Absolute Size Research Articles

Deep Learning for Small and Tiny Object Detection: A Survey

In recent years, thanks to the development of Deep Learning methods, there has been significant progress in object detection and other computer vision tasks. While generic object detection is becoming less of an issue for modern algorithms, with the Average Precision for medium and large objects in the COCO dataset approaching 70 and 80 percent, respectively, small object detection still remains an unsolved problem. Limited appearance information, blurring, and low signal-to-noise ratio cause state-of-the-art general detectors to fail when applied to small objects. Traditional feature extractors rely on downsampling, which can cause the smallest objects to disappear, and standard anchor assignment methods have proven to be less effective when used to detect low-pixel instances. In this work, we perform an exhaustive review of the literature related to small and tiny object detection. We aggregate the definitions of small and tiny objects, distinguish between small absolute and small relative sizes, and highlight their challenges. We comprehensively discuss datasets, metrics, and methods dedicated to small and tiny objects, and finally, we make a quantitative comparison on three publicly available datasets.

Diversification measures: Mutual fund family case

This study introduces a portfolio theory motivated approach to measuring mutual fund family-level risk diversification. The average cross-fund correlation in idiosyncratic returns measures diversification of idiosyncratic risk, while the correlation of predicted returns from the multifactor model measures factor risk diversification within a fund family. We document a substantial cross-sectional variation in family-level diversification measured with our new proxies independent of the number of funds and objectives in the family. While number of objectives is a popular yet possibly misleading measure of diversification, there is a link between portfolio theory-based diversification measures and the number of objectives in a family. On average, fund families with more investment objectives are more diversified in terms of both idiosyncratic and factor risks; yet, in large families, more investment objectives are associated with increased diversification of idiosyncratic risk but decreased diversification of factor risk. Fund family diversification improves family performance during market downturns and in large families. However, fund family diversification does not significantly affect absolute or relative family size, except for the number of investment objectives, which has a negative relation to family size.

Cyclic relationship of mechanical likelihood: Coupling perception-action states in extended haptic accuracy

The present study investigates the dynamic nature of haptic accuracy in racket sports, specifically focusing on self-produced movements in participants with different skill levels (novice vs. expert). The study examines performance accuracy using indicators such as absolute error size and the coefficient of restitution as measures of haptic accuracy. To collect and analyze the data, custom-made devices, including shock and vibration sensors and Qualisys Track Manager, were used. The results indicate that skilled participants demonstrated higher accuracy, reflected by smaller absolute error sizes, and exhibited reduced variability in impulse vibration during self-produced movements. Moreover, employing maximum likelihood estimation and differential equations, we reveal cyclic relationships among these mechanical features. These findings provide valuable insights into perception-action coupling within different haptic skill levels, contributing to a comprehensive understanding of expertise in racket sports. By shedding light on the intricate relationship between haptic accuracy and performance, this research offers a valuable framework for studying perception-action coupling in racket sports and can potentially guide future investigations.

Phylogenetic meta-analysis reveals system-specific behavioural type-behavioural predictability correlations.

The biological significance of behavioural predictability (environment-independent within-individual behavioural variation) became accepted recently as an important part of an individual's behavioural strategy besides behavioural type (individual mean behaviour). However, we do not know how behavioural type and predictability evolve. Here, we tested different evolutionary scenarios: (i) the two traits evolve independently (lack of correlations) and (ii) the two traits' evolution is constrained (abundant correlations) due to either (ii/a) proximate constraints (direction of correlations is similar) or (ii/b) local adaptations (direction of correlations is variable). We applied a set of phylogenetic meta-analyses based on 93 effect sizes across 44 vertebrate and invertebrate species, focusing on activity and risk-taking. The general correlation between behavioural type and predictability did not differ from zero. Effect sizes for correlations showed considerable heterogeneity, with both negative and positive correlations occurring. The overall absolute (unsigned) effect size was high (Zr = 0.58), and significantly exceeded the null expectation based on randomized data. Our results support the adaptive scenario: correlations between behavioural type and predictability are abundant in nature, but their direction is variable. We suggest that the evolution of these behavioural components might be constrained in a system-specific way.

