Size-consistent variational approaches to non-local pseudopotentials: standard and lattice regularized diffusion Monte Carlo methods revisited

We propose improved versions of the standard diffusion Monte Carlo (DMC) and the lattice regularized diffusion Monte Carlo (LRDMC) algorithms. For the DMC method, we refine a scheme recently devised to treat non-local pseudopotential in a variational way. We show that such scheme --when applied to large enough systems-- maintains its effectiveness only at correspondingly small enough time-steps, and we present two simple upgrades of the method which guarantee the variational property in a size-consistent manner. For the LRDMC method, which is size-consistent and variational by construction, we enhance the computational efficiency by introducing (i) an improved definition of the effective lattice Hamiltonian which remains size-consistent and entails a small lattice-space error with a known leading term, and (ii) a new randomization method for the positions of the lattice knots which requires a single lattice-space.Comment: 10 pages, 4 figures, submitted to the Journal of Chemical Physic

Automazione e lavoro: una ricerca su cambiamento tecnologico e impatto sull’occupazione

Le tecnologie di automazione sembrano sempre più in grado di sostituire il lavoro umano. Ci si aspetta una “disoccupazione tecnologica” di massa? Quali categorie di lavoratori e lavoratrici sono più a rischio? In questo libro si prova a rispondere in modo sintetico ma rigoroso a queste domande, fornendo al lettore tutte le conoscenze e gli strumenti necessari. La paura per le “macchine” ha una storia che risale alla Rivoluzione Industriale. Il tema è oggi tornato di grande attualità. La ricerca economica recente tenta di stimare l’impatto dell’automazione sull’occupazione cercando di calcolare la probabilità di automazione delle varie professioni. Questo libro fornisce per la prima volta una stima dei rischi di sostituzione da parte delle macchine dei lavoratori e delle lavoratrici in Italia e discute di quali sono i fattori strutturali che potrebbero influire sull’effettiva introduzione di robot e di altre forme di tecnologie di automazione nell’economia italiana

Avaliação qualitativa da arborização da cidade de Bento Gonçalves, RS.

A survey conducted in centric streets of Bento Gonçalves city permited to evaluate the conditions of the urban arboreus vegetation. The physical and sanitary aspects was considered as “good” and no damage to the sidewalks was observed since the plants have deep roots. Most of the plants (51,7 %) was not placed under electric wires however branch cutting is a frequent practice.Um levantamento nas 56 ruas que formam a área central da cidade de Bento Gonçalves, permitiu avaliar de forma qualitativa as condições em que se encontram os vegetais que formam a arborização urbana. Os exemplares quanto aos aspectos físicos e sanitários são considerados "bons" e não exercem danos às calçadas, pois apresentam raízes profundas. A maioria dos vegetais (51,7%) não se encontram sob fiação, porém a poda se constitue em uma prática frequente

COVID-19 rehabilitation units are twice as expensive as regular rehabilitation units

Objective: The COVID-19 pandemic has caused significant motor, cognitive, psychological, neurological and cardiological disabilities in many infected patients. Functional rehabilitation of infectious COVID-19 patients has been implemented in the acute care wards and in appropriate, ad hoc, multidisciplinary COVID-19 rehabilitation units. However, because COVID-19 rehabilitation units are a clinical novelty, clinical and organizational benchmarks are not yet available. The aim of this study is to describe the organizational needs and operational costs of such a unit, by comparing its activity, organization, and costs with 2 other functional rehabilitation units, in San Raffaele Hospital, Milan, Italy. Methods: The 2-month activity of the COVID-19 Rehabilitation Unit at San Raffaele Hospital, Milan, Italy, which was created in response to the emergency need for rehabilitation of COVID-19 patients, was compared with the previous year's activity of the Cardiac Rehabilitation and Motor Rehabilitation Units of the same institute. Results: The COVID-19 Rehabilitation Unit had the same number of care beds as the other units, but required twice the amount of staff and instrumental equipment, leading to a deficit in costs. Discussion: The COVID-19 Rehabilitation Unit was twice as expensive as the 2 other units studied. World health systems are organizing to respond to the pandemic by expanding capacity in acute intensive care and sub-intensive care units. This study shows that COVID-19 rehabilitation units must be organized and equiped according to the clinical and rehabilitative needs of patients, following specific measures to prevent the spread of infection amongs patients and workers

