bluuebunny/crossref_metadata_2025 huggingface dataset:
The Geometric Component Of Technical Innovations
Authors: Сальков Николай , Sal'kov Nikolay
Published: July 2018

In technical inventions related to innovative developments, the role of one of the main components belongs to geometry. A follow hypothesis has been adopted: in technical inventions the geometrical component is the determining one. This hypothesis applied to technical inventions can be confirmed by any copyright certificate, any patent both in Russia and abroad. In proposed paper this statement is proved by examples developed based on geometry of following inventions. 1. Screen feeder for sticky masses. Screen feeder’s grates are made in pairs, and between grate pairs there are gaps for screening of material’s size-defined fractions. In the screen-feeder has been proposed such geometry of grates that grates of each pair could clean each other, thereby preventing sticking on the surface and destroying the gaps between the pairs, which transforms the usual screen-feeder with cylindrical grates at an ordinary feeder. 2. Double-screw mixer for paste-like masses. The mixer consists of two contiguous worms. Their surfaces are the helical ones, in cross-section consisting of two quarters of circles stacked at the ends. Such cross-section allows homogenize the mixed paste-like material in the best way, and also deliver it under higher pressure in an extrusion head, that improves a final product. 3. Machine for processing of multi-faceted surfaces. This invention serves for manufacture of worms with a cross-section composed of two, three, etc. pieces of circles of the same radius and angle. Worms, made with this machine, are designed for the above mentioned two-screw mixer. 4. Method of mechanical processing. This method is also intended to manufacture of worms for two-screw mixer.
Second Order Curves on Computer Screen
Authors: Короткий Виктор , Korotkiy Viktor , Усманова Е. , Usmanova E.
Published: July 2018

Modern computer graphics is based on methods of computational geometry. The curves and surfaces’ description is based on apparatus of spline functions, which became the main tool for geometric modeling. Methods of projective geometry are almost not applying. One of the reasons for this is impossibility to exactly construct a second-order curve passing through given points and tangent to given straight lines. To eliminate this defect a computer program for second order curves construction has been developed. The program performs the construction of second-order curve’s metric (center, vertices, asymptotes, foci) for following combinations: • The second-order curve is given by five points; • The second-order curve is given by five tangent lines; • The second-order curve is given by a point and two tangent lines with points of contact indicated on them; • The parabola is given by four tangent lines; • The parabola is given by four points. In this paper are presented algorithms for construction a metric for each combination. After construction the metric the computer program written in AutoLISP language and using geometrically exact projective algorithms which don’t require algebraic computations draws a second-order curve. For example, to construct vertices and foci of two parabolas passing through four given points, it is only necessary to draw an arbitrary circle and several straight lines. To construct a conic metric passing through five given points, it is necessary to perform only three geometrically exact operations: to construct an involution of conjugate diameters, to find the main axes and asymptotes; to note the vertices of desired second-order curve. Has been considered the architectural appearance of a new airport in Simferopol. It has been demonstrated that a terminal facade’s wavelike form can be obtained with a curve line consisting of conic sections’ areas with common tangent lines at junction points. The developed computer program allows draw second-order curves. The program application will promote the development of computer graphics’ tools and techniques.
Military-legal study of citizens ' participation in national defense and state security
Authors: Федотова Юлия , Fedotova Yuliya
Published: July 2018

The monograph is devoted to the participation of citizens in the defense of the country and state security. The author's concept is to justify it as the highest form of democracy, involving the implementation of the functions of citizens to carry out state-significant activities within the military organization of the state and outside it. The elements of the concept are the forms of participation, the legal status of citizens and the activities of the authorized bodies to attract them to participate.
The monograph is intended for students, graduate students, teachers, specialists in the field of military and legal problems, practitioners, as well as a wide range of readers interested in the problems of defense and security.
Technologies of personnel management
Authors: Чуланова Оксана , Chulanova Oksana
Published: July 2018

The textbook "Personnel Management Technologies" has been developed in accordance with the curriculum (in accordance with the Federal State Educational Standard of Higher Education in the direction of 38.03.03 "Personnel Management" preparing the final qualifying work in this direction).
The textbook includes an analysis of modern technologies in the field of personnel management that can be used in working with the staff of modern organizations.
The textbook consistently presents the technologies of humanizing the labor activity of the personnel of organizations, the technology of working with personnel in various models of the organization. Consistently reviewed modern technologies work with the staffing reserve of the organization (talent management and the development of soft skills managers). Presented from the perspective of opportunities and risks are modern technologies of training and development of the personnel of the organization, modern technologies of recruiting, selection and hiring of personnel, technology of effective work with the personnel of the organization and technology of optimization of labor activity of the personnel. Current technologies for the release of personnel are represented by outplacement technology. Prospects and risks of all technologies presented in the textbook are considered.
Addressed to students, undergraduates, graduate students, doctoral students, researchers, students and conduct research in the field of personnel management. For the teaching staff of universities and practitioners to work with the staff of modern organizations.
Technical Note—The Competitive Facility Location Problem in a Duopoly: Advances Beyond Trees
Authors: Gur Yonatan , Saban Daniela , Stier-Moses Nicolas E.
Published: July 2018

