Measured Concentrations Research Articles

Assessment of pharmacokinetics and tolerability following single-dose administration of molnupiravir in participants with hepatic or renal impairment.

Individuals with chronic liver or kidney disease are at increased risk of severe COVID-19. Molnupiravir is an orally administered antiviral authorized for the treatment of mild-to-moderate COVID-19 in adults at risk of progression to severe disease. Two nonrandomized, open-label, single-dose, multicenter, phase 1 trials were conducted to investigate the effects of hepatic and renal impairment on the tolerability and pharmacokinetics of molnupiravir (800 mg) and its metabolite β-D-N4-hydroxycytidine (NHC; NCT05386589/NCT05386758). The impact of renal impairment on urinary excretion of NHC was also assessed. The 90% CI for the geometric mean ratio of the plasma NHC area under the concentration-time curve (AUC) from zero to infinity was <2.0 for participants with moderate hepatic or severe renal impairment versus healthy mean-matched controls. Comparable geometric mean values were observed for other pharmacokinetic parameters-including AUC from 0 to 12 h, AUC from zero to the last measurable concentration, and peak plasma concentration-in participants with moderate hepatic or severe renal impairment and in healthy mean-matched controls. Urinary excretion of NHC was low in healthy participants and participants with severe renal impairment; renal clearance was numerically lower in those with renal impairment. In both trials, all adverse events were of mild or moderate intensity and resolved by study completion. There were no clinically relevant treatment-related effects on other safety evaluations. Overall, molnupiravir was generally well-tolerated, with similar pharmacokinetic profiles in participants with hepatic or renal impairment and healthy participants, supporting its use for treating COVID-19 in these individuals without the need for dose adjustment.

Pharmacokinetics and Bioequivalence Evaluation of Trazodone Hydrochloride Sustained-Release Tablets in Healthy Chinese Volunteers.

The aim of this study was to investigate the pharmacokinetics, bioequivalence, and safety of generic trazodone hydrochloride sustained-release tablet and its reference listed product in healthy Chinese subjects. An open, randomized, single-dose, and 2-period crossover study was involved under fasting and fed conditions, with a 7-day washout period. A single oral dose of 150mg of 2 trazodone hydrochloride sustained-release tablets was administered to 84 healthy volunteers, with 36 in the fasting group and 48 consuming a high-fat diet, respectively. The plasma concentrations of trazodone were analyzed using a liquid chromatography-tandem mass spectrometry method, and pharmacokinetic parameters were obtained from concentration-time profiles. The geometric mean ratio with 90% confidence intervals of the maximum trazodone concentration, area under the plasma concentration-time curve (AUC) from time 0 to the last measurable concentration, and AUC from time 0 to infinity were within the bioequivalence acceptance criteria (80%-125%) under fasting and fed conditions, which indicated that the test and reference formulations were bioequivalent. Compared with the fasting study, the concomitant administration of trazodone with a high-fat diet had a negligible influence on the drug pharmacokinetic behavior. Adverse events were recorded, and no serious adverse events were observed during either fasting or fed conditions. Trazodone has proven to have an acceptable safety profile in the Chinese population, with bioequivalence successfully established under both fasting and fed conditions.

Budget-Driven Multiperiod Hub Location: A Robust Time-Series Approach

A Robust Time-Series Approach to the Budget-Driven Multiperiod Hub Location Problem The (un)capacitated multiperiod hub location problem involves uncertain time-series demands, the distribution of which is unobservable and correlated over periods. In “Budget-Driven Multiperiod Hub Location: A Robust Time-Series Approach,” Hu, Chen, and Wang develop a nested ambiguity set that characterizes uncertain periodic demands via a general multivariate time-series model and propose a budget-driven model that constrains each expected periodic cost within a budget while optimizing the robustness level by maximizing the size of the nested ambiguity set. Under certain regularity conditions on the underlying VAR(p) or VARMA(p,q) process of the stochastic demand, the developed ambiguity set enjoys the desirable property of measure concentration that translates to finite-sample performance guarantees of optimization problems’ decisions. In the uncapacitated case, the proposed budget-driven model essentially optimizes a Sharpe ratio–type criterion over the worst case among all periods. This research contributes to time-series predictive distributionally robust optimization.

