Large Bodies Research Articles

A narrative review of pelvic floor muscle training in the management of incontinence following prostate treatment.

Background and ObjectiveUrinary incontinence following prostate treatment (IPT) is a common complication with corresponding negative impacts on quality of life. Pelvic floor muscle training (PFMT) is a non-invasive treatment strategy to treat combat this clinical issue, and has been recognized by medical associations globally and increasingly supported by large bodies of literature. Accordingly, many studies demonstrate a significant benefit of pelvic floor muscle training to continence status and quality of life in men with incontinence following prostate treatment. However, related research is limited by variety in treatment regimens, outcome measures, and study designs, with unclear impact on treatment success. We aim to provide a brief overview of pathology and incidence of incontinence following prostate surgery and an understanding how PFMT is currently used to treat and prevent this clinical consequence.MethodsA comprehensive literature search was conducted utilizing PubMed, Medline, and Google Scholar. Search criteria included systematic reviews and randomized control trials published in the year 2000 to present. References of resulting studies were further analyzed to identify further articles of relevance. Keywords searched included: “post-prostatectomy incontinence”, “pelvic muscle strengthening”, “Benign Prostatic Hyperplasia”, and “pelvic floor muscle training”. Peer-reviewed publications that demonstrated a novel addition to the existing body of literature on this subject were included.Key Content and FindingsUpon review of the current research landscape, PFMT is largely supported in treatment of IPT. Analysis of current literature on this subject demonstrates heterogeneity in protocols, measures of treatment success, and patient numbers. Nevertheless, benefits to continence and quality of life are noted across an expansive body of literature and as such, PFMT is therefore recommended as an important part of the treatment algorithm following radical prostatectomy.ConclusionsPFMT is an important and effective part of the treatment algorithm in the prevention and treatment of IPT. Additional research is needed to more extensively assess PFMT’s role in treating this clinical consequence, especially following other prostate surgeries.

Promoting body positivity through stories: How protagonist body size and esteem influence readers’ self-concepts

Through two experiments (N = 497), we documented how distinct portrayals of women in stories can impact readers’ engagement in social comparisons and influence important aspects of their self-concepts. Specifically, this research investigated the effects of character body size (thin vs. large), body esteem (low vs. high), and story ending valence (sad vs. happy) with two distinct storylines. Results indicated that high (vs. low) body esteem characters are not only rated more aspirational, but also led readers with greater self-discrepancy to report lower state body image, suggesting upward social comparison processes are at play. Further, results indicated that reading about characters with large (vs. thin) bodies can positively affect readers’ body image; however, this positive effect may be explained by downward social comparison. Findings highlight the complexities of body appearance and confidence. Strategies for effectively promoting body positivity via text-based interventions are discussed.

Vendian age of igneous rocks of the Chamberlain valley area (Northern part of the Wedel Jarlsberg Land, Svalbard Archipelago)

The geological structure, structural relations with the underlying complexes, mineral composition, age and origin of sedimentary-volcanogenic and intrusive formations of the Chamberlain valley area (northern part of the Wedel Jarlsberg Land, Svalbard Archipelago) are considered. As a result of the studies, two stages of the Late Precambrian endogenous activity in this area have been identified. For the first time the Vendian ages (593-559 Ma) of intrusive (dolerites) and effusive (basalts, andesites, tuffs) rocks were determined by U-Pb-method (SHRIMP-II) for Svalbard Archipelago. At the same time, the Grenville ages for large bodies of gabbro-diorites, metadolerites bodies (1152-967 Ma), and metagranites (936 Ma) were determined for the first time for this area, which correlates well with the ages of magmatic formations obtained earlier in the southern part of Wedel Jarlsberg Land. A detailed petrographic and petrochemical characterization of all the described objects were compiled and the paleotectonic conditions of their formation were reconstructed. Based on these data, the Chemberlendalen series, which is dated to the Late Vendian, and the Rechurchbreen series, which the authors attribute to the Middle Riphean and correlate with the lower part of the Nordbucht series are distinguished. The data obtained indicate a two-stage Precambrian magmatism in this area of the Svalbard archipelago and, most importantly, provide evidence for the first time ever of endogenous activity on Svalbard in the Vendian time. This fact makes it possible to reconsider in the future the history of the formation of folded basement of the Svalbard archipelago and the nature of the geodynamic conditions in which it was formed.