We consider a competitive facility location problem on a network where consumers located on vertices wish to connect to the nearest facility. Knowing this, each competitor locates a facility on a vertex, trying to maximize market share. We focus on the two-player case and study conditions that guarantee the existence of a pure-strategy Nash equilibrium for progressively more complicated classes of networks. For general graphs, we show that attention can be restricted to a subset of vertices referred to as the central block. By constructing trees of maximal bi-connected components, we obtain sufficient conditions for equilibrium existence. Moreover, when the central block is a vertex or a cycle (for example, in cactus graphs), this provides a complete and efficient characterization of equilibria. In that case, we show that both competitors locate their facilities in a solution to the 1-median problem, generalizing a well-known insight arising from Hotelling’s model. We further show that an equilibrium must solve the 1-median problem in other classes of graphs, including grids, which essentially capture the topology of urban networks. In addition, when both players select a 1-median, the solution must be at equilibrium for strongly-chordal graphs, generalizing a previously known result for trees.

The electronic companion is available at https://doi.org/10.1287/opre.2017.1694 .
Technical Note—A Conic Integer Optimization Approach to the Constrained Assortment Problem Under the Mixed Multinomial Logit Model
Authors: Şen Alper , Atamtürk Alper , Kaminsky Philip
Published: July 2018

We consider the constrained assortment optimization problem under the mixed multinomial logit model. Even moderately sized instances of this problem are challenging to solve directly using standard mixed-integer linear optimization formulations. This has motivated recent research exploring customized optimization strategies and approximation techniques. In contrast, we develop a novel conic quadratic mixed-integer formulation. This new formulation, together with McCormick inequalities exploiting the capacity constraints, enables the solution of large instances using commercial optimization software.
Informational Braess’ Paradox: The Effect of Information on Traffic Congestion
Authors: Acemoglu Daron , Makhdoumi Ali , Malekian Azarakhsh , Ozdaglar Asuman
Published: July 2018

To systematically study the implications of additional information about routes provided to certain users (e.g., via GPS-based route guidance systems), we introduce a new class of congestion games in which users have differing information sets about the available edges and can only use routes consisting of edges in their information set. After defining the notion of an information-constrained wardrop equilibrium (ICWE) for this class of congestion games and studying its basic properties, we turn to our main focus: whether additional information can be harmful (in the sense of generating greater equilibrium costs/delays). We formulate this question in the form of an informational Braess’ paradox (IBP), which extends the classic Braess’ paradox in traffic equilibria and asks whether users receiving additional information can become worse off. We provide a comprehensive answer to this question showing that in any network in the series of linearly independent (SLI) class, which is a strict subset of series-parallel networks, the IBP cannot occur, and in any network that is not in the SLI class, there exists a configuration of edge-specific cost functions for which the IBP will occur. In the process, we establish several properties of the SLI class of networks, which include the characterization of the complement of the SLI class in terms of embedding a specific set of networks, and also an algorithm that determines whether a graph is SLI in linear time. We further prove that the worst-case inefficiency performance of ICWE is no worse than the standard Wardrop equilibrium.
The Attrition Dynamics of Multilateral War
Authors: Kress Moshe , Lin Kyle Y. , MacKay Niall J.
Published: July 2018

We extend classical force-on-force combat models to study the attrition dynamics of three-way and multilateral war. We introduce a new multilateral combat model—the multiduel—which generalizes the Lanchester models, and we solve it under an objective function that values one’s own surviving force minus that of one’s enemies. The outcome is stark: either one side is strong enough to destroy all the others combined, or all sides are locked in a stalemate, which results in collective mutual annihilation. The situation in Syria fits this paradigm.
Nobres e magistrados: uma discussão sobre o conceito de nobreza
Authors: Tinoco Nara Maria De Paula
Published: July 2018

