124 research outputs found
An Affordance-Actualization Perspective on Smart Service Systems
Smart physical products increasingly shape a connected IoT world and serve as boundary objects for the formation of âsmart service systemsâ. While these systems bear the potential to co-create value between partners in various industries, IS research still struggles to fully capture the phenomenon to support successful digital innovation in IoT settings.
In our work, we analyze the phenomenon of smart service systems taking an affordance-actualization perspective. Based on a qualitative content analysis of a multi-case study, we identify elements and propositions to build mid-range theoretical knowledge for smart service systems. We suggest that providers and users of smart products not only realize their own affordances via their actions but might also affect the immediate concrete outcomes of partners. The developed theoretical framework and six distinct propositions should build the theoretical base for further research into the phenomenon in IS research
An Affordance-Actualization Perspective on Smart Service Systems
Smart physical products increasingly shape a connected IoT world and serve as boundary objects for the formation of âsmart service systemsâ. While these systems bear the potential to co-create value between partners in various industries, IS research still struggles to fully capture the phenomenon to support successful digital innovation in IoT settings. In our work, we analyze the phenomenon of smart service systems taking an affordance-actualization perspective. Based on a qualitative content analysis of a multi-case study, we identify elements and propositions to build mid-range theoretical knowledge for smart service systems. We suggest that providers and users of smart products not only realize their own affordances via their actions but might also affect the immediate concrete outcomes of partners. The developed theoretical framework and six distinct propositions should build the theoretical base for further research into the phenomenon in IS research
A Combined Score of Circulating miRNAs Allows Outcome Prediction in Critically Ill Patients
Background and aims: Identification of patients with increased risk of mortality represents an important prerequisite for an adapted adequate and individualized treatment of critically ill patients. Circulating micro-RNA (miRNA) levels have been suggested as potential biomarkers at the intensive care unit (ICU), but none of the investigated miRNAs displayed a sufficient sensitivity or specificity to be routinely employed as a single marker in clinical practice. Methods and results: We recently described alterations in serum levels of 7 miRNAs (miR-122, miR-133a, miR-143, miR-150, miR-155, miR-192, and miR-223) in critically ill patients at a medical ICU. In this study, we re-analyzed these previously published data and performed a combined analysis of these markers to unravel their potential as a prognostic scoring system in the context of critical illness. Based on the Youdenâs index method, cut-off values were systematically defined for dysregulated miRNAs, and a âmiRNA survival scoreâ was calculated. Patients with high scores displayed a dramatically impaired prognosis compared to patients with low values. Additionally, the predictive power of our score could be further increased when the patientâs age was additionally incorporated into this score. Conclusions: We describe the first miRNA-based biomarker score for prediction of medical patientsâ outcome during and after ICU treatment. Adding the patientsâ age into this score was associated with a further increase in its predictive power. Further studies are needed to validate the clinical utility of this score in risk-stratifying critically ill patients
A case report of an excellent response to interferon- α in a patient with functional metastasized neuroendocrine tumor refractory to other treatments
Introduction:
Interferon alpha (IFNα) has been used for a long time in patients with functionally active neuroendocrine tumors (NET). However, due to the unfavorable toxicity profile of interferon, the perceived limited efficacy as well as the development of novel substances, IFNα is only used sparingly in the treatment of NET to date.
Patients concerns and diagnosis:
We describe the case of a 63-year-old male patient with highly differentiated, functional NET of the ileum and synchronous liver metastasis.
Interventions:
After failure of classical therapies including dose-intensified somatostatin analog treatment and palliative primary tumor resection, a therapy with pegylated IFNα2a (135 Όg/wk) was initiated. Following this treatment, the patient fully recovered from signs of hypersecretion and demonstrated an impressive tumor response.
Outcomes:
Thirty months after initiating IFNα, the patient is still free of clinical symptoms and shows a sustained tumor response. Notably, no relevant side effects were observed.
Conclusion:
Our case report supports the use of IFNα in patients with functional NET refractory to classical treatments
Smoothed Particle Hydrodynamics simulations of white dwarf collisions and close encounters
The collision of two white dwarfs is a quite frequent event in dense stellar
systems, like globular clusters and galactic nuclei. In this paper we present
the results of a set of simulations of the close encounters and collisions of
two white dwarfs. We use an up- to-date smoothed particle hydrodynamics code
that incorporates very detailed input physics and an improved treatment of the
artificial viscosity. Our simulations have been done using a large number of
particles (~ 4 \times 10^5) and covering a wide range of velocities and initial
distances of the colliding white dwarfs. We discuss in detail when the initial
eccentric binary white dwarf survives the closest approach, when a lateral
collision in which several mass transfer episodes occur is the outcome of the
newly formed binary system, and which range of input parameters leads to a
direct collision, in which only one mass transfer episode occurs. We also
discuss the characteristics of the final configuration and we assess the
possible observational signatures of the merger, such as the associated
gravitational waveforms and the fallback luminosities. We find that the overall
evolution of the system and the main characteristics of the final object agree
with those found in previous studies. We also find that the fallback
luminosities are close to 10^48 erg/s. Finally, we find as well that in the
case of lateral and direct collisions the gravitational waveforms are
characterized by large-amplitude peaks which are followed by a ring-down phase,
while in the case in which the binary white dwarf survives the closest
approach, the gravitational pattern shows a distinctive behavior, typical of
eccentric systems.Comment: 16 pages, 12 figures. Accepted for publication in MNRA
Real-time energy dynamics in spin-1/2 Heisenberg chains
We study the real-time dynamics of the local energy density in the spin-1/2
XXZ chain starting from initial states with an inhomogeneous profile of bond
energies. Numerical simulations of the dynamics of the initial states are
carried out using the adaptive time-dependent density matrix renormalization
group method. We analyze the time dependence of the spatial variance associated
with the local energy density to classify the dynamics as either ballistic or
diffusive. Our results are consistent with ballistic behavior both in the
massless and the massive phase. We also study the same problem within Luttinger
Liquid theory and obtain that energy wave-packets propagate with the sound
velocity. We recover this behavior in our numerical simulations in the limit of
very weakly perturbed initial states.Comment: 15 pages, 21 figures, version as published, minor stylistic change
A comprehensive set of simulations of high-velocity collisions between main sequence stars
We report on a very large set of simulations of collisions between two main
sequence (MS) stars. These computations were done with the ``Smoothed Particle
Hydrodynamics'' method. Realistic stellar structure models for evolved MS stars
were used. In order to sample an extended domain of initial parameters space
(masses of the stars, relative velocity and impact parameter), more than 15000
simulations were carried out. We considered stellar masses ranging between 0.1
and 75 Msun and relative velocities up to a few thousands km/s. To limit the
computational burden, a resolution of 2000-30000 particles per star was used.
