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Showing papers by "Australian National University published in 2009"


Journal ArticleDOI
23 Sep 2009-Nature
TL;DR: Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockstrom and colleagues.
Abstract: Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockstrom and colleagues.

8,837 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a new approach to global sustainability in which they define planetary boundaries within which they expect that humanity can operate safely. But the proposed concept of "planetary boundaries" lays the groundwork for shifting our approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development.
Abstract: Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them. These seven are climate change (CO2 concentration in the atmosphere <350 ppm and/or a maximum change of +1 W m-2 in radiative forcing); ocean acidification (mean surface seawater saturation state with respect to aragonite ≥ 80% of pre-industrial levels); stratospheric ozone (<5% reduction in O3 concentration from pre-industrial level of 290 Dobson Units); biogeochemical nitrogen (N) cycle (limit industrial and agricultural fixation of N2 to 35 Tg N yr-1) and phosphorus (P) cycle (annual P inflow to oceans not to exceed 10 times the natural background weathering of P); global freshwater use (<4000 km3 yr-1 of consumptive use of runoff resources); land system change (<15% of the ice-free land surface under cropland); and the rate at which biological diversity is lost (annual rate of <10 extinctions per million species). The two additional planetary boundaries for which we have not yet been able to determine a boundary level are chemical pollution and atmospheric aerosol loading. We estimate that humanity has already transgressed three planetary boundaries: for climate change, rate of biodiversity loss, and changes to the global nitrogen cycle. Planetary boundaries are interdependent, because transgressing one may both shift the position of other boundaries or cause them to be transgressed. The social impacts of transgressing boundaries will be a function of the social-ecological resilience of the affected societies. Our proposed boundaries are rough, first estimates only, surrounded by large uncertainties and knowledge gaps. Filling these gaps will require major advancements in Earth System and resilience science. The proposed concept of "planetary boundaries" lays the groundwork for shifting our approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries define, as it were, the boundaries of the "planetary playing field" for humanity if we want to be sure of avoiding major human-induced environmental change on a global scale.

4,771 citations


Journal ArticleDOI
TL;DR: This target article summarizes decades of cross-linguistic work by typologists and descriptive linguists, showing just how few and unprofound the universal characteristics of language are, once the authors honestly confront the diversity offered to us by the world's 6,000 to 8,000 languages.
Abstract: Talk of linguistic universals has given cognitive scientists the impression that languages are all built to a common pattern. In fact, there are vanishingly few universals of language in the direct sense that all languages exhibit them. Instead, diversity can be found at almost every level of linguistic organization. This fundamentally changes the object of enquiry from a cognitive science perspective. This target article summarizes decades of cross-linguistic work by typologists and descriptive linguists, showing just how few and unprofound the universal characteristics of language are, once we honestly confront the diversity offered to us by the world's 6,000 to 8,000 languages. After surveying the various uses of "universal," we illustrate the ways languages vary radically in sound, meaning, and syntactic organization, and then we examine in more detail the core grammatical machinery of recursion, constituency, and grammatical relations. Although there are significant recurrent patterns in organization, these are better explained as stable engineering solutions satisfying multiple design constraints, reflecting both cultural-historical factors and the constraints of human cognition. Linguistic diversity then becomes the crucial datum for cognitive science: we are the only species with a communication system that is fundamentally variable at all levels. Recognizing the true extent of structural diversity in human language opens up exciting new research directions for cognitive scientists, offering thousands of different natural experiments given by different languages, with new opportunities for dialogue with biological paradigms concerned with change and diversity, and confronting us with the extraordinary plasticity of the highest human skills.