Resumo: Neste trabalho, discutiremos a importância do conceito de nobreza para um grupo em particular: os magistrados. Diferente dos demais oficiais régios, devido à formação em Direito, eles se destacavam por exercerem e interpretarem as Leis, bem como por representarem a face mais visível dos Monarcas: a Justiça. Os magistrados formavam um grupo mais alargado e heterogêneo em suas obrigações e interesses pessoais: os letrados, que influenciaram todo o período moderno português. Ao longo do tempo, surgiu a indispensabilidade de situarmos o conceito de nobreza e suas subdivisões para construirmos o perfil, as carreiras, as hierarquias e as estratégias/estratagemas destes indivíduos e dos demais grupos constituintes da administração portuguesa e de suas conquistas.Abstract: In this work we will discuss the importance of the concept of nobility for a particular group, the magistrates. Unlike the other royal officials due to the formation in Law, they stood out from the other groups for exercising and interpreting the laws and for representing the most visible face of the Monarchs, Justice. The magistrates were participants of a larger and heterogeneous group in their obligations and personal interests, that is, of the literate ones and that they influenced all the Portuguese modern period. Over time, the indispensability of placing the concept of nobility and its subdivisions in order to construct the profile, the careers, the hierarchies and strategies / stratagems of these individuals and the other constituent groups of the Portuguese administration and its conquests arose.
The Effects of Out-of-School Learning Settings Science Activities on 5th Graders’ Academic Achievement
Authors: Bakioglu Busra , Karamustafaoglu Orhan , Karamustafaoglu Sevilay , Yapici Senay
Published: July 2018

The purpose of this study was to investigate the effect of lessons conducted in out-of-school learning settings on 5th graders science achievement within the scope of a guidance material that was prepared to be used in out-of-school learning settings in accordance with the “Let’s Solve the Riddle of Our Body” chapter objectives. The pretest / posttest equalized control group design, which is one of the quasi-experimental designs, was used in this study. The sample of this study was composed of a total of 31 5th grade students (15 were in experimental group, 16 were in control group) that were selected from secondary schools in the first semester of the 2015-2016 academic year in Tokat Province. Let’s Solve the Riddle of Our Body Chapter Achievement Test (LeSROBAT) was administered before and after the implementation of the guidance material to measure the students’ achievements and retention. The lessons were conducted as suggested by the current curriculum in the control group. The data were analyzed using independent samples t-test and covariance analysis (ANCOVA). As a result of the analyses, it was found that the LeSROBAT post-test scores of experimental group were significantly higher than the control group. Within this context, it was concluded that the out-of-school learning settings positively contributed to academic achievement and the guidance material that was developed within the scope of this study was effective. The results of retention test analyses didn’t reveal any significant difference between the posttest and retention test scores of experimental and control groups. When the LeSROBAT retention test scores were examined, it was observed that the scores of experimental group was higher than the control group.
The Quest for Quality in Teacher Education in Turkey: The Abrogation of Teacher Programs from Secondary Education
Authors: Sanal Mustafa , Ozen Fatmanur
Published: July 2018

Within the scope of restructuring the secondary education efforts of the Ministry of National Education, it has been decided to abrogate the secondary school level teachers' schools. The purpose of this study is to evaluate Turkey's teacher education practices and the quest for qualified teacher education through the perceptions of the graduates of these high schools. The study is a phenomenological research based on interpretation. Data were obtained through interviews. The data obtained were analyzed in the vetting of candidate teachers, the curriculum to be used in the education process and its accreditation, and whom to be certified as teachers. The main results of this study, conducted with participants from the secondary school level teachers schools’ graduates, show that, in terms of teacher education, teachers' high schools present various opportunities by enrolling successful candidates, educating them as leaders, preparing them for multi-cultural environments. In order to educate qualified teachers, the participants suggest teacher education programs should include individual and group activities, involve training, arts, basic science, and values education courses. In the selection and approval of tenure teacher, besides academic achievement and diploma, advanced communication skills, patience, confidence, and patriotism should be sought in the candidates.
School Administrators’ Self-Efficacy Beliefs and Leadership Styles
Authors: Cobanoglu Fatma , Yurek Ugur
Published: July 2018

The effectiveness of schools, that is, their ability to achieve their pre-determined goals depends on many variables but especially the effectiveness of the administrators who are responsible for the implementation of the educational programs and curricula. An administrator must have a healthy perception of being "an effective administrator" in order to be able to demonstrate expected roles successfully. Concerning school effectiveness, in addition to the emphasis of self-efficacy of administrator, the leadership role of the educational administrators has gained importance with modern educational administration approaches. If an administrator wants to be effective, he/she must act as a leader and convince followers. In this context, when questioning the effectiveness of schools, it is important to determine the level of self-efficacy perceptions of administrators and to determine the leadership styles displayed by them. In this study, it was aimed to examine whether there is a significant relationship between the perceived self-efficacy belief and leadership style. The results show that self-efficacy perceptions of the administrators make a difference in their leadership style and there is a relationship between the self-efficacy belief and exhibitors of transformational leadership behaviors; the more administrators feel themselves efficient, the more they exhibit transformational leadership behaviors.
Examination of the Effect of the GEMS Program on Problem Solving and Science Process Skills of 6 Years Old Children
Authors: Unal Merve , Saglam Mehmet
Published: July 2018

