Disposal Rate Research Articles

Assessment of the risk to public health from soil contamination on the territory of solid waste landfills

Introduction. Domestic waste management is an extremely important issue for all countries of the world, especially for the countries of the former Soviet Union, as the current state of solid waste disposal in Ukraine is extremely unsatisfactory. According to the European Commission, the amount of waste in the European Union has increased in recent years to more than 2.5 billion tons per year. The results of the Waste Atlas report on the world's 50 largest landfills show that 64 million people are affected by the 50 largest landfills every day. Ukraine has a total of 6045 landfills and dumpsites. The general trend in Ukraine, in contrast to European countries, is a low level of recycling and utilization of solid waste and a high rate of landfill disposal. The vast majority of landfills (80 to 90%) operate in overload mode. Landfills, in particular solid waste landfills, are the main pollutants of the atmosphere, hydrosphere and soil. Therefore, determining the level of environmental hazard of heavy metals in the soil as a result of the impact of landfills and solid waste dumps is very important. Objective. The purpose of the article is to determine the impact of solid waste landfills on public health due to soil contamination with heavy metals. Methodology. In order to determine the level of environmental hazard of household waste storage at landfills and dumps, the paper assesses the risk to public health from soil contamination in the area of the Hrybovychi landfill (Lviv oblast), Rohan landfill (Kharkiv oblast), and Novovodolazhske landfill (Kharkiv oblast). The risk to public health from soil contamination at solid waste landfills was assessed using the traditional US EPA method and a new method for determining the potential risk to public health from soil contamination with heavy metals. Results. The article compares two fundamentally different methodological approaches to determining the level of environmental hazard of soil contamination with heavy metals. The risk to public health from soil contamination on the territory of solid waste landfills according to the US EPA method corresponds to hazard class 5 (extremely high hazard level) according to all calculations. The results of the assessment of the potential risk to public health from soil contamination using the new method at solid waste landfills correspond to hazard classes 2-4. Comparison of methodological principles for assessing the risk to public health from soil pollution has shown the advantages of using the new method of potential risk assessment. The use of the new method of assessing the potential risk to public health from soil pollution will help improve science-based management of household waste and direct financial resources to reduce the environmental hazard of soil and land pollution in Ukraine. Scientific novelty. The article presents an improved method for assessing the risk to public health from soil pollution, which represents the scientific novelty of the work Practical significance. Determining the environmental hazard of soil pollution due to the impact of landfills and solid waste dumps makes it possible to prioritize the implementation of environmental protection measures and will contribute to the implementation of environmentally sound environmental management, so the research is of practical importance.

Useful metals recovery from electronic scraps of headphones – A sustainable approach

The utilization of electronic devices has been consistently increasing each year. In the fiscal year 2020–2021, India handled more than 340,000 tonnes of electronic waste, a significant surge from the 69,414 tonnes recorded in 2017–2018. Over the past four years, there has been a remarkable fourfold increase in the collection and processing of e-waste. This project focuses on e-waste generated from headphones, considering their widespread usage globally. Surprisingly, despite their ubiquity, only 15 % of headphones are recycled, with more than 85 % being discarded as waste. To address this issue, hydrometallurgy treatment is employed to extract valuable metals such as copper and iron. Following this treatment, this research successfully obtained copper carbonate and iron oxide as essential elements. The leached solution undergoes analysis using Atomic Absorption Spectroscopy (AAS). Further characterization through X-Ray Diffraction (XRD) of batteries and magnets aids in identifying the crystalline materials. Additionally, a cost-benefit analysis was carried out, revealing a 57 % and a 39 % profit in copper carbonate and iron oxide extraction respectively and this validates the confirmation of circular economy. Finally, a questionnaire survey was conducted with approximately 192 students, revealing that most headset replacements occur roughly once a year, typically within a budget of around Rs. 500–1000. This strongly indicates a high rate of waste disposal.

