A comparison of rate and methods of probable suicide for 2 years pre and post the onset of the COVID-19 pandemic.

OBJECTIVES: To examine and compare rates and methods of probable suicide in a Western region of Ireland during a 24 month period since the onset of the COVID-19 pandemic compared with a similar period immediately prior to the pandemic onset. METHODS: Post-mortem reports between March 1st 2018 and February 29th 2020 were reviewed and compared with data from March 1st 2020 to February 28th 2022. Relevant demographic data, rates and methods of probable suicide and lifetime engagement with mental health services were compared across the two time points. RESULTS: Identical rates of probable suicide (85 individuals at both time points) were demonstrated with no difference evident in the utilisation of violent compared to non-violent methods. CONCLUSIONS: This study demonstrates that despite previous reports of increased rates of self-harm and some evidence of increased mental distress since the onset of the COVID-19 pandemic, no change in rates of or methods employed by individuals who died by probable suicide were evident in this geographical region.

Resonant x-ray scattering investigation of magnetic ordering in NpAs(1 - x)Se(x) (x = 0.05, 0.10).

A resonant x-ray scattering investigation of the NpAs(1 - x)Se(x) system with single crystals of 5 and 10% Se content is reported. The main features of the magnetic phase diagram previously studied by neutron scattering were confirmed. The coexistence within a single domain of ferro- and antiferro-components in the low-T ferrimagnetic phase was established, as well as the single-k character of the incommensurate phase and of the antiferromagnetic component of the ferrimagnetic phase. A tetragonal lattice distortion was found in the ferro- and ferrimagnetic phases which is not compatible with the proposed model for the ferromagnetic phase. The study of ferromagnetism was carried out using polarization analysis of the diffracted beam to separate the scattering intensities originating from magnetism and charge, which are superimposed in reciprocal space. The magnetic character of the ferromagnetic signal calculated from the measured intensities in the polarization analysis σπ and σσ channels was confirmed by analysis of the corresponding temperature dependence.

Nature of the magnetic order and origin of induced ferroelectricity in TbMnO3.

The magnetic structures which endow TbMnO(3) with its multiferroic properties have been reassessed on the basis of a comprehensive soft x-ray resonant scattering (XRS) study. The selectivity of XRS facilitated separation of the various contributions (Mn L(2) edge, Mn 3d moments; Tb M(4) edge, Tb 4f moments), while its variation with azimuth provided information on the moment direction of distinct Fourier components. When the data are combined with a detailed group theory analysis, a new picture emerges of the ferroelectric transition at 28 K. Instead of being driven by the transition from a collinear to a noncollinear magnetic structure, as has previously been supposed, it is shown to occur between two noncollinear structures.

Epitaxial TbMnO(3) thin films on SrTiO(3) substrates: a structural study.

TbMnO(3) films have been grown under compressive strain on (001)-oriented SrTiO(3) crystals. They have an orthorhombic structure and display the (001) orientation. With increasing thickness, the structure evolves from a more symmetric (tetragonal) to a less symmetric (bulk-like orthorhombic) structure, while keeping constant the in-plane compression, thereby leaving the out-of-plane lattice spacing unchanged. The domain microstructure of the films is also revealed, showing an increasing number of orthorhombic domains as the thickness is decreased: we directly observe ferroelastic domains as narrow as 4 nm. The high density of domain walls may explain the induced ferromagnetism observed in the films, while both the decreased anisotropy and the small size of the domains could account for the absence of a ferroelectric spin spiral phase.

cys-3, the positive-acting sulfur regulatory gene of Neurospora crassa, encodes a protein with a putative leucine zipper DNA-binding element.

The sulfur-regulatory circuit of Neurospora crassa consists of a set of unlinked structural genes which encode sulfur-catabolic enzymes and two major regulatory genes which govern their expression. The positive-acting cys-3 regulatory gene is required to turn on the expression of the sulfur-related enzymes, whereas the other regulatory gene, scon, acts in a negative fashion to repress the synthesis of the same set of enzymes. Expression of the cys-3 regulatory gene was found to be controlled by scon and by sulfur availability. The nucleotide sequence of the cys-3 gene was determined and can be translated to yield a protein of molecular weight 25,892 which displays significant homology with the oncogene protein Fos, yeast GCN4 protein, and sea urchin histone H1. Moreover, the putative cys-3 protein has a well-defined leucine zipper element plus an adjacent charged region which together may make up a DNA-binding site. A cys-3 mutant and a cys-3 temperature-sensitive mutant lead to substitutions of glutamine for basic amino acids within the charged region and thus may alter DNA-binding properties of the cys-3 protein.

Effect of surface polishing and oxidization induced strain on electronic order at the Verwey transition in Fe3O4.

