306 research outputs found
A precision study of the fine tuning in the DiracNMSSM
Recently the DiracNMSSM has been proposed as a possible solution to reduce
the fine tuning in supersymmetry. We determine the degree of fine tuning needed
in the DiracNMSSM with and without non-universal gaugino masses and compare it
with the fine tuning in the GNMSSM. To apply reasonable cuts on the allowed
parameter regions we perform a precise calculation of the Higgs mass. In
addition, we include the limits from direct SUSY searches and dark matter
abundance. We find that both models are comparable in terms of fine tuning,
with the minimal fine tuning in the GNMSSM slightly smaller.Comment: 20 pages + appendices, 10 figure
Hospital service areas – a new tool for health care planning in Switzerland
BACKGROUND: The description of patient travel patterns and variations in health care utilization may guide a sound health care planning process. In order to accurately describe these differences across regions with homogeneous populations, small area analysis (SAA) has proved as a valuable tool to create appropriate area models. This paper presents the methodology to create and characterize population-based hospital service areas (HSAs) for Switzerland. METHODS: We employed federal hospital discharge data to perform a patient origin study using small area analysis. Each of 605 residential regions was assigned to one of 215 hospital provider regions where the most frequent number of discharges took place. HSAs were characterized geographically, demographically, and through health utilization indices and rates that describe hospital use. We introduced novel planning variables extracted from the patient origin study and investigated relationships among health utilization indices and rates to understand patient travel patterns for hospital use. Results were visualized as maps in a geographic information system (GIS). RESULTS: We obtained 100 HSAs using a patient origin matrix containing over four million discharges. HSAs had diverse demographic and geographic characteristics. Urban HSAs had above average population sizes, while mountainous HSAs were scarcely populated but larger in size. We found higher localization of care in urban HSAs and in mountainous HSAs. Half of the Swiss population lives in service areas where 65% of hospital care is provided by local hospitals. CONCLUSION: Health utilization indices and rates demonstrated patient travel patterns that merit more detailed analyses in light of political, infrastructural and developmental determinants. HSAs and health utilization indices provide valuable information for health care planning. They will be used to study variation phenomena in Swiss health care
Simple, Fast and Accurate Implementation of the Diffusion Approximation Algorithm for Stochastic Ion Channels with Multiple States
The phenomena that emerge from the interaction of the stochastic opening and
closing of ion channels (channel noise) with the non-linear neural dynamics are
essential to our understanding of the operation of the nervous system. The
effects that channel noise can have on neural dynamics are generally studied
using numerical simulations of stochastic models. Algorithms based on discrete
Markov Chains (MC) seem to be the most reliable and trustworthy, but even
optimized algorithms come with a non-negligible computational cost. Diffusion
Approximation (DA) methods use Stochastic Differential Equations (SDE) to
approximate the behavior of a number of MCs, considerably speeding up
simulation times. However, model comparisons have suggested that DA methods did
not lead to the same results as in MC modeling in terms of channel noise
statistics and effects on excitability. Recently, it was shown that the
difference arose because MCs were modeled with coupled activation subunits,
while the DA was modeled using uncoupled activation subunits. Implementations
of DA with coupled subunits, in the context of a specific kinetic scheme,
yielded similar results to MC. However, it remained unclear how to generalize
these implementations to different kinetic schemes, or whether they were faster
than MC algorithms. Additionally, a steady state approximation was used for the
stochastic terms, which, as we show here, can introduce significant
inaccuracies. We derived the SDE explicitly for any given ion channel kinetic
scheme. The resulting generic equations were surprisingly simple and
interpretable - allowing an easy and efficient DA implementation. The algorithm
was tested in a voltage clamp simulation and in two different current clamp
simulations, yielding the same results as MC modeling. Also, the simulation
efficiency of this DA method demonstrated considerable superiority over MC
methods.Comment: 32 text pages, 10 figures, 1 supplementary text + figur
Motivators of and barriers to becoming a COVID-19 convalescent plasma donor: A survey study
Objectives: To determine the motivators and barriers to COVID-19 convalescent plasma donation by those in the United Kingdom who have been diagnosed with or who have had symptoms of SARS-CoV-2 (COVID-19) but who have not donated. Background: Convalescent plasma from people recovered from COVID-19 with sufficient antibody titres is a potential option for the treatment and prevention of COVID-19. However, to date, recruiting and retaining COVID-19 convalescent plasma donors has been challenging. Understanding why those eligible to donate COVID-19 convalescent plasma have not donated is critical to developing recruitment campaigns. Methods/Materials: A total of 419 UK residents who indicated that they had been infected with COVID-19 and who lived within 50 km of sites collecting COVID-19 convalescent plasma completed an online survey between 25th June and 5th July 2020. Respondents completed items assessing their awareness of convalescent plasma, motivations and barriers to donation and intention to donate COVID-19 convalescent plasma. Results: Awareness of COVID-19 convalescent plasma was low. Exploratory factor analysis identified six motivations and seven barriers to donating. A stronger sense of altruism through adversity and moral and civic duty were positively related to intention to donate, whereas generic donation fears was negatively related. Conclusions: Once potential donors are aware of convalescent plasma, interventions should focus on the gratitude and reciprocity that those eligible to donate feel, along with a focus on (potentially) helping family and norms of what people ought to do. Fears associated with donation should not be neglected, and strategies that have been successfully used tor recruit whole-blood donors should be adapted and deployed to recruit COVID-19 convalescent plasma donors
The Role of Bile in the Regulation of Exocrine Pancreatic Secretion
As early as 1926 Mellanby (1) was able to show that introduction of bile into the duodenum of anesthetized cats produces a copious flow of pancreatic juice. In conscious dogs, Ivy & Lueth (2) reported, bile is only a weak stimulant of pancreatic secretion. Diversion of bile from the duodenum, however, did not influence pancreatic volume secretion stimulated by a meal (3,4). Moreover, Thomas & Crider (5) observed that bile not only failed to stimulate the secretion of pancreatic juice but also abolished the pancreatic response to intraduodenally administered peptone or soap
Higgs Boson Masses in the Complex NMSSM at One-Loop Level
The Next-to-Minimal Supersymmetric Extension of the Standard Model (NMSSM)
with a Higgs sector containing five neutral and two charged Higgs bosons allows
for a rich phenomenology. In addition, the plethora of parameters provides many
sources of CP violation. In contrast to the Minimal Supersymmetric Extension,
CP violation in the Higgs sector is already possible at tree-level. For a
reliable understanding and interpretation of the experimental results of the
Higgs boson search, and for a proper distinction of Higgs sectors provided by
the Standard Model or possible extensions, the Higgs boson masses have to be
known as precisely as possible including higher-order corrections. In this
paper we calculate the one-loop corrections to the neutral Higgs boson masses
in the complex NMSSM in a Feynman diagrammatic approach adopting a mixed
renormalization scheme based on on-shell and conditions. We study
various scenarios where we allow for tree-level CP-violating phases in the
Higgs sector and where we also study radiatively induced CP violation due to a
non-vanishing phase of the trilinear coupling in the stop sector. The
effects on the Higgs boson phenomenology are found to be significant. We
furthermore estimate the theoretical error due to unknown higher-order
corrections by both varying the renormalization scheme of the top and bottom
quark masses and by adopting different renormalization scales. The residual
theoretical error can be estimated to about 10%
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