Sample records for chlamydomonas present realities

  1. Reality

    Directory of Open Access Journals (Sweden)

    Jocelyn Benoist


    Full Text Available This paper deals with the question what reality is and how can we describe it. Reality is as such beyond the dichotomy of meaning and meaningless, because it is the soil of every possibility to create such a meaning. A meaning, in other words, can succeed or fail only because it refers to a reality, which is not itself pure meaning. This reality does not need to be a transcendent reality: it is just what meaning is about. This means to forswear the perspective of a meaning and a thing which stay in front of each other. Meaning is a take or grasp on reality but it remains not in front of it. Reality is the space in which meaning can occur, it is its context. The question about the actual grasp of meaning on reality is therefore a question about our act of meaning: when are we really in our meaning?

  2. Language Learning in Virtual Reality Environments: Past, Present, and Future (United States)

    Lin, Tsun-Ju; Lan, Yu-Ju


    This study investigated the research trends in language learning in a virtual reality environment by conducting a content analysis of findings published in the literature from 2004 to 2013 in four top ranked computer-assisted language learning journals: "Language Learning & Technology," "CALICO Journal," "Computer…

  3. Reaalsuse re/presenteerimise strateegiad etenduskunstides / Strategies to Re-(Present Reality in the Performing Arts

    Directory of Open Access Journals (Sweden)

    Anneli Saro


    Full Text Available Contemporary theatre, and performing arts in general, no longer seems to be interested in the representation of illusion and reality. There seems to be an increasing emphasis on free play or/and an immediate presentation of reality. And, thus, the mainstream is moving towards the aesthetics of performance art and happenings, where recurrence is shunned and improvisation is emphasized on one hand, while the boundary between performance and reality is obscured on the other. This means that representative theatre, where performers and objects signify someone/something other, is retreating to give way to presentative theatre, where the performers and objects primarily signify themselves.  In the light of the aforementioned, this paper attempts to answer the following questions: how has the presentation of reality in theatre changed over the last forty years, how does presentative theatre differ from representative theatre and does presentative theatre arrive at a deeper/more objective understanding of reality or merely create yet another illusion? In order to answer these questions, the complicated relationship between art and reality as well as issues intrinsic to realist theatre are analysed. The author attempts to prove that it is difficult to find anything fundamentally new in 21st century theatre practice. A lot of the currently fashionable strategies are further developments of older waves, such as realism, or experiments placed in a new temporal and cultural context.  Considering the physical relationship between performing arts and reality, the third section of the paper analyses three strategies of (re-presenting reality: 1. Presenting the elements of reality on stage: performances of documentary material in as authentic a manner as possible, i.e. the self-presentations of so-called regular people or actors, etc. 2. Giving reality an artistic framework: audience tours through the city led by guide(s/performer(s or audio guides. 3

  4. KioskAR: An Augmented Reality Game as a New Business Model to Present Artworks

    Directory of Open Access Journals (Sweden)

    Yoones A. Sekhavat


    Full Text Available This paper presents the architecture of KioskAR, which is a pervasive game implemented using augmented reality (AR. This game introduces a new business model that makes it possible for players to present their artworks in virtual kiosks using augmented reality, while they are having fun playing the game. In addition to competition between the players in the game, this game requires social interaction between players to earn more points. A user study is conducted to evaluate the sense of presence and the usability of the application. The results of experiments show that KioskAR can achieve a high level of usability as well as sense of presence.

  5. Reality (United States)

    Harteveld, Casper

    The first of the three worlds to be discussed is Reality. This whole level is devoted to this world consisting of consultants, subject-matter experts, and disciplines related to the domain and subject of the game. After a short introduction where I show—amongst many other things—a virtual reproduction and game interpretation of Magritte's famous painting of a pipe, I explain by using my experiences from Levee Patroller and drawing upon other examples, four relevant aspects from this world that designers need to consider. The first concerns defining the problem. This is quite hard, especially because at many times, different problem definitions can be conceived. When a problem is finally defined, the second aspect, the factors which are involved with the problem, need to be found and elaborated on. If designers start to relate the factors to each other, they are preoccupied with the third aspect, the relationships. To picture this well, it helps to draw a diagram. Mostly, games are not static and that is why the process needs to be taken into account as well. After considering this fourth aspect, the “model of reality” can be said to be complete. To judge this model and the eventual game, Reality has its own criteria of which I discuss flexibility, fidelity, and validity.

  6. [Memory assessment by means of virtual reality: its present and future]. (United States)

    Diaz-Orueta, Unai; Climent, Gema; Cardas-Ibanez, Jaione; Alonso, Laura; Olmo-Osa, Juan; Tirapu-Ustarroz, Javier


    The human memory is a complex cognitive system whose close relationship with executive functions implies that, in many occasions, a mnemonic deficit comprises difficulties to operate with correctly stored contents. Traditional memory tests, more focused in the information storage than in its processing, may be poorly sensitive both to subjects' daily life functioning and to changes originated by rehabilitation programs. In memory assessment, there is plenty evidence with regards to the need of improving it by means of tests which offer a higher ecological validity, with information that may be presented in various sensorial modalities and produced in a simultaneous way. Virtual reality reproduces three-dimensional environments with which the patient interacts in a dynamic way, with a sense of immersion in the environment similar to the presence and exposure to a real environment, and in which presentation of such stimuli, distractors and other variables may be systematically controlled. The current review aims to go deeply into the trajectory of neuropsychological assessment of memory based in virtual reality environments, making a tour through existing tests designed for assessing learning, prospective, episodic and spatial memory, as well as the most recent attempts to perform a comprehensive evaluation of all memory components.

  7. Development of a Virtual Museum Including a 4d Presentation of Building History in Virtual Reality (United States)

    Kersten, T. P.; Tschirschwitz, F.; Deggim, S.


    In the last two decades the definition of the term "virtual museum" changed due to rapid technological developments. Using today's available 3D technologies a virtual museum is no longer just a presentation of collections on the Internet or a virtual tour of an exhibition using panoramic photography. On one hand, a virtual museum should enhance a museum visitor's experience by providing access to additional materials for review and knowledge deepening either before or after the real visit. On the other hand, a virtual museum should also be used as teaching material in the context of museum education. The laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has developed a virtual museum (VM) of the museum "Alt-Segeberger Bürgerhaus", a historic town house. The VM offers two options for visitors wishing to explore the museum without travelling to the city of Bad Segeberg, Schleswig-Holstein, Germany. Option a, an interactive computer-based, tour for visitors to explore the exhibition and to collect information of interest or option b, to immerse into virtual reality in 3D with the HTC Vive Virtual Reality System.

  8. Augmented Reality for Augmented Reality


    Pankratz, Frieder


    A recurring challenge when setting up any augmented reality system is the correct calibration and registration of the involved devices. Augmented Reality for Augmented Reality (AR4AR) generates augmented reality guides by using the already existing knowledge about the AR system which stems from the setup of the AR system itself. As these guides involve plenty of 3D information, it is again best presented through means of Augmented Reality, thus the name AR4AR. Eine wiederkehrende Herausfor...

  9. The Chlamydomonas genome project: a decade on (United States)

    Blaby, Ian K.; Blaby-Haas, Crysten; Tourasse, Nicolas; Hom, Erik F. Y.; Lopez, David; Aksoy, Munevver; Grossman, Arthur; Umen, James; Dutcher, Susan; Porter, Mary; King, Stephen; Witman, George; Stanke, Mario; Harris, Elizabeth H.; Goodstein, David; Grimwood, Jane; Schmutz, Jeremy; Vallon, Olivier; Merchant, Sabeeha S.; Prochnik, Simon


    The green alga Chlamydomonas reinhardtii is a popular unicellular organism for studying photosynthesis, cilia biogenesis and micronutrient homeostasis. Ten years since its genome project was initiated, an iterative process of improvements to the genome and gene predictions has propelled this organism to the forefront of the “omics” era. Housed at Phytozome, the Joint Genome Institute’s (JGI) plant genomics portal, the most up-to-date genomic data include a genome arranged on chromosomes and high-quality gene models with alternative splice forms supported by an abundance of RNA-Seq data. Here, we present the past, present and future of Chlamydomonas genomics. Specifically, we detail progress on genome assembly and gene model refinement, discuss resources for gene annotations, functional predictions and locus ID mapping between versions and, importantly, outline a standardized framework for naming genes. PMID:24950814

  10. MEETING: Chlamydomonas Annotation Jamboree - October 2003

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, Arthur R


    Shotgun sequencing of the nuclear genome of Chlamydomonas reinhardtii (Chlamydomonas throughout) was performed at an approximate 10X coverage by JGI. Roughly half of the genome is now contained on 26 scaffolds, all of which are at least 1.6 Mb, and the coverage of the genome is ~95%. There are now over 200,000 cDNA sequence reads that we have generated as part of the Chlamydomonas genome project (Grossman, 2003; Shrager et al., 2003; Grossman et al. 2007; Merchant et al., 2007); other sequences have also been generated by the Kasuza sequence group (Asamizu et al., 1999; Asamizu et al., 2000) or individual laboratories that have focused on specific genes. Shrager et al. (2003) placed the reads into distinct contigs (an assemblage of reads with overlapping nucleotide sequences), and contigs that group together as part of the same genes have been designated ACEs (assembly of contigs generated from EST information). All of the reads have also been mapped to the Chlamydomonas nuclear genome and the cDNAs and their corresponding genomic sequences have been reassembled, and the resulting assemblage is called an ACEG (an Assembly of contiguous EST sequences supported by genomic sequence) (Jain et al., 2007). Most of the unique genes or ACEGs are also represented by gene models that have been generated by the Joint Genome Institute (JGI, Walnut Creek, CA). These gene models have been placed onto the DNA scaffolds and are presented as a track on the Chlamydomonas genome browser associated with the genome portal ( Ultimately, the meeting grant awarded by DOE has helped enormously in the development of an annotation pipeline (a set of guidelines used in the annotation of genes) and resulted in high quality annotation of over 4,000 genes; the annotators were from both Europe and the USA. Some of the people who led the annotation initiative were Arthur Grossman, Olivier Vallon, and Sabeeha Merchant (with many individual

  11. Multi-Modal presentation of Works of Art in Virtual Reality with Simulation of Multi-Mirror Reflections

    DEFF Research Database (Denmark)

    Livatino, Salvatore


    The use of different media such as photography and virtual reality combined with different presentation modalities may provide a user with an extraordinary tool for exploration and appreciation of real work of art. This is especially important in case of time-spatial works-of-art where the problem...... of functionalities presentation becomes much more demanding. The possibility offered by latest graphics machines has attracted the interest of researchers to investigate this new area. The goal of the presented work is the creation of a multi-modal presentation of a piece of contemporary art, tightening the relation...... between computer graphics and arts. The focus is on an application that it is capable to cope in real-time with simulation of mirror reflections including multi reflections. The results were very encouraging which led to optimistic conclusions with a wide range of options for future works....

  12. Mastoparan-Induced Cell Death Signalling in Chlamydomonas Reinhardtii

    NARCIS (Netherlands)

    Yordanova, Z.P.; Kapchina-Toteva, V.M.; Woltering, E.J.; Cristescu, S.M.; Harren, F.J.M.; Yakimova, E.T.


    The present study was focused on the elucidation of stress-induced cell death signaling events in the unicellular alga Chlamydomonas reinhardtii exposed to treatment with wasp venom mastoparan. By applying pharmacological approach with specific inhibitors, we have investigated the involvement of eth

  13. Forget the hype or reality. Big data presents new opportunities in Earth Science. (United States)

    Lee, T. J.


    Earth science is arguably one of the most mature science discipline which constantly acquires, curates, and utilizes a large volume of data with diverse variety. We deal with big data before there is big data. For example, while developing the EOS program in the 1980s, the EOS data and information system (EOSDIS) was developed to manage the vast amount of data acquired by the EOS fleet of satellites. EOSDIS continues to be a shining example of modern science data systems in the past two decades. With the explosion of internet, the usage of social media, and the provision of sensors everywhere, the big data era has bring new challenges. First, Goggle developed the search algorithm and a distributed data management system. The open source communities quickly followed up and developed Hadoop file system to facility the map reduce workloads. The internet continues to generate tens of petabytes of data every day. There is a significant shortage of algorithms and knowledgeable manpower to mine the data. In response, the federal government developed the big data programs that fund research and development projects and training programs to tackle these new challenges. Meanwhile, comparatively to the internet data explosion, Earth science big data problem has become quite small. Nevertheless, the big data era presents an opportunity for Earth science to evolve. We learned about the MapReduce algorithms, in memory data mining, machine learning, graph analysis, and semantic web technologies. How do we apply these new technologies to our discipline and bring the hype to Earth? In this talk, I will discuss how we might want to apply some of the big data technologies to our discipline and solve many of our challenging problems. More importantly, I will propose new Earth science data system architecture to enable new type of scientific inquires.

  14. Associations between facial emotion recognition, cognition and alexithymia in patients with schizophrenia: comparison of photographic and virtual reality presentations. (United States)

    Gutiérrez-Maldonado, J; Rus-Calafell, M; Márquez-Rejón, S; Ribas-Sabaté, J


    Emotion recognition is known to be impaired in schizophrenia patients. Although cognitive deficits and symptomatology have been associated with this impairment there are other patient characteristics, such as alexithymia, which have not been widely explored. Emotion recognition is normally assessed by means of photographs, although they do not reproduce the dynamism of human expressions. Our group has designed and validated a virtual reality (VR) task to assess and subsequently train schizophrenia patients. The present study uses this VR task to evaluate the impaired recognition of facial affect in patients with schizophrenia and to examine its association with cognitive deficit and the patients' inability to express feelings. Thirty clinically stabilized outpatients with a well-established diagnosis of schizophrenia or schizoaffective disorder were assessed in neuropsychological, symptomatic and affective domains. They then performed the facial emotion recognition task. Statistical analyses revealed no significant differences between the two presentation conditions (photographs and VR) in terms of overall errors made. However, anger and fear were easier to recognize in VR than in photographs. Moreover, strong correlations were found between psychopathology and the errors made.

  15. Augmented Reality

    DEFF Research Database (Denmark)

    Arusoaie, Andrei; Cristei, Alexandru Ionuţ; Chircu, Cristian


    Virtual Reality is becoming more than a part of our everyday life, helping us to identify quickly the elements of the environment or to better entertain us. The purpose of this paper is to present an application framework that we are developing, in order to help others implement their own...... applications. In the first section the focus is set on the Augmented Reality basic concepts and the necessity of developing such a framework. The prototype that we present in the second part of this paper comes to demonstrate how our framework can be used to achieve our targeted application for Augmented...... Reality. It also contains some future works to highlight the capabilities of the AR API. © 2010 IEEE....

  16. Regulation by glutathionylation of isocitrate lyase from Chlamydomonas reinhardtii. (United States)

    Bedhomme, Mariette; Zaffagnini, Mirko; Marchand, Christophe H; Gao, Xing-Huang; Moslonka-Lefebvre, Mathieu; Michelet, Laure; Decottignies, Paulette; Lemaire, Stéphane D


    Post-translational modification of protein cysteine residues is emerging as an important regulatory and signaling mechanism. We have identified numerous putative targets of redox regulation in the unicellular green alga Chlamydomonas reinhardtii. One enzyme, isocitrate lyase (ICL), was identified both as a putative thioredoxin target and as an S-thiolated protein in vivo. ICL is a key enzyme of the glyoxylate cycle that allows growth on acetate as a sole source of carbon. The aim of the present study was to clarify the molecular mechanism of the redox regulation of Chlamydomonas ICL using a combination of biochemical and biophysical methods. The results clearly show that purified C. reinhardtii ICL can be inactivated by glutathionylation and reactivated by glutaredoxin, whereas thioredoxin does not appear to regulate ICL activity, and no inter- or intramolecular disulfide bond could be formed under any of the conditions tested. Glutathionylation of the protein was investigated by mass spectrometry analysis, Western blotting, and site-directed mutagenesis. The enzyme was found to be protected from irreversible oxidative inactivation by glutathionylation of its catalytic Cys(178), whereas a second residue, Cys(247), becomes artifactually glutathionylated after prolonged incubation with GSSG. The possible functional significance of this post-translational modification of ICL in Chlamydomonas and other organisms is discussed.

  17. Augmented reality: a review. (United States)

    Berryman, Donna R


    Augmented reality is a technology that overlays digital information on objects or places in the real world for the purpose of enhancing the user experience. It is not virtual reality, that is, the technology that creates a totally digital or computer created environment. Augmented reality, with its ability to combine reality and digital information, is being studied and implemented in medicine, marketing, museums, fashion, and numerous other areas. This article presents an overview of augmented reality, discussing what it is, how it works, its current implementations, and its potential impact on libraries.

  18. High quality metabolomic data for Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Fiehn Oliver


    Full Text Available Abstract The green eukaryote alga Chlamydomonas reinhardtii is a unicellular model to study control of metabolism in a photosynthetic organism. We here present method improvements for metabolite profiling based on GC-TOF mass spectrometry focusing on three parameters: quenching and cell disruption, extract solvent composition and metabolite annotation. These improvements facilitate using smaller cell numbers and hence, smaller culture volumes which enable faster and more precise sampling techniques that eventually lead to a higher number of samples that can be processed, e.g. for time course experiments. Quenching of metabolism was achieved by mixing 1 ml of culture to 1 ml of -70°C cold 70% methanol. After centrifugation, cells were lyophilized and disrupted by milling using 2-6E6 lyophilized cells, around 500-fold less than previously reported. Glass beads were compared to metal balls for milling, and five different extraction solvents were tested. Additionally, all peaks were annotated in an automated way using the GC-TOF database BinBase instead of manual investigation of a single reference chromatogram. Median precision of analysis was used to decide for the eventual procedure which was applied to a proof-of-principle study of time dependent changes of metabolism under standard conditions.

  19. Selenoprotein-Transgenic Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Jiazuan Ni


    Full Text Available Selenium (Se deficiency is associated with the occurrence of many diseases. However, excessive Se supplementation, especially with inorganic Se, can result in toxicity. Selenoproteins are the major forms of Se in vivo to exert its biological function. Expression of those selenoproteins, especially with the application of a newly developed system, is thus very important for studying the mechanism of Se in nutrition. The use of Chlamydomonas reinhardtii (C. reinhardtii as a biological vector to express an heterogeneous protein is still at the initial stages of development. In order to investigate the possibility of using this system to express selenoproteins, human 15-KDa selenoprotein (Sep15, a small but widely distributed selenoprotein in mammals, was chosen for the expression platform test. Apart from the wild-type human Sep15 gene fragment, two Sep15 recombinants were constructed containing Sep15 open reading frame (ORF and the selenocysteine insertion sequence (SECIS element from either human Sep15 or C. reinhardtii selenoprotein W1, a highly expressed selenoprotein in this alga. Those Sep15-containing plasmids were transformed into C. reinhardtii CC-849 cells. Results showed that Sep15 fragments were successfully inserted into the nuclear genome and expressed Sep15 protein in the cells. The transgenic and wild-type algae demonstrated similar growth curves in low Se culture medium. To our knowledge, this is the first report on expressing human selenoprotein in green alga.

  20. Virtual Reality

    Directory of Open Access Journals (Sweden)

    Bhavana Gupta


    Full Text Available An artificial environment created with co mputer hardware and software and presented to the user in such a way that it appears and feels like a real environment. To "enter" a virtual reality, a user does special gloves, earphones, and goggles, all of which receive their input from the computer system. In this way, at least three of the five senses are controlled by the computer. In addition to feeding sensory input to the user, the devices also monitor the user's actions

  1. Mastoparan-induced programmed cell death in the unicellular alga Chlamydomonas reinhardtti

    NARCIS (Netherlands)

    Yordanova, Z.P.; Woltering, E.J.; Kapchina-Toteva, V.M.; Iakimova, E.T.


    The present study was focused on the elucidation of stress-induced cell death signaling events in the unicellular alga Chlamydomonas reinhardtii exposed to treatment with wasp venom mastoparan. By applying pharmacological approach with specific inhibitors, we have investigated the involvement of eth

  2. Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality. (United States)

    Grubert, Jens; Langlotz, Tobias; Zollmann, Stefanie; Regenbrecht, Holger


    Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

  3. Augmented Reality in Astrophysics

    CERN Document Server

    Vogt, Frédéric P A


    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging technology of Augmented Reality can already be used and implemented without expert knowledge using currently available apps. Our experiments highlight the potential of Augmented Reality to improve the communication of scientific results in the field of astrophysics. We also present feedback gathered from the Australian astrophysics community that reveals evidence of some interest in this technology by astronomers who experimented with Augmented Posters. In addition, we discuss p...

  4. Presentation

    Directory of Open Access Journals (Sweden)

    Nicanor Lopes


    Full Text Available The Journal Caminhando debuts with a new editorial format: eachmagazine will have a Dossier.In 2010 Christianity celebrated the centenary of Edinburgh. TheWorld Missionary Conference in Edinburgh in 1910 is regarded by manyas missiological watershed in the missionary and ecumenical movement.So the Faculty of Theology of the Methodist Church (FATEO decidedto organize a Wesleyan Week discussing the issue of mission. For anevent of this magnitude FATEO invited the Rev. Dr. Wesley Ariarajah,Methodist pastor and teacher of Sri Lanka with extensive experience inpastoral ministry in local churches and professor of History of Religionsand the New Testament at the Theological College of Lanka, maintainedby the Protestant Churches in Sri Lanka. In 1981 he was invited to jointhe World Council of Churches, where he presided for over ten years theCouncil of Interreligious Dialogue. From 1992 he served as Deputy GeneralSecretary of the WCC.The following texts are not the speeches of the Rev. Dr. WesleyAriarajah, for they will be published separately. Nevertheless, the journaldialogs with the celebrations of the centenary of Edinburgh, parting formthe intriguing theme: "Mission in the 21st century in Brazil". After all, howis it that mission takes place among us in personal, church, and communityactivities?Within the Dossier, as common to the journal, the textos are organizedas follows: Bible, Theology / History and Pastoral Care. Other items thatdo not fit within the Dossier, but, do articulate mission, can be found inthe section Declarations and Documents and Book Reviews.The authors of the Dossier have important considerations in buildinga contemporary missiological concept considering Brazilian reality.Anderson de Oliveira, in the Bible-Section, presents a significantexegeses of Matthew 26.6-13. What does it mean when Jesus is quotedwith the words: "For the poor always ye have with you, but me ye havenot always." Is this declaration challenging the gospels

  5. Augmented Reality

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter Bech; Rahn, Annette


    This chapter describes the use of iPad-facilitated application of augmented reality in the teaching of highly complex anatomical and physiological subjects in the training of nurses at undergraduate level. The general aim of the project is to investigate the potentials of this application in terms...... of augmented reality are discussed....

  6. Virtual realities and education

    Directory of Open Access Journals (Sweden)

    Curcio Igor D.D.


    Full Text Available The purpose of this article is to highlight the state of the art of virtual reality, augmented reality, mixed reality technologies and their applications in formal education. We also present a selected list of case studies that prove the utility of these technologies in the context of formal education. Furthermore, as byproduct, the mentioned case studies show also that, although the industry is able to develop very advanced virtual environment technologies, their pedagogical implications are strongly related to a well-designed theoretical framework.

  7. Virtual reality


    Zheng, JM; Chan, KW; Gibson, I.


    Virtual reality is still in its infancy. However, many contemporary applications already have proven virtual reality to be indispensable to everyday life. For instance, the technology of virtual product design and manufacturing makes the new products better and cheaper. The applications of VR in medicine allow doctors to diagnose a disease more accurately. Without a doubt, it has and will foster more innovative research and applications. High-resolution, low-lag and low-price systems will be ...

  8. Light stress and photoprotection in Chlamydomonas reinhardtii. (United States)

    Erickson, Erika; Wakao, Setsuko; Niyogi, Krishna K


    Plants and algae require light for photosynthesis, but absorption of too much light can lead to photo-oxidative damage to the photosynthetic apparatus and sustained decreases in the efficiency and rate of photosynthesis (photoinhibition). Light stress can adversely affect growth and viability, necessitating that photosynthetic organisms acclimate to different environmental conditions in order to alleviate the detrimental effects of excess light. The model unicellular green alga, Chlamydomonas reinhardtii, employs diverse strategies of regulation and photoprotection to avoid, minimize, and repair photo-oxidative damage in stressful light conditions, allowing for acclimation to different and changing environments.

  9. A Review on Virtual Reality

    Directory of Open Access Journals (Sweden)

    Pallavi Halarnkar


    Full Text Available Virtual Reality is a major asset and aspect of our future. It is the key to experiencing, feeling and touching the past, present and the future. It is the medium of creating our own world, our own customized reality. It could range from creating a video game to having a virtual stroll around the universe, from walking through our own dream house to experiencing a walk on an alien planet. With virtual reality, we can experience the most intimidating and gruelling situations by playing safe and with a learning perspective. In this review paper, we present our survey about virtual reality: the levels of virtual reality, the components used, the factors affecting the virtual environment, its origin, future and the challenges to overcome in order to obtain an impeccable virtual reality experience.

  10. [An experiment with Chlamydomonas reinhardtii on the Kosmos-2044 biosatellite]. (United States)

    Gavrilova, O V; Gabova, A V; Goriainova, L N; Filatova, E V


    Space experiment with Chlamydomonas reinhardtii demonstrated that the microgravity effects were noted in Chlamydomonas at both cellular and population levels: in space the cell size is increased, stage of active growth of the culture is extended, it contains the juvenile vegetative motile cells in greater quantities. Ultrastructural analysis indicated that in microgravity the changes in shape, structure and distribution of intracellular organelles and in volume ratio of organelles and cytoplasma are absent. Chlamydomonas data are in line with the results of the Infusoria and Chlorella experiments.

  11. Phototaxis beyond turning: persistent accumulation and response acclimation of the microalga Chlamydomonas reinhardtii

    CERN Document Server

    Arrieta, Jorge; Chioccioli, Maurizio; Polin, Marco; Tuval, Idan


    Phototaxis is an important reaction to light displayed by a wide range of motile microorganisms. Flagellated eukaryotic microalgae in particular, like the model organism Chlamydomonas reinhardtii, steer either towards or away from light by a rapid and precisely timed modulation of their flagellar activity. Cell steering, however, is only the beginning of a much longer process which ultimately allows cells to determine their light exposure history. This process is not well understood. Here we present a first quantitative study of the long timescale phototactic motility of Chlamydomonas at both single cell and population levels. Our results reveal that the phototactic strategy adopted by these microorganisms leads to an efficient exposure to light, and that the phototactic response is modulated over typical timescales of tens of seconds. The adaptation dynamics for phototaxis and chlorophyll fluorescence show a striking quantitative agreement, suggesting that photosynthesis controls quantitatively how cells nav...

  12. Paternal inheritance of mitochondria in Chlamydomonas. (United States)

    Nakamura, Soichi


    To analyze mitochondrial DNA (mtDNA)inheritance, differences in mtDNA between Chlamydomonas reinhardtii and Chlamydomonas smithii, respiration deficiency and antibiotic resistance were used to distinguish mtDNA origins. The analyses indicated paternal inheritance. However, these experiments raised questions regarding whether paternal inheritance occurred normally.Mitochondrial nucleoids were observed in living zygotes from mating until 3 days after mating and then until progeny formation. However, selective disappearance of nucleoids was not observed. Subsequently, experimental serial backcrosses between the two strains demonstrated strict paternal inheritance. The fate of mt+ and mt- mtDNA was followed using the differences in mtDNA between the two strains. The slow elimination of mt+ mtDNA through zygote maturation in darkness was observed, and later the disappearance of mt+ mtDNA was observed at the beginning of meiosis. To explain the different fates of mtDNA, methylation status was investigated; however, no methylation was detected. Variously constructed diploid cells showed biparental inheritance. Thus, when the mating process occurs normally, paternal inheritance occurs. Mutations disrupting mtDNA inheritance have not yet been isolated. Mutations that disrupt maternal inheritance of chloroplast DNA (cpDNA) do not disrupt inheritance of mtDNA. The genes responsible for mtDNA inheritance are different from those of chloroplasts.

  13. Confronting Reality

    Institute of Scientific and Technical Information of China (English)


    Confronting Reality will change the way you think about and run your business, It is the first book that shows how to connect the big picture of the new era of business with the nitty-gritty of what to do about it. Through a completely new way to understand and use the business model as the primary tool for confronting reality-breakthrough that will become the management innovaticn of this decade you'll know sooner rather than later whether your fundamental business premise is under assault where your best opportunities lie .

  14. A brief introduction to the model microswimmer {\\it Chlamydomonas reinhardtii}

    CERN Document Server

    Jeanneret, Raphaël; Polin, Marco


    The unicellular biflagellate green alga {\\it Chlamydomonas reinhardtii} has been an important model system in biology for decades, and in recent years it has started to attract growing attention also within the biophysics community. Here we provide a concise review of some of the aspects of {\\it Chlamydomonas} biology and biophysics most immediately relevant to physicists that might be interested in starting to work with this versatile microorganism.

  15. Presentation

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Freire Vieira


    Full Text Available This dossier focuses on one of the essential debate topics today about the territorial dimension of the new development strategies concerned with the worsening of the global socioecological crisis, that is: the challenges related to the activation and integration in networks of localized agri-food systems. For its composition, some contributions presented and debated during the VI International Conference on Localized Agri-food System - The LAFS facing the opportunities and challenges of the new global context have been gathered. The event took place in the city of Florianópolis, from May 21th to 25th of 2013. The event was promoted by the Federal University of Santa Catarina (UFSC and by the Center for the International Cooperation on Agricultural Research for Development (CIRAD. Besides UFSC and CIRAD, EPAGRI, State University of Santa Catarina (UDESC, as well as research institutes and universities from other states (UFMG, IEA/SP, UFS, UFRGS and Mexican and Argentinian partners from the RED SIAL Latino Americana also participated in the organization of lectures, discussion tables and workshops.

  16. Augmented Reality

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher; Kjeldsen, Lars Peter Bech; Rahn, Annette


    This chapter describes the use of iPad-facilitated application of augmented reality in the teaching of highly complex anatomical and physiological subjects in the training of nurses at undergraduate level. The general aim of the project is to investigate the potentials of this application in term...

  17. Contesting realities

    Directory of Open Access Journals (Sweden)

    Jessica Whyte


    Full Text Available In 2004, an unnamed Bush adviser accused a senior Wall Street Journal reporter of belonging to the “reality based community”—a community that believed solutions stem from the judicious study of reality. “We're history's actors, “ he told the journalist, “and you, all of you, will be left to just study what we do.” Overwhelmingly, the response of those on the left, and of US progressives to this comment was to smugly deride the irrationalism and the arrogance of the Bush Administration. This paper, in contrast, will examine what is missed in the rush to accept membership of the reality based community. It will suggest that that the advisor's comments express something that was once a central tenet of the left: the belief that political action is capable of transforming reality. Today, on the left, this belief has been all but abandoned in the face of a seemingly unstoppable onslaught of free market capitalism and increasingly repressive state power. This paper will ask what it would mean today, to begin to re-imagine political action as capable of remaking the world.

  18. Virtual Reality. (United States)

    Newby, Gregory B.


    Discusses the current state of the art in virtual reality (VR), its historical background, and future possibilities. Highlights include applications in medicine, art and entertainment, science, business, and telerobotics; and VR for information science, including graphical display of bibliographic data, libraries and books, and cyberspace.…

  19. Alternate Realities (United States)

    Jones, Robert


    Two identical learners, observing different example input, or the same examples, but in different order, can form different categories and so judge newer/later input differently. (Machine Learning, T. Mitchell, McGraw Hill, 1997 and Asa H., R. Jones, Trans. Kansas Acad. Sci., vol 109, # 3/4, pg 159, 2006) It seems certain that each of us experiences a somewhat different reality, the question is just how widely these realities can vary one from another. Perhaps 4% of people exhibit synesthesia, perceiving letters or numbers as colored, numbers and dates as having personalities or occupying locations in space. (Synesthesia, R. Cytowic, MIT Press, 2002) The Sapir- Whorf hypothesis claims that a speakers language influences his category structure and the way he thinks. (Language, thought, and reality, B. Whorf, MIT Press, 1956) Those who are skillful at mathematics may know an additional language and be able to think thoughts that the layman can not. The philosophers Plato and Descartes claimed to have had, at certain moments in their lives, a new view of the world, its basic constituents, and its rules which were totally different from our conventional view of reality. (Reflections on Kurt Godel, H. Wang, MIT Press, 1987, pg. 46) Fairly large scale differences are experienced by those who believe in (make use of) concepts like spirit(s), soul(s), god(s), life after death, platonism or Everett's many worlds interpretation of quantum mechanics (The Physics of Immortality, F. Tipler, Doubleday, 1994, pg. 176) )

  20. Presentation

    Directory of Open Access Journals (Sweden)

    Eduardo Vicente


    Full Text Available In the present edition of Significação – Scientific Journal for Audiovisual Culture and in the others to follow something new is brought: the presence of thematic dossiers which are to be organized by invited scholars. The appointed subject for the very first one of them was Radio and the invited scholar, Eduardo Vicente, professor at the Graduate Course in Audiovisual and at the Postgraduate Program in Audiovisual Media and Processes of the School of Communication and Arts of the University of São Paulo (ECA-USP. Entitled Radio Beyond Borders the dossier gathers six articles and the intention of reuniting works on the perspectives of usage of such media as much as on the new possibilities of aesthetical experimenting being build up for it, especially considering the new digital technologies and technological convergences. It also intends to present works with original theoretical approach and original reflections able to reset the way we look at what is today already a centennial media. Having broadened the meaning of “beyond borders”, four foreign authors were invited to join the dossier. This is the first time they are being published in this country and so, in all cases, the articles where either written or translated into Portuguese.The dossier begins with “Radio is dead…Long live to the sound”, which is the transcription of a thought provoking lecture given by Armand Balsebre (Autonomous University of Barcelona – one of the most influential authors in the world on the Radio study field. It addresses the challenges such media is to face so that it can become “a new sound media, in the context of a new soundscape or sound-sphere, for the new listeners”. Andrew Dubber (Birmingham City University regarding the challenges posed by a Digital Era argues for a theoretical approach in radio studies which can consider a Media Ecology. The author understands the form and discourse of radio as a negotiation of affordances and

  1. Presentation

    Directory of Open Access Journals (Sweden)

    Helmut Renders


    Full Text Available We present to our esteemed readers the second edition of our journal for 2008. We have chosen the theme “The life and work of Prof. Dr. Jürgen Moltmann” as its special emphasis. It is our way to pay homage to J. Moltmann in the year the Universidade Metodista de São Paulo awards him an honorary Doctor Honoris Causa degree. Sincethe seventies, Moltmann and Latin America have been in dialog. In his emblematic work “A Theology of Liberation”, Gustavo Gutiérrez, the Catholic, discussed with Moltmann, the Reformed, the relationship between eschatology and history (GUTIÉRREZ, Gustavo.Teologia da Libertação. 5ª edição. Petrópolis, RJ: Vozes, 1985, p. 27, 137-139. A dialog held in the premises of IMS, which nowadays is called UMESP, has produced the little book “Passion for life” (MOLTMANN, Jürgen. Paixão pela vida. São Paulo, SP: ASTE - Associaçãode Seminários Teológicos Evangélicos, 1978.In the following years, the wide theological work of J. Moltmann went all the way from debates to congresses and has conquered the classrooms. Most probably, J. Moltmann is nowadays the most widely read European author in Brazilian theological seminaries. Thisrecognition can only be held in unison and the wide response to our request for articles confirms the huge repercussion that Moltmann’s work has been having up to today in Brazil. The ecumenical theologian J. Moltmann is ecumenically read. We believe that thisway we may be better equipped to answer to anyone who asks us for the reason there is hope in us. We have organized the articles on J. Moltmann’s theology according to the original publication date of the books dealt with in each essay. We also communicate that some articles which were originally requested for this edition of the journal will be published in the journal Estudos de Regilião in May 2009.As it is usual with the journal Caminhando, we have, besides this thematic emphasis, yet other contributions in the areas of

  2. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj


    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...

  3. Physics imagination and reality

    CERN Document Server

    Wallace, Philip Russell


    Physics: Imagination and Reality introduces the reader to major ideas and the conceptual structure of modern physics, by tracing its development from the introduction of fields into physics by Faraday and Maxwell in the last century. Because the approach is historical, the book provides a comprehensive overview of the subjects. It should appeal to anyone interested in a basic understanding of the contemporary physicists view of the physical world. It avoids all but the simplest mathematics and presents ideas and concepts in everyday language.Physics: Imagination and Reality attempts to provide

  4. Identification of the Elusive Pyruvate Reductase of Chlamydomonas reinhardtii Chloroplasts (United States)

    Burgess, Steven J.; Taha, Hussein; Yeoman, Justin A.; Iamshanova, Oksana; Chan, Kher Xing; Boehm, Marko; Behrends, Volker; Bundy, Jacob G.; Bialek, Wojciech; Murray, James W.; Nixon, Peter J.


    Under anoxic conditions the green alga Chlamydomonas reinhardtii activates various fermentation pathways leading to the creation of formate, acetate, ethanol and small amounts of other metabolites including d-lactate and hydrogen. Progress has been made in identifying the enzymes involved in these pathways and their subcellular locations; however, the identity of the enzyme involved in reducing pyruvate to d-lactate has remained unclear. Based on sequence comparisons, enzyme activity measurements, X-ray crystallography, biochemical fractionation and analysis of knock-down mutants, we conclude that pyruvate reduction in the chloroplast is catalyzed by a tetrameric NAD+-dependent d-lactate dehydrogenase encoded by Cre07.g324550. Its expression during aerobic growth supports a possible function as a ‘lactate valve’ for the export of lactate to the mitochondrion for oxidation by cytochrome-dependent d-lactate dehydrogenases and by glycolate dehydrogenase. We also present a revised spatial model of fermentation based on our immunochemical detection of the likely pyruvate decarboxylase, PDC3, in the cytoplasm. PMID:26574578

  5. Genetic tools and techniques for Chlamydomonas reinhardtii. (United States)

    Mussgnug, Jan H


    The development of tools has always been a major driving force for the advancement of science. Optical microscopes were the first instruments that allowed discovery and descriptive studies of the subcellular features of microorganisms. Although optical and electron microscopes remained at the forefront of microbiological research tools since their inventions, the advent of molecular genetics brought about questions which had to be addressed with new "genetic tools". The unicellular green microalgal genus Chlamydomonas, especially the most prominent species C. reinhardtii, has become a frequently used model organism for many diverse fields of research and molecular genetic analyses of C. reinhardtii, as well as the available genetic tools and techniques, have become increasingly sophisticated throughout the last decades. The aim of this review is to provide an overview of the molecular key features of C. reinhardtii and summarize the progress related to the development of tools and techniques for genetic engineering of this organism, from pioneering DNA transformation experiments to state-of-the-art techniques for targeted nuclear genome editing and high-throughput screening approaches.

  6. Radial spoke proteins of Chlamydomonas flagella (United States)

    Yang, Pinfen; Diener, Dennis R.; Yang, Chun; Kohno, Takahiro; Pazour, Gregory J.; Dienes, Jennifer M.; Agrin, Nathan S.; King, Stephen M.; Sale, Winfield S.; Kamiya, Ritsu; Rosenbaum, Joel L.; Witman, George B.


    Summary The radial spoke is a ubiquitous component of ‘9+2’ cilia and flagella, and plays an essential role in the control of dynein arm activity by relaying signals from the central pair of microtubules to the arms. The Chlamydomonas reinhardtii radial spoke contains at least 23 proteins, only 8 of which have been characterized at the molecular level. Here, we use mass spectrometry to identify 10 additional radial spoke proteins. Many of the newly identified proteins in the spoke stalk are predicted to contain domains associated with signal transduction, including Ca2+-, AKAP- and nucleotide-binding domains. This suggests that the spoke stalk is both a scaffold for signaling molecules and itself a transducer of signals. Moreover, in addition to the recently described HSP40 family member, a second spoke stalk protein is predicted to be a molecular chaperone, implying that there is a sophisticated mechanism for the assembly of this large complex. Among the 18 spoke proteins identified to date, at least 12 have apparent homologs in humans, indicating that the radial spoke has been conserved throughout evolution. The human genes encoding these proteins are candidates for causing primary ciliary dyskinesia, a severe inherited disease involving missing or defective axonemal structures, including the radial spokes. PMID:16507594

  7. Drosophila roadblock and Chlamydomonas Lc7 (United States)

    Bowman, Aaron B.; Patel-King, Ramila S.; Benashski, Sharon E.; McCaffery, J. Michael; Goldstein, Lawrence S.B.; King, Stephen M.


    Eukaryotic organisms utilize microtubule-dependent motors of the kinesin and dynein superfamilies to generate intracellular movement. To identify new genes involved in the regulation of axonal transport in Drosophila melanogaster, we undertook a screen based upon the sluggish larval phenotype of known motor mutants. One of the mutants identified in this screen, roadblock (robl), exhibits diverse defects in intracellular transport including axonal transport and mitosis. These defects include intra-axonal accumulations of cargoes, severe axonal degeneration, and aberrant chromosome segregation. The gene identified by robl encodes a 97–amino acid polypeptide that is 57% identical (70% similar) to the 105–amino acid Chlamydomonas outer arm dynein–associated protein LC7, also reported here. Both robl and LC7 have homology to several other genes from fruit fly, nematode, and mammals, but not Saccharomyces cerevisiae. Furthermore, we demonstrate that members of this family of proteins are associated with both flagellar outer arm dynein and Drosophila and rat brain cytoplasmic dynein. We propose that roadblock/LC7 family members may modulate specific dynein functions. PMID:10402468

  8. Dynamic regulation of photosynthesis in Chlamydomonas reinhardtii. (United States)

    Minagawa, Jun; Tokutsu, Ryutaro


    Plants and algae have acquired the ability to acclimatize to ever-changing environments to survive. During photosynthesis, light energy is converted by several membrane protein supercomplexes into electrochemical energy, which is eventually used to assimilate CO2 . The efficiency of photosynthesis is modulated by many environmental factors, including temperature, drought, CO2 concentration, and the quality and quantity of light. Recently, our understanding of such regulators of photosynthesis and the underlying molecular mechanisms has increased considerably. The photosynthetic supercomplexes undergo supramolecular reorganizations within a short time after receiving environmental cues. These reorganizations include state transitions that balance the excitation of the two photosystems: qE quenching, which thermally dissipates excess energy at the level of the light-harvesting antenna, and cyclic electron flow, which supplies the increased ATP demanded by CO2 assimilation and the pH gradient to activate qE quenching. This review focuses on the recent findings regarding the environmental regulation of photosynthesis in model organisms, paying particular attention to the unicellular green alga Chlamydomonas reinhardtii, which offer a glimpse into the dynamic behavior of photosynthetic machinery in nature.

  9. Navigation in Augmented Reality, Navigation i Augmented Reality


    Bernelind, Sarah


    The concept of augmented reality has existed since the 60’s. In this thesis it has been investigated if navigation using a mobile device would benefit, from a usability perspective, if the navigational data were presented using augmented reality instead of a standardized map. The usability principles from which the applications were evaluated are learnability, user satisfaction, efficiency and effectivity. An AR prototype was developed and tested against a standard map, in the form of Google ...

  10. Adaptation prevents the extinction of Chlamydomonas reinhardtii under toxic beryllium

    Directory of Open Access Journals (Sweden)

    Beatriz Baselga-Cervera


    Full Text Available The current biodiversity crisis represents a historic challenge for natural communities: the environmental rate of change exceeds the population’s adaptation capability. Integrating both ecological and evolutionary responses is necessary to make reliable predictions regarding the loss of biodiversity. The race against extinction from an eco-evolutionary perspective is gaining importance in ecological risk assessment. Here, we performed a classical study of population dynamics—a fluctuation analysis—and evaluated the results from an adaption perspective. Fluctuation analysis, widely used with microorganisms, is an effective empirical procedure to study adaptation under strong selective pressure because it incorporates the factors that influence demographic, genetic and environmental changes. The adaptation of phytoplankton to beryllium (Be is of interest because human activities are increasing the concentration of Be in freshwater reserves; therefore, predicting the effects of human-induced pollutants is necessary for proper risk assessment. The fluctuation analysis was performed with phytoplankton, specifically, the freshwater microalgae Chlamydomonas reinhardtii, under acute Be exposure. High doses of Be led to massive microalgae death; however, by conducting a fluctuation analysis experiment, we found that C. reinhardtii was able to adapt to 33 mg/l of Be due to pre-existing genetic variability. The rescuing adapting genotype presented a mutation rate of 9.61 × 10−6 and a frequency of 10.42 resistant cells per million wild-type cells. The genetic adaptation pathway that was experimentally obtained agreed with the theoretical models of evolutionary rescue (ER. Furthermore, the rescuing genotype presented phenotypic and physiologic differences from the wild-type genotype, was 25% smaller than the Be-resistant genotype and presented a lower fitness and quantum yield performance. The abrupt distinctions between the wild-type and the Be

  11. Reality Branding

    Directory of Open Access Journals (Sweden)

    Adam Arvidsson


    Full Text Available Artiklen tager ’reality branding’ som udgangspunkt for at diskutere markedsføringens kultur- og livsstilsproducerende potentialer på en mediearena, hvor den kommercielle og hverdagslige virkelighed smelter sammen i virksomheders og konsumenters ’joint effort’ i at skabe meningsfyldte historier. Tankegangen er, at forbrugere har gennemskuet reklamernes mere eller mindre fantasifulde tegnkon- struktioner og forholder sig blasert til budskaberne. Som modsvar til denne ligegyldighed forsøger den moderne og avancerede markeds- føring at skabe nye involverende mediemiljøer og nye brugssituatio- ner for produktet – for eksempel er Polle fra Snave debuteret i film- mediet, og Starbucks skabte et nyt fysisk og symbolsk rum for kaffe og kaffedrikning så godt som uden hjælp af traditionel reklame. Artik- lens ærinde er at diskutere denne udvikling i markedsføringen – ikke ud fra traditionelle sociologiske og psykologiske antagelser om foran- dringer i mentalitetsformer, men ud fra en historisk belysning af mar- kedsføringens diskurser set i relation til udviklingen i mediesystemerne.

  12. Proteomic Alterations of Antarctic Ice Microalga Chlamydomonas sp. Under Low-Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    Guang-Feng Kan; Jin-Lai Miao; Cui-Juan Shi; Guang-You Li


    Antarctic ice microalga can survive and thrive in cold channels or pores in the Antarctic ice layer. In order to understand the adaptive mechanisms to low temperature, in the present study we compared two-dimensional polyacrylamide gel electrophoresis (2-DE) profiles of normal and low temperature-stressed Antarctic ice microalga Chlamydomonas sp. cells. In addition, new protein spots induced by low temperature were identified with peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching. Well-resolved and reproducible 2-DE patterns of both normal and low temperature-stressed cells were acquired. A total of 626 spots was detected in control cells and 652 spots were detected in the corresponding low temperature-stressed cells. A total of 598 spots was matched between normal and stressed cells. Two newly synthesized proteins (a and b) in low temperature-stressed cells were characterized. Protein spot A (53 kDa, pI 6.0) was similar to isopropylmalate/homocitrate/citramalate synthases, which act in the transport and metabolism of amino acids. Protein spot b (25 kDa, pI 8.0) was related to glutathione S-transferase, which functions as a scavenger of active oxygen, free radicals, and noxious metabolites. The present study is valuable for the application of ice microalgae, establishing an ice microalga Chlamydomonas sp. proteome database, and screening molecular biomarkers for further studies.

