Contrast Values Research Articles

Constraining small-scale primordial magnetic fields from the abundance of primordial black holes

The presence of magnetic fields in the early universe affects the cosmological processes, leading to the distinct signature, which allows constraining their properties and the genesis mechanisms. In this study, we revisit the method to constrain the amplitude of the magnetic fields on small scales in the radiation-dominated era from the abundance of primordial black holes. Constraints in the previous work were based on the fact that the density perturbations sourced by stronger magnetic fields become large enough to gravitationally collapse to form PBHs. However, we demonstrate that this picture is incomplete because magnetic fields also increase the threshold value of the density contrast required for PBH formation. The increase in threshold density contrast is more pronounced on smaller scales, and in extreme cases, it might even prevent PBH production despite the presence of significant magnetic field. Taking into account the relevant physical effects on the magnetized overdense region, we establish an upper-limit on the amplitude of comoving magnetic fields, approximately 0.13-0.15 μG at a scale of 1017 Mpc-1. Additionally, we compare our constraints with various small-scale probes.

Validity and Reliability of Mathematical Reasoning Ability Instruments in High Schools with Winsteps

The mathematical reasoning ability in understanding mathematical material in high school students still has not touched perfect scores. A valid and reliable instrument is needed in measuring mathematical reasoning skills in students. Validity and reliability testing of the instrument is carried out to ensure whether an instrument can be used to provide accurate results in a measurement being performed. Therefore, this study aims to determine the level of validity and reliability of mathematical reasoning skills in students using Winsteps. The method used in this study is a quantitative survey method, with 252 respondents in high schools in Jakarta. This study uses 3 indicators that are a reference in measuring the mathematical reasoning ability possessed by students. The validity test on the instrument shows that all items on the instrument are valid because they meet the criteria of MNSQ, ZSTD, and Pt Mean Corr except for item 1 which has a ZSTD value of > 2.0 and item 3 has a ZSTD value of < -2.0. Meanwhile, the reliability test obtained an Alpha Cronbach calculation of 0.74 which means that the value of the reliability item is high so that the instrument is declared reliable for use. The DIF analysis using winsteps shows that all question items used in the instrument are valid because none of the question items contain bias referring to the DIF Analysis criteria, namely the DIF Contrast value > 0.5 and the probability value < 0.05 where all the value of the question items actually obtained a DIF Contrast value of < 0.5 and a probability value > 0.05.

Stability of Thermal Convection in Two Superimposed Miscible Viscous Fluids Under Gravitational Modulation

Abstract The thermal stability of a system of two superimposed miscible viscous fluid layers, under gravitational modulation, is investigated using linear stability analysis. It is well known in the literature that in the absence of gravitational modulation, there exist two convection regimes depending on the buoyancy number: the single-cell regime, where convection is oscillating and occupies the entire volume of the two fluid layers, and the stratified regime where stationary convection occurs in each fluid layer. Using Chebyshev's spectral collocation method and Floquet's theory, the numerical results show that under gravitational modulation, single-cell convection oscillates at half the frequency of the external oscillation (subharmonic threshold), while the stratified regime oscillates at a frequency equal to that of the forcing (harmonic threshold). The critical buoyancy number corresponding to the transition between the two convection regimes depends, in addition to the viscosity ratio and the depth of the two layers, on certain dimensionless frequencies permeating this transition and also on the amplitude of oscillation via the Froude number. In the plane of the critical Rayleigh number versus dimensionless modulation frequency, the branch associated with stratified convection does not depend on the buoyancy number for equal viscosities whereas this is the case for the whole-convection regime. For different viscosities, both convection regimes depend on the buoyancy number. At last, in the stratified regime (harmonic threshold), the critical value of the viscosity contrast, corresponding to the passage from an active layer to a passive layer and vice versa, increases with the modulation frequency.

