We propose a method to estimate the amplitude of an unexpected power loss which, leveraging on a calibration, enables the real-time monitoring of a network link. It is based on an existing ...fiber-longitudinal power profile evaluation technique. The reliability of the method is assessed experimentally. When the anomaly is located at 0 km from the beginning of the span, the estimation bias is smaller than 0.2 dB for losses up to 10 dB. When the anomaly is located at 25 km from the beginning of the span, the same estimation bias is observed but for losses up to 5 dB. In both cases, the standard deviation of the estimation is smaller than 0.2 dB.
Clouds play an important role in controlling the radiative energy budget of the Arctic atmospheric boundary layer. To quantify the impact of clouds on the radiative heating or cooling of the lower ...atmosphere and of the surface, vertical profile observations of thermal-infrared irradiances were collected using a radiation measurement system carried by a tethered balloon. We present 70 profiles of thermal-infrared radiative quantities measured in summer 2020 during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition and in autumn 2021 and spring 2022 in Ny-Ålesund, Svalbard. Measurements are classified into four groups: cloudless, low-level liquid-bearing cloud, elevated liquid-bearing cloud, and elevated ice cloud. Cloudless cases display an average radiative cooling rate of about −2 K d−1 throughout the atmospheric boundary layer. Instead, low-level liquid-bearing clouds are characterized by a radiative cooling up to −80 K d−1 within a shallow layer at cloud top, while no temperature tendencies are identified underneath the cloud layer. Radiative transfer simulations are performed to quantify the sensitivity of radiative cooling rates to cloud microphysical properties. In particular, cloud top cooling is strongly driven by the liquid water path, especially in optically thin clouds, while for optically thick clouds the cloud droplet number concentration has an increased influence. Additional radiative transfer simulations are used to demonstrate the enhanced radiative importance of the liquid relative to ice clouds. To analyze the temporal evolution of thermal-infrared radiation profiles during the transitions from a cloudy to a cloudless atmosphere, a respective case study is investigated.
Airborne observations of vertical aerosol particle distributions are crucial
for detailed process studies and model improvements. Tethered balloon
systems represent a less expensive alternative to ...aircraft to probe shallow
atmospheric boundary layers (ABLs). This study presents the newly developed
cubic aerosol measurement platform (CAMP) for balloon-borne observations of
aerosol particle microphysical properties. With an edge length of 35 cm and a weight of 9 kg, the cube is an environmentally robust instrument platform intended for measurements at low temperatures, with a particular focus on applications in cloudy Arctic ABLs. The aerosol instrumentation on board CAMP
comprises two condensation particle counters with different lower detection
limits, one optical particle size spectrometer, and a miniaturized
absorption photometer. Comprehensive calibrations and characterizations of
the instruments were performed in laboratory experiments. The first field
study with a tethered balloon system took place at the Leibniz Institute for Tropospheric Research (TROPOS) station in Melpitz, Germany, in the winter of 2019. At ambient temperatures between −8 and 15 ∘C, the platform was operated up to a 1.5 km height on 14 flights under both clear-sky and cloudy conditions. The continuous aerosol observations at the ground station served as a reference for evaluating the CAMP measurements.
Exemplary profiles are discussed to elucidate the performance of the system
and possible process studies. Based on the laboratory instrument
characterizations and the observations during the field campaign, CAMP
demonstrated the capability to provide comprehensive aerosol particle
measurements in cold and cloudy ABLs.
This study analyzes turbulent energy fluxes in the Arctic atmospheric boundary layer (ABL) using measurements with a small uncrewed aircraft system (sUAS). Turbulent fluxes constitute a major part of ...the atmospheric energy budget and influence the surface heat balance by distributing energy vertically in the atmosphere. However, only few in situ measurements of the vertical profile of turbulent fluxes in the Arctic ABL exist. The study presents a method to derive turbulent heat fluxes from DataHawk2 sUAS turbulence measurements, based on the flux gradient method with a parameterization of the turbulent exchange coefficient. This parameterization is derived from high-resolution horizontal wind speed measurements in combination with formulations for the turbulent Prandtl number and anisotropy depending on stability. Measurements were taken during the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition in the Arctic sea ice during the melt season of 2020. For three example cases from this campaign, vertical profiles of turbulence parameters and turbulent heat fluxes are presented and compared to balloon-borne, radar, and near-surface measurements. The combination of all measurements draws a consistent picture of ABL conditions and demonstrates the unique potential of the presented method for studying turbulent exchange processes in the vertical ABL profile with sUAS measurements.
