Evidence for polarised boron in Co-B and Fe-B alloys

By exploiting the tunability of synchrotron radiation in measurements of spin-resolved photoemission it has proved possible to obtain information on the polarisation of the valence electrons of Co-B and Fe-B amorphous magnetic alloys, Both the spin-integrated and spin-resolved energy distribution curves show a marked dependence on photon energy indicating that the p states of boron hybridise with the d states of the transition metals giving rise to mixed states in the binding energy range 1 to 5 eV, The observed polarisation and spin-resolved densities of states imply that in the above restricted energy range there is a net negative polarisation of the boron states

Ultrathin epitaxial Fe films in vicinal GaAs(001): A study by spin-resolved photoelectron spectroscopy

Thin epitaxial Fe films have been grown on vicinal GaAs(001) substrates and their remanent magnetic properties and the degree of substrate atom diffusion investigated using synchrotron-based photoelectron spectroscopy. The vicinal Fe films, though exhibiting greater As diffusion than their singular homologues, displayed better film quality both from the structural and the magnetic points of view. The spin-resolved valence spectra of the vicinal films resemble those for crystalline bulk Fe at lower film thicknesses than for singular films

Calculation of the Phase Behavior of Lipids

The self-assembly of monoacyl lipids in solution is studied employing a model in which the lipid's hydrocarbon tail is described within the Rotational Isomeric State framework and is attached to a simple hydrophilic head. Mean-field theory is employed, and the necessary partition function of a single lipid is obtained via a partial enumeration over a large sample of molecular conformations. The influence of the lipid architecture on the transition between the lamellar and inverted-hexagonal phases is calculated, and qualitative agreement with experiment is found.Comment: to appear in Phys.Rev.

A review of methods for detecting rats at low densities, with implications for surveillance

Invasive rats are the biggest threat to island biodiversity world-wide. Though the ecological impacts of rats on insular biota are well documented, introduced rats present a difficult problem for detection and management. In recent decades, improved approaches have allowed for island-wide eradications of invasive rats on small-medium sized islands and suppression on large islands, although both these still represent a formidable logistical and financial challenge. A key aspect of eradication or suppression and ongoing management is the ability to detect the presence of rats, especially at low densities. Here we review recent developments in the field of rat surveillance and summarise current published literature to recommend practices and the factors to consider when developing a surveillance program for either eradication or suppression plans. Of 51 empirical studies covering 17 countries, 58% were from New Zealand. Although detecting rats at low density is extremely challenging, advances over the past 15 years, have significantly improved our ability to detect rats. Motion-sensored cameras and rodent detection dogs have greatly improved our ability to detect rats at low densities, with cameras consistently showing an ability to detect rats at lower densities than other techniques. Rodent detection dogs are also able to reliably detect even an individual rat, although there are challenges to their widespread adoption, particularly in developing countries, due to the cost and skills required for their training and maintenance. New monitoring devices, the use of eDNA and drones represent current and future innovations to improve detection

Human cytomegalovirus immunoglobulin G response and pulmonary tuberculosis in adolescents: a case-control study

Background Emerging evidence suggests a link between infection with herpes viruses, particularly human cytomegalovirus (HCMV) and Epstein Barr Virus (EBV), and progression to tuberculosis (TB) disease. Methods An unmatched case-control study was conducted amongst adolescents aged 10-19 years enrolled in an observational study (Teen TB), between November 2020 and November 2021, in Cape Town, South Africa. Fifty individuals with pulmonary TB and 51 healthy TB-exposed individuals without TB were included. Demographics and clinical data were obtained, and serum samples collected at enrolment were tested for HCMV IgG and EBV Nuclear Antigen (EBNA) IgG using two automated enzyme immunoassays. Odds ratios (ORs) were estimated using unconditional logistic regression. Results The median age of 101 participants was 15 years (interquartile range [IQR] 13 to 17); 55 (54%) were female. All participants were HCMV IgG seropositive and 95% were EBNA IgG seropositive. Individuals with TB had higher HCMV IgG titres than healthy controls (p=0.04). Individuals with upper tertile HCMV IgG titres had a 3.7 times greater odds of pulmonary TB compared to those with IgG titres in the lower tertile (95%CI: 1.05–12.84; p=0.04). There was a trend for increasing odds of pulmonary TB with increasing titres of HCMV IgG (p=0.04). In contrast, there was no association between TB and higher EBNA IgG values. Conclusions There is a high prevalence of sensitisation to HCMV and EBV amongst adolescents in this high-TB burden setting. Higher HCMV IgG titres were associated with pulmonary TB in adolescents

