Monitoring Time Interval Research Articles

Predictive Value of Circulating Tumor Cells Based on Subtraction Enrichment for Recurrence Risk in Stage II Colorectal Cancer.

Current guidelines recommend adjuvant chemotherapy (ACT) for stage II colorectal cancer (CRC) patients by using clinical high risk factors, with which circulating tumor cells (CTCs) were not considered. Here, an assessment to detect CTCs based on subtraction enrichment mediated by magnetic beads conjugated with CD45, immunofluorescence staining of CK, and fluorescence in situ hybridization of CEP8 is established. Both CEP8- and CK-positive CTCs have the potential to improve the risk stratification of stage II CRC patients. Patients with preoperative CTCs of ≥4 had a significantly higher recurrence risk than those with preoperative CTCs of <4 in two external validation cohorts (P < 0.0001). In the subgroup with clinical high risk, when preoperative CTCs were <4, patients did not benefit from ACT (P = 0.5764); however, when preoperative CTCs were ≥4, patients received benefit from ACT (P = 0.0064). Additionally, regardless of clinical risk status and preoperative CTC levels, if postoperative CTC levels were ≥4 for more than three consecutive time points (monitoring time interval, 2-6 months), the recurrence rate was 100%. Our findings suggested that the subtraction enrichment of CTCs could provide a reliable method to stratify the recurrence risk and make therapeutic decisions after surgery in stage II CRC patients.

Guideline for ultrasonic diagnosis of liver diseases

Ultrasound is a non-invasive, real-time, inexpensive, radiation-free and easily repeatable method, usually used for liver imaging. In recent years, new ultrasound examination techniques for liver diseases such as contrast-enhanced ultrasound and elastography have been rapidly developed, which can effectively identify intrahepatic space-occupying lesions, assess the degree of liver fibrosis and portal hypertension, and monitor the effects of treatment. Therefore, these technologies play an important diagnostic role in clinical liver diseases and have therapeutic interventional value. This guideline classifies the instrument set-up, patient preparation, and physician examination methods through multimodal ultrasound examinations (gray-scale ultrasound, color Doppler ultrasound, contrast-enhanced ultrasound, elastic ultrasound) for liver diseases. In addition, liver diseases multimodal ultrasound technology diagnostic criteria for diffuse hepatic lesions (inflammatory lesions, fibrosis, and sclerosis), multiple space-occupying lesions, and interventional procedures have been defined and standardized. Concurrently, we also recommend the ultrasound monitoring time interval and diagnostic report writing standard for liver diseases.

Are American follow-up recommendations in endocrinology actionable? A systematic review of clinical practice guidelines.

Clinical guidelines include recommendations to guide patient's longitudinal care. These recommendations may differ in content and quality of supporting evidence from those guiding diagnosis and treatment. We aimed to identify recommendations guiding the follow-up of patients with endocrine conditions, describe their content and quality of evidence. We systematically assessed the Endocrine Society and the American Thyroid Association clinical guidelines and identified recommendations guiding follow-up strategies to evaluate direction, content, strength, and quality of evidence. Out of 1540 recommendations, 138(8.9%) guided follow-up strategies. From these, 109 (79%) recommendations included goal of follow-up, 121(97.7%) suggested follow-up methods, and 56 (40.6%) a specific monitoring frequency. A total of 76 (55.1%) assessed treatment response, 65 (47.1%) disease progression, and 30 (21.7%) side effects. A total of 90 (65.2%) described the use of laboratory studies, 30 (21.7%) clinical exam/history, and 27 (19.6%) imaging studies. Finally, 91 (65.9%) suggested a monitoring time interval and 42 (30.4%) directed an action based on results. Most recommendations [88 (55.3%)] were based on low/very low-quality evidence. A total of 73 (52.9%) recommendations were labeled as strong, from which 12% were based on high-quality evidence. One out of ten clinical recommendations for endocrine conditions guide follow-up and their content is variable. More than half of the follow-up recommendations are supported by low/very low-quality evidence and the majority does not provide an action threshold. A specific framework for developing follow-up recommendations can aid guideline panelists and support evidence-based monitoring.

