An Acute Stressor Enhances Sensitivity to a Chemical Irritant and Increases 51CrEDTA Permeability of the Colon in Adult Rats

We investigated the effect of prior acute stress on colonic permeability induced by a chemical irritant known to induce symptoms similar to inflammatory bowel disease in rodents. Adult male rats (n = 12) were stressed by a single session of ten unpredictable, uncontrollable foot shocks, and half were home cage controls (n = 12). Twenty-nine days later, half of each treatment group was exposed to 4% DSS (dextran sulphate sodium) solution in their drinking water for 48 hours while half received pure water over two periods separated by 17 days. After food deprivation overnight and light isoflurane anaesthesia the following morning, the animals were given a colonic infusion of 2000 nCi (nanocurie) 51CrEDTA (51Cr-labelled ethylenediaminetetraacetic acid) and then placed individually in metabolic cages for a six hours continuous urine collection. Radioactivity in urine was measured by a gamma counter and percentage recovery of 51CrEDTA calculated as an indicator of colonic mucosal permeability. Results concluded that pre-shocked animals exposed to DSS showed significantly higher mucosal permeability than the pre-shocked animals given water, and the non-shocked animals given either DSS or water. Pre-shock in combination with two exposures to a chemical irritant separated by 17 days had a pronounced effect on colonic permeability, indicating that stress should be considered a possible initiating or contributory factor to increased intestinal permeability related to a mucosal challenge.     

Psychological stress reactivates dextran sulfate sodium-induced chronic colitis in mice

Inflammatory bowel disease (IBD) is a chronic condition with alternating active and quiescent phases of inflammation. Stress has been suggested as a factor triggering a relapse of IBD. We investigated the role of repetitive psychological stress [water avoidance stress (WAS)] in reactivating colonic inflammation in a murine model of dextran sulfate sodium (DSS)-induced chronic colitis. Colitis was induced in C57BL/6 female mice by exposure to 3% DSS (5 days). During chronic inflammation(day 34), mice underwent repetitive WAS (1 h/day/7 days) and were given a sub-threshold concentration of DSS (1%, 5 days)or normal water to drink. At euthanasia (day 40), inflammatory parameters were assessed (colon inflammatory score, levels of inflammatory markers and histology). Mice with chronic colitis exposed to WAS had higher macroscopic and microscopic colonic inflammatory scores and levels of inflammatory markers (mainly IL-1beta, IL12p40 and CCL5) than non-stressed mice. Inflammatory responses were further enhanced by the presence of a sub-threshold concentration of DSS (1%). In mice without chronic inflammation, neither WAS nor 1% DSS, individually or in combination, elicited any inflammation. Hence stress, per se, reactivates a quiescent chronic inflammation, but does not initiate inflammation in healthy mice. Stress should be regarded as an environmental factor triggering IBD relapses in humans.     

Children's recall and the cognitive interview: do the positive effects hold over time?

Most studies investigating how the Cognitive Interview affects children's recall have employed short retention intervals (a week or less). In our study children (10–11 years old) saw a film picturing an extraordinary performance by a professional fakir. Half of the children were interviewed after seven days (n = 24) and the other half after six months (n = 25). At each test session, half were interviewed according to the Cognitive Interview (CI), and half according to the Structured Interview (SI). We found that: (a) the children in the CI condition recalled significantly more correct information than the children in the SI condition (both after seven days and after six months), and (b) the children interviewed after seven days recalled significantly more correct information, and less confabulations, compared to the children interviewed after six months. The results suggest that the CI can be used as an investigative tool both after short and long retention intervals. Copyright © 2002 John Wiley & Sons, Ltd.     

Alexithymia and relaxation: Considerations in optimising the emotional effectiveness of journaling about stressful experiences

The emotional benefits of pairing a brief relaxation with journaling about a stressful event were considered through an experimental design, with alexithymia included as a potential moderator. Participants (n=217) were randomly assigned to a full treatment group (n=54), relaxation-only group (n=57), journaling-only group (n=51), or control group (n=55). The results indicated an interaction, with high-alexithymic participants in the full treatment group reporting increased levels of emotional distress several days after writing. The hypothesis that preceding journaling with a relaxation would be beneficial for non-alexithymic participants was not supported. These findings contribute to the ongoing examination of how best to optimise the effectiveness of journaling. They also lend support to the importance of including alexithymia as a moderator variable in future journaling research.     

