510 research outputs found

    Localization of planar acoustic reflectors from the combination of linear estimates

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    In this paper we present a simple yet effective method for estimating the geometry of an acoustic enclosure in three-dimensions. By capturing the acoustic impulse responses using a microphone array and a loudspeaker at different spatial locations we transform the localization of planar reflectors into the estimation of multiple linear reflectors. By decomposing the microphone array into co-planar sub-arrays the line parameters of the reflectors lying on the corresponding planes can be inferred using a geometric constraint. By intersecting these lines the actual lying plane of each reflector can be estimated. The proposed method is evaluated using a three-dimensional microphone array in a real conference room

    ā€˜Malvasia nera di Brindisi/Lecceā€™ grapevine cultivar (Vitis vinifera L.) originated from ā€˜Negroamaroā€™ and ā€˜Malvasia bianca lungaā€™

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    ā€˜Malvasia nera di Brindisiā€™ and ā€˜Malvasia nera di Lecceā€™ are two of the few Malvasias with black berries and belong to the Apulian ampelographic assortment (South Italy). Their presumed synonymy has been recently ascertained with SSR markers and therefore these two black 'Malvasias' can be considered as an unique variety. We discovered that this cultivar is the cross between ā€˜Malvasia bianca lungaā€™ alias ā€˜Malvasia del Chiantiā€™ and ā€˜Negroamaroā€™ by using 42 nuclear SSR. Both parents belong to the Apulian varietal resources, since centuries. So far, ā€˜Malvasia nera di Brindisi/Lecceā€™ origin has been obscure; now we may assert that this cultivar was born right in Apulia. Three sets of chloroplast SSR loci were used to determine the female and the male parent: 6 ccmp loci, already used in previous pedigree studies, 15 ccSSR loci and 2 NTCP loci, derived from tobacco. The second set of loci was sequenced in order to compare the length of the markers with the reference species where they were originally obtained: in 4 cases no microsatellite motives were detected and in other 4 cases the perfect repetition found in tobacco was not maintained in grape. Unfortunately, the three sets of markers failed to show any polymorphism. A detailed comparison of the black Malvasia morphology with its two parents showed a closer similarity to ā€˜Negroamaroā€™. Also the anthocyanin profile is in agreement with that of the black parent; its varietal aroma presents interesting levels of free and bound 2-phenylethanol, responsible for rose flavor, and of bound linalool compounds.

    Density correlations in ultracold atomic Fermi gases

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    We investigate density fluctuations in a coherent ensemble of interacting fermionic atoms. Adapting the concept of full counting statistics, well-known from quantum optics and mesoscopic electron transport, we study second-order as well as higher-order correlators of density fluctuations. Using the mean-field BCS state to describe the whole interval between the BCS limit and the BEC limit, we obtain an exact expression for the cumulant-generating function of the density fluctuations of an atomic cloud. In the two-dimensional case, we obtain a closed analytical expression. Poissonian fluctuations of a molecular condensate on the BEC side are strongly suppressed on the BCS side. The size of the fluctuations in the BCS limit is a direct measure of the pairing potential. We also discuss the BEC-BCS crossover of the third cumulant and the temperature dependence of the second cumulant.Comment: 4 pages, 4 figures. To appear in Phys. Rev. A. New calculation of the bin statistics of a free Bose gas; updated and extended bibliograph

    Model-predicted geometry variations to compensate material variability in the design of classical guitars

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    Musical instrument making is often considered a mysterious form of art, its secrets still escaping scientific quantification. There is not yet a formula to make a good instrument, so historical examples are regarded as the pinnacle of the craft. This is the case of Stradivariā€™s violins or Torres guitars that serve as both models and examples to follow. Geometric copies of these instruments are still the preferred way of building new ones, yet reliably making acoustic copies of them remains elusive. One reason for this is that the variability of the wood used for instruments makes for a significant source of uncertaintyā€”no two pieces of wood are the same. In this article, using state-of-the-art methodologies, we show a method for matching the vibrational response of two guitar top plates made with slightly different materials. To validate our method, we build two guitar soundboards: one serving as a reference and the second acting as a copy to which we apply model-predicted geometry variations. The results are twofold. Firstly, we can experimentally validate the predictive capabilities of our numerical model regarding geometry changes. Secondly, we can significantly reduce the deviation between the two plates by these precisely predicted geometry variations. Although applied to guitars here, the methodology can be extended to other instruments, e.g. violins, in a similar fashion. The implications of such a methodology for the craft could be far-reaching by turning instrument-making more into a science than artistic craftsmanship and paving the way to accurately copy historical instruments of a high value

