559 research outputs found

    High Performance Antenna System in MIMO Configuration for 5G Wireless Communications Over Sub-6 GHz Spectrum

    Get PDF
    This paper presents a high-performance multiple input and multiple output (MIMO) antenna comprising 2 x 2 configuration of radiating elements that is designed for sub-6 GHz applications. The proposed MIMO antenna employs four identical radiating elements. High isolation between the radiating elements and therefore reduced mutual coupling is achieved by spatially arranging the radiating elements in an orthogonal configuration. Also, a novel frequency selective surface (FSS) was employed to increase the gain of the MIMO antenna over a wide bandwidth from 3 to 6 GHz. This was achieved by locating the FSS above the antenna at a certain height. The FSS essentially enhanced the antenna's directivity, reduced back lobe radiation and mutual coupling. The antenna was fabricated on a standard Rogers RT Duroid 5880 dielectric substrate with a 0.8 mm thickness. The overall dimension of the MIMO antenna is 50 x 50 x 12.5 mm(3) and it operates from 3.8 to 6 GHz, which corresponds to a fractional bandwidth of 41%. The proposed MIMO antenna has a measured peak gain of 4.8 dBi and inter radiation element isolation >20 dB. Its envelope correlation coefficient is <0.1 and diversity gain >9.9 (dB). These characteristics make the proposed MIMO antenna system suitable for 5G communication systems

    Frequency beam steering antenna for millimeter wave checkpoint scanners

    Full text link

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

    Get PDF
    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Sex-specific disruption of murine midbrain astrocytic and dopaminergic developmental trajectories following antenatal GC treatment

    Get PDF
    The mammalian midbrain dopaminergic systems arising in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) are critical for coping behaviours and are implicated in neuropsychiatric disorders where early life challenges comprise significant risk factors. Here, we aimed to advance our hypothesis that glucocorticoids (GCs), recognised key players in neurobiological programming, target development within these systems, with a novel focus on the astrocytic population. Mice received antenatal GC treatment (AGT) by including the synthetic GC, dexamethasone, in the mothers' drinking water on gestational days 16-19; controls received normal drinking water. Analyses of regional shapes and volumes of the adult SNc and VTA demonstrated that AGT induced long-term, dose-dependent, structural changes that were accompanied by profound effects on astrocytes (doubling/tripling of numbers and/or density). Additionally, AGT induced long-term changes in the population size and distribution of SNc/VTA dopaminergic neurons, confirming and extending our previous observations made in rats. Furthermore, glial/neuronal structural remodelling was sexually dimorphic and depended on the AGT dose and sub-region of the SNc/VTA. Investigations within the neonatal brain revealed that these long-term organisational effects of AGT depend, at least in part, on targeting perinatal processes that determine astrocyte density and programmed cell death in dopaminergic neurons. Collectively, our characterisation of enduring, AGT-induced, sex-specific cytoarchitectural disturbances suggests novel mechanistic links for the strong association between early environmental challenge (inappropriate exposure to excess GCs) and vulnerability to developing aberrant behaviours in later life, with translational implications for dopamine-associated disorders (such as schizophrenia, ADHD, autism, depression), which typically show a sex bia

    Antenatal glucocorticoid treatment induces adaptations in adult midbrain dopamine neurons, which underpin sexually dimorphic behavioral resilience

    Get PDF
    We demonstrated previously that antenatal glucocorticoid treatment (AGT, gestational days 16-19) altered the size and organization of the adult rat midbrain dopaminergic (DA) populations. Here we investigated the consequences of these AGT-induced cytoarchitectural disturbances on indices of DA function in adult rats. We show that in adulthood, enrichment of striatal DA fiber density paralleled AGT-induced increases in the numbers of midbrain DA neurons, which retained normal basal electrophysiological properties. This was co-incident with changes in (i) striatal D2-type receptor levels (increased, both sexes); (ii) D1-type receptor levels (males decreased; females increased); (iii) DA transporter levels (males increased; females decreased) in striatal regions; and (iv) amphetamine-induced mesolimbic DA release (males increased; females decreased). However, despite these profound, sexually dimorphic changes in markers of DA neurotransmission, in-utero glucocorticoid overexposure had a modest or no effect on a range of conditioned and unconditioned appetitive behaviors known to depend on mesolimbic DA activity. These findings provide empirical evidence for enduring AGT-induced adaptive mechanisms within the midbrain DA circuitry, which preserve some, but not all, functions, thereby casting further light on the vulnerability of these systems to environmental perturbations. Furthermore, they demonstrate these effects are achieved by different, often opponent, adaptive mechanisms in males and females, with translational implications for sex biases commonly found in midbrain DA-associated disorders

    Not Quite Right: Representations of Eastern Europeans in ECJ Discourse

    Get PDF
    Although the increasing responsiveness of the Court of Justice of the European Union (the ‘ECJ’) jurisprudence to western Member States’ concerns regarding Central and Eastern European (‘CEE’) nationals’ mobility has garnered academic attention, ECJ discourse has not been scrutinised for how it approaches the CEE region or CEE movers. Applying postcolonial theory, this article seeks to fill this gap and to explore whether there are any indications that ECJ discourse is in line with the historical western-centric inferiorisation of the CEE region. A critical discourse analysis of a set of ECJ judgments and corresponding Advocate General opinions pertaining to CEE nationals illustrates not only how the ECJ adopts numerous discursive strategies to maintain its authority, but also how it tends to prioritise values of the western Member States, while overlooking interests of CEE movers. Its one-sided approach is further reinforced by referring to irrelevant facts and negative assumptions to create an image of CEE nationals as socially and economically inferior to westerners, as not belonging to the proper EU polity and as not quite deserving of EU law’s protections. By silencing CEE nationals’ voices, while disregarding the background of east/west socio-economic and political power differentials and precariousness experienced by many CEE workers in the west, such racialising discourse normalises ethnicity- and class-based stereotypes. These findings also help to contextualise both EU and western policies targeting CEE movers and evidence of their unequal outcomes in the west, and are in line with today’s nuanced expressions of racisms. By illustrating the ECJ’s role in addressing values pertinent to mobile CEE individuals, this study facilitates a fuller appreciation of the ECJ’s power in shaping and reflecting western-centric EU identity and policies. Engaging with such issues will not only allow us to better appreciate—and question—the ECJ’s legitimacy, but might also facilitate a better understanding of power dynamics within the EU. This study also makes significant theoretical and methodological contributions. It expands (and complicates) the application of postcolonial theory to contemporary intra-EU processes, while illustrating the usefulness of applying critical discourse analysis to exploring differentiation, exclusion, subordination and power within legal language

    Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev

    Get PDF
    Peer reviewe

    Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

    Get PDF
    Peer reviewe
    corecore