The impact of environmental quality on mental health: an ecological study

PurposeA growing body of research suggests that exposure to natural environments has several mental health effects. This paper aims to evaluate whether countries with high-quality environments report fewer mental health disorders.Design/methodology/approachThis study uses secondary data from the Legatum Centre for National Prosperity. The data set consists of data from 167 countries collected between 2007 and 2023. The authors use panel data regressions to formally investigate the impact of environmental quality on mental health outcomes.FindingsThe results suggest that overall environmental quality is positively related to mental well-being. However, the connection between environmental quality and mental health varies depending on the specific environmental and mental health factors analysed. Specifically, the authors find that air quality and the quality of blue spaces are positively associated with emotional well-being. Furthermore, death by suicide is negatively correlated with air quality and the quality of a country’s green spaces. The authors find no evidence to suggest that environmental quality impacts the prevalence of depressive disorders in a country.Originality/valueIn contrast to previous studies that primarily focused on individual-level analyses, the research adopts an ecological approach. In addition, this study evaluates the relationship between mental health and a wide range of environmental factors, namely, emissions, air quality, ocean health, land use, forest and soil quality, freshwater quality and preservation efforts. This research further distinguishes itself by using a large panel database to investigate the impacts of the natural environment on mental health.

Chinese version of the Death Anxiety Beliefs and Behaviours Scale: Psychometric properties based on CTT and IRT

ObjectivesThe Death Anxiety Beliefs and Behaviour Scale (DABBS) is a unique tool designed to assess the detrimental beliefs and avoidant behaviors linked to death anxiety. This study aimed to adapt the DABBS into Chinese and verify its psychometric characteristics within a community-dwelling older adult population. MethodsThis study used a cross-sectional design and translated the DABBS into Chinese. The psychometric properties of 437 community-dwelling older persons were assessed using the Classical Test Theory (CTT) and Item Response Theory (IRT). ResultsThe DABBS consisted of affect, beliefs, and behaviours, with 18 entries in 3 dimensions. The I-CVI of the DABBS ranged from 0.857 to 1.000, and the S-CVI was 0.968; Cronbach's alpha of 0.905. Rasch analysis results showed that the 3 dimensions of the scale possessed good unidimensionality, and the entries were well-fitted to the dimensions in which they were located; each entry Infit MNSQ and Outfit MNSQ were in the range of 0.50 to 1.50; the analysis of the functional differences of items in different characteristic subgroups (gender) showed that the absolute value of DIF Contrast was <0.50. The results of the Wright map showed that the ability of the participants was normally distributed, and the difficulty of the scale's entries was adapted to the average ability level of older adults. ConclusionsThe present data indicate that the revised DABBS is a valid and reliable tool for assessing affect, beliefs, and behaviors associated with death anxiety in community-dwelling older individuals.

Sources and exploration potential of Ordovician subsalt natural gas in Ordos Basin, China

With the continuous increase in exploration efforts in new zones and new strata, significant breakthroughs have been made in the natural gas exploration of the O1m56 to O1m4 formations in the Ordos Basin. Thus, the origin and exploration potential of subsalt natural gas have attracted much attention and urgently need to be addressed. On the basis of certain geochemical characteristics, genetic types, and sources of natural gas, a comprehensive study on the sedimentary environment, organic geochemical characteristics, and spatial distribution scale of source rocks are conducted in this paper by using geological and geochemical methods. The study shows that: (1) The Ordovician subsalt natural gas is mainly “pyrolysis dry gas,” among which the δ13C1 of Ordovician subsalt low sulfur (sulfur-free) natural gas is lighter, with an average value of −39.6 ‰; the δ13C2 ranges more largely from −35.6 ‰ to −25.8 ‰. In contrast, both δ13C1 and δ13C2 values are heavier in high-sulfur natural gas, revealing that different Thermochemical Sulfate Reduction (TSR) reaction stages have different degrees of influence on natural gas components and carbon isotope composition. (2) Subsalt natural gas is classified as “oil-type gas,” which is self-generated and self-accumulated, whose source rocks are mainly Ordovician subsalt marine deposits. (3) Three types of marine source rocks are developed in Ordovician subsalt, including black argillaceous rock, dark argillaceous dolomite (dolomitic mudstone), and dark micrite (bioclastic) limestone. In addition to micrite limestone, these rocks were mainly formed in a confined lagoon sedimentary environment with high salinity and anoxia. Sedimentary water was significantly stratified and the environment was highly reduced. The organic matter content of the source rocks is relatively high, with an average TOC value of 0.45 %. The hydrocarbon-generating parent materials are mainly composed of bacteria and algae, and the organic matter evolution reaches high-over maturity stage. The total gas generation amount of the marine source rocks in Ordovician subsalt is approximately 43.8 × 1012 m3, which can provide hydrocarbons and accumulate for the subsalt favorable reservoir facies located far from Upper Paleozoic gas sources.

