On monotonicity of regression quantile functions

In the linear regression quantile model, the conditional quantile of the response, Y, given x is QY|x(τ)≡x′β(τ). Though QY|x(τ) must be monotonically increasing, the Koenker–Bassett regression quantile estimator, View the MathML source, is not monotonic outside a vanishingly small neighborhood of View the MathML source. Given a grid of mesh δn, let View the MathML source be the linear interpolation of the values of View the MathML source along the grid. We show here that for a range of rates, δn, View the MathML source will be strictly monotonic (with probability tending to one) and will be asymptotically equivalent to View the MathML source in the sense that n1/2 times the difference tends to zero at a rate depending on δn

Examining Children’s Cognitions in Response to Interparental Conflict

Extensive research has found that interparental conflict is associated with children’s adjustment and cognitive appraisals. This study aims to address two questions. First, does exposure to interparental conflict predict children’s immediate and long-term cognitions regarding interparental conflict? Second, do children’s immediate and long-term cognitions predict internalizing problems, such as anxiety and depression? Children ages 9- to 11-years-old (n = 96; 59 females, 1 gender-neutral) were shown video presentations of conflict between two actors portraying a married couple. Children evaluated the actors’ behaviors as good or bad, and these evaluations were used as a measure of their immediate cognitions regarding interparental conflict stimuli. These immediate cognitions were compared to measures of children’s long-term cognitions regarding interparental conflict, exposure to interparental conflict, and internalizing problems using bivariate correlation and simple regression analyses. In contrast to the hypotheses, more exposure to interparental conflict did not predict immediate or long-term cognitions, nor did immediate or long-term cognitions predict children’s internalizing problems. Implications for future studies comparing immediate and long-term cognitions are discussed

M-estimation of multivariate regressions

Includes bibliographical references (p.19-20)

A Partially Linear Censored Quantile Regression Model for Unemployment Duration

Censored Regression Quantile (CRQ) methods provide a powerful and flexible approach for the analysis of censored survival data when standard linear models are felt to be appropriate. In many cases however, greater flexibility is desired to go beyond the usual multiple regression paradigm. One area of common interest is that of partially linear models, where one (or more) of the explanatory variables are assumed to act on the response through a non-linear function. Here the CRQ approach (Portnoy, 2003) is extended to such partially linear setting. Basic consistency results are presented. A simulation experiment and analysis of unemployment data example justify the use of the partially linear approach over methods based on the Cox proportional hazards regression model and methods not permitting nonlinearity.quantile regression ; partially linear models ; B-splines ; censored data ; unemployment duration

Insulated ECG electrodes

Insulated, capacitively coupled electrode does not require electrolyte paste for attachment. Other features of electrode include wide range of nontoxic material that may be employed for dielectric because of sputtering technique used. Also, electrode size is reduced because there is no need for external compensating networks with FET operational amplifier

Insulated electrocardiographic electrodes

An integrated system is disclosed including an insulated electrode and an impedance transformer which can be assembled in a small plastic housing and used for the acquisition of electrocardiographic data. The electrode may be employed without a paste electrolyte and may be attached to the body for extended usage without producing skin reaction. The electrode comprises a thin layer of suitable nontoxic dielectric material preferably deposited by radio frequency sputtering onto a conductive substrate. The impedance transformer preferably comprises an operational amplifier having an FET input stage connected in the unity gain configuration which provides a very low lower cut-off frequency, a high input impedance with a very small input bias current, a low output impedance, and a high signal-to-noise ratio

The development of insulated electrocardiogram electrodes

An integrated system was developed, consisting of an insulated electrode and an impedance transformer, which can be used for the acquisition of electrocardiographic data. The electrode consists of a thin layer of dielectric material deposited onto a silicon substrate. The impedance transformer is an operational amplifier used in the unity gain configuration. Both electrode and impedance transformer are contained in a plastic housing identical to that used with the NASA Apollo-type electrode. The lower cut off frequency of the electrode system is between 0.01 and 1.0 Hz, depending on the dielectric used and its thickness. Clinical quality electrocardiograms were obtained with these electrodes

From phonetics to phonology : The emergence of first words in Italian

This study assesses the extent of phonetic continuity between babble and words in four Italian children followed longitudinally from 0; 9 or 0; 10 to 2;0-two with relatively rapid and two with slower lexical growth. Prelinguistic phonetic characteristics, including both (a) consistent use of specific consonants and (b) age of onset and extent of consonant variegation in babble, are found to predict rate of lexical advance and to relate to the form of the early words. In addition, each child's lexical profile is analyzed to test the hypothesis of non-linearity in phonological development. All of the children show the expected pattern of phonological advance: 'Relatively accurate first word production is followed by lexical expansion, characterized by a decrease in accuracy and an increase of similarity between word forms. We interpret such a profile as reflecting the emergence of word templates, a first step in phonological organization