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To date, Ireland has been a leading light in the provision of youth mental health services. However, cognisant of the efforts of governmental and non-governmental agencies working in youth mental health, there is much to be done. Barriers into care as well as discontinuity of care across the spectrum of services remain key challenges. This editorial provides guidance for the next stage of development in youth mental care and support that will require significant national engagement and resource investment.
The diagnosis and control of Mycobacterium bovis infection (bovine tuberculosis: TB) continues to present huge challenges to the British cattle industry. A clearer understanding of the magnitude and duration of immune response to M. bovis infection in the European badger (Meles meles) – a wildlife maintenance host – may assist with the future development of diagnostic tests, and vaccination and disease management strategies. Here, we analyse 5280 diagnostic test results from 550 live wild badgers from a naturally-infected population to investigate whether one diagnostic test (a gamma interferon release [IFNγ] assay, n = 550 tests) could be used to predict future positive results on two other tests for the same disease (a serological test [n = 2342 tests] and mycobacterial culture [n = 2388 tests]) and hence act as an indicator of likely bacterial excretion or disease progression. Badgers with the highest IFNγ optical density (OD) values were most likely to subsequently test positive on both serological and culture tests, and this effect was detectable for up to 24 months after the IFNγ test. Furthermore, the higher the original IFNγ OD value, the greater the chance that a badger would subsequently test positive using serology. Relationships between IFNγ titres and mycobacterial culture results from different types of clinical sample suggest that the route of infection may affect the magnitude of immune response in badgers. These findings identify further value in the IFNγ test as a useful research tool, as it may help us to target studies at animals and groups that are most likely to succumb to more progressive disease.
Complex oxides and semiconductors exhibit distinct yet complementary properties
owing to their respective ionic and covalent natures. By electrically coupling
oxides to semiconductors within epitaxial heterostructures, enhanced or novel
functionalities beyond those of the constituent materials can potentially be
realized. Key to electrically coupling oxides to semiconductors is controlling
the physical and electronic structure of semiconductor – crystalline
oxide heterostructures. Here we discuss how composition of the oxide can be
manipulated to control physical and electronic structure in
Ba1-xSrxTiO3/ Ge and
SrZrxTi1-xO3/Ge heterostructures. In the
case of the former we discuss how strain can be engineered through composition
to enable the re-orientable ferroelectric polarization to be coupled to carriers
in the semiconductor. In the case of the latter we discuss how composition can
be exploited to control the band offset at the semiconductor - oxide interface.
The ability to control the band offset, i.e. band-gap engineering, provides a
pathway to electrically couple crystalline oxides to semiconductors to realize a
host of functionalities.
Accurate detection of infection with Mycobacterium bovis in live badgers would enable targeted tuberculosis control. Practical challenges in sampling wild badger populations mean that diagnosis of infection at the group (rather than the individual) level is attractive. We modelled data spanning 7 years containing over 2000 sampling events from a population of wild badgers in southwest England to quantify the ability to correctly identify the infection status of badgers at the group level. We explored the effects of variations in: (1) trapping efficiency; (2) prevalence of M. bovis; (3) using three diagnostic tests singly and in combination with one another; and (4) the number of badgers required to test positive in order to classify groups as infected. No single test was able to reliably identify infected badger groups if <90% of the animals were sampled (given an infection prevalence of 20% and group size of 15 badgers). However, the parallel use of two tests enabled an infected group to be correctly identified when only 50% of the animals were tested and a threshold of two positive badgers was used. Levels of trapping efficiency observed in previous field studies appear to be sufficient to usefully employ a combination of two existing diagnostic tests, or others of similar or greater accuracy, to identify infected badger groups without the need to capture all individuals. To improve on this, we suggest that any new diagnostic test for badgers would ideally need to be >80% sensitive, at least 94% specific, and able to be performed rapidly in the field.
The environmental setting of two late-prehistoric enclosures in upland Ardudwy, Gwynedd was investigated by pollen analysis of nearby valley mire deposits and of old ground surfaces revealed during excavation of the sites. Radiocarbon-dated pollen data indicate human influence on the local environment since Mesolithic times, with the major period of woodland clearance in the early Bronze Age. The two enclosures appear to have been constructed in an environment already substantially deforested. Remanent upland timber resources appear to have been substantially depleted during occupation of the sites, whilst soil acidification and/or climatic change may also have contributed to their eventual abandonment.