Following the controversy between two previous publications (Lorenzo et al 2008 Phys. Rev. Lett. 101 226401 and Garcia et al 2009 Phys. Rev. Lett. 102 176405), we report on the influence of mechanical polishing, and subsequent sample storage, on the electronic order at the Verwey transition of highly pure magnetite, Fe(3)O(4), by resonant x-ray scattering. Contrary to expectations, mechanically polishing the surface induces an inhomogeneous micron deep dead layer, probably of powdered Fe(3)O(4). In addition, we have found that polishing the sample immediately before the experiment influences and favors the appearance of long range order electronic correlations, whereas samples polished well in advance have their electronic order quenched. Conversely, lattice distortions associated with the Verwey transition appear less affected by the surface state. We conclude that mechanical polishing induces stresses at the surface that may propagate into the core of the single crystal sample. These strains relax with time, which affects the different order parameters, as measured by x-ray resonant diffraction.

Charge and orbital correlations at and above the Verwey phase transition in magnetite.

The subtle interplay among electronic degrees of freedom (charge and orbital orderings), spin and lattice distortion that conspire at the Verwey transition in magnetite (Fe3O4) is still a matter of controversy. Here, we provide compelling evidence that these electronic orderings are manifested as a continuous phase transition at the temperature where a spin reorientation takes place at around 130 K, i.e., well above TV approximately 121 K. The Verwey transition seems to leave the orbital ordering unaffected whereas the charge ordering development appears to be quenched at this temperature and the temperature dependence below TV is controlled by the lattice distortions. Finally, we show that the orbital ordering does not reach true long range (disorder), and the correlation length along the c-direction is limited to 100 angstroms.

Perpendicular antiferromagnetic ordering of Mn and exchange anisotropy in Fe/Mn multilayers.

Fe/Mn is a model system in which to study exchange bias, since the antiferromagnetic (AF) Mn layers are believed to have uncompensated moments with all spins aligned in the plane and parallel to those of the Fe. We have determined the microscopic AF ordering at the interfaces using single-crystal neutron diffraction. An unexpected magnetic structure is obtained, with out-of-plane Mn moments perpendicular to those of Fe. This explains the low bias field and shows that the simple AF ordering assumed in a variety of exchange-biased systems may well have to be revised.

Dipolar excitations at the LIII x-ray absorption edges of the heavy rare-earth metals.

We report measured dipolar asymmetry ratios at the LIII edges of the heavy rare-earth metals. The results are compared with a first-principles calculation and excellent agreement is found. A simple model of the scattering is developed, enabling us to reinterpret the resonant x-ray scattering in these materials and to identify the peaks in the asymmetry ratios with features in the spin and orbital moment densities.

Resonant x-ray diffraction studies on the charge ordering in magnetite.

Here we show that the low temperature phase of magnetite is associated with an effective, although fractional, ordering of the charge. Evidence and a quantitative evaluation of the atomic charges are achieved by using resonant x-ray diffraction (RXD) experiments whose results are further analyzed with the help of ab initio calculations of the scattering factors involved. By confirming the results obtained from x-ray crystallography we have shown that RXD is able to probe quantitatively the electronic structure in very complex oxides, whose importance covers a wide domain of applications.

Order parameter segregation in Ce0.7La0.3B6: 4f octopole and 5d dipole magnetic order.

The intriguing thermophysical properties of CeB6 have been subject to investigation for more than 20 years. In particular, an exotic ground state, phase IV, emerges under doping with La. We report resonant x-ray scattering results on the order parameter symmetries in phase IV of Ce0.7La0.3B6, which condenses below T(IV)=1.5 K. The results reveal a degree of mesoscopic 5d dipole antiferromagnetic order, with propagation vector Q0=(1/2 1/2 1/2), both below and above T(IV). Below T(IV), this polarization coexists with long-range 4f antiferro-octupole (AFO) order also at Q0. The marked differences in temperature dependence and spatial correlation suggest a state of order parameter segregation at low temperature. A simple model of AFO order, consistent with the polarization dependent azimuth symmetries, the Bragg angle, and temperature dependence is given.

HNF transfection with chondrosarcoma DNA results in the development of a sarcoma cell surface-associated epitope.