    The genomic organisation of the tra/trd locus validates the peculiar characteristics of dromedary Ī“-chain expression

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    The role of Ī³Ī“ T cells in vertebrate immunity is still an unsolved puzzle. Species such as humans and mice display a low percentage of these T lymphocytes (i.e., ā€œĪ³Ī“ low speciesā€) with a restricted diversity of Ī³Ī“ T cell receptors (TR). Conversely, artiodactyl species (i.e., ā€œĪ³Ī“ high speciesā€) account for a high proportion of Ī³Ī“ T cells with large Ī³ and Ī“ chain repertoires. The genomic organisation of the TR Ī³ (TRG) and Ī“ (TRD) loci has been determined in sheep and cattle, noting that a wide number of germline genes that encode for Ī³ and Ī“ chains characterise their genomes. Taking advantage of the current improved version of the genome assembly, we have investigated the genomic structure and gene content of the dromedary TRD locus, which, as in the other mammalian species, is nested within the TR Ī± (TRA) genes. The most remarkable finding was the identification of a very limited number of variable germline genes (TRDV) compared to sheep and cattle, which supports our previous expression analyses for which the somatic hypermutation mechanism is able to enlarge and diversify the primary repertoire of dromedary Ī“ chains. Furthermore, the comparison between genomic and expressed sequences reveals that D genes, up to four incorporated in a transcript, greatly contribute to the increased diversity of the dromedary Ī“ chain antigen binding-site

    Laniakea: a Galaxy-on-demand Provider Platform Through Cloud Technologies

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    Galaxy is rapidly becoming the de facto standard workflow manager for bioinformatics. Although several Galaxy public services are currently available, the usage of a private Galaxy instance is still mandatory or preferable for several use cases, including heavy workloads, data privacy concerns or particular customization needs. In this context, cloud computing technologies and infrastructures can provide a powerful and scalable solution to avoid the onerous deployment and maintenance of a local hardware and software infrastructure. Laniakea is a software framework that facilitates the provisioning of on-demand Galaxy instances as a cloud service over e-infrastructures, by leveraging on the open source software catalogue developed by the INDIGO-DataCloud H2020 project, which aimed to make cloud e-infrastructures more accessible by scientific communities. End-users interact with Laniakea through a web front-end that allows a general setup of a Galaxy instance. The deployment of the virtual hardware and of the Galaxy software ecosystem is subsequently performed by the INDIGO Platform as a Service layer. At the end of the process, the user gains access to a private, production-grade, fully customizable, Galaxy virtual instance. Laniakea features the deployment of a stand-alone or cluster backed Galaxy instances, shared reference data volumes, encrypted data volumes and rapid development of novel Galaxy flavours for specific tasks. We present here the latest development iteration of Laniakea, introducing a novel and strongly configurable web interface that facilitates a more straightforward customisation of the user experience through human readable YAML syntax and a reworked encryption procedure that exploits Hashicorp Vault as encryption keys management system

    Laniakea : an open solution to provide Galaxy "on-demand" instances over heterogeneous cloud infrastructures

