Gerbner, Dániel; Lemons, Nathan; Mubayi, Dhruv; Palmer, Cory; Patkós, Balázs
2011-01-01
The two part Sperner theorem of Katona and Kleitman states that if $X$ is an $n$-element set with partition $X_1 \\cup X_2$, and $\\cF$ is a family of subsets of $X$ such that no two sets $A, B \\in \\cF$ satisfy $A \\subset B$ (or $B \\subset A$) and $A \\cap X_i=B \\cap X_i$ for some $i$, then $|\\cF| \\le {n \\choose \\lfloor n/2 \\rfloor}$. We consider variations of this problem by replacing the Sperner property with the intersection property and considering families that satisfiy various combinations of these properties on one or both parts $X_1$, $X_2$. Along the way, we prove the following new result which may be of independent interest: let $\\cF, \\cG$ be families of subsets of an $n$-element set such that $\\cF$ and $\\cG$ are both intersecting and cross-Sperner, meaning that if $A \\in \\cF$ and $B \\in \\cG$, then $A \
Approximation of the two-part MDL code
Adriaans, P.; Vitányi, P.M.B.
2009-01-01
Approximation of the optimal two-part minimum description length (MDL) code for given data, through successive monotonically length-decreasing two-part MDL codes, has the following properties: (i) computation of each step may take arbitrarily long; (ii) we may not know when we reach the optimum, or
Approximation of the two-part MDL code
P. Adriaans; P.M.B. Vitányi (Paul)
2009-01-01
htmlabstractApproximation of the optimal two-part minimum description length (MDL) code for given data, through successive monotonically length-decreasing two-part MDL codes, has the following properties: (i) computation of each step may take arbitrarily long; (ii) we may not know when we reach the
A two-part model for censored medical cost data.
Tian, Lu; Huang, Jie
2007-10-15
The two-part model is often used to analyse medical cost data which contain a large proportion of zero cost and are highly skewed with some large costs. The total medical costs over a period of time are often censored due to incomplete follow-up, making the analysis difficult as the censoring can be informative. We propose to apply the inverse probability weighting method on a two-part model to analyse right-censored cumulative medical costs with informative censoring. We also introduce a set of simple functionals based on the intermediate cost history to be applied with the efficiency augmentation technique. In addition, we propose a practical model-checking technique based on the cumulative residuals. Simulation studies are conducted to evaluate the finite sample performance of the proposed method. We use a data set on the cardiovascular disease (CVD)-related Medicare costs to illustrate our proposed method.
Much ado about two: reconsidering retransformation and the two-part model in health econometrics.
Mullahy, J
1998-06-01
In health economics applications involving outcomes (y) and covariates (x), it is often the case that the central inferential problems of interest involve E[y/x] and its associated partial effects or elasticities. Many such outcomes have two fundamental statistical properties: y > or = 0; and the outcome y = 0 is observed with sufficient frequency that the zeros cannot be ignored econometrically. This paper (1) describes circumstances where the standard two-part model with homoskedastic retransformation will fail to provide consistent inferences about important policy parameters; and (2) demonstrates some alternative approaches that are likely to prove helpful in applications.
Describe Your Favorite Teacher.
Dill, Isaac; Dill, Vicky
1993-01-01
A third grader describes Ms. Gonzalez, his favorite teacher, who left to accept a more lucrative teaching assignment. Ms. Gonzalez' butterflies unit covered everything from songs about social butterflies to paintings of butterfly wings, anatomy studies, and student haiku poems and biographies. Students studied biology by growing popcorn plants…
Simple Waveforms, Simply Described
Baker, John G.
2008-01-01
Since the first Lazarus Project calculations, it has been frequently noted that binary black hole merger waveforms are 'simple.' In this talk we examine some of the simple features of coalescence and merger waveforms from a variety of binary configurations. We suggest an interpretation of the waveforms in terms of an implicit rotating source. This allows a coherent description, of both the inspiral waveforms, derivable from post-Newtonian(PN) calculations, and the numerically determined merger-ringdown. We focus particularly on similarities in the features of various Multipolar waveform components Generated by various systems. The late-time phase evolution of most L these waveform components are accurately described with a sinple analytic fit. We also discuss apparent relationships among phase and amplitude evolution. Taken together with PN information, the features we describe can provide an approximate analytic description full coalescence wavefoRms. complementary to other analytic waveforns approaches.
Pharmacobezoars described and demystified.
Simpson, Serge-Emile
2011-02-01
A bezoar is a concretion of foreign material that forms and persists in the gastrointestinal tract. Bezoars are classified by their material origins. Phytobezoars contain plant material, trichobezoars contain hair, lactobezoars contain milk proteins, and pharmacobezoars contain pharmaceutical products. Tablets, suspensions, and even insoluble drug delivery vehicles can, on rare occasions, and sometimes under specific circumstances, form pharmacobezoars. The goal of this review is to catalog and examine all of the available reports in the English language medical literature that convincingly describe the formation and management of pharmacobezoars. Articles included in this review were identified by performing searches using the terms "bezoar," "pharmacobezoar," and "concretion" in the following databases: OVID MEDLINE, PubMed, and JSTOR. The complete MEDLINE and JSTOR holdings were included in the search without date ranges. The results were limited to English language publications. Articles that described nonmedication bezoars were not included in the review. Articles describing phytobezoars, food bezoars, fecal impactions, illicit drug packet ingestions, enteral feeding material bezoars, and hygroscopic diet aid bezoars were excluded. The bibliographic references within the articles already accumulated were then examined in order to gather additional pharmacobezoar cases. The cases are grouped by pharmaceutical agent that formed the bezoar, and groupings are arranged in alphabetical order. Discussions and conclusions specific to each pharmaceutical agent are included in that agent's subheading. Patterns and themes that emerged in the review of the assembled case reports are reviewed and presented in a more concise format. Pharmacobezoars form under a wide variety of circumstances and in a wide variety of patients. They are difficult to diagnose reliably. Rules for suspecting, diagnosing, and properly managing a pharmacobezoar are highly dependent on the
How Mathematics Describes Life
Teklu, Abraham
2017-01-01
The circle of life is something we have all heard of from somewhere, but we don't usually try to calculate it. For some time we have been working on analyzing a predator-prey model to better understand how mathematics can describe life, in particular the interaction between two different species. The model we are analyzing is called the Holling-Tanner model, and it cannot be solved analytically. The Holling-Tanner model is a very common model in population dynamics because it is a simple descriptor of how predators and prey interact. The model is a system of two differential equations. The model is not specific to any particular set of species and so it can describe predator-prey species ranging from lions and zebras to white blood cells and infections. One thing all these systems have in common are critical points. A critical point is a value for both populations that keeps both populations constant. It is important because at this point the differential equations are equal to zero. For this model there are two critical points, a predator free critical point and a coexistence critical point. Most of the analysis we did is on the coexistence critical point because the predator free critical point is always unstable and frankly less interesting than the coexistence critical point. What we did is consider two regimes for the differential equations, large B and small B. B, A, and C are parameters in the differential equations that control the system where B measures how responsive the predators are to change in the population, A represents predation of the prey, and C represents the satiation point of the prey population. For the large B case we were able to approximate the system of differential equations by a single scalar equation. For the small B case we were able to predict the limit cycle. The limit cycle is a process of the predator and prey populations growing and shrinking periodically. This model has a limit cycle in the regime of small B, that we solved for
New Described Dermatological Disorders
Directory of Open Access Journals (Sweden)
Müzeyyen Gönül
2014-01-01
Full Text Available Many advances in dermatology have been made in recent years. In the present review article, newly described disorders from the last six years are presented in detail. We divided these reports into different sections, including syndromes, autoinflammatory diseases, tumors, and unclassified disease. Syndromes included are “circumferential skin creases Kunze type” and “unusual type of pachyonychia congenita or a new syndrome”; autoinflammatory diseases include “chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE syndrome,” “pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH syndrome,” and “pyogenic arthritis, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PAPASH syndrome”; tumors include “acquired reactive digital fibroma,” “onychocytic matricoma and onychocytic carcinoma,” “infundibulocystic nail bed squamous cell carcinoma,” and “acral histiocytic nodules”; unclassified disorders include “saurian papulosis,” “symmetrical acrokeratoderma,” “confetti-like macular atrophy,” and “skin spicules,” “erythema papulosa semicircularis recidivans.”
Sample selection versus two-part models revisited: the case of female smoking and drinking.
Madden, David
2008-03-01
There is a well-established debate between Heckman sample selection and two-part models in health econometrics, particularly when no obvious exclusion restrictions are available. Most of this debate has focussed on the application of these models to health care expenditure. This paper revisits the debate in the context of female smoking and drinking, and evaluates the two approaches on three grounds: theoretical, practical and statistical. The two-part model is generally favoured but it is stressed that this comparison should be carried out on a case-by-case basis.
A Study on Digital Analysis of Bach’s “Two-Part Inventions”
Directory of Open Access Journals (Sweden)
Xiao-Yi Song
2015-01-01
Full Text Available In the field of music composition, creating polyphony is relatively one of the most difficult parts. Among them, the basis of multivoice polyphonic composition is two-part counterpoint. The main purpose of this paper is, through the computer technology, conducting a series of studies on “Two-Part Inventions” of Bach, a Baroque polyphony master. Based on digitalization, visualization and mathematical methods, data mining algorithm has been applied to identify bipartite characteristics and rules of counterpoint polyphony. We hope that the conclusions drawn from the article could be applied to the digital creation of polyphony.
A Cost-Effective Two-Part Experiment for Teaching Introductory Organic Chemistry Techniques
Sadek, Christopher M.; Brown, Brenna A.; Wan, Hayley
2011-01-01
This two-part laboratory experiment is designed to be a cost-effective method for teaching basic organic laboratory techniques (recrystallization, thin-layer chromatography, column chromatography, vacuum filtration, and melting point determination) to large classes of introductory organic chemistry students. Students are exposed to different…
Development of the two-part pattern during regeneration of the head in hydra
DEFF Research Database (Denmark)
Bode, Matthias; Awad, T A; Koizumi, O;
1988-01-01
The head of a hydra is composed of two parts, a domed hypostome with a mouth at the top and a ring of tentacles below. When animals are decapitated a new head regenerates. During the process of regeneration the apical tip passes through a transient stage in which it exhibits tentacle...... began evaginating in a ring, both the TS-19 antigen and RLI+ ganglion cells gradually disappeared from the presumptive hypostome area and RLI+ sensory cells appeared at the apex. By tracking tissue movements during morphogenesis it became clear that the apical cap, in which these changes took place, did...... not undergo tissue turnover. The implications of this tentacle-like stage for patterning the two-part head are discussed....
DeFina, Laura F; Haskell, William L; Willis, Benjamin L; Barlow, Carolyn E; Finley, Carrie E; Levine, Benjamin D; Cooper, Kenneth H
2015-01-01
Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to cardiovascular (CV) morbidity and mortality. Recent position papers and guidelines have identified the important role of both of these factors in CV health. The benefits of PA and CRF in the prevention of CV disease and risk factors are reviewed. In addition, assessment methodology and utilization in the research and clinical arenas are discussed. Finally, the benefits, methodology, and utilization are compared and contrasted to better understand the two (partly) distinct components and their impact on CV health.
Two-part silicone mold. A new tool for flexible ureteroscopy surgical training
Directory of Open Access Journals (Sweden)
Bruno Marroig
Full Text Available ABSTRACT Introduction and objectives: Flexible ureteroscopy is a common procedure nowadays. Most of the training programs use virtual reality simulators. The aim of this study was to standardize the building of a three-dimensional silicone mold (cavity of the collecting system, on the basis of polyester resin endocasts, which can be used in surgical training programs. Materials and Methods: A yellow polyester resin was injected into the ureter to fill the collecting system of 24 cadaveric fresh human kidneys. After setting off the resin, the kidneys were immersed in hydrochloric acid until total corrosion of the organic matter was achieved and the collecting system endocasts obtained. The endocasts were used to prepare white color two-part silicone molds, which after endocasts withdrawn, enabled a ureteroscope insertion into the collecting system molds (cavities. Also, the minor calices were painted with different colors in order to map the access to the different caliceal groups. The cost of the materials used in the molds is $30.00 and two days are needed to build them. Results: Flexible ureteroscope could be inserted into all molds and the entire collecting system could be examined. Since some anatomical features, as infundular length, acute angle, and perpendicular minor calices may difficult the access to some minor calices, especially in the lower caliceal group, surgical training in models leads to better surgical results. Conclusions: The two-part silicone mold is feasible, cheap and allows its use for flexible ureteroscopy surgical training.
Alanazi, Hamdan O; Zaidan, B B; Jalab, Hamid A; AL-Ani, Zaidoon Kh
2010-01-01
With the rapid development of various multimedia technologies, more and more multimedia data are generated and transmitted in the medical, commercial, and military fields, which may include some sensitive information which should not be accessed by or can only be partially exposed to the general users. Therefore, security and privacy has become an important, Another problem with digital document and video is that undetectable modifications can be made with very simple and widely available equipment, which put the digital material for evidential purposes under question .With the large flood of information and the development of the digital format Information hiding considers one of the techniques which used to protect the important information. The main goals for this paper, provides a general overview of the New Classification Methods for Hiding Information into Two Parts: Multimedia Files and Non Multimedia Files.
Five Describing Factors of Dyslexia
Tamboer, Peter; Vorst, Harrie C. M.; Oort, Frans J.
2016-01-01
Two subtypes of dyslexia (phonological, visual) have been under debate in various studies. However, the number of symptoms of dyslexia described in the literature exceeds the number of subtypes, and underlying relations remain unclear. We investigated underlying cognitive features of dyslexia with exploratory and confirmatory factor analyses. A…
Five describing factors of dyslexia
Tamboer, P.; Vorst, H.C.M.; Oort, F.J.
2016-01-01
Two subtypes of dyslexia (phonological, visual) have been under debate in various studies. However, the number of symptoms of dyslexia described in the literature exceeds the number of subtypes, and underlying relations remain unclear. We investigated underlying cognitive features of dyslexia with
Five Describing Factors of Dyslexia
Tamboer, Peter; Vorst, Harrie C. M.; Oort, Frans J.
2016-01-01
Two subtypes of dyslexia (phonological, visual) have been under debate in various studies. However, the number of symptoms of dyslexia described in the literature exceeds the number of subtypes, and underlying relations remain unclear. We investigated underlying cognitive features of dyslexia with exploratory and confirmatory factor analyses. A…
Directory of Open Access Journals (Sweden)
Bryce B. Reeve
2016-03-01
Full Text Available Measurement equivalence across differing socio-demographic groups is essential for valid assessment. This is one of two issues of Psychological Test and Assessment Modeling that contains articles describing methods and substantive findings related to establishing measurement equivalence in self-reported health, mental health and social functioning measures. The articles in this two part series describe analyses of items assessing eight domains: fatigue, depression, anxiety, sleep, pain, physical function, cognitive concerns and social function. Additionally, two overview articles describe the methods and sample characteristics of the data set used in these analyses. An additional article describes the important topic of assessing magnitude and impact of differential item functioning. These articles provide the first strong evidence supporting the measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short form measures in ethnically, socio-demographically diverse groups, and is a beginning step in meeting the international call for further study of their performance in such groups.
Felder, Stefan
2004-12-01
Drug price differences across national markets as they exist in the EU are often justified by the concept of Ramsey prices: with fixed costs for R&D, the optimal mark-ups on marginal costs are inversely related to the price elasticity in the individual markets. This well-known result prevails if consumer moral hazard is taken into account. Contrary to the situation without moral hazard, the uniform price does not necessarily dominate discriminatory pricing in welfare terms. The two-part tariff is a better alternative as it allows governments to address moral hazard. A uniform price combined with lump-payments reflecting differences in the willingness to pay and the moral hazard in member states appears to be an attractive option for a common EU drug market.
Directory of Open Access Journals (Sweden)
Zunya Shi
2016-01-01
Full Text Available The importance of remanufacturing has been recognized in research and practice. The integrated system, combining the forward and reverse activities of supply chains, is called closed-loop supply chain (CLSC system. By coordination in the CLSC system, players will get economic improvement. This paper studies different coordination performances of two types of contracts, two-part tariff (TTC and reverse revenue sharing contract (RRSC, in a closed-loop system. Through mathematical analysis based on Stackelberg Game Theory, we find that it is easy for manufacturer to improve more profits and retailer’s collection effects by adjusting the ratio of transfer collection price through RRSC, and we also give the function to calculate the best ratio of transfer collection price, which may be a valuable reference for the decision maker in practice. Besides, our results also suggest that although the profits of the coordinated CLSC system are always higher than the contradictory scenario, the RRSC is more favorable to the manufacturer than to the retailer, as results show that the manufacturer will share more profits from the system through RRSC. Therefore, RRSC has attracted the manufacturers more to closing the supply chain for economic consideration.
Directory of Open Access Journals (Sweden)
Lawrence N Kazembe
Full Text Available Despite remarkable gains in life expectancy and declining mortality in the 21st century, in many places mostly in developing countries, adult mortality has increased in part due to HIV/AIDS or continued abject poverty levels. Moreover many factors including behavioural, socio-economic and demographic variables work simultaneously to impact on risk of mortality. Understanding risk factors of adult mortality is crucial towards designing appropriate public health interventions. In this paper we proposed a structured additive two-part random effects regression model for adult mortality data. Our proposal assumed two processes: (i whether death occurred in the household (prevalence part, and (ii number of reported deaths, if death did occur (severity part. The proposed model specification therefore consisted of two generalized linear mixed models (GLMM with correlated random effects that permitted structured and unstructured spatial components at regional level. Specifically, the first part assumed a GLMM with a logistic link and the second part explored a count model following either a Poisson or negative binomial distribution. The model was used to analyse adult mortality data of 25,793 individuals from the 2006/2007 Namibian DHS data. Inference is based on the Bayesian framework with appropriate priors discussed.
Directory of Open Access Journals (Sweden)
Alawi Luetz
Full Text Available Analgesia, sedation and delirium management are important parts of intensive care treatment as they are relevant for patients' clinical and functional long-term outcome. Previous surveys showed that despite this fact implementation rates are still low. The primary aim of the prospective, observational multicenter study was to investigate the implementation rate of delirium monitoring among intensivists. Secondly, current practice concerning analgesia and sedation monitoring as well as treatment strategies for patients with delirium were assesed. In addition, this study compares perceived and actual practice regarding delirium, sedation and analgesia management. Data were obtained with a two-part, anonymous survey, containing general data from intensive care units in a first part and data referring to individual patients in a second part. Questionnaires from 101 hospitals (part 1 and 868 patients (part 2 were included in data analysis. Fifty-six percent of the intensive care units reported to monitor for delirium in clinical routine. Fourty-four percent reported the use of a validated delirium score. In this respect, the survey suggests an increasing use of delirium assessment tools compared to previous surveys. Nevertheless, part two of the survey revealed that in actual practice 73% of included patients were not monitored with a validated score. Furthermore, we observed a trend towards moderate or deep sedation which is contradicting to guideline-recommendations. Every fifth patient was suffering from pain. The implementation rate of adequate pain-assessment tools for mechanically ventilated and sedated patients was low (30%. In conclusion, further efforts are necessary to implement guideline recommendations into clinical practice. The study was registered (ClinicalTrials.gov identifier: NCT01278524 and approved by the ethical committee.
The U. S. transportation sector in the year 2030: results of a two-part Delphi survey.
Energy Technology Data Exchange (ETDEWEB)
Morrison, G.; Stephens, T.S. (Energy Systems); (Univ. of California at Davis); (ES)
2011-10-11
A two-part Delphi Survey was given to transportation experts attending the Asilomar Conference on Transportation and Energy in August, 2011. The survey asked respondents about trends in the US transportation sector in 2030. Topics included: alternative vehicles, high speed rail construction, rail freight transportation, average vehicle miles traveled, truck versus passenger car shares, vehicle fuel economy, and biofuels in different modes. The survey consisted of two rounds -- both asked the same set of seven questions. In the first round, respondents were given a short introductory paragraph about the topic and asked to use their own judgment in their responses. In the second round, the respondents were asked the same questions, but were also given results from the first round as guidance. The survey was sponsored by Argonne National Lab (ANL), the National Renewable Energy Lab (NREL), and implemented by University of California at Davis, Institute of Transportation Studies. The survey was part of the larger Transportation Energy Futures (TEF) project run by the Department of Energy, Office of Energy Efficiency and Renewable Energy. Of the 206 invitation letters sent, 94 answered all questions in the first round (105 answered at least one question), and 23 of those answered all questions in the second round. 10 of the 23 second round responses were at a discussion section at Asilomar, while the remaining were online. Means and standard deviations of responses from Round One and Two are given in Table 1 below. One main purpose of Delphi surveys is to reduce the variance in opinions through successive rounds of questioning. As shown in Table 1, the standard deviations of 25 of the 30 individual sub-questions decreased between Round One and Round Two, but the decrease was slight in most cases.
How Do Children Describe Spatial Relationships?
Cox, M. V.; Richardson, J. Ryder
1985-01-01
Describes a study of children's production of locative prepositions in order to test H. Clark's hypotheses regarding the acquisition of spatial terms. Subjects were required to describe the spatial arrangement of two balls arranged in each of three spatial dimensions. (SED)
Did goethe describe attention deficit hyperactivity disorder?
Bonazza, Sara; Scaglione, Cesa; Poppi, Massimo; Rizzo, Giovanni
2011-01-01
As early as 1846, the typical symptoms of attention deficit hyperactivity disorder (ADHD) were described by Heinrich Hoffmann (1809-1894). However, in Goethe's masterpiece Faust (1832), the character of Euphorion strongly suggests ADHD diagnosis.
describing a collaborative clothing design process between ...
African Journals Online (AJOL)
user
ISSN 0378-5254 Journal of Family Ecology and Consumer Sciences, Vol 43, 2015. Designing success: describing a ... PROCESS BETWEEN APPRENTICE DESIGNERS AND EXPERT DESIGN ...... decision-making. Thinking Skills and ...
Quantum formalism to describe binocular rivalry.
Manousakis, Efstratios
2009-11-01
On the basis of the general character and operation of the process of perception, a formalism is sought to mathematically describe the subjective or abstract/mental process of perception. It is shown that the formalism of orthodox quantum theory of measurement, where the observer plays a key role, is a broader mathematical foundation which can be adopted to describe the dynamics of the subjective experience. The mathematical formalism describes the psychophysical dynamics of the subjective or cognitive experience as communicated to us by the subject. Subsequently, the formalism is used to describe simple perception processes and, in particular, to describe the probability distribution of dominance duration obtained from the testimony of subjects experiencing binocular rivalry. Using this theory and parameters based on known values of neuronal oscillation frequencies and firing rates, the calculated probability distribution of dominance duration of rival states in binocular rivalry under various conditions is found to be in good agreement with available experimental data. This theory naturally explains an observed marked increase in dominance duration in binocular rivalry upon periodic interruption of stimulus and yields testable predictions for the distribution of perceptual alteration in time.
Recently described neoplasms of the sinonasal tract.
Bishop, Justin A
2016-03-01
Surgical pathology of the sinonasal region (i.e., nasal cavity and the paranasal sinuses) is notoriously difficult, due in part to the remarkable diversity of neoplasms that may be encountered in this area. In addition, a number of neoplasms have been only recently described in the sinonasal tract, further compounding the difficulty for pathologists who are not yet familiar with them. This manuscript will review the clinicopathologic features of some of the recently described sinonasal tumor types: NUT midline carcinoma, HPV-related carcinoma with adenoid cystic-like features, SMARCB1 (INI-1) deficient sinonasal carcinoma, biphenotypic sinonasal sarcoma, and adamantinoma-like Ewing family tumor.
Disposition of recently described species of Penicillium
Frisvad, Jens C.; Samson, Robert A.; Stolk, Amelia C.
1990-01-01
Hundred and twenty-two species, varieties, and new combinations of Penicillium, Eupenicillium, and Talaromyces described since 1977 have been studied taxonomically and screened for mycotoxin production. Only 48 taxa could be accepted: Eupenicillium angustiporcatum, E. cryptum, E. lineolatum, E. limo
Disposition of recently described species of Penicillium
Frisvad, Jens C.; Samson, Robert A.; Stolk, Amelia C.
1990-01-01
Hundred and twenty-two species, varieties, and new combinations of Penicillium, Eupenicillium, and Talaromyces described since 1977 have been studied taxonomically and screened for mycotoxin production. Only 48 taxa could be accepted: Eupenicillium angustiporcatum, E. cryptum, E. lineolatum, E. limo
How Digital Native Learners Describe Themselves
Thompson, Penny
2015-01-01
Eight university students from the "digital native" generation were interviewed about the connections they saw between technology use and learning, and also their reactions to the popular press claims about their generation. Themes that emerged from the interviews were coded to show patterns in how digital natives describe themselves.…
Is the Water Heating Curve as Described?
Riveros, H. G.; Oliva, A. I.
2008-01-01
We analysed the heating curve of water which is described in textbooks. An experiment combined with some simple heat transfer calculations is discussed. The theoretical behaviour can be altered by changing the conditions under which the experiment is modelled. By identifying and controlling the different parameters involved during the heating…
A Dualistic Model To Describe Computer Architectures
Nitezki, Peter; Engel, Michael
1985-07-01
The Dualistic Model for Computer Architecture Description uses a hierarchy of abstraction levels to describe a computer in arbitrary steps of refinement from the top of the user interface to the bottom of the gate level. In our Dualistic Model the description of an architecture may be divided into two major parts called "Concept" and "Realization". The Concept of an architecture on each level of the hierarchy is an Abstract Data Type that describes the functionality of the computer and an implementation of that data type relative to the data type of the next lower level of abstraction. The Realization on each level comprises a language describing the means of user interaction with the machine, and a processor interpreting this language in terms of the language of the lower level. The surface of each hierarchical level, the data type and the language express the behaviour of a ma-chine at this level, whereas the implementation and the processor describe the structure of the algorithms and the system. In this model the Principle of Operation maps the object and computational structure of the Concept onto the structures of the Realization. Describing a system in terms of the Dualistic Model is therefore a process of refinement starting at a mere description of behaviour and ending at a description of structure. This model has proven to be a very valuable tool in exploiting the parallelism in a problem and it is very transparent in discovering the points where par-allelism is lost in a special architecture. It has successfully been used in a project on a survey of Computer Architecture for Image Processing and Pattern Analysis in Germany.
LiveDescribe: Can Amateur Describers Create High-Quality Audio Description?
Branje, Carmen J.; Fels, Deborah I.
2012-01-01
Introduction: The study presented here evaluated the usability of the audio description software LiveDescribe and explored the acceptance rates of audio description created by amateur describers who used LiveDescribe to facilitate the creation of their descriptions. Methods: Twelve amateur describers with little or no previous experience with…
Frameworks for understanding and describing business models
DEFF Research Database (Denmark)
Nielsen, Christian; Roslender, Robin
2014-01-01
This chapter provides in a chronological fashion an introduction to six frameworks that one can apply to describing, understanding and also potentially innovating business models. These six frameworks have been chosen carefully as they represent six very different perspectives on business models ...... Maps (2001) • Intellectual Capital Statements (2003) • Chesbrough’s framework for Open Business Models (2006) • Business Model Canvas (2008)......This chapter provides in a chronological fashion an introduction to six frameworks that one can apply to describing, understanding and also potentially innovating business models. These six frameworks have been chosen carefully as they represent six very different perspectives on business models...... and in this manner “complement” each other. There are a multitude of varying frameworks that could be chosen from and we urge the reader to search and trial these for themselves. The six chosen models (year of release in parenthesis) are: • Service-Profit Chain (1994) • Strategic Systems Auditing (1997) • Strategy...
Modeling Approaches for Describing Microbial Population Heterogeneity
DEFF Research Database (Denmark)
Lencastre Fernandes, Rita
, ethanol and biomass throughout the reactor. This work has proven that the integration of CFD and population balance models, for describing the growth of a microbial population in a spatially heterogeneous reactor, is feasible, and that valuable insight on the interplay between flow and the dynamics......Although microbial populations are typically described by averaged properties, individual cells present a certain degree of variability. Indeed, initially clonal microbial populations develop into heterogeneous populations, even when growing in a homogeneous environment. A heterogeneous microbial......) to predict distributions of certain population properties including particle size, mass or volume, and molecular weight. Similarly, PBM allow for a mathematical description of distributed cell properties within microbial populations. Cell total protein content distributions (a measure of cell mass) have been...
Describing Spirituality at the End of Life.
Stephenson, Pam Shockey; Berry, Devon M
2015-09-01
Spirituality is salient to persons nearing the end of life (EOL). Unfortunately, researchers have not been able to agree on a universal definition of spirituality reducing the effectiveness of spiritual research. To advance spiritual knowledge and build an evidence base, researchers must develop creative ways to describe spirituality as it cannot be explicitly defined. A literature review was conducted to determine the common attributes that comprise the essence of spirituality, thereby creating a common ground on which to base spiritual research. Forty original research articles (2002 to 2012) focusing on EOL and including spiritual definitions/descriptions were reviewed. Analysis identified five attributes that most commonly described the essence of spirituality, including meaning, beliefs, connecting, self-transcendence, and value.
On Gaussian Beams Described by Jacobi's Equation
Smith, Steven Thomas
2013-01-01
Gaussian beams describe the amplitude and phase of rays and are widely used to model acoustic propagation. This paper describes four new results in the theory of Gaussian beams. (1) It is shown that the \\v{C}erven\\'y equations for the amplitude and phase are equivalent to the classical Jacobi Equation of differential geometry. The \\v{C}erven\\'y equations describe Gaussian beams using Hamilton-Jacobi theory, whereas the Jacobi Equation expresses how Gaussian and Riemannian curvature determine geodesic flow on a Riemannian manifold. Thus the paper makes a fundamental connection between Gaussian beams and an acoustic channel's so-called intrinsic Gaussian curvature from differential geometry. (2) A new formula $\\pi(c/c")^{1/2}$ for the distance between convergence zones is derived and applied to several well-known profiles. (3) A class of "model spaces" are introduced that connect the acoustics of ducting/divergence zones with the channel's Gaussian curvature $K=cc"-(c')^2$. The "model" SSPs yield constant Gauss...
Directory of Open Access Journals (Sweden)
Jeanne A. Teresi
2016-06-01
Full Text Available The articles in this two-part series of Psychological Test and Assessment Modeling describe the psychometric performance and measurement equivalence of the Patient Reported Outcomes Measurement Information System® (PROMIS® short form measures in ethnically, socio-demographically diverse groups of cancer patients. Measures in eight health-related quality of life domains were evaluated: fatigue, depression, anxiety, cognition, pain, sleep, and physical and social function. State-of-the-art latent variable methods, most based on item response theory, and described in two methods overview articles in this series were used to examine differential item functioning (DIF. Findings were generally supportive of the performance of the PROMIS measures. Although use of powerful methods and large samples resulted in the identification of many items with DIF, practi-cally none were identified with high magnitude. The aggregate level impact of DIF was small, and minimal individual impact was detected. Some methodological challenges were encountered in-volving positively and negatively worded items, but most were resolved through modest item removal. Sensitivity analyses showed minimal impact of model assumption violation on the results presented. A cautionary note is the observance of a few instances of individual-level impact of DIF in the analyses of depression, anxiety, and pain, and one instance of aggregate level impact just below threshold in the analyses of physical function. Although this sample of over 5,000 individuals was diverse, ethnically, a limitation was the lack of ability to examine language groups other than Spanish and English and specific ethnic subgroups within Hispanic, Asian/Pacific Islander, and Black subsamples. Extensive qualitative and quantitative analyses were performed in the development of PROMIS item banks. These sets of analyses, performed by several teams of psychometricians, statisticians, and qualitative experts, were the
Using fundamental equations to describe basic phenomena
DEFF Research Database (Denmark)
Jakobsen, Arne; Rasmussen, Bjarne D.
1999-01-01
constraining the total charge of refrigerant in the system, which is missing.In traditional mathematical modelling of a refrigeration cycle/system, the influence from the total charge of refrigerant on the system behaviour is normally not modelled explicitly. Instead, parameters such as superheat......When the fundamental thermodynamic balance equations (mass, energy, and momentum) are used to describe the processes in a simple refrigeration system, then one finds that the resulting equation system will have a degree of freedom equal to one. Further investigations reveal that it is the equation...... and the before mentioned parameters. In doing so, a systematic use of control volumes for modelling a refrigeration system is outlined....
Classification system to describe workpieces definitions
Macconnell, W R
2013-01-01
A Classification System to Describe Workpieces provides information pertinent to the fundamental aspects and principles of coding. This book discusses the various applications of the classification system of coding.Organized into three chapters, this book begins with an overview of the requirements of a system of classification pertaining adequately and equally to design, production, and work planning. This text then examines the purpose of the classification system in production to determine the most suitable means of machining a component. Other chapters consider the optimal utilization of m
Directory of Open Access Journals (Sweden)
Jeanne A. Teresi
2016-03-01
Full Text Available The purpose of this article is to introduce the methods used and challenges confronted by the authors of this two-part series of articles describing the results of analyses of measurement equivalence of the short form scales from the Patient Reported Outcomes Measurement Information System® (PROMIS®. Qualitative and quantitative approaches used to examine differential item functioning (DIF are reviewed briefly. Qualitative methods focused on generation of DIF hypotheses. The basic quantitative approaches used all rely on a latent variable model, and examine parameters either derived directly from item response theory (IRT or from structural equation models (SEM. A key methods focus of these articles is to describe state-of-the art approaches to examination of measurement equivalence in eight domains: physical health, pain, fatigue, sleep, depression, anxiety, cognition, and social function. These articles represent the first time that DIF has been examined systematically in the PROMIS short form measures, particularly among ethnically diverse groups. This is also the first set of analyses to examine the performance of PROMIS short forms in patients with cancer. Latent variable model state-of-the-art methods for examining measurement equivalence are introduced briefly in this paper to orient readers to the approaches adopted in this set of papers. Several methodological challenges underlying (DIF-free anchor item selection and model assumption violations are presented as a backdrop for the articles in this two-part series on measurement equivalence of PROMIS measures.
Is an eclipse described in the Odyssey?
Baikouzis, Constantino; Magnasco, Marcelo O
2008-07-01
Plutarch and Heraclitus believed a certain passage in the 20th book of the Odyssey ("Theoclymenus's prophecy") to be a poetic description of a total solar eclipse. In the late 1920s, Schoch and Neugebauer computed that the solar eclipse of 16 April 1178 B.C.E. was total over the Ionian Islands and was the only suitable eclipse in more than a century to agree with classical estimates of the decade-earlier sack of Troy around 1192-1184 B.C.E. However, much skepticism remains about whether the verses refer to this, or any, eclipse. To contribute to the issue independently of the disputed eclipse reference, we analyze other astronomical references in the Epic, without assuming the existence of an eclipse, and search for dates matching the astronomical phenomena we believe they describe. We use three overt astronomical references in the epic: to Boötes and the Pleiades, Venus, and the New Moon; we supplement them with a conjectural identification of Hermes's trip to Ogygia as relating to the motion of planet Mercury. Performing an exhaustive search of all possible dates in the span 1250-1115 B.C., we looked to match these phenomena in the order and manner that the text describes. In that period, a single date closely matches our references: 16 April 1178 B.C.E. We speculate that these references, plus the disputed eclipse reference, may refer to that specific eclipse.
Using neural networks to describe tracer correlations
Directory of Open Access Journals (Sweden)
D. J. Lary
2004-01-01
Full Text Available Neural networks are ideally suited to describe the spatial and temporal dependence of tracer-tracer correlations. The neural network performs well even in regions where the correlations are less compact and normally a family of correlation curves would be required. For example, the CH4-N2O correlation can be well described using a neural network trained with the latitude, pressure, time of year, and methane volume mixing ratio (v.m.r.. In this study a neural network using Quickprop learning and one hidden layer with eight nodes was able to reproduce the CH4-N2O correlation with a correlation coefficient between simulated and training values of 0.9995. Such an accurate representation of tracer-tracer correlations allows more use to be made of long-term datasets to constrain chemical models. Such as the dataset from the Halogen Occultation Experiment (HALOE which has continuously observed CH4 (but not N2O from 1991 till the present. The neural network Fortran code used is available for download.
On Redundancy in Describing Linguistic Systems
Directory of Open Access Journals (Sweden)
Vladimir Borissov Pericliev
2015-12-01
Full Text Available On Redundancy in Describing Linguistic Systems The notion of system of linguistic elements figures prominently in most post-Saussurian linguistics up to the present. A “system” is the network of the contrastive (or, distinctive features each element in the system bears to the remaining elements. The meaning (valeur of each element in the system is the set of features that are necessary and jointly sufficient to distinguish this element from all others. The paper addresses the problems of “redundancy”, i.e. the occurrence of features that are not strictly necessary in describing an element in a system. Redundancy is shown to smuggle into the description of linguistic systems, this infelicitous practice illustrated with some examples from the literature (e.g. the classical phonemic analysis of Russian by Cherry, Halle, and Jakobson, 1953. The logic and psychology of the occurrence of redundancy are briefly sketched and it is shown that, in addition to some other problems, redundancy leads to a huge and unresolvable ambiguity of descriptions of linguistic systems (the Buridan’s ass problem.
Stimulated recall interviews for describing pragmatic epistemology
Shubert, Christopher W.; Meredith, Dawn C.
2015-12-01
Students' epistemologies affect how and what they learn: do they believe physics is a list of equations, or a coherent and sensible description of the physical world? In order to study these epistemologies as part of curricular assessment, we adopt the resources framework, which posits that students have many productive epistemological resources that can be brought to bear as they learn physics. In previous studies, these epistemologies have been either inferred from behavior in learning contexts or probed through surveys or interviews outside of the learning context. We argue that stimulated recall interviews provide a contextually and interpretively valid method to access students' epistemologies that complement existing methods. We develop a stimulated recall interview methodology to assess a curricular intervention and find evidence that epistemological resources aptly describe student epistemologies.
A Semantic Approach to Describe Geospatial Resources
de Sousa, Sidney Roberto
Geographic information systems (GIS) are increasingly using geospatial data from the Web to produce geographic information. One big challenge is to find the relevant data, which often is based on keywords or even file names. However, these approaches lack semantics. Thus, it is necessary to provide mechanisms to prepare data to help retrieval of semantically relevant data. This paper proposes an approach to attack this problem. This approach is based on semantic annotations that use geographic metadata and ontologies to describe heterogeneous geospatial data. Semantic annotations are RDF/XML files that rely on a FGDC metadata schema, filled with appropriate ontology terms, and stored in a XML database. The proposal is illustrated by a case study of semantic annotations of agricultural resources, using domain ontologies.
Does Guru Granth Sahib describe depression?
Kalra, Gurvinder; Bhui, Kamaldeep; Bhugra, Dinesh
2013-01-01
Sikhism is a relatively young religion, with Guru Granth Sahib as its key religious text. This text describes emotions in everyday life, such as happiness, sadness, anger, hatred, and also more serious mental health issues such as depression and psychosis. There are references to the causation of these emotional disturbances and also ways to get out of them. We studied both the Gurumukhi version and the English translation of the Guru Granth Sahib to understand what it had to say about depression, its henomenology, and religious prescriptions for recovery. We discuss these descriptions in this paper and understand its meaning within the context of clinical depression. Such knowledge is important as explicit descriptions about depression and sadness can help encourage culturally appropriate assessment and treatment, as well as promote public health through education.
Using default inheritance to describe LTAG
Evans, R; Weir, D; Evans, Roger; Gazdar, Gerald; Weir, David
1995-01-01
We present the results of an investigation into how the set of elementary trees of a Lexicalized Tree Adjoining Grammar can be represented in the lexical knowledge representation language DATR (Evans & Gazdar 1989a,b). The LTAG under consideration is based on the one described in Abeille et al. (1990). Our approach is similar to that of Vijay-Shanker & Schabes (1992) in that we formulate an inheritance hierarchy that efficiently encodes the elementary trees. However, rather than creating a new representation formalism for this task, we employ techniques of established utility in other lexically-oriented frameworks. In particular, we show how DATR's default mechanism can be used to eliminate the need for a non-immediate dominance relation in the descriptions of the surface LTAG entries. This allows us to embed the tree structures in the feature theory in a manner reminiscent of HPSG subcategorisation frames, and hence express lexical rules as relations over feature structures.
Describing Ecosystem Complexity through Integrated Catchment Modeling
Shope, C. L.; Tenhunen, J. D.; Peiffer, S.
2011-12-01
Land use and climate change have been implicated in reduced ecosystem services (ie: high quality water yield, biodiversity, and agricultural yield. The prediction of ecosystem services expected under future land use decisions and changing climate conditions has become increasingly important. Complex policy and management decisions require the integration of physical, economic, and social data over several scales to assess effects on water resources and ecology. Field-based meteorology, hydrology, soil physics, plant production, solute and sediment transport, economic, and social behavior data were measured in a South Korean catchment. A variety of models are being used to simulate plot and field scale experiments within the catchment. Results from each of the local-scale models provide identification of sensitive, local-scale parameters which are then used as inputs into a large-scale watershed model. We used the spatially distributed SWAT model to synthesize the experimental field data throughout the catchment. The approach of our study was that the range in local-scale model parameter results can be used to define the sensitivity and uncertainty in the large-scale watershed model. Further, this example shows how research can be structured for scientific results describing complex ecosystems and landscapes where cross-disciplinary linkages benefit the end result. The field-based and modeling framework described is being used to develop scenarios to examine spatial and temporal changes in land use practices and climatic effects on water quantity, water quality, and sediment transport. Development of accurate modeling scenarios requires understanding the social relationship between individual and policy driven land management practices and the value of sustainable resources to all shareholders.
Describing and Enhancing Collaboration at the Computer
Directory of Open Access Journals (Sweden)
Ken Beatty
2002-06-01
Full Text Available Computer-based learning materials differ from classroom practice in that they seldom explicitly offer opportunities for collaboration. Despite this, students do collaborate, helping one another through the content and affordances of computer materials. But, in doing so, students meet with challenges. Paradoxically, these challenges can either inspire or discourage learning and second-language acquisition. This paper, based on research with twenty Hong Kong university students in a controlled experiment, evaluates challenges to collaboration at the computer as evidenced by discourse. The students were videotaped and their discourse transcribed and evaluated both qualitatively and quantitatively, according to a set of discourse markers created to describe collaborative, non-collaborative and ambiguous strategies. The paper begins by exploring the differences between collaboration and similar terms such as teamwork and cooperative learning then goes on to define collaboration in the context of computer-assisted learning. It ends by presenting practical suggestions for software designers, teachers and students to enhance collaboration at the computer.
Plans should abstractly describe intended behavior
Energy Technology Data Exchange (ETDEWEB)
Pfleger, K.; Hayes-Roth, B. [Stanford Univ., CA (United States)
1996-12-31
Planning is the process of formulating a potential course of action. How courses of action (plans) produced by a planning module are represented and how they are used by execution-oriented modules of a complex agent to influence or dictate behavior are critical architectural issues. In contrast to the traditional model of plans as executable programs that dictate precise behaviors, we claim that autonomous agents inhabiting dynamic, unpredictable environments can make better use of plans that only abstractly describe their intended behavior. Such plans only influence or constrain behavior, rather than dictating it. This idea has been discussed in a variety of contexts, but it is seldom incorporated into working complex agents. Experiments involving instantiations of our Adaptive Intelligent Systems architecture in a variety of domains have demonstrated the generality and usefulness of the approach, even with our currently simple plan representation and mechanisms for plan following. The behavioral benefits include (1) robust improvisation of goal-directed behavior in response to dynamic situations, (2) ready exploitation of dynamically acquired knowledge or behavioral capabilities, and (3) adaptation based on dynamic aspects of coordinating diverse behaviors to achieve multiple goals. In addition to these run-time advantages, the approach has useful implications for the design and configuration of agents. Indeed, the core ideas of the approach are natural extensions of fundamental ideas in software engineering.
Can the genetic code be mathematically described?
Gonzalez, Diego L
2004-04-01
From a mathematical point of view, the genetic code is a surjective mapping between the set of the 64 possible three-base codons and the set of 21 elements composed of the 20 amino acids plus the Stop signal. Redundancy and degeneracy therefore follow. In analogy with the genetic code, non-power integer-number representations are also surjective mappings between sets of different cardinality and, as such, also redundant. However, none of the non-power arithmetics studied so far nor other alternative redundant representations are able to match the actual degeneracy of the genetic code. In this paper we develop a slightly more general framework that leads to the following surprising results: i) the degeneracy of the genetic code is mathematically described, ii) a new symmetry is uncovered within this degeneracy, iii) by assigning a binary string to each of the codons, their classification into definite parity classes according to the corresponding sequence of bases is made possible. This last result is particularly appealing in connection with the fact that parity coding is the basis of the simplest strategies devised for error correction in man-made digital data transmission systems.
Directory of Open Access Journals (Sweden)
George O Agogo
Full Text Available In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.
Research on Estimates of Xi’an City Life Garbage Pay-As-You-Throw Based on Two-part Tariff method
Yaobo, Shi; Xinxin, Zhao; Fuli, Zheng
2017-05-01
Domestic waste whose pricing can’t be separated from the pricing of public economics category is quasi public goods. Based on Two-part Tariff method on urban public utilities, this paper designs the pricing model in order to match the charging method and estimates the standard of pay-as-you-throw using data of the past five years in Xi’an. Finally, this paper summarizes the main results and proposes corresponding policy recommendations.
基于二部制的价格歧视方法%Price Discrimination Method Based on Two-parts Tariff
Institute of Scientific and Technical Information of China (English)
彭云飞
2012-01-01
产品实施价格二部制的企业大量采用二级价格歧视、三级价格歧视方法外,还存在混合价格歧视.研究表明:企业收益最大化目标下实施这些价格歧视方法时,固定价格和从量价格的需求弹性、用户数、单位时间里的收益以及用户区间、资费区间分别需要满足不同的条件.这些结论为企业实施二部价格歧视提供了理论依据和决策参考.%Second-degree and third-degree price discriminaions are widely adopted in he product pricing. Research shows: under the constraints of income maximization, some con-ditions for the fixed fee of service packages and the demand elasticity of the quantity rate of bundled services, the number of users, the income per unit time, the users; and price's intervals should be meet in order to implement these price discrimination decision-making methods. These conclusions provide the theoretical and decision-making bases when the enterprises carry out two parts price discrimination
Directory of Open Access Journals (Sweden)
Bakhshandeh H
2011-07-01
% when measured in the 400–800 nm wavelength range. The plasma-treated PCL nanofibrous scaffold promoted limbal stem cell adhesion and proliferation within 10 days. These results confirmed that the polymeric artificial cornea showed suitable physical properties and good biocompatibility and epithelialization ability.Keywords: two part artificial cornea, nanofibers, electrospun, poly (ε-caprolactone, polyvinyl alcohol hydrogel, limbal stem cells
Sartorius, B; Sartorius, K; Aldous, C; Madiba, T E; Stefan, C; Noakes, T
2016-01-04
required. The final results of this two part systematic review (plus multiplicative calculations) will be published in a relevant international peer-reviewed journal. PROSPERO CRD42015023257. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Describing Earth System Simulations with the Metafor CIM
Directory of Open Access Journals (Sweden)
B. N. Lawrence
2012-06-01
Full Text Available The Metafor project has developed a Common Information Model (CIM using the ISO1900 series formalism to describe the sorts of numerical experiments carried out by the earth system modelling community, the models they use, and the simulations that result. Here we describe the mechanism by which the CIM was developed, and its key properties. We introduce the conceptual and application versions and the controlled vocabularies developed in the context of supporting the fifth Coupled Model Intercomparison Project (CMIP5. We describe how the CIM has been used in experiments to describe model coupling properties and describe the near term expected evolution of the CIM.
Describing Earth system simulations with the Metafor CIM
Lawrence, B. N.; Balaji, V.; Bentley, P.; Callaghan, S.; DeLuca, C.; Denvil, S.; Devine, G.; Elkington, M.; Ford, R. W.; Guilyardi, E.; Lautenschlager, M.; Morgan, M.; Moine, M.-P.; Murphy, S.; Pascoe, C.; Ramthun, H.; Slavin, P.; Steenman-Clark, L.; Toussaint, F.; Treshansky, A.; Valcke, S.
2012-11-01
The Metafor project has developed a common information model (CIM) using the ISO19100 series formalism to describe numerical experiments carried out by the Earth system modelling community, the models they use, and the simulations that result. Here we describe the mechanism by which the CIM was developed, and its key properties. We introduce the conceptual and application versions and the controlled vocabularies developed in the context of supporting the fifth Coupled Model Intercomparison Project (CMIP5). We describe how the CIM has been used in experiments to describe model coupling properties and describe the near term expected evolution of the CIM.
Describing Earth system simulations with the Metafor CIM
Directory of Open Access Journals (Sweden)
B. N. Lawrence
2012-11-01
Full Text Available The Metafor project has developed a common information model (CIM using the ISO19100 series formalism to describe numerical experiments carried out by the Earth system modelling community, the models they use, and the simulations that result. Here we describe the mechanism by which the CIM was developed, and its key properties. We introduce the conceptual and application versions and the controlled vocabularies developed in the context of supporting the fifth Coupled Model Intercomparison Project (CMIP5. We describe how the CIM has been used in experiments to describe model coupling properties and describe the near term expected evolution of the CIM.
Describing Service-Oriented Architecture by Extended Darwin
Institute of Scientific and Technical Information of China (English)
ZHANG Tao; SHEN Mei-e; YING Shi; YE Peng; LIANG Zao-qing
2005-01-01
Describing Service-Oriented Architecture (SOA) is critical in the development of Web-based system. In this paper, an approach for describing SOA by extended Darwin is proposed. The requirements for describing SOA, which are different from that of ordinary architecture, are highlighted firstly, and then a solution for extending Darwin is presented. Using the extended Darwin, service components and connectors can be described explicit by the extended construct, as well as precise operational semantics of SOA by the π-calculus. Finally an example of supply-chain management system is given for manifesting the effect of the extended Darwin.
Audio-Described Educational Materials: Ugandan Teachers' Experiences
Wormnaes, Siri; Sellaeg, Nina
2013-01-01
This article describes and discusses a qualitative, descriptive, and exploratory study of how 12 visually impaired teachers in Uganda experienced audio-described educational video material for teachers and student teachers. The study is based upon interviews with these teachers and observations while they were using the material either…
Type specimens of Pectinidae (Bivalvia) described by Ignaz von Born
Dijkstra, H.H.
