266 research outputs found

    Biological measurement beyond the quantum limit

    Full text link
    Quantum noise places a fundamental limit on the per photon sensitivity attainable in optical measurements. This limit is of particular importance in biological measurements, where the optical power must be constrained to avoid damage to the specimen. By using non-classically correlated light, we demonstrated that the quantum limit can be surpassed in biological measurements. Quantum enhanced microrheology was performed within yeast cells by tracking naturally occurring lipid granules with sensitivity 2.4 dB beyond the quantum noise limit. The viscoelastic properties of the cytoplasm could thereby be determined with a 64% improved measurement rate. This demonstration paves the way to apply quantum resources broadly in a biological context

    Control of Jupiter's radio emission and aurorae by the solar wind

    Full text link
    Radio emissions from Jupiter provided the first evidence that this giant planet has a strong magnetic field(1,2) and a large magnetosphere(3). Jupiter also has polar aurorae(4), which are similar in many respects to Earth's aurorae(5). The radio emissions are believed to be generated along the high-latitude magnetic field lines by the same electrons that produce the aurorae, and both the radio emission in the hectometric frequency range and the aurorae vary considerably(6,7). The origin of the variability, however, has been poorly understood. Here we report simultaneous observations using the Cassini and Galileo spacecraft of hectometric radio emissions and extreme ultraviolet auroral emissions from Jupiter. Our results show that both of these emissions are triggered by interplanetary shocks propagating outward from the Sun. When such a shock arrives at Jupiter, it seems to cause a major compression and reconfiguration of the magnetosphere, which produces strong electric fields and therefore electron acceleration along the auroral field lines, similar to the processes that occur during geomagnetic storms at the Earth.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62740/1/415985a.pd

    The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

    Get PDF
    The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of “dead zones” in modern oceans