Assessment of the trend in demographic processes of population aging in the northern and equated territories of the Irkutsk region

Introduction. The process of population aging, characterized by a gain in the group of people of older working age in the age structure, has begun in Russia, and in the developed countries. The demographic policy of the state is aimed at creating a favourable age and gender structure of the population with the aim of systematic socio-economic development of the regions.
 The purpose of the study is to give a comprehensive assessment of the trend in demographic aging of the population of the northern and equated territories of the Irkutsk region over 2011–2019.
 Materials and methods. The selection of territories is based on the Decree of the Government of the Russian Federation of November 16, 2021 N 1946 “On approval of the list of regions of the Far North and areas equated to regions of the Far North”. Information on the absolute size of the total population, population by gender and individual age groups was obtained from the Rosstat service for the Irkutsk region. In accordance with the methodological provisions on demographic statistics, special aging coefficients were studied in the formed statistical population using the Statistica 6.0 MS Excel 2017 software packages.
 Results. In the northern and equated territories of the Irkutsk region, population aging processes are taking place. The intensity of the aging process in the regions in time proceeds differently. There is a disproportion in the age-gender structure due to the feminization of aging, which leads to deformation of the age-gender pyramid. In most regions, the depth of aging is decreasing, the number of people surviving to the age group of 75–89 years is becoming smaller. There is a twofold gain in the pension burden coefficient, its trend in the regions is similar to the Irkutsk region in general, with the exception of Bratsky, Nizhneilimsky, Ust-Kutsky industrial areas.
 Research limitations. The method used is applicable in the study of the trend in the population aging rate in certain territories.
 Conclusion. The formation of a steady growth trend of indicators characterizing the processes of population aging in the territories determines the need to develop programs to improve demographic policy in the subject of the Federation.

Parametric study on utilization of PV-energy in residential microgrids with hot water heating

The seamless coexistence of distributed photovoltaics (PV) with the utility network may be maintained by focusing on higher energy autonomy of micro-grids.This may be approached by seeking any opportunities to increase local energy consumption, especially when legal regulations are cutting-down the benefits for energy overproduction.The microgrids combining PV with electric storage and heat pumps largely fail at satisfying local energy needs autonomously in winter periods and create excessive load of power network. Although the all-electric microgrid is a long term target, any improvements to the existing residential infrastructure with mixed-supply sources are worth revisiting as low-cost steps towards more conscious energy utilization.The concept of using Domestic Hot Water (DHW) heating to dump locally the excess of PV-energy is affordable method to improve energy autonomy of residential microgrids with minimal interference to their existing configuration and the advantage of no additional energy demand.The use of PV for DHW heating was studied in various configurations, but in contrast to former works, this paper presents the parametric analysis focusing on increasing the local consumption (goal A), minimizing the interference with utility grid (goal B) and optimal adjustment to net-metering accounting rules (goal C).The case study is the residential-type micro-grid in climate of Central Europe. The study uses both simulated (energy consumption profiles) and recorded (solar irradiance) data. The simulation is based on microgrid proportions and provides the results beyond reach of single experiments and conclusions applicable to similar cases, regardless the absolute size.

Appraisal of evidence reliability and applicability of Paxlovid as treatment for SARS-COV-2 infection: A systematic review.

This study aimed to clarify the beneficial effect and the clinical application value of Paxlovid in the treatment of coronavirus disease-19 (COVID-19) through a systematic review. Databases including PubMed, Cochrane Library, Chinese Clinical Trial Registry, and ClinicalTrials.gov were systematically searched for interventional or observational studies on the efficacy and safety of Paxlovid in the treatment of SARS-COV-2. The relative and absolute effect sizes for the outcomes were calculated based on the data reported in the original intervention literature. The external applicability of the evidence was analysed in terms of clinical application scenarios, patient willingness, and cost utility. One interventional and three observational studies were conducted. Four studies published in 2022, had participation sample sizes ranging 1780-109,254. Based on the randomised controlled trial data, the risk of all-cause mortality, all-cause death, and hospitalisation was significantly reduced in the Paxlovid group. Serious adverse events were reduced during the study. Based on observational studies, Paxlovid can significantly reduce the risk of death and hospitalisation in older patients with COVID-19 (moderate certainty) and improve in-hospital disease progression, composite disease progression, and viral load (low certainty). Paxlovid did not improve the outcomes of death and hospitalisation (low certainty) in patients aged <65years. As per the economic utility analysis, the economic cost of reducing one death dramatically decreased with increasing age. Early use of Paxlovid in the older adult population with COVID-19 is beneficial. However, in the setting of limited resources, Paxlovid should be prioritised for older patients.

