Sequeval: A Framework to Assess and Benchmark Sequence-based Recommender Systems

In this paper, we present sequeval, a software tool capable of performing the offline evaluation of a recommender system designed to suggest a sequence of items. A sequence-based recommender is trained considering the sequences already available in the system and its purpose is to generate a personalized sequence starting from an initial seed. This tool automatically evaluates the sequence-based recommender considering a comprehensive set of eight different metrics adapted to the sequential scenario. sequeval has been developed following the best practices of software extensibility. For this reason, it is possible to easily integrate and evaluate novel recommendation techniques. sequeval is publicly available as an open source tool and it aims to become a focal point for the community to assess sequence-based recommender systems.Comment: REVEAL 2018 Workshop on Offline Evaluation for Recommender System

Sequeval: an offline evaluation framework for sequence-based recommender systems

Recommender systems have gained a lot of popularity due to their large adoption in various industries such as entertainment and tourism. Numerous research efforts have focused on formulating and advancing state-of-the-art of systems that recommend the right set of items to the right person. However, these recommender systems are hard to compare since the published evaluation results are computed on diverse datasets and obtained using different methodologies. In this paper, we researched and prototyped an offline evaluation framework called Sequeval that is designed to evaluate recommender systems capable of suggesting sequences of items. We provide a mathematical definition of such sequence-based recommenders, a methodology for performing their evaluation, and the implementation details of eight metrics. We report the lessons learned using this framework for assessing the performance of four baselines and two recommender systems based on Conditional Random Fields (CRF) and Recurrent Neural Networks (RNN), considering two different datasets. Sequeval is publicly available and it aims to become a focal point for researchers and practitioners when experimenting with sequence-based recommender systems, providing comparable and objective evaluation results

Sequeval: A framework to assess and benchmark sequence-based recommender systems

In this paper, we present sequeval, a software tool capable of performing the offline evaluation of a recommender system designed to suggest a sequence of items. A sequence-based recommender is trained considering the sequences already available in the system and its purpose is to generate a personalized sequence starting from an initial seed. This tool automatically evaluates the sequence-based recommender considering a comprehensive set of eight different metrics adapted to the sequential scenario. Sequeval has been developed following the best practices of software extensibility. For this reason, it is possible to easily integrate and evaluate novel recommendation techniques. Sequeval is publicly available as an open source tool and it aims to become a focal point for the community to assess sequence-based recommender systems

Amphiphilic CCK peptides assembled in supramolecular aggregates: structural investigations and in vitro studies

Supramolecular aggregates obtained by self-aggregation of five new cationic amphiphilic CCK8 peptides have been obtained in water solution and characterized for: (i) aggregate structure and stability; (ii) CCK8 peptide conformation and bioavailability on the external aggregate surface; and (iii) for their cell binding properties. The cationic amphiphilic CCK8 peptides self-aggregate giving a combination of liposomal and micelle structures, with radii ranging between B60 nm and B90 nm, and between B5 and B10 nm, respectively. The presence of CCK8 peptide well-exposed on the aggregate surface is demonstrated by fluorescence measurements. Peptide conformation changes in the five supramolecular aggregates: the CCK8 conformational behaviour is probably induced by the presence of three charged lysine residues close to the bioactive peptide sequence. Only aggregates in which the CCK8 peptide presents a structural arrangement similar to that found for the same peptide in DPC micelles give promising binding properties to CCK2-R receptors overexpressed by transfected A431 cells. Chemical modifications on the CCK8 N-terminus seem to play an important role in stabilizing the peptide active conformation, either when the peptide derivative is in monomeric or in aggregate form. For their easy preparation procedures and their binding properties, supramolecular aggregates based on cationic peptide amphiphiles can be considered as promising candidates for target selective drug carriers on cancer cells

Sugar-Incorporated N-Heterocyclic-Carbene-Containing Gold(I) Complexes: Synthesis, Characterization, and Cytotoxic Evaluation