  13. The small molecule fenpropimorph rapidly converts chloroplast membrane lipids to triacylglycerols in Chlamydomonas reinhardtii (United States)

    Kim, Hanul; Jang, Sunghoon; Kim, Sangwoo; Yamaoka, Yasuyo; Hong, Daewoong; Song, Won-Yong; Nishida, Ikuo; Li-Beisson, Yonghua; Lee, Youngsook


    Concern about global warming has prompted an intense interest in developing economical methods of producing biofuels. Microalgae provide a promising platform for biofuel production, because they accumulate high levels of lipids, and do not compete with food or feed sources. However, current methods of producing algal oil involve subjecting the microalgae to stress conditions, such as nitrogen deprivation, and are prohibitively expensive. Here, we report that the fungicide fenpropimorph rapidly causes high levels of neutral lipids to accumulate in Chlamydomonas reinhardtii cells. When treated with fenpropimorph (10 μg mL-1) for 1 h, Chlamydomonas cells accumulated at least fourfold the amount of triacylglycerols (TAGs) present in the untreated control cells. Furthermore, the quantity of TAGs present after 1 h of fenpropimorph treatment was over twofold higher than that formed after 9 days of nitrogen starvation in medium with no acetate supplement. Biochemical analysis of lipids revealed that the accumulated TAGs were derived mainly from chloroplast polar membrane lipids. Such a conversion of chloroplast polar lipids to TAGs is desirable for biodiesel production, because polar lipids are usually removed during the biodiesel production process. Thus, our data exemplified that a cost and time effective method of producing TAGs is possible using fenpropimorph or similar drugs. PMID:25759683

  14. Measurement of Lipid Droplet Accumulation Kinetics in Chlamydomonas reinhardtii Using Seoul-Fluor

    Directory of Open Access Journals (Sweden)

    Noo Li Jeon


    Full Text Available Alternative energy resources have become an important issue due to the limited stocks of petroleum-based fuel. Microalgae, a source of renewable biodiesel, use solar light to convert CO2 into lipid droplets (LDs. Quantification of LDs in microalgae is required for developing and optimizing algal bioprocess engineering. However, conventional quantification methods are both time and labor-intensive and difficult to apply in high-throughput screening systems. LDs in plant and mammalian cells can be visualized by staining with various fluorescence probes such as the Nile Red, BODIPY, and Seoul-Fluor (SF series. This report describes the optimization of LD staining in Chlamydomonas reinhardtii with SF probes via systematic variations of dye concentration, staining time, temperature, and pH. A protocol for quantitative measurement of accumulation kinetics of LDs in C. reinhardtii was developed using a spectrofluorimeter and the accuracy of LD size measurement was confirmed by transmission electron microscopy (TEM. Our results indicate that our spectrofluorimeter-based measurement approach can monitor kinetics of intracellular LDs (in control and nitrogen-source-starved Chlamydomonas reinhardtii accumulation that has not been possible in the case of conventional imaging-based methods. Our results presented here confirmed that an SF44 can be a powerful tool for in situ monitoring and tracking of intracellular LDs formation.

  15. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  16. Morphine: Myths and Reality (United States)

    ... and Families Take the Quiz Morphine: Myths and Reality February, 2013 The mere mention of “Morphine” can ... due to misinformation and lack of training. The reality is that Morphine (and other opiates that work ...

  17. Cell types and their status in Chlamydomonas-like algae (Chlorophyceae on agar medium culture

    Directory of Open Access Journals (Sweden)

    M.М. Pavlovska


    Full Text Available The classification of cell types under agar culture was proposed. Six cell morphotypes were allocated. The statuses were identified depending on the reduction of monade attributes of cells. The variants of transition from one cell morphotype to another under dissolving mucilage were shown. The monade, cocciod, palmeloid and gloeocysta morphotypes approximately equally represented in all clades. The asterococcus and mucogleocysta morphotypes presented only in Reinhardtinia аnd Oogamochlamydinia clades. Any morphotype isn’t typical for all clades of Chlamydomonas-like algae at once. The most of morphotypes numbers (5 from 6 are presented in Reinhardtinia clade. This demonstrates the diversity of the Reinhardtinia clade species. There are only one morphotype presented in Polytominia and Monadinia clades. There are four morphotypes presented in Oogamochlamydinia clade, three – in Moewusinia, two morphotypes – in Chloromonadinia.

  18. Kaleidoscopes of reality. (United States)

    Franquemont, Sharon


    This article addresses the broad context of shifting definitions of how knowledge and reality can be described, including the transition from positivism to postpositivism in the 20th century. It provides an exploration of ways of knowing, from ancient Greek and yogic traditions to Barbara Carper's Fundamental Patterns of Knowing in Nursing (1978). It examines three reported components of modern care (intuition, cultural knowing, and spirituality) which are simultaneously present and absent in nursing. It concludes with an imaginative exploration of how nursing might be changed by transdisciplinary scholarship and education, new knowledge creation through interactive online communities, and the emergence of collective wisdom.

  19. Reverse genetics in Chlamydomonas: a platform for isolating insertional mutants


    de Montaigu Amaury; Magneschi Leonardo; Catalanotti Claudia; Yang Wenqiang; Mus Florence; Pootakham Wirulda; Gonzalez-Ballester David; Higuera Jose J; Prior Matthew; Galván Aurora; Fernandez Emilio; Grossman Arthur R


    Abstract A method was developed to identify insertional mutants of Chlamydomonas reinhardtii disrupted for selected target genes. The approach relies on the generation of thousands of transformants followed by PCR-based screenings that allow for identification of strains harboring the introduced marker gene within specific genes of interest. Our results highlight the strengths and limitations of two independent screens that differed in the nature of the marker DNA used (PCR-amplified fragment...

  20. An optimized, chemically regulated gene expression system for Chlamydomonas.

    Directory of Open Access Journals (Sweden)

    Paola Ferrante

    Full Text Available BACKGROUND: Chlamydomonas reinhardtii is a model system for algal and cell biology and is used for biotechnological applications, such as molecular farming or biological hydrogen production. The Chlamydomonas metal-responsive CYC6 promoter is repressed by copper and induced by nickel ions. However, induction by nickel is weak in some strains, poorly reversible by chelating agents like EDTA, and causes, at high concentrations, toxicity side effects on Chlamydomonas growth. Removal of these bottlenecks will encourage the wide use of this promoter as a chemically regulated gene expression system. METHODOLOGY: Using a codon-optimized Renilla luciferase as a reporter gene, we explored several strategies to improve the strength and reversibility of CYC6 promoter induction. Use of the first intron of the RBCS2 gene or of a modified TAP medium increases the strength of CYC6 induction up to 20-fold. In the modified medium, induction is also obtained after addition of specific copper chelators, like TETA. At low concentrations (up to 10 microM TETA is a more efficient inducer than Ni, which becomes a very efficient inducer at higher concentrations (50 microM. Neither TETA nor Ni show toxicity effects at the concentrations used. Unlike induction by Ni, induction by TETA is completely reversible by micromolar copper concentrations, thus resulting in a transient "wave" in luciferase activity, which can be repeated in subsequent growth cycles. CONCLUSIONS: We have worked out a chemically regulated gene expression system that can be finely tuned to produce temporally controlled "waves" in gene expression. The use of cassettes containing the CYC6 promoter, and of modified growth media, is a reliable and economically sustainable system for the temporally controlled expression of foreign genes in Chlamydomonas.

  1. Creating augmented reality


    Kuusisto, Raine


    Augmented reality (AR) is used in different occasions in our daily lives. The idea of an electronic display and spectacles that overlays data to people came in 1901. Augmented reality revolution started in 1990, it is a combination of real life and virtual reality. The beginning of AR is being examined from the very beginning of it. In 1999, it gained momentum when Hirokazu Kato published the ARToolkit to the open source community. After this, augmented reality has evolved everywhere, includi...

  2. Actin is required for IFT regulation in Chlamydomonas reinhardtii. (United States)

    Avasthi, Prachee; Onishi, Masayuki; Karpiak, Joel; Yamamoto, Ryosuke; Mackinder, Luke; Jonikas, Martin C; Sale, Winfield S; Shoichet, Brian; Pringle, John R; Marshall, Wallace F


    Assembly of cilia and flagella requires intraflagellar transport (IFT), a highly regulated kinesin-based transport system that moves cargo from the basal body to the tip of flagella [1]. The recruitment of IFT components to basal bodies is a function of flagellar length, with increased recruitment in rapidly growing short flagella [2]. The molecular pathways regulating IFT are largely a mystery. Because actin network disruption leads to changes in ciliary length and number, actin has been proposed to have a role in ciliary assembly. However, the mechanisms involved are unknown. In Chlamydomonas reinhardtii, conventional actin is found in both the cell body and the inner dynein arm complexes within flagella [3, 4]. Previous work showed that treating Chlamydomonas cells with the actin-depolymerizing compound cytochalasin D resulted in reversible flagellar shortening [5], but how actin is related to flagellar length or assembly remains unknown. Here we utilize small-molecule inhibitors and genetic mutants to analyze the role of actin dynamics in flagellar assembly in Chlamydomonas reinhardtii. We demonstrate that actin plays a role in IFT recruitment to basal bodies during flagellar elongation and that when actin is perturbed, the normal dependence of IFT recruitment on flagellar length is lost. We also find that actin is required for sufficient entry of IFT material into flagella during assembly. These same effects are recapitulated with a myosin inhibitor, suggesting that actin may act via myosin in a pathway by which flagellar assembly is regulated by flagellar length.

  3. Two types of chloroplast gene promoters in Chlamydomonas reinhardtii. (United States)

    Klein, U; De Camp, J D; Bogorad, L


    Structures of the promoters of Chlamydomonas reinhardtii plastid atpB and 16S rRNA-encoding genes were analyzed in vivo. Chimeric constructs, containing the Chlamydomonas chloroplast atpB or 16S rRNA-encoding gene promoter coupled to the Escherichia coli uidA (beta-glucuronidase, GUS) reporter gene and bordered by C. reinhardtii chloroplast sequences, were stably introduced into the chloroplast of Chlamydomonas by microprojectile bombardment. Activity of the promoters in the chloroplast of GUS gene-positive transformants was assayed by measuring the abundance of GUS transcripts and determining the relative rates of GUS transcription in vivo. Deletion analyses of the 16S rRNA gene and atpB promoter fragments showed that the two promoters differ structurally. The 16S rRNA gene promoter resembles the bacterial sigma 70 type with typical -10 and -35 elements. The atpB promoter, on the other hand, lacks a conserved motif in the -35 region but contains, in the -10 region, a characteristic octameric palindrome (TATAATAT) that is conserved in the promoter sequences of some other C. reinhardtii chloroplast genes. For maximum activity, the atpB promoter requires sequences of approximately 22 base pairs upstream and approximately 60 base pairs downstream of the transcription start site.

  4. Engaging With Reality

    DEFF Research Database (Denmark)

    Bondebjerg, Ib

    to engage us with reality. Engaging with Reality investigates some of the major global themes as they are reflected in documentaries from the USA, UK and Denmark. Engaging with Reality is a contribution to comparative, transnational studies of documentary in contemporary media culture. By comparing...

  5. Confronting an Augmented Reality (United States)

    Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert


    How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

  6. Enhancing Education through Mobile Augmented Reality (United States)

    Joan, D. R. Robert


    In this article, the author has discussed about the Mobile Augmented Reality and enhancing education through it. The aim of the present study was to give some general information about mobile augmented reality which helps to boost education. Purpose of the current study reveals the mobile networks which are used in the institution campus as well…

  7. "Madame Bovary": Illusion and Reality. [Lesson Plan]. (United States)

    Carangelo, Audrey

    Based on Gustave Flaubert's novel "Madame Bovary," this lesson plan presents activities designed to help students explore the theme of "illusion versus reality" in the novel; identify and list alternate themes in the novel; and cite specific examples of illusion versus reality from the novel. It includes objectives, materials, procedures,…

  8. Functional analysis of Photosystem I light-harvesting complexes (Lhca) gene products of Chlamydomonas reinhardtii

    NARCIS (Netherlands)

    Mozzo, Milena; Mantelli, Manuela; Passarini, Francesca; Caffarri, Stefano; Croce, Roberta; Bassi, Roberto


    The outer antenna system of Chlamydomonas reinhardtii Photosystem I is composed of nine gene products, but due to difficulty in purification their individual properties are not known. In this work, the functional properties of the nine Lhca antennas of Chlamydomonas, have been investigated upon expr

  9. Augmented Reality Tower Technology Assessment (United States)

    Reisman, Ronald J.; Brown, David M.


    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  10. Emotional Expression in Reality TV

    DEFF Research Database (Denmark)

    Rasmussen, Tove Arendt

    are being treated as ordinary people. My article will discuss different presentations of selves and especially the emotional verbal and nonverbal expressions in reality TV communication. Aspects of the intimate self and its emotional expressions seem to be strategically managed in reality TV and even......, that information ‘given off’ in lying behavior will must often be found in non-verbal mikro expressions and mikro gestures. I will end by discussing the strategic emotional expressions as production of floating identities in a broader framework on the basis of among others Gergen, Lipovetsky and Baumann...... commodified in the celebrity culture. The article will discuss and analyze examples of reality TV’s interpersonal strategically communication in relation to ordinary interpersonal communication where much information about the self is communicated incidentally to the purpose of the situation, and some...

  11. Crime Scenes as Augmented Reality

    DEFF Research Database (Denmark)

    Sandvik, Kjetil


    Using the concept of augmented reality, this article will investigate how places in various ways have become augmented by means of different mediatization strategies. Augmentation of reality implies an enhancement of the places' emotional character: a certain mood, atmosphere or narrative surplus...... of meaning has been implemented. This may take place at different levels, which will be presented and investigated in this article and exemplified by some cases from the fields of tourism and computer games.                       The article suggests that we may use the forensic term crime scene in order...

  12. Satisfying Reality

    CERN Document Server

    Mould, R A


    It is claimed elsewhere that the conscious states of humans must have evolved together with their biological states, and that an ongoing interaction between the two must have occurred to insure that they mirror one another in any species. A quantum mechanical mechanism and an evolutionary model for the assumed mind/body interaction are described below. The present paper outlines the related ontological and epistemological assumptions, showing how the claimed connection between conscious states and physical states should be understood.

  13. Aspects of User Experience in Augmented Reality

    DEFF Research Database (Denmark)

    Madsen, Jacob Boesen

    In Augmented Reality applications, the real environment is annotated or enhanced with computer-generated graphics. This is a topic that has been researched in the recent decades, but for many people this is a brand new and never heard of topic. The main focus of this thesis is investigations...... in human factors related to Augmented Reality. This is investigated partly as how Augmented Reality applications are used in unsupervised settings, and partly in specific evaluations related to user performance in supervised settings. The thesis starts by introducing Augmented Reality to the reader......, followed by a presentation of the technical areas related to the field, and different human factor areas. As a contribution to the research area, this thesis presents five separate, but sequential, papers within the area of Augmented Reality....

  14. Augmented Reality in Science Education

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Swensen, Hakon


    Augmented reality (AR) holds great promise as a learning tool. However, most extant studies in this field have focused on the technology itself. The poster presents findings from the first stage of the AR-sci project addressing the issue of applying AR for educational purposes. Benefits...

  15. Efficient phototrophic production of a high-value sesquiterpenoid from the eukaryotic microalga Chlamydomonas reinhardtii. (United States)

    Lauersen, Kyle J; Baier, Thomas; Wichmann, Julian; Wördenweber, Robin; Mussgnug, Jan H; Hübner, Wolfgang; Huser, Thomas; Kruse, Olaf


    The heterologous expression of terpene synthases in microbial hosts has opened numerous possibilities for bioproduction of desirable metabolites. Photosynthetic microbial hosts present a sustainable alternative to traditional fermentative systems, using freely available (sun)light and carbon dioxide as inputs for bio-production. Here, we report the expression of a patchoulol synthase from Pogostemon cablin Benth in the model green microalga Chlamydomonas reinhardtii. The sesquiterpenoid patchoulol was produced from the alga and was used as a marker of sesquiterpenoid production capacity. A novel strategy for gene loading was employed and patchoulol was produced up to 922±242µgg(-1) CDW in six days. We additionally investigated the effect of carbon source on sesquiterpenoid productivity from C. reinhardtii in scale-up batch cultivations. It was determined that up to 1.03mgL(-1) sesquiterpenoid products could be produced in completely photoautotrophic conditions and that the alga exhibited altered sesquiterpenoid production metabolism related to carbon source.

  16. Augmented Reality Implementation Methods in Mainstream Applications

    CERN Document Server

    Prochazka, David


    Augmented reality has became an useful tool in many areas from space exploration to military applications. Although used theoretical principles are well known for almost a decade, the augmented reality is almost exclusively used in high budget solutions with a special hardware. However, in last few years we could see rising popularity of many projects focused on deployment of the augmented reality on different mobile devices. Our article is aimed on developers who consider development of an augmented reality application for the mainstream market. Such developers will be forced to keep the application price, therefore also the development price, at reasonable level. Usage of existing image processing software library could bring a significant cut-down of the development costs. In the theoretical part of the article is presented an overview of the augmented reality application structure. Further, an approach for selection appropriate library as well as the review of the existing software libraries focused in th...

  17. Coping with Reality

    DEFF Research Database (Denmark)

    Madsen, Poul Thøis

    explicitly refers to the actually existing economy or comments upon or relates to the question of theorizing versus reality. By analyzing (or generalizing) this empirical material it is demonstrated that Keynes copes with reality by generalizing from experience, giving priority to the most important parts...... of economic reality and by making empirically based assumptions rather than assumptions consistent to a theoretical model. If economic textbooks were to apply the same stringent principles not much would be left…...

  18. Virtual reality exposure therapy


    Rothbaum, BO; Hodges, L; Kooper, R


    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

  19. Virtual reality and hallucination: a technoetic perspective (United States)

    Slattery, Diana R.


    Virtual Reality (VR), especially in a technologically focused discourse, is defined by a class of hardware and software, among them head-mounted displays (HMDs), navigation and pointing devices; and stereoscopic imaging. This presentation examines the experiential aspect of VR. Putting "virtual" in front of "reality" modifies the ontological status of a class of experience-that of "reality." Reality has also been modified [by artists, new media theorists, technologists and philosophers] as augmented, mixed, simulated, artificial, layered, and enhanced. Modifications of reality are closely tied to modifications of perception. Media theorist Roy Ascott creates a model of three "VR's": Verifiable Reality, Virtual Reality, and Vegetal (entheogenically induced) Reality. The ways in which we shift our perceptual assumptions, create and verify illusions, and enter "the willing suspension of disbelief" that allows us entry into imaginal worlds is central to the experience of VR worlds, whether those worlds are explicitly representational (robotic manipulations by VR) or explicitly imaginal (VR artistic creations). The early rhetoric surrounding VR was interwoven with psychedelics, a perception amplified by Timothy Leary's presence on the historic SIGGRAPH panel, and the Wall Street Journal's tag of VR as "electronic LSD." This paper discusses the connections-philosophical, social-historical, and psychological-perceptual between these two domains.

  20. Synthesizing and salvaging NAD: lessons learned from Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Huawen Lin


    Full Text Available The essential coenzyme nicotinamide adenine dinucleotide (NAD+ plays important roles in metabolic reactions and cell regulation in all organisms. Bacteria, fungi, plants, and animals use different pathways to synthesize NAD+. Our molecular and genetic data demonstrate that in the unicellular green alga Chlamydomonas NAD+ is synthesized from aspartate (de novo synthesis, as in plants, or nicotinamide, as in mammals (salvage synthesis. The de novo pathway requires five different enzymes: L-aspartate oxidase (ASO, quinolinate synthetase (QS, quinolate phosphoribosyltransferase (QPT, nicotinate/nicotinamide mononucleotide adenylyltransferase (NMNAT, and NAD+ synthetase (NS. Sequence similarity searches, gene isolation and sequencing of mutant loci indicate that mutations in each enzyme result in a nicotinamide-requiring mutant phenotype in the previously isolated nic mutants. We rescued the mutant phenotype by the introduction of BAC DNA (nic2-1 and nic13-1 or plasmids with cloned genes (nic1-1 and nic15-1 into the mutants. NMNAT, which is also in the de novo pathway, and nicotinamide phosphoribosyltransferase (NAMPT constitute the nicotinamide-dependent salvage pathway. A mutation in NAMPT (npt1-1 has no obvious growth defect and is not nicotinamide-dependent. However, double mutant strains with the npt1-1 mutation and any of the nic mutations are inviable. When the de novo pathway is inactive, the salvage pathway is essential to Chlamydomonas for the synthesis of NAD+. A homolog of the human SIRT6-like gene, SRT2, is upregulated in the NS mutant, which shows a longer vegetative life span than wild-type cells. Our results suggest that Chlamydomonas is an excellent model system to study NAD+ metabolism and cell longevity.

  1. Individual Flagellar Waveform Affects Collective Behavior of Chlamydomonas reinhardtii. (United States)

    Kage, Azusa; Mogami, Yoshihiro


    Bioconvection is a form of collective motion that occurs spontaneously in the suspension of swimming microorganisms. In a previous study, we quantitatively described the "pattern transition," a phase transition phenomenon that so far has exclusively been observed in bioconvection of the unicellular green alga Chlamydomonas. We suggested that the transition could be induced by changes in the balance between the gravitational and shear-induced torques, both of which act to determine the orientation of the organism in the shear flow. As both of the torques should be affected by the geometry of the Chlamydomonas cell, alteration in the flagellar waveform might change the extent of torque generation by altering overall geometry of the cell. Based on this working hypothesis, we examined bioconvection behavior of two flagellar mutants of Chlamydomonas reinhardtii, ida1 and oda2, making reference to the wild type. Flagella of ida1 beat with an abnormal waveform, while flagella of oda2 show a normal waveform but lower beat frequency. As a result, both mutants had swimming speed of less than 50% of the wild type. ida1 formed bioconvection patterns with smaller spacing than those of wild type and oda2. Two-axis view revealed the periodic movement of the settling blobs of ida1, while oda2 showed qualitatively similar behavior to that of wild type. Unexpectedly, ida1 showed stronger negative gravitaxis than did wild type, while oda2 showed relatively weak gravitaxis. These findings suggest that flagellar waveform, not swimming speed or beat frequency, strongly affect bioconvection behavior in C. reinhardtii.

  2. Mobile Augmented Reality Applications

    CERN Document Server

    Prochazka, David; Popelka, Ondrej; Stastny, Jiri


    Augmented reality have undergone considerable improvement in past years. Many special techniques and hardware devices were developed, but the crucial breakthrough came with the spread of intelligent mobile phones. This enabled mass spread of augmented reality applications. However mobile devices have limited hardware capabilities, which narrows down the methods usable for scene analysis. In this article we propose an augmented reality application which is using cloud computing to enable using of more complex computational methods such as neural networks. Our goal is to create an affordable augmented reality application suitable which will help car designers in by 'virtualizing' car modifications.

  3. Virtual Reality Laboratory (United States)

    Federal Laboratory Consortium — FUNCTION: Performs basic and applied research in interactive 3D computer graphics, including visual analytics, virtual environments, and augmented reality (AR). The...

  4. Reverse genetics in Chlamydomonas: a platform for isolating insertional mutants

    Directory of Open Access Journals (Sweden)

    de Montaigu Amaury


    Full Text Available Abstract A method was developed to identify insertional mutants of Chlamydomonas reinhardtii disrupted for selected target genes. The approach relies on the generation of thousands of transformants followed by PCR-based screenings that allow for identification of strains harboring the introduced marker gene within specific genes of interest. Our results highlight the strengths and limitations of two independent screens that differed in the nature of the marker DNA used (PCR-amplified fragment containing the plasmid-free marker versus entire linearized plasmid with the marker and in the strategies used to maintain and store transformants.

  5. Genome-wide analysis of alternative splicing in Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Thomas Julie


    Full Text Available Abstract Background Genome-wide computational analysis of alternative splicing (AS in several flowering plants has revealed that pre-mRNAs from about 30% of genes undergo AS. Chlamydomonas, a simple unicellular green alga, is part of the lineage that includes land plants. However, it diverged from land plants about one billion years ago. Hence, it serves as a good model system to study alternative splicing in early photosynthetic eukaryotes, to obtain insights into the evolution of this process in plants, and to compare splicing in simple unicellular photosynthetic and non-photosynthetic eukaryotes. We performed a global analysis of alternative splicing in Chlamydomonas reinhardtii using its recently completed genome sequence and all available ESTs and cDNAs. Results Our analysis of AS using BLAT and a modified version of the Sircah tool revealed AS of 498 transcriptional units with 611 events, representing about 3% of the total number of genes. As in land plants, intron retention is the most prevalent form of AS. Retained introns and skipped exons tend to be shorter than their counterparts in constitutively spliced genes. The splice site signals in all types of AS events are weaker than those in constitutively spliced genes. Furthermore, in alternatively spliced genes, the prevalent splice form has a stronger splice site signal than the non-prevalent form. Analysis of constitutively spliced introns revealed an over-abundance of motifs with simple repetitive elements in comparison to introns involved in intron retention. In almost all cases, AS results in a truncated ORF, leading to a coding sequence that is around 50% shorter than the prevalent splice form. Using RT-PCR we verified AS of two genes and show that they produce more isoforms than indicated by EST data. All cDNA/EST alignments and splice graphs are provided in a website at Conclusions The extent of AS in Chlamydomonas that we observed is much

  6. ARSC: Augmented Reality Student Card--An Augmented Reality Solution for the Education Field (United States)

    El Sayed, Neven A. M.; Zayed, Hala H.; Sharawy, Mohamed I.


    Augmented Reality (AR) is the technology of adding virtual objects to real scenes through enabling the addition of missing information in real life. As the lack of resources is a problem that can be solved through AR, this paper presents and explains the usage of AR technology we introduce Augmented Reality Student Card (ARSC) as an application of…

  7. Virtual Reality: An Overview. (United States)

    Franchi, Jorge


    Highlights of this overview of virtual reality include optics; interface devices; virtual worlds; potential applications, including medicine and archaeology; problems, including costs; current research and development; future possibilities; and a listing of vendors and suppliers of virtual reality products. (Contains 11 references.) (LRW)

  8. Data, model, and reality

    DEFF Research Database (Denmark)

    Galle, Per


    What does it mean for a database (or any other computer representation) to ‘model’ reality as it is, was, or might be? If the database ‘models’ reality in some way, is the same true of its schema or the underlying data model; and if not, what do they express? These questions, though more...

  9. A role for the membrane in regulating Chlamydomonas flagellar length.

    Directory of Open Access Journals (Sweden)

    William Dentler

    Full Text Available Flagellar assembly requires coordination between the assembly of axonemal proteins and the assembly of the flagellar membrane and membrane proteins. Fully grown steady-state Chlamydomonas flagella release flagellar vesicles from their tips and failure to resupply membrane should affect flagellar length. To study vesicle release, plasma and flagellar membrane surface proteins were vectorially pulse-labeled and flagella and vesicles were analyzed for biotinylated proteins. Based on the quantity of biotinylated proteins in purified vesicles, steady-state flagella appeared to shed a minimum of 16% of their surface membrane per hour, equivalent to a complete flagellar membrane being released every 6 hrs or less. Brefeldin-A destroyed Chlamydomonas Golgi, inhibited the secretory pathway, inhibited flagellar regeneration, and induced full-length flagella to disassemble within 6 hrs, consistent with flagellar disassembly being induced by a failure to resupply membrane. In contrast to membrane lipids, a pool of biotinylatable membrane proteins was identified that was sufficient to resupply flagella as they released vesicles for 6 hrs in the absence of protein synthesis and to support one and nearly two regenerations of flagella following amputation. These studies reveal the importance of the secretory pathway to assemble and maintain full-length flagella.

  10. Molecular techniques to interrogate and edit the Chlamydomonas nuclear genome. (United States)

    Jinkerson, Robert E; Jonikas, Martin C


    The success of the green alga Chlamydomonas reinhardtii as a model organism is to a large extent due to the wide range of molecular techniques that are available for its characterization. Here, we review some of the techniques currently used to modify and interrogate the C. reinhardtii nuclear genome and explore several technologies under development. Nuclear mutants can be generated with ultraviolet (UV) light and chemical mutagens, or by insertional mutagenesis. Nuclear transformation methods include biolistic delivery, agitation with glass beads, and electroporation. Transforming DNA integrates into the genome at random sites, and multiple strategies exist for mapping insertion sites. A limited number of studies have demonstrated targeted modification of the nuclear genome by approaches such as zinc-finger nucleases and homologous recombination. RNA interference is widely used to knock down expression levels of nuclear genes. A wide assortment of transgenes has been successfully expressed in the Chlamydomonas nuclear genome, including transformation markers, fluorescent proteins, reporter genes, epitope tagged proteins, and even therapeutic proteins. Optimized expression constructs and strains help transgene expression. Emerging technologies such as the CRISPR/Cas9 system, high-throughput mutant identification, and a whole-genome knockout library are being developed for this organism. We discuss how these advances will propel future investigations.

  11. Virtual reality exposure therapy. (United States)

    Rothbaum, B O; Hodges, L; Kooper, R


    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer-generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first controlled study of virtual reality in treatment of a psychiatric disorder. A case study supported the efficacy of VR exposure therapy for the fear of flying. The potential for virtual reality exposure treatment for these and other disorders is explored, and therapeutic issues surrounding the delivery of VR exposure are discussed.

  12. Virtual Reality: A State-of-the-Art Survey

    Institute of Scientific and Technical Information of China (English)

    Ning-Ning Zhou; Yu-Long Deng


    This paper presents a survey on virtual reality systems and provides an in-depth understanding toward the notion of immersion, according to the semantic meanings of the terms "virtual" and "reality". The paper analyses the structure and functions of a virtual reality system and takes the three dimensional display as the immersive medium to identify the key issues for construction of virtual environments. The paper also reviews the development of virtual reality technology and introduces new image processing techniques into the design of virtual reality systems and virtual environments.

  13. Virtual reality excursions with programs in C

    CERN Document Server

    Watkins, Christopher D


    Virtual Reality Excursions with Programs in C provides the history, theory, principles and an account of the milestones in the development of virtual reality technology.The book is organized into five chapters. The first chapter explores the applications in the vast field of virtual reality. The second chapter presents a brief history of the field and its founders. Chapter 3 discusses human perception and how it works. Some interesting notes and much of the hot debate in the field are covered in Chapter 4. The fifth chapter describes many of the complexities involved in implementing virtual en

  14. Augmented reality-assisted skull base surgery. (United States)

    Cabrilo, I; Sarrafzadeh, A; Bijlenga, P; Landis, B N; Schaller, K


    Neuronavigation is widely considered as a valuable tool during skull base surgery. Advances in neuronavigation technology, with the integration of augmented reality, present advantages over traditional point-based neuronavigation. However, this development has not yet made its way into routine surgical practice, possibly due to a lack of acquaintance with these systems. In this report, we illustrate the usefulness and easy application of augmented reality-based neuronavigation through a case example of a patient with a clivus chordoma. We also demonstrate how augmented reality can help throughout all phases of a skull base procedure, from the verification of neuronavigation accuracy to intraoperative image-guidance.


    Askay, Shelley Wiechman; Patterson, David R; Sharar, Sam R


    Scientific evidence for the viability of hypnosis as a treatment for pain has flourished over the past two decades (Rainville, Duncan, Price, Carrier and Bushnell, 1997; Montgomery, DuHamel and Redd, 2000; Lang and Rosen, 2002; Patterson and Jensen, 2003). However its widespread use has been limited by factors such as the advanced expertise, time and effort required by clinicians to provide hypnosis, and the cognitive effort required by patients to engage in hypnosis.The theory in developing virtual reality hypnosis was to apply three-dimensional, immersive, virtual reality technology to guide the patient through the same steps used when hypnosis is induced through an interpersonal process. Virtual reality replaces many of the stimuli that the patients have to struggle to imagine via verbal cueing from the therapist. The purpose of this paper is to explore how virtual reality may be useful in delivering hypnosis, and to summarize the scientific literature to date. We will also explore various theoretical and methodological issues that can guide future research.In spite of the encouraging scientific and clinical findings, hypnosis for analgesia is not universally used in medical centres. One reason for the slow acceptance is the extensive provider training required in order for hypnosis to be an effective pain management modality. Training in hypnosis is not commonly offered in medical schools or even psychology graduate curricula. Another reason is that hypnosis requires far more time and effort to administer than an analgesic pill or injection. Hypnosis requires training, skill and patience to deliver in medical centres that are often fast-paced and highly demanding of clinician time. Finally, the attention and cognitive effort required for hypnosis may be more than patients in an acute care setting, who may be under the influence of opiates and benzodiazepines, are able to impart. It is a challenge to make hypnosis a standard part of care in this environment

  16. The energy balance of the biomass generation of Chlamydomonas acidophila under acidic and neutral conditions and Chlamydomonas reinhardtii; Die Energiebilanz der Biomasseneubildung von Chlamydomonas acidophila unter sauren und neutralen Bedingungen und von Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Langner, Uwe


    In this study the influence of pH < 3 as an extreme environment has been investigated for the eukaryotic green alga Chlamydomonas (C.) acidophila. The limited number of trophic levels, consisting of bacteria, phytoplankton, zooplankton and macrophytes, is a special characteristic of extreme acidic water bodies. C. acidophila was isolated from an extreme acidic mining lake (RL 111) (Bissinger et al. 2000). A special feature of the examined algal species is its wide tolerance range of external pH values from 2 to 7 (Cassin 1874, Gerloff-Elias et al. 2005a). C. acidophila is a dominant species in the acidic mining lakes, it can grow up to chlorophyll maxima of 500 {mu}g L{sup -1} during the summer time (Nixdorf et al. 1998, 2003). The alga can be found elsewhere in extreme acidic water bodies around the world. The hydrochemistry of the acidic mining lakes in the central regions of Germany and Lusatia show clear differences compared to neutral water bodies. Some of the characteristics of acidic mining lakes are high metal and heavy metal (aluminum) concentrations, high ion concentrations, which lead to high conductivity, as well as low phosphate concentrations, ammonium as the only nitrogen source and CO{sub 2} as the only inorganic carbon source. Many eukaryotic microalgae in acidic water bodies including C. acidophila show a neutral cytosolic pH. This is provided by special adaptations of the organisms. Thus, organisms in extreme acidic environments have a positive cell surface charge, a very efficient H{sup +}-ATPase and high internal buffer capacities. These mechanisms work contrary to the proton influx and the acidification of the cytosol and are therefore proof for the physiological impact of osmoregulation by microalgae in extreme acidic environments (Sekler et al.1991, Weiss et al. 1999). Hence, these mechanisms also complicate the access to nutrients for the algal cell. The passive influx of positively charged ions such as potassium or ammonium is reduced by

  17. Present time

    CERN Document Server

    Romero, Gustavo E


    The idea of a moving present or `now' seems to form part of our most basic beliefs about reality. Such a present, however, is not reflected in any of our theories of the physical world. I show in this article that presentism, the doctrine that only what is present exists, is in conflict with modern relativistic cosmology and recent advances in neurosciences. I argue for a tenseless view of time, where what we call `the present' is just an emergent secondary quality arising from the interaction of perceiving self-conscious individuals with their environment. I maintain that there is no flow of time, but just an ordered system of events.

  18. Frontal tDCS modulates orbitofrontal reality filtering. (United States)

    Manuel, A L; David, A W; Bikson, M; Schnider, A


    Orbitofrontal reality filtering denotes a memory control mechanism necessary to keep thought and behavior in phase with reality. Its failure induces reality confusion as evident in confabulation and disorientation. In the present study, we explored the influence of orbitofrontal transcranial direct current stimulation (tDCS) on reality filtering. Twenty healthy human subjects made a reality filtering task, while receiving cathodal, anodal, or sham stimulation over the frontal pole in three sessions separated by at least 1week. Computational models predicted that this montage can produce polarity-specific current flow across the posterior medial orbitofrontal cortex (OFC). In agreement with our hypothesis, we found that cathodal tDCS over the frontal pole specifically impaired reality filtering in comparison to anodal and sham stimulation. This study shows that reality filtering, an orbitofrontal function, can be modulated with tDCS.

  19. Making nonlocal reality compatible with relativity


    Nikolic, H.


    It is often argued that hypothetic nonlocal reality responsible for nonlocal quantum correlations between entangled particles cannot be consistent with relativity. I review the most frequent arguments of that sort, explain how they can all be circumvented, and present an explicit Bohmian model of nonlocal reality (compatible with quantum phenomena) that fully obeys the principle of relativistic covariance and does not involve a preferred Lorentz frame.

  20. Quantum computing: towards reality (United States)

    Trabesinger, Andreas


    The concept of computers that harness the laws of quantum mechanics has transformed our thinking about how information can be processed. Now the environment exists to make prototype devices a reality.


    Directory of Open Access Journals (Sweden)

    Piotr Jaroszynski


    Full Text Available The article examines the difference between ontology and metaphysics. It shows that as soon as the composition of being from essence and existence is treated as purely mental or in a “reified” way (where essence and existence are independent elements, then essence as essence becomes a thing, and then simply becomes a being, or what is called reality. Both versions in which the real difference disappears or in which the road leads to “reification,” influence the treatment of essence as independent, where essence as thing fills the field of reality. However, if essence was only possibility, then (1 the reality also would be merely possible, (2 the realistic field of philosophical terminology would get curtailed, and (3 there would be no terms to maintain the difference between reality and possibility, between metaphysics and ontology.

  2. Ecophysiology, secondary pigments and ultrastructure of Chlainomonas sp. (Chlorophyta) from the European Alps compared with Chlamydomonas nivalis forming red snow. (United States)

    Remias, Daniel; Pichrtová, Martina; Pangratz, Marion; Lütz, Cornelius; Holzinger, Andreas


    Red snow is a well-known phenomenon caused by microalgae thriving in alpine and polar regions during the melting season. The ecology and biodiversity of these organisms, which are adapted to low temperatures, high irradiance and freeze-thaw events, are still poorly understood. We compared two different snow habitats containing two different green algal genera in the European Alps, namely algae blooming in seasonal rock-based snowfields (Chlamydomonas nivalis) and algae dominating waterlogged snow bedded over ice (Chlainomonassp.). Despite the morphological similarity of the red spores found at the snow surface, we found differences in intracellular organization investigated by light and transmission electron microscopy and in secondary pigments investigated by chromatographic analysis in combination with mass spectrometry. Spores ofChlainomonassp. show clear differences fromChlamydomonas nivalisin cell wall arrangement and plastid organization. Active photosynthesis at ambient temperatures indicates a high physiological activity, despite no cell division being present. Lipid bodies containing the carotenoid astaxanthin, which produces the red color, dominate cells of both species, but are modified differently. While inChlainomonassp. astaxanthin is mainly esterified with two fatty acids and is more apolar, inChamydomonas nivalis, in contrast, less apolar monoesters prevail.

  3. New thioredoxin targets in the unicellular photosynthetic eukaryote Chlamydomonas reinhardtii (United States)

    Lemaire, Stéphane D.; Guillon, Blanche; Le Maréchal, Pierre; Keryer, Eliane; Miginiac-Maslow, Myroslawa; Decottignies, Paulette


    Proteomics were used to identify the proteins from the eukaryotic unicellular green alga Chlamydomonas reinhardtii that can be reduced by thioredoxin. These proteins were retained specifically on a thioredoxin affinity column made of a monocysteinic thioredoxin mutant able to form mixed disulfides with its targets. Of a total of 55 identified targets, 29 had been found previously in higher plants or Synechocystis, but 26 were new targets. Biochemical tests were performed on three of them, showing a thioredoxin-dependent activation of isocitrate lyase and isopropylmalate dehydrogenase and a thioredoxin-dependent deactivation of catalase that is redox insensitive in Arabidopsis. In addition, we identified a Ran protein, a previously uncharacterized nuclear target in a photosynthetic organism. The metabolic and evolutionary implications of these findings are discussed. PMID:15123830

  4. A deoxyribonuclease from Chlamydomonas reinhardii. 1. Purification and properties. (United States)

    Tait, G C; Harris, W J


    A deoxyribonuclease has been purified more than 2000-fold from the green algae, Chlamydomonas reinhardii. The enzyme is most active on denatured DNA. Optimum activity is at pH 8.5, in 80 mM Tris-HCl buffer and 2 mM CaCl2. Other divalent cations can replace Ca2+ with varying lower efficiency. EDTA and inorganic phosphate are strongly inhibitory, while ATP and high concentrations of 2-mercaptoethanol are slightly inhibitory. The molecular weight is approximately 35 000, the Stokes radius is 2.7 nm, and the sedimentation coefficient 2.8 S. It is a single polypeptide chain, and the frictional ratio of 1.27 suggests it is only slightly asymetrical. The isoelectric point is 9.5. This enzyme has been termed exonuclease 1.

  5. Cilia and ciliopathies:From Chlamydomonas and beyond

    Institute of Scientific and Technical Information of China (English)


    The biological function of motile cilia/flagella has long been recognized. The non-motile primary cilium, once regarded as a vestigial organelle, however, has been found recently to play unexpected roles in mammalian physiology and development. Defects in cilia have profound impact on human health. Diseases related to cilia, collectively called ciliopathies include male infertility, primary cilia dyskinesia, renal cyst formation, blindness, polydactyly, obesity, hypertension, and even mental retardation. Our current understanding of cilia and ciliopathies has been fueled by basic research employing various model organisms including Chlamydomonas, a unicellular green alga. This review article provides a general introduction to the cell biology of cilia and an overview of various cilia-related diseases.

  6. Augmented Reality Binoculars. (United States)

    Oskiper, Taragay; Sizintsev, Mikhail; Branzoi, Vlad; Samarasekera, Supun; Kumar, Rakesh


    In this paper we present an augmented reality binocular system to allow long range high precision augmentation of live telescopic imagery with aerial and terrain based synthetic objects, vehicles, people and effects. The inserted objects must appear stable in the display and must not jitter and drift as the user pans around and examines the scene with the binoculars. The design of the system is based on using two different cameras with wide field of view and narrow field of view lenses enclosed in a binocular shaped shell. Using the wide field of view gives us context and enables us to recover the 3D location and orientation of the binoculars much more robustly, whereas the narrow field of view is used for the actual augmentation as well as to increase precision in tracking. We present our navigation algorithm that uses the two cameras in combination with an inertial measurement unit and global positioning system in an extended Kalman filter and provides jitter free, robust and real-time pose estimation for precise augmentation. We have demonstrated successful use of our system as part of information sharing example as well as a live simulated training system for observer training, in which fixed and rotary wing aircrafts, ground vehicles, and weapon effects are combined with real world scenes.

  7. What Should Guide Reality Construction?

    DEFF Research Database (Denmark)

    Ravn, Ib


    The constructivist movement in the social sciences (Berger & Luckmann, Gergen) argues that social institutions are the constructions of a community of human agents. This implies that people possess the power to radically change those institutions. This raises what may be called the values problem...... in constructivism, which, in its simplest form, is put in the title of the present chapter: What should guide reality construction? What principles or values should guide our construction of economic institutions, foreign policies, roles for the sexes, schooling, care for the sick? This values problem......-constructing the reality of her hosts. This acknowledgement implies responsibility and, hence, a personal set of values. If the values problem is central in constructivism as a general outlook on the world, it is even more so in the practice of constructivist research, since the values aspect has been actively suppressed...

  8. Achieving Presence through Evoked Reality. (United States)

    Pillai, Jayesh S; Schmidt, Colin; Richir, Simon


    The sense of "Presence" (evolving from "telepresence") has always been associated with virtual reality research and is still an exceptionally mystifying constituent. Now the study of presence clearly spans over various disciplines associated with cognition. This paper attempts to put forth a concept that argues that it's an experience of an "Evoked Reality (ER)" (illusion of reality) that triggers an "Evoked Presence (EP)" (sense of presence) in our minds. A Three Pole Reality Model is proposed to explain this phenomenon. The poles range from Dream Reality to Simulated Reality with Primary (Physical) Reality at the center. To demonstrate the relationship between ER and EP, a Reality-Presence Map is developed. We believe that this concept of ER and the proposed model may have significant applications in the study of presence, and in exploring the possibilities of not just virtual reality but also what we call "reality."

  9. Virtual reality training improves balance function

    Institute of Scientific and Technical Information of China (English)

    Yurong Mao; Peiming Chen; Le Li; Dongfeng Huang


    Virtual reality is a new technology that simulates a three-dimensional virtual world on a com-puter and enables the generation of visual, audio, and haptic feedback for the full immersion of users. Users can interact with and observe objects in three-dimensional visual space without limitation. At present, virtual reality training has been widely used in rehabilitation therapy for balance dysfunction. This paper summarizes related articles and other articles suggesting that virtual reality training can improve balance dysfunction in patients after neurological diseases. When patients perform virtual reality training, the prefrontal, parietal cortical areas and other motor cortical networks are activated. These activations may be involved in the reconstruction of neurons in the cerebral cortex. Growing evidence from clinical studies reveals that virtual reality training improves the neurological function of patients with spinal cord injury, cerebral palsy and other neurological impairments. These ifndings suggest that virtual reality training can acti-vate the cerebral cortex and improve the spatial orientation capacity of patients, thus facilitating the cortex to control balance and increase motion function.

  10. Virtual reality training improves balance function. (United States)

    Mao, Yurong; Chen, Peiming; Li, Le; Huang, Dongfeng


    Virtual reality is a new technology that simulates a three-dimensional virtual world on a computer and enables the generation of visual, audio, and haptic feedback for the full immersion of users. Users can interact with and observe objects in three-dimensional visual space without limitation. At present, virtual reality training has been widely used in rehabilitation therapy for balance dysfunction. This paper summarizes related articles and other articles suggesting that virtual reality training can improve balance dysfunction in patients after neurological diseases. When patients perform virtual reality training, the prefrontal, parietal cortical areas and other motor cortical networks are activated. These activations may be involved in the reconstruction of neurons in the cerebral cortex. Growing evidence from clinical studies reveals that virtual reality training improves the neurological function of patients with spinal cord injury, cerebral palsy and other neurological impairments. These findings suggest that virtual reality training can activate the cerebral cortex and improve the spatial orientation capacity of patients, thus facilitating the cortex to control balance and increase motion function.

