First Determination of the Level Structure of an sd-Shell Hypernucleus, _{Λ}^{19}F

We report on the first observation of γ rays emitted from an sd-shell hypernucleus, _{Λ}^{19}F. The energy spacing between the ground state doublet, 1/2^{+} and 3/2^{+} states, of _{Λ}^{19}F is determined to be 315.5±0.4(stat)_{-0.5}^{+0.6}(syst)  keV by measuring the γ-ray energy of the M1(3/2^{+}→1/2^{+}) transition. In addition, three γ-ray peaks are observed and assigned as E2(5/2^{+}→1/2^{+}), E1(1/2^{-}→1/2^{+}), and E1(1/2^{-}→3/2^{+}) transitions. The excitation energies of the 5/2^{+} and 1/2^{-} states are determined to be 895.2±0.3(stat)±0.5(syst) and 1265.6±1.2(stat)_{-0.5}^{+0.7}(syst)  keV, respectively. It is found that the ground state doublet spacing is well described by theoretical models based on existing s- and p-shell hypernuclear data.

Self-harm and Suicide Attempts in a Japanese Psychiatric Hospital

OBJECTIVE

Self-harm and attempted suicide are risk factors for suicide in psychiatric hospital in-patients. This study aimed to analyse the circumstances of self-harm and suicide attempts in a Japanese psychiatric hospital so as to improve management and care.

METHODS

Incident reports of self-harm and suicide attempts during a 12.4-year period from November 2000 to March 2013 were reviewed. A descriptive analysis was conducted in terms of age, sex, and diagnosis of patients, as well as level, ward, situations, and causes of incidents.

RESULTS

During the study period, 90 cases of self-harm and attempted suicide involving 58 patients were reported. The rate of self-harm and suicide attempts was 0.05 per 1000 patient-days. The types of selfharm and suicide attempts included hanging (n = 25), wrist cutting (n = 19), ingestion of foreign objects (n = 17), and others (n = 29). The single case of completed suicide involved hanging, in a patient with schizophrenia. Among 55 patients with relevant data, the most common clinical diagnosis was mood disorder (41.8%), followed by schizophrenia (36.4%). Mood disorder was 3.5 times as prevalent in females as in males (14 vs. 4). Fourteen patients with mood disorder (n = 8) or schizophrenia (n = 6) were repeatedly involved in 46 of 89 cases of self-harm or attempted suicide; 11 were female. One woman with mood disorder attempted suicide 9 times within the same year. The top 3 management and care factors related to self-harm and suicide attempts were failure to adhere to preventive procedures (28%), insufficient therapeutic communication (28%), and difficulty in predicting suicide (20%).

CONCLUSION

Self-harm and suicide attempts at this psychiatric hospital occurred at a rate of 0.05 per 1000 patient-days between late 2000 and early 2013. Efforts are needed to increase compliance with suicide prevention procedures and therapeutic communication, so as to improve management and care of psychiatric in-patients and prevent them from committing suicide.

Observation of Spin-Dependent Charge Symmetry Breaking in ΛN Interaction: Gamma-Ray Spectroscopy of _{Λ}^{4}He

The energy spacing between the spin-doublet bound state of _{Λ}^{4}He(1^{+},0^{+}) was determined to be 1406±2±2  keV, by measuring γ rays for the 1^{+}→0^{+} transition with a high efficiency germanium detector array in coincidence with the ^{4}He(K^{-},π^{-})_{Λ}^{4}He reaction at J-PARC. In comparison to the corresponding energy spacing in the mirror hypernucleus _{Λ}^{4}H, the present result clearly indicates the existence of charge symmetry breaking (CSB) in ΛN interaction. By combining the energy spacings with the known ground-state binding energies, it is also found that the CSB effect is large in the 0^{+} ground state but is vanishingly small in the 1^{+} excited state, demonstrating that the ΛN CSB interaction has spin dependence.

