Showing papers by "Macquarie University published in 2014"
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TL;DR: This paper discusses all of these topics, identifying key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue.
Abstract: What will 5G be? What it will not be is an incremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backward compatibility. Indeed, 5G will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities, and unprecedented numbers of antennas. However, unlike the previous four generations, it will also be highly integrative: tying any new 5G air interface and spectrum together with LTE and WiFi to provide universal high-rate coverage and a seamless user experience. To support this, the core network will also have to reach unprecedented levels of flexibility and intelligence, spectrum regulation will need to be rethought and improved, and energy and cost efficiencies will become even more critical considerations. This paper discusses all of these topics, identifying key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue.
7,139 citations
Commonwealth Scientific and Industrial Research Organisation1, Rutgers University2, Heidelberg Institute for Theoretical Studies3, University of Jena4, University of Bonn5, Naturhistorisches Museum6, University of Vienna7, University of Tsukuba8, Landcare Research9, Johns Hopkins University10, University of Hamburg11, Ehime University12, Florida Museum of Natural History13, Staatliches Museum für Naturkunde Stuttgart14, Australian National University15, Macquarie University16, National Evolutionary Synthesis Center17, American Museum of Natural History18, University of Memphis19, University of Guadalajara20, Bavarian Academy of Sciences and Humanities21, Natural History Museum22, Karlsruhe Institute of Technology23, California Academy of Sciences24, South China Agricultural University25, North Carolina State University26, Hokkaido University27
TL;DR: The phylogeny of all major insect lineages reveals how and when insects diversified and provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.
Abstract: Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.
1,998 citations
George Washington University1, University of Idaho2, University of New South Wales3, University of Michigan4, University of British Columbia5, Utah State University6, University of Tennessee7, University of Western Sydney8, Wesleyan University9, University of Florida10, University of Missouri11, Macquarie University12, Queen's University13, College of the Holy Cross14, Royal Botanic Gardens15, Polish Academy of Sciences16, Michigan State University17
TL;DR: It is shown that woody clades successfully moved into freezing-prone environments by either possessing transport networks of small safe conduits and/or shutting down hydraulic function by dropping leaves during freezing.
Abstract: Early flowering plants are thought to have been woody species restricted to warm habitats 1–3 . This lineage has since radiated into almost every climate, with manifold growth forms 4 . As angiosperms spread and climate changed, they evolved mechanisms to cope with episodic freezing. To explore the evolution of traits underpinning the ability to persist in freezing conditions, we assembled a large species-level database of growth habit (woody or herbaceous; 49,064 species), as well as leaf phenology (evergreen or deciduous), diameter of hydraulic conduits (that is, xylem vessels and tracheids) and climate occupancies (exposure to freezing). To model the evolution of species’ traits and climate occupancies, we combined these data with an unparalleled dated molecular phylogeny (32,223 species) for land plants. Here we show that woody clades successfully move di nto freezingprone environments by either possessing transport networks of small
1,221 citations
University of Tokyo1, University of Wisconsin-Madison2, University of Toronto3, University of Kentucky4, University of Texas at Austin5, University of Washington6, University of St Andrews7, University of Portsmouth8, European Southern Observatory9, University of Nottingham10, National Autonomous University of Mexico11, University of Pittsburgh12, University of Cambridge13, New Mexico State University14, Carnegie Institution for Science15, University of Sydney16, New York University17, University of Utah18, University of Oxford19, University of California, Santa Cruz20, Max Planck Society21, Claude Bernard University Lyon 122, École normale supérieure de Lyon23, Texas Christian University24, University of Iowa25, Princeton University26, Case Western Reserve University27, University of La Laguna28, Chinese Academy of Sciences29, Academia Sinica30, University of Manchester31, Macquarie University32, Australian Astronomical Observatory33, Yale University34, Lawrence Berkeley National Laboratory35, University of Potsdam36, University of Victoria37, University of Groningen38
TL;DR: MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) as mentioned in this paper employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers).
Abstract: We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. MaNGA employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers). Two dual-channel spectrographs provide simultaneous wavelength coverage over 3600-10300 A at R ~ 2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 (A–1 per 2'' fiber) at 23 AB mag arcsec–2, which is typical for the outskirts of MaNGA galaxies. Targets are selected with M * 109 M ☉ using SDSS-I redshifts and i-band luminosity to achieve uniform radial coverage in terms of the effective radius, an approximately flat distribution in stellar mass, and a sample spanning a wide range of environments. Analysis of our prototype observations demonstrates MaNGA's ability to probe gas ionization, shed light on recent star formation and quenching, enable dynamical modeling, decompose constituent components, and map the composition of stellar populations. MaNGA's spatially resolved spectra will enable an unprecedented study of the astrophysics of nearby galaxies in the coming 6 yr.