Pricing Discretely Monitored Barrier Options under Markov Processes through Markov Chain Approximation

The authors propose an explicit closed-form approximation formula for the price of discretely monitored single or double barrier options with an underlying asset that evolves according to a one-dimensional Markov process, which includes diffusion and jump-diffusion processes. The prices and Greeks of a discretely monitored double barrier option are explicitly expressed in terms of rudimentary matrix operations. In addition, this framework may be extended to include additional features of barrier options often encountered in practice—for example, time-dependent barriers and nonuniform monitoring time intervals. They provide numerical examples to demonstrate the accuracy and efficiency of the proposed formula as well as its ability to reproduce existing benchmark results in the relevant literature in a unified framework. TOPICS:Derivatives, options Key Findings ▪ Markov chain approximations to stochastic processes are used to develop a simple closed-form pricing formula for discretely monitored barrier options. ▪ This article explores price and Greek computations within the constant elasticity of a variance model and Merton’s and Kou’s jump-diffusions models. ▪ Numerical examples are provided to demonstrate the robustness and accuracy of the pricing technique, both to recreate specialized results in related barrier option literature and to extend to multiple novel settings.

Optimization Design of Groundwater Pollution Monitoring Scheme and Inverse Identification of Pollution Source Parameters Using Bayes’ Theorem

In the process of identifying groundwater pollution sources, in order to solve the problem that the monitoring data of monitoring wells was insufficient or the correlation between monitoring data and model parameters was weak, a monitoring well optimization method based on Bayesian formula and information entropy was proposed. Two-dimensional phreatic groundwater solute transport model was built and solved by using GMS software. To reduce the computational load of calling the numerical model repeatedly in the optimization design of the monitoring schemes and the identification process of the pollution sources, the Kriging method was used to establish the surrogate model of the numerical model. Under the condition of single well monitoring and determined monitoring frequency, with the target of optimization of monitoring position number D and monitoring time interval ∆t, both the single-objective monitoring scheme with the minimum information entropy of the model parameter posterior distribution and the multi-objective monitoring scheme with the minimum information entropy and the shortest monitoring time were optimized respectively. According to the above-optimized monitoring schemes, the delayed rejection adaptive Metropolis algorithm was used to identify the pollution source parameters. The case study results showed that under the condition of pre-set single well monitoring with monitoring frequency of 10 times, the single-objective optimized monitoring scheme was D = 37 and Δt = 20 days. Under this monitoring scheme, the mean errors of inversion pollution source parameters α = (XS, YS, T1, T2, QS) were 0.09%, 0.4%, 4.72%, 2.43%, and 9.29%, respectively. The multi-objective optimized monitoring scheme was D = 37 and Δt = 2 days. Under this monitoring scheme, the mean errors of the inversion parameters α = (XS, YS, T1, T2, QS) were 12.76%, 3.77%, 5.13%, 1.36%, and 7.68%, respectively. Compared with the monitoring scheme based on the single-objective optimization, although the inversion mean error of the five parameters based on the multi-objective optimized monitoring scheme increased by 2.75%, the monitoring time significantly reduced from 180 to 18 days.

