2,125 research outputs found

    Controlling quantum entanglement through photocounts

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    We present a protocol to generate and control quantum entanglement between the states of two subsystems (the system S{\cal S}) by making measurements on a third subsystem (the monitor M{\cal M}), interacting with S{\cal S}. For the sake of comparison we consider first an ideal, or instantaneous projective measurement, as postulated by von Neumann. Then we compare it with the more realistic or generalized measurement procedure based on photocounting on M{\cal M}. Further we consider that the interaction term (between S{\cal S} and M{\cal M}) contains a quantum nondemolition variable of S{\cal S} and discuss the possibility and limitations for reconstructing the initial state of S{\cal S} from information acquired by photocounting on M{\cal M}.Comment: 12 pages, 3 figures, accepted for publication in Phys. Rev

    Scale invariant scalar metric fluctuations during inflation: non-perturbative formalism from a 5D vacuum

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    We extend to 5D an approach of a 4D non-perturbative formalism to study scalar metric fluctuations of a 5D Riemann-flat de Sitter background metric. In contrast with the results obtained in 4D, the spectrum of cosmological scalar metric fluctuations during inflation can be scale invariant and the background inflaton field can take sub-Planckian values.Comment: final version to be published in Eur. Phys. J.

    The Developmental Competence of Oocytes Retrieved from The Leading Follicle in Controlled Ovarian Stimulated Cycles

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    Abstract Background: This study compares the developmental capacity of gametes retrieved from the largest follicle with small follicles of a cohort in controlled ovarian stimulated cycles

    Bat fauna (Mammalia, chiroptera) from guarapuava highlands, Southern Brazil

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    Here, we present an updated list of bats fromGuarapuava highlands, center-southern of Paraná state, southern Brazil. This species list is based on four literature records (secondary data) and data from fieldwork (primary data) in three localities. All species recorded (primary and secondary data) were evaluated by the relative frequency and their conservation status were assessed. The species recorded from fieldwork were also evaluated by relative abundance. A beta diversity analysis was done to verify dissimilarities in the bat fauna among the seven localities. We recorded 28 species in the Guarapuava highlands (14 Vespertilionidae, 10 Phyllostomidae and 4 Molossidae), of which, eight are new records for the region. Sturnira lilium was the most abundant in three localities (primary data), and the most frequent species in all studies (primary and secondary data). Only four species were classified globally as “Near Threatened” or “Data Deficient”, nevertheless they were frequent in this region. The mean regional beta diversity was 0.72, what could be mostly explained by turnover (0.64) rather than by nestedness (0.08). The greatest species richness of the family Vespertilionidae is a common pattern in subtropical and temperate regions as in highlands and mountains. As turnover was the main component of the beta diversity, the communities seemed to be structured mainly by replacement of species among the studied localities. The Guarapuava highlands present a diverse bat fauna, however, this region requires more sampling effort to become well known. © 2019, Universidade Federal do Rio de Janeiro (UFRJ). All rights reserved

    Discrete symmetries, invisible axion and lepton number symmetry in an economic 3-3-1 model

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    We show that Peccei-Quinn and lepton number symmetries can be a natural outcome in a 3-3-1 model with right-handed neutrinos after imposing a Z_11 x Z_2 symmetry. This symmetry is suitably accommodated in this model when we augmented its spectrum by including merely one singlet scalar field. We work out the breaking of the Peccei-Quinn symmetry, yielding the axion, and study the phenomenological consequences. The main result of this work is that the solution to the strong CP problem can be implemented in a natural way, implying an invisible axion phenomenologically unconstrained, free of domain wall formation and constituting a good candidate for the cold dark matter.Comment: 17 pages, Revtex

    Potential red-flag identification of colorectal adenomas with wide-field fluorescence molecular endoscopy

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    Adenoma miss rates in colonoscopy are unacceptably high, especially for sessile serrated adenomas / polyps (SSA/Ps) and in high-risk populations, such as patients with Lynch syndrome. Detection rates may be improved by fluorescence molecular endoscopy (FME), which allows morphological visualization of lesions with high-definition white-light imaging as well as fluorescence-guided identification of lesions with a specific molecular marker. In a clinical proof-of-principal study, we investigated FME for colorectal adenoma detection, using a fluorescently labelled antibody (bevacizumab-800CW) against vascular endothelial growth factor A (VEGFA), which is highly upregulated in colorectal adenomas. Methods: Patients with familial adenomatous polyposis (n = 17), received an intravenous injection with 4.5, 10 or 25 mg of bevacizumab-800CW. Three days later, they received NIR-FME. Results: VEGFA-targeted NIR-FME detected colorectal adenomas at all doses. Best results were achieved in the highest (25 mg) cohort, which even detected small adenomas ( < 3 mm). Spectroscopy analyses of freshly excised specimen demonstrated the highest adenoma-to-normal ratio of 1.84 for the 25 mg cohort, with a calculated median tracer concentration in adenomas of 6.43 nmol/mL. Ex vivo signal analyses demonstrated NIR fluorescence within the dysplastic areas of the adenomas. Conclusion: These results suggest that NIR-FME is clinically feasible as a real-time, red-flag technique for detection of colorectal adenomas

    Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification.

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    Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromosome 21q21.3 and identified bi-allelic variants in JAM2. JAM2 encodes for the junctional-adhesion-molecule-2, a key tight-junction protein in blood-brain-barrier permeability. We show that JAM2 variants lead to reduction of JAM2 mRNA expression and absence of JAM2 protein in patient's fibroblasts, consistent with a loss-of-function mechanism. We show that the human phenotype is replicated in the jam2 complete knockout mouse (jam2 KO). Furthermore, neuropathology of jam2 KO mouse showed prominent vacuolation in the cerebral cortex, thalamus, and cerebellum and particularly widespread vacuolation in the midbrain with reactive astrogliosis and neuronal density reduction. The regions of the human brain affected on neuroimaging are similar to the affected brain areas in the myorg PFBC null mouse. Along with JAM3 and OCLN, JAM2 is the third tight-junction gene in which bi-allelic variants are associated with brain calcification, suggesting that defective cell-to-cell adhesion and dysfunction of the movement of solutes through the paracellular spaces in the neurovascular unit is a key mechanism in CNS calcification

    Typification and authorship of Drosera intermedia (Droseraceae)

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    Drosera intermedia is lectotypified with the herbarium specimen on which the type drawing in the 1798 protologue was based. The collection history of the specimen, the history of the botanical drawing as original material, and the correct nomenclatural author and publication date of the name are presented based on historical notes and literature. Additionally, the global distribution of the species is given, including the first record from Africa
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