2009-01-01
Born described in two publications (1778, 1780) the molluscs in the collection of Empress Maria Theresa (1717-1780), now in the Natural History Museum at Vienna. In this paper the Pectinidae type material is described. Ten new species were introduced of which Argopecten nucleus (Born, 1778) and Minn
Type specimens of Pectinidae (Bivalvia) described by Ignaz von Born
Dijkstra, H.H.
2009-01-01
Born described in two publications (1778, 1780) the molluscs in the collection of Empress Maria Theresa (1717-1780), now in the Natural History Museum at Vienna. In this paper the Pectinidae type material is described. Ten new species were introduced of which Argopecten nucleus (Born, 1778) and Minn
Controlling chaos in dynamical systems described by maps
Energy Technology Data Exchange (ETDEWEB)
Crispin, Y.; Marduel, C. [Embry-Riddle Aeronautical Univ., Daytona Beach, FL (United States)
1994-12-31
The problem of suppressing chaotic behavior in dynamical systems is treated using a feedback control method with limited control effort. The proposed method is validated on archetypal systems described by maps, i.e. discrete-time difference equations. The method is also applicable to dynamical systems described by flows, i.e. by systems of ordinary differential equations. Results are presented for the one-dimensional logistic map and for a two-dimensional Lotka-Volterra map describing predator-prey population dynamics. It is shown that chaos can be suppressed and the system stabilized about a period-1 fixed point of the maps.
Storyboard GALILEO CRUISE SCIENCE OPPORTUNITIES describes asteroid encounters
1989-01-01
Storyboard with mosaicked image of an asteroid and entitled GALILEO CRUISE SCIENCE OPPORTUNITIES describes asteroid objectives. These objectives include: first asteroid encounter; surface geology, composition size, shape, mass; and relation of primitive bodies to meteorites.
US Forest Service Survey parcels described by metes and bounds
US Forest Service, Department of Agriculture — A map service on the www depicting survey parcels described by a metes and bounds description. Examples include: land lots, housing subdivision lots, mineral...
On the Cauchy Problem Describing an Electron-Phonon Interaction
Institute of Scientific and Technical Information of China (English)
Jo(a)o-Paulo DIAS; Mário FIGUEIRA; Filipe OLIVEIRA
2011-01-01
In this paper, a model is derived to describe a quartic anharmonic interatomic interaction with an external potential involving a pair electron-phonon. The authors study the corresponding Cauchy Problem in the semilinear and quasilinear cases.
Digital data sets describing metropolitan areas in the conterminous US
U.S. Geological Survey, Department of the Interior — This data set describes metropolitan areas in the conterminous United States, developed from U.S. Bureau of the Census boundaries of Consolidated Metropolitan...
Zulma Ageitos de Castellanos: Publications and status of described taxa.
Signorelli, Javier H; Urteaga, Diego; Teso, Valeria
2015-10-28
Zulma Ageitos de Castellanos was an Argentinian malacologist working in the "Facultad de Ciencias Naturales y Museo" at La Plata University where she taught invertebrate zoology between 1947 and 1990. Her scientific publications are listed in chronological order. Described genus-group and species-group taxa are listed. Information about the type locality and type material, and taxonomic remarks are also provided. Finally, type material of all described taxa was requested and, when located, illustrated.
Model checking biological systems described using ambient calculus
DEFF Research Database (Denmark)
Mardare, Radu Iulian; Priami, Corrado; Qualia, Paola;
2005-01-01
Model checking biological systems described using ambient calculus. In Proc. of the second International Workshop on Computational Methods in Systems Biology (CMSB04), Lecture Notes in Bioinformatics 3082:85-103, Springer, 2005.......Model checking biological systems described using ambient calculus. In Proc. of the second International Workshop on Computational Methods in Systems Biology (CMSB04), Lecture Notes in Bioinformatics 3082:85-103, Springer, 2005....
Describing spatiotemporal couplings in ultrashort pulses using coupling coefficients
Institute of Scientific and Technical Information of China (English)
Zeng Shu-Guang; Dan You-Quan; Zhang Bin; Sun Nian-Chun; Sui Zhan
2011-01-01
Three coupling coefficients are defined to describe spatiotemporal coupling in ultrashort pulses.With these coupling coefficients,the first-order spatiotemporal couplings of Gaussian pulse and beam are described analytically.Also,the first-order and the second-order spatiotemporal couplings caused by angular dispersion elements are studied using these coupling coefficients.It can be shown that these coupling coefficients are dimensionless and normalized,and readily indicate the severity of spatiotemporal coupling.
Describing the Elephant: Framing a Discussion on Command and Control
2014-08-01
July–August 2014 Air & Space Power Journal | 17 From the Guest Editor Describing the Elephant Framing a Discussion on Command and Control Col Henry...DATE JUL 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Describing the Elephant: Framing a Discussion on...path ahead for better understanding and op- erational performance in this complex core function. To move down this path requires a common frame of
The Coriolis Effect Further Described in the Seventeenth Century
Graney, Christopher M
2016-01-01
Claude Francis Milliet Dechales described the Coriolis effect in his 1674 Cursus seu Mundus Mathematicus. Dechales discussed and illustrated the deflection of both falling bodies and of projectiles launched toward the poles that should occur on a rotating Earth. Interestingly, this was done as an argument against the Earth's rotation, the deflections not having been observed at the time. Dechales's work follows on that of Giovanni Battista Riccioli, who had also described the effect in his Almagestum Novum of 1651.
Linguistic terms describing different types of armour in Persian manuscripts
Directory of Open Access Journals (Sweden)
Moshtagh Khorasani, Manouchehr
2011-12-01
Full Text Available The present article investigates different terms describing armour and its diverse typology in Persian martial tradition taken from a selected number of 47 dated Persian manuscripts from the 10th to the 19th centuries C.E. Both human and animal armour used in battlefields are described.
El presente artículo describe, a partir de 47 manuscritos persas datados entre el siglo X y el siglo XIX d.C., los diversos términos que han designado las armaduras y sus diversas tipologías en la tradición marcial persa, tanto en lo que se refiere a armaduras para hombres como aquellas elaboradas para los animales de batalla.
Algorithm describing pressure distribution of non-contact TNT explosion
Directory of Open Access Journals (Sweden)
Radosław Kiciński
2014-12-01
Full Text Available [b]Abstract[/b]. The aim of this study is to develop a computational algorithm, describing the shock wave pressure distribution in the space induced by non-contact TNT explosion. The procedure describes pressure distribution on a damp surface of the hull. Simulations have been carried out using Abaqus/CAE. The study also shows the pressure waveform descriptions provided by various authors and presents them in charts. The formulated conclusions convince efficiency of the algorithm application.[b]Keywords:[/b] Underwater explosion, shock wave, CAE, TNT, Kobben class submarine
Dynamic modelling of pectin extraction describing yield and functional characteristics
DEFF Research Database (Denmark)
Andersen, Nina Marianne; Cognet, T.; Santacoloma, P. A.
2017-01-01
A dynamic model of pectin extraction is proposed that describes pectin yield, degree of esterification and intrinsic viscosity. The dynamic model is one dimensional in the peel geometry and includes mass transport of pectin by diffusion and reaction kinetics of hydrolysis, degradation and de-esterification....... The model takes into account the effects of the process conditions such as temperature and acid concentration on extraction kinetics. It is shown that the model describes pectin bulk solution concentration, degree of esterification and intrinsic viscosity in pilot scale extractions from lime peel...
Describing baseball pitch movement with right-hand rules.
Bahill, A Terry; Baldwin, David G
2007-07-01
The right-hand rules show the direction of the spin-induced deflection of baseball pitches: thus, they explain the movement of the fastball, curveball, slider and screwball. The direction of deflection is described by a pair of right-hand rules commonly used in science and engineering. Our new model for the magnitude of the lateral spin-induced deflection of the ball considers the orientation of the axis of rotation of the ball relative to the direction in which the ball is moving. This paper also describes how models based on somatic metaphors might provide variability in a pitcher's repertoire.
An autocatalytic kinetic model for describing microbial growth during fermentation.
Ibarz, Albert; Augusto, Pedro E D
2015-01-01
The mathematical modelling of the behaviour of microbial growth is widely desired in order to control, predict and design food and bioproduct processing, stability and safety. This work develops and proposes a new semi-empirical mathematical model, based on an autocatalytic kinetic, to describe the microbial growth through its biomass concentration. The proposed model was successfully validated using 15 microbial growth patterns, covering the three most important types of microorganisms in food and biotechnological processing (bacteria, yeasts and moulds). Its main advantages and limitations are discussed, as well as the interpretation of its parameters. It is shown that the new model can be used to describe the behaviour of microbial growth.
A Quark Transport Theory to describe Nucleon--Nucleon Collisions
Kalmbach, U; Biro, T S; Mosel, U
1993-01-01
On the basis of the Friedberg-Lee model we formulate a semiclassical transport theory to describe the phase-space evolution of nucleon-nucleon collisions on the quark level. The time evolution is given by a Vlasov-equation for the quark phase-space distribution and a Klein-Gordon equation for the mean-field describing the nucleon as a soliton bag. The Vlasov equation is solved numerically using an extended testparticle method. We test the confinement mechanism and mean-field effects in 1+1 dimensional simulations.
Newly Described Tumor Entities in Sinonasal Tract Pathology.
Bishop, Justin A
2016-03-01
Surgical pathology of the sinonasal tract (nasal cavity and paranasal sinuses) is extremely challenging due in part to the tremendous diversity of tumor types that may arise in this region. Compounding the difficulty, a number of new sinonasal tumor entities have been recently described, and pathologists may not yet be familiar with these neoplasms. This manuscript will review the clinicopathologic features of some of the newly described sinonasal tumor types: NUT midline carcinoma, HPV-related carcinoma with adenoid cystic-like features, SMARCB1 (INI-1) deficient sinonasal carcinoma, biphenotypic sinonasal sarcoma, and renal cell-like adenocarcinoma.
Describing dengue epidemics: Insights from simple mechanistic models
Aguiar, Maíra; Stollenwerk, Nico; Kooi, Bob W.
2012-09-01
We present a set of nested models to be applied to dengue fever epidemiology. We perform a qualitative study in order to show how much complexity we really need to add into epidemiological models to be able to describe the fluctuations observed in empirical dengue hemorrhagic fever incidence data offering a promising perspective on inference of parameter values from dengue case notifications.
Superintendents Describe Their Leadership Styles: Implications for Practice
Bird, James J.; Wang, Chuang
2013-01-01
Superintendents from eight southeastern United States school districts self-described their leadership styles across the choices of autocratic, laissez-faire, democratic, situational, servant, or transformational. When faced with this array of choices, the superintendents chose with arguable equitableness, indicating that successful leaders can…
Comparing Theoretical Perspectives in Describing Mathematics Departments: Complexity and Activity
Beswick, Kim; Watson, Anne; De Geest, Els
2010-01-01
We draw on two studies of mathematics departments in 11-18 comprehensive maintained schools in England to compare and contrast the insights provided by differing theoretical perspectives. In one study, activity theory was used to describe common features of the work of three departments. In the other, a mathematics department was viewed and…
Describing Elementary Certification Methods across the Elementary Music Career Cycle
Svec, Christina L.
2017-01-01
The purpose of the study was to describe elementary music method choice and certification method choice overall and across the elementary music career cycle. Participants (N = 254) were categorized as Level I or Elementary Division in a southwestern music education association database. The questionnaire included 25 four-point Likert-type items…
Icosahedral symmetry described by an incommensurately modulated crystal structure model
DEFF Research Database (Denmark)
Wolny, Janusz; Lebech, Bente
1986-01-01
A crystal structure model of an incommensurately modulated structure is presented. Although six different reciprocal vectors are used to describe the model, all calculations are done in three dimensions making calculation of the real-space structure trivial. Using this model, it is shown that both...
Describing, Instantiating and Evaluating a Reference Architecture : A Case Study
Avgeriou, Paris
2003-01-01
The result of a domain maturing is the emergence of reference architectures that offer numerous advantages to software architects and other stakeholders. However there is no straightforward way to describe a reference architecture and in sequence to design instances for specific systems, while at th
The Tortricidae described by J. C. Fabricius (Lepidoptera)
DEFF Research Database (Denmark)
Baixeras, Joaquin; Karsholt, Ole
2011-01-01
The identity and nomenclature of the 88 species of Tortricidae (Lepidoptera) described by J. C. Fabricius are reviewed. Type material deposited in the Natural History Museum Denmark is illustrated. Lectotypes for Tinea compositella (Fabricius, 1775), Pyralis rivellana (Fabricius, 1775) and P...
Digital data set describing surficial geology in the conterminous US
U.S. Geological Survey, Department of the Interior — This digital data set describes surficial geology of the conterminous United States. The data set was generated from a U.S. Geological Survey 1:7,500,000-scale map...
Describing the Corneal Shape after Wavefront-Optimized Photorefractive Keratectomy
de Jong, Tim; Wijdh, Robert H. J.; Koopmans, Steven A.; Jansonius, Nomdo M.
2014-01-01
PURPOSE: To develop a procedure for describing wavefront-optimized photorefractive keratectomy (PRK) corneas and to characterize PRK-induced changes in shape. METHODS: We analyzed preoperative and postoperative corneal elevation data of 41 eyes of 41 patients (mean [±SD] age, 38 [±11] years) who und
An Evolving Framework for Describing Student Engagement in Classroom Activities
Azevedo, Flavio S.; diSessa, Andrea A.; Sherin, Bruce L.
2012-01-01
Student engagement in classroom activities is usually described as a function of factors such as human needs, affect, intention, motivation, interests, identity, and others. We take a different approach and develop a framework that models classroom engagement as a function of students' "conceptual competence" in the "specific content" (e.g., the…
Avicenna, the first to describe thyroid-related orbitopathy.
Nabipour, Iraj; Burger, Albert; Moharreri, Muhammad-Reza; Azizi, Fereidoun
2009-01-01
The history of the association of goiter and orbital disease is discussed. Although Graves and Basedow are credited with the first descriptions of this association, it was described many years earlier between AD 1000 and 1110 by two Persian physicians and philosophers, Avicenna and Al-Jurjani.
Interpersonal Problems of People Who Describe Themselves as Lonely.
French, Rita de Sales; Horowitz, Leonard M.
1979-01-01
The complaint "I am lonely" summarizes specific interpersonal difficulties in socializing. The UCLA Loneliness Scale identifies lonely and not-lonely students who described their major interpersonal problems by performing a Q-sort with a standardized set of problems. Results show that lonely people consistently report problems of…
Collective learning in schools described: building collective learning capacity
Verbiest, Eric; Teurlings, C.; Ansems, E.; Bakx, A.; Grootswagers, A.; Heijmen-Versteegen,; Jongen,; Uphoff,
2005-01-01
Processes of collective learning are expected to increase the professionalism of teachers and school leaders. Little is known about the processes of collective learning which take place in schools and about the way in which those processes may be improved. This paper describes a research into proces
A Framework for Describing Variations in State Early Intervention Systems.
Spiker, Donna; Hebbeler, Kathleen; Wagner, Mary; Cameto, Renee; McKenna, Patti
2000-01-01
Information about the early intervention service systems in 20 states was gathered and organized into dimensions of a framework for describing early intervention systems at the state and local levels. Results indicate considerable variation exists on eligibility criteria, agencies involved in early intervention, and models of intake and service…
A visual metaphor describing neural dynamics in schizophrenia.
Directory of Open Access Journals (Sweden)
Nico J M van Beveren
Full Text Available BACKGROUND: In many scientific disciplines the use of a metaphor as an heuristic aid is not uncommon. A well known example in somatic medicine is the 'defense army metaphor' used to characterize the immune system. In fact, probably a large part of the everyday work of doctors consists of 'translating' scientific and clinical information (i.e. causes of disease, percentage of success versus risk of side-effects into information tailored to the needs and capacities of the individual patient. The ability to do so in an effective way is at least partly what makes a clinician a good communicator. Schizophrenia is a severe psychiatric disorder which affects approximately 1% of the population. Over the last two decades a large amount of molecular-biological, imaging and genetic data have been accumulated regarding the biological underpinnings of schizophrenia. However, it remains difficult to understand how the characteristic symptoms of schizophrenia such as hallucinations and delusions are related to disturbances on the molecular-biological level. In general, psychiatry seems to lack a conceptual framework with sufficient explanatory power to link the mental- and molecular-biological domains. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present an essay-like study in which we propose to use visualized concepts stemming from the theory on dynamical complex systems as a 'visual metaphor' to bridge the mental- and molecular-biological domains in schizophrenia. We first describe a computer model of neural information processing; we show how the information processing in this model can be visualized, using concepts from the theory on complex systems. We then describe two computer models which have been used to investigate the primary theory on schizophrenia, the neurodevelopmental model, and show how disturbed information processing in these two computer models can be presented in terms of the visual metaphor previously described. Finally, we describe the
New models for describing outliers in meta-analysis.
Baker, Rose; Jackson, Dan
2016-09-01
An unobserved random effect is often used to describe the between-study variation that is apparent in meta-analysis datasets. A normally distributed random effect is conventionally used for this purpose. When outliers or other unusual estimates are included in the analysis, the use of alternative random effect distributions has previously been proposed. Instead of adopting the usual hierarchical approach to modelling between-study variation, and so directly modelling the study specific true underling effects, we propose two new marginal distributions for modelling heterogeneous datasets. These two distributions are suggested because numerical integration is not needed to evaluate the likelihood. This makes the computation required when fitting our models much more robust. The properties of the new distributions are described, and the methodology is exemplified by fitting models to four datasets. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.
Galactic Rotation Described with Bulge+Disk Gravitational Models
Gallo, C F
2008-01-01
Observations reveal that mature spiral galaxies consist of stars, gases and plasma approximately distributed in a thin disk of circular shape, usually with a central bulge. The rotation velocities quickly increase from the galactic center and then achieve a constant velocity from the core to the periphery. The basic dynamic behavior of a mature spiral galaxy, such as the Milky Way, is well described by simple models balancing Newtonian gravitational forces against the centrifugal forces associated with a rotating thin axisymmetric disk. In this research, we investigate the effects of adding central bulges to thin disk gravitational models. Even with the addition of substantial central bulges, all the critical essential features of our thin disk gravitational models are preserved. (1) Balancing Newtonian gravitational and centrifugal forces at every point within the disk yields computed radial mass distributions that describe the measured rotation velocity profiles of mature spiral galaxies successfully. (2) T...
Oculoectodermal syndrome: twentieth described case with new manifestations*
Figueiras, Daniela de Almeida; Leal, Deborah Maria de Castro Barbosa; Kozmhinsky, Valter; Querino, Marina Coutinho Domingues; Regueira, Marina Genesia da Silva; Studart, Maria Gabriela de Morais
2016-01-01
Oculoectodermal syndrome is a rare disease characterized by the association of aplasia cutis congenita, epibulbar dermoids, and other abnormalities. This report describes the twentieth case of the disease. We report a 4-year-old female child who presented with the classical features of the syndrome: aplasia cutis congenita and epibulbar dermoids. Our case expands the clinical spectrum of the disease to include: diffuse hyperpigmentation (some following the Blaschko´s lines); hypopigmented skin areas on the trunk; arachnoid cyst on the right fronto-parietal border; rounded left side of the hippocampus; and dermoid cyst underlying the bulb-medullary transition. Our patient also reported infantile hemangioma on the right wrist and verrucous hemangioma on the left leg, the latter not previously described in the literature.
A six-parameter space to describe galaxy diversification
Fraix-Burnet, Didier; Chattopadhyay, Asis Kumar; Davoust, Emmanuel; Thuillard, Marc
2012-01-01
Galaxy diversification proceeds by transforming events like accretion, interaction or mergers. These explain the formation and evolution of galaxies that can now be described with many observables. Multivariate analyses are the obvious tools to tackle the datasets and understand the differences between different kinds of objects. However, depending on the method used, redundancies, incompatibilities or subjective choices of the parameters can void the usefulness of such analyses. The behaviour of the available parameters should be analysed before an objective reduction of dimensionality and subsequent clustering analyses can be undertaken, especially in an evolutionary context. We study a sample of 424 early-type galaxies described by 25 parameters, ten of which are Lick indices, to identify the most structuring parameters and determine an evolutionary classification of these objects. Four independent statistical methods are used to investigate the discriminant properties of the observables and the partitioni...
Statistical models describing the energy signature of buildings
DEFF Research Database (Denmark)
Bacher, Peder; Madsen, Henrik; Thavlov, Anders
2010-01-01
Approximately one third of the primary energy production in Denmark is used for heating in buildings. Therefore efforts to accurately describe and improve energy performance of the building mass are very important. For this purpose statistical models describing the energy signature of a building, i.......e. the heat dynamics of the building, have been developed. The models can be used to obtain rather detailed knowledge of the energy performance of the building and to optimize the control of the energy consumption for heating, which will be vital in conditions with increasing fluctuation of the energy supply...... or varying energy prices. The paper will give an overview of statistical methods and applied models based on experiments carried out in FlexHouse, which is an experimental building in SYSLAB, Risø DTU. The models are of different complexity and can provide estimates of physical quantities such as UA...
Double sigmoidal models describing the growth of coffee berries
Directory of Open Access Journals (Sweden)
Tales Jesus Fernandes
Full Text Available ABSTRACT: This study aimed to verify if the growth pattern of coffee berries, considering fresh mass accumulation over time, is double sigmoid and to select the most suitable nonlinear model to describe such behavior. Data used consisted of fourteen longitudinal observations of average fresh mass of coffee berries obtained in an experiment with the cultivar Obatã IAC 1669-20. The fits provided by the Logistic and Gompertz models were compared in their single and double versions. Parameters were estimated using the least squares method using the Gauss-Newton algorithm implemented in the nls function of the R software. It can be concluded that the growth pattern of the coffee fruit, in fresh mass accumulation, is double sigmoid. The double Gompertz and double Logistic models were adequate to describe such a growth curve, with a superiority of the double Logistic model.
Which number system is "best" for describing empirical reality?
Visser, Matt
2013-01-01
Eugene Wigner's much discussed notion of the "unreasonable effectiveness of mathematics" in describing the physics of empirical reality is simultaneously both trivial and profound. After all, the relevant mathematics was, (in the first instance), originally developed in order to be useful in describing empirical reality. On the other hand, certain aspects of the mathematical superstructure have now taken on a life of their own, with at least some features of the mathematical superstructure greatly exceeding anything that can be directly probed or verified, or even justified, by empirical experiment. Specifically, I wish to raise the possibility that the real number system, (with its nevertheless pragmatically very useful tools of real analysis, and mathematically rigorous notions of differentiation and integration), may nevertheless constitute a "wrong turn" when it comes to modelling empirical reality. Without making any definitive recommendation, I shall discuss several alternatives.
Curie law for systems described by kappa distributions
Livadiotis, George
2016-01-01
We derive the magnetization of a system, Pierre Curie's law, for paramagnetic particles out of thermal equilibrium described by kappa distributions. The analysis uses the theory and formulation of the kappa distributions that describe particle systems with a non-zero potential energy. Among other results, emphasis is placed on the effect of kappa distribution on the phenomenon of having strong magnetization at high temperatures. At thermal equilibrium, high temperature leads to weak magnetization. Out of thermal equilibrium, however, strong magnetization at high temperatures is rather possible, if the paramagnetic particle systems reside far from thermal equilibrium, i.e., at small values of kappa. The application of the theory to the space plasma at the outer boundaries of our heliosphere, the inner heliosheath, leads to an estimation of the ion magnetic moment for this space plasma, that is, μ ≈ 138+/-7 \\text{eV/nT} .
A geostatistical approach for describing spatial pattern in stream networks
Ganio, L.M.; Torgersen, C.E.; Gresswell, R.E.
2005-01-01
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other hand, data collected in the network may be spatially autocorrelated and thus not suitable for traditional statistical analyses. Here we provide a method that uses commercially available software to construct an empirical variogram to describe spatial pattern in the relative abundance of coastal cutthroat trout in headwater stream networks. We describe the mathematical and practical considerations involved in calculating a variogram using a non-Euclidean distance metric to incorporate the network pathway structure in the analysis of spatial variability, and use a non-parametric technique to ascertain if the pattern in the empirical variogram is non-random.
Describing spatial pattern in stream networks: A practical approach
Ganio, L.M.; Torgersen, C.E.; Gresswell, R.E.
2005-01-01
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other hand, data collected in the network may be spatially autocorrelated and thus not suitable for traditional statistical analyses. Here we provide a method that uses commercially available software to construct an empirical variogram to describe spatial pattern in the relative abundance of coastal cutthroat trout in headwater stream networks. We describe the mathematical and practical considerations involved in calculating a variogram using a non-Euclidean distance metric to incorporate the network pathway structure in the analysis of spatial variability, and use a non-parametric technique to ascertain if the pattern in the empirical variogram is non-random.
The first fossil cephalopod statoliths to be described from Europe
Clarke, M. R.; MADDOCK, LINDA; Steurbaut, E.
1980-01-01
Statoliths of cephalopods are small, hard calcareous stones which lie within the cartilaginous skulls of octopods, sepioids and teuthoids1. Fossil statoliths, clearly belonging to genera which are alive today, have previously been described from 11 Cenozoic deposits spanning from the Eocene to the Pleistocene in North America2–5. Such statoliths are of particular interest because they provide a means of studying the evolution of living cephalopod groups which have no calcareous shells, includ...
New model describing the dynamical behaviour of penetration rates
Tashiro, Tohru; Minagawa, Hiroe; Chiba, Michiko
2013-02-01
We propose a hierarchical logistic equation as a model to describe the dynamical behaviour of a penetration rate of a prevalent stuff. In this model, a memory, how many people who already possess it a person who does not process it yet met, is considered, which does not exist in the logistic model. As an application, we apply this model to iPod sales data, and find that this model can approximate the data much better than the logistic equation.
The scentscape: An integrative framework describing scents in servicescapes
Girard, Marc; Girard, Anna; Suppin, Anna-Caroline; Bartsch, Silke
2016-01-01
The systematic use of ambient scents is a trend in service companies that is accompanied by increasing research attention. However, we lack a theoretical framework that ad-dresses ambient scents' specific role in physical surroundings of services. Thus, this article develops the 'scentscape', a model that describes the process of olfactory stimulation and its impacts on customers and employees in service environments. The paper extends Bitner's servicescape model (1992) and combines it with G...
On the problems of describing joint axis alignment.
Ball, Kevin A; Greiner, Thomas M
2008-01-01
Each three-dimensional joint possesses at least one potentially oblique axis of rotation. Several systems are used to express joint axis alignment. One system, designated the plane projection (PP) method, describes angles based on orthogonal projections onto two, of the three, anatomical planes. Alternatively, a joint axis may be described in two different ways using two sequential Cardan angle rotations. These expression systems all lay claim to similar descriptive labels, such as deviation and elevation. Difficulties arise as researchers use these various methods to compare their own data to the results of others. A joint axis alignment, described as 27 degrees deviation and 41 degrees elevation in PP, differs by as much as 6 degrees when expressed as Cardan angles. Differences among expression systems increase as the joint axis alignment becomes more oblique -- eventually differing by as much as 75 degrees . This paper explores implications for this lack of congruence among the joint axis expression systems. Effective steps in dealing with these issues begin with recognizing the existence and extent of the problem. The paper provides a common set of algorithms to illustrate and alleviate the possible problems associated with the exchange of joint axis alignment data.
On Differential Equations Describing 3-Dimensional Hyperbolic Spaces
Institute of Scientific and Technical Information of China (English)
WU Jun-Yi; DING Qing; Keti Tenenblat
2006-01-01
In this paper, we introduce the notion of a (2+1)-dimensional differential equation describing threedimensional hyperbolic spaces (3-h.s.). The (2+1)-dimensional coupled nonlinear Schrodinger equation and its sister equation, the (2+1)-dimensional coupled derivative nonlinear Schrodinger equation, are shown to describe 3-h.s. The (2+1)-dimensional generalized HF model: St = (1/2i [S, Sy] + 2iσS)x, σx = 1-4itr(SSxSy), in which S ∈ GLC(2)/GLC(1)×GLC(1),provides another example of (2+1)-dimensional differential equations describing 3-h.s. As a direct consequence, the geometric construction of an infinite number of conservation laws of such equations is illustrated. Furthermore we display a new infinite number of conservation laws of the (2+1)-dimensional nonlinear Schrodinger equation and the (2+1)odimensional derivative nonlinear Schrodinger equation by a geometric way.
HERMES: A Model to Describe Deformation, Burning, Explosion, and Detonation
Energy Technology Data Exchange (ETDEWEB)
Reaugh, J E
2011-11-22
HERMES (High Explosive Response to MEchanical Stimulus) was developed to fill the need for a model to describe an explosive response of the type described as BVR (Burn to Violent Response) or HEVR (High Explosive Violent Response). Characteristically this response leaves a substantial amount of explosive unconsumed, the time to reaction is long, and the peak pressure developed is low. In contrast, detonations characteristically consume all explosive present, the time to reaction is short, and peak pressures are high. However, most of the previous models to describe explosive response were models for detonation. The earliest models to describe the response of explosives to mechanical stimulus in computer simulations were applied to intentional detonation (performance) of nearly ideal explosives. In this case, an ideal explosive is one with a vanishingly small reaction zone. A detonation is supersonic with respect to the undetonated explosive (reactant). The reactant cannot respond to the pressure of the detonation before the detonation front arrives, so the precise compressibility of the reactant does not matter. Further, the mesh sizes that were practical for the computer resources then available were large with respect to the reaction zone. As a result, methods then used to model detonations, known as {beta}-burn or program burn, were not intended to resolve the structure of the reaction zone. Instead, these methods spread the detonation front over a few finite-difference zones, in the same spirit that artificial viscosity is used to spread the shock front in inert materials over a few finite-difference zones. These methods are still widely used when the structure of the reaction zone and the build-up to detonation are unimportant. Later detonation models resolved the reaction zone. These models were applied both to performance, particularly as it is affected by the size of the charge, and to situations in which the stimulus was less than that needed for reliable
HERMES: A Model to Describe Deformation, Burning, Explosion, and Detonation
Energy Technology Data Exchange (ETDEWEB)
Reaugh, J E
2011-11-22
HERMES (High Explosive Response to MEchanical Stimulus) was developed to fill the need for a model to describe an explosive response of the type described as BVR (Burn to Violent Response) or HEVR (High Explosive Violent Response). Characteristically this response leaves a substantial amount of explosive unconsumed, the time to reaction is long, and the peak pressure developed is low. In contrast, detonations characteristically consume all explosive present, the time to reaction is short, and peak pressures are high. However, most of the previous models to describe explosive response were models for detonation. The earliest models to describe the response of explosives to mechanical stimulus in computer simulations were applied to intentional detonation (performance) of nearly ideal explosives. In this case, an ideal explosive is one with a vanishingly small reaction zone. A detonation is supersonic with respect to the undetonated explosive (reactant). The reactant cannot respond to the pressure of the detonation before the detonation front arrives, so the precise compressibility of the reactant does not matter. Further, the mesh sizes that were practical for the computer resources then available were large with respect to the reaction zone. As a result, methods then used to model detonations, known as {beta}-burn or program burn, were not intended to resolve the structure of the reaction zone. Instead, these methods spread the detonation front over a few finite-difference zones, in the same spirit that artificial viscosity is used to spread the shock front in inert materials over a few finite-difference zones. These methods are still widely used when the structure of the reaction zone and the build-up to detonation are unimportant. Later detonation models resolved the reaction zone. These models were applied both to performance, particularly as it is affected by the size of the charge, and to situations in which the stimulus was less than that needed for reliable
A proposal to describe a phenomenon of expanding language
Swietorzecka, Kordula
Changes of knowledge, convictions or beliefs are subjects of interest in frame of so called epistemic logic. There are various proposed descriptions of a process (or its results) in which so a called agent may invent certain changes in a set of sentences that he had already chosen as a point of his knowledge, convictions or beliefs (and this is also considered in case of many agents). In the presented paper we are interested in the changeability of an agent's language which is by its own independent from already mentioned changes. Modern epistemic formalizations assume that the agent uses a fixed (and so we could say: static) language in which he expresses his various opinions which may change. Our interest is to simulate a situation when a language is extended by adding to it new expressions which were not known by the agent so he couldn't even consider them as subjects of his opinions. Actually such a phenomenon happens both in natural and scientific languages. Let us mention a fact of expanding languages in process of learning or in result of getting of new data about some described domain. We propose a simple idealization of extending sentential language used by one agent. Actually the language is treated as a family of so called n-languages which get some epistemic interpretation. Proposed semantics enables us to distinguish between two different types of changes - these which occur because of changing agent's convictions about logical values of some n-sentences - we describe them using one place operator C to be read it changes that - and changes that consist in increasing the level of n-language by adding to it new expressions. However the second type of change - symbolized by variable G - may be also considered independently of the first one. The logical frame of our considerations comes from and it was originally used to describe Aristotelian theory of substantial changes. This time we apply the mentioned logic in epistemology.
Two heuristic approaches to describe periodicities in genomic microarrays
Directory of Open Access Journals (Sweden)
Jörg Aßmus
2009-09-01
Full Text Available In the first part we discuss the filtering of panels of time series based on singular value decomposition. The discussion is based on an approach where this filtering is used to normalize microarray data. We point out effects on the periodicity and phases for time series panels. In the second part we investigate time dependent periodic panels with different phases. We align the time series in the panel and discuss the periodogram of the aligned time series with the purpose of describing the periodic structure of the panel. The method is quite powerful assuming known phases in the model, but it deteriorates rapidly for noisy data.
Analysis of a mathematical model describing necrotic tumor growth
Escher, Joachim; Matioc, Bogdan-Vasile
2010-01-01
In this paper we study a model describing the growth of necrotic tumors in different regimes of vascularisation. The tumor consists of a necrotic core of death cells and a surrounding nonnecrotic shell. The corresponding mathematical formulation is a moving boundary problem where both boundaries delimiting the nonnecrotic shell are allowed to evolve in time.We determine all radially symmetric stationary solutions of the problem and reduce the moving boundary problem into a nonlinear evolution. Parabolic theory provides us the perfect context in order to show local well-posed of the problem for small initial data.
Extended nonlinear feedback model for describing episodes of high inflation
Szybisz, M A; Szybisz, L.
2016-01-01
An extension of the nonlinear feedback (NLF) formalism to describe regimes of hyper- and high-inflation in economy is proposed in the present work. In the NLF model the consumer price index (CPI) exhibits a finite time singularity of the type $1/(t_c -t)^{(1- \\beta)/\\beta}$, with $\\beta>0$, predicting a blow up of the economy at a critical time $t_c$. However, this model fails in determining $t_c$ in the case of weak hyperinflation regimes like, e.g., that occurred in Israel. To overcome this...
Can all neurobiological processes be described by classical physics?
Lisewski, A M
1999-01-01
We discuss results recently given in an article by M. Tegmark (quant-ph/9907009) where he argues that neurons can be described appropriately by pure classical physics. This letter is dedicated to the question if this is really the case when the role of dissipation and noise -- the two concurrent phenomena present in these biological structures -- is taken into account. We argue that dissipation and noise might well be of quantum origin and give also a possible reason why neural dynamics is not classical.
[Health consequences of smoking electronic cigarettes are poorly described].
Tøttenborg, Sandra Søgaard; Holm, Astrid Ledgaard; Wibholm, Niels Christoffer; Lange, Peter
2014-09-01
Despite increasing popularity, health consequences of vaping (smoking electronic cigarettes, e-cigarettes) are poorly described. Few studies suggest that vaping has less deleterious effects on lung function than smoking conventional cigarettes. One large study found that e-cigarettes were as efficient as nicotine patches in smoking cessation. The long-term consequences of vaping are however unknown and while some experts are open towards e-cigarettes as a safer way of satisfying nicotine addiction, others worry that vaping in addition to presenting a health hazard may lead to an increased number of smokers of conventional cigarettes.
Quadrupolar gravitational fields described by the $q-$metric
Quevedo, Hernando; Yerlan, Aimuratov
2013-01-01
We investigate the Zipoy-Voorhees metric ($q-$metric) as the simplest static, axially symmetric solution of Einstein's vacuum field equations that possesses as independent parameters the mass and the quadrupole moment. In accordance with the black holes uniqueness theorems, the presence of the quadrupole completely changes the geometric properties of the corresponding spacetime that turns out to contain naked singularities for all possible values of the quadrupole parameter. The naked singularities, however, can be covered by interior solutions that correspond to perfect fluid sources with no specific equations of state. We conclude that the $q-$metric can be used to describe the entire spacetime generated by static deformed compact objects.
Spectral Gaps of Dirac Operators Describing Graphene Quantum Dots
Benguria, Rafael D.; Fournais, Søren; Stockmeyer, Edgardo; Van Den Bosch, Hanne
2017-06-01
The two-dimensional Dirac operator describes low-energy excitations in graphene. Different choices for the boundary conditions give rise to qualitative differences in the spectrum of the resulting operator. For a family of boundary conditions, we find a lower bound to the spectral gap around zero, proportional to |Ω|-1/2, where {Ω } \\subset R2 is the bounded region where the Dirac operator acts. This family contains the so-called infinite mass and armchair cases used in the physics literature for the description of graphene quantum dots.
Failure of random matrix theory to correctly describe quantum dynamics.
Kottos, T; Cohen, D
2001-12-01
Consider a classically chaotic system that is described by a Hamiltonian H(0). At t=0 the Hamiltonian undergoes a sudden change (H)0-->H. We consider the quantum-mechanical spreading of the evolving energy distribution, and argue that it cannot be analyzed using a conventional random-matrix theory (RMT) approach. Conventional RMT can be trusted only to the extent that it gives trivial results that are implied by first-order perturbation theory. Nonperturbative effects are sensitive to the underlying classical dynamics, and therefore the Planck's over 2 pi-->0 behavior for effective RMT models is strikingly different from the correct semiclassical limit.
Can CA describe collective effects of polluting agents?
Troisi, A.
2015-03-01
Pollution represents one of the most relevant issues of our time. Several studies are on stage but, generally, they do not consider competitive effects, paying attention only to specific agents and their impact. In this paper, it is suggested a different scheme. At first, it is proposed a formal model of competitive noxious effects. Second, by generalizing a previous algorithm capable of describing urban growth, it is developed a cellular automata (CA) model that provides the effective impact of a variety of pollutants. The final achievement is a simulation tool that can model pollution combined effects and their dynamical evolution in relation to anthropized environments.
Theory of control systems described by differential inclusions
Han, Zhengzhi; Huang, Jun
2016-01-01
This book provides a brief introduction to the theory of finite dimensional differential inclusions, and deals in depth with control of three kinds of differential inclusion systems. The authors introduce the algebraic decomposition of convex processes, the stabilization of polytopic systems, and observations of Luré systems. They also introduce the elemental theory of finite dimensional differential inclusions, and the properties and designs of the control systems described by differential inclusions. Addressing the material with clarity and simplicity, the book includes recent research achievements and spans all concepts, concluding with a critical mathematical framework. This book is intended for researchers, teachers and postgraduate students in the area of automatic control engineering.
Ruin Probabilities of a Surplus Process Described by PDMPs
Institute of Scientific and Technical Information of China (English)
Jing-min He; Rong Wu; Hua-yue Zhang
2008-01-01
In this paper we mainly study the ruin probability of a surplus process described by a piecewise deterministic Markov process (PDMP). An integro-differentiai equation for the ruin probability is derived. Under a certain assumption, it can be transformed into the ruin probability of a risk process whose premiums depend on the current reserves. Using the same argument as that in Asmussen and Nielsen[2], the ruin probability and its upper bounds are obtained. Finally, we give an analytic expression for ruin probability and its upper bounds when the claim-size is exponentially distributed.
Describing fuzzy sets using a new concept:fuzzify functor
Institute of Scientific and Technical Information of China (English)
魏克新; 王兆霞; 王权
2009-01-01
This paper proposed a fuzzify functor as an extension of the concept of fuzzy sets.The fuzzify functor and the first-order operated fuzzy set are defined.From the theory analysis,it can be observed that when the fuzzify functor acts on a simple crisp set,we get the first order fuzzy set or type-1 fuzzy set.By operating the fuzzify functor on fuzzy sets,we get the higher order fuzzy sets or higher type fuzzy sets and their membership functions.Using the fuzzify functor we can exactly describe the type-1 fuzz...
Using UMLS metathesaurus concepts to describe medical images: dermatology vocabulary.
Woods, James W; Sneiderman, Charles A; Hameed, Kamran; Ackerman, Michael J; Hatton, Charlie
2006-01-01
Web servers at the National Library of Medicine (NLM) displayed images of ten skin lesions to practicing dermatologists and provided an online form for capturing text they used to describe the pictures. The terms were submitted to the UMLS Metathesaurus (Meta). Concepts retrieved, their semantic types, definitions and synonyms, were returned to each subject in a second web-based form. Subjects rated the concepts against their own descriptive terms. They submitted 825 terms, 346 of which were unique and 300 mapped to UMLS concepts. The dermatologists rated 295 concepts as 'Exact Match' and they accomplished both tasks in about 30 min.
In their own words: describing Canadian physician leadership.
Snell, Anita J; Dickson, Graham; Wirtzfeld, Debrah; Van Aerde, John
2016-07-04
Purpose This is the first study to compile statistical data to describe the functions and responsibilities of physicians in formal and informal leadership roles in the Canadian health system. This mixed-methods research study offers baseline data relative to this purpose, and also describes physician leaders' views on fundamental aspects of their leadership responsibility. Design/methodology/approach A survey with both quantitative and qualitative fields yielded 689 valid responses from physician leaders. Data from the survey were utilized in the development of a semi-structured interview guide; 15 physician leaders were interviewed. Findings A profile of Canadian physician leadership has been compiled, including demographics; an outline of roles, responsibilities, time commitments and related compensation; and personal factors that support, engage and deter physicians when considering taking on leadership roles. The role of health-care organizations in encouraging and supporting physician leadership is explicated. Practical implications The baseline data on Canadian physician leaders create the opportunity to determine potential steps for improving the state of physician leadership in Canada; and health-care organizations are provided with a wealth of information on how to encourage and support physician leaders. Using the data as a benchmark, comparisons can also be made with physician leadership as practiced in other nations. Originality/value There are no other research studies available that provide the depth and breadth of detail on Canadian physician leadership, and the embedded recommendations to health-care organizations are informed by this in-depth knowledge.
Extended nonlinear feedback model for describing episodes of high inflation
Szybisz, Martín A.; Szybisz, Leszek
2017-01-01
An extension of the nonlinear feedback (NLF) formalism to describe regimes of hyper- and high-inflation in economy is proposed in the present work. In the NLF model the consumer price index (CPI) exhibits a finite time singularity of the type 1 /(tc - t) (1 - β) / β, with β > 0, predicting a blow up of the economy at a critical time tc. However, this model fails in determining tc in the case of weak hyperinflation regimes like, e.g., that occurred in Israel. To overcome this trouble, the NLF model is extended by introducing a parameter γ, which multiplies all terms with past growth rate index (GRI). In this novel approach the solution for CPI is also analytic being proportional to the Gaussian hypergeometric function 2F1(1 / β , 1 / β , 1 + 1 / β ; z) , where z is a function of β, γ, and tc. For z → 1 this hypergeometric function diverges leading to a finite time singularity, from which a value of tc can be determined. This singularity is also present in GRI. It is shown that the interplay between parameters β and γ may produce phenomena of multiple equilibria. An analysis of the severe hyperinflation occurred in Hungary proves that the novel model is robust. When this model is used for examining data of Israel a reasonable tc is got. High-inflation regimes in Mexico and Iceland, which exhibit weaker inflations than that of Israel, are also successfully described.
Asphere, O asphere, how shall we describe thee?
Forbes, G. W.; Brophy, C. P.
2008-09-01
Two key criteria govern the characterization of nominal shapes for aspheric optical surfaces. An efficient representation describes the spectrum of relevant shapes to the required accuracy by using the fewest decimal digits in the associated coefficients. Also, a representation is more effective if it can, in some way, facilitate other processes - such as optical design, tolerancing, or direct human interpretation. With the development of better tools for their design, metrology, and fabrication, aspheric optics are becoming ever more pervasive. As part of this trend, aspheric departures of up to a thousand microns or more must be characterized at almost nanometre precision. For all but the simplest of shapes, this is not as easy as it might sound. Efficiency is therefore increasingly important. Further, metrology tools continue to be one of the weaker links in the cost-effective production of aspheric optics. Interferometry particularly struggles to deal with steep slopes in aspheric departure. Such observations motivated the ideas described in what follows for modifying the conventional description of rotationally symmetric aspheres to use orthogonal bases that boost efficiency. The new representations can facilitate surface tolerancing as well as the design of aspheres with cost-effective metrology options. These ideas enable the description of aspheric shapes in terms of decompositions that not only deliver improved efficiency and effectiveness, but that are also shown to admit direct interpretations. While it's neither poetry nor a cure-all, an old blight can be relieved.
Evaluation of Geographic Indices Describing Health Care Utilization.
Kim, Agnus M; Park, Jong Heon; Kang, Sungchan; Kim, Yoon
2017-01-01
The accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization. We measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates. In higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index. Health care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.
Workplace culture in psychiatric nursing described by nurses.
Kurjenluoma, K; Rantanen, A; McCormack, B; Slater, P; Hahtela, N; Suominen, T
2017-04-24
This study looks to describe the workplace culture from the viewpoints of stress, job satisfaction and practice environment. Data were collected from nurses (n = 109) using a web-based survey, The Person-Centred Nursing Index, from two purposefully selected hospital districts in Finland. Data were statistically analysed. Nurses described their workplace culture in slightly positive terms. Nurses only occasionally experienced stress (mean = 2.56, SD = 0.55) and were fairly satisfied with their job (mean = 4.75, SD = 0.66) and their practice environment (mean = 4.42, SD = 0.81). Demographic variables such as the nurses' age, length of time in nursing, time at their present hospital, working shifts and their use of patient restriction were more frequently associated with their perceived workplace culture. Older nurses and those with a longer work history in the nursing profession tended to be more satisfied with their workplace culture in psychiatric nursing. Young and/or newly graduated nurses felt more negatively on their workplace culture; this issue should be recognised and addressed with appropriate support and mentoring. Nurses who used restrictive measures were more often less satisfied with their workplace culture. Continuous efforts are needed to reduce the use of coercive measures, which challenge also the managers to support nursing practice to be more person-centred. © 2017 Nordic College of Caring Science.
First order reversal curves diagrams for describing ferroelectric switching characteristics
Directory of Open Access Journals (Sweden)
Liliana Mitoseriu
2009-06-01
Full Text Available First Order Reversal Curves (FORC are polarization-field dependences described between saturation field Esat and a variable reversal field Er∈(-Esat, Esat. The FORC diagrams were proposed to describe some characteristics of the switching process in ferroelectrics. The approach is related to the Preisach model which considers the distribution of the elementary switchable units over their coercive and bias fields. The influence of the anisotropic porosity in Pb(Zr,TiO3 bulk ceramics on the FORC distributions demonstrated the existence of a positive/negative bias as a result of the confinement induced by anisotropy. The reducing of grain size in Ba(Zr,TiO3 ceramics causes an increase of the ratio of the reversible/irreversible components of the polarization on the FORC distribution indicating the tendency of system towards the superparaelectric state. The FORC method demonstrates to provide a kind of ‘fingerprinting’ of various types of switching characteristics in ferroic systems.
Conjugated Molecules Described by a One-Dimensional Dirac Equation.
Ernzerhof, Matthias; Goyer, Francois
2010-06-08
Starting from the Hückel Hamiltonian of conjugated hydrocarbon chains (ethylene, allyl radical, butadiene, pentadienyl radical, hexatriene, etc.), we perform a simple unitary transformation and obtain a Dirac matrix Hamiltonian. Thus already small molecules are described exactly in terms of a discrete Dirac equation, the continuum limit of which yields a one-dimensional Dirac Hamiltonian. Augmenting this Hamiltonian with specially adapted boundary conditions, we find that all the orbitals of the unsaturated hydrocarbon chains are reproduced by the continuous Dirac equation. However, only orbital energies close to the highest occupied molecular orbital/lowest unoccupied molecular orbital energy are accurately predicted by the Dirac equation. Since it is known that a continuous Dirac equation describes the electronic structure of graphene around the Fermi energy, our findings answer the question to what extent this peculiar electronic structure is already developed in small molecules containing a delocalized π-electron system. We illustrate how the electronic structure of small polyenes carries over to a certain class of rectangular graphene sheets and eventually to graphene itself. Thus the peculiar electronic structure of graphene extends to a large degree to the smallest unsaturated molecule (ethylene).
Motion in a stochastic layer described by symbolic dynamics
Energy Technology Data Exchange (ETDEWEB)
Misguich, J.H.; Reuss, J.D. [Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Elskens, Y. [Universite de Provence, 13 - Marseille (France); Balescu, R. [Association Euratom, Brussels (Belgium)
1997-07-01
The motion in the stochastic layer surrounding an island can be studied by using the standard map: this problem is of direct relevance to the diffusion of magnetic field lines in a tokamak. In a previous work it was shown that this process can be adequately modelled by a continuous time random walk (CTRW) describing transitions of the running point between three basins representing, respectively, trapped motion around the island, and passing motion above or below the island. The sticking property of the island deeply modifies the nature of the transport process, leading to sub-diffusive behavior. In the present work it is shown that the motion can be analyzed in terms of a symbolic dynamics which leads to the possibility of an automatic measurement of the data necessary for the construction of the CTRW. The logical features of the procedure are described, and the method is applied to an analysis of long time series, thus completing the results of the previous work. (author) 10 refs.
Strength in Numbers: Describing the Flooded Area of Isolated Wetlands
Lee, Terrie M.; Haag, Kim H.
