70 research outputs found
Efficient Cloud-based Secret Shuffling via Homomorphic Encryption
When working with joint collections of confidential data from multiple
sources, e.g., in cloud-based multi-party computation scenarios, the ownership
relation between data providers and their inputs itself is confidential
information. Protecting data providers' privacy desires a function for secretly
shuffling the data collection. We present the first efficient secure
multi-party computation protocol for secret shuffling in scenarios with a
central server. Based on a novel approach to random index distribution, our
solution enables the randomization of the order of a sequence of encrypted data
such that no observer can map between elements of the original sequence and the
shuffled sequence with probability better than guessing. It allows for
shuffling data encrypted under an additively homomorphic cryptosystem with
constant round complexity and linear computational complexity. Being a
general-purpose protocol, it is of relevance for a variety of practical use
cases
Cryptographic protocol for privacy-preserving integration of HAZOPs in modular process plants
Information which is contained in Hazard & Operability (HAZOP) studies is highly sensitive since it can reveal the vulnerabilities of a system and potential ways in which to bypass safeguards. Through the design of systems involving collaboration along a value chain, at some point this information is shared between several parties. In this paper, we propose a methodology for the secure exchange of safety information whilst preserving sensitive information for the application of modular Hazard & Operability (HAZOP) studies. We use homomorphic encryption in a workflow for the sharing of information between plant owners and operators as well as module vendors. We apply encryption to the risks from different modular HAZOPs (mHAZOPs), and combine and compare them without disclosing the risk level. Our contribution is a privacy-preserving protocol for mHAZOP comparison during the integration of modular process and equipment. We provide an exemplary implementation of the protocol and demonstrate the protocol’s privacy and correctness
Fermionic corrections to the interference of the electro- and chromomagnetic dipole operators in anti-B --> X(s) gamma at O(alpha(s)**2)
We calculate the virtual and bremsstrahlung fermionic corrections due to the
interference of the electro- and chromomagnetic dipole operators in the
inclusive \bar{B}\to X_s\gamma decay at O(\alpha_s^2) and present analytical
results for both the total decay rate and the photon energy spectrum.Comment: 13 pages, uses axodraw.sty; minor changes, matches published versio
Mature oligodendrocytes actively increase in vivo cytoskeletal plasticity following CNS damage
Background: Oligodendrocytes are myelinating cells of the central nervous system which support functionally, structurally, and metabolically neurons. Mature oligodendrocytes are generally believed to be mere targets of destruction in the context of neuroinflammation and tissue damage, but their real degree of in vivo plasticity has become a matter of debate. We thus investigated the in vivo dynamic, actin-related response of these cells under different kinds of demyelinating stress. Methods: We used a novel mouse model (oLucR) expressing luciferase in myelin oligodendrocyte glycoproteinpositive oligodendrocytes under the control of a beta-actin promoter. Activity of this promoter served as surrogate for dynamics of the cytoskeleton gene transcription through recording of in vivo bioluminescence following diphtheria toxin-induced oligodendrocyte death and autoimmune demyelination. Cytoskeletal gene expression was quantified from mature oligodendrocytes directly isolated from transgenic animals through cell sorting. Results: Experimental demyelinating setups augmented oligodendrocyte-specific in vivo bioluminescence. These changes in luciferase signal were confirmed by further ex vivo analysis of the central nervous system tissue from oLucR mice. Increase in bioluminescence upon autoimmune inflammation was parallel to an oligodendrocytespecific increased transcription of beta-tubulin. Conclusions: Mature oligodendrocytes acutely increase their cytoskeletal plasticity in vivo during demyelination. They are therefore not passive players under demyelinating conditions but can rather react dynamically to external insults
SCET sum rules for B->P and B->V transition form factors
We investigate sum rules for heavy-to-light transition form factors at large
recoil derived from correlation functions with interpolating currents for light
pseudoscalar or vector fields in soft-collinear effective theory (SCET). We
consider both, factorizable and non-factorizable contributions at leading power
in the Lambda/m_b expansion and to first order in the strong coupling constant
alpha_s, neglecting contributions from 3-particle distribution amplitudes in
the B-meson. We pay particular attention to various sources of parametric and
systematic uncertainties. We also discuss certain form factor ratios where part
of the hadronic uncertainties related to the B-meson distribution amplitude and
to logarithmically enhanced alpha_s corrections cancel.Comment: 27 pages, 19 figures, minor corrections, matches journal versio
Applying for, reviewing and funding public health research in Germany and beyond
