147 research outputs found
Нестандартна діяльність бібліотек вищих навчальних закладів Польщі
Artykuł opisuje rezultaty badania ankietowego wykonanego w celu uzyskania informacji o niestandardowej działalności bibliotek polskich uczelni akademickich. Wyniki pokazują, że prawie wszystkie biblioteki prowadzą różnorodną działalność kulturalną, promocyjną i edukacyjną. Znacznie mniejszy procent angażuje się w nietypową działalność w obszarze tworzenia i utrzymania systemów informacji o nauce czy systemów dydaktycznych.The paper describes the results of a survey conducted in order to obtain information
about non-standard activities in libraries of Polish academic institutions. The results show that almost all libraries are involved in diverse cultural, promotional and educational activities. A much smaller percentage engages in non-typical activities in the area of supporting the university in creating and maintaining current research information systems or teaching systems.У статті представлено результати анкетування і проведеного дослідження з метою аналізу інформації про нестандартну діяльність польських бібліотек ВНЗ. Результати показали, що практично усі бібліотеки здійснюють різноманітну культурну, рекламну і освітню діяльність. Значно менша кількість бібліотек займається нетиповою діяльністю у сфері створення і підтримки автоматизованих інформаційних систем у сфері науки або сучасних систем електронного навчання
Hepatitis B infection and the prevention of primary hepatocellular carcinoma : studies in Senegal
Lumpability Abstractions of Rule-based Systems
The induction of a signaling pathway is characterized by transient complex
formation and mutual posttranslational modification of proteins. To faithfully
capture this combinatorial process in a mathematical model is an important
challenge in systems biology. Exploiting the limited context on which most
binding and modification events are conditioned, attempts have been made to
reduce the combinatorial complexity by quotienting the reachable set of
molecular species, into species aggregates while preserving the deterministic
semantics of the thermodynamic limit. Recently we proposed a quotienting that
also preserves the stochastic semantics and that is complete in the sense that
the semantics of individual species can be recovered from the aggregate
semantics. In this paper we prove that this quotienting yields a sufficient
condition for weak lumpability and that it gives rise to a backward Markov
bisimulation between the original and aggregated transition system. We
illustrate the framework on a case study of the EGF/insulin receptor crosstalk.Comment: In Proceedings MeCBIC 2010, arXiv:1011.005
Towards scalable estimation of plant functional diversity from Sentinel-2: In-situ validation in a heterogeneous (semi-)natural landscape
Secrecy capacity of a class of orthogonal relay eavesdropper channels
The secrecy capacity of relay channels with orthogonal components is studied
in the presence of an additional passive eavesdropper node. The relay and
destination receive signals from the source on two orthogonal channels such
that the destination also receives transmissions from the relay on its channel.
The eavesdropper can overhear either one or both of the orthogonal channels.
Inner and outer bounds on the secrecy capacity are developed for both the
discrete memoryless and the Gaussian channel models. For the discrete
memoryless case, the secrecy capacity is shown to be achieved by a partial
decode-and-forward (PDF) scheme when the eavesdropper can overhear only one of
the two orthogonal channels. Two new outer bounds are presented for the
Gaussian model using recent capacity results for a Gaussian multi-antenna
point-to-point channel with a multi-antenna eavesdropper. The outer bounds are
shown to be tight for two sub-classes of channels. The first sub-class is one
in which the source and relay are clustered and the and the eavesdropper
receives signals only on the channel from the source and the relay to the
destination, for which the PDF strategy is optimal. The second is a sub-class
in which the source does not transmit to the relay, for which a
noise-forwarding strategy is optimal.Comment: Submitted to Eurasip Journal on Wireless Communications and
Networking special issue on Wireless physical layer security, Dec. 2008,
Revised Jun. 200
Automatic Verification of Finite Precision Implementations of Linear Controllers
We consider the problem of verifying finite precision implementation of linear time-invariant controllers against mathematical specifications. A specification may have multiple correct implementations which are different from each other in controller state representation, but equivalent from a perspective of input-output behavior (e.g., due to optimization in a code generator). The implementations may use finite precision computations (e.g. floating-point arithmetic) which cause quantization (i.e., roundoff) errors. To address these challenges, we first extract a controller\u27s mathematical model from the implementation via symbolic execution and floating-point error analysis, and then check approximate input-output equivalence between the extracted model and the specification by similarity checking. We show how to automatically verify the correctness of floating-point controller implementation in C language using the combination of techniques such as symbolic execution and convex optimization problem solving. We demonstrate the scalability of our approach through evaluation with randomly generated controller specifications of realistic size
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Ketamine's antidepressant effect is mediated by energy metabolism and antioxidant defense system.