  11. Fast mental states decoding in mixed reality.

    Directory of Open Access Journals (Sweden)

    Daniele eDe Massari


    Full Text Available The combination of Brain-Computer Interface technology, allowing online monitoring and decoding of brain activity, with virtual and mixed reality systems may help to shape and guide implicit and explicit learning using ecological scenarios. Real-time information of ongoing brain states acquired through BCI might be exploited for controlling data presentation in virtual environments. In this context, assessing to what extent brain states can be discriminated during mixed reality experience is critical for adapting specific data features to contingent brain activity. In this study we recorded EEG data while participants experienced a mixed reality scenario implemented through the eXperience Induction Machine (XIM. The XIM is a novel framework modeling the integration of a sensing system that evaluates and measures physiological and psychological states with a number of actuators and effectors that coherently reacts to the user's actions. We then assessed continuous EEG-based discrimination of spatial navigation, reading and calculation performed in mixed reality, using LDA and SVM classifiers. Dynamic single trial classification showed high accuracy of LDA and SVM classifiers in detecting multiple brain states as well as in differentiating between high and low mental workload, using a 5 s time-window shifting every 200 ms. Our results indicate overall better performance of LDA with respect to SVM and suggest applicability of our approach in a BCI-controlled mixed reality scenario. Ultimately, successful prediction of brain states might be used to drive adaptation of data representation in order to boost information processing in mixed reality.

  12. Virtual reality concepts and technologies

    CERN Document Server

    Fuchs, Philippe


    A manual for both designers and users, comprehensively presenting the current state of experts' knowledge on virtual reality (VR) in computer science, mechanics, optics, acoustics, physiology, psychology, ergonomics, ethics, and related area. Designed as a reference book and design guide to help the reader develop a VR project, it presents the reader with the importance of the user's needs and various aspects of the human computer interface (HCI). It further treats technical aspects of VR, hardware and software implementations, and details on the sensory and psycho-sensory interfaces. Providin

  13. Potential perils of peri-Pokémon perambulation: the dark reality of augmented reality? (United States)

    Joseph, Bellal; Armstrong, David G.


    Recently, the layering of augmented reality information on top of smartphone applications has created unprecedented user engagement and popularity. One augmented reality-based entertainment application, Pokémon Go (Pokémon Company, Tokyo, Japan) has become the most rapidly downloaded in history. This technology holds tremendous promise to promote ambulatory activity. However, there exists the obvious potential for distraction-related morbidity. We report two cases, presenting simultaneously to our trauma center, with injuries sustained secondary to gameplay with this augmented reality-based application. PMID:27713831

  14. Potential perils of peri-Pokémon perambulation: the dark reality of augmented reality? (United States)

    Joseph, Bellal; Armstrong, David G


    Recently, the layering of augmented reality information on top of smartphone applications has created unprecedented user engagement and popularity. One augmented reality-based entertainment application, Pokémon Go (Pokémon Company, Tokyo, Japan) has become the most rapidly downloaded in history. This technology holds tremendous promise to promote ambulatory activity. However, there exists the obvious potential for distraction-related morbidity. We report two cases, presenting simultaneously to our trauma center, with injuries sustained secondary to gameplay with this augmented reality-based application.


    Directory of Open Access Journals (Sweden)

    M. en C. Martha Rosa Cordero López


    Full Text Available Work In Terminal presents the analysis, design, implementation and results of Reconstruction Xicocotitlan Tollan-through augmented reality (Extended, which will release information about the Toltec capital supplemented by presenting an overview of the main premises of the Xicocotitlan Tollan city supported dimensional models based on the augmented reality technique showing the user a virtual representation of buildings in Tollan phase.


    Directory of Open Access Journals (Sweden)

    M. en C. Martha Rosa Cordero Lopez


    Full Text Available Work In Terminal presents the analysis, design, implementation and results of Reconstruction Xicocotitlan Tollan-through augmented reality (Extended, which will release information about the Toltec capital supplemented by presenting an overview of the main premises of the Xicocotitlan Tollan city supported dimensional models based on the augmented reality technique showing the user a virtual representation of buildings in Tollan phase.

  17. Virtual reality for engineering

    CERN Document Server

    De Gennaro, Silvano; CERN. Geneva


    Virtual Reality for Engineers. Virtual Reality is a very powerful visualization technique for 3D data, which can bring enormous benefits to engineering design. CAD models can be exported to a VR application and used as "Virtual Prototypes". Virtual Prototypes are an ideal replacement for wooden models as they can be generated automatically from most CAD products. They are totally reliable, they can be updated in a matter of minutes, and they allow designers to explore them from inside, on a one-to-one scale and using a 3D-stereo vision. Navigation can be performed using a number of instinctive tools, such as joysticks, spaceballs, VR helmets and 3D mice. The lectures will cover today's Virtual Reality products and methods, and describe how to transform CAD models into Virtual Prototypes. A "hands on" VR experience featuring the LHC detectors models can be organized for people interested.

  18. Effect of aluminum on cellular division and photosynthetic electron transport in Euglena gracilis and Chlamydomonas acidophila. (United States)

    Perreault, François; Dewez, David; Fortin, Claude; Juneau, Philippe; Diallo, Amirou; Popovic, Radovan


    The present study investigated aluminum's effect on cellular division and the photosynthetic processes in Euglena gracilis and Chlamydomonas acidophila at pH 3.0, at which Al is present mostly as Al(3+), AlSO(4) (+), and Al(SO(4))(2) (-). These algal species were exposed to 100, 188, and 740 microM Al, and after 24 h cell-bound Al was significantly different from control only for the highest concentration tested. However, very different effects of Al on algal cellular division, biomass per cell, and photosynthetic activity were found. Aluminum stimulated cell division but decreased at some level biomass per cell in C. acidophila. Primary photochemistry of photosynthesis, as Photosystem II quantum yield, and energy dissipation via nonphotochemical activity were slightly affected. However, for E. gracilis, under the same conditions, Al did not show a stimulating effect on cellular division or photosynthetic activity. Primary photochemical activity was diminished, and energy dissipation via nonphotochemical pathways was strongly increased. Therefore, when Al is highly available in aquatic ecosystems, these effects may indicate very different response mechanisms that are dependent on algal species.

  19. Prototyping Augmented Reality

    CERN Document Server

    Mullen, Tony


    Learn to create augmented reality apps using Processing open-source programming language Augmented reality (AR) is used all over, and you may not even realize it. Smartphones overlay data onto live camera views to show homes for sale, restaurants, or historical sites. American football broadcasts use AR to show the invisible first-down line on the field to TV viewers. Nike and Budweiser, among others, have used AR in ads. Now, you can learn to create AR prototypes using 3D data, Processing open-source programming language, and other languages. This unique book is an easy-to-follow guide on how

  20. Augmented reality som wearable

    DEFF Research Database (Denmark)

    Buhl, Mie; Rahn, Annette


    Artiklen omhandler design og implementering af Augmented Reality (AR) i form af en wearable i sygeplejerskeuddannelsens anatomiundervisning, mere specifikt undervisning i lungeanatomi og respiration, med fokus på potentialer for visuel læring. Projektet undersøger, hvordan en udviklet AR-applikat......Artiklen omhandler design og implementering af Augmented Reality (AR) i form af en wearable i sygeplejerskeuddannelsens anatomiundervisning, mere specifikt undervisning i lungeanatomi og respiration, med fokus på potentialer for visuel læring. Projektet undersøger, hvordan en udviklet AR...

  1. Quantum Physics and Reality

    CERN Document Server

    d'Espagnat, Bernard


    Contrary to classical physics, which was strongly objective i.e. could be interpreted as a description of mind-independent reality, standard quantum mechanics (SQM) is only weakly objective, that is to say, its statements, though intersubjectively valid, still merely refer to operations of the mind. Essentially, in fact, they are predictive of observations. On the view that SQM is universal conventional realism is thereby refuted. It is shown however that this does not rule out a broader form of realism, called here 'open realism', restoring the notion of mind-independent reality.

  2. Exploring Urban Environments Using Virtual and Augmented Reality

    Directory of Open Access Journals (Sweden)

    Stelios Papakonstantinou


    Full Text Available In this paper, we propose the use of specific system architecture, based on mobile device, for navigation in urban environments. The aim of this work is to assess how virtual and augmented reality interface paradigms can provide enhanced location based services using real-time techniques in the context of these two different technologies. The virtual reality interface is based on faithful graphical representation of the localities of interest, coupled with sensory information on the location and orientation of the user, while the augmented reality interface uses computer vision techniques to capture patterns from the real environment and overlay additional way-finding information, aligned with real imagery, in real-time. The knowledge obtained from the evaluation of the virtual reality navigational experience has been used to inform the design of the augmented reality interface. Initial results of the user testing of the experimental augmented reality system for navigation are presented.

  3. Virtual reality and virtual bodies (United States)

    Richards, Catherine; Korba, Larry W.; Shaw, Christopher D.; Green, Mark


    There are many ways to produce the sense of `presence' or telepresence in the user of virtual reality. For example attempting to increase the realism of the visual environment is a commonly accepted strategy. In contrast, this paper explores a way for the user to feel present in an unrealistic virtual body. It investigates an unusual approach, proprioceptive illusions. Proprioceptive or body illusions are used to generate and explore the experience of virtuality and presence outside of the normal body limits. These projects are realized in art installations.

  4. The phenomena of social reality


    Tina Kumelj; Barbara Turk


    Social reality originates from social interaction in a social group. It is consolidated with social consensus. It is transcendent and relatively stable. Social reality is maintained in relatively isolated, balanced social environment. Majority of members in a social group spontaneously reacts to deviations. These are characteristics which many authors contribute to social reality. If social reality is to be understood as a collection of social-psychological phenomena, of which the important f...

  5. A Reality Check

    DEFF Research Database (Denmark)

    Skovsgaard, Morten; Albæk, Erik; Bro, Peter


    Objectivity is a cornerstone in the journalistic profession. There is a widespread acknowledgement that a one-to-one representation of reality is not possible, and thus the norm must be interpreted by journalists in their daily work. Based on a journalist survey among Danish journalists (N=2008) we...

  6. Augmented Reality i naturfagsundervisningen

    DEFF Research Database (Denmark)

    Radmer, Ole; Surland, Mogens; Nielsen, Birgitte Lund


    Augmented Reality (AR) giver ny mulighed for, at elever kan lave undersøgelser i naturfag med enkel teknologi, hvor animationer og simulationer kobles med det virkelige fænomen. I workshoppen kan I afprøve AR eksempler, udviklet i et internationalt EU projekt. Der vil være noget, der direkte kan...

  7. Selections of Reality

    DEFF Research Database (Denmark)

    Järvinen, Margaretha; Miller, Gale


    substitution (methadone) treatment to users. Burke's dramatistic perspective calls attention to the recurring relationships among rhetorical elements within accounts of social reality. The elements form a pentad: scene, purpose, agent, agency and acts. Our analysis examines how the ideal of governmentality...

  8. Augmented Reality og kulturarv

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Kirkedahl Lysholm


    Museerne står overfor at skulle omfavne den digitale kultur i håndteringen af den store mængde viden, institutionerne repræsenterer. Augmented Reality-systemer forbinder ved hjælp af moderne teknologi det virtuelle med det virkelige, og kan derfor synes som en oplagt anvendelsesmulighed i...

  9. Collaborative augmented reality environments

    DEFF Research Database (Denmark)

    Büscher, Monika; Christensen, Michael; Grønbæk, Kaj


    This paper describes Manufaktur, a prototype of a concept and infrastructure that goes beyond the classical CVE systems toward a collaborative augmented reality environment, where users? documents and objects appear as live representations in a 3D workspace. Manufaktur supports collaborative...

  10. Vision, Plan and Reality

    DEFF Research Database (Denmark)

    Steinø, Nicolai

    How come, that there is often a gap between what is considered good urban design and the built reality of the urban environment? This is the question which the thesis aims to investigate. It has often been stated that urban development can no longer be controlled, and the reason for this has been...

  11. The Reality Game. (United States)

    Colorado Migrant Education Resource Center (CoMerc), Longmont.

    "The Reality Game" is intended to provide players with an opportunity to experience the harsh lifestyle of a migrant family in their daily struggle for survival. By shedding light on many variables impeding the education of migrant children, the players should be able to infer implications for their academic and personal growth. The gameboard…

  12. Augmented reality som wearable

    DEFF Research Database (Denmark)

    Buhl, Mie; Rahn, Annette


    Artiklen omhandler design og implementering af Augmented Reality (AR) i form af en wearable i sygeplejerskeuddannelsens anatomiundervisning, mere specifikt undervisning i lungeanatomi og respiration, med fokus på potentialer for visuel læring. Projektet undersøger, hvordan en udviklet AR...

  13. Collaboration in Augmented Reality

    NARCIS (Netherlands)

    Lukosch, S.; Billinghurst, M.; Alem, L.; Kiyokawa, K.


    Augmented Reality (AR) is a technology that allows users to view and interact in real time with virtual images seamlessly superimposed over the real world. AR systems can be used to create unique collaborative experiences. For example, co-located users can see shared 3D virtual objects that they int

  14. Phosphoprotein SAK1 is a regulator of acclimation to singlet oxygen in Chlamydomonas reinhardtii. (United States)

    Wakao, Setsuko; Chin, Brian L; Ledford, Heidi K; Dent, Rachel M; Casero, David; Pellegrini, Matteo; Merchant, Sabeeha S; Niyogi, Krishna K


    Singlet oxygen is a highly toxic and inevitable byproduct of oxygenic photosynthesis. The unicellular green alga Chlamydomonas reinhardtii is capable of acclimating specifically to singlet oxygen stress, but the retrograde signaling pathway from the chloroplast to the nucleus mediating this response is unknown. Here we describe a mutant, singlet oxygen acclimation knocked-out 1 (sak1), that lacks the acclimation response to singlet oxygen. Analysis of genome-wide changes in RNA abundance during acclimation to singlet oxygen revealed that SAK1 is a key regulator of the gene expression response during acclimation. The SAK1 gene encodes an uncharacterized protein with a domain conserved among chlorophytes and present in some bZIP transcription factors. The SAK1 protein is located in the cytosol, and it is induced and phosphorylated upon exposure to singlet oxygen, suggesting that it is a critical intermediate component of the retrograde signal transduction pathway leading to singlet oxygen acclimation.DOI:

  15. Phosphoprotein SAK1 is a regulator of acclimation to singlet oxygen in Chlamydomonas reinhardtii (United States)

    Wakao, Setsuko; Chin, Brian L; Ledford, Heidi K; Dent, Rachel M; Casero, David; Pellegrini, Matteo; Merchant, Sabeeha S; Niyogi, Krishna K


    Singlet oxygen is a highly toxic and inevitable byproduct of oxygenic photosynthesis. The unicellular green alga Chlamydomonas reinhardtii is capable of acclimating specifically to singlet oxygen stress, but the retrograde signaling pathway from the chloroplast to the nucleus mediating this response is unknown. Here we describe a mutant, singlet oxygen acclimation knocked-out 1 (sak1), that lacks the acclimation response to singlet oxygen. Analysis of genome-wide changes in RNA abundance during acclimation to singlet oxygen revealed that SAK1 is a key regulator of the gene expression response during acclimation. The SAK1 gene encodes an uncharacterized protein with a domain conserved among chlorophytes and present in some bZIP transcription factors. The SAK1 protein is located in the cytosol, and it is induced and phosphorylated upon exposure to singlet oxygen, suggesting that it is a critical intermediate component of the retrograde signal transduction pathway leading to singlet oxygen acclimation. DOI: PMID:24859755

  16. Antagonistic and synergistic effects of light irradiation on the effects of copper on Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Cheloni, Giulia; Cosio, Claudia; Slaveykova, Vera I., E-mail:


    Highlights: • Light intensity and spectral composition affect Cu uptake and effects to C. reinhardtii. • High light (HL) reduced Cu effect on growth inhibition, oxidative stress and damage. • HL in combination with Cu up-regulated genes involved in the antioxidant responses. • HL with increased UVB radiation exacerbated Cu uptake and Cu-induced toxic effects. - Abstract: The present study showed the important role of light intensity and spectral composition on Cu uptake and effects on green alga Chlamydomonas reinhardtii. High-intenisty light (HL) increased cellular Cu concentrations, but mitigated the Cu-induced decrease in chlorophyll fluorescence, oxidative stress and lipid peroxidation at high Cu concentrations, indicating that Cu and HL interact in an antagonistic manner. HL up-regulated the transcription of genes involved in the antioxidant response in C. reinhardtii and thus reduced the oxidative stress upon exposure to Cu and HL. Combined exposure to Cu and UVBR resulted in an increase of cellular Cu contents and caused severe oxidative damage to the cells. The observed effects were higher than the sum of the effects corresponding to exposure to UVBR or Cu alone suggesting a synergistic interaction.

  17. Influence of sulphate on the reduction of cadmium toxicity in the microalga Chlamydomonas moewusii. (United States)

    Mera, Roi; Torres, Enrique; Abalde, Julio


    Cadmium is considered as one of the most hazardous metals for living organism and ecosystems. Environmental factors play an important role since they alter the toxicity of metals by varying the bioavailability of these elements for the organisms. The aim of the present study was to investigate, using the freshwater microalga Chlamydomonas moewusii, the existence of an interaction between cadmium and sulphate as a factor that varied the toxicity of this metal. Different cell parameters such as cell growth, content of chlorophylls and biosynthesis of phytochelatins (PCs) were determined. A two-way ANOVA showed that the interaction had a significant effect size of 21% (pmicroalga and around of a 6% on the content of chlorophylls/cell. The effect of this inhibition was that when the concentration of sulphate increased, a lower toxic effect of cadmium on the growth and on the content of chlorophylls was observed. In addition, the increase of sulphate concentration allowed the biosynthesis of a higher amount of PCs and/or PCs with higher chain length. This higher biosynthesis was responsible for the reduction of the toxic effect of cadmium and explained the interaction.

  18. Light/electricity conversion by defined cocultures of Chlamydomonas and Geobacter. (United States)

    Nishio, Koichi; Hashimoto, Kazuhito; Watanabe, Kazuya


    Biological energy-conversion systems are attractive in terms of their self-organizing and self-sustaining properties and are expected to be applied towards environmentally friendly bioenergy processes. Recent studies have demonstrated that sustainable light/electricity-conversion systems, termed microbial solar cells (MSCs), can be constructed using naturally occurring microbial communities. To better understand the energy-conversion mechanisms in microbial communities, the present study attempted to construct model MSCs comprised of defined cocultures of a green alga, Chlamydomonas reinhardtii, and an iron-reducing bacterium, Geobacter sulfurreducens, and examined their metabolism and interactions in MSCs. When MSC bioreactors were inoculated with these microbes and irradiated on a 12-h light/dark cycle, periodic current was generated in the dark with energy-conversion efficiencies of 0.1%. Metabolite analyses revealed that G. sulfurreducens generated current by oxidizing formate that was produced by C. reinhardtii in the dark. These results demonstrate that the light/electricity conversion occurs via syntrophic interactions between phototrophs and electricity-generating bacteria. Based on the results and data in literatures, it is estimated that the excretion of organics by the phototroph was the bottleneck step in the syntrophic light/electricity conversion. We also discuss differences between natural-community and defined-coculture MSCs.

  19. A simple and non-invasive method for nuclear transformation of intact-walled Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Sora Kim

    Full Text Available Genetic engineering in microalgae is gaining attraction but nuclear transformation methods available so far are either inefficient or require special equipment. In this study, we employ positively charged nanoparticles, 3-aminopropyl-functionalized magnesium phyllosilicate (aminoclay, approximate unit cell composition of [H2N(CH23]8Si8Mg6O12(OH4, for nuclear transformation into eukaryotic microalgae. TEM and EDX analysis of the process of transformation reveals that aminoclay coats negatively-charged DNA biomolecules and forms a self-assembled hybrid nanostructure. Subsequently, when this nanostructure is mixed with microalgal cells and plated onto selective agar plates with high friction force, cell wall is disrupted facilitating delivery of plasmid DNA into the cell and ultimately to the nucleus. This method is not only simple, inexpensive, and non-toxic to cells but also provides efficient transformation (5.03×10(2 transformants/µg DNA, second only to electroporation which needs advanced instrumentation. We present optimized parameters for efficient transformation including pre-treatment, friction force, concentration of foreign DNA/aminoclay, and plasticity of agar plates. It is also confirmed the successful integration and stable expression of foreign gene in Chlamydomonas reinhardtii through molecular methods.

  20. Effects of chromium on photosynthetic and photoreceptive apparatus of the alga Chlamydomonas reinhardtii. (United States)

    Rodríguez, M Cecilia; Barsanti, Laura; Passarelli, Vincenzo; Evangelista, Valter; Conforti, Visitacion; Gualtieri, Paolo


    Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The presence of Cr leads to the selection of algal populations able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms include biosorption, diminished accumulation, precipitation, reduction of Cr(6+) to Cr(3+), and chromate efflux. In this paper we describe the effects of Cr(6+) (the more toxic species) on the photosynthetic and photoreceptive apparatus of the fresh water unicellular alga Chlamydomonas reinhardtii. We measured the effect of the heavy metal by means of in vivo absorption microspectroscopy of both the thylakoid compartments and the eyespot. The decomposition of the overall absorption spectra in pigment constituents indicates that Cr(6+) induced a complete pheophinitization of the chrorophylls and a modification of the carotenoids present in the eyespot only when its concentration is equal or greater than 10 microM. Due to this low tolerance level, C. reinhardtii could be used as indicator of Cr pollution, but it is not feasible for bioremediation purposes.

  1. Phosphoregulation of an Inner Dynein Arm Complex in Chlamydomonas reinhardtii Is Altered in Phototactic Mutant Strains (United States)

    King, Stephen J.; Dutcher, Susan K.


    To gain a further understanding of axonemal dynein regulation, mutant strains of Chlamydomonas reinhardtii that had defects in both phototactic behavior and flagellar motility were identified and characterized. ptm1, ptm2, and ptm3 mutant strains exhibited motility phenotypes that resembled those of known inner dynein arm region mutant strains, but did not have biochemical or genetic phenotypes characteristic of other inner dynein arm mutations. Three other mutant strains had defects in the f class of inner dynein arms. Dynein extracts from the pf9-4 strain were missing the entire f complex. Strains with mutations in pf9/ida1, ida2, or ida3 failed to assemble the f dynein complex and did not exhibit phototactic behavior. Fractionated dynein from mia1-1 and mia2-1 axonemes exhibited a novel f class inner dynein arm biochemical phenotype; the 138-kD f intermediate chain was present in altered phosphorylation forms. In vitro axonemal dynein activity was reduced by the mia1-1 and mia2-1 mutations. The addition of kinase inhibitor restored axonemal dynein activity concomitant with the dephosphorylation of the 138-kD f intermediate chain. Dynein extracts from uni1-1 axonemes, which specifically assemble only one of the two flagella, contained relatively high levels of the altered phosphorylation forms of the 138-kD intermediate chain. We suggest that the f dynein complex may be phosphoregulated asymmetrically between the two flagella to achieve phototactic turning. PMID:9008712

  2. Alleviation of copper-induced oxidative damage in Chlamydomonas reinhardtii by carbon monoxide. (United States)

    Zheng, Qi; Meng, Qian; Wei, Yuan Yuan; Yang, Zhi Min


    Carbon monoxide (CO) is an endogenous gaseous molecule in plants and animals. Recent studies have shown that it is one of the most essential cellular components regulating many aspects of plant growth and development. However, whether CO regulates the green algae adaptive response to heavy metal toxicity is unknown. The present study investigated the role of CO in regulating Cu-induced oxidative stress in eukaryotic algae Chlamydomonas reinhardtii. Cells pretreated with 5 μM CO for 30 min and followed by exposure to 5 μM Cu(II) for 4 days showed attenuated toxicity. The CO-improved growth of algae was correlated with reduced lipid peroxidation and increased chlorophyll accumulation. The beneficial effect of CO was confirmed by histochemical staining with reactive oxygen species. Further, treatment with 5 μM CO increased the activity of catalase with Cu. However, a reduced superoxide dismutase activity was observed in the CO + Cu-treated algae compared to the control (activity of Cu treatment alone). Under the same condition, the activity of ascorbate peroxidase was not significantly changed. These results suggest that CO can play an important role in regulating the response of algae to Cu stress.

  3. The Chlamydomonas Genome Reveals the Evolution of Key Animal and Plant Functions

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Sabeeha S


    Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella.

  4. Virtual Reality in the Classroom. (United States)

    Pantelidis, Veronica S.


    Considers the concept of virtual reality; reviews its history; describes general uses of virtual reality, including entertainment, medicine, and design applications; discusses classroom uses of virtual reality, including a software program called Virtus WalkThrough for use with a computer monitor; and suggests future possibilities. (34 references)…

  5. AR DOC: Augmented reality documentaries

    DEFF Research Database (Denmark)

    Vistisen, Peter


    Augmented Reality Documentaries (AR DOC) er et ’lille’ Shareplay projekt (ansøgte midler augmented reality cross media løsninger, til at skabe engagerende publikumsformidling...... indenfor oplevelsesindustrien. Projektet har genereret ny viden omkring, hvordan fysisk og digital formidling kan understøttes via Augmented Reality som formidlingsformat....

  6. Retrograde bilin signaling enables Chlamydomonas greening and phototrophic survival (United States)

    Duanmu, Deqiang; Casero, David; Dent, Rachel M.; Gallaher, Sean; Yang, Wenqiang; Rockwell, Nathan C.; Martin, Shelley S.; Pellegrini, Matteo; Niyogi, Krishna K.; Merchant, Sabeeha S.; Grossman, Arthur R.; Lagarias, J. Clark


    The maintenance of functional chloroplasts in photosynthetic eukaryotes requires real-time coordination of the nuclear and plastid genomes. Tetrapyrroles play a significant role in plastid-to-nucleus retrograde signaling in plants to ensure that nuclear gene expression is attuned to the needs of the chloroplast. Well-known sites of synthesis of chlorophyll for photosynthesis, plant chloroplasts also export heme and heme-derived linear tetrapyrroles (bilins), two critical metabolites respectively required for essential cellular activities and for light sensing by phytochromes. Here we establish that Chlamydomonas reinhardtii, one of many chlorophyte species that lack phytochromes, can synthesize bilins in both plastid and cytosol compartments. Genetic analyses show that both pathways contribute to iron acquisition from extracellular heme, whereas the plastid-localized pathway is essential for light-dependent greening and phototrophic growth. Our discovery of a bilin-dependent nuclear gene network implicates a widespread use of bilins as retrograde signals in oxygenic photosynthetic species. Our studies also suggest that bilins trigger critical metabolic pathways to detoxify molecular oxygen produced by photosynthesis, thereby permitting survival and phototrophic growth during the light period. PMID:23345435

  7. Lipidomic Analysis of Chlamydomonas reinhardtii under Nitrogen and Sulfur Deprivation.

    Directory of Open Access Journals (Sweden)

    Dawei Yang

    Full Text Available Chlamydomonas reinhardtii accumulates lipids under complete nutrient starvation conditions while overall growth in biomass stops. In order to better understand biochemical changes under nutrient deprivation that maintain production of algal biomass, we used a lipidomic assay for analyzing the temporal regulation of the composition of complex lipids in C. reinhardtii in response to nitrogen and sulfur deprivation. Using a chip-based nanoelectrospray direct infusion into an ion trap mass spectrometer, we measured a diversity of lipid species reported for C. reinhardtii, including PG phosphatidylglycerols, PI Phosphatidylinositols, MGDG monogalactosyldiacylglycerols, DGDG digalactosyldiacylglycerols, SQDG sulfoquinovosyldiacylglycerols, DGTS homoserine ether lipids and TAG triacylglycerols. Individual lipid species were annotated by matching mass precursors and MS/MS fragmentations to the in-house LipidBlast mass spectral database and MS2Analyzer. Multivariate statistics showed a clear impact on overall lipidomic phenotypes on both the temporal and the nutrition stress level. Homoserine-lipids were found up-regulated at late growth time points and higher cell density, while triacyclglycerols showed opposite regulation of unsaturated and saturated fatty acyl chains under nutritional deprivation.

  8. Response of Chlamydomonas reinhardtii to naphthenic acid exposure

    Energy Technology Data Exchange (ETDEWEB)

    Goff, K.; Wilson, K. [Saskatchewan Univ., Saskatoon, SK (Canada); Headley, J. [Environment Canada, Ottawa, ON (Canada)


    This study examined the feasibility of using a model organism for the algal bioremediation of oil sands process water (OSPW), a highly toxic mixture of sediments, bitumen, ions, and organic and inorganic compounds. Naphthenic acids (NAs) are a contaminant class of particular concern. Bioremediation techniques may mitigate toxicity of OSPW in general, and NAs in particular. Although most studies on the biodegradation of NAs focus on the role of bacteria, fungi, and emergent macrophytes, studies have indicated that algae may also play a key role through direct degradation, biosequestration, or photosynthetic aeration of waters to promote other biological reactions. Chlamydomonas frigida is of particular interest, but no cultures are currently available. Therefore, this study used C. reinhardtii, a well-characterized model organism, to begin analysis of potential algal bioremediation of OSPW. Cultures of C. reinhardtii were grown heterotrophically in nutrient media spiked with a dilution series of NAs. Culture densities were measured to compile growth curves over time, changes in rate of growth, and survivability. Negative ion electrospray mass spectrometry was used to determine the concentration of NAs in solution in relation to growth rate and culture density. The study determined the tolerance of C. reinhardtii to NAs. A mechanism for this tolerance was then proposed.

  9. Insecticides induced biochemical changes in freshwater microalga Chlamydomonas mexicana. (United States)

    Kumar, Muthukannan Satheesh; Kabra, Akhil N; Min, Booki; El-Dalatony, Marwa M; Xiong, Jiuqiang; Thajuddin, Nooruddin; Lee, Dae Sung; Jeon, Byong-Hun


    The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L(-1) of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L(-1), beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L(-1) of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21% removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress.

  10. Establishing Chlamydomonas reinhardtii as an industrial biotechnology host. (United States)

    Scaife, Mark A; Nguyen, Ginnie T D T; Rico, Juan; Lambert, Devinn; Helliwell, Katherine E; Smith, Alison G


    Microalgae constitute a diverse group of eukaryotic unicellular organisms that are of interest for pure and applied research. Owing to their natural synthesis of value-added natural products microalgae are emerging as a source of sustainable chemical compounds, proteins and metabolites, including but not limited to those that could replace compounds currently made from fossil fuels. For the model microalga, Chlamydomonas reinhardtii, this has prompted a period of rapid development so that this organism is poised for exploitation as an industrial biotechnology platform. The question now is how best to achieve this? Highly advanced industrial biotechnology systems using bacteria and yeasts were established in a classical metabolic engineering manner over several decades. However, the advent of advanced molecular tools and the rise of synthetic biology provide an opportunity to expedite the development of C. reinhardtii as an industrial biotechnology platform, avoiding the process of incremental improvement. In this review we describe the current status of genetic manipulation of C. reinhardtii for metabolic engineering. We then introduce several concepts that underpin synthetic biology, and show how generic parts are identified and used in a standard manner to achieve predictable outputs. Based on this we suggest that the development of C. reinhardtii as an industrial biotechnology platform can be achieved more efficiently through adoption of a synthetic biology approach.

  11. Modulation of Chlamydomonas reinhardtii flagellar motility by redox poise (United States)

    Wakabayashi, Ken-ichi; King, Stephen M.


    Redox-based regulatory systems are essential for many cellular activities. Chlamydomonas reinhardtii exhibits alterations in motile behavior in response to different light conditions (photokinesis). We hypothesized that photokinesis is signaled by variations in cytoplasmic redox poise resulting from changes in chloroplast activity. We found that this effect requires photosystem I, which generates reduced NADPH. We also observed that photokinetic changes in beat frequency and duration of the photophobic response could be obtained by altering oxidative/reductive stress. Analysis of reactivated cell models revealed that this redox poise effect is mediated through the outer dynein arms (ODAs). Although the global redox state of the thioredoxin-related ODA light chains LC3 and LC5 and the redox-sensitive Ca2+-binding subunit of the docking complex DC3 did not change upon light/dark transitions, we did observe significant alterations in their interactions with other flagellar components via mixed disulfides. These data indicate that redox poise directly affects ODAs and suggest that it may act in the control of flagellar motility. PMID:16754958

  12. Expression of human soluble TRAIL in Chlamydomonas reinhardtii chloroplast

    Institute of Scientific and Technical Information of China (English)

    YANG Zongqi; LI yinü; CHEN Feng; LI Dong; ZHANG Zhifang; LIU Yanxin; ZHENG Dexian; WANG Yong; SHEN Guifang


    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces selectively apoptosis in various tumor cells and virus-infected cells, but rarely in normal cells. A chloroplast expression vector, p64TRAIL, containing the cDNA coding for the soluble TRAIL (sTRAIL), was constructed with clpP-trnL-petB-chlL-rpl23-rpl2 as Chlamydomonas reinhardtii plastid homologous recombinant fragments and spectinomycin-resistant aadA gene as a select marker. The plasmid p64TRAIL was transferred into the chloroplast genome of C. reinhardtii by the biolistic method. Three independently transformed lines were obtained by 100 mg/L spectinomycin selection. PCR amplification, Southern blot analysis of the sTRAIL coding region DNA and cultivation cells in the dark all showed that the exogenous DNA had been integrated into chloroplast genome of C. reinhardtii. Western blot analysis showed that human soluble TRAIL was expressed in C. reinhardtii chloroplast. The densitometric analysis of Western blot indicated that the expressed human sTRAIL protein in the chloroplasts of C. reinhardtii accounted for about 0.43%-0.67% of the total soluble proteins.These experimental results demonstrated the possibility of using transgenic chloroplasts of green alga as bioreactors for production of biopharmaceuticals.

  13. Designing a Mixed Reality Intergenerational Entertainment System (United States)

    Khoo, Eng Tat; Merritt, Tim; Cheok, Adrian David

    This chapter presents steps for designing an intergenerational mixed reality entertainment system, which focuses on physical and social interactions using a mixed reality floor system. The main design goals include the following: facilitating interactions between users with varied levels of skill in utilizing technology, utilizing the familiar physical motions from other activities to make an intuitive physical interface, and encouraging social interactions among families and friends. Detailed implementation of these steps is presented in the design of our intergenerational entertainment system, Age Invaders. Our design process is based on user-centered design. The results of the study help to focus the refinements of the existing platform from a usability standpoint and also aid in the development of new physical entertainment and interactive applications. This study provides insights into user issues including how users interact in a complex mixed reality experience.

  14. Transcriptomic and Physiological Responses of the Green Microalga Chlamydomonas reinhardtii during Short-Term Exposure to Subnanomolar Methylmercury Concentrations. (United States)

    Beauvais-Flück, Rebecca; Slaveykova, Vera I; Cosio, Claudia


    The effects of short-term exposure to subnanomolar methyl-mercury (MeHg) concentrations, representative of contaminated environments, on the microalga Chlamydomonas reinhardtii were assessed using both physiological end points and gene expression analysis. MeHg bioaccumulated and induced significant increase of the photosynthesis efficiency, while the algal growth, oxidative stress, and chlorophyll fluorescence were unaffected. At the molecular level, MeHg significantly dysregulated the expression of genes involved in motility, energy metabolism, lipid metabolism, metal transport, and antioxidant enzymes. Data suggest that the cells were able to cope with subnanomolar MeHg exposure, but this tolerance resulted in a significant cost to the cell energy and reserve metabolism as well as ample changes in the nutrition and motility of C. reinhardtii. The present results allowed gaining new insights on the effects and uptake mechanisms of MeHg at subnanomolar concentrations in aquatic primary producers.

  15. Pose estimation for mobile devices and augmented reality

    NARCIS (Netherlands)

    Caarls, J.


    In this thesis we introduce the reader to the field of Augmented Reality (AR) and describe aspects of an AR system. We show the current uses in treatment of phobias, games, sports and industry. We present the challenges for Optical See-Through Augmented Reality in which the real world is perceived n

  16. Visual Environment for Designing Interactive Learning Scenarios with Augmented Reality (United States)

    Mota, José Miguel; Ruiz-Rube, Iván; Dodero, Juan Manuel; Figueiredo, Mauro


    Augmented Reality (AR) technology allows the inclusion of virtual elements on a vision of actual physical environment for the creation of a mixed reality in real time. This kind of technology can be used in educational settings. However, the current AR authoring tools present several drawbacks, such as, the lack of a mechanism for tracking the…

  17. Treatment of Complicated Grief Using Virtual Reality: A Case Report (United States)

    Botella, C.; Osma, J.; Palacios, A. Garcia; Guillen, V.; Banos, R.


    This is the first work exploring the application of new technologies, concretely virtual reality, to facilitate emotional processing in the treatment of Complicated Grief. Our research team has designed a virtual reality environment (EMMA's World) to foster the expression and processing of emotions. In this study the authors present a description…

  18. The LC7 Light Chains of Chlamydomonas Flagellar Dyneins Interact with Components Required for Both Motor Assembly and Regulation (United States)

    DiBella, Linda M.; Sakato, Miho; Patel-King, Ramila S.; Pazour, Gregory J.; King, Stephen M.


    Members of the LC7/Roadblock family of light chains (LCs) have been found in both cytoplasmic and axonemal dyneins. LC7a was originally identified within Chlamydomonas outer arm dynein and associates with this motor's cargo-binding region. We describe here a novel member of this protein family, termed LC7b that is also present in the Chlamydomonas flagellum. Levels of LC7b are reduced ∼20% in axonemes isolated from strains lacking inner arm I1 and are ∼80% lower in the absence of the outer arms. When both dyneins are missing, LC7b levels are diminished to <10%. In oda9 axonemal extracts that completely lack outer arms, LC7b copurifies with inner arm I1, whereas in ida1 extracts that are devoid of I1 inner arms it associates with outer arm dynein. We also have observed that some LC7a is present in both isolated axonemes and purified 18S dynein from oda1, suggesting that it is also a component of both the outer arm and inner arm I1. Intriguingly, in axonemal extracts from the LC7a null mutant, oda15, which assembles ∼30% of its outer arms, LC7b fails to copurify with either dynein, suggesting that it interacts with LC7a. Furthermore, both the outer arm γ heavy chain and DC2 from the outer arm docking complex completely dissociate after salt extraction from oda15 axonemes. EDC cross-linking of purified dynein revealed that LC7b interacts with LC3, an outer dynein arm thioredoxin; DC2, an outer arm docking complex component; and also with the phosphoprotein IC138 from inner arm I1. These data suggest that LC7a stabilizes both the outer arms and inner arm I1 and that both LC7a and LC7b are involved in multiple intradynein interactions within both dyneins. PMID:15304520

  19. Legal reality of Russia: constants and variables

    Directory of Open Access Journals (Sweden)

    Andrey Valeryevich Skorobogatov


    Full Text Available Objective to develop the sciencebased knowledge about essential and substantial aspects of the current legal reality of Russia in the context of postclassical paradigm. Methods the methodological basis of this research is the synthesis of classical and postclassical paradigms that determine the choice of specific methods of research formallegal comparative legal modeling method hermeneutic discursive methods. Results basing on the postclassical methodology it is proved that the legal reality of Russia consists of three levels legislation law enforcement and legal behavior. The determinant level of legal reality is legal behavior that is aimed at observing the unwritten rules. The legal reality of Russia is characterized by a transgressive state of the modern Russian society expressed in broad application of nonlegislative nonlegal practices low level of legal culture legal nihilism and legal infantilism. Scientific novelty the article for the first time analyzes the ontological and phenomenological essence of the legal reality in Russia and determines its transgressive nature at the present stage of development. Practical value the main provisions and conclusions of the article can be used in scientific and pedagogical activity when considering questions about the nature and content of legal development. nbsp

  20. Influence of temperature on glutathione level and glutathione-related enzyme activities of Antarctic ice microalgae Chlamydomonas sp.ICE-L

    Institute of Scientific and Technical Information of China (English)


    GSH system plays a role in the control of the redox balance state, anti-oxidation and protecting life from injury of ROS (reactive oxygen species).In present paper, the possible GSH system of Chlamydomonas sp.ICE-L has been investigated by evaluating GSH and GSH-related enzymatic responses at different temperatures using speetrophotometer methods.The results showed that the GSH system is correlated positively to low temperature, and other factors but GR are correlated negatively to high temperature.So GSH and GSH-related enzymes play an important role in the adaptation of Antarctic ice microulgae to low temperature.

  1. Augmented Reality vs Virtual Reality for 3D Object Manipulation. (United States)

    Krichenbauer, Max; Yamamoto, Goshiro; Taketomi, Takafumi; Sandor, Christian; Kato, Hirokazu


    Virtual Reality (VR) Head-Mounted Displays (HMDs) are on the verge of becoming commodity hardware available to the average user and feasible to use as a tool for 3D work. Some HMDs include front-facing cameras, enabling Augmented Reality (AR) functionality. Apart from avoiding collisions with the environment, interaction with virtual objects may also be affected by seeing the real environment. However, whether these effects are positive or negative has not yet been studied extensively. For most tasks it is unknown whether AR has any advantage over VR. In this work we present the results of a user study in which we compared user performance measured in task completion time on a 9 degrees of freedom object selection and transformation task performed either in AR or VR, both with a 3D input device and a mouse. Our results show faster task completion time in AR over VR. When using a 3D input device, a purely VR environment increased task completion time by 22.5% on average compared to AR (p < 0:024). Surprisingly, a similar effect occurred when using a mouse: users were about 17.3% slower in VR than in AR (p < 0:04). Mouse and 3D input device produced similar task completion times in each condition (AR or VR) respectively. We further found no differences in reported comfort.

  2. Mixed Reality Serious Games: The Therapist Perspective

    CERN Document Server

    Ines, Ines Di Loreto


    The objective of this paper is to present a Mixed Reality System (MRS) for rehabilitation of the upper limb after stroke. The system answers the following challenges: (i) increase motivation of patients by making the training a personalized experience; (ii) take into account patients' impairments by offering intuitive and easy to use interaction modalities; (iii) make it possible to therapists to track patient's activities and to evaluate/track their progress; (iv) open opportunities for telemedicine and tele rehabilitation; (v) and provide an economically acceptable system by reducing both equipment and management costs. In order to test this system a pilot study has been conducted in conjunction with a French hospital in order to understand the potential and benefits of mixed reality. The pilot involved 3 therapists who 'played the role' of patients. Three sessions, one using conventional rehabilitation, another using an ad hoc developed game on a PC, and another using a mixed reality version of the same ga...

  3. Handling Occlusions for Robust Augmented Reality Systems

    Directory of Open Access Journals (Sweden)

    Madjid Maidi


    Full Text Available In Augmented Reality applications, the human perception is enhanced with computer-generated graphics. These graphics must be exactly registered to real objects in the scene and this requires an effective Augmented Reality system to track the user's viewpoint. In this paper, a robust tracking algorithm based on coded fiducials is presented. Square targets are identified and pose parameters are computed using a hybrid approach based on a direct method combined with the Kalman filter. An important factor for providing a robust Augmented Reality system is the correct handling of targets occlusions by real scene elements. To overcome tracking failure due to occlusions, we extend our method using an optical flow approach to track visible points and maintain virtual graphics overlaying when targets are not identified. Our proposed real-time algorithm is tested with different camera viewpoints under various image conditions and shows to be accurate and robust.

  4. Handling Occlusions for Robust Augmented Reality Systems

    Directory of Open Access Journals (Sweden)

    Maidi Madjid


    Full Text Available Abstract In Augmented Reality applications, the human perception is enhanced with computer-generated graphics. These graphics must be exactly registered to real objects in the scene and this requires an effective Augmented Reality system to track the user's viewpoint. In this paper, a robust tracking algorithm based on coded fiducials is presented. Square targets are identified and pose parameters are computed using a hybrid approach based on a direct method combined with the Kalman filter. An important factor for providing a robust Augmented Reality system is the correct handling of targets occlusions by real scene elements. To overcome tracking failure due to occlusions, we extend our method using an optical flow approach to track visible points and maintain virtual graphics overlaying when targets are not identified. Our proposed real-time algorithm is tested with different camera viewpoints under various image conditions and shows to be accurate and robust.

  5. Mixed reality and human-robot interaction

    CERN Document Server

    Wang, Xiangyu


    MR technologies play an increasing role in different aspects of human-robot interactions. The visual combination of digital contents with real working spaces creates a simulated environment that is set out to enhance these aspects. This book presents and discusses fundamental scientific issues, technical implementations, lab testing, and industrial applications and case studies of Mixed Reality in Human-Robot Interaction. It is a reference book that not only acts as meta-book in the field that defines and frames Mixed Reality use in Human-Robot Interaction, but also addresses up-coming trends

  6. Reality from Simplicity

    CERN Document Server

    Ruffini, Giulio


    We discuss some fundamental aspects of information theory and its relationship to physics and neuroscience. The aim is to identify some questions and point out the relevance of the concept of Kolmogovov complexity in their eventual resolution. The discussion is based on two premises: 1) all human experience is generated in the brain, 2) all the brain has access to is information. Taken together these imply that concepts such as "reality", the "universe" and even "physics" are derived mental constructs based on information, i.e., algorithmic models. It is argued that the concept of Kolmogorov complexity can play a fundamental role in this union, and that in some sense, reality arises from simplicity. A consequence of these ideas is that neuroscience and physics have to merge at a fundamental level for mutual advancement.

  7. Big Data and reality

    Directory of Open Access Journals (Sweden)

    Ryan Shaw


    Full Text Available DNA sequencers, Twitter, MRIs, Facebook, particle accelerators, Google Books, radio telescopes, Tumblr: what do these things have in common? According to the evangelists of “data science,” all of these are instruments for observing reality at unprecedentedly large scales and fine granularities. This perspective ignores the social reality of these very different technological systems, ignoring how they are made, how they work, and what they mean in favor of an exclusive focus on what they generate: Big Data. But no data, big or small, can be interpreted without an understanding of the process that generated them. Statistical data science is applicable to systems that have been designed as scientific instruments, but is likely to lead to confusion when applied to systems that have not. In those cases, a historical inquiry is preferable.

  8. Cultural realities of being

    DEFF Research Database (Denmark)

    Cultural Realities of Being offers a dialogue between academic activity and everyday lives by providing an interface between several perspectives on human conduct. Very often, academic pursuits are arcane and obscure for ordinary people, this book will attempt to disentangle these dialogues......, lifting everyday discourse and providing a forum for advancing discussion and dialogue. Nandita Chaudhary, S. Anandalakshmy and Jaan Valsiner bring together contributors from the field of cultural psychology to consider how people living within social groups, regardless of how liberal, are guided...... by collective reality and interconnected with life circumstances. The book discusses experiences and events in the lives of people of Indian cultures covering topics including family, food, pilgrimages, social dynamics and truth, in order to expand the material on human phenomena under the broad frame...

  9. Augmented reality system (United States)

    Lin, Chien-Liang; Su, Yu-Zheng; Hung, Min-Wei; Huang, Kuo-Cheng


    In recent years, Augmented Reality (AR)[1][2][3] is very popular in universities and research organizations. The AR technology has been widely used in Virtual Reality (VR) fields, such as sophisticated weapons, flight vehicle development, data model visualization, virtual training, entertainment and arts. AR has characteristics to enhance the display output as a real environment with specific user interactive functions or specific object recognitions. It can be use in medical treatment, anatomy training, precision instrument casting, warplane guidance, engineering and distance robot control. AR has a lot of vantages than VR. This system developed combines sensors, software and imaging algorithms to make users feel real, actual and existing. Imaging algorithms include gray level method, image binarization method, and white balance method in order to make accurate image recognition and overcome the effects of light.

