 52.64% with father, in 3.85% with grandmother, in 9.38% with grandfather. So, the girls more frequent showed there likeness to ancestors of women sex, and boys--to men sex. Authors thinking, that this thing is conditioned not only by heredity cytoplasmatic factors, but by alternative action of womanish and masculine sexual hormones.     

Bradykinin B2 receptors activate Na+/H+ exchange in mIMCD-3 cells via Janus kinase 2 and Ca2+/calmodulin

We used a cultured murine cell model of the inner medullary collecting duct (mIMCD-3 cells) to examine the regulation of the ubiquitous sodium-proton exchanger, Na+/H+ exchanger isoform 1 (NHE-1), by a prototypical G protein-coupled receptor, the bradykinin B2 receptor. Bradykinin rapidly activates NHE-1 in a concentration-dependent manner as assessed by proton microphysiometry of quiescent cells and by 2'-7'-bis[2-carboxymethyl]-5(6)-carboxyfluorescein fluorescence measuring the accelerated rate of pH(i) recovery from an imposed acid load. The activation of NHE-1 is blocked by inhibitors of the bradykinin B2 receptor, phospholipase C, Ca2+/calmodulin (CaM), and Janus kinase 2 (Jak2), but not by pertussis toxin or by inhibitors of protein kinase C and phosphatidylinositol 3'-kinase. Immunoprecipitation studies showed that bradykinin stimulates the assembly of a signal transduction complex that includes CaM, Jak2, and NHE-1. CaM appears to be a direct substrate for phosphorylation by Jak2 as measured by an in vitro kinase assay. We propose that Jak2 is a new indirect regulator of NHE-1 activity, which modulates the activity of NHE-1 by increasing the tyrosine phosphorylation of CaM and most likely by increasing the binding of CaM to NHE-1.     

Comparison of cholinergic systems in Ep neocortical regions of cats with high and low cognitive ability

Cats were behaviorally tested for the ability to solve the abstraction and generalization tasks. Fractions of light (C) and heavy (D) synaptosomes of the associative temporal (Ep) areas were prepared, and subfractions of synaptic membranes and synaptoplasm were isolated. Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity and the content of protein and protein sulphydric (SH-) groups were measured in synaptic subfractions. All the studied characteristics were lower in subfractions C of cats with higher cognitive abilities. In subfractions D, the ChAT activity was correlated neither with ChAT activity in the respective C fraction, nor with cognitive abilities of cats. It is suggested that cholinergic terminals originating from neurons of the basal magnocellular nuclei are concentrated in the C fractions, and those from the cortical cholinergic neurons are concentrated in the D fractions. Physiological significance of the "deficiency" of cholinergic inputs of the Ep areas from the basal magnocellular nuclei in animals with higher cognitive abilities is discussed.     

The use of chitosan solutions for defatting and clarification of protein hydrolysates]

The possibility of the use of small amounts of chitosan for defatting and clarification of protein solutions prepared by enzymatic hydrolysis was tested. The following treatment conditions were shown to be optimal: chitosan concentration range, from 1.0 to 1.5 g per kg raw weight; pH of precipitation medium, from 8.0 to 8.5; and duration of incubation of protein hydrolysate solution with chitosan, less than 1 h. The hydrolysate defatting grade was found to depend on the degree of chitosan deacetylation. A possible mechanism of the chitosan-induced effects was suggested. The use of chitosan allows the mass fraction of enzyme protein hydrolysates to be reduced fourfold to fivefold.     

6-[18F]fluoro-A-85380, a novel radioligand for in vivo imaging of central nicotinic acetylcholine receptors

A novel positron emission tomography (PET) radiotracer, 6-[18F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (6-[18F]fluoro-A-85380, 6-[18F]FA) was synthesized by a no-carrier-added fluorination. In vitro 6-[18F]FA bound to nicotinic acetylcholine receptors (nAChRs), with very high affinity (Kd 28 pM). In PET studies, 6-[18F]FA specifically labeled central nAChRs in the brain of the Rhesus monkey and demonstrated highest levels of accumulation of radioactivity in brain regions enriched with the alpha4beta2 subtype of nAChR. 6-[18F]FA exhibited a target-to-non-target ratio (estimated as radioactivity in the thalamus to that in the cerebellum) of binding in primate brain similar to that previously determined for a labeled analog of epibatidine, [18F]FPH. In contrast to [18F]FPH, the novel tracer is expected to exhibit substantially less toxicity. Thus, the novel radioligand, 6-[18F]FA, appears to be a suitable candidate for imaging nAChRs in human brain.     

Genetic demographic data of Ukrainian urban populations in the 1990s: ethno-geographic characteristics of migrants in the Donetsk region

Analysis of data on the birthplaces and ethnicity of persons who contracted marriages in the city of Donetsk in 1960, 1985, and 1992 demonstrated that the proportions of Russians and Ukrainians (the dominant ethnic groups among Donetsk residents) in the migration flow increased. The trend towards formation of ethnically disperse groups from the city residents became stronger. The index of isolation by distance (parameter b of Malecot's model) was 0.00103, 0.00071, and 0.00083 in 1960, 1985, and 1992, respectively. The proportions of long-range and short-range migrants increased by 1.2 times and decreased by 2.3 times, respectively, during the period studied. The locality size of the Donetsk population was 50, 62, and 53 km in 1960, 1985, and 1992, respectively. The highest isolation by distance was observed in Jews and Greeks and the lowest one, in Russians.