34 research outputs found

    280 one-opposition near-Earth asteroids recovered by the EURONEAR with the <i>Isaac Newton</i> Telescope

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    Context. One-opposition near-Earth asteroids (NEAs) are growing in number, and they must be recovered to prevent loss and mismatch risk, and to improve their orbits, as they are likely to be too faint for detection in shallow surveys at future apparitions. Aims. We aimed to recover more than half of the one-opposition NEAs recommended for observations by the Minor Planet Center (MPC) using the Isaac Newton Telescope (INT) in soft-override mode and some fractions of available D-nights. During about 130 h in total between 2013 and 2016, we targeted 368 NEAs, among which 56 potentially hazardous asteroids (PHAs), observing 437 INT Wide Field Camera (WFC) fields and recovering 280 NEAs (76% of all targets). Methods. Engaging a core team of about ten students and amateurs, we used the THELI, Astrometrica, and the Find_Orb software to identify all moving objects using the blink and track-and-stack method for the faintest targets and plotting the positional uncertainty ellipse from NEODyS. Results. Most targets and recovered objects had apparent magnitudes centered around V ~ 22.8 mag, with some becoming as faint as V ~ 24 mag. One hundred and three objects (representing 28% of all targets) were recovered by EURONEAR alone by Aug. 2017. Orbital arcs were prolonged typically from a few weeks to a few years; our oldest recoveries reach 16 years. The O−C residuals for our 1854 NEA astrometric positions show that most measurements cluster closely around the origin. In addition to the recovered NEAs, 22 000 positions of about 3500 known minor planets and another 10 000 observations of about 1500 unknown objects (mostly main-belt objects) were promptly reported to the MPC by our team. Four new NEAs were discovered serendipitously in the analyzed fields and were promptly secured with the INT and other telescopes, while two more NEAs were lost due to extremely fast motion and lack of rapid follow-up time. They increase the counting to nine NEAs discovered by the EURONEAR in 2014 and 2015. Conclusions. Targeted projects to recover one-opposition NEAs are efficient in override access, especially using at least two-meter class and preferably larger field telescopes located in good sites, which appear even more efficient than the existing surveys

    RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

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    ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients

    Endothelin-1 as a neuropeptide: neurotransmitter or neurovascular effects?

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    Endothelin-1 (ET-1) is an endothelium-derived peptide that also possesses potent mitogenic activity. There is also a suggestion the ET-1 is a neuropeptide, based mainly on its histological identification in both the central and peripheral nervous system in a number of species, including man. A neuropeptide role for ET-1 is supported by studies showing a variety of effects caused following its administration into different regions of the brain and by application to peripheral nerves. In addition there are studies proposing that ET-1 is implicated in a number of neural circuits where its transmitter affects range from a role in pain and temperature control to its action on the hypothalamo-neurosecretory system. While the effect of ET-1 on nerve tissue is beyond doubt, its action on nerve blood flow is often ignored. Here, we review data generated in a number of species and using a variety of experimental models. Studies range from those showing the distribution of ET-1 and its receptors in nerve tissue to those describing numerous neurally-mediated effects of ET-1

    TEOAE monitoring of Cisplatin induced ototoxicity in guinea pigs: the protective effect of vitamin B treatment

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    Objective: To evaluate Cisplatin (CP) induced ototoxicity and the effects of vitamin B treatment on ototoxicity in guinea pigs by using the Transient Evoked Otoacoustic Emission (TEOAE) technique. Methods: Eleven guinea pigs were divided into two groups and they were tested by TEOAE before and after the experiment. A TEOAE response was regarded as positive when all of the following criteria were met: 1. The mean amplitude of the cochlear response in dB pe SPL should be greater than that of the noise in the external auditory canal; 2. The reproducibility rate of the response should be greater than 50%; 3. The stimulus stability rate should be greater than 65%; 4. The signal to noise ratio of the response in 1, 2, 3, 4 and 5 kHz band frequencies should be greater than 3 dB pe SPL in at least two bands. The first group included five animals that had only CP injections. Six animals in the second group received additional 0.2 ml/kg combined vitamin B preparations for 7 consecutive days. Thereafter, the right and left ears of all animals in both groups were tested by TEOAE. Results: TEOAE responses recorded from 22 ears of 11 guinea pigs before drug administrations showed that the responses with maximum amplitude were originated from the mid-frequency legion. Positive TEOAE responses were significantly reduced after CP administrations in both groups when compared with their respective pretreatment results (P < 0.01). However, vitamin B injections, in addition to a single large dose of CP, resulted in significantly better TEOAE responses than those obtained after only CP injections (P < 0.05). Conclusions: The routine use of TEOAE monitoring is recommended in clinical CP treatment protocols for the early detection and follow up of ototoxicity. Also, prospective clinical trials are needed in order to validate the protective effects of vitamin B treatment against ototoxicity. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved

    Solution of the plane wave diffraction problem by an impedance strip using a numerical-analytical method: E-polarized case

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    In this study, the diffraction of a plane wave by an infinitely long strip, having the same impedance on both faces with a width of 2a is investigated. The diffracted field is expressed by an integral in terms of the induced electric and magnetic current densities. Applying the boundary condition to the integral representation of the scattered field, the problem is formulated as simultaneous integral equations satisfied by the electric and magnetic current density functions. By obtaining the Fourier transform of the integral equations the unknown current density functions can be expanded into the infinite series containing the Chebyshev polynomials. This leads to two infinite systems of linear algebraic equations satisfied by the expansion coefficients. These coef-ficients are determined numerically with high accuracy via appropriate truncation of the systems of linear algebraic equations. Evaluating the scattered field asymptotically, a far field expression is derived. Some illustrative numerical examples on the monostatic and bistatic radar cross section (RCS) are presented and the far field scattering charac-teristics are discussed. © Journal of electromagnetic waves and applications. All Rights reserved

    Patterns of cervical lymph node metastases in oral tongue squamous cell carcinoma: implications for elective and therapeutic neck dissection

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    Objectives: To determine the patterns of lymph node metastases in oral tongue carcinomas, and examine the implications for elective and therapeutic neck dissection

    Patterns of cervical lymph node metastases in oral tongue squamous cell carcinoma: implications for elective and therapeutic neck dissection

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    Objectives: To determine the patterns of lymph node metastases in oral tongue carcinomas, and examine the implications for elective and therapeutic neck dissection

    Submandibular gland invasion and feasibility of gland-sparing neck dissection in oral cavity carcinoma

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    Objective: This study investigated the incidence and routes of submandibular gland involvement in oral cavity carcinoma to determine the feasibility of submandibular gland sparing neck dissection

    Submandibular gland invasion and feasibility of gland-sparing neck dissection in oral cavity carcinoma

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    Objective: This study investigated the incidence and routes of submandibular gland involvement in oral cavity carcinoma to determine the feasibility of submandibular gland sparing neck dissection
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