Sample Composition: Parasite Ecology's Dirty Little Secret

2021 ◽  
Vol 107 (5) ◽  
Author(s):  
C. Allen Bacon ◽  
Madison E. Spires ◽  
Cori M. Hood ◽  
Derek A. Zelmer
Keyword(s):  
Sample Composition

Interim Reporting Frequency and the Mispricing of Accruals

2018 ◽  
Vol 32 (3) ◽  
pp. 29-47
Author(s):  
Shou-Min Tsao ◽  
Hsueh-Tien Lu ◽  
Edmund C. Keung
Keyword(s):  
Financial Reporting ◽  
Stock Prices ◽  
Data Availability ◽  
Financial Reports ◽  
Regulatory Changes ◽  
Sample Composition ◽  
Reporting Frequency ◽  
Over Time ◽  
Jel Classifications ◽  
Accrual Mispricing

SYNOPSIS This study examines the association between mandatory financial reporting frequency and the accrual anomaly. Based on regulatory changes in reporting frequency requirements in Taiwan, we divide our sample period into three reporting regimes: a semiannual reporting regime from 1982 to 1985, a quarterly reporting regime from 1986 to 1987, and a monthly reporting regime (both quarterly financial reports and monthly revenue disclosure) from 1988 to 1993. We find that although both switches (from the semiannual reporting regime to the quarterly reporting regime and from the quarterly reporting regime to the monthly reporting regime) hasten the dissemination of the information contained in annual accruals into stock prices and reduce annual accrual mispricing, the switch to monthly reporting has a lesser effect. Our results are robust to controlling for risk factors, transaction costs, and potential changes in accrual, cash flow persistence, and sample composition over time. These results imply that more frequent reporting is one possible mechanism to reduce accrual mispricing. JEL Classifications: G14; L51; M41; M48. Data Availability: Data are available from sources identified in the paper.

scholarly journals Bulk and Confined Benzene-Cyclohexane Mixtures Studied by an Integrated Total Neutron Scattering and NMR Method

2021 ◽  
Author(s):  
Terri-Louise Hughes ◽  
Marta Falkowska ◽  
Markus Leutzsch ◽  
Andrew J. Sederman ◽  
Mick D. Mantle ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Structure Refinement ◽  
Computational Simulation ◽  
Liquid Mixtures ◽  
Coordination Shell ◽  
Bulk Liquid ◽  
Total Neutron ◽  
Time Resolved ◽  
Sample Composition ◽  
Potential Structure

AbstractHerein mixtures of cyclohexane and benzene have been investigated in both the bulk liquid phase and when confined in MCM-41 mesopores. The bulk mixtures have been studied using total neutron scattering (TNS), and the confined mixtures have been studied by a new flow-utilising, integrated TNS and NMR system (Flow NeuNMR), all systems have been analysed using empirical potential structure refinement (EPSR). The Flow NeuNMR setup provided precise time-resolved chemical sample composition through NMR, overcoming the difficulties of ensuring compositional consistency for computational simulation of data ordinarily found in TNS experiments of changing chemical composition—such as chemical reactions. Unique to the liquid mixtures, perpendicularly oriented benzene molecules have been found at short distances from the cyclohexane rings in the regions perpendicular to the carbon–carbon bonds. Upon confinement of the hydrocarbon mixtures, a stronger parallel orientational preference of unlike molecular dimers, at short distances, has been found. At longer first coordination shell distances, the like benzene molecular spatial organisation within the mixture has also found to be altered upon confinement.

scholarly journals Comparison of Elemental Analysis Techniques for the Characterization of Commercial Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 736
Author(s):  
Peter Seidel ◽  
Doreen Ebert ◽  
Robert Schinke ◽  
Robert Möckel ◽  
Simone Raatz ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Analytical Techniques ◽  
Optical Emission ◽  
Breakdown Spectroscopy ◽  
General Evaluation ◽  
Sample Composition ◽  
Laser Induced Breakdown ◽  
Copper Aluminum

