541 research outputs found
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death
Intracellular Calcium Deficits in Drosophila Cholinergic Neurons Expressing Wild Type or FAD-Mutant Presenilin
Much of our current understanding about neurodegenerative diseases can be attributed to the study of inherited forms of these disorders. For example, mutations in the presenilin 1 and 2 genes have been linked to early onset familial forms of Alzheimer's disease (FAD). Using the Drosophila central nervous system as a model we have investigated the role of presenilin in one of the earliest cellular defects associated with Alzheimer's disease, intracellular calcium deregulation. We show that expression of either wild type or FAD-mutant presenilin in Drosophila CNS neurons has no impact on resting calcium levels but does give rise to deficits in intracellular calcium stores. Furthermore, we show that a loss-of-function mutation in calmodulin, a key regulator of intracellular calcium, can suppress presenilin-induced deficits in calcium stores. Our data support a model whereby presenilin plays a role in regulating intracellular calcium stores and demonstrate that Drosophila can be used to study the link between presenilin and calcium deregulation
Pervasiveness of Parasites in Pollinators
Many pollinator populations are declining, with large economic and ecological
implications. Parasites are known to be an important factor in the some of the
population declines of honey bees and bumblebees, but little is known about the
parasites afflicting most other pollinators, or the extent of interspecific
transmission or vectoring of parasites. Here we carry out a preliminary
screening of pollinators (honey bees, five species of bumblebee, three species
of wasp, four species of hoverfly and three genera of other bees) in the UK for
parasites. We used molecular methods to screen for six honey bee viruses,
Ascosphaera fungi, Microsporidia, and
Wolbachia intracellular bacteria. We aimed simply to detect
the presence of the parasites, encompassing vectoring as well as actual
infections. Many pollinators of all types were positive for
Ascosphaera fungi, while Microsporidia were rarer, being
most frequently found in bumblebees. We also detected that most pollinators were
positive for Wolbachia, most probably indicating infection with
this intracellular symbiont, and raising the possibility that it may be an
important factor in influencing host sex ratios or fitness in a diversity of
pollinators. Importantly, we found that about a third of bumblebees
(Bombus pascuorum and Bombus terrestris)
and a third of wasps (Vespula vulgaris), as well as all honey
bees, were positive for deformed wing virus, but that this virus was not present
in other pollinators. Deformed wing virus therefore does not appear to be a
general parasite of pollinators, but does interact significantly with at least
three species of bumblebee and wasp. Further work is needed to establish the
identity of some of the parasites, their spatiotemporal variation, and whether
they are infecting the various pollinator species or being vectored. However,
these results provide a first insight into the diversity, and potential
exchange, of parasites in pollinator communities
Cancer metabolism: current perspectives and future directions
Cellular metabolism influences life and death decisions. An emerging theme in cancer biology is that metabolic regulation is intricately linked to cancer progression. In part, this is due to the fact that proliferation is tightly regulated by availability of nutrients. Mitogenic signals promote nutrient uptake and synthesis of DNA, RNA, proteins and lipids. Therefore, it seems straight-forward that oncogenes, that often promote proliferation, also promote metabolic changes. In this review we summarize our current understanding of how ‘metabolic transformation' is linked to oncogenic transformation, and why inhibition of metabolism may prove a cancer′s ‘Achilles' heel'. On one hand, mutation of metabolic enzymes and metabolic stress sensors confers synthetic lethality with inhibitors of metabolism. On the other hand, hyperactivation of oncogenic pathways makes tumors more susceptible to metabolic inhibition. Conversely, an adequate nutrient supply and active metabolism regulates Bcl-2 family proteins and inhibits susceptibility to apoptosis. Here, we provide an overview of the metabolic pathways that represent anti-cancer targets and the cell death pathways engaged by metabolic inhibitors. Additionally, we will detail the similarities between metabolism of cancer cells and metabolism of proliferating cells
Shedding light on local kinase activation
Phosphorylation is the predominant language of cell signaling. And, as with any common language, an abundance of dialects has evolved to convey complex information. We discuss here how biosensors are being used to decode this language, affording an unprecedented glimpse into spatio-temporal patterns of protein phosphorylation events within the cell