Estimated glucose disposal rate and risk of cardiovascular disease and mortality in U.S. adults with prediabetes: a nationwide cross-sectional and prospective cohort study.

Estimated glucose disposal rate (eGDR), a noninvasive and convenient measure of insulin resistance, has been demonstrated to be associated with mortality in both type 1 and type 2 diabetes. We aimed to explore whether eGDR is associated with cardiovascular disease (CVD) risk and mortality in prediabetic adults. A nationwide population-based cohort of prediabetic individuals from the National Health and Nutrition Examination Survey 1999-2018 with available data on eGDR was included and categorized into eGDR ≥ 8 (reference), 6-7.99, 4-5.99, and < 4mg/kg/min groups. Cox proportional hazards model was used to estimate the associations of eGDR with mortality. A total of 4725 prediabetic adults, 60.12% men, mean age 48years were included. The odds ratio and 95% confidence interval (CI) for CVD risk were 1.74 (1.08-2.78), 2.90 (1.79-4.67), and 4.58 (2.15-9.76) for the eGDR 6-7.99, 4-5.99, and < 4mg/kg/min groups, respectively, compared with the reference group. There were 410 deaths (116 CVD-related) during a median follow-up of 107months in 4,332 participants without baseline CVD. The hazard ratios and 95%CI for the eGDR 6-7.99, 4-5.99, and < 4mg/kg/min groups were 1.70 (1.23-2.35), 2.01 (1.45-2.77), and 1.84 (1.11-3.04), respectively, for all-cause mortality (P for trend < 0.0001), and 3.84 (2.04-7.21), 4.01 (2.01-8.00), and 2.88 (1.03-8.06), respectively, for CVD mortality (P for trend = 0.01). Smoking status significantly modified the associations between eGDR and all-cause or CVD mortality. Increased insulin resistance, as indicated by a lower eGDR, is associated with increased risks of all-cause and CVD mortality in U.S. prediabetic adults.

Socio-environmental Opportunities for Organic Material Management in California's Sustainability Transition.

Contemporary resource management is doubly burdened by high rates of organic material disposal in landfills, generating potent greenhouse gases (GHG), and globally degraded soils, which threaten future food security. Expansion of composting can provide a resilient alternative, by avoiding landfill GHG emissions, returning valuable nutrients to the soil to ensure continued agricultural production, and sequestering carbon while supporting local communities. Recognizing this opportunity, California has set ambitious organics diversion targets in the Short-Lived Climate Pollutant Law (SB1383) which will require significant increases (5 to 8 million tonnes per year) in organic material processing capacity. This paper develops a spatial optimization model to consider how to handle this flow of additional material while achieving myriad social and ecological benefits through compost production. We consider community-based and on-farm facilities alongside centralized, large-scale infrastructure to explore decentralized and diversified alternative futures of composting infrastructure in the state of California. We find using a diversity of facilities would provide opportunity for cost savings while achieving significant emissions reductions of approximately 3.4 ± 1 MMT CO2e and demonstrate that it is possible to incorporate community protection into compost infrastructure planning while meeting economic and environmental objectives.

Associations between estimated glucose disposal rate and arterial stiffness and mortality among US adults with non-alcoholic fatty liver disease.

