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"A. Falabella"
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Experience in dynamic tape drive allocation to manage scientific data
2023
The main computing and storage facility of INFN (Italian Institute for Nuclear Physics) running at CNAF hosts and manages tens of Petabytes of data produced by the LHC (Large Hadron Collider) experiments at CERN and other scientific collaborations in which INFN is involved. Most of these data are stored on tape resources of different technologies. All the tape drives can be used for administrative tasks (as repack, audit, space reclamation), as well to write and read data of all the experiments. Moreover, the usage of tape resources by scientific communities will become considerably more intense in the next years and the amount of data on tape will double by 2025. For these reasons, the issue of the concurrent access to tape drives is significant. We designed a software solution to optimize the efficiency of the shared usage of tape drives in our environment and put it in production in January 2020. In this paper we present the experience with such dynamic tape resources allocation in production. Comparing it with the previous static allocation method, we observed an improvement in reading throughput up to 85%. Moreover, we describe the new features added to our solution to optimize the efficiency of the shared usage of tape drives of different technologies.
Journal Article
EDUCADORAS DIFERENCIALES EN CHILE FRENTE A LAS POLÍTICAS DE RENDICIÓN DE CUENTAS: Incluir, estandarizar y desobedecer
2021
En el mundo, se han expandido las políticas de estandarización y rendición de cuentas por resultados, y a su vez, en los últimos años, ha crecido la demanda por generar escuelas más inclusivas. Uno de los actores centrales para lograr tal inclusión son las educadoras diferenciales (maestra de educación especial), sin embargo, existe escasa investigación sobre ellas. Esta investigación pretende comprender los modos en que estas políticas influyen en su trabajo y en sus subjetividades. Para ello, se desarrolló un estudio de casos, en el que se entrevistaron a diez educadoras en Chile, luego se seleccionaron a dos de ellas, a las que se les realizó un seguimiento etnográfico durante cinco meses (240 horas de observación). Los hallazgos relevan una identidad docente tensionada que se debate entre la inclusión y la estandarización, como también se evidencian resistencias por parte de las docentes frente a los mandatos de la rendición de cuentas.
Journal Article
Last developments of the INFN CNAF Long Term Data Preservation (LTDP) project: the CDF data recover and safekeeping
2018
The INFN CNAF Tier-1 has become the Italian national data center for the INFN computing activities since 2005. As one of the reference sites for data storage and computing provider in the High Energy Physics (HEP) community it offers resources to all the four LHC experiments and many other HEP and non-HEP collaborations. The CDF experiment has used the INFN Tier-1 resources for many years and, after the end of data taking in 2011, it faced the challenge to both preserve the large amount of scientific data produced and give the possibility to access and reuse the whole information in the future using the specific computing model. For this reason starting from the end of 2012 the CDF Italian collaboration, together with the INFN CNAF and Fermilab (FNAL), introduced a Long Term Data Preservation (LTDP) project with the purpose of preserving and sharing all the CDF data and the related analysis framework and knowledge. This is particularly challenging since part of the software releases is no longer supported and the amount of data to be preserved is rather large. The first objective of the collaboration was the copy of all the CDF RUN-2 raw data and user level ntuples (about 4 PB) from FNAL to the INFN CNAF tape library backend using a dedicated network link. This task was successfully accomplished during the last years and, in addition, a system to implement regular integrity check of data has been developed. This system ensures that all the data are completely accessible and it can automatically retrieve an identical copy of problematic or corrupted file from the original dataset at FNAL. The setup of a dedicated software framework, which allows users to access and analyse the data with the complete CDF analysis chain, was also carried out with the addition of users and system administrators detailed documentation for the long-term future. Furthermore a second and more ambitious objective emerged during 2016 with a feasibility study for reading the first CDF RUN-1 dataset now stored as an unique copy in a huge amount (about 4000) of old Exabyte tape cartridges. With the installation of compatible refurbished tape drive autoloaders an initial test bed was completed and the first phase of the Exabyte tapes reading activity started. In the present article, we will illustrate the state of the art of the LTDP project with a particular attention to the technical solutions adopted in order to store and maintain the CDF data and the analysis framework, and to overcome the issues that have arisen during the recent activities. The CDF model could also prove useful for designing new data preservation projects for other experiments or use cases.
