Today, the on-board Spacecraft (SC) communication requires an impressive network of massive wires, both in flight and in the Assembly Integration and Test (AIT) phase. Here, we present the design and ...the experimental characterization of novel Optical Wireless Communication (OWC) transceivers compatible with MIL-STD-1553B, which is the shared bus predominantly deployed in SCs. Each transceiver works as an interface that transports the bipolar Manchester-coded signal by converting it to/from the optical domain. These OWC interfaces can effectively reduce the overall weight and cost of the SC and can also largely decrease the AIT time. Since they are fully analog and do not need any microprocessors or Digital Signal Processing, they have a small footprint and a very low power consumption. We initially characterize the transceivers using a non-return-to-zero (NRZ) signal, then we used them to replace a cable and connect a pair of test units, transmitting MIL-STD-1553B signals: the measurements show that our solution has a good power budget (+65dB), which will allow the interoperability with MIL-STD-1553B boards in a wide range of scenarios. Furthermore, it is realized by means of commercially available components; it could also be implemented by using proven space-graded devices.
We determine the renormalization constants for flavor nonsinglet fermion bilinear operators of Möbius domain-wall fermions. The renormalization condition is imposed on the correlation functions in ...the coordinate space, such that the nonperturbative lattice calculation reproduces the perturbatively calculated counterpart at short distances. The perturbative expansion is precise as the coefficients are available up to O(αs4). We employ 2+1-flavor lattice ensembles at three lattice spacings in the range 0.044–0.080 fm.
Primary intracranial lymphomas (Weller et al. in Neuro Oncol 14(12):1481–1484,
2012
) are an emerging disease and an isolated localization in the pituitary gland i.e. primary pituitary lymphoma (PPL) ...represents a rare condition. We present an update of the most recent evidence for PPL through a systematic review of the literature. A systematic literature review was conducted using PubMed database up to October 2015. The population was defined as immunocompetent patients with a pathologically confirmed diagnosis of PPL. Patients’ characteristics, clinical presentation, radiological features, pathology reports, adjuvant treatment and follow-up data were analyzed. We reported one case of PPL and included our data in this analysis. A total of 33 cases of PPL were identified, including ours. A slight not significant female prevalence was evident, with a mean age of 59 years at diagnosis. Visual troubles and headaches were the most common presenting symptoms. About 80 % of patients presented a cranial nerve (CN) deficit. The most frequently involved were the II and III CN. Anterior hypopituitarism was present in 70 % of cases and a diabetes insipidus in 36 % of cases. PPL was rarely limited to the sella and most often extended to the suprasellar and parasellar space. 70 % of cases underwent resection, 21 % a biopsy. A B-cell lymphoma was isolated in 82 % of cases, a T-cell lymphoma in 15 % and a NK/T cell lymphoma in one case. Overall mean survival rate was 14.4 months (95 % confidence interval 9.0–19.8 months) and there was no difference in terms of survival rates when patients were stratified according to the treatment they received. PPL is an emerging clinical entity. Literature data are too scarce to allow the definition of specific protocols of treatment and the management is based on the guidelines present for PCNSL. The role of surgery aiming at a complete resection of PPL should be reevaluated in wider studies including only this category of patients, to establish the real role of each therapeutic strategy.
We study spatial isovector meson correlators in Nf=2 QCD with dynamical domain-wall fermions on 323×8 lattices at temperatures T=220–380 MeV. We measure the correlators of spin-one (J=1) operators ...including vector, axial-vector, tensor and axial-tensor. Restoration of chiral U(1)A and SU(2)L×SU(2)R symmetries of QCD implies degeneracies in vector–axial-vector (SU(2)L×SU(2)R) and tensor–axial-tensor (U(1)A) pairs, which are indeed observed at temperatures above Tc. Moreover, we observe an approximate degeneracy of all J=1 correlators with increasing temperature. This approximate degeneracy suggests emergent SU(2)CS and SU(4) symmetries at high temperatures, that mix left- and right-handed quarks.