1,104 citations
TL;DR: The pros and cons of how participants in Internet treatment trials have been recruited are reviewed and the assessment procedures often involved in Internet interventions are commented on, concluding that, while online questionnaires yield robust results, diagnoses cannot be determined without any contact with the patient.
787 citations
TL;DR: A novel maximum neighborhood margin discriminant projection technique for dimensionality reduction of high-dimensional data that cannot only detect the true intrinsic manifold structure of the data but also strengthen the pattern discrimination among different classes.
Abstract: We develop a novel maximum neighborhood margin discriminant projection (MNMDP) technique for dimensionality reduction of high-dimensional data. It utilizes both the local information and class information to model the intraclass and interclass neighborhood scatters. By maximizing the margin between intraclass and interclass neighborhoods of all points, MNMDP cannot only detect the true intrinsic manifold structure of the data but also strengthen the pattern discrimination among different classes. To verify the classification performance of the proposed MNMDP, it is applied to the PolyU HRF and FKP databases, the AR face database, and the UCI Musk database, in comparison with the competing methods such as PCA and LDA. The experimental results demonstrate the effectiveness of our MNMDP in pattern classification.
771 citations
University of New South Wales1, Georgia Institute of Technology2, Spanish National Research Council3, University of South Alabama4, University of Technology, Sydney5, New South Wales Department of Primary Industries6, University of Sydney7, University of Western Australia8, Macquarie University9, University of Queensland10, Kōchi University11, Marine Biological Association of the United Kingdom12, Oregon State University13
TL;DR: It is argued that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas.
Abstract: Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to ‘barrens’ when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs.
721 citations
TL;DR: Seasonal variations in CH4 emissions from a wide range of ecosystems exhibit an average temperature dependence similar to that of CH4 production derived from pure cultures of methanogens and anaerobic microbial communities, suggesting that global warming may have a large impact on the relative contributions of CO2 and CH4 to total greenhouse gas emissions from aquatic ecosystems, terrestrial wetlands and rice paddies.
Abstract: Methane (CH4) is an important greenhouse gas because it has 25 times the global warming potential of carbon dioxide (CO2) by mass over a century. Recent calculations suggest that atmospheric CH4 emissions have been responsible for approximately 20% of Earth's warming since pre-industrial times. Understanding how CH4 emissions from ecosystems will respond to expected increases in global temperature is therefore fundamental to predicting whether the carbon cycle will mitigate or accelerate climate change. Methanogenesis is the terminal step in the remineralization of organic matter and is carried out by strictly anaerobic Archaea. Like most other forms of metabolism, methanogenesis is temperature-dependent. However, it is not yet known how this physiological response combines with other biotic processes (for example, methanotrophy, substrate supply, microbial community composition) and abiotic processes (for example, water-table depth) to determine the temperature dependence of ecosystem-level CH4 emissions. It is also not known whether CH4 emissions at the ecosystem level have a fundamentally different temperature dependence than other key fluxes in the carbon cycle, such as photosynthesis and respiration. Here we use meta-analyses to show that seasonal variations in CH4 emissions from a wide range of ecosystems exhibit an average temperature dependence similar to that of CH4 production derived from pure cultures of methanogens and anaerobic microbial communities. This average temperature dependence (0.96 electron volts (eV)), which corresponds to a 57-fold increase between 0 and 30°C, is considerably higher than previously observed for respiration (approximately 0.65 eV) and photosynthesis (approximately 0.3 eV). As a result, we show that both the emission of CH4 and the ratio of CH4 to CO2 emissions increase markedly with seasonal increases in temperature. Our findings suggest that global warming may have a large impact on the relative contributions of CO2 and CH4 to total greenhouse gas emissions from aquatic ecosystems, terrestrial wetlands and rice paddies.
688 citations
TL;DR: How adequately genetic factors are currently incorporated into population viability analysis (PVA) models used to estimate minimum viable population sizes is assessed, and population size thresholds of the IUCN Red List criteria for threatened species that were derived from genetic considerations are related.