Type 2 diabetes rather than the presence of significant coronary stenoses is associated with quality of life in angiographied coronary patients

Abstract Chronic medical conditions such as type 2 diabetes (T2DM) or coronary artery disease (CAD) and their treatment have a crucial impact on patients’ daily life. The EQ-5D-5L questionnaire is a validated and widely used tool to measure the health-related quality of life (HRQL). We investigated and compared the HRQL in patients with or without T2DM and CAD. We included 481 consecutive patients undergoing coronary angiography for the evaluation of established or suspected stable CAD in a tertiary care setting in Central Europe. Patients’ HRQL was measured using the EQ-5D-5L, comprising the EQ index calculated from the domains: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. A response rate of 88.1% was achieved. From our patients, 166 (34.5%) had T2DM according to ADA criteria, and 254 (52.8%) had significant CAD with stenoses ≥50% at angiography. Patients with T2DM showed significantly lower EQ index values than patients without T2DM (0.891 [IQR=0.783-0.970]) vs. 0.943, [IQR=0.861-1.0], p=0.002)). Regarding the different dimensions of the questionnaire, patients with T2DM reported to have significantly more problems with anxiety and depression (p=0.002) and mobility (p&amp;lt;0.001) than non-diabetic patients. EQ index values in contrast did not differ significantly between patients with vs. those without significant CAD. Accordingly, in analysis of covariance T2DM (F=7.38, p=0.007) but not significant CAD (F=1.74, p=0.183) predicted EQ index values after adjustment for age, sex and body-mass-index. We conclude that T2DM rather than the presence of significant CAD is associated with quality of life in angiographied coronary patients.

Long-Term Physical Activity Mitigates Inflammaging Progression in Older Adults Amidst the COVID-19 Pandemic.

Inflammaging and physical performance were investigated in older adults before and after the COVID-19 pandemic. Older women (n = 18) and men (n = 7) (mean age = 73.8 ± 7.1) were evaluated before the COVID-19 pandemic (PRE), 12 months after the lockdown (POST), and 10 months after resuming exercise training (POST-TR). Physical tests [gait speed (GS) and timed-up-and-go (TUG)]; muscle strength (handgrip-HG); and serum cytokine levels were assessed. Older women showed higher GS and TUG at POST than PRE and POST-TR but lower HG at POST-TR than PRE, whereas older men exhibited lower HG at POST and POST-TR than PRE. Both groups presented (1) lower IL-10 and IL-12p70 values in contrast to higher IL-6/IL-10 and IL-8/IL-10 ratios at POST than PRE; (2) higher IL-10 values and lower IL-8/IL-10 ratio at POST-TR than POST; (3) higher IL-12p70/IL-10 ratio at POST-TR than PRE and POST. Particularly, older women showed (4) lower IL-6 values at POST and POST-TR than PRE; (5) lower IL-8 and IL-10 values at POST-TR than POST; (6) and higher TNF-α/IL-10 and IFN-γ/IL-10 ratios at POST than PRE and POST-TR. Significant correlations between the variables were found in both groups. During the COVID-19 pandemic, detraining and resumption of exercise training promoted distinct alterations in physical capacity and inflammaging among older women and older men.

Continuously-tunable, compact, freespace notch-filter design using an all-dielectric metagrating capped with a low-loss phase change material

Abstract Active metasurfaces utilizing phase change materials (PCMs) are currently under investigation for applications in free-space optical communication, optical signal processing, neuromorphic photonics, quantum photonics, and compact LiDAR. Attention has now turned towards novel PCM like Sb2S3 which exhibit lower optical absorption and reasonable values of refractive-index contrast in comparison to traditional data-storage PCM. We propose and numerically study the class of all-dielectric metagratings capped with low-loss PCM and predict the possibility of continuously tunable resonances whose quality factors degrade gracefully during the amorphous-to-crystalline phase transition of the PCM. Specifically, we consider the CMOS-compatible silicon-nitride on silica substrate material platform for simple and asymmetric metagratings (in particular, the symmetric-broken dimerization) and Sb2S3 capping. Our numerical study predicts that notch-filters operating around the 1550 nm NIR wavelength window can be achieved with tuning range of over 76 nm with Q-factors ranging from 784 (amorphous-phase) to 510 (crystalline-phase) (a degradation in Q of about 35%) and insertion loss of about 0.9 dB. These performance figures are a significant improvement over previously published designs utilizing data-storage PCMs and other traditional notch-filter mechanisms. We examine the influence of grating dimerization and geometrical parameters on performance metrics of the notch-filter and predicts the possibility to trade-off rejection-band and in-band spectral transmission properties. Lastly, we perform a study of all-optical phase change mechanism. Our study is promising for the miniaturization of tunable notch-filter based optical systems.