Water Body Extraction in Remote Sensing Imagery Using Domain Adaptation-Based Network Embedding Selective Self-Attention and Multi-Scale Feature Fusion

A water body is a common object in remote sensing images and high-quality water body extraction is important for some further applications. With the development of deep learning (DL) in recent years, semantic segmentation technology based on deep convolution neural network (DCNN) brings a new way for automatic and high-quality body extraction from remote sensing images. Although several methods have been proposed, there exist two major problems in water body extraction, especially for high resolution remote sensing images. One is that it is difficult to effectively detect both large and small water bodies simultaneously and accurately predict the edge position of water bodies with DCNN-based methods, and the other is that DL methods need a large number of labeled samples which are often insufficient in practical application. In this paper, a novel SFnet-DA network based on the domain adaptation (DA) embedding selective self-attention (SSA) mechanism and multi-scale feature fusion (MFF) module is proposed to deal with these problems. Specially, the SSA mechanism is used to increase or decrease the space detail and semantic information, respectively, in the bottom-up branches of the network by selective feature enhancement, thus it can improve the detection capability of water bodies with drastic scale change and can prevent the prediction from being affected by other factors, such as roads and green algae. Furthermore, the MFF module is used to accurately acquire edge information by changing the number of the channel of advanced feature branches with a unique fusion method. To skip the labeling work, SFnet-DA reduces the difference in feature distribution between labeled and unlabeled datasets by building an adversarial relationship between the feature extractor and the domain classifier, so that the trained parameters of the labeled datasets can be directly used to predict the unlabeled images. Experimental results demonstrate that the proposed SFnet-DA has better performance on water body segmentation than state-of-the-art methods.

Geomorphic and sedimentary signatures of catastrophic glacier detachments: A first assessment from Flat Creek, Alaska

Large-volume detachments of low-angle mountain glaciers involve the sudden mobilization of large amounts of glacier ice and lithic material in long-runout mass flows. Scientific investigations of these events have only recently brought to light their global occurrence and the similarities in the conditions under which they occur. While this recent research suggests that glacier detachments may become more frequent in a warming climate, a long-term record is largely lacking. Knowledge of the geomorphic signatures of glacier detachments could help establish such a record. Here, we present the first geomorphic and sedimentary assessment of a glacier detachment deposit. We investigate the landscape impacts of the Flat Creek glacier detachments in Alaska's St. Elias mountains through a combination of remote sensing analyses, field observations, Electrical Resistivity Tomography, and grain size and grain orientation analyses. From these data, we outline a land-system model that may help identify past glacier detachments elsewhere. Some of the most distinguishing features we documented were large bodies of buried ice-conglomerates, a rapid response of the remnant glacier ice, clusters of small-scale thermokarst ponds, countless molards, parallel striations etched into the hillslope and individual clasts, and a very long runout distance. We assess these features in terms of their longevity in the landscape and compare them to what has been described at glacier detachment sites elsewhere. Finally, we discuss to what extent glacier detachment deposits can be distinguished from deposits left by rock(−ice) avalanches, debris flows, and surging glaciers, and show that a differentiation is possible if detailed field investigations are undertaken.

The state of use of fish resources in small reservoirs of the Rivne Oblast

Poaching and unregulated amateur fishing have led to impoverishment and, in some places, complete extermination of populations of industrially valuable fish species in Rivne Oblast, so the activities of special commercial fisheries ensure the preservation of fish resources. The purpose of the study is to analyse the state of the water fund of the Rivne Oblast, the use of fish resources of these reservoirs, in particular, the results of the activities of special commercial fisheries, industrial and amateur fishing, and aquatic bioresources. According to the State Agency of land reclamation and fisheries in Rivne Oblast, over the past twenty years, there has been a tendency to reduce the volume of fish caught and introduced into natural and artificial reservoirs. Since 2010, due to low profitability, the activities of fishing organisations have been completely stopped, although previously commercial fishing of aquatic living resources took place on large water bodies, in particular in Rivers (Horyn, Ikva, Styr), lakes (Nobel, Putylivske), reservoirs (Mlynivske, Khrinnytske). Nowadays, the main method of fishing, in addition to the activities of special commercial fisheries, is unorganised amateur fishing. Specialised public organisations of amateur fishermen unite from 8 to 15 thousand amateur fishermen and sportsmen, carry out organised amateur fishing, are engaged in the introduction of fish resources into the water bodies of the region (carp, herbivorous fish, common pike, and silver crucian carp). Carp and crucian carp make up the largest share of fishermen’s catches; pike, common perch, silver carp, roach and rudd are less common. The state of fishery management in special commercial fisheries of the Rivne Oblast has not changed over the past 10 years. As of 2021, there were only 11 of them left in the region, working on lease terms; and several private enterprises where commercial fish is grown in full-system and non-system farms. The volume of young fish entering almost all farms has tripled compared to 2015, while the volume of fish caught has slightly increased. Analysis of the state of use of fish resources in small reservoirs is necessary for further rational extraction and restoration of fish resources in small reservoirs of the Rivne Oblast

