379 research outputs found
Your data is (not) my data: The role of social value orientation in sharing data about others
The personal data consumers share with companies on a daily basis often also involves other people. However, prior research has focused almost exclusively on how consumers make decisions about their own data. In this research, we explore how consumersâ social value orientation impacts their decisions regarding data about others. In contrast to the notion of proselfs as âselfishâ decision-makers, across four studies we find that proselfs are less likely than prosocials to share data about others with third parties. We show that this effect arises because proselfs feel less ownership over data they hold about others than prosocials, which in turn reduces their willingness to share it. Overall, this work contributes to literature on social value orientation as well as privacy decision-making and helps marketers and policy makers in designing interdependent privacy choice contexts
Computation with Advice
Computation with advice is suggested as generalization of both computation
with discrete advice and Type-2 Nondeterminism. Several embodiments of the
generic concept are discussed, and the close connection to Weihrauch
reducibility is pointed out. As a novel concept, computability with random
advice is studied; which corresponds to correct solutions being guessable with
positive probability. In the framework of computation with advice, it is
possible to define computational complexity for certain concepts of
hypercomputation. Finally, some examples are given which illuminate the
interplay of uniform and non-uniform techniques in order to investigate both
computability with advice and the Weihrauch lattice
Making big steps in trajectories
We consider the solution of initial value problems within the context of
hybrid systems and emphasise the use of high precision approximations (in
software for exact real arithmetic). We propose a novel algorithm for the
computation of trajectories up to the area where discontinuous jumps appear,
applicable for holomorphic flow functions. Examples with a prototypical
implementation illustrate that the algorithm might provide results with higher
precision than well-known ODE solvers at a similar computation time
Radiofrequency applicator concepts for simultaneous MR imaging and hyperthermia treatment of glioblastoma multiforme: a 298 MHz(7.0 Tesla) thermal magnetic resonancesimulation study
Glioblastoma multiforme is the most frequent and most aggressive malignant brain tumor with de facto no long term curation by the use of current multimodal therapeutic approaches. The efficacy of brachytherapy and enhancing interstitial hyperthermia has been demonstrated. RF heating at ultrahigh fields (B0=7.0T, f=298MHz) has the potential of delivering sufficiently large thermal dosage for hyperthermia of relatively large tumor areas. This work focuses on electromagnetic field (EMF) simulations and provides realistic applicator designs tailored for simultaneous RF heating and MRI. Our simulations took advantage of target volumes derived from patient data, and our preliminary results suggest that RF power can be focused to both a small tumor area and a large clinical target volume
Physiological concentrations of bile acids down-regulate agonist induced secretion in colonic epithelial cells
In patients with bile acid malabsorption, high concentrations of bile acids enter the colon and stimulate Clâ and fluid secretion, thereby causing diarrhoea. However, deoxycholic acid (DCA), the predominant colonic bile acid, is normally present at lower concentrations where its role in regulating transport is unclear. Thus, the current study set out to investigate the effects of physiologically relevant DCA concentrations on colonic epithelial secretory function. Clâ secretion was measured as changes in short-circuit current across voltage-clamped T84 cell monolayers. At high concentrations (0.5â1 mM), DCA acutely stimulated Clâ secretion but this effect was associated with cell injury, as evidenced by decreased transepithelial resistance (TER) and increased lactate dehydrogenase (LDH) release. In contrast, chronic (24 hrs) exposure to lower DCA concentrations (10â200 ÎŒM) inhibited responses to Ca2+ and cAMP-dependent secretagogues without altering TER, LDH release, or secretagogue-induced increases in intracellular second messengers. Other bile acids â taurodeoxycholic acid, chenodeoxycholic acid and cholic acid â had similar antisecretory effects. DCA (50 ÎŒM) rapidly stimulated phosphorylation of the epidermal growth factor receptor (EGFr) and both ERK and p38 MAPKs (mitogen-activated protein kinases). The EGFr inhibitor, AG1478, and the protein synthesis inhibitor, cycloheximide, reversed the antisecretory effects of DCA, while the MAPK inhibitors, PD98059 and SB203580, did not. In summary, our studies suggest that, in contrast to its acute prosecretory effects at pathophysiological concentrations, lower, physiologically relevant, levels of DCA chronically down-regulate colonic epithelial secretory function. On the basis of these data, we propose a novel role for bile acids as physiological regulators of colonic secretory capacity
Computing domains of attraction for planar dynamics
In this note we investigate the problem of computing the
domain of attraction of a
ow on R2 for a given attractor. We consider
an operator that takes two inputs, the description of the
ow and a cover
of the attractors, and outputs the domain of attraction for the given
attractor. We show that: (i) if we consider only (structurally) stable
systems, the operator is (strictly semi-)computable; (ii) if we allow all
systems de ned by C1-functions, the operator is not (semi-)computable.
