Large-scale heterochromatin remodeling linked to overreplication-associated DNA damage.

Previously, we have shown that loss of the histone 3 lysine 27 (H3K27) monomethyltransferases ARABIDOPSIS TRITHORAX-RELATED 5 (ATXR5) and ATXR6 (ATXR6) results in the overreplication of heterochromatin. Here we show that the overreplication results in DNA damage and extensive chromocenter remodeling into unique structures we have named "overreplication-associated centers" (RACs). RACs have a highly ordered structure with an outer layer of condensed heterochromatin, an inner layer enriched in the histone variant H2AX, and a low-density core containing foci of phosphorylated H2AX (a marker of double-strand breaks) and the DNA-repair enzyme RAD51.

Open and closed: the roles of linker histones in plants and animals.

Histones package DNA in all eukaryotes and play key roles in regulating gene expression. Approximately 150 base pairs of DNA wraps around an octamer of core histones to form the nucleosome, the basic unit of chromatin. Linker histones compact chromatin further by binding to and neutralizing the charge of the DNA between nucleosomes.

Age modifies the response to recombinant human thyrotropin.

Background: A standardized protocol is used to administer recombinant human thyrotropin (rhTSH) in preparation for diagnostic studies and treatment in patients with thyroid cancer. The expectation is that serum TSH concentrations will peak on the day after the second injection and will be sufficiently elevated to stimulate uptake of radioiodine. We wished to test the hypothesis that TSH concentrations achieved after rhTSH injection are influenced by age.

Age and the thyrotropin response to hypothyroxinemia.

Context: Some studies suggest altered pituitary functioning and TSH production with aging.

Objective: Our objective was to test the hypothesis that less TSH production occurs despite comparable hypothyroxinemia with advancing age.

Design: We retrospectively studied adult outpatients of all ages with confirmed hypothyroidism and documented their TSH and free T4 concentrations.

Combination pharmacotherapy with incretins: what works best and when?

The incretin hormone glucagon-like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors fill an unaddressed therapeutic gap in the treatment of type 2 diabetes mellitus (T2DM) by potentiating insulin secretion in pancreatic beta cells, suppressing glucagon secretion, delaying gastric emptying, and reducing appetite. The incretin therapies, alone or in combination with metformin and/or thiazolidinediones, yield improved glycemic control without risk of hypoglycemia and the potential for weight neutrality or even weight loss. New incretin-based approaches offer promising new strategies for treating T2DM by recruiting new, physiologically based mechanisms of action for glucoregulation in the context of a favorable safety profile.

Habituation of male sexual arousal: effects of attentional focus.

Three experiments are reported demonstrating that levels of penile tumescence and subjective sexual arousal are greater when men employ participant-oriented rather than spectator-oriented attentional focus while viewing an erotic film segment. Under each instructional set, there was a reduction in sexual arousal during repeated erotic stimulation. As sexual arousal habituated, the men reported feeling less absorbed during erotic stimulation.

Changes in the magnitude of the eyeblink startle response during habituation of sexual arousal.

Modulation of the startle response was used to examine emotional processing of sexual stimulation across trials within a session. Eyeblink startle was elicited by a probe (burst of intense white noise) presented intermittently while men were viewing an erotic film segment. Repeated display of the film segment resulted in a progressive decrease in sexual arousal.

Allocation of attentional resources during habituation and dishabituation of male sexual arousal.

A secondary-task probe (tone) was presented intermittently while men viewed erotic film segments across a session involving 18 trials with the same film segment (habituation), then 2 trials with different film segments (novelty) and 2 trials with reinstatement of the original segment (dishabituation). Reaction time to the tone (an index of the extent processing resources were being committed to the erotic stimulus) shifted during the session in parallel with changes that occurred in penile tumescence and subjective sexual arousal. The decrease in sexual arousal over the first 18 trials in the session was accompanied by a progressively faster reaction to the tone, novel stimulation led to recovery of sexual arousal and a slower reaction to the tone, and on trials 21 and 22 sexual arousal and reaction time levels were above the values that prevailed immediately prior to novel stimulation.