    A combined estimator using TEC and b-value for large earthquake prediction

    Full text link
    [EN] Ionospheric anomalies have been shown to occur a few days before several large earthquakes. The published works normally address examples limited in time (a single event or few of them) or space (a particular geographic area), so that a clear method based on these anomalies which consistently yields the place and magnitude of the forthcoming earthquake, anytime and anywhere on earth, has not been presented so far. The current research is aimed at prediction of large earthquakes, that is with magnitude M-w 7 or higher. It uses as data bank all significant earthquakes occurred worldwide in the period from January 1, 2011 to December 31, 2018. The first purpose of the research is to improve the use of ionospheric anomalies in the form of TEC grids for earthquake prediction. A space-time TEC variation estimator especially designed for earthquake prediction will show the advantages with respect to the use of simple TEC values. Further, taking advantage of the well-known predictive abilities of the Gutenberg-Richter law's b-value, a combined estimator based on both TEC anomalies and b-values will be designed and shown to improve prediction performance even more.Baselga Moreno, S. (2020). A combined estimator using TEC and b-value for large earthquake prediction. Acta Geodaetica et Geophysica Hungarica. 55(1):63-82. https://doi.org/10.1007/s40328-019-00281-5S6382551Abordán A, Szabó NP (2018) Metropolis algorithm driven factor analysis for lithological characterization of shallow marine sediments. Acta Geod Geophys 53:189–199. https://doi.org/10.1007/s40328-017-0210-zAkhoondzadeh M, Saradjian MR (2011) TEC variations analysis concerning Haiti (January 12, 2010) and Samoa (September 29, 2009) earthquakes. Adv Space Res 47(1):94–104. https://doi.org/10.1016/j.asr.2010.07.024Asencio-Cortés G, Morales-Esteban A, Shang X, Martínez-Álvarez F (2018) Earthquake prediction in California using regression algorithms and cloud-based big data infrastructure. Comput Geosci 115:198–210. https://doi.org/10.1016/j.cageo.2017.10.011Baselga S (2018) Fibonacci lattices for the evaluation and optimization of map projections. Comput Geosci 117:1–8. https://doi.org/10.1016/j.cageo.2018.04.012Baselga S (2019) TestGrids: evaluating and optimizing map projections. J Surv Eng 144(3):04019004Berényi KA, Barta V, Kis Á (2018) Midlatitude ionospheric F2-layer response to eruptive solar events-caused geomagnetic disturbances over Hungary during the maximum of the solar cycle 24: a case study. Adv Space Res 61(5):1230–1243. https://doi.org/10.1016/j.asr.2017.12.021Biswas A, Sharma SP (2017) Interpretation of self-potential anomaly over 2-D inclined thick sheet structures and analysis of uncertainty using very fast simulated annealing global optimization. Acta Geod Geophys 52:439–455. https://doi.org/10.1007/s40328-016-0176-2Borgohain JM, Borah K, Biswas R, Bora DK (2018) Seismic b-value anomalies prior to the 3rd January 2016, Mw = 6.7 Manipur earthquake of northeast India. J Asian Earth Sci 154:42–48. https://doi.org/10.1016/j.jseaes.2017.12.013Buonsanto M (1999) Ionospheric storms—a review. Space Sci Rev 88:563–601. https://doi.org/10.1023/A:1005107532631Buskirk RE, Frohlich CL, Latham GV (1981) Unusual animal behavior before earthquakes: a review of possible sensory mechanisms. Rev Geophys 19:247–270. https://doi.org/10.1029/RG019i002p00247Dobrovolsky IR, Zubkov SI, Myachkin VI (1979) Estimation of the size of earthquake preparation zones. Pure appl Geophys 117:1025–1044. https://doi.org/10.1007/BF00876083Dogan U, Ergintav S, Skone S, Arslan N, Oz D (2011) Monitoring of the ionosphere TEC variations during the 17th August 1999 Izmit earthquake using GPS data. Earth Planets Space 63(12):1183–1192. https://doi.org/10.5047/eps.2011.07.020Florido E, Martínez-Álvarez F, Morales-Esteban A, Reyes J, Aznarte-Mellado JL (2015) Detecting precursory patterns to enhance earthquake prediction in Chile. Comput Geosci 76:112–120. https://doi.org/10.1016/j.cageo.2014.12.002Florido E, Asencio-Cortés G, Aznarte JL, Rubio-Escudero C, Martínez-Álvarez F (2018) A novel tree-based algorithm to discover seismic patterns in earthquake catalogs. Comput Geosci 115:96–104. https://doi.org/10.1016/j.cageo.2018.03.005Freund FT, Kulahci IG, Cyr G, Ling J, Winnick M, Tregloan-Reed J, Freund MM (2009) Air ionization at rock surfaces and pre-earthquake signals. J Atmos Sol Terr Phys 71(17–18):1824–1834. https://doi.org/10.1016/j.jastp.2009.07.013Gopinath S, Prince PR (2018) Nonextensive and distance-based entropy analysis on the influence of sunspot variability in magnetospheric dynamics. Acta Geod Geophys 53:639–659. https://doi.org/10.1007/s40328-018-0235-yGrant RA, Halliday T (2010) Predicting the unpredictable; evidence of pre-seismic anticipatory behaviour in the common toad. J Zool 