In the amniote embryos, specification of skeletal myoblasts occurs in the paraxial mesoderm in response to a number of signaling molecules produced by neighboring tissues such as neural tube, ...notochord and dorsal ectoderm. Candidate molecules for this complex signaling activity include Sonic hedgehog, Wnts and Noggin as positive activators and BMP4 as a possible inhibitor. Recently, the receptors and the post‐receptor pathways for Sonic hedgehog and Wnts have been characterized, and this has opened up the possibility of linking these signaling events to the activation of myogenic regulatory factor genes such as Myf5 and MyoD and functionally related genes such as Pax3. Here we focus on the role of Wnts, their putative receptors Frizzled and the soluble antagonist Frzb1 in regulating mammalian myogenesis. Although it is becoming evident that the signaling downstream of Frizzled receptors is much more complex than anticipated, it is conceivable that it may lead to transcriptional activation of Myf5 and MyoD and to initiation of myogenesis. However, the fact that both Wnts and Sonic hedgehog have a strong effect on cell proliferation and survival suggests that they may contribute to the overall process of myogenesis by a combination of these different biological activities.
We study the vector and axial-vector current correlators in perturbative and nonperturbative regimes of QCD. The correlators in Euclidean coordinate space are calculated on the lattice using the ...Möbius domain-wall fermion formulation at three lattice spacings covering 0.044–0.080 fm. The dynamical quark effects of 2+1 light flavors are included. The sum V+A and the difference V−A of the vector (V) and axial-vector (A) current correlators calculated on the lattice after extrapolating to the physical point agree with those converted from the ALEPH experimental data of hadronic τ decays. The level of the agreement in the V+A channel is about 1.3σ or smaller in the region of |x|≥0.4 fm, while that in the V−A channel is about 1.8σ at |x|=0.74 fm and smaller at other distances. We also extract the chiral condensate from the short-distance correlators on the lattice using the partially conserved axial current relation. Its result extrapolated to the chiral and continuum limit is compatible with other estimates at low energies.
During myogenic differentiation the short mitochondria of myoblasts change into the extensively elongated network observed in myotubes. The functional relevance and the molecular mechanisms driving ...the formation of this mitochondrial network are unknown. We now show that mitochondrial elongation is required for myogenesis to occur and that this event depends on the cellular generation of nitric oxide (NO). Inhibition of NO synthesis in myogenic precursor cells leads to inhibition of mitochondrial elongation and of myogenic differentiation. This is due to the enhanced activity, translocation and docking of the pro-fission GTPase dynamin-related protein-1 (Drp1) to mitochondria, leading also to a latent mitochondrial dysfunction that increased sensitivity to apoptotic stimuli. These effects of NO inhibition were not observed in myogenic precursor cells containing a dominant-negative form of Drp1. Both NO-dependent repression of Drp1 action and maintenance of mitochondrial integrity and function were mediated through the soluble guanylate cyclase. These data uncover a novel level of regulation of differentiation linking mitochondrial morphology and function to myogenic differentiation.
We calculate the form factors of the K→πlν semileptonic decays in three-flavor lattice QCD and study their chiral behavior as a function of the momentum transfer and the Nambu-Goldstone boson masses. ...Chiral symmetry is exactly preserved by using the overlap quark action, which enables us to directly compare the lattice data with chiral perturbation theory (ChPT). We generate gauge ensembles at a lattice spacing of 0.11 fm with four pion masses covering 290–540 MeV and a strange quark mass ms close to its physical value. By using the all-to-all quark propagator, we calculate the vector and scalar form factors with high precision. Their dependence on ms and the momentum transfer is studied by using the reweighting technique and the twisted boundary conditions for the quark fields. We compare the results for the semileptonic form factors with ChPT at next-to-next-to-leading order in detail. While many low-energy constants appear at this order, we make use of our data of the light meson electromagnetic form factors in order to control the chiral extrapolation. We determine the normalization of the form factors as f+(0)=0.9636(36)(−35+57) and observe reasonable agreement of their shape with experiment.
We study the chiral behavior of the electromagnetic (EM) form factors of pions and kaons in three-flavor lattice QCD. In order to make a direct comparison of the lattice data with chiral perturbation ...theory (ChPT), we employ the overlap quark action that has exact chiral symmetry. Gauge ensembles are generated at a lattice spacing of 0.11 fm with four pion masses ranging between M sub(pi)=290MeV and 540 MeV and with a strange quark mass m sub(s)close to its physical value. We utilize the all-to-all quark propagator technique to calculate the EM form factors with high precision. Their dependence on m sub(s)and on the momentum transfer is studied by using the reweighting technique and the twisted boundary conditions for the quark fields, respectively. A detailed comparison with SU(2) and SU(3) ChPT reveals that the next-to-next-to-leading order terms in the chiral expansion are important to describe the chiral behavior of the form factors in the pion mass range studied in this work. We estimate the relevant low-energy constants and the charge radii, and find reasonable agreement with phenomenological and experimental results.
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