Inverse Proportion Research Articles

MaxEnt modeling of the potential risk of schistosomiasis in the Philippines using bioclimatic factors

Schistosomiasis is a parasitic infection caused by Schistosoma japonicum. It remains a principal local health issue in the Philippines, demonstrating endemicity in 28 provinces and afflicting thousands of Filipino individuals annually. Despite this, no clear distribution maps for the disease have been comprehensively reported. Therefore, species distribution modeling (SDM) employing the MaxEnt algorithm and GIS application techniques was utilized to denote the potential risk of schistosomiasis in the country. With a high AUC score of 0.846, the SDM yielded a favorable and reliable correlative map illustrating a predicted schistosomal temporal distribution concentrated primarily on the country's eastern portion with a more pronounced wet than dry season. The precipitation of the driest quarter was determined to be the most significant contributing factor among the bioclimatic variables evaluated. This suggests a possible increase in adaptations concerning the rainfall and thermal tolerances of the parasites' vectors. Moreover, socioeconomic status between Philippine regions revealed an inverse proportion with the number of schistosomiasis cases. This study also discussed the potential role of climate change on the range shifts and the potential risk of parasite infection in the Philippines.

A novel model-based equation for size dependent mean recovery coefficients for spheres and other shapes

BackgroundIn NM-imaging, theoretical curves for the recovery coefficient (RC) of the signal maximum and mean are known for spheres and cubes, if a 3D Gaussian PSF is assumed. The RC of the maximum is also known for cylinders. For these and other shapes empirical equations with one or two fit-parameters have been utilized. MethodsAn equation for the RC for large objects of arbitrary shape is derived and generalized into an empirical equation for smaller objects, which is verified by numerical simulations. The proposed equation is compared to published results on SPECT kidney phantom measurements and to PET measurements on the NEMA IEC PET body phantom with six spheres. ResultsThe signal loss (1-RC) for large spheres is inversely proportional to the radius, where the slope is proportional to the FWHM of the spatial resolution. For non-spherical shapes the generalized instead of the volume equivalent radius should be utilized. For smaller objects, an equation with one added empirical fit-parameter is presented. It is demonstrated that the EANM-guidelines’ two-parameter logistic function results in a poor fit if the theoretical slope and inverse proportionality are forced and it gives a suboptimal fit when both parameters are fitted. ConclusionsA novel model-based equation for the mean RC-curve is derived. It can be used for arbitrary shapes as long as the sphericity is taken into account and it is accurate down to RC = 10 %. One parameter is directly related to the spatial resolution, while the other is a shape depending fit-parameter.

Ivermectin decreases parasite load, testosterone, and potentially antler length in a group of captive red deer males (Cervus elaphus)

Secondary sex traits (SSTs) can favour males in intra-sexual competition, allowing females to reliably assess their quality. They can also be connected to other aspects of fitness, such as resistance to parasites and pathogens, as parasites have negative effects on the development of SSTs. Antlers are one of the most recognizable examples of SSTs whose development is regulated by testosterone and reflects the actual condition of the bearer. Elevated testosterone can exaggerate the size of SSTs while impairing the function of the immune system (“The Immunocompetence Handicap Hypothesis”) posing a trade-off between antler development and immune function. In this study, we experimentally manipulated the parasite load in captive red deer (Cervus elaphus) males with Ivermectin during antler development for two consecutive years. Expecting an inverse proportionality between parasite load and antler size, we hypothesized the treated deer to have larger antlers than the untreated ones. Our results showed that, following the immunocompetence handicap hypothesis, parasite load was positively associated with testosterone levels. However, the application of Ivermectin suppressed the parasite load of the treated animals but did not lead to the development of larger antlers. Instead, it significantly suppressed the concentration of testosterone in the treated animals, whilst the animals that had higher testosterone also had the highest parasite load. Our findings show that Ivermectin can potentially decrease the levels of testosterone and, consequently, antler size. These findings have important implications for the management of captive populations, especially in contexts where the development of large trophies is desired.