Epidemiology of intracerebral haemorrhage in Livorno district

BACKGROUND: Intracranial haemorrhage represents the most feared stroke subtype. AIM: To evaluate the burden of intracranial haemorrhage in Tuscany hospitals with special reference to Livorno district. MATERIALS AND METHODS: Data of patients discharged in 2009 from Tuscan and Livorno hospitals with codes ICD-9-CM related to any type of spontaneous intracranial haemorrhage were selected and analyzed. RESULTS: 3,472 patients were discharged from Tuscan hospitals with these diagnoses. Overall mortality was 24.3%. 50% of patients were admitted in Internal Medicine wards. Incidence of intracranial haemorrhage and intracerebral haemorrhage (ICH) in population of Livorno district was 64 and 45/100,000 inhabitants/year with related mortality of 36.5% and 39.4%respectively. Intra-hospital mortality of patients admitted in Livorno hospitals for intracranial haemorrhage were 36.7%. 40% of deaths occurred in the first 48 hours. 69.6% of intracranial haemorrhage were ICHs, 16.8% subaracnoideal. Intra-hospital mortality, admissions for intracranial haemorrhage in respect of total admissions and mortality for intracranial haemorrhage in respect to total mortality increased in the last decade. 23% of patients with intracranial haemorrhage and 16% of patients with ICH underwent to surgical procedures. ICHs related to antithrombotic treatment significantly increased in the last years. Mortality in patients on antithrombotic drugs was three times over compared to that in patients not undergone these drugs (43.7% vs 12.8%, p < 0.01). CONCLUSION: There is an increasing trend in frequency, mortality and hospital burden of intracranial haemorrhage and ICH. Efforts aimed at reducing the burden and consequences of this devasting disease are warranted

Variant-specific vulnerability in metabolic connectivity and resting-state networks in behavioural variant of frontotemporal dementia.

Brain connectivity measures represent candidate biomarkers of neuronal dysfunction in neurodegenerative diseases. Previous findings suggest that the behavioural variant of frontotemporal dementia (bvFTD) and its variants (i.e., frontal and temporo-limbic) may be related to the vulnerability of distinct functional connectivity networks. In this study, 82 bvFTD patients were included, and two patient groups were identified as frontal and temporo-limbic bvFTD variants. Two advanced multivariate analytical approaches were applied to FDG-PET data, i.e., sparse inverse covariance estimation (SICE) method and seed-based interregional correlation analysis (IRCA). These advanced methods allowed the assessment of (i) the whole-brain metabolic connectivity, without any a priori assumption, and (ii) the main brain resting-state networks of crucial relevance for cognitive and behavioural functions. In the whole bvFTD group, we found dysfunctional connectivity patterns in frontal and limbic regions and in all major brain resting-state networks as compared to healthy controls (HC N = 82). In the two bvFTD variants, SICE and IRCA analyses identified variant-specific reconfigurations of whole-brain connectivity and resting-state networks. Specifically, the frontal bvFTD variant was characterised by metabolic connectivity alterations in orbitofrontal regions and anterior resting-state networks, while the temporo-limbic bvFTD variant was characterised by connectivity alterations in the limbic and salience networks. These results highlight different neural vulnerabilities in the two bvFTD variants, as shown by the dysfunctional connectivity patterns, with relevance for the different neuropsychological profiles. This new evidence provides further insight in the variability of bvFTD and may contribute to a more accurate classification of these patients

Diffusion Monte Carlo method with lattice regularization

We introduce an efficient lattice regularization scheme for quantum Monte Carlo calculations of realistic electronic systems. The kinetic term is discretized by a finite difference Laplacian with two mesh sizes, a and a', chosen so that the electrons can diffuse in a configuration space which is in practice indistinguishable from the continuum, and the different length scales in the system can be efficiently taken in account. The regularized Hamiltonian goes to the continuous limit for a -> 0 and allows the inclusion of nonlocal potentials in a consistent variational scheme, substantially improving the accuracy upon previous nonvariational approaches