45 research outputs found
Higgs boson mass limits in perturbative unification theories
Motivated in part by recent demonstrations that electroweak unification into
a simple group may occur at a low scale, we detail the requirements on the
Higgs mass if the unification is to be perturbative. We do this for the
Standard Model effective theory, minimal supersymmetry, and next-to-minimal
supersymmetry with an additional singlet field. Within the Standard Model
framework, we find that perturbative unification with sin2(thetaW)=1/4 occurs
at Lambda=3.8 TeV and requires mh<460 GeV, whereas perturbative unification
with sin2(thetaW)=3/8 requires mh<200 GeV. In supersymmetry, the presentation
of the Higgs mass predictions can be significantly simplified, yet remain
meaningful, by using a single supersymmetry breaking parameter Delta_S. We
present Higgs mass limits in terms of Delta_S for the minimal supersymmetric
model and the next-to-minimal supersymmetric model. We show that in
next-to-minimal supersymmetry, the Higgs mass upper limit can be as large as
500 GeV even for moderate supersymmetry masses if the perturbative unification
scale is low (e.g., Lambda=10 TeV).Comment: 20 pages, latex, 6 figures, references adde
Are Solar Active Regions with Major Flares More Fractal, Multifractal, or Turbulent than Others?
Multiple recent investigations of solar magnetic field measurements have
raised claims that the scale-free (fractal) or multiscale (multifractal)
parameters inferred from the studied magnetograms may help assess the eruptive
potential of solar active regions, or may even help predict major flaring
activity stemming from these regions. We investigate these claims here, by
testing three widely used scale-free and multiscale parameters, namely, the
fractal dimension, the multifractal structure function and its inertial-range
exponent, and the turbulent power spectrum and its power-law index, on a
comprehensive data set of 370 timeseries of active-region magnetograms (17,733
magnetograms in total) observed by SOHO's Michelson Doppler Imager (MDI) over
the entire Solar Cycle 23. We find that both flaring and non-flaring active
regions exhibit significant fractality, multifractality, and non-Kolmogorov
turbulence but none of the three tested parameters manages to distinguish
active regions with major flares from flare-quiet ones. We also find that the
multiscale parameters, but not the scale-free fractal dimension, depend
sensitively on the spatial resolution and perhaps the observational
characteristics of the studied magnetograms. Extending previous works, we
attribute the flare-forecasting inability of fractal and multifractal
parameters to i) a widespread multiscale complexity caused by a possible
underlying self-organization in turbulent solar magnetic structures, flaring
and non-flaring alike, and ii) a lack of correlation between the fractal
properties of the photosphere and overlying layers, where solar eruptions
occur. However useful for understanding solar magnetism, therefore, scale-free
and multiscale measures may not be optimal tools for active-region
characterization in terms of eruptive ability or, ultimately,for major
solar-flare prediction.Comment: 25 pages, 7 figures, 2 tables, Solar Phys., in pres
Surveillance des ecosystemes pastoraux Sahaliens et cartographie de la couverture nuageuse et des precipitations
Colorectal cancer screening
Colorectal cancer is one of the most common malignancies in Australia, and screening to detect it an earlier stage is cost-effective. Furthermore, detection and removal of precursor polyps can reduce incidence. Currently, there are limited data to determine the screening rate in Australia, but it is certainly lower than the 80% screening rate considered desirable. Whether colonoscopy is used as the screening test or to follow up positive results of an initial non-invasive test, it plays a fundamental role. Despite high sensitivity and specificity, it is expensive and invasive with measurable risk and is not acceptable as an initial test to many participants. It does not provide complete protection, and interval cancers between planned colonoscopies are associated with proximal location, origin in sessile serrated adenomas and operator-dependent factors. An essential component of colorectal screening is the measurement of colonoscopy quality indicators, such as caecal intubation and adenoma detection rates, which are known to be associated with the rate of interval cancer. The non-invasive screening test currently recommended in Australia is biennial testing for faecal occult blood between the ages of 50 and 75 using a faecal immunochemical test, with positives evaluated by colonoscopy. This is provided through the National Bowel Cancer Screening Programme, currently for those at the ages of 50, 55, 60 and 65 years, with full implementation of biennial screening by 2020. To improve screening in Australia, the most fruitful approach may be to acknowledge that there is a choice of screening tests and to focus on the goal of improving overall participation rate and being able to measure this
SG_Nested_Data
Historic dataset of Scottish coastal grasslands, derived from the Scottish Coastal Survey (1975–1977); For details see: Shaw, M.W., Hewett, D.G. & Pizzey, J.M. (1983). Scottish coastal survey. Institute of Terrestrial Ecology. Bangor Research Station, Bangor, Gwynedd. The dataset is nested: i.e. records of plant species with taken following a hierarchical sampling design, measuring nested community compositions at 4m2 and 200m2. The uploaded dataset comprises species information (recorded as octets) on 3033 nested samples
Communication in medical records : Intergroup language and patient care
Communication failures in the complex environment of hospital care affect the quality of care and occurrence of inadvertent harm. This study investigated doctors' written communication using a sample of medical records, specifically doctors' progress notes, and the frameworks of social identity and communication accommodation theories. These records include standardized and stylized language, and are intended to record assessment and treatment of patients according to known guidelines for practice. An interpretive analysis of the language and discourse in these records revealed that doctors used medical record entries both to express their specialty identity and to negotiate intergroup conflict. Nonaccommodation and interspecialty conflict sometimes took precedence over facilitation of patient treatment and management. Thus, intergroup communication in this context can constitute a serious threat to the quality of patient care