A PARTIAL INDEPENDENCE ITEM RESPONSE MODEL FOR SURVEYS WITH FILTER QUESTIONS

In many surveys, responses to earlier questions determine whether later questions are asked. The probability of an affirmative response to a given item is therefore nonzero only if the participant responded affirmatively to some set of logically prior items, known as "filter items." In such surveys, the usual conditional independence assumption of standard item response models fails. A weaker "partial independence" assumption may hold, however, if an individual's responses to different items are independent conditional on the item parameters, the individual's latent trait, and the participant's affirmative responses to each of a set of filter items. In this paper, we propose an item response model for such "partially independent" item response data. We model such item response patterns as a function of a person-specific latent trait and a set of item parameters. Our model can be seen as a generalized hybrid of a discrete-time hazard model and a Rasch model. The proposed procedure yields estimates of (1) person-specific, interval-scale measures of a latent trait (or traits), along with person-specific standard errors of measurement; (2) conditional and marginal item severities for each item in a protocol; (3) person-specific conditional and marginal probabilities of an affirmative response to each item in a protocol; and (4) item information and total survey information. In addition, we show here how to investigate and test alternative conceptions of the dimensionality of the latent trait(s) being measured. Finally, we compare our procedure with a simpler alternative approach to summarizing data of this type.     

Concurrent training protocol for men with androgen deficiency in the aging male: a randomized clinical trial

Background: The androgen deficiency in the aging male (ADAM) affects physical, sexual, and psychological aspects with characteristics symptoms of middle-aged men. The practice of regular physical activity and physical exercise can attenuate these symptoms. The aim of this randomized clinical trial is to propose a physical exercise protocol based on concurrent training for middle-aged men with ADAM.

Method: Randomized clinical trial with a 6-month intervention will randomly divided into two groups: experimental group (EG) and control group (CG). Four evaluations will be carried out, (1) pre-intervention; (2) in the first month of intervention; (3) in the third month of intervention; (4) post-intervention, evaluating: physical, psychological, sexual, and hormonal aspects. The intervention protocol with concurrent training will have duration of 6 months; frequency of 3 times weekly, with 60?min per session. The two-way ANOVA test will be used for the inter-group and intra-group comparisons with repeated measurements, and also Sydak’s comparison test.

Conclusion: This protocol was developed with the intent of easing the symptoms of ADAM. In addition, it is believed that the concurrent training protocol could be capable to recover hormonal, physical, psychological, and sexual aspect of middle-aged men with ADAM.     

Comparing swimsuits in 3D

In competitive swimming, suits have become more important. These suits influence friction, pressure and wave drag. Friction drag is related to the surface properties whereas both pressure and wave drag are greatly influenced by body shape. To find a relationship between the body shape and the drag, the anthropometry of several world class female swimmers wearing different suits was accurately defined using a 3D scanner and traditional measuring methods. The 3D scans delivered more detailed information about the body shape. On the same day the swimmers did performance tests in the water with the tested suits. Afterwards the result of the performance tests and the differences found in body shape was analyzed to determine the deformation caused by a swimsuit and its effect on the swimming performance. Although the amount of data is limited because of the few test subjects, there is an indication that the deformation of the body influences the swimming performance.     

Actors and networks as objects

This paper explores the application of two contemporary computational methods to the development of sociological theory. Specifically, we combine the methods of object-orientation with discrete event simulation. This approach has several advantages for constructing and evaluating dynamic social theories.In object-oriented program design, objects combine and integrate the traditional concepts of data structures and algorithms, the building blocks of structured programming. Algorithms associated with objects are called methods or member functions. Constructing social actors as objects involves defining both their data attributes and the methods associated with these attributes. We also treat a social network as a computational object. It has data types of nodes and ties. As an object, the network must also have methods that add and delete nodes and ties. Once a network exists, we can create other data types and methods that describe and analyze the network. For example, networks have in-degree and out-degree vectors, and measures of hierarchy. In principle, we can create attributes of networks for all of the structural measures we use to describe networks.We use actor and network objects in a discrete event simulation of a process of formation of dominance structures, exploring several dynamic variations of the underlying theoretical model.     

SCANAM method for the assessment of industrial noise

Work in an industrial environment is often associated with high levels of noise. For measuring and evaluating of noise levels, sometimes it is necessary to use several instruments. These instruments can be very expensive and require qualified personnel. Medium and small-sized firms often lack sufficient financial resources to ensure continuous measurement and assessment of noise levels. For this reason, a new SCANAM method for assessing the levels of noise is designed. This method involves the use of cheap and accurate sound level meter and specially designed software for assessing the effects of noise. Application of this method is very simple. Based on a noise sample in duration of eight hours, the accuracy of the SCANAM method was confirmed. Application of this method is significantly cheaper than an approach based on the use of expensive multi-function devices, or separate devices for measuring and assessing noise at the workplace.     