679 citations
TL;DR: This article reviews the specific flavour-active characteristics of those non-Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments and raises important questions about the direction of mixed-fermentation research to address market trends regarding so-called 'natural' wines.
Abstract: Saccharomyces cerevisiae and grape juice are ‘natural companions’ and make a happy wine marriage. However, this relationship can be enriched by allowing ‘wild’ non- Saccharomyces yeast to participate in a sequential manner in the early phases of grape must fermentation. However, such a triangular relationship is complex and can only be taken to ‘the next level’ if there are no spoilage yeast present and if the ‘wine yeast’ – S. cerevisiae – is able to exert its dominance in time to successfully complete the alcoholic fermentation. Winemakers apply various ‘matchmaking’ strategies (e.g. cellar hygiene, pH, SO2, temperature and nutrient management) to keep ‘spoilers’ (e.g. Dekkera bruxellensis ) at bay, and allow ‘compatible’ wild yeast (e.g. Torulaspora delbrueckii, Pichia kluyveri, Lachancea thermotolerans and Candida/Metschnikowia pulcherrima ) to harmonize with potent S. cerevisiae wine yeast and bring the best out in wine. Mismatching can lead to a ‘two is company, three is a crowd’ scenario. More than 40 of the 1500 known yeast species have been isolated from grape must. In this article, we review the specific flavour-active characteristics of those non- Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments. We seek to present ‘single-species’ and ‘multi-species’ ferments in a new light and a new context, and we raise important questions about the direction of mixed-fermentation research to address market trends regarding so-called ‘natural’ wines. This review also highlights that, despite the fact that most frontier research and technological developments are often focussed primarily on S. cerevisiae , non- Saccharomyces research can benefit from the techniques and knowledge developed by research on the former.
649 citations
TL;DR: In this paper, a tunable luminescence lifetime τ in the microsecond region can be exploited to code individual upconversion nanocrystals, which can be used for multichannel bioimaging, high-throughput cytometry quantification, and high-density data storage.
Abstract: Optical multiplexing plays an important role in applications such as optical data storage1, document security2, molecular probes3,4 and bead assays for personalized medicine5. Conventional fluorescent colour coding is limited by spectral overlap and background interference, restricting the number of distinguishable identities. Here, we show that tunable luminescent lifetimes τ in the microsecond region can be exploited to code individual upconversion nanocrystals. In a single colour band, one can generate more than ten nanocrystal populations with distinct lifetimes ranging from 25.6 µs to 662.4 µs and decode their well-separated lifetime identities, which are independent of both colour and intensity. Such ‘τ-dots’ potentially suit multichannel bioimaging, high-throughput cytometry quantification, high-density data storage, as well as security codes to combat counterfeiting. This demonstration extends the optical multiplexing capability by adding the temporal dimension of luminescent signals, opening new opportunities in the life sciences, medicine and data security. Control over the luminescence lifetimes of upconversion nanocrystals allows a new form of temporal multiplexing for imaging and data-storage applications.
TL;DR: In the case of an earlier spring and a later autumn, carbon uptake (photosynthesis) increases considerably more than carbon release (respiration) in temperate forests in the eastern US as mentioned in this paper.
Abstract: The timing of life-history events has a strong impact on ecosystems. Now, analysis of the phenology of temperate forests in the eastern US indicates that in the case of an earlier spring and a later autumn, carbon uptake (photosynthesis) increases considerably more than carbon release (respiration).
17 Dec 2014
TL;DR: This review examines the functions and activities of integrons before the antibiotic era and shows how antibiotic use selected particular integrons from among the environmental pool of these elements, such that integrons carrying resistance genes are now present in the majority of Gram-negative pathogens.
Abstract: SUMMARY Integrons are versatile gene acquisition systems commonly found in bacterial genomes. They are ancient elements that are a hot spot for genomic complexity, generating phenotypic diversity and shaping adaptive responses. In recent times, they have had a major role in the acquisition, expression, and dissemination of antibiotic resistance genes. Assessing the ongoing threats posed by integrons requires an understanding of their origins and evolutionary history. This review examines the functions and activities of integrons before the antibiotic era. It shows how antibiotic use selected particular integrons from among the environmental pool of these elements, such that integrons carrying resistance genes are now present in the majority of Gram-negative pathogens. Finally, it examines the potential consequences of widespread pollution with the novel integrons that have been assembled via the agency of human antibiotic use and speculates on the potential uses of integrons as platforms for biotechnology.
