Threshold Level Research Articles

Environmental health risk assessment and acute effects of sulfur dioxide (SO2) inhalation exposure on traditional sulfur miners at Ijen Crater Volcano, Indonesia

The Ijen Crater volcano is one of the geological wonders recognized by UNESCO. Inside it is a blue lake with a high acidity level, and a blue fire phenomenon has formed due to the very high concentration of sulfur. This crater is also one of Indonesia's largest sources of sulfur and is used by locals as a traditional sulfur mine. This study aims to measure SO2 concentrations and assess the health risks of SO2 exposure in traditional sulfur mine workers. The SO2 measurements were taken using impingers at six sample points along the mine workers' path. In addition, anthropometric data, work activity patterns, and health complaints during work were collected through direct interviews with 30 respondents selected based on inclusion criteria. Short-Term Health Impact Method was carried out based on a comparison of threshold level values and acute effects obtained from interviews regarding health complaints. The Hazard Question Index (HQ Index) of SO2 exposure was calculated using the health risk assessment method. The SO2 concentrations between 3.14 and 18.24 mg/m3. All sample points were above the quality standard threshold set by the EPA of 1.97 mg/m3. The most common health complaints workers experienced were eye irritation and coughing while working, followed by headache, shortness of breath, and skin irritation. The HQ index of SO2 exposure in workers was 1.02 for real-time exposure and 2.15 for long-term exposure. An HQ index ≥ 1 indicates a potential health risk for workers. Therefore, it is important to control workers' SO2 exposure.

Bicycling tasks relation to stability measures during alcohol intoxication

Bicycling accidents are a major traffic safety problem and are deemed ‘an unacceptable human and social price for EU citizens’. One of the major causes for bicycling accidents is loss of balance. A related influencing factor is alcohol intoxication. It is a primary, long term, safety objective to develop safety systems for the cyclist. The present work aimed to understand how to measure cyclists’ instability via steering and leaning inputs, while considering that steering and leaning might vary depending on the cycling task being performed. Of 28 participants, 19 were given doses of alcohol up to 1.0‰ and 9 remained sober (control group). Breath alcohol concentration was measured. The participants repeated the cycling test track session five times (with each block lasting 35 minutes). The track session contained three different tasks: cycling slalom, straight, and slowly. Speed, yaw rate, and roll rate were assessed continuously. Yaw rate and roll rate were relatively sensitive for the different cycling tasks. The threshold level of the angular velocity measurements was related to the cycling task performed. Alcohol intoxication at 0.7‰ had a significant impact on performance. The rather simple measurements used can detect instability. Instability should be measured differently depending on the cycling task performed. The study represents a small step towards a safety system for cyclists.

International financial integration and financial stress of emerging market economies: The role of institutional quality

In the wake of unprecedented financial liberalization policies adopted by Emerging Market Economies (EMEs) since the late 20th century, their integration into global financial markets has brought forth both opportunities and challenges. This paper endeavors to assess the intricate relationship between international financial integration (IFI) and financial stress in EMEs, focusing on the potential moderating effect of institutional quality. Addressing key questions, it examines how various IFI indicators impact financial stress and evaluates the role of different dimensions of institutional quality in influencing this relationship. Using a Financial Stress Index (FSI) and employing the panel threshold regression technique, the study unveils significant threshold effects of institutional quality on the IFI-FSI nexus, with variations across different institutional factors. This study underscores the vital need for policymakers to identify threshold levels in institutional quality indicators to strike a balance between attracting investments and preventing unwarranted financial distress.

Heavy metals in commonly consumed rice grains in Bangladesh and associated probabilistic human health risks

