488 research outputs found
Concurrent isolation of hepatic stem cells and hepatocytes from the human liver
Hepatocytes differentiated from induced pluripotent stem cells or stem cells have the potential to be representative in vitro models of the human liver for research as well as early safety assessment programs. However, up until now, there has been no definitive proof that differentiated hepatocytes recapitulate the phenotype and functional characteristics of primary hepatocytes from the same individual. Thus, a method for the concurrent isolation of hepatocytes and hepatic stem cells is presented here to provide the cells necessary for the evaluation of the required benchmarking. The method presented here generated high-quality hepatocytes with a purity of 94â±â1% and a high percentage viability of 79â±â2%. Furthermore, the hepatic stem cells isolated were found to be actively proliferating and have a purity of 98â±â1%. Thus, these isolated cells can be used as a powerful tool for the validation of differentiated hepatocyte in vitro models
Efficient Passive ICS Device Discovery and Identification by MAC Address Correlation
Owing to a growing number of attacks, the assessment of Industrial Control
Systems (ICSs) has gained in importance. An integral part of an assessment is
the creation of a detailed inventory of all connected devices, enabling
vulnerability evaluations. For this purpose, scans of networks are crucial.
Active scanning, which generates irregular traffic, is a method to get an
overview of connected and active devices. Since such additional traffic may
lead to an unexpected behavior of devices, active scanning methods should be
avoided in critical infrastructure networks. In such cases, passive network
monitoring offers an alternative, which is often used in conjunction with
complex deep-packet inspection techniques. There are very few publications on
lightweight passive scanning methodologies for industrial networks. In this
paper, we propose a lightweight passive network monitoring technique using an
efficient Media Access Control (MAC) address-based identification of industrial
devices. Based on an incomplete set of known MAC address to device
associations, the presented method can guess correct device and vendor
information. Proving the feasibility of the method, an implementation is also
introduced and evaluated regarding its efficiency. The feasibility of
predicting a specific device/vendor combination is demonstrated by having
similar devices in the database. In our ICS testbed, we reached a host
discovery rate of 100% at an identification rate of more than 66%,
outperforming the results of existing tools.Comment: http://dx.doi.org/10.14236/ewic/ICS2018.
Spatiotemporal dissemination of ESBL-producing Enterobacterales in municipal sewer systems: a prospective, longitudinal study in the city of Basel, Switzerland
BACKGROUND: The contribution of community and hospital sources to the transmission of extended-spectrum ÎČ-lactamase producing Enterobacterales (ESBL-PE) remains elusive.
AIM: To investigate the extent of community dissemination and the contribution of hospitals to the spread of ESBL-PE by exploring their spatiotemporal distribution in municipal wastewater of the central European city of Basel.
METHODS: Wastewater samples were collected monthly for two consecutive years throughout Basel, Switzerland, including 21 sites across 10 postcode areas of the city collecting either community wastewater (urban sites, nâ=â17) or community and hospital wastewater (mixed sites, nâ=â4). Presumptive ESBL-PE were recovered by selective culture methods. Standard methodologies were applied for species identification, ESBL-confirmation, and quantification.
RESULTS: Ninety-five percent (477/504) of samples were positive for ESBL-PE. Among these isolates, Escherichia coli (85%, 1,140/1,334) and Klebsiella pneumoniae (11%, 153/1,334) were most common. They were recovered throughout the sampling period from all postcodes, with E. coli consistently predominating. The proportion of K. pneumoniae isolates was higher in wastewater samples from mixed sites as compared to samples from urban sites, while the proportion of E. coli was higher in samples from urban sites (pâ=â0.003). Higher numbers of colony forming units (CFUs) were recovered from mixed as compared to urban sites (median 3.2âĂâ10 vs. 1.6âĂâ10 CFU/mL). E. coli-counts showed moderate correlation with population size (rhoâ=â0.44), while this correlation was weak for other ESBL-PE (rhoâ=â0.21).
CONCLUSION: ESBL-PE are widely spread in municipal wastewater supporting that community sources are important reservoirs entertaining the spread of ESBL-PE. Hospital-influenced abundance of ESBL-PE appears to be species dependent
Gender, age and the MBA: An analysis of extrinsic and intrinsic career benefits
Against the background of an earlier UK study, this paper presents the findings of a Canadian based survey of career benefits from the MBA. Results indicate firstly that gender and age interact to influence perceptions of career outcomes (young men gain most in terms of extrinsic benefits of career change and pay), and secondly that both men and women gain intrinsic benefits from the MBA. However, intrinsic benefits vary by gender: men in the study were more likely to say they gained confidence from having a fuller skill set while women were more likely to say they gained confidence from feelings of self worth; men emphasised how they had learned to give up control while women argued that they had gained a âvoiceâ in the organization. The role of the MBA in career self- management and the acquisition of key skills are examined as well as the implications for the design of programmes in meeting the varied need of men and women in different age groups
Resolving the Ortholog Conjecture: Orthologs Tend to Be Weakly, but Significantly, More Similar in Function than Paralogs
The function of most proteins is not determined experimentally, but is extrapolated from homologs. According to the âortholog conjectureâ, or standard model of phylogenomics, protein function changes rapidly after duplication, leading to paralogs with different functions, while orthologs retain the ancestral function. We report here that a comparison of experimentally supported functional annotations among homologs from 13 genomes mostly supports this model. We show that to analyze GO annotation effectively, several confounding factors need to be controlled: authorship bias, variation of GO term frequency among species, variation of background similarity among species pairs, and propagated annotation bias. After controlling for these biases, we observe that orthologs have generally more similar functional annotations than paralogs. This is especially strong for sub-cellular localization. We observe only a weak decrease in functional similarity with increasing sequence divergence. These findings hold over a large diversity of species; notably orthologs from model organisms such as E. coli, yeast or mouse have conserved function with human proteins
The state of the Martian climate
60°N was +2.0°C, relative to the 1981â2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
LICSTER -- A Low-cost ICS Security Testbed for Education and Research
Unnoticed by most people, Industrial Control Systems (ICSs) control entire
productions and critical infrastructures such as water distribution, smart grid
and automotive manufacturing. Due to the ongoing digitalization, these systems
are becoming more and more connected in order to enable remote control and
monitoring. However, this shift bears significant risks, namely a larger attack
surface, which can be exploited by attackers. In order to make these systems
more secure, it takes research, which is, however, difficult to conduct on
productive systems, since these often have to operate twenty-four-seven.
Testbeds are mostly very expensive or based on simulation with no real-world
physical process. In this paper, we introduce LICSTER, an open-source low-cost
ICS testbed, which enables researchers and students to get hands-on experience
with industrial security for about 500 Euro. We provide all necessary material
to quickly start ICS hacking, with the focus on low-cost and open-source for
education and research
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