Vision-State Fusion: Improving Deep Neural Networks for Autonomous Robotics

Vision-based perception tasks fulfill a paramount role in robotics, facilitating solutions to many challenging scenarios, such as acrobatics maneuvers of autonomous unmanned aerial vehicles (UAVs) and robot-assisted high precision surgery. Most control-oriented and egocentric perception problems are commonly solved by taking advantage of the robot state estimation as an auxiliary input, particularly when artificial intelligence comes into the picture. In this work, we propose to apply a similar approach for the first time - to the best of our knowledge - to allocentric perception tasks, where the target variables refer to an external subject. We prove how our general and intuitive methodology improves the regression performance of deep convolutional neural networks (CNNs) with ambiguous problems such as the allocentric 3D pose estimation. By analyzing three highly-different use cases, spanning from grasping with a robotic arm to following a human subject with a pocket-sized UAV, our results consistently improve the R2 metric up to +0.514 compared to their stateless baselines. Finally, we validate the in-field performance of a closed-loop autonomous pocket-sized UAV in the human pose estimation task. Our results show a significant reduction, i.e., 24% on average, on the mean absolute error of our stateful CNN.Comment: 8 pages, 8 figure

Estimate features relevance for groups of users

In item cold-start, collaborative filtering techniques cannot be used directly since newly added items have no interactions with users. Hence, content-based filtering is usually the only viable option left. In this paper we propose a feature-based machine learning model that addresses the item cold-start problem by jointly exploiting item content features, past user preferences and interactions of similar users. The pro- posed solution learns a relevance of each content feature referring to a community of similar users. In our experiments, the proposed approach outperforms classical content-based filtering on an enriched version of the Netflix datase

Exploring the Semantic Gap for Movie Recommendations

In the last years, there has been much attention given to the semantic gap problem in multimedia retrieval systems. Much effort has been devoted to bridge this gap by building tools for the extraction of high-level, semantics-based features from multimedia content, as low-level features are not considered useful because they deal primarily with representing the perceived content rather than the semantics of it. In this paper, we explore a different point of view by leveraging the gap between low-level and high-level features. We experiment with a recent approach for movie recommendation that extract low-level Mise-en-Scéne features from multimedia content and combine it with high-level features provided by the wisdom of the crowd. To this end, we first performed an offline performance assessment by implementing a pure content-based recommender system with three different versions of the same algorithm, respectively based on (i) conventional movie attributes, (ii) mise-en-scene features, and (iii) a hybrid method that interleaves recommendations based on movie attributes and mise-en-scene features. In a second study, we designed an empirical study involving 100 subjects and collected data regarding the quality perceived by the users. Results from both studies show that the introduction of mise-en-scéne features in conjunction with traditional movie attributes improves both offline and online quality of recommendations

Deriving Item Features Relevance from Past User Interactions

Item-based recommender systems suggest products based on the similarities between items computed either from past user prefer- ences (collaborative filtering) or from item content features (content- based filtering). Collaborative filtering has been proven to outper- form content-based filtering in a variety of scenarios. However, in item cold-start, collaborative filtering cannot be used directly since past user interactions are not available for the newly added items. Hence, content-based filtering is usually the only viable option left. In this paper we propose a novel feature-based machine learning model that addresses the item cold-start problem by jointly exploit- ing item content features and past user preferences. The model learns the relevance of each content feature from the collaborative item similarity, hence allowing to embed collaborative knowledge into a purely content-based algorithm. In our experiments, the proposed approach outperforms classical content-based filtering on an enriched version of the Netflix dataset, showing that collabo- rative knowledge can be effectively embedded into content-based approaches and exploited in item cold-start recommendation

Prognostic factors in gemcitabine-cisplatin polychemotherapy regimens in pancreatic cancer: XPD-Lys751Gln polymorphism strikes back

