47 research outputs found

    Different copies of SENSITIVITY TO RED LIGHT REDUCED 1 show strong subfunctionalization in Brassica napus

    Get PDF
    Schiessl S, Williams N, Specht P, Staiger D, Johansson M. Different copies of SENSITIVITY TO RED LIGHT REDUCED 1 show strong subfunctionalization in Brassica napus. BMC Plant Biology. 2019;2019(19): 372.#### Background Correct timing of flowering is critical for plants to produce enough viable offspring. In Arabidopsis thaliana (Arabidopsis), flowering time is regulated by an intricate network of molecular signaling pathways. Arabidopsis srr1–1 mutants lacking SENSITIVITY TO RED LIGHT REDUCED 1 (SRR1) expression flower early, particularly under short day (SD) conditions (1). SRR1 ensures that plants do not flower prematurely in such non-inductive conditions by controlling repression of the key florigen FT. Here, we have examined the role of SRR1 in the closely related crop species Brassica napus. #### Results Arabidopsis SRR1 has five homologs in Brassica napus. They can be divided into two groups, where the A02 and C02 copies show high similarity to AtSRR1 on the protein level. The other group, including the A03, A10 and C09 copies all carry a larger deletion in the amino acid sequence. Three of the homologs are expressed at detectable levels: A02, C02 and C09. Notably, the gene copies show a differential expression pattern between spring and winter type accessions of B. napus. When the three expressed gene copies were introduced into the srr1–1 background, only A02 and C02 were able to complement the srr1–1 early flowering phenotype, while C09 could not. Transcriptional analysis of known SRR1 targets in Bna.SRR1-transformed lines showed that CYCLING DOF FACTOR 1 (CDF1) expression is key for flowering time control via SRR1. #### Conclusions We observed subfunctionalization of the B. napus SRR1 gene copies, with differential expression between early and late flowering accessions of some Bna.SRR1 copies. This suggests involvement of Bna.SRR1 in regulation of seasonal flowering in B. napus. The C09 gene copy was unable to complement srr1–1 plants, but is highly expressed in B. napus, suggesting specialization of a particular function. Furthermore, the C09 protein carries a deletion which may pinpoint a key region of the SRR1 protein potentially important for its molecular function. This is important evidence of functional domain annotation in the highly conserved but unique SRR1 amino acid sequence

    A systematic review and an individual patient data meta-analysis of ivermectin use in children weighing less than fifteen kilograms: Is it time to reconsider the current contraindication?

    Get PDF
    BACKGROUND: Oral ivermectin is a safe broad spectrum anthelminthic used for treating several neglected tropical diseases (NTDs). Currently, ivermectin use is contraindicated in children weighing less than 15 kg, restricting access to this drug for the treatment of NTDs. Here we provide an updated systematic review of the literature and we conducted an individual-level patient data (IPD) meta-analysis describing the safety of ivermectin in children weighing less than 15 kg. METHODOLOGY/PRINCIPAL FINDINGS: A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for IPD guidelines by searching MEDLINE via PubMed, Web of Science, Ovid Embase, LILACS, Cochrane Database of Systematic Reviews, TOXLINE for all clinical trials, case series, case reports, and database entries for reports on the use of ivermectin in children weighing less than 15 kg that were published between 1 January 1980 to 25 October 2019. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017056515. A total of 3,730 publications were identified, 97 were selected for potential inclusion, but only 17 sources describing 15 studies met the minimum criteria which consisted of known weights of children less than 15 kg linked to possible adverse events, and provided comprehensive IPD. A total of 1,088 children weighing less than 15 kg were administered oral ivermectin for one of the following indications: scabies, mass drug administration for scabies control, crusted scabies, cutaneous larva migrans, myiasis, pthiriasis, strongyloidiasis, trichuriasis, and parasitic disease of unknown origin. Overall a total of 1.4% (15/1,088) of children experienced 18 adverse events all of which were mild and self-limiting. No serious adverse events were reported. CONCLUSIONS/SIGNIFICANCE: Existing limited data suggest that oral ivermectin in children weighing less than 15 kilograms is safe. Data from well-designed clinical trials are needed to provide further assurance

    Kepler K2 Campaign 9: II. First space-based discovery of an exoplanet using microlensing

    Get PDF
    We report on the discovery of a bound exoplanetary microlensing event from a blind search of data gathered from Campaign 9 of the Kepler K2 mission (K2C9). K2-2016-BLG-0005Lb is a densely sampled, binary caustic-crossing microlensing event with caustic entry and exit points that are resolved in the K2C9 data, enabling the lens-source relative proper motion to be measured. We have fitted a binary microlens model to the K2 dataset, and to simultaneous observations from the Optical Gravitational Lensing Experiment (OGLE-IV), Canada-France-Hawaii Telescope (CFHT), Microlensing Observations in Astrophysics (MOA-2), the Korean Microlensing Telescope Network (KMTNet), and the United Kingdom InfraRed Telescope (UKIRT). Whilst the ground-based data only sparsely sample the binary caustic, they provide a clear detection of parallax that allows us to break completely the microlensing mass-position-velocity degeneracy and measure the planet's mass directly. We find a host mass of 0.58±0.03 M⊙0.58\pm0.03 ~{\rm M}_\odot and a planetary mass of 1.1±0.1 MJ1.1 \pm 0.1 ~{\rm M_J}. The system lies at a distance of 5.2±0.2 5.2 \pm 0.2~kpc from Earth towards the Galactic bulge. The projected physical separation of the planet from its host is found to be 4.2±0.3 4.2 \pm 0.3~au which, for circular orbits, corresponds to a=4.4−0.4+1.9 a = 4.4^{+1.9}_{-0.4}~au and period P=13−2+9 P = 13^{+9}_{-2}~yr, making K2-2016-BLG-0005Lb a close Jupiter analogue. Though previous exoplanet microlensing events have included space-based data, this event is the first bound microlensing exoplanet to be discovered from space-based data. Even through a space telescope not designed for microlensing studies, this result highlights the advantages for exoplanet microlensing discovery that come from continuous, high-cadence temporal sampling that is possible from space. (Abridged).Comment: 17 pages. Submitted to MNRA

