63 research outputs found
Projecting Climate Dependent Coastal Flood Risk With a Hybrid Statistical Dynamical Model
ABSTRACT: Numerical models for tides, storm surge, and wave runup have demonstrated ability to accurately define spatially varying flood surfaces. However these models are typically too computationally expensive to dynamically simulate the full parameter space of future oceanographic, atmospheric, and hydrologic conditions that will constructively compound in the nearshore to cause both extreme event and nuisance flooding during the 21st century. A surrogate modeling framework of waves, winds, and tides is developed in this study to efficiently predict spatially varying nearshore and estuarine water levels contingent on any combination of offshore forcing conditions. The surrogate models are coupled with a time-dependent stochastic climate emulator that provides efficient downscaling for hypothetical iterations of offshore conditions. Together, the hybrid statistical-dynamical framework can assess present day and future coastal flood risk, including the chronological characteristics of individual flood and wave-induced dune overtopping events and their changes into the future. The framework is demonstrated at Naval Base Coronado in San Diego, CA, utilizing the regional Coastal Storm Modeling System (CoSMoS; composed of Delft3D and XBeach) as the dynamic simulator and Gaussian process regression as the surrogate modeling tool. Validation of the framework uses both in-situ tide gauge observations within San Diego Bay, and a nearshore cross-shore array deployment of pressure sensors in the open beach surf zone. The framework reveals the relative influence of large-scale climate variability on future coastal flood resilience metrics relevant to the management of an open coast artificial berm, as well as the stochastic nature of future total water levels.This work was funded by the Strategic Environmental Research Development Program (DOD/SERDP RC-2644). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. F. J. Mendez, A. Rueda, and L. Cagigal acknowledge the partial funding from the Spanish Ministry of Science and Innovation, project Beach4cast PID2019-107053RB-I00. The authors thank the Scripps Center for Coastal Studies for their efforts to deploy, recover, and process surf zone pressure sensor data used as validation in this study. The authors thank Melisa Menendez for sharing GOW2 hindcast data for Southern California. The authors thank the sea-level rise projection authors for developing and making the sea-level rise projections available, multiple funding agencies for supporting the development of the projections, and the NASA Sea-Level Change Team for developing and hosting the IPCC AR6 Sea-Level Projection Tool
Genetic Interactions with Age, Sex, Body Mass Index, and Hypertension in Relation to Atrial Fibrillation: The AFGen Consortium
It is unclear whether genetic markers interact with risk factors to influence atrial fibrillation (AF) risk. We performed genome-wide interaction analyses between genetic variants and age, sex, hypertension, and body mass index in the AFGen Consortium. Study-specific results were combined using meta-analysis (88,383 individuals of European descent, including 7,292 with AF). Variants with nominal interaction associations in the discovery analysis were tested for association in four independent studies (131,441 individuals, including 5,722 with AF). In the discovery analysis, the AF risk associated with the minor rs6817105 allele (at the PITX2 locus) was greater among subjects ≤ 65 years of age than among those > 65 years (interaction p-value = 4.0 × 10-5). The interaction p-value exceeded genome-wide significance in combined discovery and replication analyses (interaction p-value = 1.7 × 10-8). We observed one genome-wide significant interaction with body mass index and several suggestive interactions with age, sex, and body mass index in the discovery analysis. However, none was replicated in the independent sample. Our findings suggest that the pathogenesis of AF may differ according to age in individuals of European descent, but we did not observe evidence of statistically significant genetic interactions with sex, body mass index, or hypertension on AF risk
Dust in Supernovae and Supernova Remnants I : Formation Scenarios
Supernovae are considered as prime sources of dust in space. Observations of local supernovae over the past couple of decades have detected the presence of dust in supernova ejecta. The reddening of the high redshift quasars also indicate the presence of large masses of dust in early galaxies. Considering the top heavy IMF in the early galaxies, supernovae are assumed to be the major contributor to these large amounts of dust. However, the composition and morphology of dust grains formed in a supernova ejecta is yet to be understood with clarity. Moreover, the dust masses inferred from observations in mid-infrared and submillimeter wavelength regimes differ by two orders of magnitude or more. Therefore, the mechanism responsible for the synthesis of molecules and dust in such environments plays a crucial role in studying the evolution of cosmic dust in galaxies. This review summarises our current knowledge of dust formation in supernova ejecta and tries to quantify the role of supernovae as dust producers in a galaxy.Peer reviewe
The Regulatory Factor ZFHX3 Modifies Circadian Function in SCN via an at Motif-Driven Axis