Is there a trade-off between sperm production and sexual weaponry in the Amazon River prawn Macrobrachium amazonicum (Heller, 1862)?

The Amazon River prawn Macrobrachium amazonicum shows populations with four well-defined morphotypes in males. Dominant males of morphotypes green claw 1 (GC1) and green claw 2 (GC2) have large bodies and chelipeds and a higher reproductive success in comparison with the submissive morphotypes - translucent claw (TC) and cinnamon claw (CC). However, recently, some populations of the species do not have dominant morphotypes. Here, we compared the patterns of spermatic production and concentration among morphotypes and populations with three different phenotypes: (i) large-size amphidromous prawns, and (ii) large-size (“i” and “ii” with dominant morphotypes) and (iii) small-size hololimnetic prawns (without morphotypes). We described the spermatogenesis and the histochemical features of vasa deferentia (VD) and evaluated the relationship between the investment in spermatic production and sexual weapons acquisition in males of different phenotypes. The spermatic production and concentration in populations with four morphotypes were similar between morphotypes. The exception was the CC morphotype in which males had the seminiferous tubules filled with spermatocytes and low spermatic concentration. The spermatogenesis, spermiogenesis, and VD structure were not different among the studied phenotypes and populations. The seminal fluid of M. amazonicum is comprised by glycoproteins and by concentric layers of secretions of types I, II (basophilic), and III (eosinophilic). We could infer that males of dominant morphotypes allocate a higher amount of energy to the development of strong sexual weapons at the expense of the energy allocated to the reproductive system during the sequential growth. Inversely, small-size males direct more energy toward the spermatic production and transference at the expense of sexual weapons. Therefore, there is a clear trade-off between the investment in the gonadal and sexual weapons development in males of M. amazonicum.

Monitoring Water Turbidity in a Temperate Floodplain Using UAV: Potential and Challenges

The Lake Saint-Pierre (LSP) is a wide (≈300 km2) and shallow (≈3 m) lake created through a widening of the St. Lawrence River. Each spring, freshet makes it the largest floodplain in the province of Quebec. Agricultural practices in the littoral increase the water turbidity, which deteriorate the habitat’s quality of many fish species. However, measuring spatio-temporal turbidity patterns in the LSP floodplain remain difficult because turbidity is highly variable in space and time. This study aims to evaluate the potential to use an Unmanned Aerial Vehicle (UAV) to measure the water turbidity in the LSP’s floodplain. The results show that the UAV can efficiently measure the variation of turbidity in the LSP with a RMSE of 28.22 FNU. We also compared the turbidity retrieved from UAV with those retrieved from Sentinel-2 observations. The results show that the two models are comparable, even if Sentinel-2 yields better results. However, challenges remain when using UAV for turbidity monitoring, such as software limitations for mosaics creation over large water bodies. Nevertheless, the high spatial and temporal information can provide insights into the complex water turbidity patterns which characterize floodplains. The method could help land use management to improve the water quality of these ecosystems.