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

    Get PDF
    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Differential regulation of glycinergic and GABAergic nanocolumns at mixed inhibitory synapses

    No full text
    International audienceSuper-resolution imaging has revealed that key synaptic proteins are dynamically organized within sub-synaptic domains (SSDs). To examine how different inhibitory receptors are regulated, we carried out dual-color direct stochastic optical reconstruction microscopy (dSTORM) of GlyRs and GABAA Rs at mixed inhibitory synapses in spinal cord neurons. We show that endogenous GlyRs and GABAA Rs as well as their common scaffold protein gephyrin form SSDs that align with pre-synaptic RIM1/2, thus creating trans-synaptic nanocolumns. Strikingly, GlyRs and GABAA Rs occupy different sub-synaptic spaces, exhibiting only a partial overlap at mixed inhibitory synapses. When network activity is increased by 4-aminopyridine treatment, the GABAA R copy numbers and the number of GABAA R SSDs are reduced, while GlyRs remain largely unchanged. This differential regulation is likely the result of changes in gephyrin phosphorylation that preferentially occurs outside of SSDs. The activity-dependent regulation of GABAA Rs versus GlyRs suggests that different signaling pathways control the receptors' sub-synaptic clustering. Taken together, our data reinforce the notion that the precise sub-synaptic organization of GlyRs, GABAA Rs, and gephyrin has functional consequences for the plasticity of mixed inhibitory synapses.L'imagerie à super-résolution a révélé que les protéines synaptiques clés sont organisées dynamiquement au sein de domaines sous-synaptiques (SSD). Pour examiner comment différents récepteurs inhibiteurs sont régulés, nous avons effectué une microscopie de reconstruction optique stochastique directe bicolore (dSTORM) de GlyRs et GABAA Rs au niveau de synapses inhibitrices mixtes dans les neurones de la moelle épiniÚre. Nous montrons que les GlyR et GABAA endogÚnes ainsi que leur protéine d'échafaudage commune, la géphyrine, forment des SSD qui s'alignent avec le RIM1/2 pré-synaptique, créant ainsi des nanocolonnes trans-synaptiques. De maniÚre frappante, les GlyR et les GABAA R occupent différents espaces sous-synaptiques, ne présentant qu'un chevauchement partiel au niveau des synapses inhibitrices mixtes. Lorsque l'activité du réseau est augmentée par un traitement à la 4-aminopyridine, le nombre de copies GABAA R et le nombre de SSD GABAA R sont réduits, tandis que les GlyR restent largement inchangés. Cette régulation différentielle est probablement le résultat de changements dans la phosphorylation de la géphyrine qui se produisent préférentiellement en dehors des SSD. La régulation dépendante de l'activité des GABAA Rs par rapport aux GlyRs suggÚre que différentes voies de signalisation contrÎlent le regroupement sous-synaptique des récepteurs. Pris ensemble, nos données renforcent l'idée que l'organisation sous-synaptique précise des GlyR, des GABAA R et de la géphyrine a des conséquences fonctionnelles sur la plasticité des synapses inhibitrices mixtes

    Designing mobile inquiry-based learning activities: Learners’ agency and technological affordances

    No full text
    Recent discourse and research studies on mobile learning showed increasing awareness of the complexity of mobile learning in the digital age. Notwithstanding mobile devices, Web 2.0 and Web 3.0 technologies have greatly empowered learners and educators to overcome the constraints of conventional education, such as time, space, location and to learn on the move. However, balancing technological dependency and learner autonomy remains an area of contention in designing meaningful mobile learning activities. Hence, this interactive and participatory workshop aims to bring together researchers and practitioners working on this issue to share their experience and to engage in facilitated activities and discussions on designing mobile learning activities that effectively balance learners’ agency with mobile technology. Additionally, this workshop also provides a platform for unsolved challenges and future research directions on smart technology and smart learning spaces in the context of mobile learning, laying the groundwork for joint research efforts.</p

    Structure of Yttria Stabilized Zirconia Beads Produced by Gel Supported Precipitation

    No full text
    Yttria stabilized zirconia (YSZ) is one of the inert matrix candidates selected for investigation as host matrix for minor actinide (MA) transmutation. The structural properties of (Zr0.84, Y0.16)O1.92 beads prepared by a sol–gel method for MA infiltration, are characterized as calcined (850 C) and sintered (1,600 C) beads. The calcined YSZ beads are finegrained and homogenous over the entire sphere and are surrounded by a uniform outer layer of approximately 30 lm thickness. After sintering at 1,600 C, the beads are compacted to 51% of their initial volume and exhibit a granular structure. The thermal expansion is nearly linear for the calcined material, but shows a parabolic behavior for the sintered (1,400 C) beads. In addition, the thermal expansion of calcined material is 20–25% less than after sintering. During heating up to 1,400 C, two processes can be distinguished. The first occurs between 900 and 1,000 C and is related to an increase in unit cell order. The second process involves grain-growth of the less crystalline calcined material between 1,100 and 1,300 C. These results have implications for preparation of YSZ and its use as an inert MA transmutation matix.JRC.E.4-Nuclear fuel
    corecore