The reliability of models for converting formaldehyde emissions from wood-based materials to different environmental conditions

The monitoring of the formaldehyde emission potential of wood-based materials by means of test chamber investigations has been established by national and international standards and has made an important contribution to significantly reducing the formaldehyde concentrations indoors. The procedures used are mostly methodologically different, so that the results cannot be directly compared. The first empirical models for converting formaldehyde steady-state concentrations as a function of temperature, air humidity, air change rate and loading were derived in the 1970s. However, the development of lower-emitting materials made it necessary to modify and adapt these models. Formaldehyde emissions from wood-based materials are complex from both a reaction-kinetic and dynamic perspective. There is an exponential dependence of the steady-state concentration on temperature and humidity and an inverse proportionality to the air change rate. The mathematical analysis requires multiple non-linear regression tools. A large data set with reliable results obtained under different conditions is available from previous investigations. With a total of 128 measurement data, there was very good agreement between theory and experiment for a wide range of chamber settings from a statistical point of view. However, the model is not suitable for predicting the emission behavior of individual products. Some uncertainty also exists due to the allowed tolerance limits of the chamber parameters. Since the formaldehyde emission rate depends on the air change rate, a simple linear conversion of steady-state chamber concentrations into room air concentrations for indoor exposure assessments is not possible even at constant temperature and humidity.

Mechanical performance assessment of sustainable coal plastic composite building materials

This paper presents a study for developing a high filler content coal plastic composite (CPC) for use in building and construction applications as a substitute for the state-of-the-art wood-plastic composites (WPCs). The influence of coal type (bituminous, sub-bituminous) and content (up to 70 wt%) on the mechanical performance was characterized and compared with predominant commercially available WPC products. SEM micrographs revealed good adhesion between coal and the polymer at the interface with less porosity than WPCs. Additionally, particle fracture and particle pull-out failure mechanisms were evident in the SEM micrographs, with the latter being more dominant. DSC thermal analyses revealed potential chemical reactions between the coal and HDPE interfaces, resulting in enhanced composite performance. Results indicate the tensile strength for CPC material had inverse proportionality with coal content. Despite the reduction, tensile strength for CPC with 60 wt% bituminous coal was not significantly different from a typical WPC formulation. Flexural strength increased to a maximum value, at 60 wt% for bituminous coal and 50 wt% for sub-bituminous coal, followed by a decrease. CPC with 60 wt% bituminous coal possessed higher flexural strength and, in some cases, comparable flexural modulus as compared to WPC products. Flexural properties indicated that a composite deck made from the CPC material could meet or exceed the loading and deflection requirements for decking boards. FEA models indicated that a hollow deck profile would potentially have a better load-deflection curve with less localized stresses compared to common decking board profiled sections.

Role of V(C, N) on gradient structure formation and mechanical properties of nanocrystalline cemented carbides

We investigated the relationship between the V(C, N) content in nanocrystalline cemented carbides and the thickness of the gradient layer, while also exploring the effects of V(C, N) content on the mechanical properties. Nanocrystalline cemented carbides featuring a cubic-phase gradient layer on their surfaces were prepared through a one-step sintering process, utilizing V(C, N) as the gradient-forming agent. The results showed that as the V(C, N) content increased, the thickness of the V(C, N) gradient layer decreased. Following the principles of the first diffusion law, we derived the kinetic equation for nanocrystalline cemented carbides with a V(C, N) gradient layer, establishing a clear connection between the gradient layer's thickness and the V(C, N) content. The thickness of the V(C, N) gradient layer exhibited a direct proportionality to the difference in V activity between the surface and the core, while displaying an inverse proportionality to the average V content of the specimen. Furthermore, the introduction of V(C, N) was found to enhance the mechanical properties of nanocrystalline cemented carbides, leading to simultaneous improvements in both hardness and fracture toughness. This enhancement underscores the significance of V(C, N) in optimizing the performance of these materials.