1,385 citations


Journal ArticleDOI
Brian Yanny1, Constance M. Rockosi2, Heidi Jo Newberg3, Gillian R. Knapp4, Jennifer K. Adelman-McCarthy1, Bonnie Alcorn1, S. Allam1, Carlos Allende Prieto5, Carlos Allende Prieto6, Deokkeun An7, K. S. J. Anderson8, K. S. J. Anderson9, Scott F. Anderson10, Coryn A. L. Bailer-Jones11, Steve Bastian1, Timothy C. Beers12, Eric F. Bell11, Vasily Belokurov13, Dmitry Bizyaev9, Norm Blythe9, John J. Bochanski10, William N. Boroski1, Jarle Brinchmann14, J. Brinkmann9, Howard Brewington9, Larry N. Carey10, Kyle M. Cudworth15, Michael L. Evans10, Nick Evans13, Evalyn Gates15, Boris T. Gänsicke16, Bruce Gillespie9, G. F. Gilmore13, Ada Nebot Gomez-Moran, Eva K. Grebel17, Jim Greenwell10, James E. Gunn4, Cathy Jordan9, Wendell Jordan9, Paul Harding18, Hugh C. Harris, John S. Hendry1, Diana Holder9, Inese I. Ivans4, Željko Ivezić10, Sebastian Jester11, Jennifer A. Johnson7, Stephen M. Kent1, S. J. Kleinman9, Alexei Y. Kniazev11, Jurek Krzesinski9, Richard G. Kron15, Nikolay Kuropatkin1, Svetlana Lebedeva1, Young Sun Lee12, R. French Leger1, Sébastien Lépine19, Steve Levine, Huan Lin1, Dan Long9, Craig P. Loomis4, Robert H. Lupton4, O. Malanushenko9, Viktor Malanushenko9, Bruce Margon2, David Martínez-Delgado11, P. M. McGehee20, Dave Monet, Heather L. Morrison18, Jeffrey A. Munn, Eric H. Neilsen1, Atsuko Nitta9, John E. Norris21, Daniel Oravetz9, Russell Owen10, Nikhil Padmanabhan22, Kaike Pan9, R. S. Peterson1, Jeffrey R. Pier, Jared Platson1, Paola Re Fiorentin23, Paola Re Fiorentin11, Gordon T. Richards24, Hans-Walter Rix11, David J. Schlegel22, Donald P. Schneider25, Matthias R. Schreiber26, Axel Schwope, Valena C. Sibley1, Audrey Simmons9, Stephanie A. Snedden9, J. Allyn Smith27, Larry Stark10, Fritz Stauffer9, Matthias Steinmetz, Christopher Stoughton1, Mark SubbaRao15, Mark SubbaRao28, Alexander S. Szalay29, Paula Szkody10, Aniruddha R. Thakar29, Sivarani Thirupathi12, Douglas L. Tucker1, A. Uomoto30, Daniel E. Vanden Berk25, S. Vidrih17, Yogesh Wadadekar31, Yogesh Wadadekar4, S. Watters9, R. Wilhelm32, Rosemary F. G. Wyse29, Jean Yarger9, Daniel B. Zucker13 
TL;DR: The Sloan Extension for Galactic Understanding and Exploration (SEGUE) Survey as mentioned in this paper obtained approximately 240,000 moderate-resolution spectra from 3900 to 9000 of fainter Milky Way stars (14.0 10 per resolution element).
Abstract: The Sloan Extension for Galactic Understanding and Exploration (SEGUE) Survey obtained {approx}240,000 moderate-resolution (R {approx} 1800) spectra from 3900 {angstrom} to 9000 {angstrom} of fainter Milky Way stars (14.0 10 per resolution element, stellar atmospheric parameters are estimated, including metallicity, surface gravity, and effective temperature. SEGUE obtained 3500 deg{sup 2} of additional ugriz imaging (primarily at low Galactic latitudes) providing precise multicolor photometry ({sigma}(g, r, i) {approx} 2%), ({sigma}(u, z) {approx} 3%) and astrometry ({approx}0.1) for spectroscopic target selection. The stellar spectra, imaging data, and derived parameter catalogs for this survey are publicly available as part of Sloan Digital Sky Survey Data Release 7.

1,133 citations


Journal ArticleDOI
18 Sep 2009-Immunity
TL;DR: It is shown that Bcl-6 positively directs Tfh cell differentiation, through combined repression of miRNAs and transcription factors.

1,098 citations


Journal ArticleDOI
TL;DR: In this article, a hierarchy of rational solutions of the nonlinear Schrodinger equation (NLSE) with increasing order and with progressively increasing amplitude is presented. And the authors apply the WANDT title to two objects: rogue waves in the ocean and rational solution of the NLSE.