On the Measure Concentration of Infinitely Divisible Distributions

On the Measure Concentration of Infinitely Divisible Distributions

Population pharmacokinetic modeling of paired plasma-breast milk lamivudine data for estimation of infant exposure in breastfeeding mother-infant pairs.

Around 1.2 million women living with HIV give birth annually, majority of whom will breastfeed their infants while receiving antiretroviral therapy (ART). Lamivudine, a component of first-line ART regimens crosses from maternal plasma to breast milk, with measurable concentrations in some breastfed infants. Wide variability in plasma-to-breast milk transfer has been reported within- or across studies, probably due to differences in sampling framework. This work sought to characterize the milk-to-plasma transfer of lamivudine, quantify inter-patient variability and associated factors, and predict exposure of a breastfed infant. We explored data from an observational pharmacokinetic study that included 35 Ugandan mothers and their infants. Mothers received lamivudine doses of 150 mg twice daily or 300 mg once daily as part of their antiretroviral regimen. Pharmacokinetic sampling was undertaken across two visits approximately 8 weeks apart, providing 248 maternal plasma, 256 breast milk-, and 151 infant blood concentrations, measured across a 24-h sampling interval. A one-compartmental model best described the plasma disposition of lamivudine, with first-order absorption, interindividual variability on clearance and volume of distribution, and a proportional residual error model. A lag in time of plasma-to-breast milk drug accumulation was described using an effect compartment model with a milk-to-plasma ratio of 1.77. An estimated daily infant dose of 179.3 μg/kg (range: 125.8, 282.3) closely predicted the observed infant steady-state concentrations and translated into 3.34% (2.13, 7.20) and 3.35% (1.10, 7.15) of the standard daily maternal dose in visits 1 and 2, respectively. The established modeling framework can be extended to other drugs.

Pharmacokinetics and Bioequivalence of 2 Oral Formulations of Vildagliptin in Healthy Chinese Subjects.

A randomized, open-label, 2-period, 2-sequence crossover study was conducted to evaluate the pharmacokinetics and bioequivalence of 2 oral formulations of vildagliptin tablets under both fasting and fed conditions in healthy Chinese subjects. A total of 56 healthy subjects were randomized to receive a single 50-mg dose of either a generic vildagliptin tablet (T) or the reference formulation (R). The washout period was 3 days. Blood samples were collected up to 24hours postdosing during each period and analyzed for vildagliptin using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The 90% confidence intervals for the geometric mean ratios (T:R) of maximum serum concentration, area under the serum concentration-time curve from time 0 to the last measurable concentration, and area under the serum concentration-time curve from time 0 to infinity were all within the predefined bioequivalence range of 80%-125%. This indicates that the generic and reference formulations are bioequivalent under both fasting and fed states. All adverse events reported were mild and transient. High-fat meals delayed absorption and reduced the maximum peak concentration of both formulations; however, they did not affect the overall exposure. Therefore, vildagliptin can be taken without regard to meals.

A Bioequivalence Study of Azilsartan in Healthy Chinese Subjects.

Azilsartan is an angiotensin II receptor blocker used for treating adult hypertension. It significantly improves cardiovascular outcomes in patients with high-risk hypertension, heart failure, and diabetic nephropathy. A single-center, randomized, open-label, single-dose, dual-cycle, dual-crossover clinical trial was conducted to evaluate the bioequivalence of azilsartan under fasting and postprandial conditions in 60 Chinese healthy volunteers. Thirty healthy subjects were enrolled in each test group, with random cross-administration for fasting and postprandial tests. The concentration of azilsartan in human plasma was evaluated using liquid chromatography-tandem mass spectrometry after a single oral administration of test and reference preparations, each at a dose of 20mg (1 tablet). Pharmacokinetic parameters were determined using WinNonlin8.2 software, and bioequivalence was evaluated using SAS 9.4 software. The geometric mean ratios and 90% confidence intervals for maximum concentration, area under the plasma concentration-time curve from time 0 to the time of last measurable concentration, and area under the plasma concentration-time curve from time 0 to infinity of the test and reference preparations in the fasting and postprandial test groups were in the range of 80%-125%. The incidence of adverse events in the fasting and postprandial test groups was 30% (9/30) and 33.3% (10/30), respectively. No serious adverse events or unexpected adverse drug reactions were observed. In conclusion, the test and reference preparations of azilsartan tablets demonstrate bioequivalence and good safety in healthy Chinese subjects under fasting and postprandial conditions.

