Group therapy with sexually abused boys: Notes toward managing behavior

This article examines the gender-specific defense mechanisms of sexually abused boys as they emerge in group therapy, using Finkelhor's model of traumagenic dynamics. Concrete interventions address the acting out behavious that are typical for this population, connecting the acting out behaviors to the boys' common background of sexual abuse. Without these concrete interventions to address the unsafe, aggressive behaviours of sexually abused boys, their problems and experiences cannot be shared, nor can the group therapist address the issues outlined in a curriculum for group therapy for sexually abused children.     

Social Class Differentials During Fertility Decline: England and Wales Revisited

This paper reviews the relationship between landholdings and fertility. Two dimensions of land are identified as salient for fertility behaviour: size of operational holdings and land ownership. It is suggested that these two dimensions and the resulting income streams have disparate effects on fertility. Size of holdings is assumed to have a positive influence on fertility due to the greater labour demands of larger holdings, while land ownership is posited to exert a negative long-term effect because of the increase in old-age security associated with the income returns to equity. In addition to these effects on the demand for children, landholding is also thought to influence the supply of children. A systematic review of the literature finds support for the impact of both dimensions of landholding on fertility preferences, contraceptive behaviour, the proximate determinants and fertility. Both the demand and supply of children appear to be influenced by landholdings. The observed regularities suggest the need for further research on this connection, not the abandonment of this line of inquiry.     

Estimates of above-ground tree carbon after projected land-use and land cover change in a subtropical urban watershed

Urban Ecosystems - This study investigates the effect of land-use and land cover (LULC) change on above-ground tree carbon (AGTC) in a subbasin of the Tampa Bay Watershed, Florida. LULC change was...     

Estimators for a simultaneous equation model with lagged endogenous variables and autocorrelated errors

Two full information estimators and a limited information estimator for the simultaneous equation model with autocorrelated errors are studies by the Monte Carlo method.The estimators share features of the two-step Gauss-Newton procedure and of Aitken generalized least squares.One full information method generates the estimated endogenous variables used in the later stages of computation from the unrestricted reduced form while the other uses a restricted reduced form.The observed small sample behavior was close to that suggested by asymptotic theory.     

Bootstrap tests for multivariate directional alternatives

Tests on multivariate means that are hypothesized to be in a specified direction have received attention from both theoretical and applied points of view. One of the most common procedures used to test this cone alternative is the likelihood ratio test (LRT) assuming a multivariate normal model for the data. However, the resulting test for an ordered alternative is biased in that the only usable critical values are bounds on the null distribution. The present paper provides empirical evidence that bootstrapping the null distribution of the likelihood ratio statistic results in a bootstrap test (BT) with comparable power properties without the additional burden of assuming multivariate normality. Additionally, the tests based on the LRT statistic can reject the null hypothesis in favor of the alternative even though the true means are far from the alternative region. The BT also has similar properties for normal and nonnormal data. This anomalous behavior is due to the formulation of the null hypothesis and a possible remedy is to reformulate the null to be the complement of the alternative hypothesis. We discuss properties of a BT for the modified set of hypotheses (MBT) based on a simulation study. The resulting test is conservative in general and in some specific cases has power estimates comparable to those for existing methods. The BT has higher sensitivity but relatively lower specificity, whereas the MBT has higher specificity but relatively lower sensitivity.     

An Evaluation of Conditional Manding Using a Four-Component Multiple Schedule

Most verbal behavior curricula for children with autism spectrum disorder (ASD) focus on teaching multiple mands during the early stages of training (e.g., picture exchange communication system; Bondy & Frost, 1994). However, few, if any, of those curricula train children with ASD to differentially mand only for reinforcers that are reasonable for a caregiver to deliver in a given context (e.g., mands to cuddle at bedtime) and to refrain from manding for reinforcers that would be inappropriate to deliver in that context (e.g., mands to play outside at bedtime). In this study, we first taught a boy with ASD two initial mands. Immediately thereafter we brought those mands under the conditional discriminative control of a four-component multiple schedule with (a) S¹ correlated with one reinforcer available (i.e., edibles), (b) S² correlated with both reinforcers available (i.e., edibles or drink), (c) S³ correlated with another reinforcer available (i.e., drink), and (d) S^Δ correlated with no reinforcer available. Following treatment, the child displayed conditionally discriminated manding in accordance with each of the four components of the schedule. We discuss these findings relative to the potential benefits of bringing mands under both evocative and discriminative control.

     

Bounds for the error in an approximation to the distribution of continuous random vectors with bounded supports

An approximation for the distributions of m-dimensional random variables with absolutely continuous cumulative distribution functions and bounded supports is presented. In addition, two easily computed bounds for the error in using the approximation rather than the actual distribution are provided for any measurable region.     

A semiparametric estimator of the distribution function of a variable measured with error

The estimation of the distribution functon of a random variable X measured with error is studied. Let the i-th observation on X be denoted by Y_iX_i+ε_i where ε_i is the measuremen error. Let {Y_i} (i=1,2,…,n) be a sample of independent observations. It is assumed that {X_i} and {∈_i} are mutually independent and each is identically distributed. As is standard in the literature for this problem, the distribution of e is assumed known in the development of the methodology. In practice, the measurement error distribution is estimated from replicate observations.

The proposed semiparametric estimator is derived by estimating the quantises of X on a set of n transformed V-values and smoothing the estimated quantiles using a spline function. The number of parameters of the spline function is determined by the data with a simple criterion, such as AIC. In a simulation study, the semiparametric estimator dominates an optimal kernel estimator and a normal mixture estimator for a wide class of densities.

The proposed estimator is applied to estimate the distribution function of the mean pH value in a field plot. The density function of the measurement error is estimated from repeated measurements of the pH values in a plot, and is treated as known for the estimation of the distribution function of the mean pH value.     

A Comparison of Unit-Root Test Criteria

During the past 15 years, the ordinary least squares estimator and the corresponding pivotal statistic have been widely used for testing the unit-root hypothesis in autoregressive processes. Recently, several new criteria, based on maximum likelihood estimators and weighted symmetric estimators, have been proposed. In this article, we describe several different test criteria. Results from a Monte Carlo study that compares the power of the different criteria indicate that the new tests are more powerful against the stationary alternative. Of the procedures studied, the weighted symmetric estimator and the unconditional maximum likelihood estimator provide the most powerful tests against the stationary alternative. As an illustration, the weekly series of one-month treasury-bill rates is analyzed.     

Hanging Out With Which Friends? Friendship‐Level Predictors of Unstructured and Unsupervised Socializing in Adolescence

Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship‐level data on over 5,000 middle schoolers. Adolescents hang out most with their most available friends and their most generally similar friends, not with their most at‐risk or similarly at‐risk friends. These findings vary little by gender and wave. Together, the findings suggest that the risks of hanging out stem from the nature of hanging out as an activity, not the nature of adolescents' companions, and that hanging out is a context for friends' mutual reinforcement of preexisting characteristics.