Better quality control for alloy manufacturing and sorting of post-consumer scraps relies heavily on the accurate determination of their chemical composition. In recent decades, analytical techniques, such as X-ray fluorescence spectroscopy (XRF), laser-induced breakdown spectroscopy (LIBS), and spark optical emission spectroscopy (spark-OES), found widespread use in the metal industry, though only a few studies were published about the comparison of these techniques for commercially available alloys. Hence, we conducted a study on the evaluation of four analytical techniques (energy-dispersive XRF, wavelength-dispersive XRF, LIBS, and spark-OES) for the determination of metal sample composition. It focuses on the quantitative analysis of nine commercial alloys, representing the three most important alloy classes: copper, aluminum, and steel. First, spark-OES is proven to serve as a validation technique in the use of certified alloy reference samples. Following an examination of the lateral homogeneity by XRF, the results of the techniques are compared, and reasons for deviations are discussed. Finally, a more general evaluation of each technique with its capabilities and limitations is given, taking operation-relevant parameters, such as measurement speed and calibration effort, into account. This study shall serve as a guide for the routine use of these methods in metal producing and recycling industries.

scholarly journals Do Temporary Dropouts Improve the Composition of Panel Data? An Analysis of “Gap Interviews” in the German Family Panel pairfam

2017 ◽  
Vol 49 (1) ◽  
pp. 193-215 ◽  
Author(s):  
Bettina Müller ◽  
Laura Castiglioni
Keyword(s):  
Social Research ◽  
Life Changes ◽  
Cross Sectional ◽  
German Family ◽  
Sample Composition ◽  
Adequate Representation ◽  
Data Source ◽  
Panel Studies ◽  
Survey Estimates ◽  
The Impact

In the context of cross-sectional surveys, the scope of research on the impact of response enhancing strategies on sample composition and nonresponse bias is vast. This topic has rarely been addressed for panel studies, however, although these are becoming an increasingly important data source in social research. In this article, we evaluate the impact of reissuing wave nonrespondents on sample composition and survey estimates in the German Family Panel pairfam. In light of concerns about an adequate representation of life changes in panel studies, we focus on whether temporary dropouts improve sample composition in this respect: Using retrospective information from these cases provided at reentry, we approximate the impact of “lost” reports of life changes due to attrition. Our analysis reveals that the inclusion of temporary dropouts does increase sample variability regarding life changes. However, example analyses indicate that substantive conclusions would not be compromised if temporary dropouts were excluded.

scholarly journals CHARACTERISTICS OF FISH CRACKERS BASED ON TYPES OF FISH AND DIFFERENT TYPES OF STARCH

2018 ◽  
Vol 5 (2) ◽  
pp. 102
Author(s):  
Dede Zaenal Arif
Keyword(s):  
Economic Value ◽  
Free Variable ◽  
Physical Analysis ◽  
Second Stage ◽  
Sample Composition ◽  
Different Types ◽  
Development Levels ◽  
Tapioca Flour ◽  
Two Stages ◽  
Organoleptic Parameters

The purpose of this research is to produce fish crackers from different types of fish, namely catfish and patin fish as well as different types of starch and know the characteristics of a good fish crackers. The benefit that can be expected from this research was to utilize catfish and patin fish abundant potency and add economic value. The method of this research was divided into two stages, namely the first stage is the stage which determines the range of the comparison with the fish flour, determine the type of fish and determine the type of flour used by using the hedonik method of organoleptic parameters. On the second stage has a purpose and that is to analyze chemical and physical fish crackers by comparison. The data were analyzed using the method of experiment results simple linear variable (x) increase in comparison of fish and flour (part). The free variable (y) consists of the response of the color, flavor, aroma, texture, volume and the development levels of crispness. The type of fish and the type of starch correlated against all response organoleptic, except the catfish and tapioca flour was not correlated against sense, catfish and cornmeal were not correlated against the texture of the fish, and catfish and sago flour not correlated against scent. The highest correlation is indicated by the sample composition of the cornmeal and catfish fish total value index by 17 of the total value of the correlation coefficient in classification. The sample was selected based on organoleptic level consumer favorite is with the composition of samples catfish and tapioca flour with a 1:1 comparison (111). Based on the results of the chemical analysis of protein obtained 24,38%, fat content of 1.6%, levels of starch of 44.69% and water content of 5.5%. Physical analysis of the parameter and the mobilising of the volume development of IE of 146.43% and the level of crispness that is of 0.56 mm/s/50gram.  