IMPMH, direct tunable diode laser absorption spectroscopy for detection of water vapour under “Optically thick Condition”

Water vapour plays a crucial role in atmospheric processes. Hence, monitoring the altitude-related variations in water vapour properties is important to decipher atmospheric processes. Direct tunable diode laser absorption spectroscopy (dTDLAS) measures the concentration and temperature of gas molecules by scanning the rotation-vibration absorption lines using a high-spectral-resolution laser. In this study, we devised an integrated measurement and data processing method (integrative measurement and processing method for hygrometry, IMPMH) to enhance the in-situ airborne measurement capability of dTDLAS. We measured a wide range (240–18,000 ppm) of water vapour concentrations, aiming for atmospheric measurements in a highly water-saturated regime, called the “optically thick condition”. For recovering the full absorption spectra, the “integrative area” was defined and a difference factor D, which is the distance between two spectral regions with width corresponding to the half width of half maximum of the Voigt profile, was used to calculate the area. From the data, the low-bound concentration was measured to be 244 ppm. At D = 1.8, the transition concentration to the “optically thick condition” was measured to be 5,800 ppm. By increasing D from 1.8 to 2.8, the measurable upper-bound concentration increased to 17,993 ppm. IMPMH was applied to the measured data to estimate the final absorber density or water vapour concentration. The estimation was well-fitted with the measured detector signal with signal-to-noise ratio (SNR) of ∼ 300 of the residual spectrum, promising its applicability to in-situ airborne measurements. To validate IMPMH, the water vapour concentration range was divided into two regimes: (1) optically thick (5,800 < c < 18,000 ppm) and (2) optically thin (c < 5,800 ppm) conditions. Under the optically thick condition, IMPMH was validated by comparing the results between the short and long-path cells. In the optically thin condition, IMPMH was validated through comparison with the general dTDLAS method. Lastly, long-term stability of the dTDLAS system was validated by measuring 10 different concentrations (240–18,000 ppm) for 1000 s by characterising the precision and SNRs of the residual. The results demonstrate that IMPMH significantly enhances the in-situ airborne measurement capability of dTDLAS under both optically thick and thin conditions. Furthermore, requirements for the implementation of IMPMH in airborne measurement were investigated considering four aspects—sampling, low-pressure measurement, accuracy and precision, and multiplex detection. The results were examined with regard to atmospheric implications.

Speed of sound measurements of binary n-octane+ ethylcyclohexane mixture at liquid-gas phase transition curve

Bio-jet fuel is a key element in the aviation industry to reduce operating costs and environmental impacts. Bio-jet fuel is a complex mixture of four hydrocarbons (n-alkanes, isoalkanes, cycloalkanes and aromatics). In the present work, the speed of sound in pure n-octane, ethylcyclohexane, and their mixtures with six selected compositions of (0.3004, 0.4191, 0.4999, 0.5538, 0.6991, and 0.7852 mole fraction of ethylcyclohexane) has been measured along the l-G saturation curve in the temperature ranges from (286 to 443) K using the pulse method with a constant (acoustic) sounding base. The combined expanded absolute and relative uncertainties (0.95 level of confidence, k = 2) of the temperature, concentration, and speed of sound measurements are estimated to be 20 mK, 0.0006 mole fraction, and 0.2 %, respectively. The measured speed of sound data together with our previous reported density data for the pure component (ethylcyclohexane) and the mixture were used to calculate derived thermodynamic properties, such as isentropic compressibility kS and heat capacity ratios CPCV as a function of temperature along the l-G saturation curve for the pure components and the mixture for selected concentration of x = 0.8 mole fraction of ethylcyclohexane. The deviation of the measured speed of sound data for the mixture from the linear additive rule has been determined using the pure component data.