The estimated glucose disposal rate (eGDR), an effective indicator of insulin resistance, has been related to acute coronary syndrome, ischemic stroke and heart failure. This study aims to explore the relationship between eGDR and arterial stiffness, all-cause mortality and cardiovascular mortality in patients with non-alcoholic fatty liver disease (NAFLD). Participants with NAFLD were chosen from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018. The main outcomes are arterial stiffness (represented by estimated pulse wave velocity, ePWV), all-cause and cardiovascular mortality. Multiple cox regression models, restricted cubic spline, sensitivity analysis and subgroup analysis were carried out to investigate the correlation between the insulin resistance indicators and mortality and arterial stiffness. Furthermore, receiver operating characteristic curves were used to compare the predictive value of the eGDR with the triglyceride-glucose (TyG) index and the homeostasis model assessment of insulin resistance (HOMA-IR) for all-cause and cardiovascular mortality. In this study, a total of 4,861 participants were included for analysis. After adjusting confounding factors in the multivariate weighted cox regression model, the eGDR was inversely associated with the all-cause mortality (Q4 vs. Q1, HR =0.65 (0.48-0.89, P=0.01) and cardiovascular mortality (Q4 vs. Q1, HR =0.35 (0.19-0.65, P<0.001). Compared with TyG index and HOMA-IR, the eGDR shows excellent predictive value in all-cause mortality (0.588 vs. 0.550 vs. 0.513, P < 0.001) and cardiovascular mortality (0.625 vs. 0.553 vs. 0.537, P < 0.001). In addition, we found a significant negative correlation between eGDR and arterial stiffness (β=-0.13(-0.14-0.11, P< 0.001). However, TyG index and HOMA-IR showed no significant correlation to arterial stiffness. Low eGDR (an indicator of insulin resistance) levels are related to an increased risk of arterial stiffness and mortality in NAFLD patients in the United States.

Frequency of prediabetes in individuals with increased adiposity and metabolically healthy or unhealthy phenotypes.

To utilize the estimated glucose disposal rate (eGDR) index of insulin sensitivity, which is based on readily available clinical variables, namely, waist circumference, hypertension and glycated haemoglobin, to discriminate between metabolically healthy and unhealthy phenotypes, and to determine the prevalence of prediabetic conditions. Non-diabetic individuals (n = 2201) were stratified into quartiles of insulin sensitivity based on eGDR index. Individuals in the upper quartiles of eGDR were defined as having metabolically healthy normal weight (MHNW), metabolically healthy overweight (MHOW) or metabolically healthy obesity (MHO) according to their body mass index, while those in the lower quartiles were classified as having metabolically unhealthy normal weight (MUNW), metabolically unhealthy overweight (MUOW) and metabolically unhealthy obesity (MUO), respectively. The frequency of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and IFG + IGT status was comparable among the MHNW, MHOW and MHO groups, while it increased from those with MUNW status towards those with MUOW and MUO status. As compared with participants with MHNW, the odds ratio of having IFG, IGT, or IFG + IGT was significantly higher in participants with MUOW and MUO but not in those with MUNW, MHOW and MHO, respectively. A metabolically healthy phenotype is associated with lower frequency of IFG, IGT, and IFG + IGT status across all body weight categories.

Estimated glucose disposal rate as a predictor of chronic complications in type 1 diabetes - a cross-sectional study

Estimated glucose disposal rate as a predictor of chronic complications in type 1 diabetes - a cross-sectional study

Insulin sensitivity estimates and their longitudinal association with coronary artery disease in type 1 diabetes. Does it matter?

BackgroundInsulin resistance and chronic kidney disease are both associated with increased coronary artery disease risk. Many formulae estimating glucose disposal rate in type 1 diabetes infer insulin sensitivity from clinical data. We compare associations and performance relative to traditional risk factors and kidney disease severity between three formulae estimating the glucose disposal rate and coronary artery disease in people with type 1 diabetes.MethodsThe baseline glucose disposal rate was estimated by three (Williams, Duca, and Januszewski) formulae in FinnDiane Study participants and related to subsequent incidence of coronary artery disease, by baseline kidney status.ResultsIn 3517 adults with type 1 diabetes, during median (IQR) 19.3 (14.6, 21.4) years, 539 (15.3%) experienced a coronary artery disease event, with higher rates with worsening baseline kidney status. Correlations between the three formulae estimating the glucose disposal rate were weak, but the lowest quartile of each formula was associated with higher incidence of coronary artery disease. Importantly, only the glucose disposal rate estimation by Williams showed a linear association with coronary artery disease risk in all analyses. Of the three formulae, Williams was the strongest predictor of coronary artery disease. Only age and diabetes duration were stronger predictors. The strength of associations between estimated glucose disposal rate and CAD incidence varied by formula and kidney status.ConclusionsIn type 1 diabetes, estimated glucose disposal rates are associated with subsequent coronary artery disease, modulated by kidney disease severity. Future research is merited regarding the clinical usefulness of estimating the glucose disposal rate as a coronary artery disease risk factor and potential therapeutic target.