  10. Augmented Reality als Bildungsenhancement?


    Damberger, Thomas


    Die Realität, die sich mithilfe von Datenbrillen und Smartphone Applikationen in die virtuelle Welt hinein ausdehnt, erfährt eine Form des Enhancements. Ein solches Enhancement kann unter bestimmten Voraussetzungen als Bildungsenhancement verstanden werden. Der Text befasst sich mit Formen der erweiterten Realität, ferner mit dem, um was es wesentlich bei der Bildung geht und zuletzt mit den Bedingungen, die erforderlich sind, um diesem Wesentlichen mit Hilfe von augmented reality besser zum ...

  11. A fluorescence-activated cell sorting-based strategy for rapid isolation of high-lipid Chlamydomonas mutants. (United States)

    Terashima, Mia; Freeman, Elizabeth S; Jinkerson, Robert E; Jonikas, Martin C


    There is significant interest in farming algae for the direct production of biofuels and valuable lipids. Chlamydomonas reinhardtii is the leading model system for studying lipid metabolism in green algae, but current methods for isolating mutants of this organism with a perturbed lipid content are slow and tedious. Here, we present the Chlamydomonas high-lipid sorting (CHiLiS) strategy, which enables enrichment of high-lipid mutants by fluorescence-activated cell sorting (FACS) of pooled mutants stained with the lipid-sensitive dye Nile Red. This method only takes 5 weeks from mutagenesis to mutant isolation. We developed a staining protocol that allows quantification of lipid content while preserving cell viability. We improved separation of high-lipid mutants from the wild type by using each cell's chlorophyll fluorescence as an internal control. We initially demonstrated 20-fold enrichment of the known high-lipid mutant sta1 from a mixture of sta1 and wild-type cells. We then applied CHiLiS to sort thousands of high-lipid cells from a pool of about 60,000 mutants. Flow cytometry analysis of 24 individual mutants isolated by this approach revealed that about 50% showed a reproducible high-lipid phenotype. We further characterized nine of the mutants with the highest lipid content by flame ionization detection and mass spectrometry lipidomics. All mutants analyzed had a higher triacylglycerol content and perturbed whole-cell fatty acid composition. One arbitrarily chosen mutant was evaluated by microscopy, revealing larger lipid droplets than the wild type. The unprecedented throughput of CHiLiS opens the door to a systems-level understanding of green algal lipid biology by enabling genome-saturating isolation of mutants in key genes.

  12. Shewanella oneidensis: a new and efficient System for Expression and Maturation of heterologous [Fe-Fe] Hydrogenase from Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Sybirna Kateryna


    Full Text Available Abstract Background The eukaryotic green alga, Chlamydomonas reinhardtii, produces H2 under anaerobic conditions, in a reaction catalysed by a [Fe-Fe] hydrogenase HydA1. For further biochemical and biophysical studies a suitable expression system of this enzyme should be found to overcome its weak expression in the host organism. Two heterologous expression systems used up to now have several advantages. However they are not free from some drawbacks. In this work we use bacterium Shewanella oneidensis as a new and efficient system for expression and maturation of HydA1 from Chlamydomonas reinhardtii. Results Based on codon usage bias and hydrogenase maturation ability, the bacterium S. oneidensis, which possesses putative [Fe-Fe] and [Ni-Fe] hydrogenase operons, was selected as the best potential host for C. reinhardtii [Fe-Fe] hydrogenase expression. Hydrogen formation by S. oneidensis strain AS52 (ΔhydAΔhyaB transformed with a plasmid bearing CrHydA1 and grown in the presence of six different substrates for anaerobic respiration was determined. A significant increase in hydrogen evolution was observed for cells grown in the presence of trimethylamine oxide, dimethylsulfoxide and disodium thiosulfate, showing that the system of S. oneidensis is efficient for heterologous expression of algal [Fe-Fe] hydrogenase. Conclusion In the present work a new efficient system for heterologous expression and maturation of C. reinhardtii hydrogenase has been developed. HydA1 of C. reinhardtii was purified and shown to contain 6 Fe atoms/molecule of protein, as expected. Using DMSO, TMAO or thiosulfate as substrates for anaerobic respiration during the cell growth, 0.4 – 0.5 mg l-1(OD600 = 1 of catalytically active HydA1 was obtained with hydrogen evolution rate of ~700 μmol H2 mg-1 min-1.

  13. Models of Reality.

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S. A.


    Conscious awareness of our environment is based on a feedback loop comprised of sensory input transmitted to the central nervous system leading to construction of our ''model of the world,'' (Lewis et al, 1982). We then assimilate the neurological model at the unconscious level into information we can later consciously consider useful in identifying belief systems and behaviors for designing diverse systems. Thus, we can avoid potential problems based on our open-to-error perceived reality of the world. By understanding how our model of reality is organized, we allow ourselves to transcend content and develop insight into how effective choices and belief systems are generated through sensory derived processes. These are the processes which provide the designer the ability to meta model (build a model of a model) the user; consequently, matching the mental model of the user with that of the designer's and, coincidentally, forming rapport between the two participants. The information shared between the participants is neither assumed nor generalized, it is closer to equivocal; thus minimizing error through a sharing of each other's model of reality. How to identify individual mental mechanisms or processes, how to organize the individual strategies of these mechanisms into useful patterns, and to formulate these into models for success and knowledge based outcomes is the subject of the discussion that follows.

  14. Locality and reality

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry P.


    Einstein's principle that no signal travels faster than suggests that observations in one spacetime region should not depend on whether or not a radioactive decay is detected in a spacelike separated region. This locality property is incompatible with the predictions of quantum theory, and this incompatibility holds independently of the questions of realism, objective reality, and hidden variables. It holds both in the pragmatic quantum theory of Bohr and in realistic frameworks. It is shown here to hold in a completed realistic quantum theory that reconciles Einstein's demand for a description of reality itself with Bohr's contention that quantum theory is complete. This completed realistic quantum theory has no hidden variables, and no objective reality in which observable attributes can become definite independently of observers. The, theory is described in some detail, with particular attention to those aspects related to the question of locality. This completed realistic quantum theory is in principle more comprehensive than Bohr.' s pragmatic quantum theory because it is not limited in principle by the requirement that the observed system be physically separated from the observing one. Applications are discussed.


    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry P.


    Einstein's principle that no signal travels faster than suggests that observations in one spacetime region should not depend on whether or not a radioactive decay is detected in a spacelike separated region. This locality property is incompatible with the predictions of quantum theory, and this incompatibility holds independently of the questions of realism, objective reality, and hidden variables. It holds both in the pragmatic quantum theory of Bohr and in realistic frameworks. It is shown here to hold in a completed realistic quantum theory that reconciles Einstein's demand for a description of reality itself with Bohr's contention that quantum theory is complete. This completed realistic quantum theory has no hidden variables, and no objective reality in which observable attributes can become definite independently of observers. The, theory is described in some detail, with particular attention to those aspects related to the question of locality. This completed realistic quantum theory is in principle more comprehensive than Bohr.' s pragmatic quantum theory because it is not limited in principle by the requirement that the observed system be physically separated from the observing one. Applications are discussed.


    Directory of Open Access Journals (Sweden)



    Full Text Available The concept of Augmented Reality can be explained as a superimposition of computer generated two dimensional or three dimensional objects over the real time scene acquired into thecapturing device. Thus Augmented Reality adds additional information to the real scene and this can be implemented with the help of markers. The development of the application is simple and easier in case of AR. This idea is extended to the development of Augmented Reality based book that act as a tour guide. This travel guide can give all the basic information regarding the necessities of a finer travel around the places of the destinations. The application will detect the markers found in the real scene and superimpose them with multimedia data giving enormous information. The application can also be made to redirect to the web links for easy access of certain other utilities by interaction. The same idea can also be utilized in engineering laboratories to understand the working of the circuit by visualizing the working of the same circuit where the diagram itself can be used as a marker and thus enhancing the self learning among the students.

  17. Remodeling of Membrane Lipids in Iron-starved Chlamydomonas* (United States)

    Urzica, Eugen I.; Vieler, Astrid; Hong-Hermesdorf, Anne; Page, M. Dudley; Casero, David; Gallaher, Sean D.; Kropat, Janette; Pellegrini, Matteo; Benning, Christoph; Merchant, Sabeeha S.


    Chlamydomonas reinhardtii cells exposed to abiotic stresses (e.g. nitrogen, zinc, or phosphorus deficiency) accumulate triacylglycerols (TAG), which are stored in lipid droplets. Here, we report that iron starvation leads to formation of lipid droplets and accumulation of TAGs. This occurs between 12 and 24 h after the switch to iron-starvation medium. C. reinhardtii cells deprived of iron have more saturated fatty acid (FA), possibly due to the loss of function of FA desaturases, which are iron-requiring enzymes with diiron centers. The abundance of a plastid acyl-ACP desaturase (FAB2) is decreased to the same degree as ferredoxin. Ferredoxin is a substrate of the desaturases and has been previously shown to be a major target of the iron deficiency response. The increase in saturated FA (C16:0 and C18:0) is concomitant with the decrease in unsaturated FA (C16:4, C18:3, or C18:4). This change was gradual for diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) and digalactosyldiacylglycerol (DGDG), whereas the monogalactosyldiacylglycerol (MGDG) FA profile remained stable during the first 12 h, whereas MGDG levels were decreasing over the same period of time. These changes were detectable after only 2 h of iron starvation. On the other hand, DGTS and DGDG contents gradually decreased until a minimum was reached after 24–48 h. RNA-Seq analysis of iron-starved C. reinhardtii cells revealed notable changes in many transcripts coding for enzymes involved in FA metabolism. The mRNA abundances of genes coding for components involved in TAG accumulation (diacylglycerol acyltransferases or major lipid droplet protein) were increased. A more dramatic increase at the transcript level has been observed for many lipases, suggesting that major remodeling of lipid membranes occurs during iron starvation in C. reinhardtii. PMID:23983122

  18. Remodeling of membrane lipids in iron-starved Chlamydomonas. (United States)

    Urzica, Eugen I; Vieler, Astrid; Hong-Hermesdorf, Anne; Page, M Dudley; Casero, David; Gallaher, Sean D; Kropat, Janette; Pellegrini, Matteo; Benning, Christoph; Merchant, Sabeeha S


    Chlamydomonas reinhardtii cells exposed to abiotic stresses (e.g. nitrogen, zinc, or phosphorus deficiency) accumulate triacylglycerols (TAG), which are stored in lipid droplets. Here, we report that iron starvation leads to formation of lipid droplets and accumulation of TAGs. This occurs between 12 and 24 h after the switch to iron-starvation medium. C. reinhardtii cells deprived of iron have more saturated fatty acid (FA), possibly due to the loss of function of FA desaturases, which are iron-requiring enzymes with diiron centers. The abundance of a plastid acyl-ACP desaturase (FAB2) is decreased to the same degree as ferredoxin. Ferredoxin is a substrate of the desaturases and has been previously shown to be a major target of the iron deficiency response. The increase in saturated FA (C16:0 and C18:0) is concomitant with the decrease in unsaturated FA (C16:4, C18:3, or C18:4). This change was gradual for diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) and digalactosyldiacylglycerol (DGDG), whereas the monogalactosyldiacylglycerol (MGDG) FA profile remained stable during the first 12 h, whereas MGDG levels were decreasing over the same period of time. These changes were detectable after only 2 h of iron starvation. On the other hand, DGTS and DGDG contents gradually decreased until a minimum was reached after 24-48 h. RNA-Seq analysis of iron-starved C. reinhardtii cells revealed notable changes in many transcripts coding for enzymes involved in FA metabolism. The mRNA abundances of genes coding for components involved in TAG accumulation (diacylglycerol acyltransferases or major lipid droplet protein) were increased. A more dramatic increase at the transcript level has been observed for many lipases, suggesting that major remodeling of lipid membranes occurs during iron starvation in C. reinhardtii.

  19. Ultraviolet modification of Chlamydomonas reinhardtii for carbon capture

    Directory of Open Access Journals (Sweden)

    Gopal NS


    Full Text Available Nikhil S Gopal,1 K Sudhakar2 1The Lawrenceville School, Lawrenceville, NJ, USA; 2Bioenergy Laboratory, Malauna Azad National Institute of Technology, Bhopal, India Purpose: Carbon dioxide (CO2 levels have been rising rapidly. Algae are single-cell organisms with highly efficient CO2 uptake mechanisms. Algae yield two to ten times more biomass versus terrestrial plants and can grow nearly anywhere. Large scale CO2 sequestration is not yet sustainable due to high amounts of nitrogen (N and phosphate (P needed to grow algae in media. Methods: Mutant strains of Chlamydomonas reinhardtii were created using ultraviolet light (2.2–3 K J/m2 and natural selection using media with 20%–80% lower N and P compared to standard Sueoka's high salt medium. Strains were selected based upon growth in media concentrations varying from 20% to 80% less N/P compared to control. Biomass was compared to wild-type control (CC-125 using direct counts, optical density dry weight, and mean doubling time. Results: Mean doubling time was 20 and 25 hours in the low N and N/P strains, respectively (vs 66 hours in control. Using direct counts, growth rates of mutant strains of low N and N/P cultures were not statistically different from control (P=0.37 and 0.70, respectively. Conclusion: Two new strains of algae, as well as wild-type control, were able to grow while using 20%–40% less N and P. Ultraviolet light-based modification of algae is an inexpensive and alternative option to genetic engineering techniques. This technique might make larger scale biosequestration possible. Keywords: biosequestration, ultraviolet, carbon sequestration, carbon capture, algae

  20. Physiological characterization of cadmium-exposed Chlamydomonas reinhardtii. (United States)

    Bräutigam, Anja; Schaumlöffel, Dirk; Preud'homme, Hugues; Thondorf, Iris; Wesenberg, Dirk


    Chlamydomonas reinhardtii is a common model organism for investigation of metal stress. This green alga produces phytochelatins in the presence of metal ions. The influence of cadmium is of main interest, because it is a strong activator of phytochelatin synthase. Cell wall bound and intracellular cadmium content was determined after exposition to 70 µm CdCl(2), showing the main portion of the metal outside the cell. Nevertheless, imported cadmium was sufficient to cause significant changes in thiolpeptide metabolism and its transcriptional regulation. Modern analytical approaches enable new insights into phytochelatin (PC) distribution. A new rapid and precise UPLC-MS method allowed high-throughput PC quantification in algal samples after 1, 4, 24 and 48 h cadmium stress. Initially, canonic PCs were synthesized in C. reinhardtii during cadmium exposition, but afterwards CysPCs became the major thiolpeptides. Thus, after 48 h the concentration of the PC-isoforms CysPC(2-3) and CysGSH attained between 105 and 199 nmol g(-1) fresh weight (FW), whereas the PC(2-3) concentrations were only 15 nmol g(-1) FW. The relative quantification of γ-glutamyl transpeptidase (γ-GT) mRNA suggests the generation of CysPCs by glutamate cleavage from canonic PCs by γ-GT. Furthermore, a homology model of C. reinhardtii phytochelatin synthase was constructed to verify the use of crystal structures from Anabaena sp. phytochelatin synthase (PCS) for docking studies with canonical PCs and CysPCs. From the difference in energy scores, we hypothesize that CysPC may prevent the synthesis of canonical PCs by blocking the binding pocket. Finally, possible physiological reasons for the high abundance of CysPC compared with their canonic precursors are discussed.

  1. Flagellar coordination in Chlamydomonas cells held on micropipettes. (United States)

    Rüffer, U; Nultsch, W


    The two flagella of Chlamydomonas are known to beat synchronously: During breaststroke beating they are generally coordinated in a bilateral way while in shock responses during undulatory beating coordination is mostly parallel [Rüffer and Nultsch, 1995: Botanica Acta 108:169-276]. Analysis of a great number of shock responses revealed that in undulatory beats also periods of bilateral coordination are found and that the coordination type may change several times during a shock response, without concomitant changes of the beat envelope and the beat period. In normal wt cells no coordination changes are found during breaststroke beating, but only short temporary asynchronies: During 2 or 3 normal beats of the cis flagellum, the trans flagellum performs 3 or 4 flat beats with a reduced beat envelope and a smaller beat period, resulting in one additional trans beat. Long periods with flat beats of the same shape and beat period are found in both flagella of the non-phototactic mutant ptx1 and in defective wt 622E cells. During these periods, the coordination is parallel, the two flagella beat alternately. A correlation between normal asynchronous trans beats and the parallel-coordinated beats in the presumably cis defective cells and also the undulatory beats is discussed. In the cis defective cells, a perpetual spontaneous change between parallel beats with small beat periods (higher beat frequency) and bilateral beats with greater beat periods (lower beat frequency) are observed and render questionable the existence of two different intrinsic beat frequencies of the two flagella cis and trans. Asynchronies occur spontaneously but may also be induced by light changes, either step-up or step-down, but not by both stimuli in turn as breaststroke flagellar photoresponses (BFPRs). Asynchronies are not involved in phototaxis. They are independent of the BFPRs, which are supposed to be the basis of phototaxis. Both types of coordination must be assumed to be regulated

  2. Mixed Reality: Concepts, Tools and Applications

    Directory of Open Access Journals (Sweden)

    Ildeberto Aparecido Rodello


    Full Text Available The Mixed Reality proposes scenes combining between virtual and real worlds offering to the user an intuitive way of interaction according to a specific application. This tutorial paper aims at presenting the fundamentals concepts of this emergent kind of human-computer interface.

  3. Representing social reality in OWL 2

    NARCIS (Netherlands)

    Hoekstra, R.


    This paper introduces a design pattern that allows for the OWL 2 DL representation of concepts central to social reality: roles. The work presented here is motivated by experiences in the development of the LKIF Core ontology of basic legal concepts [10,8]. This paper applies modelling steps identie

  4. A Mixed Reality Game for Urban Planning

    DEFF Research Database (Denmark)

    Nielsen, Rune; Delman, Thomas Fabian; Løssing, Tobias


    This paper presents a case study based on an innovative collaborative, game-based approach to urban planning utilizing mixed and augmented reality techniques. Modern urban planning involves a wide variety of interests and individuals, consequently new methods and tools are needed to assure...

  5. Interactive Assembly Guide using Augmented Reality

    DEFF Research Database (Denmark)

    Andersen, Martin; Andersen, Rasmus Skovgaard; Larsen, Christian Lindequist


    This paper presents an Augmented Reality system for aiding a pump assembling process at Grundfos, one of the leading pump producers. Stable pose estimation of the pump is required in order to augment the graphics correctly. This is achieved by matching image edges with synthesized edges from CAD...

  6. Corporal Punishment: Legalities, Realities, and Implications. (United States)

    Hinchey, Patricia H.


    Presents a quiz that will help readers determine the reliability of their own perceptions relating to corporal punishment in schools. Discusses U.S. Courts and corporal punishment, worldwide and nationwide legality, and the realities of corporal punishment in the United States. Discusses implications for what teachers can do to address corporal…

  7. Sensors for Location-Based Augmented Reality the Example of Galileo and Egnos (United States)

    Pagani, Alain; Henriques, José; Stricker, Didier


    Augmented Reality has long been approached from the point of view of Computer Vision and Image Analysis only. However, much more sensors can be used, in particular for location-based Augmented Reality scenarios. This paper reviews the various sensors that can be used for location-based Augmented Reality. It then presents and discusses several examples of the usage of Galileo and EGNOS in conjonction with Augmented Reality.

  8. Rapid induction of lipid droplets in Chlamydomonas reinhardtii and Chlorella vulgaris by Brefeldin A.

    Directory of Open Access Journals (Sweden)

    Sangwoo Kim

    Full Text Available Algal lipids are the focus of intensive research because they are potential sources of biodiesel. However, most algae produce neutral lipids only under stress conditions. Here, we report that treatment with Brefeldin A (BFA, a chemical inducer of ER stress, rapidly triggers lipid droplet (LD formation in two different microalgal species, Chlamydomonas reinhardtii and Chlorella vulgaris. LD staining using Nile red revealed that BFA-treated algal cells exhibited many more fluorescent bodies than control cells. Lipid analyses based on thin layer chromatography and gas chromatography revealed that the additional lipids formed upon BFA treatment were mainly triacylglycerols (TAGs. The increase in TAG accumulation was accompanied by a decrease in the betaine lipid diacylglyceryl N,N,N-trimethylhomoserine (DGTS, a major component of the extraplastidic membrane lipids in Chlamydomonas, suggesting that at least some of the TAGs were assembled from the degradation products of membrane lipids. Interestingly, BFA induced TAG accumulation in the Chlamydomonas cells regardless of the presence or absence of an acetate or nitrogen source in the medium. This effect of BFA in Chlamydomonas cells seems to be due to BFA-induced ER stress, as supported by the induction of three homologs of ER stress marker genes by the drug. Together, these results suggest that ER stress rapidly triggers TAG accumulation in two green microalgae, C. reinhardtii and C. vulgaris. A further investigation of the link between ER stress and TAG synthesis may yield an efficient means of producing biofuel from algae.

  9. Effect of O2:CO2 Ratio on the Primary Metabolism of Chlamydomonas reinhardtii

    NARCIS (Netherlands)

    Kliphuis, A.M.J.; Martens, D.E.; Janssen, M.G.J.; Wijffels, R.H.


    High oxygen:carbon dioxide ratios may have a negative effect on growth and productivity of microalgae. To investigate the effect of O2 and CO2 concentrations and the ratio between these on the metabolism of Chlamydomonas reinhardtii we performed turbidostat experiments at different O2:CO2 ratios. Th

  10. Phytochelatins do not correlate with the level of Cd accumulation in Chlamydomonas spp. (United States)

    Nishikawa, Kahoko; Onodera, Ai; Tominaga, Noriko


    Chlamydomonas acidophila KT-1 and Chlamydomonas acidophila DVB238 exhibit a strong heavy metal tolerance, but C. acidophila DVB238 can accumulate a much higher amount of Cadmium (Cd) than C. acidophila KT-1. Phytochelatins (PCs) are known to play an important role in the detoxification of several toxic heavy metals, but the relationship between PCs and Cd accumulation is not clear. PC metabolism and Cd accumulation were investigated by using three Chlamydomonas strains including Chlamydomonas reinhardtii C-9 as a standard alga. The results showed that the PC content did not correlate closely with the level of Cd accumulation, maintenance of a high GSH level seeming to be more important for Cd accumulation. The ultrastructure of C. acidophila KT-1 was extremely disrupted by a great increase in starch granules, which resulted in a moribund state, but hyper-accumulator C. acidophila DVB238 did not exhibit an increase in starch granules in its cells, in spite of Cd accumulation in its chloroplasts, cytosol and vacuoles. These results indicated that C. acidophila DVB238 probably has a developed detoxification system preventing such as destruction of the cells due to Cd toxicity.

  11. Virtual, augmented reality and serious games for healthcare

    CERN Document Server

    Jain, Lakhmi; Anderson, Paul


    There is a tremendous interest among researchers for the development of virtual, augmented reality and games technologies due to their widespread applications in medicine and healthcare. To date the major applications of these technologies include medical simulation, telemedicine, medical and healthcare training, pain control, visualisation aid for surgery, rehabilitation in cases such as stroke, phobia, and trauma therapies. Many recent studies have identified the benefits of using Virtual Reality, Augmented Reality, or serious games in a variety of medical applications.   This research volume on Virtual, Augmented Reality and Serious Games for Healthcare 1 offers an insightful introduction to the theories, development and applications of virtual, augmented reality and digital games technologies in medical and clinical settings and healthcare in general. It is divided into six sections: section one presents a selection of applications in medical education and healthcare management; Section two relates to th...

  12. Augmented Reality as a Countermeasure for Sleep Deprivation. (United States)

    Baumeister, James; Dorrlan, Jillian; Banks, Siobhan; Chatburn, Alex; Smith, Ross T; Carskadon, Mary A; Lushington, Kurt; Thomas, Bruce H


    Sleep deprivation is known to have serious deleterious effects on executive functioning and job performance. Augmented reality has an ability to place pertinent information at the fore, guiding visual focus and reducing instructional complexity. This paper presents a study to explore how spatial augmented reality instructions impact procedural task performance on sleep deprived users. The user study was conducted to examine performance on a procedural task at six time points over the course of a night of total sleep deprivation. Tasks were provided either by spatial augmented reality-based projections or on an adjacent monitor. The results indicate that participant errors significantly increased with the monitor condition when sleep deprived. The augmented reality condition exhibited a positive influence with participant errors and completion time having no significant increase when sleep deprived. The results of our study show that spatial augmented reality is an effective sleep deprivation countermeasure under laboratory conditions.

  13. L,L-diaminopimelate aminotransferase from Chlamydomonas reinhardtii: a target for algaecide development.

    Directory of Open Access Journals (Sweden)

    Renwick C J Dobson

    Full Text Available In some bacterial species and photosynthetic cohorts, including algae, the enzyme L,L-diaminopimelate aminotransferase (DapL (E.C. is involved in the anabolism of the essential amino acid L-lysine. DapL catalyzes the conversion of tetrahydrodipicolinate (THDPA to L,L-diaminopimelate (L,L-DAP, in one step bypassing the DapD, DapC and DapE enzymatic reactions present in the acyl DAP pathways. Here we present an in vivo and in vitro characterization of the DapL ortholog from the alga Chlamydomonas reinhardtii (Cr-DapL. The in vivo analysis illustrated that the enzyme is able to functionally complement the E. coli dap auxotrophs and was essential for plant development in Arabidopsis. In vitro, the enzyme was able to inter-convert THDPA and L,L-DAP, showing strong substrate specificity. Cr-DapL was dimeric in both solution and when crystallized. The structure of Cr-DapL was solved in its apo form, showing an overall architecture of a α/β protein with each monomer in the dimer adopting a pyridoxal phosphate-dependent transferase-like fold in a V-shaped conformation. The active site comprises residues from both monomers in the dimer and shows some rearrangement when compared to the apo-DapL structure from Arabidopsis. Since animals do not possess the enzymatic machinery necessary for the de novo synthesis of the amino acid L-lysine, enzymes involved in this pathway are attractive targets for the development of antibiotics, herbicides and algaecides.

  14. Preventive effect of the microalga Chlamydomonas debaryana on the acute phase of experimental colitis in rats. (United States)

    Avila-Román, Javier; Talero, Elena; Alcaide, Antonio; Reyes, Carolina de Los; Zubía, Eva; García-Mauriño, Sofía; Motilva, Virginia


    Inflammatory bowel diseases (IBD) are characterised by chronic uncontrolled inflammation of intestinal mucosa. Diet and nutritional factors have emerged as possible interventions for IBD. Microalgae are rich sources of n-3 PUFA and derived oxylipins. Oxylipins are lipid mediators involved in the resolution of many inflammatory disorders. The aim of the present study was to investigate the effects of the oxylipin-containing biomass of the microalga Chlamydomonas debaryana and its major oxylipin constituent, (9Z,11E,13S,15Z)-13-hydroxyoctadeca-9,11,15-trienoic acid ((13S)-HOTE), on acute 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. Lyophilised microalgal biomass and (13S)-HOTE were administered by oral route 48, 24 and 1 h before the induction of colitis and 24 h later, and the rats were killed after 48 h. The treatment with the lyophilised microalga and (13S)-HOTE improved body-weight loss and colon shortening, as well as attenuated the extent of colonic damage and increased mucus production. Cellular neutrophil infiltration, with the subsequent increase in myeloperoxidase levels induced by TNBS, were also reduced after the administration of the lyophilised microalga or (13S)-HOTE. The anti-inflammatory effects of these treatments were confirmed by the inhibition of colonic TNF-α production. Moreover, lyophilised microalga or (13S)-HOTE down-regulated cyclo-oxygenase-2 and inducible nitric oxide synthase expression. The present study was the first to show the prophylactic effects of a lyophilised biomass sample of the microalga C. debaryana and the oxylipin (13S)-HOTE on TNBS-induced acute colitis in rats. Our findings suggest that the microalga C. debaryana or derived oxylipins could be used as nutraceuticals in the treatment of the active phase of IBD.

  15. Cyclic AMP functions as a primary sexual signal in gametes of Chlamydomonas reinhardtii. (United States)

    Pasquale, S M; Goodenough, U W


    When Chlamydomonas reinhardtii gametes of opposite mating type are mixed together, they adhere by a flagella-mediated agglutination that triggers three rapid mating responses: flagellar tip activation, cell wall loss, and mating structure activation accompanied by actin polymerization. Here we show that a transient 10-fold elevation of intracellular cAMP levels is also triggered by sexual agglutination. We further show that gametes of a single mating type can be induced to undergo all three mating responses when presented with exogenous dibutyryl-cAMP (db-cAMP). These events are also induced by cyclic nucleotide phosphodiesterase inhibitors, which elevate endogenous cAMP levels and act synergistically with db-cAMP. Non-agglutinating mutants of opposite mating type will fuse efficiently in the presence of db-cAMP. No activation of mating events is induced by calcium plus ionophores, 8-bromo-cGMP, dibutyryl-cGMP, nigericin at alkaline pH, phorbol esters, or forskolin. H-8, an inhibitor of cyclic nucleotide-dependent protein kinase, inhibits mating events in agglutinating cells and antagonizes the effects of cAMP on non-agglutinating cells. Adenylate cyclase activity was detected in both the gamete cell body and flagella, with the highest specific activity displayed in flagellar membrane fractions. The flagellar membrane adenylate cyclase is preferentially stimulated by Mn++, unresponsive to NaF, GTP, GTP gamma S, AlF4-, and forskolin, and is inhibited by trifluoperazine. Cyclic nucleotide phosphodiesterase activity is also present in flagella. Our observations indicate that cAMP is a sufficient initial signal for all of the known mating reaction events in C. reinhardtii, and suggest that the flagellar cyclase and/or phosphodiesterase may be important loci of control for the agglutination-stimulated production of this signal.

  16. Calibração das câmaras de ionização para feixes de tomografia computadorizada no Brasil: a realidade atual Calibration of ionization chambers for computed tomography beams in Brazil: the present reality

    Directory of Open Access Journals (Sweden)

    Ana Figueiredo Maia


    Full Text Available OBJETIVO: O objetivo deste trabalho foi estabelecer, no Laboratório de Calibração de Instrumentos do Instituto de Pesquisas Energéticas e Nucleares, uma metodologia de calibração específica para as câmaras de ionização tipo lápis, que são utilizadas em procedimentos dosimétricos em feixes de tomografia computadorizada, seguindo as mais recentes recomendações internacionais. MATERIAIS E MÉTODOS: Foram utilizados, neste estudo, um equipamento de radiação X industrial, várias câmaras de ionização, um sistema de colimação móvel (tipo diafragma e vários filtros de alumínio de alta pureza. RESULTADOS: Foram estabelecidos os campos padrões de radiodiagnóstico descritos na norma internacional IEC 61267, e foi elaborado um procedimento de calibração adequado para as câmaras de ionização tipo lápis. CONCLUSÃO: Atualmente, já é possível calibrar apropriadamente as câmaras de ionização tipo lápis no Brasil. O procedimento de calibração foi definido com base nas recomendações internacionais e em testes feitos com duas metodologias distintas.OBJECTIVE: The aim of this study was to establish a calibration methodology specific for pencil ionization chambers used in computed tomography dosimetric procedures, in compliance with the most recent recommendations. The study was developed at the Calibration Laboratory of the Instituto de Pesquisas Energéticas e Nucleares. MATERIALS AND METHODS: An industrial x-ray equipment, several types of ionization chambers, a mobile collimator (diaphragm type, and several high purity aluminum filters were utilized in this study. RESULTS: Diagnostic radiology standard irradiation fields were established according to IEC 61267 standard, and an adequate calibration procedure for pencil ionization chambers was elaborated. CONCLUSION: The appropriate calibration of pencil ionization chambers is already a reality in Brazil. The calibration procedure was defined on the basis of

  17. Collaboration in Augmented Reality


    Lukosch, S.; Billinghurst, M; Alem, L.; Kiyokawa, K.


    Augmented Reality (AR) is a technology that allows users to view and interact in real time with virtual images seamlessly superimposed over the real world. AR systems can be used to create unique collaborative experiences. For example, co-located users can see shared 3D virtual objects that they interact with, or a user can annotate the live video view of a remote worker, enabling them to collaborate at a distance. The overall goal is to augment the face-to-face collaborative experience, or t...

  18. Augmented Reality Oculus Rift


    Höll, Markus; Heran, Nikolaus; Lepetit, Vincent


    This paper covers the whole process of developing an Augmented Reality Stereoscopig Render Engine for the Oculus Rift. To capture the real world in form of a camera stream, two cameras with fish-eye lenses had to be installed on the Oculus Rift DK1 hardware. The idea was inspired by Steptoe \\cite{steptoe2014presence}. After the introduction, a theoretical part covers all the most neccessary elements to achieve an AR System for the Oculus Rift, following the implementation part where the code ...

  19. Facing quantum mechanical reality. (United States)

    Rohrlich, F


    Two recent precision experiments provide conclusive evidence against any local hidden variables theory and in favor of standard quantum mechanics. Therefore the epistemology and the ontology of quantum mechanics must now be taken more seriously than ever before. The consequences of the standard interpretation of quantum mechanics are summarized in nontechnical language. The implications of the finiteness of Planck's constant (h > 0) for the quantum world are as strange as the implications of the finiteness of the speed of light (c < infinity for space and time in relativity theory. Both lead to realities beyond our common experience that cannot be rejected.

  20. The Geminoid Reality

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik


    Our society is on the borderline of information era, experiencing a transition towards a robotic one. Humanoid and android robots are entering with a steady pace into our everyday lives taking up roles related to companionship, partnership, wellness, healthcare, and education among others....... The fusion of information technology, ubiquitous computing, robotics, and android science has generated the Geminoid Reality. The Geminoid is a teleoperated, connected to a computer network, android robot that works as a duplicate of an existing person. A motion-capture system tracks facial expressions...


    Directory of Open Access Journals (Sweden)

    Liviu-Adrian Cotfas


    Full Text Available In this paper, we present an alternate reality games platform that facilitates the creation of ARG projects with different themes and sizes. The platform is well integrated with the most important social media networks, thus facilitating both the involvement of the public and the creation of a more engaging interaction for the participants. A cloud-based architecture was used in order to allow the platform to easily accommodate projects of various sizes and to provide a good level of scalability. The platform is fully localizable in any language and multiple languages can be used at once to create projects that target users from different countries. An initial project that uses gamification to create an immersive learning environment has been created around the developed platform. The project combines professional and public feedback in order to provide an enhanced learning experience.

  2. Virtual Reality with Haptic Application

    Institute of Scientific and Technical Information of China (English)

    李益明; 吕慧强; 孔繁胜


    Virtual reality (VR) is the use of advanced technologies, including computers and various multimedia peripherals (such as haptic), to produce a simulated environment that users perceive as comparable to real world objects and events. With the aid of specially designed transducers and sensors, users interact with displayed images, moving and manipulating virtual objects, and performing other actions in a way that engenders a feeling of actual presence (immersion) in the simulated environment. Haptic interfaces provide carefully controlled force feedback to the fingers of the user so that they feel as though they are touching objects in the virtual landscape. This article presented an overview to the concepts of VR focusing on haptics in a variety of interfaces and applications.

  3. A survey on virtual reality

    Institute of Scientific and Technical Information of China (English)

    ZHAO QinPing


    Virtual reality (VR) Is a scientific method and technology created during the exploration of the nature by human beings to understand,simulate,and better adapt and use the nature.Based on the analysis on the whole process of VR,this paper presents different categories of VR problems and a type of theoretical expression,and abstracts three kinds of scientific and technical problems in VR field.On the basis of foresaid content,this paper also studies current major research objectives,research results and development trend of VR in the aspects of VR modeling method,VR representation technology,human-machine interaction and devices,VR development suites and supporting infrastructure,as well as VR applications.Finally,several theoretical and technical problems that need to be further studied and solved are addressed.

  4. ATLASrift - a Virtual Reality application

    CERN Document Server

    Vukotic, Ilija; The ATLAS collaboration


    We present ATLASrift - a Virtual Reality application that provides an interactive, immersive visit to ATLAS experiment. We envision it being used in two different ways: first as an educational and outreach tool - for schools, universities, museums and interested individuals, and secondly as an event viewer for ATLAS physicists – for them it will provide a much better spatial awareness of an event, track and jet directions, occupancies and interactions with detector structures. Using it, one can learn about the experiment as a whole, visit individual sub-detectors, view real interactions, or take a scripted walkthrough explaining questions physicists are trying to answer. We briefly describe our platform of choice – OculusRift VR system, the development environment – UnrealEngine, and, in detail, the numerous technically demanding requirements that had to be fulfilled in order to provide a comfortable user experience. Plans for future versions include making the experience social by adding multi-user/vir...

  5. ATLASrift - a Virtual Reality application

    CERN Document Server

    INSPIRE-00225336; Moyse, Edward; Bianchi, Riccardo Maria


    We present ATLASrift - a Virtual Reality application that provides an interactive, immersive visit to ATLAS experiment. We envision it being used in two different ways: first as an educational and outreach tool - for schools, universities, museums and interested individuals, and secondly as an event viewer for ATLAS physicists - for them it will provide a much better spatial awareness of an event, track and jet directions, occupancies and interactions with detector structures. Using it, one can learn about the experiment as a whole, visit individual sub-detectors, view real interactions, or take a scripted walkthrough explaining questions physicists are trying to answer. We briefly describe our platform of choice - OculusRift VR system, the development environment - UnrealEngine, and, in detail, the numerous technically demanding requirements that had to be fulfilled in order to provide a comfortable user experience. Plans for future versions include making the experience social by adding multi-user/virtual p...

  6. Experimental Definition and Validation of Protein Coding Transcripts in Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Kourosh Salehi-Ashtiani; Jason A. Papin


    Algal fuel sources promise unsurpassed yields in a carbon neutral manner that minimizes resource competition between agriculture and fuel crops. Many challenges must be addressed before algal biofuels can be accepted as a component of the fossil fuel replacement strategy. One significant challenge is that the cost of algal fuel production must become competitive with existing fuel alternatives. Algal biofuel production presents the opportunity to fine-tune microbial metabolic machinery for an optimal blend of biomass constituents and desired fuel molecules. Genome-scale model-driven algal metabolic design promises to facilitate both goals by directing the utilization of metabolites in the complex, interconnected metabolic networks to optimize production of the compounds of interest. Using Chlamydomonas reinhardtii as a model, we developed a systems-level methodology bridging metabolic network reconstruction with annotation and experimental verification of enzyme encoding open reading frames. We reconstructed a genome-scale metabolic network for this alga and devised a novel light-modeling approach that enables quantitative growth prediction for a given light source, resolving wavelength and photon flux. We experimentally verified transcripts accounted for in the network and physiologically validated model function through simulation and generation of new experimental growth data, providing high confidence in network contents and predictive applications. The network offers insight into algal metabolism and potential for genetic engineering and efficient light source design, a pioneering resource for studying light-driven metabolism and quantitative systems biology. Our approach to generate a predictive metabolic model integrated with cloned open reading frames, provides a cost-effective platform to generate metabolic engineering resources. While the generated resources are specific to algal systems, the approach that we have developed is not specific to algae and

  7. Cellular oxido-reductive proteins of Chlamydomonas reinhardtii control the biosynthesis of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Barwal Indu


    Full Text Available Abstract Background Elucidation of molecular mechanism of silver nanoparticles (SNPs biosynthesis is important to control its size, shape and monodispersity. The evaluation of molecular mechanism of biosynthesis of SNPs is of prime importance for the commercialization and methodology development for controlling the shape and size (uniform distribution of SNPs. The unicellular algae Chlamydomonas reinhardtii was exploited as a model system to elucidate the role of cellular proteins in SNPs biosynthesis. Results The C. reinhardtii cell free extract (in vitro and in vivo cells mediated synthesis of silver nanoparticles reveals SNPs of size range 5 ± 1 to 15 ± 2 nm and 5 ± 1 to 35 ± 5 nm respectively. In vivo biosynthesized SNPs were localized in the peripheral cytoplasm and at one side of flagella root, the site of pathway of ATP transport and its synthesis related enzymes. This provides an evidence for the involvement of oxidoreductive proteins in biosynthesis and stabilization of SNPs. Alteration in size distribution and decrease of synthesis rate of SNPs in protein-depleted fractions confirmed the involvement of cellular proteins in SNPs biosynthesis. Spectroscopic and SDS-PAGE analysis indicate the association of various proteins on C. reinhardtii mediated in vivo and in vitro biosynthesized SNPs. We have identified various cellular proteins associated with biosynthesized (in vivo and in vitro SNPs by using MALDI-MS-MS, like ATP synthase, superoxide dismutase, carbonic anhydrase, ferredoxin-NADP+ reductase, histone etc. However, these proteins were not associated on the incubation of pre-synthesized silver nanoparticles in vitro. Conclusion Present study provides the indication of involvement of molecular machinery and various cellular proteins in the biosynthesis of silver nanoparticles. In this report, the study is mainly focused towards understanding the role of diverse cellular protein in the synthesis and capping of silver

  8. Inorganic polyphosphate occurs in the cell wall of Chlamydomonas reinhardtii and accumulates during cytokinesis

    Directory of Open Access Journals (Sweden)

    Freimoser Florian M


    Full Text Available Abstract Background Inorganic polyphosphate (poly P, linear chains of phosphate residues linked by energy rich phosphoanhydride bonds, is found in every cell and organelle and is abundant in algae. Depending on its localization and concentration, poly P is involved in various biological functions. It serves, for example, as a phosphate store and buffer against alkali, is involved in energy metabolism and regulates the activity of enzymes. Bacteria defective in poly P synthesis are impaired in biofilm development, motility and pathogenicity. PolyP has also been found in fungal cell walls and bacterial envelopes, but has so far not been measured directly or stained specifically in the cell wall of any plant or alga. Results Here, we demonstrate the presence of poly P in the cell wall of Chlamydomonas reinhardtii by staining with specific poly P binding proteins. The specificity of the poly P signal was verified by various competition experiments, by staining with different poly P binding proteins and by correlation with biochemical quantification. Microscopical investigation at different time-points during growth revealed fluctuations of the poly P signal synchronous with the cell cycle: The poly P staining peaked during late cytokinesis and was independent of the high intracellular poly P content, which fluctuated only slightly during the cell cycle. Conclusion The presented staining method provides a specific and sensitive tool for the study of poly P in the extracellular matrices of algae and could be used to describe the dynamic behaviour of cell wall poly P during the cell cycle. We assume that cell wall poly P and intracellular poly P are regulated by distinct mechanisms and it is suggested that cell wall bound poly P might have important protective functions against toxic compounds or pathogens during cytokinesis, when cells are more vulnerable.

  9. Genetic and biochemical analysis of the TLA1 gene in Chlamydomonas reinhardtii. (United States)

    Mitra, Mautusi; Melis, Anastasios


    The Chlamydomonas reinhardtii genomic DNA database contains a predicted open reading frame (ORF-P) without an apparent stop-codon and unknown coding sequence, located in close proximity and immediately upstream of the TLA1 gene (GenBank Accession No. AF534570). The latter was implicated in the regulation of the light-harvesting chlorophyll antenna size of photosynthesis (Tetali et al. Planta 225:813-829, 2007). To provide currently lacking information on ORF-P and its potential participation in TLA1 gene expression, thus in the regulation of the chlorophyll antenna size, genetic and biochemical analyses were undertaken. The coding and UTR regions of the ORF-P were defined and delineated from those of the adjacent TLA1 gene. ORF-P is shown to encode a protein with a distinct RING-like zinc finger domain that is present in numerous eukaryotic proteins, believed to play a role in cellular ubiquitination, leading to regulation of cellular processes like signaling, growth, transcription, and DNA repair. It is further shown that the two genes share a 74-bp overlap between the 3' UTR region of ORF-P and the 5' UTR region of TLA1. However, they possess distinct start and stop codons and separate coding sequences, and transcribed as separate mRNAs without any trans-splicing between them. Complementation experiments showed that the TLA1 gene alone is sufficient to rescue the truncated chlorophyll antenna size phenotype of the tla1 mutant. Protein sequence alignments in C. reinhardtii and the colorless microalga Polytomella parva suggested that TLA1 defines the relationship between nucleus and organelle in microalgae, indirectly affecting the development of the chlorophyll antenna size.

  10. Characterization of lead induced metal-phytochelatin complexes in Chlamydomonas reinhardtii. (United States)

    Scheidegger, Christian; Sigg, Laura; Behra, Renata


    Accumulation of Pb and induction of phytochelatin synthesis were observed in Chlamydomonas reinhardtii upon Pb(II) exposure. Our aim was to examine whether Pb(II) is bound by phytochelatins (PCs) in C. reinhardtii and to examine formed complexes for their stoichiometry and composition. Metal-phytochelatin (Me-PC) complexes induced by Pb were isolated by size-exclusion chromatography in 13 collected fractions, which were analyzed for their PC and metal content by high-performance liquid chromatography and inductively coupled plasma mass spectrometry. A recovery of more than 90% of Pb from standard Pb-PC₂ complexes within the total volume of the size-exclusion column indicated the adequacy of the method for Pb-PC(n) complex separation and characterization. Phytochelatins were detected mainly in a molecular weight ranging from 1,000 to 5,300 daltons (Da), indicating the formation of complexes with various stoichiometries. Approximately 72% of total PC₂ eluted in the range from 1,000 to 1,600 Da, and 80% of total PC₃ eluted in the molecular weight range from 1,600 to 2,300 Da. The distribution of Cu, Zn, and Pb showed that more than 70% of these metals were associated with the high-molecular-weight fractions. Copper, zinc, and lead were also observed in PC-containing fractions, suggesting the formation of various Me-PC complexes. The results of the present study indicate that the role of PCs in Pb detoxification is minor, because only 13% of total Pb was associated with PCs.

  11. Saturating Light Induces Sustained Accumulation of Oil in Plastidal Lipid Droplets in Chlamydomonas reinhardtii. (United States)

    Goold, Hugh Douglas; Cuiné, Stéphan; Légeret, Bertrand; Liang, Yuanxue; Brugière, Sabine; Auroy, Pascaline; Javot, Hélène; Tardif, Marianne; Jones, Brian; Beisson, Fred; Peltier, Gilles; Li-Beisson, Yonghua


    Enriching algal biomass in energy density is an important goal in algal biotechnology. Nitrogen (N) starvation is considered the most potent trigger of oil accumulation in microalgae and has been thoroughly investigated. However, N starvation causes the slow down and eventually the arrest of biomass growth. In this study, we show that exposing a Chlamydomonas reinhardtii culture to saturating light (SL) under a nonlimiting CO2 concentration in turbidostatic photobioreactors induces a sustained accumulation of lipid droplets (LDs) without compromising growth, which results in much higher oil productivity than N starvation. We also show that the polar membrane lipid fraction of SL-induced LDs is rich in plastidial lipids (approximately 70%), in contrast to N starvation-induced LDs, which contain approximately 60% lipids of endoplasmic reticulum origin. Proteomic analysis of LDs isolated from SL-exposed cells identified more than 200 proteins, including known proteins of lipid metabolism, as well as 74 proteins uniquely present in SL-induced LDs. LDs induced by SL and N depletion thus differ in protein and lipid contents. Taken together, lipidomic and proteomic data thus show that a large part of the sustained oil accumulation occurring under SL is likely due to the formation of plastidial LDs. We discuss our data in relation to the different metabolic routes used by microalgae to accumulate oil reserves depending on cultivation conditions. Finally, we propose a model in which oil accumulation is governed by an imbalance between photosynthesis and growth, which can be achieved by impairing growth or by boosting photosynthetic carbon fixation, with the latter resulting in higher oil productivity.

