199 research outputs found
Quantum Circuits for the Unitary Permutation Problem
We consider the Unitary Permutation problem which consists, given unitary
gates and a permutation of , in
applying the unitary gates in the order specified by , i.e. in
performing . This problem has been
introduced and investigated by Colnaghi et al. where two models of computations
are considered. This first is the (standard) model of query complexity: the
complexity measure is the number of calls to any of the unitary gates in
a quantum circuit which solves the problem. The second model provides quantum
switches and treats unitary transformations as inputs of second order. In that
case the complexity measure is the number of quantum switches. In their paper,
Colnaghi et al. have shown that the problem can be solved within calls in
the query model and quantum switches in the new model. We
refine these results by proving that quantum switches
are necessary and sufficient to solve this problem, whereas calls
are sufficient to solve this problem in the standard quantum circuit model. We
prove, with an additional assumption on the family of gates used in the
circuits, that queries are required, for any
. The upper and lower bounds for the standard quantum circuit
model are established by pointing out connections with the permutation as
substring problem introduced by Karp.Comment: 8 pages, 5 figure
Super-resolution study of PIAS SUMO E3-ligases in hippocampal and cortical neurons
The SUMOylation machinery is a regulator of neuronal activity and synaptic plasticity. It is composed of SUMO isoforms and specialized enzymes named E1, E2 and E3 SUMO ligases. Recent studies have highlighted how SUMO isoforms and E2 enzymes localize with synaptic markers to support previous functional studies but less information is available on E3 ligases. PIAS proteins - belonging to the protein inhibitor of activated STAT (PIAS) SUMO E3-ligase family - are the best-characterized SUMO E3-ligases and have been linked to the formation of spatial memory in rodents. Whether however they exert their function co-localizing with synaptic markers is still unclear. In this study, we applied for the first time structured illumination microscopy (SIM) to PIAS ligases to investigate the co-localization of PIAS1 and PIAS3 with synaptic markers in hippocampal and cortical murine neurons. The results indicate partial co-localization of PIAS1 and PIAS3 with synaptic markers in hippocampal neurons and much rarer occurrence in cortical neurons. This is in line with previous super-resolution reports describing the co-localization with synaptic markers of other components of the SUMOylation machinery
Comparison between two different modes of non-invasive ventilatory support in preterm newborn infants with respiratory distress syndrome mild to moderate: preliminary data
Despite of improved survival of premature infants, the incidence of long term pulmonary complications, mostly associated with ventilation-induced lung injury, remains high. Non invasive ventilation (NIV) is able to reduce the adverse effects of mechanical ventilation. Although nasal continuous positive airway pressure (NCPAP) is an effective mode of NIV, traumatic nasal complications and intolerance of the nasal interface are common. Recently high flow nasal cannula (HFNC) is emerging as a better tolerated form of NIV, allowing better access to the baby's face, which may improve nursing, feeding and bonding. HFNC may be effective in the treatment of some neonatal respiratory conditions while being more user-friendly for care-givers than conventional NCPAP. Limited evidence is available to support the specific role, efficacy and safety of HFNC in newborns and to demonstrate efficacy compared with NCPAP; some studies suggest a potential role for HFNC in respiratory care of the neonate as a distinct non invasive ventilatory support. We present the preliminary data of a randomized clinical trial; the aim of this study was to assess efficacy and safety of HFNC compared to NCPAP in preterm newborns with mild to moderate respiratory distress syndrome (RDS)
Neonatal respiratory distress syndrome: are risk factors the same in preterm and term infants?
Objective: To analyze respiratory distress syndrome (RDS) incidence and risk factors at different gestational age. Methods: We considered data from 321 327 infants born in Lombardy, a Northern Italian Region. We computed multivariate analysis to identify risk factors for RDS by dividing infants in early- and moderate-preterm, late-preterm and term infants. Results: Low-birth weight is the main risk factor for RDS, with higher odds ratio in term births. The risk was higher in infants delivered by cesarean section and in male, for all gestational age. Pathological course of pregnancy resulted in increased risk only in late-preterm and term infants. Maternal age and multiple birth were not associated with increased risk in any group. Babies born at term after assisted conception were at higher risk of RDS. Conclusion: Our analysis suggests as some risk factors do not influence RDS incidence in the same way at different gestational age
The three-dimensional structure of Galactic molecular cloud complexes out to 2.5 kpc
Knowledge of the three-dimensional structure of Galactic molecular clouds is
important for understanding how clouds are affected by processes such as
turbulence and magnetic fields and how this structure effects star formation
within them. Great progress has been made in this field with the arrival of the
Gaia mission, which provides accurate distances to stars.