Examining the role of different weakness categories for mobility and future falls in older Americans.

Recently developed absolute and body size normalized handgrip strength (HGS) cut-points could be used individually and collectively to predict mobility problems and falls. We examined the associations of (1) each absolute and normalized weakness cut-point, (2) collective weakness categories, and (3) changes in weakness status on future falls in older Americans. The analytic sample included 11,675 participants from the 2006-2018 waves of the Health and Retirement Study. Falls were self-reported. Men were classified as weak if their HGS was < 35.5-kg (absolute), < 0.45kg/kg (body mass normalized), or < 1.05kg/kg/m2 (body mass index normalized). While, women were considered weak if their HGS was < 20.0-kg, < 0.337kg/kg, or < 0.79kg/kg/m2. Collective weakness categorized those below 1, 2, or all 3 cut-points. The collective weakness categories were also used to observe changes in weakness status over time. Older Americans below each absolute and normalized cut-point had greater odds for future falls: 1.23 (95% confidence interval (CI): 1.15-1.32) for absolute weakness, 1.20 (CI 1.11-1.29) for body mass index normalized weakness, and 1.26 (CI 1.17-1.34) for body mass normalized weakness. Persons below 1, 2, or all 3 weakness cut-points had 1.17 (CI 1.07-1.27), 1.29 (CI 1.18-1.40), and 1.36 (CI 1.24-1.48) greater odds for future falls, respectively. Those in some changing weakness categories had greater odds for future falls: 1.26 (CI 1.08-1.48) for persistent and 1.31 (CI 1.11-1.55) for progressive. Collectively using these weakness cut-points may improve their predictive value. We recommend HGS be evaluated in mobility and fall risk assessments.

Numerical study on spray characteristics of liquid jets in supersonic crossflow

The spray characteristics of liquid jets in supersonic crossflow at different injection jet-gas momentum ratios are investigated numerically. The compressible two-phase flow large eddy simulation (LES) method is based on the Eulerian-Lagrangian scheme. The average droplet volume fraction is defined to quantify spray concentration distribution, which can also reflect the oscillation boundary of the spray. The LES predicted the spray boundaries at different injection jet-gas momentum ratios in the central and cross-sectional planes, which agree reasonably well with the experiment. Two sets of counter-rotating vortex pair (CVP) are in the gas-liquid mixing region. As injection momentum ratio q increases, the upper CVP increases. Still, the absolute size of the wall CVP remains almost unchanged, which means that the relative size of the wall CVP to the upper CVP becomes smaller. As q increases, the spray's overall distribution position is generally upward, and the number of droplets entering the near-wall region becomes small. Thus, droplet-wall interactions are weakened. The spray body increases with the increase of q, while the spray foot decreases gradually. In the central plane, the coherent structures near the wall are mainly composed of splashed droplets, and this phenomenon gradually weakens as q increases. Although the increase of q can increase the total droplet mass flow rate, the proportion of the droplet mass flow rate in the near-wall region to the total mass flow rate decreases, and the droplet mass flow rate in the near-wall region decreases.

Croatian Regional Export Value-Added Chains

This paper examines Croatian Regional Value Chains (RVCs). We use the value chain approach to study supply chains, examining data specifically for Croatia and its proximate trading partners in the European Union, as well as some other European countries. The value added in Croatian exports is statistically related to the value added in the exports of Croatian trading partners. We argue that Croatian RVCs are organized around regional production centers, with proximity to production capacity, raw materials, and customers as driving factors, and thus most of the value added originates in these RVCs. This paper emphasizes the advantages of representing trade through value added over traditional gross trade statistics and highlights the robustness of RVCs in Croatia to global shocks and transportation reliability issues. We conclude that despite its small absolute size, the Croatian economy is dynamically well-integrated into the EU RVCs, which is crucial for increasing business efficiency and competitiveness, notwithstanding the constraints of relatively low returns to scale. Overall, this study contributes to a better understanding of RVCs in Croatia and their potential benefits for Croatia in the global production organization.

