Phenolphthalein-containing laxative use in relation to adenomatous colorectal polyps in three studies.

Phenolphthalein, the active ingredient in many laxatives, was recently found to be a carcinogen in animal models. Human data suggest a laxative-colon cancer association, but few data specifically address the effects of phenolthalein-containing laxatives. We examined use of phenolphtalein-containing laxatives in relation to occurrence of adenomatous colorectal polyps in data from three case-control studies. The study conducted in Los Angeles, California (1991-1993), and the two studies conducted in North Carolina (1988-1990 and 1992-1995) altogether included 866 cases and 1,066 controls. The prevalence of using phenolphthalein-containing laxatives at least once a week in the recent past, however, was less than 5% among these subjects. The multivariate-adjusted odds ratios associated with recent use of phenolphthalein-containing laxatives once a week or more were 1.8 -95% confidence interval (CI), 0.5-6.2] in Los Angeles, 1.0 (CI, 0.4-2.2) in North Carolina (1988-1990), and 1.1 (CI, 0.2-5.7) in North Carolina (1992-1995). For use of other types of laxatives, the corresponding odds ratios were 1.3 (CI, 0.9-1.9) in Los Angeles, 1.0 (CI, 0.5-1.7) in North Carolina (1988-1990), and 0.9 (CI, 0.4-1.8) in North Carolina (1992-1995). Although the low prevalence of frequent use made for relatively wide confidence intervals, overall these data suggest that use of phenolphthalein-containing laxatives does not increase risk of adenomatous colorectal polyps

Signatures of quantum phase transitions in parallel quantum dots: Crossover from local-moment to underscreened spin-1 Kondo physics

We study a strongly interacting "quantum dot 1" and a weakly interacting "dot 2" connected in parallel to metallic leads. Gate voltages can drive the system between Kondo-quenched and non-Kondo free-moment phases separated by Kosterlitz-Thouless quantum phase transitions. Away from the immediate vicinity of the quantum phase transitions, the physical properties retain signatures of first-order transitions found previously to arise when dot 2 is strictly noninteracting. As interactions in dot 2 become stronger relative to the dot-lead coupling, the free moment in the non-Kondo phase evolves smoothly from an isolated spin-one-half in dot 1 to a many-body doublet arising from the incomplete Kondo compensation by the leads of a combined dot spin-one. These limits, which feature very different spin correlations between dot and lead electrons, can be distinguished by weak-bias conductance measurements performed at finite temperatures.Comment: 7 pages, 7 figures. Accepted for publication in Phys. Rev.

Childhood cancer mortality and radon concentration in drinking water in North Carolina.

We explored the association between groundwater radon levels and childhood cancer mortality in North Carolina. Using data from two state-wide surveys of public drinking water supplies, counties were ranked according to average groundwater radon concentration. Age and sex-adjusted 1950-79 cancer death rates among children under age 15 were calculated for counties with high, medium, and low radon levels. Overall cancer mortality was increased in counties with medium and high radon levels. The strongest association was for the leukaemias, but risks were also suggested for other sites. These associations could be due to confounding or other biases, but the findings are consistent with other recent reports

Phonon Rabi-assisted tunneling in diatomic molecules

We study electronic transport in diatomic molecules connected to metallic contacts in the regime where both electron-electron and electron-phonon interactions are important. We find that the competition between these interactions results in unique resonant conditions for interlevel transitions and polaron formation: the Coulomb repulsion requires additional energy when electrons attempt phonon-assisted interlevel jumps between fully or partially occupied levels. We apply the equations of motion approach to calculate the electronic Green's functions. The density of states and conductance through the system are shown to exhibit interesting Rabi-like splitting of Coulomb blockade peaks and strong temperature dependence under the it interacting resonant conditions.Comment: Updated version, 5 pages, 4 figures, to be published in Phys. Rev. B on 9/1

Evaluation of positive G sub Z tolerance following simulated weightlessness (bedrest)