Bearing fault diagnosis based on enhanced Canberra distance feature in SDP image

Abstract Feature enhancement is important in mechanical equipment fault diagnosis. A limited set of characteristic parameters is insufficient for diagnosing bearing signals with multiple fault types. The presence of noise increases the difficulty of extracting fault features from images. To address the challenge of diagnosing rolling bearing faults in complex environments, this study presents an enhanced weighted image fusion framework aimed at enhancing fault features within the images, which enables accurate diagnosis of bearing faults using a limited number of features. The proposed method encompasses four distinct stages. In the first stage, a symmetrized dot pattern method is employed to transform one-dimensional time-series data into two-dimensional images, visualizing the signal in a 2D format. In the second stage, image binarization and an improved weighted fusion method are utilized to simplify subsequent processing and enhance the image features. The third stage involves extracting the image’s contrast and maximum singular value to improve the Canberra distance calculation. Finally, the enhanced Canberra distance is used for classifying bearing faults. Performance testing of the image feature enhancement is conducted on various datasets containing rolling bearings. Comparative experiments with alternative enhancement methods demonstrate the superiority of the proposed improved weighted image fusion framework. Comparative experiments with the original Canberra distance validate the effectiveness of the enhanced Canberra distance. Additionally, experiments conducted in noisy environments confirm the robustness of the proposed approach. Furthermore, the image feature enhancement method is applied to other bearing datasets, and the experimental results demonstrate its effectiveness in enhancing fault feature representation and achieving accurate diagnosis of rolling bearings.

Flexible polyaniline/carbon quantum dots films for enhanced electrochromic performance

Polyaniline (PANI) conducting polymers exhibit potential electrochromic properties. However, the electrochromic response of PANI films in the infrared (IR) ranges is restricted by their dense structure. Herein, the polyaniline/carbon quantum dots (PANI/CQDs) films were synthesized with sulfuric acid (SA) and CQDs as the dopants. The tetrahedral structures of SA contribute to the formation of highly oriented lamellar PANI. The synergistic effect between CQDs and PANI promotes the loose and porous surface morphology, thereby improving the electrochromic performance of PANI film. The PANI/CQDs porous film for the polymerization charge of 0.5C (PANI/CQDs-5) shows the optimal electrochromic properties and IR modulation capacity, achieving an optical contrast (ΔT) values of 53 % at 850 nm, and with the emittance variation (Δε) values of 0.41, 0.46 and 0.42 in 3–5 μm, 8–14 μm, and 2.5–25 μm, respectively. Furthermore, the switching time of the PANI/CQDs-5 films for coloration and blanching are 2.5 s and 3.6 s, respectively, with over 95 % retention after 100 cycles. Theoretical calculations verified that PANI/CQDs composite films displayed outstanding electron and ion transfer kinetics, facilitating superior electrochromic properties.

Infrared Weak Target Detection in Dual Images and Dual Areas

This study proposes a novel approach for detecting weak small infrared (IR) targets, called double-image and double-local contrast measurement (DDLCM), designed to overcome challenges of low contrast and complex backgrounds in images. In this approach, the original image is decomposed into odd and even images, and the gray difference contrast is determined using a dual-neighborhood sliding window structure, enhancing target saliency and contrast by increasing the distinction between the target and the local background. A central unit is then constructed to capture relationships between neighboring and non-neighboring units, aiding in clutter suppression and eliminating bright non-target interference. Lastly, the output value is derived by extracting the lowest contrast value of the weak small targets from the saliency map in each direction. Experimental results on two datasets demonstrate that the DDLCM algorithm significantly enhances real-time IR dim target detection, achieving an average performance improvement of 32.83%. The area under the ROC curve (AUC) decline is effectively controlled, with a maximum reduction limited to 3%. Certain algorithms demonstrate a notable AUC improvement of up to 43.96%. To advance infrared dim target detection research, we introduce the IFWS dataset for benchmarking and validating algorithm performance.