: The use of platinated agents in combination chemotherapy regimens for advanced pancreatic cancer is controversial owing to the lack of an outstanding impact on the outcome and a substantial increase in hematologic and extra-hematologic toxicities. Pharmacogenetic studies to identify patients who could benefit most from such therapies are urgently needed. The Xeroderma-Pigmentosum group-D polymorphism at codon-751 (XPD-Lys751Gln) emerged as the most significant independent predictor for death- and progression-risk in our previous study on functional polymorphisms in 122 advanced pancreatic cancer patients treated with cisplatin-docetaxel-capecitabine-gemcitabine and cisplatin-epirubicin-capecitabine-gemcitabine (or EC-GemCap). To confirm the prognostic role of this variable, we further evaluated the correlation of XPD-Lys751Gln with outcome in another 125 patients treated with the same regimens, and 90 treated with gemcitabine monotherapy. Genotyping was successfully carried out in the vast majority of DNA samples. Genotype frequencies followed Hardy-Weinberg equilibrium, and XPD-Lys751Gln was associated with differential progression-free and overall-survival. Multivariate analysis confirmed its prognostic significance in platinum-based regimens. In particular, XPD-Gln751Gln was significantly associated with risk of death (hazard ratio, HR = 1.7, 95% confidence interval [CI], 1.1-2.6, p = 0.011) and risk of progression (HR = 1.7, 95% CI, 1.1-2.5, p = 0.013). No correlation was observed in gemcitabine monotherapy-treated patients. The analysis of DNA damage using extra-long-PCR in lymphocytes supported the association of XPD-Gln751Gln with greater resistance to cisplatin-induced damage. The increasing evidence of XPD-Lys751Gln impact on the outcome of gemcitabine-cisplatin-based polychemotherapy leads to plan prospective studies to validate the role of this polymorphism as a new tool for optimization of the currently available treatments in pancreatic cancer

A quantitative assessment of epidemiological parameters required to investigate COVID-19 burden

Solid estimates describing the clinical course of SARS-CoV-2 infections are still lacking due to under-ascertainment of asymptomatic and mild-disease cases. In this work, we quantify age-specific probabilities of transitions between stages defining the natural history of SARS-CoV-2 infection from 1965 SARS-CoV-2 positive individuals identified in Italy between March and April 2020 among contacts of confirmed cases. Infected contacts of cases were confirmed via RT-PCR tests as part of contact tracing activities or retrospectively via IgG serological tests and followed-up for symptoms and clinical outcomes. In addition, we provide estimates of time intervals between key events defining the clinical progression of cases as obtained from a larger sample, consisting of 95,371 infections ascertained between February and July 2020. We found that being older than 60 years of age was associated with a 39.9% (95%CI: 36.2–43.6%) likelihood of developing respiratory symptoms or fever ≥ 37.5 °C after SARS-CoV-2 infection; the 22.3% (95%CI: 19.3–25.6%) of the infections in this age group required hospital care and the 1% (95%CI: 0.4–2.1%) were admitted to an intensive care unit (ICU). The corresponding proportions in individuals younger than 60 years were estimated at 27.9% (95%CI: 25.4–30.4%), 8.8% (95%CI: 7.3–10.5%) and 0.4% (95%CI: 0.1–0.9%), respectively. The infection fatality ratio (IFR) ranged from 0.2% (95%CI: 0.0–0.6%) in individuals younger than 60 years to 12.3% (95%CI: 6.9–19.7%) for those aged 80 years or more; the case fatality ratio (CFR) in these two age classes was 0.6% (95%CI: 0.1–2%) and 19.2% (95%CI: 10.9–30.1%), respectively. The median length of stay in hospital was 10 (IQR: 3–21) days; the length of stay in ICU was 11 (IQR: 6–19) days. The obtained estimates provide insights into the epidemiology of COVID-19 and could be instrumental to refine mathematical modeling work supporting public health decisions

Vitamin D 25OH Deficiency and Mortality in Moderate to Severe COVID-19: A Multi-Center Prospective Observational Study

Introduction: Several studies and meta-analyses suggested the role of vitamin D 25OH in preventing severe forms of coronavirus disease 2019 (COVID-19). However, the evidence on the clinical benefits of vitamin D 25OH adequacy in patients hospitalized for COVID-19 remain conflicting and speculative. We aimed to investigate the association between vitamin D 25OH serum levels and mortality in hospitalized patients with moderate to severe COVID-19. Method: This prospective observational multicentre study included 361 consecutive patients with moderate to severe COVID-19 admitted to the Italian hospitals involved in the NUTRI-COVID19 trial from March to August 2020. For each patient, serum vitamin D 25OH levels were assessed 48 h since admission and classified as deficient (<20 ng/mL) or adequate (≥20 ng/mL). We built a propensity score for low/adequate vitamin D 25OH levels to balance the clinical and demographic properties of the cohort, which resulted in 261 patients with good common support used for the survival analysis. Results: Two Hundred-seventy-seven (77%) of the 361 enrolled patients (207 [57%] males, median age 73 ± 15.6 years) had vitamin D 25OH deficiency. Fifty-two (20%) of the 261 matched patients died during the hospital stay, corresponding to a hazard ratio of 1.18 for vitamin D 25OH deficiency (95% confidence interval: 0.86–1.62; p = 0.29). Discussion: The prevalence of vitamin D 25OH deficiency was confirmed to be very high in hospitalized patients with COVID-19. The use of a propensity score demonstrate an absence of significant association between vitamin D deficiency and mortality in hospitalized patients

