Luca Cappelletti

Dr. Luca Cappelletti

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 November 2023 in Nucleic Acids Research
Verified
Journal Article
Open access
PDF file
TPTim E Putman
Tim E Putman
KSKevin Schaper
Kevin Schaper
NMNicolas Matentzoglu
Nicolas Matentzoglu
VRVincent P Rubinetti
Vincent P Rubinetti
FAFaisal S Alquaddoomi
Faisal S Alquaddoomi
MMMonica C Munoz-Torres
Monica C Munoz-Torres
Bridging the gap between genetic variations, environmental determinants, and phenotypic outcomes is critical for supporting clinical diagnosis and understanding mechanisms of diseases. It requires integrating open data at a global scale. The Monarch Initiative advances these goals by developing open ontologies, semantic data models, and knowledge graphs for translational research. The Monarch App is an integrated platform combining data about genes, phenotypes, and diseases across species. Monarch's APIs enable access to carefully curated datasets and advanced analysis tools that support the understanding and diagnosis of disease for diverse applications such as variant prioritization, deep phenotyping, and patient profile-matching. We have migrated our system into a scalable, cloud-based infrastructure; simplified Monarch's data ingestion and knowledge graph integration systems; enhanced data mapping and integration standards; and developed a new user interface with novel search and graph navigation features. Furthermore, we advanced Monarch's analytic tools by developing a customized plugin for OpenAI’s ChatGPT to increase the reliability of its responses about phenotypic data, allowing us to interrogate the knowledge in the Monarch graph using state-of-the-art Large Language Models. The resources of the Monarch Initiative can be found at monarchinitiative.org and its corresponding code repository at github.com/monarch-initiative/monarch-app.

1 January 2021 in Patterns
Verified
Journal Article
Open access
JRJustin T. Reese
Justin T. Reese
DUDeepak Unni
Deepak Unni
Tiffany Jean Lee CallahanTiffany Jean Lee Callahan
Tiffany Jean Lee Callahan
LCLuca Cappelletti
Luca Cappelletti
VRVida Ravanmehr
Vida Ravanmehr
CMChristopher J. Mungall
Christopher J. Mungall
Integrated, up-to-date data about SARS-CoV-2 and COVID-19 is crucial for the ongoing response to the COVID-19 pandemic by the biomedical research community. While rich biological knowledge exists for SARS-CoV-2 and related viruses (SARS-CoV, MERS-CoV), integrating this knowledge is difficult and time consuming, since much of it is in siloed databases or in textual format. Furthermore, the data required by the research community varies drastically for different tasks—the optimal data for a machine learning task, for example, is much different from the data used to populate a browsable user interface for clinicians. To address these challenges, we created KG-COVID-19, a flexible framework that ingests and integrates heterogeneous biomedical data to produce knowledge graphs (KGs), and applied it to create a KG for COVID-19 response. This KG framework can also be applied to other problems in which siloed biomedical data must be quickly integrated for different research applications, including future pandemics.

26 October 2020 in IEEE Access
Verified
Journal Article
Open access
Elena CasiraghiElena Casiraghi
Elena Casiraghi
DMDario Malchiodi
Dario Malchiodi
GTGabriella Trucco
Gabriella Trucco
MFMarco Frasca
Marco Frasca
LCLuca Cappelletti
Luca Cappelletti
Giorgio ValentiniGiorgio Valentini
Giorgio Valentini
Between January and October of 2020, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has infected more than 34 million persons in a worldwide pandemic leading to over one million deaths worldwide (data from the Johns Hopkins University). Since the virus begun to spread, emergency departments were busy with COVID-19 patients for whom a quick decision regarding in- or outpatient care was required. The virus can cause characteristic abnormalities in chest radiographs (CXR), but, due to the low sensitivity of CXR, additional variables and criteria are needed to accurately predict risk. Here, we describe a computerized system primarily aimed at extracting the most relevant radiological, clinical, and laboratory variables for improving patient risk prediction, and secondarily at presenting an explainable machine learning system, which may provide simple decision criteria to be used by clinicians as a support for assessing patient risk. To achieve robust and reliable variable selection, Boruta and Random Forest (RF) are combined in a 10-fold cross-validation scheme to produce a variable importance estimate not biased by the presence of surrogates. The most important variables are then selected to train a RF classifier, whose rules may be extracted, simplified, and pruned to finally build an associative tree, particularly appealing for its simplicity. Results show that the radiological score automatically computed through a neural network is highly correlated with the score computed by radiologists, and that laboratory variables, together with the number of comorbidities, aid risk prediction. The prediction performance of our approach was compared to that that of generalized linear models and shown to be effective and robust. The proposed machine learning-based computational system can be easily deployed and used in emergency departments for rapid and accurate risk prediction in COVID-19 patients.