Journal Article
The InfiniBand based Event Builder implementation for the LHCb upgrade
2017
The LHCb experiment will undergo a major upgrade during the second long shutdown (2019 - 2020). The upgrade will concern both the detector and the Data Acquisition system, which are to be rebuilt in order to optimally exploit the foreseen higher event rate. The Event Builder is the key component of the DAQ system, for it gathers data from the sub-detectors and builds up the whole event. The Event Builder network has to manage an incoming data rate of 32 Tb/s from a 40 MHz bunch-crossing frequency, with a cardinality of about 500 nodes. In this contribution we present an Event Builder implementation based on the InfiniBand network technology. This software relies on the InfiniBand verbs, which offers a user space interface to employ the Remote Direct Memory Access capabilities provided by the InfiniBand network devices. We will present the performance of the software on a cluster connected with 100 Gb/s InfiniBand network.
Journal Article
Extending the farm on external sites: the INFN Tier-1 experience
2017
The Tier-1 at CNAF is the main INFN computing facility offering computing and storage resources to more than 30 different scientific collaborations including the 4 experiments at the LHC. It is also foreseen a huge increase in computing needs in the following years mainly driven by the experiments at the LHC (especially starting with the run 3 from 2021) but also by other upcoming experiments such as CTA[1] While we are considering the upgrade of the infrastructure of our data center, we are also evaluating the possibility of using CPU resources available in other data centres or even leased from commercial cloud providers. Hence, at INFN Tier-1, besides participating to the EU project HNSciCloud, we have also pledged a small amount of computing resources (∼ 2000 cores) located at the Bari ReCaS[2] for the WLCG experiments for 2016 and we are testing the use of resources provided by a commercial cloud provider. While the Bari ReCaS data center is directly connected to the GARR network[3] with the obvious advantage of a low latency and high bandwidth connection, in the case of the commercial provider we rely only on the General Purpose Network. In this paper we describe the set-up phase and the first results of these installations started in the last quarter of 2015, focusing on the issues that we have had to cope with and discussing the measured results in terms of efficiency.
Journal Article
Swimming : a data driven acceptance correction algorithm
by
Gligorov, V V
,
Stagni, F
,
Gersabeck, M
in
Algorithms
,
Architecture (computers)
,
Computer architecture
2012
The high data rates at the LHC necessitate the use of biasing selections already at the trigger level. Consequently, the correction of the biases induced by these selections becomes one of the main challenges for analyses. This paper presents the LHCb implementation of a data driven method for extracting such biases which entirely avoids uncertainties associated with detector simulation. Its novelty lies in the LHCb trigger which is implemented entirely in software, allowing its decisions to be reproduced in an exact manner offline. It is demonstrated that this method allows the control of selection biases to better than 0.1%, and that it greatly enhances the range of physics which can be performed by the LHCb experiment. The implications of trigger and software architectures on the long term viability of this method, in particular with respect to the reproducibility of trigger decisions when running the same code on different underlying hardware or compilers, is discussed.
