Lower Confidence Limit Research Articles

Dietary Exposure to Acrylamide and Associated Health Risks for the Korean Population.

The aim of the study was to estimate the dietary exposure to acrylamide (AA) from the consumption of various processed food and to assess the associated health risks in different age groups in Korea. Potato crisps and French fries presented the highest mean levels of AA (546 and 372 μg/kg, respectively) followed by coffee (353 μg/kg) and tea products (245 μg/kg). The mean AA dietary exposure values for toddlers (≤2 years), children (3–6 years), children (7–12 years), adolescents (13–19 years), adults (20–64 years), and seniors (≥65 years) were estimated to be 0.15, 0.13, 0.06, 0.06, 0.08, and 0.06 μg/kg body weight (BW)/day, respectively. Based on the benchmark dose lower confidence limit (BMDL10) of 0.18 and 0.31 mg/kg BW/day, the calculated mean and 95th percentile values for the margin of exposure were below 10,000 for the all age groups suggesting possible health concern for Koreans. Biscuits, crisps, and coffee were the primary foods contributing to dietary AA exposure among these in the Korean populations. In children, considering the health risk of AA dietary exposure, especially from biscuits and crisps, there is a need to further control and modify dietary habits to ensure lower AA exposure.

Reliability Interval Estimation for a System Model with Element Duplication in Different Subsystems

The problem was considered of estimating reliability for a complex system model with element duplication of various subsystems and ensuring possibility of additional redundancy in a more flexible dynamic (or 'sliding') mode in each of the subsystems, which significantly increases reliability of the system in general. For the system considered, general model and analytical expressions were obtained in regard to the main reliability indicators, i.e., probability of the system failure-free operation (reliability function) for a given time and mean time of the system failure-free operation. On the basis of these analytical expressions, the lower confidence limit for the system reliability function was found in a situation, where the element reliability parameters were unknown, and only results of testing the system elements for reliability were provided. It was shown that the system resource function was convex in the reliability parameters vector of the system separate elements various types. Based on this, the lower confidence boundary construction for the system reliability function was reduced to the problem of finding the convex function extremum on a confidence set in the system element parameter space. In this case, labor consumption of the corresponding computational procedure increases linearly with an increase in the problem dimension. Numerical examples of calculating the lower confidence boundary for the system reliability function were provided

Development of a benchmark dose for lead-exposure based on its induction of micronuclei, telomere length changes and hematological toxicity

BackgroundExcessive lead exposure is associated with adverse health effects. However, there is a lack of systematic investigation using large populations to ascertain acceptable exposure limits. ObjectivesOur study was aimed to identify human exposure–response relationships between lead exposure and health-related outcomes, and to determine a benchmark dose (BMD). MethodsA total of 1896 participants from a lead-acid battery plant were recruited. Blood lead levels (BLLs) were detected for all participants. Hematological parameters (n = 1896), micronuclei (MN) frequencies (n = 934), and relative telomere length (rTL) (n = 757) were also determined. Multivariate linear/Poisson regression analyses were performed to examine associations between BLLs and these health outcomes. Restricted cubic splines were used to identify dose-response relationships. Three BMD approaches were used to calculate BMD and its 95% lower confidence limit (BMDL). ResultsAmong all participants, BLLs show a right-skewed distribution (median, 185.40 μg/L; 25th − 75th percentile, 104.63–271.70 μg/L). There existed significant differences for red blood cell (RBC), hemoglobin (Hb), MN and rTL among different BLL dose groups. After adjusting for possible confounders, all indicators were significantly associated with BLLs. Restricted cubic splines show that there were linear dose-response relationships for RBC and Hb with BLLs, while non-linear for MN and rTL. Results from the three BMD approaches indicate that the dichotomous models were better than continuous models to calculate BMD and BMDL of BLLs. The conservative BMDL obtained from RBC data was 135 for total, 104 for male and 175 μg/L for female. The corresponding BMDL obtained from Hb data was 105 for total, 116 for male and 70 μg/L for female. As for MN data, the BMDL estimate was 66 for total, 69 for male and 64 μg/L for female. Finally, the BMDL from rTL data was 35 for total, 32 for male and 43 μg/L for female. ConclusionsOur data show significant dose-response relationships between lead exposure and expressions of hematological toxicity and genotoxicity. The new BMDLs of 135 and 105 μg/L based on RBC and Hb, and even more strict level of 66 and 35 μg/L based on MN and rTL are lower than current exposure limits in China. Therefore, the four values can be considered as novel exposure limits. In addition, sex effect should be taken into account when setting occupational health standard. Considering that different biomarkers have different sensitivities, better understanding their relationships will certainly improve the current emphasis on precision health risk assessment.