The aim of this study is to determine the problem solving skills and science process skills of six year-old children who attended kindergarten and whether or not there is a difference in problem solving skills and science process skills of children receiving and not receiving the education with GEMS program. In the study using the experimental model with pre-test, post-test and control group, the sample group consisted of a total of 25 children including 11 children in experimental group and 14 children in control group who attended the preschool education. The “GEMS Program” was applied throughout a school year after applying pre-test to the children in the experimental group. In the scope of the study, “General Information Form” to obtain the data about the children and their families, “Parental Evaluation Form” including the evaluation of the parents about their children, “Problem Solving Scale in Science Education (PSSSE)” to determine the problem solving skills of the children and “Science Processes Observation Form (SPOF)” to measure the science process skills of the children were used. According to the results of the study, while a statistically significant difference was observed between the Problem Solving Scale in Science Education mean scores of the children in the experimental group who participated in the GEMS Education Program and of the children in control group, no statistically significant difference was observed between the mean scores obtained by the children in the experimental group from Science Processes Observation Form and the mean scores of the children in the control group.
The Relationship between Resilience and Constant Hope in Students Studying Sports Science
Authors: Togo Osman Tolga , Caz Cagdas , Kayhan Recep Fatih
Published: July 2018

Individuals face negative events throughout their lives and such events can cause problems in every aspect of life. A high level of resilience is required to cope with such negative events. There are various factors that affect resilience. Hope is one of those factors. This factor provides a strong structure to individuals and keeps identified objectives alive. Based on this view, the aim of this study was to investigate the relationship between resilience and constant hope of students studying in a sports science department. Accordingly, the study group of this study consisted of 203 students with 91 female and 112 male students studying in a sports science faculty/school of physical education and sports of universities. The data collection tools of this study were the “Resilience Scale” and the “Constant Hope Scale”. Additionally, to collect information about the students, the “Personal Information Form” developed by the researchers was adopted during the data collection process. The analysis of the obtained data was done with descriptive statistics, t-test for independent two groups, one- way variance analysis (Anova), and Pearson Correlation. To determine which groups caused the statistical difference after one-way variance analysis (Anova), the Tukey HSD multiple comparative test was applied. The results of the study indicated that the data obtained on a scale basis had normal distribution. While there was no significant difference for gender between the relationship of resilience and constant hope, there was a statistically significant difference between different age groups. Additionally, the correlation analysis indicated that there was a positive, moderate level relationship between the two scales.
An Investigation into the Learning of Ecological Concepts
Authors: Toman Ufuk
Published: July 2018

The aim of this research; secondary, high school and university levels of the students to understand the concepts related to ecology of Bayburt in Turkey. In this study, a progressive research method was used. In this method, conceptual understanding test was used as data collection tool. Open-ended test questions were used in this study. The test consisted of 150 students, 50 were from the secondary school, 50 were from the high school and 50 from the university in Bayburt. The data obtained from the test indicate that the meanings of the ecological concept are in different categories and that this concept is not fully understood by the students at all three levels of learning. While students at secondary level relate the concepts related to ecology to their everyday use, high school and university students have more scientific definitions in their descriptions. In addition, misconceptions regarding these concepts have been identified at all levels of learning.
The Math Teachers’ Self-Efficacy Beliefs about Classroom Management (A Case Study of Elementary Schools in Diyarbakir)
Authors: Bulut Ilhami , Topdemir Selcuk
Published: July 2018

This study aims to evaluate elementary school math teachers' self-efficacy beliefs about classroom management. With the aim of investigating elementary school math teachers' self-efficacy beliefs about classroom management, a classroom management self-efficacy scale was developed.  The 5 point likert scale is composed of 46 items. The scale was applied to 142 math teachers working at elementary schools in Diyarbakir central district. Data were analyzed in terms of gender, seniority, classroom population and weekly course load. To analyze the data, t-test, one way variance analysis (ANOVA), Scheffe and LSD tests were used. The results showed that the math teachers have a positive self-efficacy belief of classroom management and that male teachers are better at maintaining discipline in class. In addition, the research shows that teachers with more experience are better at course design and classroom management and that classroom population has an effect on math teachers' self-efficacy beliefs about classroom management.
Evaluation of the Constructivist Learning Environments of Physical Education Teacher Candidates
Authors: Ozgul Fatih , Kangalgil Murat , Diker Gurkan , Yamen Erturk
Published: July 2018

The aim of this research is to evaluate the constructivist learning environments of physical education and sport teacher candidates. For this purpose, 928 students (523 male, 405 female) selected by the appropriate sampling method from the Physical Education and Sport Teaching Department of 17 universities consisted the sample of the research. In the study; "Constructivist Learning Environments Evaluation Scale" developed by Arkun and Askar (2010) was used in order to reveal the opinions of the students about the constructivist learning environment. The scale consists of 7 Likert type, 6 sub dimensions and 28 items. The Cronbach alpha reliability coefficient for this study was found to be .93. The lowest score that can be taken from the scale is 28 and the highest score is 196. Kruskal Wallis Variance Analysis and Mann Whitney U test were used because the obtained data did not show normal distribution (Kolmogorov-Smirnov), and the significance level was taken as 0.05. As a result of the research, the constructivist learning environments of 17th universities 3rd and 4th grade teacher candidates were evaluated in terms of age, gender and grade variables. According to this, there was no significant difference when the average scores of constructivist learning environments were compared in terms of age and class levels of physical education and sports teacher candidates. In comparison with gender, female teacher candidates were found to have a more constructive learning environment.
Comparison of Social Skill Levels of 11-14 Age Students Who Choose/ Don’t Choose Sport and Physical Activity Course
Authors: Eroglu Mehtap Tekdemir , Harmandar-Demirel Duygu
Published: July 2018