University of Edinburgh1, Macquarie University2, Wake Forest University3, National Centre for Biological Sciences4, University of Leeds5, Goethe University Frankfurt6, University of Otago7, Council for Scientific and Industrial Research8, University of the Witwatersrand9, North Carolina State University10, South Dakota State University11, Commonwealth Scientific and Industrial Research Organisation12, University of Queensland13, University of Brasília14, Charles Darwin University15, Venezuelan Institute for Scientific Research16, Simón Bolívar University17, University of Toulouse18, University of Tasmania19, University of Cape Town20
TL;DR: Using data from 2154 sites in savannas across Africa, Australia, and South America, it is found that increasing moisture availability drives increases in fire and tree basal area, whereas fire reduces tree basal Area.
Abstract: Ecologists have long sought to understand the factors controlling the structure of savanna vegetation. Using data from 2154 sites in savannas across Africa, Australia, and South America, we found that increasing moisture availability drives increases in fire and tree basal area, whereas fire reduces tree basal area. However, among continents, the magnitude of these effects varied substantially, so that a single model cannot adequately represent savanna woody biomass across these regions. Historical and environmental differences drive the regional variation in the functional relationships between woody vegetation, fire, and climate. These same differences will determine the regional responses of vegetation to future climates, with implications for global carbon stocks.
TL;DR: In this paper, the authors investigated and examined the effect of capital structure on Jordanian corporate performance using a panel data sample representing of 167 Jordanian companies during 1989-2003 and found that a firm's capital structure had a significantly negative impact on the firm's performance measures, in both the accounting and market's measures.
Abstract: The central objective of this study is to investigate and examine the effect which capital structure has had on corporate performance using a panel data sample representing of 167 Jordanian companies during 1989-2003. This paper also examines the effect which external shocks have had on Jordanian corporate performance and industrial sectors. Our results showed that a firm’s capital structure had a significantly negative impact on the firm’s performance measures, in both the accounting and market’s measures. This result suggests that agency issues may lead to higher debt in the capital structure than there should be. We also found that the short-term debt to total assets (STDTA) level has a significantly positive effect on the market performance measure (Tobin’s Q), which could support Myers' (1977) argument that firms with a high STDTA have a high growth rate and high performance. The Gulf Crisis 1990-1991 was found to have a positive impact on Jordanian corporate performance as the Jordanian market was the only market that was open to Iraq. On the other hand, the outbreak of Intifadah in the West Bank and Gaza in September 2000 had a negative impact on corporate performance, as most of the Jordanian companies exported to the West Bank.
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TL;DR: In this paper, the authors identify key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue.
Abstract: What will 5G be? What it will not be is an incremental advance on 4G. The previous four generations of cellular technology have each been a major paradigm shift that has broken backwards compatibility. And indeed, 5G will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities and unprecedented numbers of antennas. But unlike the previous four generations, it will also be highly integrative: tying any new 5G air interface and spectrum together with LTE and WiFi to provide universal high-rate coverage and a seamless user experience. To support this, the core network will also have to reach unprecedented levels of flexibility and intelligence, spectrum regulation will need to be rethought and improved, and energy and cost efficiencies will become even more critical considerations. This paper discusses all of these topics, identifying key challenges for future research and preliminary 5G standardization activities, while providing a comprehensive overview of the current literature, and in particular of the papers appearing in this special issue.
TL;DR: A comprehensive, in‐depth overview of literature on the structural changes of glycosylation and their associated synthetic enzymes in five different cancer types originating from the breast, colon, liver, skin and ovary is presented.
Abstract: Glycosylation of proteins is one of the most important PTMs, with more than half of all human proteins estimated to be glycosylated. It is widely known that aberrant glycosylation has been implicated in many different diseases due to changes associated with biological function and protein folding. In cancer, there is increasing evidence pertaining to the role of glycosylation in tumour formation and metastasis. Alterations in cell surface glycosylation, particularly terminal motifs, can promote invasive behaviour of tumour cells that ultimately lead to the progression of cancer. While a majority of studies have investigated protein glycosylation changes in cancer cell lines and tumour tissue for individual cancers, the review presented here represents a comprehensive, in-depth overview of literature on the structural changes of glycosylation and their associated synthetic enzymes in five different cancer types originating from the breast, colon, liver, skin and ovary. More importantly, this review focuses on key similarities and differences between these cancers that reflect the importance of structural changes of cell surface N- and O-glycans, such as sialylation, fucosylation, degree of branching and the expression of specific glycosyltransferases for each cancer. It is envisioned that the understanding of these biologically relevant glycan alterations on cellular proteins will facilitate the discovery of novel glycan-based biomarkers which could potentially serve as diagnostic and prognostic indicators of cancer.