Dampak Peremajaan Sawit Rakyat (PSR) Terhadap Kesejahteraan Petani Kelapa Sawit Di LabuanBatu Utara, Sumatera Utara

Palm oil is a leading commodity in North Sumatra, but the age of oil palm plants was old and must be immediately rejuvenated From surveys and identification problems of palm oil plantation with farmers in South Kualuh District, North Batu Regency, farmers are constrained by capital and knowledge for oil palm plant rejuvenation. The purpose of this study is to determine the welfare impact of oil palm farmers in the implementation of the smallholder oil palm replanting program (PSR) and determine the factors that influence the impact of smallholder oil palm replanting (PSR) on the welfare of oil palm farmers and will be carried out from March 20 to May 31, 2023. The sampling technique uses proportional random sampling with 52 respondents. Data collection method with questionnaires tested for validity and reliability. The data analysis method uses the Paired T test and Multiple Linear Regression Test. The results showed that there was a difference in the average income of farmers before and after participating in the Smallholder Palm Oil Replanting (PSR) program where based on the results of the Paired T test obtained a significance value of ≤ 0.05 and a t-value calculated > t table that shows smallholder oil palm replanting (PSR) can improve the welfare of oil palm farmers. variables Consumption Patterns, FFB Prices, Capital Assistance, and variables The availability of study programs has a significant effect and positive value. However, the variables Land Area and Income have a partial effect and are negative. This shows that the variables of Land Area and Income have a negative or inverse proportion to the Impact of Smallholder oil Replanting (ISR) on the welfare of oil palm farmers in South Kualuh District.

Numerical study on upstream smoke propagation and induced airflow velocity in a tilted channel under natural ventilation

A series of fire simulations were executed to explore the upstream smoke propagation characteristics and induced airflow velocity in tilted channels under natural ventilation. The channel slope ranging from horizontal to 58% (30°) and five heat release rates were used. Simulative results indicate that the airflow introduced by stack effect can enable the upstream smoke spread to reach sub-critical, critical and super-critical states without forced longitudinal ventilation. Meanwhile, taking the effect of fire heat release rate and height difference between the fire source and the upper portal into account, a piecewise function is developed to estimate the induced airflow velocity. It is found that when Ld∗·Q∗0.2 is less than or equal to 1.05, the airflow velocity increases exponentially with the variety of dimensionless elevation difference, but slowly rises logarithmically when Ld∗·Q∗0.2 is greater than 1.05. Besides, for scenarios in the sub-critical state, the relationship between the induced airflow velocity and the upstream smoke backflow length is revealed, which demonstrates that the dimensionless reverse flow length is in inverse proportion to the 1.5 power of dimensionless airflow velocity. For scenarios in the critical and super-critical states, there is still smoke backflow upstream of the fire source at the early period of a fire. And the disappearing time of smoke backflow reduces exponentially with the increase of heat release rate and elevation difference. Based on dimensional analysis and simulative data, a novel predictive model for the backflow disappearing time is proposed.

Exploring the effects of B10 biodiesel contamination on Canavalia ensiformis growth and nutrition in artificially contaminated soil

AbstractSoil contamination caused by fossil fuels and biofuels can alter the chemical and physical properties of soil, limiting its use for agricultural, residential, and recreational purposes. Phytoremediation offers a cost‐effective and manageable solution to mitigate these environmental impacts that can be applied to large areas. The aim of this study was to evaluate Canavalia ensiformis (jack bean) growth and nutrition during the remediation of B10 biodiesel in artificially contaminated soil. The experimental design was fully randomized, with four replications and three contamination levels with B10, 0%, 1%, and 2% vol/wt, evaluated over 20, 40, and 60 days after sowing. Plant growth was assessed: shoot and root dry biomass, height, number of leaves, leaf area, and plant nutrition: macro‐ and micronutrient vegetable tissue. Dry biomass of shoots and roots, plant height, the number of leaves, and the leaf area decreased significantly in inverse proportion to the level of contamination. Twenty days after sowing, C. ensiformis growing in B10‐contaminated soil reduced the nitrogen and potassium concentrations, while phosphorus and sulfur increased, and calcium and magnesium remained unaffected. However, all except potassium tended to equilibrium after 60 days of sowing. Regarding micronutrients, manganese increased after 20 days of sowing, while iron decreased, and copper and zinc remained unchanged. Despite its growth and nutrition limitations, C. ensiformis is a viable option for phytoremediation in areas contaminated with hydrocarbons. Its nitrogen absorption capacity makes it an ideal natural fertilizer for the remediation of fuel‐contaminated soils.

