Quantitative Concepts Research Articles

Endophenotypes, Epigenetics, Polygenicity and More: Irv Gottesman's Dynamic Legacy.

First, we describe the hallmark contributions of Irv Gottesman's pioneering scholarship for schizophrenia research including concepts of polygenicity, gene × environment interactions, epigenetics and the endophenotype concept. Gottesman and colleagues' twin studies showed that genes, not social factors, mediate schizophrenia risk. He then showed that schizophrenia is highly polygenic. Next, he introduced the concept of epigenetics into schizophrenia research. Gottesman then introduced the quantitative endophenotype concept. Endophenotypes are laboratory-based measures that show deficits in schizophrenia patients and lesser deficits in their first degree "unaffected" relatives and are viewed as being more proximal to genes and having a simpler genetic architecture than are "fuzzy" qualitative diagnostic disorders. Endophenotypes offer an exciting path to gene discovery, neural circuits, genetic architecture and new treatment pathways of schizophrenia and related psychotic disorders. Second, we were asked to discuss 2 of many endophenotype Consortia and related studies, in order to illustrate the impact of Gottesman's work. We describe the Consortium on the Genetics of Schizophrenia (COGS) exploring neurocognitive and neurophysiological endophenotypes in family and case-control studies. Association, linkage, sequencing and epigenetic studies are described. The Bipolar and Schizophrenia Network for Intermediate Phenotypes (BSNIP) uses an array of endophenotypes including brain imaging in studies across the psychosis dimension, allowing for dimensional analyses. BSNIP results have led to the concept of biotypes, advancing the field. Irv Gottesman was imaginatively prescient in generating novel insights and predicting many major issues which challenge schizophrenia researchers who still use his concepts to guide current research approaches.

Modern Poisons:A Brief Introduction to Contemporary Toxicology

Toxicology is the branch of science that deals with poisons or toxic substances. Poison is referred to as any substance that causes harmful effect when administered, either by accident or by design, to a living organism. Poison is a quantitative concept; almost any substance is harmful at certain doses. At the same time, it may not be harmful at lower dose rates.

The Gist of Delay of Gratification: Understanding and Predicting Problem Behaviors.

Delay of gratification captures elements of temptation and self-denial that characterize real-life problems with money and other problem behaviors such as unhealthy risk taking. According to fuzzy-trace theory, decision makers mentally represent social values such as delay of gratification in a coarse but meaningful form of memory called "gist." Applying this theory, we developed a gist measure of delay of gratification that does not involve quantitative trade-offs (as delay discounting does) and hypothesize that this construct explains unique variance beyond sensation seeking and inhibition in accounting for problem behaviors. Across four studies, we examine this Delay-of-gratification Gist Scale by using principal components analyses and evaluating convergent and divergent validity with other potentially related scales such as Future Orientation, Propensity to Plan, Time Perspectives Inventory, Spendthrift-Tightwad, Sensation Seeking, Cognitive Reflection, Barratt Impulsiveness, and the Monetary Choice Questionnaire (delay discounting). The new 12-item measure captured a single dimension of delay of gratification, correlated as predicted with other scales, but accounted for unique variance in predicting such outcomes as overdrawing bank accounts, substance abuse, and overall subjective well-being. Results support a theoretical distinction between reward-related approach motivation, including sensation seeking, and inhibitory faculties, including cognitive reflection. However, individuals' agreement with the qualitative gist of delay of gratification, as expressed in many cultural traditions, could not be reduced to such dualist distinctions nor to quantitative conceptions of delay discounting, shedding light on mechanisms of self-control and risk taking.

Information Integration and Energy Expenditure in Gene Regulation

The quantitative concepts used to reason about gene regulation largely derive from bacterial studies. We show that this bacterial paradigm cannot explain the sharp expression of a canonical developmental gene in response to a regulating transcription factor (TF). In the absence of energy expenditure, with regulatory DNA at thermodynamic equilibrium, information integration across multiple TF binding sites can generate the required sharpness, but with strong constraints on the resultant "higher-order cooperativities." Even with such integration, there is a "Hopfield barrier" to sharpness; for n TF binding sites, this barrier is represented by the Hill function with the Hill coefficient n. If, however, energy is expended to maintain regulatory DNA away from thermodynamic equilibrium, as in kinetic proofreading, this barrier can be breached and greater sharpness achieved. Our approach is grounded in fundamental physics, leads to testable experimental predictions, and suggests how a quantitative paradigm for eukaryotic gene regulation can be formulated.