Phylogenetic Processes and Key Driving Factors of Bacterial Communities in Jinze Reservoir

To investigate the ecological mechanisms of the bacterial response to human disturbance in micro-polluted water ecosystems, we studied the relationship between the environmental factors and bacterial community development in the incoming water and various areas of a reservoir based on an ecological null model. The results showed that the phylogenetic clustering of bacterial communities was more dispersed than expected (the single-sample t-test of SES.MNTD has a 95% lower confidence limit of 9.79). Temperature is an important environmental factor affecting community phylogeny. The relative importance of stochastic and deterministic processes in the bacterial community succession of different samples showed seasonal characteristics. The bacterial community succession in spring, summer, and autumn samples was dominated by random and deterministic processes. NH4+-N is the main environmental factor affecting the relative importance of random and deterministic processes. When the concentration of NH4+-N is 0.06-0.40 mg ·L-1, the bacterial community succession is dominated by random processes; when the concentration is 0.40-0.80 mg ·L-1, it is dominated by both random and deterministic processes. Dispersal limitation (61.68%) and heterogeneous selection (26.65%) played important roles in bacterial community changes at different sampling points in the study area.

Policy Implications for the COVID-19 Pandemic in Light of Most Patients (≥72%) Spending at Most One Night at the Hospital After Elective, Major Therapeutic Procedures.

A large number of inpatients with Coronavirus disease 2019 (COVID-19) in some regions of the United States may interfere with the ability of hospitals to take care of patients requiring treatment for other conditions. Nonetheless, many patients need surgery to improve their quality of life and to prevent deterioration in health. Curtailment of services also negatively affects the financial health of hospitals and health systems. Broad policies to prohibit all “elective” surgical procedures to ensure that there is sufficient hospital capacity for pandemic patients may be unnecessarily restrictive because, for many such procedures, patients are rarely admitted following surgery or only stay overnight. We studied all elective inpatient and ambulatory cases involving major therapeutic procedures performed in the state of Florida in 2018. We mapped the primary procedure to the corresponding Clinical Classification Software (CCS) category. We determined the distributions of lengths of stay overall and as stratified by CCS category, then calculated the percentage of cases that had a hospital length of stay of ≤1 night (i.e., 0 or 1 day). A threshold of one night was selected because patients discharged home on the day of surgery have no effect on the inpatient census, and those staying overnight would either have a transient effect or no effect if observed overnight in the postoperative care unit. Among the 1,852,391 elective cases with one or more major therapeutic procedures, 65.2% (95% lower confidence limit [LCL] = 65.1%) of cases had a length of stay of 0 days and 72.9% (95% LCL = 72.8%) had stay ≤1 day. There were 38 different CCS categories for which at least 95% of patients had a length of stay of ≤1 day. There were 28 CCS codes that identified 80% of the patients who were discharged with a length of stay ≤1 day, showing representation of multiple surgical specialties. Our results show that even in the face of constraints imposed by a high hospital census, many categories of major therapeutic elective procedures could be performed without necessarily compromising hospital capacity. Most patients will be discharged on the day of surgery. If overnight admission is required, there would be an option to care for them in the postanesthesia care unit, thus not affecting the census. Thus, policies can reasonably be based on allowing cases with a substantial probability of at most an overnight stay rather than a blanket ban on “elective” surgery or creating a carve-out for specified surgical subspecialties. Such policies would apply to at least 72% of elective, major therapeutic surgical procedures.

