69 research outputs found
Rapid and complete hitless defragmentation method using a coherent RX LO with fast wavelength tracking in elastic optical networks
This paper demonstrates a rapid and full hitless defragmentation method in elastic optical networks exploiting a new technique for fast wavelength tracking in coherent receivers. This technique can be applied to a single-carrier connection or each of the subcarriers forming a superchannel. A proof-of-concept demonstration shows hitless defragmentation of a 10 Gb/s QPSK single-carrier connection from 1547.75 nm to 1550.1 nm in less than 1 mu s. This was obtained using a small (0.625 kB) link-layer transmitter buffer without the need for any additional transponder. We also demonstrated that the proposed defragmentation technique is capable of hopping over an existing connection, i.e. 10 Gb/s OOK at 1548.5 nm, without causing any degradation of its real-time Bit Error Rate (BER) value. The proposed scheme gives advantages in terms of overall network blocking probability reduction up to a factor of 40. (C) 2012 Optical Society of Americ
Disease- and age-related changes in histone acetylation at gene promoters in psychiatric disorders
Increasing evidence suggests that epigenetic factors have critical roles in gene
regulation in neuropsychiatric disorders and in aging, both of which are
typically associated with a wide range of gene expression abnormalities. Here,
we have used chromatin immunoprecipitation-qPCR to measure levels of acetylated
histone H3 at lysines 9/14 (ac-H3K9K14), two epigenetic marks associated
with transcriptionally active chromatin, at the promoter regions of eight
schizophrenia-related genes in n=82 postmortem prefrontal
cortical samples from normal subjects and those with schizophrenia and bipolar
disorder. We find that promoter-associated ac-H3K9K14 levels are correlated with
gene expression levels, as measured by real-time qPCR for several genes,
including, glutamic acid decarboxylase 1 (GAD1), 5-hydroxytryptamine
receptor 2C (HTR2C), translocase of outer mitochondrial membrane 70
homolog A (TOMM70A) and protein phosphatase 1E (PPM1E).
Ac-H3K9K14 levels of several of the genes tested were significantly negatively
associated with age in normal subjects and those with bipolar disorder, but not
in subjects with schizophrenia, whereby low levels of histone acetylation were
observed in early age and throughout aging. Consistent with this observation,
significant hypoacetylation of H3K9K14 was detected in young subjects with
schizophrenia when compared with age-matched controls. Our results demonstrate
that gene expression changes associated with psychiatric disease and aging
result from epigenetic mechanisms involving histone acetylation. We further find
that treatment with a histone deacetylase (HDAC) inhibitor alters the expression
of several candidate genes for schizophrenia in mouse brain. These findings may
have therapeutic implications for the clinical use of HDAC inhibitors in
psychiatric disorders
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transientâs position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Ras induces experimental lung metastasis through up-regulation of RbAp46 to suppress RECK promoter activity
Rapid development of proteomics in China: from the perspective of the Human Liver Proteome Project and technology development
Molecular and functional properties of P2X receptorsârecent progress and persisting challenges
Multi-condition optimization and experimental study of impeller blades in a mixed-flow pump
Identification of a major quantitative trait locus underlying salt tolerance in âJidou 12â soybean cultivar
- âŠ