2,843 research outputs found
Retrieving unobserved consideration sets from household panel data. (3rd round revision for Marketing Science).
Impact of sorbic acid on germinant receptor-dependent and -independent germination pathways in Bacillus cereus
Amino acid- and inosine-induced germination of Bacillus cereus ATCC 14579 spores was reversibly inhibited in the presence of 3 mM undissociated sorbic acid. Exposure to high hydrostatic pressure, Ca-dipicolinic acid (DPA), and bryostatin, an activator of PrkC kinase, negated this inhibition, pointing to specific blockage of signal transduction in germinant receptor-mediated germination
Running with Rugby Balls: Bulk Renormalization of Codimension-2 Branes
We compute how one-loop bulk effects renormalize both bulk and brane
effective interactions for geometries sourced by codimension-two branes. We do
so by explicitly integrating out spin-zero, -half and -one particles in
6-dimensional Einstein-Maxwell-Scalar theories compactified to 4 dimensions on
a flux-stabilized 2D geometry. (Our methods apply equally well for D dimensions
compactified to D-2 dimensions, although our explicit formulae do not capture
all divergences when D>6.) The renormalization of bulk interactions are
independent of the boundary conditions assumed at the brane locations, and
reproduce standard heat-kernel calculations. Boundary conditions at any
particular brane do affect how bulk loops renormalize this brane's effective
action, but not the renormalization of other distant branes. Although we
explicitly compute our loops using a rugby ball geometry, because we follow
only UV effects our results apply more generally to any geometry containing
codimension-two sources with conical singularities. Our results have a variety
of uses, including calculating the UV sensitivity of one-loop vacuum energy
seen by observers localized on the brane. We show how these one-loop effects
combine in a surprising way with bulk back-reaction to give the complete
low-energy effective cosmological constant, and comment on the relevance of
this calculation to proposed applications of codimension-two 6D models to
solutions of the hierarchy and cosmological constant problems.Comment: 42 pages + appendices. This is the final version which appears in
JHE
The nicotinic acetylcholine receptor subunit family expressed in the central nervous system of the freshwater snail Lymnaea stagnalis: Molecular and functional diversity of the neuronal nicotinic acetylcholine receptors in a molluscan species
Smit, A.B. [Promotor
Serving the king and resisting him: dilemmas of loyalty and treason in the revolt of the Netherlands
Associated factors of hope in cancer patients during treatment : a systematic literature review
Aim: To identify the associated factors of hope during treatment in cancer patients.
Background: Hope is very important to cancer patients at all stages of the disease process. Hope is seen as an important coping mechanism. Most research about hope in cancer patients considered the end of life or in palliative care. Several and different factors are associated with hope. It is not yet sufficiently clear which factors are associated with hope during the treatment.
Design: A systematic literature review of quantitative empirical studies on hope in cancer patients during treatment.
Data Sources: Search in MEDLINE (PubMed interface), CINAHL (EBSCO interface), Psychinfo and Cochrane (January 2009-December 2018).
Review Methods: Empirical quantitative studies were included regardless of the disease stage, written in English or Dutch, measuring hope from the perspective of cancer patients. Two authors independently screened all the studies and assessed their quality.
Results: Thirty-three studies were included. Positive relationship has been established between hope and quality of life, social support, spiritual and existential well-being. Hope appears to be negatively associated with symptom burden, psychological distress and depression. There appears to be no relationship between hope and demographic and clinical variables. The relationship between anxiety and hope remains unclear.
Conclusions: Hope primarily seems to be a process that takes place in a person's inner being rather than being determined from outside.