Gerhardus A, Becher H, Groenewegen P, et al. Applying for, reviewing and funding public health research in Germany and beyond. HEALTH RESEARCH POLICY AND SYSTEMS. 2016;14(1): 43.Public health research is complex, involves various disciplines, epistemological perspectives and methods, and is rarely conducted in a controlled setting. Often, the added value of a research project lies in its inter- or trans-disciplinary interaction, reflecting the complexity of the research questions at hand. This creates specific challenges when writing and reviewing public health research grant applications. Therefore, the German Research Foundation (DFG), the largest independent research funding organization in Germany, organized a round table to discuss the process of writing, reviewing and funding public health research. The aim was to analyse the challenges of writing, reviewing and granting scientific public health projects and to improve the situation by offering guidance to applicants, reviewers and funding organizations. The DFG round table discussion brought together national and international public health researchers and representatives of funding organizations. Based on their presentations and discussions, a core group of the participants (the authors) wrote a first draft on the challenges of writing and reviewing public health research proposals and on possible solutions. Comments were discussed in the group of authors until consensus was reached. Public health research demands an epistemological openness and the integration of a broad range of specific skills and expertise. Applicants need to explicitly refer to theories as well as to methodological and ethical standards and elaborate on why certain combinations of theories and methods are required. Simultaneously, they must acknowledge and meet the practical and ethical challenges of conducting research in complex real life settings. Reviewers need to make the rationale for their judgments transparent, refer to the corresponding standards and be explicit about any limitations in their expertise towards the review boards. Grant review boards, funding organizations and research ethics committees need to be aware of the specific conditions of public health research, provide adequate guidance to applicants and reviewers, and ensure that processes and the expertise involved adequately reflect the topic under review
The Novel Human Influenza A(H7N9) Virus Is Naturally Adapted to Efficient Growth in Human Lung Tissue
A novel influenza A virus (IAV) of the H7N9 subtype has been isolated from severely diseased patients with pneumonia and acute respiratory distress syndrome and, apparently, from healthy poultry in March 2013 in Eastern China. We evaluated replication, tropism, and cytokine induction of the A/Anhui/1/2013 (H7N9) virus isolated from a fatal human infection and two low-pathogenic avian H7 subtype viruses in a human lung organ culture system mimicking infection of the lower respiratory tract. The A(H7N9) patient isolate replicated similarly well as a seasonal IAV in explanted human lung tissue, whereas avian H7 subtype viruses propagated poorly. Interestingly, the avian H7 strains provoked a strong antiviral type I interferon (IFN-I) response, whereas the A(H7N9) virus induced only low IFN levels. Nevertheless, all viruses analyzed were detected predominantly in type II pneumocytes, indicating that the A(H7N9) virus does not differ in its cellular tropism from other avian or human influenza viruses. Tissue culture-based studies suggested that the low induction of the IFN-β promoter correlated with an efficient suppression by the viral NS1 protein. These findings demonstrate that the zoonotic A(H7N9) virus is unusually well adapted to efficient propagation in human alveolar tissue, which most likely contributes to the severity of lower respiratory tract disease seen in many patients
Theoretical and Phenomenological Constraints on Form Factors for Radiative and Semi-Leptonic B-Meson Decays
We study transition form factors for radiative and rare semi-leptonic B-meson
decays into light pseudoscalar or vector mesons, combining theoretical
constraints and phenomenological information from Lattice QCD, light-cone sum
rules, and dispersive bounds. We pay particular attention to form factor
parameterisations which are based on the so-called series expansion, and study
the related systematic uncertainties on a quantitative level. In this context,
we also provide the NLO corrections to the correlation function between two
flavour-changing tensor currents, which enters the unitarity constraints for
the coefficients in the series expansion.Comment: 52 pages; v2: normalization error in (29ff.) corrected, conclusion
about relevance of unitarity bounds modified; form factor fits unaffected;
references added; v3: discussion on truncation of series expansion added,
matches version to be published in JHEP; v4: corrected typos in Tables 5 and
IGF1R expression by adult oligodendrocytes is not required in the steady-state but supports neuroinflammation.
In the central nervous system (CNS), insulin-like growth factor 1 (IGF-1) regulates myelination by oligodendrocyte (ODC) precursor cells and shows anti-apoptotic properties in neuronal cells in different in vitro and in vivo systems. Previous work also suggests that IGF-1 protects ODCs from cell death and enhances remyelination in models of toxin-induced and autoimmune demyelination. However, since evidence remains controversial, the therapeutic potential of IGF-1 in demyelinating CNS conditions is unclear. To finally shed light on the function of IGF1-signaling for ODCs, we deleted insulin-like growth factor 1 receptor (IGF1R) specifically in mature ODCs of the mouse. We found that ODC survival and myelin status were unaffected by the absence of IGF1R until 15 months of age, indicating that IGF-1 signaling does not play a major role in post-mitotic ODCs during homeostasis. Notably, the absence of IGF1R did neither affect ODC survival nor myelin status upon cuprizone intoxication or induction of experimental autoimmune encephalomyelitis (EAE), models for toxic and autoimmune demyelination, respectively. Surprisingly, however, the absence of IGF1R from ODCs protected against clinical neuroinflammation in the EAE model. Together, our data indicate that IGF-1 signaling is not required for the function and survival of mature ODCs in steady-state and disease
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