We identified a dominant missense mutation in the SCN transcription factor Zfhx3, termed short circuit (Zfhx3Sci), which accelerates circadian locomotor rhythms in mice. ZFHX3 regulates transcription via direct interaction with predicted AT motifs in target genes. The mutant protein has a decreased ability to activate consensus AT motifs in vitro. Using RNA sequencing, we found minimal effects on core clock genes in Zfhx3Sci/+ SCN, whereas the expression of neuropeptides critical for SCN intercellular signaling was significantly disturbed. Moreover, mutant ZFHX3 had a decreased ability to activate AT motifs in the promoters of these neuropeptide genes. Lentiviral transduction of SCN slices showed that the ZFHX3-mediated activation of AT motifs is circadian, with decreased amplitude and robustness of these oscillations in Zfhx3Sci/+ SCN slices. In conclusion, by cloning Zfhx3Sci, we have uncovered a circadian transcriptional axis that determines the period and robustness of behavioral and SCN molecular rhythms
History of clinical transplantation
How transplantation came to be a clinical discipline can be pieced together by perusing two volumes of reminiscences collected by Paul I. Terasaki in 1991-1992 from many of the persons who were directly involved. One volume was devoted to the discovery of the major histocompatibility complex (MHC), with particular reference to the human leukocyte antigens (HLAs) that are widely used today for tissue matching.1 The other focused on milestones in the development of clinical transplantation.2 All the contributions described in both volumes can be traced back in one way or other to the demonstration in the mid-1940s by Peter Brian Medawar that the rejection of allografts is an immunological phenomenon.3,4 © 2008 Springer New York
Galaxy bulges and their massive black holes: a review
With references to both key and oft-forgotten pioneering works, this article
starts by presenting a review into how we came to believe in the existence of
massive black holes at the centres of galaxies. It then presents the historical
development of the near-linear (black hole)-(host spheroid) mass relation,
before explaining why this has recently been dramatically revised. Past
disagreement over the slope of the (black hole)-(velocity dispersion) relation
is also explained, and the discovery of sub-structure within the (black
hole)-(velocity dispersion) diagram is discussed. As the search for the
fundamental connection between massive black holes and their host galaxies
continues, the competing array of additional black hole mass scaling relations
for samples of predominantly inactive galaxies are presented.Comment: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590
references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic
Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer
Publishin
Strong Interaction Between A Single Carbon Nanotube And An Optical Microresonator
We couple a single suspended carbon nanotube to the near field of a free standing optical microdisk. The strong interaction between the nanotube and the microcavity produces an ultrahigh photocurrent response as large as 0.35mA/W. © 2013 Optical Society of America.Minot, E.D., Yaish, Y., Sazonova, V., Park, J.-Y., Brink, M., McEuen, P.L., Tuning carbon nanotube band gaps with strain (2003) Physical Review Letters, 90 (15), p. 156401. , PRLAvouris, P., Freitag, M., Perebeinos, V., Carbon-nanotube photonics and optoelectronics (2008) Nat Photon, 2 (6), pp. 341-350Schneider, B.H., Etaki, S., Van Der Zant, H.S.J., Steele, G.A., Coupling carbon nanotube mechanics to a superconducting circuit (2012) Sci. Rep., 2. , 10.1038/srep00599Stapfner, S., Ost, L., Hunger, D., Weig, E.M., Reichel, J., Favero, I., Cavity-enhanced optical detection of carbon nanotube brownian motion (2012), arXiv preprint arXiv:1211.1608Vahala, K.J., Optical microcavities (2003) Nature, 424 (6950), pp. 839-846Anetsberger, G., Arcizet, O., Unterreithmeier, Q.P., Riviere, R., Schliesser, A., Weig, E.M., Kotthaus, J.P., Kippenberg, T.J., Near-field cavity optomechanics with nanomechanical oscillators (2009) Nat Phys, 5 (12), pp. 909-91
Synchronization Of Coupled Optomechanical Oscillators
We demonstrate experimentally the synchronization of two micromechanical oscillators actuated by the optical radiation field. The mutual coupling is purely optical and fully tunable. Upon synchronization, the phase noise drops in agreement with the prediction. © 2012 OSA.Kaka, S., Pufall, M.R., Rippard, W.H., Silva, T.J., Russek, S.E., Katine, J.A., Mutual phase-locking of microwave spin torque nano-oscillators (2005) Nature, 437 (7057), pp. 389-392Mohanty, P., Shim, S.B., Imboden, M., Synchronized oscillation in coupled nanomechanical oscillators (2007) Science, 316 (5821), pp. 95-99Kippenberg, T.J., Vahala, K.J., Cavity opto-mechanics (2007) Optics Express, 15 (25), pp. 17172-17205Wiederhecker, G.S., Chen, L., Gondarenko, A., Lipson, M., Controlling photonic structures using optical forces (2009) Nature, 462 (7273), pp. 633-U103Lin, Q., Rosenberg, J., Jiang, X., Vahala, K.J., Painter, O., Mechanical oscillation and cooling actuated by the optical gradient force (2009) Physical Review Letters, 103 (10), p. 103601Manipatruni, S., Wiederhecker, G.S., Lipson, M., Long-range synchronization of optomechanical structures Quantum Electronics and Laser Science Conference, 2011Heinrich, G., Ludwig, M., Qian, J., Kubala, B., Marquardt, F., Collective dynamics in optomechanical arrays (2011) Physical Review Letters, 107 (4), p. 043603Hossein-Zadeh, M., Vahala, K.J., Observation of injection locking in an optomechanical rf oscillator (2008) Applied Physics Letters, 93 (19), pp. 191115-191115-3Chang, H.C., Cao, X., Mishra, U.K., York, R.A., Phase noise in coupled oscillators: Theory and experiment (1997) Microwave Theory and Techniques, IEEE Transactions on, 45 (5), pp. 604-61
Early holocene high magnitude debris flow events and environmental change as illustrated by the Moxi Platform, Hengduan Mountains, SW China
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