PALB2, CHEK2 and ATM rare variants and cancer risk: data from COGS
Background: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study.Methods: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant.Results: For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p=7.1×10−5), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p=6.9×10−8) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p≤0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p=0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p=0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants.Conclusions: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important.</p
Integrable microwave filter based on a photonic crystal delay line
The availability of a tunable delay line with a chip-size footprint is a crucial step towards the full implementation of integrated microwave photonic signal processors. Achieving a large and tunable group delay on a millimetre-sized chip is not trivial. Slow light concepts are an appropriate solution, if propagation losses are kept acceptable. Here we use a low-loss 1.5 mm-long photonic crystal waveguide to demonstrate both notch and band-pass microwave filters that can be tuned over the 0 50-GHz spectral band. The waveguide is capable of generating a controllable delay with limited signal attenuation (total insertion loss below 10 dB when the delay is below 70 ps) and degradation. Owing to the very small footprint of the delay line, a fully integrated device is feasible, also featuring more complex and elaborate filter functions.This work was funded by the European Union under the project GOSPEL (grant 219299) and by the Valencian Government (Prometeo GVA 2008-92). We thank S. Hughes and P. Lalanne for enlightening discussion about the impact of disorder in photonic crystal waveguides.Sancho Durá, J.; Bourderionnet, J.; Lloret Soler, JA.; Combrie, S.; Gasulla Mestre, I.; Xavier, S.; Sales Maicas, S.... (2012). Integrable microwave filter based on a photonic crystal delay line. Nature Communications. 3:1-9. https://doi.org/10.1038/ncomms2092S193Seeds, A. Microwave photonics. IEEE Trans. Microwave Theory Tech. 50, 877–887 (2002).Capmany, J. & Novak, D. Microwave photonics combines two worlds. Nat. Photon 1, 319–330 (2007).Yao, J. P. Microwave photonics. J. Lightwave Technol. 27, 314–335 (2009).See special technology focus on microwave photonics. Nat. Photon 5, 723–736 (2011).Capmany, J., Ortega, B. & Pastor, D. A tutorial on microwave photonic filters. J. Lightwave. Technol. 24, 201–229 (2006).Long, J. et al. A tunable microstrip bandpass filter with two independently adjustable transmission zeros. IEEE Microw. Wireless Compon. Lett. 21, 74–76 (2011).Velez, A. et al. Tunable coplanar waveguide band-stop and band-pass filters based on open split ring resonators and open complementary split ring resonators. IEEE Microw. Antennas Propag. 5, 277–281 (2011).Sekar, V., Armendariz, M. & Entesari, K. A 1.2-1.6-GHz substrate-integrated-waveguide RF MEMS tunable filter. IEEE Trans. Microwave Theory Tech. 59, 866–876 (2011).Rafique, M. R. et al. Miniaturized superconducting microwave filters. Supercond. Sci. Technol. 21, 075004 (2008).Velu, G. et al. A 360° BST phase shifter with moderate bias voltage at 30 GHz. IEEE Trans. Microwave Theory Tech. 55, 438–444 (2007).Koh, K. J. & Rebeiz, G. M. A 6-18 GHz active phase shifter. In Proceedings IEEE Microwave Symposium Digest 792–795 (2010).Capmany, J., Pastor, D. & Ortega, B. New and flexible fiber-optic delay-line filters using chirped Bragg gratings and laser arrays. IEEE Trans. Microwave Theory Tech. 47, 1321–1326 (1999).Minasian, R. A. Photonic signal processing of microwave signals. IEEE Trans. Microwave Theory Tech. 54, 832–846 (2006).Dai, Y. & Yao, J. P. Nonuniformly-spaced photonic microwave delay-line filter. Opt. Express 16, 4713–4718 (2008).Hamidi, E., Leaird, D. E. & Weiner, A. M. Tunable programmable microwave photonic filters based on an optical frequency comb. IEEE Trans. Microwave Theory Tech. 58, 3269–3278 (2010).Chan, E. H. W. & Minasian, R. A. Coherence-free high-resolution RF/microwave photonic bandpass filter with high skirt selectivity and high stopband attenuation. J. Lightwave Technol. 28, 1646–1651 (2010).Norberg, E. J. et al. Programmable photonic microwave filters monolithically integrated in InPinGaAsP. J. Lightwave. Technol. 29, 1611–1619 (2011).Chen, H. W. et al. Integrated microwave photonic filter on a hybrid silicon platform. IEEE Trans. Microwave Theory Tech. 58, 3213–3219 (2010).Dong, P. et al. GHz-bandwidth optical filters based on high-order silicon ring resonators. Opt. Express 18, 23784–23789 (2010).Lloret, J. et al. Tunable complex-valued multi-tap microwave photonic filter based on single silicon-on-insulator microring resonator. Opt. Express 19, 12402–12407 (2011).Notomi, M. et al. Extremely large group-velocity dispersion of line-defect waveguides in photonic crystal slabs. Phys. Rev. Lett. 87, 253902 (2001).Knight, J. C. Photonic crystal fibres. Nature 424, 847–851 (2003).Supradeepa, V. R. et al. Comb-based radiofrequency photonic filters with rapid tunability and high selectivity. Nat. Photon. 