The aim of sports and physical effect on the course chosen and the selection (choosing different courses) students to determine the difference between the levels of social skills. Research, Sports and Physical Activities are important in determining the contribution of the social skills of course. Research elective sports and physical activities screening to determine their level of social skills among students taking the course and take the 11-14 age model is designed. The population of the 2015- 2016 academic year in the fall semester research, Malatya affiliated school in sports and physical activities constitute 11-14 age students choose the courses. Elective sports and physical activity as a data collection tool for taking the course and receive a questionnaire for students to determine their level of social skills are used. The survey consists of a personal information form and social skills inventory to determine the defining characteristics of the students in the first chapter. In the evaluation of the data obtained as a number descriptive statistical methods, percentage, mean, standard deviation is used. in comparing quantitative data between two independent groups of continuous man-Whitney U test for continuous quantitative comparison of data between more than two independent groups Kruskal wallis test. Kruskal wallis complementary test to determine differences in man-to-Whitney test after test. Research results in emotional expressivity, sensitivity, social expressivity, social sensitivity, social control, social skills and physical effect on the total level of the sport was concluded to be higher in the group selects the course.
Views of School Administrators Regarding the Assignment of School Principals
Authors: Yildirim Atila
Published: July 2018

The aim of the study is to determine views of principals regarding assignment procedure. Data were gathered with the implementation of semi-structured interview forms from 14 administrators in the center of Konya according to ‘Purposive sampling’ method. The data were analyzed by content analysis and the following findings have been reached. There should be criteria such as an examination (written and verbal), developing projects related with the school, receiving academic or in-service training in administration, having experience as assistant principal, preparation of evaluation forms aiming at objectivity and improvement, election of the assistant principal by the principal without any intervention among the successful ones from the written exams, appointment of administrators instead of assignment, acceptance of school administration as a profession, regulations respecting of the objectivity, justice and equality. It is recommended that similar studies be conducted through quantitative research.
‘More than Just Waste Paper’ – It Could Be an Indicator of a Stereotypical Image of a Scientist
Authors: Karacam Sedat , Bilir Volkan , Digilli-Baran Azize
Published: July 2018

The purpose of this study was to investigate the meanings assigned by pre-service teachers to the wastepaper basket and waste (crumpled) papers in their drawings of a scientist. The study was carried out with 220 pre-service teachers during the 2015-2016 academic years. A phenomenological research method was used. First, the pre-service teachers were administered the ‘Draw-A-Scientist Test’ in order to identify their images of a scientist and then they were asked to describe and explain the scientist they drew. And a semi-structured interview was performed with the 34 pre-service teachers who included a wastepaper basket and waste paper in their drawings in order to identify the meanings assigned to the wastepaper and wastepaper basket by these teachers. The data were analysed by using content analysis. The results of the analysis showed that with these figures the pre-service teachers revealed their belief that when scientists conduct research, they follow a confirmatory experimental process in a similar manner to the way school science experiments. Based on these results, it can be suggested in the analysis of the drawings that waste paper and wastepaper baskets can be regarded as indicators of the stereotypical image of scientists and of the scientific method they use.
Residual Platinum Concentrations in Post-Cancer Chemotherapy and Healthy Control Populations Using an Automated, 96-Well Plate Method and Inductively Coupled Plasma Mass Spectrometry
Authors: Strathmann Frederick G , Travis Lois B , Ardeshirrouhanifard Shirin , Fossa Sophie D , Moody Steve , Clarke David , Law Christian L
Published: July 2018

Background

Platinating agents are among the most commonly used cytotoxic drugs worldwide. It is recognized that Pt concentration can remain significantly increased in serum up to 20 years after completion of chemotherapy, with levels related to late treatment effects.

Methods

A Freedom EVO® Tecan liquid handler was used for aliquoting 50 μL serum at 10-fold dilution into 96-well plates. The Teledyne MVX-7100 low-volume autosampler was used for sample introduction into an Agilent 7900 inductively coupled plasma mass spectrometry. There was <1.2 min needed between injections. Time to completion for a maximum batch size using two 96-well plates was approximately 3.5 h, including preparation and analysis.