КЛИНИКО-ЭПИДЕМИОЛОГИЧЕСКИЕ И РЕПРОДУКТИВНЫЕ АСПЕКТЫ ГИПОСПАДИИ

Hypospadias refers to a congenital pathology of the genitourinary system. This bibliographical review analyzes and systematizes historical, epidemiological, clinical, populational and genetic data, highlights the problem of reproductive health of adult patients. An expert evaluation of materials related to the modern classification of hypospadias for both genders, diagnosis, surgical treatment options, family planning and childbearing taken from the PubMed database of the scientific periodicals was carried out. Authors noted the increased dynamics of the disease in the population. Hereditary predisposition of hypospadias was confirmed as well as the inverse proportionality of the severity of the disease and the ability of a patient to enter the relationships and the reproductive function in the event that hypospadias is not aggravated by testicular dysfunction, reduction of the vas deferens and other factors.

The mechanism underlying the inverse proportion between serum IgE concentration and Stat3 transcriptional activity depends on Stat3 mutation type

Abnormalities in the IL-6/STAT3 signaling pathway can sometimes result in extremely high levels of IgE concentration in serum, however, the regulatory role of STAT3 in IgE production is elusive. We used several genetically modified mice with distinctive germline Stat3 transcriptional activity to assess the influence of Stat3 on the biochemical characteristics of IgE and found that the IgE concentration in serum is inversely proportional to Stat3 transcriptional activity. Intriguingly, the serum IgE concentration is directly proportional to IgE-producing B cells in Stat3-GOF mice but inversely proportional in mice carrying Stat3 mutations with reduced transcriptional activity. For reduced Stat3 transcriptional activity induced high levels of IgE in the mice, IL-4/Stat6 signaling is indispensable for IgE production, but it was observed that an increased IgE concentration was accompanied by reduced IL-4/Stat6 signaling and lessened IgE-producing B cells, which implies that an increase in IgE concentration may result from an extended half-life of IgE but not an increasing number of IgE-producing cells.

An Evaluation of the Hitit Index in Differential Diagnosis of Crimean-Congo Hemorrhagic Fever in the Emergency Department.

Background and Objectives: Crimean-Congo Hemorrhagic Fever (CCHF) is a viral zoonotic infection, which is seen over a wide geographic area. The mortality rate is in inverse proportion to the ability of patients to access healthcare services. Therefore, early identification of patients is extremely important. The aim of this study was to test the sensitivity and specificity of the Hitit Index in the differentiation of CCHF cases at the time of presentation at the Emergency Department and to evaluate the agreement of this index with molecular (CCHFV RNA) and/or serological diagnostic tests (ELISA-CCHF IgM). Materials and Methods: The patients included were those who presented at the Emergency Department (ED) with the complaint of a tick bite or those identified as potential CCHF cases as a result of complaints and/or laboratory findings. For cases that met the study inclusion criteria, the Hitit Index score was calculated automatically from the parameters included in the index formula uploaded to the automation system in the ED at the time of presentation. Through comparisons of the agreement of the Hitit Index with the CCHFV-RNA and/or IgM results the power of the Hitit Index for differentiation of CCHF cases in ED was evaluated. Results: The data of 273 patients were analyzed. There was a history of tick bite in 236 (86%) cases. Of the evaluated cases, 110 (40.2%) were hospitalized; CCHF positivity was determined in 72 (26.4%). The Hitit Index values calculated in ED and at 24 h after hospitalization were determined to be significant in the prediction of the CCHF cases (p < 0.001, AUC = 0.919 (0.887-0.951); p < 0.001, AUC = 0.902 (0.841-0.962). For a cut-off point of 0 of the Hitit Index evaluated in ED, the classification success was found to have a sensitivity of 75% and specificity of 88% (PPV-NPV). For a cut-off point of 0 of the Hitit Index evaluated at 24 h after hospitalization, the classification success was found to have a sensitivity of 79.7% and specificity of 84% (PPV-NPV). Conclusions: The defined form of the Hitit Index can be used in the differentiation of CCHF cases in ED with high sensitivity and specificity levels. Just as evaluation with the Hitit Index prevents unnecessary hospitalization, it can also contribute to reducing mortality rates with the early identification of CCHF cases.

