Search for axioelectric effect of 5.5 MeV solar axions using BGO detectors

A search for axioelectric absorption of solar axions produced in the $p + d \rightarrow {^3\rm{He}}+\gamma (5.5 \rm{MeV})$ reactions has been performed with a BGO detector placed in a low-background setup. A model-independent limit on an axion-nucleon and axion-electron coupling constant has been obtained: $| g_{Ae}\times g_{AN}^3|< 2.9\times 10^{-9}$ for 90% confidence level. The constrains of the axion-electron coupling have been obtained for hadronic axion with masses in (0.1 - 1) MeV range: $|g_{Ae}| \leq (1.4 - 9.7)\times 10^{-7}$.Comment: 6 pages, 4 figures, to be published in EPJ C. arXiv admin note: substantial text overlap with arXiv:1007.338

Search for solar axions produced by Compton process and bremsstrahlung using the resonant absorption and axioelectric effect

The search for resonant absorption of Compton and bremsstrahlung solar axions by $^{169}$Tm nuclei have been performed. Such an absorption should lead to the excitation of low-lying nuclear energy level: $A+^{169}$Tm $\rightarrow ^{169}$Tm$^*$ $\rightarrow ^{169}$Tm $+ \gamma$ (8.41 keV). Additionally the axio-electric effect in silicon atoms is sought. The axions are detected using a Si(Li) detectors placed in a low-background setup. As a result, a new model independent restrictions on the axion-electron and the axion-nucleon coupling: $g_{Ae}\times|g^0_{AN}+ g^3_{AN}|\leq 2.1\times10^{-14}$ and the axion-electron coupling constant: $|g_{Ae}| \leq 2.2\times 10^{-10}$ has been obtained. The limits leads to the bounds $m_{A}\leq$ 7.9 eV and $m_{A}\leq$ 1.3 keV for the mass of the axion in the DFSZ and KSVZ models, respectively ($90\%$ C.L.).Comment: 6 pages, 3 figures, contributed to the 9th Patras Workshop on Axions, WIMPs and WISPs, Mainz, June 24-28, 201

Anxiolytic and antidepressive effects of electric stimulation of the paleocerebellar cortex in pentylenetetrazol kindled rats

Anxiety and depression are component of interictal behavioral deteriorations that occur as a consequence of kindling, a procedure to induce chronic epilepsy. The aim of this study was to evaluate the possible effects of electrical stimulation (ES) of paleocerebellar cortex on anxiety and depressive-like behavior in a PTZ kindled epilepsy model. Kindling was induced via pentylenetetrazol (PTZ) (25.0 mg/kg IP daily) during three weeks. Locomotion in open field, elevated plus-maze (EPM) and Porsolt forced swimming test have been used for the assessment of anxiety and depression-like behavior. ES (100 Hz) has been delivered to V–VII lobules of vermal cortex of kindled rats. ES of paleocerebellum reversed kindling-induced reduction of crossings of central squares, increased rearings, and decreased the number of defecations in open field. The duration that kindled animals spent in the open arms of the EPM increased in post- ES period, and the number of enterings into the closed arms of the EPM decreased. The duration of the immobility response in the swimming test in kindled rats was reduced after ESs of paleocerebellum. In all: ES of paleocerebellar structures suppressed anxious and depressive-like behavior in PTZ-kindled rats

New limit on the mass of 9.4-keV solar axions emitted in an M1 transition in 83^{83}Kr nuclei

A search for resonant absorption of the solar axion by $^{83}\rm{Kr}$ nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the combination of isoscalar and isovector axion-nucleon couplings $|g_3-g_0|\leq 1.69\times 10^{-6}$ allowed us to set the new upper limit on the hadronic axion mass of $m_{A}\leq 130$ eV (95\% C.L.) with the generally accepted values $S$=0.5 and $z$=0.56.Comment: 5 pages, 2 figures, Proceedings of the 10th Patras Workshop on Axions, WIMPs and WISP 29 June - 4 July 2014, CERN, Geneva, Switzerlan

Effect of copper ions on the associations of <i>Azospirillum</i> bacteria with wheat seedlings (<i>Triticum aestivum</i> L.)

The physiological and biochemical activity of plant–microbial associations enables them to determine the mobility, bioavailability, and accumulation of heavy metals in plant tissues. These abilities are the basis for the use of plants and their associated microorganisms in the development of approaches that ensure both the prevention of the ingress of toxic metals into food crops and the extraction of pollutants from polluted soils by using phytoremediation technologies. Whether plant–microbial complexes are used successfully depends on the knowledge of how specific organisms interact with heavy metals. We evaluated the effect of copper ions on common wheat (Triticum aestivum L.) inoculated with three plant-growth-promoting rhizobacteria (PGPR) of the genus Azospirillum. We analyzed the growth variables of 14-day-old wheat seedlings, the content of photosynthesis pigments, the activity of plant oxidoreductases, and the accumulation of copper by plant tissues. All strains more or less compensated for copper toxicity to seedling development and increased metal accumulation in roots and shoots. Copper affected the photosynthetic apparatus of the inoculated plants, primarily by decreasing the content of chlorophyll b. An analysis of the activity of plant oxidoreductases (peroxidases and phenoloxidases), which are involved in the physiological responses of plants to pollutant stress, showed strain-specific dependence and a significant effect of copper on the inoculated plants. Overall, the obtained results clearly show that the effect of Azospirillum on the physiological and biochemical status of wheat is diverse. The compensatory effect of bacteria on copper toxicity and the simultaneous increase in metal accumulation in plant tissues can be considered as mutually exclusive crop-production aspects associated with the growing of food plants in heavy-metal-polluted areas