Results

Imprecision was <15%, and the limit of quantification was set at 5 ng/L based on imprecision of 18.3%. Bias based on fortified samples ranged from 0% to −4.3% within the analytical measurement range of 5–10 000 ng/L. The nonparametric reference interval for platinum in serum using 147 residual clinical samples was determined to be 8–47 ng/L. Serum platinum concentrations in 675 enrolled patients having an average time since chemotherapy completion of 6.4 (± 5.5 years) ranged from 20.1 to 8252.4 ng/L. Among all patients, 633 (94%) had serum concentrations exceeding 47 ng/L, and 42 (6%) had serum platinum concentrations between 8 and 47 ng/L.

Conclusions

This method used an automated liquid handler, a novel 96-well autosampler and 50 μL patient serum to quantify platinum levels. The method was successfully validated according to current clinical guidelines for laboratory developed tests.
Performance Evaluation of an ELISA for the Quantitative Measurement of α1-Antitrypsin in Stool
Authors: Erickson J Alan , Jensen Ryan A , Grenache David G
Published: July 2018

Background

The diagnosis of protein-losing enteropathy is aided by the measurement of α1-antitrypsin (A1A) in stool and serum to calculate A1A clearance. The objective of this study was to determine the performance characteristics of an ELISA for the measurement of A1A in stool and to determine reference limits for stool A1A and A1A clearance.

Methods

A1A in stool was measured with a polyclonal antibody-based ELISA. Assay imprecision, analytical sensitivity, linearity, accuracy, analyte stability, and reference intervals were determined.

Results

Within-run and total CVs were 5.4% and 6.5% and 13.8% and 14.5% at 17.3 and 66.9 ng/mL, respectively. The limit of quantification was 2.0 ng/mL, and the assay was linear to 85 ng/mL. Mean recovery of A1A added to samples was 108.2%. A1A was stable in stool for a minimum of 2 days, 7 days, and 3 months at room temperature, 4–8 °C and −20 °C, respectively. The upper 95th percentile reference limits for A1A in stool and A1A clearance were 0.48 mg/g and 49 mL/day, respectively.

Conclusions

The A1A ELISA demonstrates acceptable performance for quantifying A1A in stool. The assay can be used in conjunction with serum A1A measurements for determining A1A clearance.
Discovery and Validation of Plasma-Protein Biomarker Panels for the Detection of Colorectal Cancer and Advanced Adenoma in a Danish Collection of Samples from Patients Referred for Diagnostic Colonoscopy
Authors: Blume John E , Wilhelmsen Michael , Benz Ryan W , Brünner Nils , Christensen Ib J , Croner Lisa J , Dillon Roslyn , Hillig Thore , Jones Jeffrey J , Jørgensen Lars N , Kao Athit , Klaerke Michael , Laurberg Søren , Madsen Mogens R , Nielsen Knud T , Vilandt Jesper , Wilcox Bruce E , You Jia , Nielsen Hans J
Published: July 2018

Background

Well-collected and well-documented sample repositories are necessary for disease biomarker development. The availability of significant numbers of samples with the associated patient information enables biomarker validation to proceed with maximum efficacy and minimum bias. The creation and utilization of such a resource is an important step in the development of blood-based biomarker tests for colorectal cancer.

Methods

We have created a subject data and biological sample resource, Endoscopy II, which is based on 4698 individuals referred for diagnostic colonoscopy in Denmark between May 2010 and November 2012. Of the patients referred based on 1 or more clinical symptoms of colorectal neoplasia, 512 were confirmed by pathology to have colorectal cancer and 399 were confirmed to have advanced adenoma. Using subsets of these sample groups in case-control study designs (300 patients for colorectal cancer, 302 patients for advanced adenoma), 2 panels of plasma-based proteins for colorectal cancer and 1 panel for advanced adenoma were identified and validated based on ELISA data obtained for 28 proteins from the samples.

Results

One of the validated colorectal cancer panels was comprised of 8 proteins (CATD, CEA, CO3, CO9, SEPR, AACT, MIF, and PSGL) and had a validation ROC curve area under the curve (AUC) of 0.82 (CI 0.75–0.88). There was no significant difference in the performance between early- and late-stage cancer. The advanced adenoma panel was comprised of 4 proteins (CATD, CLUS, GDF15, SAA1) and had a validation ROC curve AUC of 0.65 (CI 0.56–0.74).

Conclusions

These results suggest that the development of blood-based aids to colorectal cancer detection and diagnosis is feasible.
Reference Intervals for Intestinal Disaccharidase Activities Determined from a Non-Reference Population
Authors: Hackenmueller Sarah A , Grenache David G
Published: July 2018

Background

Cutoff activities for diagnosing disaccharidase deficiencies are historical and are difficult to verify from a reference population. The objectives of this study were to validate the utility of historical disaccharidase cutoffs using data from clinical samples and to evaluate the demographics of individuals for whom intestinal disaccharidase testing was performed.