Food contamination by heavy metals is a concerning issue worldwide. The presence of elevated levels of heavy metals in commonly consumed rice has emerged as a critical issue in ensuring food safety. This research encompassed the collection of 44 rice samples, representing seven distinct varieties, through a randomized sampling approach across various retail markets within Dhaka city. The investigation of heavy metal content (including Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb) within the rice samples was carried out employing Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The findings disclosed substantial disparities in heavy metal concentrations among the different rice varieties. Notably, the concentrations of Cr (0.99 mg/kg), Fe (8.35 mg/kg), Pb (0.49 mg/kg), and Co (0.02 mg/kg) were observed to exceed the established maximum permissible limits. This contamination of the rice varieties may stem from either natural processes or human activities. Utilizing these metal concentrations, this study employed Monte-Carlo simulation to calculate health risk and probabilistic health risk. The Target Hazard Quotients (THQs) for Cr, Fe, and As exceeded the threshold of 1 in each rice variety, particularly in Amon and Lal Biroi in Mymensingh, Najirshail in Bogra, 28 in Sherpur and Kushtia, Miniket in Bogra and Rajshahi, and lastly, paijam in Rangpur and Tangail. Furthermore, the Hazard Index (HI) exceeded 1 in all rice varieties, implying that the consumption of these selected rice grains may have a substantial impact on overall food quality and its potential health consequences. Both carcinogenic risk and probabilistic risk for As, Ni, Cd, Cr, and Pb were found to surpass the threshold levels and safe limits, respectively. This suggests that individuals who have regularly consumed these rice varieties may face a heightened probability of developing cancer in the future, as predicted. According to sensitivity analysis, metal concentration and food ingestion rate (FIR) are the most relevant components that contribute to the significant impact of carcinogenic health hazards. Finally, the study concluded that heavy metal intake from food poses a risk to human health, necessitating the effective monitoring based on each geographic location and identify the source of this heavy metal to limit its exposure.

Augmenting human-guided progressive learning with machine vision systems for robust surface defect detection

Machine vision systems commonly utilize Convolutional Neural Networks (CNNs) for in-line surface defect detection of manufactured components. The prediction abilities of vision-based inspection systems deteriorate with time as the defect detection model trained on fixed image datasets fails to accommodate deviations. This paper proposes a human-guided progressive learning approach that systematically imparts learning of new features to the CNN-powered vision-based defect detection system. The approach augments the surface defect detection model with human intelligence, using an intuitive user interface to address model drift. The human expert monitors the trained model performance under specific conditions leading to the change of characteristics during implementation, identifies misclassifications, and initiates re-training. The algorithm accumulates misclassified data till a pre-defined threshold level is reached or a human expert terminates inspection. The misclassified results merge with the original datasets for progressive re-training using a strategy similar to the base model development. The present work utilizes pre-trained CNN Efficientnet-b0 to develop the surface defect detection model for tapered roller inspection through transfer learning. It is concluded that the progressive re-training improves defect detection performance and reduces misclassifications. The Matthews Correlation Coefficient (MCC) score, derived from the confusion matrix, showed improvement from 0.6 to 0.82 after four iterations. A cross-model benchmarking study is also performed to show the versatility of the proposed approach. The present work demonstrated that the human-guided progressive learning approach can provide adaptability to vision-based surface defect detection utilizing deep learning algorithms and enhance system performance during real-time implementation.

Does the material recycling rate matter in the effect of the generated waste on environmental pollution? Panel smooth transition regression approach

This study examined the effect of material recycling on the relationship between the waste amount and environmental pollution in EU-15 countries for the 1995-2019 period through panel smooth regression analysis by using the material recycling rate as the threshold variable. Based on the analysis results, the material recycling rate threshold level was estimated as 11.79. In these countries, if the material recycling rate is below the threshold level, the rise in the waste amount will increase environmental pollution. If the material recycling rate is above the threshold value, the rise in the waste amount will still increase environmental pollution, but the pollution increase rate will decrease. With the increase in the waste amount in the long term, environmental pollution can only be reduced by raising the material recycling rate. For the reduction of environmental pollution, which is one of the most prioritized issues in Europe in recent years, policy makers should take measures to increase the material recycling rate by taking the results of this study into consideration and pay attention to the implementation of these measures.

Serial Multimodal Biometrics Authentication and Liveness Detection Using Speech Recognition with Normalized Longest Word Subsequence Method