Particle size effects on the axial pull-out and push-in behaviour of roots

For smaller plant roots in coarse-grained soils, large relative size of soil particles compared to roots can affect their axial resistance. Even for the larger roots of trees, particle size effects may be important, e.g. when testing 1:N scale models of tree uprooting in a geotechnical centrifuge. In this study the distinct element method (DEM) was used to investigate this problem. The sinker root of a centrifuge model tree root system under axial loading was analysed, with its simulated behaviour compared with finite element method (FEM) simulations, where the soil was modelled as a continuum and hence did not incorporate particle size effects. Both were validated against laboratory tests. Considering the same prototype size and soil particle size distribution, different scale factors/g-levels were applied to model roots, hence varying the ratio of root diameter (dr\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${d}_{\\rm r}$$\\end{document}) to mean particle size (D50\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${D}_{50}$$\\end{document}). Even at the lower dr/D50\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${d}_{\\rm r}/{D}_{50}$$\\end{document} values investigated (6–21), particle size effects on end-bearing capacity were negligible upon push-in of the root. In contrast, effects on shaft resistance (for pull-out) were significant and were interpreted by a simplified analytical model developed in this study using a combination of cavity expansion and root-particle size ratio. The absolute size of the root analogues considered was also representative of small diameter roots present in other plant species at 1:1 scale, making the analytical model also applicable to crop-lodging problems and for defining input parameters for analyses of nature-based solutions (NBS) using vegetation (e.g. for slope stabilisation).

ECONOMIC PERFORMANCE OF THE ENTERPRISES: A BIBLIOMETRIC ANALYSIS AT THE LEVEL OF EUROPE AND THE USA FOR THE LAST 5 YEARS

Performance can be seen as a concept that, after six decades of studies and approaches, is still seeking clarification. Over time, the performance has been viewed from several perspectives such as: the equivalent of organizational effectiveness, adaptability, sensitivity, and productivity, up to concepts from the economic-financial sphere such as: increasing added value, profitability, productivity, indebtedness, and solvency. If we look at performance as a term, we notice that it presents a certain imprecision and is rarely defined. In DEX “performance” is represented as “the outcome (especially good) obtained by someone in a sports competition”, “special achievement in a field of activity”, or “the best result obtained by a technical system…” (DEX, 1998). The meaning of word performance comes from the English language from the verb “to perform” which according to the translation made by google translate means to do something regularly, to fulfil an obligation, to execute a contract, to perform in the activity you carry out, to achieve the work. If we look at the word “performance” not from the perspective of the verb but of the subject, this approach leads us to the goal and the way in which an organization achieves its proposed objectives, a fact that can be viewed from the point of view of effectiveness and productivity. The indicators that are presented can be used to measure the economic-financial performance of the entities from a relative perspective and some of their limits have been identified in absolute size. An important trend that manifests itself in the field of measuring the economic-financial results of companies is represented by the increasing importance of intangible assets and intellectual capital, which must be reflected with the help of specific indicators. With the development of new technologies in the information field, many of the work tools of the industrial era have become outdated. The economic entities can no longer obtain long-term competitive advantages only through the rapid assimilation of new technologies or through very good management of financial resources. The ability of an economic entity to mobilize and exploit its intangible assets has become much more important than investments in fixed assets. The difficulties in the financial evaluation of some elements of the business activity such as the ability to organize production, the knowledge and skills of employees, their motivation, flexibility, customer loyalty, available databases, care for the environment, etc., have not allowed that these assets to be recognized as such in the companies’ balance sheets, although they are essential in the present and future competitive environment for the success of economic entities.

Fast, simple and calibration-free size characterization and quality control of extracellular vesicles using capillary Taylor dispersion analysis

This study reports the development of a Taylor Dispersion Analysis (TDA) method for the size characterization of Extracellular Vesicles (EVs), which are highly heterogeneous nanoscale cell-derived vesicles (30–1000 nm). Here, we showed that TDA, conducted in uncoated fused silica capillaries (50 µm i.d.) using a conventional Capillary Electrophoresis instrument, is able to provide absolute sizing (requiring no calibration) of bovine milk-derived EVs in a small sample volume (∼ 7 nL) and over their entire size range, even the smallest ones (< 70 nm) not accessible via other techniques that provide nanoparticle sizing in suspension. TDA size measurements were repeatable (RSD < 10%) and the average EV sizes were found in the range of 120–210 nm, in very good agreement with those measured with Nanoparticle Tracking Analysis, commonly used for EV characterization. TDA allowed quantitative estimation of EVs for concentrations ≥ 2 × 1011 EVs/mL. Furthermore, TDA was able to detect minor changes in EV size (i.e. by ∼25 nm upon interaction with specific anti-CD9 antibodies of ∼150 kDa), and to highlight the impact of extraction methods (i.e. milk pretreatment: freezing, acid precipitation or centrifugation; the type of size-exclusion chromatography column) and of fluorescent labeling (i.e. intravesicular or surface labeling) on the isolated EV population size. In parallel to EV sizing, TDA allowed to detect molecular contaminants (average sizes ∼1–13 nm) present within the sample, rendering this method a valuable tool to assess the quality and quantity of EV isolates.