Tongji University1, Woods Hole Oceanographic Institution2, Texas A&M University3, Lamont–Doherty Earth Observatory4, ETH Zurich5, Centre national de la recherche scientifique6, University of South Florida St. Petersburg7, Chinese Academy of Sciences8, Louisiana State University9, Oregon State University10, Macquarie University11, State Oceanic Administration12, Oeschger Centre for Climate Change Research13, Korean Ocean Research and Development Institute14, China University of Geosciences (Wuhan)15, University of São Paulo16, University of the Philippines17, China University of Geosciences (Beijing)18, Japan Agency for Marine-Earth Science and Technology19, Virginia Tech College of Natural Resources and Environment20
TL;DR: In this paper, the authors combined analyses of deep tow magnetic anomalies and International Ocean Discovery Program Expedition 349 cores to show that seafloor spreading started around 33 Ma in the northeastern South China Sea (SCS), but varied slightly by 1-2 Myr along the northern continent-ocean boundary.
Abstract: Combined analyses of deep tow magnetic anomalies and International Ocean Discovery Program Expedition 349 cores show that initial seafloor spreading started around 33 Ma in the northeastern South China Sea (SCS), but varied slightly by 1-2 Myr along the northern continent-ocean boundary (COB). A southward ridge jump of approximate to 20 km occurred around 23.6 Ma in the East Subbasin; this timing also slightly varied along the ridge and was coeval to the onset of seafloor spreading in the Southwest Subbasin, which propagated for about 400 km southwestward from approximate to 23.6 to approximate to 21.5 Ma. The terminal age of seafloor spreading is approximate to 15 Ma in the East Subbasin and approximate to 16 Ma in the Southwest Subbasin. The full spreading rate in the East Subbasin varied largely from approximate to 20 to approximate to 80 km/Myr, but mostly decreased with time except for the period between approximate to 26.0 Ma and the ridge jump (approximate to 23.6 Ma), within which the rate was the fastest at approximate to 70 km/Myr on average. The spreading rates are not correlated, in most cases, to magnetic anomaly amplitudes that reflect basement magnetization contrasts. Shipboard magnetic measurements reveal at least one magnetic reversal in the top 100 m of basaltic layers, in addition to large vertical intensity variations. These complexities are caused by late-stage lava flows that are magnetized in a different polarity from the primary basaltic layer emplaced during the main phase of crustal accretion. Deep tow magnetic modeling also reveals this smearing in basement magnetizations by incorporating a contamination coefficient of 0.5, which partly alleviates the problem of assuming a magnetic blocking model of constant thickness and uniform magnetization. The primary contribution to magnetic anomalies of the SCS is not in the top 100 m of the igneous basement.
TL;DR: Threats linked to the definition of TGB, the Clean Development Mechanism (CDM) and Reducing Emissions from Deforestation and Forest Degradation schemes (REDD+), and enhanced atmospheric CO2, which may facilitate future state shifts are discussed.
Abstract: Tropical grassy biomes (TGBs) are globally extensive, provide critical ecosystem services, and influence the earth–atmosphere system. Yet, globally applied biome definitions ignore vegetation characteristics that are critical to their functioning and evolutionary history. Hence, TGB identification is inconsistent and misinterprets the ecological processes governing vegetation structure, with cascading negative consequences for biodiversity. Here, we discuss threats linked to the definition of TGB, the Clean Development Mechanism (CDM) and Reducing Emissions from Deforestation and Forest Degradation schemes (REDD+), and enhanced atmospheric CO2, which may facilitate future state shifts. TGB degradation is insidious and less visible than in forested biomes. With human reliance on TGBs and their propensity for woody change, ecology and evolutionary history are fundamental to not only the identification of TGBs, but also their management for future persistence.
TL;DR: It is argued the merit of having students design Augmented Reality experiences in order to develop their higher order thinking capabilities, as well as establishing a future outlook forAugmented Reality and setting a research agenda going forward.