2006-01-01
Thousands of isolated, freshwater wetlands are scattered across the karst1 landscape of central Florida. Most are small (less than 15 acres), shallow, marsh and cypress wetlands that flood and dry seasonally. Wetland health is threatened when wetland flooding patterns are altered either by human activities, such as land-use change and ground-water pumping, or by changes in climate. Yet the small sizes and vast numbers of isolated wetlands in Florida challenge our efforts to characterize them collectively as a statewide water resource. In the northern Tampa Bay area of west-central Florida alone, water levels are measured monthly in more than 400 wetlands by the Southwest Florida Water Management Distirct (SWFWMD). Many wetlands have over a decade of measurements. The usefulness of long-term monitoring of wetland water levels would greatly increase if it described not just the depth of water at a point in the wetland, but also the amount of the total wetland area that was flooded. Water levels can be used to estimate the flooded area of a wetland if the elevation contours of the wetland bottom are determined by bathymetric mapping. Despite the recognized importance of the flooded area to wetland vegetation, bathymetric maps are not available to describe the flooded areas of even a representative number of Florida's isolated wetlands. Information on the bathymetry of isolated wetlands is rare because it is labor intensive to collect the land-surface elevation data needed to create the maps. Five marshes and five cypress wetlands were studied by the U.S. Geological Survey (USGS) during 2000 to 2004 as part of a large interdisciplinary study of isolated wetlands in central Florida. The wetlands are located either in municipal well fields or on publicly owned lands (fig. 1). The 10 wetlands share similar geology and climate, but differ in their ground-water settings. All have historical water-level data and multiple vegetation surveys. A comprehensive report by Haag and
A more robust Boolean model describing inhibitor binding
Institute of Scientific and Technical Information of China (English)
Zhaoqian Steven XIE; Chao TANG
2008-01-01
From the first application of the Boolean model to the cell cycle regulation network of budding yeast, new regulative pathways have been discovered, par-ticularly in the G1/S transition circuit. This discovery called for finer modeling to study the essential biology, and the resulting outcomes are first introduced in the ar-ticle. A traditional Boolean network model set up for the new G1/S transition circuit shows that it cannot correctly simulate real biology unless the model parameters are fine tuned. The deficiency is caused by an overly coarse-grained description of the inhibitor binding process, which shall be overcome by a two-vector model proposed whose robustness is surveyed using random perturba-tions. Simulations show that the proposed two-vector model is much more robust in describing inhibitor binding processes within the Boolean framework.
Does classical mechanics always adequately describe "classical physical reality"
Shemi-zadeh, V E
2002-01-01
The article is dedicated to discussion of irreversibility and foundation of statistical mechanics "from the first principles". Taking into account infinitesimal and, as it seems, neglectful for classical mechanics fluctuations of the physical vacuum, makes a deterministic motion of unstable dynamic systems is broken ("spontaneous determinism breaking", "spontaneous stochastization"). Vacuum fluctuations play part of the trigger, starting the powerful mechanism of exponent instability. The motion of the dynamic systems becomes irreversible and stochastic. Classical mechanics turns out to be applicable only for a small class of stable dynamic systems with zero Kolmogorov-Sinay entropy $h=0$. For alternative "Stochastic mechanics" there are corresponding equations of motion and Master Equation, describing irreversible evolution of the initial distribution function to equilibrium state.
Detecting and describing the modular structures of weighted networks
Institute of Scientific and Technical Information of China (English)
Li Ke-Ping; Gao Zi-You
2007-01-01
In the functional properties of complex networks, modules play a central role.In this paper,we propose a new method to detect and describe the modular structures of weighted networks. In order to test the proposed method, as an example, we use our method to analyse the structural properties of the Chinese railway network. Here, the stations are regarded as the nodes and the track sections are regarded as the links. Rigorous analysis of the existing data shows that using the proposed algorithm, the nodes of network can be classified naturally. Moreover, there are several core nodes in each module. Remarkably, we introduce the correlation function Grs, and use it to distinguish the different modules in weighted networks.
Angular momentum and torque described with the complex octonion
Weng, Zi-Hua
2015-01-01
The paper aims to adopt the complex octonion to formulate the angular momentum, torque, and force etc in the electromagnetic and gravitational fields. Applying the octonionic representation enables one single definition of angular momentum (or torque, force) to combine some physics contents, which were considered to be independent of each other in the past. J. C. Maxwell used simultaneously two methods, the vector terminology and quaternion analysis, to depict the electromagnetic theory. It motivates the paper to introduce the quaternion space into the field theory, describing the physical feature of electromagnetic and gravitational fields. The spaces of two fields can be chosen as the quaternion spaces, while the coordinate component of quaternion space is able to be the complex number. The quaternion space of electromagnetic field is independent of that of gravitational field. These two quaternion spaces may compose one octonion space. Contrarily, one octonion space can be separated into two subspaces, the...
Describing linguistic information in a behavioural framework: Possible or not?
Energy Technology Data Exchange (ETDEWEB)
De Cooman, G. [Universiteit Gent, Zwijnaarde (Belgium)
1996-12-31
The paper discusses important aspects of the representation of linguistic information, using imprecise probabilities with a behavioural interpretation. We define linguistic information as the information conveyed by statements in natural language, but restrict ourselves to simple affirmative statements of the type {open_quote}subject-is-predicate{close_quote}. Taking the behavioural stance, as it is described in detail, we investigate whether it is possible to give a mathematical model for this kind of information. In particular, we evaluate Zadeli`s suggestion that we should use possibility measures to this end. We come to tile conclusion that, generally speaking, possibility measures are possibility models for linguistic information, but that more work should be done in order to evaluate the suggestion that they may be the only ones.
Describing pulsar wind nebulae with a simple leptonic model
Energy Technology Data Exchange (ETDEWEB)
Hahn, Joachim; Hoppe, Stefan; Domainko, Wilfried; Hofmann, Werner [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Egberts, Kathrin [Institut fuer Astro- und Teilchenphysik, Leopold-Franzens-Universitaet Innsbruck (Austria)
2010-07-01
In recent years, Cherenkov telescopes like e.g. H.E.S.S. have identified a large number of very-high-energy (VHE) gamma-ray sources as Pulsar wind nebulae (PWNe). The VHE-gamma-ray emission shows a rich diversity of spectral and spatial morphologies. Theoretical models can help to understand and interprete the observed source properties. A simple semi-analytical leptonic model describing VHE gamma-ray emission from PWNe is presented. It assumes diffusion with radiative cooling as the transport mechanism for electrons and their interaction with radiative and interstellar magnetic fields as the origin of electromagnetic radiation. In the framework of this model, spectral and spatial properties of the expected VHE gamma-ray emission from single PWNe may be estimated.
Sociodemographic differences in dietary habits described by food frequency questions
DEFF Research Database (Denmark)
Dynesen, Anja Weirsøe; Haraldsdottír, Johanna; Holm, Lotte;
2003-01-01
be a valuable supplement to traditional quantitative dietary surveys in monitoring sociodemographic changes in eating patterns. The results also underline the influence of sociodemographic status on dietary habits. SPONSORSHIP: The Danish Nutrition Council funded the study.......OBJECTIVES: To investigate whether a modest number of food frequency questions are sufficient to describe sociodemographic differences in dietary habits, and to identify sociodemographic characteristics of subjects adhering to food-based dietary guidelines operationalised in a "healthy-diet index...... frequency questions, a question on type of fat spreads used on bread, questions on seven sociodemographic variables. RESULTS: The summary of the healthy-diet index showed that the subjects who adhered to food-based dietary guidelines (top quintile) compared to those who did not (bottom quintile) were most...
Knowledge epidemics and population dynamics models for describing idea diffusion
Vitanov, Nikolay K
2012-01-01
The diffusion of ideas is often closely connected to the creation and diffusion of knowledge and to the technological evolution of society. Because of this, knowledge creation, exchange and its subsequent transformation into innovations for improved welfare and economic growth is briefly described from a historical point of view. Next, three approaches are discussed for modeling the diffusion of ideas in the areas of science and technology, through (i) deterministic, (ii) stochastic, and (iii) statistical approaches. These are illustrated through their corresponding population dynamics and epidemic models relative to the spreading of ideas, knowledge and innovations. The deterministic dynamical models are considered to be appropriate for analyzing the evolution of large and small societal, scientific and technological systems when the influence of fluctuations is insignificant. Stochastic models are appropriate when the system of interest is small but when the fluctuations become significant for its evolution...
Probable technologies behind the Vimanas described in Ramayana
Directory of Open Access Journals (Sweden)
Shruthi.K.R
2016-06-01
Full Text Available In Sanskrit literature there is a prominent place for Maharshi Valmiki‟s Ramayana. This is one of the very few popular epics which are translated to multiple languages across the world. It has seven kaandas (books, five hundred sargas (chapters and twenty four thousand slokas (verses in it. The vimanas are described in various kaandas of Ramayana. It is said that Ravana had the vimana which could appear and disappear, travel long distances with high speed based on the thought power of the master. A few years ago in the year 2013 researchers from the University of Minnesota have designed a model quadcopter which can be flown by the human thought power. As per Prof Bin He from the University of Minnesota, for the first time humans are able to control the flight of flying robots using just their thought sensed from non-invasive brain waves. German scientists from the Technical University of Munich under the leadership of Professor Tim Fricke have simulated the flight of aircraft using thought power of the pilots. This makes us think if such an aircraft with an advanced technology like this existed once upon a time during the era of Ramayana. Carvings of Ravana‟s vimana in Ellora cave temples help us in comparing it with that of modern Jetpack. Descriptions on seating capacity of Pushpaka vimana help us in comparing the same with Airbus 380-800 which can accommodate 853 passengers. Concepts of invisibility of aircrafts make us think of camouflaging techniques and stealth technology used in modern military aircrafts. All these features help us in analyzing the probable technologies behind vimanas described in Ramayana
Assessing the state of substitution models describing noncoding RNA evolution.
Allen, James E; Whelan, Simon
2014-01-01
Phylogenetic inference is widely used to investigate the relationships between homologous sequences. RNA molecules have played a key role in these studies because they are present throughout life and tend to evolve slowly. Phylogenetic inference has been shown to be dependent on the substitution model used. A wide range of models have been developed to describe RNA evolution, either with 16 states describing all possible canonical base pairs or with 7 states where the 10 mismatched nucleotides are reduced to a single state. Formal model selection has become a standard practice for choosing an inferential model and works well for comparing models of a specific type, such as comparisons within nucleotide models or within amino acid models. Model selection cannot function across different sized state spaces because the likelihoods are conditioned on different data. Here, we introduce statistical state-space projection methods that allow the direct comparison of likelihoods between nucleotide models and 7-state and 16-state RNA models. To demonstrate the general applicability of our new methods, we extract 287 RNA families from genomic alignments and perform model selection. We find that in 281/287 families, RNA models are selected in preference to nucleotide models, with simple 7-state RNA models selected for more conserved families with shorter stems and more complex 16-state RNA models selected for more divergent families with longer stems. Other factors, such as the function of the RNA molecule or the GC-content, have limited impact on model selection. Our models and model selection methods are freely available in the open-source PHASE 3.0 software.
Conceptual framework describing a child's total (built, natural ...
The complexity of the components and their interactions that characterize children’s health and well-being are not adequately captured by current public health paradigms. Children are exposed to combinations of chemical and non-chemical stressors from their built, natural, and social environments at each lifestage and throughout their lifecourse. Children’s inherent characteristics (e.g., sex, genetics, pre-existing disease) and their activities and behaviors also influence their exposures to chemical and non-chemical stressors from these environments. We describe a conceptual framework that considers the interrelationships between inherent characteristics, activities and behaviors, and stressors (both chemical and non-chemical) from the built, natural, and social environments in influencing children’s health and well-being throughout their lifecourse. This framework is comprised of several intersecting circles that represent how stressors from the total environment interact with children’s inherent characteristics and their activities and behaviors to influence their health and well-being at each lifestage and throughout their lifecourse. We used this framework to examine the complex interrelationships between chemical and non-chemical stressors for two public health challenges specific to children: childhood obesity and general cognitive ability. One systematic scoping review showed that children’s general cognitive ability was influenced not only by
Second order evolution equations which describe pseudospherical surfaces
Catalano Ferraioli, D.; de Oliveira Silva, L. A.
2016-06-01
Second order evolution differential equations that describe pseudospherical surfaces are considered. These equations are equivalent to the structure equations of a metric with Gaussian curvature K = - 1, and can be seen as the compatibility condition of an associated sl (2 , R) -valued linear problem, also referred to as a zero curvature representation. Under the assumption that the linear problem is defined by 1-forms ωi =fi1 dx +fi2 dt, i = 1 , 2 , 3, with fij depending on (x , t , z ,z1 ,z2) and such that f21 = η, η ∈ R, we give a complete and explicit classification of equations of the form zt = A (x , t , z) z2 + B (x , t , z ,z1) . According to the classification, these equations are subdivided in three main classes (referred to as Types I-III) together with the corresponding linear problems. Explicit examples of differential equations of each type are determined by choosing certain arbitrary differentiable functions. Svinolupov-Sokolov equations admitting higher weakly nonlinear symmetries, Boltzmann equation and reaction-diffusion equations like Murray equation are some known examples of such equations. Other explicit examples are presented, as well.
The complexity of organizational change: describing communication during organizational turbulence.
Salem, Philip
2013-01-01
Organizational researchers and practitioners have been interested in organizational change for some time. Historically, they have directed most of their efforts at improving the efficiency of planned top-down change. These efforts were strategic attempts at altering parameters leading to transformational change. Most efforts failed to meet their intended purposes. Transformational organizational change has not been likely. The legitimate systems have been robust. There has been little systematic investigation of the communication occurring during these efforts. The purpose of this essay is to describe results of a mixed methods research project answering two research questions. (a) How do organizational members communicate during a time of turbulence? (b) What features of this communication suggest the potential for or resistance to transformative change? Comparing the results at the beginning of the period to other periods, gives insight into how social actors communicate and enact the organization during a threshold period where transformational change was possible. Results reveal identifiable patterns of communication as communication strategies, parameters, or basins of attraction. The overall pattern explains how micro communication patterns intersect and how the accumulation of these patterns may resist or accomplish change at a macro level.
Describing the Breakbone Fever: IDODEN, an Ontology for Dengue Fever
Mitraka, Elvira; Topalis, Pantelis; Dritsou, Vicky; Dialynas, Emmanuel; Louis, Christos
2015-01-01
Background Ontologies represent powerful tools in information technology because they enhance interoperability and facilitate, among other things, the construction of optimized search engines. To address the need to expand the toolbox available for the control and prevention of vector-borne diseases we embarked on the construction of specific ontologies. We present here IDODEN, an ontology that describes dengue fever, one of the globally most important diseases that are transmitted by mosquitoes. Methodology/Principal Findings We constructed IDODEN using open source software, and modeled it on IDOMAL, the malaria ontology developed previously. IDODEN covers all aspects of dengue fever, such as disease biology, epidemiology and clinical features. Moreover, it covers all facets of dengue entomology. IDODEN, which is freely available, can now be used for the annotation of dengue-related data and, in addition to its use for modeling, it can be utilized for the construction of other dedicated IT tools such as decision support systems. Conclusions/Significance The availability of the dengue ontology will enable databases hosting dengue-associated data and decision-support systems for that disease to perform most efficiently and to link their own data to those stored in other independent repositories, in an architecture- and software-independent manner. PMID:25646954
Describing current and potential markets for alternative-fuel vehicles
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-03-26
Motor vehicles are a major source of greenhouse gases, and the rising numbers of motor vehicles and miles driven could lead to more harmful emissions that may ultimately affect the world`s climate. One approach to curtailing such emissions is to use, instead of gasoline, alternative fuels: LPG, compressed natural gas, or alcohol fuels. In addition to the greenhouse gases, pollutants can be harmful to human health: ozone, CO. The Clean Air Act Amendments of 1990 authorized EPA to set National Ambient Air Quality Standards to control this. The Energy Policy Act of 1992 (EPACT) was the first new law to emphasize strengthened energy security and decreased reliance on foreign oil since the oil shortages of the 1970`s. EPACT emphasized increasing the number of alternative-fuel vehicles (AFV`s) by mandating their incremental increase of use by Federal, state, and alternative fuel provider fleets over the new few years. Its goals are far from being met; alternative fuels` share remains trivial, about 0.3%, despite gains. This report describes current and potential markets for AFV`s; it begins by assessing the total vehicle stock, and then it focuses on current use of AFV`s in alternative fuel provider fleets and the potential for use of AFV`s in US households.
Entropic-Skins Geometry to Describe Wall Turbulence Intermittency
Directory of Open Access Journals (Sweden)
Diogo Queiros-Conde
2015-04-01
Full Text Available In order to describe the phenomenon of intermittency in wall turbulence and, more particularly, the behaviour of moments and and intermittency exponents ζP with the order p and distance to the wall, we developed a new geometrical framework called “entropic-skins geometry” based on the notion of scale-entropy which is here applied to an experimental database of boundary layer flows. Each moment has its own spatial multi-scale support Ωp (“skin”. The model assumes the existence of a hierarchy of multi-scale sets Ωp ranged from the “bulk” to the “crest”. The crest noted characterizes the geometrical support where the most intermittent (the highest fluctuations in energy dissipation occur; the bulk is the geometrical support for the whole range of fluctuations. The model assumes then the existence of a dynamical flux through the hierarchy of skins. The specific case where skins display a fractal structure is investigated. Bulk fractal dimension and crest dimension are linked by a scale-entropy flux defining a reversibility efficiency (d is the embedding dimension. The model, initially developed for homogeneous and isotropic turbulent flows, is applied here to wall bounded turbulence where intermittency exponents are measured by extended self-similarity. We obtained for intermittency exponents the analytical expression with γ ≈ 0.36 in agreement with experimental results.
Folding superfunnel to describe cooperative folding of interacting proteins.
Smeller, László
2016-07-01
This paper proposes a generalization of the well-known folding funnel concept of proteins. In the funnel model the polypeptide chain is treated as an individual object not interacting with other proteins. Since biological systems are considerably crowded, protein-protein interaction is a fundamental feature during the life cycle of proteins. The folding superfunnel proposed here describes the folding process of interacting proteins in various situations. The first example discussed is the folding of the freshly synthesized protein with the aid of chaperones. Another important aspect of protein-protein interactions is the folding of the recently characterized intrinsically disordered proteins, where binding to target proteins plays a crucial role in the completion of the folding process. The third scenario where the folding superfunnel is used is the formation of aggregates from destabilized proteins, which is an important factor in case of several conformational diseases. The folding superfunnel constructed here with the minimal assumption about the interaction potential explains all three cases mentioned above. Proteins 2016; 84:1009-1016. © 2016 Wiley Periodicals, Inc.
An ontological approach to describing neurons and their relationships
Hamilton, David J.; Shepherd, Gordon M.; Martone, Maryann E.; Ascoli, Giorgio A.
2012-01-01
The advancement of neuroscience, perhaps one of the most information rich disciplines of all the life sciences, requires basic frameworks for organizing the vast amounts of data generated by the research community to promote novel insights and integrated understanding. Since Cajal, the neuron remains a fundamental unit of the nervous system, yet even with the explosion of information technology, we still have few comprehensive or systematic strategies for aggregating cell-level knowledge. Progress toward this goal is hampered by the multiplicity of names for cells and by lack of a consensus on the criteria for defining neuron types. However, through umbrella projects like the Neuroscience Information Framework (NIF) and the International Neuroinformatics Coordinating Facility (INCF), we have the opportunity to propose and implement an informatics infrastructure for establishing common tools and approaches to describe neurons through a standard terminology for nerve cells and a database (a Neuron Registry) where these descriptions can be deposited and compared. This article provides an overview of the problem and outlines a solution approach utilizing ontological characterizations. Based on illustrative implementation examples, we also discuss the need for consensus criteria to be adopted by the research community, and considerations on future developments. A scalable repository of neuron types will provide researchers with a resource that materially contributes to the advancement of neuroscience. PMID:22557965
Conceptual hierarchical modeling to describe wetland plant community organization
Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.
2010-01-01
Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.
An ontological approach to describing neurons and their relationships
Directory of Open Access Journals (Sweden)
David J. Hamilton
2012-04-01
Full Text Available The advancement of neuroscience, perhaps the most information rich discipline of all the life sciences, requires basic frameworks for organizing the vast amounts of data generated by the research community to promote novel insights and integrated understanding. Since Cajal, the neuron remains a fundamental unit of the nervous system, yet even with the explosion of information technology, we still have few comprehensive or systematic strategies for aggregating cell-level knowledge. Progress toward this goal is hampered by the multiplicity of names for cells and by lack of a consensus on the criteria for defining neuron types. However, through umbrella projects like the Neuroscience Information Framework and the International Neuroinformatics Coordinating Facility, we have the opportunity to propose and implement an informatics infrastructure for establishing common tools and approaches to describe neurons through a standard terminology for nerve cells and a database (a Neuron Registry where these descriptions can be deposited and compared. This article provides an overview of the problem and outlines a solution approach utilizing ontological characterizations.
Canonical quantization of a string describing N branes at angles
Pesando, Igor
2014-12-01
We study the canonical quantization of a bosonic string in presence of N twist fields. This generalizes the quantization of the twisted string in two ways: the in and out states are not necessarily twisted and the number of twist fields N can be bigger than 2. In order to quantize the theory we need to find the normal modes. Then we need to define a product between two modes which is conserved. Because of this we need to use the Klein-Gordon product and to separate the string coordinate into the classical and the quantum part. The quantum part has different boundary conditions than the original string coordinates but these boundary conditions are precisely those which make the operator describing the equation of motion self adjoint. The splitting of the string coordinates into a classical and quantum part allows the formulation of an improved overlap principle. Using this approach we then proceed in computing the generating function for the generic correlator with L untwisted operators and N (excited) twist fields for branes at angles. We recover as expected the results previously obtained using the path integral. This construction explains why these correlators are given by a generalization of the Wick theorem.
Advanced Mathematical Model to Describe the Production of Biodiesel Process
Directory of Open Access Journals (Sweden)
Hikmat S. Al-Salim
2009-12-01
Full Text Available Advanced mathematical model was used to capture the batch reactor characteristics of reacting compounds. The model was applied to batch reactor for the production of bio-diesel from palm and kapok oils. Results of the model were compared with experimental data in terms of conversion of transesterification reaction for the production of bio-diesel under unsteady state. A good agreement was obtained between our model predictions and the experimental data. Both experimental and modeling results showed that the conversion of triglycerides to methyl ester was affected by the process conditions. The transesterification process with temperature of about 70 oC, and methanol ratio to the triglyceride of about 5 times its stoichiometry, and the NAOH catalyst of wt 0.4%, appear to be acceptable process conditions for bio diesel process production from palm oil and kapok oil. The model can be applied for endothermic batch process. © 2009 BCREC UNDIP. All rights reserved[Received: 12 August 2009, Revised: 15 October 2009; Accepted: 18 October 2009][How to Cite: A.S. Ibrehem, H. S. Al-Salim. (2009. Advanced Mathematical Model to Describe the Production of Biodiesel Process. Bulletin of Chemical Reaction Engineering and Catalysis, 4(2: 37-42. doi:10.9767/bcrec.4.2.28.37-42][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.4.2.28.37-42
Sensitivity analysis approach to multibody systems described by natural coordinates
Li, Xiufeng; Wang, Yabin
2014-03-01
The classical natural coordinate modeling method which removes the Euler angles and Euler parameters from the governing equations is particularly suitable for the sensitivity analysis and optimization of multibody systems. However, the formulation has so many principles in choosing the generalized coordinates that it hinders the implementation of modeling automation. A first order direct sensitivity analysis approach to multibody systems formulated with novel natural coordinates is presented. Firstly, a new selection method for natural coordinate is developed. The method introduces 12 coordinates to describe the position and orientation of a spatial object. On the basis of the proposed natural coordinates, rigid constraint conditions, the basic constraint elements as well as the initial conditions for the governing equations are derived. Considering the characteristics of the governing equations, the newly proposed generalized-α integration method is used and the corresponding algorithm flowchart is discussed. The objective function, the detailed analysis process of first order direct sensitivity analysis and related solving strategy are provided based on the previous modeling system. Finally, in order to verify the validity and accuracy of the method presented, the sensitivity analysis of a planar spinner-slider mechanism and a spatial crank-slider mechanism are conducted. The test results agree well with that of the finite difference method, and the maximum absolute deviation of the results is less than 3%. The proposed approach is not only convenient for automatic modeling, but also helpful for the reduction of the complexity of sensitivity analysis, which provides a practical and effective way to obtain sensitivity for the optimization problems of multibody systems.
Describing rainfall in northern Australia using multiple climate indices
Wilks Rogers, Cassandra Denise; Beringer, Jason
2017-02-01
Savanna landscapes are globally extensive and highly sensitive to climate change, yet the physical processes and climate phenomena which affect them remain poorly understood and therefore poorly represented in climate models. Both human populations and natural ecosystems are highly susceptible to precipitation variation in these regions due to the effects on water and food availability and atmosphere-biosphere energy fluxes. Here we quantify the relationship between climate phenomena and historical rainfall variability in Australian savannas and, in particular, how these relationships changed across a strong rainfall gradient, namely the North Australian Tropical Transect (NATT). Climate phenomena were described by 16 relevant climate indices and correlated against precipitation from 1900 to 2010 to determine the relative importance of each climate index on seasonal, annual and decadal timescales. Precipitation trends, climate index trends and wet season characteristics have also been investigated using linear statistical methods. In general, climate index-rainfall correlations were stronger in the north of the NATT where annual rainfall variability was lower and a high proportion of rainfall fell during the wet season. This is consistent with a decreased influence of the Indian-Australian monsoon from the north to the south. Seasonal variation was most strongly correlated with the Australian Monsoon Index, whereas yearly variability was related to a greater number of climate indices, predominately the Tasman Sea and Indonesian sea surface temperature indices (both of which experienced a linear increase over the duration of the study) and the El Niño-Southern Oscillation indices. These findings highlight the importance of understanding the climatic processes driving variability and, subsequently, the importance of understanding the relationships between rainfall and climatic phenomena in the Northern Territory in order to project future rainfall patterns in the
Probabilistic models to describe the dynamics of migrating microbial communities.
Directory of Open Access Journals (Sweden)
Joanna L Schroeder
Full Text Available In all but the most sterile environments bacteria will reside in fluid being transported through conduits and some of these will attach and grow as biofilms on the conduit walls. The concentration and diversity of bacteria in the fluid at the point of delivery will be a mix of those when it entered the conduit and those that have become entrained into the flow due to seeding from biofilms. Examples include fluids through conduits such as drinking water pipe networks, endotracheal tubes, catheters and ventilation systems. Here we present two probabilistic models to describe changes in the composition of bulk fluid microbial communities as they are transported through a conduit whilst exposed to biofilm communities. The first (discrete model simulates absolute numbers of individual cells, whereas the other (continuous model simulates the relative abundance of taxa in the bulk fluid. The discrete model is founded on a birth-death process whereby the community changes one individual at a time and the numbers of cells in the system can vary. The continuous model is a stochastic differential equation derived from the discrete model and can also accommodate changes in the carrying capacity of the bulk fluid. These models provide a novel Lagrangian framework to investigate and predict the dynamics of migrating microbial communities. In this paper we compare the two models, discuss their merits, possible applications and present simulation results in the context of drinking water distribution systems. Our results provide novel insight into the effects of stochastic dynamics on the composition of non-stationary microbial communities that are exposed to biofilms and provides a new avenue for modelling microbial dynamics in systems where fluids are being transported.
Describing failure in geomaterials using second-order work approach
Directory of Open Access Journals (Sweden)
François Nicot
2015-04-01
Full Text Available Geomaterials are known to be non-associated materials. Granular soils therefore exhibit a variety of failure modes, with diffuse or localized kinematical patterns. In fact, the notion of failure itself can be confusing with regard to granular soils, because it is not associated with an obvious phenomenology. In this study, we built a proper framework, using the second-order work theory, to describe some failure modes in geomaterials based on energy conservation. The occurrence of failure is defined by an abrupt increase in kinetic energy. The increase in kinetic energy from an equilibrium state, under incremental loading, is shown to be equal to the difference between the external second-order work, involving the external loading parameters, and the internal second-order work, involving the constitutive properties of the material. When a stress limit state is reached, a certain stress component passes through a maximum value and then may decrease. Under such a condition, if a certain additional external loading is applied, the system fails, sharply increasing the strain rate. The internal stress is no longer able to balance the external stress, leading to a dynamic response of the specimen. As an illustration, the theoretical framework was applied to the well-known undrained triaxial test for loose soils. The influence of the loading control mode was clearly highlighted. It is shown that the plastic limit theory appears to be a particular case of this more general second-order work theory. When the plastic limit condition is met, the internal second-order work is nil. A class of incremental external loadings causes the kinetic energy to increase dramatically, leading to the sudden collapse of the specimen, as observed in laboratory.
Advanced Mathematical Model to Describe the Production of Biodiesel Process
Directory of Open Access Journals (Sweden)
Ahmmed S. Ibrehem
2009-12-01
Full Text Available Advanced mathematical model was used to capture the batch reactor characteristics of reacting compounds. The model was applied to batch reactor for the production of bio-diesel from palm and kapok oils. Results of the model were compared with experimental data in terms of conversion of transesterification reaction for the production of bio-diesel under unsteady state. A good agreement was obtained between our model predictions and the experimental data. Both experimental and modeling results showed that the conversion of triglycerides to methyl ester was affected by the process conditions. The transesterification process with temperature of about 70 oC, and methanol ratio to the triglyceride of about 5 times its stoichiometry, and the NAOH catalyst of wt 0.4%, appear to be acceptable process conditions for bio diesel process production from palm oil and kapok oil. The model can be applied for endothermic batch process. © 2009 BCREC UNDIP. All rights reserved[Received: 12 August 2009, Revised: 15 October 2009; Accepted: 18 October 2009][How to Cite: A.S. Ibrehem, H. S. Al-Salim. (2009. Advanced Mathematical Model to Describe the Production of Biodiesel Process. Bulletin of Chemical Reaction Engineering and Catalysis, 4(2: 37-42. doi:10.9767/bcrec.4.2.7109.37-42][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.4.2.7109.37-42 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/7109 ]
Describing soil surface microrelief by crossover length and fractal dimension
Directory of Open Access Journals (Sweden)
E. Vidal Vázquez
2007-05-01
Full Text Available Accurate description of soil surface topography is essential because different tillage tools produce different soil surface roughness conditions, which in turn affects many processes across the soil surface boundary. Advantages of fractal analysis in soil microrelief assessment have been recognised but the use of fractal indices in practice remains challenging. There is also little information on how soil surface roughness decays under natural rainfall conditions. The objectives of this work were to investigate the decay of initial surface roughness induced by natural rainfall under different soil tillage systems and to compare the performances of a classical statistical index and fractal microrelief indices. Field experiments were performed on an Oxisol at Campinas, São Paulo State (Brazil. Six tillage treatments, namely, disc harrow, disc plow, chisel plow, disc harrow + disc level, disc plow + disc level and chisel plow + disc level were tested. Measurements were made four times, firstly just after tillage and subsequently with increasing amounts of natural rainfall. Duplicated measurements were taken per treatment and date, yielding a total of 48 experimental surfaces. The sampling scheme was a square grid with 25×25 mm point spacing and the plot size was 1350×1350 mm, so that each data set consisted of 3025 individual elevation points. Statistical and fractal indices were calculated both for oriented and random roughness conditions, i.e. after height reading have been corrected for slope and for slope and tillage tool marks. The main drawback of the standard statistical index random roughness, RR, lies in its no spatial nature. The fractal approach requires two indices, fractal dimension, D, which describes how roughness changes with scale, and crossover length, l, specifying the variance of surface microrelief at a reference scale. Fractal parameters D and l, were estimated by two independent self-affine models
1985-01-01
York. Do Carmo , Manfredo P, [1976], Differential Geometry of Curves and Surfaces, Prent- ice-Hall, Englewood Cliffs, NJ. Faugeras, 0. D., et. al, [1982...lightbulb. It is well-known (for exam~ple, do Carmo "" "..-’,.’.V .. .V...i ra I s ; ul ing-.. "’. Figure 11. The helicoid of a single blade. (Reproduced from [do Carmo 1976, Figure 2-27 Page 94]) where m and 1 are assumed
Institute of Scientific and Technical Information of China (English)
孙素苗
2015-01-01
Aiming at the problems of selling power price classification complexity, executing difficulty,cross subsidies severity,and not conducive to rational allocation of power resources, based on the deep analysis of selling power price classification frame,designs the merger scheme that adopting two parts load factor tariff to put together the selling power prices of large industry and general industry. The result shows that the merger more rationally reflects customer cost,decreases cross subsidies of selling power price,and has a role in promoting rational allocation of power resources.%针对我国目前销售电价分类复杂，执行中矛盾较多，交叉补贴严重，不利于电力资源合理配置的问题，在深入分析电价分类结构的基础上，设计了按两部制负荷率电价对大工业与一般工商业电价的归并方案。结果表明：归并后的电价方案较为合理地反映了用户的用电成本，减少了电价交叉补贴，对于电力资源的合理配置具有促进作用。
Institute of Scientific and Technical Information of China (English)
牟宗玉; 曹德弼; 刘晓冰; 李新然
2013-01-01
This paper studies the coordination of the closed-loop supply chain(CLSC)with one manufacturer and one retailer who recollects the used products .We design the model that can be coordinated by a two-part tariff contract in static environment .Based on the model , we get the optimal profits by K-T condition and the optimal response strategy of the centralized CLSC under demand disruptions caused by an emergent event .The conclu-sion shows that the two-part tariff contract which has been signed can ’ t coordinate the decentralized CLSC any more under disruptions .Then we give two strategies to coordinate the CLSC .One strategy is that the wholesale price and the transfer price of used products with the original contract are improved in the case that the manufac -turer bears the deviation costs , and the other is that we retain the wholesale price and the transfer price of used products with the original contract unchanged under the condition that the retailer bears the deviation costs .The manufacturer and the retailer need to bargain with each other to determine the fixed fee in both of the above strat-egies , and we can realize the coordination of the CLSC under disruptions .In addition , we have proved the feasi-bility of them .%本文针对由一个制造商和一个零售商组成的零售商负责回收闭环供应链的协调问题，首先设计了稳定环境下两部收费契约协调闭环供应链模型。在此基础上，针对突发事件影响下造成零售商面临的市场需求发生变化时，运用K-T条件对集中式决策下的闭环供应链的最优利润进行求解，给出了最优应对策略。通过研究表明：当突发事件发生时，原适用于稳定环境下的两部收费契约将不再对分散式决策下的闭环供应链起协调作用。为此，本研究给出了两种协调策略，一是在制造商自身承担突发事件引起的偏差成本的情况下，通过对原有的两部收费契约中的批
Bogojevski, Ljubomir; Doksevska, Milena Bogojevska
2017-01-01
Introduction: In order to achieve the right balance of the posterior cruciate ligament using the skeletal method is very difficult, almost impossible (Mahoney). Our hypothesis for the right balance of the PCL by using the skeletal method is based on several defined facts: - PCL is a union based of two anatomically independent, but functionally synergic parts, posteromedial and anterolateral part. - The length of the posteromedial part of the PCL is determined by the belonging of the medial compartment and is shortest in varus and longest in valgus deformation. - The length of the anterolateral part of the PCL, placed centrally is unchangeable (cca 38 mm) in every knee and is independent from the anatomical appearance (deformation). - The cylindrical shape of the distal posterior part of the femur (Ficat) depends of the molding function of the PCL (Kapandji) and is a result of the proportion of the both parts of the PCL that is consisted of: shorter posteromedial part, less bone stock on the medial and more bone stock on the lateral condyle (varus knee) and vice versa, longer posteromedial part, more bone stock on the medial condyle and less on the lateral (valgus knee). According to that, the neutral bone stock is achieved by equalization of the lengths of the two parts (common radius of the cylinder) of the PCL, that is basis for the interligamentary balance of the posterior cruciate ligament. Methods: The basic characteristics of the interligamentary balance of the PCL that we started in 2008 are the following: 1. Posterior condylar offset is equal to the even length of the both part of the PCL. 2. Decrease of the values of proximal tibial resection from 10 in varus to 4-6 in valgus. 3. Femoral valgus cut from 6 in excessive varus deformity to 4 in valgus. Results: The clinical evaluation of the cases divided in groups excessive varus, mean varus, valgus type 1, 2 (Krakow) showed right distribution in the groups of the postoperative ROM and intraoperative
NSGIC GIS Inventory (aka Ramona) — This Employment Densities dataset, was produced all or in part from Other information as of unknown. It is described as '(Note: Describe as available)'. Data by...
NSGIC GIS Inventory (aka Ramona) — This Population, Nighttime dataset, was produced all or in part from Other information as of unknown. It is described as '(Note: Describe as available)'. Data by...
NSGIC GIS Inventory (aka Ramona) — This Immigration Information dataset, was produced all or in part from Other information as of unknown. It is described as '(Note: Describe as available)'. Data by...
Decision‐making process of prenatal screening described by pregnant women and their partners
National Research Council Canada - National Science Library
Wätterbjörk, Inger; Blomberg, Karin; Nilsson, Kerstin; Sahlberg‐Blom, Eva
2015-01-01
... describe complex feelings regarding the risk assessment. The decision making about prenatal screening has been described as easy by some women who viewed the decision as a mere formality and a confirmation that all is well. Women have also described decision making on screening as a process in which they considered their own...
29 CFR 779.238 - Engagement in described activities determined on annual basis.
2010-07-01
... 29 Labor 3 2010-07-01 2010-07-01 false Engagement in described activities determined on annual... Apply; Enterprise Coverage Covered Enterprises § 779.238 Engagement in described activities determined...” must have at least some employees engaged in certain described activities. This requirement will be...
Fantauzzi, Donato; Bandlow, Jochen; Sabo, Lehel; Mueller, Jonathan E; van Duin, Adri C T; Jacob, Timo
2014-11-14
ReaxFF force field parameters describing Pt-Pt and Pt-O interactions have been developed and tested. The Pt-Pt parameters are shown to accurately account for the chemical nature, atomic structures and other materials properties of bulk platinum phases, low and high-index platinum surfaces and nanoclusters. The Pt-O parameters reliably describe bulk platinum oxides, as well as oxygen adsorption and oxide formation on Pt(111) terraces and the {111} and {100} steps connecting them. Good agreement between the force field and both density functional theory (DFT) calculations and experimental observations is demonstrated in the relative surface free energies of high symmetry Pt-O surface phases as a function of the oxygen chemical potential, making ReaxFF an ideal tool for more detailed investigations of more complex Pt-O surface structures. Validation for its application to studies of the kinetics and dynamics of surface oxide formation in the context of either molecular dynamics (MD) or Monte Carlo simulations are provided in part by a two-part investigation of oxygen diffusion on Pt(111), in which nudged elastic band (NEB) calculations and MD simulations are used to characterize diffusion processes and to determine the relevant diffusion coefficients and barriers. Finally, the power of the ReaxFF reactive force field approach in addressing surface structures well beyond the reach of routine DFT calculations is exhibited in a brief proof-of-concept study of oxygen adsorbate displacement within ordered overlayers.
DescribeX: A Framework for Exploring and Querying XML Web Collections
Rizzolo, Flavio
2008-01-01
This thesis introduces DescribeX, a powerful framework that is capable of describing arbitrarily complex XML summaries of web collections, providing support for more efficient evaluation of XPath workloads. DescribeX permits the declarative description of document structure using all axes and language constructs in XPath, and generalizes many of the XML indexing and summarization approaches in the literature. DescribeX supports the construction of heterogeneous summaries where different document elements sharing a common structure can be declaratively defined and refined by means of path regular expressions on axes, or axis path regular expression (AxPREs). DescribeX can significantly help in the understanding of both the structure of complex, heterogeneous XML collections and the behaviour of XPath queries evaluated on them. Experimental results demonstrate the scalability of DescribeX summary refinements and stabilizations (the key enablers for tailoring summaries) with multi-gigabyte web collections. A com...
National Research Council Canada - National Science Library
Yarash K. Abuev; Albert B. Babaev; Pharkhat E. Esetov
2017-01-01
Objectives A computer simulation of the antiferromagnetic structures described by the three-vertex Potts model on a triangular lattice is performed, taking into account the antiferromagnetic exchange...
A New Density Operator Formalism for Describing Nuclear Magnetic Resonance Experiments
Institute of Scientific and Technical Information of China (English)
林东海; 吴钦义
1994-01-01
A density operator formalism has been proposed to describe the evolution of two-spin-1/2 systems in nuclear magnetic resonance experiments:The formalism is particularly convenient and has distinct physical meaning for describing the evolution of spin systems under the Hamiltonian containing non-commutable terms. Some examples are presented to demonstrate the new formalism.
Head-Mounted Eye Tracking: A New Method to Describe Infant Looking
Franchak, John M.; Kretch, Kari S.; Soska, Kasey C.; Adolph, Karen E.
2011-01-01
Despite hundreds of studies describing infants' visual exploration of experimental stimuli, researchers know little about where infants look during everyday interactions. The current study describes the first method for studying visual behavior during natural interactions in mobile infants. Six 14-month-old infants wore a head-mounted eye-tracker…
Bukejs, Andris; Alekseev, Vitalii I; Mckellar, Ryan C
2016-07-26
Based on two relatively well-preserved specimens from Eocene Baltic amber, Passandra septentrionaria sp. nov. is described and illustrated. It is the first formally described species of Passandridae from Baltic amber, and the first known European representative of the family. The global distribution of extant Passandra Dalman is mapped, and the historical distribution of the group is briefly discussed.
Which Terms Should Be Used to Describe Autism? Perspectives from the UK Autism Community
Kenny, Lorcan; Hattersley, Caroline; Molins, Bonnie; Buckley, Carole; Povey, Carol; Pellicano, Elizabeth
2016-01-01
Recent public discussions suggest that there is much disagreement about the way autism is and should be described. This study sought to elicit the views and preferences of UK autism community members--autistic people, parents and their broader support network--about the terms they use to describe autism. In all, 3470 UK residents responded to an…
Native metastability in chalcogenide glasses described within configuration-coordinate model
Energy Technology Data Exchange (ETDEWEB)
Shpotyuk, M [Institute of Materials of Scientific Research Company ' Carat' , 202, Stryjska str., Lviv (Ukraine); Vakiv, M [Institute of Materials of Scientific Research Company ' Carat' , 202, Stryjska str., Lviv (Ukraine)
2007-08-15
It was created configuration-coordinate model for describing of native metastability in chalcogenide glasses. It was shown that potential should be at least triple-well. System of differential equations for describing transitions between the atomic states was made and solved within present configuration-coordinate model.
Butler–Volmer–Monod model for describing bio-anode polarization curves
Hamelers, H.V.M.; Heijne, ter A.; Stein, N.; Rozendal, R.A.; Buisman, C.J.N.
2011-01-01
A kinetic model of the bio-anode was developed based on a simple representation of the underlying biochemical conversions as described by enzyme kinetics, and electron transfer reactions as described by the Butler–Volmer electron transfer kinetics. This Butler–Volmer–Monod model was well able to des
Some plants described by Pliny for the treatment of renal diseases.
De Matteis Tortora, M
1994-01-01
Pliny the Elder described medicinal plants in books XX-XXVII of Naturalis Historia, reporting the therapeutic properties and preparations of the plants for use in different parts of the body. An exhibition of 20 plants chosen from those indicated for renal diseases is described.
John T. Huber; Gary A.P. Gibson; Leah S. Bauer; Houping Liu; Michael Gates
2008-01-01
A key is given to the five described extant species of Mymaromella. Two new species, Mymaromella pala Huber & Gibson, sp. n. and M. palella Huber & Gibson, sp. n. (Mymarommatoidea: Mymarommatidae), are described as the first species of the family from North America. Psocoptera (Insecta) are proposed as...
Hageseth, Gaylord T.
1982-01-01
Describes a project for students to collect and fit data to a theoretical mathematical model that describes the rate of isothermal seed germination, including activation energy for substrate and produce and the autocatalytic reaction, and changes in enthalpy, entropy, and the Gibb's free energy. (Author/SK)
Peña-Rehbein, Patricio; De los Ríos-Escalante, Patricio; Castro, Raúl; Navarrete, Carolina
2013-01-01
This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.
Carson, Nancy E; Blake, Christine E; Saunders, Ruth
2015-04-01
The aim of this exploratory study was to examine how community-dwelling adults with severe mental illness describe themselves as eaters and how these eating identities relate to dietary intake. Twenty participants completed one in-depth qualitative interview and three 24-h dietary recalls. Two distinct groups were identified; self-described healthy eaters (n = 10) and self-described unhealthy eaters (n = 10). Healthy eaters emphasized fruits and vegetables, limiting sweets, three meals a day, overcoming cost concerns, and benefits of healthy eating. Unhealthy eaters emphasized junk foods, fried foods, few fruits and vegetables, cost and household barriers to healthy eating, and concerns about consequences of unhealthy eating. Self-described healthy eaters consumed significantly more vegetables and less kilocalories, carbohydrates, fat, and saturated fat than self-described unhealthy eaters. Understanding how eating identities relate to dietary intake provides important insights for development of more effective approaches to promote healthy eating in this high risk population.
Gibson, Margaret F
2017-08-11
How are lesbian/gay/bisexual/trans/queer (LGBTQ) parents of children with disabilities categorized by service providers, and how do parents anticipate, interpret, and respond to such categorizations? This intersectional study investigated the experiences of LGBTQ parents of children with disabilities with service providers in Toronto, Canada. Parents described pressures to "fit" into providers' limited understanding of family. Some parents described facing overt discrimination, including one parent who was seen as a possible sexual predator. Some described being perceived as representatives of "diversity" for organizations, or "pet lesbians" in the words of one couple. Others described being misread as a non-parent, as in "just the nanny," particularly in conjunction with their racial minority status. Parents described how their experiences of being "outside the mainstream" helped them challenge systems and normative beliefs. Findings suggest that a context of scarce disability resources shapes parents' experiences of how LGBTQ identity comes to matter.
The colour of pain: can patients use colour to describe osteoarthritis pain?
Wylde, Vikki; Wells, Victoria; Dixon, Samantha; Gooberman-Hill, Rachael
2014-03-01
The aim of the present study was to explore patients' views on the acceptability and feasibility of using colour to describe osteoarthritis (OA) pain, and whether colour could be used to communicate pain to healthcare professionals. Six group interviews were conducted with 17 patients with knee OA. Discussion topics included first impressions about using colour to describe pain, whether participants could associate their pain with colour, how colours related to changes to intensity and different pain qualities, and whether they could envisage using colour to describe pain to healthcare professionals. The group interviews indicated that, although the idea of using colour was generally acceptable, it did not suit all participants as a way of describing their pain. The majority of participants chose red to describe high-intensity pain; the reasons given were because red symbolized inflammation, fire, anger and the stop signal in a traffic light system. Colours used to describe the absence of pain were chosen because of their association with positive emotional feelings, such as purity, calmness and happiness. A range of colours was chosen to represent changes in pain intensity. Aching pain was consistently identified as being associated with colours such as grey or black, whereas sharp pain was described using a wider selection of colours. The majority of participants thought that they would be able to use colour to describe their pain to healthcare professionals, although issues around the interpretability and standardization of colour were raised. For some patients, using colour to describe their pain experience may be a useful tool to improve doctor-patient communication. Copyright © 2013 John Wiley & Sons, Ltd.
DEFF Research Database (Denmark)
Madsen, Henrik; Bacher, Peder; Andersen, Philip Hvidthøft Delff
2010-01-01
, existence of prior physical knowledge, the data and the available statistical soft- ware tools. The importance of statistical model validation is discussed, and some simple tools for that purpose are demonstrated. This paper also brieﬂy describes some of the most frequently used software tools for modelling......This paper describes a number of statistical methods and models for describing the thermal characteristics of buildings using frequent readings of heat consumption, ambient air temperature, and other available climate variables. For some of the methods frequent readings of the indoor air...
What do we teach? What do we know? A methodology for describing archaeological skills and knowledge
Directory of Open Access Journals (Sweden)
John Collis
2002-07-01
Full Text Available I recommend that we should move to a flexible, modular system, in describing courses and training, in defining the skills needed to operate as archaeologists and professional career structures, and in describing ourselves as archaeologists. A 'Thesaurus' of skills and knowledge can be constructed, with levels of expertise, which will give us a simple and flexible tool for describing the range of activities necessary to the profession. Two or three examples are discussed, and ways in which quality can be controlled without too much bureaucracy. Potentially this approach has a world-wide application.
DEFF Research Database (Denmark)
Chambon, Julie Claire Claudia; Bjerg, Poul Løgstrup; Scheutz, Charlotte;
2013-01-01
Reductive dechlorination is a major degradation pathway of chlorinated ethenes in anaerobic subsurface environments, and reactive kinetic models describing the degradation process are needed in fate and transport models of these contaminants. However, reductive dechlorination is a complex biologi...
Doctors Describe First U.S. Case of Locally Acquired Zika in Pregnancy
... Doctors Describe First U.S. Case of Locally Acquired Zika in Pregnancy Baby shows no signs of brain ... HealthDay News) -- The first case of locally acquired Zika virus in a pregnant woman in the United ...
Endorsement of Models Describing Sexual Response of Men and Women with a Sexual Partner
DEFF Research Database (Denmark)
Giraldi, Annamaria; Kristensen, Ellids; Sand, Michael
2015-01-01
INTRODUCTION: Several models have been used to describe men's and women's sexual responses. These models have been conceptualized as linear or circular models. The circular models were proposed to describe women's sexual function best. AIM: This study aims to determine whether men and women thought...... that current theoretical models of sexual responses accurately reflected their own sexual experience and to what extent this was influenced by sexual dysfunction. METHODS: A cross-sectional study of a large, broadly sampled, nonclinical population, cohort of Danish men and women. The Female Sexual Function...... Index, Female Sexual Distress Scale, and the International Index of Erectile Function were used to describe sexual function. Also, participants completed questionnaires with written descriptions of different sexual responses to describe their most experienced sexual response. MAIN OUTCOME MEASURE...
Suicidal shooting masked using a method described in Conan Doyle's novel.
Gross, A; Kunz, J
1995-06-01
The case of a suicide by gunshot is presented in which the person committing the suicide used a method described by Conan Doyle in one of his novels: conceal the weapon and make the suicide appear to be a homicide.
IVOA Recommendation: SimpleDALRegExt: Describing Simple Data Access Services
Plante, Raymond; Harrison, Paul; Tody, Doug
2014-01-01
An application that queries or consumes descriptions of VO resources must be able to recognize a resource's support for standard IVOA protocols. This specification describes how to describe a service that supports any of the four fundamental data access protocols -- Simple Cone Search (SCS), Simple Image Access (SIA), Simple Spectral Access (SSA), Simple Line Access (SLA) -- using the VOResource XML encoding standard. A key part of this specification is the set of VOResource XML extension schemas that define new metadata that are specific to those protocols. This document describes in particular rules for describing such services within the context of IVOA Registries and data discovery as well as the VO Standard Interface (VOSI) and service self-description. In particular, this document spells out the essential markup needed to identify support for a standard protocol and the base URL required to access the interface that supports that protocol.
Mattsson, Ann E.; Wills, John M.
2013-03-01
The inability to computationally describe the physics governing the properties of actinides and their alloys is the poster child of failure of existing Density Functional Theory exchange-correlation functionals. The intricate competition between localization and delocalization of the electrons, present in these materials, exposes the limitations of functionals only designed to properly describe one or the other situation. We will discuss the manifestation of this competition in real materials and propositions on how to construct a functional able to accurately describe properties of these materials. I addition we will discuss both the importance of using the Dirac equation to describe the relativistic effects in these materials, and the connection to the physics of transition metal oxides. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
U.S. Geological Survey, Department of the Interior — This data set describes ground-water regions in the United States defined by the U.S. Geological Survey. These ground-water regions are useful for dividing the...