Nest complexity correlates with larger brain size but smaller body mass across bird species.

Amniotes differ substantially in absolute and relative brain size after controlling for allometry, and numerous hypotheses have been proposed to explain brain size evolution. Brain size is thought to correlate with processing capacity and the brain's ability to support complex manipulation such as nest-building skills. The increased complexity of nest structure is supposed to be a measure of an ability to manipulate nesting material into the required shape. The degree of nest-structure complexity is also supposed to be associated with body mass, partly because small species lose heat faster and delicate and insulated nests are more crucial for temperature control of eggs during incubation by small birds. Here, we conducted comparative analyses to test these hypotheses by investigating whether the complexity of species-typical nest structure can be explained by brain size and body mass (a covariate also to control for allometric effects on brain size) across 1353 bird species from 147 families. Consistent with these hypotheses, our results revealed that avian brain size increases as the complexity of the nest structure increases after controlling for a significant effect of body size, and also that a negative relationship exists between nest complexity and body mass.

Deciphering the Morphology of Tumor-Stromal Features in Invasive Breast Cancer Using Artificial Intelligence

Tumor-associated stroma in breast cancer (BC) is complex and exhibits a high degree of heterogeneity. To date, no standardized assessment method has been established. Artificial intelligence (AI) could provide an objective morphologic assessment of tumors and stroma, with the potential to identify new features not discernible by visual microscopy. In this study, we used AI to assess the clinical significance of (1) stroma-to-tumor ratio (S:TR) and (2) the spatial arrangement of stromal cells, tumor cell density, and tumor burden in BC. Whole-slide images of a large cohort (n = 1968) of well-characterized luminal BC cases were examined. Region and cell-level annotation was performed, and supervised deep learning models were applied for automated quantification of tumor and stromal features. S:TR was calculated in terms of surface area and cell count ratio, and the S:TR heterogeneity and spatial distribution were also assessed. Tumor cell density and tumor size were used to estimate tumor burden. Cases were divided into discovery (n = 1027) and test (n = 941) sets for validation of the findings. In the whole cohort, the stroma-to-tumor mean surface area ratio was 0.74, and stromal cell density heterogeneity score was high (0.7/1). BC with high S:TR showed features characteristic of good prognosis and longer patient survival in both the discovery and test sets. Heterogeneous spatial distribution of S:TR areas was predictive of worse outcome. Higher tumor burden was associated with aggressive tumor behavior and shorter survival and was an independent predictor of worse outcome (BC-specific survival; hazard ratio: 1.7, P = .03, 95% CI, 1.04-2.83 and distant metastasis-free survival; hazard ratio: 1.64, P = .04, 95% CI, 1.01-2.62) superior to absolute tumor size. The study concludes that AI provides a tool to assess major and subtle morphologic stromal features in BC with prognostic implications. Tumor burden is more prognostically informative than tumor size.

Selection for Reduced Fear of Humans Changes Brain and Cerebellum Size in Red Junglefowl in Line with Effects of Chicken Domestication.

A central part of the domestication syndrome is a reduction in relative brain size. In chickens, it has previously been shown that domesticated birds have smaller relative brain mass, but larger relative mass of cerebellum, compared to their ancestors, the Red Junglefowl. It has been suggested that tameness may drive the domestication syndrome, so we examined the relationship between brain characteristics and tameness in 31 Red Junglefowl from lines divergently selected during ten generations for tameness. Our focus was on the whole brain, cerebellum, and the remainder of the brain. We used the isotropic fractionator technique to estimate the total number of cells in the cerebellum and differentiate between neurons and non-neuronal cells. We stained the cell nuclei with DAPI and performed cell counting using a fluorescence microscope. NeuN immunostaining was used to identify neurons. The absolute and relative masses of the brains and their regions were determined through weighing. Our analysis revealed that birds selected for low fear of humans (LF) had larger absolute brain mass, but smaller relative brain mass, compared to those selected for high fear of humans (HF). Sex had a significant impact only on the absolute size of the cerebellum, not its relative size. These findings support the notion that selection for increased tameness leads to an enlargement of the relative size of cerebellum in chickens consistent with comparisons of domesticated and ancestral chickens. Surprisingly, the HF birds had a higher density of neurons in the cerebellum compared to the LF line, despite having a smaller cerebellum overall. These findings highlight the intricate relationship between brain structure and behavior in the context of domestication.

