Modulation of the nucleation rate pre-exponential in a low-temperature Ising system

A metastable lattice gas with nearest-neighbor interactions and continuous-time dynamics is studied using a generalized Becker-Doring approach in the multidimensional space of cluster configurations. The pre-exponential of the metastable state lifetime (inverse of nucleation rate) is found to exhibit distinct peaks at integer values of the inverse supersaturation. Peaks are unobservable (infinitely narrow) in the strict limit T->0, but become detectable and eventually dominate at higher temperatures.Comment: 4 pages, 2 Postscript figures, LaTeX, submitted to Phys. Rev. Lett. Changes: updated references, re-written section around eqs.(5),(6), typos, minor wording changes in conclusion and other parts of text (mostly in response to referees' comments). Paper resubmitted to PR

Analytical description of shape transition in nuclear alternating parity bands

© 2018 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd. The angular momentum dependencies of parity splitting and electric dipole transitions in the alternating parity bands of heavy nuclei have been analyzed. It is shown that these dependencies can be treated in a universal manner with a single critical angular momentum parameter, which characterizes phase transition from octupole vibrations to the stable octupole deformation. Using the simple but useful model of axially-symmetric reflection-asymmetric mode, the analytical expressions for parity splitting and electric dipole transitional moment have been obtained. The findings are in good agreement with the experimental data for various isotopes of Ra, Th, U, and Pu

Avoidance of psychological pain and suicidal ideation in community samples: Replication across two countries and two languages

Objectives: A multidimensional psychological pain model of suicide has been developed that includes three dimensions: affective, cognitive, and avoidance. In the present research, we evaluated the relationships between the three dimensions of psychological pain and suicidal ideation. Method: Two community samples from Portugal and the U.S. participated in the research. Results: Hierarchical multiple regression analysis demonstrated that when controlling for the effects of depressive symptoms and psychache, the avoidance dimension, but not the cognitive or affective dimension of psychological pain, explained significant, and unique variance in suicidal ideation in each sample. Conclusion: Even when individuals perceive psychological pain, there may not be an elevated risk of suicide, provided that they do not consider suicide as a form of coping to decrease that pain

Test of the Kolmogorov-Johnson-Mehl-Avrami picture of metastable decay in a model with microscopic dynamics

The Kolmogorov-Johnson-Mehl-Avrami (KJMA) theory for the time evolution of the order parameter in systems undergoing first-order phase transformations has been extended by Sekimoto to the level of two-point correlation functions. Here, this extended KJMA theory is applied to a kinetic Ising lattice-gas model, in which the elementary kinetic processes act on microscopic length and time scales. The theoretical framework is used to analyze data from extensive Monte Carlo simulations. The theory is inherently a mesoscopic continuum picture, and in principle it requires a large separation between the microscopic scales and the mesoscopic scales characteristic of the evolving two-phase structure. Nevertheless, we find excellent quantitative agreement with the simulations in a large parameter regime, extending remarkably far towards strong fields (large supersaturations) and correspondingly small nucleation barriers. The original KJMA theory permits direct measurement of the order parameter in the metastable phase, and using the extension to correlation functions one can also perform separate measurements of the nucleation rate and the average velocity of the convoluted interface between the metastable and stable phase regions. The values obtained for all three quantities are verified by other theoretical and computational methods. As these quantities are often difficult to measure directly during a process of phase transformation, data analysis using the extended KJMA theory may provide a useful experimental alternative.Comment: RevTex, 21 pages including 14 ps figures. Submitted to Phys. Rev. B. One misprint corrected in Eq.(C1

Mental turmoil, suicide risk, illness perception, and temperament, and their impact on quality of life in chronic daily headache

To evaluate the relationship among quality of life, temperament, illness perception, and mental turmoil in patients affected by chronic daily headache with concomitant medication overuse headache. Participants were 116 consecutive adult outpatients admitted to the Department of General Medicine of the Sant’Andrea Hospital in Rome, between January 2007 and December 2007 with a diagnosis of chronic daily headache (illness duration >5 years). Patients were administered the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-autoquestionnaire version (TEMPS-A), the Beck Hopelessness Scale (BHS), the Hamilton Rating Scale for Depression (HAM-D), the Mini-International Neuropsychiatric Interview (MINI), the Revised Illness Perception Questionnaire (IPQ), the Suicide Score Scale (SSS), and the Quality of Life Index (QL-Index). Twenty-eight percent of the patients evidenced moderate to severe depression, and 35% evidenced severe hopelessness. Analyses also indicated that quality of life, temperament, illness perception, and psychological turmoil are associated. However, a hierarchical multivariate regression analysis with quality of life as dependent variable indicated that only a model with mental turmoil variables may fit data; further, only the MINI suicidal intent resulted associated with quality of life (standardized regression coefficient = −0.55; t = −3.06; P < 0.01). Suicide risk may play a central role in affecting the quality of life of patients with chronic headache. The investigation of the interplay of factors that precipitate suicide risk should include assessment of chronic headache and its effects on wellbeing

“We now have a patient and not a criminal” : An exploratory study of judges and lawyers’ views on suicide attempters and the law in Ghana

This study explored the views of judges and lawyers of the superior courts of Ghana on the law criminalizing attempted suicide. Qualitative data were collected from 12 experienced legal practitioners of the superior courts (five judges and seven lawyers) using a semi-structured interview schedule. Thematic analysis of the data yielded three main perspectives: In defence of the Law, Advocating a Repeal, and Pro-Health Orientation. Although exploratory, the findings of this study offer cues for stepping up suicide literacy and advocacy programmes toward either a repeal of the law or a reform