Best-fit index for describing physical perspectives in Sasang typology
National Research Council Canada - National Science Library
Chae, Han; Kown, Youngkyu
2015-01-01
Introduction: We examined the best-fit index for describing the constitutional or physical characteristics of Sasang typology for its universal application. Methods: Ponderal index (PI), body mass index (BMI...
WELL-POSEDNESS OF THE MODEL DESCRIBING A REPAIRABLE, STANDBY, HUMAN & MACHINE SYSTEM
Institute of Scientific and Technical Information of China (English)
Geni Gupur
2003-01-01
By using the strong continuous semigroup theory of linear operators we prove the existence of a unique positive time-dependent solution of the model describing a repairable, standby, human & machine system.
Directory of Open Access Journals (Sweden)
Patricio Peña-Rehbein
Full Text Available This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.
Describing a Decision Support System for Nuisance Management of Urban Building Sites
Hankach, Pierre; CHACHOUA, Mohamed; MARTIN, Jean Marc; GOYAT, YANN
2011-01-01
In this paper, a decision support system for managing urban building sites nuisances is described. First, the decision process for nuisance management is studied in order to understand the use context of the decision support system. Two levels are identified where decision support is appropriate : at the territorial level for the administrator of the public space and at the building site level for the project owner. The decision support system at the former level is described. The interactio...
Kurek,Marcin Andrzej; Piwińska, Monika; Wyrwisz, Jarosław; Wierzbicka, Agnieszka
2015-01-01
Abstract The growing interest in the usage of dietary fiber in food has caused the need to provide precise tools for describing its physical properties. This research examined two dietary fibers from oats and beets, respectively, in variable particle sizes. The application of automated static image analysis for describing the hydration properties and particle size distribution of dietary fiber was analyzed. Conventional tests for water holding capacity (WHC) were conducted. The particles were...
Institute of Scientific and Technical Information of China (English)
YANGWen-Xing; LIJia-Hua; LIWei-Bin; LUOJin-Ming; XIEXiao-Tao; WEIHua
2004-01-01
We present an efficient approach to studying the spectra and eigenstates for the model describing interactions among five bosonic modes without using the assumption of the Bethe ansatz. The exact analytical results of all the eigenstates and eigenvalues are in terms of a parameter A for a class of models describing five-mode multiphoton process. The parameter is determined by the roots of a polynomial and is solvable analytically or numerically.
Walcott, Sam
2014-10-01
Molecular motors, by turning chemical energy into mechanical work, are responsible for active cellular processes. Often groups of these motors work together to perform their biological role. Motors in an ensemble are coupled and exhibit complex emergent behavior. Although large motor ensembles can be modeled with partial differential equations (PDEs) by assuming that molecules function independently of their neighbors, this assumption is violated when motors are coupled locally. It is therefore unclear how to describe the ensemble behavior of the locally coupled motors responsible for biological processes such as calcium-dependent skeletal muscle activation. Here we develop a theory to describe locally coupled motor ensembles and apply the theory to skeletal muscle activation. The central idea is that a muscle filament can be divided into two phases: an active and an inactive phase. Dynamic changes in the relative size of these phases are described by a set of linear ordinary differential equations (ODEs). As the dynamics of the active phase are described by PDEs, muscle activation is governed by a set of coupled ODEs and PDEs, building on previous PDE models. With comparison to Monte Carlo simulations, we demonstrate that the theory captures the behavior of locally coupled ensembles. The theory also plausibly describes and predicts muscle experiments from molecular to whole muscle scales, suggesting that a micro- to macroscale muscle model is within reach.
Tan, Liying; Ma, Jing; Wang, Guangming
2005-12-01
The image formation and the point-spread function of an optical system are analyzed by use of the wavelet basis function. The image described by a wavelet is no longer an indivisible whole image. It is, rather, a complex image consisting of many wavelet subimages, which come from the changes of different parameters (scale) a and c, and parameters b and d show the positions of wavelet subimages under different scales. A Gaussian frequency-modulated complex-valued wavelet function is introduced to express the point-spread function of an optical system and used to describe the image formation. The analysis, in allusion to the situation of illumination with a monochromatic plain light wave, shows that using the theory of wavelet optics to describe the image formation of an optical system is feasible.
A Meta-model Describing the Development Process of Mobile Learning
Wingkvist, Anna; Ericsson, Morgan
This paper presents a meta-model to describe the development process of mobile learning initiatives. These initiatives are often small scale trials that are not integrated in the intended setting, but carried out outside of the setting. This results in sustainability issues, i.e., problems to integrate the results of the initiative as learning aids. In order to address the sustainability issues, and in turn help to understand the scaling process, a meta-model is introduced. This meta-model divides the development into four areas of concern, and the life cycle of any mobile learning initiative into four stages. The meta-model was developed by analyzing and describing how a podcasting initiative was developed, and is currently being evaluated as a tool to both describe and evaluate mobile learning initiatives. The meta-model was developed based on a mobile learning initiative, but the meta-model itself is extendible to other forms of technology-enhanced learning.
Navier-Stokes equation describes the movement of a special superfluid medium
Sbitnev, Valeriy I
2015-01-01
The Navier-Stokes equation contains two terms which have been subjected to slight modification: (a) the viscosity term depends of time (the viscosity in average on time is zero, but its variance is nonzero); (b) the pressure gradient contains an added term describing the entropy gradient multiplied by the pressure. Owing to these modifications, the Navier-Stokes equation can be reduced to the Schr\\"odinger equation describing behavior of a particle into the vacuum, where the vacuum is a superfluid medium. Vortex structures arising in this medium show infinitely long life owing to zero average viscosity. The nonzero variance describes exchange of the vortex energy with zero-point energy of the vacuum. Radius of the vortex trembles around some average value. This observation sheds the light to the Zitterbewegung phenomenon. The vortex has a non-zero core where the vortex velocity vanishes. Its organization is discussed with the point of view of the Calabi-Yau manifold.
Evaluation of the MALDI-TOF MS profiling for identification of newly described Aeromonas spp.
Vávrová, Andrea; Balážová, Tereza; Sedláček, Ivo; Tvrzová, Ludmila; Šedo, Ondrej
2015-09-01
The genus Aeromonas comprises primarily aquatic bacteria and also serious human and animal pathogens with the occurrence in clinical material, drinking water, and food. Aeromonads are typical for their complex taxonomy and nomenclature and for limited possibilities of identification to the species level. According to studies describing the use of MALDI-TOF MS in diagnostics of aeromonads, this modern chemotaxonomical approach reveals quite high percentage of correctly identified isolates. We analyzed 64 Aeromonas reference strains from the set of 27 species. After extending the range of analyzed Aeromonas species by newly described ones, we proved that MALDI-TOF MS procedure accompanied by Biotyper tool is not a reliable diagnostic technique for aeromonads. We obtained quite high percentage of false-positive, incorrect, and uncertain results. The identification of newly described species is accompanied with misidentifications that were observed also in the case of pathogenic aeromonads.
A method for describing the canopy architecture of coppice poplar with allometric relationships.
Casella, Eric; Sinoquet, Hervé
2003-12-01
A multi-scale biometric methodology for describing the architecture of fast-growing short-rotation woody crops is used to describe 2-year-old poplar clones during the second rotation. To allow for expressions of genetic variability observed within this species (i.e., growth potential, leaf morphology, coppice and canopy structure), the method has been applied to two clones: Ghoy (Gho) (Populus deltoides Bartr. ex Marsh. x Populus nigra L.) and Trichobel (Tri) (Populus trichocarpa Torr. & A. Gray x Populus trichocarpa). The method operates at the stool level and describes the plant as a collection of components (shoots and branches) described as a collection of metameric elements, themselves defined as a collection of elementary units (internode, petiole, leaf blade). Branching and connection between the plant units (i.e., plant topology) and their spatial location, orientation, size and shape (i.e., plant geometry) describe the plant architecture. The methodology has been used to describe the plant architecture of 15 selected stools per clone over a 5-month period. On individual stools, shoots have been selected from three classes (small, medium and large) spanning the diameter distribution range. Using a multi-scale approach, empirical allometric relationships were used to parameterize elementary units of the plant, topological relationships and geometry (e.g., distribution of shoot diameters on stool, shoot attributes from shoot diameter). The empirical functions form the basis of the 3-D Coppice Poplar Canopy Architecture model (3-D CPCA), which recreates the architecture and canopy structure of fast-growing coppice crops at the plot scale. Model outputs are assessed through visual and quantitative comparisons between actual photographs of the coppice canopy and simulated images. Overall, results indicate a good predictive ability of the 3-D CPCA model.
Straus, Sharon E; Sales, Anne; Wensing, Michel; Michie, Susan; Kent, Bridie; Foy, Robbie
2015-09-28
Alongside the growth in interest in implementation science, there has been a marked increase in training programs, educational courses, degrees, and other offerings in implementation research and practice to meet the demand for this expertise. We believe that the science of capacity building has matured but that we can advance it further by shining light on excellent work in this area and by highlighting gaps for future research. At Implementation Science, we regularly receive manuscripts that describe or evaluate training materials, competencies, and competency development in implementation curricula. We are announcing a renewed interest in manuscripts in this area, with specifications described below.
Stability margin of linear systems with parameters described by fuzzy numbers.
Husek, Petr
2011-10-01
This paper deals with the linear systems with uncertain parameters described by fuzzy numbers. The problem of determining the stability margin of those systems with linear affine dependence of the coefficients of a characteristic polynomial on system parameters is studied. Fuzzy numbers describing the system parameters are allowed to be characterized by arbitrary nonsymmetric membership functions. An elegant solution, graphical in nature, based on generalization of the Tsypkin-Polyak plot is presented. The advantage of the presented approach over the classical robust concept is demonstrated on a control of the Fiat Dedra engine model and a control of the quarter car suspension model.
Dimopoulos, Vassilios G; Robinson, Joe Sam; Fountas, Kostas N
2008-01-01
The purpose of our current study is to describe the guidelines regarding trephination as suggested in the Hippocratic writer's book, "Peri ton en cephali traumaton" ("On Head Wounds"). The ancient Greek text was reviewed as well as two English translations. The Hippocratic author described the indications, timing, and techniques of trephination for patients with head injury. He emphasized that attention should be paid to the details of the employed technique. He also commented on the difference of skull thickness at different anatomical sites and also between different age groups. The Hippocratic recommendations provided details for the performance of trephination by the ancient Greek physicians that are still considered important in modern neurosurgery.
Using visible-near infrared spectra to describe the distribution of Danish topsoils
DEFF Research Database (Denmark)
Knadel, Maria; Rossel, Raphael A. Viscarra; Deng, Fan
modeling to predict soil properties. However, information derived from spectra can also be used to describe the soil and how it varies across landscapes. The reason is that spectra contain information on the fundamental composition of soil: its organic matter, and iron oxide, clay and carbonate minerals...... the PCA were clustered using k-means to help with interpretation. Soil properties of the clusters were described using the mean spectrum of each class. We mapped the scores of the first three principal components using ordinary kriging. These maps and a cluster map derived with k-means clustering were...
A Model to Describe the Magnetomechanical Behavior of Martensite in Magnetic Shape Memory Alloy
Directory of Open Access Journals (Sweden)
Zaoyang Guo
2014-01-01
Full Text Available A model to describe the constitutive behavior of magnetic shape memory alloy composed with pure martensite is proposed based on the analysis of variants reorientation. A hyperbolic tangent expression is given to describe the variants transition during magnetic and mechanical loading process. The main features of magnetic shape memory alloy, such as pseudoelastic and partially pseudoelastic behavior as well as minor hysteretic loops, can be successfully replicated with the proposed model. A good agreement is achieved between calculated results and experimental data for NiMnGa single crystal.
Red Sea Leucothoidae (Crustacea: Amphipoda) including new and re-described species
White, Kristine N.
2017-05-31
Examination of leucothoid amphipods of the Red Sea has revealed seven species not previously reported from this location. Leucothoe minoculis sp. nov., Leucothoe pansa sp. nov., Leucothoe reimeri sp. nov., and Paranamixis sommelieri sp. nov. are described and the range of Leucothoe predenticulata Ledoyer, 1978, L. acutilobata Ledoyer, 1978 and L. squalidens Ledoyer, 1978 is expanded to include the Red Sea. Clarification of reports of L. acanthopus Schellenberg, 1928 and L. bannwarthi (Schellenberg, 1928) is provided and Leucothoe alani sp. nov. is described from outside the Red Sea.
Use of negative binomial distribution to describe the presence of Anisakis in Thyrsites atun.
Peña-Rehbein, Patricio; De los Ríos-Escalante, Patricio
2012-01-01
Nematodes of the genus Anisakis have marine fishes as intermediate hosts. One of these hosts is Thyrsites atun, an important fishery resource in Chile between 38 and 41° S. This paper describes the frequency and number of Anisakis nematodes in the internal organs of Thyrsites atun. An analysis based on spatial distribution models showed that the parasites tend to be clustered. The variation in the number of parasites per host could be described by the negative binomial distribution. The maximum observed number of parasites was nine parasites per host. The environmental and zoonotic aspects of the study are also discussed.
Which Metrics Are Appropriate to Describe the Value of New Cancer Therapies?
Directory of Open Access Journals (Sweden)
Peter Johnson
2015-01-01
Full Text Available Patients with certain cancers are treated with curative intent, but for others the results are less favorable and different therapeutic approaches are needed. Early data suggest that new therapies, which modulate immune responses to cancers, may have potential for long-term survival in a proportion of cases. Therefore, it is timely to consider whether metrics generally used to describe the medical value of therapies for patients with common solid tumors remain appropriate for therapies with curative potential. Literature reviews were conducted to define how various stakeholders describe cure in oncology and to identify the endpoints used in clinical trials for selected solid tumors. The results showed that “cure” is described using various terms that can be divided broadly into lack of disease progression, eradication of cancerous cells, and survival. The review of trial endpoints showed frequent use of median overall survival (OS and progression- and response-related endpoints. Because these endpoints were mainly described in the context of chemotherapies that are not generally curative, they may not adequately capture outcomes of new therapeutic modalities with potential for long-term survival. More appropriate endpoints may include mean OS, cure fraction, and OS rate at landmark time points.
Brambach, F.; Nooteboom, H.P.; Culmsee, H.
2013-01-01
Magnolia sulawesiana is described as new species and a modified key of Magnolia subsect. Elmerrillia is included. In addition, a new key of the ten Magnolia species occurring in Sulawesi is provided based on vegetative characters for easy identification in the field.
Davis, Paige E.; Meins, Elizabeth; Fernyhough, Charles
2014-01-01
Relations between having an imaginary companion (IC) and (i) descriptions of a real-life friend, (ii) theory of mind performance, and (iii) reported prosocial behaviour and behavioural difficulties were investigated in a sample of 5-year-olds (N?=?159). Children who had an IC were more likely than their peers without an IC to describe their best…
Describing the Climate of Student Organizations: The Student Organization Environment Scales.
Winston, Roger B., Jr.; Bledsoe, Tyrone; Goldstein, Adam R.; Wisbey, Martha E.; Street, James L.; Brown, Steven R.; Goyen, Kenneth D.; Rounds, Linda E.
1997-01-01
Using M. R. Weisbord's model of organizational diagnosis, researchers developed the Student Organization Environment Scales to measure students' perceptions of the psychosocial environment or climate of college student organizations. Development of the instrument is described and estimates of its reliability and validity are reported. Describes…
TYPE STUDIES IN THE CLAVARIOID FUNGI. V. THE TAXA DESCRIBED BY CASPAR VAN OVEREEM
Directory of Open Access Journals (Sweden)
RONALD H. PETERSEN
1980-03-01
Full Text Available ABSTRACTiType specimens of Javanese clavarias described by van Overeem —.e. Clavaria depokensis. Clavaria luteo-tenerrima, Clavaria sanguineo-acutaand Clavulinopsis sulcata — are extant and well preserved in HerbariumBogoriense. These are reexamined and reassigned to their respectivegenera and infrageneric complexes.
Dawis, Rene V.; And Others
1974-01-01
Job satisfaction data on managerial personnel were used to illustrate how organizations can be differentiated and described as reinforcer systems. Twenty-seven specific satisfaction scales were regressed on overall job satisfaction. Overall satisfaction was found to be determined mainly by scales concerning challenge of the job and prospects of…
"We All We Got": Describing and Connecting Football and Classroom Figured Worlds and Literacies
Rudd, Lynn L.
2013-01-01
Adolescents use literacies in order to build identities in a variety of figured worlds. Some identities become more powerful than others as adolescents attempt to understand and successfully utilize the valuations and literacies of the diverse figured worlds in which they participate. The goals of this study were to describe the figured worlds of…
Institute of Scientific and Technical Information of China (English)
ZHAO Chunshan; LI Kaitai; HUANG Aixiang
2002-01-01
In this paper, the long time behaviors of non-autonomous evolution system describing geophysical flow within the earth are studied. The uniqueness and existence of the solution to the evolution system and the existence of uniform attractor are proven.Moreover, the upper bounds of the uniform attractor's Hausdorff and Fractal dimensions are obtained.
A describing function approach to bipolar RF-power amplifier simulation
DEFF Research Database (Denmark)
Vidkjær, Jens
1981-01-01
A method for fast and accurate computations of the primary performance parameters such as gain, efficiency, output power, and bandwidth in class-C biased RF-power amplifier stages is presented. The method is based on a describing function characterization of the RF-power transistor where the term...
29 CFR 794.103 - Dependence of exemption on engagement in described distribution.
2010-07-01
... 29 Labor 3 2010-07-01 2010-07-01 false Dependence of exemption on engagement in described distribution. 794.103 Section 794.103 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION... Act Scope and Application in General § 794.103 Dependence of exemption on engagement in...
[Neurological aspects described in The treasure of medicines for all illnesses by Gregorio López].
Carod-Artal, F J; Vázquez-Cabrera, C B
Latin American medicine in the 16th century produced the first collections of herbs with native plants from the New World. Treatises on popular therapies appeared, which included gallenic remedies as well as incorporating autochthonous plants. We review the main neurological diseases and their treatments described in The Treasure of Medicines for All Illnesses by Gregorio Lopez (1542-1596). Some critics claim that his work was an enumeration of empirical prescriptions, sometimes with a magico-religious influence, which was extended in successive reprints. Yet, this manuscript is probably the first treatise on therapeutics written by a European in the New World to describe the native remedies employed in the treatment of diseases. In the section entitled Remedies in alphabetical order the following neurological ailments and appropriate remedies to treat them are described: abscess, apoplexy, brain, chilling, cramp, gota coral or epilepsy, headache, melancholy, memory, migraine, nerves, palsy, paralysis, sciatica, stupor and vertigo. The list of diseases is very complete and includes syndromes ranging from fevers, colics and bruises to phthisis, scabs or burns. The copy of the manuscript in the Vatican contains a final section on Indian medicines, which includes a list of medicinal plants used at that time, with the names given in Nahuatl language. Headaches, epilepsy and conditions affecting the peripheral nerves were the neurological pathologies that were described at greatest length in The Treasure of Medicines for All Illnesses, and for which a greater number of natural prescriptions were compiled.
Comment on "What does the Letelier-Gal'tsov metric describe?"
Clément, G; Letelier, P S
2005-01-01
We show that the Letelier-Gal'tsov (LG) metric describing multiple crossed strings in relative motion does solve the Einstein equations, in spite of the discontinuity uncovered recently by Krasnikov [gr-qc/0502090] provided the strings are straight and moving with constant velocities.
"We All We Got": Describing and Connecting Football and Classroom Figured Worlds and Literacies
Rudd, Lynn L.
2013-01-01
Adolescents use literacies in order to build identities in a variety of figured worlds. Some identities become more powerful than others as adolescents attempt to understand and successfully utilize the valuations and literacies of the diverse figured worlds in which they participate. The goals of this study were to describe the figured worlds of…
Palazzo, Steven J.; Skager, Cherie; Kraiger, Anneliese
2014-01-01
There is emerging evidence to suggest community-based interventions can change community-wide behaviors and attitudes toward cardiovascular health. This article describes a partnership between an academic institution and a community nonprofit organization to develop and implement a cardiovascular health promotion program targeting at risk high…
Development of a model and computer code to describe solar grade silicon production processes
Gould, R. K.; Srivastava, R.
1979-01-01
Two computer codes were developed for describing flow reactors in which high purity, solar grade silicon is produced via reduction of gaseous silicon halides. The first is the CHEMPART code, an axisymmetric, marching code which treats two phase flows with models describing detailed gas-phase chemical kinetics, particle formation, and particle growth. It can be used to described flow reactors in which reactants, mix, react, and form a particulate phase. Detailed radial gas-phase composition, temperature, velocity, and particle size distribution profiles are computed. Also, deposition of heat, momentum, and mass (either particulate or vapor) on reactor walls is described. The second code is a modified version of the GENMIX boundary layer code which is used to compute rates of heat, momentum, and mass transfer to the reactor walls. This code lacks the detailed chemical kinetics and particle handling features of the CHEMPART code but has the virtue of running much more rapidly than CHEMPART, while treating the phenomena occurring in the boundary layer in more detail.
Taxonomic status of the roses (Rosa) described by S.G. Dimitrov from Bulgaria
DEFF Research Database (Denmark)
Zielinski, J.; Petrova, A; Tan, Kit
2004-01-01
The original herbarium vouchers for six species of Rosa (Rosaceae) described by S. G. Dimitrov from Bulgaria are taxonomically evaluated. Two species (R. balcanica, R. orphei) are considered hybrids, four other names (R. bulgarica, R. parilica, R. pontica and R. rhodopaea) are taxonomic synonyms...
Flexible alternatives to the Gompertz equation for describing growth with age in turkey hens
DEFF Research Database (Denmark)
Porter, T; Kebreab, E; Darmani Kuhi, H
2010-01-01
A total of 49 profiles of growing turkey hens from commercial flocks were used in this study. Three flexible growth functions (von Bertalanffy, Richards, and Morgan) were evaluated with regard to their ability to describe the relationship between BW and age and were compared with the Gompertz...
The perception of static colored noise: detection and masking described by CIE94
Lucassen, M.P.; Bijl, P.; Roelofsen, J.
2008-01-01
We present psychophysical data on the perception of static colored noise. In our experiments, we use the CIE94 color difference formula to quantify the noise strength and for describing our threshold data. In Experiment 1 we measure the visual detection thresholds for fixed pattern noise on a unifor
Exley, Beryl; Cottrell, Amber
2012-01-01
The recently introduced "Australian Curriculum: English" (Australian Curriculum, Assessment and Reporting Authority (ACARA), 2012) requires students to "read" multimodal text and describe the effects of structure and organisation. We begin this article by tracing the variable understandings of what reading multimodal text might entail through the…
Hoeven, van der N.; Elsas, van J.D.; Heijnen, C.E.
1996-01-01
A computer simulation model was developed which describes growth and competition of bacteria in the soil environment. In the model, soil was assumed to contain millions of pores of a few different size classes. An introduced bacterial strain, e.g. a genetically modified micro-organism (GEMMO), was a
Raggi, Alberto; Leonardi, Matilde; Ajovalasit, Daniela; Carella, Francesco; Soliveri, Paola; Albanese, Alberto; Romito, Luigi
2011-01-01
The objective of this study was to describe the functional profiles of patients with Parkinson's disease (PD), and the relationships between impairment in body functions, limitations in activities, and environmental factors, using the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). Patients…
Millican, J. Si
2013-01-01
Pedagogical content knowledge, the particular ways that teachers understand their subjects in order to instruct others, has been described and explored in the math and science education fields in some depth, yet little research exists illustrating this concept in music instruction. I used a descriptive approach to explore expert beginning band…
A model for describing the thermodynamics of multivalent host-guest interactions at interfaces
Huskens, Jurriaan; Mulder, A.; Auletta, T.; Nijhuis, C.A.; Ludden, M.J.W.; Reinhoudt, David
2004-01-01
A model has been described for interpreting the binding of multivalent molecules to interface-immobilized monovalent receptors through multiple, independent interactions. It is based on the concept of effective concentration, Ceff, which has been developed before for multivalent binding in solution
A transient-network model describing the rheological behaviour of concentrated dispersions
Kamphuis, H.; Jongschaap, R.J.J.; Mijnlieff, P.F.
1984-01-01
Attractive forces acting between particles in dispersions may cause a three-dimensional structure to be built up. A temporary-network model is postulated that describes the rheological behaviour of such systems. Chains of particles are assumed to be created and broken by thermal actions and by appli
control theory to systems described by partial differential equations. The intent is not to advance the theory of partial differential equations per se. Thus all considerations will be restricted to the more familiar equations of the type which often occur in mathematical physics. Specifically, the distributed parameter systems under consideration are represented by a set of field
The Hypopi of the genus Sennertia Oudemans, 1905, described by Oudemans (Acarina, Sarcoptiformes)
Fain, A.
1974-01-01
Introduction Oudemans has described several species of mites of the genus Sennertia, most of them only after their heteromorphic deutonymphs (or hypopi). These species live as adults in the nests of Hymenoptera, especially bees, and are transported phoretically from nest to nest by means of their
Students with Low Vision Describe Their Visual Impairments and Visual Functioning
Guerette, Amy R.; Lewis, Sandra; Mattingly, Cameron
2011-01-01
In the study reported here, the responses to a survey that was designed to determine the knowledge of their visual impairment of 51 students with low vision were analyzed. Although the students described their visual weaknesses and strengths, they had limited knowledge of, and difficulty communicating about, the medical aspects of their…
Benes, Nieck Edwin; Verweij, H.
2000-01-01
A detailed discussion is presented of three well-known macroscopic theories for describing the mass transport behavior of multicomponent mixtures; these include Fick's law, the Onsager theory of irreversible thermodynamics, and the Maxwell-Stefan theory. The merits and drawbacks of these theories ar
How Do Students Studying Turkish in Lithuania Describe Turkish Culture and People?
Varisoglu, M. Celal
2017-01-01
The aim of this paper is to describe ideas that students learning Turkish in Lithuania have about Turkish culture and Turkish people. A descriptive method was used in the research. The data for the research was collected from 15 students who learn Turkish at Vilnius University in Vilnius, Lithuania. For the participating in the research students,…
Yu, H.; Erp, N. van; Bins, S.; Mathijssen, R.H.; Schellens, J.H.; Beijnen, J.H.; Steeghs, N.; Huitema, A.D.
2017-01-01
BACKGROUND AND OBJECTIVE: Pazopanib is a multi-targeted anticancer tyrosine kinase inhibitor. This study was conducted to develop a population pharmacokinetic (popPK) model describing the complex pharmacokinetics of pazopanib in cancer patients. METHODS: Pharmacokinetic data were available from 96
A model to describe potential effects of chemotherapy on critical radiobiological treatments
Rodríguez-Pérez, D.; Desco, M. M.; Antoranz, J. C.
2016-08-01
Although chemo- and radiotherapy can annihilate tumors on their own. they are also used in coadjuvancy: improving local effects of radiotherapy using chemotherapy as a radiosensit.izer. The effects of radiotherapy are well described by current radiobiological models. The goal of this work is to describe a discrete radiotherapy model, that has been previously used describe high radiation dose response as well as unusual radio-responses of some types of tumors (e.g. prostate cancer), to obtain a model of chemo+radiotherapy that can describe how the outcome of their combination is a more efficient removal of the tumor. Our hypothesis is that, although both treatments haven different mechanisms, both affect similar key points of cell metabolism and regulation, that lead to cellular death. Hence, we will consider a discrete model where chemotherapy may affect a fraction of the same targets destroyed by radiotherapy. Although radiotherapy reaches all cells equally, chemotherapy diffuses through a tumor attaining lower concentration in its center and higher in its surface. With our simulations we study the enhanced effect of combined therapy treatment and how it depends on the tissue critical parameters (the parameters of the lion-extensive radiobiological model), the number of “targets” aimed at by chemotherapy, and the concentration and diffusion rate of the drug inside the tumor. The results show that an equivalent, cliemo-radio-dose can be computed that allows the prediction of the lower radiation dose that causes the same effect than a radio-only treatment.
Lettinga, AT; van Twillert, S; Poels, BJJ; Postema, K
2006-01-01
Background: An editorial by Wade ( Clinical Rehabilitation 2005; 19: 811 - 18) suggested a method for describing rehabilitation interventions. Objective: To review the editorial critically, and to suggest a more complete theory. Editorial: The editorial develops a model identifying factors that shou
INSEAN REPORT DESCRIBING THE DESIGN OF THE CRANE AND THE CATAPULT SYSTEM FOR GUIDED DITCHING TESTS
Iafrati, Alessandro
2012-01-01
The present report describes the key points of the design of the facility to be used for the guided ditching test in T4.1. The system is made by three main components: guide, trolley, acceleration and release system (catapult). Each component is illustrated separately in the following.
Dynamic behaviour of reactive distillation tray columns described with a non-equilibrium cell model
Baur, R.; Taylor, R.; Krishna, R.
2001-01-01
In this paper we develop a generic, dynamic, nonequilibrium (NEQ) cell model for reactive distillation (RD) tray columns. The features of our model are (1) the use of Maxwell–Stefan equations for describing mass transfer between fluid phases, (2) the reaction is assumed to take place in the liquid
Describing the Climate of Student Organizations: The Student Organization Environment Scales.
Winston, Roger B., Jr.; Bledsoe, Tyrone; Goldstein, Adam R.; Wisbey, Martha E.; Street, James L.; Brown, Steven R.; Goyen, Kenneth D.; Rounds, Linda E.
1997-01-01
Using M. R. Weisbord's model of organizational diagnosis, researchers developed the Student Organization Environment Scales to measure students' perceptions of the psychosocial environment or climate of college student organizations. Development of the instrument is described and estimates of its reliability and validity are reported. Describes…
The objective of this work was to evaluate eight closed-form unimodal analytical expressions that describe the soil-water retention curve over the complete range of soil water contents. To meet this objective, the eight models were compared in terms of their accuracy (root mean square error, RMSE), ...
Wiebes, J.T.
1970-01-01
After having given for publication my report on the West African Agaonidae (Wiebes, 1969b), I received on loan the type specimens of several species described by J. Risbec (1951a, b; 1954a, b). A few lines on the results of the study of these specimens could be incorporated in the proof of my paper
Hoeven, van der N.; Elsas, van J.D.; Heijnen, C.E.
1996-01-01
A computer simulation model was developed which describes growth and competition of bacteria in the soil environment. In the model, soil was assumed to contain millions of pores of a few different size classes. An introduced bacterial strain, e.g. a genetically modified micro-organism (GEMMO), was a
Using SensorML to describe scientific workflows in distributed web service environments
CSIR Research Space (South Africa)
Van Zyl, TL
2009-07-01
Full Text Available for increased collaboration through workflow sharing. The Sensor Web is an open complex adaptive system the pervades the internet and provides access to sensor resources. One mechanism for describing sensor resources is through the use of SensorML. It is shown...
Water in micro- and nanofluidics systems described using the water potential
Eijkel, Jan C.T.; van den Berg, Albert
2005-01-01
This Tutorial Review shows the behaviour of water in micro- and nanofluidic systems. The chemical potential of water (‘water potential’) conveniently describes the energy level of the water at different locations in and around the system, both in the liquid and gaseous state. Since water moves from
Chandrasegaran, A. L.; Treagust, David F.; Mocerino, Mauro
2011-01-01
This study involved the evaluation of the efficacy of a planned instructional program to facilitate understanding of the macroscopic, submicroscopic and symbolic representational systems when describing and explaining chemical reactions by sixty-five Grade 9 students in a Singapore secondary school. A two-tier multiple-choice diagnostic instrument…
Energy Technology Data Exchange (ETDEWEB)
Czejdo, Bogdan [ORNL; Bhattacharya, Sambit [North Carolina Fayetteville State University; Ferragut, Erik M [ORNL
2012-01-01
This paper describes the syntax and semantics of multi-level state diagrams to support probabilistic behavior of cooperating robots. The techniques are presented to analyze these diagrams by querying combined robots behaviors. It is shown how to use state abstraction and transition abstraction to create, verify and process large probabilistic state diagrams.
Type-studies in the Polyporaceae—I. Tropical species described by C. H. Persoon
Ryvarden, Leif
1973-01-01
The type specimens of 20 tropical polypores described by C. H. Persoon have been examined. Eleven species are accepted, seven are reduced to synonymy, while one name is a nomen nudum. One type is so poorly developed that no conclusive determination is possible. The combination Trametes marianna
Using a Model to Describe Students' Inductive Reasoning in Problem Solving
Canadas, Maria C.; Castro, Encarnacion; Castro, Enrique
2009-01-01
Introduction: We present some aspects of a wider investigation (Canadas, 2007), whose main objective is to describe and characterize inductive reasoning used by Spanish students in years 9 and 10 when they work on problems that involved linear and quadratic sequences. Method: We produced a test composed of six problems with different…
Identifying and Describing Tutor Archetypes: The Pragmatist, the Architect, and the Surveyor
Harootunian, Jeff A.; Quinn, Robert J.
2008-01-01
In this article, the authors identify and anecdotally describe three tutor archetypes: the pragmatist, the architect, and the surveyor. These descriptions, based on observations of remedial mathematics tutors at a land-grant university, shed light on a variety of philosophical beliefs regarding and pedagogical approaches to tutoring. An analysis…
28 CFR 75.6 - Statement describing location of books and records.
2010-07-01
... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Statement describing location of books... of books and records. (a) Any producer of any book, magazine, periodical, film, videotape, digitally... the book, magazine, periodical, film, videotape, digitally- or computer-manipulated image,...
Collective properties of deformed atomic clusters described within a projected spherical basis
Raduta, A. A.; Raduta, Al. H.; Budaca, R.
2011-01-01
Several relevant properties of the Na clusters were studied by using a projected spherical single particle states.The proposed model is able to describe in an unified fashion the spherical and deformed clusters. Photoabsorbtion cross section is realistically explained within an RPA approach and a Shiff dipole moment as a transition operator
Jeffrey D. Kline; Alissa Moses; David L. Azuma; Andrew. Gray
2009-01-01
Forestry professionals are concerned about how forestlands are affected by residential and other development. To address those concerns, researchers must find appropriate data with which to describe and evaluate rates and patterns of forestland development and the impact of development on the management of remaining forestlands. We examine land use data gathered from...
THE LONG TIME BEHAVIORS OF NON－AUTONOMOUS EVOLUTION SYSTEM DESCRIBING GEOPHYSICAL FLOW WITHIN THE
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
In this paper,the long time behaviors of non-autonomous evolution system describing geophysical flow within the earth are studied.The uniqueness and existence of the solution to the evolution system and the existence of uniform attractor are proven.Moreover,the upper bounds of the uniform attractor's hausdorff and Fractal dimensions are obtained.
Introducing enzyme selectivity: a quantitative parameter to describe enzymatic protein hydrolysis
Butré, C.I.; Sforza, S.; Gruppen, H.; Wierenga, P.A.
2014-01-01
Enzyme selectivity is introduced as a quantitative parameter to describe the rate at which individual cleavage sites in a protein substrate are hydrolyzed relative to other cleavage sites. Whey protein isolate was hydrolyzed by Bacillus licheniformis protease, which is highly specific for Glu and
DEFF Research Database (Denmark)
Van den Bosch, Thierry; Dueholm, Margit; Leone, FP
2015-01-01
The MUSA (Morphological Uterus Sonographic Assessment) statement is a consensus statement on terms, definitions and measurements that may be used to describe and report the sonographic features of the myometrium using gray-scale sonography, color/power Doppler and three-dimensional ultrasound...
A comparison of the Schumacher with other functions for describing growth in pigs
Schulin-Zeuthen, M.; Kebreab, E.; Dijkstra, J.; Lopez, S.; Bannink, A.; Darmani Kuhi, H.; Thornley, J.H.M.; France, J.
2008-01-01
This study was undertaken to introduce the Schumacher equation and compare it with established functions for describing growth in pigs. The relationship between live weight (LW) and cumulative feed intake was also investigated. A database was constructed from three independent trials in which LW, ag
Robustness of a cross contamination model describing transfer of pathogens during grinding of meat
DEFF Research Database (Denmark)
Møller, Cleide Oliveira de Almeida; Sant’Ana, A. S.; Hansen, Solvej Katrine Holm
2016-01-01
This study aimed to evaluate a cross contamination model for its capability of describing transfer of Salmonella spp. and L. monocytogenes during grinding of varying sizes and numbers of pieces of meats in two grinder systems. Data from 19 trials were collected. Three evaluation approaches were...
Robustness of a cross contamination model describing transfer of pathogens during grinding of meat
DEFF Research Database (Denmark)
Møller, Cleide Oliveira de Almeida; Sant’Ana, A. S.; Hansen, Solvej Katrine Holm
2016-01-01
This study aimed to evaluate a cross contamination model for its capability of describing transfer of Salmonella spp. and L. monocytogenes during grinding of varying sizes and numbers of pieces of meats in two grinder systems. Data from 19 trials were collected. Three evaluation approaches were...
Using the Language of Sets to Describe Nested Systems in Emergy Evaluations
The language of set theory has been recently used to describe the emergy evaluation of a process. In this paper this mathematical language is used as a guide to evaluate the emergy of nested systems. We analyze a territorial system on multiple scales as an example of hierarchical...
Combining the CIDOC CRM and MPEG-7 to Describe Multimedia in Museums.
Hunter, Jane
This paper describes a proposal for an interoperable metadata model, based on international standards, that has been designed to enable the description, exchange and sharing of multimedia resources both within and between cultural institutions. Domain-specific ontologies have been developed by two different ISO Working Groups to standardize the…
The perception of static colored noise: detection and masking described by CIE94
Lucassen, M.P.; Bijl, P.; Roelofsen, J.
2008-01-01
We present psychophysical data on the perception of static colored noise. In our experiments, we use the CIE94 color difference formula to quantify the noise strength and for describing our threshold data. In Experiment 1 we measure the visual detection thresholds for fixed pattern noise on a
Elsener, K; Schlatter, D; Siegrist, N
2011-01-01
The CLIC_ILD and CLIC_SiD detector concepts as used for the CDR Vol. 2 in 2011 exist both in GEANT4 simulation models and in engineering layout drawings. At this early stage of a conceptual design, there are inevitably differences between these models, which are described in this note.
Notes on the Pentatomidae (Hemiptera Heteroptera) described by Dr. Snellen van Vollenhoven
Schouteden, H.
1908-01-01
During a short stay made last year in Leyden, I was enabled, through the courtesy of Mr. Ritsema, to examine the types of the Pentatomidae in the Leyden Museum, described by the late Snellen van Vollenhoven. Various doubtful species were thus identified and observations of previous authors controlle
Directory of Open Access Journals (Sweden)
R.L.G.M. Blom
2009-11-01
Full Text Available Background: Postoperative pancreatitis is a rare but devastating complication after esophageal surgery. It has been described in connection with abdominal surgery but the etiology in connection with esophageal surgery has never been evaluated. The present study describes 4 cases of postoperative pancreatitis, and a hypothesis about the etiology is formed. Methods: We performed a search for patients with postoperative pancreatitis after esophagectomy using our prospective database including all patients that underwent esophageal resection at our institution between 1993 and 2008. Pancreatitis was described as abdominal pain, hyperamylasemia, signs of pancreatitis on CT scan or findings during laparotomy or autopsy. Results: A total of 950 patients underwent esophagectomy at our institution, 4 patients developed postoperative pancreatitis (incidence 0.4%. Two out of four patients died. Discussion: Pancreatitis following esophageal surgery is a serious, potentially lethal complication. Diagnosis can be difficult as clear clinical or laboratory findings might be lacking. Peroperative manipulation of the pancreas, mobilization of the duodenum or compromized vascularization have been suggested as etiological factors; although in the described patients, none of these factors were identified as the cause of pancreatitis. In conclusion, pancreatitis following esophageal surgery is a serious but rare complication that should always be considered in patients who deteriorate postoperatively.
Raggi, Alberto; Leonardi, Matilde; Ajovalasit, Daniela; Carella, Francesco; Soliveri, Paola; Albanese, Alberto; Romito, Luigi
2011-01-01
The objective of this study was to describe the functional profiles of patients with Parkinson's disease (PD), and the relationships between impairment in body functions, limitations in activities, and environmental factors, using the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). Patients…
Energy Technology Data Exchange (ETDEWEB)
Foss, O.A.; Klaksvik, J.; Benum, P.; Anda, S. [Norwegian Orthopedic Implant Research Unit, and Dept. of Radiology, St. Olav' s Hospital, Trondheim Univ. Hosp ital, Trondheim (Norway)
2007-11-15
Background: A method to describe pelvic rotations between pairs of standard sequential pelvic anteroposterior radiographs based on a pelvic phantom is described in a former study. Purpose: To expand this method into clinical use based on clinical data. Material and Methods: Teardrop distances were measured on 262 pelvic radiographs from 46 patients in a clinical material using a computer program designed to perform measurements on digital radiographs. Anthropometric data recorded from 141 pelvises in an anatomical collection were employed in a computer program designed to simulate radiographs of virtual objects. Virtual rotations of the pelvises were carried out with 4653 virtual radiographs obtained. Virtual radiographic measures were analyzed. Results: A statistically significant difference of 8 mm between mean teardrop distance in females (120 mm) and males (112 mm) was found in the clinical material. A set of formulas describing the relations between differences of two rotation ratios and pelvic rotations were derived. Four simple regression analyses were carried out with the use of virtual measures. Adjusted teardrop distances were implemented. Conclusion: A clinical method to describe pelvic rotations using standard pelvic radiographs was developed.
Phillips, David E.
2011-01-01
Every administrative action a principal will take is reduced to a decision. These decisions are made in an arena of overlapping moralities stemming from the organizational morality in concert with his/her personal morality. As Barnard stated, it is impossible to divorce one from the other. The purpose of this study was to attempt to describe and…
Features described and illustrated in 1684 suggesting Meckel-Gruber syndrome.
Kompanje, Erwin J O
2003-01-01
In 1684, Mr. Christopher Krahe described a monstrous child, born in Denmark on Friday, February 29, 1684. The description is suggestive of a diagnosis of Meckel-Gruber syndrome (dysencephalia splanchnocystica). This may represent the oldest description and illustration of the syndrome, of which the first detailed description is attributed to Johann Friedrich der Jüngere in 1822.
The Metaphors That Elementary School Students Use to Describe the Term "Teacher"
Karadag, Ruhan; Gültekin, Mehmet
2012-01-01
The aim of this study is to investigate metaphors that elementary school 5th and 8th grade students (N = 567) use in order to describe the term "teacher". The data were collected using a questionnaire consisting of open-ended questions, and analyzed using qualitative and quantitative analysis techniques. Content analysis technique was…
A transient-network model describing the rheological behaviour of concentrated dispersions
Kamphuis, H.; Jongschaap, R.J.J.; Mijnlieff, P.F.
1984-01-01
Attractive forces acting between particles in dispersions may cause a three-dimensional structure to be built up. A temporary-network model is postulated that describes the rheological behaviour of such systems. Chains of particles are assumed to be created and broken by thermal actions and by appli
A simple equation for describing the temperature dependent growth of free-floating macrophytes
Heide, van Tj.; Roijackers, R.M.M.; Nes, van E.H.; Peeters, E.T.H.M.
2006-01-01
Temperature is one of the most important factors determining growth rates of free-floating macrophytes in the field. To analyse and predict temperature dependent growth rates of these pleustophytes, modelling may play an important role. Several equations have been published for describing temperatur
A constrained von Mises distribution to describe fiber organization in thin soft tissues.
Gouget, Cecile L M; Girard, Michael J; Ethier, C Ross
2012-03-01
The semi-circular von Mises distribution is widely used to describe the unimodal planar organization of fibers in thin soft tissues. However, it cannot accurately describe the isotropic subpopulation of fibers present in such tissues, and therefore an improved mathematical description is needed. We present a modified distribution, formed as a weighted mixture of the semi-circular uniform distribution and the semi-circular von Mises distribution. It is described by three parameters: β, which weights the contribution from each mixture component; k, the fiber concentration factor; and θ ( p ), the preferred fiber orientation. This distribution was used to fit data obtained by small-angle light scattering experiments from various thin soft tissues. Initial use showed that satisfactory fits of fiber distributions could be obtained (error generally constrained 2-parameter fiber distribution. Compared to the 3-parameter distribution, the constrained 2-parameter distribution fits experimental data well (error generally constrained 2-parameter approach was more robust to experimental noise. The constrained 2-parameter fiber distribution can replace the semi-circular von Mises distribution to describe unimodal planar organization of fibers in thin soft tissues. Inclusion of such a function in constitutive models for finite element simulations should provide better quantitative estimates of soft tissue biomechanics under normal and pathological conditions.
Directory of Open Access Journals (Sweden)
Sharma S
2016-11-01
Full Text Available Saurab Sharma,1 Anupa Pathak,2 Mark P Jensen3 1Department of Physiotherapy, Kathmandu University School of Medical Sciences, Dhulikhel Hospital Kathmandu University Hospital, Dhulikhel, 2Department of Physiotherapy, Kathmandu University School of Medical Sciences, Dhulikhel, Kavre, Nepal; 3Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA Background: People from different cultures who speak different languages may experience pain differently. This possible variability has important implications for evaluating the validity of pain quality measures that are directly translated into different languages without cultural adaptations. The aim of this study was to evaluate the impact of language and culture on the validity of pain quality measures by comparing the words that individuals with chronic pain from Nepal use to describe their pain with those used by patients from the USA. Methods: A total of 101 individuals with chronic musculoskeletal pain in Nepal were asked to describe their pain. The rates of the different pain descriptor domains and phrases used by the Nepali sample were then compared to the published rates of descriptors used by patients from the USA. The content validity of commonly used measures for assessing pain quality was then evaluated. Results: While there was some similarity between patients from Nepal and the USA in how they describe pain, there were also important differences, especially in how pain quality was described. For example, many patients from Nepal used metaphors to describe their pain. Also, the patients from Nepal often used a category of pain descriptor – which describes a physical state – not used by patients from the USA. Only the original McGill Pain Questionnaire was found to have content validity for assessing pain quality in patients from Nepal, although other existing pain quality measures could be adapted to be content valid by adding one or two additional descriptors
A Porosity Method to Describe Complex 3D-Structures Theory and Application to an Explosion
Directory of Open Access Journals (Sweden)
M.-F. Robbe
2006-01-01
Full Text Available A theoretical method was developed to be able to describe the influence of structures of complex shape on a transient fluid flow without meshing the structures. Structures are considered as solid pores inside the fluid and act as an obstacle for the flow. The method was specifically adapted to fast transient cases.The porosity method was applied to the simulation of a Hypothetical Core Disruptive Accident in a small-scale replica of a Liquid Metal Fast Breeder Reactor. A 2D-axisymmetrical simulation of the MARS test was performed with the EUROPLEXUS code. Whereas the central internal structures of the mock-up could be described with a classical shell model, the influence of the 3D peripheral structures was taken into account with the porosity method.
Benchmarking of numerical models describing the dispersion of radionuclides in the Arctic Seas
Energy Technology Data Exchange (ETDEWEB)
Scott, E.M.; Harms, I. [Department of Statistics, University of Glasgow, Glasgow (United Kingdom); Gurbutt, P. [MAFF, Fisheries Laboratory, Lowestoft (United Kingdom); Heling, R. [KEMA, Arnhem (Netherlands); Nielsen, S.P. [Risoe National Laboratory, Roskilde (Denmark); Osvath, I. [IAEA Marine Environment Laboratory, Monaco (France); Preller, R. [Naval Research Laboratory, Stennis Space Center (United States); Sazykina, T. [SPA Typhoon, Obninsk (Russian Federation); Wada, A. [Department of Civil Engineering, College of Industrial Technology, Nihon University, Nihon (Japan); Sjoeblom, K.L. [IAEA Waste Management Division, Vienna (Austria)
1997-08-25
As part of the International Arctic Seas Assessment Project (IASAP) of the International Atomic Energy Agency (IAEA), a working group was created to model the dispersal and transfer of radionuclides released from radioactive waste disposed of in the Kara Sea. The objectives of this group are: (1) development of realistic and reliable assessment models for the dispersal of radioactive contaminants both within, and from, the Arctic ocean; and (2) evaluation of the contributions of different transfer mechanisms to contaminant dispersal and hence, ultimately, to the risks to human health and environment. With regard to the first objective, the modelling work has been directed towards assessment of model reliability and as one aspect of this, a benchmarking exercise has been carried out. This paper briefly describes the benchmark scenario, the models developed and used, and discusses some of the benchmarking results. The role of the exercise within the modelling programme of IASAP will be discussed and future work described.
Refinement of a discontinuity-free edge-diffraction model describing focused wave fields.
Sedukhin, Andrey G
2010-03-01
Two equivalent forms of a refined discontinuity-free edge-diffraction model describing the structure of a stationary focused wave field are presented that are valid in the framework of the scalar Debye integral representation for a diffracted rotationally symmetric converging spherical wave of a limited yet not-too-low angular opening. The first form describes the field as the sum of a direct quasi-spherical wave and a plurality of edge quasi-conical waves of different orders, the optimum discontinuity-free angular spectrum functions of all the waves being dependent on the polar angle only. According to the second form, the focused field is fully characterized by only three components--the same quasi-spherical wave and two edge quasi-conical waves of the zero and first order, of which the optimum discontinuity-free angular spectrum functions are dependent on both the polar angle and the polar radius counted from the geometrical focus.
Nicolaou, Georgios
2016-01-01
This paper presents the misestimation of temperature when observations from a kappa distributed plasma are analyzed as a Maxwellian. One common method to calculate the space plasma parameters is by fitting the observed distributions using known analytical forms. More often, the distribution function is included in a forward model of the instrument's response, which is used to reproduce the observed energy spectrograms for a given set of plasma parameters. In both cases, the modeled plasma distribution fits the measurements to estimate the plasma parameters. The distribution function is often considered to be Maxwellian even though in many cases the plasma is better described by a kappa distribution. In this work we show that if the plasma is described by a kappa distribution, the derived temperature assuming Maxwell distribution can be significantly off. More specifically, we derive the plasma temperature by fitting a Maxwell distribution to pseudo-data produced by a kappa distribution, and then examine the d...
