410 research outputs found

    High-Q Si3N4 Ring Resonators for Locking 780nm GaAs-Based Distributed Feedback Laser

    Get PDF
    High-Q microring resonators have applications in gyroscopes, frequency comb generation, and feedback systems to control narrow linewidth integrated lasers [1–3]. This paper demonstrates the highest Q values measured for microring resonators at 780 nm wavelength. These sub mm integrated cavities can be used to provide an error signal for locking a distributed feedback laser (DFB), Fig. 1(a), using the Pound-Drever-Hall (PDH) method. High stability DFBs can also be achieved using a micro-electro-mechanical system (MEMS) cell containing 87 Rb vapour and taking advantage of the absorption line at 780.24 nm. This provides an absolute reference for locking the laser but only to the 87 Rb transition wavelengths. The microring resonator can be tailor made for any wavelength but is susceptible to thermal effects; this could in part be overcome using a top cladding with a thermo-optic coefficient that counteracts that of the waveguide core

    Alum Activates the Bovine NLRP3 Inflammasome

    Get PDF
    peer-reviewedThere has been a move away from vaccines composed of whole or inactivated antigens toward subunit-based vaccines, which although safe, provide less immunological protection. As a result, the use of adjuvants to enhance and direct adaptive immune responses has become the focus of much targeted bovine vaccine research. However, the mechanisms by which adjuvants work to enhance immunological protection in many cases remains unclear, although this knowledge is critical to the rational design of effective next generation vaccines. This study aimed to investigate the mechanisms by which alum, a commonly used adjuvant in bovine vaccines, enhances IL-1β secretion in bovine peripheral blood mononuclear cells (PBMCs). Unlike the case with human PBMCs, alum promoted IL-1β secretion in a subset of bovine PBMCs without priming with a toll-like receptor agonist. This suggests that PBMCs from some cattle are primed to produce this potent inflammatory cytokine and western blotting confirmed the presence of preexisting pro-IL-1β in PBMCs from a subset of 8-month-old cattle. To address the mechanism underlying alum-induced IL-1β secretion, specific inhibitors identified that alum mediates lysosomal disruption which subsequently activates the assembly of an NLRP3, ASC, caspase-1, and potentially caspase-8 containing complex. These components form an inflammasome, which mediates alum-induced IL-1β secretion in bovine PBMCs. Given the demonstrated role of the NLRP3 inflammasome in regulating adaptive immunity in murine systems, these results will inform further targeted research into the potential of inflammasome activation for rational vaccine design in cattle

    Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way

    Get PDF
    This document is the Accepted Manuscript version of the following article: L. M. Howes, et al, ‘Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way’, Nature, Vol. 527, November 2015. This manuscript version is made available under the Nature Research’s Conditions of Use, http://www.nature.com/authors/policies/license.html#Self_archiving_policy. The final, published version is available online at DOI: http://www.nature.com/doifinder/10.1038/nature15747. © 2015 Macmillan Publishers Limited. All rights reservedThe first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time. The Milky Way bulge underwent a rapid chemical enrichment during the first 1-2 billion years, leading to a dearth of early, metal-poor stars. Here we report observations of extremely metal-poor stars in the Milky Way bulge, including one star with an iron abundance about 10,000 times lower than the solar value without noticeable carbon enhancement. We confirm that the most metal-poor bulge stars are on tight orbits around the Galactic Centre, rather than being halo stars passing through the bulge, as expected for stars formed at redshifts greater than 15. Their chemical compositions are in general similar to typical halo stars of the same metallicity although intriguing differences exist, including lower abundances of carbon.Peer reviewedFinal Accepted Versio

    Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) and annotated catalog of the species and subspecies