1,036 citations


Journal ArticleDOI
TL;DR: A systematic review of randomized controlled trials using Internet interventions for anxiety and depression was conducted, and data was collected on dropout and adherence, predictors of adherence, and reasons for dropout.
Abstract: Background: Open access websites which deliver cognitive and behavioral interventions for anxiety and depression are characterised by poor adherence. We need to understand more about adherence in order to maximize the impact of Internet-based interventions on the disease burden associated with common mental disorders. Objective: The aims of this paper are to review briefly the adherence literature with respect to Internet interventions and to investigate the rates of dropout and compliance in randomized controlled trials of anxiety and depression Web studies. Methods: A systematic review of randomized controlled trials using Internet interventions for anxiety and depression was conducted, and data was collected on dropout and adherence, predictors of adherence, and reasons for dropout. Results: Relative to reported rates of dropout from open access sites, the present study found that the rates of attrition in randomized controlled trials were lower, ranging from approximately 1 - 50%. Predictors of adherence included disease severity, treatment length, and chronicity. Very few studies formally examined reasons for dropout, and most studies failed to use appropriate statistical techniques to analyze missing data. Conclusions: Dropout rates from randomized controlled trials of Web interventions are low relative to dropout from open access websites. The development of theoretical models of adherence is as important in the area of Internet intervention research as it is in the behavioral health literature. Disease-based factors in anxiety and depression need further investigation. [J Med Internet Res 2009;11(2):e13]

1,003 citations


Journal ArticleDOI
TL;DR: The 6dF Galaxy Survey (6dFGS) as discussed by the authors is a combined redshift and peculiar velocity survey over the southern sky (|b| > 10°) which yielded 110 256 new extragalactic redshifts and a new catalogue of 125 071 galaxies.
Abstract: We report the final redshift release of the 6dF Galaxy Survey (6dFGS), a combined redshift and peculiar velocity survey over the southern sky (|b| > 10°). Its 136 304 spectra have yielded 110 256 new extragalactic redshifts and a new catalogue of 125 071 galaxies making near-complete samples with (K, H, J, r_F, b_J) ≤ (12.65, 12.95, 13.75, 15.60, 16.75). The median redshift of the survey is 0.053. Survey data, including images, spectra, photometry and redshifts, are available through an online data base. We describe changes to the information in the data base since earlier interim data releases. Future releases will include velocity dispersions, distances and peculiar velocities for the brightest early-type galaxies, comprising about 10 per cent of the sample. Here we provide redshift maps of the southern local Universe with z ≤ 0.1, showing nearby large-scale structures in hitherto unseen detail. A number of regions known previously to have a paucity of galaxies are confirmed as significantly underdense regions. The URL of the 6dFGS data base is http://www-wfau.roe.ac.uk/6dFGS.

977 citations


Journal ArticleDOI
TL;DR: This paper found that individual follower's "power distance" orientation and their group's shared perceptions of tra... using 560 followers and 174 leaders in the People's Republic of China and United States.
Abstract: Using 560 followers and 174 leaders in the People's Republic of China and United States, we found that individual follower's “power distance” orientation and their group's shared perceptions of tra...

846 citations


Journal ArticleDOI
TL;DR: This work can elucidate the appearance of rogue waves in the deep ocean and can be applied to the observation of rogue light pulse waves in optical fibers.
Abstract: We present a method for finding the hierarchy of rational solutions of the self-focusing nonlinear Schrodinger equation and present explicit forms for these solutions from first to fourth order. We also explain their relation to the highest amplitude part of a field that starts with a plane wave perturbed by random small amplitude radiation waves. Our work can elucidate the appearance of rogue waves in the deep ocean and can be applied to the observation of rogue light pulse waves in optical fibers.

845 citations


Journal ArticleDOI
TL;DR: The estimation of phylogenetic divergence times from sequence data is an important component of many molecular evolutionary studies, and a variety of local- and relaxed-clock methods have been proposed and implemented.
Abstract: The estimation of phylogenetic divergence times from sequence data is an important component of many molecular evolutionary studies. There is now a general appreciation that the procedure of divergence dating is considerably more complex than that initially described in the 1960s by Zuckerkandl and Pauling (1962, 1965). In particular, there has been much critical attention toward the assumption of a global molecular clock, resulting in the development of increasingly sophisticated techniques for inferring divergence times from sequence data. In response to the documentation of widespread departures from clocklike behavior, a variety of local- and relaxed-clock methods have been proposed and implemented. Local-clock methods permit different molecular clocks in different parts of the phylogenetic tree, thereby retaining the advantages of the classical molecular clock while casting off the restrictive assumption of a single, global rate of substitution (Rambaut and Bromham 1998; Yoder and Yang 2000).