Assessment of the risk of exposure to cadmium and lead as a result of the consumption of coffee infusions

The paper aimed to analyse the safety of drinking coffee by adult Poles in terms of Pb and Cd content. The degree to which Cd and Pb passed from coffee grounds into the coffee infusion was also examined. Twenty-three samples of natural coffee were examined. The content of metals was determined using the ICP method. On average, dry coffee contained ca. 0.004 μg Cd and 0.05 μg Pb per 1 g, and 95.5% Cd and 94% Pb passed into the infusion. Drinking coffee supplies these metals in the amount of less than 2% TWI (tolerable weekly intake) for Cd and BMDL (benchmark dose lower confidence limit) for Pb. In the presented studies, the values of CDI (chronic daily intake), THQ (target hazard quotient) and HI (hazard index) indicators were lower than 1, which means that the risk of developing diseases connected with chronic exposure to Cd and Pb consumed with coffee must be evaluated as very low. The content of Cd and Pb in the analysed coffee infusions was very low, so drinking coffee does not pose a risk for consumers in terms of the content of these metals. However, it must be remembered that no threshold limits for toxic metal consumption exist because these metals accumulate in the body for a long time. The studies presented here also showed a low (r = 0.26) but still a positive correlation between the content of Pb in coffee and the degree (%) to which Pb passed into the infusion. This problem should be thoroughly investigated.

Heavy metals in commercial fish and seafood products and risk assessment in adult population in Bosnia and Herzegovina

This work investigates the level of exposure to cadmium (Cd), mercury (Hg), and lead (Pb) via fish and seafood products in adult population in Bosnia and Herzegovina (BiH). Metals content was determined in seven commercial species of fish and seafood products widely available and consumed in BiH. Analysis of Cd and Pb was performed by GFAAS (Graphite furnace atomic absorption spectrometry), and analysis of Hg by FIAS AAS (flow injection cold vapour atomic absorption spectrometry) in accredited laboratory for food analysis. The health risk was determined by the estimated weekly intake, hazard index, target hazard quotients, and percent of tolerable weekly intake or percent of benchmark dose lower confidence limit. Concentration above the maximum residue level (MRL) set in the European Union was found in only one sample (Hg in mackerel). Cd content was generally high in squid, approaching the corresponding MRL in two samples. The hazard index was close to 1 in bluefin tuna and mackerel, mostly due to Hg content. These two fish species should be consumed in moderation, especially by pregnant women. While consumption of various fish and seafood on average is not of significant concern, health risk could not be ruled out for high consumers.

Acute Toxicity of Mercuric Chloride to the Freshwater Catfish, Heteropneustes fossilis

Four-day static renewal acute toxicity test was used for Heteropneustes fossilis to determine the LC 50 values for chromium chloride. Six replicates each containing ten fish (kept in glass aquarium containing 30 L of the test solution) were subjected to chromium chloride (50, 75, 100, 125, 150, 200 and 250 mg/L). The per cent mortality after exposure to various concentrations of chromium chloride to H. fossilis for 24, 48, 72 and 96 h has been observed and the LC 50 values at different exposure periods as well as their upper and lower confidence limits and slope functions were calculated by PoloPlus software version 2.0 Computer programme. The LC50 values of chromium chloride for H. fossilis at 24, 48, 72, and 96 h were calculated as 138.50 mg/L; 119.38 mg/L; 92.77 mg/L and 63.26 mg/L, respectively.

Assessment of Lockdown Effectiveness in the Wake of COVID-19 in India Using ARIMA Model

Background: Novel coronavirus disease COVID-19 has been recognized as a global threat, and several studies are being conducted using various mathematical models to predict the probable evolution of this epidemic which are subject to potential bias. In this study we aimed to assess and compare the impact of lockdown between Punjab, Delhi and Gujarat states of India using Auto Regressive Integrated Moving Average (ARIMA) model by comparing forecasted COVID-19 data with real time data. Methods: We analyzed COVID-19 data of Indian states from index case till 17th of May, 2020. ARIMA (1,1,3) (0,0,0) model was used to forecast the possible cumulative cases till May 17, from data up to May 3rd. and compared with real time data. Collated recovery rate, case-fatality rate, test per million of states. Results: Trend of cumulative cases in Punjab was moving downward below the forecasted lower confidence limit (R2 = 0.9799) whereas, the cumulative case trend of Delhi was moving along the forecasted upper confidence limit with the forecasted data till May 3rd (R2 = 0.9971) and the trend of cumulative cases was below the forecasted upper confidence limit (R2 =0.9992) in Gujarat. Conclusions: In Gujarat and Delhi, the lockdown was not merely effective in controlling the rise in COVID-19 cases even after 56th day of lockdown whereas, Punjab state was succeeded in preventing havoc of COVID-19. In lieu of lockdown, using facemasks, improving ventilation in closed workspace settings, crowded spaces and close contact settings is more pragmatic than keeping away from others in India.