Altered Glucose Kinetics Occurs With Aging

Metabolic flexibility is the ability to respond or adapt to conditional changes in metabolic demand. The purpose of our study was to determine how age affects metabolic flexibility and underlying glucose kinetics in young and older healthy adults. We hypothesized that in response to a glucose challenge: 1) young participants would exhibit greater glucose clearance than older participants, and 2) young participants would have decreased endogenous glucose production via gluconeogenesis. Glucose and lactate tracers, along with gas exchange data were used to measure glucose kinetics and respiratory exchange ratios (RER=VCO2/VO2) to determine metabolic flexibility during a 2-hour 75-gram oral glucose tolerance test (OGTT). After a 12-hour overnight fast, 28 participants, 15 young (21-35 yr; 7 men and 8 women) and 13 older (60-80 yr; 7 men and 6 women) individuals received venous primed continuous infusions of [6,6-2H]glucose, and [3-13C]lactate with a H13CO3− bolus. Following a 90-minute metabolic stabilization and tracer equilibration period, volunteers underwent an OGTT. In all study participants arterialized glucose concentrations ([glucose]) rose 15 minutes post-glucose consumption, peaked at 60 minutes, and remained elevated. Older individuals had sustained increases in [glucose] compared to the young. As assessed by rates of appearance (Ra), disposal (Rd) and metabolic clearance (MCR) glucose kinetics were suppressed in older compared to young individuals. As well, unlike in young individuals, fractional gluconeogenesis (fGNG) remained elevated in the older population during the OGTT. Lastly, there were no differences in RER between young and older volunteers, making RER an incomplete measure of metabolic flexibility in volunteers studied. Our study revealed that glucose kinetics are significantly altered in an aged population following a glucose challenge. Further, these physiological deficits are not detected from changes in RER during an OGTT. Supported by NIH grant R01 AG059715 to GAB. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Association Between Triglyceride-Glucose Index and Homeostasis Model Assessment for Insulin Resistance with Estimated Glucose Disposal Rate.

This cross-sectional study was aimed to compare insulin resistance, Triglyceride- Glucose (TyG) index, fatty liver index (FLI) and hepatic steatosis index (HSI), glycaemic and lipids among groups/quartiles based upon estimated Glucose Disposal Rate (eGDR) from August 2022 to December 2022 among 249 male participants. The eGDR results in (mg/kg/min) were divided into four quartiles as: Group-I: {<6.88, n = 62}, Group-II: {<6.88-9.45, n = 63}, Group-III: {9.46-10.39, n = 62}, and Group-IV: {>10.39, n = 62}. Fasting plasma glucose (FPG), HbA1c, low density lipoprotein (LDL), homeostasis model assessment for insulin-resistance (HOMAIR), and TyG index demonstrated significant worsening increase from high to low eGDR groups. Receiver operating curve (ROC) analysis to calculate area under curve (AUC) for diagnostic efficiency candidate indices for eGDR demonstrated highest AUC for FLI as AUC: 0.736 (95% CI: 0.669-0.803), p < 0.001, followed by FPG: AUC: 0.682 (95% CI: 0.606-0.757), HOMAIR: AUC: 0.670 (95% CI: 0.602-0.739), HSI: AUC: 0.660 (95% CI: 0.589-0.731), TyG index: 0.658 (95% CI: 0.583-0.732), and HbA1c: 0.639 (95% CI: 0.583-0.732). Glycaemic measures, lipid indices, insulin resistance and TyG index deteriorated with declining eGDR. Diagnostic performance as evaluated by AUC for eGDR was highest for FLI, followed by FPG, HOMAIR, HSI, TyG index, HbA1c, and triglycerides. Key Words: Triglyceride, Insulin, Glucose, Diabetes.