Journal ArticleDOI
20 Nov 2009
TL;DR: GEM-CAP should be considered as one of the standard first-line options in locally advanced and metastatic pancreatic cancer and the meta-analysis of published studies showed a significant survival benefit in favor of GEM- CAP.
Abstract: Purpose Both gemcitabine (GEM) and fluoropyrimidines are valuable treatment for advanced pancreatic cancer. This open-label study was designed to compare the overall survival (OS) of patients randomly assigned to GEM alone or GEM plus capecitabine (GEM-CAP). Patients and Methods Patients with previously untreated histologically or cytologically proven locally advanced or metastatic carcinoma of the pancreas with a performance status ≤ 2 were recruited. Patients were randomly assigned to GEM or GEM-CAP. The primary outcome measure was survival. Meta-analysis of published studies was also conducted. Results Between May 2002 and January 2005, 533 patients were randomly assigned to GEM (n = 266) and GEM-CAP (n = 267) arms. GEM-CAP significantly improved objective response rate (19.1% v 12.4%; P = .034) and progression-free survival (hazard ratio [HR], 0.78; 95% CI, 0.66 to 0.93; P = .004) and was associated with a trend toward improved OS (HR, 0.86; 95% CI, 0.72 to 1.02; P = .08) compared with GEM alone. This trend for OS benefit for GEM-CAP was consistent across different prognostic subgroups according to baseline stratification factors (stage and performance status) and remained after adjusting for these stratification factors (P = .077). Moreover, the meta-analysis of two additional studies involving 935 patients showed a significant survival benefit in favor of GEM-CAP (HR, 0.86; 95% CI, 0.75 to 0.98; P = .02) with no intertrial heterogeneity. Conclusion On the basis of our trial and the meta-analysis, GEM-CAP should be considered as one of the standard first-line options in locally advanced and metastatic pancreatic cancer.

Journal ArticleDOI
TL;DR: A framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities is described, including relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition.
Abstract: From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome). Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance. Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized.

Journal Article
TL;DR: A variety of local and relaxed clock methods have been proposed and implemented for phylogenetic divergence dating as discussed by the authors, which allows different molecular clocks in different parts of the phylogenetic tree, thereby retaining the advantages of the classical molecular clock while casting off the restrictive assumption of a single, global rate of substitution.
Abstract: The estimation of phylogenetic divergence times from sequence data is an important component of many molecular evolutionary studies. There is now a general appreciation that the procedure of divergence dating is considerably more complex than that initially described in the 1960s by Zuckerkandl and Pauling (1962, 1965). In particular, there has been much critical attention toward the assumption of a global molecular clock, resulting in the development of increasingly sophisticated techniques for inferring divergence times from sequence data. In response to the documentation of widespread departures from clocklike behavior, a variety of local- and relaxed-clock methods have been proposed and implemented. Local-clock methods permit different molecular clocks in different parts of the phylogenetic tree, thereby retaining the advantages of the classical molecular clock while casting off the restrictive assumption of a single, global rate of substitution (Rambaut and Bromham 1998; Yoder and Yang 2000).

Journal ArticleDOI
29 Oct 2009-Nature
TL;DR: In this paper, the authors reported that GRB 090423 lies at a redshift of z approximate to 8.2, implying that massive stars were being produced and dying as GRBs similar to 630 Myr after the Big Bang.
Abstract: Long-duration gamma-ray bursts (GRBs) are thought to result from the explosions of certain massive stars(1), and some are bright enough that they should be observable out to redshifts of z > 20 using current technology(2-4). Hitherto, the highest redshift measured for any object was z = 6.96, for a Lyman-alpha emitting galaxy(5). Here we report that GRB 090423 lies at a redshift of z approximate to 8.2, implying that massive stars were being produced and dying as GRBs similar to 630 Myr after the Big Bang. The burst also pinpoints the location of its host galaxy.

Journal ArticleDOI
TL;DR: The paradigm of adaptive monitoring is proposed, which aims to resolve many of the problems that have undermined previous attempts to establish long-term research and monitoring.
Abstract: Long-term research and monitoring can provide important ecological insights and are crucial for the improved management of ecosystems and natural resources. However, many long-term research and monitoring programs are either ineffective or fail completely owing to poor planning and/or lack of focus. Here we propose the paradigm of adaptive monitoring, which aims to resolve many of the problems that have undermined previous attempts to establish long-term research and monitoring. This paradigm is driven by tractable questions, rigorous statistical design at the outset, a conceptual model of the ecosystem or other entity being examined and a human need to know about ecosystem change. An adaptive monitoring framework enables monitoring programs to evolve iteratively as new information emerges and research questions change.

