2,718 research outputs found
Influence of different commercial scaffolds on the in vitro differentiation of human mesenchymal stem cells to nucleus pulposus-like cells
Introduction: Cell-based therapies for regeneration of the degenerated intervertebral disc (IVD) are an alternative to current surgical intervention. Mesenchymal stem cells (MSCs), in combination with a scaffold, might be ideal candidates for regenerating nucleus pulposus (NP), the pressure-distributing part of the IVD. While the use of growth factors for MSCs differentiation currently receives major attention, in this study we compare the performance of sponge-like matrixes in supporting cell differentiation into NP-like cells. Materials and methods: Four types matrixes approved as medical devices for other applications were tested as scaffolds for MSCs: two made of equine or porcine collagen, one of gelatin and one of chitosan. Bone marrow-derived human MSCs were seeded in these scaffolds or embedded in alginate, as a three-dimensional control. After five weeks in culture, NP-like differentiation of the cell-scaffold constructs was analyzed by qRT-PCR, histology, total DNA quantification, proteoglycan accumulation and immunohistochemistry. Results: MSCs in collagen matrixes and gelatin produced more mRNA and proteins of the chondrogenic markers collagen type I, collagen type II (COL2) and aggrecan (ACAN), when compared with cells embedded in alginate or chitosan. Proteoglycan accumulation and cell survival were also higher in collagen and gelatin matrixes. Gene expression results were also confirmed by histological and immunohistochemical staining. In contrast to alginate control, the gene expression of the undesired bone marker osteopontin was lower in all tested groups. In porcine collagen supports, MSC expression ratio between COL2/ACAN closely resembled the expression of nucleus pulposus cells, but gene expression of recently described NP markers keratin19, PAX1 and FOXF1 was lower. Conclusions: Collagen supports provide a readily available, medically approved and effective scaffold for chondrogenic differentiation in vitro, but the phenotype of differentiated MSCs is not yet completely equivalent to that of NP cell
FlexEnergy - A Prosumer-based Approach For The Automated Marketing Of Manufacturing Companies' Energy Flexibility
The transition to renewable energy sources and the need to address climate change has significantly changed the energy landscape. However, the fluctuating nature of renewables and increased electricity price volatility pose challenges to power grids and companies. This study focuses on energy flexibility achieved through industrial demand-side management (DSM) as a solution. Information technology (IT) and standardization are vital for enabling energy flexibility by optimizing energy consumption and facilitating interoperability. Digital energy platforms allow energy-intensive industries to optimize energy usage, thus enabling industrial demand optimization and effective communication within the energy ecosystem. Standardization ensures the efficient implementation of energy flexibilitymeasures across diverse energymarkets.Thisstudy proposes a process model to streamline the integration of energy flexibility measures into production processes. This model eliminates the labor-intensive manual implementation process, enabling seamless adoption of energy flexibility measures and participation in energy markets. Marketing energy flexibility is addressed through the prosumer-based process that leverages standardized communication facilitated by the energy flexibility data model (EFDM), optimizing the energy consumption of manufacturing companies. The contributions of this research lie in the proposed processmodelfor marketing energy flexibility,streamlining energy flexibility implementation through automated EFDM modeling. The findings provide insights for researchers and practitioners, guiding the adoption of energy flexibility measures and supporting a sustainable energy future
Design and clinical evaluation of an image-guided surgical microscope with an integrated tracking system
A new image-guided microscope system using augmented reality image overlays has been developed. With this system, CT cut-views and segmented objects such as tumors that have been previously extracted from preoperative tomographic images can be directly displayed as augmented reality overlays on the microscope image. The novelty of this design stems from the inclusion of a precise mini-tracker directly on the microscope. This device, which is rigidly mounted to the microscope, is used to track the movements of surgical tools and the patient. In addition to an accuracy gain, this setup offers improved ergonomics since it is much easier for the surgeon to keep an unobstructed line of sight to tracked objects. We describe the components of the system: microscope calibration, image registration, tracker assembly and registration, tool tracking, and augmented reality display. The accuracy of the system has been measured by validation on plastic skulls and cadaver heads, obtaining an overlay error of 0.7mm. In addition, a numerical simulation of the system has been done in order to complement the accuracy study, showing that the integration of the tracker onto the microscope could lead to an improvement of the accuracy to the order of 0.5mm. Finally, we describe our clinical experience using the system in the operation room, where three operations have been performed to dat
How Smart Is âSmart Securityâ? Exploring Data Subjectivity and Resistance
âSmart securityâ is currently being used as an umbrella term that embraces several initiatives proposed by the aviation industry in order to enhance security procedures at airports. The idea of smarter security opposes the traditional screening framework of passenger security at airports which enacts a one-size-fits-all approach in order to detect dangerous items that might threaten flight safety and security. Recently however, the security industry claims that smart solutions could provide better security, less intrusive screening, and better cost efficiency by employing tailored security procedures based on individual data-driven risk assessment of passengers and corresponding different levels of security screening.
As smart security solutions are currently still under development, this report analyses potential human rights problems connected to a broader implementation of smart security routines in a timely fashion. Constituent elements of smart security, such as computer-based sorting of individuals into risk-groups and algorithms preparing or taking decisions on passengersâ mobility, can have severe consequences. Critical questions to be asked include: Who is accountable for smart security decisions? Is it possible to appeal against such decisions? How dangerous is the data-driven approach with regard to structural discrimination and equality of all passengers?
We review and summarise the state of the art in the field of data-driven risk analysis and analyse eight interviews that we have conducted with representatives of European aviation associations, state authorities and the civil society. Bearing in mind the human rights implications of smart security, the report identifies six central policy gaps, issues recommendations to address them and provides a basis for a much needed public debate on smart security
Enhancing Federated Cloud Management with an Integrated Service Monitoring Approach
Cloud Computing enables the construction and the provisioning of virtualized service-based applications in a simple and cost effective outsourcing to dynamic service environments. Cloud Federations envisage a distributed, heterogeneous environment consisting of various cloud infrastructures by aggregating different IaaS provider capabilities coming from both the commercial and the academic area. In this paper, we introduce a federated cloud management solution that operates the federation through utilizing cloud-brokers for various IaaS providers. In order to enable an enhanced provider selection and inter-cloud service executions, an integrated monitoring approach is proposed which is capable of measuring the availability and reliability of the provisioned services in different providers. To this end, a minimal metric monitoring service has been designed and used together with a service monitoring solution to measure cloud performance. The transparent and cost effective operation on commercial clouds and the capability to simultaneously monitor both private and public clouds were the major design goals of this integrated cloud monitoring approach. Finally, the evaluation of our proposed solution is presented on different private IaaS systems participating in federations. Š 2013 Springer Science+Business Media Dordrecht
Insektenvielfalt in der Schweiz: Bedeutung, Trends, Handlungsoptionen
Die Situation der Insekten in der Schweiz sei besorgniserregend, schreiben Forschende im ersten umfassenden Zustandsbericht Insektenvielfalt in der Schweiz, publiziert vom Forum Biodiversität der Akademie der Naturwissenschaften Schweiz. Sie haben die verfßgbaren Daten der Roten Listen, von Monitoringprogrammen und Studien analysiert. Demnach gingen Vielfalt und GrÜsse der Insektenbestände vor allem im Mittelland stark zurßck, mittlerweile aber auch im Jura und in den Alpen. Um die teils dramatischen Entwicklungen zu stoppen, schlagen die Autorinnen und Autoren das wissenschaftlich basierte 12-Punkte-Programm Insekten vor
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
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