Sn-doped Bi1.1Sb0.9Te2S bulk crystal topological insulator with excellent properties.

A long-standing issue in topological insulator research has been to find a bulk single crystal material that provides a high-quality platform for characterizing topological surface states without interference from bulk electronic states. This material would ideally be a bulk insulator, have a surface state Dirac point energy well isolated from the bulk valence and conduction bands, display quantum oscillations from the surface state electrons and be growable as large, high-quality bulk single crystals. Here we show that this material obstacle is overcome by bulk crystals of lightly Sn-doped Bi1.1Sb0.9Te2S grown by the vertical Bridgman method. We characterize Sn-BSTS via angle-resolved photoemission spectroscopy, scanning tunnelling microscopy, transport studies, X-ray diffraction and Raman scattering. We present this material as a high-quality topological insulator that can be reliably grown as bulk single crystals and thus studied by many researchers interested in topological surface states.

Magnetic transitions and spin-glass reentrance in two-dimensional [MnII(TCNE)(NCMe)2]X (X = PF6,AsF6,SbF6) molecular magnets.

The structural, spectroscopic and magnetic properties of the two-dimensional (2D) molecule-based magnets of [Mn(II)(TCNE)(NCMe)2]X (X = PF6, AsF6, SbF6; TCNE = tetracyanoethylene, NCMe = acetonitrile) composition are reported. It is shown that the alteration of the interlayer distance by increasing the anion size has little effect on the critical magnetic ordering temperature, Tc, suggesting that it depends predominantly on the intra-plane magnetic exchange. The observed field-induced irreversibility in static magnetization, a slow decay of isothermal remanence below Tc, and the dynamic susceptibility data are in accord with a re-entrant spin-glass nature of the ground state of all materials. In contrast to the isostructural Fe-based magnets, in which strong magnetocrystalline anisotropy facilitates the finite temperature magnetic ordering with the magnetization easy axis perpendicular to the µ4-TCNE(•-) plane, in the studied Mn-based magnets the easy axis is canted away from the normal direction, due to a small magnetocrystalline anisotropy. The two magnetic transitions observed on cooling are assigned to the ferrimagnetic long-range ordering of the normal magnetization component followed by the re-entrant spin-glass type transition resulting from a random freezing of the in-plane magnetization component.

The effects of temperature and dissolved oxygen on antioxidant defences and oxidative damage in the fathead minnow Pimephales promelas.

Fathead minnows Pimephales promelas maintained at 25° C for 6 h had significantly higher superoxide dismutase (SOD) activity than fish maintained at 7 or 32° C, but hypoxic conditions (3 mg l(-1) O2 ) over the same time period did not affect SOD activity. Fish in better body condition (length-adjusted mass) had higher SOD activity. In a separate experiment, P. promelas maintained at three water temperatures (7, 23 and 32° C) for 31 days did not differ in liver acrolein, a biomarker of oxidative stress.

Social behavior and off-target verbosity in elderly people.

This study investigated social behavior in older adults with varying levels of off-target verbosity (OTV). After screening 455 adults in Phase 1, 198 individuals were selected to participate in both a get-acquainted conversation and an experimental cues situation and to complete social and cognitive measures. Higher OTV participants had lower cognitive inhibitory scores, talked more, were less interested in their partners, and focused more on themselves. Their conversational partners were less satisfied. Age and cognitive functioning were not related to OTV scores or conversational style for low- and mid-range participants. Although high-OTV individuals talked less when exposed to social cues signalling boredom, they spoke more relative to other participants. Self-reported social behavior had little relation with OTV and conversational style, but higher OTV individuals were less accurate in judging videotaped social interactions. Gender differences in conversational behavior are also discussed.

Measurement of lifetime alcohol consumption.

The reliability and validity of a retrospective, self-report measure, the Concordia Lifetime Drinking Questionnaire (CLDQ), were assessed with a group of 72 elderly Canadian men. The CLDQ includes quantity and frequency questions on current beverage-specific alcohol use and a series of questions about the start of alcohol use. The innovative features of the CLDQ include requiring subjects to collaborate with the interviewer in drawing a graph that represents their lifetime drinking patterns and encouraging more accurate recall by the use of salient events in the subject's life history. Drinking was assessed on two occasions approximately 33 months apart. Forty-six wives responded to questions about their husband's drinking. The reliability coefficient for lifetime drinking was .78. A comparison of the two graphs every fifth year from 1945 to 1985 yielded significant correlations that ranged from .65 to .87. Validity was tested by comparing each wife's rating of her husband's drinking at present and at time of marriage with similar points on the husband's graphs; the correlations were .87 and .72, respectively. Moderate correlations were obtained between the MAST and the CLDQ. The CLDQ was judged to be a reliable and valid measure of lifetime drinking, appropriate for use with the elderly. The longitudinal lifetime drinking patterns appeared similar to those found in cross-sectional studies.

Adult age differences in memory in relation to availability and accessibility of knowledge-based schemas.

Three experiments investigated whether, over adulthood, the use of schemas to process and remember new information increases (developmental shift hypothesis), decreases (production deficiency hypothesis) or remains constant (age-invariance hypothesis). Effects of schema access were studied by having young, middle-aged, and old music experts and nonexperts recall information that was relevant or irrelevant to music (Experiment 1) and by comparing young and old participants' memory for prose passages when they knew or did not know the subject of the passage (Experiments 2 and 3). In each case, schema access facilitated memory equally across age levels, supporting the age-invariance hypothesis and implying that the basic structures and operations of memory do not necessarily change with age. Possible limits on the independence of age and schema utilization were considered in relation to the conditions under which each of the two alternative hypotheses might hold.

Hibernoma: report of two cases.

Hibernomas are rare tumors of fat which are most often benign. Arteriographic fingings may be misleading with respect to the diagnosis of malignancy preoperatively. These uncommon tumors may be confused prior to surgery with lipomas, soft tissue sarcomas, and hemangiomas.

The tricho system: hypertrichosis, radiation, and cancer.

Five women in their 6th to 8th decades were treated for facial hypertrichosis in Erie, Pennsylvania, 30 to 40 years ago. The epilations were performed with an X-ray device called "Tricho System," which was manufactured, sold, and proclaimed safe by its physician-inventor. The beauty shop operator who administered these treatments may or may not have received "instruction" by the company in the operation of the equipment. At varying intervals, each of the 5 women developed radiodermatitis and basal cell and/or squamous cell carcinoma at the sites of epilation. All presented to the plastic surgical service at the Hamot Medical Center in Erie, Pennsylvania. Two underwent massive radical resective surgery, 2 required extensive excision and resurfacing, and 1 refused resective surgery although she had had a previous surgical attempt 17 years earlier. Case histories are presented in detail. This series is representative of the epidemic nature of Tricho-System-induced disease.