We also address the problem of computing limit cycles on these systems
BDNF is a mediator of glycolytic fiber-type specification in mouse skeletal muscle
Brain-derived neurotrophic factor (BDNF) influences the differentiation, plasticity, and survival of central neurons and likewise, affects the development of the neuromuscular system. Besides its neuronal origin, BDNF is also a member of the myokine family. However, the role of skeletal muscle-derived BDNF in regulating neuromuscular physiology in vivo remains unclear. Using gain- and loss-of-function animal models, we show that muscle-specific ablation of BDNF shifts the proportion of muscle fibers from type IIB to IIX, concomitant with elevated slow muscle-type gene expression. Furthermore, BDNF deletion reduces motor end plate volume without affecting neuromuscular junction (NMJ) integrity. These morphological changes are associated with slow muscle function and a greater resistance to contraction-induced fatigue. Conversely, BDNF overexpression promotes a fast muscle-type gene program and elevates glycolytic fiber number. These findings indicate that BDNF is required for fiber-type specification and provide insights into its potential modulation as a therapeutic target in muscle diseases
Continuous Team Semantics
Peer reviewe
Continuous Team Semantics
We study logics with team semantics in computable metric spaces. We show how to define approximate versions of the usual independence/dependence atoms. For restricted classes of formulae, we show that we can assume w.l.o.g.~that teams are closed sets. This then allows us to import techniques from computable analysis to study the complexity of formula satisfaction and model checking
Radiofrequency applicator concepts for thermal magnetic resonance of brain tumors at 297 MHz (7.0 Tesla)
PURPOSE: Thermal intervention is a potent sensitizer of cells to chemo- and radiotherapy in cancer treatment. Glioblastoma multiforme (GBM) is a potential clinical target, given the cancer's aggressive nature and resistance to current treatment options. The annular phased array (APA) technique employing electromagnetic waves in the radiofrequency (RF) range allows for localized temperature increase in deep seated target volumes (TVs). Reports on clinical applications of the APA technique in the brain are still missing. Ultrahigh field magnetic resonance (MR) employs higher frequencies than conventional MR and has potential to provide focal temperature manipulation, high resolution imaging and noninvasive temperature monitoring using an integrated RF applicator (ThermalMR). This work examines the applicability of RF applicator concepts for ThermalMR of brain tumors at 297âMHz (7.0 Tesla). METHODS: Electromagnetic field (EMF) simulations are performed for clinically realistic data based on GBM patients. Two algorithms are used for specific RF energy absorption rate based thermal intervention planning for small and large TVs in the brain, aiming at maximum RF power deposition or RF power uniformity in the TV for 10âRF applicator designs. RESULTS: For both TVs , the power optimization outperformed the uniformity optimization. The best results for the small TV are obtained for the 16 element interleaved RF applicator using an elliptical antenna arrangement with water bolus. The two row elliptical RF applicator yielded the best result for the large TV. DISCUSSION: This work investigates the capacity of ThermalMR to achieve targeted thermal interventions in model systems resembling human brain tissue and brain tumors
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