5,208 research outputs found
Frequency invariant beamforming for two-dimensional and three-dimensional arrays
A novel method for the design of two-dimensional (2-D) and three-dimensional (3-D)arrays with frequency invariant beam patterns is proposed. By suitable substitu-
tions, the beam pattern of a 2-D or 3-D arrays can be regarded as the 3-D or 4-D Fourier transform of its spatial and temporal parameters. Since frequency invariance
can be easily imposed in the Fourier domain, a simple design method is derived. Design examples for the 2-D case are provided
A simulation model of Rhizome networks for Fallopia japonica (Japanese Knotweed) in the United Kingdom
Fallopia japonica (Japanese knotweed) is an aggressively invasive herbaceous perennial
that causes substantial economic and environmental damage in the United
Kingdom (UK). As such, it is of considerable concern to councils, environmental
groups, private landowners and property developers. We construct a 3D correlated
random walk model of the development of the subterranean rhizome network for a
single stand of F. japonica. The formulation of this model uses detailed knowledge
of the morphology and physiology of the plant, both of which differ in the UK to
that of its native habitat due to factors including a lack of predation and competition,
longer growth seasons and favourable environmental conditions in the UK.
Field data obtained as a part of this study are discussed and used in the model for
parameterisation and validation. The simulation captures the field data well and predicts, for example, quadratic growth in time for the stand area. Furthermore,
the role of a selection of parameters on long-term stand development are discussed,
highlighting some key factors affecting vegetative spread rates
First-in-human phase 1 study of the BTK inhibitor GDC-0853 in relapsed or refractory B-cell NHL and CLL
Portfolio Vol. III N 4
Moll, Willlie. I Was in Kitchener Camp. Prose. 5-6.
Barrington, John. The Pledging of Homer McGunk. Prose. 7-9.
Stewart, John. In Time of Death. Prose. 10.
Lindsey, Arthur Ward. Retrospect. Prose. 11-13.
Phillips, Allison. Blue Moon. Poetry. 14.
Yoxall, Lindsey E. Pro Patria. Prose. 15-16.
Beckham, Adela. Wind--Dreams. Poetry. 18.
Fields, Brooks. The Doctor Takes a Trip. Prose. 19-20.
Deane, Dorothy. Review of New Books. Prose. 21.
Smith, Duke. Review of New Recordings. Prose. 21.
Timrud, David. Refugee. Prose. 22-23
Youth ministry at the margins and/or centre as space of the other: Reflections on the resolutions of the Anglican dioceses in the Western Cape 2017
Youth within the context of faith-based organisations carry with them certain power relations
and misconstrued connotations. These power relations and connotations can contribute to
alienation and marginalisation. The resolutions taken at the recent synods of the three
dioceses within the Western Cape reflect and identify the areas - both liturgical and
governance - of marginalisation of youth within the Anglican Church in southern Africa. The
resolutions also call on the church governing bodies and the leaders to create safe spaces
for the youth to be a central part of the mission of the church. Areas such as liturgy, training
and formation, contemporary worship and nurturing relationships are identified within
the resolutions. Theological notions of personhood within the Anglican tradition are to be
investigated as possible motivations for more acceptable power relations of the youth and
leaders and governance structures. What implications do such theological formulations have
for the space that the youth occupy within the margins of the church? A critical reflection of
the synod resolutions answers such questions and points to some contours for sense making
of the youth within the margins of the church from a faith-based organisational perspective
Living alone, loneliness and lack of emotional support as predictors of suicide and self-harm: A nine-year follow up of the UK Biobank cohort
Background:
The association between loneliness and suicide is poorly understood. We investigated how living alone, loneliness and emotional support were related to suicide and self-harm in a longitudinal design.
Methods:
Between 2006 and 2010 UK Biobank recruited and assessed in detail over 0.5 million people in middle age. Data were linked to prospective hospital admission and mortality records. Adjusted Cox regression models were used to investigate relationships between living arrangements, loneliness and emotional support, and both suicide and self-harm as outcomes.
Results:
For men, both living alone (Hazard Ratio (HR) 2.16, 95%CI 1.51-3.09) and living with non-partners (HR 1.80, 95%CI 1.08-3.00) were associated with death by suicide, independently of loneliness, which had a modest relationship with suicide (HR 1.43, 95%CI 0.1.01-2.03). For women, there was no evidence that living arrangements, loneliness or emotional support were associated with death by suicide. Associations between living alone and self-harm were explained by health for women, and by health, loneliness and emotional support for men. In fully adjusted models, loneliness was associated with hospital admissions for self-harm in both women (HR 1.89, 95%CI 1.57-2.28) and men (HR 1.74, 95%CI 1.40-2.16).
Limitations:
Loneliness and emotional support were operationalized using single item measures.
