Decadal changes in the Canary upwelling system as revealed by satellite observations: Their impact on productivity

Satellite-derived sea-surface temperature (SST) data were used to study the variability of the Canary Upwelling Ecosystem-CUE (12 to 43N) over the last two decades of the 20th century. The analysis reveals well known patterns of climatology and seasonal variability in this upwelling system. In contrast to quasi-regular decadal oscillations of SST anomalies observed in the open ocean, the coastal variability during the 1980s–1990s was better described as a decadal scale shift of the upwelling regime intensity. The analysis of the upwelling index and coastal zonal gradient of SST showed that this shift occurred earlier (∼1992) in the northern part of the CUE (off western Iberia) and some years later (∼1995) off the northwest African coast. The long-term variability of upwelling-favorable wind forcing during the examined period provides reasonable explanations for the observed shift of the upwelling intensity and its timing for the whole CUE. Finally, changes in the productivity of several small pelagic fish species observed for the same period suggest that there was a response of the ecosystem to these changes

The time-frequency method of signal analysis in internal combustion engine diagnostics

The paper presents the results of the study of applicability of time-frequency correlation functions to solving the problems of internal combustion engine fault diagnostics. The proposed methods are theoretically justified and experimentally tested. In particular, the method's applicability is illustrated by the example of specially generated signals that simulate the vibration of an engine both during the normal operation and in the case of a malfunction in the system supplying fuel to the cylinders. This method was confirmed during an experiment with an automobile internal combustion engine. The study offers the main findings of the simulation and the experiment and highlights certain characteristic features of time-frequency autocorrelation functions that allow one to identify malfunctions in an engine's cylinder. The possibility in principle of using time-frequency correlation functions in function testing of the internal combustion engine is demonstrated. The paper's conclusion proposes further research directions including the application of the method to diagnosing automobile gearboxes

Renal Lymph Oxygen Tension During Graded Renal Ischemia

Renal lymph oxygen tension in dogs during graded renal ischemi

The use of nitinol rods in stabilization of the lumbar spine for patients under 21 years

The outcomes of surgical treatment of 25 young patients with degenerative diseases of the lumbar spine in two groups were compared in patients with nitinol rods (dynamic stabilization) without spondylodesis and with rigid lumbar fixation of titanium rods. Men - 12, women - 13, the average age is 17.6 years (from 16 to 21 years). These patients are divided into 2 groups depending on the stabilization method. Clinical and radiological results were monitored at least 1 year after the operation. In our study we used nitinol rods of 2 standard sizes - 60 and 80 mm. The size and curvature of the bending of the rods is calculated from the average anatomical parameters characteristic of the lumbar spine and lumbosacral junction. In all groups, there were no statistically significant differences in preoperative values and in the control periods of observation of the VAS (for both the back and the lower limb), Oswestry and SF-36 between patients with nitinol and titanium rods (p> 0.05). In both cases (rigid and dynamic stabilization), statistically significant changes were noted in the postoperative period (p <0.01). In both groups, in comparison with preoperative values, improvement was observed in all control periods, which were highly statistically significant (p <0.01). When studying the mobility in stabilized segment with dynamic nitinol rods, it is determined that the mobility, which persists in 1 segment, averages 4.8°. This index is within the limits of measurement error (up to 5°), however, when measuring mobility in two segments, the mobility is 9.6°. Transpedicular fixation of the lumbosacral spine with the use of nitinol rods is an effective technology that allows to keep movements in the lumbosacral spine in combination with a stable fixation. Further study of this technology should continue, including with reference to deformations of the spine

Peripheral nerve sheath malignancy with multiple metastasis: a rare clinical case

Background. Tumours of peripheral nervous system are represented by benign and malignant neoplasms with different clinical and biological traits. Malignant peripheral nerve sheath tumours of paraspinal localisation with the involvement of nerve structures are extremely rare and may occur isolated or comorbid with congenital neurofibromatosis. Current literature contains a few bioptic and selected autopsy clinical reports. Herewith, we present an own sectional observation of a rare malignant peripheral nerve sheath tumour with multiple metastasis supplemented with morphological and immunohistochemical descriptions.Clinical Case Description. An autopsy was performed on a 30-yo man’s cadaver. A tumour infiltrate was observed along Th5—Th9 of the spinal column intimately associated with thoracic vertebral bodies. Metastases were detected in the right lung, myocardium, peripancreatic and perirenal adipose tissue. Histological tumour examination revealed heterogeneous solid and rosette-like structures. Tumour immunophenotype: vimentin+, pancytokeratin-, CD45-, S-100+, NSE+, GFAP-, proliferative activity index (Ki-67 = 75-80%). This profile is descriptive of peripheral nerve sheath malignancy of high grade with multiple organic metastases.Conclusion. The sectional observation presented illustrates the difficulty to in vivo diagnose rare peripheral nerve sheath malignancies due to their infiltrative growth into spinal bone marrow and metastasis to organs (lungs, myocardium, peripancreatic and perirenal adipose tissue)