Prophet time series modeling of waste disposal rates in four North American cities.

In this study, three different univariate municipal solid waste (MSW) disposal rate forecast models (SARIMA, Holt-Winters, Prophet) were examined using different testing periods in four North American cities with different socioeconomic conditions. A review of the literature suggests that the selected models are able to handle seasonality in a time series; however, their ability to handle outliers is not well understood. The Prophet model generally outperformed the Holt-Winters model and the SARIMA model. The MAPE and R2 of the Prophet model during pre-COVID-19 were 4.3-22.2% and 0.71-0.93, respectively. All three models showed satisfactory predictive results, especially during the pre-COVID-19 testing period. COVID-19 lockdowns and the associated regulatory measures appear to have affected MSW disposal behaviors, and all the univariate models failed to fully capture the abrupt changes in waste disposal behaviors. Modeling errors were largely attributed to data noise in seasonality and the unprecedented event of COVID-19 lockdowns. Overall, the modeling errors of the Prophet model were evenly distributed, with minimum modeling biases. The Prophet model also appeared to be versatile and successfully captured MSW disposal rates from 3000 to 39,000 tons/month. The study highlights the potential benefits of the use of univariate models in waste forecast.

Empirical and simulated investigation of the solid waste reverse supply chain: A complex adaptive system perspective

Solid waste is increasing rapidly worldwide. In this study, the solid waste (household waste, construction and demolition waste and industrial waste) management systems are treated as reverse supply chain to analyze the critical operational issues based on complex adaptive system theory. At the single-layer, the complexity of the various nodes at a layer arises from rational decision-making and behavioral heterogeneity. The solid waste generation layer is employed as an example to investigate the complexity of node behavioral decisions. Regression analysis results reveal that both endogenous (Attitude, Subjective norm, and Perceived behavioral control) and exogenous factors (Economic incentive, Government supervision, Technical support) positively influence sorting behavior. The effect of Economic incentive (β=0.327P<0.001) and Attitude (β=0.249P<0.001) on sorting behavior are the largest. In the multi-layer system, different layers communicate with each other through the material and financial flows and have cross-layer impacts. An agent-based model is developed to investigate the multi-layer feedforward influence mechanism of changes in key layers (e.g., sorting rate, disposal rate) and the material and financial flows adaptive adjustment direction of the solid waste reverse supply chain. High rate of participation and accuracy of source sorting can shorten material flow paths and reduce storage and transportation costs. The increase in disposal rate encourages the transition of solid waste from backfill to resource utilization. This study provides a practice reference for solid waste reverse supply chain and related enterprises managers.

Comparative impact of Roux-en-Y gastric bypass, sleeve gastrectomy or diet alone on beta-cell function in insulin-treated type 2 diabetes patients.

Although bariatric surgery is an effective treatment for type 2 diabetes by inducing weight loss and augmenting gut hormone secretion, the immediate effect on beta-cell function itself remains to be elucidated in type 2 diabetes. Therefore, a prospective, randomized trial was performed in 30 patients with insulin-treated type 2 diabetes and a body mass index ≥ 35kg/m2. Patients were randomly assigned (1:1:1) to Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in combination with protein-sparing modified fast (PSMF), or to PSMF alone. Eu- and hyperglycemic clamps were performed before and 3weeks after surgery and/or PSMF initiation. The primary outcome was the evolution of insulin sensitivity and beta-cell function after surgery, calculated using the composite measures of glucose disposal rate, insulin secretion rate, and disposition index (DI). Results revealed that markers of insulin sensitivity increased similarly in all arms (p = 0.43). A higher marker for maximal beta-cell function was observed when comparing SG to PSMF (p = 0.007). The DI showed a clear positive evolution after RYGB and SG, but not after PSMF alone. Altogether, these findings indicate that bariatric surgery results in an immediate beta-cell function recovery in insulin-treated type 2 diabetes.

