Soil nutrient status and revegetation practices of downhill skiing areas in Finnish Lapland — a case study of Mt. Ylläs

Ski slope construction is one of the major anthropogenic factors responsible for ecosystem degradation in mountain areas in Finnish Lapland. Mt. Ylläs has been used as a downhill skiing slope for about 30 years. Until 1992, the ski slopes were kept in their natural condition: there was no removal of vegetation and soil above the tree line. After 1992, Mt. Ylläs went through an extensive construction, the ski slopes were machine-graded and machine-levelled, which caused damage to both vegetation and soil. The aim of the study presented here was to examine nutrient status of various soils on the machine-graded and machine-levelled ski slopes in relation to their potential use as a substrate for revegetation practices.Soil organic matter and nutrient status were analysed in three sites on the slopes of Mt. Ylläs in the tree line zone (transit zone between wooded vegetation and treeless alpine vegetation): (1) reference site on the undisturbed area between the ski-runs (Control); (2) disturbed site on the ski-run area (DSP — ‘DiSturbed Podzol’, DSL — ‘DiSturbed Leptosol’ and DSB — ‘DiSturbed Bare soil’); and (3) Revegetation study Plots established on the ski-runs (RP). The analysis of element concentrations and their relative proportions allow us to conclude that only DSP and DSL can be considered as potentially appropriate for unassisted ecosystem recovery on the ski-runs. Presence of native plant species on these patches supports our conclusion. As a recommendation for revegetation of ski-runs, we propose implementation of substrate composed of upper layer of initial soil. Such substrate can be collected during the construction work on ski slopes or on building sites in the area with similar soils. Uncomposted substrate or at least short period of composting is preferable.     

Sonochemical Activation of Al/Ni Hydrogenation Catalyst

This paper proposes a sonochemical approach to the nanostructuring of Al/Ni catalyst with high content of accessible Ni centers and a high reusability. The surface and bulk composition as well as pore size distribution of this catalyst are controlled synergistically by adjusting the ultrasound intensity in aqueous solution. Sonochemical activation of Al/Ni alloy leads to formation of mesoporous Al/Ni metallic based frameworks with surface area up to 125 m² g^?1, and regular distribution of nickel active center in the porous matrix. One of the opportunities of porous Al/Ni catalyst is that due to a time‐resolved controllable formation of protective oxide layer it can be stored and handled under air in comparison to traditional Raney catalysts which need inert conditions. The Al/Ni catalyst is characterized by scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), X‐ray photoelectron spectroscopy (XPS), confocal scanning fluorescence microscopy (CSFM), solid‐state NMR experiments, and powder X‐ray diffraction analysis (PXRD). The catalytic activity was investigated for the hydrogenation of acetophenone.     

Transduction of Brain Neurons in Juvenile Chum Salmon (Oncorhynchus keta) with Recombinant Adeno-Associated Hippocampal Virus Injected into the Cerebellum during Long-Term Monitoring

Corpus cerebelli in juvenile chum salmon is a multiprojective region of the brain connected via afferent and efferent projections with the higher regions of the brainstem and synencephalon, as well as with multiprojection regions of the medulla oblongata and spinal cord. During the postembryonic development of the cerebellum in chum salmon, Oncorhynchus keta, the lateral part of the juvenile cerebellum gives rise to the caudomedial part of the definitive cerebellum, which is consistent with the data reported for zebrafish and mouse cerebellum. Thus, the topographic organization of the cerebellum and its efferents are similar between fish (chum salmon and zebrafish) and mammals, including mice and humans. The distributions of recombinant adeno-associated viral vectors (rAAVs) after an injection of the base vector into the cerebellum have shown highly specific patterns of transgene expression in bipolar neurons in the latero-caudal lobe of the juvenile chum tectum opticum. The distribution of rAAVs in the dorsal thalamus, epithalamus, nucleus rotundus, and pretectal complex indicates the targeted distribution of the transgene via the thalamo-cerebellar projections. The detection of GFP expression in the cells of the epiphysis and posterior tubercle of juvenile chum salmon is associated with the transgene’s distribution and with the cerebrospinal fluid flow, the brain ventricles and its outer surface. The direct delivery of the rAAV into the central nervous system by intracerebroventricular administration allows it to spread widely in the brain. Thus, the presence of special projection areas in the juvenile chum salmon cerebellum, as well as outside it, and the identification of the transgene’s expression in them confirm the potential ability of rAAVs to distribute in both intracerebellar and afferent and efferent extracerebellar projections of the cerebellum.     