281:263–271. https://doi.org/10.1111/j.1469-7998.2010.00700.xGrant RA, Halliday T, Balderer WP, Leuenberger F, Newcomer M, Cyr G, Freund FT (2011) Ground water chemistry changes before major earthquakes and possible effects on animals. Int J Environ Res Public Health 8:1936–1956. https://doi.org/10.3390/ijerph8061936Guo J, Yu H, Li W, Liu X, Kong Q, Zhao C (2017) Total electron content anomalies before Mw 6.0 + earthquakes in the seismic zone of southwest China between 2001 and 2013. J Test Eval 45(1):131–139. https://doi.org/10.1520/JTE20160032International GNSS Service (2019) IGS products. https://www.igs.org/products. Accessed 5 May 2019Kane RP (2005) Ionospheric foF2 anomalies during some intense geomagnetic storms. Ann Geophys 23:2487–2499. https://doi.org/10.5194/angeo-23-2487-2005Kulhanek O, Persson L, Nuannin P (2018) Variations of b-values preceding large earthquakes in the shallow subduction zones of Cocos and Nazca plates. J South Am Earth Sci 82:207–214. https://doi.org/10.1016/j.jsames.2018.01.005Lin JW (2010) Ionospheric total electron content (TEC) anomalies associated with earthquakes through Karhunen–Loéve Transform (KLT). Terr Atmos Ocean Sci 21(2):253–265. https://doi.org/10.3319/TAO.2009.06.11.01(T)Lin JW (2011) Latitude-time total electron content anomalies as precursors to Japan’s large earthquakes associated with principal component analysis. Int J Geophys. https://doi.org/10.1155/2011/763527Liu JY, Chen YI, Chuo YJ, Chen CS (2006) A statistical investigation of preearthquake ionospheric anomaly. J Geophys Res 111:A05304. https://doi.org/10.1029/2005JA011333Liu JY, Chen YI, Chen CH, Liu CY, Chen CY, Nishihashi M, Li JZ, Xia YQ, Oyama KI, Hattori K, Lin CH (2009) Seismoionospheric GPS total electron content anomalies observed before the 12 May 2008 Mw7.9 Wenchuan earthquake. J Geophys Res 114:A04320. https://doi.org/10.1029/2008JA013698Nuannin P, Kulhanek O, Persson L (2005) Spatial and temporal b value anomalies preceding the devastating off coast of NW Sumatra earthquake of December 26, 2004. Geophys Res Lett 32:L11307. https://doi.org/10.1029/2005GL022679Pardalos PM, Romeijn HE (eds) (2002) Handbook of global optimization, vols. 1 & 2. Kluwer, DordretchPaul B, De BK, Guha A (2018) Latitudinal variation of F-region ionospheric response during three strongest geomagnetic storms of 2015. Acta Geod Geophys 53:579–606. https://doi.org/10.1007/s40328-018-0221-4Pulinets S, Boyarchuk K (2004) Ionospheric precursors of earthquakes. Springer, BerlinPulinets SA, Legen’ka AD, Gaivoronskaya TV, Depuev VKh (2003) Main phenomenological features of ionospheric precursors of strong earthquakes. J Atmos Sol Terr Phys 65:1337–1347. https://doi.org/10.1016/j.jastp.2003.07.011Reyes J, Morales-Esteban A, Martínez-Álvarez F (2013) Neural networks to predict earthquakes in Chile. Appl Soft Comput 13:1314–1328. https://doi.org/10.1016/j.asoc.2012.10.014Şentürk E, Çepni MS (2018a) A statistical analysis of seismo ionospheric TEC anomalies before 63 Mw ≥ 5.0 earthquakes in Turkey during 2003–2016. Acta Geophys 66:1495–1507. https://doi.org/10.1007/s11600-018-0214-2Şentürk E, Çepni MS (2018b) Ionospheric temporal variations over the region of Turkey: a study based on long-time TEC observations. Acta Geod Geophys 53:623–637. https://doi.org/10.1007/s40328-018-0233-0Şentürk E, Çepni MS (2019) Performance of different weighting and surface fitting techniques on station-wise TEC calculation and modified sine weighting supported by the sun effect. J Spat Sci 64(2):209–220. https://doi.org/10.1080/14498596.2017.1417169Şentürk E, Livaoğlu H, Çepni MS (2019) A comprehensive analysis of ionospheric anomalies before the mw 7.1 Van earthquake on 23 October 2011. J Navig 72(3):702–720. https://doi.org/10.1017/S0373463318000826Shiuly A, Roy N (2018) A generalized VS–N correlation using various regression analysis and genetic algorithm. Acta Geod Geophys 53:479–502. https://doi.org/10.1007/s40328-018-0220-5U.S. Geological Survey (2019) Earthquake catalog. https://earthquake.usgs.gov/earthquakes/search/. Accessed 5 May 2019Warwick JW, Stoker C, Meyer TR (1982) Radio emission associated with rock fracture: possible application to the Great Chilean Earthquake of May 22, 1960. J Geophys Res Solid Earth 87:2851–2859. https://doi.org/10.1029/JB087iB04p02851Yao Y, Chen P, Wu H, Zhang S, Peng W (2012) Analysis of ionospheric anomalies before the 2011 M w 9.0 Japan earthquake. Chin Sci Bull 57(5):500–510. https://doi.org/10.1007/s11434-011-4851-yZakharenkova IE, Shagimuratov II, Krankowski A (2007a) Features of the ionosphere behavior before the Kythira 2006 earthquake. Acta Geophys 55(4):524–534. https://doi.org/10.2478/s11600-007-0031-5Zakharenkova IE, Shagimuratov II, Krankowski A, Lagovsky AF (2007b) Precursory phenomena observed in the total electron content measurements before great Hokkaido earthquake of September 25, 2003 (M = 8.3). Stud Geophys Geod 51(2):267–278. https://doi.org/10.1007/s11200-007-0014-

