202 research outputs found
Fault Models for Quantum Mechanical Switching Networks
The difference between faults and errors is that, unlike faults, errors can
be corrected using control codes. In classical test and verification one
develops a test set separating a correct circuit from a circuit containing any
considered fault. Classical faults are modelled at the logical level by fault
models that act on classical states. The stuck fault model, thought of as a
lead connected to a power rail or to a ground, is most typically considered. A
classical test set complete for the stuck fault model propagates both binary
basis states, 0 and 1, through all nodes in a network and is known to detect
many physical faults. A classical test set complete for the stuck fault model
allows all circuit nodes to be completely tested and verifies the function of
many gates. It is natural to ask if one may adapt any of the known classical
methods to test quantum circuits. Of course, classical fault models do not
capture all the logical failures found in quantum circuits. The first obstacle
faced when using methods from classical test is developing a set of realistic
quantum-logical fault models. Developing fault models to abstract the test
problem away from the device level motivated our study. Several results are
established. First, we describe typical modes of failure present in the
physical design of quantum circuits. From this we develop fault models for
quantum binary circuits that enable testing at the logical level. The
application of these fault models is shown by adapting the classical test set
generation technique known as constructing a fault table to generate quantum
test sets. A test set developed using this method is shown to detect each of
the considered faults.Comment: (almost) Forgotten rewrite from 200
The Epidemiology of Hypoparathyroidism in Italy: An 8-Year Register-Based Study
Hypoparathyroidism is a rare endocrine disorder,
but few studies have focused on the epidemiology and
hospital management of the disease and none has been
performed in Italy. We investigated the prevalence of dif-
ferent forms of hypoparathyroidism among hospitalized
patients in Italy during an 8-year period. This study is
designed as a retrospective register-based study. We
retrieved data from the ‘‘Record of Hospital Discharge’’
(SDO) of the Italian Health Ministry, from the year 2006 to
2013
and
analyzed
the
codes
corresponding
to
hypoparathyroidism-related
diagnoses.
The
inpatient
prevalence of the disease was also calculated after
excluding repeated hospitalizations. Overall, 27,692 hos-
pitalization episodes for hypoparathyroidism were identi-
fied during the entire period (72.2% in women and 27.8%
in men; mean age 49.5
±
22.9 years). The mean length of
stay was 7.4
±
9.8 days (25.9% of the episodes requiring
less than 3 days of stay). The mean hospitalization rate for
hypoparathyroidism was 5.9/100,000 inhabitants per year
and there was a significant decrease during the period of
2006–2013 (
p
\
0.0001). The mean hospitalization rate for
postsurgical hypoparathyroidism was 1.4/100,000 inhabi-
tants per year and the trend showed a significant reduction during the years (
p
\
0.0001). The mean prevalence of
hypoparathyroidism among inpatients was 5.3/100,000
inhabitants per year, and there was a significant decrease
over the years (
p
\
0.0001). Hypoparathyroidism, partic-
ularly the postsurgical form of the disease, is not an
uncommon condition among hospitalized patients in Italy.
We observed a tendency to a decrease in the frequency of
hospitalization during the period 2006–201
COVID-19 and schools: what is the risk of contagion? Results of a rapid-antigen-test-based screening campaign in Florence, Italy
INTRODUCTION: in the COVID-19 era, the debate around the risk of contagion at school, is intense in Italy. The Department of Welfare and Wealth of Florence promoted a screening campaign with antigen rapid tests for all the students and school personnel. The aim of this study is to assess the SARS-Cov2 circulation in the school setting by means of a mass screening conducted in every primary and middle school of Florence. METHODS: All the students attending primary and middle schools of Florence and the school personnel were asked to take part. The campaign started on 16(th) November 2020 and was completed on 12(th) February 2021. If the antigen rapid test resulted positive, a molecular test was provided to confirm the result. RESULTS: 18,414 subjects were tested with 15,233 students (82.7%) and 3,181 members of the school personnel (17.3%). Only in 27 cases (0.15%) the rapid test gave a positive result. Moreover, only 14 of the 27 positive rapid tests were confirmed as positive by the molecular test. These results show a very low number of SARS-CoV-2 cases among the people tested (0.08% of the total). CONCLUSIONS: These results show that the spread of SARS-CoV-2 infection at school, during the months of the screening and with the respect of strict preventive measures was low
Imaging technologies in the differential diagnosis and follow-up of brown tumor in primary hyperparathyroidism: case report and review of the literature
Brown tumors are osteolytic lesions associated with hyperparathyroidism (HPT). They may involve various skeletal segments, but rarely the cranio-facial bones. We report a case of a young boy with a swelling of the jaw secondary to a brown tumor presenting as the first manifestation of primary HPT (PHPT). He was found to have brown tumor located in the skull, as well. Different imaging technologies were employed for the diagnosis and follow-up after parathyroidectomy. We enclose a review of the literature on the employment of such imaging technologies in the differential diagnosis of osteolytic lesions. A multidisciplinary approach comprising clinical, laboratory and imaging findings is essential for the differential diagnosis of brown tumor in PHPT
Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance
Quantum ground-state problems are computationally hard problems; for general
many-body Hamiltonians, there is no classical or quantum algorithm known to be
able to solve them efficiently. Nevertheless, if a trial wavefunction
approximating the ground state is available, as often happens for many problems
in physics and chemistry, a quantum computer could employ this trial
wavefunction to project the ground state by means of the phase estimation
algorithm (PEA). We performed an experimental realization of this idea by
implementing a variational-wavefunction approach to solve the ground-state
problem of the Heisenberg spin model with an NMR quantum simulator. Our
iterative phase estimation procedure yields a high accuracy for the
eigenenergies (to the 10^-5 decimal digit). The ground-state fidelity was
distilled to be more than 80%, and the singlet-to-triplet switching near the
critical field is reliably captured. This result shows that quantum simulators
can better leverage classical trial wavefunctions than classical computers.Comment: 11 pages, 13 figure
Taking gradients through experiments: LSTMs and memory proximal policy optimization for black-box quantum control
In this work we introduce the application of black-box quantum control as an
interesting rein- forcement learning problem to the machine learning community.