Summary Background In the TRIBE study, FOLFOXIRI (fluorouracil, leucovorin, oxaliplatin, and irinotecan) plus bevacizumab significantly improved progression-free survival of patients with metastatic ...colorectal cancer compared with FOLFIRI (fluorouracil, leucovorin, and irinotecan) plus bevacizumab. In this updated analysis, we aimed to provide mature results for overall survival—a secondary endpoint—and report treatment efficacy in RAS and BRAF molecular subgroups. Methods TRIBE was an open-label, multicentre, phase 3 randomised study of patients (aged 18–70 years with Eastern Cooperative Oncology Group ECOG performance status of 2 or less and aged 71–75 years with an ECOG performance status of 0) with unresectable metastatic colorectal cancer who were recruited from 34 Italian oncology units. Patients were randomly assigned (1:1) via a web-based procedure to receive FOLFIRI plus bevacizumab or FOLFOXIRI plus bevacizumab. Bevacizumab was given as a 5 mg/kg intravenous dose. FOLFIRI consisted of a 180 mg/m2 intravenous infusion of irinotecan for 60 min followed by a 200 mg/m2 intravenous infusion of leucovorin for 120 min, a 400 mg/m2 intravenous bolus of fluorouracil, and a 2400 mg/m2 continuous infusion of fluorouracil for 46 h. FOLFOXIRI consisted of a 165 mg/m2 intravenous infusion of irinotecan for 60 min, followed by an 85 mg/m2 intravenous infusion of oxaliplatin given concurrently with 200 mg/m2 leucovorin for 120 min, followed by a 3200 mg/m2 continuous infusion of fluorouracil for 48 h. Tissue samples for RAS and BRAF mutational status analyses were centrally collected. In this updated analysis, we assessed the secondary endpoint of overall survival in the main cohort and treatment efficacy in RAS and BRAF molecular subgroups. All analyses were by intention to treat. TRIBE was concluded on Nov 30, 2014. The trial is registered with ClinicalTrials.gov , number NCT00719797. Findings Between July 17, 2008, and May 31, 2011, 508 patients were randomly assigned. At a median follow-up of 48·1 months (IQR 41·7–55·6), median overall survival was 29·8 months (95% CI 26·0–34·3) in the FOLFOXIRI plus bevacizumab group compared with 25·8 months (22·5–29·1) in the FOLFIRI plus bevacizumab group (hazard ratio HR 0·80, 95% CI 0·65–0·98; p=0·03). Median overall survival was 37·1 months (95% CI 29·7–42·7) in the RAS and BRAF wild-type subgroup compared with 25·6 months (22·4–28·6) in the RAS -mutation-positive subgroup (HR 1·49, 95% CI 1·11–1·99) and 13·4 months (8·2–24·1) in the BRAF -mutation-positive subgroup (HR 2·79, 95% CI 1·75–4·46; likelihood-ratio test p<0·0001). Treatment effect was not significantly different across molecular subgroups (pinteraction =0·52). Interpretation FOLFOXIRI plus bevacizumab is a feasible treatment option for those patients who meet the inclusion criteria of the present study, irrespective of baseline clinical characteristics and RAS or BRAF mutational status. Funding GONO (Gruppo Oncologico del Nord Ovest) Cooperative Group and ARCO Foundation.