Development and Psychometric Characteristics of the Dissociation Tension Scale

The newly developed Dissoziations-Spannungs-Skala (Dissociation Tension Scale; DSS) is a self-rating instrument for the assessment of psychological and somatoform dissociative features (ranging from normal up to pathological) as well as aversive inner tension occurring within the past 7 days. The DSS contains 21 items assessing dissociative symptoms and 1 additional item assessing aversive inner tension. Ratings are made on a time-oriented scale ranging from 0% (never) to 100% (constantly). We measured the psychometric qualities of the DSS in a total of 294 patients and healthy controls. Internal consistency of the DSS was high (Cronbach's α = .92; Gutmann's split-half r = .92). We found good support for convergent, discriminant, and differential validity. There was clear evidence for the DSS being a sensitive instrument for the assessment of changing symptomatology. Assessment of dissociation and other psychopathological features over the same period of time are now possible.     

Rotation of Water in the Morris Water Maze Interferes with Path Integration Mechanisms of Place Navigation

The idea that place navigation in the Morris water maze is implemented by path integration between locations determined by landmark sighting was investigated in a 200-cm-diameter pool in which circular (7.2°/s) motion of water could be induced by tangentially arranged water jets. The rats were trained at 8 trials per day to navigate to an erectable platform which was raised after the rat had spent a criterion time in the target annulus (30 cm in diameter) in the midpoint of the NW quadrant. Asymptotic escape latency of 7 s was reached after 9 days in moving water (n= 8) and after 6 days in stationary water (n= 8). The group overtrained for 13 days in stable water performed well even after it was transferred to moving water. Changing the sense of rotation of water from counterclockwise to clockwise did not affect the asymptotic performance. The above findings show that overtrained rats rely on landmark sighting rather than on path integration. The influence of water movement reappeared when place navigation to a new target (SW) was examined in alternating 2-s periods of light (L) and darkness (D). On the first day, the latencies were 15.2 ± 1.2 and 22.8 ± 1.9 s in stable and moving water, respectively, but dropped to 10 s on the following day. The tracks generated in the L period were more tortuous than those generated in the D period and this difference was more pronounced in moving than in stable water. It is concluded that path integration mechanisms supporting navigation during intervals of darkness are impaired in moving water but that this impairment disappears in overtrained animals.     

Some necessary conditions for common-factor analysis

LetR be any correlation matrix of ordern, with unity as each main diagonal element. Common-factor analysis, in the Spearman-Thurstone sense, seeks a diagonal matrixU ² such thatG = R – U ² is Gramian and of minimum rankr. Lets ₁ be the number of latent roots ofR which are greater than or equal to unity. Then it is proved here thatr s ₁. Two further lower bounds tor are also established that are better thans ₁. Simple computing procedures are shown for all three lower bounds that avoid any calculations of latent roots. It is proved further that there are many cases where the rank of all diagonal-free submatrices inR is small, but the minimum rankr for a GramianG is nevertheless very large compared withn. Heuristic criteria are given for testing the hypothesis that a finiter exists for the infinite universe of content from which the sample ofn observed variables is selected; in many cases, the Spearman-Thurstone type of multiple common-factor structure cannot hold.This research was made possible in part by an uncommitted grant-in-aid from the Behavioral Sciences Division of the Ford Foundation.     

The Dimensions of Stress Scale: Psychometric Properties1

Although cognitive appraisal, situational properties, and attributions are important parts of the stress process, few multidimensional measures are available to examine these constructs simultaneously. This paper investigates the properties of the Dimensions of Stress Scale (DSS). The DSS is a brief self-report questionnaire designed to assess appraisals of personal relevance (salience) and control; stressor properties (novelty, duration, and predictability); and self-attributions (causality). The items were derived theoretically, using the cognitive-phenomenological model of stress and the stress literature. Empirical support for the six dimensions (scales) was generated first on a sample of elderly individuals (n= 269) and then replicated on an independent sample of younger individuals (n= 162). In both investigations, the factor structure of five of the scales was shown to approximate a simple structure. Evidence of internal consistency and content validity was also provided. The scales’ construct validity was supported by their relationships with stressor type (e. g., physical health problems, relationships, work, finances, individuals with indeterminate Western Blots, and caregivers of patients with Alzheimer's disease), coping, and depressed mood. The DSS should be useful in examining stressful experiences.     

