404 research outputs found

    Redefining legacy : a technical debt perspective

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    Organisations that manage legacy systems at scale, such as those found within large government agencies and commercial enterprises, face a set of unique challenges. They manage complex software landscapes that have evolved over decades. Current conceptual definitions of legacy systems give practitioners limited insights that can inform their daily work. In this research, we compare conceptual definitions of large-scale legacy and technical debt. We hypothesise that large-scale legacy reflects an accumulation of technical debt that has never been through a remediation phase. To pursue this hypothesis, we identified the following question: How do practitioners describe their experience of managing large-scale legacy landscapes? We conducted 16 semi-structured open-ended, recorded and transcribed interviews with industry practitioners from 4 government organisations and 9 large enterprises involved with the maintenance and migration of large-scale legacy systems. A snowball sampling technique was used to identify participants. We adopted an approach informed by grounded theory. There was consensus among the practitioners in our study that the landscape is fragmented and inflexible, consisting of many dispersed and fragile applications. Practitioners report challenges with shifting paradigms from batch processing to near real-time customer-focused information systems. Our findings show there is overlap between challenges experienced by participants and symptoms typified by technical debt. We identify a novel type of technical debt, ``Ecosystem Debt'' which arises from the scale, and age, of many large-scale legacy applications. By positioning Legacy within the context of Technical Debt, practitioners have a more concrete understanding of the state of the systems they maintain

    Gorab is a Golgi protein required for structure and duplication of Drosophila centrioles.

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    We demonstrate that a Drosophila Golgi protein, Gorab, is present not only in the trans-Golgi but also in the centriole cartwheel where, complexed to Sas6, it is required for centriole duplication. In addition to centriole defects, flies lacking Gorab are uncoordinated due to defects in sensory cilia, which lose their nine-fold symmetry. We demonstrate the separation of centriole and Golgi functions of Drosophila Gorab in two ways: first, we have created Gorab variants that are unable to localize to trans-Golgi but can still rescue the centriole and cilia defects of gorab null flies; second, we show that expression of C-terminally tagged Gorab disrupts Golgi functions in cytokinesis of male meiosis, a dominant phenotype overcome by mutations preventing Golgi targeting. Our findings suggest that during animal evolution, a Golgi protein has arisen with a second, apparently independent, role in centriole duplication.D.M.G. is grateful for a Wellcome Investigator Award, which supported this work. The study was initiated with support from Cancer Research UK

    Genome Sequence of Erythromelalgia-Related Poxvirus Identifies it as an Ectromelia Virus Strain

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    Erythromelagia is a condition characterized by attacks of burning pain and inflammation in the extremeties. An epidemic form of this syndrome occurs in secondary students in rural China and a virus referred to as erythromelalgia-associated poxvirus (ERPV) was reported to have been recovered from throat swabs in 1987. Studies performed at the time suggested that ERPV belongs to the orthopoxvirus genus and has similarities with ectromelia virus, the causative agent of mousepox. We have determined the complete genome sequence of ERPV and demonstrated that it has 99.8% identity to the Naval strain of ectromelia virus and a slighly lower identity to the Moscow strain. Small DNA deletions in the Naval genome that are absent from ERPV may suggest that the sequenced strain of Naval was not the immediate progenitor of ERPV

    Retinoids cause apoptosis in pancreatic cancer cells via activation of RAR-γ and altered expression of Bcl-2/Bax