Benchmark dose estimation for coke oven emissions based on oxidative damage in Chinese exposed workers

Coke oven emissions (COEs) can cause oxidative stress of the body, which in turn induces the occupational lung disease and also increases the risk of other diseases. COEs are the major occupational hazard factors for coke oven workers. The aim of the study is to explore the influences of COEs exposure on oxidative damage and estimate the benchmark dose (BMD) of COEs. A group of 542 workers exposed to COEs and 237 healthy controls from the same city were recruited in this study. The corresponding measuring kits were used to determine the plasma biomarkers of oxidative damage level. Generalized linear models and trend tests were used to analyze the relationship between COEs exposure and biomarkers. EPA Benchmark Dose Software was performed to calculate BMD and the lower confidence limit of the benchmark dose (BMDL) of COEs exposure. A significant association was observed between COEs exposure and oxidative damage with T-AOC as a biomarker. The BMD of COEs exposure were 2.83 mg/m3 and 1.39 mg/m3 for males and females, respectively, and the corresponding BMDL were 1.47 mg/m3 and 0.75 mg/m3, respectively. Our results suggested that the exposure level of COEs below the current national occupational exposure limits (OELs) would induce oxidative damage, and the OEL of COEs based on the T-AOC damage was suggested at 0.03 mg/m3 in this study.

Developing a quality-based supplier selection model from the buying company perspective

ABSTRACT In the face of increased competition and globalization, supply chain management has become a crucial aspect of securing competitive advantage. Within this, the quality offered by suppliers is vital. Thus, in this paper, we develop a model to select the best supplier based on process quality from the perspective of the buyer. We first employ the process capability index , which can provide an exact measure of process yield, to evaluate the process quality of suppliers. However, must be estimated from preliminary samples or obtained subsamples. This increases uncertainty and can lead to miscalculation. To ensure the reliability of assessment, we derive the lower confidence limit of to serve as a standard of process quality assessment and construct a process capability analysis chart to select the best supplier. The chart also provides recommendations for process improvement to serve as a reference for suppliers with poor performance. Finally, we present two real-world case studies to demonstrate the practical applicability of the proposed method.

Magnetic Tracking and Electrocardiography-Guided Tip Confirmation System Versus Fluoroscopy for Placement of Peripherally Inserted Central Catheters: A Randomized, Noninferiority Comparison

PurposeTo determine whether the use of a magnetic tracking and electrocardiography-guided catheter tip confirmation system (TCS) is safe and noninferior to fluoroscopy concerning positioning accuracy of a peripheral inserted central catheter (PICC).MethodsIn this prospective, randomized, single-center study, adult patients scheduled for PICC insertion were assigned 1:1 either to TCS or fluoroscopy. The primary objective was a noninferiority comparison of correct PICC tip position confirmed by X-ray obtained immediately after catheter insertion. Time needed for PICC insertion and insertion-related complications up to 14 days after the procedure were secondary outcomes to be assessed for superiority.ResultsA total of 210 patients (62.3 ± 14.4 years, 63.8% male) were included at a single German center between June 2016 and October 2017. Correct PICC tip position was achieved in 84 of 103 TCS (82.4%) and 103 of 104 fluoroscopy patients (99.0%). One-sided 95% lower confidence limit on the difference between proportions was −23.1%. Thus, noninferiority of TCS was not established (p > 0.99). Insertion of PICC took longer with TCS compared to fluoroscopy (8.4 ± 3.7 min vs. 5.0 ± 2.7 min, p < 0.001). Incidence of complications within a mean follow-up of 5.0 ± 2.3 days did not differ significantly between groups.ConclusionNoninferiority of TCS to fluoroscopy in the incidence of correct PICC tip position was not reached. Ancillary benefit of TCS over fluoroscopy including less radiation exposure and lower resource requirements may nonetheless justify the use of TCS. The study is registered with Clinical.Trials.gov (Identifier: NCT02929368).