B-069 Characterization of a panel of antibodies as diagnostics for NASH and NAFL

Abstract Background Nonalcoholic fatty liver disease (NAFLD) is on the rise in Western industrialized countries and associated comorbidities like e.g. cirrhosis are a major cause of liver transplantations in the USA. In NAFLD, excess fat is accumulated in the liver whereas this build-up is not caused by alcohol. NASH (nonalcoholic steatohepatitis) and NAFL (nonalcoholic fatty liver) are two forms of NAFLD. NAFL represents a stage of the disease in which the liver does not exhibit major signs of inflammation or damage, while NASH does. NAFL does not necessarily progress to cause liver damage. NASH on the other hand may cause fibrosis and lead to cirrhosis with a risk of progression into liver cancer. Since NAFLD shows a prevalence of over 24-25% in both the USA and Europe, diagnosis moves more and more into focus. The current gold standard for NASH diagnosis is liver biopsy, and NAFLD as such can also be diagnosed by ultrasound and MRI, among others. A quest for biomarkers is ongoing to develop blood tests that allow NAFLD diagnosis by immunoassays for example. We have developed high affinity and specificity antibodies against four highly discussed marker proteins for NAFLD: RBP4 (Retinol Binding Protein 4), FGF21 (Fibroblast Growth factor 21), CHI3L1 (Chitinase-3-like protein 1) and PAI-1 (Plasminogen activator inhibitor-1). All four markers are discussed to be elevated in NAFLD patient serum. Methods We characterized the developed anti-RBP4 and anti-FGF21 antibodies via an in-house developed Chemiluminescence Immunoassay (CLIA). Results We have determined the limit of quantification (LoQ), limit of detection (LoD) and linear range of measurable concentrations for our antibody pairs. We further conducted spike and recovery experiments showing the precision of the developed antibodies against RBP4 and FGF21. Conclusions Together, we present antibody pairs for RBP4 and FGF21 suitable as a part of a diagnostic panel that has high potential to be applied in the diagnosis of NAFLD.

In vitro and in vivo antineoplastic activities of solamargine in colorectal cancer through the suppression of PI3K/AKT pathway.

Previous research has demonstrated the efficacy of SM in inhibiting tumor growth in various cancer types. The objective of this study was to examine the antineoplastic effects and molecular mechanisms of Solamargine (SM) in colorectal cancer. Colorectal cancer (CRC) cells were treated with different concentrations of SM to evaluate the anticancer concentration for further experimental measurements. Additionally, the antitumor efficacy of SM was assessed in a subcutaneously implanted tumor model of colorectal cancer. RNA-seq and bioinformatics analyses were employed to identify differentially expressed genes (DEGs) and elucidate the underlying molecular mechanisms in LoVo cells. Subsequently, the specific mechanism of SM-mediated anti-tumor activities was analyzed by protein expression methods. The results of in vitro assays demonstrated that SM exhibits significant inhibitory effects on cell proliferation, clone formation, and invasion, while also promoting apoptosis in SW48 and LoVo cells. In a mouse xenograft tumor model, intragastric administration of SM at doses of 5 or 10 mg/kg effectively suppressed tumor volume and weight, and induced cell apoptosis in vivo. SM treatment also down-regulated PCNA and Cyclin E protein expression, contributing to the regulation of apoptosis. Further analysis using RNA-seq, bioinformatics, and experimental measurements revealed that SM treatment upregulates PTEN expression, while significantly reducing the phosphorylation levels of Akt and mTOR in LoVo cells. Our study provides further evidence to support the notion that SM primarily induces apoptosis in colorectal cancer cells through the inhibition of the PI3K/Akt signaling pathway. Additionally, our investigation demonstrated the favorable safety profile of SM in a mouse model of colorectal cancer, thereby suggesting its potential as a promising therapeutic approach for the management of CRC.

