Whiteness-based bilevel learning of regularization parameters in imaging

We consider an unsupervised bilevel optimization strategy for learning regularization parameters in the context of imaging inverse problems in the presence of additive white Gaussian noise. Compared to supervised and semi-supervised metrics relying either on the prior knowledge of reference data and/or on some (partial) knowledge on the noise statistics, the proposed approach optimizes the whiteness of the residual between the observed data and the observation model with no need of ground-truth data.We validate the approach on standard Total Variation-regularized image deconvolution problems which show that the proposed quality metric provides estimates close to the mean-square error oracle and to discrepancy-based principles

Contact Lens Wear Induces Alterations of Lactoferrin Functionality in Human Tears

The tear film is a complex matrix composed of several molecular classes, from small metal ions to macromolecules. Contact lens (CL) wear can affect the protein homeostasis of the tear film, by accumulating deposits on the CL surface and/or altering their structural and functional properties. This work investigates the effect of CL wear on lactoferrin (Lf), one of the most abundant tear proteins, known as an unspecific biomarker of inflammation. Tears from eight volunteers were collected and analyzed after alternated periods of CL wear and without CL. The experimental approach is to probe Lf into unprocessed human tears by the peculiar fluorescence emission originating from complex formation of Lf with terbium (Tb3+) at the iron-binding sites. The experimental data indicate that CL wear does not significantly affect the total amount of Lf. On the other hand, Lf affinity for Tb3+ is reduced upon CL wear, suggesting relevant changes in Lf structure and possible alterations of protein functionality. Future studies based on this approach will help define CL features (material, lens-care solution, wearing time, etc.) with minimal effects on tear protein activity, in order to obtain more biocompatible and comfortable devices

Surgical therapy for ischemic heart failure: Single-center experience with surgical anterior ventricular restoration

ObjectivesOur objectives were (1) to report operative and long-term mortality in patients submitted to anterior surgical ventricular restoration, (2) to report changes in clinical and cardiac status induced by surgical ventricular restoration, and (3) to report predictors of death in a large cohort of patients operated on at San Donato Hospital, Milan, Italy.MethodsA total of 1161 consecutive patients (83% men, 62 ± 10 years) had anterior surgical ventricular restoration with or without coronary artery bypass grafting and with or without mitral repair/replacement. A complete echocardiographic study was performed in 488 of 1161 patients operated on between January 1998 and October 2005 (study group). The indication for surgery was heart failure in 60% of patients, angina, and/or a combination of the two.ResultsThirty-day cardiac mortality was 4.7% (55/1161) in the overall group and 4.9% (24/488) in the study group. Determinants of hospital mortality were mitral valve regurgitation and need for a mitral valve repair/replacement. Mitral regurgitation (>2+) associated with a New York Heart Association class greater than II and with diastolic dysfunction (early-to-late diastolic filling pressure >2) further increases mortality risk. Global systolic function improved postoperatively: ejection fraction improved from 33% ± 9% to 40% ± 10% (P < .001); end-diastolic and end-systolic volumes decreased from 211 ± 73 to 142 ± 50 and 145 ± 64 to 88 ± 40 mL, respectively (P < .001) early after surgery. New York Heart Association functional class improved from 2.7 ± 0.9 to 1.6 ± 0.7 (P < .001) late after surgery. Long-term survival in the overall population was 63% at 120 months.ConclusionsSurgical ventricular restoration for ischemic heart failure reduces ventricular volumes, improves cardiac function and functional status, carries an acceptable operative mortality, and results in good long-term survival. Predictors of operative mortality are mitral regurgitation of 2+ or more, New York Heart Association class greater than II, and diastolic dysfunction (early-to-late diastolic filling pressure >2)

Quality of Service Driven Runtime Resource Allocation in Reconfigurable HPC Architectures