Zoning of the Arctic zone of the Russian Federation as the basis for the development of a fresh water observation system

Solving the problem of developing the Arctic zone of the Russian Federation without causing irreparable damage to the environment requires monitoring its various components. The article discusses the need to create a network of systems for the observation of the state of water resources in the polar regions. It is shown that, along with the existing monitoring system for large water bodies and streams, it is necessary to create a program of facilitated research on small lakes and rivers, which are extremely numerous within the Arctic zone and extremely vulnerable to various types of anthropogenic impact. In developing a network of such observation systems, the main attention should be paid not to the state of specific objects, but to identifying negative trends in various parts of the Russian Arctic zone in order to timely prevent large-scale fresh waters disasters. It is proposed that the creation of the network should be based on the principle of landscape-hydrological zoning, which takes into account both the genesis of water bodies and the specific features of the functioning of aquatic ecosystems. After the zoning of the territory of the Russian Federation Arctic Zone is completed, it is recommended that observations be carried out at reference water bodies located within all the selected regions, taking into account landscapes, both at the regional and, in the case of a significant scale of anthropogenic impact, at the local level. Along with general observations that need to be carried out at all points, which will make it possible to obtain data on the features of hydrological and in-lake processes in various parts of the Arctic zone and compare their course, it is also necessary to develop special observations. The latter, developed within each selected region, must meet the requirements for identifying the features of regional processes and information support for mathematical modeling of emergency situations and the ecological crisis caused by the main types of anthropogenic activity. The information obtained on reference lakes and streams of a hydrological region may reveal negative processes occurring throughout its area and indicate the need for emergency measures.

Direct Formation of Planetary Embryos in Self-gravitating Disks

Giant planets have been discovered at large separations from the central star. Moreover, a striking number of young circumstellar disks have gas and/or dust gaps at large orbital separations, potentially driven by embedded planetary objects. To form massive planets at large orbital separations through core accretion within the disk lifetime, however, an early solid body to seed pebble and gas accretion is desirable. Young protoplanetary disks are likely self-gravitating, and these gravitoturbulent disks may efficiently concentrate solid material at the midplane driven by spiral waves. We run 3D local hydrodynamical simulations of gravitoturbulent disks with Lagrangian dust particles to determine whether particle and gas self-gravity can lead to the formation of dense solid bodies, seeding later planet formation. When self-gravity between dust particles is included, solids of size St = 0.1–1 concentrate within the gravitoturbulent spiral features and collapse under their own self-gravity into dense clumps up to several M ⊕ in mass at wide orbits. Simulations with dust that drift most efficiently, St = 1, form the most massive clouds of particles, while simulations with smaller dust particles, St = 0.1, have clumps with masses an order of magnitude lower. When the effect of dust backreaction onto the gas is included, dust clumps become smaller by a factor of a few but more numerous. The existence of large solid bodies at an early stage of the disk can accelerate the planet formation process, particularly at wide orbital separations, and potentially explain planets distant from the central stars and young protoplanetary disks with substructures.

Size always matters, shape matters only for the big: potential optical effects of silica bodies in Selaginella.

Silica bodies are commonly found in Selaginella, but their function is unclear. Lens-like appearance and location in many species above giant chloroplasts of dorsal epidermal cells suggest optical functions. Silica body morphology in three Selaginella species was studied by microscopy. Optical effects were assessed by wave-optic simulations. Large convex, approximately hemispherical (papillose) and small approximately conical (concave–convex) silica bodies were found in different species. Both types lead to a concentrated spot of light high in the dorsal epidermal cell. Large convex bodies concentrate light 10–25 times in a shape-dependent manner by refraction, and small silica bodies concentrate light in a shape-insensitive, but wavelength-dependent, manner by diffraction (red light: approx. 2.3 times; blue light: approx. 1.5 times). Due to chloroplast movement, this concentrated light is above the chloroplast under high light, but within it under low light. Beyond the spot of concentration, light is dispersed into the chloroplast. Thin Selaginella leaves mean these effects may enhance light capture and minimize photodamage, but other effects such as inhibition of herbivory, mechanical support, and immune responses need to be considered. Silica bodies undoubtedly have optical effects, but their significance to the functioning of the plant requires direct studies of ecophysiological performance.

Assessment of spatial–temporal changes in water bodies and its influencing factors using remote sensing and GIS – a model study in the southeast coast of India

Concerns have been raised about the threat of ecological imbalance due to the loss of water bodies in densely populated areas. The present study explored the changes in water bodies in terms of area, number, and size in northern districts of Tamil Nadu, India, between 1978 and 2018 using satellite data, geographic information system, spatial analysis, ground truth verification, and field validation. The analysis indicated that the water bodies' area has reduced by 3027ha and 4363ha in the Kancheepuram and Tiruvallur Districts, respectively. Almost 179 water bodies have entirely disappeared, and 628 water bodies have been partly converted for other purposes. Of the disappeared water bodies, small, medium, and large water bodies account for 53, 93, and 33, respectively. The main reason for the changes in water bodies was the conversion to agriculture and buildings. Overall, the water bodies' area and number have been reduced by 9% and 12%, respectively, while the population has grown by 37%. The water bodies lost due to anthropogenic activities demand the scientific inventory of water bodies and integrated water resources management at a state or national level with strict monitoring regulations to protect them.