Association of physical activity and sports participation with insulin resistance and non-alcoholic fatty liver disease in people with type 1 diabetes.

To evaluate the association between physical activity (PA) and sports participation with insulin resistance and non-alcoholic fatty liver disease (NAFLD) in people with type 1 diabetes (T1D). People with T1D from a secondary and tertiary care centre were included. Questionnaire-derived PA was expressed in metabolic equivalent of task hours per week (METh/week). Insulin sensitivity was calculated with the estimated glucose disposal rate (eGDR). NAFLD was assessed by transient elastography (TE). Multivariate linear and logistic regression models were conducted, adjusted for age, sex, diabetes duration and BMI. In total, 254 participants were included (men 56%, age 44 ± 14 years, diabetes duration 24 ± 14 years, median BMI 24.8 kg/m2), of which 150 participants underwent TE. Total PA (median 50.7 METh/week) was not significantly associated with insulin resistance (median eGDR 7.31 mg/kg/min) (beta -0.00, 95% CI -0.01 to 0.00) or with NAFLD (OR 1.00, 95% CI 0.99-1.01). Participating in sports was significantly associated with eGDR (beta 0.94, 95% CI 0.48-1.41) and with NAFLD (OR 0.21, 95% CI 0.08-0.56). In our T1D population, we could not find any dose-dependent association between PA, insulin resistance and NAFLD. People participating in sports had a lower degree of insulin resistance and lower odds for NAFLD.

Reinventing waste: Transforming discarded optical discs into polycarbonate-organosilane adsorbent for effective removal of mercury(II) in water

Polycarbonate, renowned for its versatile properties, has become indispensable in numerous domestic applications. However, the escalating rates of consumption and disposal raise significant concerns for sustainable development. Of particular concern is the inadequate management of obsolete optical discs, which pose a serious environmental threat due to the non-biodegradable polycarbonate component. To address this challenge, this study aimed to repurpose polycarbonate derived from optical disc waste into adsorbent materials using 3-aminopropyl triethoxysilane (APTES) coupling. The waste-derived products underwent comprehensive characterization employing Fourier transform infrared spectroscopy, field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, and Barrett-Joyner-Halenda techniques. Additionally, batch experiments were conducted to evaluate the mercury(II) adsorption behaviours. The successful immobilisation of APTES on polycarbonate surfaces was confirmed by the detection of nitrogen, silicon, and urethane groups. Notably, the product modified with 3 mL of APTES exhibited the highest surface area (61.992 m2 g−1), suggesting its potential for the adsorptive removal of mercury(II). Analysis based on the Langmuir (R2 =0.9824) and Redlich-Peterson (R2 =0.9834) isotherm models suggested a predominantly monolayer adsorption mechanism with an estimated maximum capacity of 1.284 mg g–1, while the adsorption process followed pseudo second-order kinetics (R2 =0.9998). The results highlight the efficacy of waste-derived polycarbonate-organosilane adsorbents in removing mercury(II) from diverse water matrices, rendering them attractive from both economic and environmental sustainability perspectives.

Short, frequent, light-intensity walking activity improves postprandial vascular-inflammatory biomarkers in people with type 1 diabetes: The SIT-LESS randomized controlled trial.