Psychological and psychomotor skills associated with prowess at ten-pin bowling.

Psychological and psychomotor skills associated with prowess at ten-pin bowling were identified through factor analysis of ratings provided by 172 bowlers (87 males, 85 females) across a range of current averages (a measure based on recent performance in competition). Skilled bowlers (current average of 170 pins or more) differed significantly from less skilled bowlers (current average of less than 135 pins) on seven component skills. They demonstrated greater mental toughness, a higher degree of planning and evaluation, greater consistency, more interest in improvement, less use of luck attributions, more confidence in equipment and technique, and greater competitiveness.

Differences between heterosexual, bisexual, and lesbian women in recalled childhood experiences.

Heterosexual, bisexual, and lesbian women recalled the extent to which they had engaged in gender conforming (female-stereotypic) behaviors and gender nonconforming (male-stereotypic) behaviors in childhood. Heterosexual women were more likely to recall having had female-stereotypic experiences as children, whereas lesbian women often recalled a childhood characterized by male-stereotypic experiences. Multiple discriminant function allowed the heterosexual women in the sample to be distinguished from the lesbian women with 80% accuracy in classification of individual cases on the basis of four recollected attributes (imagined self as a male character, wished to become a mother, preference for boys' games, and considered a tomboy as a child).

Age and skilled psychomotor performance: a comparison of younger and older golfers.

Younger golfers (mean age 33.6 years) and older golfers (mean age 62.3 years) who were equivalent at a molar level of performance (shots taken per round of golf) were compared through componential analysis in order to identify age differences in psychomotor skills.

Female sexual arousal and the law of initial value: assessment at several phases of the menstrual cycle.

Genital responses to erotic film and fantasy were recorded from 10 women at five phases of the menstrual cycle by means of vaginal photoplethysmography. Relationships between baseline (prestimulation) and difference (stimulation minus prestimulation) levels of response were examined. Neither vaginal blood volume nor average pulse amplitude conformed to the law of initial value ("the higher the baseline level, the less will be the difference score").

Habituation and dishabituation of male sexual arousal.

Sixteen men were tested under conditions where they viewed the same segment of erotic film on many occasions or engaged repeatedly in the same erotic fantasy. Decrements in penile tumescence and subjective sexual arousal over trials were accompanied by reports from Ss that they felt less absorbed in the events depicted in film or fantasy (and in the case of fantasy, that the images they formed became less vivid). Analysis of covariance showed that habituation (reduction in physiological and subjective measures of sexual arousal over trials) was less when allowance was made for the manner in which absorption (and in vividness of imagery in the case of fantasy) changed during erotic stimulation.

Information processing by tree fellers: signal detection analysis.

Eighteen experienced tree fellers and eighteen forestry students watched video recordings of mature eucalypts being felled by a man using a chain saw, and then rated whether each tree had fallen normally or abnormally. Signal-detection analysis showed that the tree fellers were more accurate than the forestry students in predicting eventual outcome. Further, the tree fellers achieved peak accuracy in discrimination by the time the logger had completed cutting the scarf (typically several minutes before the tree hit the ground), whereas the forestry students predicted outcome most accurately only when a tree was falling (and about 1 s from hitting the ground).

Adult sexual orientation in relation to memories of childhood gender conforming and gender nonconforming behaviors.

Heterosexual, bisexual, and homosexual men recalled the extent to which they had engaged in gender conforming (masculine) and gender nonconforming (feminine) behaviors as a child. Adult sexual orientation was predicted as accurately by memories of childhood gender conforming behaviors as by memories of childhood gender nonconforming behaviors. However, childhood scripts as recalled by homosexual men were considerably more diverse.

Sexual arousal across phases of the human menstrual cycle.

Three experiments assessing sexual arousal to erotic stimulation at several phases within the menstrual cycle are reported. Cross-sectional as well as longitudinal comparisons indicated that the subjective sexual arousal elicited during fantasy depicting specific themes was stable across the menstrual cycle. Measures of physiological sexual arousal recorded during film episodes and during fantasy demonstrated only minor variation over the course of the cycle.

Multidimensionality of the content of female sexual fantasy.