Laparoscopic Retrieval of multiple Sharp Foreign Bodies from Stomach in a Patient of Acuphagia – A Case Report

Foreign body ingestion is a common clinical scenario encountered in the emergency room with commonest cases presenting among children and in psychiatric adults. The key principle of management is dependent upon appropriate diagnosis and exact localization of the foreign body ingested and its type. Once an appropriate characterization of the ingested foreign body is made, further decision about its retrieval is based on whether any complication related to the foreign body, such as peritonitis is present or not. The method of retrieval can vary from minimally invasive to open surgery mostly dependent on availability of instruments and surgeon’s expertise. Unless any complication has occurred, surgeons in the current era are erring more towards minimally invasive methods. In cases where large or sharp foreign bodies are involved, that would demerit the use of endoscopy for its removal, surgeons are nowadays opting for laparoscopic removal instead of the traditional laparotomy. This case report highlights the use of laparoscopy for salvaging such foreign bodies especially when advantages such as, early post-operative recovery, less pain, minimal scar and decreased hospital stay over traditional laparotomy is involved Keywords: Gastro-intestinal tract, stomach, Foreign body, Acuphagia, Laparoscopic retrieval, Complications

On the Need for Collaborative Intelligence in Cybersecurity

The success of artificial intelligence (and particularly data-driven machine learning) in classifying and making predictions from large bodies of data has led to an expectation that autonomous AI systems can be deployed in cybersecurity applications. In this position paper we outline some of the problems facing machine learning in cybersecurity and argue for a collaborative approach where humans contribute insight and understanding, whilst machines are used to gather, filter and process data into a convenient and understandable form. In turn this requires a convenient representation for exchanging information between machine and human, and we argue that graded concepts are suitable, allowing summarisation at multiple levels of discernibility (granularity). We conclude with some suggestions for developing a hierarchical and graded representation.

Academic Vocabulary in Applied Linguistics Research Articles: A Corpus-based Study

Background. Generally operationalized as the words used more frequently in academic discourse for describing abstract ideas and processes, academic vocabulary poses a major learning burden for native and non-native speakers of English. Recent developments in corpus-based technologies and tools have made it possible to analyze large bodies of texts for profiling vocabulary items, and a growing number of studies investigated such vocabulary in research articles published in different disciplines.
 Purpose. Despite significant progress in academic word list development, research focusing on the contribution of the newly developed word lists in academic texts remained largely limited. Accordingly, the majority of studies used outdated lists for general and academic vocabulary as the starting points in their studies.
 Methods. The current study investigated a large corpus of applied linguistics research articles (2000 RAs, 15.5 million words, 20 journals) to identify frequently used academic words based on New Academic Word List (NAWL). In analyzing the data, predefined criteria were used and the study used flemma for counting and defining words.
 Results. The findings indicated that 310 out of 960 academic words in NAWL were used frequently in the corpus and provided 4.19% coverage. This coverage differs considerably with the previous studies that investigated similar corpora using the Academic Word List (AWL) and reported around and more than 10% coverage for academic vocabulary. Since the base lists used for profiling the corpus in this study were different from those employed by the previous studies, such differences mainly arise as a result of improvements in operationalizing general service and academic vocabulary.
 Implications. In light of these findings and recent calls for more replication research in vocabulary studies, the study draws some implications for researching and teaching academic vocabulary. Additionally, in order to facilitate academic vocabulary learning in applied linguistics, the study presents a list of frequently used NAWL items divided into six bands based on their frequency in the corpus.