The magnitude of physiologic changes which are known to occur in human subjects exposed to varying levels of + G sub Z acceleration following bed rest simulation of weightlessness was studied. Bed rest effects were documented by fluid and electrolyte balance studies, maximal exercise capability, 70 deg passive tilt and lower body negative pressure tests and the ability to endure randomly prescribed acceleration profiles of +2G sub Z, +3G sub Z, and +4G sub Z. Six healthy male volunteers were studied during two weeks of bed rest after adequate control observations, followed by two weeks of recovery, followed by a second two-week period of bed rest at which time an Air Force cutaway anti-G suit was used to determine its effectiveness as a countermeasure for observed cardiovascular changes during acceleration. Results showed uniform and significant changes in all measured parameters as a consequence of bed rest including a reduced ability to tolerate +G sub Z acceleration. The use of anti-G suits significantly improved subject tolerance to all G exposures and returned measured parameters such as heart rate and blood pressure towards or to pre-bed-rest (control) values in four of the six cases

Growth-related profiles of remanent flux in bulk melt-textured YBaCuO crystal magnetized by pulsed fields

We have studied the remanent magnetic flux distribution in bulk melt-textured YBa2Cu3O7 (YBCO) crystals after their magnetization in quasi-static and pulsed magnetic fields up to 6T. It has been shown that, provided that the magnetic pulse is sharp enough and its amplitude much exceeds the twice penetration magnetic field, the pulse magnetization technique becomes extremely sensitive to the sample inhomogeneities. Using this method with appropriate parameters of the magnetic pulse, we have particularly demonstrated that the growth of YBCO crystals in the growth sectors (GSs) responds for a macroscopic arrangement of weaks links -- they mostly appear inside of GSs, but not along the GS boundaries.Comment: 8 pages in LaTeX2e, 5 figures. Revised version, submitted to Supercond. Sci. Techno

Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man

Compositionality in the language of emotion

Emotions are signaled by complex arrays of face and body actions. The main point of contention in contemporary treatments is whether these arrays are discrete, holistic constellations reflecting emotion categories, or whether they are compositional-comprised of smaller components, each of which contributes some aspect of emotion to the complex whole. We address this question by investigating spontaneous face and body displays of athletes and place it in the wider context of human communicative signals and, in particular, of language. A defining property of human language is compositionality-the ability to combine and recombine a relatively small number of elements to create a vast number of complex meaningful expressions, and to interpret them. We ask whether this property of language can be discerned in a more ancient communicative system: intense emotional displays. In an experiment, participants interpreted a range of emotions and their strengths in pictures of athletes who had just won or lost a competition. By matching participants' judgements with minutely coded features of face and body, we find evidence for compositionality. The distribution of participants' responses indicates that most of the athletes' face and body features contribute to displays of dominance or submission. More particular emotional components related, for example, to positive valence (e.g. happy) or goal obstruction (e.g. frustrated), were also found to significantly correlate with certain face and body features. We propose that the combination of features linked to broader components (i.e, dominant or submissive) and to more particular emotions (e.g, happy or frustrated) reflects more complex emotional states. In sum, we find that the corporeal expression of intense, unfiltered emotion has compositional properties, potentially providing an ancient scaffolding upon which, millions of years later, the abstract and constrained compositional system of human language could build

Organic nanowires and chiral patterns of tetracyanoquinodimethane (TCNQ) grown by vacuum vapor deposition

Organic nanowires and quasi-two-dimensional chiral patterns of tetracyanoquinodimethane have been successfully generated by vacuum thermal evaporation. The nanowires and patterns were characterized by using atomic force microscopy and transmission electron microscopy. The influence of electric charged clusters, deposition rate, and substrate temperature were experimentally investigated. Contrary to previous reports, charged clusters are found to be unnecessary to the chiral pattern formation. It was shown that the nanowire and pattern formation should be mainly dominated by its special crystallization properties, though the effect of the growth conditions cannot be neglected.Comment: 4 pages, 4 figures, original draf