Processes of causal explanation and dispositional attribution.

Causal explanation and dispositional attribution are distinguished. Causal explanation involves giving an explanation for why a particular event occurred, whereas dispositional attribution involves learning about the characteristics of some entity. Moreover, it is proposed that production of causal explanations requires J. S. Mill's (1872/1973) method of difference, whereas production of dispositional attributions requires Mill's method of agreement. Exp 1 shows that both the method of difference and the method of agreement are used to make causal explanations. Experiments 1, 2, and 3 indicate that lay attributors consistently favor use of the method of agreement but not the method of difference to make dispositional attributions of both faciliatory and inhibitory characteristics. The distinction between causal explanation and dispositional attribution is used to organize seemingly contradictory findings and to provide an integrative framework for models of causal judgment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavior of Fe, Mn, Cu and Cd in the duwamish river estuary downstream of a sewage treatment plant

The behavior of dissolved Fe, Mn, Cu and Cd in the Duwamish River downstream of a sewage treatment plant located near Seattle, Washington, was investigated in three distinct zones: (1) immediately downstream of the effluent outfall, (2) further downstream in the freshwater portion of the river and (3) in the estuarine mixing zone. A three-end-member tracer model utilizing salinity and dissolved inorganic nitrogen was developed to distinguish physical mixing processes from biogeochemical reactions. The results of this investigation indicate that Fe was removed from the dissolved phase onto particulates near the plant. Although no additional reactions controlled the distribution of dissolved Fe, Mn and Cu in the freshwater portion of the river, Cd was removed from the dissolved phase. In the estuarine mixing zone, a significant fraction of the dissolved Fe and Cu was removed from solution, while Mn and Cd desorbed from particulates. The chemical forms of the trace metals rather than their sources appear to determine their participation in these reactions.     

Sre—a syntax recognizing editor

This paper presents a syntax-directed editor dubbed SRE, for syntax recognizing editor. Unlike other syntax-directed editors, SRE enables the user to edit programs with nearly the same natural and unrestrictive ease as a conventional text editor. In addition, it helps identify syntax errors and many typing errors before leaving the editor and attempting to compile a program. Programs are also formatted during entry, thereby providing immediate visual feedback of the recognized structure. The editor replaces the scanner/parser pass of a conventional compiler and thus reduces compilation time substantially.     

Thrifty execution of task pipelines

Summary A sequence of tasks that must be performed on a sequential database can be scheduled in various ways. Schedules will differ with respect to the number of accesses made to peripheral storage devices and the amount of memory space consumed by buffers. Buffer requirements are discussed for task schedules that avoid accesses to peripherals storing the sequential database. The relationship between certain thrifty scheduling policies and loop jamming, a standard code optimization technique, is also identified. Application to UNIX pipelines and to file processing is discussed.This work is supported in part by NSF Grant MCS-8003340 and MCS-8103605. Schneider is also supported by a Faculty Development Grant from IBM Corporation     

Family status, family constellation, and home environmental variables as predictors of cognitive performance of Mexican American children.

Examined the relative contributions of several family status variables (child and parental language, parental schooling attainment and location, and SES), a family constellation variable (family size), and the Henderson Environmental Learning Process Scale (HELPS) to the prediction of cognitive performance among 140 Mexican-American preschool children (aged 38–71 mo) from low-income backgrounds. Ss were administered the McCarthy Scales of Childrens' Abilities (MSCA). A factor analysis of the family status and constellation variables produced 3 factors. The General Cognitive Index (GCI) of the MSCA was predicted by multiple regression procedures. The 3 status/constellation factors and HELPS served as independent variables. As hypothesized, the best predictor of GCI was HELPS. A Language/Schooling factor made an additional significant contribution to the explained variance. The theoretical and practical implications of including proximal as well as distal background variables in future research on relations between family characteristics and intellectual performance are discussed. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A DIAGNOSTIC TEST FOR NONLINEAR SERIAL DEPENDENCE IN TIME SERIES FITTING ERRORS