(Invited) Selective Area Growth, Etching, and Doping of GaN By MOCVD for Power Electronics

The lack of selective-area doping technique in GaN greatly hinders the demonstration of sophisticated device structures for high power application. We explored the possibility of using selective-area etching followed by selective area growth to achieve SAD. For the etching step, we explored the in-situ TBCl etching, where we achieved controlled etch rate and smooth trenches. The TBCl etching was proven to be a low-damage etching process compared to the conventional dry etching. Moreover, selective area growth of p-GaN in a patterned trench was analyzed by atom probe tomography (APT). We found Mg atoms cannot diffuse on the GaN surface, which led to an observed inverse proportionality between Mg concentration and local growth rate. However, it was discovered that Mg precursors, like Ga, exhibit inter-trench diffusion through the gas phase.

Experimental study on the combustion properties of four common engineered bamboo and wood composites

AbstractEngineered bamboo and wood composites are increasingly utilized in construction due to their eco‐friendly, low‐carbon footprint, and superior mechanical properties. To investigate the effect of heat flux and grain direction on the combustion properties of parallel strand bamboo (PSB), laminated veneer bamboo (LVB), cross‐laminated timber (CLT), and laminated veneer lumber (LVL), a total of 54 specimens in 3 groups were tested through a cone calorimeter. Parameters including the ignition time, heat release rate, mass loss rate, and smoke production rate were investigated. The analytic hierarchy process method was adopted for a multi‐level, qualitative, and quantitative comprehensive fire risk assessment of the corresponding structural materials. The test results reveal that PSB and LVB demonstrated superior performance to the CLT and LVL through the comparison of four combustion characteristics parameters, despite their drawbacks and virtues. The heat flux increases in inverse proportion to the ignition time. As for the heat release rate, the larger peak value is accompanied by an earlier appearance, along with the greater average mass loss rate and the lower smoke rate of engineered bamboo. The peak heat release rate of engineered bamboo composites parallel to the grain is larger than that perpendicular to the grain, whereas other parameters are not significantly influenced by the grain direction. Compared with engineered wood, engineered bamboo composites have the potential to be a safer and more reliable building material in terms of fire risk assessment.Highlights Cone calorimeter was used to analyze the combustion properties of materials. PSB, LVB, CLT, and LVL were studied considering different grain directions. Analytic hierarchy process method was adopted for a fire risk assessment. Engineered bamboo has the potential to be a reliable building material.

Evolution of tensile strength and cracking in granite containing prefabricated holes under high temperature and loading rate

For present applications in deep significant rock engineering, including underground repositories of high-level nuclear waste, an exhaustive comprehension of the impacts of high temperature and loading rate effects on the mechanical characteristics of granite emerges as an imperative necessity. Based on the Brazilian splitting test, Brazilian disc specimens with prefabricated holes were meticulously employed to guarantee the occurrence of radial compression failure. Combining microscopic experiments such as scanning electron microscopy and X-ray diffraction, the indirect tensile strength and damage mechanism of granite from the Yueyang area under the action of different temperatures and loading rates were thoroughly investigated. Furthermore, a nonlinear fitting equation between the two factors and tensile strength is suggested. At the same time, a simplified surface crack density based on pixel processing was defined. This allowed for a comparative assessment of how variations in temperature and loading rates induce varying degrees of macroscopic crack development and damage to the specimens. The findings suggest a direct proportionality between the tensile strength of granite and the loading rate, while an inverse proportionality is observed concerning temperature above 400 °C. However, a transient "gain effect" phenomenon manifests at temperatures below 400 °C. However, the impact of temperature on tensile strength is significantly greater than that of the loading rate, exhibiting a difference of approximately 8.7 times. Furthermore, the temperature is more prone to lead to the occurrence of secondary tensile cracks in specimens. The results of this research provide valuable guidance for ensuring the security of deep major rock engineering during construction.

Fractal study on permeability characteristics in rough and dense porous media

The research in this paper explores the roughness of pores in rough and dense porous media using the model of rough capillary bundles. By taking into account the influence of boundary layer effects and microscale phenomena on fluid flow, a fractal model is derived to determine the efficient permeability of fluid flow in rough dense porous media. The connection between effective permeability and relative roughness and pore microstructure structure is discussed. It is revealed that the effective permeability exhibits an inverse proportionality to the relative roughness and viscosity, while concurrently displaying a direct proportionality to the pore fractal dimension. Furthermore, through the validation of experimental data and a comparative analysis with existing research models, it is evident that the model studied in this paper aligns more closely with real-world conditions.