Abstract: Augmented Reality is poised to profoundly transform Education as we know it. The capacity to overlay rich media onto the real world for viewing through web-enabled devices such as phones and tablet devices means that information can be made available to students at the exact time and place of need. This has the potential to reduce cognitive overload by providing students with “perfectly situated scaffolding”, as well as enable learning in a range of other ways. This paper will review uses of Augmented Reality both in mainstream society and in education, and discuss the pedagogical potentials afforded by the technology. Based on the prevalence of information delivery uses of Augmented Reality in Education, we argue the merit of having students design Augmented Reality experiences in order to develop their higher order thinking capabilities. A case study of “learning by design” using Augmented Reality in high school Visual Art is presented, with samples of student work and their feedback indicating that the...
Max Planck Society1, Macquarie University2, Oak Ridge National Laboratory3, Boston University4, Goethe University Frankfurt5, University of Oklahoma6, CSIRO Marine and Atmospheric Research7, University of Illinois at Urbana–Champaign8, Natural Resources Canada9, Lund University10, Princeton University11, Colorado State University12, University of Bordeaux13, Institut national de la recherche agronomique14, Imperial College London15, Duke University16, Swedish University of Agricultural Sciences17
TL;DR: The results suggest that improved representation of above-ground–below-ground interactions and better constraints on plant stoichiometry are important for a predictive understanding of eCO2 effects and improved accuracy of soil organic matter inventories is pivotal to reduce uncertainty in the observed C–N budgets.
Abstract: We analysed the responses of 11 ecosystem models to elevated atmospheric [CO2] (eCO(2)) at two temperate forest ecosystems (Duke and Oak Ridge National Laboratory (ORNL) Free-Air CO2 Enrichment (FACE) experiments) to test alternative representations of carbon (C)-nitrogen (N) cycle processes. We decomposed the model responses into component processes affecting the response to eCO(2) and confronted these with observations from the FACE experiments. Most of the models reproduced the observed initial enhancement of net primary production (NPP) at both sites, but none was able to simulate both the sustained 10-yr enhancement at Duke and the declining response at ORNL: models generally showed signs of progressive N limitation as a result of lower than observed plant N uptake. Nonetheless, many models showed qualitative agreement with observed component processes. The results suggest that improved representation of above-ground-below-ground interactions and better constraints on plant stoichiometry are important for a predictive understanding of eCO(2) effects. Improved accuracy of soil organic matter inventories is pivotal to reduce uncertainty in the observed C-N budgets. The two FACE experiments are insufficient to fully constrain terrestrial responses to eCO(2), given the complexity of factors leading to the observed diverging trends, and the consequential inability of the models to explain these trends. Nevertheless, the ecosystem models were able to capture important features of the experiments, lending some support to their projections. (Less)
Leibniz Institute for Astrophysics Potsdam1, University of Cambridge2, Villanova University3, University of Strasbourg4, University of Sydney5, Heidelberg University6, Australian National University7, University of Central Lancashire8, Kapteyn Astronomical Institute9, INAF10, University of Victoria11, Australian Astronomical Observatory12, Macquarie University13, University College London14, Johns Hopkins University15, University of Ljubljana16
TL;DR: In this article, the authors used the statistics for halo concentration parameters in large cosmological simulations as a constraint to estimate the escape speed of the Milky Way-sized galaxies.
Abstract: We made new estimates of the Galactic escape speed at various Galactocentric radii using the latest data release of the RAdial Velocity Experiment (RAVE DR4) Compared to previous studies we have a database that is larger by a factor of 10, as well as reliable distance estimates for almost all stars Our analysis is based on statistical analysis of a rigorously selected sample of 90 highvelocity halo stars from RAVE and a previously published data set We calibrated and extensively tested our method using a suite of cosmological simulations of the formation of Milky Way-sized galaxies Our best estimate of the local Galactic escape speed, which we define as the minimum speed required to reach three virial radii R340, is 533 +54 −41 km s −1 (90% confidence), with an additional 4% systematic uncertainty, where R340 is the Galactocentric radius encompassing a mean overdensity of 340 times the critical density for closure in the Universe From the escape speed we further derived estimates of the mass of the Galaxy using a simple mass model with two options for the mass profile of the dark matter halo: an unaltered and an adiabatically contracted Navarro, Frenk & White (NFW) sphere If we fix the local circular velocity, the latter profile yields a significantly higher mass than the uncontracted halo, but if we instead use the statistics for halo concentration parameters in large cosmological simulations as a constraint, we find very similar masses for both models Our best estimate for M340, the mass interior to R340 (dark matter and baryons), is 13 +04 −03 × 10 12 M� (corresponds to M200 = 16 +05 −04 × 10 12 M� ) This estimate is in good agreement with recently published, independent mass estimates based on the kinematics of more distant halo stars and the satellite galaxy LeoI
University of New South Wales1, University of California, Los Angeles2, Max Planck Society3, Queen's University4, University of Guelph5, University of Innsbruck6, University of Arizona7, VU University Amsterdam8, National University of Cordoba9, Royal Botanic Gardens10, Centre national de la recherche scientifique11, ETH Zurich12, Austral University of Chile13, Goethe University Frankfurt14, University of Oldenburg15, Tohoku University16, Macquarie University17, University of Life Sciences in Lublin18, Moscow State University19, Kyoto University20, Spanish National Research Council21, Universidade Federal do Rio Grande do Sul22, Hokkaido University23, Syracuse University24, Empresa Brasileira de Pesquisa Agropecuária25, University of Amsterdam26, University of Aberdeen27, Michigan State University28, University of Wisconsin–Eau Claire29, University of Tartu30
TL;DR: This work quantified the strength of the relationships between temperature and precipitation and 21 plant traits from 447,961 species-site combinations worldwide and used meta-analysis to provide an overall answer to the question.