Conclusions:
For men - but not for women - living alone or living with a non-partner increased the risk of suicide, a finding not explained by subjective loneliness. Overall, loneliness may be more important as a risk factor for self-harm than for suicide. Loneliness also appears to lessen the protective associations of cohabitation
Different bacterial gene expression patterns and attenuated host immune responses are associated with the evolution of low-level vancomycin resistance during persistent methicillin-resistant Staphylococcus aureus bacteraemia
BACKGROUND: Low-level vancomycin resistance in Staphylococcus aureus (vancomycin-intermediate S. aureus (VISA) and hetero-VISA [hVISA]) emerges during persistent infection and failed vancomycin therapy. Up-regulation of genes associated with the "cell wall stimulon" and mutations in the vraSR operon have both been implicated in the development of resistance, however the molecular mechanisms of resistance are not completely understood. To further elucidate the mechanisms leading to resistance transcriptome comparisons were performed using multiple clinical pairs of vancomycin-susceptible S. aureus (VSSA) and hVISA/VISA (n = 5), and three VSSA control pairs from hospitalized patients with persistent bacteraemia that did not develop hVISA/VISA. Based on the transcriptome results multiple genes were sequenced and innate immune system stimulation was assessed in the VSSA and hVISA/VISA pairs. RESULTS: Here we show that up-regulation of vraS and the "cell wall stimulon" is not essential for acquisition of low-level vancomycin resistance and that different transcriptional responses occur, even between closely related hVISA/VISA strains. DNA sequencing of vraSR, saeSR, mgrA, rot, and merR regulatory genes and upstream regions did not reveal any differences between VSSA and hVISA/VISA despite transcriptional changes suggesting mutations in these loci may be linked to resistance in these strains. Enhanced capsule production and reduced protein A expression in hVISA/VISA were confirmed by independent bioassays and fully supported the transcriptome data. None of these changes were observed in the three control pairs that remained vancomycin-susceptible during persistent bacteremia. In a macrophage model of infection the changes in cell surface structures in hVISA/VISA strains were associated with significantly reduced NF-kappaB activation resulting in reduced TNF-alpha and IL-1beta expression. CONCLUSION: We conclude that there are multiple pathways to low-level vancomycin resistance in S. aureus, even among closely related clinical strains, and these can result in an attenuated host immune response. The persistent infections associated with hVISA/VISA strains may be a consequence of changes in host pathogen interactions in addition to the reduced antibiotic susceptibility
The properties of SCUBA cores in the Perseus molecular cloud: the bias of clump-finding algorithms
We present a new analysis of the properties of star-forming cores in the
Perseus molecular cloud, identified in SCUBA 850 micron data. Our goal is to
determine which core properties can be robustly identified and which depend on
the extraction technique. Four regions in the cloud are examined: NGC1333,
IC348/HH211, L1448 and L1455. We identify clumps of dust emission using two
popular automated algorithms, CLFIND and GAUSSCLUMPS, finding 85 and 122 clumps
in total respectively. Some trends are true for both populations: clumps become
increasingly elongated over time and are consistent with constant surface
brightness objects, with an average brightness ~4 to 10 times larger than the
surrounding molecular cloud; the clump mass distribution (CMD) resembles the
stellar intial mass function, with a slope alpha = -2.0+/-0.1 for CLFIND and
alpha = -3.15+/-0.08 for GAUSSCLUMPS, which straddle the Salpeter value. The
mass at which the slope shallows (similar for both algorithms at M~6 Msun)
implies a star-forming efficiency of between 10 and 20 per cent. Other trends
reported elsewhere depend on the clump-finding technique: we find protostellar
clumps are both smaller (for GAUSSCLUMPS) and larger (for CLFIND) than their
starless counterparts; the functional form, best-fitting to the CMD, is
different for the two algorithms. The GAUSSCLUMPS CMD is best-fitted with a
log-normal distribution, whereas a broken power law is best for CLFIND; the
reported lack of massive starless cores in previous studies can be seen in the
CLFIND but not the GAUSSCLUMPS data. Our approach highlights similarities and
differences between the clump populations, illustrating the caution that must
be exercised when comparing results from different studies and interpreting the
properties of continuum cores.Comment: 19 pages, 17 figures, accepted for publication by MNRA
D-Brane Dynamics and NS5 Rings
We consider the classical motion of a probe D-brane moving in the background
geometry of a ring of NS5 branes, assuming that the latter are non-dynamical.
We analyse the solutions to the Dirac-Born-Infield (DBI) action governing the
approximate dynamics of the system. In the near horizon (throat) approximation
we find several exact solutions for the probe brane motion. These are compared
to numerical solutions obtained in more general cases. One solution of
particular interest is when the probe undergoes oscillatory motion through the
centre of the ring (and perpendicular to it). By taking the ring radius
sufficiently large, this solution should remain stable to any stringy
corrections coming from open-strings stretching between the probe and the
NS5-branes along the ring.Comment: 17 pages, Latex, 8 figures; References adde
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