Journal Article
Study of the ψ 2(3823) and χ c1(3872) states in B+ → (J/ψπ + π − )K+ decays
by
S. Petrucci
,
O. Deschamps
,
J. Closier
in
B physics
,
Branching fraction
,
Hadron-Hadron scattering (experiments)
2020
Abstract The decays B+ → J/ψπ+π − K+ are studied using a data set corresponding to an integrated luminosity of 9 fb −1 collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate ψ2(3823), χc1(3872) and ψ(2S) states are reported. The values are B B + → ψ 2 3823 K + × B ψ 2 3823 → J / ψπ + π − B B + → χ c 1 3872 K + × B χ c 1 3872 → J / ψπ + π − = 3.56 ± 0.67 ± 0.11 × 10 − 2 , B B + → ψ 2 3823 K + × B ψ 2 3823 → J / ψπ + π − B B + → ψ 2 S K + × B ψ 2 S → J / ψπ + π − = 1.31 ± 0.25 ± 0.04 × 10 − 3 , B B + → χ c 1 3872 K + × B χ c 1 3872 → J / ψπ + π − B B + → ψ 2 S K + × B ψ 2 S → J / ψπ + π − = 3.69 ± 0.07 ± 0.06 × 10 − 2 , $$ {\\displaystyle \\begin{array}{c}\\frac{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to {\\uppsi}_2(3823){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi_2(3823)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to {\\upchi}_{\\mathrm{c}1}(3872){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\upchi_{\\mathrm{c}1}(3872)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}=\\left(3.56\\pm 0.67\\pm 0.11\\right)\\times {10}^{-2},\\\ {}\\frac{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to {\\uppsi}_2(3823){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi_2(3823)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to \\uppsi \\left(2\\mathrm{S}\\right){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi \\left(2\\mathrm{S}\\right)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}=\\left(1.31\\pm 0.25\\pm 0.04\\right)\\times {10}^{-3},\\\ {}\\frac{{\\mathcal{B}}_{\\mathrm{B}+\\to {\\upchi}_{\\mathrm{c}1}(3872){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\upchi_{\\mathrm{c}1}(3872)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to \\uppsi \\left(2\\mathrm{S}\\right){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi \\left(2\\mathrm{S}\\right)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}=\\left(3.69\\pm 0.07\\pm 0.06\\right)\\times {10}^{-2},\\end{array}} $$ where the first uncertainty is statistical and the second is systematic. The decay of B+ → ψ2(3823)K+ with ψ2(3823) → J/ψπ+π − is observed for the first time with a significance of 5.1 standard deviations. The mass differences between the ψ2(3823), χc1(3872) and ψ(2S) states are measured to be m χ c 1 3872 − m ψ 2 3823 = 47.50 ± 0.53 ± 0.13 MeV / c 2 , m ψ 2 3823 − m ψ 2 2 S = 137.98 ± 0.53 ± 0.14 MeV / c 2 , m χ c 1 3872 − m ψ 2 2 S = 185.49 ± 0.06 ± 0.03 MeV / c 2 , $$ {\\displaystyle \\begin{array}{c}{m}_{\\upchi_{\\mathrm{c}1}(3872)}-{m}_{\\uppsi_2(3823)}=47.50\\pm 0.53\\pm 0.13\\;\\mathrm{MeV}/{c}^2,\\\ {}{m}_{\\uppsi_2(3823)}-{m}_{\\uppsi_2\\left(2\\mathrm{S}\\right)}=137.98\\pm 0.53\\pm 0.14\\;\\mathrm{MeV}/{c}^2,\\\ {}{m}_{\\upchi_{\\mathrm{c}1}(3872)}-{m}_{\\uppsi_2\\left(2\\mathrm{S}\\right)}=185.49\\pm 0.06\\pm 0.03\\;\\mathrm{MeV}/{c}^2,\\end{array}} $$ resulting in the most precise determination of the χc1(3872) mass. The width of the ψ2(3823) state is found to be below 5.2 MeV at 90% confidence level. The Breit-Wigner width of the χc1(3872) state is measured to be Γ χ c 1 3872 BW = 0.96 − 0.18 + 0.19 ± 0.21 MeV $$ {\\Gamma}_{\\upchi_{\\mathrm{c}1}(3872)}^{\\mathrm{BW}}={0.96}_{-0.18}^{+0.19}\\pm 0.21\\;\\mathrm{MeV} $$ which is inconsistent with zero by 5.5 standard deviations.