0600 Automated Oximetric Versus Standard Sleep Polygraphy Scoring

Abstract Introduction Agreement between automated standard respiratory event scoring and a novel, validated, and patented oximetry-based algorithm was assessed. Methods The standard apnea-hypopnea index (AHI) was derived by adding apneas (flow drop &amp;gt;= 90% for 10 to 30 s) and hypopneas (flow drop &amp;gt;= 30% for 10 to 60 s with oxygen saturation (SpO2) dropping &amp;gt;=3%). The novel oxygen index (ODI4) was derived by scoring events where SpO2 dropped in each of three successive samples and cumulatively by &amp;gt;= 4%. Agreement was assessed by Bland-Altman analysis Results AHI versus ODI4 and Bland-Altman plots showed a high prevalence of AHI &amp;gt; ODI4 when AHI was&amp;lt; 30/h. Negative difference outliers were frequent when mean index difference was &amp;gt; 30/h. There was a bias of 2.83/h in the difference between AHI and ODI4 with upper and lower confidence limits of 22.0/h and -16.3/h. Conclusion Standard respiratory event scoring overestimates respiratory disturbance compared to a novel oximetric index. Standard automated scoring frequently over scores events when basal flow amplitude is low. Support None.

Comparison of Diagnostic Sleep Studies in Hospitalized Neurorehabilitation Patients With Moderate to Severe Traumatic Brain Injury

OSA is prevalent during a time of critical neural repair after traumatic brain injury (TBI). The diagnostic utility of existing sleep studies is needed to inform clinical management during acute recovery from TBI. This study aimed to evaluate the non-inferiority and diagnostic accuracy of a portable level 3 sleep study relative to level 1 polysomnography in hospitalized neurorehabilitation patients with TBI. This is a prospective clinical trial conducted at six TBI Model System study sites between May 2017 and February 2019. Of 896 admissions, 449 were screened and eligible for the trial, with 345 consented. Additional screening left 263 eligible for and completing simultaneous administration of both level 1 and level 3 sleep studies, with final analyses completed on 214 (median age= 42 years; ED Glasgow Coma Scale= 6; time to polysomnography [PSG]= 52days). Agreement was moderate to strong (weighted kappa= 0.78, 95%CI, 0.72-0.83) with the misclassification commonly occurring with mild sleep apnea due to underestimation of apnea hypopnea index (AHI). Most of those with moderate to severe sleep apnea were correctly classified (n= 54/72). Non-inferiority was not demonstrated: the minimum tolerable specificity of 0.5 was achieved across all AHI cutoff scores (lower confidence limits [LCL] range, 0.807-0.943), but the minimum tolerable sensitivity of 0.8 was not (LCL range, 0.665-0.764). Although the non-inferiority of level 3 portable diagnostic testing relative to level 1 was not established, strong agreement was seen across sleep apnea indexes. Most of those with moderate to severe sleep apnea were correctly identified; however, there was risk of misclassification with level 3 sleep studies underestimating disease severity for those with moderate to severe AHI and disease presence for those with mild AHI during early TBI neurorehabilitation.