The primary goal of this study was to build a complete database from which the
result of any collision can be interpolated. This allows us to incorporate the
effects of stellar collisions with an unprecedented level of realism into
dynamical simulations of galactic nuclei and other dense stellar clusters. We
make the data describing the initial condition and outcome (mass and energy
loss, angle of deflection) of all our simulations freely available on the
Internet. We find that the outcome of collisions depends sensitively on the
stellar structure and that, in most cases, using polytropic models is
inappropriate. Published fitting formulas for the collision outcomes,
established from a limited set of collisions, prove of limited use because they
do not allow robust extrapolation to other stellar structures or relative
velocities.Comment: 45 pages, 44 figures. Modified to reflect the changes in the
published version (MNRAS). PDF version with high-res figures at
http://obswww.unige.ch/~freitag/papers/article_collisions.pdf, simulation
data at http://obswww.unige.ch/~freitag/MODEST_WG4/FB_Collision_Data/, movies
at http://obswww.unige.ch/~freitag/collisions/animations/index.htm
Circulating MicroRNA-223 Serum Levels Do Not Predict Sepsis or Survival in Patients with Critical Illness
Background and Aims. Dysregulation of miR-223 was recently linked to various diseases associated with systemic inflammatory responses such as type 2 diabetes, cancer, and bacterial infections. However, contradictory results are available on potential alterations of miR-223 serum levels during sepsis. We thus aimed to evaluate the diagnostic and prognostic value of miR-223 serum concentrations in patients with critical illness and sepsis. Methods. We used i.v. injection of lipopolysaccharide (LPS) as well as cecal pole ligation and puncture (CLP) for induction of polymicrobial sepsis in mice and measured alterations in serum levels of miR-223. These results from mice were translated into a large and well-characterized cohort of critically ill patients admitted to the medical intensive care unit (ICU). Finally, results from analysis in patients were correlated with clinical data and extensive sets of routine and experimental biomarkers. Results. Although LPS injection induced moderately elevated serum miR-223 levels in mice, no significant alterations in miR-223 serum levels were found in mice after CLP-induced sepsis. In accordance with these results from animal models, serum miR-223 levels did not differ between critically ill patients and healthy controls. However, ICU patients with more severe disease (APACHE-II score) showed moderately reduced circulating miR-223. Strikingly, no differences in miR-223 levels were found in critically ill patients with or without sepsis, and serum levels of miR-223 did not correlate with classical markers of inflammation or bacterial infection. Finally, low miR-223 serum levels were moderately associated with an unfavorable prognosis of patients during the ICU treatment but did not predict long-term mortality. Conclusion. Recent reports on alterations in miR-223 serum levels during sepsis revealed contradictory results, preventing a potential use of this miRNA in clinical routine. We clearly show that miR-223 serum levels do not reflect the presence of sepsis neither in mouse models nor in a large cohort of ICU patients and do not indicate clinical outcome of critically ill patients. Thus miR-223 serum levels should not be used as a biomarker in this setting
Serum levels of bone sialoprotein correlate with portal pressure in patients with liver cirrhosis
Liver cirrhosis represents the common end-stage of chronic liver diseases regardless of its etiology. Patients with compensated disease are mostly asymptomatic, however, progression to a decompensated disease stage is common. The available stratification strategies are often unsuitable to identify patients with a higher risk for disease progression and a limited prognosis. SIBLINGs, soluble glycophosphoproteins, are secreted into the blood by immune-cells. While osteopontin, the most prominent member of the SIBLINGs family, has been repeatedly associated with liver cirrhosis, data on the diagnostic and/or prognostic value of bone sialoprotein (BSP) are scarce and partly inconclusive. In this study, we analyzed the diagnostic and prognostic potential of circulating BSP in comparison to other standard laboratory markers in a large cohort of patients with liver cirrhosis receiving transjugular intrahepatic portosystemic shunt (TIPS). Serum levels of BSP were similar in patients with different disease stages and were not indicative for prognosis. Interestingly, BSP serum levels did correlate inversely with portal pressure, as well as its surrogates such as platelet count, the portal vein cross-sectional area and correlated positively with the portal venous velocity. In summary, our data highlight that BSP might represent a previously unrecognized marker for portal hypertension in patients with liver cirrhosis
- âŠ