Sub-Angstrom Microscopy Through Incoherent Imaging and Image Reconstruction

Z-contrast scanning transmission electron microscopy (STEM) with a high-angle annular detector breaks the coherence of the imaging process, and provides an incoherent image of a crystal projection. Even in the presence of strong dynamical diffraction, the image can be accurately described as a convolution between an object function, sharply peaked at the projected atomic sites, and the probe intensity profile. Such an image can be inverted intuitively without the need for model structures, and therefore provides the important capability to reveal unanticipated interfacial arrangements. It represents a direct image of the crystal projection, revealing the location of the atomic columns and their relative high-angle scattering power. Since no phase is associated with a peak in the object function or the contrast transfer function, extension to higher resolution is also straightforward. Image restoration techniques such as maximum entropy, in conjunction with the 1.3 A probe anticipated for a 300 kV STEM, appear to provide a simple and robust route to the achievement of sub-Angstrom resolution electron microscopy

Vitamin D deficiency is associated with tuberculosis disease in British children

Background53Basic science, epidemiological and interventional research supports a link between vitamin D and 54tuberculosis immunity, infection and disease. We evaluated the association between vitamin D 55levels and tuberculosis (TB) infection and disease in UK children recruited to the NIHR IGRA Kids 56Study (NIKS).57Methods58Children presenting between 2011-2014 were eligible if they had history of exposure to an adult 59case with sputum smear/culture-positive TB, or were referred and diagnosed with TB disease. 60Children were assessed at baseline and 6-8 weeks for immunological evidence of TB infection (IGRA 61and/or tuberculin skin test) and evidence of TB disease. Some centres routinely measured total 25-62hydroxy vitamin D levels.63Results64166 children were included. Median 25-hydroxy vitamin D levels were higher in uninfected children 65(45.5 nmol/l) compared to those with infection (36.2 nmol/l) and disease (20.0 nmol/l). The 66difference between TB infection and disease was statistically significant (p<0.001). By logistic 67regression, lower vitamin D levels were associated with TB disease among participants with 68infection/disease, with no evidence of confounding by age, sex, BCG status, ethnicity, non-contact 69referral, season or centre.70Conclusion71Children with TB disease had lower vitamin D levels than children with infection. Implications for 72prevention and treatment remain to be established

The Influence of Child Sexual Abuse on the Self from Adult Narrative Perspectives

The impact of child sexual abuse on the adult self is not yet clearly understood. We explored adult perspectives through the use of narrative interviews (N = 30). Three key themes or views of self were identified in all narratives to varying degrees: the worthless self, the self as unknown, and the potential/developing self. Ambivalence and tension were present in all narratives. Individuals were challenged to integrate the sexual abuse experience in a constructive way and develop a more coherent perception of the self. The narrative method highlighted the dynamic nature of peoples� experiences at the same time recognizing that the narratives themselves are in progress. Reactions to disclosure, social support, and interpersonal connections are crucial at every turn

Characterisation of ferroelectric domains in magnetite (Fe3O4)

Magnetite has long been investigated across many disciplines due to the interplay between its ferroic order parameters, namely its ferrimagnetism, ferroelasticity and ferroelectricty. Despite this, the experimental difficulty in measuring low temperature real space images of the ferroelectric domains has meant that the local behaviour of ferroelectric domains emergent below the 38 K phase transition have yet to be realised. This work presents real space images of the ferroelectric domains, and uses piezo force microscopy to, as a function of temperature, probe the onset of piezoelectricty and ferroelectricity across the 38 K transitionComment: 6 Pages, 3 figure