Ecological and environmental transition across the forested-to-open bog ecotone in a west Siberian peatland

Climate change may cause increasing tree cover in boreal peatlands, and the impacts of this encroachment will be noted first at forested-to-open bog ecotones. We investigate key metrics of ecosystem function in five such ecotones at a peatland complex in Western Siberia. Stratigraphic analysis of three cores from one of these transects shows that the ecotone has been dynamic over time with evidence for recent expansion of forested peatland. We observed that the two alternative states for northern boreal peatlands (forested/open) clearly support distinct plant and microbial communities. These in turn drive and respond to a number of feedback mechanisms. This has led to steep ecological gradients across the ecotones. Tree cover was associated with lower water tables and pH, along with higher bulk density, aquatic carbon concentrations, and electrical conductivity. We propose that the conditions found in the forested peatland of Western Siberia make the carbon sink more vulnerable to warmer and drier conditions

Ag-Nanowire Bundles with Gap Hot Spots Synthesized in Track-Etched Membranes as Effective SERS-Substrates

This paper presents a cost-effective approach for the template-assisted electrodeposition fabrication of substrates for surface-enhanced Raman scattering (SERS) with metal nanowires (NWs) grown in pores of polymer track-etched membranes (TM). This technique allows the synthesis of NWs array with its certain surface density and diameter (from dozen to hundreds of nm). NWs length also may be varied (order of μm) by controlling deposition time. Here we grow vertical Ag-NWs which are leaning towards their nearest neighbors, forming self-assembled bundles whose parameters depend on the NW aspect ratio (length to diameter). We show that in such bundles there are “hot spots” in the nm-gaps between NWs tips. Computer simulations have demonstrated a strong enhancement of the electric field within these hot spots; thus, the Raman signal is markedly amplified for analyte molecules placed directly inside the gaps. We have experimentally proved the potential of this SERS-technique on the example of 4-Mercaptophenylboronic acid (4-MPBA). For 4-MPBA the maximal enhancement of Raman signal was found at NWs length of ~1.6 μm and diameter of ~100 nm. The effect is higher (up to twice) if “wet” substrate is used just immediately after the TM polymer removal so that the tips are brought to lean after analyte exposure. We suggest this new type of nanostructured SERS-substrates as a base of effective sensing of extremely low concentration of analytes

THE ROLE OF APICAL SUPPORT AND RECTAL MUCOSAL PROLAPSE EXCISION IN SUCCESSFUL TREATMENT OF RECTOCELE COMBINED WITH PERINEUM DESCENDING: SHORT- TERM AND FOLLOW-UP RESULTS

Pelvic descending syndrome for the first time was described by A.G.Parks in 1966. But in our days the problem of it surgical treatment is not completely solved. Large number of complications and recurrence, unsatisfactory functional results forced surgeons to develop new surgical techniques. The aim of the research was to improve the results of surgery treatment of posterior compartment of pelvic floor using abdominal sacrocolpopexy and stapled trance-anal resection (STARR). 59 patients underwent abdominal sacrocolpopexy with syntheticl mesh as apical support and in 52 patients this method was complementary with STARR. The post-operative outcomes were assessed in 6 months and in 2 years. The following diagnostic methods were used: POP-Q classification, defecography, anorectal functional tests with Polygraf ID device. The quantity of post-operative complications depended of mesh graft was few and didn’t increase because of simultaneous STARR. Vaginal mesh erosion was in 2 (3.4%) patients underwent sacrocolpopexy and in 1 (1.9%) patient underwent sacrocolpopexy and simultaneous STARR, mesh contraction in 1 (1.9%) patient of the 2nd group, vaginal shrinkage in 1 (1.7%) patient of the 1st group, dispareunia de novo was noted in 3 (5.1%) patients of the 1st group and in 2 (3.8%) patients of the 2nd group (p ˃0.05). With POP-Q classification stage 0 of rectocele was achieved in 22(38.9%) patients underwent sacrocolpopexy and in 25(48.1%) patients underwent sacrocolpopexy with simultaneous STARR. In the other patients of both groups stage I was diagnosed. Defecography showed the lifting of the perineum body in all patients of two groups without significant difference, but absolute figures were closer to normal value in the group underwent combined surgery: in the rest -3.7±0.5cm and - 3.5±0.6 cm, in the straining -5.9±0.6 cm and -6.2±0.7 cm in the 1st and 2nd groups accordingly. The anatomical normalization of posterior anorectal angle measurement rentgenologically was noted in both groups and didn’t differ statistically on surgery methods. Rentgenological absence of rectal mucosal prolapse has been noted in 15 (25.4%) patients of the 1st group and in 47(90.4%) patients of the 2nd group (p ˃0.05). Voiding was better in the 2nd group patients. Voiding normalization noted 12(20.3%) and 15(28.8%) patients, voiding improvement 28(47.4%) and 30(57.7%) and didn’t change in 19(32.2%) and in 7(13.4%) patients of the 1st and 2nd groups accordingly (p<0.05). But in spite of these we observed the constant worsening of the results over time. Abdominal sacrocolpopexy with surgical mesh demonstrated satisfactory anatomical results with low complications rate for rectocele reconstruction in patients with perineum descending, including incontinence improvement. Together with STARR procedure they became even better as revealed good functional results in respect to voiding normalization, as rectal mucosal prolapsed is incised simultaneously, which is not corrected by sacrocolpopexy along. In the end our experience showed that abdominal sacrocolpopexy combined with STARR is a safe enough procedure. Keywords: Rectocele, perineum descending, rectal mucosal prolapse, sacrocolpopexy, stapled trance-anal resection, constipatio

High-Energy Neutrino Follow-up at the Baikal-GVD Neutrino Telescope

The Baikal-GVD deep underwater neutrino experiment participates in the international multi-messenger program to detect the astrophysical sources of high- and ultrahigh-energy cosmic-ray particles, being at the stage of array deployment and a step-by-step increase of the telescope’s effective volume to the scale of a cubic kilometer. At present, the telescope consists of seven clusters containing 2016 photodetectors. The effective volume of the detector has reached 0.35 km${}^{3}$ for the selection of shower events from neutrino interactions in Baikal water. The experimental data have been accumulated in a continuous exposure mode since 2015, allowing a prompt data analysis and a celestial-sphere monitoring program to be implemented in real time. We discuss the structure of the data acquisition system, describe the physical event reconstruction procedure in the mode of fast response to alerts, and present the results of our analysis of nine alerts from the polar IceCube telescope from early September to late October 2020