scholarly journals Temporal averaging across multiple response options: insight into the mechanisms underlying integration

2015 ◽  
Vol 19 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Benjamin J. De Corte ◽  
Matthew S. Matell
Keyword(s):  
Multiple Response ◽  
Response Options ◽  
Temporal Averaging ◽  
Insight Into

scholarly journals Seasonal dynamics of a generalist and a specialist predator on a single prey

2021 ◽  
pp. 1-20
Author(s):  
Noah Bolohan ◽  
Victor LeBlanc ◽  
Frithjof Lutscher
Keyword(s):  
Seasonal Variation ◽  
Community Dynamics ◽  
Alternative Prey ◽  
Ecological Communities ◽  
Season Length ◽  
Simplified Models ◽  
Hunting Behaviour ◽  
Temporal Averaging ◽  
Invasion Analysis ◽  
Insight Into

In ecological communities, the behaviour of individuals and the interaction between species may change between seasons, yet this seasonal variation is often not represented explicitly in mathematical models. As global change is predicted to alter season length and other climatic aspects, such seasonal variation needs to be included in models in order to make reasonable predictions for community dynamics. The resulting mathematical descriptions are nonautonomous models with a large number of parameters, and are therefore challenging to analyze. We present a model for two predators and one prey, whereby one predator switches hunting behaviour to seasonally include alternative prey when available. We use a combination of temporal averaging and invasion analysis to derive simplified models and determine the behaviour of the system, in particular to gain insight into conditions under which the two predators can coexist in a changing climate. We compare our results with numerical simulations of the temporally varying model.

Questionnaire Design in Short Message Service (SMS) Surveys

Field Methods ◽  
2019 ◽  
Vol 31 (3) ◽  
pp. 214-229
Author(s):  
Charles Q. Lau ◽  
Herschel Sanders ◽  
Ansie Lombaard
Keyword(s):  
Text Messaging ◽  
Short Message Service ◽  
Questionnaire Design ◽  
Short Message ◽  
Multiple Response ◽  
African Countries ◽  
Response Options ◽  
Face To Face ◽  
Message Service ◽  
Randomize Response

Short message service (SMS or text messaging) surveys can collect data quickly and inexpensively. However, SMS surveys have space constraints that pose difficulties to questionnaire designers: Questions can only be 160 characters or less, surveys must be short, and many respondents use phones with small screens. In this article, we compare SMS and benchmark face-to-face surveys across four African countries to address three common questions in SMS questionnaire design. First, are multiple response questions feasible? Second, is it necessary to randomize response option order? Third, should “don’t know” response options be included? Our results provide practical guidance about how to improve data quality with this emerging mode of data collection.

scholarly journals Cognitive Interviews: Testing the Digital Health Literacy Instrument (Preprint)

2020 ◽  
Author(s):  
Eunhee Park ◽  
Misol Kwon
Keyword(s):  
Health Literacy ◽  
Content Validity ◽  
Digital Health ◽  
Cognitive Interviews ◽  
Thinking Aloud ◽  
Web Based ◽  
Response Options ◽  
Digital Devices ◽  
Device Use ◽  
Insight Into

BACKGROUND Despite the increasing number of youth seeking health information on the internet, few studies have been conducted to measure digital health literacy in this population. Digital Health Literacy Instruments (DHLI) is defined as a scale that measures the ability to operate digital devices, and read and write in online-based modes; it assesses seven sub-constructs: operational skills, navigation skills, evaluating reliability, determining relevance, adding self-generated content to a web-based app, and protecting and respecting privacy. Currently, there has been no validation process for adolescents on this instrument yet. OBJECTIVE To explore the usability and content validity of DHLIs. METHODS Upon the approval of IRB protocol, cognitive interviews were conducted. Thirty-four adolescents aged 10-18 years old (50% female) participated in individual cognitive interviews. Two rounds of concurrent cognitive interviews were conducted to measure the content validity of DHLI utilizing the ‘thinking aloud’ method and probing questions. RESULTS Major issues of comprehension and communication including unclear wording, undefined technical terms, vague terms, and difficult vocabularies were identified. Problems related to potentially inappropriate assumptions were also identified. In addition, concerns related to recall bias with unclear reference periods, and bias by measuring socially uncommon phenomena were raised. No issue regarding response options or instrument instructions were noted. CONCLUSIONS The initial round of interviews provided potential resolution to the identified problems with comprehension and communication, while the second round prompted improvement in content validity. More work needs to be conducted to address issues related to inappropriate assumptions or bias when Internet and digital device use are considered uncommon phenomena among adolescents. Dual rounds of cognitive interviews provided substantial insight into survey interpretation when introduced to US adolescents. This validation study suggests revision points for assessing adolescent digital health literacy.

scholarly journals MRCV: A Package for Analyzing Categorical Variables with Multiple Response Options

The R Journal ◽  
2014 ◽  
Vol 6 (1) ◽  
pp. 144 ◽  
Author(s):  
Natalie,A. Koziol ◽  
Christopher,R. Bilder
Keyword(s):  
Categorical Variables ◽  
Multiple Response ◽  
Response Options

Multivariate Analysis of Multiple Response Data

2003 ◽  
Vol 40 (3) ◽  
pp. 321-334 ◽  
Author(s):  
Yancy D. Edwards ◽  
Greg M. Allenby
Keyword(s):  
Multivariate Analysis ◽  
Probit Model ◽  
Estimation Algorithm ◽  
Multiple Response ◽  
Multivariate Normal ◽  
Response Options ◽  
Response Data ◽  
Marketing Data ◽  
Multiple Response Data ◽  
The Relationship

Multiple response questions, also known as a pick any/J format, are frequently encountered in the analysis of survey data. The relationship among the responses is difficult to explore when the number of response options, J, is large. The authors propose a multivariate binomial probit model for analyzing multiple response data and use standard multivariate analysis techniques to conduct exploratory analysis on the latent multivariate normal distribution. A challenge of estimating the probit model is addressing identifying restrictions that lead to the covariance matrix specified with unit-diagonal elements (i.e., a correlation matrix). The authors propose a general approach to handling identifying restrictions and develop specific algorithms for the multivariate binomial probit model. The estimation algorithm is efficient and can easily accommodate many response options that are frequently encountered in the analysis of marketing data. The authors illustrate multivariate analysis of multiple response data in three applications.

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

Stochasting modeling of planetary ring systems

1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart
Keyword(s):  
Maximum Entropy ◽  
Ring System ◽  
The Sun ◽  
Ultimate State ◽  
Interparticle Interactions ◽  
Ring Systems ◽  
First Order ◽  
Planetary Ring ◽  
Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

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