The relationship between blood lead, bone lead and child intelligence.

We report associations between serial measures of blood lead and intelligence in children age 10-12 years, half heavily exposed to lead from the prenatal period onward, and half relatively unexposed. For a subsample, we examine bone lead-IQ associations, comparing them with bone lead associations. Both blood and bone lead levels were associated with intelligence decrements, small relative to the contribution of social factors. For each doubling of Tib-Pb, Full Scale, Performance, and Verbal IQ decreased by an estimated 5.5, 6.2, and 4.1 points, respectively. Bone lead-IQ associations were stronger than those for blood lead, which nonetheless provide robust analogues. Current BPb, easy to obtain, provides a useful means for assessing Pb exposure/IQ associations.     

Studentized maximum root procedures for coherent analyses of two-factor fixed-effects designs

The authors provide generalizations of R. J. Boik's (1993) studentized maximum root (SMR) procedure that allow for simultaneous inference on families of product contrasts including simple effect contrasts and differences among simple effect contrasts in coherent analyses of data from 2-factor fixed-effects designs. Unlike the F-based simultaneous test procedures (STPs) proposed by M. A. Betz and K. R. Gabriel (1978) for coherent analyses allowing for inferences on all factorial contrasts, SMR STPs are designed for analyses where each contrast of interest is a product contrast, which is usually the case in analyses of data from factorial experiments. When both factors have more than 2 levels, SMR STPs always provide more power and precision than F STPs for inferences on product contrasts.     

The links between self-determined motivations and behavioral automaticity in a variety of real-life behaviors

The different motivations postulated by the Self-Determination Theory have proved to be meaningful to predict the level of engagement in a wide variety of life domains. The present research examines the relation between the different forms of self-determined motivation and behavioral automaticity of 12 behaviors associated with different life domains. Following 1743 measurements of self-determination (using a short version of the situational motivational scale, SIMS8), behavioral automaticity (using the self-reported behavioral automaticity index, SRBAI), and behavioral frequency (self-reported number of executions in a unit of time) for 12 various common behaviors collected on 315 young adults (M_age = 20.60?±?2.87 years) through an online survey, the results of crossed linear mixed models indicated that self-determined motivations are more associated with behavioral automaticity than non-self-determined motivations (intrinsic motivation: β?=?0.13, p?<?.001, identified extrinsic motivation: β?=?0.13, p?<?.001; external extrinsic motivation : β?=?0.08, p?<?.001; amotivation: β?=?0.02, p?=?.433). Furthermore, self-determination played a moderating role between the repetition of behaviors and behavioral automaticity (β?=?0.06, p?<?.002) suggesting that self-determination facilitated automatization, as high level of behavioral automaticity was achieved with less frequent behaviors when behaviors were performed for highly self-determined (β?=?0.41, p?<?.001) than weakly self-determined reasons (β?=?0.29, p?<?.001). The applications of these findings for learning and habit formation are discussed.     

Clients’ Perception of Outcome of Team-Based Prenatal and Reproductive Genetic Counseling in Serbian Service Using the Perceived Personal Control (PPC) Questionnaire

This is the first study in Serbia and the region of South-East Europe dedicated to clients’ perception of outcome and efficiency of prenatal and reproductive genetic counseling. The primary aim of this study was to assess overall value and success of genetic counseling in prenatal and reproductive care with regard to perceived personal control of clients, reflecting also in a part patient comprehension, knowledge retention, and empowerment in decision-making. The standardized Perceived Personal Control questionnaire (PPC) was used for the assessment of 239 female participants. First, we performed a complete validation of the psychometric characteristics of the Serbian-language version of the PPC questionnaire. The validation of the questionnaire permits other researchers from Serbian-speaking regions of South-East Europe to use this standard instrument to assess the effectiveness of prenatal genetic counseling in their communities and analyze advantages and disadvantages of their counseling models. We also measured social and demographic characteristics of participants. Further, we analyzed effects of our team-based prenatal and reproductive genetic counseling model through (a) calculation of PPC scores at three different stages (before initial, after initial, and before second counseling session), and (b) by assessing participants’ responses by indication for referral (advanced maternal age, abnormal biochemical screening, family history of hereditary disorders, maternal exposure to drugs, exposure to radiation, exposure to infective agents, infertility or recurrent abortions, and miscellaneous). The results indicate that participants’ knowledge after initial counseling increased significantly and after that remained stable and sustainable. A satisfactory level of confidence among participants had been achieved, in that many felt an increased sense of control over their situation and emotional response to it. Indirectly, these results indicate the success of a team-based prenatal genetic counseling model, which has not been assessed in the literature to date.     

Psychosocial and organic variables as predictors of lung cancer,cardiac infarct and apoplexy: Some differential predictors

In a longitudinal study started in 1965 in Crvenka (Yugoslavia), a number of psychosocial and organic variables were measured in 1353 Ss and related to the incidence of cancer, circulatory and other diseases in the subsequent 10-yr period by multivariate statistical methods. The present article reports on an attempt at differential prediction of lung cancer and cardiac infarct or apoplexy, which were selected because smoking is usually held to be a common risk factor for them. In a discriminant analysis (minimizing the overall classification error), 86–87% of the lung cancer and infarct/apoplexy cases could be predicted correctly, as well as 97% of the cases showing neither of the diseases. Some psychosocial variables like rationality and anti-emotionality or long-lasting hopelessness were about as relevant as the strongest organic predictors like level and variability of blood cholesterol.     

Selective and protracted effect of nifedipine on fear memory extinction correlates with induced stress response

Memory extinction, defined as a decrease of a conditioned response as a function of a non-reinforced conditioned stimulus presentation, has high biological and clinical relevance. Extinction is not a passive reversing or erasing of the plasticity associated with acquisition, but a novel, active learning process. Nifedipine blocks L-type voltage gated calcium channels (LVGCC) and has been shown previously to selectively interfere with the extinction, but not the acquisition, of fear memory. We studied here the effect of retrograde and anterograde shifts of nifedipine application, with respect to an extinction training, on the extinction of fear conditioning. Subcutaneous injection of 30 mg/kg nifedipine, at least up to 4 h before the extinction session, significantly impaired extinction, as did intraperitoneal injection of 15 mg/kg nifedipine, at least up to 2 h before extinction training. However, the injection of nifedipine also induced a strong and protracted stress response. The pharmacokinetics of nifedipine suggest that it was mainly this stress response that triggered the specific inhibition of extinction, not the blockade of LVGCC in the brain. Our results support recent findings that stress selectively interferes with the extinction, but not the acquisition, of fear memory. They also indicate that a pharmacological approach is not sufficient to study the role of brain LVGCC in learning and memory. Further research using specific genetically modified animals is necessary to delineate the role of LVGCC in fear memory extinction.