6, 186–194 (2012).Capmany, J., Ortega, B., Pastor, D. & Sales, S. Discrete-time optical processing of microwave signals. J. Lightwave Technol. 23, 702–723 (2005).Hunter, D. B. & Minasian, R. A Tunable microwave fiber-optic bandpass filters. IEEE Photon. Tech. Lett. 11, 874–876 (1999).Baba, T. Slow light in photonic crystals. Nat. Photon. 2, 465–473 (2008).Kuramochi, E. et al. Disorder-induced scattering loss of line-defect waveguides in photonic crystal slabs. Phys. Rev B 72, 161318 (2005).Ishikura, N., Baba, T., Kuramochi, E. & Notomi, M. Large tunable fractional delay of slow light pulse and its application to fast optical correlator. Opt. Express 19, 24102–24108 (2011).O'Faolain, L. et al. Loss engineered slow light waveguides. Opt. Express 18, 27627–27638 (2010).Baron, A., Mazoyer, S., Smigaj, W. & Lalanne, P. Attenuation Coefficient of Single-Mode Periodic Waveguides. Phys. Rev. Lett. 107, 153901 (2011).Patterson, M. et al. Disorder-Induced Coherent Scattering in Slow-Light Photonic Crystal Waveguides. Phys. Rev. Lett. 102, 253903 (2009).Mazoyer, S., Hugonin, J. P. & Lalanne, P. Disorder-Induced Multiple Scattering in Photonic-Crystal Waveguides. Phys. Rev. Lett. 103, 063903 (2009).Combrié, S. et al. Time-delay measurement in singlemode, low-loss photonic crystal waveguides. Electron. Lett. 42, 86–87 (2006).Liang, J. et al. Wideband ultraflat slow light with large group index in a W1 photonic crystal waveguide. J. App. Phys. 110, 063103 (2011).Roy, S. Modeling the dispersion of the nonlinearity in slow mode photonic crystal waveguides. IEEE Photonics. Journal 4, 224–233 (2012).Colman, P., Combrié, S. & De Rossi, A. Control of dispersion in photonic crystal waveguides using group symmetry theory. Opt. Express 20, 13108–13114 (2012).Vy Tran, Q., Combrié, S., Colman, P. & De Rossi, A. Photonic crystal membrane waveguides with low insertion losses. Appl. Phys. Lett. 95, 061105 (2009).Bolea, M., Mora, J., Ortega, B. & Capmany, J. Highly chirped single-bandpass microwave photonic filter with reconfiguration capabilities. Opt. Express 19, 4566–4576 (2011).Binetti, P. et al. Indium phosphide integrated circuits for coherent optical links. IEEE J. Quantum Electron. 48, 279–291 (2012).Thomson, D. J. et al. High contrast 40Gbit/s optical modulation in silicon. Opt. Express 19, 11507–11516 (2011).Asghari, M. & Krishnamoorthy, A. V. Energy efficient communication. Nat. Photon. 5, 268–270 (2011).Vivien, L. et al. Zero-bias 40Gbit/s germanium waveguide photodetector on silicon. Opt. Express 20, 1096–1101 (2012).Feng, N. N. et al. 30GHz Ge electro-absorption modulator integrated with 3 μm silicon-on-insulator waveguide. Opt. Express 19, 7062–7067 (2011).Trinh, P. D., Yegnanarayanan, S., Coppinger, F. & Jalali, B. Compact multimode interference couplers in Silicon-on-insulator technology. Conference on Lasers and Electro-Optics CLEO '97CThV4, 441 (Baltimore, USA, 1997).Loayssa, A., Capmany, J., Sagues, M. & Mora, J. Demonstration of incoherent microwave photonic filters with all-optical complex coefficients. IEEE Photon. Tech. Lett. 18, 1744–1746 (2006).Zhang, W. & Minasian, R. A. Widely tunable single-passband microwave photonic filter based on stimulated Brillouin scattering. IEEE Photon. Tech. Lett. 23, 1775–1777 (2011).Xue, W., Sales, S., Mork, J. & Capmany, J. Widely tunable microwave photonic notch filter based on slow and fast light effects. IEEE Photon. Tech. Lett. 21, 167–169 (2009).Norberg, E. J. et al. A monolithic programmable optical filter for RF signal processing. in Proceedings Microwave Photonics Conf. (Montreal, Canada, 2010).Vlasov, Y. A., O'Boyle, M., Hamann, H. F. & McNab, S. J. Active control of slow light on a chip with photonic crystal waveguides. Nature 438, 65–69 (2005).Eckhouse, V. et al. Highly efficient four wave mixing in GaInP photonic crystal waveguides. Opt. Lett. 35, 1440–1442 (2010).Sagues, M. et al. Multi-tap complex-coefficient incoherent microwave photonic filters based on optical single-sideband modulation and narrow band optical filtering. Opt. Express 16, 295–303 (2008).Huang, T. X. H., Yi, X. & Minasian, R. A. Single passband microwave photonic filter using continuous-time impulse response. Opt. Express 19, 6231–6242 (2011).Burla, M. et al. On-chip CMOS compatible reconfigurable optical delay line with separate carrier tuning for microwave photonic signal processing. Opt. Express 19, 21475–21484 (2011)
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector
This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations
- …