Charge Density Waves in YBa_{2}Cu_{3}O_{6.67} Probed by Resonant X-Ray Scattering under Uniaxial Compression.

We report a comprehensive Cu L_{3}-edge resonant x-ray scattering (RXS) study of two- and three-dimensional (2D and 3D) incommensurate charge correlations in single crystals of the underdoped high-temperature superconductor YBa_{2}Cu_{3}O_{6.67} under uniaxial compression up to 1% along the two inequivalent Cu─O─Cu bond directions (a and b) in the CuO_{2} planes. We confirm the strong in-plane anisotropy of the 2D charge correlations and observe their symmetric response to pressure: pressure along a enhances correlations along b, and vice versa. Our results imply that the underlying order parameter is uniaxial. In contrast, 3D long-range charge order is only observed along b in response to compression along a. Spectroscopic RXS measurements show that the 3D charge order resides exclusively in the CuO_{2} planes and may thus be generic to the cuprates. We discuss implications of these results for models of electronic nematicity and for the interplay between charge order and superconductivity.

Uniaxial pressure control of competing orders in a high-temperature superconductor.

Cuprates exhibit antiferromagnetic, charge density wave (CDW), and high-temperature superconducting ground states that can be tuned by means of doping and external magnetic fields. However, disorder generated by these tuning methods complicates the interpretation of such experiments. Here, we report a high-resolution inelastic x-ray scattering study of the high-temperature superconductor YBa2Cu3O6.67 under uniaxial stress, and we show that a three-dimensional long-range-ordered CDW state can be induced through pressure along the a axis, in the absence of magnetic fields. A pronounced softening of an optical phonon mode is associated with the CDW transition. The amplitude of the CDW is suppressed below the superconducting transition temperature, indicating competition with superconductivity. The results provide insights into the normal-state properties of cuprates and illustrate the potential of uniaxial-pressure control of competing orders in quantum materials.

Resistivity in the Vicinity of a van Hove Singularity: Sr_{2}RuO_{4} under Uniaxial Pressure.

We report the results of a combined study of the normal-state resistivity and superconducting transition temperature T_{c} of the unconventional superconductor Sr_{2}RuO_{4} under uniaxial pressure. There is strong evidence that, as well as driving T_{c} through a maximum at ∼3.5 K, compressive strains ϵ of nearly 1% along the crystallographic [100] axis drive the γ Fermi surface sheet through a van Hove singularity, changing the temperature dependence of the resistivity from T^{2} above, and below the transition region to T^{1.5} within it. This occurs in extremely pure single-crystals in which the impurity contribution to the resistivity is <100 nΩ cm, so our study also highlights the potential of uniaxial pressure as a more general probe of this class of physics in clean systems.

Histopathological and molecular analysis of gastrectomy specimens from hereditary diffuse gastric cancer patients has implications for endoscopic surveillance of individuals at risk.

Hereditary diffuse gastric cancer (HDGC) is caused by germline E-cadherin (CDH1) mutations in 25-40% of tested families. Management options for asymptomatic mutation carriers are fraught, since endoscopic surveillance can miss cancer foci and prophylactic gastrectomy has profound clinical sequelae. The aims of this study were to evaluate the impact of current surveillance practices on pre-operative diagnosis and to characterize the microscopic lesions in gastrectomy specimens to better inform clinical practice. Histological assessment and mapping of endoscopic surveillance and gastrectomy specimens were performed for eight asymptomatic CDH1 mutation carriers. E-cadherin expression and proliferation were analysed and evidence of epithelial-mesenchymal transition (EMT) was sought by immunohistochemistry for vimentin and cytokeratin 8/18. Four of eight patients had lesions detected at endoscopic surveillance. A median of 20.5 (range 0-66) signet ring foci were identified per gastrectomy (including in situ lesions and pagetoid spread). Foci were predominantly identified in the fundus and body (90% endoscopic biopsies and 85% in gastrectomy). The likelihood of detecting foci pre-operatively was positively correlated with the number of biopsies taken and the number of lesions in the gastrectomy specimen. E-cadherin expression in gastrectomy specimens was reduced or absent in all of the foci compared with the intervening gastric tissue, suggesting that these lesions are polyclonal. The foci had a low proliferative index (<2%) and there was no evidence for EMT. Multiple endoscopic biopsy sampling of the gastric mucosa increases the yield of microscopic cancer foci. The low proliferative index and lack of EMT suggests that these foci may represent an indolent stage of HDGC.

