255,652 research outputs found
Functional models for large-scale gene regulation networks: realism and fiction
High-throughput experiments are shedding light on the topology of large
regulatory networks and at the same time their functional states, namely the
states of activation of the nodes (for example transcript or protein levels) in
different conditions, times, environments. We now possess a certain amount of
information about these two levels of description, stored in libraries,
databases and ontologies. A current challenge is to bridge the gap between
topology and function, i.e. developing quantitative models aimed at
characterizing the expression patterns of large sets of genes. However,
approaches that work well for small networks become impossible to master at
large scales, mainly because parameters proliferate. In this review we discuss
the state of the art of large-scale functional network models, addressing the
issue of what can be considered as realistic and what the main limitations may
be. We also show some directions for future work, trying to set the goals that
future models should try to achieve. Finally, we will emphasize the possible
benefits in the understanding of biological mechanisms underlying complex
multifactorial diseases, and in the development of novel strategies for the
description and the treatment of such pathologies.Comment: to appear on Mol. BioSyst. 200
A digital global map of irrigated areas : an update for Asia
The Land and Water Development Division of the Food and Agriculture Organization of the United Nations and the Johann Wolfgang Goethe University, Frankfurt am Main, Germany, are cooperating in the development of a global irrigation-mapping facility. This report describes an update of the Digital Global Map of Irrigated Areas for the continent of Asia. For this update, an inventory of subnational irrigation statistics for the continent was compiled. The reference year for the statistics is 2000. Adding up the irrigated areas per country as documented in the report gives a total of 188.5 million ha for the entire continent. The total number of subnational units used in the inventory is 4 428. In order to distribute the irrigation statistics per subnational unit, digital spatial data layers and printed maps were used. Irrigation maps were derived from project reports, irrigation subsector studies, and books related to irrigation and drainage. These maps were digitized and compared with satellite images of many regions. In areas without spatial information on irrigated areas, additional information was used to locate areas where irrigation is likely, such as land-cover and land-use maps that indicate agricultural areas or areas with crops that are usually grown under irrigation. Contents 1. Working Report I: Generation of a map of administrative units compatible with statistics used to update the Digital Global Map of Irrigated Areas in Asia 2. Working Report II: The inventory of subnational irrigation statistics for the Asian part of the Digital Global Map of Irrigated Areas 3. Working Report III: Geospatial information used to locate irrigated areas within the subnational units in the Asian part of the Digital Global Map of Irrigated Areas 4. Working Report IV: Update of the Digital Global Map of Irrigated Areas in Asia, Results Map
A fast algorithm for LR-2 factorization of Toeplitz matrices
In this paper a new order recursive algorithm for the efficient â1 factorization of Toeplitz matrices is described. The proposed algorithm can be seen as a fast modified Gram-Schmidt method which recursively computes the orthonormal columns i, i = 1,2, âŠ,p, of , as well as the elements of Râ1, of a Toeplitz matrix with dimensions L Ă p. The factor estimation requires 8Lp MADS (multiplications and divisions). Matrix â1 is subsequently estimated using 3p2 MADS. A faster algorithm, based on a mixed and â1 updating scheme, is also derived. It requires 7Lp + 3.5p2 MADS. The algorithm can be efficiently applied to batch least squares FIR filtering and system identification. When determination of the optimal filter is the desired task it can be utilized to compute the least squares filter in an order recursive way. The algorithm operates directly on the experimental data, overcoming the need for covariance estimates. An orthogonalized version of the proposed â1 algorithm is derived. Matlab code implementing the algorithm is also supplied
An optimized conflict-free replicated set
Eventual consistency of replicated data supports concurrent updates, reduces
latency and improves fault tolerance, but forgoes strong consistency.
Accordingly, several cloud computing platforms implement eventually-consistent
data types. The set is a widespread and useful abstraction, and many replicated
set designs have been proposed. We present a reasoning abstraction, permutation
equivalence, that systematizes the characterization of the expected concurrency
semantics of concurrent types. Under this framework we present one of the
existing conflict-free replicated data types, Observed-Remove Set. Furthermore,
in order to decrease the size of meta-data, we propose a new optimization to
avoid tombstones. This approach that can be transposed to other data types,
such as maps, graphs or sequences.Comment: No. RR-8083 (2012
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Time-trends and treatment gaps in the antithrombotic management of patients with atrial fibrillation after percutaneous coronary intervention: Insights from the CHUM AF-STENT Registry.
BACKGROUND: The management of atrial fibrillation and flutter (AF) patients undergoing percutaneous coronary intervention (PCI) has undergone a rapid recent evolution. In 2016, the Canadian Cardiovascular Society (CCS) published expert recommendations to help guide clinicians in balancing bleeding and thrombotic risks in these patients. HYPOTHESIS: Antithrombotic regimen prescriptions for AF patients undergoing PCI evolved after the publication of the 2016 CCS AF guidelines. METHODS: A prospective cohort of AF patients undergoing PCI with placement of a coronary stent from a single tertiary academic center was analyzed for the recommended antithrombotic regimen at discharge. Prescribing behavior was compared between three time periods (Cohort A [2010-2011]; Cohort B [2014-2015]; Cohort C [2017]) using the Ï2 test. In addition, antithrombotic management in Cohorts B and C were compared to guideline-recommended therapy. RESULTS: A total of 459 patients with AF undergoing PCI were identified. Clinical and procedural characteristics were similar between cohorts, with the exception of an increase in drug-eluting stent (DES) use over time (P <â.01). Overall, the rate of oral anticoagulation (OAC) increased over time (P <â.01), associated with an increase in nonvitamin K OAC prescription (P <â.01) and a concomitant decrease in vitamin K antagonist prescription (P <â.01). Despite this, the overall rate of anticoagulation remains below what would be predicted with perfect guideline compliance (75% vs 94%, P <â.01). CONCLUSION: There has been a dramatic shift in clinical practice for AF patients requiring PCI, with increases in prescription of OAC even in the context of an increase in the use of DES. However, room for further practice optimization still exists
GCP: Gossip-based Code Propagation for Large-scale Mobile Wireless Sensor Networks
Wireless sensor networks (WSN) have recently received an increasing interest.
They are now expected to be deployed for long periods of time, thus requiring
software updates. Updating the software code automatically on a huge number of
sensors is a tremendous task, as ''by hand'' updates can obviously not be
considered, especially when all participating sensors are embedded on mobile
entities. In this paper, we investigate an approach to automatically update
software in mobile sensor-based application when no localization mechanism is
available. We leverage the peer-to-peer cooperation paradigm to achieve a good
trade-off between reliability and scalability of code propagation. More
specifically, we present the design and evaluation of GCP ({\emph Gossip-based
Code Propagation}), a distributed software update algorithm for mobile wireless
sensor networks. GCP relies on two different mechanisms (piggy-backing and
forwarding control) to improve significantly the load balance without
sacrificing on the propagation speed. We compare GCP against traditional
dissemination approaches. Simulation results based on both synthetic and
realistic workloads show that GCP achieves a good convergence speed while
balancing the load evenly between sensors
Iowa Law Enforcement Academy Annual Report, FY 2009
The Iowa Law Enforcement Academy (ILEA) was created by an act of the Iowa
legislature in 1967 with its purpose being to upgrade law enforcement to professional
status. The specific goals were to maximize training opportunities for law enforcement
officers, to coordinate training and to set standards for the law enforcement services. The
Academy establishes minimum standards for Iowa law enforcement and grants officer
certification. The Academy has the responsibility to de-certify or to suspend officerâs
certification when necessary
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