  12. Phosphorylation controls the localization and activation of the lumenal carbonic anhydrase in Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Amaya Blanco-Rivero

    Full Text Available BACKGROUND: Cah3 is the only carbonic anhydrase (CA isoform located in the thylakoid lumen of Chlamydomonas reinhardtii. Previous studies demonstrated its association with the donor side of the photosystem II (PSII where it is required for the optimal function of the water oxidizing complex. However this enzyme has also been frequently proposed to perform a critical function in inorganic carbon acquisition and CO(2 fixation and all mutants lacking Cah3 exhibit very poor growth after transfer to low CO(2 conditions. RESULTS/CONCLUSIONS: In the present work we demonstrate that after transfer to low CO(2, Cah3 is phosphorylated and that phosphorylation is correlated to changes in its localization and its increase in activity. When C. reinhardtii wild-type cells were acclimated to limiting CO(2 conditions, the Cah3 activity increased about 5-6 fold. Under these conditions, there were no detectable changes in the level of the Cah3 polypeptide. The increase in activity was specifically inhibited in the presence of Staurosporine, a protein kinase inhibitor, suggesting that the Cah3 protein was post-translationally regulated via phosphorylation. Immunoprecipitation and in vitro dephosphorylation experiments confirm this hypothesis. In vivo phosphorylation analysis of thylakoid polypeptides indicates that there was a 3-fold increase in the phosphorylation signal of the Cah3 polypeptide within the first two hours after transfer to low CO(2 conditions. The increase in the phosphorylation signal was correlated with changes in the intracellular localization of the Cah3 protein. Under high CO(2 conditions, the Cah3 protein was only associated with the donor side of PSII in the stroma thylakoids. In contrast, in cells grown at limiting CO(2 the protein was partly concentrated in the thylakoids crossing the pyrenoid, which did not contain PSII and were surrounded by Rubisco molecules. SIGNIFICANCE: This is the first report of a CA being post

  13. Use of microalgae Chlamydomonas reinhardtii for production of double-stranded RNA against shrimp virus

    Directory of Open Access Journals (Sweden)

    Parinyachat Somchai


    Full Text Available RNA interference has been proposed to be a promising tool for combating shrimp viruses. Antiviral double-stranded (dsRNA has been mostly produced in Escherichia coli-expression system because of its high efficiency and inexpensive operations. However, overusing the bacteria may raise concerns regarding public health and environmental contamination, and seeking for a new dsRNA production platform would be alternative for future molecular farming. In this study, we exploited the green microalgae Chlamydomonas reinhardtii to produce dsRNA targeting the lethal shrimp yellow head virus (YHV. The expression plasmid pSL18 for C. reinhardtii was constructed to contain YHV-specific hairpin RNA expression cassette, and the successful assembly of pSL18-YHV was confirmed by PCR and enzymatic digestions. Glass bead method was employed for transformation of C. reinhardtii nuclear genome with pSL18-YHV. Microalgal expression of dsRNA-YHV, approximately 45 ng from 100-mL culture, was detected by qRT-PCR. Oral feeding experiment on postlarval shrimp revealed that the formulated feed with C. reinhardtii expressing dsRNA-YHV, at the ratio of 1 × 108 transformants per gram feed, improved 22% survival rate after YHV challenge. The present study suggests that C. reinhardtii can be bioengineered to produce viral-specific dsRNA for shrimp viral disease control, and the developed qRT-PCR could detect microalgal dsRNA with detection limit of subpicogram.

  14. The Virtual Reality Conjecture

    CERN Document Server

    Whitworth, Brian


    We take our world to be an objective reality, but is it? The assumption that the physical world exists in and of itself has struggled to assimilate the findings of modern physics for some time now. For example, an objective space and time would just "be", but in relativity, space contracts and time dilates. Likewise objective "things" should just inherently exist, but the entities of quantum theory are probability of existence smears, that spread, tunnel, superpose and entangle in physically impossible ways. Cosmology even tells us that our entire physical universe just "popped up", from nowhere, about 14 billion years ago. This is not how an objectively real world should behave! Yet traditional alternatives don't work much better. That the world is just an illusion of the mind doesn't explain its consistent realism and Descartes dualism, that another reality beyond the physical exists, just doubles the existential problem. It is time to consider an option we might normally dismiss out of hand. This essay exp...

  15. Military Applications of Augmented Reality (United States)


    This chapter reviews military benefits and requirements that have led to a series of research efforts in augmented reality (AR) and related systems...Battlefield Augmented Reality System at the Naval Research Laboratory, which was the first system developed to meet the needs of the dismounted warfighter


    Directory of Open Access Journals (Sweden)

    Rifiana Arief


    Full Text Available ABSTRACT Augmanted Reality for android handphone has been a trend among collage students of computer department who join New Media course. To develop this application, the knowladge about visual presentation theory and case study of Augmanted Reality on android phoneneed to be conducted. Learning media through virtual class can facilitate the students’ needs in learning and developing Augmanted Reality. The method of this study in developing virtual class for Augmented Reality learning were: a having preparation to arrange learning unit, b analyzing and developing the content of learning materials, c designing storyboard or scenario of the virtual class, d making website of virtual class, e implementing the website as facility of online learning for Augmanted Reality. The available facilities in virtual class were to check learning units, to choose and download the material in the forms of e-book and presentation slides, to open the relevant website link for material enrichment as well as students’ practice with pre-test and post-test for measuring students’ understanding. By implementing virtual class for Augmanted Reality learning based Android, it is expected to provide alternative learning strategies for students that are interesting and easy to understand. The students are expected to be able to utilize this facility optimally in order to achieve the purposes of learning process and graduates’ competence. Keywords: VirtualClass, Augmented Reality (AR


    Directory of Open Access Journals (Sweden)

    Fábio de Farias Neves


    Full Text Available Microalgae have been culturing to fix carbon and produce biofuels from the biomass. However, it is important to develop low cost strategies for microalgae production in orther to make it a viable alternative of renewable energy. The present research studied the effect of treated wastewater used as an alternative culture medium for growth and productivity of a Chlamydomonas sp. strain isolated from landfills leachate of a treatment pond located in Southern Brazil. Three culture media were evaluated, the control consisted of synthetic TAP medium, other, consisting of 50% TAP medium and 50% wastewater, and another consisting of 100% wastewater. The growth parameters do not have significant difference among the three culture media. Also, productivity do not have significant difference among the cultures with TAP medium and with 100% wastewater, resulting in dry weight values of 1,4±0,14g/L and 1,3±0,19g/L respectively. The culture with 50% TAP medium and 50% wastewater showed the highest productivity, showing an average dry weight value of 1,7±0,07g/L. The results indicate that treated wastewater can be used as an alternative culture medium for Chlamydomonas sp. strain without negative effects on growth and productivity, and possible leading to a decrease in production costs.

  18. Understanding augmented reality concepts and applications

    CERN Document Server

    Craig, Alan B


    Augmented reality is not a technology. Augmented reality is a medium. Likewise, a book on augmented reality that only addresses the technology that is required to support the medium of augmented reality falls far short of providing the background that is needed to produce, or critically consume augmented reality applications. One reads a book. One watches a movie. One experiences augmented reality. Understanding Augmented Reality addresses the elements that are required to create compelling augmented reality experiences. The technology that supports

  19. Augmented reality as a design tool for mobile interfaces

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Nielsen, Christina


    This paper challenges user interface paradigms for mobile devices, by using the technical classification of augmented reality interfaces as a thinking tool to develop ideas for interaction with mobile devices. The paper presents future work scenarios from a wastewater treatment plant embodying PDA...... applications derived from the classification of augmented reality interfaces. The focus on physical interaction with objects of work and with the mobile device provides us with a range of interaction styles, based on e.g. gestures and manipulation of objects. Furthermore, issues of transparency and directness...... are addressed. The future scenarios indicate that the concepts of augmented reality support solving context problems in mobile design....

  20. 3D augmented reality with integral imaging display (United States)

    Shen, Xin; Hua, Hong; Javidi, Bahram


    In this paper, a three-dimensional (3D) integral imaging display for augmented reality is presented. By implementing the pseudoscopic-to-orthoscopic conversion method, elemental image arrays with different capturing parameters can be transferred into the identical format for 3D display. With the proposed merging algorithm, a new set of elemental images for augmented reality display is generated. The newly generated elemental images contain both the virtual objects and real world scene with desired depth information and transparency parameters. The experimental results indicate the feasibility of the proposed 3D augmented reality with integral imaging.

  1. SmartG: Spontaneous Malaysian Augmented Reality Tourist Guide (United States)

    Kasinathan, Vinothini; Mustapha, Aida; Subramaniam, Tanabalan


    In effort to attract higher tourist expenditure along with higher tourist arrivals, this paper proposes a travel application called the SmartG, acronym for Spontaneous Malaysian Augmented Reality Tourist Guide, which operates by making recommendations to user based on the travel objective and individual budget constraints. The applications relies on augmented reality technology, whereby a three dimensional model is presented to the user based on input from real world environment. User testing returned a favorable feedback on the concept of using augmented reality in promoting Malaysian tourism.

  2. Virtual reality at work (United States)

    Brooks, Frederick P., Jr.


    The utility of virtual reality computer graphics in telepresence applications is not hard to grasp and promises to be great. When the virtual world is entirely synthetic, as opposed to real but remote, the utility is harder to establish. Vehicle simulators for aircraft, vessels, and motor vehicles are proving their worth every day. Entertainment applications such as Disney World's StarTours are technologically elegant, good fun, and economically viable. Nevertheless, some of us have no real desire to spend our lifework serving the entertainment craze of our sick culture; we want to see this exciting technology put to work in medicine and science. The topics covered include the following: testing a force display for scientific visualization -- molecular docking; and testing a head-mounted display for scientific and medical visualization.

  3. Augmented Virtual Reality Laboratory (United States)

    Tully-Hanson, Benjamin


    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  4. Not a "reality" show. (United States)

    Wrong, Terence; Baumgart, Erica


    The authors of the preceding articles raise legitimate questions about patient and staff rights and the unintended consequences of allowing ABC News to film inside teaching hospitals. We explain why we regard their fears as baseless and not supported by what we heard from individuals portrayed in the filming, our decade-long experience making medical documentaries, and the full un-aired context of the scenes shown in the broadcast. The authors don't and can't know what conversations we had, what documents we reviewed, and what protections we put in place in each televised scene. Finally, we hope to correct several misleading examples cited by the authors as well as their offhand mischaracterization of our program as a "reality" show.

  5. System Architecture of a Mixed Reality Framework

    Directory of Open Access Journals (Sweden)

    Patrick Dähne


    Full Text Available In this paper the software architecture of a framework which simplifies the development of applications in the area of Virtual and Augmented Reality is presented. It is based on VRML/X3D to enable rendering of audio-visual information. We extended our VRML rendering system by a device management system that is based on the concept of a data-flow graph. The aim of the system is to create Mixed Reality (MR applications simply by plugging together small prefabricated software components, instead of compiling monolithic C++ applications. The flexibility and the advantages of the presented framework are explained on the basis of an exemplary implementation of a classic Augmented Realityapplication and its extension to a collaborative remote expert scenario.


    Directory of Open Access Journals (Sweden)

    Fernando Sambinelli


    Full Text Available The technology evolution of smartphones, systems and the growing of telecommunications, allow the use of Augmented Reality in the exploration of geo-referenced information, complementing the real environment of the users with various types of content displayed on robust mobile cameras through applications called augmented reality browsers. Although this type of application is being in development and growing use by society, the technology, and especially its software architecture do not have any kind of standardization. This work presents concepts about augmented reality browsers for mobile devices. It shows the main aspects and applications of those types of reality. Besides that, the specific features of those types of architecture are discussed and compared, and new architecture, whose most relevant feature is the interoperability of applications in various platforms for mobile devices, are presented. This work has the objective to develop an architectural framework for the development of these browsers.

  7. Expression and molecular analysis of phbB gene in Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    WANG Chaogang; HU Zhangli; HU Wei; LEI Anping


    The expression vector containing phbB and ble genes was constructed and transformed into cell-walldeficient strain Chlamydomonas reinhardtii CC-849 by the glass-bead method. The transgenic alga was selected and maintained in the TAP agar plates containing 10 μg/mL Zeomycin. Transgenic alga, which could express phbB at the transcriptional level, was obtained and further confirmed with PCR, Southern blot and RT-PCR-DNA hybridization analysis.

  8. Crime Scenes as Augmented Reality

    DEFF Research Database (Denmark)

    Sandvik, Kjetil


    Using the concept of augmented reality, this article will investigate how places in various ways have become augmented by means of different mediatization strategies. Augmentation of reality implies an enhancement of the places' emotional character: a certain mood, atmosphere or narrative surplus......, physical damage: they are all readable and interpretable signs. As augmented reality the crime scene carries a narrative which at first is hidden and must be revealed. Due to the process of investigation and the detective's ability to reason and deduce, the crime scene as place is reconstructed as virtual...

  9. Survival of Human Metallothionein-2 Transplastomic Chlamydomonas reinhardtii to Ultraviolet B Exposure

    Institute of Scientific and Technical Information of China (English)

    Yu-Kun ZHANG; Gui-Fang SHEN; Bing-Gen RU


    Solar ultraviolet (UV) radiation has a great influence on green organisms, especially plankton like Chlamydomonas. A human metallothionein-2 gene, which is generally considered to have an anti-radiation function by its coding product, was transferred into the chloroplast genome of Chlamydomonas reinhardtii.To dynamically measure the UV effects on Chlamydomonas cells grown in liquid tris-acetate-phosphate medium, a new method was developed based on the relationship between the chlorophyll content of an algal culture and its absorbance at 570 nm after the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In this experiment, both the wild-type and the transplastomic C. reinhardtii cells were cultivated in 96-well microplates containing liquid tris-acetate-phosphate medium in the absence or presence of zinc, copper,cadmium and cysteine. The transgenic C. reinhardtii showed a higher resistance than wild-type to UV-B exposure under all the examined conditions. Metals in the medium had positive impacts on both types of cells,but had significant influence only on the transplastomic cells. However, the high cell viability of the transgenic alga at the end of the 8 h UV-B treatment disappeared after a 20-h recovery culture. Cysteine did not protect cells from UV-B damage, but clearly enhanced the growth of both wild-type and transgenic C.reinhardtii.

  10. Virtual reality musical instruments: Guidelines for multisensory interaction design

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj


    The rapid development and availability of low cost technologies has created a wide interest in virtual reality (VR), but how to design and evaluate multisensory interactions in VR remains as a challenge. In this paper, we focus on virtual reality musical instruments, present an overview of our...... design and evaluation guidelines, and examine historical case studies. Our main contribution is to inform the design and evaluation of the future VRMIs and consider the challenges....

  11. 3D Vision in a Virtual Reality Robotics Environment


    Schütz, Christian L.; Natonek, Emerico; Baur, Charles; Hügli, Heinz


    Virtual reality robotics (VRR) needs sensing feedback from the real environment. To show how advanced 3D vision provides new perspectives to fulfill these needs, this paper presents an architecture and system that integrates hybrid 3D vision and VRR and reports about experiments and results. The first section discusses the advantages of virtual reality in robotics, the potential of a 3D vision system in VRR and the contribution of a knowledge database, robust control and the combination of in...

  12. Virtual Reality and Public Administration

    Directory of Open Access Journals (Sweden)

    István TÓZSA


    Full Text Available This study serves as an introduction to how virtual reality systems could be applied in public administration and what research tasks would be necessary to accomplish a project. E-government solutions began to emerge in public administration approximately a decade ago all over the developed world. Administration service facilities via the Internet did not attract many customers, because of the digital divide. E-government solutions were extended to mobile devices as well, but the expected breakthrough of usage has not ensued. The virtual reality form of public administration services recommended in this study has the most attractive outlay and the simplest navigation tools if compared to ‘traditional’ Internet based e-government. Thus, in accordance with the worldwide amazingly quick spread of the virtual reality systems of Second Life and 3 D types of entertainment, virtual reality applications in public administration could rely on a wide range of acceptance as well.

  13. Ultimate Realities: Deterministic and Evolutionary (United States)

    Moxley, Roy A


    References to ultimate reality commonly turn up in the behavioral literature as references to determinism. However, this determinism is often difficult to interpret. There are different kinds of determinisms as well as different kinds of ultimate realities for a behaviorist to consider. To clarify some of the issues involved, the views of ultimate realities are treated as falling along a continuum, with extreme views of complete indeterminism and complete determinism at either end and various mixes in between. Doing so brings into play evolutionary realities and the movement from indeterminism to determinism, as in Peirce's evolutionary cosmology. In addition, this framework helps to show how the views of determinism by B. F. Skinner and other behaviorists have shifted over time. PMID:22478489

  14. Augmented reality som wearable technology

    DEFF Research Database (Denmark)

    Rahn, Annette


    “How Augmented reality can facilitate learning in visualizing human anatomy “ At this station I demonstrate how Augmented reality can be used to visualize the human lungs in situ and as a wearable technology which establish connection between body, image and technology in education. I will show t...... MSO, Aalborg University, Copenhagen. Annette Rahn, MSc, senior lecturer and teacher in anatomy and physiology at the School of Nursing, VIA Health- and Welfare Technology, VIA University College.......“How Augmented reality can facilitate learning in visualizing human anatomy “ At this station I demonstrate how Augmented reality can be used to visualize the human lungs in situ and as a wearable technology which establish connection between body, image and technology in education. I will show...

  15. Science and Ultimate Reality (United States)

    Barrow, John D.; Davies, Paul C. W.; Harper, Charles L., Jr.


    This preview of the future of physics comprises contributions from recognized authorities inspired by the pioneering work of John Wheeler. Quantum theory represents a unifying theme within the book, as it relates to the topics of the nature of physical reality, cosmic inflation, the arrow of time, models of the universe, superstrings, quantum gravity and cosmology. Attempts to formulate a final unification theory of physics are also considered, along with the existence of hidden dimensions of space, hidden cosmic matter, and the strange world of quantum technology. John Archibald Wheeler is one of the most influential scientists of the twentieth century. His extraordinary career has spanned momentous advances in physics, from the birth of the nuclear age to the conception of the quantum computer. Famous for coining the term "black hole," Professor Wheeler helped lay the foundations for the rebirth of gravitation as a mainstream branch of science, triggering the explosive growth in astrophysics and cosmology that followed. His early contributions to physics include the S matrix, the theory of nuclear rotation (with Edward Teller), the theory of nuclear fission (with Niels Bohr), action-at-a-distance electrodynamics (with Richard Feynman), positrons as backward-in-time electrons, the universal Fermi interaction (with Jayme Tiomno), muonic atoms, and the collective model of the nucleus. His inimitable style of thinking, quirky wit, and love of the bizarre have inspired generations of physicists.

  16. Virtual Reality in Psychology

    Directory of Open Access Journals (Sweden)

    Nigel Foreman


    Full Text Available The benefits of using virtual environments (VEs in psychology arise from the fact that movements in virtual space, and accompanying perceptual changes, are treated by the brain in much the same way as those in equivalent real space. The research benefits of using VEs, in areas of psychology such as spatial learning and cognition, include interface flexibility, the reproducibility of virtual experience, and the opportunity for on-line monitoring of performance. Applications of VEs are many and varied, but are especially beneficial where experience can be tailored via augmentation, and where dangerous training situations can be avoided. The use of programmable agents has great future potential in relation to training and interpersonal skill development, also perhaps in clinical diagnosis and therapy. Progress in VE usage in psychological education is limited by cost and availability, though VEs are being used increasingly in classroom and laboratory teaching exercises. Virtual Reality was said to be “an answer waiting for a question”, but questions are being recognized, so that applications of VEs within the behavioural sciences are likely to multiply.

  17. Reality television and the muscular male ideal. (United States)

    Dallesasse, Starla L; Kluck, Annette S


    Although researchers have examined the negative effects of viewing reality television (RTV) on women's body image, this research has not been extended to men. Exploring the extent to which RTV depicts men who embody the muscular ideal may enhance our understanding of the potential influence of this media genre. We explored the extent to which RTV depicted men who embodied the muscular ideal using a quantitative content analysis. Based on binomial tests, the primary male cast members of programs airing on networks popular among young adult men during the Fall 2009 broadcast season were more muscular, with lower levels of body fat, than average U.S. men. The chest-to-waist and shoulder-to-waist ratios of these cast members did not differ as a function of program type (i.e., reality drama, endurance, and romance). Young men who view RTV programs included in the present study would be exposed to an unrepresentative muscular ideal.

  18. Interactive learning environments in augmented reality technology

    Directory of Open Access Journals (Sweden)

    Rafał Wojciechowski


    Full Text Available In this paper, the problem of creation of learning environments based on augmented reality (AR is considered. The concept of AR is presented as a tool for safe and cheap experimental learning. In AR learning environments students may acquire knowledge by personally carrying out experiments on virtual objects by manipulating real objects located in real environments. In the paper, a new approach to creation of interactive educational scenarios, called Augmented Reality Interactive Scenario Modeling (ARISM, is mentioned. In this approach, the process of building learning environments is divided into three stages, each of them performed by users with different technical and domain knowledge. The ARISM approach enables teachers who are not computer science experts to create AR learning environments adapted to the needs of their students.

  19. Archetypal dynamics, emergent situations, and the reality game. (United States)

    Sulis, William


    The classical approach to the modeling of reality is founded upon its objectification. Although successful dealing with inanimate matter, objectification has proven to be much less successful elsewhere, sometimes to the point of paradox. This paper discusses an approach to the modeling of reality based upon the concept of process as formulated within the framework of archetypal dynamics. Reality is conceptualized as an intermingling of information-transducing systems, together with the semantic frames that effectively describe and ascribe meaning to each system, along with particular formal representations of same which constitute the archetypes. Archetypal dynamics is the study of the relationships between systems, frames and their representations and the flow of information among these different entities. In this paper a specific formal representation of archetypal dynamics using tapestries is given, and a dynamics is founded upon this representation in the form of a combinatorial game called a reality game. Some simple examples are presented.

  20. Tools, perspectives and avatars in blended reality space. (United States)

    Hoshi, Kei; Pesola, Ulla-Maija; Waterworth, Eva L; Waterworth, John


    Blended Reality Space is our term for an interactive mixed-reality environment where the physical and the virtual are intimately combined in the service of interaction goals and communication environments aimed at health support and rehabilitation. The present study examines the effect on rated presence and self-presence of three key factors in the way blended realities may be implemented for these purposes. Our findings emphasize the importance of tangibility for presence, but suggest that presence and self-presence are unrelated phenomena. These findings will be incorporated into design principles for our planned work to develop free movement-based interactions for motor rehabilitation as well as blended-reality spaces for collaboration between hospitals, care organizations, and the home.

  1. An improved ARS2-derived nuclear reporter enhances the efficiency and ease of genetic engineering in Chlamydomonas

    DEFF Research Database (Denmark)

    Specht, Elizabeth A; Nour-Eldin, Hussam Hassan; Hoang, Kevin T D


    The model alga Chlamydomonas reinhardtii has been used to pioneer genetic engineering techniques for high-value protein and biofuel production from algae. To date, most studies of transgenic Chlamydomonas have utilized the chloroplast genome due to its ease of engineering, with a sizeable suite o...... nuclear promoters. This enhanced arylsulfatase reporter construct improves the efficiency and ease of genetic engineering within the Chlamydomonas nuclear genome, with potential application to other algal strains.......The model alga Chlamydomonas reinhardtii has been used to pioneer genetic engineering techniques for high-value protein and biofuel production from algae. To date, most studies of transgenic Chlamydomonas have utilized the chloroplast genome due to its ease of engineering, with a sizeable suite...... of reporters and well-characterized expression constructs. The advanced manipulation of algal nuclear genomes has been hampered by limited strong expression cassettes, and a lack of high-throughput reporters. We have improved upon an endogenous reporter gene - the ARS2 gene encoding an arylsulfatase enzyme...

  2. X-Ray Fiber Diffraction Recordings from Oriented Demembranated Chlamydomonas Flagellar Axonemes. (United States)

    Toba, Shiori; Iwamoto, Hiroyuki; Kamimura, Shinji; Oiwa, Kazuhiro


    The high homology of its axonemal components with humans and a large repertoire of axonemal mutants make Chlamydomonas a useful model system for experiments on the structure and function of eukaryotic cilia and flagella. Using this organism, we explored the spatial arrangement of axonemal components under physiological conditions by small-angle x-ray fiber diffraction. Axonemes were oriented in physiological solution by continuous shear flow and exposed to intense and stable x rays generated in the synchrotron radiation facility SPring-8, BL45XU. We compared diffraction patterns from axonemes isolated from wild-type and mutant strains lacking the whole outer arm (oda1), radial spoke (pf14), central apparatus (pf18), or the α-chain of the outer arm dynein (oda11). Diffraction of the axonemes showed a series of well-defined meridional/layer-line and equatorial reflections. Diffraction patterns from mutant axonemes exhibited a systematic loss/attenuation of meridional/layer-line reflections, making it possible to determine the origin of various reflections. The 1/24 and 1/12 nm(-1) meridional reflections of oda1 and oda11 were much weaker than those of the wild-type, suggesting that the outer dynein arms are the main contributor to these reflections. The weaker 1/32 and 1/13.7 nm(-1) meridional reflections from pf14 compared with the wild-type suggest that these reflections come mainly from the radial spokes. The limited contribution of the central pair apparatus to the diffraction patterns was confirmed by the similarity between the patterns of the wild-type and pf18. The equatorial reflections were complex, but a comparison with electron micrograph-based models allowed the density of each axonemal component to be estimated. Addition of ATP to rigor-state axonemes also resulted in subtle changes in equatorial intensity profiles, which could report nucleotide-dependent structural changes of the dynein arms. The first detailed description of axonemal reflections

  3. Enhanced Ascorbate Regeneration Via Dehydroascorbate Reductase Confers Tolerance to Photo-Oxidative Stress in Chlamydomonas reinhardtii. (United States)

    Lin, Shu-Tseng; Chiou, Chih-Wen; Chu, Yen-Lin; Hsiao, Yu; Tseng, Yu-Fei; Chen, Yi-Chun; Chen, Hsien-Jung; Chang, Hsin-Yang; Lee, Tse-Min


    The role of ascorbate (AsA) recycling via dehydroascorbate reductase (DHAR) in the tolerance of Chlamydomonas reinhardtii to photo-oxidative stress was examined. The activity of DHAR and the abundance of the CrDHAR1 (Cre10.g456750) transcript increased after moderate light (ML; 750 µmol m(-2) s(-1)) or high light (HL; 1,800 µmol m(-2) s(-1)) illumination, accompanied by dehydroascorbate (DHA) accumulation, decreased AsA redox state, photo-inhibition, lipid peroxidation, H2O2 overaccumulation, growth inhibition and cell death. It suggests that DHAR and AsA recycling is limiting under high-intensity light stress. The CrDHAR1 gene was cloned and its recombinant CrDHAR1 protein was a monomer (25 kDa) detected by Western blot that exhibits an enzymatic activity of 965 µmol min(-1)( )mg(-1) protein. CrDHAR1 was overexpressed driven by a HSP70A:RBCS2 fusion promoter or down-regulated by artificial microRNA (amiRNA) to examine whether DHAR-mediated AsA recycling is critical for the tolerance of C. reinahartii cells to photo-oxidative stress. The overexpression of CrDHAR1 increased DHAR protein abundance and enzyme activity, AsA pool size, AsA:DHA ratio and the tolerance to ML-, HL-, methyl viologen- or H2O2-induced oxidative stress. The CrDHAR1-knockdown amiRNA lines that have lower DHAR expression and AsA recycling ability were sensitive to high-intensity illumination and oxidative stress. The glutathione pool size, glutathione:oxidized glutathione ratio and glutathione reductase and ascorbate peroxidase activities were increased in CrDHAR1-overexpressing cells and showed a further increase after high-intensity illumination but decreased in wild-type cells after light stress. The present results suggest that increasing AsA regeneration via enhanced DHAR activity modulates the ascorbate-glutathione cycle activity in C. reinhardtii against photo-oxidative stress.

  4. Interactive effects of copper oxide nanoparticles and light to green alga Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Cheloni, Giulia; Marti, Elodie; Slaveykova, Vera I., E-mail:


    Highlights: • Comparable stability of CuO-NP suspensions under different light conditions. • UVR* inhibits growth, bleaches chlorophyll fluorescence and damages membrane. • Below 1 mg L{sup −1} CuO-NPs do not attenuate light in algal suspension. • SNL enhances significantly the effect of 0.8 mg L{sup −1} CuO-NPs on microalgae. • Synergistic interactions between UVR* and CuO-NPs. - Abstract: The present study explores the effect of light with different spectral composition on the stability of CuO-nanoparticle (CuO-NP) dispersions and their effects to green alga Chlamydomonas reinhardtii. The results showed that simulated natural light (SNL) and light with enhanced UVB radiation (UVR*) do not affect the dissolution of CuO-NPs as compared to light irradiation conditions typically used in laboratory incubator (INC). Comparable values of ζ-potential and hydrodynamic size during 24 h were found under all studied conditions. Concentrations of CuO-NPs below 1 mg L{sup −1} do not attenuate the light penetration in the algal suspensions in comparison with NP-free system. Exposure to a combination of 8 μg L{sup −1} or 0.8 mg L{sup −1} CuO-NPs and INC or SNL has no significant effect on the algal growth inhibition, algal fluorescence and membrane integrity under short-term exposure. However, an enhancement of the percentage of cells experiencing oxidative stress was observed upon exposure to 0.8 mg L{sup −1} CuO-NPs and SNL for 4 and 8 h. Combination of UVR* and 0.8 mg L{sup −1} CuO-NPs resulted in synergistic effects for all biological endpoints. Despite the photocatalytic properties of CuO-NPs no significant increase in abiotic reactive oxygen species (ROS) production under simulated solar radiation was observed suggesting that the synergistic effect observed might be correlated to other factors than CuO-NP-mediated ROS photoproduction. Tests performed with CuSO{sub 4} confirmed the important role of dissolution as toxicity driving force for lower

  5. Harvesting microalgae cultures with superabsorbent polymers: desulfurization of Chlamydomonas reinhardtii for hydrogen production. (United States)

    Martín del Campo, Julia S; Patiño, Rodrigo


    It is presented in this work a new methodology to harvest fresh water microalgae cultures by extracting the culture medium with superabsorbent polymers (SAPs). The microalgae Chlamydomonas reinhardtii were grown in the Sueoka culture medium, harvested with polyacrylic SAPs and re-suspended in the culture medium tris-acetate-potassium without sulfur (TAP-S) to generate hydrogen (H2 ) under anoxic conditions. The H2 production as an alternative fuel is relevant since this gas has high-energy recovery without involving carbon. Before microalgae harvesting, a number of range diameters (1-7 mm) for SAPs spherical particles were tested, and the initial rate (V0 ) and the maximal capacity (Qmax ) were determined for the Sueoka medium absorption. The SAP particles with the diameter range 2.0-2.5 mm performed the best and these were employed for the rest of the experiments. The Sueoka medium has a high salt content and the effect of the ionic strength was also studied for different medium concentrations (0-400%). The SAPs were reused in consecutive absorption/desorption cycles, maintaining their absorption capacity. Although the Sueoka medium reduces the SAPs absorption capacity to 40% compared with deionized water, the use of SAPs was very significant for the desulfurization process of C. reihardtii. The presence of C. reinhardtii at different concentrations does not affect the absorption capacity of the Sueoka culture medium by the SAPs. In order to reduce the time of the process, an increase of the SAPs concentration was tested, being 20 g of SAP per liter of medium, a condition to harvest the microalgae culture in 4 h. There were no evident cell ruptures during the harvesting process and the cells remained alive. Finally, the harvested biomass was re-suspended in TAP-S medium and kept under anaerobic conditions and illumination to produce H2 that was monitored by a PEM fuel cell. The use of SAPs for microalgae harvesting is a feasible non-invasive procedure to obtain

  6. Real-time monitoring of genetically modified Chlamydomonas reinhardtii during the Foton M3 space mission (United States)

    Lambreva, M.; Rea, G.; Antonacci, A.; Serafini, A.; Damasso, M.; Pastorelli, S.; Margonelli, A.; Johanningmeier, U.; Bertalan, I.; Pezzotti, G.; Giardi, M. T.


    Long-term space exploration, colonization or habitation requires biological life support systems capable to cope with the deleterious space environment. The use of oxygenic photosynthetic microrganisms is an intriguing possibility mainly for food, O2 and nutraceutical compounds production. The critical points of utilizing plants- or algae-based life support systems are the microgravity and the ionizing radiation, which can influence the performance of these organisms. The aim of the present study was to assess the effects of space environment on the photosynthetic activity of various microrganisms and to select space stresstolerant strains. Photosystem II D1 protein sitedirected and random mutants of the unicellular green alga Chlamydomonas reinhardtii [1] were used as a model system to test and select the amino acid substitutions capable to account for space stress tolerance. We focussed our studies also on the accumulation of the Photosystem II photoprotective carotenoids (the xantophylls violaxanthin, anteraxanthin and zeaxanthin), powerful antioxidants that epidemiological studies demonstrated to be human vision protectors. For this purpose some mutants modified at the level of enzymes involved in the biosynthesis of xanthophylls were included in the study [2]. To identify the consequences of the space environment on the photosynthetic apparatus the changes in the Photosystem II efficiency were monitored in real time during the ESA-Russian Foton- M3 mission in September 2007. For the space flight a high-tech, multicell fluorescence detector, Photo-II, was designed and built by the Centre for Advanced Research in Space Optics in collaboration with Kayser-Italy, Biosensor and DAS. Photo-II is an automatic device developed to measure the chlorophyll fluorescence and to provide a living conditions for several different algae strains (Fig.1). Twelve different C. reinhardti strains were analytically selected and two replications for each strain were brought to space

  7. Quantum Nonlocality and Reality (United States)

    Bell, Mary; Gao, Shan


    Preface; Part I. John Stewart Bell: The Physicist: 1. John Bell: the Irish connection Andrew Whitaker; 2. Recollections of John Bell Michael Nauenberg; 3. John Bell: recollections of a great scientist and a great man Gian-Carlo Ghirardi; Part II. Bell's Theorem: 4. What did Bell really prove? Jean Bricmont; 5. The assumptions of Bell's proof Roderich Tumulka; 6. Bell on Bell's theorem: the changing face of nonlocality Harvey R. Brown and Christopher G. Timpson; 7. Experimental tests of Bell inequalities Marco Genovese; 8. Bell's theorem without inequalities: on the inception and scope of the GHZ theorem Olival Freire, Jr and Osvaldo Pessoa, Jr; 9. Strengthening Bell's theorem: removing the hidden-variable assumption Henry P. Stapp; Part III. Nonlocality: Illusions or Reality?: 10. Is any theory compatible with the quantum predictions necessarily nonlocal? Bernard d'Espagnat; 11. Local causality, probability and explanation Richard A. Healey; 12. Bell inequality and many-worlds interpretation Lev Vaidman; 13. Quantum solipsism and non-locality Travis Norsen; 14. Lessons of Bell's theorem: nonlocality, yes; action at a distance, not necessarily Wayne C. Myrvold; 15. Bell non-locality, Hardy's paradox and hyperplane dependence Gordon N. Fleming; 16. Some thoughts on quantum nonlocality and its apparent incompatibility with relativity Shan Gao; 17. A reasonable thing that just might work Daniel Rohrlich; 18. Weak values and quantum nonlocality Yakir Aharonov and Eliahu Cohen; Part IV. Nonlocal Realistic Theories: 19. Local beables and the foundations of physics Tim Maudlin; 20. John Bell's varying interpretations of quantum mechanics: memories and comments H. Dieter Zeh; 21. Some personal reflections on quantum non-locality and the contributions of John Bell Basil J. Hiley; 22. Bell on Bohm Sheldon Goldstein; 23. Interactions and inequality Philip Pearle; 24. Gravitation and the noise needed in objective reduction models Stephen L. Adler; 25. Towards an objective

  8. The realities of idealism. (United States)

    Roslyn, J J


    I started out asking the question can we achieve our goals and are our goals realistic in the 1990s? I believe that we can achieve anything that we set our minds to. Our goals of providing quality care to our patients, performing research, teaching the next generation, and having an impact on our local environment are worth pursuing. However, the rules have changed and the status quo is simply not good enough. If we are to survive, we must be prepared for the future. You have the ability to change and the power to control the future. You are the future. Seize the opportunity and get involved. Become knowledgeable about health care economics, become involved with the political process, and position yourselves so that you can be a part of the solution to our health care system's woes. Don't allow the moment to pass. Don't be afraid of the realities of today, and don't forget your ideals and principles. Confront today's challenges with the same determination that academic surgeons through the years have confronted the unknown mysteries of disease. Let me conclude by trying to synthesize my remarks in five generic recommendations: 1. We need to go forward in the research area by developing multidisciplinary programs that involve basic science. These programs can be used to highlight our clinical areas and expertise. In this manner, both areas will be benefitted. 2. We need to educate the public and the government about the virtues of research and the importance of maintaining academic surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Adaptive information design for outdoor augmented reality. (United States)

    Neuhöfer, Jan A; Govaers, Felix; El Mokni, Hichem; Alexander, Thomas


    Augmented Reality focuses on the enrichment of the user's natural field of view by consistent integration of text, symbols and interactive three-dimensional objects in real time. Placing virtual objects directly into the user's view in a natural context empowers highly dynamic applications. On the other hand, this necessitates deliberate choice of information design and density, in particular for deployment in hazardous environments like military combat scenarios. As the amount of information needed is not foreseeable and strongly depends on the individual mission, an appropriate system must offer adequate adaptation capabilities. The paper presents a prototypical, vehicle-mountable Augmented Reality vision system, designed for enhancing situation awareness in stressful urban warfare scenarios. Tracking, as one of the most crucial challenges for outdoor Augmented Reality, is accomplished by means of a Differential-GPS approach while the type of display to attach can be modified, ranging from ocular displays to standard LCD mini-screens. The overall concept also includes envisioning of own troops (blue forces), for which a multi-sensor tracking approach has been chosen. As a main feature, the system allows switching between different information categories, focusing on friendly, hostile, unidentified or neutral data. Results of an empirical study on the superiority of an in-view navigation cue approach conclude the paper.

  10. Green algal cytochrome b6-f complexes: isolation and characterization from Dunaliella saline, Chlamydomonas reinhardtii and Scenedesmus obliquus. (United States)

    Wynn, R M; Bertsch, J; Bruce, B D; Malkin, R


    Cytochrome b6-f complexes have been isolated from Chlamydomonas reinhardtii, Dunaliella saline and Scenedesmus obliquus. Each complex is essentially free of chlorophyll and carotenoids and contains cytochrome b6 and cytochrome f hemes in a 2:1 molar ratio. C. reinhardtii and S. obliquus complexes contain the Rieske iron-sulfur protein (present in approx 1:1 molar ratio to cytochrome f) and each catalyzes a DBMIB- and DNP-INT-sensitive electron transfer from duroquinol to spinach plastocyanin. Immunological assays using antibodies to the peptides from the spinach cytochrome complex show varying cross-reactivity patterns except for the complete absence of binding to the Rieske proteins in any of the three complexes, suggesting little structural similarity between the Rieske proteins of algae with those from higher plants. One complex (D. salina) has been uniformly labeled by growth in NaH14CO3 to determine stoichiometries of constituent polypeptide subunits. Results from these studies indicate that all functionally active cytochrome b6-f complexes contain four subunits which occur in equimolar amounts.

  11. The chloroplast atpA gene cluster in Chlamydomonas reinhardtii. Functional analysis of a polycistronic transcription unit. (United States)

    Drapier, D; Suzuki, H; Levy, H; Rimbault, B; Kindle, K L; Stern, D B; Wollman, F A


    Most chloroplast genes in vascular plants are organized into polycistronic transcription units, which generate a complex pattern of mono-, di-, and polycistronic transcripts. In contrast, most Chlamydomonas reinhardtii chloroplast transcripts characterized to date have been monocistronic. This paper describes the atpA gene cluster in the C. reinhardtii chloroplast genome, which includes the atpA, psbI, cemA, and atpH genes, encoding the alpha-subunit of the coupling-factor-1 (CF1) ATP synthase, a small photosystem II polypeptide, a chloroplast envelope membrane protein, and subunit III of the CF0 ATP synthase, respectively. We show that promoters precede the atpA, psbI, and atpH genes, but not the cemA gene, and that cemA mRNA is present only as part of di-, tri-, or tetracistronic transcripts. Deletions introduced into the gene cluster reveal, first, that CF1-alpha can be translated from di- or polycistronic transcripts, and, second, that substantial reductions in mRNA quantity have minimal effects on protein synthesis rates. We suggest that posttranscriptional mRNA processing is common in C. reinhardtii chloroplasts, permitting the expression of multiple genes from a single promoter.

  12. Physics Education in Virtual Reality: An Example

    Directory of Open Access Journals (Sweden)

    Hannes Kaufmann


    Full Text Available We present an immersive virtual reality (VR application for physics education. It utilizes a recent physics engine developed for the PC gaming market to simulate physical experiments correctly and accurately. Students are enabled to actively build their own experiments and study them. A variety of tools are provided to analyze forces, mass, paths and other properties of objects before, during and after experiments. Innovative teaching content is presented thatexploits the strengths of the 3D virtual environment. Physics Playground serves as an example of how current technologies can be combined to deliver a new quality in physics education.

  13. Beyond the Constraints of Reality

    DEFF Research Database (Denmark)

    Hansen, Kim Toft

    Lucio Fulci’s classic The Beyond (1981) contributes to an understanding of abstract horror and an original poetics of the undead in its focus on breaking down the representation of reality. Understanding reality as a naturalistic comprehension of time and space the film slowly crumbles the founda......Lucio Fulci’s classic The Beyond (1981) contributes to an understanding of abstract horror and an original poetics of the undead in its focus on breaking down the representation of reality. Understanding reality as a naturalistic comprehension of time and space the film slowly crumbles...... the foundation of reality with special attention to religious metaphors and suspension of disbelief. On the one hand the film applies a common type of hesitation, which means that the film in itself deals with the basic poetics of horror, but on the other hand the film’s center of attention is horizontal time...... and space. Slowly, a new vertical, divine perception of time is imposed on mainly the two central characters without which survival is impossible, but as they accept the new insight space seems to break down as well. This means that a close analysis of The Beyond conveys a basic conception of the poetics...

  14. Composition and structure of the 80S ribosome from the green alga Chlamydomonas reinhardtii: 80S ribosomes are conserved in plants and animals. (United States)

    Manuell, Andrea L; Yamaguchi, Kenichi; Haynes, Paul A; Milligan, Ronald A; Mayfield, Stephen P


    We have conducted a proteomic analysis of the 80S cytosolic ribosome from the eukaryotic green alga Chlamydomonas reinhardtii, and accompany this with a cryo-electron microscopy structure of the ribosome. Proteins homologous to all but one rat 40S subunit protein, including a homolog of RACK1, and all but three rat 60S subunit proteins were identified as components of the C. reinhardtii ribosome. Expressed Sequence Tag (EST) evidence and annotation of the completed C. reinhardtii genome identified genes for each of the four proteins not identified by proteomic analysis, showing that algae potentially have a complete set of orthologs to mammalian 80S ribosomal proteins. Presented at 25A, the algal 80S ribosome is very similar in structure to the yeast 80S ribosome, with only minor distinguishable differences. These data show that, although separated by billions of years of evolution, cytosolic ribosomes from photosynthetic organisms are highly conserved with their yeast and animal counterparts.

  15. Species-specific isotope tracers to study the accumulation and biotransformation of mixtures of inorganic and methyl mercury by the microalga Chlamydomonas reinhardtii. (United States)

    Bravo, Andrea Garcia; Le Faucheur, Séverine; Monperrus, Mathilde; Amouroux, David; Slaveykova, Vera I


    The present study demonstrates that species-specific isotope tracing is an useful tool to precisely measure Hg accumulation and transformations capabilities of living organisms at concentrations naturally encountered in the environment. To that end, a phytoplanktonic green alga Chlamydomonas reinhardtii Dangeard (Chlamydomonadales, Chlorophyceae) was exposed to mixtures of (199)-isotopically enriched inorganic mercury ((199)IHg) and of (201)-isotopically enriched monomethylmercury ((201)CH3Hg) at a concentration range between less than 1 pM to 4 nM. Additionally, one exposure concentration of both mercury species was also studied separately to evaluate possible interactive effects. No difference in the intracellular contents was observed for algae exposed to (199)IHg and (201)CH3Hg alone or in their mixture, suggesting similar accumulation capacity for both species at the studied concentrations. Demethylation of (201)CH3Hg was observed at the highest exposure concentrations, whereas no methylation was detected.

  16. Investigation and modeling of biomass decay rate in the dark and its potential influence on net productivity of solar photobioreactors for microalga Chlamydomonas reinhardtii and cyanobacterium Arthrospira platensis. (United States)

    Le Borgne, François; Pruvost, Jérémy


    Biomass decay rate (BDR) in the dark was investigated for Chlamydomonas reinhardtii (microalga) and Arthrospira platensis (cyanobacterium). A specific setup based on a torus photobioreactor with online gas analysis was validated, enabling us to follow the time course of the specific BDR using oxygen monitoring and mass balance. Various operating parameters that could limit respiration rates, such as culture temperature and oxygen deprivation, were then investigated. C. reinhardtii was found to present a higher BDR in the dark than A. platensis, illustrating here the difference between eukaryotic and prokaryotic cells. In both cases, temperature proved an influential parameter, and the Arrhenius law was found to efficiently relate specific BDR to culture temperature. The utility of decreasing temperature at night to increase biomass productivity in a solar photobioreactor is also illustrated.

  17. The ethnography of virtual reality

    Directory of Open Access Journals (Sweden)

    Gavrilović Ljiljana 1


    Full Text Available This paper discusses possible application of ethnographic research in the realm of virtual reality, especially in the relationship between cultures in virtual communities. This represents an entirely new area of ethnographic research and therefore many adjustments in the research design are needed for example, a development of a specific method of data gathering and tools for their verification. A virtual, cyber space is a version of social space more or less synchronous with it, but without the, "real", that is, physical presence of the people who create it. This virtual reality, defined and bounded by virtual space, is in fact real - and though we are not able to observe real, physical parameters of its existence, we can perceive its consequences. In sum, an innovative ethnographic research method is fully applicable for exploring the realm of virtual reality; in order to do so we need to expand, in addition to the new research design and methods, the field of science itself.