A Polydisperse Sphere Model Describing the Propagation of Light in Biological Tissue
Institute of Scientific and Technical Information of China (English)
WANG Qing-Hua; LI Zhen-Hua; LAI Jian-Cheng; HE An-Zhi
2007-01-01
A polydisperse sphere model with the complex refractive index is employed to describe the propagation of light in biological tissue.The scattering coefficient,absorption coefficient and scattering phase function are calculated.At the same time,the inverse problem on retrieving the particles size distribution,imaginary part of the refractive index and number density of scatterers is investigated.The result shows that the retrieval scheme together with the Chahine algorithm is effective in dealing with such an inverse problem.IT is also clarified that a group of parameters including the scattering coefficient,absorption coefficient and phase function are associated with another group including the refractive index,particle size distribution and number density of scatterers,which is a problem described in two different ways and the anisotropy factor is not an independent variable,but is determined by the phase function.
Karimirad, Fatemeh; Shirinzadeh, Bijan; Yan, Wenyi; Fatikow, Sergej
2013-02-01
The main objective of this article is to mechanize the procedure of tracking and describing the various phases of deformation of a biological circular cell during micromanipulation. The devised vision-based methodology provides a real-time strategy to track and describe the cell deformation by extracting a geometric feature called dimple angle. An algorithm based on Snake was established to acquire the boundary of the indenting cell and measure the aforementioned feature. Micromanipulation experiments were conducted for zebrafish embryos. Experimental results were used to characterize the deformation of the manipulating embryo by the devised geometric parameter. The results demonstrated the high capability of the methodology. The proposed method is applicable to the micromanipulation of other circular biological embryos such as injection of the mouse oocyte/embryo. Supplemental materials are available for this article. Go to the publisher's online edition of the International Journal of Optomechatronics to view the supplemental files.
Filippov, A T
2016-01-01
The dynamics of any spherical cosmology with a scalar field (`scalaron') coupling to gravity is described by the nonlinear second-order differential equations for two metric functions and the scalaron depending on the `time' parameter. The equations depend on the scalaron potential and on arbitrary gauge function that describes time parameterizations. This dynamical system can be integrated for flat, isotropic models with very special potentials. But, somewhat unexpectedly, replacing the independent variable $t$ by one of the metric functions allows us to completely integrate the general spherical theory in any gauge and with arbitrary potentials. In this approach, inflationary solutions can be easily identified, explicitly derived, and compared to the standard approximate expressions. This approach is also applicable to intrinsically anisotropic models with a massive vector field (`vecton') as well as to some non-inflationary models.
African American mothers' self-described discipline strategies with young children in 1992 and 2012.
LeCuyer, Elizabeth A; Christensen, Julie J; Kreher, Donna; Kearney, Margaret H; Kitzman, Harriet J
2015-01-01
In this qualitative descriptive study, 30 young, unmarried, low-income African American mothers in Memphis, TN, were interviewed in 2011-2012 about their discipline strategies with their 12- to 19-month-old children. Using content analyses, their strategies were described and compared with those from a similar sample in 1992. Findings suggest both continuity and change during that 20-year period. More mothers in 2011-2012 described the use of distraction and time out, suggesting a wider variety of strategies than were used in 1992. These findings may help clinicians to better understand disciplinary methods in young low-income African American mothers such as these in Memphis. Approaching mothers in a respectful and culturally sensitive manner will help them focus on effective, developmentally appropriate strategies consistent with their own parenting goals.
Energy Technology Data Exchange (ETDEWEB)
Ibragimov, Nail H [Department of Mathematics and Science, Blekinge Institute of Technology, SE-371 79 Karlskrona (Sweden); Meleshko, Sergey V [School of Mathematics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Rudenko, Oleg V, E-mail: nib@bth.se, E-mail: sergey@math.sut.ac.th, E-mail: rudenko@acs366.phys.msu.ru [Department of Physics, Moscow State University, 119991 Moscow (Russian Federation)
2011-08-05
The paper deals with an evolutionary integro-differential equation describing nonlinear waves. A particular choice of the kernel in the integral leads to well-known equations such as the Khokhlov-Zabolotskaya equation, the Kadomtsev-Petviashvili equation and others. Since the solutions of these equations describe many physical phenomena, the analysis of the general model studied in this paper is important. One of the methods for obtaining solutions of differential equations is provided by the Lie group analysis. However, this method is not applicable to integro-differential equations. Therefore, we discuss new approaches developed in modern group analysis and apply them to the general model considered in this paper. Reduced equations and exact solutions are also presented.
Core - Corona Model describes the Centrality Dependence of v_2/epsilon
Aichelin, J
2010-01-01
Event by event EPOS calculations in which the expansion of the system is described by {\\it ideal} hydrodynamics reproduce well the measured centrality dependence of $v_2/\\epsilon_{part}$, although it has been claimed that only viscous hydrodynamics can reproduce these data. This is due to the core - corona effect which manifests itself in the initial condition of the hydrodynamical expansion. The centrality dependence of $v_2/\\epsilon_{part}$ can be understood in the recently advanced core-corona model, a simple parameter free EPOS inspired model to describe the centrality dependence of different observables from SPS to RHIC energies. This model has already been successfully applied to understand the centrality dependence of multiplicities and of the average transverse momentum of identified particles.
A consilience model to describe N2O production during biological N removal
DEFF Research Database (Denmark)
Domingo Felez, Carlos; Smets, Barth F.
2016-01-01
(NO) and N2O dynamics have been proposed. Here, a first comprehensive model that considers all relevant NO and N2O production and consumption mechanisms is proposed. The model describes autotrophic NO production by ammonia oxidizing bacteria associated with ammonia oxidation and with nitrite reduction......Nitrous oxide (N2O), a potent greenhouse gas, is produced during biological nitrogen conversion in wastewater treatment operations. Complex mechanisms underlie N2O production by autotrophic and heterotrophic organisms, which continue to be unravelled. Mathematical models that describe nitric oxide......, followed by NO reduction to N2O. It also considers NO and N2O as intermediates in heterotrophic denitrification in a 4-step model. Three biological NO and N2O production pathways are accounted for, improving the capabilities of existing models while not increasing their complexity. Abiotic contributions...
Efficient computation of GW energy level corrections for molecules described in a plane wave basis
Rousseau, Bruno; Laflamme Janssen, Jonathan; Côté, Michel
2013-03-01
An efficient computational approach is presented to compute the ionisation energy and quasiparticle band gap at the level of the GW approximation when the Hilbert space is described in terms of plane waves. The method relies on ab initio calculations as a starting point. Then, the use of the Sternheimer equation eliminates slowly convergent sums on conduction states. Further, the Lanczos method is used to efficiently extract the most important eigenstates of the dielectric operator. This approach avoids the explicit computation of matrix elements of the dielectric operator in the plane wave basis, a crippling bottleneck of the brute force approach. The method is initially applied to organic molecules of current interest in the field of organic photovoltaics. Given the completeness of the plane wave basis, systematic convergence studies can be conducted. Furthermore, the method can readily be extended to describe polymers, which are also of interest for photovoltaic applications, but remain a significant computational challenge for methods based on localized basis sets.
Inaccessibility and Subinaccessibility. In two parts. Part II
Kiselev, A
2010-01-01
The work presents the second part of the second edition of its previous one published in 2000 under the same title, containing the proof (in $ZF$) of the inaccessible cardinals nonexistence, which is enriched and improved now. This part contains applications of the subinaccessible cardinals apparatus and its basic tools -- theories of reduced formula spectra and matrices, disseminators and others, which are used here in this proof and are set forth now in their more transparent and simplified form. Much attention is devoted to the explicit and substantial development and cultivation of basic ideas, serving as grounds for all main constructions and reasonings. The proof of the theorem about inaccessible cardinals nonexistence is presented in its detailed exposition. Several easy consequences of this theorem and some well-known results are presented.
Inaccessibility and subinaccessibility. In two parts. Part I (in Russian)
Kiselev, Alexander
2011-01-01
This work represents a translation from English into Russian of the first part of the monograph by Alexander Kiselev under the same title, containing the proof (in ZF) of inaccessible cardinals nonexistence. The first edition of this work was published in 2000. This part contains the apparatus of subinaccessible cardinals and its basic tools - theories of reduced formula spectra and matrices, disseminators and others - which are used in this proof and are set forth now in their more transparent and detailed form. Much attention is devoted to the explicit and substantial development and cultivation of basic ideas, serving as grounds for all main constructions and reasonings. Appropriated for specialists in Set Theory and Mathematical Logic, and also for teachers and students of faculties of the mathematical profile.
Inaccessibility and subinaccessibility. In two parts. Part II (in Russian)
Kiselev, Alexander
2011-01-01
This work represents a translation from English into Russian of the second part of the monograph by Alexander Kiselev under the same title. It contains the proof (in ZF) of inaccessible cardinals nonexistence. The first edition of this work was published in 2000. This part II contains applications of the subinaccessible cardinals apparatus and its basic tools - theories of reduced formula spectra and matrices, disseminators and others, which are used here in this proof and are set forth now in their more transparent and refined form. Much attention is devoted to the more explicit and substantial development and cultivation of basic ideas, serving as grounds for all main constructions and reasonings. The proof of the theorem about inaccessible cardinals nonexistence is presented in its detailed exposition. Several easy consequences of this theorem and some well-known results are presented. Appropriated for specialists in Set Theory and Mathematical Logic, and also for teachers and students of faculties of the ...
Two-Part Tariff and Aftermarket Duopoly: An Illustration
Felder, Joseph; Scott, Robert
2010-01-01
The authors shed light on the original equipment manufacturer's strategic behavior in the duopoly aftermarket. The original equipment manufacturer, firm 1, captures via its foremarket price some fraction of the aftermarket consumer surplus, where that surplus is generated by consumption of its own and its competitor's aftermarket products. The…
Intelligence Gathering; A Two-Part Twentieth Century Bibliography.
1978-09-15
Soviet Political Warfare Techniques; R9K57 Espionaje and Propaganda in the 1970’s, Strate~ r Papers No. U,N. L , N. Y . : Natio nal Str ate ~~r In...c~widran~lc/N . Y. TimesRef Book Co., N. D. 1)13270 Newman , Bernard . ~pic~ of Espionaj ~e, N. Y. , N. Y. : Ph ilosophi— 7J39 cal Library, c1951
Torto-Alalibo, Trudy; Collmer, Candace W; Gwinn-Giglio, Michelle; Lindeberg, Magdalen; Meng, Shaowu; Chibucos, Marcus C; Tseng, Tsai-Tien; Lomax, Jane; Biehl, Bryan; Ireland, Amelia; Bird, David; Dean, Ralph A; Glasner, Jeremy D; Perna, Nicole; Setubal, Joao C; Collmer, Alan; Tyler, Brett M
2010-12-01
Microbes form intimate relationships with hosts (symbioses) that range from mutualism to parasitism. Common microbial mechanisms involved in a successful host association include adhesion, entry of the microbe or its effector proteins into the host cell, mitigation of host defenses, and nutrient acquisition. Genes associated with these microbial mechanisms are known for a broad range of symbioses, revealing both divergent and convergent strategies. Effective comparisons among these symbioses, however, are hampered by inconsistent descriptive terms in the literature for functionally similar genes. Bioinformatic approaches that use homology-based tools are limited to identifying functionally similar genes based on similarities in their sequences. An effective solution to these limitations is provided by the Gene Ontology (GO), which provides a standardized language to describe gene products from all organisms. The GO comprises three ontologies that enable one to describe the molecular function(s) of gene products, the biological processes to which they contribute, and their cellular locations. Beginning in 2004, the Plant-Associated Microbe Gene Ontology (PAMGO) interest group collaborated with the GO consortium to extend the GO to accommodate terms for describing gene products associated with microbe-host interactions. Currently, over 900 terms that describe biological processes common to diverse plant- and animal-associated microbes are incorporated into the GO database. Here we review some unifying themes common to diverse host-microbe associations and illustrate how the new GO terms facilitate a standardized description of the gene products involved. We also highlight areas where new terms need to be developed, an ongoing process that should involve the whole community.
Describing, using 'recognition cones'. [parallel-series model with English-like computer program
Uhr, L.
1973-01-01
A parallel-serial 'recognition cone' model is examined, taking into account the model's ability to describe scenes of objects. An actual program is presented in an English-like language. The concept of a 'description' is discussed together with possible types of descriptive information. Questions regarding the level and the variety of detail are considered along with approaches for improving the serial representations of parallel systems.
Anomalously large capacitance of an ionic liquid described by the restricted primitive model
Loth, M S; Shklovskii, B I
2010-01-01
We use Monte Carlo simulations to examine the simplest model of an ionic liquid, called the restricted primitive model, at a metal surface. We find that at moderately low temperatures the capacitance of the metal/ionic liquid interface is so large that the effective thickness of the electrostatic double-layer is smaller than the ion radius. We suggest a semi-quantitative theory to describe these results.
Interconnection between static regimes in the LJJs described by the double sine-Gordon equation
Atanasova, P. Kh; Zemlyanaya, E. V.; Shukrinov, Yu M.
2012-11-01
The second harmonic contribution to the current-phase relation changes the properties of the static magnetic flux distributions in the long Josephson junction (LJJ) and inspires new homogenious and fluxon static states. We study stability properties and bifurcations of these static regimes within the frame of a model described by the double sine-Gordon equation. The critical curves behavior and the interconnection between different types of magnetic flux distributions are analyzed.
Orsi, Renato H; Wiedmann, Martin
2016-01-01
The genus Listeria is currently comprised of 17 species, including 9 Listeria species newly described since 2009. Genomic and phenotypic data clearly define a distinct group of six species (Listeria sensu strictu) that share common phenotypic characteristics (e.g., ability to grow at low temperature, flagellar motility); this group includes the pathogen Listeria monocytogenes. The other 11 species (Listeria sensu lato) represent three distinct monophyletic groups, which may warrant recognitio...
Articles with short titles describing the results are cited more often
Directory of Open Access Journals (Sweden)
Carlos Eduardo Paiva
2012-01-01
Full Text Available OBJECTIVE: The aim of this study was to evaluate some features of article titles from open access journals and to assess the possible impact of these titles on predicting the number of article views and citations. METHODS: Research articles (n = 423, published in October 2008 from all Public Library of Science (PLoS journals and from 12 Biomed Central (BMC journals were evaluated. Publication metrics (views and citations were analyzed in December 2011. The titles were classified according to their contents, namely methods-describing titles and results-describing titles. The number of title characters, title typology, the use of a question mark, reference to a specific geographical region, and the use of a colon or a hyphen separating different ideas within a sentence were analyzed to identify predictors of views and citations. A logistic regression model was used to identify independent title characteristics that could predict citation rates. RESULTS: Short-titled articles had higher viewing and citation rates than those with longer titles. Titles containing a question mark, containing a reference to a specific geographical region, and that used a colon or a hyphen were associated with a lower number of citations. Articles with results-describing titles were cited more often than those with methods-describing titles. After multivariate analysis, only a low number of characters and title typology remained as predictors of the number of citations. CONCLUSIONS: Some features of article titles can help predict the number of article views and citation counts. Short titles presenting results or conclusions were independently associated with higher citation counts. The findings presented here could be used by authors, reviewers, and editors to maximize the impact of articles in the scientific community.
Kebreab, E; Schulin-Zeuthen, M; Lopez, S; Soler, J; Dias, R S; de Lange, C F M; France, J
2007-10-01
Success of pig production depends on maximizing return over feed costs and addressing potential nutrient pollution to the environment. Mathematical modeling has been used to describe many important aspects of inputs and outputs of pork production. This study was undertaken to compare 4 mathematical functions for the best fit in terms of describing specific data sets on pig growth and, in a separate experiment, to compare these 4 functions for describing of P utilization for growth. Two data sets with growth data were used to conduct growth analysis and another data set was used for P efficiency analysis. All data sets were constructed from independent trials that measured BW, age, and intake. Four growth functions representing diminishing returns (monomolecular), sigmoidal with a fixed point of inflection (Gompertz), and sigmoidal with a variable point of inflection (Richards and von Bertalanffy) were used. Meta-analysis of the data was conducted to identify the most appropriate functions for growth and P utilization. Based on Bayesian information criteria, the Richards equation described the BW vs. age data best. The additional parameter of the Richards equation was necessary because the data required a lower point of inflection (138 d) than the Gompertz, with a fixed point of inflexion at 1/e times the final BW (189 d), could accommodate. Lack of flexibility in the Gompertz equation was a limitation to accurate prediction. The monomolecular equation was best at determining efficiencies of P utilization for BW gain compared with the sigmoidal functions. The parameter estimate for the rate constant in all functions decreased as available P intake increased. Average efficiencies during different stages of growth were calculated and offer insight into targeting stages where high feed (nutrient) input is required and when adjustments are needed to accommodate the loss of efficiency and the reduction of potential pollution problems. It is recommended that the Richards
How to describe mouth patterns in the Danish Sign Language Dictionary
DEFF Research Database (Denmark)
Kristoffersen, Jette Hedegaard; Boye Niemela, Janne
2008-01-01
The Danish Sign Language dictionary project aims at creating an electronic dictionary of the basic vocabulary of Danish Sign Language. One of many issues in compiling the dictionary has been to analyse the status of mouth patterns in Danish Sign Language and, consequently, to decide at which level...... mouth patterns should be described in the dictionary: That is either at the entry level or at the meaning level....
Research on the stability of control systems described by fractional-order transfer functions
Institute of Scientific and Technical Information of China (English)
Zeng Qingshan; Zhu Xinjian; Cao Guangyi
2005-01-01
The stability of control systems described by fractional-order transfer function form is mainly investigated. The stability analysis of integer-order linear systems was extended to the fractional-order control systems. The stability definition of fractional-order linear control systems is presented in terms of the Lyapunov's stability theory. Using the theorems of the Mittag-Leffler function in two parameters directly derives the stability conclusion. The illustrative examples are also given by simulation results.
Scientific heritage of Alexandru Roşca: publications, spider collection, described species
Directory of Open Access Journals (Sweden)
Fedoriak, Mariia
2016-04-01
During the period 1931–1939, Roşca described 13 spider species. To date, five species names have been synonymised. We propose that six species should be treated as nomina dubia because of their poor descriptions and lack of availability of types and/or other specimens. For two of Roşca’s species, Pardosa roscai (Roewer, 1951 and Tetragnatha reimoseri (Roşca, 1939, data and figures are presented and information on them is updated.
Uniqueness of Inversion Problems Described by First-Kind Integral Equations
Institute of Scientific and Technical Information of China (English)
徐铁峰
2002-01-01
We propose a general method to prove the uniqueness of the inversion problems described by first-kind integral equations. The method depends on the analytical properties of the Fourier transform of the integral kernel and the finiteness of the total states (or probability, if normalized), the integration of the "local" density of states, which is a rather moderate condition and satisfied by many inversion problems arising from physics and engineering.
Why simple regression models work so well describing 'risk behaviors' in the USA
Wallace, R.; R Fullilove
1999-01-01
The generalized anger created by individual experience of marginalization in the USA makes violent behavior frequent enough to become a 'typical' symbol, in the information-theoretic sense, for use in communicating along the damaged social networks of oppressed communities. Simple regression models relating violence and other risk behaviors to indices of relative deprivation emerge, after some mathematical development, as a natural consequence of this underlying dynamic, described elegantly b...
Expected IPS variations due to a disturbance described by a 3-D MHD model
Tappin, S. J.; Dryer, M.; Han, S. M.; Wu, S. T.
1988-01-01
The variations of interplanetary scintillation due to a disturbance described by a three-dimensional, time-dependent, MHD model of the interplanetary medium are calculated. The resulting simulated IPS maps are compared with observations of real disturbances and it is found that there is some qualitative agreement. It is concluded that the MHD model with a more realistic choice of input conditions would probably provide a useful description of many interplanetary disturbances.
Gay, Guillaume; Courtheoux, Thibault; Reyes, Céline; Tournier, Sylvie; Gachet, Yannick
2012-01-01
In fission yeast, erroneous attachments of spindle microtubules to kinetochores are frequent in early mitosis. Most are corrected before anaphase onset by a mechanism involving the protein kinase Aurora B, which destabilizes kinetochore microtubules (ktMTs) in the absence of tension between sister chromatids. In this paper, we describe a minimal mathematical model of fission yeast chromosome segregation based on the stochastic attachment and detachment of ktMTs. The model accurately reproduce...
Using Multiple Metadata Standards to Describe Climate Datasets in a Semantic Framework
Blumenthal, M. B.; Del Corral, J.; Bell, M.
2007-12-01
The standards underlying the Semantic Web -- Resource Description Framework (RDF) and Web Ontology Language (OWL), among others -- show great promise in addressing some of the basic problems in earth science metadata. In particular they provide a single framework that allows us to describe datasets according to multiple standards, creating a more complete description than any single standard can support, and avoiding the difficult problem of creating a super-standard that can describe everything about everything. The Semantic Web standards provide a framework for explicitly describing the data models implicit in programs that display and manipulate data. They also provide a framework where multiple metadata standards can be described. Most importantly, these data models and metadata standards can be interrelated, a key step in creating interoperability, and an important step in creating a practical system. As a exercise in understanding how this framework might be used, we have created an RDF expression of the datasets and some of the metadata in the IRI/LDEO Climate Data Library. This includes concepts like datasets, units, dependent variables, and independent variables. These datasets have been provided under diverse frameworks that have varied levels of associated metadata, including netCDF, GRIB, GeoTIFF, and OpenDAP: these frameworks have some associated concepts that are common, some that are similar and some that are quite distinct. We have also created an RDF expression of a taxonomy that forms the basis of a earth data search interface. These concepts include location, time, quantity, realm, author, and institution. A series of inference engines using currently-evolving semantic web technologies are then used to infer the connections between the diverse data-oriented concepts of the data library as well as the distinctly different conceptual framework of the data search.
DEFF Research Database (Denmark)
Rup, B; Pallardy, M; Sikkema, D
2015-01-01
scientists are involved in: interpretation and management of clinical and biological outcomes of BP immunogenicity, improvement of methods for describing, predicting and mitigating immunogenicity risk and elucidation of underlying causes. Collaboration and alignment of efforts across these communities...... the Risk; www.abirisk.eu] was formed by leading clinicians, academic scientists and EFPIA (European Federation of Pharmaceutical Industries and Associations) members to elucidate underlying causes, improve methods for immunogenicity prediction and mitigation and establish common definitions around terms...
Exploring place through user-generated content: Using Flickr to describe city cores
Directory of Open Access Journals (Sweden)
Livia Hollenstein
2010-07-01
Full Text Available Terms used to describe city centers, such as Downtown, are key concepts in everyday or vernacular language. Here, we explore such language by harvesting georeferenced and tagged metadata associated with 8 million Flickr images and thus consider how large numbers of people name city core areas. The nature of errors and imprecision in tagging and georeferencing are quantified, and automatically generated precision measures appear to mirror errors in the positioning of images. Users seek to ascribe appropriate semantics to images, though bulk-uploading and bulk-tagging may introduce bias. Between 0.5-2% of tags associated with georeferenced images analyzed describe city core areas generically, while 70% of all georeferenced images analyzed include specific place name tags, with place names at the granularity of city names being by far the most common. Using Flickr metadata, it is possible not only to describe the use of the term Downtown across the USA, but also to explore the borders of city center neighborhoods at the level of individual cities, whilst accounting for bias by the use of tag profiles.
Numerical model describing optimization of fibres winding process on open and closed frame
Petrů, M.; Mlýnek, J.; Martinec, T.
2016-08-01
This article discusses a numerical model describing optimization of fibres winding process on open and closed frame. The quality production of said type of composite frame depends primarily on the correct winding of fibers on a polyurethane core. It is especially needed to ensure the correct angles of the fibers winding on the polyurethane core and the homogeneity of individual winding layers. The article describes mathematical model for use an industrial robot in filament winding and how to calculate the trajectory of the robot. When winding fibers on the polyurethane core which is fastened to the robot-end-effector so that during the winding process goes through a fibre-processing head on the basis of the suitably determined robot-end-effector trajectory. We use the described numerical model and matrix calculus to enumerate the trajectory of the robot-end-effector to determine the desired passage of the frame through the fibre-processing head. The calculation of the trajectory was programmed in the Delphi development environment. Relations of the numerical model are important for use a real solving of the passage of a polyurethane core through fibre-processing head.
Jiménez-Valverde, Alberto; Ortuño, Vicente M.
2007-01-01
iological correlates of species description dates can be used to predict the characteristics of yet-to-be-described species. Such information can be useful in the planning of biodiversity field surveys. This paper explores the influence of five factors—body size, geographic range size, geographic location, habitat and number of congeners—on the probability of description of endemic Iberian ground-beetles, and attempts to identify the effects of each factor, alone or in combination, through variation partitioning. Small-bodied and hypogean species were found to have been described later, as were those with smaller geographic ranges, while the number of congeners did not significantly affect description date. Additionally, Eastern hypogean species were described earlier than Western ones because of major lithology differences from east to west in the Iberian Peninsula, and concomitant geographic taxonomic bias. However, effects of each factor alone are quite small in comparison with effects of the combination of factors, due to their considerable correlation. Thus, "rarity", in its broadest sense, has been the determining factor of date of description of endemic Iberian ground-beetles. Previously, the technical difficulty encountered in the study of rare species retarded their description, whereas now they have become a "fashionable" object of study among carabidologists, due to the possibility of rapid publication. In order to improve the incomplete checklist of Iberian ground beetles it would be necessary to focus sampling efforts on marginal habitats and hypogean fauna.
Attributes of clinical role models as described by senior veterinary students in Australia.
Schull, Daniel N; Kyle, Greg J; Coleman, Glen T; Mills, Paul C
2012-01-01
Role models incite admiration and provide inspiration, contributing to learning as students aspire to emulate their example. The attributes of physician role models for medical trainees are well documented, but they remain largely unexplored in the context of veterinary medical training. The aim of the current study was to describe the attributes that final-year veterinary students (N=213) at the University of Queensland identified when reflecting on their clinical role models. Clinical role model descriptions provided by students were analyzed using concept-mapping software (Leximancer v. 2.25). The most frequent and highly connected concepts used by students when describing their role model(s) included clients, vet, and animal. Role models were described as good communicators who were skilled at managing relationships with clients, patients, and staff. They had exemplary knowledge, skills, and abilities, and they were methodical and conducted well-structured consultations. They were well respected and, in turn, demonstrated respect for clients, colleagues, staff, and students alike. They were also good teachers and able to tailor explanations to suit both clients and students. Findings from this study may serve to assist with faculty development and as a basis for further research in this area.
Ion-cyclotron instability in plasmas described by product-bi-kappa distributions
Energy Technology Data Exchange (ETDEWEB)
Santos, M. S. dos; Ziebell, L. F., E-mail: luiz.ziebell@ufrgs.br; Gaelzer, R., E-mail: rudi.gaelzer@ufrgs.br [Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP: 91501-970 Porto Alegre, RS (Brazil)
2015-12-15
The dispersion relation for parallel propagating waves in the ion-cyclotron branch is investigated numerically by considering that the velocity distribution of the ion population is a function of type product-bi-kappa. We investigate the effects of the non-thermal features and of the anisotropy associated with this type of distribution on the ion-cyclotron instability, as well as the influence of different forms of the electron distribution, by considering Maxwellian distributions, bi-kappa distributions, and product-bi-kappa distributions. The cases of ions described by either Maxwellian or bi-kappa distributions are also considered, for comparison. The results of the numerical analysis show that the increase in the non-thermal character associated with the anisotropic kappa distributions for ions contributes to enhance the instability as compared to that obtained in the Maxwellian case, in magnitude and in wave number range, with more significant enhancement for the case of ion product-bi-kappa distributions than for the case of ion bi-kappa distributions. It is also shown that the ion-cyclotron instability is decreased if the electrons are described by product-bi-kappa distributions, while electrons described by bi-kappa distributions lead to growth rates which are very similar to those obtained considering a Maxwellian distribution for the electron population.
A Principle for Describing and Verifying Brain Mechanisms Using Ongoing Activity
Eriksson, David
2017-01-01
Not even the most informed scientist can setup a theory that takes all brain signals into account. A neuron not only receives neuronal short range and long range input from all over the brain but a neuron also receives input from the extracellular space, astrocytes and vasculature. Given this complexity, how does one describe and verify a typical brain mechanism in vivo? Common to most described mechanisms is that one focuses on how one specific input signal gives rise to the activity in a population of neurons. This can be an input from a brain area, a population of neurons or a specific cell type. All remaining inputs originating from all over the brain are lumped together into one background input. The division into two inputs is attractive since it can be used to quantify the relative importance of either input. Here we have chosen to extract the specific and the background input by means of recording and inhibiting the specific input. We summarize what it takes to estimate the two inputs on a single trial level. The inhibition should not only be strong but also fast and the specific input measurement has to be tailor-made to the inhibition. In essence, we suggest ways to control electrophysiological experiments in vivo. By applying those controls it may become possible to describe and verify many brain mechanisms, and it may also allow the study of the integration of spontaneous and ongoing activity, which in turn governs cognition and behavior. PMID:28174523
A prospective study of SCA3 gait ataxia described through a Markovian method.
Camey, Suzi; Jardim, Laura Bannach; Kieling, Christian; Saute, Jonas Alex Morales; Vigo, Alvaro
2010-01-01
Studies on the natural history of rare, chronic diseases like spinocerebellar ataxia 3 (SCA3) are hard to be done, since patients enter the study with variable disease durations and are followed up at irregular intervals. Our purpose was to use all the available data to describe the progression of gait ataxia in a long-term cohort of patients with SCA3 through a markovian method. SCA3 patients were recruited between 1998 and 2005 and were invited to annual neurological follow-ups until 2007. Gait ataxia was described through a mean score graph and a mean trajectory graph. We followed up 105 patients; at baseline, the mean age and disease duration were, 40.5 (SD = 12.6) and 7.7 (SD = 5.8) years, respectively. The mean time to reach stages 1, 2, 3 and 4 of gait ataxia were 3, 5.4, 10.8 and 19.4 years of disease duration. The mean score graph was unsmooth, showing several unlikely ups and downs. The mean trajectory graph produced a continuous curve. The markovian method described the natural history of gait ataxia without any a posteriori adjustment of data and allowed statistical comparisons between subgroups. This method will be useful in future clinical trials in this and in other chronic degenerative diseases. 2010 S. Karger AG, Basel.
The Shape of Solar Cycles Described by a Simplified Binary Mixture of Gaussian Functions
Li, F. Y.; Xiang, N. B.; Kong, D. F.; Xie, J. L.
2017-01-01
Sunspot cycles usually present a double-peak structure. This work is devoted to using a function to describe the shape of sunspot cycles, including bimodal cycles, and we find that the shape of sunspot cycles can be described by a binary mixture of Gaussian functions with six parameters, two amplitudes, two gradients of curve, and two rising times, and the parameters could be reduced to three. The fitting result of this binary mixture of Gaussian functions is compared with some other functions used previously in the literature, and this function works pretty well, especially at cycle peaks. It is worth mentioning that the function can describe well the shape of those sunspot cycles that show double peaks, and it is superior to the binary mixture of the Laplace functions that was once utilized. The Solar Influences Data Analysis Center, on behalf of the World Data Center, recently issued a new version (version 2) of sunspot number. The characteristics of sunspot cycles are investigated, based on the function description of the new version.
Everyday Living with Diabetes Described by Family Members of Adult People with Type 1 Diabetes
Directory of Open Access Journals (Sweden)
Tuula-Maria Rintala
2013-01-01
Full Text Available The aim of this study was to explore family members’ experiences of everyday life in families with adult people living with type 1 diabetes. The grounded theory method was used to gather and analyse data from the interviews of nineteen family members. Six concepts describing the family members’ views on everyday living with diabetes were generated on the basis of the data. Everyday life with diabetes is described as being intertwined with hypoglycemia. Becoming acquainted with diabetes takes place little by little. Being involved in the management and watching self-management from the sidelines are concepts describing family members’ participation in the daily management of diabetes. The family members are also integrating diabetes into everyday life. Living on an emotional roller-coaster tells about the thoughts and feelings that family members experience. Family members of adult people with diabetes are involved in the management of the diabetes in many ways and experience many concerns. The family members’ point of view is important to take into consideration when developing education for adults with diabetes.
Medicinal aspects of opium as described in Avicenna's Canon of Medicine.
Heydari, Mojtaba; Hashempur, Mohammad Hashem; Zargaran, Arman
2013-01-01
Throughout history, opium has been used as a base for the opioid class of drugs used to suppress the central nervous system. Opium is a substance extracted from the opium poppy (Papaver somniferum L.). Its consumption and medicinal application date back to antiquity. In the medieval period, Avicenna, a famous Persian scholar (980-1037 AD) described poppy under the entry Afion of his medical encyclopedia Canon of Medicine. Various effects of opium consumption, both wanted and unwanted are discussed in the encyclopedia. The text mentions the effects of opioids such as analgesic, hypnotic, antitussive, gastrointestinal, cognitive, respiratory depression, neuromuscular disturbance, and sexual dysfunction. It also refers to its potential as a poison. Avicenna describes several methods of delivery and recommendations for doses of the drug. Most of opioid effects described by Avicenna have subsequently been confirmed by modern research, and other references to opium use in medieval texts call for further investigation. This article highlights an important aspect of the medieval history of medicine.
Durand, Marie-Anne; Stiel, Mareike; Boivin, Jacky; Elwyn, Glyn
2008-04-01
To identify and describe the extent to which theory or theoretical frameworks informed the development and evaluation of decision support technologies (DSTs). The analysis was based on the decision technologies used in studies included in the Cochrane systematic review of patient decision aids for people facing health screening or treatment decisions. The assumption was made that DSTs evaluated by randomized controlled trials, and therefore included in the updated Cochrane review have been the most rigorously developed. Of the 50 DSTs evaluated only 17 (34%) were based on a theoretical framework. Amongst these, 11 decision-making theories were described but the extent to which theory informed the development, field-testing and evaluation of these interventions was highly variable between DSTs. The majority of the 17 DSTs that relied on a theory was not explicit about how theory had guided their design and evaluation. Many had superficial descriptions of the theory or theories involved. Furthermore, based on the analysis of those 17 DSTs, none had reported field-testing prior to evaluation. The use of decision-making theory in DST development is rare and poorly described. The lack of theoretical underpinning to the design and development of DSTs most likely reflects the early development stage of the DST field. The findings clearly indicate the need to give more attention to how the most important decision-making theories could be better used to guide the design of key decision support components and their modes of action.
The white matter query language: a novel approach for describing human white matter anatomy.
Wassermann, Demian; Makris, Nikos; Rathi, Yogesh; Shenton, Martha; Kikinis, Ron; Kubicki, Marek; Westin, Carl-Fredrik
2016-12-01
We have developed a novel method to describe human white matter anatomy using an approach that is both intuitive and simple to use, and which automatically extracts white matter tracts from diffusion MRI volumes. Further, our method simplifies the quantification and statistical analysis of white matter tracts on large diffusion MRI databases. This work reflects the careful syntactical definition of major white matter fiber tracts in the human brain based on a neuroanatomist's expert knowledge. The framework is based on a novel query language with a near-to-English textual syntax. This query language makes it possible to construct a dictionary of anatomical definitions that describe white matter tracts. The definitions include adjacent gray and white matter regions, and rules for spatial relations. This novel method makes it possible to automatically label white matter anatomy across subjects. After describing this method, we provide an example of its implementation where we encode anatomical knowledge in human white matter for ten association and 15 projection tracts per hemisphere, along with seven commissural tracts. Importantly, this novel method is comparable in accuracy to manual labeling. Finally, we present results applying this method to create a white matter atlas from 77 healthy subjects, and we use this atlas in a small proof-of-concept study to detect changes in association tracts that characterize schizophrenia.
On describing human white matter anatomy: the white matter query language.
Wassermann, Demian; Makris, Nikos; Rathi, Yogesh; Shenton, Martha; Kikinis, Ron; Kubicki, Marek; Westin, Carl-Fredrik
2013-01-01
The main contribution of this work is the careful syntactical definition of major white matter tracts in the human brain based on a neuroanatomist's expert knowledge. We present a technique to formally describe white matter tracts and to automatically extract them from diffusion MRI data. The framework is based on a novel query language with a near-to-English textual syntax. This query language allows us to construct a dictionary of anatomical definitions describing white matter tracts. The definitions include adjacent gray and white matter regions, and rules for spatial relations. This enables automated coherent labeling of white matter anatomy across subjects. We use our method to encode anatomical knowledge in human white matter describing 10 association and 8 projection tracts per hemisphere and 7 commissural tracts. The technique is shown to be comparable in accuracy to manual labeling. We present results applying this framework to create a white matter atlas from 77 healthy subjects, and we use this atlas in a proof-of-concept study to detect tract changes specific to schizophrenia.
Can an Ising-like cluster expansion describe atomic relaxations in alloys?
Zunger, Alex; Wolverton, C.
1996-03-01
Ising-like lattice models are often described as ``fixed lattice'' models, incapable of describing the effects of structural relaxation. However, we have recently demonstrated^1 the ability of generalized k-space^2 Ising-like cluster expansions to describe the energetics and thermodynamics associated with large atomic displacements in alloys. Although the expansion is constructed only from the energies of a few (small-unit-cell) ordered structures, it provides accurate predictions of the atomically-relaxed energies of random, ordered, or partially ordered alloys, as compared with direct, large scale ( ~1000 atom) energy-minimizing simulations. Moreover, unlike molecular dynamics, here relaxed energies are obtained without having to compute relaxed geometries. Combination of the cluster expansion with Monte Carlo calculations is shown to provide a far more efficient means for calculating thermodynamic properties than explicit molecular dynamics or other structural minimization methods. [1] C. Wolverton and A. Zunger, Phys. Rev. Lett. 75, 3162 (1995). [2] D. B. Laks, L. G. Ferreira, S. Froyen, and A. Zunger, Phys. Rev. B 46, 12587 (1992). Supported by BES/OER/DMS under contract DE-AC36-83CH10093.
Santoro, Ilaria; Murgia, Mauro; Sors, Fabrizio; Prpic, Valter; Agostini, Tiziano
2017-08-11
Previous studies demonstrated that physical movement enhanced spatial updating in described environments. However, those movements were executed only after the encoding of the environment, minimally affecting the development of the spatial representation. Thus, we investigated whether and how participants could benefit from the execution of physical movement during the encoding of described environments, in terms of enhanced spatial updating. Using the judgement of relative directions task, we compared the effects of walking both during and after the description of the environment, and walking only after the description on spatial updating. Spatial updating was evaluated in terms of accuracy and response times in different headings. We found that the distribution of response times across Headings seemed not to be related to the physical movement executed, whereas the distribution of accuracy scores seemed to significantly change with the action executed. Indeed, when no movement occurred during the encoding of the environment, a preference for the learning heading was found, which did not emerge when walking during encoding occurred. Therefore, the results seem to suggest that physical movement during encoding supports the development of a heading-independent representation of described environments, reducing the anchoring for a preferred heading in favor of a global representation. Copyright © 2017 Elsevier B.V. All rights reserved.
Intelligence for education: as described by Piaget and measured by psychometrics.
Shayer, Michael
2008-03-01
Two separate paths to the concept of intelligence are discussed: the psychometric path being concerned with the measurement of intelligence, involving the methodology of norm-referenced testing; the path followed by Piaget, and others, addresses from the start the related question of how intelligence can be described, and employs a criterion-referenced methodology. The achievements of psychometrics are briefly described, with an argument that they now remain important tools of what Kuhn called 'normal science'. The criterion-referenced approach of Piaget and others is described, with evidence from intervention studies that the Genevan descriptions of children-in-action have allowed the choice of contexts within which children can profitably be challenged to go further in their thinking. Hence, Genevan psychology is also now a part of the normal science with important uses, shown both in neo-Piagetian studies and further research stemming from Geneva. Discussion of the 'Flynn effect' sheds light on both paths, with problems still unresolved. The argument is then developed that the relevance of neuroscience needs to be discussed to try to decide in what ways it may provide useful insights into intelligence.
A simple model describes large individual differences in simultaneous colour contrast.
Ekroll, Vebjørn; Faul, Franz
2009-09-01
We report experimental evidence for substantial individual differences in the susceptibility to simultaneous colour contrast. Interestingly, we found that not only the general amount of colour induction varies across observers, but also the general shape of the curves describing asymmetric matching data. A simple model based on von Kries adaptation and crispening describes the data rather well when we regard its free parameters as observer specific. We argue that the von Kries component reflects the action of a temporal adaptation mechanism, while the crispening component describes the action of the instantaneous, purely spatial mechanism most appropriately labeled simultaneous colour contrast. An interesting consequence of this view is that traditional ideas about the general characteristics of simultaneous contrast must be considered as misleading. According to Kirschmann's 4th law, for instance, the simultaneous contrast effect should increase with increasing saturation of the surround, but crispening predicts the converse. Based on this reasoning, we offer a plausible explanation for the mixed evidence on the validity of Kirschmann's 4th law. We also argue that simultaneous contrast, the crispening effect, Meyer's effect and the gamut expansion effect are just different names for the same basic phenomenon.
Use of the 4/5 Kolmogorov equation for describing some characteristics of fully developed turbulence
Tatarskii, V. I.
2005-03-01
The Kolmogorov equation, which relates the second-order structure function Dll(r ) and the third-ordrer structure function Dlll(r ), may be presented as a closed linear integrodifferential equation for the probability distribution function W(U ,r) of longitudinal velocity difference U. In general, without any restrictions, the function of two variables W(U ,r) may be presented as [Dll(r )]-1/2F(U/√Dll(r ) ,r). As a first approximation, we neglect dependence of F on the second argument r. In this approximation (self-similarity of the probability density function), the integrodifferential equation for W reduces to the ordinary nonlinear differential equation for Dll(r ). It follows from this equation that for r →∞ the function Dll(r )˜r2/3. This consideration does not use the 1941 Kolmogorov hypothesis that is based on dimension analysis. Any deviations from the 2/3 law, including intermittency effects, must be related to the violation of the above-mentioned self-similarity of W, i.e., with the additional dependence of F on the second argument r. On the basis of experimental data, we suggest a simple model of W, which allows us to describe deviations from the 2/3 law, caused by intermittency, and describe the local exponents κ in the structure functions ⟨∣U(r)∣ρ⟩˜rκ(ρ ) for moderate ρ. The so called "bottleneck effect" also can be described by 4/5 Kolmogorov equation.
Genetic resources for advanced biofuel production described with the Gene Ontology.
Torto-Alalibo, Trudy; Purwantini, Endang; Lomax, Jane; Setubal, João C; Mukhopadhyay, Biswarup; Tyler, Brett M
2014-01-01
Dramatic increases in research in the area of microbial biofuel production coupled with high-throughput data generation on bioenergy-related microbes has led to a deluge of information in the scientific literature and in databases. Consolidating this information and making it easily accessible requires a unified vocabulary. The Gene Ontology (GO) fulfills that requirement, as it is a well-developed structured vocabulary that describes the activities and locations of gene products in a consistent manner across all kingdoms of life. The Microbial ENergy processes Gene Ontology () project is extending the GO to include new terms to describe microbial processes of interest to bioenergy production. Our effort has added over 600 bioenergy related terms to the Gene Ontology. These terms will aid in the comprehensive annotation of gene products from diverse energy-related microbial genomes. An area of microbial energy research that has received a lot of attention is microbial production of advanced biofuels. These include alcohols such as butanol, isopropanol, isobutanol, and fuels derived from fatty acids, isoprenoids, and polyhydroxyalkanoates. These fuels are superior to first generation biofuels (ethanol and biodiesel esterified from vegetable oil or animal fat), can be generated from non-food feedstock sources, can be used as supplements or substitutes for gasoline, diesel and jet fuels, and can be stored and distributed using existing infrastructure. Here we review the roles of genes associated with synthesis of advanced biofuels, and at the same time introduce the use of the GO to describe the functions of these genes in a standardized way.
Using correlation functions to describe complex multi-phase porous media structures
Karsanina, Marina; Sizonenko, Timofey; Korost, Dmitry; Gerke, Kirill
2017-04-01
Multi-scale flow and transport modelling relies on multi-scale image/property fusion techniques. Previusly we have rigorously addressed binary porous media description and stochastic reconstruction problems. However, numerous porous media have more than two, usually solids and pores, phases, e.g., clays, organic, heavy minerals and such. In this contribution we develop efficient approaches to utilize correlation functions to describe such muti-phase soil and rock structures using large sets of cluster, linear and probability functions, including cross-correlations. The approach is tested on numerous 3D images, which were segmented into 3 and more relevant phases. It is shown that multi-phase correlation functions are potentially a very powerful tool to describe any type of porous media at hand and this study also provides a basis for multi-phase stochastic reconstruction techniques, necessary for multi-phase image fusion to obtain large 3D images of hierarchical porous media based on, for example, macro and micro X-ray tomography scans and FIB/BIB-SEM and SEM. References: 1) Karsanina, M.V., Gerke, K.M., Skvortsova, E.B. and Mallants, D. (2015) Universal spatial correlation functions for describing and reconstructing soil microstructure. PLoS ONE 10(5), e0126515. 2) Gerke, K. M., & Karsanina, M. V. (2015). Improving stochastic reconstructions by weighting correlation functions in an objective function. EPL (Europhysics Letters),111(5), 56002. 3) Gerke, K. M., Karsanina, M. V., Vasilyev, R. V., & Mallants, D. (2014). Improving pattern reconstruction using directional correlation functions. EPL (Europhysics Letters), 106(6), 66002. 4) Gerke, K.M., Karsanina, M. V, Mallants, D., 2015. Universal Stochastic Multiscale Image Fusion: An Example Application for Shale Rock. Sci. Rep. 5, 15880. doi:10.1038/srep15880
Directory of Open Access Journals (Sweden)
George Livadiotis
2014-07-01
Full Text Available The paper studies the “Lagrangian temperature” defined through the entropy maximization in the canonical ensemble, which is the negative inverse Lagrangian multiplier corresponding to the constraint of internal energy. The Lagrangian temperature is derived for systems out of thermal equilibrium described by kappa distributions such as space plasmas. The physical meaning of temperature is manifested by the equivalency of two different definitions, that is, through Maxwell’s kinetic theory and Clausius’ thermodynamics. The equivalency of the two definitions is true either for systems at thermal equilibrium described by Maxwell distributions or for systems out of thermal equilibrium described by kappa distributions, and gives the meaning of the actual temperature, that is, the real or measured temperature. However, the third definition, that of the Lagrangian temperature, coincides with the primary two definitions only at thermal equilibrium, and thus, in the general case of systems out of thermal equilibrium, it does not represent the actual temperature, but it is rather a function of this. The paper derives and examines the exact expression and physical meaning of the Lagrangian temperature, showing that it has essentially different content to what is commonly thought. This is achieved by: (i maximizing the entropy in the continuous description of energy within the general framework of non-extensive statistical mechanics, (ii using the concept of the “N-particle” kappa distribution, which is governed by a special kappa index that is invariant of the degrees of freedom and the number of particles, and (iii determining the appropriate scales of length and speed involved in the phase-space microstates. Finally, the paper demonstrates the behavior of the Lagrangian against the actual temperature in various datasets of space plasmas.
Genetic Resources for Advanced Biofuel Production Described with the Gene Ontology
Directory of Open Access Journals (Sweden)
Trudy eTorto-Alalibo
2014-10-01
Full Text Available Dramatic increases in research in the area of microbial biofuel production coupled with high-throughput data generation on bioenergy-related microbes has led to a deluge of information in the scientific literature and in databases. Consolidating this information and making it easily accessible requires a unified vocabulary. The Gene Ontology (GO fulfills that requirement, as it is a well-developed structured vocabulary that describes the activities and locations of gene products in a consistent manner across all kingdoms of life. The Microbial Energy Gene Ontology (MENGO: http://www.mengo.biochem.vt.edu project is extending the GO to include new terms to describe microbial processes of interest to bioenergy production. Our effort has added over 600 bioenergy related terms to the Gene Ontology. These terms will aid in the comprehensive annotation of gene products from diverse energy-related microbial genomes. An area of microbial energy research that has received a lot of attention is microbial production of advanced biofuels. These include alcohols such as butanol, isopropanol, isobutanol, and fuels derived from fatty acids, isoprenoids, and polyhydroxyalkanoates. These fuels are superior to first generation biofuels (ethanol and biodiesel esterified from vegetable oil or animal fat, can be generated from non-food feedstock sources, can be used as supplements or substitutes for gasoline, diesel and jet fuels, and can be stored and distributed using existing infrastructure. Here we review the roles of genes associated with synthesis of advanced biofuels, and at the same time introduce the use of the GO to describe the functions of these genes in a standardized way.
Vogelsmeier, Amy; Anderson, Ruth A; Anbari, Allison; Ganong, Lawrence; Farag, Amany; Niemeyer, MaryAnn
2017-08-04
Medication reconciliation is a safety practice to identify medication order discrepancies when patients' transitions between settings. In nursing homes, registered nurses (RNs) and licensed practical nurses (LPNs), each group with different education preparation and scope of practice responsibilities, perform medication reconciliation. However, little is known about how they differ in practice when making sense of medication orders to detect discrepancies. Therefore, the purpose of this study was to describe differences in RN and LPN sensemaking when detecting discrepancies. We used a qualitative methodology in a study of 13 RNs and 13 LPNs working in 12 Midwestern United States nursing homes. We used both conventional content analysis and directed content analysis methods to analyze semi-structured interviews. Four resident transfer vignettes embedded with medication order discrepancies guided the interviews. Participants were asked to describe their roles with medication reconciliation and their rationale for identifying medication order discrepancies within the vignettes as well as to share their experiences of performing medication reconciliation. The analysis approach was guided by Weick's Sensemaking theory. RNs provided explicit stories of identifying medication order discrepancies as well as examples of clinical reasoning to assure medication order appropriateness whereas LPNs described comparing medication lists. RNs and LPNs both acknowledged competing demands, but when performing medication reconciliation, RNs were more concerned about accuracy and safety, whereas LPNs were more concerned about time. Nursing home nurses, particularly RNs, are in an important position to identify discrepancies that could cause resident harm. Both RNs and LPNs are valuable assets to nursing home care and keeping residents safe, yet RNs offer a unique contribution to complex processes such as medication reconciliation. Nursing home leaders must acknowledge the differences
The Application of Spherical Harmonics for Describing a Cube-Shape Particle
Directory of Open Access Journals (Sweden)
Urtė Radvilaitė
2015-03-01
Full Text Available The paper disccusses various models for discrete element methods of modelling particle shapes. The multi-sphere method is most frequently used, though a polyhedral approach and a hybrid sphero-polyhedral model can also be introduced. All above mentioned methods precisely approximate particle shapes, and difficulties in modelling contact between particles arise. Thus, there is a need to have an universal method that gives the analytical expression of the shape. For this purpose, spherical harmonics have been introduced. The article presents the concept of the spherical harmonics model and experimental results describing the cube-shape particle.