Complex neuroimaging study of the proximal segment after rigid fixation and dynamic stabilization in patients with degenerative lumbar disease

Background. The development of the adjacent level syndrome and, as a consequence, adjacent segment degenerative disease are currently the most common complications of decompression and stabilization surgery with the development of segmental instability. The aim of the study. To conduct a comprehensive neuroimaging assessment of  the proximal adjacent segment after rigid fixation and dynamic stabilization in degenerative lumbar disease. Materials and methods. We conducted a prospective multicenter study of the results of surgical treatment of 274 patients with degenerative-dystrophic diseases of the lumbar spine, who underwent monosegmental decompression and stabilization surgery using the TLIF (transforaminal lumbar interbody fusion) technique and open transpedicular rigid fixation, as well as open hemilaminectomy with stabilization of the operated segments with nitinol rods. The study included radiography, diffusion-weighted magnetic resonance imaging and computed tomography (dualenergy mode) of intervertebral discs and isolated facet degeneration of the upper adjacent level. Results and discussion. Combination of the initial proximal segment degeneration in the form of  facet joints degeneration (density of cartilaginous plate  – 163.5 ± 14.2 HU, density of external facet – 709.35 ± 13.6 HU, density of internal facet – 578.1  ±  12.1  HU), Pfirrmann III, IV  grade degeneration of intervertebral disc and a measured diffusion coefficient of less than 1300 mm2/s cause high risks of developing adjacent segment degenerative disease, which regulates the use of monosegmental dynamic fixation with nitinol rods, or preventive rigid fixation of the adjacent segment. Conclusion. Using complex neuroimaging in the preoperative period makes it possible to predict the results of surgical treatment, take timely measures to prevent degenerative diseases of the adjacent segment, and to carry out dynamic monitoring of processes in the structures of the spinal motion segment

Технология осевой обработки высокопроизводительным инструментом деталей типа «ступица»

Basic technological process of producing holes in the hub of the epicycle MTZ using the tool: center drill, twist drill, countersink is analyzed. Modes are chosen for the base treatment process and the tool life was measured. The tests of the instrument with a modified geometry series DRILL RUSH are conducted. The optimal treatment regimens are found and the tool life is measured. It was found that in the area of optimum cutting resistance the life of one of the drill head series DRILL RUSH is within 240-260 machined hubs. Significantly higher than the tool life for the base variant 20-80 times. A performance of the drilling operation for 12 holes is increased by 24 times.Проведен анализ базового технологического процесса получения отверстий в ступице эпицикла трактора МТЗ с использованием центровочного сверла, спирального сверла, зенкера. Подобраны режимы обработки для базового технологического процесса и измерена стойкость инструмента. Проведены испытания инструмента с измененной геометрией серии DRILL RUSH, подобраны оптимальные режимы обработки и замерена стойкость инструмента. В ходе проведения исследования установлено, что в зоне оптимального режима резания стойкость одной сверлильной головки серии DRILL RUSH находится в пределах 240-260 обработанных ступиц. Стойкость инструмента по предложенному варианту в 20-80 раз превышает стойкость базового варианта технологического процесса обработки. Производительность операции сверления 12 отверстий увеличивается в 24 раза

Distribution of sedimentary rock types through time in a back-arc basin: A case study from the Jurassic of the Greater Caucasus (Northern Neotethys)