We describe epidemiological trends in Mycobacterium bovis infection in an undisturbed wild badger (Meles meles) population. Data were derived from the capture, clinical sampling and serological testing of 1803 badgers over 9945 capture events spanning 24 years. Incidence and prevalence increased over time, exhibiting no simple relationship with host density. Potential explanations are presented for a marked increase in the frequency of positive serological test results. Transmission rates (R0) estimated from empirical data were consistent with modelled estimates and robust to changes in test sensitivity and the spatial extent of the population at risk. The risk of a positive culture or serological test result increased with badger age, and varied seasonally. Evidence consistent with progressive disease was found in cubs. This study demonstrates the value of long-term data and the repeated application of imperfect diagnostic tests as indices of infection to reveal epidemiological trends in M. bovis infection in badgers.
The behaviour of certain infected individuals within socially structured populations can have a disproportionately large effect on the spatio-temporal distribution of infection. Endemic infection with Mycobacterium bovis in European badgers (Meles meles) in Great Britain and Ireland is an important source of bovine tuberculosis in cattle. Here we quantify the risk of infection in badger cubs in a high-density wild badger population, in relation to the infection status of resident adults. Over a 24-year period, we observed variation in the risk of cub infection, with those born into groups with resident infectious breeding females being over four times as likely to be detected excreting M. bovis than cubs from groups where there was no evidence of infection in adults. We discuss how our findings relate to the persistence of infection at both social group and population level, and the potential implications for disease control strategies.
We have imaged the magnetic domain structure on the surface of Fe (100) single crystals using energy resolved photoemission microscopy with circularly polarized soft x-rays. The contrast between different domains arises due to Magneto-dichroic effects in the emitted Auger electrons. This new approach offers a surface sensitive way to combine chemical and magnetic information on a microscopic scale.
The lattice reconstructed bec Ni (001) in Fe/Ni (001) ultrathin layers allows one to engineer films in which the in-plane 4-fold anisotropies and coercive fields can be varied and adjusted according to specific requirements. Magnetization reversals have been studied in layered structures of Fe/Ag/Fe/Ni (001). For Ag (001) interlayers thicker than 13 ML Magnetization reversal can proceed in two steps. In these samples the minor loops switch the magnetization of the Fe (001) layer from the parallel to the antiparallel configurations with respect to the magnetic moment of the Fe/Ni film. Such Minor loops exhibit a rectangular behavior with switching fields of 15–25 Oe. The lattice transformed Fe/Ni layers could be useful in spin-valve structures.
The Magnetoresistance (MR), Magnetic properties, and crystal structure of dc magnetron sputtered CO/Ag periodic multilayers have been investigated. The Co layer thickness was fixed at -30 Å while the thickness of the Ag layer was systematically varied. ‘Giant’ magnetoresistance was observed. The MR ratio has been found to decline monotonically with increasing Ag thickness in the range 30 Å to 107 Å. Although the maximum room temperature MR ratio is a Modest 4.78%, a more technologically significant measurement of field sensitivity (MR ratio/FWHM of the MR vs. H peak) is a promising 0.1%/Oe at its best. The effect of the number of bilayer units has also been examined and no substantial differences were noted between multilayers containing 8, 9, and 10 bilayer units. Coercivities as determined by both magnetometer and the splitting of the MR peaks are in agreement and increase from 25 to 38 Oe with increasing Ag thickness. Evidence for antiferromagnetic coupling is apparent in the hysteresis loops. High angle X-ray diffractometry (HXRD) in the θ-2θ mode revealed a strong Ag (111) texture in the film, with satellite peaks indicating a layered structure. Low angle XRD (LXRD) also yielded broad superlattice peaks in all samples at least to the second order.
Magnetic properties of ultrathin Fe and Fe60Au40, alloy films on Au (111) were studied by SQUID Magnetometry and conversion electron Mössbauer spectroscopy. In order to get information on the influence of interdiffusion, iron films with thin alloy zones at the interfaces to Au have been prepared by co-evaporation of iron and gold and compared with iron films with presumably sharp interfaces. It was found that the presence of an 0.5 ML (Mass coverage in Monolayer) alloy zone reduces the effective magnetic interface anisotropy field and affects the growth mode of a subsequently deposited iron film such that the film is more sensitive to annealing. Groundstate Magnetic Moments and hyperfine fields are significantly enhanced in Fe/Au(111) (tFe ≤ 4 ML) and Fe60Au40 films, compared to bulk Fe.
Structural features in magnetic multilayer films such as interfacial sharpness and in-plane stress are regarded as responsible for the perpendicular magnetic anisotropy observed in these films. The Multilayers often consist of alternating magnetic and non-Magnetic layers, and the degree of interfacial sharpness between the two is a critical component in producing perpendicular anisotropy. Additionally, in-plane stress affects the anisotropy through Magnetostriction. In this work, we measure both the composition modulation and the stress in multilayers of Pt/CO with x-ray diffraction. Quantitative information about the composition modulation is extracted by recursively fitting a model of multilayer diffraction to the high angle superlattice lines. The Model incorporates a composition modulation of variable amplitude, along with a statistical description of the layer thickness fluctuations.