Decent wage floors in Europe: Does the minimum wage directive get it right?

The Directive on Adequate Minimum Wages represents a watershed initiative adding substance to the EU’s social dimension. It contains two ambitious objectives: establishing the minimum level of statutory minimum wages at 60% of the gross median wage, and increasing collective bargaining coverage (CBC) to at least 80% of workers. In this article, we assess how statutory minimum wages and collective bargaining coverage are associated with the likelihood of low pay. Using a time series cross-section of EU-SILC for income years 2004–2019, we identify and assess the absolute and relative size of ‘effective wage floors’ for full-time employees in 30 countries. We specify multilevel, random effects within-between regression models to assess the individual and joint associations of SMW and collective bargaining coverage with wage floors. Our results indicate that SMWs and CBC both have distinct roles in establishing the effective wage floor. First, higher collective bargaining coverage is on average associated with a lower share of workers earning below 60% gross median wages. Second, higher SMWs are strongly associated with higher effective wage floors. Third, both collective bargaining coverage and union density are strongly associated with higher wage floors.

ПИЛОТНАЯ ВЕРСИЯ ШКАЛЫ СЛОЖНОСТИ ЛАПАРОСКОПИЧЕСКИХ ОПЕРАЦИЙ ПРИ НЕЙРОГЕННЫХ ОПУХОЛЯХ АБДОМИНАЛЬНОЙ ЛОКАЛИЗАЦИИ У ДЕТЕЙ

The purpose of this research was to develop a scale for risk, difficulty and complexity assessment of laparoscopic surgical interventions for neurogenic tumors of abdominal localization in children taking into account IDRF, tumor size and other criteria that affect the surgical outcome. Materials and methods used: 124 patients (68 (55%) boys/56 (45%) girls) aged 0 to 18 y/o (median age of 20.5 [5-50.5] months old) who have undergone laparoscopic surgery for neurogenic tumors of abdominal localization in Jan. 2018-Apr. 2022 were included in a single-center retrospective cohort study. An analysis was made of the relationship between the 24 criteria for the complexity of the surgical intervention and the parametric evaluation of its results (duration of surgical intervention; intraoperative blood loss; intraoperative blood transfusion; intraoperative complications and access conversion). As for the quantitative variables, the Spearman's rank correlation coefficient was used, and the eta coefficient for qualitative variables. Cluster analysis was used to distribute points by the difficulty levels. The ROC curve analysis with sensitivity and specificity for high level of complexity was used to check the scale of complexity. Results: median duration of surgical intervention was 105 [75; 150] min, volume of intraoperative blood loss - 5 [5; 20] ml. Blood transfusion was required in 15 (12%) cases, median blood transfusion was 0 [0; 0] ml. Intraoperative complications developed in 4 (3%) cases. Conversions were performed in 4 (3%) patients. 10 complexity criteria were selected: IDRF F1, F2, F3, F4, F5, location of the tumor center, extension beyond the midline, previous open surgery, contact of the tumor with the inferior vena cava, and the tumor volume (ml)/height (m) ratio of &gt; or &lt;/= 28. A pilot difficulty scale with three levels of difficulty has been developed. Sensitivity for a high level of complexity (6 or over pts) was 60% (95% CI 23.1-88.2%), specificity was 98.3% (95% CI 94.1-99.5%). Conclusion: different IDRFs contribute differently to the complexity and risk of laparoscopic surgery. The ratio of tumor size to growth is more significant criterion of complexity than the absolute size of the neoplasm. Other criteria of complexity also play an important role, such as previous open surgeries and tumor localization, in particular. The Authors do not recommend this scale for clinical use because the results obtained in this research would form the basis for further prospective study aiming to the development of a more accurate scale of the complexity of laparoscopic operations in neurogenic tumors of the abdominal localization.