Effects of Salt Concentration on a Magnetic Nanoparticle-Based Aggregation Assay with a Tunable Dynamic Range.

Magnetic nanoparticles (MNPs) can be functionalized with antibodies to give them an affinity for a biomarker of interest. Functionalized MNPs (fMNPs) cluster in the presence of a multivalent target, causing a change in their magnetization. Target concentration can be proportional to the 3rd harmonic phase of the fMNP magnetization signal. fMNP clustering can also be induced with salt. Generally, salt can alter the stability of charge stabilized fMNPs causing a change in magnetization that is not proportional to the target concentration. We have developed a model system consisting of biotinylated MNPs (biotin-MNPs) that target streptavidin to study the effects of salt concentration on fMNP-based biosensing in simulated in vivo conditions. We have found that biotin-MNP streptavidin targeting was independent of salt concentration for 0.005x to 1.00x phosphate buffered saline (PBS) solutions. Additionally, we show that our biosensor's measurable concentration range (dynamic range) can be tuned with biotin density. Our results can be leveraged to design an in vivo nanoparticle (NP)-based biosensor with enhanced efficacy in the event of varying salt concentrations.

Rapid and sensitive liquid chromatographic–tandem mass spectrometric methods for the quantitation of dolutegravir in human plasma and breast milk

BackgroundDolutegravir (DTG) is part of a first-line antiretroviral therapy (ART) for HIV management in drug-naïve individuals and is recommended for the treatment of HIV during pregnancy. Robust analytical tools to quantify DTG are necessary to support clinical trials that characterize its multi-compartment drug distribution. MethodsPotassium EDTA (K2EDTA) plasma or whole breast milk was spiked with DTG and an isotopically labeled internal standard. Samples were prepared via protein precipitation prior to LC–MS/MS analysis. The assays were validated in accordance with regulatory recommendations. ResultsAnalytical measuring ranges for DTG quantitation in plasma and breast milk were 100–10,000 ng/mL and 0.500 to 1000 ng/mL, respectively. Inter-assay precision and accuracy were 2.73 % to 3.41 % and −10.6 % to −5.37 % for plasma, and 4.24 % to 12.4 % and −5.63 % to 7.49 % for breast milk, respectively. DTG was stable for three freeze–thaw cycles and for at least 72 h at room temperature in matrix (plasma or breast milk). Additionally, whole blood was stable for 24 h at room temperature and 2 h under conditions of extended heat and humidity. Matrix effects for DTG in plasma and breast milk ranged from 101 % to 108 % and 78.2 % to 99.3 %, respectively. Quantitation in remnant plasma samples yielded measurable concentrations within the primary linearity of the assay. ConclusionsMethods to quantify DTG in human plasma and breast milk have been developed and validated. These assays were designed to satisfy all criteria for implementation in clinical and clinical trial settings.

Real-Time and Wireless Transmission of a Nitrogen-Doped Ti3C2Tx Wearable Gas Sensor for Efficient Detection of Food Spoilage and Ammonia Leakage.

With the rising popularity of smart homes, there is an urgent need for devices that can perform real-time online detection of ammonia (NH3) concentrations for food quality measurement. In addition, timely warning is crucial to preventing individual deaths from NH3. However, few studies can realize continuous monitoring of NH3 with high stability and subsequent application validation. Herein, we report on an integrated device equipped with a nitrogen-doped Ti3C2Tx gas sensor that shows great potential in detecting food spoilage and NH3 leakage. The nitrogen doping results in the lattice misalignment of Ti3C2Tx, subsequently realizing effective barrier height modulation and enhanced charge transfer efficiency of nitrogen-doped Ti3C2Tx. Density functional theory calculations confirm the greatly enhanced adsorption of NH3 on nitrogen-doped Ti3C2Tx. Our work can inspire the design of efficient gas sensors for real-time and wireless detection of food spoilage and NH3 leakage.