PRECISION AND CONFIDENCE LEVEL OF CHANGES IN MEASUREMENTS OF GAS ANALYTICAL COMPLEXES BY MEANS OF APPLYING INERT COVERS ON GAS TRACT ELEMENTS

2021 ◽  
pp. 4-13
Author(s):  
P. A. Topolianskii ◽  
S. A. Ermakov ◽  
A. P. Topolianskii
Keyword(s):  
Vapor Deposition ◽  
Air Conditioning ◽  
Chemical Vapor ◽  
Active Compounds ◽  
Sample Composition ◽  
Quality Testing ◽  
Precision And Accuracy ◽  
Air Conditioning Systems ◽  
Active Substances ◽  
Over Time

The relevance of using inert (barrier) nanocoatings for protection (passivation) of parts made of stainless steel has been considered. Such coatings ensure solving problems related to the precision and accuracy of the assay and quality testing of substances with the minimum content of active compounds in a sample, lack of stability in the content of active compounds in a sample over time, inability to treat large amounts of samples without repeated calibration. The findings of the research into the new inert SilcoPateks coating applied by plasma assisted chemical vapor deposition (PACVD process) have been presented. Such coating is used for protection against chemically active substances capable of absorbing and interacting with metals, of changing the sample composition, for countering sulfide and other corrosion. We present a comparative analysis of the SilcoPateks coating with its close analogues – SilcoNert® and DurSan® coatings developed by the world’s leading companies – the Restek Co. and SilkoTek Co. (USA). The SilcoPateks coating is widely used in the domestic equipment for chromatography, mass spectrometry, in ultraviolet fluorescent and other analyzers of substances, in samplers for storage, for transportation, testing and research of samples of substances, for stainless fixtures (valves, faucets), fittings and manometers, for sampling stands, air conditioning systems, calibration panels, coolers for cooling samples, water-oil traps (filters) and other items.

Exploring Fieldwork Effects in a Mobile CATI Survey

2017 ◽  
Vol 59 (1) ◽  
pp. 57-76
Author(s):  
Paula Vicente
Keyword(s):  
Mobile Phone ◽  
Future Research ◽  
Computer Assisted ◽  
Contact Rates ◽  
Time Period ◽  
Sample Composition ◽  
Interview Survey ◽  
Day Of The Week ◽  
Time Periods ◽  
Cati Survey

This study explores the effects of call attempts and time periods on call outcomes and sample composition. A mobile computer-assisted telephone interview survey was conducted to collect data from adult mobile phone users about use and attitudes towards mobile phones; paradata regarding call dispositions, time and day of the week of calls and number of call attempts was also available. The first call contact rate was approximately 27% and varied significantly across time periods; the rate fell to below 20% for the second call. Weekend time periods yielded higher contact rates than weekday time periods. The interview rate on the first call was 12% and decreased steadily in subsequent calls. Mobile phone numbers that yielded call rejection, voicemail or were busy on the first call were very difficult to convert into interview on the second call. The number of call attempts and time period of the calls affect sample composition, namely in relation to respondents' age, educational level and area of residence. Future research and practical implications of the findings for mobile CATI surveys are discussed.

scholarly journals On Unbalanced Sampling in Bankruptcy Prediction

2019 ◽  
Vol 7 (2) ◽  
pp. 28 ◽  
Author(s):  
Marek Gruszczyński
Keyword(s):  
Final Section ◽  
Bankruptcy Prediction ◽  
Common Error ◽  
Sample Bias ◽  
Sample Composition ◽  
Random Samples ◽  
Unbalanced Sampling ◽  
Extended View ◽  
The Relationship ◽  
Binomial Models

The paper discusses methodological topics of bankruptcy prediction modelling—unbalanced sampling, sample bias, and unbiased predictions of bankruptcy. Bankruptcy models are typically estimated with the use of non-random samples, which creates sample choice biases. We consider two types of unbalanced samples: (a) when bankrupt and non-bankrupt companies enter the sample in unequal numbers; and (b) when sample composition allows for different ratios of bankrupt and non-bankrupt companies than those in the population. An imbalance of type (b), being more general, is examined in several sections of the paper. We offer an extended view of the relationship between the biased and unbiased estimated probabilities of bankruptcy—probability of default (PD). A common error in applications is neglecting the possibility of calibrating the PD obtained from a bankruptcy model to the unbiased PD that is population adjusted. We show that Skogsviks’ formula of 2013 coincides with prior correction known for the logit model. This, together with solutions for other binomial models, serves as practical advice for obtaining the calibration of unbiased PDs from popular bankruptcy models. In the final section, we explore sample bias effects on classification.

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