33 research outputs found
Profiling for run-time checking of computational properties and performance debugging in logic programs
Although several profiling techniques for identifying performance bottlenecks in logic programs have been developed, they are generally not automatic and in most cases they do not provide enough information for identifying the root causes of such bottlenecks. This complicates using their results for guiding performance improvement. We present a profiling method and tool that provides such explanations. Our profiler associates cost centers to certain program elements and can measure different types of resource-related properties that affect performance, preserving the precedence of cost centers in the cali graph. It includes an automatic method for detecting procedures that are performance bottlenecks.
The profiling tool has been integrated in a previously developed run-time checking framework to allow verification of certain properties when they cannot be verified statically. The approach allows checking global computational properties which require complex instrumentation tracking information about previous execution states, such as, e.g., that the execution time accumulated by a given procedure is not greater than
a given bound. We have built a prototype implementation, integrated it in the Ciao/CiaoPP system and successfully applied it to performance improvement, automatic optimization (e.g., resource-aware specialization
of programs), run-time checking, and debugging of global computational properties (e.g., resource usage) in Prolog programs
Research activity and capability in the European reference network MetabERN
Background: MetabERN is one of the 24 European Reference Networks created according to the European Union
directive 2011/24/EU on patientâs rights in cross border healthcare. MetabERN associates 69 centres in 18 countries,
which provide care for patients with Hereditary Metabolic Diseases, and have the mission to reinforce research and
provide training for health professionals in this field. MetabERN performed a survey in December 2017 with the aim
to produce an overview documenting research activities and potentials within the network. As the centres are
multidisciplinary, separated questionnaires were sent to the clinical, university and laboratory teams. Answers
were received from 52 out of the 69 centres of the network, covering 16 countries. A descriptive analysis of
the information collected is presented.
Results: The answers indicate a marked interest of the respondents for research, who expressed high motivation and
commitment, and estimated that the conditions to do research in their institution were mostly satisfactory. They are
active in research, which according to several indicators, is competitive and satisfies standards of excellence, as well as
the education programs offered in the respondentâs universities. Research in the centres is primarily performed in
genetics, pathophysiology, and epidemiology, and focuses on issues related to diagnosis. Few respondents declared
having activity in human and social sciences, including research on patientâs quality of life, patientâs awareness, or
methods for social support. Infrastructures offering services for medical research were rarely known and used
by respondents, including national and international biobanking platforms. In contrast, respondents often
participate to patient registries, even beyond their specific field of interest.
Conclusions: Taken as a whole, these results provide an encouraging picture of the research capacities and activities
in the MetabERN network, which, with respect to the number and representativeness of the investigated centres, gives
a comprehensive picture of research on Hereditary Metabolic Diseases in Europe, as well as the priorities for future
actions. Marginal activity in human and social sciences points out the limited multidisciplinary constitution of the
responding teams with possible consequences on their current capability to participate to patientâs empowerment
programs and efficiently collaborate with patientâs advocacy groups
Kidney and vascular function in adult patients with hereditary fructose intolerance
Objective: Previous studies have shown that patients with hereditary fructose intolerance (HFI) are characterized by a greater intrahepatic triglyceride content, despite a fructose-restricted diet. The present study aimed to examine the long-term consequences of HFI on other aldolase-B-expressing organs, i.e. the kidney and vascular endothelium. Methods: Fifteen adult HFI patients were compared to healthy control individuals matched for age, sex and body mass index. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cf-PWV) and endothelial function by peripheral arterial tonometry, skin laser doppler flowmetry and the endothelial function biomarkers soluble E-selectin [sE-selectin] and von Willebrand factor. Serum creatinine and cystatin C were measured to estimate the glomerular filtration rate (eGFR). Urinary glucose and amino acid excretion and the ratio of tubular maximum reabsorption of phosphate to GFR (TmP/GFR) were determined as measures of proximal tubular function. Results: Median systolic blood pressure was significantly higher in HFI patients (127 versus 122 mmHg, p = .045). Pulse pressure and cf-PWV did not differ between the groups (p = .37 and p = .49, respectively). Of all endothelial function markers, only sE-selectin was significantly higher in HFI patients (p = .004). eGFR was significantly higher in HFI patients than healthy controls (119 versus 104 ml/min/1.73m2, p = .001, respectively). All measurements of proximal tubular function did not differ significantly between the groups. Conclusions: Adult HFI patients treated with a fructose-restricted diet are characterized by a higher sE-selectin level and slightly higher systolic blood pressure, which in time could contribute to a greater cardiovascular risk. The exact cause and, hence, clinical consequences of the higher eGFR in HFI patients, deserves further study.</p
Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides
Ballistic spin transport through waveguides, with symmetric or asymmetric
double stubs attached to them periodically, is studied systematically in the
presence of a weak spin-orbit coupling that makes the electrons precess. By an
appropriate choice of the waveguide length and of the stub parameters injected
spin-polarized electrons can be blocked completely and the transmission shows a
periodic and nearly square-type behavior, with values 1 and 0, with wide gaps
when only one mode is allowed to propagate in the waveguide. A similar behavior
is possible for a certain range of the stub parameters even when two-modes can
propagate in the waveguide and the conductance is doubled. Such a structure is
a good candidate for establishing a realistic spin transistor. A further
modulation of the spin current can be achieved by inserting defects in a
finite-number stub superlattice. Finite-temperature effects on the spin
conductance are also considered.Comment: 19 pages, 8 figure
Autoantibodies against type I IFNs in patients with life-threatening COVID-19
Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men
Neutron diffraction study of the compressibility of TTF-TCNQ under hydrostatic pressure
The linear axial compressibilities of a deuterated sample of TTF-TCNQ (tetrathiafulvalene-tetracyanoquinodimethane) have been measured by a neutron diffraction technique under hydrostatic pressures up to ⌠20 kbar at room temperature. The observed compressibilities along the crystallographic axes are, respectively, ka = 2.7, kb = 4.7 and kc = 3.2 x 10-12 cm2/dyne. These results indicate a strong Coulomb type interchain interaction. It is suggested that the dominant part of the crystal cohesion results from a stacking of strongly dynamically polarized TTF and TCNQ molecules acting as effective molecular dipoles.Nous prĂ©sentons des mesures de compressibilitĂ© de TTF-TCNQ deutĂ©rĂ© par diffraction de neutrons sous hautes pressions hydrostatiques jusqu'Ă âŒ 20 kbar Ă la tempĂ©rature ambiante. Les valeurs observĂ©es sont respectivement suivant les axes a, b et c, ka = 2,7, kb = 4,7 et kc = 3,2 x 10-12 cm2/dyne. Ces rĂ©sultats indiquent l'existence d'une contribution importante de type Ă©lectrostatique (coulomb) Ă l'interaction interchaĂźnes. Nous suggĂ©rons que la cohĂ©sion des cristaux de TTF-TCNQ provient de l'empilement de dipĂŽles molĂ©culaires fluctuants