583 research outputs found
Study of sequential semileptonic decays of b hadrons produced at the Tevatron
We present a study of rates and kinematical properties of lepton pairs
contained in central jets with transverse energy E_T > 15 GeV that are produced
at the Fermilab Tevatron collider. We compare the data to a QCD prediction
based on the HERWIG and QQ Monte Carlo generator programs.We find that the data
are poorly described by the simulation, in which sequential semileptonic decays
of single b quarks (b --> l c X with c --> l s X) are the major source of such
lepton pairs.Comment: 25 pages, 8 figures. Some typos were fixed in the text and
bibliography. Submitted to Phys. Rev.
Towards Master Data Management for Cultural Heritage: the Sacri Monti web platform
This paper focuses on managing the Cultural Heritage maintenance process through web platforms, exploring a data-driven new approach that relies on the framework of Master Data Management (MDM). The MDM framework is based on data quality, revisioning and auditing of information, and the Microsoft SQL Server Master Data Services (MDS) was used. It is a highly customizable commercial tool that proved to be effective and able to manage extended and articulated databases and provide stability and long-term software support. MDS provides powerful tools to avoid duplicates, ensure data quality, and record all the modifications that occurred on the dataset over time. These are key features to build a reliable platform for information management of complex CH assets. The paper presents some first tests applied for the Sacri Monti of Piedmont and Lombardy case of study. It is a UNESCO wide religious architectural complex site in northern Italyâs mountainous part. The paper compares approaches and previous experiences of Sacri Monti management using web platform information systems, such as the BIM3DSG, Chimera, and Main10ance, to support Sacri Monti management activity
Phenomenological study of the atypical heavy flavor production observed at the Fermilab Tevatron
We address known discrepancies between the heavy flavor properties of jets
produced at the Tevatron collider and the prediction of conventional-QCD
simulations. In this study, we entertain the possibility that these effects are
real and due to new physics. We show that all anomalies can be simultaneously
fitted by postulating the additional pair production of light bottom squarks
with a 100% semileptonic branching fraction.Comment: 30 pages, 13 figures, 3 tables. Submitted to Phys. Rev.
Morphoâphysiological classification of italian tomato cultivars (Solanum lycopersicum l.) according to drought tolerance during vegetative and reproductive growth
Irrigation is fundamental for agriculture but, as climate change becomes more persistent, there is a need to conserve water and use it more efficiently. It is therefore crucial to identify cultivars that can tolerate drought. For economically relevant crops, such as tomatoes, this purpose takes on an even more incisive role and local agrobiodiversity is a large genetic reservoir of promising cultivars. In this study, nine local Italian cultivars of tomatoes plus four widely used commercial cultivars were considered. These experienced about 20 d of drought, either at vegetative or reproductive phase. Various physioâmorphological parameters were monitored, such as stomatal conductance (gs), photosynthesis (A), water use efficiency (WUE), growth (GI) and soil water content (SWC). The different responses and behaviors allowed to divide the cultivars into three groups: tolerant, susceptible, and intermediate. The classification was also confirmed by a principal component analysis (PCA). The study, in addition to deepening the knowledge of local Italian tomato cultivars, reveals how some cultivars perform better under stress condition than commercial ones. Moreover, the different behavior depends on the genotype and on the growth phase of plants. In fact, the Perina cultivar is the most tolerant during vegetative growth while the Quarantino cultivar is mostly tolerant at reproductive stage. The results suggest that selection of cultivars could lead to a more sustainable agriculture and less wasteful irrigation plans
A Distributed IoT Air Quality Measurement System for High-Risk Workplace Safety Enhancement
The safety of an operator working in a hazardous environment is a recurring topic in the technical literature of recent years, especially for high-risk environments such as oil and gas plants, refineries, gas depots, or chemical industries. One of the highest risk factors is constituted by the presence of gaseous substances such as toxic compounds such as carbon monoxide and nitric oxides, particulate matter or indoors, in closed spaces, low oxygen concentration atmospheres, and high concentrations of CO2 that can represent a risk for human health. In this context, there exist many monitoring systems for lots of specific applications where gas detection is required. In this paper, the authors present a distributed sensing system based on commercial sensors aimed at monitoring the presence of toxic compounds generated by a melting furnace with the aim of reliably detecting the insurgence of dangerous conditions for workers. The system is composed of two different sensor nodes and a gas analyzer, and it exploits commercial low-cost commercially available sensors
