2,493 research outputs found

    Online and Offline BIST in IP-Core Design

    Get PDF
    This article presents an online and offline built-in self-test architecture implemented as an SRAM intellectual-property core for telecommunication applications. The architecture combines fault-latency reduction, code-based fault detection, and architecture-based fault avoidance to meet reliability constraint

    Molecular Mechanism of DNA Topoisomerase I-Dependent rDNA Silencing: Sir2p Recruitment at Ribosomal Genes

    Get PDF
    Saccharomyces cerevisiae sir2Δ or top1Δ mutants exhibit similar phenotypes involving ribosomal DNA, including (i) loss of transcriptional silencing, resulting in non-coding RNA hyperproduction from cryptic RNA polymerase II promoters; (ii) alterations in recombination; and (iii) a general increase in histone acetylation. Given the distinct enzymatic activities of Sir2 and Top1 proteins, a histone deacetylase and a DNA topoisomerase, respectively, we investigated whether genetic and/or physical interactions between the two proteins could explain the shared ribosomal RNA genes (rDNA) phenotypes. We employed an approach of complementing top1Δ cells with yeast, human, truncated, and chimeric yeast/human TOP1 constructs and of assessing the extent of non-coding RNA silencing and histone H4K16 deacetylation. Our findings demonstrate that residues 115–125 within the yeast Top1p N-terminal domain are required for the complementation of the top1Δ rDNA phenotypes. In chromatin immunoprecipitation and co-immunoprecipitation experiments, we further demonstrate the physical interaction between Top1p and Sir2p. Our genetic and biochemical studies support a model whereby Top1p recruits Sir2p to the rDNA and clarifies a structural role of DNA topoisomerase I in the epigenetic regulation of rDNA, independent of its known catalytic activity

    An effective distributed BIST architecture for RAMs

    Get PDF
    The present paper proposes a solution to the problem of testing a system containing many distributed memories of different sizes. The proposed solution relies in the development of a BIST architecture characterized by a single BIST processor, implemented as a microprogrammable machine and able to execute different test algorithms, a wrapper for each SRAM including standard memory BIST modules, and an interface block to manage the communications between the SRAM and the BIST processor. Both area overhead and routing costs are minimized, and a scan-based approach allows full diagnostic capabilities of the faults possibly detected in the memories under test

    Cardiovascular features of possible autonomous cortisol secretion in patients with adrenal incidentalomas

    Get PDF
    Background: Low-grade incomplete post-dexamethasone cortisol suppression in patients with adrenal incidentalomas – recently defined as possible autonomous cortisol secretion (pACS) – has been associated with increased cardiovascular events and mortality. However, prospective studies documenting cardiac abnormalities in these patients are lacking. Subjects and methods: Between July 2016 and September 2017, 71 consecutive patients with adrenal lesions were prospectively screened for hypercortisolism by dexamethasone suppression test (NCT 02611258). Complete anthropometric, metabolic and hormonal parameters were recorded along with full cardiac ultrasound assessment and noninvasive measurement of arterial stiffness. All patients underwent chemical-shift magnetic resonance imaging to characterize the lesions. Cardiovascular outcomes were recorded in blind. Results: According to post-dexamethasone suppression cortisol values (post-DST), 34 patients had pACS and 37 nonfunctioning adenomas (NFA). The two groups were similar in sex, BMI, age distribution, cardiovascular risk factors and comorbidities. Left ventricular mass index (LVMIBSA) was increased in pACS compared to NFA (P=0.006) and mildly correlated to the post-DST cortisol level (rho=0.347; P=0.004). The post-DST cortisol levels explained up to 13.7% of LVMIBSAvariance (P=0.002). Compared to NFA, patients with pACS had a higher prevalence of diastolic dysfunction (35.1% vs 82.6%; P=0.001) and worse arterial stiffness assessed by pulse wave velocity (P=0.033). Conclusions: In apparently asymptomatic patients, mild autonomous cortisol secretion can sustain early cardiac and vascular remodeling, independently of other risk factors. The morphological and functional cardiovascular changes observed in pACS underline the need for further studies to correctly define the long-term management of this relatively common condition

    Performance analysis of the GR712RC dual-core LEON3FT SPARC V8 processor in an asymmetric multi-processing environment

    Get PDF
    In this paper we present the results of a series of performance tests carried out on a prototype board mounting the Cobham Gaisler GR712RC Dual Core LEON3FT processor. The aim was the characterization of the performances of the dual core processor when used for executing a highly demanding lossless compression task, acting on data segments continuously copied from the static memory to the processor RAM. The selection of the compression activity to evaluate the performances was driven by the possibility of a comparison with previously executed tests on the Cobham/Aeroflex Gaisler UT699 LEON3FT SPARCℱ V8. The results of the test activity have shown a factor 1.6 of improvement with respect to the previous tests, which can easily be improved by adopting a faster onboard board clock, and provided indications on the best size of the data chunks to be used in the compression activity