Appropriate operating room time allocations and half-day block time for low caseload proceduralists, including anesthesiologist pain medicine physicians in the State of Florida

Study objectiveWe analyzed University of Iowa operating room data to estimate whether it would be economically rational to allocate, every two weeks, an operating room to anesthesiology pain medicine physicians or a half-day session to individual proceduralists. We investigated the generalizability of the results by studying anesthesiologist pain medicine physicians working at all hospitals and ambulatory surgery centers in the State of Florida. DesignObservational, cohort study of spinal neuromodulation procedures. MeasurementsHours of daily operating room time and cases by anesthesiologist pain medicine physicians at the University of Iowa, and in Florida in 2018. For each two-week period, we calculated the difference in hours between (1) the under-utilized time from allocating 8 h and (2) time-and-a-half times the over-utilized time from no allocated time. Main resultsThe mean greater cost from allocating 8 h vs 0 h equaled 3.89 h, significantly >0 (P = 0.0001, N = 77 periods). Sample mean activities were 0.79 cases and 1.64 h, <2.00 cases and 4.00 h, respectively (both P < 0.0001). Thus, no allocated time or block time should be planned.At least 76.6% (95% lower confidence limit) of Florida surgical facilities performing ≥1 neuromodulation procedures averaged <1.08 cases per two weeks. At least 89.6% of the facilities averaged <2 cases per two weeks. At least 88.8% of combinations of anesthesiologist and facility in Florida averaged fewer cases per two weeks than anesthesiologist proceduralists at the University of Iowa. At least 96.5% of the proceduralists averaged <2 cases per two weeks at each facility where they operated. ConclusionsAmong anesthesiologist proceduralists in Florida using operating room time for neurostimulator procedures, most perform too few cases weekly for the economically appropriate planning of block time. Few Florida facilities would have enough cases, even potentially, to warrant allocating operating room time.

IMIDACLOPRID TOXICITY AND ITS ATTENUATION BY AQUEOUS EXTRACT OF MORINGA OLEIFERA LEAF IN ZEBRA FISH, DANIO RERIO

Objective: Imidacloprid (IMC) is a systemic chloro-nicotinyl insecticide that is applied in crop fields to control a wide variety of harmful insects and pests. The objective of the present study was to evaluate the mitigating effects of Moringa leaf extract (MLE) against Imidacloprid (IMC) induced mortality after acute toxicity bioassay in zebrafish, Danio rerio.&#x0D; Methods: The fishes were exposed to various concentrations of IMC to estimate the LC50 values at different exposure periods using the probit analysis.&#x0D; To assess the attenuating effect on mortality fishes were exposed to different concentrations of MLE along with 24 and 96 h LC50 of IMC. Mortality rate of fishes was recorded during all experimental periods.&#x0D; Results: The LC50 values were found to be 0.423, 0.352, 0.297 and 0.270 ml/l after 24, 48, 72 and 96 h respectively. The upper confidence limits were 0.491, 0.408, 0.334 and 0.302 ml/l and lower confidence limits were 0.355, 0.296, 0.260 and 0.238 ml/l for 24, 48, 72 and 96 h respectively.&#x0D; The fishes remain alive at 12 ml/l and 10 ml/l of MLE against 24 and 96 h LC50 respectively. Some behavioral responses such as violent, sluggish and erratic movement, respiratory distress, mucous secretion all over the body, discoloration were also observed in IMC treated fishes in comparison to MLE treated fishes.&#x0D; Conclusion: These findings demonstrated that MLE has mitigating effects against the toxic influence of IMC on mortality in zebra fishes which is attributed to its antioxidant effects.

Risk assessment of aflatoxins in food.

EFSA was asked to deliver a scientific opinion on the risks to public health related to the presence of aflatoxins in food. The risk assessment was confined to aflatoxin B1 (AFB1), AFB2, AFG1, AFG2 and AFM1. More than 200,000 analytical results on the occurrence of aflatoxins were used in the evaluation. Grains and grain‐based products made the largest contribution to the mean chronic dietary exposure to AFB1 in all age classes, while ‘liquid milk’ and ‘fermented milk products’ were the main contributors to the AFM1 mean exposure. Aflatoxins are genotoxic and AFB1 can cause hepatocellular carcinomas (HCCs) in humans. The CONTAM Panel selected a benchmark dose lower confidence limit (BMDL) for a benchmark response of 10% of 0.4 μg/kg body weight (bw) per day for the incidence of HCC in male rats following AFB1 exposure to be used in a margin of exposure (MOE) approach. The calculation of a BMDL from the human data was not appropriate; instead, the cancer potencies estimated by the Joint FAO/WHO Expert Committee on Food Additives in 2016 were used. For AFM1, a potency factor of 0.1 relative to AFB1 was used. For AFG1, AFB2 and AFG2, the in vivo data are not sufficient to derive potency factors and equal potency to AFB1 was assumed as in previous assessments. MOE values for AFB1 exposure ranged from 5,000 to 29 and for AFM1 from 100,000 to 508. The calculated MOEs are below 10,000 for AFB1 and also for AFM1 where some surveys, particularly for the younger age groups, have an MOE below 10,000. This raises a health concern. The estimated cancer risks in humans following exposure to AFB1 and AFM1 are in‐line with the conclusion drawn from the MOEs. The conclusions also apply to the combined exposure to all five aflatoxins.