Heterogeneous System Architectures (HSA) are gaining importance in the High Performance Computing (HPC) domain due to increasing computational requirements coupled with energy consumption concerns, which conventional CPU architectures fail to effectively address. Systems based on Field Programmable Gate Array (FPGA) recently emerged as an effective alternative to Graphical Processing Units (GPUs) for demanding HPC applications, although they lack the abstractions available in conventional CPU-based systems. This work tackles the problem of runtime resource management of a system using FPGA-based co-processors to accelerate multi-programmed HPC workloads. We propose a novel resource manager able to dynamically vary the number of FPGAs allocated to each of the jobs running in a multi-accelerator system, with the goal of meeting a given Quality of Service metric for the running jobs measured in terms of deadline or throughput. We implement the proposed resource manager in a commercial HPC system, evaluating its behavior with representative workloads

Glycosylation tunes neuroserpin physiological and pathological properties

Neuroserpin (NS) is a member of the serine protease inhibitors superfamily. Specific point mutations are responsible for its accumulation in the endoplasmic reticulum of neurons that leads to a pathological condition named familial encephalopathy with neuroserpin inclusion bodies (FENIB). Wild-type NS presents two N-glycosylation chains and does not form polymers in vivo, while non-glycosylated NS causes aberrant polymer accumulation in cell models. To date, all in vitro studies have been conducted on bacterially expressed NS, de facto neglecting the role of glycosylation in the biochemical properties of NS. Here, we report the expression and purification of human glycosylated NS (gNS) using a novel eukaryotic expression system, LEXSY. Our results confirm the correct N-glycosylation of wild-type gNS. The fold and stability of gNS are not altered compared to bacterially expressed NS, as demonstrated by the circular dichroism and intrinsic tryptophan fluorescence assays. Intriguingly, gNS displays a remarkably reduced polymerisation propensity compared to non-glycosylated NS, in keeping with what was previously observed for wild-type NS in vivo and in cell models. Thus, our results support the relevance of gNS as a new in vitro tool to study the molecular bases of FENIB

Disulfide driven folding for a conditionally disordered protein

Altres ajuts: ICREA, ICREA-Academia 2015 to S.V.Conditionally disordered proteins are either ordered or disordered depending on the environmental context. The substrates of the mitochondrial intermembrane space (IMS) oxidoreductase Mia40 are synthesized on cytosolic ribosomes and diffuse as intrinsically disordered proteins to the IMS, where they fold into their functional conformations; behaving thus as conditionally disordered proteins. It is not clear how the sequences of these polypeptides encode at the same time for their ability to adopt a folded structure and to remain unfolded. Here we characterize the disorder-to-order transition of a Mia40 substrate, the human small copper chaperone Cox17. Using an integrated real-time approach, including chromatography, fluorescence, CD, FTIR, SAXS, NMR, and MS analysis, we demonstrate that in this mitochondrial protein, the conformational switch between disordered and folded states is controlled by the formation of a single disulfide bond, both in the presence and in the absence of Mia40. We provide molecular details on how the folding of a conditionally disordered protein is tightly regulated in time and space, in such a way that the same sequence is competent for protein translocation and activity

α-Synuclein is a Novel Microtubule Dynamase.

α-Synuclein is a presynaptic protein associated to Parkinson's disease, which is unstructured when free in the cytoplasm and adopts α helical conformation when bound to vesicles. After decades of intense studies, α-Synuclein physiology is still difficult to clear up due to its interaction with multiple partners and its involvement in a pletora of neuronal functions. Here, we looked at the remarkably neglected interplay between α-Synuclein and microtubules, which potentially impacts on synaptic functionality. In order to identify the mechanisms underlying these actions, we investigated the interaction between purified α-Synuclein and tubulin. We demonstrated that α-Synuclein binds to microtubules and tubulin α2β2 tetramer; the latter interaction inducing the formation of helical segment(s) in the α-Synuclein polypeptide. This structural change seems to enable α-Synuclein to promote microtubule nucleation and to enhance microtubule growth rate and catastrophe frequency, both in vitro and in cell. We also showed that Parkinson's disease-linked α-Synuclein variants do not undergo tubulin-induced folding and cause tubulin aggregation rather than polymerization. Our data enable us to propose α-Synuclein as a novel, foldable, microtubule-dynamase, which influences microtubule organisation through its binding to tubulin and its regulating effects on microtubule nucleation and dynamics

