5,722 research outputs found
Exploiting non-constant safe memory in resilient algorithms and data structures
We extend the Faulty RAM model by Finocchi and Italiano (2008) by adding a
safe memory of arbitrary size , and we then derive tradeoffs between the
performance of resilient algorithmic techniques and the size of the safe
memory. Let and denote, respectively, the maximum amount of
faults which can happen during the execution of an algorithm and the actual
number of occurred faults, with . We propose a resilient
algorithm for sorting entries which requires time and uses safe memory words. Our
algorithm outperforms previous resilient sorting algorithms which do not
exploit the available safe memory and require time. Finally, we exploit our sorting algorithm for
deriving a resilient priority queue. Our implementation uses safe
memory words and faulty memory words for storing keys, and
requires amortized time for each insert and
deletemin operation. Our resilient priority queue improves the amortized time required by the state of the art.Comment: To appear in Theoretical Computer Science, 201
Not Always Sparse: Flooding Time in Partially Connected Mobile Ad Hoc Networks
In this paper we study mobile ad hoc wireless networks using the notion of
evolving connectivity graphs. In such systems, the connectivity changes over
time due to the intermittent contacts of mobile terminals. In particular, we
are interested in studying the expected flooding time when full connectivity
cannot be ensured at each point in time. Even in this case, due to finite
contact times durations, connected components may appear in the connectivity
graph. Hence, this represents the intermediate case between extreme cases of
fully mobile ad hoc networks and fully static ad hoc networks. By using a
generalization of edge-Markovian graphs, we extend the existing models based on
sparse scenarios to this intermediate case and calculate the expected flooding
time. We also propose bounds that have reduced computational complexity.
Finally, numerical results validate our models
Self-assembly of short DNA duplexes: from a coarse-grained model to experiments through a theoretical link
Short blunt-ended DNA duplexes comprising 6 to 20 base pairs self-assemble
into polydisperse semi-flexible chains due to hydrophobic stacking interactions
between terminal base pairs. Above a critical concentration, which depends on
temperature and duplex length, such chains order into liquid crystal phases.
Here, we investigate the self-assembly of such double-helical duplexes with a
combined numerical and theoretical approach. We simulate the bulk system
employing the coarse-grained DNA model recently proposed by Ouldridge et al. [
J. Chem. Phys. 134, 08501 (2011) ]. Then we evaluate the input quantities for
the theoretical framework directly from the DNA model. The resulting
parameter-free theoretical predictions provide an accurate description of the
simulation results in the isotropic phase. In addition, the theoretical
isotropic-nematic phase boundaries are in line with experimental findings,
providing a route to estimate the stacking free energy.Comment: 13 pages, 10 figure
Comprehensive analysis of the membrane phosphoproteome regulated by oligogalacturonides in Arabidopsis thaliana
Early changes in the Arabidopsis thaliana membrane phosphoproteome in response to oligogalacturonides (OGs), a class of plant damage-associated molecular patterns (DAMPs), were analyzed by two complementary proteomic approaches. Differentially phosphorylated sites were determined through phosphopeptide enrichment followed by LC-MS/MS using label-free quantification; differentially phosphorylated proteins were identified by 2D-DIGE combined with phospho-specific fluorescent staining (phospho-DIGE). This large-scale phosphoproteome analysis of early OG-signaling enabled us to determine 100 regulated phosphosites using LC-MS/MS and 46 differential spots corresponding to 34 pdhosphoproteins using phospho-DIGE. Functional classification showed that the OG-responsive phosphoproteins include kinases, phosphatases and receptor-like kinases, heat shock proteins (HSPs), reactive oxygen species (ROS) scavenging enzymes, proteins related to cellular trafficking, transport, defense and signaling as well as novel candidates for a role in immunity, for which elicitor-induced phosphorylation changes have not been shown before. A comparison with previously identified elicitor-regulated phosphosites shows only a very limited overlap, uncovering the immune-related regulation of 70 phosphorylation sites and revealing novel potential players in the regulation of elicitor-dependent immunity
Becoming Eusapia: The rise of the "Diva of Scientists"