Pricing Discretely Monitored Barrier Options Under Markov Processes Using a Markov Chain Approximation

We propose an explicit closed-form approximation formula for the price of discretely monitored single or double barrier options whose underlying asset evolves according to a generic one-dimensional Markov process. This set of stochastic processes includes, but is not limited to, diffusion and jump diffusion processes commonly used in derivative pricing applications. The formula’s derivation combines the integral equation method, the Z−transform technique, and a continuous-time Markov chain approximation of the underlying Markov process. It does not require one to perform an intermediate numerical quadrature or related potentially runtime-intensive, error-prone, or otherwise complicated numerical procedure that may require a high degree of tuning to ensure appropriate accuracy (e.g. an inverse Laplace transform or inverse Z−transform). Rather, the price and Greeks of a discretely-monitored double barrier option may be explicitly expressed in terms of rudimentary matrix operations. In addition, this framework may be extended to include additional features of barrier options often encountered in practice. Examples including time-dependent barriers and non-uniform monitoring time intervals, may be seamlessly incorporated into this framework. In addition, by limiting the monitoring frequency to a large value, we also obtain an accurate closed-form formula for the price and Greeks of continuously-monitored double barrier options with time-dependent barriers under general Markov processes. Finally, we provide many numerical examples to demonstrate the accuracy and efficiency of the proposed formula as well as its ability to reproduce existing benchmark results in the relevant literature.

Reliability of Annual Changes and Monitoring Time Intervals for Bone Strength, Size, Density, and Microarchitectural Development at the Distal Radius and Tibia in Children: A 1-Year HR-pQCT Follow-Up.

High-resolution peripheral quantitative computed tomography (HR-pQCT) imaging, together with computational finite element analysis (FEA), offers an attractive, noninvasive tool to quantify bone strength development in pediatric studies. Evidence of annual changes and errors in repeated HR-pQCT measures is limited, and time intervals required to reliably capture changes in children's bone strength or microarchitecture have not yet been defined. Our objectives were: (1) to quantify annual changes in bone strength and microarchitectural properties; (2) to define precision errors for pediatric bone strength outcomes; (3) to characterize annual changes in contrast to pediatric precision errors; and (4) to estimate monitoring time intervals (MTIs) required to reliably characterize bone development at the distal radius and tibia. We obtained distal radius (7% of ulnar length) and tibia (8%) bone properties using HR-pQCT and FEA from 38 follow-up study participants (21 girls) at baseline (mean age 10.6 years, SD 1.7 years) and after 1 year; and from 32 precision study participants (16 girls) at baseline (mean age 11.3 years, SD 1.6 years) and after 1 week. We characterized mean annual changes (paired t tests) contrasted to pediatric precision errors (CV%RMS ) and estimated MTIs. Annual increases in bone strength, total area, cortical thickness, and density ranged between 3.0% and 25.3% and 2.4% and 15.6% at the distal radius and tibia, respectively. Precision errors for all bone strength outcomes were ≤6.8% and ≤5.1% at the distal radius and tibia, respectively, and appeared lower than annual gains in bone strength at both sites. Cortical porosity decreased 19.6% at the distal radius and 6.6% at the distal tibia; these changes exceeded respective precision errors, indicating cortical bone consolidation. MTIs ranged between 0.5 years and infinity at the distal radius and 0.5 and 5.9 years at the distal tibia. Estimated MTIs suggest that pediatric bone strength, cortical bone density, and porosity development can be reliably monitored with annual measurements. © 2019 American Society for Bone and Mineral Research.

Quantitative assessment for the rockfall hazard in a post-earthquake high rock slope using terrestrial laser scanning

Geometric information and discontinuity characterization of rock masses are the key aspects of the analysis of the evolution and failure mechanisms of rockfalls. With the advantageous use of terrestrial laser scanning (TLS), the accurate three-dimensional (3D) spatial information of rock slopes can be obtained without contact. By conducting a fuzzy K-means algorithm in this study, the automatic identification of discontinuity sets is achieved, and dominant occurrences of rock mass discontinuities in each local region can be acquired in great detail. This automatic identification method permits the user to visually identify the discontinuity sets and acquire their spacial distribution features, e.g. occurrences, spacings, trace lengths and their geometric compounding relationships. At the same time, based on the shortest distance (SD) algorithm and the surface-to-plane volume calculation algorithm, the distributions, shapes, volumes and scars of the rockfalls can be accurately detected over the monitored time interval. These methods are able to provide adequate investigations and quantitative assessment for the rockfall failure mechanisms and evolutions of the Hongshiyan post failure rock slope after the 2014 Ludian earthquake. The topography of the landslide surface, mechanical properties, scales and the structural features of the discontinuities have a significant effect on the failure mechanisms, distributions and volumes of rockfalls. The main failure mechanisms of the rockfall investigated in this rock slope can be divided into plane failure, wedge failure and toppling failure. The plane and wedge failures mainly occurred in the landslide surface while the toppling failures are mainly observed along the edge of the post failure slope, which is obviously responded by preferred discontinuities. The reverse-dip stratified structure characteristics and the excavation disturbances during the recovering and slope treatment stage induce numerous progressive and continuous failures of rockfalls. The results are beneficial for the design and optimization of rockfall treatments.