Biometric authentication aims to verify whether an entity matches the claimed identity based on biometric data. Despite its advantages, vulnerabilities, particularly those related to spoofing, still exist. Efforts to mitigate these vulnerabilities include multimodal approaches and liveness detection. However, these strategies may potentially increase resource requirements in the authentication process. This paper proposes a multimodal authentication process incorporating voice and facial recognition, with liveness detection applied to voice data using speech recognition. This paper introduces Normalized Longest Word Subsequence (NLWS), a combination of Intersection Over Union (IOU) and the longest common subsequence, to compare the prompted system sentence with the user's spoken sentence at speech recognition. Unlike the Word Error Rate (WER), NLWS has a measurable range between 1 and 0. Furthermore, the paper introduces decision-level fusion in the multimodal approach, employing two threshold levels in voice authentication. This approach aims to reduce resource requirements while enhancing the overall security of the authentication process. This paper uses cosine similarity, Euclidean distance, random forest, and extreme gradient boosting (XGBoost) to measure distance or similarity. The results show that the proposed method has better accuracy compared to unimodal approaches, achieving accuracies of 98.44%, 98.83%, 97.46%, and 99.22% using cosine similarity, Euclidean distance, random forest, and XGBoost calculations. The proposed method also demonstrates resource savings, reducing from 5.19 MB to 0.792 MB, from 7.3294 MB to 1.9437 MB, from 6.6512 MB to 1.3284 MB, and from 7.8632 MB to 2.1517 MB in different distance or similarity measurements

The occurrence patterns and alternative host use of the generalist parasitoid Parvilucifera infectans (Alveolata, Perkinsozoa) of marine dinoflagellates revealed by a high-frequency time series microscopic data at a temperate coastal site

Species belonging to the genus Parvilucifera (Alveolata, Perkinsozoa) are known as generalist parasitoids that can infect a variety of marine dinoflagellates and ultimately kill the host cell. Despite the accumulation of knowledge on Parvilucifera parasitoids over the last twenty years, the occurrence pattern and use of alternative hosts for persistent transmission within fluctuating natural dinoflagellate host communities have received relatively little attention. To address this, high-frequency (i.e., daily) time series protist monitoring was conducted for 411 days, from April 2020 to May 2021, at a temperate coastal site in Jinhae Bay, Republic of Korea. This site was characterized by frequent blooms of mixed dinoflagellates throughout most of the year. Nonetheless, Parvilucifera infections were detected only in the spring seasons, and its occurrence pattern was primarily governed by the presence and cell density of its primary dinoflagellate host, Akashiwo sanguinea. As long as the primary host was present at high densities (greater than 104 cells L-1), this primary host alone could support the transmission and persistence of the parasitoid. However, if the cell density of the primary host started to decline, then Parvilucifera searched for and exploited alternative hosts for its continued survival. Taken together, this study suggests that the presence and cell density of its preferred primary host species and the duration for which the density remains above the threshold level are key factors that regulate the timing of Parvilucifera occurrence and alternative host use.

An emergency supply policy for an inventory replenishment model with returns and partial backorders

AbstractThis paper studies a continuous-review inventory replenishment model with a limited storage capacity S in an uncertain environment. We assume that the demands and returns follow independent Poisson processes. We further assume a ra1079 shelf life, a random lead time, and early loss. The storage is managed according to the base-stock (S, s) policy for $$s<S,S>0.$$ s < S , S > 0 . In case of overstock, each returned item exceeding S is transferred to a foreign facility. If during the lead time a demand reaches zero stock, we consider two alternatives: either allow partial backordering up to $$L_{B}$$ L B items, beyond which the unsatisfied demand is lost, or call for an immediate and costly emergency supply up to level $$0<Q_{B}^{e}\le S$$ 0 < Q B e ≤ S . Our objective is to study how the thresholds s, S, $$L_{B},$$ L B , and $$Q_{B}^{e}$$ Q B e are impacted by the system’s parameters, such as returns, demands, and costs. Using a Markovian framework, we derive the steady-state probabilities for the inventory level, and construct closed-form expressions for the average cost functions. Then, we numerically investigate the impact of the different parameters on the best policy and on the threshold levels. We compare the two alternatives and identify situations in which calling for an emergency supply is economically profitable.