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    All-trans-retinoic acid and 9-cis-retinoic acid have been reported to have inhibitory effects on pancreatic adenocarcinoma cells and we have shown that this is partly due to induction of apoptosis. In this study, the mechanisms whereby 9-cis-retinoic acid induces apoptosis in these cells were investigated. An involvement of the Bcl-2 family of proteins was shown, such that 9-cis-retinoic acid causes a decrease in the Bcl-2/Bax ratio. Overexpression of Bcl-2 also resulted in inhibition of apoptosis induced by 9-cis-retinoic acid. Furthermore, two broad-range caspase inhibitors blocked DNA fragmentation induced by 9-cis-retinoic acid, but had no effect on viability defined by mitochondrial activity. Using synthetic retinoids, which bind selectively to specific retinoic acid receptor subtypes, we further established that activation of retinoic acid receptor-γ is essential for induction of apoptosis. Only pan-retinoic acid receptor and retinoic acid receptor-γ selective agonists reduced viability and a cell line expressing very low levels of retinoic acid receptor-γ is resistant to the effects of 9-cis-retinoic acid. A retinoic acid receptor-β/γ selective antagonist also suppressed the cytotoxic effects of 9-cis-retinoic acid in a dose-dependent manner. This study provides important insight into the mechanisms involved in suppression of pancreatic tumour cell growth by retinoids. Our results encourage further work evaluating the clinical use of receptor subtype selective retinoids in pancreatic carcinoma

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    The Golgin GMAP210/TRIP11 Anchors IFT20 to the Golgi Complex

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    Eukaryotic cells often use proteins localized to the ciliary membrane to monitor the extracellular environment. The mechanism by which proteins are sorted, specifically to this subdomain of the plasma membrane, is almost completely unknown. Previously, we showed that the IFT20 subunit of the intraflagellar transport particle is localized to the Golgi complex, in addition to the cilium and centrosome, and hypothesized that the Golgi pool of IFT20 plays a role in sorting proteins to the ciliary membrane. Here, we show that IFT20 is anchored to the Golgi complex by the golgin protein GMAP210/Trip11. Mice lacking GMAP210 die at birth with a pleiotropic phenotype that includes growth restriction, ventricular septal defects of the heart, omphalocele, and lung hypoplasia. Cells lacking GMAP210 have normal Golgi structure, but IFT20 is no longer localized to this organelle. GMAP210 is not absolutely required for ciliary assembly, but cilia on GMAP210 mutant cells are shorter than normal and have reduced amounts of the membrane protein polycystin-2 localized to them. This work suggests that GMAP210 and IFT20 function together at the Golgi in the sorting or transport of proteins destined for the ciliary membrane

    Polymorphisms of −174G>C and −572G>C in the Interleukin 6 (IL-6) Gene and Coronary Heart Disease Risk: A Meta-Analysis of 27 Research Studies

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    OBJECTIVE: Elevated serum IL-6 level is a risk factor for coronary heart disease (CHD). The -174 G>C and -572 G>C polymorphisms in the IL-6 gene have previously been shown to modulate IL-6 levels. But the association between the -174 G>C and -572 G>C polymorphisms and the risk of CHD is still unclear. A meta-analysis of all eligible studies was carried out to clarify the role of IL-6 gene polymorphisms in CHD. METHODS AND RESULTS: PubMed, EMBASE, Vip, CNKI and CBM-disc were searched for eligible articles in English and Chinese that were published before October 2010. 27 studies involving 11580 patients with CHD and 17103 controls were included. A meta-analysis was performed for the included articles using the RevMan 5.0 and Stata 10.0 softwares. Overall, the -174 C allele was not significantly associated with CHD risk (ORs = 1.04, 95%CI = 0.98 to 1.10) when compared with the -174 G allele in the additive model, and meta-analysis under other genetic models (dominant, recessive, CC versus GG, and GC versus GG) also did not reveal any significant association. On the contrary, the -572 C allele was associated with a decreased risk of CHD when compared with the -572 G allele (ORs = 0.79, 95%CI = 0.68 to 0.93). Furthermore, analyses under the recessive model (ORs = 0.69, 95% = 0.59 to 0.80) and the allele contrast model (genotype of CC versus GG, ORs = 0.49, 95% = 0.35 to 0.70) yielded similar results. However, statistical significance was not found when the meta-analysis was restricted to studies focusing on European populations, studies with large sample size, and cohort studies by using subgroup analysis. CONCLUSIONS: The -174 G>C polymorphism in the IL-6 gene is not significantly associated with increased risks of CHD. However, The -572 G>C polymorphism may contribute to CHD development. Future investigations with better study design and large number of subjects are needed