Modelling and prediction of resources and services state evolvement for efficient runtime adaptations

Regardless of their implementation aspects and distribution elements, i.e. centralized or distributed, service-based environments such as cloud computing and edge/fog infrastructures, enable the provisioning of services addressing a wide range of application domains. The key requirement for users and consumers of such services refers to the corresponding levels of quality, which is affected both by the real-world dynamics – given the non-deterministic use of services, and by the underlying resources state – given the typically virtualized sharing nature of the resources. In this paper, an approach is presented that aims at estimating the evolvement of services and resources state in order to provide insights for runtime adaptations, as required to ensure services quality. The state refers to different metrics/parameters such as memory, number of users, throughput, etc, and can be extended and applied to different ones. The proposed approach exploits polynomial regression and prediction to identify the aforementioned state evolvement by mapping the two first monitoring data points for each metric/parameter to the corresponding function that depicts their evolvement. The latter provides added value in different cases, including among others the adaptation of monitoring time intervals, the estimation of the potential breach of quality thresholds, and the prediction of the time for runtime adaptations and scaling decisions. The effectiveness of the implemented approach is demonstrated and evaluated through a set of different scenarios.

Network Telemetry Streaming Services in SDN-Based Disaggregated Optical Networks

Accurate real-time availability of transmission parameters at the network controller has the potential to significantly improve the efficiency of control and management operations, particularly in the case of soft failures where detection and localization procedures are typically affected by the long monitoring time intervals usually adopted in current elastic optical networks (EONs). In this paper, we report on the design, implementation, and experimental demonstration of a telemetry service exploiting the gRPC protocol to enable on-demand streaming of real-time monitoring parameters, dynamically retrieved from a configurable set of network devices. The telemetry service is efficiently introduced for software-defined networking in EONs, also accounting for disaggregated network elements through standard YANG-defined network models. The implemented telemetry service is experimentally validated for partial and fully disaggregated architectures over networking scenarios where soft failures not addressable through traditional monitoring solutions are successfully detected and localized. Moreover, detailed performance evaluation is conducted varying the number of subscribed network elements, the type of communication (e.g., compressed vs. uncompressed, bundled vs. unbundled), showing remarkable scalability performance particularly in the case of compressed and bundled telemetry configurations.

Optimal Monitoring Time Interval for Radio-Electronic Equipment Unsteady Failure Rate

The method for determining the optimal duration of monitoring interval of non-stationary Poisson failure rate of radio-electronic equipment (REE) for a wide range of stationary processes, modulating it by intensity. To know the optimal du-ration of monitoring interval, taking into account the flow double stochasticity is necessary to calculate and predict REE reliability factor, operating in near-Earth space as a part of artificial Earth satellites (AES). In the course of calculation REE is exposed to ionizing radiation of unsteady flows and electrostatic charges, leading to short duration or irreversible failures. Based on the known linear model of double stochastic point process a detailed mathematical analysis is made for the first time ever and analytical expressions were obtained for the optimal monitoring time interval with respect to minimum combined standard uncertainty. Since the true nature of unsteadiness is unknown, analysis is carried out for Gaussian and Gauss-Markov modulating processes, covering a wide range of random processes. The analysis results confirm practical similarity of optimal monitoring time interval values for a wide range of modulating processes.