Journal ArticleDOI
10 Apr 2009-Science
TL;DR: It is found that genomes from two isolates shared only 90% of their predicted genes, and divergence appears to have been facilitated by selection and acquisition processes that actively shape the repertoire of genes that are mutually exclusive between the two isolate differently than the core genes.
Abstract: Picoeukaryotes are a taxonomically diverse group of organisms less than 2 micrometers in diameter. Photosynthetic marine picoeukaryotes in the genus Micromonas thrive in ecosystems ranging from tropical to polar and could serve as sentinel organisms for biogeochemical fluxes of modern oceans during climate change. These broadly distributed primary producers belong to an anciently diverged sister clade to land plants. Although Micromonas isolates have high 18S ribosomal RNA gene identity, we found that genomes from two isolates shared only 90% of their predicted genes. Their independent evolutionary paths were emphasized by distinct riboswitch arrangements as well as the discovery of intronic repeat elements in one isolate, and in metagenomic data, but not in other genomes. Divergence appears to have been facilitated by selection and acquisition processes that actively shape the repertoire of genes that are mutually exclusive between the two isolates differently than the core genes. Analyses of the Micromonas genomes offer valuable insights into ecological differentiation and the dynamic nature of early plant evolution.

Journal ArticleDOI
09 Apr 2009-Nature
TL;DR: It is shown that biome stasis at speciation has outweighed biome shifts by more than 25:1, by inferring ancestral biomes for an ecologically diverse sample of more than 11,000 plant species from around the Southern Hemisphere.
Abstract: How and why organisms are distributed as they are has long intrigued evolutionary biologists. The tendency for species to retain their ancestral ecology has been demonstrated in distributions on local and regional scales, but the extent of ecological conservatism over tens of millions of years and across continents has not been assessed. Here we show that biome stasis at speciation has outweighed biome shifts by a ratio of more than 25:1, by inferring ancestral biomes for an ecologically diverse sample of more than 11,000 plant species from around the Southern Hemisphere. Stasis was also prevalent in transocean colonizations. Availability of a suitable biome could have substantially influenced which lineages establish on more than one landmass, in addition to the influence of the rarity of the dispersal events themselves. Conversely, the taxonomic composition of biomes has probably been strongly influenced by the rarity of species' transitions between biomes. This study has implications for the future because if clades have inherently limited capacity to shift biomes, then their evolutionary potential could be strongly compromised by biome contraction as climate changes.

Journal ArticleDOI
TL;DR: One result of climate change is a reduced work capacity in heat-exposed jobs and greater difficulty in achieving economic and social development in the countries affected by this somewhat neglected impact ofClimate change.
Abstract: Background: Global climate change is already increasing the average temperature and direct heat exposure in many places around the world. Objectives: To assess the potential impact on occupational health and work capacity for people exposed at work to increasing heat due to climate change. Design: A brief review of basic thermal physiology mechanisms, occupational heat exposure guidelines and heat exposure changes in selected cities. Results: In countries with very hot seasons, workers are already affected by working environments hotter than that with which human physiological mechanisms can cope. To protect workers from excessive heat, a number of heat exposure indices have been developed. One that is commonly used in occupational health is the Wet Bulb Globe Temperature (WBGT). We use WBGT to illustrate assessing the proportion of a working hour during which a worker can sustain work and the proportion of that same working hour that (s)he needs to rest to cool the body down and maintain core body temperature below 38°C. Using this proportion a ‘work capacity’ estimate was calculated for selected heat exposure levels and work intensity levels. The work capacity rapidly reduces as the WBGT exceeds 26-30°C and this can be used to estimate the impact of increasing heat exposure as a result of climate change in tropical countries. Conclusions: One result of climate change is a reduced work capacity in heat-exposed jobs and greater difficulty in achieving economic and social development in the countries affected by this somewhat neglected impact of climate change. Keywords: climate change; work; heat; occupational health; productivity (Published: 11 November 2009) Citation: Global Health Action 2009. DOI: 10.3402/gha.v2i0.2047

Journal ArticleDOI
TL;DR: The ACS Nearby Galaxy Survey Treasury (ANGST) as mentioned in this paper is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D 14 million stars).
Abstract: The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D 14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.