    Genome-Wide Profile of Pleural Mesothelioma versus Parietal and Visceral Pleura: The Emerging Gene Portrait of the Mesothelioma Phenotype

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    Malignant pleural mesothelioma is considered an almost incurable tumour with increasing incidence worldwide. It usually develops in the parietal pleura, from mesothelial lining or submesothelial cells, subsequently invading the visceral pleura. Chromosomal and genomic aberrations of mesothelioma are diverse and heterogenous. Genome-wide profiling of mesothelioma versus parietal and visceral normal pleural tissue could thus reveal novel genes and pathways explaining its aggressive phenotype.Well-characterised tissue from five mesothelioma patients and normal parietal and visceral pleural samples from six non-cancer patients were profiled by Affymetrix oligoarray of 38 500 genes. The lists of differentially expressed genes tested for overrepresentation in KEGG PATHWAYS (Kyoto Encyclopedia of Genes and Genomes) and GO (gene ontology) terms revealed large differences of expression between visceral and parietal pleura, and both tissues differed from mesothelioma. Cell growth and intrinsic resistance in tumour versus parietal pleura was reflected in highly overexpressed cell cycle, mitosis, replication, DNA repair and anti-apoptosis genes. Several genes of the “salvage pathway” that recycle nucleobases were overexpressed, among them TYMS, encoding thymidylate synthase, the main target of the antifolate drug pemetrexed that is active in mesothelioma. Circadian rhythm genes were expressed in favour of tumour growth. The local invasive, non-metastatic phenotype of mesothelioma, could partly be due to overexpression of the known metastasis suppressors NME1 and NME2. Down-regulation of several tumour suppressor genes could contribute to mesothelioma progression. Genes involved in cell communication were down-regulated, indicating that mesothelioma may shield itself from the immune system. Similarly, in non-cancer parietal versus visceral pleura signal transduction, soluble transporter and adhesion genes were down-regulated. This could represent a genetical platform of the parietal pleura propensity to develop mesothelioma.Genome-wide microarray approach using complex human tissue samples revealed novel expression patterns, reflecting some important features of mesothelioma biology that should be further explored

    Type 1 Fimbriae, a Colonization Factor of Uropathogenic Escherichia coli, Are Controlled by the Metabolic Sensor CRP-cAMP

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    Type 1 fimbriae are a crucial factor for the virulence of uropathogenic Escherichia coli during the first steps of infection by mediating adhesion to epithelial cells. They are also required for the consequent colonization of the tissues and for invasion of the uroepithelium. Here, we studied the role of the specialized signal transduction system CRP-cAMP in the regulation of type 1 fimbriation. Although initially discovered by regulating carbohydrate metabolism, the CRP-cAMP complex controls a major regulatory network in Gram-negative bacteria, including a broad subset of genes spread into different functional categories of the cell. Our results indicate that CRP-cAMP plays a dual role in type 1 fimbriation, affecting both the phase variation process and fimA promoter activity, with an overall repressive outcome on fimbriation. The dissection of the regulatory pathway let us conclude that CRP-cAMP negatively affects FimB-mediated recombination by an indirect mechanism that requires DNA gyrase activity. Moreover, the underlying studies revealed that CRP-cAMP controls the expression of another global regulator in Gram-negative bacteria, the leucine-responsive protein Lrp. CRP-cAMP-mediated repression is limiting the switch from the non-fimbriated to the fimbriated state. Consistently, a drop in the intracellular concentration of cAMP due to altered physiological conditions (e.g. growth in presence of glucose) increases the percentage of fimbriated cells in the bacterial population. We also provide evidence that the repression of type 1 fimbriae by CRP-cAMP occurs during fast growth conditions (logarithmic phase) and is alleviated during slow growth (stationary phase), which is consistent with an involvement of type 1 fimbriae in the adaptation to stress conditions by promoting biofilm growth or entry into host cells. Our work suggests that the metabolic sensor CRP-cAMP plays a role in coupling the expression of type 1 fimbriae to environmental conditions, thereby also affecting subsequent attachment and colonization of host tissues
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