Influence of size and concentration of carbonate biomineral on biocementation and bioclogging for mitigating soil degradation

Microbially induced carbonate precipitation (MICP) is a promising technique to enhance the geotechnical properties of geomaterial either by strengthening via biocementation or reducing the hydraulic conductivity via bioclogging. This rate of modification mainly depends on the amount, and nature of biomineral precipitated and it is influenced by various environmental, chemical, and microbial factors. Given this, the present study aims to investigate the effect of biochemical conditions such as concentration of biomass and chemical reagents on the amount and nature of biomineral and its impact on the strength and permeability of biomodified sand. For this, the two microbes i.e., Sporosarcina pasteurii and isolated Proteus species at three different initial concentrations and chemical reagents by varying 0.1–1 molar of urea and calcium were considered. The amount and microstructural behavior of biomineral in different biochemical conditions concluded that the governing mechanism differs for both biocementation and bioclogging under identical MICP treatment. The strength enhancement or biocementation is dependent on the size of the biomineral precipitated whereas the reduction in permeability or bioclogging is mainly dominated by the amount of biomineral. The optimum value of biochemical conditions i.e., 108 cells/ml of biomass and 0.25 M concentration of cementation reagents was chosen to further evaluate the effect of equal MICP treatment on the biocementation and bioclogging of sands having different grain sizes. The study infers that not the absolute size of the biomineral but the relative size of soil grain and biomineral influence the linkage between the soil particles and hence affect the strength of biomodified soil.

ПИЛОТНАЯ ВЕРСИЯ ШКАЛЫ СЛОЖНОСТИ ЛАПАРОСКОПИЧЕСКИХ ОПЕРАЦИЙ ПРИ НЕЙРОГЕННЫХ ОПУХОЛЯХ АБДОМИНАЛЬНОЙ ЛОКАЛИЗАЦИИ У ДЕТЕЙ

The purpose of this research was to develop a scale for risk, difficulty and complexity assessment of laparoscopic surgical interventions for neurogenic tumors of abdominal localization in children taking into account IDRF, tumor size and other criteria that affect the surgical outcome. Materials and methods used: 124 patients (68 (55%) boys/56 (45%) girls) aged 0 to 18 y/o (median age of 20.5 [5-50.5] months old) who have undergone laparoscopic surgery for neurogenic tumors of abdominal localization in Jan. 2018-Apr. 2022 were included in a single-center retrospective cohort study. An analysis was made of the relationship between the 24 criteria for the complexity of the surgical intervention and the parametric evaluation of its results (duration of surgical intervention; intraoperative blood loss; intraoperative blood transfusion; intraoperative complications and access conversion). As for the quantitative variables, the Spearman's rank correlation coefficient was used, and the eta coefficient for qualitative variables. Cluster analysis was used to distribute points by the difficulty levels. The ROC curve analysis with sensitivity and specificity for high level of complexity was used to check the scale of complexity. Results: median duration of surgical intervention was 105 [75; 150] min, volume of intraoperative blood loss - 5 [5; 20] ml. Blood transfusion was required in 15 (12%) cases, median blood transfusion was 0 [0; 0] ml. Intraoperative complications developed in 4 (3%) cases. Conversions were performed in 4 (3%) patients. 10 complexity criteria were selected: IDRF F1, F2, F3, F4, F5, location of the tumor center, extension beyond the midline, previous open surgery, contact of the tumor with the inferior vena cava, and the tumor volume (ml)/height (m) ratio of &gt; or &lt;/= 28. A pilot difficulty scale with three levels of difficulty has been developed. Sensitivity for a high level of complexity (6 or over pts) was 60% (95% CI 23.1-88.2%), specificity was 98.3% (95% CI 94.1-99.5%). Conclusion: different IDRFs contribute differently to the complexity and risk of laparoscopic surgery. The ratio of tumor size to growth is more significant criterion of complexity than the absolute size of the neoplasm. Other criteria of complexity also play an important role, such as previous open surgeries and tumor localization, in particular. The Authors do not recommend this scale for clinical use because the results obtained in this research would form the basis for further prospective study aiming to the development of a more accurate scale of the complexity of laparoscopic operations in neurogenic tumors of the abdominal localization.