Abstract The evolution of sedimentary basins can be explored by analyzing the changes in their lithologies and lithofacies (i.e. predominant lithologies). The Greater Caucasus Basin, which was located at the northern margin of the Neotethys Ocean, represents a complete Sinemurian-Tithonian succession. A quantitative analysis of compiled datasets suggests that principal lithologies and lithofacies are represented by siliciclastics, shale and carbonates. The relative abundance of siliciclastics and shale decreased throughout the Jurassic, whereas that of carbonates increased. Evaporites are known from the Upper Jurassic, while volcaniclastics and volcanics, as well as coals, are known only in the Lower to Middle Jurassic. Siliceous rocks are extremely rare. Lithology and lithofacies proportions change accordingly. The Sinemurian-Bathonian sedimentary complex is siliciclastic-and-shale-dominated, whereas the Callovian-Tithonian sedimentary complex is carbonate-dominated. A major change in the character of sedimentation occurred during the Aalenian-Callovian time interval. Regional transgressions and regressions were more important controls of changes in the sedimentary rock proportions than average basin depth. Landward shoreline shifts were especially favorable for carbonate accumulation, whereas siliciclastics and shale were deposited preferentially in regressive settings. An extended area of the marine basin, its lower average depth, and a sharp bathymetric gradient favored a higher diversity of sedimentation. An orogeny at the Triassic-Jurassic transition was responsible for a large proportion of siliciclastics and extensive conglomerate deposition. An arcarc collision in the Middle Jurassic also enhanced the siliciclastic deposition. Both phases of tectonic activity were linked with an increase in volcanics and volcaniclastics. Volcanism itself might have been an important control on sedimentation. A transition to carbonate-dominated sedimentation occurred in the Late Jurassic, reflecting a tectonically calm period

Experimental study of negative photoconductivity in n-PbTe(Ga) epitaxial films

We report on low-temperature photoconductivity (PC) in n-PbTe(Ga) epitaxial films prepared by the hot-wall technique on -BaF_2 substrates. Variation of the substrate temperature allowed us to change the resistivity of the films from 10^8 down to 10_{-2} Ohm x cm at 4.2 K. The resistivity reduction is associated with a slight excess of Ga concentration, disturbing the Fermi level pinning within the energy gap of n-PbTe(Ga). PC has been measured under continuous and pulse illumination in the temperature range 4.2-300 K. For films of low resistivity, the photoresponse is composed of negative and positive parts. Recombination processes for both effects are characterized by nonexponential kinetics depending on the illumination pulse duration and intensity. Analysis of the PC transient proves that the negative photoconductivity cannot be explained in terms of nonequilibrium charge carriers spatial separation of due to band modulation. Experimental results are interpreted assuming the mixed valence of Ga in lead telluride and the formation of centers with a negative correlation energy. Specifics of the PC process is determined by the energy levels attributed to donor Ga III, acceptor Ga I, and neutral Ga II states with respect to the crystal surrounding. The energy level corresponding to the metastable state Ga II is supposed to occur above the conduction band bottom, providing fast recombination rates for the negative PC. The superposition of negative and positive PC is considered to be dependent on the ratio of the densities of states corresponding to the donor and acceptor impurity centers.Comment: 7 pages, 4 figure

The first report of RPSA polymorphisms, also called 37/67 kDa LRP/LR gene, in sporadic Creutzfeldt-Jakob disease (CJD)

<p>Abstract</p> <p>Background</p> <p>Although polymorphisms of <it>PRNP</it>, the gene encoding prion protein, are known as a determinant affecting prion disease susceptibility, other genes also influence prion incubation time. This finding offers the opportunity to identify other genetic or environmental factor (s) modulating susceptibility to prion disease. Ribosomal protein SA (<it>RPSA</it>), also called 37 kDa laminin receptor precursor (LRP)/67 kDa laminin receptor (LR), acts as a receptor for laminin, viruses and prion proteins. The binding/internalization of prion protein is dependent for LRP/LR.</p> <p>Methods</p> <p>To identify other susceptibility genes involved in prion disease, we performed genetic analysis of <it>RPSA</it>. For this case-control study, we included 180 sporadic Creutzfeldt-Jakob disease (CJD) patients and 189 healthy Koreans. We investigated genotype and allele frequencies of polymorphism on <it>RPSA </it>by direct sequencing or restriction fragment length polymorphism (RFLP) analysis.</p> <p>Results</p> <p>We observed four single nucleotide polymorphisms (SNPs), including -8T>C (rs1803893) in the 5'-untranslated region (UTR) of exon 2, 134-32C>T (rs3772138) in the intron, 519G>A (rs2269350) in the intron and 793+58C>T (rs2723) in the intron on the <it>RPSA</it>. The 519G>A (at codon 173) is located in the direct PrP binding site. The genotypes and allele frequencies of the <it>RPSA </it>polymorphisms showed no significant differences between the controls and sporadic CJD patients.</p> <p>Conclusion</p> <p>These results suggest that these <it>RPSA </it>polymorphisms have no direct influence on the susceptibility to sporadic CJD. This was the first genetic association study of the polymorphisms of <it>RPSA </it>gene with sporadic CJD.</p