A series of neutral and cationic gold(I) complexes bearing a glucopyranoside-incorporated N-heterocyclic carbene (NHC) ligand are synthetized and structurally characterized. Different secondary ligands (chlorido, phosphane, or sugar–NHC) are employed to tune the properties of the complexes. The antiproliferative effects of the compounds are evaluated against PC-3 prostate cancer cells and a panel of human tumor cell lines. The activities of the phosphane complexes are comparable to that observed for cisplatin. The combined results provide further insights into the biological behavior of NHC–gold complexes

Feline Aortic Thromboembolism Diagnosed by Thermography

Background: In cats, arterial thromboembolism is one of the most devastating diseases, with an acute presentation, and is often caused by undiagnosed cardiomyopathy. Defined as the obstruction of one or more arterial lumens by emboli, the arterial thromboembolism is responsible for hypoperfusion signs. As the temperature of the skin surface is directly related to tissue perfusion,thermography can be promising for the early diagnosis of thromboembolism. Therefore, this study reports the importance of thermography as a complementary examination for the diagnosis of thromboembolism in the abdominal aorta of a domestic cat.Case: A 4-year-old mixed-breed cat weighing 2.95 kg was presented with a history of sudden onset paraplegia, apathy, and pain when handled, with greater intensity in the sacro-coccidian region. During physical exam, it was noted that the femoral artery pulse was undetectable bilaterally during manual pulse measurement. Superficial and deep sensitivity in the pelvic limbs and proprioception were also absent and the plantar cushions and nail beds of the posterior limbs were pale to cyanotic. Thermographic images revealed that the temperature of both hind limbs was lower than that of forelimbs, with difference of 3.2ºC and 2.9ºC between the left and right limbs, respectively. Doppler ultrasonography revealed the absence of pulse and flow in the femoral arteries bilaterally. Electrocardiography revealed sinus tachycardia, with a heart rate of 250 bpm. Echocardiography revealed dilation of the left atrium and concentric cardiac hypertrophy. After 24 h, due to the worsening of the clinical condition and unfavorable prognosis, the animal was euthanized and sent for necropsy. Necropsy revealed that the arterial lumen of the caudal abdominal aorta and bifurcation of the iliac arteries were obliterated, with a 0.6 cm saddle thrombus adhered to the arterial wall. In addition, left ventricular thickening indicative pf hypertrophic cardiomyopathy was observed. In the left atrium, a thrombus was observed that filled the entire chamber.Discussion: Thermography is a fast and non-invasive method, and therefore, it is a tool of great relevance in emergencies. Previous study showed that a minimum temperature difference of 2.4°C between the affected and unaffected limbs has excellent specificity and high sensitivity for the diagnosis of feline aortic thromboembolism. In this report, the temperature differences between the affected and unaffected limbs on the left and right sides were found to be 3.2°C and 2.9°C, respectively, corroborated this finding. Cats with cardiomyopathies are predisposed to the development of thrombi, and rarely manifest heart disease. Here, the cat was diagnosed with hypertrophic cardiomyopathy during the diagnostic investigation for arterial thromboembolism, which is consistent with the usual findings because feline hypertrophic cardiomyopathy progresses silently with few clinical manifestations in the early stages. Clinical diagnosis of arterial thromboembolism can be made based on the presence of some physical examination findings, such as pain and paralysis of the affected limbs, absence of a femoral pulse, cold extremities, and pale or cyanotic cushions. In this report, thermography proved to be an accurate, quick, and non-invasive method for the assessment of vascular alterations that affected the pelvic limbs of the cat. Complementary examinations confirmed the presence of hypertrophic cardiomyopathy and necropsy revealed the presence of thrombus.Keywords: cyanosis, hypertrophic cardiomyopathy, ischemia, temperature

An ensemble approach of recurrent neural networks using pre-trained embeddings for playlist completion

