46 research outputs found

    Machine learning approach to the safety assessment of a prestressed concrete railway bridge

    Get PDF
    Early structural anomalies identification allows to hold maintenance activities that avoid loss of both economic resources and human life. This is extremely important for crucial infrastructures like railway bridges. This paper illustrates the structural health monitoring approach applied to a simply supported prestressed concrete railway bridge. In the framework of long-term monitoring, both static quantities (displacements, strains, and rotations) and environmental measurements (temperatures) have been recorded. Machine learning techniques, Extreme Gradient boosting machine and Multi-Layer Perceptron, have been exploited to build regression correlation models associated with the undamaged structural condition after adequate pre-processing operations. In this way, alarm thresholds based on the expected residuals between the predicted structural quantities and the measured ones, have been defined. The thresholds turned out to be able to catch early-stage anomalies not pointed out by traditional damage thresholds based on the design values. The proposed damage index is chosen as the moving median of the residuals, allowing a significant reduction of false alarms. The used correlation models and the obtained results represent a starting point for the generalization of this approach to the bridges belonging to the same static typology

    Comet Machholz (C/2004 Q2): morphological structures in the inner coma and rotation parameters

    Full text link
    Extensive observations of comet C/2004 Q2 (Machholz) were carried out between August 2004 and May 2005. The images obtained were used to investigate the comet's inner coma features at resolutions between 350 and 1500 km/pixel. A photometric analysis of the dust outflowing from the comet's nucleus and the study of the motion of the morphological structures in the inner coma indicated that the rotation period of the nucleus was most likely around 0.74 days. A thorough investigation of the inner coma morphology allowed us to observe two main active sources on the comet's nucleus, at a latitude of +85{\deg} \pm 5{\deg} and +45{\deg} \pm 5{\deg}, respectively. Further sources have been observed, but their activity ran out quite rapidly over time; the most relevant was at latcom. = 25{\deg} \pm 5{\deg}. Graphic simulations of the geometrical conditions of observation of the inner coma were compared with the images and used to determine a pole orientation at RA=95{\deg} \pm 5{\deg}, Dec=+35{\deg} \pm 5{\deg}. The comet's spin axis was lying nearly on the plane of the sky during the first decade of December 2004.Comment: 29 pages, 8 figures, 3 table

    Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

    Get PDF
    IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

    Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

    Get PDF
    Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

    Earth observation data for sustainable practices in viticulture

    No full text
    VitiGEOSS presentation delivered during the workshop “Earth Observation data for sustainable practices in viticulture” celebrated on the 2nd of October 2023 as part of the EuroGEO Workshop taking place in Bolzano, Italy.The VitiGEOSS project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 869565

    Small GTPase Rab5 participates in chromosome congression and regulates localization of the centromere-associated protein CENP-F to kinetochores

    Get PDF
    Rab5 is a small GTPase known to regulate vesicular trafficking during interphase. Here, we show that Rab5 also plays an unexpected role during mitotic progression. RNAi-mediated silencing of Rab5 caused defects in chromosome congression and extensive prometaphase delay, and it correlated with a severe reduction in the localization of the centromere-associated protein CENP-F to kinetochores. CENP-F is a component of the nuclear matrix required for chromosome congression that, at mitotic entry, localizes to the nuclear envelope and assembles on kinetochores, contributing to the establishment of kinetochore microtubule interactions. We found that Rab5 forms a complex with a subset of CENP-F in mitotic cells and regulates the kinetics of release of CENP-F from the nuclear envelope and its accumulation on kinetochores. Simultaneous depletion of both Rab5 and CENP-F recapitulated the mitotic defects caused by silencing of either Rab5 or CENP-F alone, indicating epistatic roles for these two proteins in the pathway that orchestrates chromosome congression. These results reveal the involvement of Rab5 in the proper execution of mitotic programs whose deregulation can undermine chromosomal stability

    Low rate of CNS recurrence in a cohort of 309 primary extranodal head and neck diffuse large B-cell lymphoma (HN-DLBCL) (IELSG 23)

    No full text
    Introduction: Head and neck is the second most common site of localized extranodal presentation of non-Hodgkin’s lymphomas and it is at high risk of CNS recurrence. Aim of the study: To evaluate the clinical outcome, prognostic factors and the rate of CNS recurrence in patients with HN-DLBCL. Patients and Methods: From December 1982 to June 2004, 309 patients with HN-DLBCL (median age 60 yrs, range 18–91) were referred to 9 international centers. The most common sites were Waldeyer’ring (68%), nose and paranasal sinuses (10%) and tyroid (8%). Adverse prognostic features included: stage II (67%), elevated LDH (16%), bulky disease (11%), No of extranodal sites >1(9%), B symptoms (8%), ECOG-PS >1 (8%) and stage-modified IPI (MIPI) >1 (50%). Two hundred sixty patients (84%) were given CHOP or CHOP-like regimen ± IFRT. Only few patients 26/260 (10%) received CNS prophylaxis (Methotrexate 12 mg i.t.; median of cycles 3, range 1–6). Results: Two hundred sixty two patients (85%) achieved a complete remission and 60 (23%) of them eventually relapsed, in the same site (40%), in other sites (53%) and 7% in both. Only 1/234 (0.4%) patients, who did not receive prophylaxis, relapsed in CNS. After a median followup of 42 months (range 6–220 months), 5-year estimate of OS, EFS and DFS was 72%, 55% and 73%, respectively. By Cox multivariate analysis, a risk factor >1 according to MIPI predicted a poor EFS. Conclusions: The present study showed a very low rate of CNS recurrence in high risk patients, who did not receive adequate prophylaxis, suggesting that CNS prophylaxis could not be mandatory in HN-DLBCL patients. This should be confirmed by prospective studies of clinical outcome
    corecore