Limosilactobacillus allomucosae sp. nov., a novel species isolated from wild boar faecal samples as a potential probiotic for domestic pigs

Six strains, WILCCON 0050, WILCCON 0051, WILCCON 0052, WILCCON 0053, WILCCON 0054, WILCCON 0055T, were isolated from four different faecal samples of wild boars on Pulau Ubin, Singapore, Singapore. Based on core genome phylogenetic analysis, the six strains formed a distinct clade within the genus Limosilactobacillus (Lm.), with the most closely related type strain being Lm. mucosae DSM 13345T. The minimum ANI, dDDH, and AAI values within these six strains were 97.8%, 78.8%, and 98.6%, respectively. In contrast, the ANI, dDDH, and AAI values with Lm. mucosae DSM 13345T were lower, ranging between 94.8–95.1%, 57.1–59.0%, and 95.9–97.0%, respectively. While ANI and AAI were close to the thresholds of 95% and 97% for bacterial species delineation, respectively, dDDH was significantly lower than the threshold value of 70%. Based on our phylogenomic, phenotypic and chemotaxonomic analyses, we propose a novel species with the name Limosilactobacillus allomucosae sp. nov., with WILCCON 0055T (DSM 117632T = LMG 33563T) as the designated type strain. In vitro investigations revealed the strains’ ability to break down raffinose-family oligosaccharides, and to utilize prebiotics such as xylo-oligosaccharides and galacturonic acid, thereby enhancing fibre digestion and nutrient absorption. Moreover, strong auto-aggregation properties, as well as resistance to low pH and porcine bile were observed, suggesting their potential survival and persistence during passage through the gut. The high bile tolerance of these strains appears to be attributed to their ability to deconjugate a wide range of conjugated bile compounds. In silico analysis indicated a strong potential for mucin-binding activity, which aids their colonization in the gut. These characteristics indicate the potential suitability of strains of Lm. allomucosae as probiotics for domestic pigs.

Comparison of Copper (II) Sulphate to Hemocue Analyser in the Estimation of Haemoglobin among Voluntary and Replacement Blood Donors at Bugando Medical Centre

Background Pre-donation haemoglobin (Hb) screening is among the foremost test done on blood donors to determine whether an individual is fit to donate with the intention of preventing inadvertent donation from an anaemic donor. The National Blood Transfusion Service (NBTS) in Tanzania uses the Copper II Sulphate (CuSO4) gravimetric method to estimate haemoglobin (Hb) in blood donors. The accuracy of the copper II sulphate method for the rapid screening of prospective blood donors has been questioned because this rapid screening method may lead to false deferral of truly eligible prospective blood donors. However, this and other point-of-care method may provide false results. Methods This was a cross-sectional study conducted among 236 eligible blood donors attending BMC transfusion centre at Mwanza, Tanzania. The blood donors were asked for their consent to participate in this study from 1st May to 1st August 2024. Capillary blood samples were obtained for Hb estimation by CuSO4 and HemoCue methods, and 3mls of venous blood were also collected for Hb quantification by AHA (gold standard). Descriptive statistics were used to analyse the demographic details of the donor. Kappa statistics were used to determine the level of agreement between the two methods of Hb estimation. Results The median age of the study participants was 30 years (IQR: 25-36). The proportion of false eligible donors was 5.5%, and false deferral donors were 2.3% using the CuSO4 gravimetric method. The specificity, sensitivity, positive and negative predictive values, and Kappa agreement for CuSO4 were 53.8%, 94.7%, 93.8%, 58.3%, and 0.51, respectively. In contrast, the specificity, sensitivity, positive and negative predictive values, and Kappa agreement for HemoCue were 63.6%, 97.9%, 96%, 77.7%, and 0.67, respectively. Conclusion. The current study revealed that, the performance of the CuSO4 gravimetric method is relatively poor, with a high proportion of false eligible donors than the HemoCue method. These findings warrant further studies to evaluate the quality control measures for CuSO4 gravimetric method and explore alternative point-of-care methods for Hb estimation among blood donors in similar resource limited-settings.