  18. Engineering the chloroplast targeted malarial vaccine antigens in Chlamydomonas starch granules.

    Directory of Open Access Journals (Sweden)

    David Dauvillée

    Full Text Available BACKGROUND: Malaria, an Anopheles-borne parasitic disease, remains a major global health problem causing illness and death that disproportionately affects developing countries. Despite the incidence of malaria, which remains one of the most severe infections of human populations, there is no licensed vaccine against this life-threatening disease. In this context, we decided to explore the expression of Plasmodium vaccine antigens fused to the granule bound starch synthase (GBSS, the major protein associated to the starch matrix in all starch-accumulating plants and algae such as Chlamydomonas reinhardtii. METHODS AND FINDINGS: We describe the development of genetically engineered starch granules containing plasmodial vaccine candidate antigens produced in the unicellular green algae Chlamydomonas reinhardtii. We show that the C-terminal domains of proteins from the rodent Plasmodium species, Plasmodium berghei Apical Major Antigen AMA1, or Major Surface Protein MSP1 fused to the algal granule bound starch synthase (GBSS are efficiently expressed and bound to the polysaccharide matrix. Mice were either immunized intraperitoneally with the engineered starch particles and Freund adjuvant, or fed with the engineered particles co-delivered with the mucosal adjuvant, and challenged intraperitoneally with a lethal inoculum of P. Berghei. Both experimental strategies led to a significantly reduced parasitemia with an extension of life span including complete cure for intraperitoneal delivery as assessed by negative blood thin smears. In the case of the starch bound P. falciparum GBSS-MSP1 fusion protein, the immune sera or purified immunoglobulin G of mice immunized with the corresponding starch strongly inhibited in vitro the intra-erythrocytic asexual development of the most human deadly plasmodial species. CONCLUSION: This novel system paves the way for the production of clinically relevant plasmodial antigens as algal starch-based particles

  19. Rapid construction and screening of artificial microRNA systems in Chlamydomonas reinhardtii. (United States)

    Hu, Jinlu; Deng, Xuan; Shao, Ning; Wang, Gaohong; Huang, Kaiyao


    The unicellular green algae Chlamydomonas reinhardtii is a classic model for the study of flagella/cilia and photosynthesis, and it has recently been exploited for producing biopharmaceuticals and biofuel. Due to the low frequency of homologous recombination, reverse genetic manipulation in Chlamydomonas relies mainly on miRNA- and siRNA-based knockdown methods. However, the difficulty in constructing artificial miRNA vectors, laborious screening of knockdown transformants, and undesired epigenetic silencing of exogenous miRNA constructs limit their application. We have established a one-step procedure to construct an artificial miRNA precursor by annealing eight oligonucleotides of approximately 40 nucleotides. In the final construct, the Gaussia princeps luciferase gene (G-Luc) is positioned between the promoter and the artificial miRNA precursor so that knockdown strains may quickly be screened by visualizing luciferase luminescence using a photon-counting camera. Furthermore, the luciferase activity of transformants correlates with the knockdown level of two test target proteins: the chloroplast protein VIPP1 (vesicle inducing protein in plastids 1) and the flagellar protein CDPK3 (calcium-dependent protein kinase 3). Adding an intron from RBCS2 (ribulose bisphosphate carboxylase/oxygenase small subunit 2) to the miRNA construct enhanced both the luciferase activity and the miRNA knockdown efficiency. A second miRNA vector incorporated the promoter of the nitrate reductase gene to allow inducible expression of the artificial miRNA. These vectors will facilitate application of the artificial miRNA and provide tools for studying the mechanism of epigenetics in Chlamydomonas, and may also be adapted for use in other model organisms.

  20. Acclimation of Antarctic Chlamydomonas to the sea-ice environment: a transcriptomic analysis. (United States)

    Liu, Chenlin; Wang, Xiuliang; Wang, Xingna; Sun, Chengjun


    The Antarctic green alga Chlamydomonas sp. ICE-L was isolated from sea ice. As a psychrophilic microalga, it can tolerate the environmental stress in the sea-ice brine, such as freezing temperature and high salinity. We performed a transcriptome analysis to identify freezing stress responding genes and explore the extreme environmental acclimation-related strategies. Here, we show that many genes in ICE-L transcriptome that encoding PUFA synthesis enzymes, molecular chaperon proteins, and cell membrane transport proteins have high similarity to the gens from Antarctic bacteria. These ICE-L genes are supposed to be acquired through horizontal gene transfer from its symbiotic microbes in the sea-ice brine. The presence of these genes in both sea-ice microalgae and bacteria indicated the biological processes they involved in are possibly contributing to ICE-L success in sea ice. In addition, the biological pathways were compared between ICE-L and its closely related sister species, Chlamydomonas reinhardtii and Volvox carteri. In ICE-L transcripome, many sequences homologous to the plant or bacteria proteins in the post-transcriptional, post-translational modification, and signal-transduction KEGG pathways, are absent in the nonpsychrophilic green algae. These complex structural components might imply enhanced stress adaptation capacity. At last, differential gene expression analysis at the transcriptome level of ICE-L indicated that genes that associated with post-translational modification, lipid metabolism, and nitrogen metabolism are responding to the freezing treatment. In conclusion, the transcriptome of Chlamydomonas sp. ICE-L is very useful for exploring the mutualistic interaction between microalgae and bacteria in sea ice; and discovering the specific genes and metabolism pathways responding to the freezing acclimation in psychrophilic microalgae.


    Directory of Open Access Journals (Sweden)

    Elena Korableva


    Full Text Available Objective: Civilization development in its concrete historical specificity is embodied in symbolic forms that require interpretation and understanding of its meaning. Info communication symbolic reality sets new parameters of self-determination rights, creates a new type of information behavior. Adequate entry into the modern social context requires analysis of the basic concepts of symbolic reality of human existence, and its contemporary sound. The dialectical materialist methodology allows us to investigate human immersion in contradictive meanings of the era, the skills of interaction with the increased flow of information, the ability to determine information needs and use this information right way as well as the ability to analyze this information. Scientific novelty is reflected in axiological evolutionary approach to the analysis of reproduction in the sign and symbol of the spiritual and the practical forms of human multidimensional realities of their existence in their specific historical context. Conclusions: 1 Persons' immersion into the space of cultural and historical symbolic processes determines the content of their socialization which is a process of self-identification in the symbolic reality, the process of entering the subject-shaped field of human culture; 2 An adequate model of signs and symbols reflects the diversity of information flows, that is the synthesis of a specific objective and true knowledge, its interpretation and value. Herewith, a lot of interpretations, pluralism and diversity of axiological points of view to understanding objective reality are obvious; 3 The use of signs becomes like a code or the language for communication between people. The interpretation of clip-culture determines the adequacy and efficiency of action based on the identified meanings and values of diverse information and communication symbolic reality.

  2. Core Task and Organizational Reality

    DEFF Research Database (Denmark)

    Vikkelsø, Signe


    of core objects such as ‘task’ and ‘coordination,’ contemporary organization studies emphasize, much like other social science disciplines, broader topics such as ‘network,’ ‘identity,’ and ‘change.’ The paper argues that this altered focus and vocabulary is accompanied by a diminished ability to specify...... and intervene into the practical reality of organizations. It further argues that a discipline's core objects are not anachronisms to be discarded with, but crucial for specifying reality in ways that have proven practically relevant and still are....

  3. Protocol: methodology for chromatin immunoprecipitation (ChIP in Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Strenkert Daniela


    Full Text Available Abstract We report on a detailed chromatin immunoprecipitation (ChIP protocol for the unicellular green alga Chlamydomonas reinhardtii. The protocol is suitable for the analysis of nucleosome occupancy, histone modifications and transcription factor binding sites at the level of mononucleosomes for targeted and genome-wide studies. We describe the optimization of conditions for crosslinking, chromatin fragmentation and antibody titer determination and provide recommendations and an example for the normalization of ChIP results as determined by real-time PCR.

  4. Augmented reality three-dimensional display with light field fusion. (United States)

    Xie, Songlin; Wang, Peng; Sang, Xinzhu; Li, Chengyu


    A video see-through augmented reality three-dimensional display method is presented. The system that is used for dense viewpoint augmented reality presentation fuses the light fields of the real scene and the virtual model naturally. Inherently benefiting from the rich information of the light field, depth sense and occlusion can be handled under no priori depth information of the real scene. A series of processes are proposed to optimize the augmented reality performance. Experimental results show that the reconstructed fused 3D light field on the autostereoscopic display is well presented. The virtual model is naturally integrated into the real scene with a consistence between binocular parallax and monocular depth cues.

  5. Virtual Reality: The Promise of the Future. (United States)

    Lanier, Jaron


    Defines virtual reality and describes the equipment or clothing necessary to achieve the illusion of being in a virtual world. Recent developments with this technology and current virtual reality applications are discussed, including experiential prototyping, telepresence, and educational applications. (MES)

  6. Virtual Realities and the Future of Text. (United States)

    Marcus, Stephen


    Discusses issues surrounding virtual reality and "virtual books." Suggests that those who are exploring the territory of virtual realities are already helping to expand and enrich expectations and visions for integrating technology into reading and writing. (RS)

  7. Analysis of sensitive CO2 pathways and genes related to carbon uptake and accumulation in Chlamydomonas reinhardtii through genomic scale modeling and experimental validation

    Directory of Open Access Journals (Sweden)

    Flavia Vischi Winck


    Full Text Available The development of microalgae sustainable applications needs better understanding of microalgae biology. Moreover, how cells coordinate their metabolism towards biomass accumulation is not fully understood. In this present study, flux balance analysis (FBA was performed to identify sensitive metabolic pathways of Chlamydomonas reinhardtii under varied CO2 inputs. The metabolic network model of Chlamydomonas was updated based on the genome annotation data and sensitivity analysis revealed CO2 sensitive reactions. Biological experiments were performed with cells cultivated at 0.04% (air, 2.5%, 5%, 8% and 10% CO2 concentration under controlled conditions and cell growth profiles and biomass content were measured. Pigments, lipids, proteins and starch were further quantified for the reference low (0.04% and high (10% CO2 conditions. The expression level of candidate genes of sensitive reactions was measured and validated by quantitative real time qPCR. The sensitive analysis revealed mitochondrial compartment as the major affected by high CO2 levels and glycolysis/gluconeogenesis, glyoxylate and dicarboxylate metabolism among the affected metabolic pathways. Genes coding for glycerate kinase (GLYK, glycine cleavage system, H-protein (GCSH, NAD-dependent malate dehydrogenase (MDH3, low-CO2 inducible protein A (LCIA, carbonic anhydrase 5 (CAH5, E1 component, alpha subunit (PDC3, dual function alcohol dehydrogenase/acetaldehyde dehydrogenase (ADH1 and phosphoglucomutase (GPM2, were defined, among other genes, as sensitive nodes in the metabolic network simulations. These genes were experimentally responsive to the changes in the carbon fluxes in the system. We performed metabolomics analysis using mass spectrometry validating the modulation of carbon dioxide responsive pathways and metabolites. The changes on CO2 levels mostly affected the metabolism of amino acids found in the photorespiration pathway. Our updated metabolic network was compared to

  8. Analysis of Sensitive CO2 Pathways and Genes Related to Carbon Uptake and Accumulation in Chlamydomonas reinhardtii through Genomic Scale Modeling and Experimental Validation (United States)

    Winck, Flavia V.; Melo, David O. Páez; Riaño-Pachón, Diego M.; Martins, Marina C. M.; Caldana, Camila; Barrios, Andrés F. González


    The development of microalgae sustainable applications needs better understanding of microalgae biology. Moreover, how cells coordinate their metabolism toward biomass accumulation is not fully understood. In this present study, flux balance analysis (FBA) was performed to identify sensitive metabolic pathways of Chlamydomonas reinhardtii under varied CO2 inputs. The metabolic network model of Chlamydomonas was updated based on the genome annotation data and sensitivity analysis revealed CO2 sensitive reactions. Biological experiments were performed with cells cultivated at 0.04% (air), 2.5, 5, 8, and 10% CO2 concentration under controlled conditions and cell growth profiles and biomass content were measured. Pigments, lipids, proteins, and starch were further quantified for the reference low (0.04%) and high (10%) CO2 conditions. The expression level of candidate genes of sensitive reactions was measured and validated by quantitative real time PCR. The sensitive analysis revealed mitochondrial compartment as the major affected by changes on the CO2 concentrations and glycolysis/gluconeogenesis, glyoxylate, and dicarboxylate metabolism among the affected metabolic pathways. Genes coding for glycerate kinase (GLYK), glycine cleavage system, H-protein (GCSH), NAD-dependent malate dehydrogenase (MDH3), low-CO2 inducible protein A (LCIA), carbonic anhydrase 5 (CAH5), E1 component, alpha subunit (PDC3), dual function alcohol dehydrogenase/acetaldehyde dehydrogenase (ADH1), and phosphoglucomutase (GPM2), were defined, among other genes, as sensitive nodes in the metabolic network simulations. These genes were experimentally responsive to the changes in the carbon fluxes in the system. We performed metabolomics analysis using mass spectrometry validating the modulation of carbon dioxide responsive pathways and metabolites. The changes on CO2 levels mostly affected the metabolism of amino acids found in the photorespiration pathway. Our updated metabolic network was



    Mladen M. Jakovljević


    The science fiction of Philip K. Dick examines the issues of authenticity of reality and ontologicalpluralism through unique theories and mechanisms that Dick developed by using his ownunderstanding of alternate realities, time, simulations and cognitive processes, which all play animportant role in the perception of reality. Dick’s fiction describes a search for truth and highlightsthat reality might be fake and that it may be a construct, an illusion among numerous levels of theinauthentici...

  10. Exploring Virtual Reality for Classroom Use: The Virtual Reality and Education Lab at East Carolina University. (United States)

    Auld, Lawrence W. S.; Pantelidis, Veronica S.


    Describes the Virtual Reality and Education Lab (VREL) established at East Carolina University to study the implications of virtual reality for elementary and secondary education. Highlights include virtual reality software evaluation; hardware evaluation; computer-based curriculum objectives which could use virtual reality; and keeping current…

  11. Turn the Resolutions into Reality

    Institute of Scientific and Technical Information of China (English)


    Can you remember each New Year's resolutions you made at the beginning of a year? Did you make good on them or did you forget about them by June? Here are 6 tips that will help you turn those resolutions into reality.

  12. Augmented Reality Comes to Physics (United States)

    Buesing, Mark; Cook, Michael


    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

  13. Distributed Leadership: Rhetoric or Reality? (United States)

    Corrigan, Joe


    This paper provides insight into distributed leadership by contrasting the oppositional messages found in the literature, and by examining differences in the rhetoric and reality associated with its application. Specifically, the treatment of power and accountability within the distributed leadership theoretical framework is difficult to…

  14. Virtual reality applied to teletesting

    NARCIS (Netherlands)

    Berg, T.W. van den; Smeenk, R.J.M.; Mazy, A.; Jacques, P.; Argüello, L.; Mills, S.


    The activity "Virtual Reality applied to Teletesting" is related to a wider European Space Agency (ESA) initiative of cost reduction, in particular the reduction of test costs. Reduction of costs of space related projects have to be performed on test centre operating costs and customer company costs

  15. Education Hell: Rhetoric vs. Reality (United States)

    Bracey, Gerald W.


    Are America's schools broken? "Education Hell: Rhetoric vs. Reality" seeks to address misconceptions about America's schools by taking on the credo "what can be measured matters." To the contrary, Dr. Bracey makes a persuasive case that much of what matters cannot be assessed on a multiple choice test. The challenge for educators is to deal…

  16. Magical Realities in Interaction Design

    DEFF Research Database (Denmark)

    Rasmussen, Majken


    The field of interaction design is littered with examples of artefacts, which seemingly do not adhere to well-known physical causalities and our innate expectations of how artefacts should behave in the world, thereby creating the impression of a magic reality; where things can float in mid...

  17. Augmented Reality for Science Education

    DEFF Research Database (Denmark)

    Brandt, Harald; Nielsen, Birgitte Lund; Georgsen, Marianne


    Augmented reality (AR) holds great promise as a learning tool. So far, however, most research has looked at the technology itself – and AR has been used primarily for commercial purposes. As a learning tool, AR supports an inquiry-based approach to science education with a high level of student i...

  18. We create our own reality

    CERN Multimedia


    " Yes, we create our own reality. This is one of the most fundamental tenets of the ancient oriental religions, such as Buddhism. And during the last century, modern particle physics or quantum mechanics has discovered exactly the same thing" (1 page).

  19. Bringing reality into the classroom

    NARCIS (Netherlands)

    Heck, A.


    Technology offers ample opportunities to bring reality into the classroom. Students and teachers nowadays have many tools to work in an authentic way with real data in mathematics and science education. However, much research and development are still needed to create a consistent learning trajector

  20. Enhancing Health-Care Services with Mixed Reality Systems (United States)

    Stantchev, Vladimir

    This work presents a development approach for mixed reality systems in health care. Although health-care service costs account for 5-15% of GDP in developed countries the sector has been remarkably resistant to the introduction of technology-supported optimizations. Digitalization of data storing and processing in the form of electronic patient records (EPR) and hospital information systems (HIS) is a first necessary step. Contrary to typical business functions (e.g., accounting or CRM) a health-care service is characterized by a knowledge intensive decision process and usage of specialized devices ranging from stethoscopes to complex surgical systems. Mixed reality systems can help fill the gap between highly patient-specific health-care services that need a variety of technical resources on the one side and the streamlined process flow that typical process supporting information systems expect on the other side. To achieve this task, we present a development approach that includes an evaluation of existing tasks and processes within the health-care service and the information systems that currently support the service, as well as identification of decision paths and actions that can benefit from mixed reality systems. The result is a mixed reality system that allows a clinician to monitor the elements of the physical world and to blend them with virtual information provided by the systems. He or she can also plan and schedule treatments and operations in the digital world depending on status information from this mixed reality.

  1. Mixed Reality-based Interactive Technology for Aircraft Cabin Assembly

    Institute of Scientific and Technical Information of China (English)

    LI Shiqi; PENG Tao; WANG Junfeng; XU Chi


    Due to the narrowness of space and the complexity of structure, the assembly of aircraft cabin has become one of the major bottlenecks in the whole manufacturing process. To solve the problem, at the beginning of aircraft design, the different stages of the lifecycle of aircraft must be thought about, which include the trial manufacture, assembly, maintenance, recycling and destruction of the product. Recently, thanks to the development of the virtual reality and augmented reality, some low-cost and fast solutions are found for the product assembly. This paper presents a mixed reality-based interactive technology for the aircraft cabin assembly, which can enhance the efficiency of the assemblage in a virtual environment in terms of vision, information and operation. In the mixed reality-based assembly environment, the physical scene can be obtained by a camera and then generated by a computer. The virtual parts, the features of visual assembly, the navigation information, the physical parts and the physical assembly environment will be mixed and presented in the same assembly scene. The mixed or the augmented information will provide some assembling information as a detailed assembly instruction in the mixed reality-based assembly environment. Constraint proxy and its match rules help to reconstruct and visualize the restriction relationship among different parts, and to avoid the complex calculation of constraint's match. Finally, a desktop prototype system of virtual assembly has been built to assist the assembly verification and training with the virtual hand.

  2. An automated GCxGC-TOF-MS protocol for batch-wise extraction and alignment of mass isotopomer matrixes from differential 13C-labelling experiments: a case study for photoautotrophic-mixotrophic grown Chlamydomonas reinhardtii cells. (United States)

    Kempa, Stefan; Hummel, Jan; Schwemmer, Thorsten; Pietzke, Matthias; Strehmel, Nadine; Wienkoop, Stefanie; Kopka, Joachim; Weckwerth, Wolfram


    Two dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOF-MS) is a promising technique to overcome limits of complex metabolome analysis using one dimensional GC-TOF-MS. Especially at the stage of data export and data mining, however, convenient procedures to cope with the complexity of GCxGC-TOF-MS data are still in development. Here, we present a high sample throughput protocol exploiting first and second retention index for spectral library search and subsequent construction of a high dimensional data matrix useful for statistical analysis. The method was applied to the analysis of (13)C-labelling experiments in the unicellular green alga Chlamydomonas reinhardtii. We developed a rapid sampling and extraction procedure for Chlamydomonas reinhardtii laboratory strain (CC503), a cell wall deficient mutant. By testing all published quenching protocols we observed dramatic metabolite leakage rates for certain metabolites. To circumvent metabolite leakage, samples were directly quenched and analyzed without separation of the medium. The growth medium was adapted to this rapid sampling protocol to avoid interference with GCxGC-TOF-MS analysis. To analyse batches of samples a new software tool, MetMax, was implemented which extracts the isotopomer matrix from stable isotope labelling experiments together with the first and second retention index (RI1 and RI2). To exploit RI1 and RI2 for metabolite identification we used the Golm metabolome database (GMD [1] with RI1/RI2-reference spectra and new search algorithms. Using those techniques we analysed the dynamics of (13)CO(2) and (13)C-acetate uptake in Chlamydomonas reinhardtii cells in two different steady states namely photoautotroph and mixotroph growth conditions.

  3. Immersive virtual reality simulations in nursing education. (United States)

    Kilmon, Carol A; Brown, Leonard; Ghosh, Sumit; Mikitiuk, Artur


    This article explores immersive virtual reality as a potential educational strategy for nursing education and describes an immersive learning experience now being developed for nurses. This pioneering project is a virtual reality application targeting speed and accuracy of nurse response in emergency situations requiring cardiopulmonary resuscitation. Other potential uses and implications for the development of virtual reality learning programs are discussed.

  4. Controlled interaction: strategies for using virtual reality to study perception. (United States)

    Durgin, Frank H; Li, Zhi


    Immersive virtual reality systems employing head-mounted displays offer great promise for the investigation of perception and action, but there are well-documented limitations to most virtual reality systems. In the present article, we suggest strategies for studying perception/action interactions that try to depend on both scale-invariant metrics (such as power function exponents) and careful consideration of the requirements of the interactions under investigation. New data concerning the effect of pincushion distortion on the perception of surface orientation are presented, as well as data documenting the perception of dynamic distortions associated with head movements with uncorrected optics. A review of several successful uses of virtual reality to study the interaction of perception and action emphasizes scale-free analysis strategies that can achieve theoretical goals while minimizing assumptions about the accuracy of virtual simulations.

  5. Role of virtual reality for cerebral palsy management. (United States)

    Weiss, Patrice L Tamar; Tirosh, Emanuel; Fehlings, Darcy


    Virtual reality is the use of interactive simulations to present users with opportunities to perform in virtual environments that appear, sound, and less frequently, feel similar to real-world objects and events. Interactive computer play refers to the use of a game where a child interacts and plays with virtual objects in a computer-generated environment. Because of their distinctive attributes that provide ecologically realistic and motivating opportunities for active learning, these technologies have been used in pediatric rehabilitation over the past 15 years. The ability of virtual reality to create opportunities for active repetitive motor/sensory practice adds to their potential for neuroplasticity and learning in individuals with neurologic disorders. The objectives of this article is to provide an overview of how virtual reality and gaming are used clinically, to present the results of several example studies that demonstrate their use in research, and to briefly remark on future developments.

  6. Altered Fermentative Metabolism in Chlamydomonas reinhardtii Mutants Lacking Pyruvate Formate Lyase and Both Pyruvate Formate Lyase and Alcohol Dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Catalanotti, C.; Dubini, A.; Subramanian, V.; Yang, W. Q.; Magneschi, L.; Mus, F.; Seibert, M.; Posewitz, M. C.; Grossman, A. R.


    Chlamydomonas reinhardtii, a unicellular green alga, often experiences hypoxic/anoxic soil conditions that activate fermentation metabolism. We isolated three Chlamydomonas mutants disrupted for the pyruvate formate lyase (PFL1) gene; the encoded PFL1 protein catalyzes a major fermentative pathway in wild-type Chlamydomonas cells. When the pfl1 mutants were subjected to dark fermentative conditions, they displayed an increased flux of pyruvate to lactate, elevated pyruvate decarboxylation, ethanol accumulation, diminished pyruvate oxidation by pyruvate ferredoxin oxidoreductase, and lowered H2 production. The pfl1-1 mutant also accumulated high intracellular levels of lactate, succinate, alanine, malate, and fumarate. To further probe the system, we generated a double mutant (pfl1-1 adh1) that is unable to synthesize both formate and ethanol. This strain, like the pfl1 mutants, secreted lactate, but it also exhibited a significant increase in the levels of extracellular glycerol, acetate, and intracellular reduced sugars and a decrease in dark, fermentative H2 production. Whereas wild-type Chlamydomonas fermentation primarily produces formate and ethanol, the double mutant reroutes glycolytic carbon to lactate and glycerol. Although the metabolic adjustments observed in the mutants facilitate NADH reoxidation and sustained glycolysis under dark, anoxic conditions, the observed changes could not have been predicted given our current knowledge of the regulation of fermentation metabolism.

  7. Dephosphorylation Pathway of D-myo-Inositol 1,4,5-trisphosphate in the Unicellular Green Alga Chlamydomonas eugametos

    NARCIS (Netherlands)

    Klerk, Hans; Himbergen, John A.J. van; Musgrave, Alan; Haastert, Peter J.M. van; Ende, Herman van den


    In vitro dephosphorylation of D-myo-inositol 1,4,5-trisphosphate [Ins(l,4,5)P-3] by vegetative cells, gametes and zygotes of the green alga Chlamydomonas eugametos was studied using a soluble cell fraction as enzyme source and labelled Ins(1,4,5)P-3 as substrate. This compound was dephosphorylated y

  8. Origin of pronounced differences in 77 K fluorescence of the green alga Chlamydomonas reinhardtii in state 1 and 2

    NARCIS (Netherlands)

    Ünlü, Caner; Polukhina, Iryna; Amerongen, van Herbert


    In response to changes in the reduction state of the plastoquinone pool in its thylakoid membrane, the green alga Chlamydomonas reinhardtti is performing state transitions: remodelling of its thylakoid membrane leads to a redistribution of excitations over photosystems I and II (PSI and PSII). Th

  9. An Indexed, Mapped Mutant Library Enables Reverse Genetics Studies of Biological Processes in Chlamydomonas reinhardtii. (United States)

    Li, Xiaobo; Zhang, Ru; Patena, Weronika; Gang, Spencer S; Blum, Sean R; Ivanova, Nina; Yue, Rebecca; Robertson, Jacob M; Lefebvre, Paul A; Fitz-Gibbon, Sorel T; Grossman, Arthur R; Jonikas, Martin C


    The green alga Chlamydomonas reinhardtii is a leading unicellular model for dissecting biological processes in photosynthetic eukaryotes. However, its usefulness has been limited by difficulties in obtaining mutants in specific genes of interest. To allow generation of large numbers of mapped mutants, we developed high-throughput methods that (1) enable easy maintenance of tens of thousands of Chlamydomonas strains by propagation on agar media and by cryogenic storage, (2) identify mutagenic insertion sites and physical coordinates in these collections, and (3) validate the insertion sites in pools of mutants by obtaining >500 bp of flanking genomic sequences. We used these approaches to construct a stably maintained library of 1935 mapped mutants, representing disruptions in 1562 genes. We further characterized randomly selected mutants and found that 33 out of 44 insertion sites (75%) could be confirmed by PCR, and 17 out of 23 mutants (74%) contained a single insertion. To demonstrate the power of this library for elucidating biological processes, we analyzed the lipid content of mutants disrupted in genes encoding proteins of the algal lipid droplet proteome. This study revealed a central role of the long-chain acyl-CoA synthetase LCS2 in the production of triacylglycerol from de novo-synthesized fatty acids.

  10. Introducing Dunaliella LIP promoter containing light-inducible motifs improves transgenic expression in Chlamydomonas reinhardtii. (United States)

    Baek, Kwangryul; Lee, Yew; Nam, Onyou; Park, Seunghye; Sim, Sang Jun; Jin, EonSeon


    Promoter of the light-inducible protein gene (LIP) of Dunaliella was recently isolated in our laboratory. The aim of this work is to find the light-inducible motif in the Dunaliella LIP promoter and verify its regulatory motif with a Gaussia luciferase reporter gene transformed in Chlamydomonas reinhardtii. 400 bp upstream to the translational start site of the Dunaliella LIP gene was gradually truncated and analyzed for the luciferase expression. Furthermore, this promoter comprising duplicated or triplicated light-responsive motifs was tested for its augmentation of light response. Two putative light-responsive motifs, GT-1 binding motif and sequences over-represented in light-repressed promoters (SORLIP) located in the 200 bp LIP promoter fragment were analyzed for their light responsibility. It is turned out that SORLIP was responsible for the light-inducible activity. With the copy number of SORLIP up to three showed stronger high light response compared with the native LIP promoter fragment. Therefore, we found a light-responsive DNA motif operating in Chlamydomonas and confirm a synthetic promoter including this motif displayed light inducibility in heterologously transformed green algae for the first time. This light-inducible expression system will be applied to various area of algal research including algal biotechnology.

  11. Characterization of Hydrocortisone Biometabolites and 18S rRNA Gene in Chlamydomonas reinhardtii Cultures

    Directory of Open Access Journals (Sweden)

    Seyed Bagher Mosavi-Azam


    Full Text Available A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1. This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25ºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17b-Dihydroxyandrost-4-en-3-one (2, 11b-hydroxyandrost-4-en-3,17-dione (3, 11b,17a,20b,21-tetrahydroxypregn-4-en-3-one (4 and prednisolone (5 were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp.

  12. Biofixation of Carbon dioxide by Chlamydomonas sp. in a Tubular Photobioreactor

    Directory of Open Access Journals (Sweden)

    H Hadiyanto


    Full Text Available The biogas production from anaerobic digestion is a potential fuel for power generators application, if biogas can be upgraded to the same standards as fossil natural gas by CO2, H2S, and other non-combustible component removal. Microalgae Chlamydomonas sp. has potency to biofix the carbon dioxide and can be used as an additional food ingredient. The variations of flow rate and carbon dioxide concentration in the process resulting different value of biomass production and carbon dioxide biofixation. Biomass production at 40% carbon dioxide concentration obtained 5.685 gr/dm3 at 10% carbon dioxide concentration obtained 4.892 gr/dm3. The greatest value of carbon dioxide absorption occurs at a 40% concentration amounting to 12.09%. The rate of growth and productivity of microalgae tend to rise in 10% and 20% (%v carbon dioxide concentration, but began started a constant at 30% and 40% (%v carbon dioxide concentration. Biomass production tends to increase in light conditions while a constant in dark conditions. This study used Chlamydomonas sp. as media culture and performed on bubble column and tubular reactor with 6 litres of culture medium at a temperature of 28oC and atmospheric pressure.

  13. Biofixation of Carbon dioxide by Chlamydomonas sp. in a Tubular Photobioreactor

    Directory of Open Access Journals (Sweden)

    H Hadiyanto


    Full Text Available The biogas production from anaerobic digestion is a potential fuel for power generators application, if biogas can be upgraded to the same standards as fossil natural gas by CO2, H2S, and other non-combustible component removal. Microalgae Chlamydomonas sp. has potency to biofix the carbon dioxide and can be used as an additional food ingredient. The variations of flow rate and carbon dioxide concentration in the process resulting different value of biomass production and carbon dioxide biofixation. Biomass production at 40% carbon dioxide concentration obtained 5.685 gr/dm3 at 10% carbon dioxide concentration obtained 4.892 gr/dm3. The greatest value of carbon dioxide absorption occurs at a 40% concentration amounting to 12.09%. The rate of growth and productivity of microalgae tend to rise in 10% and 20% (%v carbon dioxide concentration, but began started a constant at 30% and 40% (%v carbon dioxide concentration. Biomass production tends to increase in light conditions while a constant in dark conditions. This study used Chlamydomonas sp. as media culture and performed on bubble column and tubular reactor with 6 litres of culture medium at a temperature of 28oC and atmospheric pressure.

  14. Virtual reality, augmented reality…I call it i-Reality (United States)


    The new term improved reality (i-Reality) is suggested to include virtual reality (VR) and augmented reality (AR). It refers to a real world that includes improved, enhanced and digitally created features that would offer an advantage on a particular occasion (i.e., a medical act). I-Reality may help us bridge the gap between the high demand for medical providers and the low supply of them by improving the interaction between providers and patients. PMID:28293571

  15. The Use of Virtual Reality Tools in the Reading-Language Arts Classroom (United States)

    Pilgrim, J. Michael; Pilgrim, Jodi


    This article presents virtual reality as a tool for classroom literacy instruction. Building on the traditional use of images as a way to scaffold prior knowledge, we extend this idea to share ways virtual reality enables experiential learning through field trip-like experiences. The use of technology tools such Google Street view, Google…

  16. Mobile Augmented Reality in Supporting Peer Assessment: An Implementation in a Fundamental Design Course (United States)

    Lan, Chung-Hsien; Chao, Stefan; Kinshuk; Chao, Kuo-Hung


    This study presents a conceptual framework for supporting mobile peer assessment by incorporating augmented reality technology to eliminate limitation of reviewing and assessing. According to the characteristics of mobile technology and augmented reality, students' work can be shown in various ways by considering the locations and situations. This…

  17. Game-Based Evacuation Drill Using Augmented Reality and Head-Mounted Display (United States)

    Kawai, Junya; Mitsuhara, Hiroyuki; Shishibori, Masami


    Purpose: Evacuation drills should be more realistic and interactive. Focusing on situational and audio-visual realities and scenario-based interactivity, the authors have developed a game-based evacuation drill (GBED) system that presents augmented reality (AR) materials on tablet computers. The paper's current research purpose is to improve…

  18. Hybrid Reality Lab Capabilities - Video 2 (United States)

    Delgado, Francisco J.; Noyes, Matthew


    Our Hybrid Reality and Advanced Operations Lab is developing incredibly realistic and immersive systems that could be used to provide training, support engineering analysis, and augment data collection for various human performance metrics at NASA. To get a better understanding of what Hybrid Reality is, let's go through the two most commonly known types of immersive realities: Virtual Reality, and Augmented Reality. Virtual Reality creates immersive scenes that are completely made up of digital information. This technology has been used to train astronauts at NASA, used during teleoperation of remote assets (arms, rovers, robots, etc.) and other activities. One challenge with Virtual Reality is that if you are using it for real time-applications (like landing an airplane) then the information used to create the virtual scenes can be old (i.e. visualized long after physical objects moved in the scene) and not accurate enough to land the airplane safely. This is where Augmented Reality comes in. Augmented Reality takes real-time environment information (from a camera, or see through window, and places digitally created information into the scene so that it matches with the video/glass information). Augmented Reality enhances real environment information collected with a live sensor or viewport (e.g. camera, window, etc.) with the information-rich visualization provided by Virtual Reality. Hybrid Reality takes Augmented Reality even further, by creating a higher level of immersion where interactivity can take place. Hybrid Reality takes Virtual Reality objects and a trackable, physical representation of those objects, places them in the same coordinate system, and allows people to interact with both objects' representations (virtual and physical) simultaneously. After a short period of adjustment, the individuals begin to interact with all the objects in the scene as if they were real-life objects. The ability to physically touch and interact with digitally created

  19. A hitchhiker's guide to virtual reality

    CERN Document Server

    McMenemy , Karen


    A Hitchhiker's Guide to Virtual Reality brings together under one cover all the aspects of graphics, video, audio, and haptics that have to work together to make virtual reality a reality. Like any good guide, it reveals the practical things you need to know, from the viewpoint of authors who have been there. This two-part guide covers the science, technology, and mathematics of virtual reality and then details its practical implementation. The first part looks at how the interface between human senses and technology works to create virtual reality, with a focus on vision, the most important s

  20. Multiple-endpoint assay provides a detailed mechanistic view of responses to herbicide exposure in Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Nestler, Holger [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland); Groh, Ksenia J.; Schoenenberger, Rene; Behra, Renata [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); Schirmer, Kristin [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland); EPF Lausanne, School of Architecture, Civil and Environmental Engineering, 1015 Lausanne (Switzerland); Eggen, Rik I.L. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland); Suter, Marc J.-F., E-mail: [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland)


    The release of herbicides into the aquatic environment raises concerns about potential detrimental effects on ecologically important non-target species, such as unicellular algae, necessitating ecotoxicological risk assessment. Algal toxicity tests based on growth, a commonly assessed endpoint, are integrative, and hence do not provide information about underlying toxic mechanisms and effects. This limitation may be overcome by measuring more specific biochemical and physiological endpoints. In the present work, we developed and applied a novel multiple-endpoint assay, and analyzed the effects of the herbicides paraquat, diuron and norflurazon, each representing a specific mechanism of toxic action, on the single celled green alga Chlamydomonas reinhardtii. The endpoints added to assessment of growth were pigment content, maximum and effective photosystem II quantum yield, ATP content, esterase and oxidative activity. All parameters were measured at 2, 6 and 24 h of exposure, except for growth and pigment content, which were determined after 6 and 24 h only. Effective concentrations causing 50% of response (EC50s) and lowest observable effect concentrations (LOECs) were determined for all endpoints and exposure durations where possible. The assay provided a detailed picture of the concentration- and time-dependent development of effects elicited by the analyzed herbicides, thus improving the understanding of the underlying toxic mechanisms. Furthermore, the response patterns were unique to the respective herbicide and reflected the different mechanisms of toxicity. The comparison of the endpoint responses and sensitivities revealed that several physiological and biochemical parameters reacted earlier or stronger to disturbances than growth. Overall, the presented multiple-endpoint assay constitutes a promising basis for investigating stressor and toxicant effects in green algae.

  1. Spectroelectrochemical characterization of the active site of the [FeFe] hydrogenase HydA1 from Chlamydomonas reinhardtii. (United States)

    Silakov, Alexey; Kamp, Christina; Reijerse, Eduard; Happe, Thomas; Lubitz, Wolfgang


    Hydrogenases catalyze the reversible oxidation of molecular hydrogen. The active site of the [FeFe] hydrogenases (H-cluster) contains a catalytically active binuclear subcluster ([2Fe](H)) connected to a "cubane" [4Fe4S](H) subcluster. Here we present an IR spectroelectrochemical study of the [FeFe] hydrogenase HydA1 isolated from the green alga Chlamydomonas reinhardtii. The enzyme shows IR bands similar to those observed for bacterial [FeFe] hydrogenases. They are assigned to the stretching vibrations of the CN(-) and CO ligands on both irons of the [2Fe](H) subcluster. By following changes in frequencies of the IR bands during electrochemical titrations, two one-electron redox processes of the active enzyme could be distinguished. The reduction of the oxidized state (H(ox)) occurred at a midpoint potential of -400 mV vs NHE (H(ox)/H(red) transition) and relates to a change of the formal oxidation state of the binuclear subcluster. A subsequent reduction (H(red)/H(sred) transition) was determined to have a midpoint potential of -460 mV vs NHE. On the basis of the IR spectra, it is suggested that the oxidation state of the binuclear subcluster does not change in this transition. Tentatively, a reduction of the [4Fe4S](H) cluster has been proposed. In contrast to the bacterial [FeFe] hydrogenases, where the bridging CO ligand becomes terminal when going from H(ox) to H(red), in HydA1 the bridging CO is present in both the H(ox) and H(red) state. The removal of the bridging CO moiety has been observed in the H(red) to H(sred) transition. The significance of this result for the hydrogen conversion mechanism of this class of enzymes is discussed.

  2. Virtual and augmented reality for training on maintenance; Realidad virutal y aumentada para la formacion en mantenimiento

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, F.


    This paper presents two projects focused to support training on maintenance using new technologies. Both projects aims at specifying. designing, developing, and demonstrating prototypes allowing computer guided maintenance of complex mechanical elements using Virtual Reality (VIRMAN) and Augmented Reality (STARMATE) techniques. VIRMAN project is dedicated to training course development on maintenance using Virtual Reality. It based in the animation of three dimension images for component assembly/de-assembly or equipment movements. STARMATE will rely on Augmented Reality techniques which is a growing area in virtual Reality research. The idea of Augmented Reality is to combine a real scene, viewed by the user, with a virtual scene generated by a computer augmenting the reality with additional information. (Author)

  3. Hyper-reality in Sebold's The Lovely Bones

    Directory of Open Access Journals (Sweden)

    Shahram Kiaei


    Full Text Available Heaven and hell are good places for creating the plot of a story because no one has ever seen these lands. They are hyper-real places because we imagine them like what we see on earth and can never imagine them as they are. Their reality is based on what we read about them in the holy books. By using Jean Baudrillad's ideas of "Hyper-reality" and "Simulacra and Simulation," the present study attempts to consider the concept of hyper-reality in Alice Sebold's The Lovely Bones (2002 in which the main character starts her life on heaven. She tries to indicate heaven as a human creation a place like earth. The writer depicts heaven as an earthly landscape and makes the readers believe that whatever they read about heaven is really true and this fact puts more emphasis on the hyper-reality of heaven in the novel. Through the story heaven is simulated as a copy of a real religious one. Thus, the heaven of the novel is a hyper-reality because as it is a copy of religious one but it has no origin. We mean the things and places as amusement parks, different American cars, magic ice creams and newspapers have no place in the real religious heaven that we read about in different holy books such as The Bible and The Holy Quran.

  4. Alleviating travel anxiety through virtual reality and narrated video technology. (United States)

    Ahn, J C; Lee, O


    This study presents an empirical evidence of benefit of narrative video clips in embedded virtual reality websites of hotels for relieving travel anxiety. Even though it was proven that virtual reality functions do provide some relief in travel anxiety, a stronger virtual reality website can be built when narrative video clips that show video clips with narration about important aspects of the hotel. We posit that these important aspects are 1. Escape route and 2. Surrounding neighborhood information, which are derived from the existing research on anxiety disorder as well as travel anxiety. Thus we created a video clip that showed and narrated about the escape route from the hotel room, another video clip that showed and narrated about surrounding neighborhood. We then conducted experiments with this enhanced virtual reality website of a hotel by having human subjects play with the website and fill out a questionnaire. The result confirms our hypothesis that there is a statistically significant relationship between the degree of travel anxiety and psychological relief caused by the use of embedded virtual reality functions with narrative video clips of a hotel website (Tab. 2, Fig. 3, Ref. 26).

  5. A Survey on Augmented Reality Challenges and Tracking

    Directory of Open Access Journals (Sweden)

    Ihsan Rabbi


    Full Text Available This survey paper presents classification of different challenges and tracking techniques in the field of Augmented Reality. The challenges in augmented reality are categorized in performance challenges, alignment challenges, interaction challenges, mobility/portability challenges and visualization challenges. Augmented reality tracking techniques are mainly divided into sensor based tracking, vision based tracking and hybrid tracking. The sensor based tracking are further divided into optical tracking, magnetic tracking, acoustic tracking, inertial tracking or any combination of these to form hybrid sensors tracking. Similarly, the vision based tracking is divided into marker based tracking and markerless tracking. Each tracking technique has its advantages and limitations. Hybrid tracking provides a robust and accurate tracking but it is costly and computationally difficulties involve.

  6. Augmented reality aiding collimator exchange at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Martínez, Héctor, E-mail: [SenseTrix, PL 20 FI-00101 Helsinki (Finland); Fabry, Thomas [European Organization for Nuclear Research, CERN, CH-1211 Genève 23 (Switzerland); Laukkanen, Seppo [SenseTrix, PL 20 FI-00101 Helsinki (Finland); Mattila, Jouni [Tampere University of Technology, PO Box 527, FI-33101 Tampere (Finland); Tabourot, Laurent [SYMME, Université de Savoie, Polytech Annecy-Chambéry, 5 chemin de Bellevue, 74944 Annecy le Vieux (France)


    Novel Augmented Reality techniques have the potential to have a large positive impact on the way remote maintenance operations are carried out in hazardous areas, e.g. areas where radiation doses that imply careful planning and optimization of maintenance operations are present. This paper describes an Augmented Reality strategy, system and implementation for aiding the remote collimator exchange in the LHC, currently the world's largest and highest-energy particle accelerator. The proposed system relies on marker detection and multi-modal augmentation in real-time. A database system has been used to ensure flexibility. The system has been tested in a mock-up facility, showing real time performance and great potential for future use in the LHC. The technical-scientific difficulties identified during the development of the system and the proposed solutions described in this paper may help the development of future Augmented Reality systems for remote handling in scientific facilities.

  7. Pedagogy: Instructivism to Socio-Constructivism through Virtual Reality

    Directory of Open Access Journals (Sweden)

    Moses O. Onyesolu


    Full Text Available learning theories evolved with time, beginning with instructivism, constructivism, to social constructivism. These theories no doubt were applied in education and they had their effects on learners. Technology advanced, created a paradigm shift by creating new ways of teaching and learning as found in virtual reality (VR. VR provided creative ways in which students learn, provides opportunity to achieve learning goals by presenting artificial environments. We developed and simulated a virtual reality system on a desktop by deploying Visual Basic.NET, Java and Macromedia Flash. This simulated environment enhanced students’ understanding by providing a degree of reality unattainable in a traditional two-dimensional interface, creating a sensory-rich interactive learning environment.

  8. Physical Reality, Theoretical Physics, and Mathematics—15 Years Later

    Directory of Open Access Journals (Sweden)

    Piret Kuusk


    Full Text Available Physicists usually admit a rather naive concept of physical reality: it is the object they are investigating using experiments understood as actions in the real world. In theoretical physics, the object of investigation is not the real world itself but its mathematical description which is considered as describing physical reality as exactly as possible. I present arguments from philosophy of science and from recent work in the theory of gravitational physics which indicate a possibility to defend also antirealistic views, and clarify in which sense both standpoints can be viable.

  9. Exploring Learning through Audience Interaction in Virtual Reality Dome Theaters (United States)

    Apostolellis, Panagiotis; Daradoumis, Thanasis

    Informal learning in public spaces like museums, science centers and planetariums is increasingly popular during the last years. Recent advancements in large-scale displays allowed contemporary technology-enhanced museums to get equipped with digital domes, some with real-time capabilities like Virtual Reality systems. By conducting extensive literature review we have come to the conclusion that little to no research has been carried out on the leaning outcomes that the combination of VR and audience interaction can provide in the immersive environments of dome theaters. Thus, we propose that audience collaboration in immersive virtual reality environments presents a promising approach to support effective learning in groups of school aged children.

  10. Realities of sustainable development

    Energy Technology Data Exchange (ETDEWEB)

    Annan, R.H.


    The author gives a brief overview of rural electrification projects which have been developed worldwide based on different forms of renewable energy sources. Rural electrification provides hope to the 1.3 billion people who are still unserved by the power grid, and as a consequence are severely disadvantaged in todays economy in most facits of daily life and health. He recommends a more concerted effort to consolidate the experiences gained from present programs in order to present a more organized program by the time of the 2002 UNCED conference. His recommendation is that the National Renewable Energy Laboratory serve as a secretariat, to gather and formalize the information which has been learned to this point in time.

  11. Virtual reality technology and applications

    CERN Document Server

    Mihelj, Matjaž; Beguš, Samo


    As virtual reality expands from the imaginary worlds of science fiction and pervades every corner of everyday life, it is becoming increasingly important for students and professionals alike to understand the diverse aspects of this technology. This book aims to provide a comprehensive guide to the theoretical and practical elements of virtual reality, from the mathematical and technological foundations of virtual worlds to the human factors and the applications that enrich our lives: in the fields of medicine, entertainment, education and others. After providing a brief introduction to the topic, the book describes the kinematic and dynamic mathematical models of virtual worlds. It explores the many ways a computer can track and interpret human movement, then progresses through the modalities that make up a virtual world: visual, acoustic and haptic. It explores the interaction between the actual and virtual environments, as well as design principles of the latter. The book closes with an examination of diff...