    Get PDF
    The pelidnotine scarabs (Scarabaeidae: Rutelinae: Rutelini) are a speciose, paraphyletic assemblage of beetles that includes spectacular metallic species (“jewel scarabs”) as well as species that are ecologically important as herbivores, pollinators, and bioindicators. These beetles suffer from a complicated nomenclatural history, due primarily to 20th century taxonomic and nomenclatural errors. We review the taxonomic history of the pelidnotine scarabs, present a provisional key to genera with overviews of all genera, and synthesize a catalog of all taxa with synonyms, distributional data, type specimen information, and 107 images of exemplar species. As a result of our research, the pelidnotine leaf chafers (a paraphyletic group) include 27 (26 extant and 1 extinct) genera and 420 valid species and subspecies (419 extant and 1 extinct). Our research makes biodiversity research on this group tractable and accessible, thus setting the stage for future studies that address evolutionary and ecological trends. Based on our research, 1 new species is described, 1 new generic synonym and 12 new species synonyms are proposed, 11 new lectotypes and 1 new neotype are designated, many new or revised nomenclatural combinations, and many unavailable names are presented. The following taxonomic changes are made: New generic synonym: The genus Heteropelidnota Ohaus, 1912 is a new junior synonym of Pelidnota MacLeay, 1819. New species synonyms: Plusiotis adelaida pavonacea Casey, 1915 is a syn. n. of Chrysina adelaida (Hope, 1841); Odontognathus gounellei Ohaus, 1908 is a revised synonym of Pelidnota ebenina (Blanchard, 1842); Pelidnota francoisgenieri Moore & Jameson, 2013 is a syn. n. of Pelidnota punctata (Linnaeus, 1758); Pelidnota genieri Soula, 2009 is a syn. n. of Pelidnota punctata (Linnaeus, 1758); Pelidnota lutea (Olivier, 1758) is a revised synonym of Pelidnota punctata (Linnaeus, 1758); Pelidnota (Pelidnota) texensis Casey, 1915 is a revised synonym of Pelidnota punctata (Linnaeus, 1758); Pelidnota (Strigidia) zikani (Ohaus, 1922) is a revised synonym of Pelidnota tibialis tibialis Burmeister, 1844; Pelidnota ludovici Ohaus, 1905 is a syn. n. of Pelidnota burmeisteri tricolor Nonfried, 1894; Rutela fulvipennis Germar, 1824 is syn. n. of Pelidnota cuprea (Germar, 1824); Pelidnota pulchella blanda Burmeister, 1844 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819); Pelidnota pulchella scapularis Burmeister, 1844 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819); Pelidnota xanthogramma Perty, 1830 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819). New or revised statuses: Pelidnota fabricelavalettei Soula, 2009, revised status, is considered a species; Pelidnota rioensis Soula, 2009, stat. n., is considered a species; Pelidnota semiaurata semiaurata Burmeister, 1844, stat. rev., is considered a subspecies. New or comb. rev. and revised status: Plusiotis guaymi Curoe, 2001 is formally transferred to the genus Chrysina (C. guaymi (Curoe, 2001), comb. n.); Plusiotis transvolcanica Morón & Nogueira, 2016 is transferred to the genus Chrysina (C. transvolcanica (Morón & Nogueira, 2016), comb. n.). Heteropelidnota kuhnti Ohaus, 1912 is transferred to the genus Pelidnota (P. kuhnti (Ohaus, 1912), comb. n.); Odontognathus riedeli Ohaus, 1905 is considered a subspecies of Pelidnota rubripennis Burmeister, 1844 (Pelidnota rubripennis riedeli (Ohaus, 1905), revised status and comb. rev.); Pelidnota (Strigidia) acutipennis (F. Bates, 1904) is transferred to the genus Sorocha (Sorocha acutipennis (F. Bates, 1904), comb. rev.); Pelidnota (Odontognathus) nadiae Martínez, 1978 is transferred to the genus Sorocha (Sorocha nadiae (Martínez, 1978), comb. rev.); Pelidnota (Ganonota) plicipennis Ohaus, 1934 is transferred to the genus Sorocha (Sorocha plicipennis (Ohaus, 1934), comb. rev.); Pelidnota similis Ohaus, 1908 is transferred to the