Summary Background We previously found that dual HER2 blockade with trastuzumab and lapatinib led to inhibition of tumour growth in patient-derived xenografts of HER2 -amplified metastatic colorectal ...cancer. In this study, we aimed to assess the antitumour activity of trastuzumab and lapatinib in patients with HER2-positive colorectal cancer. Methods HERACLES was a proof-of-concept, multicentre, open-label, phase 2 trial done at four Italian academic cancer centres. We enrolled adult patients with KRAS exon 2 (codons 12 and 13) wild-type and HER2-positive metastatic colorectal cancer refractory to standard of care (including cetuximab or panitumumab), an Eastern Cooperative Oncology Group performance status of 0 or 1, and at least one measurable lesion. We defined HER2 positivity in tumour samples by use of immunohistochemistry and fluorescence in-situ hybridisation in accordance with our previously validated colorectal cancer-specific diagnostic criteria. Eligible patients received intravenous trastuzumab at 4 mg/kg loading dose followed by 2 mg/kg once per week, and oral lapatinib at 1000 mg per day until evidence of disease progression. The primary endpoint was the proportion of patients achieving an objective response (defined as complete response or partial response), which was assessed by independent central review in the intention-to-treat population. This trial is registered with EudraCT, number 2012-002128-33. Findings Between Aug 27, 2012, and May 15, 2015, we screened 914 patients with KRAS exon 2 (codons 12 and 13) wild-type metastatic colorectal cancer and identified 48 (5%) patients with HER2-positive tumours, although two died before enrolment. Of these patients, 27 were eligible for the trial. All were evaluable for response. At the time of data cutoff on Oct 15, 2015, with a median follow-up of 94 weeks (IQR 51–127), eight (30%, 95% CI 14–50) of 27 patients had achieved an objective response, with one patient (4%, 95% CI −3 to 11) achieving a complete response, and seven (26%, 95% CI 9–43) achieving partial responses; 12 (44%, 95% CI 25–63) patients had stable disease. Six (22%) of 27 patients had grade 3 adverse events, which consisted of fatigue in four patients, skin rash in one patient, and increased bilirubin concentration in one patient. No grade 4 or 5 adverse events were reported. We detected no drug-related serious adverse events. Interpretation The combination of trastuzumab and lapatinib is active and well tolerated in treatment-refractory patients with HER2-positive metastatic colorectal cancer. Funding Associazione Italiana Ricerca Cancro (AIRC), Fondazione Oncologia Niguarda Onlus, and Roche.
Summary Background Angiogenesis is an important therapeutic target in colorectal carcinoma. Ramucirumab is a human IgG-1 monoclonal antibody that targets the extracellular domain of VEGF receptor 2. ...We assessed the efficacy and safety of ramucirumab versus placebo in combination with second-line FOLFIRI (leucovorin, fluorouracil, and irinotecan) for metastatic colorectal cancer in patients with disease progression during or after first-line therapy with bevacizumab, oxaliplatin, and a fluoropyrimidine. Methods Between Dec 14, 2010, and Aug 23, 2013, we enrolled patients into the multicentre, randomised, double-blind, phase 3 RAISE trial. Eligible patients had disease progression during or within 6 months of the last dose of first-line therapy. Patients were randomised (1:1) via a centralised, interactive voice-response system to receive 8 mg/kg intravenous ramucirumab plus FOLFIRI or matching placebo plus FOLFIRI every 2 weeks until disease progression, unacceptable toxic effects, or death. Randomisation was stratified by region, KRAS mutation status, and time to disease progression after starting first-line treatment. The primary endpoint was overall survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT01183780 .ld Findings We enrolled 1072 patients (536 in each group). Median overall survival was 13·3 months (95% CI 12·4–14·5) for patients in the ramucirumab group versus 11·7 months (10·8–12·7) for the placebo group (hazard ratio 0·844 95% CI 0·730–0·976; log-rank p=0·0219). Survival benefit was consistent across subgroups of patients who received ramucirumab plus FOLFIRI. Grade 3 or worse adverse events seen in more than 5% of patients were neutropenia (203 38% of 529 patients in the ramucirumab group vs 123 23% of 528 in the placebo group, with febrile neutropenia incidence of 18 3% vs 13 2%), hypertension (59 11% vs 15 3%), diarrhoea (57 11% vs 51 10%), and fatigue (61 12% vs 41 8%). Interpretation Ramucirumab plus FOLFIRI significantly improved overall survival compared with placebo plus FOLFIRI as second-line treatment for patients with metastatic colorectal carcinoma. No unexpected adverse events were identified and toxic effects were manageable. Funding Eli Lilly.
We introduce an innovative vision transformer approach to identify and precisely locate high-risk events, including fiber cut precursors, in state-of-polarization derived spectrograms. Our method ...achieves impressive 97% diagnostic accuracy and precise temporal localization (6-ms- RMSE).
We propose and experimentally test a cross-phase modulation based algorithm to monitor network loss anomalies from detected data. The idea does not need service interruption, special signals, nor an ...exhaustive search of the anomaly coordinate.
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