A novel method of high-speed all-optical logic gate based on metalens

This paper introduces a novel approach to constructing all-optical logic gates based on metalens. The designed structure enables the realization of five commonly used logic gates (AND, OR, NOT, XOR, XNOR). Each logic gate is composed of two to three metalenses. The advantages of this approach are as follows: 1. Metalens offer flexible phase control capabilities, overcoming the strict phase requirements in traditional optical logic gate design. 2. The miniaturization of the metalens makes integration possible and provides a potential method for high-speed parallel optical computing. 3. By controlling different types and quantities of metalens, various types of logic gates can be formed, enhancing programmability during use. The contrast values for the designed logic gates are as follows: 27.95 dB (OR), 18.18 dB (AND), 10.83 dB (NOT), 10.29 dB (XNOR), and 13.56 dB (XOR). With similar structures, the bit rates for the five logic gates at a 50% duty cycle range from 1.04 to 1.05 Tb/s. Overall, these results demonstrate a successful balance between contrast and transmission speed when utilizing metalens to realize all-optical logic gates. From the results, the logic gate proposed in this paper has high contrast and transmission speed, which proves the rationality of using metalens to realize all-optical logic gate.

Contrast gain control is a reparameterization of a population response curve.

Neurons in primary visual cortex (area V1) adapt in varying degrees to the average contrast of the environment, suggesting that the representation of visual stimuli may interact with the state of cortical gain control in complex ways. To investigate this possibility, we measured and analyzed the responses of neural populations in mouse V1 to visual stimuli as a function of contrast in different environments, each characterized by a unique distribution of contrast values. Our findings reveal that, for a fixed stimulus, the population response can be described by a vector function r(gec), where the gain ge is a decreasing function of the mean contrast of the environment. Thus, gain control can be viewed as a reparameterization of a population response curve, which is invariant across environments. Different stimuli are mapped to distinct curves, all originating from a common origin, corresponding to a zero-contrast response. Altogether, our findings provide a straightforward, geometric interpretation of contrast gain control at the population level and show that changes in gain are well matched among members of a population.NEW & NOTEWORTHY The authors study the responses of neural populations in mouse primary visual cortex as a function of stimulus contrast. Measurements are performed in different "environments," each characterized by a different distribution of contrast values. They find that responses across environments can be viewed as a reparameterization of a single contrast-response curve, offering a simple, geometric account of contrast gain control in neural populations.

A novel synthesis method of medium- and long-chain triglyceride lipids from rubber seed oil catalyzed by enzymatic interesterification and its metabolism mechanism.

Medium- and long-chain triglyceride (MLCT) is a striking structural lipid for the supply of energy and essential fatty free acids (FFAs) in the food field. This study aimed to prepare MLCT by enzymatic interesterification of rubber seed oil (RSO) and medium-chain triglyceride (MCT). Fortunately, the conversion of synthesized MLCT could reach 75.4% by the catalysis of Novozym 40086 (7 wt% to MCT) at a temperature of 40 °C with the substrate mole ratio of 1 : 0.7 (RSO : MCT). The as-synthesized MLCT contained unsaturated fatty acid (USFA, 50.13%) at the sn-2 position and exhibited superior performance on the acid value, peroxide value and iodine value in contrast to grade III soybean oil. Moreover, it exhibited the simultaneous release of LCFAs and MCFAs, extremely facilitating the reduction of body weight gain and control of the level of lipids in the blood. Finally, the preferred hepatic metabolism process of the obtained MLCT was proven to be the main cause of the reduced body weight and improved lipid levels by the in vivo deposition experiments. Therefore, our study suggested that the outstanding performance of the MLCT synthesized by RSO in foods as functional lipids.

Lymph node evaluation and nodal metastasis prediction in epithelial ovarian cancers: A retrospective study.