Playing Ping- Pong: Keeping Frail Older Adults Out Of Hospital

Abstract Background EDITH (Emergency Department in the home) is a rapid response team consisting of a doctor/Advanced Nurse Practitioner and Occupational Therapist who assess patients in their home to avoid an ED attendance. The Integrated Care Team for Older People (ICPOP) is a community-based specialist multidisciplinary team that provides assessment and intervention for frail older adults in order to maintain them living at home. The teams have developed a close working relationship and utilise each other’s services to provide right time, right place patient care with the ultimate shared goal of keeping older adults living well at home. Methods A high frequency service user was identified, and a retrospective chart review was completed between the two teams. Outcome measures such a CFS, 4AT, medical status, social supports and environment set up were noted. Patient journey was conceptualised and handover of medical responsibility from team to team was explored along with identifying other factors that maintain older adults living well in their homes. Results Over a 12-month period, patient X case was “ping ponged” between the two services. The patient attended ED with EDITH review in the home facilitating a direct discharge home. The ICPOP team provided ongoing interdisciplinary and specialised intervention. ICPOP also identified changes to medical status that warranted timely EDITH review and thus negated the need for ED attendance. Patient X avoided a hospital admission during that period due to co working and open communication between both teams. Conclusion Rapid access, timely communication and team work between the EDITH/ICPOP yielded a positive result for patient X and allowed them to remain at home, despite a high level of frailty and low threshold for hospital admission. It appears that having services working with a collaborative approach affords better outcomes for this vulnerable population and reduces pressure on hospital resources.

Exposure assessment and semi-quantitative risk analysis of histamine in tuna and tuna-like fish from Indonesia

This study aimed to investigate histamine exposure associated with consumption of fresh tuna and tuna-like species in West Java, and to estimate risk of Scombroid Fish Poisoning (SFP) in Indonesia. A range of species, including tuna (Thunnus spp.), bullet tuna ( Auxis sp.), and skipjack ( Katsuwonus pelamis ) were collected from local markets and fish landing sites. Subsequently, histamine concentrations were determined using NMR analysis and exposure was calculated in mg/day for toddlers, children, and adults. The results showed that skipjack had the highest histamine exposure for all age groups, followed by bullet and regular tuna. The highest EDI for histamine was from skipjack consumption, accounting for 38.67; 37.77 and 20.74 percentage of exposure for toddlers, children and adults, respectively. These values are below the defined thresholds levels (ARfD), indicating no potential risk of acute health effect. Cooked bullet tuna and skipjack were estimated to cause similar illnesses, accounting for 6–7 cases per 100,000 individuals, which was higher than cooked tuna at 1–2 cases per 100,000 individuals. Considering the preparation of raw tuna in restaurants following Good Hygienic Practices (GHP), the predicted annual cases decreased significantly to 4–5 cases per million individuals. This risk estimation only considered histamine levels in fresh fish, without including data from fish preparation. Therefore, further studies were recommended to estimate the risk level in raw/fresh tuna and similar species before consumption.

The Environmental Kuznets Curve (EKC) Hypothesis on GHG emissions: analyses for transportation industry of South Africa

A series of energy-econometrics techniques were employed for a 5-year time span between 2016 and 2020. The tests of Environmental Kuznets Curve (EKC) hypothesis were conducted essentially to examine the significance of economic growth (GDP), energy consumption (EC), with energy intensity (EI), and on-road passenger vehicles (PV) as related to economic development on the mitigation of carbon emissions (CO2-eq) in the transportation industry of South Africa. The findings from the prevailing research imply that, with respect to South Africa’s transportation industry, CO2-eq emissions increased in the course of early phases of economic growth while it tends to decline at certain levels of economic threshold. Though the nation maintains the edge of turning points in both the industrial and circular economy. The results further indicate a nexus between GDP and EC, which consequently affect the CO2-eq emissions. The findings proffer the needs to monitor the EC from the long-run impacts alongside the short run impacts of the forecast. The per capita GDP from the short-run impacts of t-stat—(4.928) to the long run effects of t-stat—(5.033) rises, indicating its improper influence in the industry. To limit the use of fossil-based fuels, as demonstrated in the negative signal of EI for long-run impacts of a p-value (0.2835), then to the short run effects which possess a significant p-value. It also highlights the directional correlation surfacing between EC, EI and South Africa’s on-road PV. In the computation context, the series was determined to be stationary at its first differences, as evident by the R2 combined with the R2 (Adjusted) values of 0.9837 and 0.9827, respectively, for both long-run and short-run assessments. The indication of the research among others further reveals that public transportation systems of road and rail options, which have the potentials to incorporate alternative energy sources, can be the required efforts to mitigate climate change and global warming effects in the transportation industry.

Effects of Mixed Metal Exposure on MRI Metrics in Basal Ganglia.