Single-Dose Tolerability and Pharmacokinetics of Onradivir in Chinese Patients with Hepatic Impairment and Healthy Matched Controls.

This study compared the safety and pharmacokinetics of a single oral dose of onradivir, an inhibitor of polymerase basic protein 2 in influenza A virus, in patients with hepatic impairment and healthy participants with normal hepatic function. Eight participants with mild hepatic impairment (Child-Pugh A), eight participants with moderate hepatic impairment (Child-Pugh B), and eight healthy matched controls were enrolled in this open-label, parallel-group clinical trial. After the administration of 600 mg of onradivir, pharmacokinetic parameters were calculated for each cohort and compared. Onradivir was generally well tolerated by all participants. No serious adverse events (AEs) and no deaths were reported during the study. Six patients with moderate hepatic impairment and three patients with mild hepatic impairment reported AEs, all of which were mild and quickly resolved. Compared with the normal liver function group, the maximum concentration, area under the curve from time zero to the last measurable concentration, and area under the curve from time zero to infinity were 103%, 68.5%, and 69.2% higher, respectively, in the mild hepatic impairment group. In the moderate hepatic impairment group, these increases were 101%, 197%, and 204%, respectively. Overall, there were clinically relevant differences in onradivir exposure between patients with mild or moderate hepatic impairment and normal controls. These data imply that onradivir dose adjustment is warranted in patients with mild or moderate hepatic impairment. The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT05856513).

Stochastic Assessment of Predictions and Uncertainties for Reflectance Losses Based on Experimental Data for Three Australian Sites

A stochastic reflectance loss model is applied to extended datasets of experimental data collected at three sites in Australia, each representative of a different environment: urban, rural, and remote outback. The three sites are analysed in terms of TSP (Total Suspended Particles) or PM10 (Particulate Matter below 10µm in diameter), depending on the available dust sampler deployed at each location. Assessment of seasonal and daily patterns are also performed for further understanding of local phenomena likely to affect soiling in the area. Airborne dust concentration data are exploited to provide density distributions of expected daily reflectance losses. These mean losses for the three sites are 0.31 pp/day, 0.72 pp/day, and 0.77pp/day for the outback, rural, and urban location, respectively. These values and their distributions are paramount for evaluation of a prospective plant profitability, planning for operating plants cleaning scheduling, and assessment of a prospective CSP location at site selection phase. The developed methodology is capable of providing highly valuable information based on easily measurable airborne dust concentration data only, hence becoming a critical step for de-risking CSP plants financing and deployment.

Effect of Food on the Pharmacokinetics, Safety, and Tolerability of Budesonide Oral Suspension in Healthy Adult Participants: A Randomized Phase 1 Study.

Budesonide oral suspension (BOS) is a swallowed corticosteroid indicated for 12-week therapy in eosinophilic esophagitis with minimal systemic exposure following administration. We aimed to assess the relative bioavailability of a single dose of BOS administered under fasting and fed (high-fat/high-calorie meal) conditions. Healthy adult volunteers (N = 20) were enrolled in an open-label, single-center, crossover study and were randomized (1:1) to receive a single oral dose of BOS 2.0 mg under fasting or fed conditions, with a 48-h washout period before crossover to the alternative conditions. Serial plasma samples were collected before and up to 24 h after dosing. Pharmacokinetic (PK) parameters were calculated from plasma budesonide concentration-time profiles by noncompartmental analysis. The mean peak budesonide concentration (Cmax) was ∼13% lower under fed than under fasting conditions (604.1 vs 692.9 pg/mL). Areas under the concentration-time curves from dosing to the last measurable budesonide concentration and from dosing to infinity were ∼26% higher and ∼27% higher under fed than fasting conditions (3529 vs 2811 pg h/mL and 3892 vs 3075 pg h/mL, respectively). The median time to peak plasma budesonide concentration was significantly longer (∼1 h) under fed than fasting conditions (2.516 vs 1.286 h, P <.001). Safety and tolerability were also assessed throughout the study; all adverse events were mild or moderate in severity. Despite slight differences in budesonide PK parameters between fed and fasting conditions, the effect of food on systemic exposure to budesonide (BOS formulation) is not expected to be clinically meaningful.