Comparison between occupational noise measurement strategies: why is it important?

The international standard ISO 9612:2009, regarding the determination of occupational noise exposure through an engineering method, establishes a methodology for evaluating the exposure of workers to occupational noise, through the specification of three different strategies, namely: task-based measurement (TBM); job-based measurement (JBM) and; full day measurement (FDM). In this work, questions are raised, "resulting in a literature review regarding the need to test the functionality of the three strategies, through the systematic comparison between them and analysis of their application impact at several levels. There is a need to test the compare these three strategies, since there are no peer-review studies in this domain. In fact, there are still no studies that systematically do the comparison between them and analyze the impact of their application at various levels, such as the precision and accuracy of the results, the required equipment, time spent and, most important, the estimation of the uncertainty associated to the measurements.     

Maternal employment and food produced at home: evidence from Japanese data

This paper examines whether mothers’ labor supply discourages home production, focusing on food preparation at home in Japanese families. Although empirical studies on home production are usually conducted using time use data, we use data collected by scanners, which cover daily goods purchased by over 10,000 households over 3 years. Based on the composition of daily food expenditures for foods consumed, we measure how many products are made using time-consuming processes at home, and examine if time-consuming home production is discouraged by mothers’ employment away from home. Controlling for unobserved heterogeneity among households using the panel structure of our scanner data, we first show that mothers’ out-of-home employment has a negative effect on home cooking. This effect is shared across economic classes, particularly when mothers work part-time, as compared with non-working mothers. Second, we show that this negative effect is more apparent in the low economic class. Households in this class show a particular decrease in time-consuming home cooking, especially when the mothers work part-time. Third, the smaller negative effect among the higher class can be explained by stronger health-consciousness and aversion to less-healthy products in this class.     

Urban cover mapping using digital, high-spatial resolution aerial imagery

High-spatial resolution digital color-infrared aerial imagery of Syracuse, NY was analyzed to test methods for developing land cover classifications for an urban area. Five cover types were mapped: tree/shrub, grass/herbaceous, bare soil, water and impervious surface. Challenges in high-spatial resolution imagery such as shadow effect and similarity in spectral response between classes were found. Classification confusion among objects with similar spectral responses occurred between water and dark impervious surfaces, concrete and bare-soil, and grass/herbaceous and trees/shrub. Methods of incorporating texture, band ratios, masking of water objects, sieve functions, and majority filters were evaluated for their potential to improve the classification accuracy. After combining these various techniques, overall cover accuracy for the study area was 81.75%. Highest accuracies occurred for water (100%), tree/shrub (86.2%) and impervious surfaces (82.6%); lowest accuracy were for grass/herbaceous (69.3%) and bare soil (40.0%). Methods of improving cover map accuracy are discussed.     

Establishing Naming in Typically Developing Two-Year-Old Children as a Function of Multiple Exemplar Speaker and Listener Experiences

Naming is a verbal developmental capability and cusp that allows children to acquire listener and speaker functions without direct instruction (e.g., incidental learning of words for objects). We screened 19 typically developing 2- and 3-year-old children for the presence of Naming for 3-dimensional objects. All 9 3-year-olds had Naming, and 8 of 10 2-year-olds lacked Naming. For the 2-year-old children who lacked Naming, we used multiple-probe designs (2 groups of 4 children) to test the effect of multiple exemplar instruction (MEI) across speaker and listener responses on the emergence of Naming. Prior to the MEI, the children could not emit untaught listener or speaker responses following match-to-sample instruction with novel stimuli, during which they had heard the experimenter tact the stimuli. After MEI with a different set of novel stimuli, the children emitted listener and speaker responses when probed with the original stimuli, in the absence of any further instruction with those stimuli. Seven of 8 children acquired the speaker and listener responses of Naming at 83% to 100% accuracy. We discuss the basic and applied science implications.     