This paper describes the approach of the D2KLab team to the RecSys Challenge 2018 that focuses on the task of playlist completion. We propose an ensemble strategy of different recurrent neural networks leveraging pre-trained embeddings representing tracks, artists, albums, and titles as inputs. We also use lyrics from which we extract semantic and stylistic features that we fed into the network for the creative track. The RNN learns a probabilistic model from the sequences of items in the playlist, which is then used to predict the most likely tracks to be added to the playlist. Concerning the playlists without tracks, we implemented a fall-back strategy called Title2Rec that generates recommendations using only the playlist title. We optimized the RNN, Title2Rec, and the ensemble approach on a validation set, tuning hyper-parameters such as the optimizer algorithm, the learning rate, and the generation strategy. This approach is effective in predicting tracks for a playlist and flexible to include diverse types of inputs, but it is also computationally demanding in the training phase

Evaluation of Coronary Atherosclerosis by Multislice Computed Tomography in Patients With Acute Myocardial Infarction and Without Significant Coronary Artery Stenosis

Background— It is known that 9% to 31% of women and 4% to 14% of men with acute myocardial infarction have normal coronary arteries or nonsignificant coronary disease at angiography. These patients represent a diagnostic and therapeutic challenge. Multislice computed tomography (CT) can noninvasively identify the presence of coronary plaques even in the absence of significant coronary artery stenosis. This study evaluated the role of 64-slice CT, in comparison with coronary angiography, in detecting and characterizing coronary atherosclerosis in patients with acute myocardial infarction without significant coronary artery stenosis. Methods and Results— Thirty consecutive patients with acute myocardial infarction but without significant coronary stenosis at coronary angiography underwent 64-slice CT. All coronary segments were quantitatively analyzed by means of coronary angiography (CA-QCA) and 64-slice CT (CT-QCA). Forty-seven (10.4%) of the 450 coronary segments were not evaluable by CT. The mean proximal reference diameters at CT-QCA and CA-QCA were, respectively, 2.88�0.75 mm and 2.65�0.9 mm; the overall correlation between CT-QCA and CA-QCA for quantification of reference diameter was r s =0.77; P <0.001. The mean percent stenosis was 14.4�8.0% at CT-QCA and 4.0�11.0% at CA-QCA and the correlation was r s =0.11; P =0.03. Overall CT-QCA showed the presence of 50 plaques, of which only 11 were detected by CA-QCA. CT-QCA identified 25 plaques in infarct-related coronary arteries. Positive remodeling was present in 38 of the 50 plaques (76%), with a higher prevalence in the coronary plaques not visualized by CA-QCA (82.1% versus 54.5%). Conclusions— CT-QCA correlates well with CA-QCA in terms of coronary reference diameter analysis, but not stenosis quantification. Multislice CT can detect coronary atherosclerotic plaques in segments of nonstenotic coronary arteries that are underestimated by CA and may have an incremental diagnostic value for the diagnosis of acute myocardial infarction in patients without significant coronary stenosis at CA

Pyridine Ruthenium(III) complexes entrapped in liposomes with enhanced cytotoxic properties in PC-3 prostate cancer cells

The first aim of the present study is the development of a new ruthenium(III) complex, belonging to NAMI-A class, with a potentially high cytotoxic ability. The presence of a fully protected sugar moiety as ruthenium ligand should increase the complex ability to cross cellular membranes. Furthermore, it sets this molecule in the area of biocompatible agents as tumor drug. The second, more relevant, purpose is to verify the ruthenium complexes activity after loading into liposomes. We reported the characterization and in vitro biological assays of pyridine derivatives of ruthenium complexes loaded into Egg L-α-phosphatidylcholine cholesterol/DSPE-PEG liposomes. Dynamic light scattering estimates that the sizes of all obtained liposomes are in the 100 nm range. This value is suitable for in vivo use. The loading ability and release kinetic allowed selecting the best ratio between the lipid fraction and metal to be tested in cellular experiments. The growth inhibitory effects of both liposomal and free complex in PC-3 prostate cancer cell lines demonstrate a high cytotoxic ability of the liposome entrapped ruthenium (III) complex suggesting additional role further the antimetastatic function