Insights on peptide topology in the computational design of protein ligands: the example of lysozyme binding peptides

Herein, we compared the ability of linear and cyclic peptides generated in silico to target different protein sites: internal pockets and solvent-exposed sites. We selected human lysozyme (HuL) as a model target protein combined with the computational evolution of linear and cyclic peptides. The sequence evolution of these peptides was based on the PARCE algorithm. The generated peptides were screened based on their aqueous solubility and HuL binding affinity. The latter was evaluated by means of scoring functions and atomistic molecular dynamics (MD) trajectories in water, which allowed prediction of the structural features of the protein-peptide complexes. The computational results demonstrated that cyclic peptides constitute the optimal choice for solvent exposed sites, while both linear and cyclic peptides are capable of targeting the HuL pocket effectively. The most promising binders found in silico were investigated experimentally by surface plasmon resonance (SPR), nuclear magnetic resonance (NMR), and electrospray ionization mass spectrometry (ESI-MS) techniques. All tested peptides displayed dissociation constants in the micromolar range, as assessed by SPR; however, both NMR and ESI-MS suggested multiple binding modes, at least for the pocket binding peptides. A detailed NMR analysis confirmed that both linear and cyclic pocket peptides correctly target the binding site they were designed for

Italian real life experience with ibrutinib: Results of a large observational study on 77 relapsed/refractory mantle cell lymphoma

Although sometimes presenting as an indolent lymphoma, mantle cell lymphoma (MCL) is an aggressive disease, hardly curable with standard chemo-immunotherapy. Current approaches have greatly improved patients' outcomes, nevertheless the disease is still characterized by high relapse rates. Before approval by EMA, Italian patients with relapsed/refractory MCL were granted ibrutinib early access through a Named Patient Program (NPP). An observational, retrospective, multicenter study was conducted. Seventyseven heavily pretreated patients were enrolled. At the end of therapy there were 14 complete responses and 14 partial responses, leading to an overall response rate of 36.4%. At 40 months overall survival was 37.8% and progression free survival was 30%; disease free survival was 78.6% at 4 years: 11/14 patients are in continuous complete response with a median of 36 months of follow up. Hematological toxicities were manageable, and main extra-hematological toxicities were diarrhea (9.4%) and lung infections (9.0%). Overall, 4 (5.2%) atrial fibrillations and 3 (3.9%) hemorrhagic syndromes occurred. In conclusions, thrombocytopenia, diarrhea and lung infections are the relevant adverse events to be clinically focused on; regarding effectiveness, ibrutinib is confirmed to be a valid option for refractory/relapsed MCL also in a clinical setting mimicking the real world

Giustizia e letteratura II

The book explores and links different cultures, disciplines and perspectives, with a far more original and broad approach to the relations between “Justice” and “Literature” than more traditional works focused on “Law” and “Literature”. The many contributions from writers, literature and movie critics, psychologists, and criminal law practitioners and scholars, draw a complex and interdisciplinary path through primary texts of Italian and international literature, with the aim of prompting readers’ reflections about core issues related to law, crime, and responsibility. Through the analysis of masterpieces of literature, theatre and cinema, this book aims at stimulating dialogue and debate, as well as critical abilities and a deep-rooted sense of justice, amongst both law professionals and citizens at large. Literature and other forms of narration are presented here as a privileged key to approach long-standing questions about (amongst other) causes and consequences of crime; victimization and coping mechanisms; the role of criminal law and criminal proceedings; legalism and equity; law and ethics; the ‘time’ of justice; freedom, responsibility, culpability and forgiveness; rules, legality, socialization and culture; language and images as mediums for justice issues; the impact of prejudice and of existing balances of power on the application of the law; social and legal mechanisms of exclusion and inclusion; gender issues and legal systems; and so on. A whole section (Part V) is devoted to crimes against humanity and how the literary testimony may be understood both as a strategy to resist injustice and to seek justice, and as a way to prevent further horrors. Through this quest for justice in literature and arts, the volume proposes a wider cultural and research project which defies traditional formalistic and retributive approaches to criminal law, in order to open new perspectives for restorative and reintegrative strategies