Quantifying Hazard Exposure Using Real-Time Location Data of Construction Workforce and Equipment

AbstractTraditional risk-assessment methods typically evaluate accident probability, exposure frequency or duration, and consequence severity, respectively, and finally determine a quantitative risk score or a qualitative risk level. The assessment process is prospective and subjective. Changing and complex construction situations impede their practical and efficient application. To assess safety risk with regard to changing site conditions in an objective and efficient way, this study proposes a quantitative model for hazard exposure assessment based on real-time location data of construction workforce and equipment, collected by a location-based proximity warning system. In contrast with traditional risk-assessment methods, the model proposed in this study combines accident probability and hazard exposure duration into a single quantitative concept—hazard exposure amount. This concept takes into account the space factor as well as the time factor of construction activities. For ease of understanding, a ...

Virtual Engineering Sciences Learning Lab: Giving STEM Education a Second Life

Engineering education in the 21st century faces multiple obstacles including limited accessibility of course resources due, in part, to the costs associated with acquiring and maintaining equipment and staffing laboratories. Another continuing challenge is the low level of participation of women and other groups historically underrepresented in STEM disciplines. As a partial remedy for these issues, we established a Virtual Engineering Sciences Learning Lab (VESLL) that provides interactive objects and learning activities, multimedia displays, and instant feedback procedures in a virtual environment to guide students through a series of key quantitative skills and concepts. Developed in the online virtual world Second LifeTM, VESLL is an interactive environment that supports STEM education, with potential to help reach women and other underrepresented groups. VESLL exposes students to various quantitative skills and concepts through visualization, collaborative games, and problem solving with realistic learning activities. Initial assessments have demonstrated high student interest in VESLL's potential as a supplementary instructional tool and show that student learning experiences were improved by use of VESLL. Ultimately, the VESLL project contributes to the ongoing body of evidence suggesting that online delivery of course content has remarkable potential when properly deployed by STEM educators.

Students' difficulty with proportional reasoning in a university quantitative literacy course

The ability to reason about changes in quantities expressed in relative terms is essential for a critical awareness of data use in society. We regard this way of thinking, which we term 'proportional comparison', as a threshold concept (Meyer and Land 2003) for academic quantitative literacy. The extent and nature of students' difficulties with learning this concept in a quantitative literacy course for Law students were studied using a phenomenographic type of analysis of students' responses to four test questions, written at different times. Less than a quarter of students could be said to have learned this concept at any time and improvements in students' ability to reason about relative differences were very slight. This supports the view that the learning of troublesome (Meyer and Land 2003) quantitative literacy concepts takes a long time and should be addressed in a sustained way, integrated into a student's programme of study.

The Chronicity of HIV Infection Should Drive the Research Strategy of NeuroHIV Treatment Studies: A Critical Review.

HIV infection has become a chronic illness when successfully treated with combined antiretroviral therapy (cART). The long-term health prognosis of aging with controlled HIV infection and HIV-associated neurocognitive disorder (HAND) remains unclear. In this review, we propose that, almost 20 years after the introduction of cART, a change in research focus is needed, with a greater emphasis on chronicity effects driving our research strategy. We argue that pre-emptive documentation of episodes of mild neurocognitive dysfunction is needed to determine their long-term prognosis. This strategy would also seek to optimally represent the entire HAND spectrum in therapeutic trials to assess positive and/or negative treatment effects on brain functions. In the first part of the paper, to improve the standard implementation of the Frascati HAND diagnostic criteria, we provide a brief review of relevant quantitative neuropsychology concepts to clarify their appropriate application for a non-neuropsychological audience working in HIV research and wanting to conduct randomized clinical trials on brain functions. The second part comprises a review of various antiretroviral drug classes and individual agents with respect to their effects on HAND, while also addressing the question of when cART should be initiated to potentially reduce HAND incidence. In each section, we use recent observational studies and randomized controlled trials to illustrate our perspective while also providing relevant statistical comments. We conclude with a discussion of the neuroimaging methods that could be combined with neuropsychological approaches to enhance the validity of HIV neurology (neuroHIV) treatment effect studies.