Maintenance sunitinib or observation in metastatic pancreatic adenocarcinoma: a phase II randomised trial

Background: New strategies to prolong disease control warrant investigation in patients with metastatic pancreatic adenocarcinoma. This open-label, randomised, multi-centre phase II trial explored the role of maintenance sunitinib after first-line chemotherapy in this setting. Methods: Patients with pathologic diagnosis of metastatic pancreatic adenocarcinoma, performance status >50%, no progression after 6 months of chemotherapy were centrally randomised by an independent contract research organisation, which was also responsible for data collection and monitoring, to observation (arm A) or sunitinib at 37.5mg daily until progression or a maximum of 6 months (arm B). The primary outcome measure was the probability of being progression-free at 6 months (PFS-6) from randomisation. Assuming P0 = 10%; P1 = 30%, α .10; β .10, the target accrual was 26 patients per arm. Results: 28 per arm were randomised. One arm B patient had kidney cancer and was excluded. Sunitinib was given for a median of 91 days (7-186). Main grade 3-4 toxicity was thrombocytopenia, neutropenia and hand-foot syndrome (12%), diarrhoea 8%. In arm A versus B, PFS-6 was 3.6% (95% confidence interval (CI): 0-10.6%) and 22.2% (95% CI: 6.2-38.2%; P<0.01); 2 y overall survival was 7.1% (95% CI: 0-16.8%) and 22.9% (95% CI: 5.8-40.0%; P = 0.11), stable disease 21.4% and 51.9% (P = 0.02). Conclusion: This is the first randomised trial on maintenance therapy in metastatic pancreatic adenocarcinoma. The primary end-point was fulfilled and 2 y overall survival was remarkably high, suggesting that maintenance sunitinib is promising and should be further explored in this patient population

Infection fatality ratio of SARS-CoV-2 in Italy

We analyzed 5,484 close contacts of COVID-19 cases from Italy, all of them tested for SARS-CoV-2 infection. We found an infection fatality ratio of 2.2% (95%CI 1.69-2.81%) and identified male sex, age >70 years, cardiovascular comorbidities, and infection early in the epidemics as risk factors for death

Prognostic and predictive role of EGFR pathway alterations in biliary cancer patients treated with chemotherapy and anti-EGFR

The association of anti-EGFR to gemcitabine and oxaliplatin (GEMOX) chemotherapy did not improve survival in biliary tract carcinoma (BTC) patients. Multiple mechanisms might be involved in the resistance to anti-EGFR. Here, we explored the mutation profile of EGFR extracellular domain (ECD), of tyrosine kinase domain (TKD), and its amplification status. EGFR mutational status of exons 12, 18-21 was analyzed in 57 tumors by Sanger sequencing. EGFR amplification was evaluated in 37 tumors by Fluorescent In Situ Hybridization (FISH). Kaplan-Meier curves were calculated using the log-rank test. Six patients had mutations in exon 12 of EGFR ECD and 7 in EGFR TKD. Neither EGFR ECD nor TKD mutations affected progression free survival (PFS) or overall survival (OS) in the entire population. In the panitumumab plus GEMOX (P-GEMOX) arm, ECD mutated patients had a worse OS, while EGFR TKD mutated patients had a trend towards shorter PFS and OS. Overall, the presence of mutations in EGFR or in its transducers did not affect PFS or OS, while the extrahepatic cholangiocarcinoma (ECC) mutated patients had a worse prognosis compared to WT. Nineteen out of 37 tumors were EGFR amplified, but the amplification did not correlate with survival. ECC EGFR amplified patients had improved OS, whereas the amplification significantly correlated with poor PFS (p = 0.03) in gallbladder carcinoma patients. The high molecular heterogeneity is a predominant feature of BTC: the alterations found in this work seem to have a prognostic impact rather than a predictive role towards anti-EGFR therapy