Welding fumes contain various metals. Past studies, however, mainly focused on Manganese (Mn)-related neurotoxicity. This study investigated welding-related mixed metal exposure effects on MRI metrics in the basal ganglia (BG) and their dose-response relationship. Subjects with (N = 23) and without (N = 24) a welding exposure history were examined. Metal exposure was estimated with exposure history questionnaire and whole blood metal levels. T1 (weighted-intensity and relaxation time; estimates of brain Mn accumulation), diffusion tensor imaging [Axial (AD), mean (MD), radial diffusivity (RD), and fractional anisotropy (FA); estimates of microstructural differences] metrics in BG [caudate nucleus, putamen, and globus pallidus (GP)] and voxel-based morphometry (for volume) were examined and related with metal exposure measures. Compared to controls, welders showed higher GP R1 (1/T1; p = 0.034) but no differences in blood metal and T1-weighted (T1W) values in any ROIs (p's > 0.120). They also had higher AD and MD values in the GP (p's < 0.033) but lower FA values in the putamen (p = 0.039) with no morphologic differences. In welders, higher blood Mn and Vanadium (V) levels predicted higher BG R1 and T1W values (p's < 0.015). There also were significant overall metal mixture effects on GP T1W and R1 values. Moreover, GP AD and MD values showed non-linear associations with BG T1W values: They increased with increasing T1W values only above certain threshold of T1 values. The current findings suggest that Mn and V individually but also metal mixtures jointly predict GP T1 signals that may in turn contribute to altered DTI metrics in the BG after certain exposure threshold levels.

Construction and assessment of a fire risk index system for typical grasslands in Xinjiang, China

BackgroundFire hazards have a substantial impact on grassland ecosystems, and they are becoming more frequent and widespread because of global changes and human activities. However, there is still a lack of a widely accepted or practical method to evaluate grassland fire risk. In our study of typical grasslands in northern Xinjiang, we selected 18 evaluation indicators for grassland fires from three aspects of hazard, exposure, and vulnerability. Employing the analytic hierarchy process, weighted comprehensive evaluation method, and standard deviation classification, we determined the fire risk level thresholds, aiming to develop efficient and precise methods for assessing grassland fire risks, and ultimately created a grid-based map of grassland fire risk levels.ResultsThe risk level of grassland fires is determined by the combined spatial heterogeneity of fire-causing factors’ hazard and fire hazard-bearing bodies’ vulnerability and exposure. The hazard of grassland fire and fire hazard-bearing bodies’ vulnerability and exposure are dominated by medium level and medium–low level. Most areas of grassland fire risk levels are medium–low, medium, or medium–high risk, with few areas being high risk or low risk. The grassland fire risk exhibits a spatial distribution characterized by higher risks in the western and lower in the eastern; high and medium–high risk areas are primarily distributed in the western and some northeastern regions of the study area. The simulate result effectively represents the spatial distribution of grassland fire in the research area.ConclusionWe established a grassland fire risk index system and model, creating a spatial distribution map of grassland fire risk levels based on grid. Few grassland areas have fire risks and show a patchy distribution. The results generally reflect the spatial distribution pattern of grassland fire risks in the study area. This research provides technical support for scientifically formulating local grassland fire disaster prevention and relief strategies.

Comparative efficacy of pharmaceutical (Ibuprofen) and non-pharmaceutical (photobiomodulation, and chewing gum) interventions for pain reduction after elastomeric separator placement in orthodontic patients: a randomized clinical trial.