Concentrations and health risk parameters of heavy metals in water samples from Epe Lagoon in Lagos State, Nigeria

Lagoons are large bodies of water that provide essential economic and ecosystem services such as fishing, erosion protection, transportation, as well as water for domestic, industrial, and agricultural use, among others. Unfortunately, municipal, agricultural, and industrial waste are often dumped in lagoons, polluting the water and predisposing humans and aquatic organisms to environmental and health hazards. This calls for regular monitoring of lagoons worldwide. This study assessed the water quality of Epe lagoon in Lagos State, Nigeria, with regard to heavy metal contamination. Water samples obtained at three settlements (Epe, Ejinrin, and Agbowa) along the lagoon were treated and subjected to heavy metal analysis using standard protocols. The heavy metals analysed were lead (Pb), copper (Cu), nickel (Ni), cadmium (Cd), and chromium (Cr). The chronic daily intake (CDI), chronic dermal contact (CDC), hazard quotients (HQ), heavy metal index (HMI), and probability of cancer risk (PCR) of the heavy metals were also calculated. The results revealed that the water samples from the three locations contained non-permissible levels of Pb, Cu, Ni, Cd, and Cr. The CDI, CDC, and HQ of the heavy metals via ingestion and dermal contact were within the recommended limits, except for Pb. Meanwhile, the HMI and PCR of all the heavy metals exceeded the permissible limits. The results obtained suggest that Epe lagoon’s water is contaminated with heavy metals and thus poses health hazards. Consequently, there is a need for heavy metal remediation and control in the lagoon.

The Reproduction of Shame: Pregnancy, Nutrition and Body Weight in the Translation of Developmental Origins of Adult Disease

Developmental origins of health and disease (DOHaD) and epigenetics have expanded understanding of how the environment affects the health of women before and during pregnancy—with lifelong health consequences for the fetus. This has translated to a narrow focus on women’s lifestyle during pregnancy, especially for women classified as obese. In this study, we show that psychosocial harms such as distress or shame felt by pregnant women are rarely countenanced in these endeavors. To demonstrate this, we examine published documents about a large set of trials of lifestyle interventions united through an international consortium. Yet there is now a literature in which pregnant women with large bodies report feeling humiliated and a wider literature on the stigma of obesity. We argue that shame is produced and reproduced through the discursive and material knowledge-making scientific practices of DOHaD translation. Interventions that intensify the shame of large body size in pregnancy may be stressful, and neurophysiological stress pathways are well-known within DOHaD to have consequences for fetal development, so these interventions potentially undermine the very processes they set out to protect. A feminist response may protect women from shame and redirect attention to the social and structural determinants of health.

Principles governing the selection of ore regions for gold deposit search

Background. In 2020, the Auditing Chamber of the Russian Federation, based on a representative report by its expert analysts M. Men’ and A. Kaulbars, proposed expanding the search for deposits of a number of metals, including gold. Since the fund of easily discovered gold deposits coming to the surface has been significantly reduced, prospecting of ore regions most promising in terms of gold deposits becomes highly relevant.Aim. In connection with the above task, it seems expedient to outline territories within the currently known gold provinces, where the prerequisites and signs of gold ores could be detected with minimal expenditures for their subsequent verification by drilling.Materials and methods. The study involved calculating the shares of the world’s gold reserves attributable to each type of distinguished deposits located in various rocks. The extensive experience of prospecting work carried out in recent decades and culminated in the discovery of the Muruntau deposit in Uzbekistan, a world leader in the development of gold deposits, and Russian largest and giant deposits – Natalka, Sukholozhskoe, Nezhdaninsky, Degdekansky, Maisky, Oktyabrsky, Pavlik, Kupol, as well as the Bakyrchik deposit in Kazakhstan and others, clearly shows that the most promising and largest deposits are selectively localized in favourable rocks and largescale disjunctive dislocations, or faults. To identify favourable rocks, the distribution of the world’s gold reserves in various rocks was analysed, as well as the distribution of reserves in the areas of the largest deposits in ore-bearing faults as the most favourable fault types containing the most powerful and extended gold ore bodies.Results. A comparison of the shares of reserves has shown that the most promising for prospecting are those rock complexes containing the highest proportions of the world’s gold reserves. The article presents the distribution of shares of the world’s gold reserves for near surface and deep-formed deposits of various types. The main share of the world’s gold reserves in deeply formed deposits is shown to be concentrated in the Phanerozoic strata of sandy-clayey composition and in the interlayers of easily replaceable carbonate and amphibolite shales developed in the Proterozoic quartzite-phyllite rocks. The reserves of near-surface gold-silver and gold-telluride ores are selectively located in the young Mesozoic-Cenozoic volcanic rocks of basalt-andesite composition, accompanied by dikes, subvolcanic stocks and the pipes of explosive breccias with large-scale gold ore bodies confined to them. Thus, the most promising areas for prospecting new deposits are those composed of the mentioned rock complexes and crossed by ore-bearing faults, in the zones of which the main largest ore bodies are concentrated. Conclusion. The conducted study into the distribution of the world’s gold reserves in the deposits of various types, as well as the selective localization of ores in deposits with the main and large scale ore bodies in the zones of ore-bearing faults (and, accordingly, containing the concentration of the main share of reserves in a particular deposit), provides a basis for discovering new deposits of the precious metal with minimal expenditures, thus contributing to increasing the resource base of the Russian Federation.