Utilization of Historical Maps in the Land Use Change Impact Studies: A Case Study from Myjava River Basin

Abstract The way land is used has a significant impact on many hydrological processes that determine the generation of flood runoff or soil erosion. Advancements in remote sensing which took place in the second half of the 20th century have led to the rise of a new research area focused on analyses of land use changes and their impact on hydrological processes. This study deals with an analysis of the changes in land use over a period of almost three centuries in the Myjava River catchment, which has an outlet at Šaštín-Stráže. In order to obtain information about the way the land was used in the past, three historical mappings representing various periods were used: the first (1st) military mapping (1764-1787), second (2nd) military mapping (1807-1869), and a military topographic mapping (1953-1957). The historical mappings have been manually vectorised in an ArcGIS environment to identify various land use categories. The historical evolution of land use was further compared with a concurrent land use mapping, which was undertaken in 2010 and exploited remote sensing techniques. The study also quantifies the impact of these changes on the long-term catchment runoff as well as their impact on flows induced by extreme precipitation events. This analysis was performed using the WetSpa distributed hydrological model, which enables the simulation of catchment runoff in a daily time step. The analysis showed that the selected catchment has undergone significant changes in land use, mainly characterized by massive deforestation at the end of the 18th century and land consolidation in the middle of the 20th century induced by communist collectivisation. The hydrological simulations demonstrated that the highest and lowest mean annual runoffs were simulated in the first (1st military mapping) and the last (concurrent land use monitoring) time intervals respectively with the smallest and largest percentages of forested areas.

Constructed wetlands for combined sewer overflow treatment: Ecosystem services at Gorla Maggiore, Italy

Three sampling campaigns have been done in 2014–2015 in order to temporally characterize CSOs quality and quantity during representative and seasonal-specific rain events, and to estimate the ecosystem service of a CSO-CW located in Northern Italy in terms of water quality improvement. The adoption of an on-site treatment by Constructed Wetlands for the Combined Sewer Overflows is an example of decentralized approach for the optimization of the existing sewer networks and the needed reduction of their impacts on the water quality of the receiving water bodies. The CW system, that is treating the first flush of the overflows, is joined with an extended retention basin that is acting as a tertiary treatment for the CW effluents and is also storing and treating the whole second flush, slowing down by a throttle the discharge in the river and therefore playing a role in the flooding risk control. During the monitored time interval 69 events of overflow discharges have been observed and quantified; this quantification of the total volumes discharged by the specific CSO have been useful for evaluating the approach performances also in terms of mass loads in a single year, that is in the author’s opinion a more conservative evaluation than comparing only the average concentrations removal rates. The obtained results have shown that on-site treatment for the first flush by CWs can obtain appropriate performances, as demonstrated by the about 87% and 93% of removal for COD and NH4+ respectively in terms of concentrations and the 68% and 94% in terms of mass loads in a year. A relevant analysis of the sampling program and the secondary services provided by this specific artificial ecosystems are discussed in the paper, together with a unique characterization of the role of the specific sources (washout, urban wastewater) to the loads that are reaching the on-site treatment unit.

A Numerical Method for Discrete Single Barrier Option Pricing with Time-Dependent Parameters

In this article, the researchers obtained a recursive formula for the price of discrete single barrier option based on the Black---Scholes framework in which drift, dividend yield and volatility assumed as deterministic functions of time. With some general transformations, the partial differential equations (PDEs) corresponding to option value problem, in each monitoring time interval, were converted into well-known Black---Scholes PDE with constant coefficients. Finally, an innovative numerical approach was proposed to utilize the obtained recursive formula efficiently. Despite some claims, it has considerably low computational cost and could be competitive with the other introduced method. In addition, one advantage of this method, is that the Greeks of the contracts were also calculated.