Abstract: Question: Are plant traits more closely correlated with mean annual temperature, or with mean annual precipitation? Location: Global. Methods: We quantified the strength of the relationships between temperature and precipitation and 21 plant traits from 447,961 species-site combinations worldwide. We used meta-analysis to provide an overall answer to our question.
TL;DR: This work reports the synthesis of luminescent crystals based on hexagonal-phase NaYF4 upconversion microrods and demonstrates that these novel materials offer opportunities as optical barcodes for anticounterfeiting and multiplexed labeling applications.
Abstract: We report the synthesis of luminescent crystals based on hexagonal-phase NaYF4 upconversion microrods. The synthetic procedure involves an epitaxial end-on growth of upconversion nanocrystals comprising different lanthanide activators onto the NaYF4 microrods. This bottom-up method readily affords multicolor-banded crystals in gram quantity by varying the composition of the activators. Importantly, the end-on growth method using one-dimensional microrods as the template enables facile multicolor tuning in a single crystal, which is inaccessible in conventional upconversion nanoparticles. We demonstrate that these novel materials offer opportunities as optical barcodes for anticounterfeiting and multiplexed labeling applications.
14 Apr 2014
TL;DR: This work describes mechanisms for secure exception handling and communication between protected modules, enabling seamless interoperability with untrusted operating systems and tasks, and presents the TrustLite security architecture for flexible, hardware-enforced isolation of software modules.
Abstract: Embedded systems are increasingly pervasive, interdependent and in many cases critical to our every day life and safety Tiny devices that cannot afford sophisticated hardware security mechanisms are embedded in complex control infrastructures, medical support systems and entertainment products [51] As such devices are increasingly subject to attacks, new hardware protection mechanisms are needed to provide the required resilience and dependency at low costIn this work, we present the TrustLite security architecture for flexible, hardware-enforced isolation of software modules We describe mechanisms for secure exception handling and communication between protected modules, enabling seamless interoperability with untrusted operating systems and tasks TrustLite scales from providing a simple protected firmware runtime to advanced functionality such as attestation and trusted execution of userspace tasks Our FPGA prototype shows that these capabilities are achievable even on low-cost embedded systems
TL;DR: This work demonstrates the first three-dimensional optical manipulation of single 50 nm dielectric objects with near-field nanotweezers, offering an unprecedented level of control of nanosized objects, including heat-sensitive biospecimens.
Abstract: Objects as small as 50 nm can be manipulated in three dimensions with near-field-based optical tweezers.
TL;DR: It is shown that infused negatively charged, immune-modifying microparticles, derived from polystyrene, microdiamonds, or biodegradable poly(lactic-co-glycolic) acid, were taken up by inflammatory monocytes, in an opsonin-independent fashion, via the macrophage receptor with collagenous structure (MARCO).