To identify consensus regarding lymph node (LN) evaluation in epithelial ovarian cancer (EOC). The objective of the present study was to evaluate surgico-pathological findings, LN involvement, and the prediction of LN metastasis via preoperative imaging and intraoperative assessment in women with EOC. Women with EOC who underwent cytoreductive surgery (CRS) between Jan 2019 to June 2022 were included. The distribution of histology, stage, and LN metastasis was studied. The predictive value of serum cancer antigen (CA)-125, instead of and radiologically and surgically enlarged LNs with final LN histopathology was studied. A total of 96 women with EOCs underwent CRS. Fifty women (52%) underwent primary CRS and 46 women (48%) underwent interval CRS. Seventy-five women (78.13%) with EOC underwent pelvic and/or para-aortic lymphadenectomy, out of which 23 (30.67%) were histologically positive. High-grade serous carcinoma was the commonest (n=55, 73.33%) histology. The majority of women, 56 (74.67%) were stage III or IV at presentation. Complete cytoreduction was achieved in 59 (78.66%) patients. The receiver operating characteristics curve showed a cutoff for CA-125 of 1360 U/mL (area under the curve 0.702, p=0.002) for LN metastases. Both radiologically and surgically enlarged LNs significantly predicted LN metastasis on histopathology (p=0.02 and 0.006 respectively). The combined sensitivity, specificity, positive predictive value and negative predictive value of both contrast enhanced computed tomography (CECT) and surgically enlarged LNs were 78.26%, 57.69%, 45%, and 85.71%, respectively. Serous histology, high-grade tumors, highCA-125 levels, and suspicious LNs on CECT or during surgery were significantly associated with LN metastasis. However, considering the false-negative rate of 21.74%, the combination of radiologically and surgically enlarged LNs cannot be used as the sole surrogate marker for lymphadenectomy.

Segmentation of image from a first-person-view unmanned aerial vehicle based on a simple ant algorithm

The object of this study is the process of image segmentation from the First Person View (FPV) of an unmanned aerial vehicle (UAV). The main hypothesis of the study assumes that the use of a simple ant algorithm could ensure the necessary quality of the segmented image. The segmentation method, unlike the known ones, takes into account the number of ants in the image, weight, initial amount and evaporation rate of the pheromone, the "greediness" of the algorithm and provides: – preliminary selection of individual channels of the Red-Green-Blue (RGB) color space; – preliminary placement of ants according to the uniform law; – determining the routes of ants; – taking into account the attractiveness of the route for each ant; – change (adjustment) in the concentration of ant pheromones; – calculation of the probability of movement (transition) of the ant on the movement route; – determination of the objective function at the j-th iteration and its minimization; – determining the coordinates of the route of movement (movement) of ants; – verification of the fulfillment of the stop condition; – determination of the best routes found by ants; – calculation of the brightness of the pixels of the segmented image in each channel of the RGB color space; – further combining the results of channel segmentation. An experimental study of image segmentation from UAV FPV based on a simple ant algorithm was conducted. The specified object of interest on the segmented image has a certain structure, unevenness of the contours, and can be further used for decoding, categorization, etc. Unlike the object of interest, the background ("garbage" objects) in the segmented image do not have a stable structure and can be further filtered out. It has been established that the segmented image by the known method based on the gradient module has a low contrast value, there are gaps in the segmented pixels of the object of interest. A segmented image using a method based on a simple ant algorithm is free from that drawback.

Engineering transmitted light speckle statistics with field-tunable magnetic nanofluid scatterers

The active manipulation of electromagnetic wave scattering cross-sections within disordered media is crucial for understanding mesoscopic physics. An adaptable strategy for exploring the parameter space in order to control the scattering cross-section of such systems involves employing external field-tunable disorder. In this study, we utilize magnetic nanofluid as an in-situ tunable scattering medium, whose scattering parameters like scatterer number, density, size, and shape can be adjusted by an external magnetic field which is administered either constantly or with varying ramp rates. Our study on the transmitted light and the associated speckle statistics reveals intriguing behavior in response to changes in the strength and duration of the applied magnetic field. We observe that this tunable system remains within the weak scattering regime across various scattering scenarios: Rayleigh (for scatterer sizes smaller than the light wavelength, λ), Mie (when scatterer size approaches λ), and Geometric (for scatterer sizes exceeding λ) under both constant and ramped magnetic field application. Further, the transmitted speckle patterns deviate from Rayleigh behavior, with speckle contrast values increasing over time until it reaches a saturation point. However, the speckle patterns display intriguing dynamics with faster ramp rates resulting in larger speckle contrast values. This phenomenon arises from the inability of equilibrium field-induced structures to form rapidly under faster ramp rates, leading to a broader size distribution of scatterers and consequently a wider range of phase differences among scattered light components. Our study illuminates the dynamic behavior of wave transport through a tunable disordered media and underscores the potential of magnetic nanofluid as a versatile tool for controlling mesoscopic transport.