Journal ArticleDOI
TL;DR: In this article, the existence of rogue waves in Bose-Einstein condensates either loaded into a parabolic trap or embedded in an optical lattice was shown to be possible.
Abstract: We predict the existence of rogue waves in Bose-Einstein condensates either loaded into a parabolic trap or embedded in an optical lattice. In the latter case, rogue waves can be observed in condensates with positive scattering length. They are immensely enhanced by the lattice. Local atomic density may increase up to tens times. We provide the initial conditions necessary for the experimental observation of the phenomenon. Numerical simulations illustrate the process of creation of rogue waves.

Journal ArticleDOI
TL;DR: TFH dysfunction within GCs and aberrant positive selection as a pathway to systemic autoimmunity are identified and TFH dysfunction inside GCs is identified and acts autonomously to cause accumulation of TFH cells.
Abstract: Production of high-affinity pathogenic autoantibodies appears to be central to the pathogenesis of lupus. Because normal high-affinity antibodies arise from germinal centers (GCs), aberrant selection of GC B cells, caused by either failure of negative selection or enhanced positive selection by follicular helper T (TFH) cells, is a plausible explanation for these autoantibodies. Mice homozygous for the san allele of Roquin, which encodes a RING-type ubiquitin ligase, develop GCs in the absence of foreign antigen, excessive TFH cell numbers, and features of lupus. We postulated a positive selection defect in GCs to account for autoantibodies. We first demonstrate that autoimmunity in Roquinsan/san (sanroque) mice is GC dependent: deletion of one allele of Bcl6 specifically reduces the number of GC cells, ameliorating pathology. We show that Roquinsan acts autonomously to cause accumulation of TFH cells. Introduction of a null allele of the signaling lymphocyte activation molecule family adaptor Sap into the sanroque background resulted in a substantial and selective reduction in sanroque TFH cells, and abrogated formation of GCs, autoantibody formation, and renal pathology. In contrast, adoptive transfer of sanroque TFH cells led to spontaneous GC formation. These findings identify TFH dysfunction within GCs and aberrant positive selection as a pathway to systemic autoimmunity.

Journal ArticleDOI
TL;DR: A precipitous drop in costs and increase in sequencing efficiency is anticipated, with concomitant development of improved annotation technology, and it is proposed to create a collection of tissue and DNA specimens for 10,000 vertebrate species specifically designated for whole-genome sequencing in the very near future.
Abstract: American Genetic Association, Gordon and Betty Moore Foundation, NHGRI Intramural Sequencing Center, and UCSC Alumni Association to cost of the Genome 10K workshop; Howard Hughes Medical Institute to D. H.; Gordon and Betty Moore Foundation to S. C. S.; A

Journal ArticleDOI
TL;DR: The differential quantum yield method is developed that quantifies efficiency of any monochromatic light in white light and showed that, in moderate to strong white light, green light drove photosynthesis more effectively than red light.
Abstract: The literature and our present examinations indicate that the intra-leaf light absorption profile is in most cases steeper than the photosynthetic capacity profile. In strong white light, therefore, the quantum yield of photosynthesis would be lower in the upper chloroplasts, located near the illuminated surface, than that in the lower chloroplasts. Because green light can penetrate further into the leaf than red or blue light, in strong white light, any additional green light absorbed by the lower chloroplasts would increase leaf photosynthesis to a greater extent than would additional red or blue light. Based on the assessment of effects of the additional monochromatic light on leaf photosynthesis, we developed the differential quantum yield method that quantifies efficiency of any monochromatic light in white light. Application of this method to sunflower leaves clearly showed that, in moderate to strong white light, green light drove photosynthesis more effectively than red light. The green leaf should have a considerable volume of chloroplasts to accommodate the inefficient carboxylation enzyme, Rubisco, and deliver appropriate light to all the chloroplasts. By using chlorophylls that absorb green light weakly, modifying mesophyll structure and adjusting the Rubisco/chlorophyll ratio, the leaf appears to satisfy two somewhat conflicting requirements: to increase the absorptance of photosynthetically active radiation, and to drive photosynthesis efficiently in all the chloroplasts. We also discuss some serious problems that are caused by neglecting these intra-leaf profiles when estimating whole leaf electron transport rates and assessing photoinhibition by fluorescence techniques.