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    Background: While the popular workflow manager Galaxy is currently made available through several publicly accessible servers, there are scenarios where users can be better served by full administrative control over a private Galaxy instance, including, but not limited to, concerns about data privacy, customisation needs, prioritisation of particular job types, tools development, and training activities. In such cases, a cloud-based Galaxy virtual instance represents an alternative that equips the user with complete control over the Galaxy instance itself without the burden of the hardware and software infrastructure involved in running and maintaining a Galaxy server. Results: We present Laniakea, a complete software solution to set up a \u201cGalaxy on-demand\u201d platform as a service. Building on the INDIGO-DataCloud software stack, Laniakea can be deployed over common cloud architectures usually supported both by public and private e-infrastructures. The user interacts with a Laniakea-based service through a simple front-end that allows a general setup of a Galaxy instance, and then Laniakea takes care of the automatic deployment of the virtual hardware and the software components. At the end of the process, the user gains access with full administrative privileges to a private, production-grade, fully customisable, Galaxy virtual instance and to the underlying virtual machine (VM). Laniakea features deployment of single-server or cluster-backed Galaxy instances, sharing of reference data across multiple instances, data volume encryption, and support for VM image-based, Docker-based, and Ansible recipe-based Galaxy deployments. A Laniakea-based Galaxy on-demand service, named Laniakea@ReCaS, is currently hosted at the ELIXIR-IT ReCaS cloud facility. Conclusions: Laniakea offers to scientific e-infrastructures a complete and easy-to-use software solution to provide a Galaxy on-demand service to their users. Laniakea-based cloud services will help in making Galaxy more accessible to a broader user base by removing most of the burdens involved in deploying and running a Galaxy service. In turn, this will facilitate the adoption of Galaxy in scenarios where classic public instances do not represent an optimal solution. Finally, the implementation of Laniakea can be easily adapted and expanded to support different services and platforms beyond Galaxy

    Laniakea@ReCaS: an ELIXIR-ITALY Galaxyon-demand cloud service

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    Although several Galaxy public services are available, a private Galaxy instance is still mandatory or preferable for several use cases including heavy workloads, data privacy concerns or particular customization needs. Cloud computing technologies provide a viable way to deploy Galaxy private instances, freeing users from the onerous deployment and maintenance of local IT infrastructures. In the last few years, ELIXIR-IT led the development of Laniakea, a software framework that facilitates the provisioning of on-demand Galaxy instances as a cloud service over e-infrastructures. The user interacts with a Laniakea service through a web front-end that allows to configure and launch a production-grade Galaxy instance in a straightforward way. Through the interface, the user can deploy Galaxy instances over single VMs or virtual clusters, link them to shared reference data volumes and plain or encrypted volumes for storing data. A selection of \u201cflavours\u201d, that is Galaxy instances pre-configured with sets of tools for specific tasks, is also available. When the users is satisfied, Laniakea takes oved and deploys the desired Galaxy instance over the cloud, providing a public IP and full administrative privileges over the new instance. In Dec-2018, we launched the beta-test phase of the first Laniakea-based Galaxy on-demand ELIXIR-IT service: Laniakea@ReCaS. After six months of helpful testing, we are now ready to announce the production phase of this service. Access to the service will be provided on a per-project basis through an open-ended call defining terms and conditions, project proposals will be evaluated by a scientific and technical board. Accepted proposals will be granted a package of computational resources for running on-demand Galaxy instances for a duration compatible with the project requirements

    Evolution of the T-cell receptor (TR) Loci in the adaptive immune response: The tale of the TRG locus in mammals

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    T lymphocytes are the principal actors of vertebratesā€™ cell-mediated immunity. Like B cells, they can recognize an unlimited number of foreign molecules through their antigen-specific heterodimer receptors (TRs), which consist of Ī±Ī² or Ī³Ī“ chains. The diversity of the TRs is mainly due to the unique organization of the genes encoding the Ī±, Ī², Ī³, and Ī“ chains. For each chain, multi-gene families are arranged in a TR locus, and their expression is guaranteed by the somatic recombination process. A great plasticity of the gene organization within the TR loci exists among species. Marked structural differences affect the TR Ī³ (TRG) locus. The recent sequencing of multiple whole genome provides an opportunity to examine the TR gene repertoire in a systematic and consistent fashion. In this review, we report the most recent findings on the genomic organization of TRG loci in mammalian species in order to show differences and similarities. The comparison revealed remarkable diversification of both the genomic organization and gene repertoire across species, but also unexpected evolutionary conservation, which highlights the important role of the T cells in the immune response
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