Gate questions in psychiatric interviewing: the case of suicide assessment.

Gate questions are commonly used to shorten structured interviews, by not probing negative responses with more detailed questions. This study quantified cases of aborted suicide attempts that would have been missed, if we had skipped detailed questions following a gate. To accomplish this, we interviewed a random sample of 135 adult psychiatric inpatients concerning their past suicidal behavior. Using our structured interview, subjects were asked a general question about aborted suicide attempts, and then asked method-specific questions regardless of their response to the general "gate" question. Of the seventy subjects who were found to have histories of aborted attempts, 44.3% answered "no" to the gate question. Comparing these "false negative" subjects to "true positives," who had answered "yes" to the gate question and reported bona fide aborted attempts yielded no significant associations with demographics, psychiatric diagnoses, or reported histories of actual suicide attempts. Thus, a large number of subjects with aborted attempts would have been missed if a negative response to the gate question had not been probed. Clinical and reasearch implications generally, as well as implications for suicide assessment, are discussed.

Evaluations of aggressive women: the effects of gender, socioeconomic status, and level of aggression.

Research finds gender differences in aggression and suggests that female violence is viewed differently from male violence. Participants were 94 female and 38 male students from a mid-size public university in the Southeast. Participants read a mock trial and answered questions about their attitudes concerning an aggressor in the scenario. The study was a 2 (male or female) by 2 (high socioeconomic status or low socioeconomic status) by 2 (verbal aggression or physical aggression) between-subjects factorial design. The participants responded to a revised version of the Attitudes Toward Women Scale (Nelson, 1988). As hypothesized aggressive women were evaluated more negatively than aggressive men and participants evaluated the female aggressor who used physical aggression more negatively than the female who used verbal aggression. The hypothesis that the female aggressor would be perceived as more in need of counseling than the male aggressor was not supported. Contrary to another hypothesis, respondents did not evaluate higher socioeconomic status aggressors more negatively than those of lower status. As hypothesized people with traditional views of women evaluated the female aggressor more negatively than people with more liberal views of women, and liberal participants evaluated the male and female aggressors similarly. The more negative evaluation of female aggressors and, in particular, females who use physical aggression, may result in unfair treatment of such females. These social biases may cloud perceptions of aggressive females, suggesting that their actions are more inappropriate than those of a male who committed the same act.

Aborted suicide attempts: a new classification of suicidal behavior.

OBJECTIVE: With the goal of ultimately finding early suicide predictors, the authors undertook a study of aborted suicide attempts. They defined such an attempt as an event in which an individual comes close to attempting suicide but does not complete the act and thus sustains no injury. METHODS: The authors interviewed a random sample of 135 adult psychiatric inpatients concerning their past suicidal behavior. Using standardized scales, they assessed suicidal intent for aborted suicide attempts and actual suicide attempts, as well as degree of injury for actual attempts. RESULTS: Over half of the 135 subjects reported making at least one aborted suicide attempt. Aside from younger age, no demographic characteristics were associated with aborted attempts. Aborted attempts were reported more often in subjects with a diagnosis of borderline personality disorder than in subjects with other diagnoses. Intent scores for aborted attempts were comparable to those for actual suicide attempts. Subjects who had made an aborted attempt were nearly twice as likely to have made an actual suicide attempt as subjects with no aborted attempts. Among subjects with both aborted and actual attempts, the first aborted attempt preceded the first actual attempt approximately half the time. CONCLUSIONS: Aborted suicide attempts were reported commonly by psychiatric inpatients, had a similar level of intent as actual attempts, and were highly associated with actual attempts. Thus, clinicians should specifically ask patients about aborted attempts as a part of the suicide history. Further study is needed to examine the association between aborted suicide attempts and suicide.