26 June 2023 in Nature Computational Science
Verified
Journal Article
Open access
PDF file
LCLuca Cappelletti
Luca Cappelletti
TFTommaso Fontana
Tommaso Fontana
ECElena Casiraghi
Elena Casiraghi
VRVida Ravanmehr
Vida Ravanmehr
Tiffany Jean Lee CallahanTiffany Jean Lee Callahan
Tiffany Jean Lee Callahan
Giorgio ValentiniGiorgio Valentini
Giorgio Valentini
Graph representation learning methods opened new avenues for addressing complex, real-world problems represented by graphs. However, many graphs used in these applications comprise millions of nodes and billions of edges and are beyond the capabilities of current methods and software implementations. We present GRAPE (Graph Representation Learning, Prediction and Evaluation), a software resource for graph processing and embedding that is able to scale with big graphs by using specialized and smart data structures, algorithms, and a fast parallel implementation of random-walk-based methods. Compared with state-of-the-art software resources, GRAPE shows an improvement of orders of magnitude in empirical space and time complexity, as well as competitive edge- and node-label prediction performance. GRAPE comprises approximately 1.7 million well-documented lines of Python and Rust code and provides 69 node-embedding methods, 25 inference models, a collection of efficient graph-processing utilities, and over 80,000 graphs from the literature and other sources. Standardized interfaces allow a seamless integration of third-party libraries, while ready-to-use and modular pipelines permit an easy-to-use evaluation of graph-representation-learning methods, therefore also positioning GRAPE as a software resource that performs a fair comparison between methods and libraries for graph processing and embedding.

20 February 2024 in ACS Central Science
Verified
Journal Article
Open access
AGArnaud Gaudry
Arnaud Gaudry
MPMarco Pagni
Marco Pagni
FMflorence mehl
florence mehl
SMSébastien Moretti
Sébastien Moretti
LQLuis Quiros-Guerrero
Luis Quiros-Guerrero
PAPierre-marie Allard
Pierre-marie Allard
The Experimental Natural Products Knowledge Graph (ENPKG) framework combines a sample-centric approach with semantic enrichment to organize large heterogeneous metabolomics data sets as a knowledge... The ENPKG framework organizes large heterogeneous metabolomics data sets as a knowledge graph, offering exciting opportunities for drug discovery and chemodiversity characterization.

20 July 2022 in medRxiv
Verified
Preprint
Open access
PDF file
JRJustin T. Reese
Justin T. Reese
HBHannah Blau
Hannah Blau
TBTimothy Bergquist
Timothy Bergquist
JLJohanna J. Loomba
Johanna J. Loomba
Tiffany Jean Lee CallahanTiffany Jean Lee Callahan
Tiffany Jean Lee Callahan
TCthe RECOVER Consortium
the RECOVER Consortium
Accurate stratification of patients with post-acute sequelae of SARS-CoV-2 infection (PASC, or long COVID) would allow precision clinical management strategies. However, the natural history of long COVID is incompletely understood and characterized by an extremely wide range of manifestations that are difficult to analyze computationally. In addition, the generalizability of machine learning classification of COVID-19 clinical outcomes has rarely been tested. We present a method for computationally modeling PASC phenotype data based on electronic healthcare records (EHRs) and for assessing pairwise phenotypic similarity between patients using semantic similarity. Our approach defines a nonlinear similarity function that maps from a feature space of phenotypic abnormalities to a matrix of pairwise patient similarity that can be clustered using unsupervised machine learning procedures. Using k-means clustering of this similarity matrix, we found six distinct clusters of PASC patients, each with distinct profiles of phenotypic abnormalities. There was a significant association of cluster membership with a range of pre-existing conditions and with measures of severity during acute COVID-19. Two of the clusters were associated with severe manifestations and displayed increased mortality. We assigned new patients from other healthcare centers to one of the six clusters on the basis of maximum semantic similarity to the original patients. We show that the identified clusters were generalizable across different hospital systems and that the increased mortality rate was consistently observed in two of the clusters. Semantic phenotypic clustering can provide a foundation for assigning patients to stratified subgroups for natural history or therapy studies on PASC.