An object's categorizability impacts whether infants encode surface features into their object representations

Infants encode the surface features of simple, unfamiliar objects (e.g., red triangle) and the categorical identities of familiar, categorizable objects (e.g., car) into their representations of these objects. We asked whether 16–18-month-olds ignore non-diagnostic surface features (e.g., color) in favor of encoding an object's categorical identity (e.g., car) when objects are from familiar categories. In Experiment 1 (n = 18), we hid a categorizable object inside an opaque box. In No Switch trials, infants retrieved the object that was hidden. In Switch trials, infants retrieved a different object: an object from a different category (Between-Category-Switch trials) or a different object from the same category (Within-Category-Switch trials). We measured infants' subsequent searching in the box. Infants' pattern of searching suggested that only infants who completed a Within-Category-Switch trial as their first Switch trial encoded objects' surface features, and an exploratory analysis suggested that infants who completed a Between-Category-Switch trial as their first Switch trial only encoded objects' categories. In Experiment 2 (n = 18), we confirmed that these results were due to objects' categorizability. These results suggest infants may tailor the way they encode categorizable objects depending on which object dimensions are perceived to be task relevant.     

Patterns of correlation between vehicle occupant seat pressure and anthropometry

Seat pressure is known as a major factor of seat comfort in vehicles. In passenger vehicles, there is lacking research into the seat comfort of rear seat occupants. As accurate seat pressure measurement requires significant effort, simulation of seat pressure is evolving as a preferred method. However, analytic methods are based on complex finite element modeling and therefore are time consuming and involve high investment. Based on accurate anthropometric measurements of 64 male subjects and outboard rear seat pressure measurements in three different passenger vehicles, this study investigates if a set of parameters derived from seat pressure mapping are sensitive enough to differentiate between different seats and whether they correlate with anthropometry in linear models. In addition to the pressure map analysis, H-Points were measured with a coordinate measurement system based on palpated body landmarks and the range of H-Point locations in the three seats is provided. It was found that for the cushion, cushion contact area and cushion front area/force could be modeled by subject anthropometry, while only seatback contact area could be modeled based on anthropometry for all three vehicles. Major differences were found between the vehicles for other parameters.     

The Accuracy of Respondent-Coded Occupation

This study reports results from a methodological experimentconducted in a national survey to test the accuracy of respondent-codedoccupation. For most uses, we conclude that such measures aresufficiently precise. There are, however, some systematic sourcesof error which the investigator should be aware of.     

Infants use contextual memory to attend and learn in naturalistic scenes

Infants encounter new objects and learn about object features in relation to a rich and detailed visuospatial context. Using a contextual cueing task, recent work showed that 6- and 10-month-old infants search more efficiently for target objects in repeated rather than novel visuospatial contexts (i.e., arrays of shapes on a blank background). Here, we investigate whether infants' sensitivity to visuospatial context scales up to more complex and potentially more distracting, naturalistic scenes. In an eye-tracking task, 8-month-olds searched for a novel target object in colorful photographs of everyday environments (e.g., bedrooms and kitchens). Repeated (“Old”) contexts co-varied with target locations, such that the target object appeared in exactly the same location on the same scene, while varying (“New”) contexts contained target objects placed in different counterbalanced locations across a variety of scenes. Infants exhibited faster search times, more anticipation of target animation, and longer looking at targets that appeared in Old relative to New contexts. In a subsequent memory test, infants showed better recognition of label-object pairings for target objects that had appeared in Old, rather than New, contexts. These results indicate that infants can use visuospatial contextual information in complex naturalistic scenes to facilitate memory-guided attention and learning of object-paired labels.     

MULTILEVEL COVARIANCE STRUCTURE ANALYSIS BY FITTING MULTIPLE SINGLE-LEVEL MODELS

Data in social and behavioral sciences are often hierarchically organized. Multilevel statistical procedures have been developed to analyze such data while taking into account the dependence of observations. When simultaneously evaluating models at all levels, a significant statistic provides no information on the level at which the model is misspecified. Model misspecification can exist at one or several levels simultaneously. When one level is misspecified, the other levels may be affected even when they are correctly specified. Motivated by these observations, we propose to separate a multilevel covariance structure into multiple single-level covariance structure models and to fit these single-level models as in conventional covariance structure analysis. A procedure for segregating the multilevel model into single-level models is developed. Five test statistics for evaluating a model at each level are provided. Standard error formulas for the separate estimators are also provided, and their efficiency is compared to simultaneous estimators. Empirical and Monte Carlo results demonstrate the advantages of the segregated procedure over the simultaneous procedure. Computer programs that will allow the developed procedure to be used in practice are also presented.     

How Watershed Immigration Policies Affect American Public Opinion Over a Lifetime

Important political events are known to influence political socialization and development (Green, Palmquist, and Schickler 2002 ). It is also possible that such events impact political socialization within particular age cohorts, and also across important social groups who may be impacted differently by landmark events. This paper examines whether landmark immigration events can leave a permanent mark on an individual's views toward immigrants and immigration, and whether that impact varies across different ethnic/racial groups in the United States Specifically, we examine the cohort of individuals who were in their formative years during the passage of major US immigration bills that were proposed or enacted from 1965 to 2010. Altogether, we focus on four pieces of landmark immigration legislation. The findings reveal variations on the effect of these events depending on the group in question; a relationship also emerges between these landmark legislative events and attitudes on immigration policies. The analysis contributes to an ongoing debate regarding the ways in which political elites influence attitudes, and we discuss how the findings may apply to other contexts outside the US.     