Abstract. Time series analysts have begun to consider the applicability of nonlinear models. In order for nonlinear models to be accepted by practitioners, practicai tests must be avilable to test for the presence of nonlinearity in both raw time series and in the residuals from fitted models. A diagnostic test, based on the bispectrum, for the presence of nonlinear serial dependence in these time series is investigated here using artificial data. Detection of such nonlinear dependence is taken to indicate that nonlinear modelling methods are necessary. The theory behind the test is reviewed and simulations driven by pseudorandom numbers are presented for a variety of models and sample sizes. The simulations indicate that the test has substantial power for many models. In addition, theoretical and empirical results are presented which show that the bispectral diagnostic test is equally powerful for both the source series and for the fitting errors from a line& model. Thus, while the test is suitable for use as a diagnostic test on the fitting errors of linear time series models, prior linear modeling of the time series is not required.     

B lymphocytes are critical antigen-presenting cells for the initiation of T cell-mediated autoimmune diabetes in nonobese diabetic mice

Nonobese diabetic (NOD) mice genetically deficient in B lymphocytes (NODJg mu(null)) are resistant to T cell-mediated autoimmune insulin-dependent diabetes mellitus (IDDM). Ig infusions from diabetic NOD donors did not abrogate IDDM resistance in NODJg mu(null) mice. However, T cell responses to the candidate pancreatic beta cell autoantigen glutamic acid decarboxylase (GAD), but not the control Ag keyhole limpet hemocyanin, were eliminated in NODJg mu(null) mice. To initially test whether they contribute to IDDM as APC, NOD B lymphocytes were transferred into NODJg mu(null) recipients. B lymphocytes transferred into unmanipulated NODJg mu(null) recipients were rejected by MHC class I-restricted T cells. Stable T and B lymphocyte repopulation was achieved in irradiated NODJg mu(null) mice reconstituted with syngeneic bone marrow admixed with NOD B lymphocytes. IDDM susceptibility was restored in NODJg mu(null) mice reconstituted with syngeneic marrow plus B lymphocytes, but not with syngeneic marrow only. T cell responses to GAD were restored only in NODJg mu(null) mice reconstituted with syngeneic marrow plus B lymphocytes. Hence, B lymphocytes appear to contribute to IDDM in NOD mice as APC with a preferential ability to present certain beta cell Ags such as GAD to autoreactive T cells.     

Orthographic, phonological, and articulatory contributions to masked letter and word priming.

A series of experiments assessed masked priming for letters and words that are visually similar (SIM) and dissimilar (DIS) in upper- and lowercase formats. For letters, robust DIS priming was obtained in a naming task, but this priming did not extend to a variety of non-naming tasks. For words, robust DIS priming was obtained in both naming and non-naming tasks. SIM letter and word priming extended to all tasks, but the effects were generally small for letters. The restricted set of conditions for DIS letter priming suggests that this priming is mediated by phonological-articulatory processes, and the generality of DIS word priming argues that abstract orthographic codes mediate these effects. Consistent with this conclusion, priming between homophones (for both letters and words) was found in a naming task, but little word homophone priming was obtained in a lexical decision task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of small time-delays on the closed-loop stability of boundary control systems

It has been observed that for many stable feedback systems, the introduction of arbitrarily small time-delays into the loop causes instability. In this paper we present a systematic treatment of this phenomenon for a large class of boundary control systems which allows for in-span control. Our approach is based on a combination of input-output methods and modal analysis. We give a number of sufficient conditions for robustness/nonrobustness of closed-loop input-output stability with respect to delays. Our framework includes a large class of ill-posed systems, i.e., systems whose open-loop transfer function is unbounded on any right half-plane. We then analyze the relationship between the poles of the transfer function and the exponential modes of the underlying boundary-value problem to derive internal stability properties from external ones.This work was supported by the British Council/DAAD (ARC project 464), by the Human Capital and Mobility programme (Project number CHRX-CT93-0402), by the National Science Foundation (Grant DMS-9206986) and by NATO (Grant CRG 950179).