To examine the effect of interrupting prolonged sitting with short, frequent, light-intensity activity on postprandial cardiovascular markers in people with type 1 diabetes (T1D). In a randomized crossover trial, 32 adults with T1D (mean ± SD age 28 ± 5 years, glycated haemoglobin 67.9 ± 12.6 mmol/mol, 17 women) completed two 7-h laboratory visits separated by >7 days. Participants either remained seated for 7 h (SIT) or interrupted sitting with 3-min bouts of self-paced walking at 30-min intervals commencing 1 h after each meal (SIT-LESS). Physical activity, insulin regimen, experimental start times, and meal consumption were standardized during each arm. Plasma levels of interleukin (IL)-1β, tumour necrosis factor (TNF)-α, plasminogen activator inhibitor (PAI)-1 and fibrinogen were sampled at baseline, 3.5 and 7 h, and assessed for within- and between-group effects using a repeated measures ANOVA. The estimated glucose disposal rate was used to determine the insulin resistance status. Vascular-inflammatory parameters were comparable between SIT and SIT-LESS at baseline (p > .05). TNF-α, IL-1β, PAI-1 and fibrinogen increased over time under SIT, whereas these rises were attenuated under SIT-LESS (p < .001). Specifically, over the 7 h under SIT, postprandial increases were detected in TNF-α, IL-1β, PAI-1 and fibrinogen (+67%, +49%, +49% and +62%, respectively; p < .001 for all). Conversely, the SIT-LESS group showed no change in IL-1β (-9%; p > .50), whereas reductions were observed in TNF-α, PAI-1 and fibrinogen (-22%, -42% and -44%, respectively; p < .001 for all). The intervention showed enhanced effects in insulin-resistant individuals with T1D. Interrupting prolonged sitting with light-intensity activity ameliorates postprandial increases in vascular-inflammatory markers in T1D. The trial was prospectively registered (ISRCTN13641847).

Economic impacts of constrained replacement heifer supply in dairy herds

CONTEXTIn recent years, environmental policies, especially in North-western European countries have put pressure on the total livestock on a dairy farm. On closed dairy farms this primarily has resulted in a reduction of the heifer rearing unit to maintain the production unit. The economic consequences of constrained replacement heifer supply on herd level have not been investigated. OBJECTIVEThe objective of this study is to study on herd level the economic impact of suboptimal replacement decisions due to a constrained replacement heifer supply. METHODSIn this study, we combine a single-cow MDP (Markov Decision Process) optimization model with dairy herd dynamics simulation of 10 years to account for the interdependency among dairy cows within the herd of 100 cows. Besides the base scenario of following optimal replacement policy, we simulated three input scenarios of constrained, excess, and variable replacement heifer supply. RESULTS AND CONCLUSIONIn the base scenario, optimal replacement policy resulted in a herd gross margin of €155,108, 11% voluntary replacement rate, 24% involuntary disposal rate annually for a herd of 100 cows. Constrained as well as excess heifer supply resulted in lower gross margins of €85,878 and €138,406 respectively, compared to the base scenario. Constrained heifer supply also resulted in 39% reduction of herd size, involuntary disposal of 17.5% and no voluntary replacements (0.1%) on average per year. Variable heifer supply scenario resulted in lower gross margins (€115,127), lower voluntary replacement rate (4%), highest involuntary disposal rate (28%) but did not result in reduction of herd size, compared to the base scenario.In conclusion, we developed a combination of cow level optimization with a herd level simulation to study the economic impacts of constrained replacement heifer supply. We found that severely constrained, excess, and variable heifer supply result in reduced herd average gross margin. SIGNIFICANCEOptimization replacement policy in case of limited heifer availability requires an inter-cow comparison to determine which cows need to be replaced first as this study shows. By demonstrating a simplified approach of combining individual cow optimization with herd dynamics simulation, we accounted for the inter-dependencies within herd. Such an approach can be instrumental in studying environmental impacts, longevity, and welfare of cows when heifer supply is constrained on a herd level.

Comparison of Two Estimated Glucose Disposal Rate Methods for Detecting Insulin Resistance in Adults with Type 1 Diabetes Mellitus.