On-line monitoring of batch processes using generalized additive kernel principal component analysis

Based on analyzing the special structure of three-way array and generalizing the concept of additive kernels, this paper proposes the generalized additive kernel principal component analysis (GAKPCA) method for on-line monitoring of batch processes. The proposed method is a special nonlinear principal component analysis (PCA) method which can handle the nonlinear relationships between different monitoring variables and/or time intervals. It inherits the good properties of traditional multiway PCA (MPCA) method for on-line monitoring, and solves some problems that exist in traditional multiway kernel PCA (MKPCA) method. For example, based on the decomposition of batch samples in the feature space, the total squared prediction error (SPE) statistic of an entire batch can be divided into K components corresponding to K time intervals respectively, and its score vectors can be directly estimated on-line by the least squares approach without filling the unknown observations. As a special case, when the Gaussian kernel is used as the kernel function at each time interval, the proposed method is connected with the concept of correntropy which can bring robustness to our method. The experimental results on a fed-batch penicillin fermentation process demonstrate the validity of the proposed GAKPCA-based on-line monitoring method.

Therapeutic Drug Mornitoring: Perception among Health-care Workers in a Developing Tertiary Institution

Therapeutic drug monitoring (TDM) is a pharmacologic approach that is essential in therapy. It can be used in assessing the levels of drugs in a biological system. This study assessed the perception of TDM among health-care workers in a developing institution. To assess the perception of TDM among health workers in the University of Benin Teaching Hospital, Benin City, Nigeria. Structured questionnaire were distributed randomly among health-care workers after obtaining ethical approval from the institution. Among the three hundred and eighty-two respondents that participated in the study, the male/female ratio was 1: 1.5. The health-care workers were Doctors 162 (42.41 %), Pharmacists 81 (21.20%), Nurses 116(30.37%) and Laboratory scientists 23(6. 02%). Three hundred and seventy-six (98.43%) respondents claimed to be aware of TDM, of which 247(56.26%) respondents sourced their information from pharmacists. Respondents 335(75. 79%) suggested TDM for all patients. All drugs were strongly recommended to be therapeutically monitored by 391 (76.67%) respondents. Monitoring time interval was suggested by 167(27.60%) respondents on hourly bases. Two hundred and fifty-nine (46.50%) respondents agreed that all biological samples should be routinely assessed. High Performance Liquid Chromatography was mostly recommended. Respondents 361 (94.50%) agreed that the approach will be useful in assessing pharmacokinetic and pharmaco-dynamic variation of drugs in patients. The principle was recommended for patients with chronic diseases by 339 (51.36%) respondents. Due to the general awareness of TDM, it is therefore recommended that adequate structures should be put in place to enhance the outcome of therapy among patients. Keywords : Therapeutic drug monitoring; health-workers; perception

Study Concerning the Quality Indices of Flowing Waters. A Case Study: Iara River

The water pollution is first of all a consequence of the lack of prevention and also inertia of public interest initiatives, often being claimed technical and economical difficulties. The aim of this paper is to present the results of monitoring the water quality from a mountain river. The analysis was carried on within the Laboratory of the Monitoring of Environmental Quality from the Faculty of Agriculture of the University of Agricultural Sciences and Veterinary Medicine Cluj - Napoca, during April - June 2013. Temperature recorded values between 16 -210C pH, 6.5 - 6.9, conductivity 70.2 µS/cm - 72,8 µS/cm, turbidity 0.05 - 0,16 NTU, dissolved oxygen 10.01 -9.10 mg/L. All monitored parameters that are the basis of identification of the water quality indices, during monitored time interval, April 1st - June 26th 2013 framed within normal admitted limits, which demonstrate the lack of pollution of this river segment.

