4,367 research outputs found

    In vitro Cortical Network Firing is Homeostatically Regulated: A Model for Sleep Regulation.

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    Prolonged wakefulness leads to a homeostatic response manifested in increased amplitude and number of electroencephalogram (EEG) slow waves during recovery sleep. Cortical networks show a slow oscillation when the excitatory inputs are reduced (during slow wave sleep, anesthesia), or absent (in vitro preparations). It was recently shown that a homeostatic response to electrical stimulation can be induced in cortical cultures. Here we used cortical cultures grown on microelectrode arrays and stimulated them with a cocktail of waking neuromodulators. We found that recovery from stimulation resulted in a dose-dependent homeostatic response. Specifically, the inter-burst intervals decreased, the burst duration increased, the network showed higher cross-correlation and strong phasic synchronized burst activity. Spectral power below <1.75 Hz significantly increased and the increase was related to steeper slopes of bursts. Computer simulation suggested that a small number of clustered neurons could potently drive the behavior of the network both at baseline and during recovery. Thus, this in vitro model appears valuable for dissecting network mechanisms of sleep homeostasis

    Aqua­{6,6′-dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato}(4-hydroxy­benzoato)manganese(III)

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    The title compound, [Mn(C18H18N2O4)(C7H5O3)(H2O)], was synthesized by a template reaction of ethane-1,2-diamine and 3-methoxy­salicylaldehyde in presence of manganese(II) 4-hydroxy­benzoate. The Jahn–Teller-distorted manganese(III) centre has an octa­hedral geometry. Extensive O—H⋯O hydrogen-bonding inter­actions generate a two-dimensional sheet structure parallel to (103)

    Microwave Acid Leaching of Beneficiated Ilmenite for the Production of Synthetic Rutile

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    Beneficiated ilmenite is an intermediate product formed by the aqueous rusting of metallised ilmenite and separation of iron oxide. This product enriched with TiO2 by the removal of metallic iron can further be upgraded by subs-equent removal of residual iron by acid leaching for the production of synthetic rutile which is a preferred tita-nium feedstock for the preparation of TiO2 pigment

    Breaking down the language of racism:a computerised linguistic analysis of racist groups’ self-defining online statements

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    The Internet represents a powerful tool for racist groups to build a sense of group consciousness and promote their cause. In the current study, we examined the language used by racist (n = 87), anti-racist (n = 50), and nonactivist (n = 1379) groups when describing their self-defining beliefs online. We used computerized linguistic analysis software to measure psychological indicators and antecedents of group consciousness and to examine the persuasive techniques used in online group communication. Racist and anti-racist groups were similar on some linguistic indicators of group consciousness (e.g., use of words reflecting perceived injustice), but differed on others (e.g., use of words reflecting group identification). Linguistic indicators of antecedents of group consciousness (moral foundations and focus on religion) differed across groups, with racist groups focused more on purity, respect for authority, and religion, and less on fairness than anti-racist groups. Racist groups also used less cognitively complex language than nonactivist groups (but similar levels to anti-racist groups). Our results contribute to understanding how racist groups promote their self-defining beliefs online, and identify several key factors that should be considered when designing policies to reduce racist groups' growth and impact

    Test of the photon detection system for the LHCb RICH Upgrade in a charged particle beam

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    The LHCb detector will be upgraded to make more efficient use of the available luminosity at the LHC in Run III and extend its potential for discovery. The Ring Imaging Cherenkov detectors are key components of the LHCb detector for particle identification. In this paper we describe the setup and the results of tests in a charged particle beam, carried out to assess prototypes of the upgraded opto-electronic chain from the Multi-Anode PMT photosensor to the readout and data acquisition system.Comment: 25 pages, 22 figure

    In vitro efficacy of Metarhizium anisopliae sensu lato against unfed Amblyomma parvum (Acari: Ixodidae).

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    Amblyomma parvum Aragão (Acari: Ixodidae) is a tick species found with wide distribution in the Neotropical region. Even though it is a wildlife-related tick, it is also a frequent parasite of domestic animals, is aggressive to human beings and may harbor pathogenic microorganisms. Therefore, it is a target species for control on domestic animals, particularly those at the rural?wildlife interface. Herein, the efficacy of two isolates (E9 and IBCB 425) of an entomopathogenic fungus, Metarhizium anisopliae sensu lato, already evaluated for ticks that parasitize domestic animals, was tested against unfed A. parvum adults. Both isolates displayed high acaricidal efficacy after immersion in fungal conidial suspensions for 5 min. Isolate E9 killed all ticks by the 7th day post-treatment, and isolate IBCB 425 did so by the 11th day. Tick mortality of 80 and 90% was achieved as early as the 3rd and 4th days, respectively, with both treatments. Thus, if a commercial M. anisopliae s.l. acaricide against domestic animal ticks is developed, it would also be effective against A. parvum

    The Effect of Varied Doses of Nicotine on Some Morphometric Parameters of the Testis in Albino Wistar Rats

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    Background: This study is aimed at determining the effect of nicotine on male fertility by evaluating some morphometric parameters of male Wistar rat such as testicular weight, seminiferous tubule diameter, height of epithelium, sertoli-germ cell ratio and Johnsen’s score  in order to assess the spermatogic  index. Methods: 20 adult male rats were randomly divided into four groups, the test groups were administered with 0.2mg/100g, 0.4/100g and 0.6/100g body weight of nicotine base daily for 30 days using a polythene catheter orally , while the control were administered with 2mls 0.9%physiological saline. Histological slides of the testis were made and data obtained from the slides. Results: nicotine caused a significant reduction (P < 0.05) and (P< 0.01) in the mean values of the morphometric parameters of the test group compared with control. The Johnsen’s Score results were 5.4 ± 0.51*, 5.2 ± 0.37* for groups 2 and 3 respectively. For seminiferous tubule diameter the significant values were 208.0±4.22**, 184.5±11.31**in groups 2 and 3, whilst the height of epithelium showed a significant reduction of 153.9± 13.58*, 101.6 ± 1.35**, 76.6 ± 6.65** for groups 1, 2 and 3 respectively. Sertoli-germ cell ratio showed a significant reduction in groups 2 and 3 with values of 3.6 ± 0.77 ** , 1.5 ±  0.16**for groups 2, and 3 respectively, testicular weight showed significant reduction of 1.2±0.05**,1.1±0.05** for group 2 and 3.The results stated are only those that showed a significant reduction at 95% confidence level when compared with the control. Conclusion:  It was concluded that nicotine exerted an adverse effects on the spermatogenic index with concomitant reduction in reproductive potentials of the male rat. Nicotine and nicotine- based products should therefore be taken with caution in cases of infertility in man and animal. Key words: Morphometric parameters ,Johnsen’s Score,Spermatogenic index , fertilit

    10 ps timing with highly irradiated 3D trench silicon pixel sensors

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    In this paper the results of a beam test characterization campaign of 3D trench silicon pixel sensors are presented. A time resolution in the order of 10 ps was measured both for non-irradiated and irradiated sensors up to a fluence of 2.510161MeVneqcm22.5 \cdot 10^{16}\,1\,MeV\, n_{eq}\,cm^{-2}. This feature and a detection efficiency close to 99%99\% make this sensors one of the best candidates for 4D tracking detectors in High-Energy-Physics experiments.Comment: Prepared for submission to JINST, IWORID 202
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