A Novel Photoswitchable Azobenzene-Containing Local Anesthetic Ethercaine with Light-Controlled Biological Activity In Vivo

Pain is a common symptom that impairs the quality of life for people around the world. Local anesthetics widely used for pain relief have a number of side effects, which makes the development of both new drugs and new ways to control their activity particularly important. Photopharmacology makes it possible to reduce the side effects of an anesthetic and control its biological activity in the body. The purpose of this work was to create a new light-controlled local anesthetic and study its biological activity in animals. A compound with a simple scheme of synthesis was chosen to shift the UV-Vis absorption band towards the visible range of the spectrum and was synthesized for the first time. Some computer calculations were performed to make sure that the aforementioned changes would not lead to loss of biological activity. The micellar form of the new compound was prepared, and in vivo biological studies were carried out in rabbits. The existence of a local anesthetic effect, which disappeared almost completely on irradiation with light (λ = 395 nm), was shown using the surface anesthesia model. Moreover, the possibility of multiple reversible changes in the biological activity of ethercaine under the action of light was demonstrated. The latter compound manifests no local irritating effect, either. The data obtained indicate the prospects for the development of new compounds based on azobenzene for light-controlled local anesthesia.     

Isolating Linum usitatissimum L. Nuclear DNA Enabled Assembling High-Quality Genome

High-quality genome sequences help to elucidate the genetic basis of numerous biological processes and track species evolution. For flax (Linum usitatissimum L.)—a multifunctional crop, high-quality assemblies from Oxford Nanopore Technologies (ONT) data were unavailable, largely due to the difficulty of isolating pure high-molecular-weight DNA. This article proposes a scheme for gaining a contiguous L. usitatissimum assembly using Nanopore data. We developed a protocol for flax nuclei isolation with subsequent DNA extraction, which allows obtaining about 5 μg of pure high-molecular-weight DNA from 0.5 g of leaves. Such an amount of material can be collected even from a single plant and yields more than 30 Gb of ONT data in two MinION runs. We performed a comparative analysis of different genome assemblers and polishers on the gained data and obtained the final 447.1-Mb assembly of L. usitatissimum line 3896 genome using the Canu—Racon (two iterations)—Medaka combination. The genome comprised 1695 contigs and had an N50 of 6.2 Mb and a completeness of 93.8% of BUSCOs from eudicots_odb10. Our study highlights the impact of the chosen genome construction strategy on the resulting assembly parameters and its eligibility for future genomic studies.     

Overexpression of Brain- and Glial Cell Line-Derived Neurotrophic Factors Is Neuroprotective in an Animal Model of Acute Hypobaric Hypoxia

Currently, the role of the neurotrophic factors BDNF and GDNF in maintaining the brain’s resistance to the damaging effects of hypoxia and functional recovery of neural networks after exposure to damaging factors are actively studied. The assessment of the effect of an increase in the level of these neurotrophic factors in brain tissues using genetic engineering methods on the resistance of laboratory animals to hypoxia may pave the way for the future clinical use of neurotrophic factors BDNF and GDNF in the treatment of hypoxic damage. This study aimed to evaluate the antihypoxic and neuroprotective properties of BDNF and GDNF expression level increase using adeno-associated viral vectors in modeling hypoxia in vivo. To achieve overexpression of neurotrophic factors in the central nervous system’s cells, viral constructs were injected into the brain ventricles of newborn male C57Bl6 (P0) mice. Acute hypobaric hypoxia was modeled on the 30th day after the injection of viral vectors. Survival, cognitive, and mnestic functions in the late post-hypoxic period were tested. Evaluation of growth and weight characteristics and the neurological status of animals showed that the overexpression of neurotrophic factors does not affect the development of mice. It was found that the use of adeno-associated viral vectors increased the survival rate of male mice under hypoxic conditions. The present study indicates that the neurotrophic factors’ overexpression, induced by the specially developed viral constructs carrying the BDNF and GDNF genes, is a prospective neuroprotection method, increasing the survival rate of animals after hypoxic injury.     

