First record of the starfish Luidia atlantidea in the Canary Islands

We document the first observations of Luidia atlantidea Madsen, 1950 (Luidiidae; Paxillosida, Asteroidea) along the coasts of the Canary Islands, which represents a new westward occurrence of its known range. Individuals were observed during a visual scuba diving census in the islands of Gran Canaria (northwestern and eastern coasts) and Tenerife (eastern coast). These occurrences highlight the importance of the systematic biodiversity monitoring and surveillance of the dynamic changes in the environment, whereas future research is required to reveal the underpinnings for its presence.info:eu-repo/semantics/publishedVersio

Pear-shaped lesion of the fossa of Rosenmüller

Retention cyst of the pharyngeal mucosal space is an accumulation of trapped mucous in the mucosa or adenoids of the pharynx. It is a benign lesion, often seen on routine imaging of the head and spine. It is typically a simple cyst originating from the pharyngeal mucosa, without invasion of the surrounding structures. It is important not to misinterpret a retention cyst as a malignant tumor. Patients are usually asymptomatic and do not need treatment

Cost-aware scheduling of deadline-constrained task workflows in public cloud environments

Public cloud computing infrastructure offers resources on-demand, and makes it possible to develop applications that elastically scale when demand changes. This capacity can be used to schedule highly parallellizable task workflows, where individual tasks consist of many small steps. By dynamically scaling the number of virtual machines used, based on varying resource requirements of different steps, lower costs can be achieved, and workflows that would previously have been infeasible can be executed. In this paper, we describe how task workflows consisting of large numbers of distributable steps can be provisioned on public cloud infrastructure in a cost-efficient way, taking into account workflow deadlines. We formally define the problem, and describe an ILP-based algorithm and two heuristic algorithms to solve it. We simulate how the three algorithms perform when scheduling these task workflows on public cloud infrastructure, using the various instance types of the Amazon EC2 cloud, and we evaluate the achieved cost and execution speed of the three algorithms using two different task workflows based on a document processing application

Conditional implementation of asymmetrical universal quantum cloning machine

We propose two feasible experimental implementations of an optimal asymmetric 1->2 quantum cloning of a polarization state of photon. Both implementations are based on a partial and optimal reverse of recent conditional symmetrical quantum cloning experiments. The reversion procedure is performed only by a local measurement of one from the clones and ancilla followed by a local operation on the other clone. The local measurement consists only of a single unbalanced beam splitter followed in one output by a single photon detector and the asymmetry of fidelities in the cloning is controlled by a reflectivity of the beam splitter.Comment: 5 pages, 3 figures, accepted for pulication in PR

Quantum adaptation of noisy channels

Probabilistic quantum filtering is proposed to properly adapt sequential independent quantum channels in order to stop sudden death of entanglement. In the adaptation, the quantum filtering does not distill or purify more entanglement, it rather properly prepares entangled state to the subsequent quantum channel. For example, the quantum adaptation probabilistically eliminates the sudden death of entanglement of two-qubit entangled state with isotropic noise injected into separate amplitude damping channels. The result has a direct application in quantum key distribution through noisy channels.Comment: 6 pages, 4 figure

Identifying vacancy complexes in compound semiconductors with positron annihilation spectroscopy: a case study of InN

We present a comprehensive study of vacancy and vacancy-impurity complexes in InN combining positron annihilation spectroscopy and ab-initio calculations. Positron densities and annihilation characteristics of common vacancy-type defects are calculated using density functional theory and the feasibility of their experimental detection and distinction with positron annihilation methods is discussed. The computational results are compared to positron lifetime and conventional as well as coincidence Doppler broadening measurements of several representative InN samples. The particular dominant vacancy-type positron traps are identified and their characteristic positron lifetimes, Doppler ratio curves and lineshape parameters determined. We find that In vacancies and their complexes with N vacancies or impurities act as efficient positron traps, inducing distinct changes in the annihilation parameters compared to the InN lattice. Neutral or positively charged N vacancies and pure N vacancy complexes on the other hand do not trap positrons. The predominantly introduced positron trap in irradiated InN is identified as the isolated In vacancy, while in as-grown InN layers In vacancies do not occur isolated but complexed with one or more N vacancies. The number of N vacancies per In vacancy in these complexes is found to increase from the near surface region towards the layer-substrate interface.Comment: 10 pages, 6 figure

Methodology of the biological risk classification of animal pathogens in Belgium

The biological hazards posed by micro-organisms have lead to their categorisation into risk groups and the elaboration of classification lists. Current classification systems rely on criteria defined by the World Health Organization, which cover the severity of the disease the micro-organism might cause, its ability to spread and the availability of prophylaxis or efficient treatment. Animal pathogens are classified according to the definitions of the World Organization of Animal Health, which also consider economic aspects of disease. In Europe, classification is often directly linked to containment measures. The Belgian classification system however, only considers the inherent characteristics of the micro-organism, not its use, making the risk classification independent of containment measures. A common classification list for human and animal pathogens has been developed in Belgium using as comprehensive an approach as possible. Evolution of scientific knowledge will demand regular updating of classification lists. This paper describes the Belgian risk classification system and the methodology that was used for its peer-reviewed revision (with a focus on animal pathogens)

Positron trapping kinetics in thermally generated vacancy donor complexes in highly As-doped silicon

We have measured positron lifetime and Doppler broadening in highly As-doped silicon containing thermally generated V−As3 defect complexes (vacancy is surrounded by three arsenic atoms). We observe positron detrapping from the V−As3 defect complex and determine the binding energy of 0.27 eV of a positron to the complex. The results explain why 85% of the thermal vacancies formed in highly As-doped Si at temperatures over 700 K are invisible to positron measurements at elevated temperatures.Peer reviewe