Impact: Health professionals may want to focus on the meaning of hope for cancer patients in relation to the associated factors. A better understanding of the meaning of hope during treatment can be of great value in supporting cancer patients with regard to treatment decisions, psychosocial support, the experienced quality of life and symptom burden and any wishes they may have with regard to advanced care planning
Modeling Unobserved Consideration Sets for Household Panel Data
We propose a new method to model consumers' consideration and choice processes. We develop a parsimonious probit type model for consideration and a multinomial probit model for choice, given consideration. Unlike earlier models of consideration ours is not prone to the curse of dimensionality, while we allow for very general structures of unobserved dependence in consideration among brands. In addition, our model allows for state dependence and marketing mix effects on consideration.Unique to this study is that we attempt to establish the validity of existing practice to infer consideration sets from observed choices in panel data. To this end, we use data collected in an on-line choice experiment involving interactive supermarket shelves and post-choice questionnaires to measure the choice protocol and stated consideration levels. We show with these experimental data that underlying consideration sets can be successfully retrieved from choice data alone and that there is substantial convergent validity of the stated and inferred consideration sets. We further find that consideration is a function of point-of-purchase marketing actions such as display and shelf space, and of consumer memory for recent choices.Next, we estimate the model on IRI panel data. We have three main results. First, compared with the single-stage probit model, promotion effects are larger and are inferred with smaller variances when they are included in the consideration stage of the two-stage model. Promotion effects are significant only in the two-stage model that includes consideration, whereas they are not in a single-stage choice model. Second, the price response curves of the two models are markedly diferent. The two-stage model offers a nice intuition for why promotional price response is different from regular price response. In addition and consistent with intuition, the two-stage model also implies that merchandizing has more effect on choice among those who did not buy the brand before than among those who already did. It is explained why a single-stage model does not harbor this feature. In fact, the single-stage model implies the opposite for smaller or more expensive brands. Third, we find that the consideration of brands does not covary greatly across brands once we take account of observed effects. Managerial implications and future research are also discussed.Consideration;choice;probit models
Gravitational Forces on a Codimension-2 Brane
We compute the gravitational response of six dimensional gauged, chiral
supergravity to localized stress energy on one of two space-filling branes,
including the effects of compactifying the extra dimensions and brane
back-reaction. We find a broad class of exact solutions, including various
black-brane solutions. Several approximate solutions are also described, such
as the near-horizon geometry of a small black hole which is argued to be
approximately described by a 6D Schwarzschild (or Kerr) black hole, with event
horizon appropriately modified to encode the brane back-reaction. The general
linearized far-field solutions are found in the 4D regime very far from the
source, and all integration constants are related to physical quantities
describing the branes and the localized energy source. The localized source
determines two of these, corresponding to the source mass and the size of the
strength of a coupling to a 4D scalar mode whose mass is parametrically smaller
than the KK scale. At large distances the solutions agree with those of 4D
general relativity, but for an intermediate range of distances (larger than the
KK scale) the solutions better fit a Brans-Dicke theory. For a realistic choice
of parameters the KK scale could lie at a micron, while the crossover to
Brans-Dicke behaviour could occur at around 10 microns. While allowed by
present data this points to potentially measurable changes to Newton's Law
arising at distances larger than the KK scale.Comment: 31 pages + appendices, 2 figure
Distributed SUSY Breaking: Dark Energy, Newton's Law and the LHC
We identify the underlying symmetry mechanism that suppresses the low-energy
effective 4D cosmological constant within 6D supergravity models, leading to
results suppressed by powers of the KK scale relative to the much larger masses
associated with particles localized on codimension-2 branes. In these models
the conditions for unbroken supersymmetry can be satisfied locally everywhere
within the extra dimensions, but are obstructed by global conditions like flux
quantization or the mutual inconsistency of boundary conditions at the various
branes. Consequently quantities forbidden by supersymmetry cannot be nonzero
until wavelengths of order the KK scale are integrated out, since only such
long wavelength modes see the entire space and so know that supersymmetry
breaks. We verify these arguments by extending earlier rugby-ball calculations
of one-loop vacuum energies to more general pairs of branes within two warped
extra dimensions. The predicted effective 4D vacuum energy density can be of
order C (m Mg/4 pi Mp)^4, where Mg (Mp) is the rationalized 6D (4D) Planck
scale and m is the heaviest brane-localized particle. Numerically this is C
(5.6 x 10^{-5} eV)^4 if we take m = 173 GeV and take Mg as small as possible
(10 TeV corresponding to KK size r < 1 micron), consistent with supernova
bounds. C is a constant depending on details of the bulk spectrum, which could
be ~ 500 for each of hundreds of fields. The value C ~ 6 x 10^6 gives the
observed Dark Energy density
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