    An update of the evolving epidemic of blaKPC carrying Klebsiella pneumoniae in Sicily, Italy, 2014: Emergence of multiple Non-ST258 Clones

    Get PDF
    Background: In Italy, Klebsiella pneumoniae carbapenemase producing K. pneumoniae (KPC-Kp) strains are highly endemic and KPC producing CC258 is reported as the widely predominating clone. In Palermo, Italy, previous reports have confirmed this pattern. However, recent preliminary findings suggest that an epidemiological change is likely ongoing towards a polyclonal KPC-Kp spread. Here we present the results of molecular typing of 94 carbapenem non susceptible K. pneumoniae isolates detected during 2014 in the three different hospitals in Palermo, Italy. Methods and Results: Ninety-four consecutive, non replicate carbapenem non susceptible isolates were identified in the three largest acute general hospitals in Palermo, Italy, in the six-month period March-August 2014. They were characterized by PCR for ÎČ-lactam, aminoglycoside and plasmid mediated fluoroquinolone resistance genetic determinants. The mgrB gene of the colistin resistant isolates was amplified and sequenced. Clonality was assessed by pulsed field gel electrophoresis and multilocus sequence typing. Eight non-CC258 sequence types (STs) were identified accounting for 60% of isolates. In particular, ST307 and ST273 accounted for 29% and 18% of isolates. CC258 isolates were more frequently susceptible to gentamicin and non-CC258 isolates to amikacin. Colistin non susceptibility was found in 42% of isolates. Modifications of mgrB were found in 32 isolates. Conclusions: Concurrent clonal expansion of some STs and lateral transmission of genetic resistance determinants are likely producing a thorough change of the KPC-Kp epidemiology in Palermo, Italy. In our setting mgrB inactivation proved to substantially contribute to colistin resistance. Our findings suggest the need to continuously monitor the KPC-Kp epidemiology and to assess by a nationwide survey the possible shifting towards a polyclonal epidemic

    VIALACTEA knowledge base homogenizing access to Milky Way data

    Get PDF
    The VIALACTEA project has a work package dedicated to "Tools and Infrastructure" and, inside it, a task for the "Database and Virtual Observatory Infrastructure". This task aims at providing an infrastructure to store all the resources needed by the, more purposely, scientific work packages of the project itself. This infrastructure includes a combination of: storage facilities, relational databases and web services on top of them, and has taken, as a whole, the name of VIALACTEA Knowledge Base (VLKB). This contribution illustrates the current status of this VLKB. It details the set of data resources put together; describes the database that allows data discovery through VO inspired metadata maintenance; illustrates the discovery, cutout and access services built on top of the former two for the users to exploit the data content

    Distance biases in the estimation of the physical properties of Hi-GAL compact sources - I. Clump properties and the identification of high-mass star-forming candidates

    Get PDF
    The degradation of spatial resolution in star-forming regions, observed at large distances (d ≳ 1 kpc) with Herschel, can lead to estimates of the physical parameters of the detected compact sources (clumps), which do not necessarily mirror the properties of the original population of cores. This paper aims at quantifying the bias introduced in the estimation of these parameters by the distance effect. To do so, we consider Herschel maps of nearby star-forming regions taken from the Herschel Gould Belt survey, and simulate the effect of increased distance to understand what amount of information is lost when a distant star-forming region is observed with Herschel resolution. In the maps displaced to different distances we extract compact sources, and we derive their physical parameters as if they were original Herschel infrared Galactic Plane Survey maps of the extracted source samples. In this way, we are able to discuss how the main physical properties change with distance. In particular, we discuss the ability of clumps to form massive stars: we estimate the fraction of distant sources that are classified as high-mass stars-forming objects due to their position in the mass versus radius diagram, that are only 'false positives'. We also give a threshold for high-mass star formation M>1282 (r/ [pc])^{1.42} M_{☉}. In conclusion, this paper provides the astronomer dealing with Herschel maps of distant star-forming regions with a set of prescriptions to partially recover the character of the core population in unresolved clumps

    Three cases of bone metastases in patients with gastrointestinal stromal tumors

    Get PDF
    Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal neoplasms of the gastrointestinal tract. Tumor resection is the treatment of choice for localized disease. Tyrosine kinase inhibitors (imatinib, sunitinib) are the standard therapy for metastatic or unresectable GISTs. GISTs usually metastasize to the liver and peritoneum. Bone metastases are uncommon. We describe three cases of bone metastases in patients with advanced GISTs: two women (82 and 54 years of age), and one man (62 years of age). Bones metastases involved the spine, pelvis and ribs in one patient, multiple vertebral bodies and pelvis in one, and the spine and iliac wings in the third case. The lesions presented a lytic pattern in all cases. Two patients presented with multiple bone metastases at the time of initial diagnosis and one patient after seven years during the follow-up period. This report describes the diagnosis and treatment of the lesions and may help clinicians to manage bones metastases in GIST patients
    • 

    corecore