SEM imaging of acoustically stimulated charge transport in solids

Applications of surface acoustic waves (SAWs) are of great interest for solar energy for the acoustically stimulated transport of charge carriers generated in semiconductors and dielectrics under the influence of light.1–4 A prospective application of SAWs in solar cells could provide a 90% increase in the cell efficiency. SAWs propagating in piezoelectric crystals (piezoelectric semiconductor GaN and GaAs crystals included) have opposite potential values in the SAW minima and maxima due to the piezoelectric effect. Electrons and holes generated by light in a semiconductor or in the subsurface layer of a piezoelectric crystal are correspondingly distributed between SAW minima and maxima. The charges are then transported by SAWs to the solar cell exit at the acoustic wave velocity. Taking advantage of the SAW presence in solar cells, the area of charge “harvest” from the surface of a semiconductor structure or a piezoelectric crystal can be increased, and correspondingly, the solar cell efficiency can be increased too

LIM-kinase 1 effects on memory abilities and male courtship song in Drosophila depend on the neuronal type

The signal pathway of actin remodeling, including LIM-kinase 1 (LIMK1) and its substrate cofilin, regulates multiple processes in neurons of vertebrates and invertebrates. Drosophila melanogaster is widely used as a model object for studying mechanisms of memory formation, storage, retrieval and forgetting. Previously, active forgetting in Drosophila was investigated in the standard Pavlovian olfactory conditioning paradigm. The role of specific dopaminergic neurons (DAN) and components of the actin remodeling pathway in different forms of forgetting was shown. In our research, we investigated the role of LIMK1 in Drosophila memory and forgetting in the conditioned courtship suppression paradigm (CCSP). In the Drosophila brain, LIMK1 and p-cofilin levels appeared to be low in specific neuropil structures, including the mushroom body (MB) lobes and the central complex. At the same time, LIMK1 was observed in cell bodies, such as DAN clusters regulating memory formation in CCSP. We applied GAL4 × UAS binary system to induce limk1 RNA interference in different types of neurons. The hybrid strain with limk1 interference in MB lobes and glia showed an increase in 3-h short-term memory (STM), without significant effects on long-term memory. limk1 interference in cholinergic neurons (CHN) impaired STM, while its interference in DAN and serotoninergic neurons (SRN) also dramatically impaired the flies’ learning ability. By contrast, limk1 interference in fruitless neurons (FRN) resulted in increased 15–60 min STM, indicating a possible LIMK1 role in active forgetting. Males with limk1 interference in CHN and FRN also showed the opposite trends of courtship song parameters changes. Thus, LIMK1 effects on the Drosophila male memory and courtship song appeared to depend on the neuronal type or brain structure

Value of determining the cerebrospinal fluid protein markers of amyloidosis and neurodegeneration in the diagnosis of vascular and neurodegenerative cognitive impairments

The article presents data on different forms of moderate cognitive impairments (MCI) and the specific features of their transformation to dementia. Cerebrospinal fluid (CSF) was investigated in 60 patients with the amnestic and neurodynamic types of MCI, in 15 patients with vascular dementia (VD), 50 patients with Alzheimer’s disease (AD), and 23 patients with mixed vascular and neurodegenerative dementia (MVND). The specific features of β-amyloid and τ-protein concentrations were established in the preclinical stages of dementia, which reflects the main components of the pathogenesis of neurodegeneration. In the amnestic form of MCI and AD, there was drastically decreased Aβ-42 and increased τ-protein levels in SCF. As cognitive impairments progressed, there was a rise in the concentration of τ-protein; its level correlated with the severity of dementia. In MND, the level of Aβ-42 was significantly reduced while the concentration of τ-protein was much increased; moreover, to a greater extent than in AD and VD. Cerebrovascular damage and neurodegeneration were related to each other and mutually worsened clinical and pathogenic effects

Bentho-pelagic relations in the deep-water part of the Okhotsk Sea by the data of stable isotopes С and N analysis

Composition, abundance, diet and trophic status are analyzed for dominant benthic and pelagic species in the deep-water Okhotsk Sea on the data collected in demersal and pelagic trawl surveys conducted by Pacific Fisheries Research Center (TINRO). Isotope composition of13С and15N is determined for tissues of 107 species of plankton, benthos, demersal fish, and cephalopods, which form a basis of pelagic and benthic communities. The carbon isotope content is significantly different between these groups: d13С ranges from -23.30 to -19.90 ‰ for zooplankton, from -18.90 to -13.33 ‰ for benthos, from -22.10 to -18.90 ‰ for fish (mean values), and from -20.08 to -15.75 ‰ for cephalopods. It depends mainly on proportion of pelagic and benthic food in their diet. Following to these values, 30 % of examined species of demersal fishes and cephalopods use resources of detritus food chain as the base of their diet. The range of d15N is from 6.79 ( Megayoldia thraciaeformis ), 6.88 ( Eucalanus bungii ) to 18.26 ‰ ( Molpadia roretzii ). Its highest level is observed for 4 species of benthic invertebrates and 8 species of demersal fishes on the continental slope characterized by high tropic level (≥5) and included to the bentho-pelagic food chain, that corresponds with their d13С values. Trophic relations in the deep-water Okhotsk Sea demonstrates high dependence between benthic and pelagiс communities, as far as many dominant species of pelagic and demersal nekton consume both benthic and pelagic food. Feeding about of 70 % of dominant species of demersal fishes and cephalopods is based on grazing rather than on detritus food