Combining these distances with extinctions inferred from optical-IR, we recover
the three-dimensional structure of 16 Galactic molecular cloud complexes at
pc resolution using our novel three-dimensional dust mapping algorithm
\texttt{Dustribution}. Using \texttt{astrodendro} we derive a catalogue of
physical parameters for each complex. We recover structures with aspect ratios
between 1 and 11, i.e.\ everything from near-spherical to very elongated
shapes. We find a large variation in cloud environments that is not apparent
when studying them in two-dimensions. For example, the nearby California and
Orion A clouds look similar on-sky, but we find California to be more
sheet-like, and massive, which could explain their different star-formation
rates. In Carina, our most distant complex, we observe evidence for dust
sputtering, which explains its measured low dust mass. By calculating the total
mass of these individual clouds, we demonstrate that it is necessary to define
cloud boundaries in three-dimensions in order to obtain an accurate mass;
simply integrating the extinction overestimates masses. We find that Larson's
relationship on mass vs radius holds true whether you assume a spherical shape
for the cloud or take their true extents.Comment: accepted for publication by MNRAS, 23 pages, 9 figures, 3 table
All-sky three-dimensional dust density and extinction Maps of the Milky Way out to 2.8 kpc
Three-dimensional dust density maps are crucial for understanding the
structure of the interstellar medium of the Milky Way and the processes that
shape it. However, constructing these maps requires large datasets and the
methods used to analyse them are computationally expensive and difficult to
scale up. As a result it is has only recently become possible to map
kiloparsec-scale regions of our Galaxy at parsec-scale grid sampling. We
present all-sky three-dimensional dust density and extinction maps of the Milky
Way out to 2.8~kpc in distance from the Sun using the fast and scalable
Gaussian Process algorithm \DustT. The sampling of the three-dimensional map is
~pc. The input extinction and
distance catalogue contains 120 million stars with photometry and astrometry
from Gaia DR2, 2MASS and AllWISE. This combines the strengths of optical and
infrared data to probe deeper into the dusty regions of the Milky Way. We
compare our maps with other published 3D dust maps. All maps quantitatively
agree at the ~mag~pc scale with many qualitatively similar
features, although each map also has its own features. We recover Galactic
features previously identified in the literature. Moreover, we also see a large
under-density that may correspond to an inter-arm or -spur gap towards the
Galactic Centre.Comment: Accepted for publication in MNRAS; 13 pages in main document and 7
pages in appendi
Notice of Duplicate Publication: Heated, Humidified High-Flow Nasal Cannula vs Nasal Continuous Positive Airway Pressure for Respiratory Distress Syndrome of Prematurity: A Randomized Clinical Noninferiority Trial (JAMA Pediatr. doi:10.1001/jamapediatrics.2016.1243)
Micro- and Nanoplastics’ Effects on Protein Folding and Amyloidosis
A significant portion of the world's plastic is not properly disposed of and, through various processes, is degraded into microscopic particles termed micro- and nanoplastics. Marine and terrestrial faunae, including humans, inevitably get in contact and may inhale and ingest these microscopic plastics which can deposit throughout the body, potentially altering cellular and molecular functions in the nervous and other systems. For instance, at the cellular level, studies in animal models have shown that plastic particles can cross the blood-brain barrier and interact with neurons, and thus affect cognition. At the molecular level, plastics may specifically influence the folding of proteins, induce the formation of aberrant amyloid proteins, and therefore potentially trigger the development of systemic and local amyloidosis. In this review, we discuss the general issue of plastic micro- and nanoparticle generation, with a focus on their effects on protein folding, misfolding, and their possible clinical implications
Cerebellar ataxia, neuropathy, vestibular areflexia syndrome due to RFC1 repeat expansion.
Ataxia, causing imbalance, dizziness and falls, is a leading cause of neurological disability. We have recently identified a biallelic intronic AAGGG repeat expansion in replication factor complex subunit 1 (RFC1) as the cause of cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and a major cause of late onset ataxia. Here we describe the full spectrum of the disease phenotype in our first 100 genetically confirmed carriers of biallelic repeat expansions in RFC1 and identify the sensory neuropathy as a common feature in all cases to date. All patients were Caucasian and half were sporadic. Patients typically reported progressive unsteadiness starting in the sixth decade. A dry spasmodic cough was also frequently associated and often preceded by decades the onset of walking difficulty. Sensory symptoms, oscillopsia, dysautonomia and dysarthria were also variably associated. The disease seems to follow a pattern of spatial progression from the early involvement of sensory neurons, to the later appearance of vestibular and cerebellar dysfunction. Half of the patients needed walking aids after 10 years of disease duration and a quarter were wheelchair dependent after 15 years. Overall, two-thirds of cases had full CANVAS. Sensory neuropathy was the only manifestation in 15 patients. Sixteen patients additionally showed cerebellar involvement, and six showed vestibular involvement. The disease is very likely to be underdiagnosed. Repeat expansion in RFC1 should be considered in all cases of sensory ataxic neuropathy, particularly, but not only, if cerebellar dysfunction, vestibular involvement and cough coexist
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