Background: The presence of insulin resistance (IR) in patients with type 1 diabetes mellitus (T1DM) is a significant indicator of all chronic diabetic complications, independent of other risk factors. The estimated glucose disposal rate (eGDR) is a practical method that can be easily used in daily practice to determine IR. This study aimed to determine the cutoff values for two eGDR methods and compare their diagnostic value for determining IR in adult T1DM patients with metabolic syndrome (MetS). Methods: This cross-sectional study was performed on 184 adults admitted to the endocrinology outpatient clinic diagnosed with T1DM. Demographic characteristics, anthropometric measurements, and the presence of hypertension (HT) were recorded. The eGDR of all patients was calculated using two formulas based on HbA1c level, presence of HT, waist-to-hip ratio (WHR), or waist circumference (WC). Diagnostic cutoff values for both eGDRs were defined using receiver operating characteristic (ROC) analysis. Patients were divided into two groups according to the cutoff values. The accuracy of the diagnostic cutoffs for eGDRwhr and eGDRwc was compared using a Bland-Altman plot. Results: The cutoff value for eGDRwhr was 7.37 mg/(kg·min) with 83.3% specificity and 86.7% sensitivity [area under the curve (AUC) = 0.901; P < 0.001; 95% confidence interval (CI), 0.824-0.977] and for eGDRwc 7.50 mg/(kg·min) with 79.8% specificity and 83.3% sensitivity (AUC = 0.895; P < 0.001; 95% CI, 0.817-0.972) for the presence of MetS. Further ROC analysis showed that the difference between the two AUCs (0.901 and 0.895) was not significant (P = 0.923). Conclusion: Assessment of eGDR would lead to early prevention of diabetic complications. eGDR is measured using either WHR or WC. This study is the first to compare WHR and WC in calculating eGDR in adults. WHR and WC are not superior to each other for calculating eGDR in determining IR in T1DM.

Review and Research on Medical Waste Recycling Network

The mass production of medical wastes has tested the safety of urban public health, and the recovery and disposal of medical wastes is imminent. Under various environmental backgrounds, such as the sudden increase in the number of medical wastes, the late start of the medical waste recycling industry in China, the low disposal rate, and the improper treatment of medical wastes affecting the environment and personal safety, medical wastes should be managed in a timely and standardized manner, and effective strategies should be put forward to minimize the environmental pollution caused by medical wastes. Therefore, in recent years, this paper studies the optimization of medical waste recycling network and summarizes the current research status of medical waste recycling network in academic circles.

The 13C glucose breath test accurately identifies insulin resistance in people with type 1 diabetes.

This study investigated whether the delta-over-baseline of exhaled 13CO2 (Δ13CO2), generated from a 13C glucose breath test (13C-GBT), measured insulin resistance (IR) in people with type 1 diabetes, using the hyperinsulinemic-euglycemic clamp (HEC) as reference method. Secondary objective was to compare the 13C-GBT with the estimated glucose disposal rate (eGDR). A 40 mU/m2/min HEC and two separate 13C-GBTs (euglycemic with insulin bolus and hyperglycemic without bolus) were consecutively performed in 44 adults with type 1 diabetes with varying body compositions. eGDR was calculated based on HbA1c, presence of hypertension and waist circumference. Mean M-value was 5.9 ± 3.1 mg/kg/min, mean euglycemic Δ13CO2 was 6.4 ± 2.1 δ‰, while median eGDR was 5.9 [4.3 - 9.8] mg/kg/min. The hyperglycemic Δ13CO2 did not correlate with the M-value, while the euglycemic Δ13CO2 and the M-value correlated strongly (r = 0.74, p < 0.001). Correlation between M-value and eGDR was more moderate (Spearman's rho = 0.63, p < 0.001). Linear regression showed an association between Δ13CO2 and M-value, adjusted for age, sex and HbA1c (adjusted R² = 0.52, B = 1.16, 95% CI 0.80 - 1.52, p < 0.001). The AUROC for Δ13CO2 to identify subjects with IR (M-value < 4.9 mg/kg/min) was 0.81 (95% CI 0.68 - 0.94, p < 0.001). The optimal cut-off for Δ13CO2 to identify subjects with IR was ≤ 5.8 δ‰. Under euglycemic conditions, the 13C-GBT accurately identified individuals with type 1 diabetes and concurrent IR, suggesting its potential as a valuable non-invasive index.