411 research outputs found
A realist interpretation of quantum mechanics based on undecidability due to gravity
We summarize several recent developments suggesting that solving the problem
of time in quantum gravity leads to a solution of the measurement problem in
quantum mechanics. This approach has been informally called "the Montevideo
interpretation". In particular we discuss why definitions in this approach are
not "for all practical purposes" (fapp) and how the problem of outcomes is
resolved.Comment: 7 pages, IOPAMS style, no figures, contributed to the proceedings of
DICE 2010, Castiglioncello, slightly improved versio
The relationship between truncation and phosphorylation at the C-terminus of tau protein in the paired helical filaments of Alzheimer's disease
Acknowledgements: Authors want to express their gratitude to Dr. P. Davies (Albert Einstein College of Medicine, Bronx, NY, USA) and Lester I. Binder (NorthWestern, Chicago, IL, USA) for the generous gift of mAbs (TG-3, Alz-50, and MC1), and (TauC-3), respectively, and to M. en C. Ivan J. Galván-Mendoza for his support in confocal microscopy, and Ms. Maricarmen De Lorenz for her secretarial assistance. We also want to express our gratitude to the Mexican Families who donate the brain of their loved ones affected with Alzheimer's disease, and made possible our research. This work was financially supported by CONACyT grant, No. 142293 (For R.M).Peer reviewedPublisher PD
A 15-year perspective of the fabry outcome survey
The Fabry Outcome Survey (FOS) is an international long-term observational registry sponsored by Shire for patients diagnosed with Fabry disease who are receiving or are candidates for therapy with agalsidase alfa (agala). Established in 2001, FOS provides long-term data on agala safety/efficacy and collects data on the natural history of Fabry disease, with the aim of improving clinical management. The FOS publications have helped establish prognostic and severity scores, defined the incidence of specific disease variants and implications for clinical management, described clinical manifestations in special populations, confirmed the high prevalence of cardiac morbidity, and demonstrated correlations between ocular changes and Fabry disease severity. These FOS data represent a rich resource with utility not only for description of natural history/therapeutic effects but also for exploratory hypothesis testing and generation of tools for diagnosis/management, with the potential to improve future patient outcomes
Lyman break and UV-selected galaxies at I. Stellar populations from ALHAMBRA survey
We take advantage of the exceptional photometric coverage provided by the
combination of GALEX data in the UV and the ALHAMBRA survey in the optical and
near-IR to analyze the physical properties of a sample of 1225 GALEX-selected
Lyman break galaxies (LBGs) at located in the
COSMOS field. This is the largest sample of LBGs studied at that redshift range
so far. According to a spectral energy distribution (SED) fitting with
synthetic stellar population templates, we find that LBGs at are
mostly young galaxies with a median age of 341 Myr and have intermediate dust
attenuation, . Due to their selection criterion,
LBGs at are UV-bright galaxies and have high dust-corrected total
SFR, with a median value of 16.9 . Their median stellar
mass is . We obtain that the
dust-corrected total SFR of LBGs increases with stellar mass and the specific
SFR is lower for more massive galaxies. Only 2% of the galaxies selected
through the Lyman break criterion have an AGN nature. LBGs at are
mostly located over the blue cloud of the color-magnitude diagram of galaxies
at their redshift, with only the oldest and/or the dustiest deviating towards
the green valley and red sequence. Morphologically, 69% of LBGs are disk-like
galaxies, with the fraction of interacting, compact, or irregular systems being
much lower, below 12%. LBGs have a median effective radius of 2.5 kpc and
bigger galaxies have higher total SFR and stellar mass. Comparing to their
high-redshift analogues, we find evidence that LBGs at lower redshifts are
bigger, redder in the UV continuum, and have a major presence of older stellar
populations in their SEDs. However, we do not find significant difference in
the distributions of stellar mass or dust attenuation.Comment: Accepted for publication in MNRA
Newborn screening for medium-chain acyl-CoA dehydrogenase deficiency: regional experience and high incidence of carnitine deficiency
Background
Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most common inherited defect in the mitochondrial fatty acid oxidation pathway, resulting in significant morbidity and mortality in undiagnosed patients.
Newborn screening (NBS) has considerably improved MCADD outcome, but the risk of complication remains in some patients. The aim of this study was to evaluate the relationship between genotype, biochemical parameters and clinical data at diagnosis and during follow-up, in order to optimize monitoring of these patients.
Methods
We carried out a multicenter study in southwest Europe, of MCADD patients detected by NBS. Evaluated NBS data included free carnitine (C0) and the acylcarnitines C8, C10, C10:1 together with C8/C2 and C8/C10 ratios, clinical presentation parameters and genotype, in 45 patients. Follow-up data included C0 levels, duration of carnitine supplementation and occurrence of metabolic crises.
Results
C8/C2 ratio and C8 were the most accurate biomarkers of MCADD in NBS. We found a high number of patients homozygous for the prevalent c.985A > G mutation (75%). Moreover, in these patients C8, C8/C10 and C8/C2 were higher than in patients with other genotypes, while median value of C0 was significantly lower (23 μmol/L vs 36 μmol/L).
The average follow-up period was 43 months. To keep carnitine levels within the normal range, carnitine supplementation was required in 82% of patients, and for a longer period in patients homozygotes for the c.985A>G mutation than in patients with other genotypes (average 31 vs 18 months). Even with treatment, median C0 levels remained lower in homozygous patients than in those with other genotypes (14 μmol/L vs 22 μmol/L).
Two patients died and another three suffered a metabolic crisis, all of whom were homozygous for the c.985 A>G mutation.