Methods

Results from 14,827 disaccharidase test samples were extracted from the laboratory information system. Data were analyzed by the Hoffman method to calculate a reference interval for each enzyme, and the lower limits were compared to historical cutoffs. The observed frequencies of disaccharidase deficiencies were determined using historic and calculated cutoffs.

Results

The median patient age of the entire data set was 13 years (range <1–88 years), and 45% were male. The cutoffs for lactase, maltase, palatinase, and sucrase were determined to be 10, 100, 9, and 25 U/g protein, respectively. Applying these cutoffs to the data set, 61% had no enzyme deficiencies, 35% were lactase deficient, 11% were maltase deficient, 13% were palatinase deficient, and 13% were sucrase deficient. Pandisaccharidase deficiency was present in 8%.

Conclusions

Disaccharidase testing is most commonly performed in patients <18 years. Lactase deficiency is the most frequently observed single-disaccharidase deficiency. The historical cutoffs for maltase and sucrase were validated. To align with calculated reference intervals, the palatinase cutoff should increase from 5 to 9 U/g protein, and the lactase cutoff should decrease from 15 to 10 U/g protein.
Impact of Integrating Rumke Statistics to Assist with Choosing Between Automated Hematology Analyzer Differentials vs Manual Differentials
Authors: Stephens Laura , Hintz-Prunty Wendy , Bengtsson Hans-Inge , Proudfoot James A , Patel Sandip Pravin , Broome H Elizabeth
Published: July 2018

Background

To optimize precision of nucleated blood cell counting, the clinical laboratory scientist should post the automated differential rather than the manual differential if the former is within the 95% CI of the latter, as determined by the “Rumke statistic.” The objective of this study was to determine the potential impact of real-time, computer-assisted use of Rumke statistics for more judicious use of the automated vs digitally imaged, manual differential.

Methods

Complete blood counts with automated differentials produced by a XE5000™ hematology analyzer (Sysmex) were compared with both the DM96 (CellaVision™ AB) preclassification differentials and the posted reclassified manual differentials, using the Rumke 95% CIs as calculated using the Clopper-Pearson method.

Results

A total of 44.7% of manual differentials had no statistical or clinical justification over the automated differential. In addition, 31.1% of manual differentials had statistical discrepancies between the instrument absolute neutrophil count (IANC) and manual absolute neutrophil count (ANC). Nineteen of these IANC/manual ANC discrepant samples had ANCs below 1500/μL, a decision level for cancer treatment. Holding the IANC when it is less than 2000/μL until after manual smear review would have prevented the posting of any IANC vs manual ANC discrepant results at the 1500/μL ANC decision threshold.

Conclusions

A real-time operator alert concerning the statistical identity of imaging device differentials vs automated differentials could have reduced manual differentials by nearly 45%. Not posting unnecessary manual differentials for the cases with IANC/manual ANC discrepancies would have likely reduced clinical error/confusion.
Are Heart Failure Management Recommendations and Guidelines Followed in Laboratory Medicine in Europe and North America? The Cardiac Marker Guideline Uptake in Europe (CARMAGUE) Study
Authors: Hammerer-Lercher Angelika , Collinson Paul O , Suvisaari Janne , Christenson Robert H , Pulkki Kari , van Dieijen-Visser Marja P , Duff Christopher J , Baum Hannsjörg , Stavljenic-Rukavina Ana , Aakre Kristin M , Langlois Michel R , Stankovic Sanja , Laitinen Paivi
Published: July 2018

Background

The aim of this survey was to investigate how well heart failure (HF) guidelines for use of natriuretic peptides (NPs) have been implemented in laboratory practice in Europe and North America.

Methods

In 2013 and 2014, a web-based questionnaire was distributed via North American and European biochemical societies. Questions covered assay performed, reason for method choice, decision limits for HF, and laboratory accreditation status.

Results

There were 442 European Union and 91 North American participating laboratories with response rates of 50% and 64% from major or university hospitals, respectively. NP measurements were offered in 67% of European Union and 58% of North American respondents. N-terminal pro–B-type natriuretic peptide (NT-proBNP) was most widely used in Europe (68%) and B-type natriuretic peptide (BNP) was more commonly used (58%) in North America. The most frequent reason for use of a specific assay was the availability of instruments that measure either NT-proBNP (51%) or BNP (67%). For diagnosis of acute HF, NT-proBNP decision limits were diverse; age-dependent limits based on the 2012 European Society of Cardiology (ESC) recommendations were used in only 17% of European sites and 26% of North American sites. For BNP, the guideline-recommended acute HF decision limit of 100 ng/L was better adhered to in Europe (48%) and North America (57%). Surprisingly, similar decision limits were stated for acute and chronic HF by >50% of respondents.