    Care coordination experiences of people with traumatic brain injury and their family members in the 4-years after injury: a qualitative analysis

    Get PDF
    Title: Care coordination experiences of people with traumatic brain injury and their family members 4-years after injury: A qualitative analysis. Aim: To explore experiences of care coordination in the first 4-years after severe traumatic brain injury (TBI). Methods: A qualitative study nested within a population-based longitudinal cohort study. Eighteen semi-structured telephone interviews were conducted 48-months post-injury with six adults living with severe TBI and the family members of 12 other adults living with severe TBI. Participants were identified through purposive sampling from the Victorian State Trauma Registry. A thematic analysis was undertaken. Results: No person with TBI or their family member reported a case manager or care coordinator were involved in assisting with all aspects of their care. Many people with severe TBI experienced ineffective care coordination resulting in difficulty accessing services, variable quality in the timing, efficiency and appropriateness of services, an absence of regular progress evaluations and collaboratively formulated long-term plans. Some family members attempted to fill gaps in care, often without success. In contrast, effective care coordination was reported by one family member who advocated for services, closely monitored their relative, and effectively facilitated communication between services providers. Conclusion: Given the high cost, complexity and long-term nature of TBI recovery, more effective care coordination is required to consistently meet the needs of people with severe TBI.Sandra Braaf, Shanthi Ameratunga, Nicola Christie, Warwick Teague, Jennie Ponsford, Peter A. Cameron, Belinda J. Gabb

    Genetic load and transgenic mitigating genes in transgenic Brassica rapa (field mustard) × Brassica napus (oilseed rape) hybrid populations

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>One theoretical explanation for the relatively poor performance of <it>Brassica rapa </it>(weed) × <it>Brassica napus </it>(crop) transgenic hybrids suggests that hybridization imparts a negative genetic load. Consequently, in hybrids genetic load could overshadow any benefits of fitness enhancing transgenes and become the limiting factor in transgenic hybrid persistence. Two types of genetic load were analyzed in this study: random/linkage-derived genetic load, and directly incorporated genetic load using a transgenic mitigation (TM) strategy. In order to measure the effects of random genetic load, hybrid productivity (seed yield and biomass) was correlated with crop- and weed-specific AFLP genomic markers. This portion of the study was designed to answer whether or not weed × transgenic crop hybrids possessing more crop genes were less competitive than hybrids containing fewer crop genes. The effects of directly incorporated genetic load (TM) were analyzed through transgene persistence data. TM strategies are proposed to decrease transgene persistence if gene flow and subsequent transgene introgression to a wild host were to occur.</p> <p>Results</p> <p>In the absence of interspecific competition, transgenic weed × crop hybrids benefited from having more crop-specific alleles. There was a positive correlation between performance and number of <it>B. napus </it>crop-specific AFLP markers [seed yield vs. marker number (r = 0.54, P = 0.0003) and vegetative dry biomass vs. marker number (r = 0.44, P = 0.005)]. However under interspecific competition with wheat or more weed-like conditions (i.e. representing a situation where hybrid plants emerge as volunteer weeds in subsequent cropping systems), there was a positive correlation between the number of <it>B. rapa </it>weed-specific AFLP markers and seed yield (r = 0.70, P = 0.0001), although no such correlation was detected for vegetative biomass. When genetic load was directly incorporated into the hybrid genome, by inserting a fitness-mitigating dwarfing gene that that is beneficial for crops but deleterious for weeds (a transgene mitigation measure), there was a dramatic decrease in the number of transgenic hybrid progeny persisting in the population.</p> <p>Conclusion</p> <p>The effects of genetic load of crop and in some situations, weed alleles might be beneficial under certain environmental conditions. However, when genetic load was directly incorporated into transgenic events, e.g., using a TM construct, the number of transgenic hybrids and persistence in weedy genomic backgrounds was significantly decreased.</p