NuSTAR Observations of the Transient Galactic Black Hole Binary Candidate Swift J1858.6–0814: A New Sibling of V404 Cyg and V4641 Sgr?

Swift J1858.6-0814 was discovered by Swift-BAT on October 25, 2018. Here we report on the first follow-up NuSTAR observation of the source, which shows variability spanning two orders of magnitude in count rate on timescales of ~10-100 s. The power-spectrum of the source does not show any quasi-periodic oscillations or periodicity, but has a large fractional rms amplitude of 147%$\pm3$%, exhibiting a number of large flares throughout the observation. The hardness ratio (defined as $R_{10-79 \rm keV}/R_{3-10 \rm keV}$) of the flares tends to be soft, while the source spans a range of hardness ratios during non-flaring periods. The X-ray spectrum of the source shows strong reflection features, which become more narrow and peaked during the non-flaring intervals. We fit an absorbed relativistic reflection model to the source spectra to place physical constraints on the system. Most notably, we find that the source exhibits a large and varying intrinsic absorbing column density ($N_{\rm H}=1.4-4.2\times10^{23}$ cm$^{-2}$). This large intrinsic absorption is further supported by the energy spectra extracted from two flares observed simultaneously by NuSTAR and NICER. We find that the inner accretion disk of the source has a low inclination, $i<29^{\circ}$ ( 3$\sigma$ upper-limit), while the iron abundance in the disk is close to solar, $A_{\rm Fe}=1.0\pm0.3$. We set a 90% confidence upper limit on the inner radius of the accretion disk of $r_{\rm in}<8 \ r_{\rm ISCO}$, and, by fixing $r_{\rm in}$ to be at $r_{\rm ISCO}$, a 90% confidence lower-limit on the spin of the black hole of $a^{*}>0.0$. Lastly, we compare the properties of Swift J1858.6$-$0814 to those of V404 Cygni and V4641 Sgr, which both show rapid flaring and a strong and variable absorption.

Confidence limits for compliance testing using mixed acceptance criteria

AbstractFor manufactured items sold by weight or volume, this article considers mixed acceptance criteria that put limits on the sample mean or on an upper confidence limit based on the sample mean and on the number of individual sample units that are nonconforming. For a normally distributed quality characteristic of interest, this article develops lower confidence limits for the mixed acceptance criteria applying the concept of a generalized pivotal quantity and applying a bias‐corrected and accelerated parametric bootstrap. The accuracy of the confidence limits is assessed using estimated coverage probabilities, and the results are illustrated with an example.

Značaj i procena benchmark doze u toksikologiji

This paper aims to present the importance of the benchmark dose (BMD) as a point of departure (the lowest dose or concentration in the experiment that deviates from the response that differs from the normal response) in toxicological risk assessment, as well as to present commonly used software for its calculation (BMDS and PROAST). Benchmark dose is defined as a statistical lower confidence limit of a dose that results in a small change in effect (5-10%) in comparison with the control value. The BMD approach is considered a substitution for the NOAEL approach, which uses the highest observed no-effect level (NOAEL) to obtain the reference dose. The BMD approach is a methodically more forward-thinking technique than the NOAEL approach because it has statistical power and provides a wide range of dose-response relationships and allows the determination of their uncertainty and variability. Moreover, the BMD approach contributes to the reduction of experimental animals in toxicity studies. Therefore, the European Food Safety Authority (EFSA) recommends the use of BMDL10 values for quantal and BMDL05 for continuous data.