The solid state reaction of Fe with the Si(111) vicinal surface: splitting of bunched steps

The solid state reaction of deposited Fe (four monolayers, ML) with vicinal Si(111) substrate induced by subsequent thermal treatment has been studied using scanning tunnelling microscopy. At the lower range of annealing temperatures up to 400 °C the bunched steps of bare substrate are reproduced by the surface of the covering iron silicide layer. At 400 °C the onset of three-dimensional growth of iron silicide islands is observed. In comparison to the samples covered with smaller amounts of Fe it appears at a lower annealing temperature. Above 500 °C the bunched steps split into lower ones but more densely distributed due to proceeding reactions between Fe-rich iron silicide and Si substrate. As a consequence, at 700 °C the well-developed three-dimensional nanocrystallites of iron silicide are randomly distributed on the Si surface. This observation is in contrast to the formation of a regular array of iron silicide crystallites upon deposition of 2 ML of Fe.

Activity and sleeping time monitored by an accelerometer in rotating shift workers

BACKGROUND

The relationship between total sleep time and activity levels during work before or after sleep in two rotating work shifts was compared.

METHOD

Monitoring of activity levels using an activity-detecting device in the wrist was conducted in 17 rotating shift workers, who ranged in age from 34 to 55 years. The work shifts, consisting of a morning shift (6:30 to 15:15 hours) and an evening shift (15:15 to 24:00 hours), were rotated on a weekly basis. Partial correlation coefficient was calculated after controlling for age.

RESULTS

The total sleep time after the morning shift was significantly related to the activity count before sleep (r=-0.42) or after sleep (r=-0.36). There was also a significant relationship between total sleep time after the evening shift and the activity count before sleep (r=-0.39) or after sleep (r=-0.32). The mean total sleep time of the subjects for the morning shift was 349 minutes, which was significantly lower than that after the evening shift (382 minutes). In addition, the activity count during the morning shift was significantly higher than that during the evening shift.

CONCLUSIONS

The negative relationship between sleep time and activity before or after sleep became clear in shift workers.

[Utility of OAE screener (GSI 70) for the evaluation of distortion product otoacoustic emissions]

The purpose of this study was to investigate the ability of the OAE screener GSI 70 to evaluate of cochlea function in neonates, infants and adults. Distortion product otoacoustic emissions (DPOAEs) were measured using the GSI 70 DPOAE Analyzer and evaluated in 123 human ears between December 1999 and June 2000. We performed the following four general clinical tests to determine the reliability of the GSI 70: 1) comparison of DPOAE levels measured using the ILO 92 and the GSI 70 in 55 adult ears, 2) comparison of DPOAE levels measured using the GSI 70 and hearing levels in 55 adult ears, 3) comparison of DPOAE levels measured using the GSI 70 and ABR levels in 45 neonate and infant ears, and 4) evaluation of the utility of DPOAE measurements obtained using the GSI 70 in functional deafness cases. The following results were obtained: 1) DPOAE levels measured with the ILO 92 and the GSI 70 were closely correlated (correlation coefficient, 0.773 at 2 kHz and 0.813 at 4 kHz). 2) The sensitivity of the GSI 70 in adult ears confirmed to have normal hearing was 80% at 2 kHz and 100% at 4 kHz; the specificity of hearing-impaired ears was 94% at 2 kHz and 94% at 4 kHz. 3) The sensitivity of the GSI 70 in normal neonate and infant ears with normal hearing was 100% at 2 kHz and 100% at 4 kHz; the specificity of hearing-impaired neonate and infant ears was 97% at 2 kHz and 94% at 4 kHz. 4) All of the functionally deaf ears showed excellent DPOAE responses. Examinations using the GSI 70 DPOAE analyzer were very easy and fast. Also, the results were highly reliable, with the exception of one adult who was classified as having normal hearing in an out-of-scale hearing level at 2 kHz. We suggest that specific criteria be established for the clinical usage of the GSI 70 in performing objective hearing evaluations.