A multistage ranking model

In this paper, we propose a (n–1)² parameter, multistage ranking model, which represents a generalization of Luce's model. We propose then×n item-rank relative frequency matrix (p-matrix) as a device for summarizing a set of rankings. As an alternative to the traditional maximum likelihood estimation, for the proposed model we suggest a method which estimates the parameters from thep-matrix. An illustrative numerical example is given. The proposed model and its differences from Luce's model are briefly discussed. We also show some specialp-matrix patterns possessed by the Thurstonian models and distance-based models.     

Recognition memory of retrieved sequences of words

The subject was asked to retrieve words belonging to a given category, natural or artificially created. After n words were retrieved, a recognition task was given either immediately after or after a delay (4 hours, 7, 14, or 28 days). Several probe words were presented and the subject had to decide whether each had been retrieved or not. The length of retrieval sequence, n, was systematically varied. Results of three experiments showed that, in general, mean decision time was almost independent of n. Namely, recognition regarding self-generated lists of words seems to be due to a different information processing than recognition regarding lists of words presented by the experimenter to memorize. Implications of the findings for retrieval from long term memory were discussed.     

Bias in Estimation of Misclassification Rates

When a simple random sample of size n is employed to establish a classification rule for prediction of a polytomous variable by an independent variable, the best achievable rate of misclassification is higher than the corresponding best achievable rate if the conditional probability distribution is known for the predicted variable given the independent variable. In typical cases, this increased misclassification rate due to sampling is remarkably small relative to other increases in expected measures of prediction accuracy due to samplings that are typically encountered in statistical analysis. This issue is particularly striking if a polytomous variable predicts a polytomous variable, for the excess misclassification rate due to estimation approaches 0 at an exponential rate as n increases. Even with a continuous real predictor and with simple nonparametric methods, it is typically not difficult to achieve an excess misclassification rate on the order of n ⁻¹. Although reduced excess error is normally desirable, it may reasonably be argued that, in the case of classification, the reduction in bias is related to a more fundamental lack of sensitivity of misclassification error to the quality of the prediction. This lack of sensitivity is not an issue if criteria based on probability prediction such as logarithmic penalty or least squares are employed, but the latter measures typically involve more substantial issues of bias. With polytomous predictors, excess expected errors due to sampling are typically of order n ⁻¹. For a continuous real predictor, the increase in expected error is typically of order n ^−2/3     

OPIOID ABSTINENCE REINFORCEMENT DELAYS HEROIN LAPSE DURING BUPRENORPHINE DOSE TAPERING

A positive reinforcement contingency increased opioid abstinence during outpatient dose tapering (4, 2, then 0 mg/day during Weeks 1 through 3) in non‐treatment‐seeking heroin‐dependent volunteers who had been maintained on buprenorphine (8 mg/day) during an inpatient research protocol. The control group (n = 12) received $4.00 for completing assessments at each thrice‐weekly visit during dose tapering; 10 of 12 lapsed to heroin use 1 day after discharge. The abstinence reinforcement group (n = 10) received $30.00 for each consecutive opioid‐free urine sample; this significantly delayed heroin lapse (median, 15 days).     

The Effects of Novel Stimuli on Water Ingestion in Bobwhite Quail (Colinus Virginianus)

Fifteen adult bobwhite quail (Colinus virginianus) were exposed to a series of single- and two-bottle preference tests in order to evaluate sensory sensitivity, habituation, and the effect of novelty. Control animals were exposed only to distilled water to provide a baseline whereas experimental birds were presented colored or flavored water in corresponding, counterbalanced test sequences. Although the initial presentation of a novel color or flavor led to a marked reduction in intake, subsequent presentations of color, but not flavor, led to rapid habituation. Implications of the strength of avoidance of gustatory stimuli are discussed.

     

On finite linear intermediate predicate logics

An intermediate predicate logicS ₊ ⁿ (n>0) is introduced and investigated. First, a sequent calculusGS _n is introduced, which is shown to be equivalent toS ₊ ⁿ and for which the cut elimination theorem holds. In § 2, it will be shown thatS ₊ ⁿ is characterized by the class of all linear Kripke frames of the heightn.To the memory of the late Professor Iwao Nishimura     

A central limit theorem for families of stochastic processes indexed by a small average step size parameter,and some applications to learning models

Let > 0 be a measure of the average step size of a stochastic process {p _n ⁽⁾ } _n=1 ⁽⁾. Conditions are given under whichp _n ⁽⁾ is approximately normally distributed whenn is large and is small. This result is applied to a number of learning models where is a learning rate parameter andp _n ⁽⁾ is the probability that the subject makes a certain response on thenth experimental trial. Both linear and stimulus sampling models are considered.     