Influence of Lead Nanoparticles on Structural, Morphological, and Mechanical Characteristics of (SiR-PU/Micro-Pb) Composites and Radiation Shielding Applications

This research includes the manufacture of a polymeric nanocomposite consisting of silicone rubber/polyurethane as a base, with the addition of the first filler of micro-lead with a ratio of 300 pphr and the second filler of nano-lead with different ratios (0, 0.2, 0.4, 0.6, 0.8 pphr). With the addition of hexane (liquid state) to the superposition using the casting technique at room temperature. The structural properties of the surfaces of the samples were measured using Fourier transformation spectroscopy (FT-IR) and the scanning electron microscope (SEM). In addition to studying the mechanical properties represented by each hardness, tensile, elongation, and elastic modulus. (FT-IR) showed the absence of a chemical reaction for all samples. While SEM measurements showed a homogeneous distribution of micro-lead and nano-lead in the presence of hexane equally, and there were no voids in the eyes of the prepared rubber equally. For the mechanical properties, we see that the hardness, tensile strength and modulus of elasticity continue to improve with the increase in the number of lead nanoparticles. And a decrease in elongation as a result of inverse proportion to the modulus of elasticity. From the results obtained, this composite can be used in gamma ray attenuation applications in shielding, especially in medical and industrial fields.

Quantum absorption properties of Kerr–Newman–de Sitter black hole

In this work, we utilize the Wentzel–Kramers–Brillouin (WKB) approximation to determine the Hawking temperature corresponding to the Kerr–Newman–de Sitter (KNdS) spacetime. Specifically, we calculate the low frequency absorption cross-section for the KNdS black hole in a charged scalar field and analyzed its dependence on the characteristics of the black hole. Through our research, we have established a correlation between the absorption cross-section ([Formula: see text]) and the Hawking temperature ([Formula: see text]) of the black hole, demonstrating an inverse proportionality between the two quantities. Furthermore, we also deduce the absorption cross-sections for Kerr–de Sitter, Reissner–Nordstrom–de Sitter, Schwarzschild–de Sitter and Schwarzschild black holes, and compare them with previously obtained results. The validity of our findings is demonstrated by these comparisons.

Stochastic simulation of hydrogen-oxygen auto-ignition at the microscale.

A hybrid stochastic simulation method is developed to study H2-O2 auto-ignition at the microscale. Simulation results show that the discrete and stochastic characteristics of reaction collisions have notable impacts on the ignition process, particularly in the early stages when only a few radicals exist. The statistical properties of ignition delay time, which reflect the accumulated stochasticity during ignition, are obtained and analyzed for different initial temperatures and total molecular numbers. It is found that the average and standard deviation of ignition delay time increase as the total molecular number decreases, with this phenomenon being particularly pronounced near the crossover temperature. When the total molecular number is sufficiently small, the chain initiation reaction becomes crucial to the stochastic properties, as its average firing time exhibits an inverse proportionality to the total molecular number. As the total molecular number increases, the influence of other chain reactions intensifies, causing the power law relation between standard deviation and total molecular number to shift from -1 power to -0.5 power. Owing to different chain reaction paths for high- and low-temperature auto-ignition, the strongest relative fluctuation occurs near the crossover temperature. A theoretical equation for the standard deviation of ignition delay time is obtained based on dimensional analysis, giving excellent agreement with the simulation results in both high- and low-temperature modes.

Study of backward Brillouin scattering in gas-filled anti-resonant fibers

Brillouin scattering in gas shows unmatched gain properties in hollow-core optical fibers filled at high pressure. Here, the gain characteristics are studied for two common gases, namely, N2 and CO2, which show distinct features and are compared to expected responses deduced from conventional thermodynamic models for gases. This is realized—for the first time to our knowledge—in anti-resonant hollow-core optical fibers, demonstrating their full suitability for generating and exploiting Brillouin amplification in fluidic media. The potential of Brillouin scattering in gases is manifested in a distributed temperature sensor that is totally immune to strain and benefits from the absence of shear stress in the gaseous medium. The experimental results presented indicate that gases with smaller molecular masses show a higher temperature sensitivity than gases with larger masses. This inverse proportionality between the temperature sensitivity and the molecular mass of a gas shown in the experiment qualitatively agrees with the ideal gas model.