Kinetic modeling and the rise of systems pharmacology

Kinetic modeling and the rise of systems pharmacology

Physical Conditions of Faculties of Fine Arts Departments of Painting Established in and after 2005

There have been several educational policy changes in Turkey since 2002. These changes, affecting all educational institutions, have also seen an increase in the rate of school enrollment in higher education. According to this, the number of universities in Turkey has increased to a significant level. Faculties of Fine Arts have also been affected by the increase in the number of higher education institutions. The total number of these faculties have increased from 26 in 2005 to 67 in 2013; an increase of 158 %. This numerical increase of Faculties of Fine Arts, has revealed many controversies and opinions. Positive opinions point to issues relating to an increase in access possibilities and to a wider dispersion of faculties nationwide. In the relevant literature, it can be seen that such positive opinions are discussed as a quantitative concept. The other concept which causes controversy and usually contains negative opinions is the qualitative concept. One of the issues thought to pose a problem is mistakes regarding planning. Related research expresses that planning for Faculties of Fine Arts, established in and after 2005, has been inadequate and that new institutions commenced operations without the requisite physical and technical conditions being in place. The aim of this research is to determine students’ opinions about the physical conditions of Faculties of Fine Arts Departments of Painting established in and after 2005. Descriptive research methodology was used in the study. The research sample consisted of students of five Faculties of Fine Arts Departments of Painting which were established in and after 2005. A survey containing fifteen items was used to obtain data regarding physical conditions. The obtained data was analyzed using frequency (f) and percentage (%) and the results of the research are revealed.

Beyond the nation-state Polish national identity and cultural intimacy online

ABSTRACTThis article analyses the debate on ‘new patriotism’ in a Polish online discussion forum. We study the ways in which national identity is constructed in this setting. Digital communication contributes further to expanding discourse on national identities beyond nation-state borders. We analyse close to 6000 posts from a large Polish Internet discussion forum through the methods of quantitative concept mapping and qualitative close readings. Our results show that patriotism is negotiated beyond strictly national frameworks. It is not merely a question of national interest as it also connects people through a process of establishing and maintaining of cultural intimacy.

Topological Characterization of Complex Systems: Using Persistent Entropy

In this paper, we propose a methodology for deriving a model of a complex system by exploiting the information extracted from topological data analysis. Central to our approach is the S[B] paradigm in which a complex system is represented by a two-level model. One level, the structural S one, is derived using the newly-introduced quantitative concept of persistent entropy, and it is described by a persistent entropy automaton. The other level, the behavioral B one, is characterized by a network of interacting computational agents. The presented methodology is applied to a real case study, the idiotypic network of the mammalian immune system.

Tips From The Trenches

Just what does usage mean? And how does it relate to value? Is there a fair way to ascertain the value of resources? In regards to library resources, “use” can simply be an arbitrary quantitative concept. Knowing that searches and sessions are considered input measures while result clicks and views are output measures helps the process. With electronic resources, we parse our usage statistics (when we can get them) to arrive at a cost per use, and define whether that use is a view, a printout, or a download. Of course, there are discrepancies as we examine different e-resources; for instance, cost-per-use can be very different with e-books—the definition of a “section” varies from vendor to vendor, and vendors' attempts to limit mass downloading mean that some e-book titles have page number limits with no correlation to chapter length. Analysis of usage data and other qualitative measures as part of a systematic review of current and potential e-resources highlights underutilized resources, access issues,...

Conservation of Mass: An Important Tool in Renal Research.

The dialytic treatment of end-stage renal disease (ESRD) patients is based on control of solute concentrations and management of fluid volume. The application of the principal of conservation of mass, or mass balance, is fundamental to the study of such treatment and can be extended to chronic kidney disease (CKD) in general. This review discusses the development and use of mass conservation and transport concepts, incorporated into mathematical models. These concepts, which can be applied to a wide range of solutes of interest, represent a powerful tool for quantitatively guided studies of dialysis issues currently and into the future. Incorporating these quantitative concepts in future investigations is key to achieving positive control of known solutes, and in the analysis of such studies; to relate future research to known results of prior studies; and to help in the understanding of the obligatory physiological perturbations that result from dialysis therapy.

Signalfunktion and Kodierungsgrad von sprachlichen Merkmalen in Gerichtsurteilen

This article investigates the relations between the textual conventions of a text genre and the speech acts performed within this genre. The starting point of the study is a critical view upon Katharina Reiss' concept of "Textsortenkonventionen". It is stated that a mainly quantitative concept as Reiss' cannot adequatly guide the translator in his search for the appropriate translation equivalent, and that a qualitative concept of textual convention has to be developed to fill this gap. As an example, an analysis of the speech act [report] within the text genre "legal judgements in Civil Law cases" is presented. As a result of the analysis, some of the conventions of the text genre are said to be coded signals for the speech acts performed within the genre. On the basis of these results an attempt is made to develop a theoretical concept that may describe the relation between degree of conventionalisation and the signal quality of linguistic elements within texts.