  12. Augmented reality building operations tool

    Energy Technology Data Exchange (ETDEWEB)

    Brackney, Larry J.


    A method (700) for providing an augmented reality operations tool to a mobile client (642) positioned in a building (604). The method (700) includes, with a server (660), receiving (720) from the client (642) an augmented reality request for building system equipment (612) managed by an energy management system (EMS) (620). The method (700) includes transmitting (740) a data request for the equipment (612) to the EMS (620) and receiving (750) building management data (634) for the equipment (612). The method (700) includes generating (760) an overlay (656) with an object created based on the building management data (634), which may be sensor data, diagnostic procedures, or the like. The overlay (656) is configured for concurrent display on a display screen (652) of the client (642) with a real-time image of the building equipment (612). The method (700) includes transmitting (770) the overlay (656) to the client (642).

  13. A SCM Reality Check

    DEFF Research Database (Denmark)

    Zachariassen, Frederik


    Purpose of this paper Drawing on meta-theoretical discussions in the discipline of management accounting, this paper seeks to discuss the notion of reality in SCM and logistics research, as this important discussion is currently missing. Four dimensions (facts, logic, values and communication......) and their impact on research are discussed in order to show the erroneous aspects of conducting research from three or less of the dimensions. Design/methodology/approach The paper is theoretical grounded. A literature review of ten top journals in SCM/logistics was carried out in order to explore previous...... discussions on reality in the SCM/logistics discipline. A SCM related paper was selected in order to illustrate the problematic aspects of not integrating all four dimensions in SCM/logistics related research. Findings As the SCM/logistics discipline is primarily founded in objectivistic approaches...

  14. Nursing as textually mediated reality. (United States)

    Cheek, J; Rudge, T


    Nursing and nursing practice both construct and are in turn constructed by the context in which they operate. Texts plays a central part in that construction. As such, nursing and nursing practice can be considered to represent a reality that is textually mediated. This paper explores the notion of nursing as a textually mediated reality and offers the reader the possibility of engaging in reflection on what implications this has for nursing and their own nursing practice. The analyses provided draw on aspects of the work of both Foucault and Derrida. Foucault's notion of discourse provides a vehicle for the exploration of nursing as textually mediated, as does Derrida's concept of binary oppositions. The paper thus illustrates some of the possibilities afforded nursing by poststructural analyses. In particular it does this by exploring one of the central textual constructions, impacting on the way that nursing and nursing practice are conceptualized, the mind/body binary opposition.

  15. Virtual Reality and Special Needs

    Directory of Open Access Journals (Sweden)

    Tara L. Jeffs


    Full Text Available The use of virtual environments for special needs is as diverse as the field of Special Educationitself and the individuals it serves. Individuals with special needs often face challenges withattention, language, spatial abilities, memory, higher reasoning and knowledge acquisition.Research in the use of Virtual Learning Environments (VLE targets both cognition and behavior(Rizzo,, 2001. Virtual environments encourage interactive learning and provide avariety of opportunities for the learner to have control over the learning process (Pantelidis,1993. Virtual reality technology is an exciting tool that involves a safe and supportive environmentto transfer knowledge between virtual and real worlds. Through such technology,individuals with special needs can look carefully at their own strengths, abilities, and learningpreferences in comparison to the required learning task and expected learning outcome. Thisarticle reviews relevant research that explores the use of virtual reality for individuals withspecial needs.

  16. Virtual Reality and Public Administration


    Tózsa, István


    This study serves as an introduction to how virtual reality systems could be applied in public administration and what research tasks would be necessary to accomplish a project. E-government solutions began to emerge in public administration approximately a decade ago all over the developed world. Administration service facilities via the Internet did not attract many customers, because of the digital divide. E-government solutions were extended to mobile devices as well, but the expected bre...

  17. Virtual Reality Enhanced Instructional Learning (United States)

    Nachimuthu, K.; Vijayakumari, G.


    Virtual Reality (VR) is a creation of virtual 3D world in which one can feel and sense the world as if it is real. It is allowing engineers to design machines and Educationists to design AV [audiovisual] equipment in real time but in 3-dimensional hologram as if the actual material is being made and worked upon. VR allows a least-cost (energy…

  18. Gene Therapy : myth or reality ?


    Fischer, Alain


    International audience; Gene therapy has become a reality, although still a fragile one. Clinical benefit has beenachieved over the last 17 years in a limited number of medical conditions for whichpathophysiological studies determined that they were favorable settings. They includeinherited disorders of the immune system, leukodystrophies, possibly hemoglobinopathies,hemophilia B, and retinal dystrophies. Advances in the treatment of B-cell leukemiasand lymphomas have also been achieved. Adva...

  19. Empirical Legality and Effective Reality

    Directory of Open Access Journals (Sweden)

    Hernán Pringe


    Full Text Available The conditions that Kant’s doctrine establishes are examined for the predication of the effective reality of certain empirical objects. It is maintained that a for such a predication, it is necessary to have not only perception but also a certain homogeneity of sensible data, and b the knowledge of the existence of certain empirical objects depends on the application of regulative principles of experience.

  20. Leadership between fiction and reality

    Directory of Open Access Journals (Sweden)

    Paul Marinescu


    Full Text Available Often, reality overtakes fiction as the real world always contains the fiction germs, the latter growing and becoming susceptible to provide unpredictable results. The individual and organisational development vectors can generate, in the future, leadership patterns difficult to anticipate at this moment. The social and economic networks, the new technologies will define different ways of communication, collaboration, management and decision-making. The nowadays leadership theories risk to become, very soon, inoperative.

  1. The ethnography of virtual reality



    This paper discusses possible application of ethnographic research in the realm of virtual reality, especially in the relationship between cultures in virtual communities. This represents an entirely new area of ethnographic research and therefore many adjustments in the research design are needed for example, a development of a specific method of data gathering and tools for their verification. A virtual, cyber space is a version of social space more or less synchronous with it, but without ...

  2. Excitation energy transfer in Chlamydomonas reinhardtii deficient in the PSI core or the PSII core under conditions mimicking state transitions. (United States)

    Wlodarczyk, Lucyna M; Dinc, Emine; Croce, Roberta; Dekker, Jan P


    The efficient use of excitation energy in photosynthetic membranes is achieved by a dense network of pigment-protein complexes. These complexes fulfill specific functions and interact dynamically with each other in response to rapidly changing environmental conditions. Here, we studied how in the intact cells of Chlamydomonas reinhardtii (C.r.) the lack of the photosystem I (PSI) core or the photosystem II (PSII) core affects these interactions. To that end the mutants F15 and M18 (both PSI-deficient) and FUD7 (PSII-deficient) were incubated under conditions known to promote state transitions in wild-type. The intact cells were then instantly frozen to 77K and the full-spectrum time-resolved fluorescence emission of the cells was measured by means of streak camera. In the PSI-deficient mutants excitation energy transfer (EET) towards light-harvesting complexes of PSI (Lhca) occurs in less than 0.5 ns, and fluorescence from Lhca decays in 3.1 ns. Decreased trapping by PSII and increased fluorescence of Lhca upon state 1 (S1)→state 2 (S2) transition appears in the F15 and less in the M18 mutant. In the PSII-deficient mutant FUD7, quenched (0.5 ns) and unquenched (2 ns) light-harvesting complexes of PSII (LHCII) are present in both states, with the quenched form more abundant in S2 than in S1. Moreover, EET of 0.4 ns from the remaining LHCII to PSI increases upon S1→S2 transition. We relate the excitation energy kinetics observed in F15, M18 and FUD7 to the remodeling of the photosynthetic apparatus in these mutants under S1 and S2 conditions.

  3. Efficient Spatiotemporal Analysis of the Flagellar Waveform of Chlamydomonas reinhardtii


    Bayly, P.V.; Lewis, B L; Kemp, P.S.; Pless, R.B.; Dutcher, S. K.


    The 9 + 2 axoneme is a microtubule-based machine that powers the oscillatory beating of cilia and flagella. Its highly regulated movement is essential for the normal function of many organs; ciliopathies cause congenital defects, chronic respiratory tract infections and infertility. We present an efficient method to obtain a quantitative description of flagellar motion, with high spatial and temporal resolution, from high speed video recording of bright field images. This highly automated tec...

  4. The Reality of Comenius Projects in Ten Catalan Educational Institutions (United States)

    Gutiérrez Colón-Plana, Mar


    This paper submits a qualitative study on different aspects of Comenius projects undertaken in ten educational centres in Catalonia during the academic year 07- 08. The objectives of this paper are to present these projects within the realities of particular school contexts, to emphasize the strengths and weaknesses of the projects, the…

  5. Exploration through Virtual Reality: Encounters with the Target Culture (United States)

    O'Brien, Mary Grantham; Levy, Richard M.


    This paper presents the results of a study on the use of a virtual reality (VR) world in a German language classroom. After participating in a lesson on the use of commands, students experienced the language and culture through navigation in a VR world. It is argued that this new medium allows for students to be immersed in the target culture and…

  6. Augmented Reality in science education – affordances for student learning

    DEFF Research Database (Denmark)

    Nielsen, Birgitte Lund; Brandt, Harald; Swensen, Hakon


    Most extant studies examining augmented reality (AR) have focused on the technology itself. This paper presents findings addressing the issue of AR for educational purposes based on a sequential survey distributed to 35 expert science teachers, ICT designers and science education researchers from...

  7. Virtual Reality in Psychological, Medical and Pedagogical Applications (United States)

    Eichenberg, Christiane, Ed.


    This book has an aim to present latest applications, trends and developments of virtual reality technologies in three humanities disciplines: in medicine, psychology and pedagogy. Studies show that people in both educational as well as in the medical therapeutic range expect more and more that modern media are included in the corresponding demand…

  8. Virtual Reality in the Teaching of the Technical Drawing. (United States)

    Gomez, Luis Alberto; Lemos, David; Carlos de Souza, Antonio; Speck, Henderson Jose

    This paper proposes the use of the Virtual Reality Modeling Language (VRML) language for teaching technical drawing projections. Three dimensional models and exercises are left to students over the Internet substituting the old wood models in the classroom. An introduction to the VRML language is presented. A detailed description on how models are…

  9. Virtual Reality as a Tool in the Education (United States)

    Piovesan, Sandra Dutra; Passerino, Liliana Maria; Pereira, Adriana Soares


    The virtual reality is being more and more used in the education, enabling the student to find out, to explore and to build his own knowledge. This paper presents an Educational Software for presence or distance education, for subjects of Formal Language, where the student can manipulate virtually the target that must be explored, analyzed and…

  10. Sulphate, more than a nutrient, protects the microalga Chlamydomonas moewusii from cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Mera, Roi; Torres, Enrique, E-mail:; Abalde, Julio


    Highlights: • Sulphate effect on cadmium toxicity in the microalga Chlamydomonas moewusii Gerloff. • Cadmium increases the sulphur requirements in Chlamydomonas moewusii. • Kinetic coefficients for sulphate utilization and cadmium effect on them. • Sulphate and cadmium influence on the biosynthesis of low-molecular mass thiols. • Cadmium toxicity reduction by sulphate due to higher biosynthesis of thiols. - Abstract: Sulphur is an essential macroelement that plays important roles in living organisms. The thiol rich sulphur compounds, such as cysteine, γ-Glu–Cys, glutathione and phytochelatins participate in the tolerance mechanisms against cadmium toxicity. Plants, algae, yeasts and most prokaryotes cover their demand for reduced sulphur by reduction of inorganic sulphate. The aim of this study was to investigate, using a bifactorial experimental design, the effect of different sulphate concentrations in the nutrient solution on cadmium toxicity in the freshwater microalga Chlamydomonas moewusii. Cell growth, kinetic parameters of sulphate utilization and intracellular concentrations of low-molecular mass thiol compounds were determined. A mathematical model to describe the growth of this microalga based on the effects of sulphate and cadmium was obtained. An ANOVA revealed an interaction between them, 16% of the effect sizes was explained by this interaction. A higher amount of sulphate in the culture medium allowed a higher cadmium tolerance due to an increase in the thiol compound biosynthesis. The amount of low-molecular mass thiol compounds, mainly phytochelatins, synthesized by this microalga was significantly dependent on the sulphate and cadmium concentrations; the higher phytochelatin content was obtained in cultures with 4 mg Cd/L and 1 mM sulphate. The maximum EC{sub 50} value (based on nominal cadmium concentration) reached for this microalga was 4.46 ± 0.42 mg Cd/L when the sulphate concentration added to the culture medium was also 1 m

  11. Reality in Virtual Learning

    DEFF Research Database (Denmark)

    Lindberg, Frank; Pettersson, Michael

    and develop understandings of what it might mean to be a student when learning occurs within a virtual problem based learning landscape. When students are used to the traditional classroom, challenges appear in the twilight zone between two pedagogical practices. How do the students cope with challenges...... that a new virtual program demands, and what paradoxes and ambiguities appear when old learning processes do not work anymore? The present focus reflects an existential-phenomenological point of departure. This perspective is based on the philosophical writings of Søren Kierkegaard and Martin Heidegger (1927....../1996; "Being and Time"), and the successors Hans-Georg Gadamer and Paul Ricoeur. The work is also inspired of the father of culturalism - Jerome Bruner (1996) and Wenger's (1998) community of practice. Thompson (1997) is an inspiration through his initiator of hermeneutical endeavor within consumer research...

  12. Treating cockroach phobia with augmented reality. (United States)

    Botella, Cristina; Bretón-López, Juani; Quero, Soledad; Baños, Rosa; García-Palacios, Azucena


    In vivo exposure is the recommended treatment of choice for specific phobias; however, it demonstrates a high attrition rate and is not effective in all instances. The use of virtual reality (VR) has improved the acceptance of exposure treatments to some individuals. Augmented reality (AR) is a variation of VR wherein the user sees the real world augmented by virtual elements. The present study tests an AR system in the short (posttreatment) and long term (3, 6, and 12 months) for the treatment of cockroach phobia using a multiple baseline design across individuals (with 6 participants). The AR exposure therapy was applied using the "one-session treatment" guidelines developed by Ost, Salkovskis, and Hellström (1991). Results showed that AR was effective at treating cockroach phobia. All participants improved significantly in all outcome measures after treatment; furthermore, the treatment gains were maintained at 3, 6, and 12-month follow-up periods. This study discusses the advantages of AR as well as its potential applications.

  13. Modeling Reality - How Computers Mirror Life (United States)

    Bialynicki-Birula, Iwo; Bialynicka-Birula, Iwona


    The bookModeling Reality covers a wide range of fascinating subjects, accessible to anyone who wants to learn about the use of computer modeling to solve a diverse range of problems, but who does not possess a specialized training in mathematics or computer science. The material presented is pitched at the level of high-school graduates, even though it covers some advanced topics (cellular automata, Shannon's measure of information, deterministic chaos, fractals, game theory, neural networks, genetic algorithms, and Turing machines). These advanced topics are explained in terms of well known simple concepts: Cellular automata - Game of Life, Shannon's formula - Game of twenty questions, Game theory - Television quiz, etc. The book is unique in explaining in a straightforward, yet complete, fashion many important ideas, related to various models of reality and their applications. Twenty-five programs, written especially for this book, are provided on an accompanying CD. They greatly enhance its pedagogical value and make learning of even the more complex topics an enjoyable pleasure.

  14. The educational possibilities of Augmented Reality

    Directory of Open Access Journals (Sweden)

    Julio Cabero Almenara


    Full Text Available A large number of emergent technologies have been acquiring a strong impulse in recent years. One of these emergent technologies is Augmented Reality (RA, which will surely have a high level of penetration into all our educational centers, including universities, in the next 3 to 5 years, as a number of different reports have already highlighted. The present paper shows various elements which, in our opinion, play an essential role when it comes to the incorporation of Augmented Reality into teaching, stressing the fact that this incorporation should not entail a technological problem but an educational and didactic issue. A mention is additionally made of several studies which have been performed with regard to the didactic exploitation of this emergent technology, as well as to the potential that it offers us. Our study forms part of an R&D&I initiative undertaken within the framework of the Plan Estatal de Fomento de la Investigación Científica y Técnica de Excelencia 2013-2016 [2013-16 State (National Plan for the Promotion of Excellence Scientific and Technical Research], with reference EDU2014-57446-P.

  15. Visually representing reality: aesthetics and accessibility aspects (United States)

    van Nes, Floris L.


    This paper gives an overview of the visual representation of reality with three imaging technologies: painting, photography and electronic imaging. The contribution of the important image aspects, called dimensions hereafter, such as color, fine detail and total image size, to the degree of reality and aesthetic value of the rendered image are described for each of these technologies. Whereas quite a few of these dimensions - or approximations, or even only suggestions thereof - were already present in prehistoric paintings, apparent motion and true stereoscopic vision only recently were added - unfortunately also introducing accessibility and image safety issues. Efforts are made to reduce the incidence of undesirable biomedical effects such as photosensitive seizures (PSS), visually induced motion sickness (VIMS), and visual fatigue from stereoscopic images (VFSI) by international standardization of the image parameters to be avoided by image providers and display manufacturers. The history of this type of standardization, from an International Workshop Agreement to a strategy for accomplishing effective international standardization by ISO, is treated at some length. One of the difficulties to be mastered in this process is the reconciliation of the, sometimes opposing, interests of vulnerable persons, thrill-seeking viewers, creative video designers and the game industry.

  16. Virtual manufacturing in reality (United States)

    Papstel, Jyri; Saks, Alo


    SMEs play an important role in manufacturing industry. But from time to time there is a shortage in resources to complete the particular order in time. Number of systems is introduced to produce digital information in order to support product and process development activities. Main problem is lack of opportunity for direct data transition within design system modules when needed temporary extension of design capacity (virtuality) or to implement integrated concurrent product development principles. The planning experience in the field is weakly used as well. The concept of virtual manufacturing is a supporting idea to solve this problem. At the same time a number of practical problems should be solved like information conformity, data transfer, unified technological concepts acceptation etc. In the present paper the proposed ways to solve the practical problems of virtual manufacturing are described. General objective is to introduce the knowledge-based CAPP system as missing module for Virtual Manufacturing in the selected product domain. Surface-centered planning concept based on STEP- based modeling principles, and knowledge-based process planning methodology will be used to gain the objectives. As a result the planning module supplied by design data with direct access, and supporting advising environment is expected. Mould producing SME would be as test basis.

  17. Biotechnology: reality or dream

    Directory of Open Access Journals (Sweden)

    Konstantinov Kosana


    foreign gene with a genome of an integrated organism. Also application of biotechnology provides transfer of one or several favorable genes from any evolutionary category into other category of an organism and in such a way it is possible to develop genetically modified organisms (GMO having expressed desired, target traits. A survey of the application of biotechnology in the world and our country is presented in this paper.

  18. Dynamic curvature regulation accounts for the symmetric and asymmetric beats of Chlamydomonas flagella

    CERN Document Server

    Sartori, Pablo; Scholich, Andre; Jülicher, Frank; Howard, Jonathon


    Axonemal dyneins are the molecular motors responsible for the beating of cilia and flagella. These motors generate sliding forces between adjacent microtubule doublets within the axoneme, the motile cytoskeletal structure inside the flagellum. To create regular, oscillatory beating patterns, the activities of the axonemal dyneins must be coordinated both spatially and temporally. It is thought that coordination is mediated by stresses or strains that build up within the moving axoneme, but it is not known which components of stress or strain are involved, nor how they feed back on the dyneins. To answer this question, we used isolated, reactivate axonemes of the unicellular alga Chlamydomonas as a model system. We derived a theory for beat regulation in a two-dimensional model of the axoneme. We then tested the theory by measuring the beat waveforms of wild type axonemes, which have asymmetric beats, and mutant axonemes, in which the beat is nearly symmetric, using high-precision spatial and temporal imaging....

  19. Kinesin-II is not essential for mitosis and cell growth in Chlamydomonas. (United States)

    Matsuura, Kumi; Lefebvre, Paul A; Kamiya, Ritsu; Hirono, Masafumi


    The FLA10 gene product (Fla10p) in Chlamydomonas, a heterotrimeric kinesin-II, plays a crucial role in flagellar assembly as a motor protein driving intraflagellar transport. This protein has also been suggested to play a role in mitosis based on its localization to mitotic spindle. A role for Fla10p in mitosis has been difficult to test because to date only conditional (temperature-sensitive) mutant alleles were available, and it is not known whether these retain residual function for mitosis at the non-permissive temperature. In this report, we describe a null allele of fla10 produced by insertional mutagenesis. This mutant does not assemble flagella, but proliferates at a rate identical to that of wild type cells. Observation of microtubule organization in the cell body revealed that normal mitotic spindles are formed in dividing mutant cells. Thus, we conclude that FLA10 kinesin plays no significant roles in mitosis.

  20. Inhomogeneous distribution of Chlamydomonas in a cylindrical container with a bubble plume. (United States)

    Nonaka, Yuki; Kikuchi, Kenji; Numayama-Tsuruta, Keiko; Kage, Azusa; Ueno, Hironori; Ishikawa, Takuji


    Swimming microalgae show various taxes, such as phototaxis and gravitaxis, which sometimes result in the formation of a cell-rich layer or a patch in a suspension. Despite intensive studies on the effects of shear flow and turbulence on the inhomogeneous distribution of microalgae, the effect of a bubble plume has remained unclear. In this study, we used Chlamydomonas as model microalgae, and investigated the spatial distribution of cells in a cylindrical container with a bubble plume. The results illustrate that cells become inhomogeneously distributed in the suspension due to their motility and photo-responses. A vortical ring distribution was observed below the free surface when the bubble flow rate was sufficiently small. We performed a scaling analysis on the length scale of the vortical ring, which captured the main features of the experimental results. These findings are important in understanding transport phenomena in a microalgae suspension with a bubble plume.

  1. Trichloroacetate affects the EPR SignalⅡslow and SignalⅠin the thylakoid of Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)


    One electron paramagnetic resonance (EPR) signal, named SignalⅡslow, originates from the oxidized Tyrosine 160 (YDo) of D2 polypeptide of photosystemⅡ reaction center. After adding high concentration trichloroacetate (TCA) to the Chlamydomonas reinhardtii thylakoid suspension, this signal was abolished in a minute. Treatment of TCA also removes a few of polypeptides, including three extrinsic polypeptides of oxygen-evolving complex, from the thylakoid membrane. Based upon the analysis of the microenvironment around YD with a three-dimensional model, it is indicated that relatively high hydrophobicity of this microenvironment may be the essential prerequisite for TCA to affect YD. It has been observed that TCA treatment also retards the decay of the SignalⅠ, produced by the oxidized reaction center chlorophyll dimer (P700+) of photosys- temⅠ.

  2. A chloroplast pathway for the de novo biosynthesis of triacylglycerol in Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Fan, J.; Xu, C.; Andre, C.


    Neutral lipid metabolism has been extensively studied in yeast, plants and mammals. In contrast, little information is available regarding the biochemical pathway, enzymes and regulatory factors involved in the biosynthesis of triacylglycerol (TAG) in microalgae. In the conventional TAG biosynthetic pathway widely accepted for yeast, plants and mammals, TAG is assembled in the endoplasmic reticulum (ER) from its immediate precursor diacylglycerol (DAG) made by ER-specific acyltransferases, and is deposited exclusively in lipid droplets in the cytosol. Here, we demonstrated that the unicellular microalga Chlamydomonas reinhardtii employs a distinct pathway that uses DAG derived almost exclusively from the chloroplast to produce TAG. This unique TAG biosynthesis pathway is largely dependent on de novo fatty acid synthesis, and the TAG formed in this pathway is stored in lipid droplets in both the chloroplast and the cytosol. These findings have wide implications for understanding TAG biosynthesis and storage and other areas of lipid metabolism in microalgae and other organisms.

  3. Quantification of phytochelatins in Chlamydomonas reinhardtii using ferrocene-based derivatization. (United States)

    Bräutigam, Anja; Bomke, Susanne; Pfeifer, Thorben; Karst, Uwe; Krauss, Gerd-Joachim; Wesenberg, Dirk


    A method for the identification and quantification of canonic and isoforms of phytochelatins (PCs) from Chlamydomonas reinhardtii was developed. After disulfide reduction with tris(2-carboxyethyl)phosphine (TCEP) PCs were derivatized with ferrocenecarboxylic acid (2-maleimidoyl)ethylamide (FMEA) in order to avoid oxidation of the free thiol functions during analysis. Liquid chromatography (LC) coupled to electrospray mass spectrometry (ESI-MS) and inductively coupled plasma-mass spectrometry (ICP-MS) was used for rapid and quantitative analysis of the precolumn derivatized PCs. PC(2-4), CysGSH, CysPC(2-4), CysPC(2)desGly, CysPC(2)Glu and CysPC(2)Ala were determined in the algal samples depending on the exposure of the cells to cadmium ions.

  4. Investigating the link between fermentative metabolism and hydrogen production in the unicellular green alga Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, S.J.; Nixon, P.J. [Imperial College London (United Kingdom)


    In the model green alga Chlamydomonas reinhardtii, the electrons required for hydrogen production can come from both the biophotolysis of water and from the fermentation of carbohydrate reserves. Anoxia leads to the activation of several fermentative pathways, which produce a number of end products including formic, malic and acetic acid along with ethanol, carbon dioxide and hydrogen. It has been proposed that by switching off competing fermentative pathways hydrogen production can be increased. Therefore the aim of this study was to devise an experimental strategy to down-regulate the expression of enzymes thought to control C. reinhardtii's fermentative metabolism. We demonstrate here that it is possible to use artificial microRNA (amiRNA) technology to generate knock-down mutants with reduced expression of pyruvate formate lyase (PFL1), a key fermentative enzyme in C. reinhardtii. This work opens up new possibilities to improve hydrogen yields through metabolic engineering. (orig.)

  5. Stable expression of a bifunctional diterpene synthase in the chloroplast of Chlamydomonas reinhardtii

    DEFF Research Database (Denmark)

    Zedler, Julie A Z; Gangl, Doris; Hamberger, Björn Robert;


    Chlamydomonas reinhardtii has been shown to hold significant promise as a production platform for recombinant proteins, but transformation of the nuclear genome is still a non-trivial process due to random gene insertion and frequent silencing. Insertion of transgenes into the chloroplasts...... is an alternative strategy, and we report here the stable expression of a large (91 kDa) protein in the chloroplast using a recently developed low-cost transformation protocol. Moreover, selection of transformants is based on restoration of prototrophy using an endogenous gene (psbH) as the marker, thereby allowing...... the generation of transgenic lines without the use of antibiotic-resistance genes. Here, we have expressed a bifunctional diterpene synthase in C. reinhardtii chloroplasts. Homoplasmic transformants were obtained with the expressed enzyme accounting for 3.7 % of total soluble protein. The enzyme was purified...

  6. DNA-free two-gene knockout in Chlamydomonas reinhardtii via CRISPR-Cas9 ribonucleoproteins. (United States)

    Baek, Kwangryul; Kim, Duk Hyoung; Jeong, Jooyeon; Sim, Sang Jun; Melis, Anastasios; Kim, Jin-Soo; Jin, EonSeon; Bae, Sangsu


    Microalgae are versatile organisms capable of converting CO2, H2O, and sunlight into fuel and chemicals for domestic and industrial consumption. Thus, genetic modifications of microalgae for enhancing photosynthetic productivity, and biomass and bio-products generation are crucial for both academic and industrial applications. However, targeted mutagenesis in microalgae with CRISPR-Cas9 is limited. Here we report, a one-step transformation of Chlamydomonas reinhardtii by the DNA-free CRISPR-Cas9 method rather than plasmids that encode Cas9 and guide RNAs. Outcome was the sequential CpFTSY and ZEP two-gene knockout and the generation of a strain constitutively producing zeaxanthin and showing improved photosynthetic productivity.

  7. Effective viscosity of non-gravitactic Chlamydomonas Reinhardtii microswimmer suspensions

    CERN Document Server

    Mussler, Matthias; Peyla, Philippe; Wagner, Christian


    Active microswimmers are known to affect the macroscopic viscosity of suspensions in a more complex manner than passive particles. For puller-like microswimmers an increase in the viscosity has been observed. It has been suggested that the persistence of the orientation of the microswimmers hinders the rotation that is normally caused by the vorticity. It was previously shown that some sorts of algaes are bottom-heavy swimmers, i.e. their centre of mass is not located in the centre of the body. In this way, the algae affects the vorticity of the flow when it is perpendicular oriented to the axis of gravity. This orientation of gravity to vorticity is given in a rheometer that is equipped with a cone-plate geometry. Here we present measurements of the viscosity both in a cone-plate and a Taylor-Couette cell. The two set-ups yielded the same increase in viscosity although the axis of gravitation in the Taylor-Couette cell is parallel to the direction of vorticity. In a complementary experiment we tested the ori...

  8. Zinc Deficiency Impacts CO2 Assimilation and Disrupts Copper Homeostasis in Chlamydomonas reinhardtii* (United States)

    Malasarn, Davin; Kropat, Janette; Hsieh, Scott I.; Finazzi, Giovanni; Casero, David; Loo, Joseph A.; Pellegrini, Matteo; Wollman, Francis-André; Merchant, Sabeeha S.


    Zinc is an essential nutrient because of its role in catalysis and in protein stabilization, but excess zinc is deleterious. We distinguished four nutritional zinc states in the alga Chlamydomonas reinhardtii: toxic, replete, deficient, and limited. Growth is inhibited in zinc-limited and zinc-toxic cells relative to zinc-replete cells, whereas zinc deficiency is visually asymptomatic but distinguished by the accumulation of transcripts encoding ZIP family transporters. To identify targets of zinc deficiency and mechanisms of zinc acclimation, we used RNA-seq to probe zinc nutrition-responsive changes in gene expression. We identified genes encoding zinc-handling components, including ZIP family transporters and candidate chaperones. Additionally, we noted an impact on two other regulatory pathways, the carbon-concentrating mechanism (CCM) and the nutritional copper regulon. Targets of transcription factor Ccm1 and various CAH genes are up-regulated in zinc deficiency, probably due to reduced carbonic anhydrase activity, validated by quantitative proteomics and immunoblot analysis of Cah1, Cah3, and Cah4. Chlamydomonas is therefore not able to grow photoautotrophically in zinc-limiting conditions, but supplementation with 1% CO2 restores growth to wild-type rates, suggesting that the inability to maintain CCM is a major consequence of zinc limitation. The Crr1 regulon responds to copper limitation and is turned on in zinc deficiency, and Crr1 is required for growth in zinc-limiting conditions. Zinc-deficient cells are functionally copper-deficient, although they hyperaccumulate copper up to 50-fold over normal levels. We suggest that zinc-deficient cells sequester copper in a biounavailable form, perhaps to prevent mismetallation of critical zinc sites. PMID:23439652

  9. A revised mineral nutrient supplement increases biomass and growth rate in Chlamydomonas reinhardtii (United States)

    Kropat, Janette; Hong-Hermesdorf, Anne; Casero, David; Ent, Petr; Castruita, Madeli; Pellegrini, Matteo; Merchant, Sabeeha S.; Malasarn, Davin


    Summary Interest in exploiting algae as a biofuel source and the role of inorganic nutrient deficiency in inducing triacylglyceride (TAG) accumulation in cells necessitates a strategy to efficiently formulate species-specific culture media that can easily be manipulated. Using the reference organism Chlamydomonas reinhardtii, we tested the hypothesis that modeling trace element supplements after the cellular ionome would result in optimized cell growth. We determined the trace metal content of several commonly used Chlamydomonas strains in various culture conditions and developed a revised trace element solution to parallel these measurements. Comparison of cells growing in the revised supplement versus a traditional trace element solution revealed faster growth rates and higher maximum cell densities with the revised recipe. RNA-seq analysis of cultures growing in the traditional versus revised medium suggest that the variation in transcriptomes was smaller than that found between different wild-type strains grown in traditional Hutner’s supplement. Visual observation did not reveal defects in cell motility or mating efficiency in the new supplement. Ni2+-inducible expression from the CYC6 promoter remained a useful tool, albeit with an increased requirement for Ni2+ because of the introduction of an EDTA buffer system in the revised medium. Other advantages include more facile preparation of trace element stock solutions, a reduction in total chemical use, a more consistent batch-to-batch formulation, and long-term stability (tested up to 5 years). Under the new growth regime, we analyzed cells growing under different macro- and micronutrient-deficiencies. TAG accumulation in N deficiency is comparable in the new medium. Fe and Zn deficiency also induced TAG accumulation, as suggested by Nile Red staining. This approach can be used to efficiently optimize culture conditions for other algal species to improve growth and to assay cell physiology. PMID:21309872

  10. CO2 acquisition in Chlamydomonas acidophila is influenced mainly by CO2, not phosphorus, availability. (United States)

    Spijkerman, Elly; Stojkovic, Slobodanka; Beardall, John


    The extremophilic green microalga Chlamydomonas acidophila grows in very acidic waters (pH 2.3-3.4), where CO2 is the sole inorganic carbon source. Previous work has revealed that the species can accumulate inorganic carbon (Ci) and exhibits high affinity CO2 utilization under low-CO2 (air-equilibrium) conditions, similar to organisms with an active CO2 concentrating mechanism (CCM), whereas both processes are down-regulated under high CO2 (4.5 % CO2) conditions. Responses of this species to phosphorus (Pi)-limited conditions suggested a contrasting regulation of the CCM characteristics. Therefore, we measured external carbonic anhydrase (CAext) activities and protein expression (CAH1), the internal pH, Ci accumulation, and CO2-utilization in cells adapted to high or low CO2 under Pi-replete and Pi-limited conditions. Results reveal that C. acidophila expressed CAext activity and expressed a protein cross-reacting with CAH1 (the CAext from Chlamydomonas reinhardtii). Although the function of this CA remains unclear, CAext activity and high affinity CO2 utilization were the highest under low CO2 conditions. C. acidophila accumulated Ci and expressed the CAH1 protein under all conditions tested, and C. reinhardtii also contained substantial amounts of CAH1 protein under Pi-limitation. In conclusion, Ci utilization is optimized in C. acidophila under ecologically relevant conditions, which may enable optimal survival in its extreme Ci- and Pi-limited habitat. The exact physiological and biochemical acclimation remains to be further studied.

  11. Survival and proliferation characteristics of the microalga Chlamydomonas sp. ICE-L after hypergravitational stress pretreatment (United States)

    Gao, Zhengquan; Li, Demao; Meng, Chunxiao; Xu, Dong; Zhang, Xiaowen; Ye, Naihao


    Seeking extraterrestrial life, transferring between planets, even migrating to other planets attracts more and more attention of public and scientists. However, to make it clear for the ability to survive the forces studies is prerequisite to enable the speculations by natural means. Gravity is a critical force involved in all the life on Earth and, possibly, others planets. Organisms have been grown in microgravity habitats and in centrifuges to characterize the biological response to a range of gravitational forces and radiation levels in space and on Earth. However, little is known about the profiles of eukaryotic life under conditions of hyperacceleration attributable to extreme gravities. In this study, a eukaryotic extremophile, the Antarctic green microalga Chlamydomonas sp. ICE-L, showed amazing proliferation capacity during and after hypergravitational stress for 30 min to 48 h at 110,200, 423,400, and 670,800g. These extreme gravities also had profound effects on viability, reproduction rate, photosynthesis efficiency, and gene transcriptional expression of this microalga. Most notably, all three supergravities efficiently stimulated algal cell division, but the greater the centrifugal force and the longer the duration of treatment, the lower the viable rate and breeding potential of samples in the following incubation. These results illustrated Chlamydomonas sp. ICE-L is a useful eukaryotic model system candidate for space research. Further studies could provide new insight into the physical limits of life and its evolution and enhance the possibility for interstellar space travel and the quest for extraterrestrial life according to panspermia theory. Also, it indicated that life come from the outer space is not always prokaryotes but may be eukaryotes.

  12. A Chlamydomonas-derived Human Papillomavirus 16 E7 vaccine induces specific tumor protection.

    Directory of Open Access Journals (Sweden)

    Olivia C Demurtas

    Full Text Available BACKGROUND: The E7 protein of the Human Papillomavirus (HPV type 16, being involved in malignant cellular transformation, represents a key antigen for developing therapeutic vaccines against HPV-related lesions and cancers. Recombinant production of this vaccine antigen in an active form and in compliance with good manufacturing practices (GMP plays a crucial role for developing effective vaccines. E7-based therapeutic vaccines produced in plants have been shown to be active in tumor regression and protection in pre-clinical models. However, some drawbacks of in whole-plant vaccine production encouraged us to explore the production of the E7-based therapeutic vaccine in Chlamydomonas reinhardtii, an organism easy to grow and transform and fully amenable to GMP guidelines. METHODOLOGY/PRINCIPAL FINDINGS: An expression cassette encoding E7GGG, a mutated, attenuated form of the E7 oncoprotein, alone or as a fusion with affinity tags (His6 or FLAG, under the control of the C. reinhardtii chloroplast psbD 5' UTR and the psbA 3' UTR, was introduced into the C. reinhardtii chloroplast genome by homologous recombination. The protein was mostly soluble and reached 0.12% of total soluble proteins. Affinity purification was optimized and performed for both tagged forms. Induction of specific anti-E7 IgGs and E7-specific T-cell proliferation were detected in C57BL/6 mice vaccinated with total Chlamydomonas extract and with affinity-purified protein. High levels of tumor protection were achieved after challenge with a tumor cell line expressing the E7 protein. CONCLUSIONS: The C. reinhardtii chloroplast is a suitable expression system for the production of the E7GGG protein, in a soluble, immunogenic form. The production in contained and sterile conditions highlights the potential of microalgae as alternative platforms for the production of vaccines for human uses.

  13. Light-harvesting complex II (LHCII) and its supramolecular organization in Chlamydomonas reinhardtii. (United States)

    Drop, Bartlomiej; Webber-Birungi, Mariam; Yadav, Sathish K N; Filipowicz-Szymanska, Alicja; Fusetti, Fabrizia; Boekema, Egbert J; Croce, Roberta


    LHCII is the most abundant membrane protein on earth. It participates in the first steps of photosynthesis by harvesting sunlight and transferring excitation energy to the core complex. Here we have analyzed the LHCII complex of the green alga Chlamydomonas reinhardtii and its association with the core of Photosystem II (PSII) to form multiprotein complexes. Several PSII supercomplexes with different antenna sizes have been purified, the largest of which contains three LHCII trimers (named S, M and N) per monomeric core. A projection map at a 13Å resolution was obtained allowing the reconstruction of the 3D structure of the supercomplex. The position and orientation of the S trimer are the same as in plants; trimer M is rotated by 45° and the additional trimer (named here as LHCII-N), which is taking the position occupied in plants by CP24, is directly associated with the core. The analysis of supercomplexes with different antenna sizes suggests that LhcbM1, LhcbM2/7 and LhcbM3 are the major components of the trimers in the PSII supercomplex, while LhcbM5 is part of the "extra" LHCII pool not directly associated with the supercomplex. It is also shown that Chlamydomonas LHCII has a slightly lower Chlorophyll a/b ratio than the complex from plants and a blue shifted absorption spectrum. Finally the data indicate that there are at least six LHCII trimers per dimeric core in the thylakoid membranes, meaning that the antenna size of PSII of C. reinhardtii is larger than that of plants.

  14. Research on key techniques of virtual reality applied in mining industry

    Institute of Scientific and Technical Information of China (English)

    LIAO Jun; LU Guo-bin


    Based on the applications of virtual reality technology in many fields, introduced the virtual reality technical basic concept, structure type, related technique development, etc., tallied up applications of virtual reality technique in the present mining industry, inquired into core techniques related software and hardware, especially the optimization in the setup of various 3D models technique, and carried out a virtual scene to travel extensively in real-time by stereoscopic manifestation technique and so on. Then it brought forward the solution of virtual reality technique with software and hardware to the mining industry that can satisfy the demand of different aspects and levers. Finally, it show a fine prospect of virtual reality technique applied in the mining industry.

  15. InAR:Inverse Augmented Reality


    Hu, Hao; Cui, Hainan


    Augmented reality is the art to seamlessly fuse virtual objects into real ones. In this short note, we address the opposite problem, the inverse augmented reality, that is, given a perfectly augmented reality scene where human is unable to distinguish real objects from virtual ones, how the machine could help do the job. We show by structure from motion (SFM), a simple 3D reconstruction technique from images in computer vision, the real and virtual objects can be easily separated in the recon...

  16. Augmented Reality for Maintenance and Repair (ARMAR) (United States)


    The purpose of this research, Augmented Reality for Maintenance and Repair (ARMAR), was to research the design and development of experimental... augmented reality systems for maintenance job aiding. The goal was to explore and evaluate the feasibility of developing prototype adaptive augmented ... reality systems that can be used to investigate how real time computer graphics, overlaid on and registered with the actual equipment being maintained, can

  17. Quantum mechanics and elements of reality


    Mohrhoff, Ulrich


    It is widely accepted that a Born probability of 1 is sufficient for the existence of a corresponding element of reality. Recently Vaidman has extended this idea to the ABL probabilities of the time-symmetrized version of quantum mechanics originated by Aharonov, Bergmann, and Lebowitz. Several authors have objected to Vaidman's time-symmetrized elements of reality without casting doubt on the widely accepted sufficiency condition for `ordinary' elements of reality. In this paper I show that ...

  18. An electrophysiological dissociation between orbitofrontal reality filtering and context source monitoring. (United States)

    Bouzerda-Wahlen, Aurélie; Nahum, Louis; Liverani, Maria Chiara; Guggisberg, Adrian G; Schnider, Armin


    Memory influences behavior in multiple ways. One important aspect is to remember in what precise context in the past a piece of information was acquired (context source monitoring). Another important aspect is to sense whether an upcoming thought, composed of fragments of memories, refers to present reality and can be acted upon (orbitofrontal reality filtering). Whether these memory control processes share common underlying mechanisms is unknown. Failures of both have been held accountable for false memories, including confabulation. Electrophysiological and imaging studies suggest a dissociation but used very different paradigms. In this study, we juxtaposed the requirements of context source monitoring and reality filtering within a unique continuous recognition task, which healthy participants performed while high-resolution evoked potentials were recorded. The mechanisms dissociated both behaviorally and electrophysiologically: Reality filtering induced a frontal positivity, absence of a specific electrocortical configuration, and posterior medial orbitofrontal activity at 200-300 msec. Context source monitoring had no electrophysiological expression in this early period. It was slower and less accurate than reality filtering and induced a prolonged positive potential over frontal leads starting at 400 msec. The study demonstrates a hitherto unrecognized separation between orbitofrontal reality filtering and source monitoring. Whereas deficient orbitofrontal reality filtering is associated with reality confusion in thinking, the behavioral correlates of deficient source monitoring should be verified with controlled experimental exploration.

  19. ARLearn and StreetLearn software for virtual reality and augmented reality multi user learning games

    NARCIS (Netherlands)

    Ternier, Stefaan; Klemke, Roland


    Ternier, S., & Klemke, R. (2011). ARLearn and StreetLearn software for virtual reality and augmented reality multi user learning games (Version 1.0) [Computer software]. Heerlen, The Netherlands: Open Universiteit in the Netherlands.

  20. ARLearn and StreetLearn software for virtual reality and augmented reality multi user learning games

    NARCIS (Netherlands)

    Ternier, Stefaan; Klemke, Roland


    Ternier, S., & Klemke, R. (2011). ARLearn and StreetLearn software for virtual reality and augmented reality multi user learning games (Version 1.0) [Software Documentation]. Heerlen, The Netherlands: Open Universiteit in the Netherlands.

  1. Virtual Reality for Materials Design Laboratory (United States)

    Federal Laboratory Consortium — The purpose is to research and develop materials through applied virtual reality to enable interactive "materials-by-design." Extensive theoretical and computational...

  2. Reality show: um paradoxo nietzschiano

    Directory of Open Access Journals (Sweden)

    Ilana Feldman


    Full Text Available

    O fenômeno dos reality shows - e a subseqüente relação entre imagem e verdade - assenta-se sobre uma série de paradoxos. Tais paradoxos podem ser compreendidos à luz do pensamento do filósofo alemão Friedrich Nietzsche, que, através dos usos de formulações paradoxais, concebia a realidade como um mundo de pura aparência e a verdade como um acréscimo ficcional, como um efeito. A ficção é então tomada, na filosofia de Nietzsche, não em seu aspecto falsificante e desrealizador - como sempre pleiteou nossa tradição metafísica -, mas como condição necessária para que certa espécie de invenção possa operar como verdade. Sendo assim, a própria expressão reality show, através de sua formulação paradoxal, engendra explicitamente um mundo de pura aparência, em que a verdade, a parte reality da proposição, é da ordem do suplemento, daquilo que se acrescenta ficcionalmente - como um adjetivo - a show. O ornamento, nesse caso, passa a ocupar o lugar central, apontando para o efeito produzido: o efeito-de-verdade. Seguindo, então, o pensamento nietzschiano e sua atualização na contemporaneidade, investigaremos de que forma os televisivos “shows de realidade” operam paradoxalmente, em consonância com nossas paradoxais práticas culturais.

  3. Responsibility of regulatory gene expression and repressed protein synthesis for triacylglycerol accumulation on sulfur-starvation in Chlamydomonas reinhardtii



    Triacylglycerol (TG) synthesis is induced for energy and carbon storage in algal cells under nitrogen(N)-starved conditions, and helps prevent reactive oxygen species (ROS) production through fatty acid synthesis that consumes excessive reducing power. Here, the regulatory mechanism for the TG content in sulfur(S)-starved cells of Chlamydomonas reinhardtii was examined, in comparison to that in N- or phosphorus(P)-starved cells. S- and N- starved cells exhibited markedly increased TG contents...

  4. Poster: Virtual reality interaction using mobile devices

    KAUST Repository

    Aseeri, Sahar A.


    In this work we aim to implement and evaluate alternative approaches for interacting with virtual environments on mobile devices for navigation, object selection and manipulation. Interaction with objects in virtual worlds using traditional input such as current state-of-the-art devices is often difficult and could diminish the immersion and sense of presence when it comes to 3D virtual environment tasks. We have developed new methods to perform different kinds of interactions using a mobile device (e.g. a smartphone) both as input device, performing selection and manipulation of objects, and as output device, utilizing the screen as an extra view (virtual camera or information display). Our hypothesis is that interaction via mobile devices facilitates simple tasks like the ones described within immersive virtual reality systems. We present here our initial implementation and result. © 2013 IEEE.

  5. Skin Bioprinting: Impending Reality or Fantasy? (United States)

    Ng, Wei Long; Wang, Shuai; Yeong, Wai Yee; Naing, May Win


    Bioprinting provides a fully automated and advanced platform that facilitates the simultaneous and highly specific deposition of multiple types of skin cells and biomaterials, a process that is lacking in conventional skin tissue-engineering approaches. Here, we provide a realistic, current overview of skin bioprinting, distinguishing facts from myths. We present an in-depth analysis of both current skin bioprinting works and the cellular and matrix components of native human skin. We also highlight current limitations and achievements, followed by design considerations and a future outlook for skin bioprinting. The potential of bioprinting with converging opportunities in biology, material, and computational design will eventually facilitate the fabrication of improved tissue-engineered (TE) skin constructs, making bioprinting skin an impending reality.