This study compared the efficacy of pharmaceutical (ibuprofen) and non-pharmaceutical (photobiomodulation and chewing gum) interventions for pain reduction after elastomeric separator placement in orthodontic patients. This 3-arm, parallel-group randomized clinical trial was conducted on 90 orthodontic patients. The level of anxiety and pain threshold of patients were measured at baseline using the Pain Catastrophizing Scale (PCS) and an algometer, respectively. The patients were randomly assigned to three groups (n = 30; equal number of males and females). In the laser group, 940nm diode laser (Epic X, Biolase, USA, 12.35J/cm2 energy density and 300 mW power in continuous-wave mode., The cross-sectional area of the laser handpiece tip was 1.7 cm2.) was irradiated to the buccal and lingual surfaces for 35s each, prior to placement of separators. In the gum group, the patients were asked to chew a piece of sugar-free gum immediately after the placement of separators and repeat every 8h for 5min for one week in case of pain. In the ibuprofen group, patients received 400mg ibuprofen (Hakim Pharmaceuticals, Tehran, Iran) after the placement of separators and were asked to take one tablet every 8h for one week in case of pain. The pain score was recorded using the Modified McGill Pain Questionnaire (MPQ). The normality of data distribution was analyzed by the Kolmogorov-Smirnov test. ANOVA was applied to compare age, and the Chi-square and Monte Carlo Chi-square tests were used to compare gender and patient responses to the questions among the groups. Repeated measures ANOVA was used to compare the pain score at different time points and among the three groups. All statistical analyses were conducted using SPSS version 19 (SPSS Inc., Chicago, IL, USA) at 0.05 level of significance. Data analysis in this study had an intention to treat approach. Although the pain score was slightly lower in ibuprofen and gum groups, the difference among the three groups was not statistically significant (P > 0.05). 'Repeated measures ANOVA showed no significant effect of method of pain reduction on pain score (F = 1.520, P = 0.225). Time had a significant effect on pain score (F = 20.310, P < 0.001). The interaction effect of time and pain reduction method on pain score was not significant (F = 0.737, P = 0.651). patients experienced a lower level of pain in the ibuprofen and chewing gum groups, the difference in pain score was not significant among the three groups (P = 0.225). patients experienced a higher level of pain at 12 and 24 hours after the placement of separators in all groups. Considering the comparably equal analgesic efficacy of this modalities, non-pharmaceutical interventions can be used for pain reduction of elastomeric separator. The study protocol was registered in the Iranian Registry of Clinical Trials (IRCT20210927052611N1). Date of registration 2022/03/14.

The relationship between leukocyte-based inflammation indices and essential tremor

Aim: Previous limited studies have indicated that pro-inflammatory cytokines are elevated in patients with essential tremor (ET). This elevation could lead to a more pronounced inflammatory response in these patients. Thus, this study aimed to investigate the relationship between leukocyte-based inflammatory indices and ET. Material and Methods: In this retrospective study, 103 patients diagnosed with ET between January 2021 and December 2023 were included, along with 103 healthy individuals who were matched by age and gender, participated in check-up programs, and had no other comorbidities. To evaluate tremor severity, the Fahn-Tolosa-Marin (FTM) tremor rating scale was utilized. The leukocyte-based inflammatory indices were calculated as follows: NLR= neutrophils / lymphocytes, PLR = platelets / lymphocytes, systemic immune-inflammation index (SII) = platelets × neutrophils / lymphocytes, and systemic inflammatory response index (SIRI) = neutrophils × monocytes / lymphocytes. Results: The ET group exhibited higher levels of leukocytes, their subtypes, CRP and leukocyte-based inflammatory indices compared to the control group. Increased CRP (OR= 3.71, p &lt; 0.001) and SIRI (OR= 11.73, p &lt; 0.001) levels were independent predictors of ET. In predicting ET. SIRI exhibited superior diagnostic performance compared to other inflammatory parameters. The threshold for SIRI levels was set at 7 and above, with a sensitivity of 85.4% and a specificity of 82.5%. There was a positive correlation between SIRI and FTM scores. Conclusion: Among the leukocyte-based inflammation indices, SIRI demonstrated superior diagnostic performance in predicting ET and was associated with higher tremor severity. This suggests that inflammation may play a potential role in the pathophysiology of ET.

Rich dynamics of a reaction–diffusion Filippov Leslie–Gower predator–prey model with time delay and discontinuous harvesting

To reflect the harvesting effect, a nonsmooth Filippov Leslie–Gower predator–prey model is proposed. Unlike traditional Filippov models, the time delay and reaction–diffusion under the condition of homogeneous Neumann boundary are considered in our system. The stability of equilibrium and the existence of the spatial Hopf bifurcation of the subsystems at the positive equilibrium are investigated. Furthermore, a comprehensive analysis is conducted on the sliding mode dynamics as well as the regular, virtual, and pseudoequilibria. The findings reveal that our Filippov system exhibits either a globally asymptotically stable regular equilibrium, a globally asymptotically stable time periodic solution, or a globally asymptotically stable pseudoequilibrium, contingent upon the specific values of the time delay and threshold level. A boundary point bifurcation, which transform a stable equilibrium point or periodic solution into a stable pseudoequilibrium, is demonstrated to emphasize the impact of time delay on our Filippov system and the significance of threshold control. Meanwhile, two kinds of global sliding bifurcations are exhibited, which sequentially transform a stable periodic solutions below the threshold into a grazing, sliding switching, and crossing bifurcations, depending on changes in the time delay or threshold level. Our results indicate that bucking bifurcation and crossing bifurcation pose significant challenges to the control of our Filippov system.