We analyze the structure of the reinforcement learning problems arising in
quantum physics and argue that agents parameterized by long short-term memory
(LSTM) networks trained via stochastic policy gradients yield a general method
to solving them. In this context we introduce a variant of the proximal policy
optimization (PPO) algorithm called the memory proximal policy optimization
(MPPO) which is based on this analysis. We then show how it can be applied to
specific learning tasks and present results of nu- merical experiments showing
that our method achieves state-of-the-art results for several learning tasks in
quantum control with discrete and continouous control parameters
Sam68 splicing regulation contributes to motor unit establishment in the postnatal skeletal muscle
RNA-binding proteins orchestrate the composite life of RNA molecules and impact most physiological processes, thus underlying complex phenotypes. The RNA-binding protein Sam68 regulates differentiation processes by modulating splicing, polyadenylation, and stability of select transcripts. Herein, we found that Sam68-/- mice display altered regulation of alternative splicing in the spinal cord of key target genes involved in synaptic functions. Analysis of the motor units revealed that Sam68 ablation impairs the establishment of neuromuscular junctions and causes progressive loss of motor neurons in the spinal cord. Importantly, alterations of neuromuscular junction morphology and properties in Sam68-/- mice correlate with defects in muscle and motor unit integrity. Sam68-/- muscles display defects in postnatal development, with manifest signs of atrophy. Furthermore, fast-twitch muscles in Sam68-/- mice show structural features typical of slow-twitch muscles, suggesting alterations in the metabolic and functional properties of myofibers. Collectively, our data identify a key role for Sam68 in muscle development and suggest that proper establishment of motor units requires timely expression of synaptic splice variants
Targeted cancer exome sequencing reveals recurrent mutations in myeloproliferative neoplasms
With the intent of dissecting the molecular complexity of Philadelphia-negative myeloproliferative neoplasms (MPN), we designed a target enrichment panel to explore, using next-generation sequencing (NGS), the mutational status of an extensive list of 2,000 cancer-associated genes and microRNAs. The genomic DNA of granulocytes and in-vitro-expanded CD3+ T-lymphocytes, as a germline control, was target-enriched and sequenced in a learning cohort of 20 MPN patients using Roche 454 technology. We identified 141 genuine somatic mutations, most of which were not previously described. To test the frequency of the identified variants, a larger validation cohort of 189 MPN patients was additionally screened for these mutations using Ion Torrent AmpliSeq NGS. Excluding the genes already described in MPN, for 8 genes (SCRIB, MIR662, BARD1, TCF12, FAT4, DAP3, POLG, and NRAS), we demonstrated a mutation frequency between 3 and 8%.
We also found that mutations at codon 12 of NRAS (NRASG12V and NRASG12D) were significantly associated, for primary myelofibrosis (PMF), with highest DIPSS-plus score categories. This association was then confirmed in 66 additional PMF patients composing a final dataset of 168 PMF showing an NRAS mutation frequency of 4.7%, which was associated with a worse outcome, as defined by the DIPSS plus score
Therapeutic vulnerability of multiple myeloma to MIR17PTi, a first-in-class inhibitor of pri-mir-17-92
The microRNA cluster miR-17-92 is oncogenic and represents a valuable therapeutic target in c-MYC (MYC)-driven malignancies. Here, we developed novel LNA gapmeR antisense oligonucleotides (ASOs) to induce RNase H-mediated degradation of MIR17HG primary transcripts and, consequently, to prevent biogenesis of miR-17-92 microRNAs (miR-17-92s). The leading LNA-ASO, named MIR17PTi, impaired proliferation of several cancer cell lines (n=48) established from both solid and hematologic tumors by on-target antisense activity, and more effectively as compared to miR-17-92s inhibitors. By focusing on multiple myeloma (MM), we found that MIR17PTi triggers apoptosis via impairment of homeostatic MYC/miR-17-92 feed-forward loops (FFLs) in patient-derived MM cells; and induced MYC-dependent synthetic lethality. We show that alteration of a BIM-centered FFL is instrumental for MIR17PTi to induce cytotoxicity in MM cells. MIR17PTi exerts strong in vivo anti-tumor activity in NOD-SCID mice bearing clinically relevant models of MM, with advantageous safety and pharmacokinetics profiles in non-human primates. Altogether, MIR17PTi is a novel pharmacological tool to be tested in early-phase clinical trials against MM and other MYC-driven malignancies
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