Detailed Analysis of Dorsal-Ventral Gradients of Gene Expression in the Hippocampus of Adult Rats

We performed RNA sequencing of the dorsal and ventral parts of the hippocampus and compared it with previously published data to determine the differences in the dorsoventral gradients of gene expression that may result from biological or technical variability. Our data suggest that the dorsal and ventral parts of the hippocampus differ in the expression of genes related to signaling pathways mediated by classical neurotransmitters (glutamate, GABA, monoamines, etc.) as well as peptide and Wnt ligands. These hippocampal parts also diverge in the expression of axon-guiding molecules (both receptors and ligands) and splice isoforms of genes associated with intercellular signaling and cell adhesion. Furthermore, analysis of differential expressions of genes specific for astrocytes, microglia, oligodendrocytes, and vascular cells suggests that non-neuronal cells may also differ in the characteristics between hippocampal parts. Analysis of expression of transposable elements showed that depletion of ribosomal RNA strongly increased the representation of transposable elements in the RNA libraries and helped to detect a weak predominance of expression of these elements in the ventral hippocampus. Our data revealed new molecular dimensions of functional differences between the dorsal and ventral hippocampus and points to possible cascades that may be involved in the longitudinal organization of the hippocampus.     

Experimental Crossing Confirms Reproductive Isolation between Cryptic Species within Eulimnogammarus verrucosus (Crustacea: Amphipoda) from Lake Baikal

Ancient lakes are known speciation hotspots. One of the most speciose groups in the ancient Lake Baikal are gammaroid amphipods (Crustacea: Amphipoda: Gammaroidea). There are over 350 morphological species and subspecies of amphipods in Baikal, but the extent of cryptic variation is still unclear. One of the most common species in the littoral zone of the lake, Eulimnogammarus verrucosus (Gerstfeldt, 1858), was recently found to comprise at least three (pseudo)cryptic species based on molecular data. Here, we further explored these species by analyzing their mitogenome-based phylogeny, genome sizes with flow cytometry, and their reproductive compatibility. We found divergent times of millions of years and different genome sizes in the three species (6.1, 6.9 and 8 pg), further confirming their genetic separation. Experimental crossing of the western and southern species, which are morphologically indistinguishable and have adjacent ranges, showed their separation with a post-zygotic reproductive barrier, as hybrid embryos stopped developing roughly at the onset of gastrulation. Thus, the previously applied barcoding approach effectively indicated the separate biological species within E. verrucosus. These results provide new data for investigating genome evolution and highlight the need for precise tracking of the sample origin in any studies in this morphospecies.     

Flow-Seq Evaluation of Translation Driven by a Set of Natural Escherichia coli 5′-UTR of Variable Length

Flow-seq is a method that combines fluorescently activated cell sorting and next-generation sequencing to deduce a large amount of data about translation efficiency from a single experiment. Here, we constructed a library of fluorescent protein-based reporters preceded by a set of 648 natural 5′-untranslated regions (5′-UTRs) of Escherichia coli genes. Usually, Flow-seq libraries are constructed using uniform-length sequence elements, in contrast to natural situations, where functional elements are of heterogenous lengths. Here, we demonstrated that a 5′-UTR library of variable length could be created and analyzed with Flow-seq. In line with previous Flow-seq experiments with randomized 5′-UTRs, we observed the influence of an RNA secondary structure and Shine–Dalgarno sequences on translation efficiency; however, the variability of these parameters for natural 5′-UTRs in our library was smaller in comparison with randomized libraries. In line with this, we only observed a 30-fold difference in translation efficiency between the best and worst bins sorted with this factor. The results correlated with those obtained with ribosome profiling.