Ferruginous coated grains of microbial origin from the Lower Devonian (Pragian) of the Prague Basin (Czech Republic) – Petrological and geochemical perspective

A unique occurrence of ironstone lenses represented by ferruginous oncoids is reported from the offshore Řeporyje Limestone (Lower Devonian, Pragian) from the Prague Basin (the Stydlé Vody Quarry). The oncoidal cortices show distinct arrangement of hematite/chamosite and/or iron-bearing calcite laminae, which are irregular, wavy and with a relatively high degree of inheritance of shape of the topography of the underlying laminae. Micro-domes and bulges, comparable to those observed in stromatolites and laminae overgrowing topographic irregularities represented by agglutinated foraminifers cemented to oncoid surfaces, were fairly commonly observed. The foraminifers probably represent the earliest representatives of agglutinated foraminifera encrusting surfaces of ferruginous grains. The surfaces of oncoids are wavy and often wrinkled. Although no microbial remains that could have been directly associated with oncoidal growth were recorded, we regard above mentioned features as indicators of biogenicity of the precipitates. We could only speculate the nature of the microbial consortia, but we regard the alternation of Fe2+ (chamosite, iron-bearing calcite) and Fe3+ (hematite) phases as a result of coupled oxidation - reduction processes related to passive and/or active microbial metabolic activities (precipitation of ferrihydrite – hematite precursor) and passive mineral authigenesis mediated by microorganisms (precipitation of chamosite precursor). Spatially restricted occurrence of the oncoidal lenses along with Al/Al + Fe + Mn vs. Fe/Ti, Nd vs. Ce/Ce*, Eu/Sm vs. Sm/Yb and other crossplots suggest that hydrothermal fluids were the most probable source of ferrous iron. Since most of the known oolitic or oncolitic ironstones represent rather large sedimentary bodies deposited around storm wave base to shallow subtidal environments under influence of upwelled anoxic watermasses or continental runoff, the reported oncolitic mounds represent a specific example of ironstones formation.

Технология механической обработки, цифровое моделирование и реализация устройства для контроля формы крупногабаритных деталей

Introduction. The development of a method for controlling the accuracy parameters of large axisymmetric bodies is an urgent task that is being solved by specialists from various industries. Application for adjustment and correction of machining based on the measurement of surface shape parameters directly during machining is shown. Purpose of work is to improve mobile processing technologies using special measuring devices and processing module. For this, the problems of development and analysis of mathematical models that describe the process of basing and machining of a riding ring as a cylindrical object with a non-stationary axis of rotation is solved. A study of the methodology is carried out, control schemes are designed, and equipment for processing mobile devices is developed. The methods of research are the analysis of the developed mathematical models, taking into account the assignment of effective technological modes. Three-dimensional and simulation modeling of processing, hardware-software implementation of proposed solutions, and statistical processing of measurement results are carried out. Results and discussion. The algorithm and methodology are tested with a three-dimensional simulation model. The presented methodology for measuring and calculating the allowance for mechanical restoration can significantly reduce machining time compared to active form control and compared to the traditional method of assigning an allowance for machining. The measurement and adjustment of the allowance based on the measurement data is not carried out after each measurement, but only in the case of transition to finishing transitions or for accuracy control. It is determined that by providing a single technological base for each individual technological transition within the framework of the mobile technology of machining of the rolling surface of the riding rings of technological drums, the accuracy and speed of processing increase. An original design of the device for monitoring parameters is developed; an experimental assembly and a laboratory model of the riding ring are made.