Predictors of Performance in Introductory Finance: Variables within and beyond the Student’s Control

This study examined variables that are within and beyond the control of students in explaining variations in performance in an introductory finance course. Regression models were utilized to consider whether the variables within the student’s control have a greater impact on course performance relative to the variables beyond the student’s control. Among the particular variables within the student’s control were the student’s inclination to procrastinate as evidenced by the relative delay the students exhibited in commencing online homework assignments. Also, separate measures were constructed to examine the effect of the accuracy of the homework submitted and the student’s actual completion of those assignments. Class attendance was also considered. The variables largely beyond the control of the student examined in this study were a measure of how far along in the undergraduate program the student had progressed when he/she enrolled in the introductory finance course, a measure of the credit load of the student in the semester when the student took the course, the student’s gender, the student’s overall academic ability and the relative strength of the student in comprehending quantitative versus verbal concepts. For the three measures of student performance studied, average homework grade, the mid-term exam grade and the final exam grade, all of the relevant variables within the student’s control demonstrated some impact on the various measures of performance. There was persuasive evidence that the variables within the student’s control were more influential in explaining differences in student performance than the variables beyond the student’s control.

Cross-correlations of American baby names

The quantitative description of cultural evolution is a challenging task. The most difficult part of the problem is probably to find the appropriate measurable quantities that can make more quantitative such evasive concepts as, for example, dynamics of cultural movements, behavioral patterns, and traditions of the people. A strategy to tackle this issue is to observe particular features of human activities, i.e., cultural traits, such as names given to newborns. We study the names of babies born in the United States from 1910 to 2012. Our analysis shows that groups of different correlated states naturally emerge in different epochs, and we are able to follow and decrypt their evolution. Although these groups of states are stable across many decades, a sudden reorganization occurs in the last part of the 20th century. We unambiguously demonstrate that cultural evolution of society can be observed and quantified by looking at cultural traits. We think that this kind of quantitative analysis can be possibly extended to other cultural traits: Although databases covering more than one century (such as the one we used) are rare, the cultural evolution on shorter timescales can be studied due to the fact that many human activities are usually recorded in the present digital era.

Microwave miniaturization concept for narrow band rectangular patch antenna structures

A quantitative concept of miniaturization of a narrow-band rectangular patch antenna by using a metamaterial substrate with a large value in the real part of the effective permittivity instead of a conventional homogenous high dielectric material is

Genomic heritability: what is it?

Whole-genome regression methods are being increasingly used for the analysis and prediction of complex traits and diseases. In human genetics, these methods are commonly used for inferences about genetic parameters, such as the amount of genetic variance among individuals or the proportion of phenotypic variance that can be explained by regression on molecular markers. This is so even though some of the assumptions commonly adopted for data analysis are at odds with important quantitative genetic concepts. In this article we develop theory that leads to a precise definition of parameters arising in high dimensional genomic regressions; we focus on the so-called genomic heritability: the proportion of variance of a trait that can be explained (in the population) by a linear regression on a set of markers. We propose a definition of this parameter that is framed within the classical quantitative genetics theory and show that the genomic heritability and the trait heritability parameters are equal only when all causal variants are typed. Further, we discuss how the genomic variance and genomic heritability, defined as quantitative genetic parameters, relate to parameters of statistical models commonly used for inferences, and indicate potential inferential problems that are assessed further using simulations. When a large proportion of the markers used in the analysis are in LE with QTL the likelihood function can be misspecified. This can induce a sizable finite-sample bias and, possibly, lack of consistency of likelihood (or Bayesian) estimates. This situation can be encountered if the individuals in the sample are distantly related and linkage disequilibrium spans over short regions. This bias does not negate the use of whole-genome regression models as predictive machines; however, our results indicate that caution is needed when using marker-based regressions for inferences about population parameters such as the genomic heritability.

Tips From the Trenches

Just what does usage mean? And how does it relate to value? Is there a fair way to ascertain the value of resources? In regards to library resources, “use” can simply be an arbitrary quantitative concept. Knowing that searches and sessions are considered input measures while result clicks and views are output measures helps the process. With electronic resources, we parse our usage statistics (when we can get them) to arrive at a cost per use, and define whether that use is a view, a printout, or a download. Of course, there are discrepancies as we examine different e-resources; for instance, cost-per-use can be very different with e-books—the definition of a “section” varies from vendor to vendor, and vendors' attempts to limit mass downloading mean that some e-book titles have page number limits with no correlation to chapter length. Analysis of usage data and other qualitative measures as part of a systematic review of current and potential e-resources highlights underutilized resources, access issues, and potential sources. We review and study those indicators of use to arrive at a conclusion of value, where we look at the bottom line—does the institution receive a good value in regards to particular resources, and should they be retained or replaced.