ArgumentEusapia Palladino (1854-1918) is remembered as one of the most famous mediums in the history of spiritualism. Renowned scientists attended her séances in Europe and in the United States. They often had to admit to being unable to understand the origin of the phenomena produced. Cesare Lombroso, for example, after meeting Eusapia, was converted first to mediumism, then spiritualism. This article will retrace the early stages of her career as a medium and shed light on the way she managed to gain the attention of scientists. It will also show why they chose her as an epistemic object
A Sardinian early 1st millennium BC bronze axe from Motya
An Iron Age bronze axe was found in Motya (Sicily, Italy) in a prehistoric layer dating from the 10th century BC underneath the 4th century BC patrician residency known as “Casa dei mosaici”. The axe belongs to the double-looped socketed type well known in central Mediterranean in the time span 1200-900 BC, and it is comparable with some coeval Sardinian specimens. The bronze has been characterised using the backscattering electron signal of a SEM (Scanning Electron Microscope) and EDX (Energy Dispersive X-ray Spectroscopy). The resulting composition of the metal alloy is Cu-Sn-As with an addition of Pb in some specific spots
Changes in the microsomal proteome of tomato fruit during ripening
The variations in the membrane proteome of tomato fruit pericarp during ripening have been investigated by mass spectrometry-based label-free proteomics. Mature green (MG30) and red ripe (R45) stages were chosen because they are pivotal in the ripening process: MG30 corresponds to the end of cellular expansion, when fruit growth has stopped and fruit starts ripening, whereas R45 corresponds to the mature fruit. Protein patterns were markedly different: among the 1315 proteins identified with at least two unique peptides, 145 significantly varied in abundance in the process of fruit ripening. The subcellular and biochemical fractionation resulted in GO term enrichment for organelle proteins in our dataset, and allowed the detection of low-abundance proteins that were not detected in previous proteomic studies on tomato fruits. Functional annotation showed that the largest proportion of identified proteins were involved in cell wall metabolism, vesicle-mediated transport, hormone biosynthesis, secondary metabolism, lipid metabolism, protein synthesis and degradation, carbohydrate metabolic processes, signalling and response to stress
Reconfigurable photoinduced metamaterials in the microwave regime
We investigate optically reconfigurable dielectric metamaterials at gigahertz
frequencies. More precisely, we study the microwave response of a subwavelength
grating optically imprinted into a semiconductor slab. In the homogenized
regime, we analytically evaluate the ordinary and extraordinary component of
the effective permittivity tensor by taking into account the photo-carrier
dynamics described by the ambipolar diffusion equation. We analyze the impact
of semiconductor parameters on the gigahertz metamaterial response which turns
out to be highly reconfigurable by varying the photogenerated grating and which
can show a marked anisotropic behavior.Comment: 6 figures, 7 page
Mechanisms of Primary and Acquired Resistance to Immune Checkpoint Inhibitors in Patients with Hepatocellular Carcinoma
Simple Summary Immune checkpoint inhibitors (ICIs) are now a cornerstone of systemic treatment for hepatocellular carcinoma (HCC). However, their efficacy is blunted by mechanisms of tumour resistance in many patients. This review reports on the state of the art of resistance to ICIs, focusing on HCC, with the aim to provide clear and direct information to clinicians and researchers. Growing knowledge on the mechanisms of resistance to immunotherapy can indeed guide the choice of and expand the application of novel combined treatments. Hepatocellular carcinoma (HCC) is the most common liver cancer and a relevant global health problem. Immune checkpoint inhibitors (ICIs) represent the most effective systemic treatment for HCC. However, due to primary resistance, approximately 40% of HCC patients do not achieve a disease control with ICIs. Moreover, a similar proportion will experience disease progression after an initial response caused by secondary resistance. This review describes the mechanisms of primary and secondary resistance and reports the ongoing therapeutic strategies to overcome these obstacles
Quantum information transfer from spin to orbital angular momentum of photons
The optical "spin-orbit" coupling occurring in a suitably patterned
nonuniform birefringent plate known as `q-plate' allows entangling the
polarization of a single photon with its orbital angular momentum (OAM). This
process, in turn, can be exploited for building a bidirectional "spin-OAM
interface", capable of transposing the quantum information from the spin to the
OAM degree of freedom of photons and \textit{vice versa}. Here, we
experimentally demonstrate this process by single-photon quantum tomographic
analysis. Moreover, we show that two-photon quantum correlations such as those
resulting from coalescence interference can be successfully transferred into
the OAM degree of freedom.Comment: 4 pages, 4 figure
- …