Long-Term Precision of Dual-Energy X-ray Absorptiometry Body Composition Measurements and Association With Their Covariates

Few studies have described the long-term repeatability of dual-energy X-ray absorptiometry scans. Even fewer studies have been performed with enough participants to identify possible precision covariates such as sex, age, and body mass index (BMI). Our objective was to investigate the long-term repeatability of both total and subregional body composition measurements and their associations with covariates in a large sample. Two valid whole-body dual-energy X-ray absorptiometry scans were available for 609 participants in the National Health and Nutrition Examination Survey 2000–2002. Participants with scan-quality issues were excluded. Participants varied in race and ethnicity, sex, age (mean 38.8 ± 17.5; range 16–69 yr), and BMI (mean, 26.9 ± 5.2; range 14.1–43.5 kg/m2). The length of time between scans ranged from 3 to 51 days (mean, 18.7 ± 8.4). Precision error estimates for total body measures (bone mineral density, bone mineral content, lean mass, total mass, fat mass, and percent body fat) were calculated as root mean square percent coefficients of variation and standard deviations. The average root mean square percent coefficients of variation and root mean square standard deviations of the precision error for total body variables were 1.12 and 0.01 g/cm2 for bone mineral density, 1.14 and 27.3 g for bone mineral content, 1.97 and 505 g for fat mass, 1.46 and 760 g for lean mass, 1.10 and 858 g for total mass, and 1.80 and 0.59 for percent body fat. In general, only fat and lean masses were impacted by participant and scan qualities (obesity category, sex, the magnitude of the body composition variables, and time between scans). We conclude that long-term precision error values are impacted by BMI, and sex. Our long-term precision error estimates may be more suitable than short-term precision for calculating least significant change and monitoring time intervals.

Estimation of terrestrial heat flow from temperature measurements in bottom sediments

Under study is the problem of estimation of the terrestrial heat flow from the temperature measurements in the bottom sediments. The problem is divided into the two subproblems: first, we solve the one-dimensional inverse problem of estimating the heat conductivity λ and, second, compute the heat flow value by solving the direct stationary problem using the just-found value of λ. We develop a sweep method for solving the direct problem which differs from the standard. An optimization approach is used for solving the inverse problem, and the explicit formulas are obtained for computing the gradient of the error functional. We analyze the factors that cause errors in estimating the heat flow. We show that the main contribution to the errors is given by the presence of harmonics with the periods exceeding the temperature monitoring time interval. We show that if the parameters of the harmonics are known then we can calculate some corrections for the obtained value of the heat flow. The results were applied to the data of temperature measurements carried out at the bottom of Lake Teletskoye from June of 2008 to September of 2010. For finding the long- period harmonics, we use the meteorological data about the bottom water temperature from 1968 to 2011. This allowed us to estimate the heat flow through the bottom of Lake Teletskoye as well as the thermal diffusivity in the upper layer of the sediments.

Precision Errors, Least Significant Change, and Monitoring Time Interval in Pediatric Measurements of Bone Mineral Density, Body Composition, and Mechanostat Parameters by GE Lunar Prodigy

Dual-energy X-ray absorptiometry (DXA) method is widely used in pediatrics in the study of bone density and body composition. However, there is a limit to how precise DXA can estimate bone and body composition measures in children. The study was aimed to (1) evaluate precision errors for bone mineral density, bone mass and bone area, body composition, and mechanostat parameters, (2) assess the relationships between precision errors and anthropometric parameters, and (3) calculate a “least significant change” and “monitoring time interval” values for DXA measures in children of wide age range (5–18yr) using GE Lunar Prodigy densitometer. It is observed that absolute precision error values were different for thin and standard technical modes of DXA measures and depended on age, body weight, and height. In contrast, relative precision error values expressed in percentages were similar for thin and standard modes (except total body bone mineral density [TBBMD]) and were not related to anthropometric variables (except TBBMD). Concluding, due to stability of percentage coefficient of variation values in wide range of age, the use of precision error expressed in percentages, instead of absolute error, appeared as convenient in pediatric population.