Pointing to Nothing? Empty Places Prime Infants' Attention to Absent Objects

People routinely point to empty space when referring to absent entities. These points to “nothing” are meaningful because they direct attention to places that stand in for specific entities. Typically, the meaning of places in terms of absent referents is established through preceding discourse and accompanying language. However, it is unknown whether nonlinguistic actions can establish locations as meaningful places, and whether infants have the capacity to represent a place as standing in for an object. In a novel eye‐tracking paradigm, 18‐month‐olds watched objects being placed in specific locations. Then, the objects disappeared and a point directed infants' attention to an emptied place. The point to the empty place primed infants in a subsequent scene (in which the objects appeared at novel locations) to look more to the object belonging to the indicated place than to a distracter referent. The place–object expectations were strong enough to interfere when reversing the place–object associations. Findings show that infants comprehend nonlinguistic reference to absent entities, which reveals an ontogenetic early, nonverbal understanding of places as representations of absent objects.     

Visual Attention Patterns Differ in Gynephilic and Androphilic Men and Women Depending on Age and Gender of Targets

Visual attention patterns measured with eye-tracking techniques provide indirect clues about sexual response. This study aimed to test the category specificity of sexual responses to stimuli varying in gender and age by evaluating both early and late attention of gynephilic and androphilic men and women. We simultaneously presented sexually preferred and nonpreferred stimuli and measured time to first fixation and total duration of fixation on four areas of interest: entire body, then face, chest, and pelvis. Androphilic women’s early attention patterns were nonspecific, whereas gynephilic women and both groups of men showed a category-specific pattern for the entire body. In contrast, all groups showed gender-specific patterns of late attention for all areas of interest. We also found support for age specificity of early and late visual attention in all four groups, with greater attention to adult than child stimuli. This study supports the usefulness of a competing stimulus eye-tracking paradigm as a method to examine gender specificity in gynephilic women and androphilic and gynephilic men, and as a measure of age specificity in gynephilic and androphilic men and women.     

Trajectory Discrimination and Peripersonal Space Perception in Newborns

The ability to discriminate the trajectories of moving objects is highly adaptive and fundamental for physical and social interactions. Therefore, we could reasonably expect sensitivity to different trajectories already at birth, as a precursor of later communicative and defensive abilities. To investigate this possibility, we measured newborns' looking behavior to evaluate their ability to discriminate between visual stimuli depicting motion along different trajectories happening within the space surrounding their body. Differently from previous studies, we did not take into account defensive reactions, which may not be elicited by impending collision as newborns might not categorize approaching stimuli as possible dangers. In two experiments, we showed that newborns display a spontaneous visual preference for trajectories directed toward their body. We found this visual preference when visual stimuli depicted motion in opposite directions (approaching vs. receding) as well as when they both moved toward the peripersonal space and differed only in their specific target (i.e., the body vs. the space around it). These findings suggest that at birth human infants seem to be already equipped with visual mechanisms predisposing them to perceive their presence in the environment and to adaptively focus their attention on the peripersonal space and their bodily self.     

Changes in body weight and fat mass of men and women in the first year of college: A study of the "freshman 15"

Students entering their first year of college are faced with many stresses and changes, including changes in eating and exercise behavior. A common but often undocumented myth among college students is that there is a high risk of gaining 15 pounds of weight during freshman year. The objective of this study was to measure changes in body weight and percentage of body fat among first-year college students. Using a digital scale with bio-electrical impedance, the authors measured height, weight, and percentage of body fat for a sample of students who volunteered to be weighed during a health assessment in the university dining halls. The authors sent e-mails inviting those same students to complete a second measurement in February of the academic year. Sixty-seven of the 217 students who volunteered for the health assessment agreed to undergo a second set of measurements in the spring. The mean change in body weight was 2.86 pounds (1.3 kg, SD = 4.0 kg), and the mean change in percentage of body fat was 0.7% (SD = 4.0%). For those students who gained weight only, the mean increase in body weight (as measured by body mass index, weight divided by height in kg/m2) was 6.82 pounds (3.1 +/- 2.4 kg) and percentage of body fat was 0.9 +/- 3.8%. The authors found that the first year of college is a period in which weight and fat gain may occur. The exact causes behind these changes are unclear and warrant further research to plan or improve intervention and prevention.     

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.