Journal Article
Cross-Linked Hyaluronic Acid Films to Reduce Intra-Abdominal Postsurgical Adhesions in an Experimental Model
by
Chen, Weiliam
,
Falabella, Christine A.
in
Animals
,
Cecal Diseases - etiology
,
Cecal Diseases - prevention & control
2010
Background/Aims: Intra-abdominal adhesions typically occur after surgically damaged tissues are situated in apposition, leading to fibrotic connections. The goal of this study was to demonstrate the in vivo efficacy of a cross-linked and insoluble hyaluronic acid (HA) film to reduce postsurgical adhesion in a rat model. Methods: To measure in vitro adhesion resistance, porcine monocytes were deposited on the surface of films and their attachment was monitored by scanning electron microscopy. A rat cecum abrasion and abdominal insult model was utilized to demonstrate in vivo efficacy. Briefly, an HA film was deployed as a barrier between the damaged cecal and abdominal tissue surfaces for 21 days; control animals did not receive treatment. At the study conclusion, the rats were sacrificed and the degree of adhesion was determined using a scale from 0 to 3, where 0 = no adhesion and 3 = severe fibrosis. Results: HA films resisted monocyte adhesion in vitro. The in vivo study results demonstrated a significantly lower mean adhesion score (0.625 ± 0.517) with HA film treatment compared to the controls (2.09 ± 1.22). Conclusion: Placement of HA films between injured tissues significantly decreases the severity of abdominal adhesions. Furthermore, the HA film’s resistance to monocyte adhesion could be contributory to lowering in vivo adhesion scores.
Journal Article
Search for CP violation in $${{{\\varXi }} ^+_{c}} \\rightarrow {p} {{K} ^-} {{\\pi } ^+} $$ Ξ c + → p K - π + decays using model-independent techniques
2020
Abstract A first search for $$CP$$ CP violation in the Cabibbo-suppressed $${{{\\varXi }} ^+_{c}} \\rightarrow {p} {{K} ^-} {{\\pi } ^+} $$ Ξ c + → p K - π + decay is performed using both a binned and an unbinned model-independent technique in the Dalitz plot. The studies are based on a sample of proton-proton collision data, corresponding to an integrated luminosity of $$3.0\\,\\text {fb} ^{-1} $$ 3.0 fb - 1 , and collected by the LHCb experiment at centre-of-mass energies of 7 and $$8\\,\\text {TeV} $$ 8 TeV . The data are consistent with the hypothesis of no $$CP$$ CP violation.
Journal Article
Duration of antibiotic prophylaxis in high-risk patients with penetrating abdominal trauma: a prospective randomized trial
by
Dougherty, William R.
,
Cornwell, Edward E.
,
Belzberg, Howard
in
Abdomen
,
Abdominal Injuries - microbiology
,
Abdominal Injuries - therapy
1999
To evaluate the effect of varying durations of antibiotic prophylaxis in trauma patients with multiple risk factors for postoperative septic complications, a prospective randomized trial was undertaken at an urban level I trauma center. The inclusion criteria were full-thickness colon injury and one of the following: (1) Penetrating Abdominal Trauma Index ≥25, (2) transfusion of 6 units or more of packed red blood cells, or (3) more than 4 hours from injury to operation. Patients were randomly assigned to a short course (24 hours) or a long course (5 days) of antibiotic therapy. All patients received 2 g cefoxitin en route to the operating room and 2 g intravenously piggyback every 6 hours for a total of 1 day vs. 5 days. Sixty-three patients were equally divided into short-course (n = 31) and long-course (n = 32) therapy. This was a high-risk patient population, as assessed by the mean Penetrating Abdominal Trauma Index (33), number of patients with multiple blood transfusions (51 of 63; 81%), number of patients with an Injury Severity Score greater than 15 (37 of 63; 59%), number of patients with destructive colon wounds requiring resection (27 of 63; 43%), and number of patients requiring postoperative critical care (37 of 63; 59%). Differences in intra-abdominal (1-day, 19%; 5-days, 38%) and extra-abdominal (1-day, 45%; 5-days, 25%) infection rates did not achieve statistical significance. There continues to be no evidence that extending antibiotic prophylaxis beyond 24 hours is of benefit, even among the highest risk patients with penetrating abdominal trauma. A large, multi-institutional trial will be necessary to condemn this common practice with statistical validity.
Journal Article