Conclusions
Our data show a direct association between homozygosity for c.985A>G and lower carnitine values at diagnosis, and a higher dose of carnitine supplementation for maintenance within the normal range. This study contributes to a better understanding of the relationship between genotype and phenotype in newborn patients with MCADD detected through screening which could be useful in improving follow-up strategies and clinical outcome
Gemini Observations of Galaxies in Rich Early Environments (GOGREEN) I : survey description.
We describe a new Large Program in progress on the Gemini North and South telescopes: Gemini Observations of Galaxies in Rich Early Environments (GOGREEN). This is an imaging and deep spectroscopic survey of 21 galaxy systems at 1 10 in halo mass. The scientific objectives include measuring the role of environment in the evolution of low-mass galaxies, and measuring the dynamics and stellar contents of their host haloes. The targets are selected from the SpARCS, SPT, COSMOS, and SXDS surveys, to be the evolutionary counterparts of today's clusters and groups. The new red-sensitive Hamamatsu detectors on GMOS, coupled with the nod-and-shuffle sky subtraction, allow simultaneous wavelength coverage over λ ∼ 0.6–1.05 μm, and this enables a homogeneous and statistically complete redshift survey of galaxies of all types. The spectroscopic sample targets galaxies with AB magnitudes z΄ < 24.25 and [3.6] μm < 22.5, and is therefore statistically complete for stellar masses M* ≳ 1010.3 M⊙, for all galaxy types and over the entire redshift range. Deep, multiwavelength imaging has been acquired over larger fields for most systems, spanning u through K, in addition to deep IRAC imaging at 3.6 μm. The spectroscopy is ∼50 per cent complete as of semester 17A, and we anticipate a final sample of ∼500 new cluster members. Combined with existing spectroscopy on the brighter galaxies from GCLASS, SPT, and other sources, GOGREEN will be a large legacy cluster and field galaxy sample at this redshift that spectroscopically covers a wide range in stellar mass, halo mass, and clustercentric radius
The risk of lung cancer related to dietary intake of flavonoids
It has been hypothesized that flavonoids in foods and beverages may reduce cancer risk through
antioxidation, inhibition of inflammation, and other antimutagenic and antiproliferative
properties. We examined associations between intake of five flavonoid subclasses
(anthocyanidins, flavan-3-ols, flavones, flavonols, flavanones) and lung cancer risk in a
population-based case-control study in Montreal, Canada (1,061 cases and 1,425 controls).
Flavonoid intake was estimated from a food frequency questionnaire that assessed diet two years
prior to diagnosis (cases) or interview (controls). Odds ratios (ORs) and 95% confidence
intervals (CIs) were estimated using unconditional logistic regression. Overall, total flavonoid
intake was not associated with lung cancer risk, the effect being similar regardless of sex and
smoking level. However, low flavonoid intake from food, but not from beverages, was
associated with an increased risk. The adjusted ORs (95% CIs) comparing the highest versus the
lowest quartiles of intake were 0.63 (0.47-0.85) for total flavonoids, 0.82 (0.61-1.11) for
anthocyanidins, 0.67 (0.50-0.90) for flavan-3-ols, 0.68 (0.50-0.93) for flavones, 0.62 (0.45-0.84)
for flavonols, and 0.70 (0.53-0.94) for flavanones. An inverse association with total flavone and
flavanone intake was observed for squamous cell carcinoma but not adenocarcinoma. In
conclusion, low flavonoid intake from food may increase lung cancer risk
Loop Quantum Cosmology: A Status Report
The goal of this article is to provide an overview of the current state of
the art in loop quantum cosmology for three sets of audiences: young
researchers interested in entering this area; the quantum gravity community in
general; and, cosmologists who wish to apply loop quantum cosmology to probe
modifications in the standard paradigm of the early universe. An effort has
been made to streamline the material so that, as described at the end of
section I, each of these communities can read only the sections they are most
interested in, without a loss of continuity.Comment: 138 pages, 15 figures. Invited Topical Review, To appear in Classical
and Quantum Gravity. Typos corrected, clarifications and references adde
Quantum Systems Equilibrate Rapidly for Most Observables
Considering any Hamiltonian, any initial state, and measurements with a small
number of possible outcomes compared to the dimension, we show that most
measurements are already equilibrated. To investigate non-trivial equilibration
we therefore consider a restricted set of measurements. When the initial state
is spread over many energy levels, and we consider the set of observables for
which this state is an eigenstate, most observables are initially out of
equilibrium yet equilibrate rapidly. Moreover, all two-outcome measurements,
where one of the projectors is of low rank, equilibrate rapidly.Comment: Main Text: 5 pages, 1 figure. Appendices: 7 pages, 1 figur
Mutations in SLC39A14 disrupt manganese homeostasis and cause childhood-onset parkinsonism-dystonia
Although manganese is an essential trace metal, little is known about its transport and homeostatic regulation. Here we have identified a cohort of patients with a novel autosomal recessive manganese transporter defect caused by mutations in SLC39A14. Excessive accumulation of manganese in these patients results in rapidly progressive childhood-onset parkinsonism-dystonia with distinctive brain magnetic resonance imaging appearances and neurodegenerative features on post-mortem examination. We show that mutations in SLC39A14 impair manganese transport in vitro and lead to manganese dyshomeostasis and altered locomotor activity in zebrafish with CRISPR-induced slc39a14 null mutations. Chelation with disodium calcium edetate lowers blood manganese levels in patients and can lead to striking clinical improvement. Our results demonstrate that SLC39A14 functions as a pivotal manganese transporter in vertebrates
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