Fewer than 50% of all patients with major depressive disorder (MDD) treated with currently available antidepressants (ADs) show full remission. Moreover, about one third of the patients suffering from MDD does not respond to conventional ADs and develop treatment-resistant depression (TRD). Ketamine, a non-competitive, voltage-dependent N-Methyl-D-aspartate receptor (NMDAR) antagonist, has been shown to have a rapid antidepressant effect, especially in patients suffering from TRD. Hippocampi of ketamine-treated mice were analysed by metabolome and proteome profiling to delineate ketamine treatment-affected molecular pathways and biosignatures. Our data implicate mitochondrial energy metabolism and the antioxidant defense system as downstream effectors of the ketamine response. Specifically, ketamine tended to downregulate the adenosine triphosphate (ATP)/adenosine diphosphate (ADP) metabolite ratio which strongly correlated with forced swim test (FST) floating time. Furthermore, we found increased levels of enzymes that are part of the 'oxidative phosphorylation' (OXPHOS) pathway. Our study also suggests that ketamine causes less protein damage by rapidly decreasing reactive oxygen species (ROS) production and lend further support to the hypothesis that mitochondria have a critical role for mediating antidepressant action including the rapid ketamine response
Polarization angle accuracy for future CMB experiments. The COSMOCal project and its prototype in the 1mm band
The Cosmic Microwave Background (CMB) radiation offers a unique window into
the early Universe, facilitating precise examinations of fundamental
cosmological theories. However, the quest for detecting B-modes in the CMB,
predicted by theoretical models of inflation, faces substantial challenges in
terms of calibration and foreground modeling. The COSMOCal (COsmic Survey of
Millimeter wavelengths Objects for CMB experiments Calibration) project aims at
enhancing the accuracy of the absolute calibration of the polarization angle
of current and future CMB experiments. The concept includes the build of
a very well known artificial source emitting in the frequency range [20-350]
GHz that would act as an absolute calibrator for several polarization
facilities on Earth. A feasibility study to place the artificial source in
geostationary orbit, in the far field for all the telescopes on Earth, is
ongoing. In the meanwhile ongoing hardware work is dedicated to build a
prototype to test the technology, the precision and the stability of the
polarization recovering in the 1 mm band (220-300 GHz). High-resolution
experiments as the NIKA2 camera at the IRAM 30m telescope will be deployed for
such use. Once carefully calibrated ( < 0.1 degrees) it will be
used to observe astrophysical sources such as the Crab nebula, which is the
best candidate in the sky for the absolute calibration of CMB experiments.Comment: to appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
Sharing Ghost Variables in a Collection of Abstract Domains
International audienceWe propose a framework in which we share ghost variables across a collection of abstract domains allowing precise proofs of complex properties. In abstract interpretation, it is often necessary to be able to express complex properties while doing a precise analysis. A way to achieve that is to combine a collection of domains, each handling some kind of properties, using a reduced product. Separating domains allows an easier and more modular implementation, and eases soundness and termination proofs. This way, we can add a domain for any kind of property that is interesting. The reduced product, or an approximation of it, is in charge of refining abstract states, making the analysis precise. In program verification, ghost variables can be used to ease proofs of properties by storing intermediate values that do not appear directly in the execution. We propose a reduced product of abstract domains that allows domains to use ghost variables to ease the representation of their internal state. Domains must be totally agnostic with respect to other existing domains. In particular the handling of ghost variables must be entirely decentralized while still ensuring soundness and termination of the analysis
PLoS Genet
All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells
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