Exoskeletons for workers: A case series study in an enclosures production line
This case-series study aims to investigate the effects of a passive shoulder support exoskeleton on experienced workers during their regular work shifts in an enclosures production site. Experimental activities included three sessions, two of which were conducted in-field (namely, at two workstations of the painting line, where panels were mounted and dismounted from the line; each session involved three participants), and one session was carried out in a realistic simulated environment (namely, the workstations were recreated in a laboratory; this session involved four participants). The effect of the exoskeleton was evaluated through electromyographic activity and perceived effort. After in-field sessions, device usability and user acceptance were also assessed. Data were reported individually for each participant. Results showed that the use of the exoskeleton reduced the total shoulder muscular activity compared to normal working conditions, in all subjects and experimental sessions. Similarly, the use of the exoskeleton resulted in reductions of the perceived effort in the shoulder, arm, and lower back. Overall, participants indicated high usability and acceptance of the device. This case series invites larger validation studies, also in diverse operational contexts
Comparative metabolomics of leaves and stems of three Italian olive cultivars under drought stress
The Mediterranean will be one of the focal points of climate change. The
predicted dry and hot summers will lead to water scarcity in agriculture, which
may limit crop production and growth. The olive tree serves as a model woody
plant for studying drought stress and improving water resource management;
thus, it is critical to identify genotypes that are more drought tolerant and
perform better under low irrigation or even rainfed conditions. In this study,
the metabolomic approach was used to highlight variations in metabolites in
stems and leaves of three Italian olive cultivars (previously characterized
physiologically) under two and four weeks of drought stress. Phenolic and
lipophilic profiles were obtained by gas chromatography-mass spectrometry
and ultra-high performance liquid chromatography-mass spectrometry,
respectively. The findings identified the leaf as the primary organ in which
phenolic variations occurred. The Maurino cultivar exhibited a strong stress
response in the form of phenolic compound accumulation, most likely to
counteract oxidative stress. The phenolic compound content of âGiarraffaâ and
âLeccinoâ plants remained relatively stable whether they were exposed to drought
or not. Variations in the lipid profile occurred in leaves and stems of all the
cultivars. A high accumulation of compounds related to epicuticular wax
components was observed in the leaf of âGiarraffaâ, while a strong reduction of
lipids and long-chain alkanes occurred in âMaurinoâ when exposed to drought
stress conditions
Osteopontin plasma levels and accelerated atherosclerosis in patients with CAD undergoing PCI: a prospective clinical study.
OBJECTIVES: Growing evidence supports the role played by inflammation in atherosclerosis. Identifying sensitive biomarkers is useful in predicting accelerated atherosclerosis. We investigated prospectively the relationship between plasma levels of inflammatory biomarkers [osteopontin, C-reactive protein (CRP), interleukin-6 (IL-6)] and instent restenosis, and rapid coronary plaque progression in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). METHODS: We studied 77 patients with CAD: 45 affected by unstable angina/non-ST elevation myocardial infarction [acute coronary syndrome (ACS)], and 32 by chronic coronary syndrome (CCS). Plasma osteopontin, IL-6, and CRP levels were measured before intervention in all patients; measurements were carried out on the basis of the following time course at 1,15, 30, 90, and 180 days follow-up in a subgroup of 39 consenting patients. Clinical and biohumoral data were correlated with baseline and 6-month PCI follow-up angiography. RESULTS: Osteopontin, IL-6, and CRP were higher in patients with ACS than in those with CCS (analysis of variance: P<0.001, 0.05, and 0.05, respectively). Baseline osteopontin levels proved to be associated with rapid coronary plaque progression (P=0.005) and instent restenosis (P=0.05). The highest osteopontin levels were found in patients with CAD with both rapid plaque progression and instent restenosis (P=0.003). PCI increased inflammatory markers acutely, and osteopontin remained elevated in patients with ACS. Patients with ACS showed a higher percentage (74%) of rapid plaque progression than those with CCS (26%) (P<0.05). CONCLUSION: The study prospectively shows the link between inflammatory status and accelerated atherosclerosis in patients with CAD undergoing PCI. The baseline and persistent rise of osteopontin is an expression of its contribution to the accelerated plaque progression, and therefore osteopontin may be a useful prognostic biomarker
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