Rapid measurement of liquid diffusion coefficients for different concentrations based on compound liquid-core cylindrical lenses and the finite element method.

Liquid diffusion coefficients are usually concentration-dependent (D(C)), and current methods for measuring the D(C) relationship suffer from long measurement times and large repetitive experimental workloads. This paper consequently proposes a new method for rapid measurement of D(C), which can eliminate the need to measure uncalibrated diffusion coefficients corresponding to concentration by comparing the theoretical concentration distribution of diffusion solution obtained by the finite element method and the experimental concentration distribution. The core diffusion and imaging setup is a compound liquid-core cylindrical lens, which can offer the advantages of high refractive index resolution and imaging quality, guaranteeing the accurate measurement concentration distribution. The D(C) relationship can be obtained by simply gathering an appropriate diffusion image in one experiment profiting from taking full use of the solution concentration spatiotemporal distribution information using the finite element molding fitting method, reducing the measurement time greatly from several days in traditional methods to within 2 hours, characterized by short measurement time, high measurement accuracy and small experimental workload. The D(C) relationship of NaCl solution at 25 °C was measured using this method, and the result was in accord with the instantaneous image method and the literature values.

BLOOD LEAD CONCENTRATION ANALYSIS BETWEEN REHABILITATION FACILITY AND PERI-URBAN ENVIRONMENT VIRGINIA OPOSSUMS (DIDELPHIS VIRGINIANA) OF ILLINOIS.

The Virginia opossum (Didelphis virginiana) is the only marsupial in North America with a natural range north of Mexico. Its range is widespread throughout the United States, including Illinois. Virginia opossums are opportunistic omnivores that will eat a variety of fruits, grains, insects, and even carrion. They are a ground-foraging species, with frequent soil contact allowing for potential exposure to heavy metal contaminants in terrestrial environments. They are also opportunists that thrive in human-altered ecosystems, including peri-urban environments. Lead is a naturally occurring element and highly toxic metal that is abundant in the soil, primarily due to anthropogenic factors such as fossil fuel use, paint, industrial production waste, and battery recycling. Furthermore, carrion and offal piles containing lead bullet fragments remaining from hunting result in environmental contamination of this heavy metal. Few studies exist on lead exposure in the Virginia opossum. This pilot study evaluates the blood lead burden of 16 free-ranging Virginia opossums presented to a wildlife rehabilitation facility, compared with 16 wild-caught Virginia opossums trapped in grassland, maintained forest, or mixed ecotones. In other species, lead toxicosis has been associated with cognitive dysfunction that may increase the likelihood of trauma or injury in a free-ranging setting. In addition, a high incidence of Virginia opossums presenting for wildlife rehabilitation do so as result of human-animal conflict. Therefore, it was anticipated that individuals presenting for wildlife rehabilitation would have significantly higher blood lead concentrations than their free-roaming counterparts. In this study, every Virginia opossum had measurable blood lead concentrations and the average blood lead concentration of the rehabilitated group was 2.7 times higher than that measured in wild-caught Virginia opossums. These results suggest that Virginia opossums are exposed and susceptible to lead toxicosis due to their diet and foraging behaviors, making them more prone to subsequent injury and presentation to wildlife rehabilitation centers.

On concentration of the empirical measure for radial transport costs

Let μ be a probability measure on Rd and μN its empirical measure with sample size N. We prove a concentration inequality for the optimal transport cost between μ and μN for radial cost functions with polynomial local growth, that can have superpolynomial global growth. This result generalizes and improves upon estimates of Fournier and Guillin. The proof combines ideas from empirical process theory with known concentration rates for compactly supported μ. By partitioning Rd into annuli, we infer a global estimate from local estimates on the annuli and conclude that the global estimate can be expressed as a sum of the local estimate and a mean-deviation probability for which efficient bounds are known.