Human Errors - A Taxonomy for Describing Human Malfunction in Industrial Installations
DEFF Research Database (Denmark)
Rasmussen, J.
1982-01-01
This paper describes the definition and the characteristics of human errors. Different types of human behavior are classified, and their relation to different error mechanisms are analyzed. The effect of conditioning factors related to affective, motivating aspects of the work situation as well...... as physiological factors are also taken into consideration. The taxonomy for event analysis, including human malfunction, is presented. Possibilities for the prediction of human error are discussed. The need for careful studies in actual work situations is expressed. Such studies could provide a better...... understanding of the complexity of human error situations as well as the data needed to characterize these situations....
Mazur, A. K.; Dorofeev, V. E.; Abagyan, R. A.
1991-02-01
General Lagrange's equations of motion for a system of polymeric molecules are obtained in an explicit form. They can be used for simulating molecular dynamics of large molecules. The molecular conformations are described by internal coordinates, i.e., bond lengths, valence angles, and torsion angles. The equations derived permit any internal degrees of freedom to be frozen. The method is applied to an oligopeptide in an α-helical conformation. Three models of the molecule with different degrees of fixation are compared. It is shown that the method permits one to increase significantly the time step in molecular dynamics calculations.
Stokes, Harold T; Campbell, Branton J; van Smaalen, Sander
2011-01-01
A complete table of (3 + 1)D, (3 + 2)D and (3 + 3)D superspace groups (SSGs) has been enumerated that corrects omissions and duplicate entries in previous tables of superspace groups and Bravais classes. The theoretical methods employed are not new, though the implementation is both novel and robust. The paper also describes conventions for assigning a unique one-line symbol for each group in the table. Finally, a new online data repository is introduced that delivers more complete information about each SSG than has been presented previously.
Technical note: Use of accelerometers to describe gait patterns in dairy calves
DEFF Research Database (Denmark)
Passillé, A. M. de; Jensen, Margit Bak; Chapinal, N.
2010-01-01
Developments in accelerometer technology offer new opportunities for automatic monitoring of animal behavior. Until now, commercially available accelerometers have been used to measure walking in adult cows but have failed to identify walking in calves. We described the pattern of acceleration...... associated with various gaits in calves and tested whether measures of acceleration could be used to count steps and distinguish among gait types. A triaxial accelerometer (sampling at 33 readings/s with maximum measurement at +/-3.2 g) was attached to 1 hind leg of 7 dairy calves, and each calf was walked...
Leblond, Hervé; Mihalache, Dumitru; 10.1103/PHYSREVA.81.033824
2011-01-01
By using a reductive perturbation method, we derive from Maxwell-Bloch equations a cubic generalized Kadomtsev-Petviashvili equation for ultrashort spatiotemporal optical pulse propagation in cubic (Kerr-like) media without the use of the slowly varying envelope approximation. We calculate the collapse threshold for the propagation of few-cycle spatiotemporal pulses described by the generic cubic generalized Kadomtsev-Petviashvili equation by a direct numerical method and compare it to analytic results based on a rigorous virial theorem. Besides, typical evolution of the spectrum (integrated over the transverse spatial coordinate) is given and a strongly asymmetric spectral broadening of ultrashort spatiotemporal pulses during collapse is evidenced.
Self-Organizing Two-Temperature Ising Model Describing Human Segregation
Ódor, Géza
A two-temperature Ising-Schelling model is introduced and studied for describing human segregation. The self-organized Ising model with Glauber kinetics simulated by Müller et al. exhibits a phase transition between segregated and mixed phases mimicking the change of tolerance (local temperature) of individuals. The effect of external noise is considered here as a second temperature added to the decision of individuals who consider a change of accommodation. A numerical evidence is presented for a discontinuous phase transition of the magnetization.
Can percolation model describe the evolution of mechanical properties of compacts of binary systems?
Evesque, Pierre; Busignies, Virginie; Porion, Patrice; Leclerc, Bernard; Tchoreloff, Pierre
2009-06-01
In pharmaceutical field, the percolation theory is used to describe the change of tablet's properties with the relative density. It defines critical tablet densities from which the mechanical properties start to change. The exponent in the law is expected to be universal for a mechanical property and numerical values are proposed in the literature. In this work, the percolation model was applied to the tensile strength and the reduced modulus of elasticity of three compacted pharmaceutical excipients. This work showed that the exponent seems not universal and that the model must be used carefully.
Institute of Scientific and Technical Information of China (English)
QU Jing-hua
2016-01-01
Transitivity is regarded as an effective methodology for analyzing literary works. This paper based on M. A. K. Halli-day’s transitivity system, analyzed two different texts describing the West Lake. One is from the wikipedia, the other is a tourist material from the website named AT-China. This paper demonstrates that for one thing, transitivity system can be used in analyz-ing relations between implicit or not obvious conflicting parties. For another, transitivity system manifests that there are some different stylistic features in texts of different styles, such as different participants, material processes, sentence patterns, literari-ness, etc.
Flávio Ailton Duque Zambrone; Cristiana Leslie Corrêa; Ligia Mesquita Sampaio do Amaral
2015-01-01
Abstract The aim of this study was to assess the hepatotoxicity cases described in the literature, attributed to the consumption of Herbalife(r) products, and to determine whether a causal relationship exists between the reported cases of liver injury and the use of these products. A literature search was performed on the PubMed, LILACS and PAHO databases. Seven publications reporting a total of 53 cases of hepatotoxicity linked to the use of Herbalife(r) products were retrieved. All of the s...
Indian Academy of Sciences (India)
Wang Zhi-Yun; Chen Pei-Jie
2016-06-01
A generalized Langevin equation driven by fractional Brownian motion is used to describe the vertical oscillations of general relativistic disks. By means of numerical calculation method, the displacements, velocities and luminosities of oscillating disks are explicitly obtained for different Hurst exponent $H$. The results show that as $H$ increases, the energies and luminosities of oscillating disk are enhanced, and the spectral slope at high frequencies of the power spectrum density of disk luminosity is also increased. This could explain the observational features related to the Intra Day Variability of the BL Lac objects.
NeamÅ£u, Mihaela; Stoian, Dana; Navolan, Dan Bogdan
2014-12-01
In the present paper we provide a mathematical model that describe the hypothalamus-pituitary-thyroid axis in autoimmune (Hashimoto's) thyroiditis. Since there is a spatial separation between thyroid and pituitary gland in the body, time is needed for transportation of thyrotropin and thyroxine between the glands. Thus, the distributed time delays are considered as both weak and Dirac kernels. The delayed model is analyzed regarding the stability and bifurcation behavior. The last part contains some numerical simulations to illustrate the effectiveness of our results and conclusions.
Classification and closure properties of languages for describing concurrent system behaviours
Energy Technology Data Exchange (ETDEWEB)
Szijarto, M.
1981-01-01
The correspondence between sequential program schemes and formal languages is well known. The situation is more complicated in the case of parallel program schemes, and trace languages have been introduced to describe them. The author introduces the concept of the closure of a language on a so called independence relation on the alphabet of the language, and formulate several theorems about them and the trace languages. He investigates the closedness properties of Chomsky classes under closure on independence relations, and as a special case we derive a new necessary and sufficient condition for the regularity of the commutative closure of a language. 12 references.
On the well-posedness of a mathematical model describing water-mud interaction
Escher, Joachim
2012-01-01
In this paper we consider a mathematical model describing the two-phase interaction between water and mud in a water canal when the width of the canal is small compared to its depth. The mud is treated as a non-Netwonian fluid and the interface between the mud and fluid is allowed to move under the influence of gravity and surface tension. We reduce the mathematical formulation, for small boundary and initial data, to a fully nonlocal and nonlinear problem and prove its local well-posedness by using abstract parabolic theory.
A multi-scale model for describing cancer-therapeutic transport in the human lung
Erbertseder, Karin Maria
2012-01-01
This thesis proposes a multi-scale model for describing cancer-therapeutic transport in the human lung. The developed multi-scale model represents flow, transport and reaction processes: in the pulmonary macrocirculation on the organ scale, in the capillary bed around an alveolus, in the surrounding pulmonary tissue and in the tumor on the tissue scale, and in the tumor cell population and in the single cancer cells on the cells scale. The model concept is specialized for an alveolar cell car...
A modal analysis method to describe weak nonlinear effects in metamaterials
Zeng, Y; O'Hara, J; Trugman, S A
2012-01-01
We apply a rigorous eigenmode analysis to study the electromagnetic properties of linear and weakly nonlinear metamaterials. The nonlinear response can be totally described by the linear eigenmodes when weak nonlinearities are attributed to metamaterials. We use this theory to interpret intrinsic second-harmonic spectroscopy on metallic metamaterials. Our study indicates that metamaterial eigenmodes play a critical role in optimizing a nonlinear metamaterial response to the extent that a poorly optimized modal pattern overwhelms the widely recognized benefits of plasmonic resonant field enhancements.
Realistic f(T) model describing the de Sitter epoch of the dark energy dominated universe
Nassur, S B; Rodrigues, M E; Houndjo, M J S; Tossa, J
2015-01-01
We consider an exponential model within the so-called f(T) theory of gravity, where $T$ denotes the torsion scalar. We focus our work on a cosmological feature of such a model, checking whether it may describe the de Sitter stage of the current universe through the analysis of the redshift z. Our results shows that the model reproduces the de Sitter stage only for low-redshifts, where the perturbation function goes toward zero as the low values of the redshift are reached, whereas the effective parameter of equation of state goes to -1, which is the expected behavior for any model able to reproduce de Sitter stage.
Drabble, Sarah J; O'Cathain, Alicia; Thomas, Kate J; Rudolph, Anne; Hewison, Jenny
2014-02-18
There is growing recognition of the value of conducting qualitative research with trials in health research. It is timely to reflect on how this qualitative research is presented in grant proposals to identify lessons for researchers and research commissioners. As part of a larger study focusing on how to maximise the value of undertaking qualitative research with trials, we undertook a documentary analysis of proposals of funded studies. Using the metaRegister of Controlled Trials (mRCT) database we identified trials funded in the United Kingdom, ongoing between 2001 and 2010, and reporting the use of qualitative research. We requested copies of proposals from lead researchers. We extracted data from the proposals using closed and open questions, analysed using descriptive statistics and content analysis respectively. 2% (89/3812) of trials in the mRCT database described the use of qualitative research undertaken with the trial. From these 89 trials, we received copies of 36 full proposals, of which 32 met our inclusion criteria. 25% used less than a single paragraph to describe the qualitative research. The aims of the qualitative research described in these proposals focused mainly on the intervention or trial conduct. Just over half (56%) of the proposals included an explicit rationale for conducting the qualitative research with the trial, the most frequent being to optimise implementation into clinical practice or to interpret trial findings. Key information about methods, expertise and resources was missing in a large minority of proposals, in particular sample size, type of analysis, and non-personnel resources. 28% specifically stated that qualitative researchers would conduct the qualitative research. Our review of proposals of successfully funded studies identified good practice but also identified limited space given to describing the qualitative research, with an associated lack of attention to the rationale for doing the qualitative research and
Cichański, Artur; Nowicki, Krzysztof; Mazurkiewicz, Adam; Topoliński, Tomasz
2010-01-01
The paper presents linear, logarithmic and exponential regression tabecular bone indices, fractal dimensions and strength. The analysis of the above parameters was supported by determining non-parametric correlation coefficients: Spearman's ρ, gamma and Kendall's τ. The principal components' analysis (PCA) was also performed in order to reduce the number of indices describing the variance in the data set. The analysis showed the most independent indices: lacunarity (λm, λmin, λmax), BMD, Conn.D., SMI, DA, ρA and age.
Directory of Open Access Journals (Sweden)
BABA SENOWBARI-DARYAN
2007-11-01
Full Text Available Examination of the calcareous microfossil from the Anisian reef limestones of the Aggtelek Mountains, northern Hungary, described as Axopora aggtelekensis by Scholz, supports the cyanobacterian nature of this organism. It is not a Hydrozoa as originally thought by Scholz. For this microfossils, occuring in Triassic shallow water carbonates the new genus Anisophytes is proposed. The differences between Anisophytes, as gregarious microfossil composed of tubes, and other similar looking organisms, like Tubiphytes, Aeolisaccus kotori Radoicic, Koivaella Tchuvashov or Proaulopora Vologdin is discussed. Anisophytes is attributed tentatively to Cyanophyceans.
2014-01-01
Background There is growing recognition of the value of conducting qualitative research with trials in health research. It is timely to reflect on how this qualitative research is presented in grant proposals to identify lessons for researchers and research commissioners. As part of a larger study focusing on how to maximise the value of undertaking qualitative research with trials, we undertook a documentary analysis of proposals of funded studies. Methods Using the metaRegister of Controlled Trials (mRCT) database we identified trials funded in the United Kingdom, ongoing between 2001 and 2010, and reporting the use of qualitative research. We requested copies of proposals from lead researchers. We extracted data from the proposals using closed and open questions, analysed using descriptive statistics and content analysis respectively. Results 2% (89/3812) of trials in the mRCT database described the use of qualitative research undertaken with the trial. From these 89 trials, we received copies of 36 full proposals, of which 32 met our inclusion criteria. 25% used less than a single paragraph to describe the qualitative research. The aims of the qualitative research described in these proposals focused mainly on the intervention or trial conduct. Just over half (56%) of the proposals included an explicit rationale for conducting the qualitative research with the trial, the most frequent being to optimise implementation into clinical practice or to interpret trial findings. Key information about methods, expertise and resources was missing in a large minority of proposals, in particular sample size, type of analysis, and non-personnel resources. 28% specifically stated that qualitative researchers would conduct the qualitative research. Conclusions Our review of proposals of successfully funded studies identified good practice but also identified limited space given to describing the qualitative research, with an associated lack of attention to the rationale for
Hydrodynamic-type systems describing 2-dimensional polynomially integrable geodesic flows
Manno, Gianni; Pavlov, Maxim V.
2017-03-01
Starting from a homogeneous polynomial in momenta of arbitrary order we extract multi-component hydrodynamic-type systems which describe 2-dimensional geodesic flows admitting the initial polynomial as integral. All these hydrodynamic-type systems are semi-Hamiltonian, thus implying that they are integrable according to the generalized hodograph method. Moreover, they are integrable in a constructive sense as polynomial first integrals allow to construct generating equations of conservation laws. According to the multiplicity of the roots of the polynomial integral, we separate integrable particular cases.
Hanke, J.-P.; Freimuth, F.; Nandy, A. K.; Zhang, H.; Blügel, S.; Mokrousov, Y.
2016-09-01
We address the importance of the modern theory of orbital magnetization for spintronics. Based on an all-electron first-principles approach, we demonstrate that the predictive power of the routinely employed "atom-centered" approximation is limited to materials like elemental bulk ferromagnets, while the application of the modern theory of orbital magnetization is crucial in chemically or structurally inhomogeneous systems such as magnetic thin films, and materials exhibiting nontrivial topology in reciprocal and real space, e.g., Chern insulators or noncollinear systems. We find that the modern theory is particularly crucial for describing magnetism in a class of materials that we suggest here—topological orbital ferromagnets.
The RMT method for describing many-electron atoms in intense short laser pulses
Lysaght, M. A.; Moore, L. R.; Nikolopoulos, L. A. A.; Parker, J. S.; van der Hart, H. W.; Taylor, K. T.
2012-11-01
We describe how we have developed an ab initio R-Matrix incorporating Time (RMT) method to provide an accurate description of the single ionization of a general many-electron atom exposed to short intense laser pulses. The new method implements the "division-of-space" concept central to R-matrix theory and takes over the sophisticated time-propagation algorithms of the HELIUM code. We have tested the accuracy of the new method by calculating multiphoton ionization rates of He and Ne and have found excellent agreement with other highly accurate and well-established methods.
O'Reilly, T. C.; Broering, A.; del Rio, J.; Headley, K. L.; Toma, D.; Bermudez, L. E.; Edgington, D.; Fredericks, J.; Manuel, A.
2012-12-01
Sensor technology is rapidly advancing, enabling smaller and cheaper instruments to monitor Earth's environment. It is expected that many more kinds and quantities of networked environmental sensors will be deployed in coming years. Knowledge of each instrument's command protocol is required to operate and acquire data from the network. Making sense of these data streams to create an integrated picture of environmental conditions requires that each instrument's data and metadata be accurately processed and that "suspect" data be flagged. Use of standards to operate an instrument and retrieve and describe its data generally simplifies instrument software development, integration, operation and data processing. The Open Geospatial Consortium (OGC) PUCK protocol enables instruments that describe themselves in a standard way. OGC PUCK defines a small "data sheet" that describes key instrument characteristics, and a standard protocol to retrieve the data sheet from the device itself. Data sheet fields include a universal serial number that is unique across all PUCK-compliant instruments. Other fields identify the instrument manufacturer and model. In addition to the data sheet, the instrument may also provide a "PUCK payload" which can contain additional descriptive information (e.g. a SensorML document or IEEE 1451 TEDS), as well as actual instrument "driver" code. Computers on the sensor network can use PUCK protocol to retrieve this information from installed instruments and utilize it appropriately, e.g. to automatically identify, configure and operate the instruments, and acquire and process their data. The protocol is defined for instruments with an RS232 or Ethernet interface. OGC members recently voted to adopt PUCK as a component of the OGC's Sensor Web Enablement (SWE) standards. The protocol is also supported by a consortium of hydrographic instrument manufacturers and has been implemented by several of them (https://sites.google.com/site/soscsite/). Thus far
Energy Technology Data Exchange (ETDEWEB)
Cimpoesu, Dorin, E-mail: cdorin@uaic.ro; Stoleriu, Laurentiu; Stancu, Alexandru [Department of Physics, Alexandru Ioan Cuza University of Iasi, Iasi 700506 (Romania)
2013-12-14
We propose a generalized Stoner-Wohlfarth (SW) type model to describe various experimentally observed angular dependencies of the switching field in non-single-domain magnetic particles. Because the nonuniform magnetic states are generally characterized by complicated spin configurations with no simple analytical description, we maintain the macrospin hypothesis and we phenomenologically include the effects of nonuniformities only in the anisotropy energy, preserving as much as possible the elegance of SW model, the concept of critical curve and its geometric interpretation. We compare the results obtained with our model with full micromagnetic simulations in order to evaluate the performance and limits of our approach.
The use of the Wagner function to describe poled-order relaxation processes in electrooptic polymers
Verbiest, T.; Burland, D. M.
1995-04-01
The Wagner (lognormal) time decay function is used to describe decay of the second harmonic signal due to electric field poled-order relaxation in the guest—host polymer system 20 wt% lophine 1 in Ultem ®. This function can be related to a Gaussian distribution of Arrhenius activation energies. From the temperature dependence of the relaxation process one can determine the average value for the activation energy. In the present case a value of 40 kcal/mol is found consistent with experimental values obtained for a variety of other thermally activated processes in polymers.
Chaos in a modified Henon-Heiles system describing geodesics in gravitational waves
Vesely, K
2000-01-01
A Hamiltonian system with a modified Henon-Heiles potential is investigated. This describes the motion of free test particles in vacuum gravitational pp-wave spacetimes with both quadratic ("homogeneous") and cubic ("non-homogeneous") terms in the structural function. It is shown that, for energies above a certain value, the motion is chaotic in the sense that the boundaries separating the basins of possible escapes become fractal. Similarities and differences with the standard Henon-Heiles and the monkey saddle systems are discussed. The box-counting dimension of the basin boundaries is also calculated.
Thermo Vacuum State for Describing the Density Operator of Photon-subtracted Squeezed Chaotic Light
Wan, Zhi-Long; Fan, Hong-Yi; Li, Heng-Mei; Wang, Zhen
2017-10-01
For the density operator describing s-photon-subtracted squeezed chaotic light (PSSCL) we search for its thermo vacuum state (a pure state) in the real-fictitious space. We find that it reduces to a thermo vacuum state of squeezed chaotic light when s = 0, and to a thermo vacuum state of the optical negative binomial field when no squeezing. The new thermo vacuum state simplifies calculating photon number average, quantum fluctuation and Mandel's Q parameter of PSSCL. Using the method of integration within ordered product (IWOP) of operators we also derive the normalization coefficient and explicitly analytical expressions of Wigner function for PSSCL.
Hageseth, Gaylord T.
1982-02-01
Students under the supervision of a faculty member can collect data and fit the data to the theoretical mathematical model that describes the rate of isothermal seed germination. The best-fit parameters are interpreted as an initial substrate concentration, product concentration, and the autocatalytic reaction rate. The thermodynamic model enables one to calculate the activation energy for the substrate and product, the activation energy for the autocatalytic reaction, and changes in enthalpy, entropy, and the Gibb's free energy. Turnip, lettuce, soybean, and radish seeds have been investigated. All data fit the proposed model.
Localization in physical systems described by discrete nonlinear Schrodinger-type equations.
Bishop, A R; Kalosakas, G; Rasmussen, K O; Kevrekidis, P G
2003-06-01
Following a short introduction on localized modes in a model system, namely the discrete nonlinear Schrodinger equation, we present explicit results pertaining to three different physical systems described by similar equations. The applications range from the Raman scattering spectra of a complex electronic material through intrinsic localized vibrational modes, to the manifestation of an abrupt and irreversible delocalizing transition of Bose-Einstein condensates trapped in two-dimensional optical lattices, and to the instabilities of localized modes in coupled arrays of optical waveguides.
A UML-based ontology for describing hospital information system architectures.
Winter, A; Brigl, B; Wendt, T
2001-01-01
To control the heterogeneity inherent to hospital information systems the information management needs appropriate hospital information systems modeling methods or techniques. This paper shows that, for several reasons, available modeling approaches are not able to answer relevant questions of information management. To overcome this major deficiency we offer an UML-based ontology for describing hospital information systems architectures. This ontology views at three layers: the domain layer, the logical tool layer, and the physical tool layer, and defines the relevant components. The relations between these components, especially between components of different layers make the answering of our information management questions possible.
A Statistical Approach to Describe Highly Excited Heavy and Superheavy Nuclei
Chen, Peng-Hui; Li, Jun-Qing; Zhang, Hong-Fei
2016-01-01
A statistical approach based on the Weisskopf evaporation theory has been developed to describe the de-excitation process of highly excited heavy and superheavy nuclei, in particular for the proton-rich nuclei. The excited nucleus is cooled by evaporating $\\gamma$-ray, light particles (neutrons, protons, $\\alpha$ etc) in competition with the binary fission, in which the structure effects (shell correction, fission barrier, particle separation energy) contribute to the processes. The formation of residual nuclei is evaluated via sequential emission of possible particles above the separation energies. The available data of fusion-evaporation excitation functions in the $^{28}$Si+$^{198}$Pt reaction can be reproduced nicely well within the approach.
Electrical performances of pyroelectric bimetallic strip heat engines describing a Stirling cycle
Arnaud, A.; Boughaleb, J.; Monfray, S.; Boeuf, F.; Cugat, O.; Skotnicki, T.
2015-12-01
This paper deals with the analytical modeling of pyroelectric bimetallic strip heat engines. These devices are designed to exploit the snap-through of a thermo-mechanically bistable membrane to transform a part of the heat flowing through the membrane into mechanical energy and to convert it into electric energy by means of a piezoelectric layer deposited on the surface of the bistable membrane. In this paper, we describe the properties of these heat engines in the case when they complete a Stirling cycle, and we evaluate the performances (available energy, Carnot efficiency...) of these harvesters at the macro- and micro-scale.
[Describe relationship among multi-components of Siwu decoction using game theory].
Liu, Ming; Ma, Zengchun; Liang, Qiande; Wang, Yuguang; Tan, Hongling; Xiao, Chengrong; Xiao, Rui; Zhang, Boli; Gao, Yue
2011-04-01
Game theory is an important component of complex system theory, specially used in describing bilateral or multiple cooperation and confrontation. Traditional Chinese medicine (TCM) prescription doctrines cover multiple connotation of game theory. Firstly multi-components of Siwu decoction were analyzed by using fuzzy set to get the membership functions. Then the revenue function was contructed and build the Siwu decoction's multi-player game model was built. Lastly the three kinds of different combinations Siwu decoction efficacy were analyzed by using the model to get the best compositions.
Accuracy Assessment for Cad Modeling of Freeform Surface Described by Equation
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Golba Grzegorz
2015-06-01
Full Text Available This paper presents the results of comparative analysis of modeling accuracy the freeform surface constructed by using a variety of algorithms for surface modeling. Also determined the accuracy of mapping the theoretical freeform surface described by mathematical equation. To model surface objects used: SolidWorks 2012, CATIA v5 and Geomagic Studio 12. During the design process of CAD models were used: profile curves, fitting parametric surface and polygonal mesh. To assess the accuracy of the CAD models used Geomagic Qualify 12. On the basis of analyse defined the scope of application of each modeling techniques depending on the nature of the constructed object.
If mechanics of cells can be described by elastic modulus in AFM indentation experiments?
Sokolov, Igor; Dokukin, Maxim; Guz, Nataliia; Kalaparthi, Vivekanand
2014-03-01
We study the question if cells, being highly heterogeneous objects, can be described with an elastic modulus (the Young's modulus) in a self-consistent way. We analyze the elastic modulus using indentation done with AFM of human cervical epithelial cells. Both sharp (cone) and dull AFM probes were used. The indentation data collected were processed through different elastic models. The cell was considered as a homogeneous elastic medium which had either smooth spherical boundary (Hertz/Sneddon models) or the boundary covered with a layer of glycocalyx and membrane protrusions (``brush'' models). Validity of these approximations was investigated. Specifically, we tested the independence of the elastic modulus of the indentation depth, which is assumed in these models. We demonstrate that only one model shows consistency with treating cells as homogeneous elastic medium, the bush model when processing the indentation data collected with the dull probe. The elastic modulus demonstrates strong depth dependence in all other three models. We conclude that it is possible to describe the elastic properties of the cell body by means of an effective elastic modulus in a self-consistent way when using the brush model to analyze data collected with a dull AFM probe.
Nicolaou, Georgios; Livadiotis, George
2016-11-01
This paper presents the misestimation of temperature when observations from a kappa distributed plasma are analyzed as a Maxwellian. One common method to calculate the space plasma parameters is by fitting the observed distributions using known analytical forms. More often, the distribution function is included in a forward model of the instrument's response, which is used to reproduce the observed energy spectrograms for a given set of plasma parameters. In both cases, the modeled plasma distribution fits the measurements to estimate the plasma parameters. The distribution function is often considered to be Maxwellian even though in many cases the plasma is better described by a kappa distribution. In this work we show that if the plasma is described by a kappa distribution, the derived temperature assuming Maxwell distribution can be significantly off. More specifically, we derive the plasma temperature by fitting a Maxwell distribution to pseudo-data produced by a kappa distribution, and then examine the difference of the derived temperature as a function of the kappa index. We further consider the concept of using a forward model of a typical plasma instrument to fit its observations. We find that the relative error of the derived temperature is highly depended on the kappa index and occasionally on the instrument's field of view and response.
Practical expressions describing detective quantum efficiency in flat-panel detectors
Kim, H. K.
2011-11-01
In radiology, image quality excellence is a balance between system performance and patient dose, hence x-ray systems must be designed to ensure the maximum image quality is obtained for the lowest consistent dose. The concept of detective quantum efficiency (DQE) is widely used to quantify, understand, measure, and predict the performance of x-ray detectors and imaging systems. Cascaded linear-systems theory can be used to estimate DQE based on the system design parameters and this theoretical DQE can be utilized for determining the impact of various physical processes, such as secondary quantum sinks, noise aliasing, reabsorption noise, and others. However, the prediction of DQE usually requires tremendous efforts to determine each parameter consisting of the cascaded linear-systems model. In this paper, practical DQE formalisms assessing both the photoconductor- and scintillator-based flat-panel detectors under quantum-noise-limited operation are described. The developed formalisms are experimentally validated and discussed for their limits. The formalisms described in this paper would be helpful for the rapid prediction of the DQE performances of developing systems as well as the optimal design of systems.
Fox, Craig R; Birke, Richard
2002-04-01
The study of judgment under uncertainty has revealed that people judge the probability of an event to be higher when the event is described as a disjunction of constituent events or when they judge constituent events separately. These observations have motivated the development of support theory (Y. Rottenstreich & A. Tversky, 1997; A. Tversky & D. J. Koehler, 1994), a descriptive model of judgment under uncertainty. The major predictions of support theory are that (1) the judged probabilities of complementary events sum to 1; (2) the judged probabilities of n > 2 exclusive and exhaustive events generally sum to more than 1; and (3) the judged probability of an event generally increases when it is described as a disjunction of specific possibilities. We test these predictions in 6 studies of experienced attorneys who judged the likelihood of particular trial outcomes or were asked to offer advice on whether or not to accept a settlement offer. The results demonstrate that attorneys are indeed susceptible to bias in forecasting trial outcomes, consistent with support theory.
Morandi, Stefano; Silvetti, Tiziana; Brasca, Milena
2013-01-01
The biotechnological and safety properties of a recently described enterococcal species, Enterococcus lactis, were investigated. With regard to the technological properties, in milk all the strains tested had weak acidifying and proteolytic activities, generally medium reduction activity over 24 h (-102 mV detection did not identify any of the common genetic determinants for vancomycin, tetracycline and erythromycin resistance. The E. lactis strains showed good survival in simulated in vitro digestion and were able to inhibit the growth of Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Clostridium sporogenes, Clostridium tyrobutyricum and Pseudomonas syringae. Screening for enterocin structural genes showed that all isolates harboured the entP gene. The presence of nine virulence factor genes (cylA, asa1, gelE, hyl, esp, ace, efaA, hdc and tdc) was investigated by PCR and no virulence determinants were detected. This study highlights that the recently described E. lactis may be a potential source of novel strains with interesting features that could be used for fermented dairy foods.
How do the parents describe personality of their child with cognitive disability?
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Blanka Colnerič
2011-01-01
Full Text Available The Five-Factor Model (FFM of personality domains was demonstrated as useful taxonomy to classify parents' descriptions of children and adolescents across several countries. In the present study, 156 Slovene children (Mage= 6.95 years with cognitive disabilities (CD were described by their mothers and fathers. A coding scheme developed within a previous international research project was used to categorize the expressions generated by the parents. The scheme includes five main categories, with three subcategories each, and ten additional categories outside the FFM. Over 70% of parental responses were coded within the FFM sugesting that this taxonomy is also relevant for categorizing characteristics of individuals with CD. There was a significant agreement between the spouses on describing their child with CD. In comparison to samples of normative children across different studies, Agreeableness received a higher proportion of descriptions by parents, mostly due to reports coded in Helpfulness and low Manageability subcategories. A lower proportion of descriptors was coded in the Openness/Intellect category, mostly due to reports on interests of children with CD. The lowest proportion of descriptors was ascribed to the Conscientiousness and Emotional Instability categories. Most of the responses outside the FFM were coded in the Disabilities category as the parents often mentioned their child's disabilities in the course of interview.
Methods to describe barotropic vortices by global fields and vortex characteristics
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W.-G. Früh
2002-01-01
Full Text Available Results from an experimental study of vortices in a rotating shear layer are presented. The data are in the form of maps of the instantaneous horizontal velocity field obtained by a particle tracking technique. Two fundamentally different methods to analyse time series of these velocity fields are presented and compared. One technique is the empirical orthogonal function (EOF analysis, and the other method describes the flow field in terms of a few individual localised vortices. The flows discussed here are time-dependent two-vortex flows, which could either be described as a global mode 2 or as a collection of four unequal vortices. The results show that, while EOF analysis is a very powerful tool to detect fairly regular travelling modes or stationary features, it cannot detect local dynamics. The vortex identification technique is very good at detecting local structures and events but cannot put them into the context of a global flow structure. The comparison of the techniques shows indications that the time-dependence found in the system for low mode numbers could arise from an interaction of the large scale, global-mode flow with a local mechanism of vortex generation and shedding at a solid boundary.
Stability of exact solutions describing two-layer flows with evaporation at the interface
Bekezhanova, V. B.; Goncharova, O. N.
2016-12-01
A new exact solution of the equations of free convection has been constructed in the framework of the Oberbeck-Boussinesq approximation of the Navier-Stokes equations. The solution describes the joint flow of an evaporating viscous heat-conducting liquid and gas-vapor mixture in a horizontal channel. In the gas phase the Dufour and Soret effects are taken into account. The consideration of the exact solution allows one to describe different classes of flows depending on the values of the problem parameters and boundary conditions for the vapor concentration. A classification of solutions and results of the solution analysis are presented. The effects of the external disturbing influences (of the liquid flow rates and longitudinal gradients of temperature on the channel walls) on the stability characteristics have been numerically studied for the system HFE7100-nitrogen in the common case, when the longitudinal temperature gradients on the boundaries of the channel are not equal. In the system both monotonic and oscillatory modes can be formed, which damp or grow depending on the values of the initial perturbations, flow rates and temperature gradients. Hydrodynamic perturbations are most dangerous under large gas flow rates. The increasing oscillatory perturbations are developed due to the thermocapillary effect under large longitudinal gradients of temperature. The typical forms of the disturbances are shown.
Assessment of diffusion models to describe drying of roof tiles using generalized coordinates
Farias, Vera S. O.; da Silva, Wilton Pereira; e Silva, Cleide M. D. P. S.; da Silva Júnior, Aluízio Freire; de Farias Aires, Juarez Everton; Rocha, Vicente P. T.
2016-07-01
This article aims to study the mass transient diffusion in solids with an arbitrary shape, highlighting boundary condition of the third kind. To this end, the numerical formalism to discretize the transient 3D diffusion equation written in generalized coordinates is presented. For the discretization, it was used the finite volume method with a fully implicit formulation. An application to drying of roof tiles has been done. Three models were used to describe the drying process: (1) the volume V and the effective mass diffusivity D are considered constant for the boundary condition of the first kind; (2) V and D are considered constant for the boundary condition of the third kind and (3) V and D are considered variable for the boundary condition of the third kind. For all models, the convective mass transfer coefficient h was considered constant. The analyses of the results obtained make it possible to affirm that the model 3 describes the drying process better than the other models.
Supersonic flow about cone eith ijection of gas through its surface described by power law
Antonov, A. M.; Zakrevskiy, V. A.
1986-01-01
The influence of intensive mass transfer on the supersonic flow of gas about a cone of finite length is investigated. The mathematical model describing the interaction of the primary flow and the transverse flow formed by injection is the boundary problem for a system of equations presented with boundary conditions on the cone and on the contact discontinuity. It is found that the contact surface is nonrectilinear when the injected gas is described by a power law and that the thickness of the layer coming in contact with the cone increases as the intensity of the injection becomes higher. The distribution of the pressure coefficient along a finite cone is calculated as a function of the parameter(s) associated with the injection flow rate, and the Mach number of the oncoming stream. It is found that the pressure coefficient drops off along the generatrix of a cone for all velocities of injection and oncoming stream when the injection is distributed. As the injection intensity increases, the pressure coefficient on the surface increases.
A bottom-up model to describe consumers’ preferences towards late season peaches
Energy Technology Data Exchange (ETDEWEB)
Groot, E.; Albisu, L.M.
2015-07-01
Peaches are consumed in Mediterranean countries since ancient times. Nowadays there are few areas in Europe that produce peaches with Protected Designation of Origin (PDO), and the Calanda area is one of them. The aim of this work is to describe consumers’ preferences towards late season PDO Calanda peaches in the city of Zaragoza, Spain, by a bottom-up model. The bottom-up model proves greater amount of information than top-down models. In this approach it is estimated one utility function per consumer. Thus, it is not necessary to make assumptions about preference distributions and correlations across respondents. It was observed that preference distributions were neither normal nor independently distributed. If those preferences were estimated by top-down models, conclusions would be biased. This paper also explores a new way to describe preferences through individual utility functions. Results show that the largest behavioural group gathered origin sensitive consumers. Their utility increased if the peaches were produced in the Calanda area and, especially, when peaches had the PDO Calanda brand. In sequence, the second most valuable attribute for consumers was the price. Peach size and packaging were not so important on purchase choice decision. Nevertheless, it is advisable to avoid trading smallest size peaches (weighting around 160 g/fruit). Traders also have to be careful by using active packaging. It was found that a group of consumers disliked this kind of product, probably, because they perceived it as less natural. (Author)
Keratitis caused by the recently described new species Aspergillus brasiliensis: two case reports
Directory of Open Access Journals (Sweden)
Vágvölgyi Csaba
2010-02-01
Full Text Available Abstract Introduction Human infections caused by Aspergillus brasiliensis have not yet been reported. We describe the first two known cases of fungal keratitis caused by Aspergillus brasiliensis. Case presentations A 49-year-old Indian Tamil woman agricultural worker came with pain and defective vision in the right eye for one month. Meanwhile, a 35-year-old Indian Tamil woman presented with a history of a corneal ulcer involving the left eye for 15 days. The fungal strains isolated from these two cases were originally suspected to belong to Aspergillus section Nigri based on macro- and micromorphological characteristics. Molecular identification revealed that both isolates represent A. brasiliensis. Conclusion The two A. brasiliensis strains examined in this study were part of six keratitis isolates from Aspergillus section Nigri, suggesting that this recently described species may be responsible for a significant proportion of corneal infections caused by black Aspergilli. The presented cases also indicate that significant differences may occur between the severities of keratitis caused by individual isolates of A. brasiliensis.
Describing Growth Pattern of Bali Cows Using Non-linear Regression Models
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Mohd. Hafiz A.W
2016-12-01
Full Text Available The objective of this study was to evaluate the best fit non-linear regression model to describe the growth pattern of Bali cows. Estimates of asymptotic mature weight, rate of maturing and constant of integration were derived from Brody, von Bertalanffy, Gompertz and Logistic models which were fitted to cross-sectional data of body weight taken from 74 Bali cows raised in MARDI Research Station Muadzam Shah Pahang. Coefficient of determination (R2 and residual mean squares (MSE were used to determine the best fit model in describing the growth pattern of Bali cows. Von Bertalanffy model was the best model among the four growth functions evaluated to determine the mature weight of Bali cattle as shown by the highest R2 and lowest MSE values (0.973 and 601.9, respectively, followed by Gompertz (0.972 and 621.2, respectively, Logistic (0.971 and 648.4, respectively and Brody (0.932 and 660.5, respectively models. The correlation between rate of maturing and mature weight was found to be negative in the range of -0.170 to -0.929 for all models, indicating that animals of heavier mature weight had lower rate of maturing. The use of non-linear model could summarize the weight-age relationship into several biologically interpreted parameters compared to the entire lifespan weight-age data points that are difficult and time consuming to interpret.
Pera-Titus, Marc
2010-05-15
The Dubinin-Astakhov and Dubinin-Radushkevich isotherms, originally formulated from the classical volume filling theory of micropores, constitute the most accepted models for describing gas adsorption in microporous materials. The most important weakness of these equations relies on the fact that they do not reduce to Henry's law at low pressures, not providing therefore a proper characterization of adsorbents in the early stage of adsorption. In this paper, we propose a way out of this inherent problem using the thermodynamic isotherm developed in a previous study [J. Llorens, M. Pera-Titus, J. Colloid Interface Sci. 331 (2009) 302]. This isotherm allows the generation of a series of equations that make available a comprehensive description of gas adsorption for the whole set of relative pressures (including Henry's region), also providing explicit information about energy heterogeneity of the adsorbent through the two characteristic m parameters of the thermodynamic isotherm (i.e., m(1) and m(2)). The obtained isotherm converges into the Dubinin-Astakhov isotherm for relative pressures higher than 0.1, the characteristic α parameter of this isotherm being expressed as α=m(2)-1 and the affinity coefficient (β) as a sole function of m(2). An expression differing from the Dubinin-Astakhov isotherm has been obtained for describing Henry's region, providing relevant information about confinement effects when applied to zeolites.
Cieszyńska, Agata; Białogrodzka, Jagoda; Yngve Børsheim, Knut; Stramska, Małgorzata; Jankowski, Andrzej
2016-04-01
This presentation is a part of the NORDFLUX project, and describes some of the results from experimental work carried out in 2014 in the Porsangerfjorden located in the area of the European Arctic. The fjord borders the Barents Sea. This is a region of high climatic sensitivity and our interest in the basin stemmed from this fact. One of our long-term goals is to develop an improved understanding of the undergoing changes and interactions between this fjord and the large-scale atmospheric and oceanic conditions. In present work we focus on data sets collected with High Frequency (HF) radars monitoring surface currents in the outer part of the Porsnagerfjorden. In our analysis we also use data on water salinity and temperature collected as part of the NORDFLUX experiment, and data from sea level and meteorological station located in Honningsvaag. Analysis of data sets enabled us to describe water salinity, temperature, density distributions and their variability. What is more, we have related aforementioned results to tides, meteorological conditions, and sea surface currents speed and directions. During the poster session the Author will present the schemes of water masses movement in the area of interest. This work was funded by the Norway Grants through the Polish-Norwegian Research Programme, National Centre for Research and Development (contract No. 201985). Project title: 'Application of in situ observations, high frequency radars, and ocean color, to study suspended matter, particulate carbon, and dissolved organic carbon fluxes in coastal waters of the Barents Sea'.
Conceptual framework for describing selected urban and community impacts of federal energy policies
Energy Technology Data Exchange (ETDEWEB)
Morris, F.A,; Marcus, A.A.; Keller, D.
1980-06-01
A conceptual framework is presented for describing selected urban and community impacts of Federal energy policies. The framework depends on a simple causal model. The outputs of the model are impacts, changes in the state of the world of particular interest to policymakers. At any given time, a set of determinants account for the state of the world with respect to an impact category. Application of the model to a particular impact category requires: establishing a definition and measure for the impact category and identifying the determinants of these impacts. Analysis of the impact of a particular policy requires the following: identifying the policy and its effects (as estimated by others), isolating any effects that themselves constitute an urban and community impact, identifying any effects that change the value of determinants, and describing the impact with reference to the new values of determinants. This report provides a framework for these steps. Three impacts addressed are: neighborhood stability, housing availability, and quality and availability of public services. In each chapter, a definition and measure for the impact are specified; its principal determinants are identified; how the causal model can be used to estimate impacts by applying it to three illustrative Federal policies (domestic oil price decontrol, building energy performance standards, and increased Federal aid for mass transit) is demonstrated. (MCW)
Evaluation of mathematical models to describe growth of grazing young bulls
Directory of Open Access Journals (Sweden)
Henrique Jorge Fernandes
2012-02-01
Full Text Available The objective of this study was to evaluate the use of different mathematical models to describe growth of grazing beef cattle. Data of 20 Nellore bulls with initial weight of 129±28.1 kg and final weight of 405±62.0 kg were used. The animals were randomly divided into four plots and placed on B. decumbens Stapf pastures. Three plots received concentrate supplement with different protein profiles and the fourth plot received only mineral supplement. Animals were weighed every 28 days to design growth curve of full body weight. Five mathematical models were evaluated to describe animal growth: Multiphase, Linear, Logarithmic, Gompertz and Logistic models. Assessment of adequacy of the models was performed by using coefficient of determination, simultaneous F-test for identity of parameters, concordance correlation coefficient, root of the mean square error of prediction and partition of the mean square error of prediction. The analysis of the pairwise mean square error of prediction and the delta Akaike's information criterion were used to compare the models for accuracy and precision. Evaluation of all the tested models showed that all of them were able to predict variability among animals. However, Gompertz, Logarithmic and Logistic models created individual predictions that were not satisfactory. Models differed from each other concerning accuracy and precision; the best were in the following order: Multiphase, Linear, Gompertz, Logarithmic and Logistic. The Multiphase model was more efficient than the others for description of grazing beef cattle growth.
Directory of Open Access Journals (Sweden)
Lee Robert C
2005-11-01
Full Text Available Abstract Background Most epidemiological studies of major depression report period prevalence estimates. These are of limited utility in characterizing the longitudinal epidemiology of this condition. Markov models provide a methodological framework for increasing the utility of epidemiological data. Markov models relating incidence and recovery to major depression prevalence have been described in a series of prior papers. In this paper, the models are extended to describe the longitudinal course of the disorder. Methods Data from three national surveys conducted by the Canadian national statistical agency (Statistics Canada were used in this analysis. These data were integrated using a Markov model. Incidence, recurrence and recovery were represented as weekly transition probabilities. Model parameters were calibrated to the survey estimates. Results The population was divided into three categories: low, moderate and high recurrence groups. The size of each category was approximated using lifetime data from a study using the WHO Mental Health Composite International Diagnostic Interview (WMH-CIDI. Consistent with previous work, transition probabilities reflecting recovery were high in the initial weeks of the episodes, and declined by a fixed proportion with each passing week. Conclusion Markov models provide a framework for integrating psychiatric epidemiological data. Previous studies have illustrated the utility of Markov models for decomposing prevalence into its various determinants: incidence, recovery and mortality. This study extends the Markov approach by distinguishing several recurrence categories.
Energy Technology Data Exchange (ETDEWEB)
Lestrange, Patrick J.; Egidi, Franco; Li, Xiaosong, E-mail: xsli@uw.edu [Department of Chemistry, University of Washington, Seattle, Washington 98195 (United States)
2015-12-21
The interaction between a quantum mechanical system and plane wave light is usually modeled within the electric dipole approximation. This assumes that the intensity of the incident field is constant over the length of the system and transition probabilities are described in terms of the electric dipole transition moment. For short wavelength spectroscopies, such as X-ray absorption, the electric dipole approximation often breaks down. Higher order multipoles are then included to describe transition probabilities. The square of the magnetic dipole and electric quadrupole are often included, but this results in an origin-dependent expression for the oscillator strength. The oscillator strength can be made origin-independent if all terms through the same order in the wave vector are retained. We will show the consequences and potential pitfalls of using either of these two expressions. It is shown that the origin-dependent expression may violate the Thomas-Reiche-Kuhn sum rule and the origin-independent expression can result in negative transition probabilities.
Madurga, Rodrigo; Plaza, Gustavo R.; Blackledge, Todd A.; Guinea, Gustavo. V.; Elices, Manuel; Pérez-Rigueiro, José
2016-01-01
Spider major ampullate gland silks (MAS) vary greatly in material properties among species but, this variation is shown here to be confined to evolutionary shifts along a single universal performance trajectory. This reveals an underlying design principle that is maintained across large changes in both spider ecology and silk chemistry. Persistence of this design principle becomes apparent after the material properties are defined relative to the true alignment parameter, which describes the orientation and stretching of the protein chains in the silk fiber. Our results show that the mechanical behavior of all Entelegynae major ampullate silk fibers, under any conditions, are described by this single parameter that connects the sequential action of three deformation micromechanisms during stretching: stressing of protein-protein hydrogen bonds, rotation of the β-nanocrystals and growth of the ordered fraction. Conservation of these traits for over 230 million years is an indication of the optimal design of the material and gives valuable clues for the production of biomimetic counterparts based on major ampullate spider silk.
A Comparison of Climatic Chamber Hygrothermal Characterization Techniques as Described in IEC60068
Mac Lochlainn, D.; White, M.; Wettstein, S.; Farley, R.; Aicken, C.; Gee, R.
2015-08-01
Techniques for the evaluation of the spatial temperature and humidity performance criteria of climatic chambers are described within the various sections of the International Electrotechnical Commission (IEC) Standard IEC60068 applicable to environmental testing. This paper involves the comparison of three common measurement systems used to assess the performance of climatic chambers, as well as the development of methods for determination of uncertainty contributions, and subsequent propagation into an uncertainty analysis for each method. Methods for validating the performance of these chambers should include specific uncertainty contributions, such as fluctuations, homogeneity, radiation, sampling, and loading effects. These effects are discussed and evaluated as part of this work. The procedure, as detailed in IEC60068, was followed using a chilled-mirror dew-point hygrometer with nine platinum resistance thermometers, nine calibrated RH (relative humidity) and temperature probes, and nine calibrated RH and temperature wireless data logger modules. Loading effect and dew-point uniformity were evaluated empirically and the results discussed. A summary of the results obtained and the associated uncertainty calculations are described and compared. All three systems have their merits, and lower uncertainties in both temperature and %rh were obtained for the chilled-mirror system.
A Network Model to Describe the Terminal Differentiation of B Cells
Méndez, Akram; Mendoza, Luis
2016-01-01
Terminal differentiation of B cells is an essential process for the humoral immune response in vertebrates and is achieved by the concerted action of several transcription factors in response to antigen recognition and extracellular signals provided by T-helper cells. While there is a wealth of experimental data regarding the molecular and cellular signals involved in this process, there is no general consensus regarding the structure and dynamical properties of the underlying regulatory network controlling this process. We developed a dynamical model of the regulatory network controlling terminal differentiation of B cells. The structure of the network was inferred from experimental data available in the literature, and its dynamical behavior was analyzed by modeling the network both as a discrete and a continuous dynamical systems. The steady states of these models are consistent with the patterns of activation reported for the Naive, GC, Mem, and PC cell types. Moreover, the models are able to describe the patterns of differentiation from the precursor Naive to any of the GC, Mem, or PC cell types in response to a specific set of extracellular signals. We simulated all possible single loss- and gain-of-function mutants, corroborating the importance of Pax5, Bcl6, Bach2, Irf4, and Blimp1 as key regulators of B cell differentiation process. The model is able to represent the directional nature of terminal B cell differentiation and qualitatively describes key differentiation events from a precursor cell to terminally differentiated B cells. PMID:26751566
Best-fit index for describing physical perspectives in Sasang typology.
Chae, Han; Kown, Youngkyu
2015-03-01
We examined the best-fit index for describing the constitutional or physical characteristics of Sasang typology for its universal application. Ponderal index (PI), body mass index (BMI), and basal metabolic rate (BMR) of the nationwide participants (n = 1663; age, 31-60 years) were calculated. We described and analyzed the usefulness of each index for maximizing the differences between Sasang types across age and sex using box plots, Pearson's correlation, and analysis of variance. We found that the So-Eum, So-Yang, and Tae-Eum Sasang types were significantly (p < 0.001) different from each other in terms of PI, BMI, and BMR by the World Health Organization with weight (BMR-WHOw). The BMI was significantly correlated with PI (r = 0.933) and BMR-WHOw (r = 0.577). These study results show that PI, BMR, and BMI have their own clinical values, and could contribute to the study of the pathophysiological mechanism underlying the Sasang typology as the hypothalamus hypothesis.