Abstract: Inflammatory monocyte-derived effector cells play an important role in the pathogenesis of numerous inflammatory diseases. However, no treatment option exists that is capable of modulating these cells specifically. We show that infused negatively charged, immune-modifying microparticles (IMPs), derived from polystyrene, microdiamonds, or biodegradable poly(lactic-co-glycolic) acid, were taken up by inflammatory monocytes, in an opsonin-independent fashion, via the macrophage receptor with collagenous structure (MARCO). Subsequently, these monocytes no longer trafficked to sites of inflammation; rather, IMP infusion caused their sequestration in the spleen through apoptotic cell clearance mechanisms and, ultimately, caspase-3-mediated apoptosis. Administration of IMPs in mouse models of myocardial infarction, experimental autoimmune encephalomyelitis, dextran sodium sulfate-induced colitis, thioglycollate-induced peritonitis, and lethal flavivirus encephalitis markedly reduced monocyte accumulation at inflammatory foci, reduced disease symptoms, and promoted tissue repair. Together, these data highlight the intricate interplay between scavenger receptors, the spleen, and inflammatory monocyte function and support the translation of IMPs for therapeutic use in diseases caused or potentiated by inflammatory monocytes.
TL;DR: In this paper, the authors presented the discovery of four surprisingly bright (H160 − 26 27 mag AB) galaxy candidates at z 9 10 in the complete HST CANDELS WFC3/IR GOODS-N imaging data, doubling the number of z � 10 galaxy candidates that are known, just �500 Myr after the Big Bang.
Abstract: We present the discovery of four surprisingly bright (H160 � 26 27 mag AB) galaxy candidates at z � 9 10 in the complete HST CANDELS WFC3/IR GOODS-N imaging data, doubling the number of z � 10 galaxy candidates that are known, just �500 Myr after the Big Bang. Two similarly bright sources are also detected in a systematic re-analysis of the GOODS-S data set. Three of the four galaxies in GOODS-N are significantly detected at 4.5 6.2� in the very deep Spitzer/IRAC 4.5µm data, as is one of the GOODS-S candidates. Furthermore, the brightest of our candidates (at z = 10.2 ± 0.4) is robustly detected also at 3.6µm (6.9�), revealing a flat UV spectral energy distribution with a slope � = 2.0±0.2, consistent with demonstrated trends with luminosity at high redshift. The abundance of such luminous candidates suggests that the luminosity function evolves more significantly in �∗ than in L∗ at z & 8 with a higher number density of bright sources than previously expected. Despite the discovery of these luminous candidates, the cosmic star formation rate density for galaxies with SFR > 0.7 M⊙ yr −1 shows an order-of-magnitude increase in only 170 Myr from z � 10 to z � 8, consistent with previous results given the dominance of low-luminosity sources to the total SFR density. Based on the IRAC detections, we derive galaxy stellar masses at z � 10, finding that these luminous objects are typically 10 9 M⊙. This allows for a first estimate of the cosmic stellar mass density at z � 10 resulting in log10 �∗ = 4.7 +0.5 −0.8 M⊙ Mpc −3 for galaxies brighter than MUV � 18. The remarkable brightness, and hence luminosity, of these z � 9 10 candidates highlights the opportunity for deep spectroscopy to determine their redshift and nature, demonstrates the value of additional search fields covering a wider area to understand star-formation in the very early universe, and highlights the opportunities for JWST to map the buildup of galaxies at redshifts much earlier than z � 10. Subject headings: galaxies: evolution — galaxies: high-redshift — galaxies: luminosity function
TL;DR: The theory explains the dependency of ci /ca ratios on temperature and vapour pressure deficit, and observed relationships of leaf δ(13) C and Narea to aridity, and predicts leaf-internal/ambient CO2 ratios and slopes of maximum carboxylation rate or leaf nitrogen versus stomatal conductance.
Abstract: A novel framework is presented for the analysis of ecophysiological field measurements and modelling. The hypothesis 'leaves minimise the summed unit costs of transpiration and carboxylation' predicts leaf-internal/ambient CO2 ratios (ci /ca ) and slopes of maximum carboxylation rate (Vcmax ) or leaf nitrogen (Narea ) vs. stomatal conductance. Analysis of data on woody species from contrasting climates (cold-hot, dry-wet) yielded steeper slopes and lower mean ci /ca ratios at the dry or cold sites than at the wet or hot sites. High atmospheric vapour pressure deficit implies low ci /ca in dry climates. High water viscosity (more costly transport) and low photorespiration (less costly photosynthesis) imply low ci /ca in cold climates. Observed site-mean ci /ca shifts are predicted quantitatively for temperature contrasts (by photorespiration plus viscosity effects) and approximately for aridity contrasts. The theory explains the dependency of ci /ca ratios on temperature and vapour pressure deficit, and observed relationships of leaf δ(13) C and Narea to aridity.