Concept Shift and the Development of the Concept of Class in Children

The authors compared parent-related perceptions by hospitalized adolescents (i.e., who were admitted to a specialized psychiatric unit; n = 50) and delinquent adolescents (i.e., who were placed at a juvenile treatment institution; n = 51) with adolescents from the general population (n = 51). All adolescents completed a broad set of measures of attachment, perceived parenting, and separation–individuation. Contrary to initial expectations, hospitalized adolescents scored higher than controls on indices of excessive autonomy. Ambivalence regarding issues of interpersonal closeness and distance was found among delinquent adolescents. In addition, hospitalized and delinquent adolescents were found to be struggling, each in their specific way, with attachment-related experiences of trauma. Finally, delinquent adolescents also showed a stage-appropriate form of potentially adaptive narcissism. These findings add to the growing consensus in the literature that associations between adolescent psychopathology and parent-related perceptions are typically complex and somewhat counterintuitive.     

The impact of adjacent-dependencies and staged-input on the learnability of center-embedded hierarchical structures

A theoretical debate in artificial grammar learning (AGL) regards the learnability of hierarchical structures. Recent studies using an AⁿBⁿ grammar draw conflicting conclusions (Bahlmann and Friederici, 2006 and [De Vries et al., 2008] ). We argue that 2 conditions crucially affect learning AⁿBⁿ structures: sufficient exposure to zero-level-of-embedding (0-LoE) exemplars and a staged-input. In 2 AGL experiments, learning was observed only when the training set was staged and contained 0-LoE exemplars. Our results might help understanding how natural complex structures are learned from exemplars.     

Uniform Test Assembly

In educational practice, a test assembly problem is formulated as a system of inequalities induced by test specifications. Each solution to the system is a test, represented by a 0–1 vector, where each element corresponds to an item included (1) or not included (0) into the test. Therefore, the size of a 0–1 vector equals the number of items n in a given item pool. All solutions form a feasible set—a subset of 2 ⁿ vertices of the unit cube in an n-dimensional vector space. Test assembly is uniform if each test from the feasible set has an equal probability of being assembled. This paper demonstrates several important applications of uniform test assembly for educational practice. Based on Slepian’s inequality, a binary program was analytically studied as a candidate for uniform test assembly. The results of this study establish a connection between combinatorial optimization and probability inequalities. They identify combinatorial properties of the feasible set that control the uniformity of the binary programming test assembly. Computer experiments illustrating the concepts of this paper are presented.     

Anti-intuitionism and paraconsistency

This paper aims to help to elucidate some questions on the duality between the intuitionistic and the paraconsistent paradigms of thought, proposing some new classes of anti-intuitionistic propositional logics and investigating their relationships with the original intuitionistic logics. It is shown here that anti-intuitionistic logics are paraconsistent, and in particular we develop a first anti-intuitionistic hierarchy starting with Johansson's dual calculus and ending up with Gödel's three-valued dual calculus, showing that no calculus of this hierarchy allows the introduction of an internal implication symbol. Comparing these anti-intuitionistic logics with well-known paraconsistent calculi, we prove that they do not coincide with any of these. On the other hand, by dualizing the hierarchy of the paracomplete (or maximal weakly intuitionistic) many-valued logics (Iⁿ)_nω we show that the anti-intuitionistic hierarchy (I^n*)_nω obtained from (Iⁿ)_nω does coincide with the hierarchy of the many-valued paraconsistent logics (Pⁿ)_nω. Fundamental properties of our method are investigated, and we also discuss some questions on the duality between the intuitionistic and the paraconsistent paradigms, including the problem of self-duality. We argue that questions of duality quite naturally require refutative systems (which we call elenctic systems) as well as the usual demonstrative systems (which we call deictic systems), and multiple-conclusion logics are used as an appropriate environment to deal with them.     

Abstract modal logics

In this paper we develop a general framework to deal with abstract logics associated with a given modal logic. In particular we study the abstract logics associated with the weak and strong deductive systems of the normal modal logicK and its intuitionistic version. We also study the abstract logics that satisfy the conditionC ⁺(X)=C( _in I ⁿ X) and find the modal deductive systems whose abstract logics, in addition to being classical or intuitionistic, satisfy that condition. Finally we study the deductive systems whose abstract logics satisfy, in addition to the already mentioned properties, the property that the operatorC ⁺ is classical relative to some new defined operations.Work partially supported by Spanish DGICYT grant PB90-0465-C02-01.Presented byJan Zygmunt