Energy Technology Data Exchange (ETDEWEB)
Moro, Erik A [Los Alamos National Laboratory; Puckett, Anthony D [Los Alamos National Laboratory; Todd, Michael D [UCSD
2011-01-24
The intensity distribution of a transmission from a single mode optical fiber is often approximated using a Gaussian-shaped curve. While this approximation is useful for some applications such as fiber alignment, it does not accurately describe transmission behavior off the axis of propagation. In this paper, another model is presented, which describes the intensity distribution of the transmission from a single mode optical fiber. A simple experimental setup is used to verify the model's accuracy, and agreement between model and experiment is established both on and off the axis of propagation. Displacement sensor designs based on the extrinsic optical lever architecture are presented. The behavior of the transmission off the axis of propagation dictates the performance of sensor architectures where large lateral offsets (25-1500 {micro}m) exist between transmitting and receiving fibers. The practical implications of modeling accuracy over this lateral offset region are discussed as they relate to the development of high-performance intensity modulated optical displacement sensors. In particular, the sensitivity, linearity, resolution, and displacement range of a sensor are functions of the relative positioning of the sensor's transmitting and receiving fibers. Sensor architectures with high combinations of sensitivity and displacement range are discussed. It is concluded that the utility of the accurate model is in its predicative capability and that this research could lead to an improved methodology for high-performance sensor design.
The exotic characteristics of centauro-I: a model to describe Centauro-I
Energy Technology Data Exchange (ETDEWEB)
Ohsawa, Akinori [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, 277-8582 (Japan); Shibuya, Edison H [Instituto de Fisica, Universidade Estadual de Campinas, 13081 Campinas, Sao Paulo (Brazil); Tamada, Masanobu [School of Science and Engineering, Kinki University, Higashi-Osaka, 577-8502 (Japan)
2006-11-15
In our previous paper on Centauro-I (Ohsawa et al 2004 Phys. Rev. D 70 074028), we showed that the shower cluster, found in the block I12 of the lower chamber, is produced in the target layer by a number of hadrons with appreciable lateral spread. These hadrons are accompanied by no (or one at most) {gamma}-ray(s) with energy above detection threshold, and produce no shower in the upper chamber but 28 visible C-jets (with the visible energy more than 2 TeV) in the target layer. These characteristics are quite exotic and unable to be described by a fluctuation of ordinary atmospheric families. In the present paper, we propose a model of strange quark matter (SQM) among the primary cosmic rays to describe the exotic features of the event. A large SQM droplet enters the atmosphere and fragments into a bundle of small strangelets in the atmosphere without emission of {gamma}-rays, and these small strangelets explode into nucleons in the upper chamber. The number of collisions in the upper chamber is estimated to be as small as 3-4 in contrast to 20-30 collisions in the target layer. We discuss the intensity of Centauro-I together with the exotic events observed by the balloon and satellite experiments, which were also ascribed to strange quark matter.
Non-equilibrium statistical mechanical approach for describing heavy ion reactions
Energy Technology Data Exchange (ETDEWEB)
Sventek, J.S.
1978-11-01
With the availability of heavy-ion projectiles (A > 4) at low to intermediate energies (4 < E/A < 10), products showing various stages of relaxation for certain macroscopic variables (center-of-mass energy, orbital angular momentum, etc.) were produced in various reactions. The distributions for these macroscopic variables showed a correlation between the stage of relaxation reached and the net amount of mass transfer which had occurred in the reaction. There was also evidence that there was an asymmetry in the number of net transfers necessary for complete relaxation between stripping and pickup reactions. A model for describing the time-evolution of these reactions was formulated, the keystone of which is a master-equation approach for describing the time-dependence of the mass-asymmetry. This, coupled with deterministic equations of motion for the other macroscopic coordinates in the reaction lead to calculated distributions which provide an excellent qualitative description of these reactions, and, in some cases, quantitatively reproduce the experimental data quite well. 61 figures, 2 tables.
Possible Way To Describe Breit's Interaction in Solids Composed From Heavy Elements
Energy Technology Data Exchange (ETDEWEB)
Kutepov, A L
2009-02-24
The report describes a theoretical procedure which could help evaluate the effect of quantum electrodynamic corrections on the electronic structure of crystals consisting of heavy elements. The procedure uses the effective Breit interaction as correction to traditional Coulomb interaction between electrons in non-relativistic theory. A number of other simplifying assumptions were made since even such a simplified consideration of quantum electrodynamic effects in crystals is a great challenge. These are as follows: (1) Exchange and correlation effects from the nonrelativistic interaction (the Coulomb term) between electrons are described within Density Functional Theory (DFT). (2) The Breit correction is on at the phase which involves the calculation of matrix elements between basis functions which define the single-electron spectrum of a crystal. In order to calculate the contribution from the Breit correction, the total wave function of electrons in the crystal is approximated by one Slater determinant consisting of the single-electron DFT-orbitals. (3) Only local matrix elements (i.e., the part of the two-electron integral for which both coordinate arguments belong to one and the same muffin-tin sphere) are considered.
Stein, Catherine H; Leith, Jaclyn E; Osborn, Lawrence A; Greenberg, Sarah; Petrowski, Catherine E; Jesse, Samantha; Kraus, Shane W; May, Michael C
2015-03-01
This qualitative study examined changes in community mental health care as described by adults diagnosed with schizophrenia with long-term involvement in the mental health system to situate their experiences within the context of mental health reform movements in the United States. A sample of 14 adults with schizophrenia who had been consumers of mental health services from 12 to 40 years completed interviews about their hospital and outpatient experiences over time and factors that contributed most to their mental health. Overall, adults noted gradual changes in mental health care over time that included higher quality of care, more humane treatment, increased partnership with providers, shorter hospital stays, and better conditions in inpatient settings. Regardless of the mental health reform era in which they were hospitalized, participants described negative hospitalization experiences resulting in considerable personal distress, powerlessness, and trauma. Adults with less than 27 years involvement in the system reported relationships with friends and family as most important to their mental health, while adults with more than 27 years involvement reported mental health services and relationships with professionals as the most important factors in their mental health. The sample did not differ in self-reported use of services during their initial and most recent hospitalization experiences, but differences were found in participants' reported use of outpatient services over time. Findings underscore the importance of the lived experience of adults with schizophrenia in grounding current discourse on mental health care reform.
Flexible alternatives to the Gompertz equation for describing growth with age in turkey hens.
Porter, T; Kebreab, E; Darmani Kuhi, H; Lopez, S; Strathe, A B; France, J
2010-02-01
A total of 49 profiles of growing turkey hens from commercial flocks were used in this study. Three flexible growth functions (von Bertalanffy, Richards, and Morgan) were evaluated with regard to their ability to describe the relationship between BW and age and were compared with the Gompertz equation with its fixed point of inflection, which might result in its overestimation. For each function, 4 ways of analysis were implemented. A basic model was fitted first, followed by implementation of a first-order autoregressive correlation structure. A model that considered only mature BW varied with year and another that considered only the rate coefficient varied with different years were applied. The results showed that the fixed point of inflection of the Gompertz equation can be a limitation and that the relationship between BW and age in turkeys was best described using flexible growth functions. However, the Richards equation failed to converge when fitted to the turkey growth data; therefore, it was not considered further. Inclusion of an autoregressive process of the first order rendered a substantially improved fit to data for the 3 growth functions. The Morgan equation provided the best fit to the data set and was used for characterizing mean growth curves for the 7 yr of production. It was estimated that the maximum growth rate occurred at 3.74, 3.65, 3.99, 4.18, 4.05, 4.01, and 3.77 kg BW for production years from 1997 to 2003, respectively. It is recommended that flexible growth functions should be considered as an alternative to the simpler functions (with a fixed point of inflection) for describing the relationship between BW and age in turkeys because they were easier to fit and very often gave a closer fit to data points because of their flexibility, and therefore a smaller residual MS value, than simpler models. It can also be recommended that studies should consider adding a first-order autoregressive process when analyzing repeated measures data with
Describing the apprenticeship of chemists through the language of faculty scientists
Skjold, Brandy Ann
Attempts to bring authentic science into the K-16 classroom have led to the use of sociocultural theories of learning, particularly apprenticeship, to frame science education research. Science educators have brought apprenticeship to science classrooms and have brought students to research laboratories in order to gauge its benefits. The assumption is that these learning opportunities are representative of the actual apprenticeship of scientists. However, there have been no attempts in the literature to describe the apprenticeship of scientists using apprenticeship theory. Understanding what science apprenticeship looks like is a critical component of translating this experience into the classroom. This study sought to describe and analyze the apprenticeship of chemists through the talk of faculty scientists. It used Lave and Wenger’s (1991) theory of Legitimate Peripheral Participation as its framework, concentrating on describing the roles of the participants, the environment and the tasks in the apprenticeship, as per Barab, Squire and Dueber (2000). A total of nine chemistry faculty and teaching assistants were observed across 11 settings representing a range of learning experiences from introductory chemistry lectures to research laboratories. All settings were videotaped, focusing on the instructor. About 89 hours of video was taken, along with observer field notes. All videos were transcribed and transcriptions and field notes were analyzed qualitatively as a broad level discourse analysis. Findings suggest that learners are expected to know basic chemistry content and how to use basic research equipment before entering the research lab. These are taught extensively in classroom settings. However, students are also required to know how to use the literature base to inform their own research, though they were rarely exposed to this in the classrooms. In all settings, conflicts occurred when student under or over-estimated their role in the learning
Institute of Scientific and Technical Information of China (English)
YanQuanying; ShangDeku; 等
1999-01-01
A two-dimensional mathematical model was built to describe the melting process of cylindrical basalt particle bed in a crucible.The melting processes with respect to the factors of thermal boundary conditions and particle sizes of basalt were simulated by using the numerical method (FDM).The governing equations were discretized in tridiagonal matrix form and were solved by using the tridiagonal matrix algorithm (TDMA) as well as the alternative direction implicit(ADI) solver.The temperature distribution,the moving law of the two dimensional phase-change boundaries the thermal current distribution were given through the numerical simulation.The results provided a theoretical basis for deciding heating procedure,for evaluating power import and controlling furnace temperature and for predicting basalt melting states etc.In the experiment,an electrical furnace was designed based on the computations.It has been proved that the simulation results are reasonably coincident with the experimental data.
Development of a model describing virus removal process in an activated sludge basin
Energy Technology Data Exchange (ETDEWEB)
Kim, T.; Shiragami, N. Unno, H. [Tokyo Institute of Technology, Tokyo (Japan)
1995-06-20
The virus removal process from the liquid phase in an activated sludge basin possibly consists of physicochemical processes, such as adsorption onto sludge flocs, biological processes such as microbial predating and inactivation by virucidal components excreted by microbes. To describe properly the virus behavior in an activated sludge basin, a simple model is proposed based on the experimental data obtained using a poliovirus type 1. A three-compartments model, which include the virus in the liquid phase and in the peripheral and inner regions of sludge flocs is employed. By using the model, the Virus removal process was successfully simulated to highlight the implication of its distribution in the activated sludge basin. 17 refs., 8 figs.
The use of religious metaphors by UK newspapers to describe and denigrate climate change.
Woods, Ruth; Fernández, Ana; Coen, Sharon
2012-04-01
British newspapers have denigrated anthropogenic climate change by misrepresenting scientific consensus and/or framing climate change within unsympathetic discourses. One aspect of the latter that has not been studied is the use of metaphor to disparage climate change science and proponents. This article analyses 122 British newspaper articles published using a religious metaphor between summer 2003 and 2008. Most were critical of climate change, especially articles in conservative newspapers The Daily Telegraph, Daily Mail and The Times. Articles used religion as a source of metaphor to denigrate climate change in two ways: (1) undermining its scientific status by presenting it as irrational faith-based religion, and proponents as religious extremists intolerant of criticism; (2) mocking climate change using notions of sin, e.g. describing 'green' behaviours as atonement or sacrifice. We argue that the religious metaphor damages constructive debate by emphasizing morality and how climate change is discussed, and detracting attention from the content of scientific data and theories.
Sabio, E.; Zamora, F.; González-García, C. M.; Ledesma, B.; Álvarez-Murillo, A.; Román, S.
2016-12-01
In this work, the adsorption kinetics of p-nitrophenol (PNP) onto several commercial activated carbons (ACs) with different textural and geometrical characteristics was studied. For this aim, a homogeneous diffusion solid model (HDSM) was used, which does take the adsorbent shape into account. The HDSM was solved by means of the finite element method (FEM) using the commercial software COMSOL. The different kinetic patterns observed in the experiments carried out can be described by the developed model, which shows that the sharp drop of adsorption rate observed in some samples is caused by the formation of a concentration wave. The model allows one to visualize the changes in concentration taking place in both liquid and solid phases, which enables us to link the kinetic behaviour with the main features of the carbon samples.
Modeling approaches to describe H2O and CO2 exchange in mare ecosystems
Olchev, A.; Novenko, E.; Volkova, E.
2012-04-01
The modern climatic conditions is strongly influenced by both internal variability of climatic system, and various external natural and anthropogenic factors (IPCC 2007). Significant increase of concentration of greenhouse gases in the atmosphere and especially the growth of atmospheric CO2 due to human activity are considered as the main factors that are responsible for global warming and climate changes. A significant part of anthropogenic CO2 is absorbed from the atmosphere by land biota and especially by vegetation cover. However, it is still not completely clear what is the role of different land ecosystems and especially forests and mares in global cycles of H2O and CO2 and what is a sensitivity of these ecosystems to climate changes. Within the frameworks of this study the spatial and temporal variability of H2O and CO2 fluxes in different types of mare ecosystems of the forest-steppe zone in European part of Russia was described using modeling approaches and results of field measurements. For this modeling and experimental study the mare ecosystems of Tula region were selected. The Tula region is located mostly in the forest-steppe zone and it is unique area for such studies because almost all existed types of mare ecosystems of Northern Eurasia distinguished by a geomorphological position, water and mineral supply can be found there. Most mares in Tula region have a relatively small size and surrounded by very heterogeneous forests that make not possible an application of the classical measuring and modeling approaches e.g. an eddy covariance technique or one-dimensional H2O and CO2 exchange models for flux estimation in such sites. In our study to describe the radiation, sensible heat, H2O and CO2 exchange between such heterogeneous mare ecosystems and the atmosphere a three-dimensional model Forbog-3D and one-dimensional Mixfor-SVAT were applied. The main concept used in the Forbog-3D and Mixfor-SVAT models is an aggregated description of physical and
Craeye, Christophe; Thomas, Christopher N
2014-01-01
Many new types of sensing or imaging surfaces are based on periodic thin films. It is explained how the response of those surfaces to partially coherent fields can be fully characterized by a set of functions in the wavenumber spectrum domain. The theory is developed here for the case of 2D absorbers with TE illumination and arbitrary material properties in the plane of the problem, except for the resistivity which is assumed isotropic. Sum and difference coordinates in both spatial and spectral domains are conveniently used to represent the characteristic functions, which are specialized here to the case of periodic structures. Those functions can be either computed or obtained experimentally. Simulations rely on solvers based on periodic-boundary conditions, while experiments correspond to Energy Absorption Interferometry (EAI), already described in the literature. We derive rules for the convergence of the representation versus the number of characteristic functions used, as well as for the sampling to be ...
A flowing plasma model to describe drift waves in a cylindrical helicon discharge
Chang, L; Cormac, C S
2011-01-01
A two-fluid model developed originally to describe wave oscillations in the vacuum arc centrifuge, a cylindrical, rapidly rotating, low temperature and confined plasma column, is applied to interpret plasma oscillations in a RF generated linear magnetised plasma (WOMBAT), with similar density and field strength. Compared to typical centrifuge plasmas, WOMBAT plasmas have slower normalised rotation frequency, lower temperature and lower axial velocity. Despite these differences, the two-fluid model provides a consistent description of the WOMBAT plasma configuration and yields qualitative agreement between measured and predicted wave oscillation frequencies with axial field strength. In addition, the radial profile of the density perturbation predicted by this model is consistent with the data. Parameter scans show that the dispersion curve is sensitive to the axial field strength and the electron temperature, and the dependence of oscillation frequency with electron temperature matches the experiment. These r...
The forgotten cue: Daphnia bears a not yet described gravireceptive organ system
Laforsch, Christian; Fischer, Jessica; Wolfschoon Ribeiro, Bernard; Schoppmann, Kathrin; Trotter, Benjamin
Gravity has been the only constant environmental factor in evolution of life. For plenty of pelagic organisms it is the only reliable cue for orientation in a three dimensional space especially in turbid or completely dark waters. However, there is a considerable lack of knowledge about gravisensing mechanisms in a huge variety of plankton organisms. Here we introduce a novel mechanoreceptive organ system in the model organism Daphnia functioning as a sinking receptor for the detection of the gravitational field. This organ is connected to two prominent appendages known as the postabdominal setae with so far unknown functioning. Our morphological and behavioural studies show, that the organ system is involved in gravisensing by a passive deflection mechanism not yet described in the animal kingdom. The description of this bifunctional mechanoreceptor will help to elucidate general gravity-related mechanisms valid for other organisms as well and may therefore increase our knowledge on the evolution of graviperception in aquatic ecosystems.
Computer-aided Nonlinear Control System Design Using Describing Function Models
Nassirharand, Amir
2012-01-01
A systematic computer-aided approach provides a versatile setting for the control engineer to overcome the complications of controller design for highly nonlinear systems. Computer-aided Nonlinear Control System Design provides such an approach based on the use of describing functions. The text deals with a large class of nonlinear systems without restrictions on the system order, the number of inputs and/or outputs or the number, type or arrangement of nonlinear terms. The strongly software-oriented methods detailed facilitate fulfillment of tight performance requirements and help the designer to think in purely nonlinear terms, avoiding the expedient of linearization which can impose substantial and unrealistic model limitations and drive up the cost of the final product. Design procedures are presented in a step-by-step algorithmic format each step being a functional unit with outputs that drive the other steps. This procedure may be easily implemented on a digital computer with example problems from mecha...
Fitting mathematical models to describe the rheological behaviour of chocolate pastes
Barbosa, Carla; Diogo, Filipa; Alves, M. Rui
2016-06-01
The flow behavior is of utmost importance for the chocolate industry. The objective of this work was to study two mathematical models, Casson and Windhab models that can be used to fit chocolate rheological data and evaluate which better infers or previews the rheological behaviour of different chocolate pastes. Rheological properties (viscosity, shear stress and shear rates) were obtained with a rotational viscometer equipped with a concentric cylinder. The chocolate samples were white chocolate and chocolate with varying percentages in cacao (55%, 70% and 83%). The results showed that the Windhab model was the best to describe the flow behaviour of all the studied samples with higher determination coefficients (r2 > 0.9).
Overcurvature describes the buckling and folding of rings from curved origami to foldable tents
Mouthuy, Pierre-Olivier; Coulombier, Michael; Pardoen, Thomas; Raskin, Jean-Pierre; Jonas, Alain M.
2012-12-01
Daily-life foldable items, such as popup tents, the curved origami sculptures exhibited in the Museum of Modern Art of New York, overstrained bicycle wheels, released bilayered microrings and strained cyclic macromolecules, are made of rings buckled or folded in tridimensional saddle shapes. Surprisingly, despite their popularity and their technological and artistic importance, the design of such rings remains essentially empirical. Here we study experimentally the tridimensional buckling of rings on folded paper rings, lithographically processed foldable microrings, human-size wood sculptures or closed arcs of Slinky springs. The general shape adopted by these rings can be described by a single continuous parameter, the overcurvature. An analytical model based on the minimization of the energy of overcurved rings reproduces quantitatively their shape and buckling behaviour. The model also provides guidelines on how to efficiently fold rings for the design of space-saving objects.
A characterization of Parkinson's disease by describing the visual field motion during gait
Trujillo, David; Martínez, Fabio; Atehortúa, Angélica; Alvarez, Charlens; Romero, Eduardo
2015-12-01
An early diagnosis of Parkinson's Disease (PD) is crucial towards devising successful rehabilitation programs. Typically, the PD diagnosis is performed by characterizing typical symptoms, namely bradykinesia, rigidity, tremor, postural instability or freezing gait. However, traditional examination tests are usually incapable of detecting slight motor changes, specially for early stages of the pathology. Recently, eye movement abnormalities have correlated with early onset of some neurodegenerative disorders. This work introduces a new characterization of the Parkinson disease by describing the ocular motion during a common daily activity as the gait. This paper proposes a fully automatic eye motion analysis using a dense optical flow that tracks the ocular direction. The eye motion is then summarized using orientation histograms constructed during a whole gait cycle. The proposed approach was evaluated by measuring the χ2 distance between the orientation histograms, showing substantial differences between control and PD patients.
Kononova, Olga; Barsegov, Valeri
2015-01-01
Cooperativity is a hallmark of proteins, many of which show a modular architecture comprising discrete structural domains. Detecting and describing dynamic couplings between structural regions is difficult in view of the many-body nature of protein-protein interactions. By utilizing the GPU-based computational acceleration, we carried out simulations of the protein forced unfolding for the dimer WW-WW of the all-beta-sheet WW domains used as a model multidomain protein. We found that while the physically non-interacting identical protein domains (WW) show nearly symmetric mechanical properties at low tension, reflected, e.g., in the similarity of their distributions of unfolding times, these properties become distinctly different when tension is increased. Moreover, the uncorrelated unfolding transitions at a low pulling force become increasingly more correlated (dependent) at higher forces. Hence, the applied force not only breaks "the mechanical symmetry" but also couples the physically non-interacting prot...
On the Construction and Properties of Weak Solutions Describing Dynamic Cavitation
Miroshnikov, Alexey
2014-08-21
We consider the problem of dynamic cavity formation in isotropic compressible nonlinear elastic media. For the equations of radial elasticity we construct self-similar weak solutions that describe a cavity emanating from a state of uniform deformation. For dimensions d=2,3 we show that cavity formation is necessarily associated with a unique precursor shock. We also study the bifurcation diagram and do a detailed analysis of the singular asymptotics associated to cavity initiation as a function of the cavity speed of the self-similar profiles. We show that for stress free cavities the critical stretching associated with dynamically cavitating solutions coincides with the critical stretching in the bifurcation diagram of equilibrium elasticity. Our analysis treats both stress-free cavities and cavities with contents.
Khera, Goldie; Berstock, David A
2006-08-01
The Prolene Hernia System (PHS) is already widely in use in the United Kingdom for inguinal hernias. We describe the novel technique of using the three-in-one design of the PHS (Ethicon Endo-Surgery, Bracknell, UK) for repairing incisional, epigastric and umbilical herniae. This is a three-dimensional device and consists of an onlay patch, a tubular connector and an underlay patch. We recommend a four 'corner' suturing of the underlay patch under vision (and then) through the full thickness of abdominal wall layers to ensure a flat underlay mesh. These four sutures flatten out the underlay patch and can be tied or removed with equal effect. The sutures are placed at 3, 6, 9 and 12 o'clock, which simplifies the procedure and ensures that the underlay lays correctly and is corrugation-free and tension-free, thereby providing a two-layer repair for those herniae with a high rate of recurrence.
Cosmological models described by a mixture of van der Waals fluid and dark energy
Kremer, G M
2003-01-01
The Universe is modeled as a binary mixture whose constituents are described by a van der Waals fluid and by a dark energy density. The dark energy density is considered either as the quintessence or as the Chaplygin gas. The irreversible processes concerning the energy transfer between the van der Waals fluid and the gravitational field are taken into account. This model can simulate: (a) an inflationary period where the acceleration grows exponentially and the van der Waals fluid behaves like an inflaton; (b) an inflationary period where the acceleration is positive but it decreases and tends to zero whereas the energy density of the van der Waals fluid decays; (c) a decelerated period which corresponds to a matter dominated period with a non-negative pressure; and (d) a present accelerated period where the dark energy density outweighs the energy density of the van der Waals fluid.
Energy Technology Data Exchange (ETDEWEB)
Choi, Dooho [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Korea Railroad Research Institute, 360-1 Woulam, Uiwang, Kyunggi 437-757 (Korea, Republic of); Liu, Xuan [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Schelling, Patrick K. [Advanced Materials Processing and Analysis Center and Department of Physics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); Coffey, Kevin R. [Department of Materials Science and Engineering, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); Barmak, Katayun [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, 500 West 120th Street, New York, New York 10027 (United States)
2014-03-14
The impact of electron scattering at surfaces and grain boundaries in nanometric polycrystalline tungsten (W) films was studied. A series of polycrystalline W films ranging in thickness from 10 to 310 nm and lateral grain size from 74 to 133 nm were prepared on thermally oxidized Si. The Fuchs-Sondheimer surface-scattering model and Mayadas-Shatzkes grain-boundary scattering model were employed for quantitative analyses. Predictions from the theoretical models were found to deviate systematically from the experimental data. Possible reasons for the failure of the theoretical models to describe the experimental data are explored. Finally, a discussion of the crucial features lacking from existing models is presented, along with possible avenues for improving the models to result in better agreement with experimental data.
A theoretical model to describe progressions and regressions for exercise rehabilitation.
Blanchard, Sam; Glasgow, Phil
2014-08-01
This article aims to describe a new theoretical model to simplify and aid visualisation of the clinical reasoning process involved in progressing a single exercise. Exercise prescription is a core skill for physiotherapists but is an area that is lacking in theoretical models to assist clinicians when designing exercise programs to aid rehabilitation from injury. Historical models of periodization and motor learning theories lack any visual aids to assist clinicians. The concept of the proposed model is that new stimuli can be added or exchanged with other stimuli, either intrinsic or extrinsic to the participant, in order to gradually progress an exercise whilst remaining safe and effective. The proposed model maintains the core skills of physiotherapists by assisting clinical reasoning skills, exercise prescription and goal setting. It is not limited to any one pathology or rehabilitation setting and can adapted by any level of skilled clinician.
Capability of LEP-type surfaces to describe noncollinear reactions 2 - Polyatomic systems
Espinosa-Garcia, Joaquin
2001-01-01
In this second article of the series, the popular LEP-type surface for collinear reaction paths and a "bent" surface, which involves a saddle point geometry with a nonlinear central angle, were used to examine the capacity of LEP-type surfaces to describe the kinetics and dynamics of noncollinear reaction paths in polyatomic systems. Analyzing the geometries, vibrational frequencies, curvature along the reaction path (to estimate the tunneling effect and the reaction coordinate-bound modes coupling), and the variational transition- state theory thermal rate constants for the NH//3 + O(**3P) reaction, we found that the "collinear" LEP-type and the "bent" surfaces for this polyatomic system show similar behavior, thus allowing a considerable saving in time and computational effort. This agreement is especially encouraging for this polyatomic system because in the Cs symmetry the reaction proceeds via two electronic states of symmetries **3A prime and **3A double prime , which had to be independently calibrated....
Indian Academy of Sciences (India)
DIBYENDU BISWAS; SWARUP PORIA; SANKAR NARAYAN PATRA
2016-11-01
In this communication, different classes of phenomenological universalities of carrying capacity dependent growth processes have been proposed. The logistic as well as carrying capacity-dependent West-type allometry-based biological growths can be explained in this proposed framework. It is shown that logistic and carrying capacity-dependent West-type growths are phenomenologically identical in nature. However, there is a difference between them in terms of coefficients involved in the phenomenological descriptions. Involuted Gompertz function, used to describe biological growth processes undergoing atrophy or a demographic and economic system undergoing involution or regression, can be addressed in this proposed environment-dependent description. It is also found phenomenologically that the energy intake of an organism depends on carrying capacity whereas metabolic cost does not depend on carrying capacity. In addition, some other phenomenologicaldescriptions have been examined in this proposed framework and graphical representations of variation of different parameters involved in the description are executed.
Performance of density functional theory methods to describe intramolecular hydrogen shifts
Indian Academy of Sciences (India)
Nelly González-Rivas; Andrés Cedillo
2005-09-01
The performance of three exchange and correlation density functionals, LDA, BLYP and B3LYP, with four basis sets is tested in three intramolecular hydrogen shift reactions. The best reaction and activation energies come from the hybrid functional B3LYP with triple- basis sets, when they are compared with high-level post-Hartree-Fock results from the literature. For a fixed molecular geometry, the electrophilic Fukui function is computed from a finite difference approximation. Fukui function shows a small dependence with both the exchange and correlation functional and the basis set. Evolution of the Fukui function along the reaction path describes important changes in the basic sites of the corresponding molecules. These results are in agreement with the chemical behavior of those species.
Directory of Open Access Journals (Sweden)
Matsen Frederick A
2012-05-01
Full Text Available Abstract Background Although taxonomy is often used informally to evaluate the results of phylogenetic inference and the root of phylogenetic trees, algorithmic methods to do so are lacking. Results In this paper we formalize these procedures and develop algorithms to solve the relevant problems. In particular, we introduce a new algorithm that solves a "subcoloring" problem to express the difference between a taxonomy and a phylogeny at a given rank. This algorithm improves upon the current best algorithm in terms of asymptotic complexity for the parameter regime of interest; we also describe a branch-and-bound algorithm that saves orders of magnitude in computation on real data sets. We also develop a formalism and an algorithm for rooting phylogenetic trees according to a taxonomy. Conclusions The algorithms in this paper, and the associated freely-available software, will help biologists better use and understand taxonomically labeled phylogenetic trees.
Sensory profiling: a method for describing the sensory characteristics of virgin olive oil
Directory of Open Access Journals (Sweden)
Lyon, David H.
1994-04-01
Full Text Available Sensory profiling is an objective, descriptive technique which uses a panel of trained assessors. It was used at Campden to differentiate olive oil which differed in terms of the country of origin, variety, ripeness and extraction techniques. The data were related to similar results from the Netherlands and Italy. The results indicated that all three sensory panels perceived the samples in the same way, however, the differed in the way the oils were described.
The new European legislation on olive oil is partially concerned with the sensory aspects of the oil. The sensory grading takes into account the 'positive' and 'negative' attributes in the oil before giving an overall quality grade. These attributes do not reflect the consumer requirements, therefore, the grading should be restricted to the assessment of the presence or absence of sensory defects.
AN INTEGRAL EQUATION DESCRIBING RIDING WAVES IN SHALLOW WATER OF FINITE DEPTH
Institute of Scientific and Technical Information of China (English)
An Shu-ping; Le Jia-chun; Dai Shi-qiang
2003-01-01
An integral equation describing riding waves, i.e., small-scale perturbation waves superposed on unperturbed surface waves, in shallow water of finite depth was studied via explicit Hamiltonian formulation, and the water was regarded as ideal incompressible fluid of uniform density. The kinetic energy, density of the perturbed fluid motion was formulated with Hamiltonian canonical variables[1], elevation of the free surface and the velocity potential at the free surface. Then the variables were expanded to the first order at the free surface of unperturbed waves. An integal equation for velocity potential of perturbed waves on the unperturbed free surface was derived by conformal mapping and the Fourier transformation. The integral equation could replace the Hamiltonian canonical equations which are difficult to solve. An explicit expression of Lagrangian density function could be obtained by solving the integral equation. The method used in this paper provides a new path to study the Hamiltonian formulation of riding waves and wave interaction problems.
Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol
Energy Technology Data Exchange (ETDEWEB)
Massachusetts Institute of Technology; Kroll, Jesse H.; Donahue, Neil M.; Jimenez, Jose L.; Kessler, Sean H.; Canagaratna, Manjula R.; Wilson, Kevin R.; Altieri, Katye E.; Mazzoleni, Lynn R.; Wozniak, Andrew S.; Bluhm, Hendrik; Mysak, Erin R.; Smith, Jared D.; Kolb, Charles E.; Worsnop, Douglas R.
2010-11-05
A detailed understanding of the sources, transformations, and fates of organic species in the environment is crucial because of the central roles that organics play in human health, biogeochemical cycles, and Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at least thousands of individual compounds, all of which likely evolve chemically over their atmospheric lifetimes. Here we demonstrate the utility of describing organic aerosol (and other complex organic mixtures) in terms of average carbon oxidation state (OSC), a quantity that always increases with oxidation, and is readily measured using state-of-the-art analytical techniques. Field and laboratory measurements of OSC , using several such techniques, constrain the chemical properties of the organics and demonstrate that the formation and evolution of organic aerosol involves simultaneous changes to both carbon oxidation state and carbon number (nC).
Energy Technology Data Exchange (ETDEWEB)
Sarmento, R.G. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Fulco, U.L. [Departamento de Biofisica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Albuquerque, E.L., E-mail: eudenilson@gmail.com [Departamento de Biofisica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Caetano, E.W.S. [Instituto Federal de Educacao, Ciencia e Tecnologia do Ceara, 60040-531 Fortaleza, CE (Brazil); Freire, V.N. [Departamento de Fisica, Universidade Federal do Ceara, 60455-760 Fortaleza, CE (Brazil)
2011-10-31
Highlights: → One-step renormalization approach to describe the DBL-DNA molecule. → Electronic tight-binding Hamiltonian model. → A quasiperiodic sequence to mimic the DNA nucleotides arrangement. → Electronic transmission spectra. → I-V characteristics. -- Abstract: We study the charge transport properties of a dangling backbone ladder (DBL)-DNA molecule focusing on a quasiperiodic arrangement of its constituent nucleotides forming a Rudin-Shapiro (RS) and Fibonacci (FB) Poly (CG) sequences, as well as a natural DNA sequence (Ch22) for the sake of comparison. Making use of a one-step renormalization process, the DBL-DNA molecule is modeled in terms of a one-dimensional tight-binding Hamiltonian to investigate its transmissivity and current-voltage (I-V) profiles. Beyond the semiconductor I-V characteristics, a striking similarity between the electronic transport properties of the RS quasiperiodic structure and the natural DNA sequence was found.
A new criterion to describe crossed-beam energy transfer in laser-plasma interactions
Trines, R.; Schmitz, H.; Alves, E. P.; Fiuza, F.; Vieira, J.; Silva, L. O.; Bingham, R.
2016-10-01
Crossed-beam energy transfer (CBET) between laser beams in underdense plasma is ubiquitous in both direct-drive and indirect-drive inertial confinement fusion. To understand the impact of this process on the final shape of the laser beams involved, as well as their imprint on either hohlraum walls or target surface, a detailed spatial and temporal description of the crossing beams is needed. We have developed an analytical model and derived new criteria describing both the spatial structure and temporal evolution of the beams after crossing. Numerical simulations have been carried out justifying the analytical model and confirming the criteria. The impact of our results on present and future multi-beam experiments in laser fusion and high-energy-density physics, in particular the ``bursty'' nature of beams predicted to occur in NIF experiments, will be discussed.
A simple model to describe intrinsic stellar noise for exoplanet detection around red giants
North, Thomas S H; Gilliland, Ronald L; Huber, Daniel; Campante, Tiago L; Handberg, Rasmus; Lund, Mikkel N; Veras, Dimitri; Kuszlewicz, James S; Farr, Will M
2016-01-01
In spite of the huge advances in exoplanet research provided by the NASA Kepler Mission, there remain only a small number of transit detections around evolved stars. Here we present a reformulation of the noise properties of red-giant stars, where the intrinsic stellar granulation, and the stellar oscillations described by asteroseismology play a key role. The new noise model is a significant improvement on the current Kepler results for evolved stars. Our noise model may be used to help understand planet detection thresholds for the ongoing K2 and upcoming TESS missions, and serve as a predictor of stellar noise for these missions. As an application of our noise model, we explore the minimum detectable planet radii for red giant stars, and find that Neptune sized planets should be detectable around low luminosity red giant branch stars.
The Metaphors That Elementary School Students use to Describe the Term “Teacher”
Directory of Open Access Journals (Sweden)
Ruhan KARADAĞ
2012-04-01
Full Text Available The aim of this study is to investigate metaphors that elementary school 5th and 8th grade students(N=567 use in order to describe the term “teacher”. The data were collected using a questionnaireconsisting of open-ended questions, and analyzed using qualitative and quantitative analysis techniques.Content analysis technique was used in the analysis of qualitative data, and chi square was used inquantitative data analysis. According to the results of the study, it was found out that 83 valid metaphorswere produced by 429 elementary school students. These metaphors were collected under 6 conceptualheadings according to their common features. It was observed that the conceptual categories formed relatedto the metaphors that elementary school students use have no significant difference according to gender andschool levels, but have significant differences related to their classroom levels.
Exploring the use of fuzzy logic models to describe the relation between SBP and RR values.
Gouveia, Sónia; Brás, Susana
2012-01-01
In this work, fuzzy logic based models are used to describe the relation between systolic blood pressure (SBP) and tachogram (RR) values as a function of the SBP level. The applicability of these methods is tested using real data in Lying (L) and Standing (S) conditions and generated surrogate data. The results indicate that fuzzy models exhibit a similar performance in both conditions, and their performance is significantly higher with real data than with surrogate data. These results point out the potential of a fuzzy logic approach to model properly the relation between SBP and RR values. As a future work, it remains to assess the clinical impact of these findings and inherent repercussion on the estimation of time domain baroreflex sensitivity indices.
Reeves, J B; Newell, W; Holcomb, B R; Stinson, M
2000-10-01
In collaboration with teachers and students at the National Technical Institute for the Deaf (NTID), the Sign Language Skills Classroom Observation (SLSCO) was designed to provide feedback to teachers on their sign language communication skills in the classroom. In the present article, the impetus and rationale for development of the SLSCO is discussed. Previous studies related to classroom signing and observation methodology are reviewed. The procedure for developing the SLSCO is then described. This procedure included (a) interviews with faculty and students at NTID, (b) identification of linguistic features of sign language important for conveying content to deaf students, (c) development of forms for recording observations of classroom signing, (d) analysis of use of the forms, (e) development of a protocol for conducting the SLSCO, and (f) piloting of the SLSCO in classrooms. The results of use of the SLSCO with NTID faculty during a trial year are summarized.
Unified theory to describe and engineer conservation laws in light-matter interactions
Fernandez-Corbaton, Ivan; Rockstuhl, Carsten
2017-05-01
The effects of the electromagnetic field on material systems are governed by joint light-matter conservation laws. An increasing number of these balance equations are currently being considered both theoretically and with an eye to their practical applicability. We present a unified theory to treat conservation laws in light-matter interactions. It can be used to describe and engineer the transfer of any measurable property from the electromagnetic field to any object. The theory allows one to explicitly characterize and separately compute the transfer due to asymmetry of the object and the transfer due to field absorption by the object. It also allows one to compute the upper bound of the transfer rate of any given property to any given object, together with the corresponding most efficient illumination which achieves the bound. Due to its algebraic nature, the approach is inherently suited for computer implementation.
Applying Use Cases to Describe the Role of Standards in e-Health Information Systems
Chávez, Emma; Finnie, Gavin; Krishnan, Padmanabhan
Individual health records (IHRs) contain a person's lifetime records of their key health history and care within a health system (National E-Health Transition Authority, Retrieved Jan 12, 2009 from http://www.nehta.gov.au/coordinated-care/whats-in-iehr, 2004). This information can be processed and stored in different ways. The record should be available electronically to authorized health care providers and the individual anywhere, anytime, to support high-quality care. Many organizations provide a diversity of solutions for e-health and its services. Standards play an important role to enable these organizations to support information interchange and improve efficiency of health care delivery. However, there are numerous standards to choose from and not all of them are accessible to the software developer. This chapter proposes a framework to describe the e-health standards that can be used by software engineers to implement e-health information systems.
Asymptotic behavior of nonlinear semigroup describing a model of selective cell growth regulation.
Arino, O; Kimmel, M
1991-01-01
A new scheme of regulation of cell population growth is considered, called the selective growth regulation. The principle is that cells are withdrawn from proliferation depending on their contents of certain biochemical species. The dynamics of the cell population structured by the contents of this species is described by the functional integral equation model, previously introduced by the authors. The solutions of the model equations generate a semigroup of nonlinear positive operators. The main problem solved in this paper concerns stability of the equilibria of the model. This requires stating and proving of an original abstract result on the spectral radius of a perturbation of a semigroup of positive linear operators. Biological applications are discussed.
A simple model to describe intrinsic stellar noise for exoplanet detection around red giants
North, Thomas S. H.; Chaplin, William J.; Gilliland, Ronald L.; Huber, Daniel; Campante, Tiago L.; Handberg, Rasmus; Lund, Mikkel N.; Veras, Dimitri; Kuszlewicz, James S.; Farr, Will M.
2017-02-01
In spite of the huge advances in exoplanet research provided by the NASA Kepler Mission, there remain only a small number of transit detections around evolved stars. Here, we present a reformulation of the noise properties of red-giant stars, where the intrinsic stellar granulation and the stellar oscillations described by asteroseismology play a key role. The new noise model is a significant improvement on the current Kepler results for evolved stars. Our noise model may be used to help understand planet detection thresholds for the ongoing K2 and upcoming TESSmissions, and serve as a predictor of stellar noise for these missions. As an application of our noise model, we explore the minimum detectable planet radii for red giant stars, and find that Neptune-sized planets should be detectable around low-luminosity red giant branch stars.
DEFF Research Database (Denmark)
Poulsen, Signe; Gish, Liv; Ipsen, Christine
In recent years the term fidelity has been introduced within the field of organizational level interventions. Fidelity describes the extent to which the intervention has been implemented as it was originally intended, and is regarded critical for determining the validity of the research results...... in organizational level interventions. The concept of fidelity stems from clinical interventions although the concept has developed over time (Bellg et al. 2004). Organizational level interventions differ from clinical interventions, as they are more complex regarding both the “dose” given and the number and levels...... of participants involved at the same time. Steering organizational level interventions in every detail and secure full fidelity or treatment integrity can thus seem difficult. Organizational level intervention frameworks are often built on the designer’s experiences with previous interventions as well as what...
ON THE COLLISION DETECTION PROBLEM OF TWO MOVING OBJECTS DESCRIBED BY ALGEBRAIC SETS
Institute of Scientific and Technical Information of China (English)
Shurong LI; Chunwang HOU
2007-01-01
In this paper,the collision problem of two moving objects is investigated.The objects are described by two algebraic sets(ellipses or circles in the paper).The collision problem discussed involves both static and dynamic case.The static case is that each object moves with known velocity.We use nonlinear programming to decide whether the objects collide.The dynamic case is that each object is controlled by a constraint external force which can be regulated online.For the dynamic case,the collision problem can be modelled as a Minmax problem which can be solved by using differential games.If collision occurs,the time and place of the first collision are given.The moving trajectories are provided in the paper.
Fourier Heat Conduction as a phenomenon described within the scope of the Second Law
Jesudason, Christopher G
2014-01-01
The historical development of the Carnot cycle necessitated the construction of isothermal and adiabatic pathways within the cycle that were also mechanically "reversible" which lead eventually to the Kelvin-Clausius development of the entropy function where the heat absorption is for the diathermal (isothermal) paths of the cycle only. It is deduced from traditional arguments that Fourier heat conduction involves mechanically "reversible" heat transfer with irreversible entropy increase. Here we model heat conduction as a thermodynamically reversible but mechanically irreversible process. The MD simulations conducted shows excellent agreement with the theory. Such views and results as these, if developed to a successful conclusion could imply that the Carnot cycle be viewed as describing a local process of energy-work conversion and that irreversible local processes might be brought within the scope of this cycle, implying a unified treatment of thermodynamically (i) irreversible, (ii) reversible, (iii) isot...
Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol.
Kroll, Jesse H; Donahue, Neil M; Jimenez, Jose L; Kessler, Sean H; Canagaratna, Manjula R; Wilson, Kevin R; Altieri, Katye E; Mazzoleni, Lynn R; Wozniak, Andrew S; Bluhm, Hendrik; Mysak, Erin R; Smith, Jared D; Kolb, Charles E; Worsnop, Douglas R
2011-02-01
A detailed understanding of the sources, transformations and fates of organic species in the environment is crucial because of the central roles that they play in human health, biogeochemical cycles and the Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at least thousands of individual compounds, all of which likely evolve chemically over their atmospheric lifetimes. Here, we demonstrate the utility of describing organic aerosol (and other complex organic mixtures) in terms of average carbon oxidation state, a quantity that always increases with oxidation, and is readily measured using state-of-the-art analytical techniques. Field and laboratory measurements of the average carbon oxidation state, using several such techniques, constrain the chemical properties of the organics and demonstrate that the formation and evolution of organic aerosol involves simultaneous changes to both carbon oxidation state and carbon number.
Directory of Open Access Journals (Sweden)
M. De la Sen
2009-01-01
are given to define pointwisely the causal and anticausal Toeplitz and Hankel operators from the set of switching time instants generated from the switching function. The case of the auxiliary unforced system defined by the matrix of undelayed dynamics being dichotomic (i.e., it has no eigenvalue on the complex imaginary axis is considered in detail. Stability conditions as well as dual instability ones are discussed for this case which guarantee that the whole system is either stable, or unstable but no configuration of the switched system has eigenvalues within some vertical strip including the imaginary axis. It is proved that if the system is causal and uniformly controllable and observable, then it is globally asymptotically Lyapunov stable independent of the delays, that is, for any possibly values of such delays, provided that a minimum residence time in-between consecutive switches is kept or if all the set of matrices describing the auxiliary unforced delay—free system parameterizations commute pairwise.
Describing a Laser Diode Emulation Tool Using Single Emitter Simulation Results
Directory of Open Access Journals (Sweden)
C.K. Amuzuvi
2013-02-01
Full Text Available This study describes and explores the use of a laser diode simulation tool at the single emitter level of operation and how they can be degraded. A test of the simulation tool is implemented to complement the by-emitter degradation analysis of high power laser diodes. The simulation tool is called Speclase, designed for the simulation of single emitters. Tests were performed using a 975 nm narrow-angle (<1º tapered laser structure from Alcatel Thales III-V Lab with front and rear facet reflectivities of 3 and 90%, respectively. The tool worked for both the constant current and power modes of operation. Simulation results were obtained for both constant QW trap density, based on the maximum QW temperature and variable QW trap density generation due to local heating. Single emitter degradation results are obtained using the Arrhenius equation to compare the rate of degradation between the constant and variable QW trap densities.
Assumptions and Axioms: Mathematical Structures to Describe the Physics of Rigid Bodies
Butler, Philip H; Renaud, Peter F
2010-01-01
This paper challenges some of the common assumptions underlying the mathematics used to describe the physical world. We start by reviewing many of the assumptions underlying the concepts of real, physical, rigid bodies and the translational and rotational properties of such rigid bodies. Nearly all elementary and advanced texts make physical assumptions that are subtly different from ours, and as a result we develop a mathematical description that is subtly different from the standard mathematical structure. Using the homogeneity and isotropy of space, we investigate the translational and rotational features of rigid bodies in two and three dimensions. We find that the concept of rigid bodies and the concept of the homogeneity of space are intrinsically linked. The geometric study of rotations of rigid objects leads to a geometric product relationship for lines and vectors. By requiring this product to be both associative and to satisfy Pythagoras' theorem, we obtain a choice of Clifford algebras. We extend o...
A unified theory to describe and engineer conservation laws in light-matter interactions
Fernandez-Corbaton, Ivan
2016-01-01
The effects of the electromagnetic field on material systems are governed by joint light-matter conservation laws. An increasing number of these balance equations are currently being considered both theoretically and with an eye to their practical applicability. We present a unified theory to treat conservation laws in light-matter interactions. It can be used to describe and engineer the transfer of any measurable property from the electromagnetic field to any object. The theory allows to explicitly characterize and separately compute the transfer due to asymmetry of the object and the transfer due to field absorption by the object. It also allows to compute the upper bound of the transfer rate of any given property to any given object, together with the corresponding most efficient illumination which achieves the bound. Due to its algebraic nature, the approach is inherently suited for computer implementation.
A novel approach to describing and detecting performance anti-patterns
Sheng, Jinfang; Wang, Yihan; Hu, Peipei; Wang, Bin
2017-08-01
Anti-pattern, as an extension to pattern, describes a widely used poor solution which can bring negative influence to application systems. Aiming at the shortcomings of the existing anti-pattern descriptions, an anti-pattern description method based on first order predicate is proposed. This method synthesizes anti-pattern forms and symptoms, which makes the description more accurate and has good scalability and versatility as well. In order to improve the accuracy of anti-pattern detection, a Bayesian classification method is applied in validation for detection results, which can reduce false negatives and false positives of anti-pattern detection. Finally, the proposed approach in this paper is applied to a small e-commerce system, the feasibility and effectiveness of the approach is demonstrated further through experiments.
Navarro-Barrientos, J-Emeterio; Rivera, Daniel E; Collins, Linda M
2011-01-12
We present a dynamical model incorporating both physiological and psychological factors that predicts changes in body mass and composition during the course of a behavioral intervention for weight loss. The model consists of a three-compartment energy balance integrated with a mechanistic psychological model inspired by the Theory of Planned Behavior (TPB). The latter describes how important variables in a behavioural intervention can influence healthy eating habits and increased physical activity over time. The novelty of the approach lies in representing the behavioural intervention as a dynamical system, and the integration of the psychological and energy balance models. Two simulation scenarios are presented that illustrate how the model can improve the understanding of how changes in intervention components and participant differences affect outcomes. Consequently, the model can be used to inform behavioural scientists in the design of optimised interventions for weight loss and body composition change.
A Revised Multi-Fickian Moisture Transport Model To Describe Non-Fickian Effects In Wood
DEFF Research Database (Denmark)
Frandsen, Henrik Lund; Svensson, Staffan; Damkilde, Lars
2007-01-01
This paper presents a study and a refinement of the sorption rate model in a so-called multi-Fickian or multiphase model. This type of model describes the complex moisture transport system in wood, which consists of separate water vapor and bound-water diffusion interacting through sorption....... At high relative humidities, the effect of this complex moisture transport system becomes apparent, and since a single Fickian diffusion equation fails to model the behavior, it has been referred to as non-Fickian or anomalous behavior. At low relative humidities, slow bound-water transport and fast...... conditions for the model are discussed, since discrepancies from corresponding models of moisture transport in paper products have been found....
A revised multi-Fickian moisture transport model to describe non-Fickian effects in wood
DEFF Research Database (Denmark)
Frandsen, Henrik Lund; Damkilde, Lars; Svensson, Staffan
2007-01-01
This paper presents a study and a refinement of the sorption rate model in a so-called multi-Fickian or multi-phase model. This type of model describes the complex moisture transport system in wood, which consists of separate water vapor and bound-water diffusion interacting through sorption....... At high relative humidities, the effect of this complex moisture transport system becomes apparent, and since a single Fickian diffusion equation fails to model the behavior, it has been referred to as non-Fickian or anomalous behavior. At low relative humidities, slow bound-water transport and fast...... conditions for the model are discussed, since discrepancies from corresponding models of moisture transport in paper products have been found. ©2007 by Walter de Gruyter....
Directory of Open Access Journals (Sweden)
Gilles Regniers
2009-11-01
Full Text Available In a system of coupled harmonic oscillators, the interaction can be represented by a real, symmetric and positive definite interaction matrix. The quantization of a Hamiltonian describing such a system has been done in the canonical case. In this paper, we take a more general approach and look at the system as a Wigner quantum system. Hereby, one does not assume the canonical commutation relations, but instead one just requires the compatibility between the Hamilton and Heisenberg equations. Solutions of this problem are related to the Lie superalgebras gl(1|n and osp(1|2n. We determine the spectrum of the considered Hamiltonian in specific representations of these Lie superalgebras and discuss the results in detail. We also make the connection with the well-known canonical case.