Insect pest Spodoptera litura (Fabricius) and its resistance against the chemical insecticides: A review

A polyphagous nocturnal pest Spodoptera litura (Fabr.) commonly called armyworm, infests about 150 plant species across 44 families worldwide, with nearly 60 plant species affected just in India. The majority of leaf tissues are consumed by the larvae and only the stem and side shoots will remain in the field. They entirely consume the interior content by boring into them, causing squares and young bolls to shed. This insect can badly affect crops and has a wide range of potential hosts, which can lead to financial losses for farmers and food shortages for consumers. The worldwide distribution of S. litura as a pest results in significant impact on productivity of many crops. They have the capability to invade new places as a wide-ranging species. Armyworm frequently reappears in India every year and causes evident destruction. Different records on the insect population outbreak have been reported from many countries all around the world. The larvae of insect pests enter the fruits and even contaminate it and this causes yield and economic losses. The low temperatures of winter season are the limiting factors that affect species. It migrates mainly to breed during the summer season but is unable to survive in winters. S. litura acquired resistance to several synthetic insecticides, which led to pest outbreaks that were irregular and caused failure of different crops. The resistance and cross-resistance of this pest against insecticide toxin make it more difficult to reduce its population below threshold level. Understanding the mechanisms of resistance is crucial for developing effective resistance management strategies that can restrict or halt the spread of resistance in these pest populations.

Vitamin D deficiency and thyroid cancer: is there a true association? A prospective observational study.

Literature data indicate a correlation between vitamin D deficiency and thyroid cancer (TC). We conducted this observational study to test this hypothesis. We studied 327 consecutive thyroidectomy cases, and compared patients with TC and those who had benign thyroid disease (BTD). In total, 183 cases with well-differentiated TC (group B) were compared with 144 cases of BTD (group A). We defined 25-hydroxyvitamin D (25(OH)VitD) values <10ng/ml as severe vitamin D deficiency (15.4%), 10-30ng/ml as inadequacy (70.4%) and >30ng/ml as adequate (14.2%). We further used a cut-off point of 30ng/ml (used in a recent meta-analysis) to classify patients as vitamin D deficient or not. There was no statistically significant difference in the following: age, size of the thyroid gland, preoperative calcium levels, preoperative parathormone and vitamin D levels, body mass index and anti-thyroid antibodies. Only thyroid-stimulating hormone and weight of the thyroid gland were found to differ. There was no significant difference in mean vitamin D levels (group A = 19.82ng/ml [sd 9.59] vs group B = 19.69ng/ml [sd 11.34]; p = 0.917). The same was found when we compared the two groups according to the three categories of vitamin D values (deficiency, inadequacy, adequacy; p = 0.485) and when we performed the analysis based on all threshold levels (10, 20 and 30ng/ml; p = 0.328). Using various statistical methods, no correlation was found between vitamin D deficiency and differentiated TC (overall, microcarcinomas, macrocarcinomas). Based on our results, no correlation between vitamin D deficiency and TC was confirmed, contradicting and questioning the results of two recent meta-analyses.

Inflation-threshold effect on current account imbalance in Tunisia: new evidence from a nonlinear approach

PurposeIn this article, we assess the impact of inflation on the current account balance in the case of Tunisia, covering the period 1976–2022.Design/methodology/approachThe study utilizes a threshold regression approach proposed by Hansen (2001) in a bid to identify inflation threshold values.FindingsThe results show two inflation threshold values (3.87% and 8.41%), which determine three inflation regimes in the case of Tunisia. In lower inflation regimes, inflation has a positive and statistically significant impact on the current account balance. However, in higher inflation regimes, where inflation rates exceed 3.87%, there is a negative and statistically significant correlation with the current account balance, resulting in a deficit.Originality/valueThe research suggests the need for a new policy approach that considers these threshold levels to address high inflation rates, which currently stand at approximately 11%, and aims to restore them to the targeted rate of 4%. This necessitates coordinated monetary and fiscal measures.