genus Sorocha (Sorocha similis (Ohaus, 1908), comb. rev.); Pelidnota (Ganonota) yungana Ohaus, 1934 is transferred to Sorocha (Sorocha yungana (Ohaus, 1934), comb. rev.); Pelidnota malyi Soula, 2010: 58, revised status; Xenopelidnota anomala porioni Chalumeau, 1985, revised subspecies status. To stabilize the classification of the group, a neotype is designated for the following species: Pelidnota thiliezi Soula, 2009. Lectotypes are designated for the following names (given in their original combinations): Pelidnota brevicollis Casey, 1915, Pelidnota brevis Casey, 1915, Pelidnota debiliceps Casey, 1915, Pelidnota hudsonica Casey, 1915, Pelidnota oblonga Casey, 1915, Pelidnota pallidipes Casey, 1915, Pelidnota ponderella Casey, 1915, Pelidnota strenua Casey, 1915, Pelidnota tarsalis Casey, 1915, Pelidnota texensis Casey, 1915, and Scarabaeus punctatus Linnaeus, 1758. The following published infrasubspecific names are unavailable per ICZN Article 45.6.1: Pelidnota (Odontognathus) cuprea var. coerulea Ohaus, 1913; Pelidnota (Odontognathus) cuprea var. rufoviolacea Ohaus, 1913; Pelidnota (Odontognathus) cuprea var. nigrocoerulea Ohaus, 1913; Pelidnota pulchella var. fulvopunctata Ohaus, 1913; Pelidnota pulchella var. sellata Ohaus, 1913; Pelidnota pulchella var. reducta Ohaus, 1913; Pelidnota unicolor var. infuscata Ohaus, 1913. The following published species name is unavailable per ICZN Article 11.5: Neopatatra synonyma Moore & Jameson, 2013. The following published species name is unavailable per application of ICZN Article 16.1: Parhoplognathus rubripennis Soula, 2008. Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) 3 The following published species name is unavailable per application of ICZN Article 16.4.1: Strigidia testaceovirens argentinica Soula, 2006, Pelidnota (Strigidia) testaceovirens argentinica (Soula, 2006), and Pelidnota testaceovirens argentinica (Soula, 2006). The following published species names are unavailable per application of ICZN Article 16.4.2: Homonyx digennaroi Soula, 2010; Homonyx lecourti Soula, 2010; Homonyx mulliei Soula, 2010; Homonyx simoensi Soula, 2010; Homonyx wagneri Soula, 2010; Homonyx zovii Demez & Soula, 2011; Pelidnota arnaudi Soula, 2009; Pelidnota brusteli Soula, 2010; Pelidnota chalcothorax septentrionalis Soula, 2009; Pelidnota degallieri Soula, 2010; Pelidnota lavalettei Soula, 2008; Pelidnota lavalettei Soula, 2009; Pelidnota dieteri Soula, 2011; Strigidia gracilis decaensi Soula, 2008, Pelidnota (Strigidia) gracilis decaensi (Soula, 2008), and Pelidnota gracilis decaensi (Soula, 2008); Pelidnota halleri Demez & Soula, 2011; Pelidnota injantepalominoi Demez & Soula, 2011; Pelidnota kucerai Soula, 2009; Pelidnota malyi Soula, 2010: 36-37; Pelidnota mezai Soula, 2009; Pelidnota polita darienensis Soula, 2009; Pelidnota polita orozcoi Soula, 2009; Pelidnota polita pittieri Soula, 2009; Pelidnota punctulata decolombia Soula, 2009; Pelidnota punctulata venezolana Soula, 2009; Pelidnota raingeardi Soula, 2009; Pelidnota schneideri Soula, 2010; Pelidnota simoensi Soula, 2009; Pelidnota unicolor subandina Soula, 2009; Sorocha carloti Demez & Soula, 2011; Sorocha castroi Soula, 2008; Sorocha fravali Soula, 2011; Sorocha jeanmaurettei Demez & Soula, 2011; Sorocha yelamosi Soula, 2011; Xenopelidnota bolivari Soula, 2009; Xenopelidnota pittieri pittieri Soula, 2009. Due to unavailability of the name Pseudogeniates cordobaensis Soula 2009, we describe the species as intentionally new (Pseudogeniates cordobaensis Moore, Jameson, Garner, Audibert, Smith, and Seidel, sp. n.)

    Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

    Get PDF
    Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes

    Multi-messenger observations of a binary neutron star merger

    Get PDF
    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 transient’s 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
    corecore