Journal ArticleDOI
TL;DR: In this article, the authors examined the field of the EPR gedanken experiment, from the original paper of Einstein, Podolsky, and Rosen, through to modern theoretical proposals of how to realize both the continuous-variable and discrete versions of EPR paradox.
Abstract: This Colloquium examines the field of the Einstein, Podolsky, and Rosen (EPR) gedanken experiment, from the original paper of Einstein, Podolsky, and Rosen, through to modern theoretical proposals of how to realize both the continuous-variable and discrete versions of the EPR paradox. The relationship with entanglement and Bell's theorem are analyzed, and the progress to date towards experimental confirmation of the EPR paradox is summarized, with a detailed treatment of the continuous-variable paradox in laser-based experiments. Practical techniques covered include continuous-wave parametric amplifier and optical fiber quantum soliton experiments. Current proposals for extending EPR experiments to massive-particle systems are discussed, including spin squeezing, atomic position entanglement, and quadrature entanglement in ultracold atoms. Finally, applications of this technology to quantum key distribution, quantum teleportation, and entanglement swapping are examined.

Journal ArticleDOI
TL;DR: The application of a luminescent down-shifting (LDS) layer has been proposed as a method for improving the poor spectral response (SR) of solar cells to short-wavelength light.

Journal ArticleDOI
TL;DR: In this paper, the authors present simple and general algebraic methods for describing series connections in quantum networks by allowing for more general interfaces, and by introducing an efficient algebraic tool, the series product.
Abstract: The purpose of this paper is to present simple and general algebraic methods for describing series connections in quantum networks. These methods build on and generalize existing methods for series (or cascade) connections by allowing for more general interfaces, and by introducing an efficient algebraic tool, the series product. We also introduce another product, which we call the concatenation product, that is useful for assembling and representing systems without necessarily having connections. We show how the concatenation and series products can be used to describe feedforward and feedback networks. A selection of examples from the quantum control literature are analyzed to illustrate the utility of our network modeling methodology.

Journal ArticleDOI
TL;DR: In this article, a numerical model of episodic loss assuming the presence of multiple diffusion domains yields excellent fits between synthetic and actual degassing spectra, and they used this model to isolate 40Ar∗ loss from the grains that remained intact during hydrothermal treatment at 10kbar permitting calculation of diffusion coefficients in the temperature range 730-600 ˚C.

Journal ArticleDOI
TL;DR: In this article, a plane wave is modulated by relatively weak random waves, and it is shown that the peaks with highest amplitude of the resulting wave composition can be described in terms of exact solutions of the focusing nonlinear Schrrodinger equation in the form of the collision of Akhmediev breathers.

Journal ArticleDOI
TL;DR: The parameters in greatest need of additional measurements are S(c), mesophyll cell wall thickness, and the permeabilities of the plasma membrane and chloroplast envelope.
Abstract: CO2 faces a series of resistances while diffusing between the substomatal cavities and the sites of carboxylation within chloroplasts. The absence of techniques to measure the resistance of individual steps makes it difficult to define their relative importance. Resistance to diffusion through intercellular airspace differs between leaves, but is usually of minor importance. Leaves with high photosynthetic capacity per unit leaf area reduce mesophyll resistance by increasing the surface area of chloroplasts exposed to intercellular airspace per unit leaf area, Sc. Cell walls impose a significant resistance. Assuming an effective porosity of the cell wall of 0.1 or 0.05, then cell walls could account for 25% or 50% of the total mesophyll resistance, respectively. Since the fraction of apoplastic water that is unbound and available for unhindered CO2 diffusion is unknown, it is possible that the effective porosity is 50% of the total resistance and a variable proportion. Most of the remaining resistance is imposed by one or more of the three membranes as mesophyll resistance can be altered by varying the expression of cooporins. The CO2 permeability of vesicles prepared from chloroplast envelopes has been reduced by RNA interference (RNAi) expression of NtAQP1, but not those prepared from the plasma membrane. Carbonic anhydrase activity also influences mesophyll resistance. Mesophyll resistance is relatively insensitive to the manipulation of any step in the pathway because it represents only part of the total and may also be countered by pleiotropic compensatory changes. The parameters in greatest need of additional measurements are Sc, mesophyll cell wall thickness, and the permeabilities of the plasma membrane and chloroplast envelope.