Conclusions

NP measurement for HF diagnosis was available in >50% of responding laboratories. However, guideline recommended cutoff values for both acute and chronic HF were still implemented in <30% of participating medical centers.
Serum Free Light Chain (FLC) Analysis: A Guiding Light in Monoclonal Gammopathy Management
Authors: Jenner Ellen L , Evans Josie A R , Harding Stephen J
Published: July 2018

Background

Monoclonal free light chains (FLCs) were first reported by Dr. Henry Bence Jones over 150 years ago in the urine of patients with multiple myeloma. Now established as important tumor markers, they aid not only in the diagnosis of monoclonal gammopathies but also in their clinical management by indicating the response to treatment and persistence of residual disease.

Content

A particular focus over the past 15 years has been on the replacement of urine with serum analysis for monoclonal FLC measurement. Because of the limited sensitivity and practical constraints of urine assessment, a combination of serum electrophoresis and serum FLC analysis has been adopted by many laboratories as a first-line screen for patients with a suspected monoclonal gammopathy. Early myeloma diagnosis may translate into improved clinical outcomes, and a new study, iStopMM, is underway to ascertain the benefit of population-wide screening protocols for early detection of the disease in its asymptomatic phase. Laboratory algorithms that include measurement of both monoclonal intact immunoglobulins and FLCs are important for assessing possible changes in myelomic clones in response to treatment, and recent data from Intergroupe Francophone du Myelome trials validate serum FLC as a clinically relevant disease biomarker. Whether sensitive serum techniques such as FLC analysis can be used to guide the use of more invasive procedures for detection of minimal residual disease is the subject of emerging studies.

Here we review the current and evolving utility of serum FLC measurements for the management of patients with monoclonal gammopathies.
Assessment of Two Rapid Assays for Diagnostic Capability to Accurately Identify Infection by Treponema pallidum
Authors: Constantine Niel T , Sill Anne M , Gudesblat Elizabeth , Paulus Samantha , Saleh Ahmed
Published: July 2018

Background

Rapid, point-of-care tests that accurately identify syphilis are gaining popularity and offer several advantages over classic tests.

Methods

The SD Bioline Syphilis 3.0 and the Chembio DPP Syphilis Screen and Confirm Assay (CB) were assessed using 1283 samples that had been characterized by reference tests. The challenge samples included 5 commercial panels (seroconversion, mixed-titer), archived samples, fresh samples, and a dilution series. Both tests detect specific anti-treponemal antibodies, and the CB additionally detects antibodies to a non-treponemal (NT) component. The evaluation was used to determine performance indices and compare with those cited by the manufacturers.

Results

When assessing reactivity to treponemal, the sensitivities for the 2 tests were 98.3% and 93.2%, with specificities of 100% and 99.4%, respectively. For both tests, precision, whole blood testing, and high-temperature testing produced perfect results, and there were no invalid results. Comparisons of 2 different lots of each test indicated excellent concordance (100% and 99.5%), and reproducibility was 100% and 98.0%, respectively. For the CB, the sensitivity for the NT component was between 65.3% and 80.9%, but increased to 98.5% with samples having a rapid plasma regain (RPR) titer of ≥8. The specificity for NT was found to be 100%, and the reading of results visually and when using a battery-operated reader indicated a concordance for all challenges of 95%–100%.

Conclusions

Both rapid tests produced impressive results for the detection of antibodies to treponemal for all challenges and exceeded, met, or closely approached the performance characteristics as cited by the manufacturers.
N-Terminal Pro–B-Type Natriuretic Peptide (NT-proBNP) Immunoreactivity Is Reduced After 6 Years of Storage at −70 °C
Authors: Wee Tracee , Tang Mila , Zrno Ilinka , Hamilton Jonah , Holmes Daniel T
Published: July 2018

Background

Clinical trial samples may be stored frozen for prolonged periods before analysis, which can reduce the immunoreactivity of numerous analytes, particularly peptides. We sought to determine the effect of 6 years of frozen storage on serum N-terminal pro–B-type natriuretic peptide (NT-proBNP).

Methods

NT-proBNP was measured from serum samples taken from 99 different patients enrolled in the CanPREDDICT study after <1 year of storage at −70 °C using the Roche first-generation NT-proBNP assay on an e411 instrument. Separate aliquots of the same samples were analyzed after an additional 6 years of storage at −70 °C using the Roche second-generation assay on an e601 instrument.

Results

The median NT-proBNP immunoreactivity for the first measurement was 572 pg/mL (interquartile range [IQR] 205–1606, range 49–12820), while after an additional 6 years of storage at −70 °C, this value decreased to 526 pg/mL (IQR 181–1338, range 18–12880), resulting in a median percent difference of −7% (IQR −10.6% to −3.4%, P < 0.001).

Conclusions

We report findings consistent with trends seen in previous work but have investigated the effect of a much longer storage period. Larger percent decreases in NT-proBNP reaching statistical significance are seen, although the median difference is still <10%.