High molecular weight DNA, which was isolated from a chondrosarcoma cell line, was transfected into human neonatal foreskin fibroblasts and NIH/3T3 cells. Both types of transfected cells expressed anchorage-independent growth in soft agar and produced tumors in nude mice. The tumors which developed in nude mice following injection of transfected human fibroblasts grew to approximately 0.8 cm in diameter in four weeks. The tumors which developed from transfected NIH/3T3 cells grew to greater than 2.0 cm in diameter in 6 weeks. After growth in soft agar the transfected human fibroblasts expressed a cell surface sarcoma-associated epitope recognized by the monoclonal antibody 345.134S. In addition to the transfected human fibroblasts, the original human chondrosarcoma tumor, the chondrosarcoma cell line derived from the tumor, and the nude mouse tumor which developed from transfected human fibroblasts all exhibited positive reactivity with the monoclonal antibody 345.134S. Transfected NIH/3T3 cells that exhibited anchorage-independent growth and tumorigenicity did not exhibit detectable reactivity with the monoclonal antibody. These results suggest that the expression of the tumor-associated cell surface antigen appears to be an early event correlated with transformation of the transfected human cells but not directly related to the tumorigenic potential of the DNA. The transfected cells which expressed anchorage independent growth exhibited the sarcoma cell surface antigen prior to attaining the potential for tumorigenicity.

Dependence of inessential late gene expression on early meiotic events in Saccharomyces cerevisiae.

SPR3 is one of at least nine genes which are expressed in sporulating Saccharomyces cerevisiae cells at the time of meiosis I. We show below that strains homozygous for null alleles of SPR3 are capable of normal meiosis and the production of viable ascospores. We have also monitored SPR3 expression in a series of strains that are defective in meiotic development, using an SPR3:lacZ fusion carried on a single copy plasmid. beta-Galactosidase activity occurred at wild-type levels in diploid strains homozygous for mutations in spo13, rad50, rad57 and cdc9, but was greatly reduced in strains carrying cdc8 or spo7 defects. We conclude that SPR3 expression is a valid monitor of early meiotic development, even though the gene is inessential for the sporulation process.

Nontumorigenic squamous cell carcinoma line converted to tumorigenicity with methyl methanesulfonate without activation of HRAS or MYC.

Plasticity of human tumor populations could account for the reason why many tumorigenic human cell lines lose this feature when grown in culture. Methyl methanesulfonate (MMS) was used to convert premalignant squamous cell carcinoma (SCC) cell line SCC-83-01-82 to a malignant phenotype. The MMS-treated SCC-83-01-82 cells (MMS-SCC-83-01-82) produced progressively growing tumors in 5 of 11 splenectomized BALB/c nude mice within 3-5 months. A cell line, designated SCC-83-01-82 CA, was established in vitro from one of the mouse tumors and was repassaged successively. This SCC-83-01-82 CA cell line was aggressively tumorigenic. A tumor greater than or equal to 2.0 cm in size was present within a month, as opposed to the 3-5 months required for the tumors produced by the MMS-SCC-83-01-82 cells. Examination of frozen cross sections by in situ hybridization revealed that focal areas of the tumor produced by the MMS-SCC-83-01-82 cells expressed MYC and HRAS mRNA. However, by the third passage in vivo, the levels of expression of the corresponding genes in the mouse tumors were undetectable. Blot-hybridization analysis of the RNA from the MMS-SCC-83-01-82 cells and the subsequently derived tumors and cells did not indicate any consistent overexpression of MYC, HRAS, or KRAS. Restriction fragment length polymorphism analysis of both MYC and HRAS genes revealed neither rearrangement nor amplification of MYC nor point mutation in the 11th or 12th codon of HRAS. The data suggest that alterations in MYC and HRAS were not directly involved in either the initial transformation or MMS-induced tumorigenic conversion of the SCC-83-01-82 cell line. Persistence of tumorigenicity after reisolation of the MMS-converted premalignant SCC-83-01-82 cells did not disappear immediately following the treatment with MMS.

Resonant enhancements at nonmagnetic ions: new possibilities for magnetic X-ray scattering.

Synchrotron experiments with uranium antiferromagnetic compounds have discovered large ( >1000) enhancements of the magnetic scattering intensities at the K edges of nominally nonmagnetic anions, e.g., Ga and As. The width in energy, the position with respect to the white line, and the azimuthal and polarization dependencies permit one to associate the signal with transitions of E1 dipole symmetry from 1s to 4p states. In momentum space, the signal exhibits long-range order at the antiferromagnetic wave vector. We discuss possible channels capable of generating the observed enhancements.

The XMaS beamline at ESRF: instrumental developments and high-resolution diffraction studies.

The beamline, which is situated on a bending magnet at ESRF, comprises a unique combination of instrumentation for high-resolution and magnetic single-crystal diffraction. White-beam operation is possible, as well as focused and unfocused monochromatic modes. In addition to an eleven-axis Huber diffractometer, which facilitates simple operation in both vertical and horizontal scattering geometries, there is an in-vacuum polarization analyser and slit system, mirrors for harmonic rejection, sub 4.2 K and 1 Tesla magnetic field sample environment, plus a diamond phase plate for polarization conditioning. The instrumentation developed specifically for this beamline is described, and its use illustrated by recent scientific results.