A Female Sexual Fantasy Questionnaire (FSFQ) was developed from factor analysis of ratings through which women indicated the erotic potency of fantasies depicting nominated sexual activities. Five dimensions of sexual fantasy (genital, sensual, sexual power, sexual suffering, forbidden sexual-activity themes) are assessed by FSFQ. The extent to which themes within FSFQ were rated as sexually arousing correlated with the levels of physiological response recorded by vaginal photoplethysmography while women engaged in fantasy employing these themes.

Male sexual fantasy: multidimensionality in content.

Sixty-six men provided ratings of the extent to which they regarded fantasies depicting nominated sexual activities as sexually arousing. A Male Sexual Fantasy Questionnaire (MSFQ) with five subscales was constructed following factor analysis of these ratings. The subscales yield separate scores for fantasies representing sensual, genital, public sex, sexual dominance-submission, and sexual aggression themes.

Identifying subclasses of patients with rheumatoid arthritis through cluster analysis.

Nonhierarchical cluster analysis was used to classify 92 patients with rheumatoid arthritis drawn from a community rheumatology practice into 5 groups on the basis of biochemical measures and disease indices. The major differentiating variables were the number of active joints, number of damaged joints, overall disease activity, extraarticular complications, and history of joint surgery. Although the 5 subclasses were equivalent on measures of psychological functioning, they differed systematically on such health outcome measures as mobility, physical activity, and dexterity.

Effect of pheromones from male goats on LH-secretion in anoestrous ewes.

Pheromones from ram's wool or buckhairs lead to an increase in the LH pulse frequency, thus inducing ovulations in seasonally anoestrous sheep and goats, respectively. Indications exist that pheromones from one species may be active in the other one. The changes of the LH secretion pattern were used as a bioassay to demonstrate such an interspecies effect of either ram's wool or buckhairs.

Enhancement of fantasy-induced sexual arousal in men through training in sexual imagery.

Men who in earlier experiments in the same laboratory had been unable to enhance penile tumescence to any substantial degree by engaging in erotic fantasy were given two sessions of either sexual imagery training or general imagery training. Participants in the sexual imagery training program subsequently demonstrated increased physiological and subjective sexual arousal during unstructured as well as structured sexual fantasy. The gains were undiminished at follow-up, 1 month after the end of training.

Sexual fantasies of heterosexual and homosexual men.

Heterosexual men and homosexual men rated how arousing different sexual fantasies were and how often they had used these fantasies over the previous year. Within each group, sensual and genital same-orientation fantasies were more arousing than either public-sex or dominance-submissive fantasies, which in turn were more arousing than aggressive-sex fantasies. For both heterosexual and homosexual men the extent to which a fantasy was arousing correlated with the person's experience of the activity depicted in the fantasy.

Psychophysiological assessment of male sexual arousal following spinal cord injury.

Adult males with and without permanent damage to the spinal cord were contrasted in terms of their sexual responsiveness to erotic stimulation in film, spoken-text, and fantasy modes. Among the 16 spinal cord injured (SCI) men who were studied, several who had anticipated they would achieve erection failed to do so, whereas others demonstrated penile tumescence during erotic stimulation despite claiming they had lost the capacity for psychogenic erection. Self-report is thus not a valid index of sexual responsivity following spinal cord injury.

Habituation and dishabituation of female sexual arousal.

Measures of subjective and physiological sexual arousal were taken within a session while women either viewed the same segment of erotic film on many occasions or employed the same sexual fantasy over a number of trials. For both film and fantasy there were significant reductions in subjective sexual arousal and average pulse amplitude during the course of repeated erotic stimulation. Subsequent presentation of novel erotic stimuli led to recovery in sexual arousal.

Age and scholarly impact.

The claim that older scientists generate research of lower quality than do younger scientists was tested through two analyses in which the age distribution of authors of frequently cited articles in psychology journals was compared with the age distribution of authors of low-impact articles published in the same journals. Most high-impact articles were published by relatively young psychologists, but so were most low-impact articles. When allowance was made for relative numerical representation, there was no evidence that publications from older scientists have less impact.