A toolkit to describe and interactively display three-manifolds embedded in four-space
Black, Don V
2012-01-01
A data structure and toolkit are presented here that allow for the description and manipulation of mathematical models of three-manifolds and their interactive display from multiple viewpoints via the OpenGL 3D graphics package. The data structure and vector math package can be extended to support an arbitrary number of Euclidean spatial dimensions. A model in 4-space is described by its bounding pure simplicial 3-complex. By intersecting a 3-flat with this 3-manifold, the algorithm will extract the requested closed pure simplicial 2-complex surface enclosing the desired 3D slice. The user can interactively rotate, pan, zoom, and shade arbitrary 3D solid or wire-frame views of the revealed 3D object created by intersection, thus exploring both expected and unexpected symmetries or asymmetries in the world of 3-manifolds in 4-space.
Directory of Open Access Journals (Sweden)
Berényi Dániel
2014-01-01
Full Text Available In this contribution we present results on pair production from vacuum in QED in case of inhomogeneous external electric fields. The central tool of our description is the relativistic one particle single-time Wigner-function, that describes the evolution of the e+e− densities in phase-space. We compare the influence of homogeneous and inhomogeneous external fields, and find that the inhomogeneity near the Compton-scale increases particle production proportionally to the duration of the electric pulse. We also find, that when the inhomogeneity is restricted to a single direction, a significant component of the pair yield originates from the edge or surface where the electric field gradients are large, in agreement with the prediction of Heisenberg.
Young women’s experiences with complementary therapies during cancer described through illness blogs
Keim-Malpass, Jessica; Albrecht, Tara A.; Steeves, Richard H.; Danhauer, Suzanne C.
2013-01-01
Many young women with cancer have a high symptom burden and negative psychosocial consequences as a result of their disease. To offset some of these experiences, a growing number of young women with cancer are writing about their experience with complementary therapies through online illness blogs. The purpose of this qualitative study was to examine descriptions of complementary therapy use among young women (diagnosed between 20–39 years) who maintained an online cancer blog. Women’s narratives describe several themes of the experience of using complementary therapies including: awakening, new identities (that incorporate loss), the good stuff, and release. Online illness blogs allow researchers to understand the complete experience of the patient through personal accounts and substantially contributes to the body of knowledge surrounding cancer in young adulthood and complementary therapy use. PMID:23820874
Keim-Malpass, Jessica; Albrecht, Tara A; Steeves, Richard H; Danhauer, Suzanne C
2013-11-01
Many young women with cancer have a high symptom burden and negative psychosocial consequences as a result of their disease. To offset some of these experiences, a growing number of young women with cancer are writing about their experience with complementary therapies through online illness blogs. The purpose of this qualitative study was to examine descriptions of complementary therapy use among young women (diagnosed between 20 and 39 years of age) who maintained an online cancer blog. Women's narratives describe several themes of the experience of using complementary therapies including awakening, new identities (that incorporate loss), the good stuff, and release. Online illness blogs allow researchers to understand the complete experience of the patient through personal accounts and substantially contributes to the body of knowledge surrounding cancer in young adulthood and complementary therapy use.
Analytical solutions describing the operation of a rotating magnetic field transducer
Energy Technology Data Exchange (ETDEWEB)
Savin, A.; Grimberg, R.; Mihalache, O. [Inst. of Technical Physics, Iasi (Romania). Dept. of NDT
1997-01-01
This work presents the analytical solutions describing the operation of a rotating magnetic field transducer used in the eddy current defectoscopy for detecting the long flaws situated parallelly to the inspected piece generatrix. The method uses the expanding of the real transducer`s three-phase system into an infinite sequence of axial and longitudinal currents whose intensity is given by a Fourier expansion, estimating the electromotive voltage induced in the transducer. By solving the equation of diffusion for the three media and considering the boundary conditions, the vector magnetic potential is determined for each medium. This work also presents the most important theoretical parameters of the transducer, as well as the experimental graphs obtained for concrete cases of the transducer`s applications.
Ordinal regression models to describe tourist satisfaction with Sintra's world heritage
Mouriño, Helena
2013-10-01
In Tourism Research, ordinal regression models are becoming a very powerful tool in modelling the relationship between an ordinal response variable and a set of explanatory variables. In August and September 2010, we conducted a pioneering Tourist Survey in Sintra, Portugal. The data were obtained by face-to-face interviews at the entrances of the Palaces and Parks of Sintra. The work developed in this paper focus on two main points: tourists' perception of the entrance fees; overall level of satisfaction with this heritage site. For attaining these goals, ordinal regression models were developed. We concluded that tourist's nationality was the only significant variable to describe the perception of the admission fees. Also, Sintra's image among tourists depends not only on their nationality, but also on previous knowledge about Sintra's World Heritage status.
Bauer, J H
2010-01-01
In the recent work of Vanne and Saenz [Phys. Rev. A 75, 063403 (2007)] the quasistatic limit of the velocity gauge strong-field approximation describing the ionization rate of atomic or molecular systems exposed to linearly polarized laser fields was derived. It was shown that in the low-frequency limit the ionization rate is proportional to the laser frequency (for a constant intensity of the laser field). In the present work I show that for circularly polarized laser fields the ionization rate is proportional to higher powers of the laser frequency for hydrogenic atoms. The new analytical expressions for asymptotic ionization rates (which become accurate in the quasistatic limit) contain no summations over multiphoton contributions. For very low laser frequencies (optical or infrared), these expressions usually remain with an order-of-magnitude agreement with the velocity gauge strong-field approximation.
Challenges in describing nuclear reactions outcomes at near-barrier energies
Dasgupta, M.; Simpson, E. C.; Kalkal, S.; Cook, K. J.; Carter, I. P.; Hinde, D. J.; Luong, D. H.
2017-01-01
The properties of light nuclei such as 6Li, 7Li, 9Be and 12C, and their reaction outcomes are known to be strongly influenced by their underlying α-cluster structure. Reaction models do not yet exist to allow accurate predictions of outcomes following a collision of these nuclei with another nucleus. As a result, reaction models within GEANT, and nuclear fusion models do not accurately describe measured products or cross sections. Recent measurements at the Australian National University have shown new reaction modes that lead to breakup of 6Li, 7Li into lighter clusters, again presenting a further challenge to current models. The new observations and subsequent model developments will impact on accurate predictions of reaction outcomes of 12C - a three α-cluster nucleus – that is used in heavy ion therapy.
A statistical approach to describe highly excited heavy and superheavy nuclei
Chen, Peng-Hui; Feng, Zhao-Qing; Li, Jun-Qing; Zhang, Hong-Fei
2016-09-01
A statistical approach based on the Weisskopf evaporation theory has been developed to describe the de-excitation process of highly excited heavy and superheavy nuclei, in particular for the proton-rich nuclei. The excited nucleus is cooled by evaporating γ-rays, light particles (neutrons, protons, α etc) in competition with binary fission, in which the structure effects (shell correction, fission barrier, particle separation energy) contribute to the processes. The formation of residual nuclei is evaluated via sequential emission of possible particles above the separation energies. The available data of fusion-evaporation excitation functions in the 28Si+198Pt reaction can be reproduced nicely within the approach. Supported by Major State Basic Research Development Program in China (2015CB856903), National Natural Science Foundation of China Projects (11175218, U1332207, 11475050, 11175074), and Youth Innovation Promotion Association of Chinese Academy of Sciences
Management of stroke as described by Ibn Sina (Avicenna) in the Canon of Medicine.
Zargaran, Arman; Zarshenas, Mohammad M; Karimi, Aliasghar; Yarmohammadi, Hassan; Borhani-Haghighi, Afshin
2013-11-15
Stroke or cerebrovascular accident (CVA) is caused by a disturbance of the blood supply to the brain and an accruing loss of brain function. The first recorded observations were in 2455 BC and it has been studied intensely by ancient physicians throughout history. In the early medieval period, Ibn Sina (980-1025 AD) called stroke sekteh and described it extensively. Some of Ibn Sina's definitions and his etiology of stroke are based on humoral theories and cannot be compared with medical current concepts, but most of his descriptions concur with current definitions. This review examines the definition and etiology, clinical manifestations, prognosis, differential diagnosis, and interventions for stroke based on Ibn Sina's epic work, Canon of Medicine. The pharmacological effects of medicinal herbs suggested by Ibn Sina for stroke are examined in light of current knowledge. © 2013.
Pesut, Barbara; Sawatzky, Rick
2006-06-01
Increasing attention is being paid to spirituality in nursing practice. Much of the literature on spiritual care uses the nursing process to describe this aspect of care. However, the use of the nursing process in the area of spirituality may be problematic, depending upon the understandings of the nature and intent of this process. Is it primarily a descriptive process meant to make visible the nursing actions to provide spiritual support, or is it a prescriptive process meant to guide nursing actions for intervening in the spirituality of patients? A prescriptive nursing process approach implies influencing, and in some cases reframing, the spirituality of patients and thereby extends beyond general notions of spiritual support. In this paper we discuss four problematic assumptions that form the basis for a prescriptive approach to spiritual care. We conclude that this approach extends the nursing role beyond appropriate professional boundaries, making it ethically problematic.
Gay, Guillaume; Courtheoux, Thibault; Reyes, Céline; Tournier, Sylvie; Gachet, Yannick
2012-03-19
In fission yeast, erroneous attachments of spindle microtubules to kinetochores are frequent in early mitosis. Most are corrected before anaphase onset by a mechanism involving the protein kinase Aurora B, which destabilizes kinetochore microtubules (ktMTs) in the absence of tension between sister chromatids. In this paper, we describe a minimal mathematical model of fission yeast chromosome segregation based on the stochastic attachment and detachment of ktMTs. The model accurately reproduces the timing of correct chromosome biorientation and segregation seen in fission yeast. Prevention of attachment defects requires both appropriate kinetochore orientation and an Aurora B-like activity. The model also reproduces abnormal chromosome segregation behavior (caused by, for example, inhibition of Aurora B). It predicts that, in metaphase, merotelic attachment is prevented by a kinetochore orientation effect and corrected by an Aurora B-like activity, whereas in anaphase, it is corrected through unbalanced forces applied to the kinetochore. These unbalanced forces are sufficient to prevent aneuploidy.
Sensitivity analysis of a biofilm model describing mixed growth of nitrite oxidisers in a CSTR.
Kornaros, M; Dokianakis, S N; Lyberatos, G
2006-01-01
A simple kinetic model has been developed for describing nitrite oxidation by autotrophic aerobic nitrifiers in a CSTR reactor, in which mixed (suspended and attached) growth conditions are prevailing. In this work, a critical dimensionless parameter is identified containing both biofilm characteristics and microbial kinetic parameters, as well as the specific (per volume) surface of the reactor configuration used. Evaluation of this dimensionless parameter can easily provide information on whether or not wall attachment is critical, and should be taken into account either in kinetic studies or in reactor design, when specific pollutants are to be removed from the waste influent stream. The effect of bulk dissolved oxygen (DO) concentration on the validity of this model is addressed and minimum non-limiting DO concentrations are proposed depending on the reactor configuration.
Toward Universal Half-Saturation Coefficients: Describing Extant K(s) as a Function of Diffusion.
Shaw, Andrew; Takacs, Imre; Pagilla, Krishna; Riffat, Rumana; DeClippeleir, Haydee; Wilson, Christopher; Murthy, Sudhir
2015-05-01
Observed (extant) K(s) is not a constant and it is strongly influenced by diffusion. This paper argues that diffusion can be used to describe bacterial kinetic effects that are sometimes attributed to "K-strategists" and, in fact, the physics of the system is the dominant mechanism affecting the apparent (extant) Ks--not intrinsic biological characteristics--in real water resource recovery facility systems. Four different biological processes have been modeled using the "porter-diffusion" model that was originally developed by Pasciak and Gavis (1974) for aquatic systems. The results demonstrate that diffusion is the dominant mechanism affecting K(s) in all four biological processes. Therefore, the authors argue that for treatment processes in which substrate concentrations are low, it is important to consider shifting to variable extant K(s) values or explicitly modeling the effects of diffusion.
Pinto, Rodrigo Carlos; Chambrone, Leandro; Colombini, Bella Luna; Ishikiriama, Sérgio Kiyoshi; Britto, Isabella Maria; Romito, Giuseppe Alexandre
2013-05-01
The decision-making process for the treatment of esthetic areas is based on the achievement of a healthy, harmonious, and pleasant smile. These conditions are directly associated with a solid knowledge of tooth anatomy and proportions, as well as the smile line, soft tissue morphology, and osseous architecture. To achieve these objectives, a multidisciplinary approach may be necessary to create long-term harmony between the final restoration and the adjacent teeth, and the health of the surrounding soft and hard tissues. This case report describes the application of a minimally invasive therapy on a 33-year-old woman seeking esthetic treatment. Minimally invasive periodontal plastic surgery associated with porcelain laminate veneers yielded satisfactory esthetics and minimal trauma to dental and periodontal tissues. Such a combined approach may be considered a viable option for the improvement of "white" and "red" esthetics.
Pinning Properties of Commercial Nb-Ti Wires Described by a 2-Components Model
Muzzi, L; Zignani, Chiarasole Fiamozzi; De Marzi, Gianluca; Muzzi, Luigi; Dominguez, Cesar Octavio; Bottura, Luca; Napolitano, Mathieu; Viola, Rosario; Affinito, Luigi; della Corte, Antonio; Le Naour, Sandrine
2010-01-01
We report on the magnetic and transport characterization of different NbTi commercial strands, carried out at variable temperature and magnetic field. From the critical current densities extracted from transport measurements and magnetization cycles we were able to calculate the normalized bulk pinning forces. The curves show good temperature scaling throughout the explored temperature range, and the reduced pinning force can be described by a simple two-components model system. The extension of the 2-components description of the pinning force to an expression for the critical current density gives a very good agreement with experimental measurements over the whole explored B, T range. The model works for all investigated samples, which are different in size, Cu:nonCu ratios, filament diameters and layouts. These results suggest that pinning mechanisms in conventional NbTi strands should be revised, since Nb-Ti composition gradients and grain boundaries seems to play a not negligible role.
A document describing shuttle considerations for the design of large space structures
Roebuck, J. A., Jr.
1981-01-01
A Shuttle user guide document to aid designers and analysis associated with large space structures projects is described. The format and contents are a compromise designed to satisfy the needs of several levels of users. Special features include checklists and references to source documents as a convenience to very knowledgeable readers. In addition, general, introductory and explanatory text, and art work are included for the reader less familiar with shuttle systems. Also, there are a subject index, glossary, list of acronyms, and many cross references. Throughout the document, there are suggested implications or references to the importance of the included orbiter interfaces material as it pertains to designing and planning large space structures projects. The content of the document is outlined. Shuttle payload accommodations and constraints, connections for orbiter construction fixtures, packaging, and construction space eometry are addressed.
Improving uncertainty estimation in urban hydrological modeling by statistically describing bias
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D. Del Giudice
2013-10-01
Full Text Available Hydrodynamic models are useful tools for urban water management. Unfortunately, it is still challenging to obtain accurate results and plausible uncertainty estimates when using these models. In particular, with the currently applied statistical techniques, flow predictions are usually overconfident and biased. In this study, we present a flexible and relatively efficient methodology (i to obtain more reliable hydrological simulations in terms of coverage of validation data by the uncertainty bands and (ii to separate prediction uncertainty into its components. Our approach acknowledges that urban drainage predictions are biased. This is mostly due to input errors and structural deficits of the model. We address this issue by describing model bias in a Bayesian framework. The bias becomes an autoregressive term additional to white measurement noise, the only error type accounted for in traditional uncertainty analysis. To allow for bigger discrepancies during wet weather, we make the variance of bias dependent on the input (rainfall or/and output (runoff of the system. Specifically, we present a structured approach to select, among five variants, the optimal bias description for a given urban or natural case study. We tested the methodology in a small monitored stormwater system described with a parsimonious model. Our results clearly show that flow simulations are much more reliable when bias is accounted for than when it is neglected. Furthermore, our probabilistic predictions can discriminate between three uncertainty contributions: parametric uncertainty, bias, and measurement errors. In our case study, the best performing bias description is the output-dependent bias using a log-sinh transformation of data and model results. The limitations of the framework presented are some ambiguity due to the subjective choice of priors for bias parameters and its inability to address the causes of model discrepancies. Further research should focus on
Ghyoot, Caroline; Lancelot, Christiane; Flynn, Kevin J.; Mitra, Aditee; Gypens, Nathalie
2017-04-01
Most biogeochemical/ecological models divide planktonic protists between phototrophs (phytoplankton) and heterotrophs (zooplankton). However, a large number of planktonic protists are able to combine several mechanisms of carbon and nutrient acquisition. Not representing these multiple mechanisms in biogeochemical/ecological models describing eutrophied coastal ecosystems can potentially lead to different conclusions regarding ecosystem functioning, especially regarding the success of harmful algae, which are often reported as mixotrophic. This modelling study investigates, for the first time, the implications for trophic dynamics of including 3 contrasting forms of mixotrophy, namely osmotrophy (using alkaline phosphatase activity, APA), non-constitutive mixotrophy (acquired phototrophy by microzooplankton) and also constitutive mixotrophy. The application is in the Southern North Sea, an ecosystem that faced, between 1985 and 2005, a significant increase in the nutrient supply N:P ratio (from 31 to 81 mole N:P). The comparison with a traditional model shows that, when the winter N:P ratio in the Southern North Sea is above 22 molN molP-1 (as occurred from mid-1990s), APA allows a 3 to 32% increase of annual gross primary production (GPP). In result of the higher GPP, the annual sedimentation increases as well as the bacterial production. By contrast, APA does not affect the export of matter to higher trophic levels because the increased GPP is mainly due to Phaeocystis colonies, which are not grazed by copepods. The effect of non-constitutive mixotrophy depends on light and affects the ecosystem functioning in terms of annual GPP, transfer to higher trophic levels, sedimentation, and nutrient remineralisation. Constitutive mixotrophy in nanoflagellates appears to have little influence on this ecosystem functioning. An important conclusion from this work is that different forms of mixotrophy have different impacts on system dynamics and it is thus important to
Inclusion of models to describe severe accident conditions in the fuel simulation code DIONISIO
Energy Technology Data Exchange (ETDEWEB)
Lemes, Martín; Soba, Alejandro [Sección Códigos y Modelos, Gerencia Ciclo del Combustible Nuclear, Comisión Nacional de Energía Atómica, Avenida General Paz 1499, 1650 San Martín, Provincia de Buenos Aires (Argentina); Daverio, Hernando [Gerencia Reactores y Centrales Nucleares, Comisión Nacional de Energía Atómica, Avenida General Paz 1499, 1650 San Martín, Provincia de Buenos Aires (Argentina); Denis, Alicia [Sección Códigos y Modelos, Gerencia Ciclo del Combustible Nuclear, Comisión Nacional de Energía Atómica, Avenida General Paz 1499, 1650 San Martín, Provincia de Buenos Aires (Argentina)
2017-04-15
The simulation of fuel rod behavior is a complex task that demands not only accurate models to describe the numerous phenomena occurring in the pellet, cladding and internal rod atmosphere but also an adequate interconnection between them. In the last years several models have been incorporated to the DIONISIO code with the purpose of increasing its precision and reliability. After the regrettable events at Fukushima, the need for codes capable of simulating nuclear fuels under accident conditions has come forth. Heat removal occurs in a quite different way than during normal operation and this fact determines a completely new set of conditions for the fuel materials. A detailed description of the different regimes the coolant may exhibit in such a wide variety of scenarios requires a thermal-hydraulic formulation not suitable to be included in a fuel performance code. Moreover, there exist a number of reliable and famous codes that perform this task. Nevertheless, and keeping in mind the purpose of building a code focused on the fuel behavior, a subroutine was developed for the DIONISIO code that performs a simplified analysis of the coolant in a PWR, restricted to the more representative situations and provides to the fuel simulation the boundary conditions necessary to reproduce accidental situations. In the present work this subroutine is described and the results of different comparisons with experimental data and with thermal-hydraulic codes are offered. It is verified that, in spite of its comparative simplicity, the predictions of this module of DIONISIO do not differ significantly from those of the specific, complex codes.
Equations to describe brain size across the continuum of human lifespan.
Borzage, Matthew; Blüml, Stefan; Seri, Istvan
2014-01-01
Equations fitting the normative values for gender-specific brain size changes are available. However, these equations do not fit for all age ranges across the human lifespan and particularly have failed to examine the fit across the continuum of prenatal and postnatal human life. We sought to develop a parametric equation that best describes the changes in gender-specific brain size as a function of age across the continuum of prenatal and postnatal human life. Brain weight and brain volume data retrieved from the literature were combined to perform a meta-analysis. Additions to previously published findings included collecting a dataset that spanned the continuum of human lifespan, logarithmic transformation of the data and utilization of the Birch equation. We used Akaike's Information Criterion (AIC) for quantitative evaluation of the new equations. A total of 2,011 brain weight data points spanning from 10 weeks of fetal gestation to over 90 years of age were retrieved. Using our approach, we developed equations with improved fits and lower or similar AIC values compared to the published equations. The new equations are modifications of the basic Birch model. These equations are the first to describe the gender-specific brain weight changes through the continuum of both prenatal and postnatal human life while achieving a level of accuracy similar to or better than the previous, more age-restricted models. The new equations are improved compared to previously used equations and may be useful to those who study brain development, particularly researchers interested in prenatal and postnatal brain size.
What is a Bristow-Latarjet procedure? A review of the described operative techniques and outcomes.
Cowling, P D; Akhtar, M A; Liow, R Y L
2016-09-01
A variety of operative techniques have been described as under the term 'Bristow-Latarjet' procedure. This review aims to define the original procedure, and compare the variation in techniques described in the literature, assessing any effect on clinical outcomes. A systematic review of 24 studies was performed to compare specific steps of the technique (coracoid osteotomy site, subscapularis approach, orientation and position of coracoid graft fixation and fixation method, additional labral and capsular repair) and detect any effect this variability had on outcomes. Overall recurrence rate was 5.36% (2.94% to 43%). Half of the studies performed the procedure for recurrent shoulder instability, with only five studies documenting glenoid bone loss as an indication: 12 studies used the procedure as the primary surgical intervention for recurrent instability. No change in outcome was noted when examining variation in the coracoid osteotomy site, the fixation site on the scapular neck, the fixation method or whether a capsular repair was also performed. Performing a horizontal split in subscapularis may preserve external rotation compared with performing a tenotomy. This is the first review to examine various operative techniques of the Bristow-Latarjet procedure, and their effect on outcome. We found that other than the approach through subscapularis, outcome was independent of the surgical technique, and depended more on patient selection. We would commend future publications on this procedure to provide a detailed description of the surgical technique, and as a minimum present rates of recurrence as an outcome measure. Cite this article: Bone Joint J 2016;98-B:1208-14. ©2016 The British Editorial Society of Bone & Joint Surgery.
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Schellart Antonius JM
2009-10-01
Full Text Available Abstract Background Research in different fields of medicine suggests that communication is important in physician-patient encounters and influences satisfaction with these encounters. It is argued that this also applies to the non-curative tasks that physicians perform, such as sickness certification and medical disability assessments. However, there is no conceptualised theoretical framework that can be used to describe intentions with regard to communication behaviour, communication behaviour itself, and satisfaction with communication behaviour in a medical disability assessment context. Objective The objective of this paper is to describe the conceptualisation of a model for the communication behaviour of physicians performing medical disability assessments in a social insurance context and of their claimants, in face-to-face encounters during medical disability assessment interviews and the preparation thereof. Conceptualisation The behavioural model, based on the Theory of Planned Behaviour (TPB, is conceptualised for the communication behaviour of social insurance physicians and claimants separately, but also combined during the assessment interview. Other important concepts in the model are the evaluation of communication behaviour (satisfaction, intentions, attitudes, skills, and barriers for communication. Conclusion The conceptualisation of the TPB-based behavioural model will help to provide insight into the communication behaviour of social insurance physicians and claimants during disability assessment interviews. After empirical testing of the relationships in the model, it can be used in other studies to obtain more insight into communication behaviour in non-curative medicine, and it could help social insurance physicians to adapt their communication behaviour to their task when performing disability assessments.
The Transfer Function Model as a Tool to Study and Describe Space Weather Phenomena
Porter, Hayden S.; Mayr, Hans G.; Bhartia, P. K. (Technical Monitor)
2001-01-01
The Transfer Function Model (TFM) is a semi-analytical, linear model that is designed especially to describe thermospheric perturbations associated with magnetic storms and substorm. activity. It is a multi-constituent model (N2, O, He H, Ar) that accounts for wind induced diffusion, which significantly affects not only the composition and mass density but also the temperature and wind fields. Because the TFM adopts a semianalytic approach in which the geometry and temporal dependencies of the driving sources are removed through the use of height-integrated Green's functions, it provides physical insight into the essential properties of processes being considered, which are uncluttered by the accidental complexities that arise from particular source geometrie and time dependences. Extending from the ground to 700 km, the TFM eliminates spurious effects due to arbitrarily chosen boundary conditions. A database of transfer functions, computed only once, can be used to synthesize a wide range of spatial and temporal sources dependencies. The response synthesis can be performed quickly in real-time using only limited computing capabilities. These features make the TFM unique among global dynamical models. Given these desirable properties, a version of the TFM has been developed for personal computers (PC) using advanced platform-independent 3D visualization capabilities. We demonstrate the model capabilities with simulations for different auroral sources, including the response of ducted gravity waves modes that propagate around the globe. The thermospheric response is found to depend strongly on the spatial and temporal frequency spectra of the storm. Such varied behavior is difficult to describe in statistical empirical models. To improve the capability of space weather prediction, the TFM thus could be grafted naturally onto existing statistical models using data assimilation.
Genetic resources for methane production from biomass described with gene ontology
Directory of Open Access Journals (Sweden)
Endang ePurwantini
2014-12-01
Full Text Available Methane (CH4 is a valuable fuel, constituting 70-95% of natural gas, and a potent greenhouse gas. Release of CH4 into the atmosphere contributes to climate change. Biological CH4 production or methanogenesis is mostly performed by methanogens, a group of strictly anaerobic archaea. The direct substrates for methanogenesis are H2 plus CO2, acetate, formate, methylamines, methanol, methyl sulfides, and ethanol or a secondary alcohol plus CO2. In numerous anaerobic niches in nature, methanogenesis facilitates mineralization of complex biopolymers such as carbohydrates, lipids and proteins generated by primary producers. Thus, methanogens are critical players in the global carbon cycle. The same process is used in anaerobic treatment of municipal, industrial and agricultural wastes, reducing the biological pollutants in the wastes and generating methane. It also holds potential for commercial production of natural gas from renewable resources. This process operates in digestive systems of many animals, including cattle, and humans. In contrast, in deep-sea hydrothermal vents methanogenesis is a primary production process, allowing chemosynthesis of biomaterials from H2 plus CO2. In this report we present Gene Ontology (GO terms that can be used to describe processes, functions and cellular components involved in methanogenic biodegradation and biosynthesis of specialized coenzymes that methanogens use. Some of these GO terms were previously available and the rest were generated in our Microbial Energy Gene Ontology (MENGO project. A recently discovered non-canonical CH4 production process is also described. We have performed manual GO annotation of selected methanogenesis genes, based on experimental evidence, providing gold standards for machine annotation and automated discovery of methanogenesis genes or systems in diverse genomes. Most of the GO-related information presented in this report is available at the MENGO website (http://www.mengo.biochem.vt.edu/.
Martin, Caitlin Eileen; Houston, Avril Melissa; Mmari, Kristin N; Decker, Michele R
2012-07-01
Adolescent dating violence is increasingly recognized as a public health problem. Our qualitative investigation sought input from urban, African-American adolescents at risk for dating violence concerning (Tjaden and Thoennes in Full report of the prevelance, incidence, and consequences of violence against women: findings from the national violence against women survey. US Department of Justice, Washington, DC, 2000) dating violence descriptions, (WHO multi-country study on women's health and domestic violence against women: Summary report of initial results on prevalence, health outcomes and women's responses. World Health Organization, Geneva, 2005) preferences for help-seeking for dating violence, and (Intimate partner violence in the United States. Bureau of Justice Statistics, US Department of Justice, Office of Justice Programs, Washington, DC, 2007) recommendations for a teen dating violence resource center. Four focus groups were conducted with urban, African American adolescents (n = 32) aged 13-24 recruited from an urban adolescent clinic's community outreach partners. Qualitative analysis was conducted. Participants assigned a wide range of meanings for the term "relationship drama", and used dating violence using language not typically heard among adults, e.g., "disrespect". Participants described preferences for turning to family or friends before seeking formal services for dating violence, but reported barriers to their ability to rely on these informal sources. When asked to consider formal services, they described their preferred resource center as confidential and safe, with empathetic, non-judgmental staff. Teens also gave insight into preferred ways to outreach and publicize dating violence resources. Findings inform recommendations for youth-specific tailoring of violence screening and intervention efforts. Current evidence that slang terms, i.e., "drama", lack specificity suggests that they should not be integrated within screening protocols
HepML, an XML-based format for describing simulated data in high energy physics
Belov, S.; Dudko, L.; Kekelidze, D.; Sherstnev, A.
2010-10-01
In this paper we describe a HepML format and a corresponding C++ library developed for keeping complete description of parton level events in a unified and flexible form. HepML tags contain enough information to understand what kind of physics the simulated events describe and how the events have been prepared. A HepML block can be included into event files in the LHEF format. The structure of the HepML block is described by means of several XML Schemas. The Schemas define necessary information for the HepML block and how this information should be located within the block. The library libhepml is a C++ library intended for parsing and serialization of HepML tags, and representing the HepML block in computer memory. The library is an API for external software. For example, Matrix Element Monte Carlo event generators can use the library for preparing and writing a header of an LHEF file in the form of HepML tags. In turn, Showering and Hadronization event generators can parse the HepML header and get the information in the form of C++ classes. libhepml can be used in C++, C, and Fortran programs. All necessary parts of HepML have been prepared and we present the project to the HEP community. Program summaryProgram title: libhepml Catalogue identifier: AEGL_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGL_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPLv3 No. of lines in distributed program, including test data, etc.: 138 866 No. of bytes in distributed program, including test data, etc.: 613 122 Distribution format: tar.gz Programming language: C++, C Computer: PCs and workstations Operating system: Scientific Linux CERN 4/5, Ubuntu 9.10 RAM: 1 073 741 824 bytes (1 Gb) Classification: 6.2, 11.1, 11.2 External routines: Xerces XML library ( http://xerces.apache.org/xerces-c/), Expat XML Parser ( http://expat.sourceforge.net/) Nature of problem: Monte Carlo simulation in high
Fordyce, James A.
2017-01-01
Among the greatest challenges facing the conservation of plants and animal species in protected areas are threats from a rapidly changing climate. An altered climate creates both challenges and opportunities for improving the management of protected areas in networks. Increasingly, quantitative tools like species distribution modeling are used to assess the performance of protected areas and predict potential responses to changing climates for groups of species, within a predictive framework. At larger geographic domains and scales, protected area network units have spatial geoclimatic properties that can be described in the gap analysis typically used to measure or aggregate the geographic distributions of species (stacked species distribution models, or S-SDM). We extend the use of species distribution modeling techniques in order to model the climate envelope (or “footprint”) of individual protected areas within a network of protected areas distributed across the 48 conterminous United States and managed by the US National Park System. In our approach we treat each protected area as the geographic range of a hypothetical endemic species, then use MaxEnt and 5 uncorrelated BioClim variables to model the geographic distribution of the climatic envelope associated with each protected area unit (modeling the geographic area of park units as the range of a species). We describe the individual and aggregated climate envelopes predicted by a large network of 163 protected areas and briefly illustrate how macroecological measures of geodiversity can be derived from our analysis of the landscape ecological context of protected areas. To estimate trajectories of change in the temporal distribution of climatic features within a protected area network, we projected the climate envelopes of protected areas in current conditions onto a dataset of predicted future climatic conditions. Our results suggest that the climate envelopes of some parks may be locally unique or
Directory of Open Access Journals (Sweden)
Adam B. Sefkow
2006-09-01
Full Text Available Heavy ion drivers for warm dense matter and heavy ion fusion applications use intense charge bunches which must undergo transverse and longitudinal compression in order to meet the requisite high current densities and short pulse durations desired at the target. The neutralized drift compression experiment (NDCX at the Lawrence Berkeley National Laboratory is used to study the longitudinal neutralized drift compression of a space-charge-dominated ion beam, which occurs due to an imposed longitudinal velocity tilt and subsequent neutralization of the beam’s space charge by background plasma. Reduced theoretical models have been used in order to describe the realistic propagation of an intense charge bunch through the NDCX device. A warm-fluid model is presented as a tractable computational tool for investigating the nonideal effects associated with the experimental acceleration gap geometry and voltage waveform of the induction module, which acts as a means to pulse shape both the velocity and line density profiles. Self-similar drift compression solutions can be realized in order to transversely focus the entire charge bunch to the same focal plane in upcoming simultaneous transverse and longitudinal focusing experiments. A kinetic formalism based on the Vlasov equation has been employed in order to show that the peaks in the experimental current profiles are a result of the fact that only the central portion of the beam contributes effectively to the main compressed pulse. Significant portions of the charge bunch reside in the nonlinearly compressing part of the ion beam because of deviations between the experimental and ideal velocity tilts. Those regions form a pedestal of current around the central peak, thereby decreasing the amount of achievable longitudinal compression and increasing the pulse durations achieved at the focal plane. A hybrid fluid-Vlasov model which retains the advantages of both the fluid and kinetic approaches has been
Using R-matrix ideas to describe one-nucleon transfers to resonance states
Escher, J. E.; Thompson, I. J.; Arbanas, G.; Elster, Ch.; Eremenko, V.; Hlophe, L.; Nunes, F.; Torus Collaboration
2014-09-01
(d,p) transfer reactions have long been used to investigate nuclear structure. Carried out in inverse kinematics, they are expected to play a central role in the study of weakly-bound systems at modern RIB facilities. While the theoretical framework and its computational implementation for describing (d,p) reactions have seen much progress, open questions remain. Resonances in the low-energy spectra of weakly-bound nuclei, e.g., are of interest for astrophysical applications and can in principle be studied with transfer reactions. Applying standard transfer reaction theories is problematic, both practically in terms of achieving converged solutions and conceptually in terms of interpreting the results. Recently, a new formalism that utilizes concepts known from the successful and popular R-matrix theory was proposed for the description of (d,p) reactions [Mukhamedzhanov, PRC 2011]. The formalism covers transfers to bound and resonance states and is general enough to include deuteron breakup. We present tests of the proposed formalism, compare calculations to measured cross sections, and discuss implications [Escher et al. PRC 2014]. (d,p) transfer reactions have long been used to investigate nuclear structure. Carried out in inverse kinematics, they are expected to play a central role in the study of weakly-bound systems at modern RIB facilities. While the theoretical framework and its computational implementation for describing (d,p) reactions have seen much progress, open questions remain. Resonances in the low-energy spectra of weakly-bound nuclei, e.g., are of interest for astrophysical applications and can in principle be studied with transfer reactions. Applying standard transfer reaction theories is problematic, both practically in terms of achieving converged solutions and conceptually in terms of interpreting the results. Recently, a new formalism that utilizes concepts known from the successful and popular R-matrix theory was proposed for the description
A Mulitivariate Statistical Model Describing the Compound Nature of Soil Moisture Drought
Manning, Colin; Widmann, Martin; Bevacqua, Emanuele; Maraun, Douglas; Van Loon, Anne; Vrac, Mathieu
2017-04-01
Soil moisture in Europe acts to partition incoming energy into sensible and latent heat fluxes, thereby exerting a large influence on temperature variability. Soil moisture is predominantly controlled by precipitation and evapotranspiration. When these meteorological variables are accumulated over different timescales, their joint multivariate distribution and dependence structure can be used to provide information of soil moisture. We therefore consider soil moisture drought as a compound event of meteorological drought (deficits of precipitation) and heat waves, or more specifically, periods of high Potential Evapotraspiration (PET). We present here a statistical model of soil moisture based on Pair Copula Constructions (PCC) that can describe the dependence amongst soil moisture and its contributing meteorological variables. The model is designed in such a way that it can account for concurrences of meteorological drought and heat waves and describe the dependence between these conditions at a local level. The model is composed of four variables; daily soil moisture (h); a short term and a long term accumulated precipitation variable (Y1 and Y_2) that account for the propagation of meteorological drought to soil moisture drought; and accumulated PET (Y_3), calculated using the Penman Monteith equation, which can represent the effect of a heat wave on soil conditions. Copula are multivariate distribution functions that allow one to model the dependence structure of given variables separately from their marginal behaviour. PCCs then allow in theory for the formulation of a multivariate distribution of any dimension where the multivariate distribution is decomposed into a product of marginal probability density functions and two-dimensional copula, of which some are conditional. We apply PCC here in such a way that allows us to provide estimates of h and their uncertainty through conditioning on the Y in the form h=h|y_1,y_2,y_3 (1) Applying the model to various
Assessment of parameters describing representativeness of air quality in-situ measurement sites
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S. Henne
2010-04-01
Full Text Available The atmospheric layer closest to the ground is strongly influenced by variable surface fluxes (emissions, surface deposition and can therefore be very heterogeneous. In order to perform air quality measurements that are representative of a larger domain or a certain degree of pollution, observatories are placed away from population centres or within areas of specific population density. Sites are often categorised based on subjective criteria that are not uniformly applied by the atmospheric community within different administrative domains yielding an inconsistent global air quality picture. A novel approach for the assessment of parameters reflecting site representativeness is presented here, taking emissions, deposition and transport towards 34 sites covering Western and Central Europe into account. These parameters are directly inter-comparable among the sites and can be used to select sites that are, on average, more or less suitable for data assimilation and comparison with satellite and model data. Advection towards these sites was simulated by backward Lagrangian Particle Dispersion Modelling (LPDM to determine the sites' average catchment areas for the year 2005 and advection times of 12, 24 and 48 h. Only variations caused by emissions and transport during these periods were considered assuming that these dominate the short-term variability of most but especially short lived trace gases. The derived parameters describing representativeness were compared between sites and a novel, uniform and observation-independent categorisation of the sites based on a clustering approach was established. Six groups of European background sites were identified ranging from generally remote to more polluted agglomeration sites. These six categories explained 50 to 80% of the inter-site variability of median mixing ratios and their standard deviation for NO_{2} and O_{3}, while differences between group means of the longer
Using the ecology model to describe the impact of asthma on patterns of health care
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Yawn Barbara P
2005-05-01
Full Text Available Abstract Background Asthma changes both the volume and patterns of healthcare of affected people. Most studies of asthma health care utilization have been done in selected insured populations or in a single site such as the emergency department. Asthma is an ambulatory sensitive care condition making it important to understand the relationship between care in all sites across the health service spectrum. Asthma is also more common in people with fewer economic resources making it important to include people across all types of insurance and no insurance categories. The ecology of medical care model may provide a useful framework to describe the use of health services in people with asthma compared to those without asthma and identify subgroups with apparent gaps in care. Methods This is a case-control study using the 1999 U.S. Medical Expenditure Panel Survey. Cases are school-aged children (6 to 17 years and young adults (18 to 44 years with self-reported asthma. Controls are from the same age groups who have no self-reported asthma. Descriptive analyses and risk ratios are placed within the ecology of medical care model and used to describe and compare the healthcare contact of cases and controls across multiple settings. Results In 1999, the presence of asthma significantly increased the likelihood of an ambulatory care visit by 20 to 30% and more than doubled the likelihood of making one or more visits to the emergency department (ED. Yet, 18.8% of children and 14.5% of adults with asthma (over a million Americans had no ambulatory care visits for asthma. About one in 20 to 35 people with asthma (5.2% of children and 3.6% of adults were seen in the ED or hospital but had no prior or follow-up ambulatory care visits. These Americans were more likely to be uninsured, have no usual source of care and live in metropolitan areas. Conclusion The ecology model confirmed that having asthma changes the likelihood and pattern of care for Americans
Improving uncertainty estimation in urban hydrological modeling by statistically describing bias
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D. Del Giudice
2013-04-01
Full Text Available Hydrodynamic models are useful tools for urban water management. Unfortunately, it is still challenging to obtain accurate results and plausible uncertainty estimates when using these models. In particular, with the currently applied statistical techniques, flow predictions are usually overconfident and biased. In this study, we present a flexible and computationally efficient methodology (i to obtain more reliable hydrological simulations in terms of coverage of validation data by the uncertainty bands and (ii to separate prediction uncertainty into its components. Our approach acknowledges that urban drainage predictions are biased. This is mostly due to input errors and structural deficits of the model. We address this issue by describing model bias in a Bayesian framework. The bias becomes an autoregressive term additional to white measurement noise, the only error type accounted for in traditional uncertainty analysis in urban hydrology. To allow for bigger discrepancies during wet weather, we make the variance of bias dependent on the input (rainfall or/and output (runoff of the system. Specifically, we present a structured approach to select, among five variants, the optimal bias description for a given urban or natural case study. We tested the methodology in a small monitored stormwater system described by means of a parsimonious model. Our results clearly show that flow simulations are much more reliable when bias is accounted for than when it is neglected. Furthermore, our probabilistic predictions can discriminate between three uncertainty contributions: parametric uncertainty, bias (due to input and structural errors, and measurement errors. In our case study, the best performing bias description was the output-dependent bias using a log-sinh transformation of data and model results. The limitations of the framework presented are some ambiguity due to the subjective choice of priors for bias parameters and its inability to directly
Yu, Huixin; van Erp, Nielka; Bins, Sander; Mathijssen, Ron H J; Schellens, Jan H M; Beijnen, Jos H; Steeghs, Neeltje; Huitema, Alwin D R
2017-03-01
Pazopanib is a multi-targeted anticancer tyrosine kinase inhibitor. This study was conducted to develop a population pharmacokinetic (popPK) model describing the complex pharmacokinetics of pazopanib in cancer patients. Pharmacokinetic data were available from 96 patients from three clinical studies. A multi-compartment model including (i) a complex absorption profile, (ii) the potential non-linear dose-concentration relationship and (iii) the potential long-term decrease in exposure was developed. A two-compartment model best described pazopanib pharmacokinetics. The absorption phase was modelled by two first-order processes: 36 % (relative standard error [RSE] 34 %) of the administered dose was absorbed with a relatively fast rate (0.4 h(-1) [RSE 31 %]); after a lag time of 1.0 h (RSE 6 %), the remaining dose was absorbed at a slower rate (0.1 h(-1) [RSE 28 %]). The relative bioavailability (rF) at a dose of 200 mg was fixed to 1. With an increasing dose, the rF was strongly reduced, which was modelled with an E max (maximum effect) model (E max was fixed to 1, the dose at half of maximum effect was estimated as 480 mg [RSE 23 %]). Interestingly, the plasma exposure to pazopanib also decreased over time, modelled on rF with a maximum magnitude of 50 % (RSE 27 %) and a first-order decay constant of 0.15 day(-1) (RSE 43 %). The inter-patient and intra-patient variability on rF were estimated as 36 % (RSE 16 %) and 75 % (RSE 22 %), respectively. A popPK model for pazopanib was developed that illustrated the complex absorption process, the non-linear dose-concentration relationship, the high inter-patient and intra-patient variability, and the first-order decay of pazopanib concentration over time. The developed popPK model can be used in clinical practice to screen covariates and guide therapeutic drug monitoring.
Describing Adequacy of cure with maximum hardness ratios and non-linear regression.
Bouschlicher, Murray; Berning, Kristen; Qian, Fang
2008-01-01
Knoop Hardness (KH) ratios (HR) > or = 80% are commonly used as criteria for the adequate cure of a composite. These per-specimen HRs can be misleading, as both numerator and denominator may increase concurrently, prior to reaching an asymptotic, top-surface maximum hardness value (H(MAX)). Extended cure times were used to establish H(MAX) and descriptive statistics, and non-linear regression analysis were used to describe the relationship between exposure duration and HR and predict the time required for HR-H(MAX) = 80%. Composite samples 2.00 x 5.00 mm diameter (n = 5/grp) were cured for 10 seconds, 20 seconds, 40 seconds, 60 seconds, 90 seconds, 120 seconds, 180 seconds and 240 seconds in a 2-composite x 2-light curing unit design. A microhybrid (Point 4, P4) or microfill resin (Heliomolar, HM) composite was cured with a QTH or LED light curing unit and then stored in the dark for 24 hours prior to KH testing. Non-linear regression was calculated with: H = (H(MAX)-c)(1-e(-kt)) +c, H(MAX) = maximum hardness (a theoretical asymptotic value), c = constant (t = 0), k = rate constant and t = exposure duration describes the relationship between radiant exposure (irradiance x time) and HRs. Exposure durations for HR-H(MAX) = 80% were calculated. Two-sample t-tests for pairwise comparisons evaluated relative performance of the light curing units for similar surface x composite x exposure (10-90s). A good measure of goodness-of-fit of the non-linear regression, r2, ranged from 0.68-0.95. (mean = 0.82). Microhybrid (P4) exposure to achieve HR-H(MAX = 80% was 21 seconds for QTH and 34 seconds for the LED light curing unit. Corresponding values for microfill (HM) were 71 and 74 seconds, respectively. P4 HR-H(MAX) of LED vs QTH was statistically similar for 10 to 40 seconds, while HM HR-H(MAX) of LED was significantly lower than QTH for 10 to 40 seconds. It was concluded that redefined hardness ratios based on maximum hardness used in conjunction with non-linear regression
Keller, Alexandra P.
Cancer arises through an accumulation of mutations in the genome. In cancer cells, mutations are frequently caused by DNA rearrangements, which include chromosomal breakages, deletions, insertions, and translocations. Such events contribute to genomic instability, a known hallmark of cancer. To study cycles of chromosomal instability, we are using baker's yeast as a model organism. In yeast, a ChrVII system was previously developed (Admire et al., 2006), in which a disomic yeast strain was used to identify regions of instability on ChrVII. Using this system, a fragile site on the left arm of ChrVII (Admire et al., 2006) was identified and characterized. This study led to insight into mechanisms involved in chromosomal rearrangements and mutations that arise from them as well as to an understanding of mechanisms involved in genomic instability. To further our understanding of genomic instability, I devised a strategy to study instability on a different chromosome (ChrV) (Figure 3), so that we could determine whether lessons learned from the ChrVII system are applicable to other chromosomes, and/or whether other mechanisms of instability could be identified. A suitable strain was generated and analyzed, and our findings suggest that frequencies of instability on the right arm of ChrV are similar to those found in ChrVII. The results from the work in ChrV described in this paper support the idea that the instability found on ChrVII is not an isolated occurrence. My research was supported by an NSF GK-12 grant. The aim of this grant is to improve science education in middle schools, and as part of my participation in this program, I studied and practiced effective science communication methodologies. In attempts to explain my research to middle school students, I collaborated with others to develop methods for explaining genetics and the most important techniques I used in my research. While developing these methods, I learned more about what motivates people to learn
Lindberg, Susanne; Wärnestål, Pontus; Svedberg, Petra
2017-01-01
Background Participatory research approaches have been introduced to meet end-users’ needs in the development of health promotion interventions among children. However, whereas children are increasingly involved as passive informants in particular parts of research, they are rarely involved as partners, equal to adult researchers, throughout the research process. This is especially prominent in the context of child health where the child is commonly considered to be vulnerable or when the research concerns sensitive situations. In these cases, researchers and gatekeepers to children’s involvement base their resistance to active involvement of children on potential adverse effects on the accuracy or quality of the research or on ethical or moral principles that participation might harm the child. Thus most research aimed at developing health promotion interventions for children in health care is primarily based on the involvement of parents, caregivers, and other stakeholders. Objective The objective of this paper is to discuss reasons for involving children in health promotive research and to explore models for children’s participation in research as a basis for describing how researchers can use design methodology and participatory approaches to support the participation and contribution of children in a vulnerable context. Methods We developed and applied a model for children's participation in research to the development of a digital peer support service for children cancer survivors. This guided the selection of appropriate research and design methodologies (such as interviews, focus groups, design sessions, and usability evaluation) for involving the children cancer survivors (8-12 years) in the design of a digital peer support service. Results We present a model for what children’s participation in research means and describe how we practically implemented this model in a research project on children with cancer. This paper can inform researchers in
Robinson, Jason L; Fordyce, James A
2017-01-01
Among the greatest challenges facing the conservation of plants and animal species in protected areas are threats from a rapidly changing climate. An altered climate creates both challenges and opportunities for improving the management of protected areas in networks. Increasingly, quantitative tools like species distribution modeling are used to assess the performance of protected areas and predict potential responses to changing climates for groups of species, within a predictive framework. At larger geographic domains and scales, protected area network units have spatial geoclimatic properties that can be described in the gap analysis typically used to measure or aggregate the geographic distributions of species (stacked species distribution models, or S-SDM). We extend the use of species distribution modeling techniques in order to model the climate envelope (or "footprint") of individual protected areas within a network of protected areas distributed across the 48 conterminous United States and managed by the US National Park System. In our approach we treat each protected area as the geographic range of a hypothetical endemic species, then use MaxEnt and 5 uncorrelated BioClim variables to model the geographic distribution of the climatic envelope associated with each protected area unit (modeling the geographic area of park units as the range of a species). We describe the individual and aggregated climate envelopes predicted by a large network of 163 protected areas and briefly illustrate how macroecological measures of geodiversity can be derived from our analysis of the landscape ecological context of protected areas. To estimate trajectories of change in the temporal distribution of climatic features within a protected area network, we projected the climate envelopes of protected areas in current conditions onto a dataset of predicted future climatic conditions. Our results suggest that the climate envelopes of some parks may be locally unique or have
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Yarash K. Abuev
2017-01-01
Full Text Available Abstract. Objectives A computer simulation of the antiferromagnetic structures described by the three-vertex Potts model on a triangular lattice is performed, taking into account the antiferromagnetic exchange interactions between the nearest J1 and second J2 neighbours. The main goal of the computer simulation was to elucidate the effects of ground state and areas of frustration on the thermodynamic and magnetic properties of antiferromagnetic structures described by the lowdimensional Potts model. Method The computer simulation is based on the Monte Carlo method. This method is implemented using the Metropolis algorithm in combination with the Wolff claster algorithm. The computer simulation was carried out for low-dimensional systems with periodic boundary conditions and linear dimensions L = 24124. Results On the basis of heat capacity and entropy analysis, phase transitions were observed in the considered model to possess exchange interaction parameters J1 <0 and J2 <0 in the variation intervals 0r<0.2 and 1.0