    Introduction: self-translating, from minorisation to empowerment

    Get PDF
    This introductory chapter discusses the implications of self-translation in multilingual contexts in Europe, aiming at mapping out innovative perspectives to the study of power and, by so doing, empowering self-translation. We start by critically engaging with the ‘cultural’ and ‘power turns’ in translation studies, as a way of delineating what the particularities of self-translation are when practised by author-translators in multilingual spaces. Focusing on the European milieu, defined broadly in terms of its geographies, we then discuss multilingualism, cultural awareness and ethnic diversity as staple terms in both academic and political ideologies across Europe, emphasising that one of the aspects of multilingualism is precisely the power differentials between languages and cultures. We explore these unequal power relations and centre–periphery dichotomies of Europe’s ‘minorised’ languages, literatures and cultures, suggesting the usage of ‘minorised’ in preference to the others discussed, inasmuch as it highlights both hegemonic power hierarchies and also the continual resistance to them. This is followed by a brief overview of the emerging debates in the subdiscipline of self-translation in recent times. It is within them that we situate our contribution, arguing that the self-translators’ double affiliation as authors and translators turns them into powerful cultural and ideological mediators and places them in a privileged position to challenge (or submit to) power. Here another term, ‘self-censorship,’ is suggested as invaluable to self-translation studies where self-editing often occurs before translation is begun. Finally, the introduction presents the organisation of the book and the main ideas discussed by the 11 authors in their individual chapters

    X-ray Absorption and Reflection in Active Galactic Nuclei

    Full text link
    X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of material to their host galaxies. We describe the spectral signatures that may be studied and review the X-ray spectra and spectral variability of active galaxies, concentrating on progress from recent Chandra, XMM-Newton and Suzaku data for local type 1 AGN. We describe the evidence for absorption covering a wide range of column densities, ionization and dynamics, and discuss the growing evidence for partial-covering absorption from data at energies > 10 keV. Such absorption can also explain the observed X-ray spectral curvature and variability in AGN at lower energies and is likely an important factor in shaping the observed properties of this class of source. Consideration of self-consistent models for local AGN indicates that X-ray spectra likely comprise a combination of absorption and reflection effects from material originating within a few light days of the black hole as well as on larger scales. It is likely that AGN X-ray spectra may be strongly affected by the presence of disk-wind outflows that are expected in systems with high accretion rates, and we describe models that attempt to predict the effects of radiative transfer through such winds, and discuss the prospects for new data to test and address these ideas.Comment: Accepted for publication in the Astronomy and Astrophysics Review. 58 pages, 9 figures. V2 has fixed an error in footnote

    Do Meio- and Macrobenthic Nematodes Differ in Community Composition and Body Weight Trends with Depth?

    Get PDF
    Nematodes occur regularly in macrobenthic samples but are rarely identified from them and are thus considered exclusively a part of the meiobenthos. Our study compares the generic composition of nematode communities and their individual body weight trends with water depth in macrobenthic (>250/300 µm) samples from the deep Arctic (Canada Basin), Gulf of Mexico (GOM) and the Bermuda slope with meiobenthic samples (<45 µm) from GOM. The dry weight per individual (µg) of all macrobenthic nematodes combined showed an increasing trend with increasing water depth, while the dry weight per individual of the meiobenthic GOM nematodes showed a trend to decrease with increasing depth. Multivariate analyses showed that the macrobenthic nematode community in the GOM was more similar to the macrobenthic nematodes of the Canada Basin than to the GOM meiobenthic nematodes. In particular, the genera Enoploides, Crenopharynx, Micoletzkyia, Phanodermella were dominant in the macrobenthos and accounted for most of the difference. Relative abundance of non-selective deposit feeders (1B) significantly decreased with depth in macrobenthos but remained dominant in the meiobenthic community. The occurrence of a distinct assemblage of bigger nematodes of high dry weight per individual in the macrobenthos suggests the need to include nematodes in macrobenthic studies
    corecore