  6. Augmented reality in medical education? (United States)

    Kamphuis, Carolien; Barsom, Esther; Schijven, Marlies; Christoph, Noor


    Learning in the medical domain is to a large extent workplace learning and involves mastery of complex skills that require performance up to professional standards in the work environment. Since training in this real-life context is not always possible for reasons of safety, costs, or didactics, alternative ways are needed to achieve clinical excellence. Educational technology and more specifically augmented reality (AR) has the potential to offer a highly realistic situated learning experience supportive of complex medical learning and transfer. AR is a technology that adds virtual content to the physical real world, thereby augmenting the perception of reality. Three examples of dedicated AR learning environments for the medical domain are described. Five types of research questions are identified that may guide empirical research into the effects of these learning environments. Up to now, empirical research mainly appears to focus on the development, usability and initial implementation of AR for learning. Limited review results reflect the motivational value of AR, its potential for training psychomotor skills and the capacity to visualize the invisible, possibly leading to enhanced conceptual understanding of complex causality.

  7. Reality shows: uma abordagem psicossocial

    Directory of Open Access Journals (Sweden)

    Marília Pereira Bueno Millan

    Full Text Available Desde os primórdios da civilização, o ser humano mostra necessidade de representar cenicamente seus dramas pessoais e vicissitudes existenciais. O "reality show" é uma das versões pós-modernas da encenação da vida humana. Este artigo, por meio de uma pesquisa bibliográfica, analisa criticamente as relações existentes entre o "reality show" e aspectos psicossociais do comportamento humano. Conclui-se que tais programas televisivos são o retrato da contemporaneidade, ou seja, revelam a morte do sujeito, a fugacidade das experiências vividas, a desvalorização da história e o culto à imagem e à superficialidade. Por meio da sedução do espectador, mobilizam-se aspectos primitivos de seu psiquismo, fazendo com que ele se sinta narcisicamente poderoso e onipotente e se acredite dono do destino dos participantes do programa. Sugerem-se novos estudos que contribuam para a reflexão crítica e maior conscientização.

  8. Medical applications of virtual reality. (United States)

    Satava, R M


    Medical applications for virtual reality (VR) are just beginning to emerge. These include VR surgical simulators, telepresence surgery, complex medical database visualization, and rehabilitation. These applications are mediated through the computer interface and as such are the embodiment of VR as an integral part of the paradigm shift in the field of medicine. The Green Telepresence Surgery System consists of two components, the surgical workstation and remote worksite. At the remote site there is a 3-D camera system and responsive manipulators with sensory input. At the workstation there is a 3-D monitor and dexterous handles with force feedback. The VR surgical simulator is a stylized recreation of the human abdomen with several essential organs. Using a helmet mounted display and DataGlove, a person can learn anatomy from a new perspective by 'flying' inside and around the organs, or can practice surgical procedures with a scalpel and clamps. Database visualization creates 3-D images of complex medical data for new perspectives in analysis. Rehabilitation medicine permits impaired individuals to explore worlds not otherwise available to them, allows accurate assessment and therapy for their disabilities, and helps architects understand their critical needs in public or personal space. And to support these advanced technologies, the operating room and hospital of the future will be first designed and tested in virtual reality, bringing together the full power of the digital physician.

  9. The ferredoxin-thioredoxin system of a green alga, Chlamydomonas reinhardtii: identification and characterization of thioredoxins and ferredoxin-thioredoxin reductase components (United States)

    Huppe, H. C.; de Lamotte-Guery, F.; Buchanan, B. B.


    The components of the ferredoxin-thioredoxin (FT) system of Chlamydomonas reinhardtii have been purified and characterized. The system resembled that of higher plants in consisting of a ferredoxin-thioredoxin reductase (FTR) and two types of thioredoxin, a single f and two m species, m1 and m2. The Chlamydomonas m and f thioredoxins were antigenically similar to their higher-plant counterparts, but not to one another. The m thioredoxins were recognized by antibodies to both higher plant m and bacterial thioredoxins, whereas the thioredoxin f was not. Chlamydomonas thioredoxin f reacted, although weakly, with the antibody to spinach thioredoxin f. The algal thioredoxin f differed from thioredoxins studied previously in behaving as a basic protein on ion-exchange columns. Purification revealed that the algal thioredoxins had molecular masses (Mrs) typical of thioredoxins from other sources, m1 and m2 being 10700 and f 11500. Chlamydomonas FTR had two dissimilar subunits, a feature common to all FTRs studied thus far. One, the 13-kDa ("similar") subunit, resembled its counterpart from other sources in both size and antigenicity. The other, 10-kDa ("variable") subunit was not recognized by antibodies to any FTR tested. When combined with spinach, (Spinacia oleracea L.) thylakoid membranes, the components of the FT system functioned in the light activation of the standard target enzymes from chloroplasts, corn (Zea mays L.) NADP-malate dehydrogenase (EC and spinach fructose 1,6-bisphosphatase (EC as well as the chloroplast-type fructose 1,6-bisphosphatase from Chlamydomonas. Activity was greatest if ferredoxin and other components of the FT system were from Chlamydomonas. The capacity of the Chlamydomonas FT system to activate autologous FBPase indicates that light regulates the photosynthetic carbon metabolism of green algae as in other oxygenic photosynthetic organisms.

  10. Whole-Genome Resequencing Reveals Extensive Natural Variation in the Model Green Alga Chlamydomonas reinhardtii[OPEN (United States)

    Hazzouri, Khaled M.; Rosas, Ulises; Bahmani, Tayebeh; Nelson, David R.; Abdrabu, Rasha; Harris, Elizabeth H.; Salehi-Ashtiani, Kourosh; Purugganan, Michael D.


    We performed whole-genome resequencing of 12 field isolates and eight commonly studied laboratory strains of the model organism Chlamydomonas reinhardtii to characterize genomic diversity and provide a resource for studies of natural variation. Our data support previous observations that Chlamydomonas is among the most diverse eukaryotic species. Nucleotide diversity is ∼3% and is geographically structured in North America with some evidence of admixture among sampling locales. Examination of predicted loss-of-function mutations in field isolates indicates conservation of genes associated with core cellular functions, while genes in large gene families and poorly characterized genes show a greater incidence of major effect mutations. De novo assembly of unmapped reads recovered genes in the field isolates that are absent from the CC-503 assembly. The laboratory reference strains show a genomic pattern of polymorphism consistent with their origin as the recombinant progeny of a diploid zygospore. Large duplications or amplifications are a prominent feature of laboratory strains and appear to have originated under laboratory culture. Extensive natural variation offers a new source of genetic diversity for studies of Chlamydomonas, including naturally occurring alleles that may prove useful in studies of gene function and the dissection of quantitative genetic traits. PMID:26392080

  11. Characterization of a Mutant Deficient for Ammonium and Nitric Oxide Signalling in the Model System Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Emanuel Sanz-Luque

    Full Text Available The ubiquitous signalling molecule Nitric Oxide (NO is characterized not only by the variety of organisms in which it has been described, but also by the wealth of biological processes that it regulates. In contrast to the expanding repertoire of functions assigned to NO, however, the mechanisms of NO action usually remain unresolved, and genes that work within NO signalling cascades are seldom identified. A recent addition to the list of known NO functions is the regulation of the nitrogen assimilation pathway in the unicellular alga Chlamydomonas reinhardtii, a well-established model organism for genetic and molecular studies that offers new possibilities in the search for mediators of NO signalling. By further exploiting a collection of Chlamydomonas insertional mutant strains originally isolated for their insensitivity to the ammonium (NH4+ nitrogen source, we found a mutant which, in addition to its ammonium insensitive (AI phenotype, was not capable of correctly sensing the NO signal. Similarly to what had previously been described in the AI strain cyg56, the expression of nitrogen assimilation genes in the mutant did not properly respond to treatments with various NO donors. Complementation experiments showed that NON1 (NO Nitrate 1, a gene that encodes a protein containing no known functional domain, was the gene underlying the mutant phenotype. Beyond the identification of NON1, our findings broadly demonstrate the potential for Chlamydomonas reinhardtii to be used as a model system in the search for novel components of gene networks that mediate physiological responses to NO.

  12. Enzymatic modification by point mutation and functional analysis of an omega-6 fatty acid desaturase from Arctic Chlamydomonas sp. (United States)

    Jung, Woongsic; Kim, Eun Jae; Han, Se Jong; Kang, Sung-Ho; Choi, Han-Gu; Kim, Sanghee


    Arctic Chlamydomonas sp. is a dominant microalgal strain in cold or frozen freshwater in the Arctic region. The full-length open reading frame of the omega-6 fatty acid desaturase gene (AChFAD6) was obtained from the transcriptomic database of Arctic Chlamydomonas sp. from the KOPRI culture collection of polar micro-organisms. Amino acid sequence analysis indicated the presence of three conserved histidine-rich segments as unique characteristics of omega-6 fatty acid desaturases, and three transmembrane regions transported to plastidic membranes by chloroplast transit peptides in the N-terminal region. The AChFAD6 desaturase activity was examined by expressing wild-type and V254A mutant (Mut-AChFAD6) heterologous recombinant proteins. Quantitative gas chromatography indicated that the concentration of linoleic acids in AChFAD6-transformed cells increased more than 3-fold [6.73 ± 0.13 mg g(-1) dry cell weight (DCW)] compared with cells transformed with vector alone. In contrast, transformation with Mut-AChFAD6 increased the concentration of oleic acid to 9.23 ± 0.18 mg g(-1) DCW, indicating a change in enzymatic activity to mimic that of stearoyl-CoA desaturase. These results demonstrate that AChFAD6 of Arctic Chlamydomonas sp. increases membrane fluidity by enhancing denaturation of C18 fatty acids and facilitates production of large quantities of linoleic fatty acids in prokaryotic expression systems.

  13. An improved ARS2-derived nuclear reporter enhances the efficiency and ease of genetic engineering in Chlamydomonas. (United States)

    Specht, Elizabeth A; Nour-Eldin, Hussam Hassan; Hoang, Kevin T D; Mayfield, Stephen P


    The model alga Chlamydomonas reinhardtii has been used to pioneer genetic engineering techniques for high-value protein and biofuel production from algae. To date, most studies of transgenic Chlamydomonas have utilized the chloroplast genome due to its ease of engineering, with a sizeable suite of reporters and well-characterized expression constructs. The advanced manipulation of algal nuclear genomes has been hampered by limited strong expression cassettes, and a lack of high-throughput reporters. We have improved upon an endogenous reporter gene - the ARS2 gene encoding an arylsulfatase enzyme - that was first cloned and characterized decades ago but has not been used extensively. The new construct, derived from ARS2 cDNA, expresses significantly higher levels of reporter protein and transforms more efficiently, allowing qualitative and quantitative screening using a rapid, inexpensive 96-well assay. The improved arylsulfatase expression cassette was used to screen a new transgene promoter from the ARG7 gene, and found that the ARG7 promoter can express the ARS2 reporter as strongly as the HSP70-RBCS2 chimeric promoter that currently ranks as the best available promoter, thus adding to the list of useful nuclear promoters. This enhanced arylsulfatase reporter construct improves the efficiency and ease of genetic engineering within the Chlamydomonas nuclear genome, with potential application to other algal strains.

  14. Ambient Learning Displays - Distributed Mixed Reality Information Mash-ups to support Ubiquitous Learning

    NARCIS (Netherlands)

    Börner, Dirk


    Börner, D. (2010, 19-21 March). Ambient Learning Displays Distributed Mixed Reality Information Mash-ups to support Ubiquitous Learning. Presented at the IADIS International Conference Mobile Learning 2010, Porto, Portugal.

  15. Time-dependent changes in antioxidative enzyme expression and photosynthetic activity of Chlamydomonas reinhardtii cells under acute exposure to cadmium and anthracene. (United States)

    Aksmann, Anna; Pokora, Wojciech; Baścik-Remisiewicz, Agnieszka; Dettlaff-Pokora, Agnieszka; Wielgomas, Bartosz; Dziadziuszko, Małgorzata; Tukaj, Zbigniew


    Heavy metals (HM) and polycyclic aromatic hydrocarbons (PAHs) are present in the freshwater environment at concentrations that can be hazardous to the biota. Among HMs and PAHs, cadmium (Cd) and anthracene (ANT) are the most prevalent and toxic ones. The response of Chlamydomonas cells to Cd and ANT at concentrations that markedly reduced the growth of algal population was investigated in this study. At such concentrations, both cadmium and anthracene were recognized as oxidative stress inducers, since high concentration of H2O2 in treated cultures was observed. Therefore, as a part of the "molecular phase" of the cell response to this stress, we examined the time-dependent expression of genes encoding the main antioxidative enzymes: superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), as well as the activity of these enzymes in cells, with special attention paid to chloroplastic and mitochondrial isoforms of SOD. To characterize the cell response at the "physiological level", we examined the photosynthetic activity of stressed cells via analysis of chlorophyll a fluorescence in vivo. In contrast to standard ecotoxicity studies in which the growth end-points are usually determined, herein we present time-dependent changes in algal cell response to Cd- and ANT-induced stress. The most significant effect(s) of the toxicants on photosynthetic activity was observed in the 6th hour, when strong depression of PI parameter value, an over 50 percent reduction of the active reaction center fraction (RC0) and a 3-fold increase in non-photochemical energy dissipation (DI0/RC) were noted. At the same time, the increase (up to 2.5-fold) in mRNA transcript of SOD and CAT genes, followed by the enhancement in the enzyme activity was observed. The high expression of the Msd 3 gene in treated Chlamydomonas cells probably complements the partial loss of chloroplast Fe-SOD and APX activity, while catalase and Mn-SOD 5 seem to be the major enzymes responsible for

  16. Mixing realities? An application of augmented reality for the treatment of cockroach phobia. (United States)

    Botella, C M; Juan, M C; Baños, R M; Alcañiz, M; Guillén, V; Rey, B


    Augmented reality (AR) refers to the introduction of virtual elements in the real world. That is, the person is seeing an image composed of a visualization of the real world, and a series of virtual elements that, at that same moment, are super-imposed on the real world. The most important aspect of AR is that the virtual elements supply to the person relevant and useful information that is not contained in the real world. AR has notable potential, and has already been used in diverse fields, such as medicine, the army, coaching, engineering, design, and robotics. Until now, AR has never been used in the scope of psychological treatment. Nevertheless, AR presents various advantages. Just like in the classical systems of virtual reality, it is possible to have total control over the virtual elements that are super-imposed on the real world, and how one interacts with those elements. AR could involve additional advantages; on one side it could be less expensive since it also uses the real world (this does not need to be modeled), and it could facilitate the feeling of presence (the sensation of being there), and reality judgment (the fact of judging the experience as real) of the person since the environment he or she is in, and what he or she is seeing is, in fact the "reality." In this paper, we present the data of the first case study in which AR has been used for the treatment of a specific phobia, cockroaches phobia. It addresses a system of AR that permits exposure to virtual cockroaches super-imposed on the real world. In order to carry out the exposure, the guidelines of Ost with respect to "one-session treatment" were followed. The results are promising. The participant demonstrated notable fear and avoidance in the behavioral avoidance test before the treatment, and not only was an important decrease in the scores of fear and avoidance observed after the treatment, but also the participant was capable of approaching, interacting, and killing live

  17. Development of Beliefs about Storybook Reality (United States)

    Woolley, Jacqueline D.; Cox, Victoria


    The goal of this research was to assess children's beliefs about the reality status of storybook characters and events. In Experiment 1, 156 preschool age children heard realistic, fantastical, or religious stories, and their understanding of the reality status of the characters and events in the stories was assessed. Results revealed that…

  18. Visualizing Compound Rotations with Virtual Reality (United States)

    Flanders, Megan; Kavanagh, Richard C.


    Mental rotations are among the most difficult of all spatial tasks to perform, and even those with high levels of spatial ability can struggle to visualize the result of compound rotations. This pilot study investigates the use of the virtual reality-based Rotation Tool, created using the Virtual Reality Modeling Language (VRML) together with…

  19. Location-Based Learning through Augmented Reality (United States)

    Chou, Te-Lien; Chanlin, Lih-Juan


    A context-aware and mixed-reality exploring tool cannot only effectively provide an information-rich environment to users, but also allows them to quickly utilize useful resources and enhance environment awareness. This study integrates Augmented Reality (AR) technology into smartphones to create a stimulating learning experience at a university…

  20. What is reality and what is pleasure

    DEFF Research Database (Denmark)

    Zeuthen, Katrine Egede; Køppe, Simo


    The article comments on Zygmund Bauman's article: Freudian civilization revisited and is a discussion of the relation between the reality principle and the pleasure principle in Freud's psychoanalytical theory and of the reation between pleasure and reality in society as such....

  1. Oil accumulation in the model green alga Chlamydomonas reinhardtii: characterization, variability between common laboratory strains and relationship with starch reserves

    Directory of Open Access Journals (Sweden)

    Carrier Patrick


    Full Text Available Abstract Background When cultivated under stress conditions, many microalgae species accumulate both starch and oil (triacylglycerols. The model green microalga Chlamydomonas reinhardtii has recently emerged as a model to test genetic engineering or cultivation strategies aiming at increasing lipid yields for biodiesel production. Blocking starch synthesis has been suggested as a way to boost oil accumulation. Here, we characterize the triacylglycerol (TAG accumulation process in Chlamydomonas and quantify TAGs in various wild-type and starchless strains. Results In response to nitrogen deficiency, Chlamydomonas reinhardtii produced TAGs enriched in palmitic, oleic and linoleic acids that accumulated in oil-bodies. Oil synthesis was maximal between 2 and 3 days following nitrogen depletion and reached a plateau around day 5. In the first 48 hours of oil deposition, a ~80% reduction in the major plastidial membrane lipids occurred. Upon nitrogen re-supply, mobilization of TAGs started after starch degradation but was completed within 24 hours. Comparison of oil content in five common laboratory strains (CC124, CC125, cw15, CC1690 and 11-32A revealed a high variability, from 2 μg TAG per million cell in CC124 to 11 μg in 11-32A. Quantification of TAGs on a cell basis in three mutants affected in starch synthesis (cw15sta1-2, cw15sta6 and cw15sta7-1 showed that blocking starch synthesis did not result in TAG over-accumulation compared to their direct progenitor, the arginine auxotroph strain 330. Moreover, no significant correlation was found between cellular oil and starch levels among the twenty wild-type, mutants and complemented strains tested. By contrast, cellular oil content was found to increase steeply with salt concentration in the growth medium. At 100 mM NaCl, oil level similar to nitrogen depletion conditions could be reached in CC124 strain. Conclusion A reference basis for future genetic studies of oil metabolism in Chlamydomonas

  2. A Virtual Tomb for Kelvingrove: Virtual Reality, Archaeology and Education

    Directory of Open Access Journals (Sweden)

    Melissa M. Terras


    model can be seen here. However, because of technical problems as well as the educational issues raised, it was felt that the model was not suitable in this format for inclusion in the Kelvingrove Museum. The project has illustrated that although it is technically possible to create an archaeologically based virtual model using VRML, technical issues prevent this format from being a feasible way of displaying 3D worlds in a museum environment at present. Also, the project has shown that the creation of the virtual reality world is only the beginning of developing a virtual reality display for use in education. Both the user interface and the informative aspects of a model have to be carefully designed to ensure the resulting computer display has proven educational worth, and broad issues surrounding the nature of representation and reconstruction have to be addressed before such models will become commonplace in museums.

  3. Newton's Principia: Myth and Reality (United States)

    Smith, George


    Myths about Newton's Principia abound. Some of them, such as the myth that the whole book was initially developed using the calculus and then transformed into a geometric mathematics, stem from remarks he made during the priority controversy with Leibniz over the calculus. Some of the most persistent, and misleading, arose from failures to read the book with care. Among the latter are the myth that he devised his theory of gravity in order to explain the already established ``laws'' of Kepler, and that in doing so he took himself to be establishing that Keplerian motion is ``absolute,'' if not with respect to ``absolute space,'' then at least with respect to the fixed stars taken as what came later to be known as an inertial frame. The talk will replace these two myths with the reality of what Newton took himself to have established.

  4. Marshall Engineers Use Virtual Reality (United States)


    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall Spce Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

  5. Allergy vaccines: dreams and reality. (United States)

    Crameri, Reto


    Allergy, extrinsic asthma and atopic eczema derive from deregulated immune responses against innocuous antigens. The incidence of atopic diseases is actually affecting approximately 30% of the population in industrialized countries. Although much progress has been achieved in the development of efficient symptomatic treatments for allergic diseases, the only curative treatment remains allergen-specific immunotherapy. In contrast to classical vaccines, which elicit strong host immune responses after one or a few injections, allergen-specific immunotherapy might require a long treatment time of 3-5 years with up to 80 injections to confer some protection. The reality is that 'allergy vaccines' achieve beneficial effects through immunomodulation, which takes a long time to establish. The dream would be to develop highly efficient allergy vaccines able to cure the disease with a few injections.

  6. Augmented reality for improved safety

    CERN Multimedia

    Stefania Pandolfi


    Sometimes, CERN experts have to operate in low visibility conditions or in the presence of possible hazards. Minimising the duration of the operation and reducing the risk of errors is therefore crucial to ensuring the safety of personnel. The EDUSAFE project integrates different technologies to create a wearable personnel safety system based on augmented reality.    The EDUSAFE integrated safety system uses a camera mounted on the helmet to monitor the working area.  In its everyday operation of machines and facilities, CERN adopts a whole set of measures and safety equipment to ensure the safety of its personnel, including personal wearable safety devices and access control systems. However, sometimes, scheduled and emergency maintenance work needs to be done in zones with potential cryogenic hazards, in the presence of radioactive equipment or simply in demanding conditions where visibility is low and moving around is difficult. The EDUSAFE Marie Curie Innovative&...

  7. On the Nature of Reality

    CERN Document Server

    Pfrimer, Frederico R


    What is the nature of reality? How should be an answer to this question? At this level, we are so deep that all our concepts are obscure. Quantum theory (QT) is at this level. The quest for interpreting it fails because the clarity of our actual fundamental concepts in ordinary language cannot match the precision of the theory's mathematical formalism. The interpretation of quantum mechanics should define and bring clarity to fundamental concepts; not simply rely over them. Quantum theory requires a new worldview, the one that will make it understandable. We discuss on the formulation and interpretation of closed, and final theories, in other words, completely axiomatic theories that define their own conceptual framework, and closed theories that cannot be made simpler. We claim that everything we can properly say about a theory follows from its interpretation, and that interpreting is saying the meaning of each of its mathematical statements. We argue that quantum mechanics is a closed theory; and, therefore...

  8. Chlamydomonas fla mutants reveal a link between deflagellation and intraflagellar transport

    Directory of Open Access Journals (Sweden)

    Quarmby Lynne


    Full Text Available Abstract Background Cilia and flagella are often lost in anticipation of mitosis or in response to stress. There are two ways that a cell can lose its flagella: resorption or deflagellation. Deflagellation involves active severing of the axoneme at the base of the flagellum; this process is defective in Chlamydomonas fa mutants. In contrast, resorption has been thought to occur as a consequence of constitutive disassembly at the tip in the absence of continued assembly, which requires intraflagellar transport (IFT. Chlamydomonas fla mutants are unable to build and maintain flagella due to defects in IFT. Results fla10 cells, which are defective in kinesin-II, the anterograde IFT motor, resorb their flagella at the restrictive temperature (33°C, as previously reported. We find that in standard media containing ~300 microM calcium, fla10 cells lose flagella by deflagellation at 33°C. This temperature-induced deflagellation of a fla mutant is not predicted by the IFT-based model for flagellar length control. Other fla mutants behave similarly, losing their flagella by deflagellation instead of resorption, if adequate calcium is available. These data suggest a new model whereby flagellar resorption involves active disassembly at the base of the flagellum via a mechanism with components in common with the severing machinery of deflagellation. As predicted by this model, we discovered that deflagellation stimuli induce resorption if deflagellation is blocked either by mutation in a FA gene or by lack of calcium. Further support for this model comes from our discovery that fla10-fa double mutants resorb their flagella more slowly than fla10 mutants. Conclusions Deflagellation of the fla10 mutant at the restrictive temperature is indicative of an active disassembly signal, which can manifest as either resorption or deflagellation. We propose that when IFT is halted by either an inactivating mutation or a cellular signal, active flagellar disassembly

  9. Hydrogen production by photoautotrophic sulfur-deprived Chlamydomonas reinhardtii pre-grown and incubated under high light. (United States)

    Tolstygina, Irina V; Antal, Taras K; Kosourov, Sergey N; Krendeleva, Tatyana E; Rubin, Andrey B; Tsygankov, Anatoly A


    We have previously demonstrated that Chlamydomonas reinhardtii can produce hydrogen under strictly photoautotrophic conditions during sulfur deprivation [Tsygankov et al. (2006); Int J Hydrogen Energy 3:1574-1584]. The maximum hydrogen photoproduction was achieved by photoautotrophic cultures pre-grown under a low light regime (25 microE m(-2) s(-1)). We failed to establish sustained hydrogen production from cultures pre-grown under high light (100 microE m(-2) s(-1)). A new approach for sustained hydrogen production by these cultures is presented here. Assuming that stable and reproducible transition to anerobiosis as well as high starch accumulation are important for hydrogen production, the influence of light intensity and dissolved oxygen concentration during the oxygen evolving stage of sulfur deprivation were investigated in cultures pre-grown under high light. Results showed that light higher than 175 microE m(-2) s(-1) during sulfur deprivation induced reproducible transition to anerobiosis, although the total amount of starch accumulation and hydrogen production were insignificant. The potential PSII activity measured in the presence of an artificial electron acceptor (DCBQ) and an inhibitor of electron transport (DBMIB) did not change in cultures pre-grown under 20 microE m(-2) s(-1) and incubated under 150 microE m(-2) s(-1) during sulfur deprivation. In contrast, the potential PSII activity decreased in cultures pre-grown under 100 microE m(-2) s(-1) and incubated under 420 microE m(-2) s(-1). This indicates that cultures grown under higher light experience irreversible inhibition of PSII in addition to reversible down regulation. High dissolved O(2) content during the oxygen evolving stage of sulfur deprivation has a negative regulatory role on PSII activity. To increase hydrogen production by C. reinhardtii pre-grown under 100 microE m(-2) s(-1), cultures were incubated under elevated PFD and decreased oxygen pressure during the oxygen evolving stage

  10. Alteration of proteins and pigments influence the function of photosystem I under iron deficiency from Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    Venkateswarlu Yadavalli

    Full Text Available BACKGROUND: Iron is an essential micronutrient for all organisms because it is a component of enzyme cofactors that catalyze redox reactions in fundamental metabolic processes. Even though iron is abundant on earth, it is often present in the insoluble ferric [Fe (III] state, leaving many surface environments Fe-limited. The haploid green alga Chlamydomonas reinhardtii is used as a model organism for studying eukaryotic photosynthesis. This study explores structural and functional changes in PSI-LHCI supercomplexes under Fe deficiency as the eukaryotic photosynthetic apparatus adapts to Fe deficiency. RESULTS: 77K emission spectra and sucrose density gradient data show that PSI and LHCI subunits are affected under iron deficiency conditions. The visible circular dichroism (CD spectra associated with strongly-coupled chlorophyll dimers increases in intensity. The change in CD signals of pigments originates from the modification of interactions between pigment molecules. Evidence from sucrose gradients and non-denaturing (green gels indicates that PSI-LHCI levels were reduced after cells were grown for 72 h in Fe-deficient medium. Ultrafast fluorescence spectroscopy suggests that red-shifted pigments in the PSI-LHCI antenna were lost during Fe stress. Further, denaturing gel electrophoresis and immunoblot analysis reveals that levels of the PSI subunits PsaC and PsaD decreased, while PsaE was completely absent after Fe stress. The light harvesting complexes were also susceptible to iron deficiency, with Lhca1 and Lhca9 showing the most dramatic decreases. These changes in the number and composition of PSI-LHCI supercomplexes may be caused by reactive oxygen species, which increase under Fe deficiency conditions. CONCLUSIONS: Fe deficiency induces rapid reduction of the levels of photosynthetic pigments due to a decrease in chlorophyll synthesis. Chlorophyll is important not only as a light-harvesting pigment, but also has a structural role

  11. The organization structure and regulatory elements of Chlamydomonas histone genes reveal features linking plant and animal genes. (United States)

    Fabry, S; Müller, K; Lindauer, A; Park, P B; Cornelius, T; Schmitt, R


    The genome of the green alga Chlamydomonas reinhardtii contains approximately 15 gene clusters of the nucleosomal (or core) histone H2A, H2B, H3 and H4 genes and at least one histone H1 gene. Seven non-allelic histone gene loci were isolated from a genomic library, physically mapped, and the nucleotide sequences of three isotypes of each core histone gene species and one linked H1 gene determined. The core histone genes are organized in clusters of H2A-H2B and H3-H4 pairs, in which each gene pair shows outwardly divergent transcription from a short (< 300 bp) intercistronic region. These intercistronic regions contain typically conserved promoter elements, namely a TATA-box and the three motifs TGGCCAG-G(G/C)-CGAG, CGTTGACC and CGGTTG. Different from the genes of higher plants, but like those of animals and the related alga Volvox, the 3' untranslated regions contain no poly A signal, but a palindromic sequence (3' palindrome) essential for mRNA processing is present. One single H1 gene was found in close linkage to a H2A-H2B pair. The H1 upstream region contains the octameric promoter element GGTTGACC (also found upstream of the core histone genes) and two specific sequence motifs that are shared only with the Volvox H1 promoters. This suggests differential transcription of the H1 and the core histone genes. The H1 gene is interrupted by two introns. Unlike Volvox H3 genes, the three sequenced H3 isoforms are intron-free. Primer-directed PCR of genomic DNA demonstrated, however, that at least 8 of the about 15 H3 genes do contain one intron at a conserved position. In synchronized C. reinhardtii cells, H4 mRNA levels (representative of all core histone mRNAs) peak during cell division, suggesting strict replication-dependent gene control. The derived peptide sequences place C. reinhardtii core histones closer to plants than to animals, except that the H2A histones are more animal-like. The peptide sequence of histone H1 is closely related to the V. carteri VH1-II

  12. Real-time monitoring of genetically modified Chlamydomonas reinhardtii during the Foton M3 space mission and ground irradiation experiment (United States)

    Lambreva, Maya; Rea, Giuseppina; Antonacci, Amina; Serafini, Agnese; Damasso, Mario; Margonelli, Andrea; Johanningmeier, Udo; Bertalan, Ivo; Pezzotti, Gianni; Giardi, Maria Teresa

    Long-term space exploration, colonization or habitation requires biological life support systems capable to cope with the deleterious space environment. The use of oxygenic photosynthetic microrganisms is an intriguing possibility mainly for food, O2 and nutraceutical compounds production. The critical points of utilizing plantsor algae-based life support systems are the microgravity and the ionizing radiation, which can influence the performance of these organisms. The aim of the present study was to assess the effects of space environment on the photosynthetic activity of various microrganisms and to select space stress-tolerant strains. Site-directed and random mutants of the unicellular green alga Chlamydomonas reinhardtii of Photosystem II D1 protein were used as a model system to test and select the amino acid substitutions capable to account for space stress tolerance. We focussed our studies also on the accumulation of the Photosystem II photoprotective carotenoids (the xantophylls violaxanthin, anteraxanthin and zeaxanthin), powerful antioxidants that epidemiological studies demonstrated to be human vision protectors. Metabolite profiling by quantitative HPLC methods revealed the organisms and the stress conditions capable to accumulate the highest pigment levels. In order to develop a project for a rationale metabolic engineering of algal secondary metabolites overproduction, we are performing expression analyses on the carotenoid biosynthetic pathway under physiological and mimicked space conditions. To identify the consequences of the space environment on the photosynthetic apparatus the changes in the Photosystem II efficiency were monitored in real time during the ESA-Russian Foton-M3 mission in September 2007. For the space flight a high-tech, multicell fluorescence biosensor, Photo-II, was designed and built by the Centre for Advanced Research in Space Optics in collaboration with Kayser-Italy, Biosensor and DAS. Photo-II is an automatic device

  13. A Study on Immersion of Hand Interaction for Mobile Platform Virtual Reality Contents

    Directory of Open Access Journals (Sweden)

    Seunghun Han


    Full Text Available This study proposes gaze-based hand interaction, which is helpful for improving the user’s immersion in the production process of virtual reality content for the mobile platform, and analyzes efficiency through an experiment using a questionnaire. First, three-dimensional interactive content is produced for use in the proposed interaction experiment while presenting an experiential environment that gives users a high sense of immersion in the mobile virtual reality environment. This is designed to induce the tension and concentration of users in line with the immersive virtual reality environment. Additionally, a hand interaction method based on gaze—which is mainly used for the entry of mobile virtual reality content—is proposed as a design method for immersive mobile virtual reality environment. The user satisfaction level of the immersive environment provided by the proposed gaze-based hand interaction is analyzed through experiments in comparison with the general method that uses gaze only. Furthermore, detailed analysis is conducted by dividing the effects of the proposed interaction method on user’s psychology into positive factors such as immersion and interest and negative factors such as virtual reality (VR sickness and dizziness. In this process, a new direction is proposed for improving the immersion of users in the production of mobile platform virtual reality content.

  14. Moving from virtual reality exposure-based therapy to augmented reality exposure-based therapy: a review. (United States)

    Baus, Oliver; Bouchard, Stéphane


    This paper reviews the move from virtual reality exposure-based therapy to augmented reality exposure-based therapy (ARET). Unlike virtual reality (VR), which entails a complete virtual environment (VE), augmented reality (AR) limits itself to producing certain virtual elements to then merge them into the view of the physical world. Although, the general public may only have become aware of AR in the last few years, AR type applications have been around since beginning of the twentieth century. Since, then, technological developments have enabled an ever increasing level of seamless integration of virtual and physical elements into one view. Like VR, AR allows the exposure to stimuli which, due to various reasons, may not be suitable for real-life scenarios. As such, AR has proven itself to be a medium through which individuals suffering from specific phobia can be exposed "safely" to the object(s) of their fear, without the costs associated with programing complete VEs. Thus, ARET can offer an efficacious alternative to some less advantageous exposure-based therapies. Above and beyond presenting what has been accomplished in ARET, this paper covers some less well-known aspects of the history of AR, raises some ARET related issues, and proposes potential avenues to be followed. These include the type of measures to be used to qualify the user's experience in an augmented reality environment, the exclusion of certain AR-type functionalities from the definition of AR, as well as the potential use of ARET to treat non-small animal phobias, such as social phobia.

  15. Moving from Virtual Reality Exposure-Based Therapy (VRET to Augmented Reality Exposure-Based Therapy (ARET: A review.

    Directory of Open Access Journals (Sweden)

    Oliver eBaus


    Full Text Available This paper reviews the move from virtual reality exposure-based therapy (VRET to augmented reality exposure-based therapy (ARET. Unlike virtual reality (VR, which entails a complete virtual environment (VE, augmented reality (AR limits itself to producing certain virtual elements to then merge them into the view of the physical world. Although the general public may only have become aware of AR in the last few years, AR type applications have been around since beginning of the 20th century. Since, then, technological developments have enabled an ever increasing level of seamless integration of virtual and physical elements into one view. Like VR, AR allows the exposure to stimuli which, due to various reasons, may not be suitable for real-life scenarios. As such, AR has proven itself to be a medium through which individuals suffering from specific phobia can be exposed safely to the object(s of their fear, without the costs associated with programming complete virtual environments. Thus, ARET can offer an efficacious alternative to some less advantageous exposure-based therapies. Above and beyond presenting what has been accomplished in ARET, this paper also raises some ARET related issues, and proposes potential avenues to be followed. These include the definition of an AR related term, the type of measures to be used to qualify the user’s experience in an augmented reality environment (ARE, the development of alternative geospatial referencing systems, as well as the potential use of ARET to treat social phobia. Overall, it may be said that the use of ARET, although promising, is still in its infancy but that, given a continued cooperation between clinical and technical teams, ARET has the potential of going well beyond the treatment of small animal phobia.

  16. Integral Biomathics Tracing the Road to Reality

    CERN Document Server

    Smith, Leslie; Ehresmann, Andrée


    Perhaps the most distinct question in science throughout the ages has been the one of perceivable reality, treated both in physics and philosophy. Reality is acting upon us, and we, and life in general, are acting upon reality. Potentiality, found both in quantum reality and in the activity of life, plays a key role.  In quantum reality observation turns potentiality into reality. Again, life computes possibilities in various ways based on past actions, and acts on the basis of these computations.   This book is about a new approach to biology (and physics, of course!). Its subtitle suggests a perpetual movement and interplay between two elusive aspects of modern science — reality/matter and potentiality/mind, between physics and biology — both captured and triggered by mathematics — to understand and explain emergence, development and life all the way up to consciousness.   But what is the real/potential difference between living and non-living matter? How does time in potentiality differ from time...

  17. Combining Shape-Changing Interfaces and Spatial Augmented Reality Enables Extended Object Appearance

    DEFF Research Database (Denmark)

    Lindlbauer, David; Grønbæk, Jens Emil; Birk, Morten


    We propose combining shape-changing interfaces and spatial augmented reality for extending the space of appearances and interactions of actuated interfaces. While shape-changing interfaces can dynamically alter the physical appearance of objects, the integration of spatial augmented reality...... for increasing the realism of 3D objects such as bump mapping. This extensible framework helps us identify challenges of the two techniques and benefits of their combination. We utilize our prototype shape-changing device enriched with spatial augmented reality through projection mapping to demonstrate...... the concept. We present a novel mechanical distance-fields algorithm for real-time fitting of mechanically constrained shape-changing devices to arbitrary 3D graphics. Furthermore, we present a technique for increasing effective screen real estate for spatial augmented reality through view-dependent shape...

  18. Fostering Learning Through Interprofessional Virtual Reality Simulation Development. (United States)

    Nicely, Stephanie; Farra, Sharon


    This article presents a unique strategy for improving didactic learning and clinical skill while simultaneously fostering interprofessional collaboration and communication. Senior-level nursing students collaborated with students enrolled in the Department of Interactive Media Studies to design a virtual reality simulation based upon disaster management and triage techniques. Collaborative creation of the simulation proved to be a strategy for enhancing students' knowledge of and skill in disaster management and triage while impacting attitudes about interprofessional communication and teamwork.

  19. Wind and warmth in virtual reality: implementation and evaluation


    Hülsmann, Felix; Fröhlich, Julia; Mattar, Nikita; Wachsmuth, Ipke


    One possibility to make virtual worlds more immersive is to address as many human senses as possible. This paper presents the development of a system for creating wind and warmth simulations in Virtual Reality (VR). Therefore, suitable hardware and an implemented software model are described. Technical evaluations of the hardware and of the software components demonstrate the usability of the system in VR Applications. Furthermore, a user study underlines users’ acceptance and indicates a pos...

  20. Pose Estimation for Augmented Reality: A Hands-On Survey


    Marchand, Éric; Uchiyama, Hideaki; Spindler, Fabien


    International audience; Augmented reality (AR) allows to seamlessly insert virtual objects in an image sequence. In order to accomplish this goal, it is important that synthetic elements are rendered and aligned in the scene in an accurate and visually acceptable way. The solution of this problem can be related to a pose estimation or, equivalently, a camera localization process. This paper aims at presenting a brief but almost self-contented introduction to the most important approaches dedi...

  1. Augmented reality based real-time subcutaneous vein imaging system


    Ai, Danni; Yang, Jian; Fan, Jingfan; Zhao, Yitian; Song, Xianzheng; Shen, Jianbing; Shao, Ling; Wang, Yongtian


    A novel 3D reconstruction and fast imaging system for subcutaneous veins by augmented reality is presented. The study was performed to reduce the failure rate and time required in intravenous injection by providing augmented vein structures that back-project superimposed veins on the skin surface of the hand. Images of the subcutaneous vein are captured by two industrial cameras with extra reflective near-infrared lights. The veins are then segmented by a multiple-feature clustering method. V...

  2. Augmented reality to improve teleoperation of mobile robots



    In this article we want to discuss the skills required for human teleoperators of mobile robots. We show the classical problems related with teleoperation but focus our discussion in not specialized operators. We want to show how a proposal based on augmented reality interfaces can improve the performance of operators controlling the robot. We present the validation of our solution in two experiments: one in a controlled circuit and another one in a real environment. To c...

  3. Pedagogy: Instructivism to Socio-Constructivism through Virtual Reality



    learning theories evolved with time, beginning with instructivism, constructivism, to social constructivism. These theories no doubt were applied in education and they had their effects on learners. Technology advanced, created a paradigm shift by creating new ways of teaching and learning as found in virtual reality (VR). VR provided creative ways in which students learn, provides opportunity to achieve learning goals by presenting artificial environments. We developed and simulated a virtua...

  4. Augmented Reality in Architecture: Rebuilding Archeological Heritage (United States)

    de la Fuente Prieto, J.; Castaño Perea, E.; Labrador Arroyo, F.


    With the development in recent years of augmented reality and the appearance of new mobile terminals and storage bases on-line, we find the possibility of using a powerful tool for transmitting architecture. This paper analyzes the relationship between Augmented Reality and Architecture. Firstly, connects the theoretical framework of both disciplines through the Representation concept. Secondly, describes the milestones and possibilities of Augmented Reality in the particular field of archaeological reconstruction. And lastly, once recognized the technology developed, we face the same analysis from a critical point of view, assessing their suitability to the discipline that concerns us is the architecture and within archeology.

  5. A Survey on Applications of Augmented Reality

    Directory of Open Access Journals (Sweden)

    Andrea Sanna


    Full Text Available The term Augmented Reality (AR refers to a set of technologies and devices able to enhance and improve human perception, thus bridging the gap between real and virtual space. Physical and artificial objects are mixed together in a hybrid space where the user can move without constraints. This mediated reality is spread in our everyday life: work, study, training, relaxation, time spent traveling are just some of the moments in which you can use AR applications.This paper aims to provide an overview of current technologies and future trends of augmented reality as well as to describe the main application domains, outlining benefits and open issues.

  6. Voyeurismo Televisivo, Reality Shows e Brasilidade Televisiva

    Directory of Open Access Journals (Sweden)

    Suzana Kilpp


    Full Text Available In the last years we watched a boom of reality shows in the media and also in the academic production specialized in this subject. It remains, however, a epistemological gap related to the aesthetic and techniques (which are related to the televisions grammars that TV uses in these programs to enunciate ethics directions to its own voyeurism, that goes far beyond reality shows, having repercussions on social imaginary of transparency and surveillance, and the redesign of public and private spaces. In this gap, the article points out the debate of Brazilian reality shows in the perspective of the televisions grammars.

  7. Determination of student opinions in augmented reality

    Directory of Open Access Journals (Sweden)

    Huseyin Bicen


    Full Text Available The rapid development of the new technology has changed classroom teaching methods and tools in a positive way. This study investigated the classroom learning with augmented reality and the impact of student opinions. 97 volunteer undergraduate students took part in this study. Results included data in the form of frequencies, percentages and descriptive statistics. The results show that, with gamification methods, augmented reality content affected students’ opinions in a positive way. When QR codes are used in the classroom, students feel independent from classroom materials and can access various resources. Moreover, students think that, when augmented reality in the classroom is used, education is more enjoyable.

  8. Activation of the Carbon Concentrating Mechanism by CO2 Deprivation Coincides with Massive Transcriptional Restructuring in Chlamydomonas reinhardtii[W][OA (United States)

    Brueggeman, Andrew J.; Gangadharaiah, Dayananda S.; Cserhati, Matyas F.; Casero, David; Weeks, Donald P.; Ladunga, Istvan


    A CO2-concentrating mechanism (CCM) is essential for the growth of most eukaryotic algae under ambient (392 ppm) and very low (<100 ppm) CO2 concentrations. In this study, we used replicated deep mRNA sequencing and regulatory network reconstruction to capture a remarkable scope of changes in gene expression that occurs when Chlamydomonas reinhardtii cells are shifted from high to very low levels of CO2 (≤100 ppm). CCM induction 30 to 180 min post-CO2 deprivation coincides with statistically significant changes in the expression of an astonishing 38% (5884) of the 15,501 nonoverlapping C. reinhardtii genes. Of these genes, 1088 genes were induced and 3828 genes were downregulated by a log2 factor of 2. The latter indicate a global reduction in photosynthesis, protein synthesis, and energy-related biochemical pathways. The magnitude of transcriptional rearrangement and its major patterns are robust as analyzed by three different statistical methods. De novo DNA motif discovery revealed new putative binding sites for Myeloid oncogene family transcription factors potentially involved in activating low CO2–induced genes. The (CA)n repeat (9 ≤ n ≤ 25) is present in 29% of upregulated genes but almost absent from promoters of downregulated genes. These discoveries open many avenues for new research. PMID:22634764

  9. The experimental evolution of herbicide resistance in Chlamydomonas reinhardtii results in a positive correlation between fitness in the presence and absence of herbicides. (United States)

    Vogwill, T; Lagator, M; Colegrave, N; Neve, P


    Pleiotropic fitness trade-offs will be key determinants of the evolutionary dynamics of selection for pesticide resistance. However, for herbicide resistance, empirical support for a fitness cost of resistance is mixed, and it is therefore also questionable what further ecological trade-offs can be assumed to apply to herbicide resistance. Here, we test the existence of trade-offs by experimentally evolving herbicide resistance in Chlamydomonas reinhardtii. Although fitness costs are detected for all herbicides, we find that, counterintuitively, the most resistant populations also have the lowest fitness costs as measured by growth rate in the ancestral environment. Furthermore, after controlling for differences in the evolutionary dynamics of resistance to different herbicides, we also detect significant positive correlations between resistance, fitness in the ancestral environment and cross-resistance to other herbicides. We attribute this to the highest levels of nontarget-site resistance being achieved by fixing mutations that more broadly affect cellular physiology, which results in both more cross-resistance and less overall antagonistic pleiotropy on maximum growth rate. Consequently, the lack of classical ecological trade-offs could present a major challenge for herbicide resistance management.

  10. NRT2.4 and NRT2.5 Are Two Half-Size Transporters from the Chlamydomonas NRT2 Family

    Directory of Open Access Journals (Sweden)

    Jose Javier Higuera


    Full Text Available The NRT2 transporters mediate High Affinity Nitrate/NitriteTransport (HAN/NiT, which are essential for nitrogen acquisition from these inorganic forms. The NRT2 proteins are encoded by a multigene family in plants, and contain 12 transmembrane-spanning domains. Chlamydomonas reinhardtii has six NRT2, two of which (NRT2.5 and NRT2.4 are located in Chromosome III, in tandem head to tail. cDNAs for these genes were isolated and their sequence revealed that they correspond to half-size NRT2 transporters each containing six transmembrane domains. NRT2.5 has long N- and C- termini sequences without known homology. NRT2.4 also contains long termini sequences but smaller than NRT2.5. Expression of both studied genes occurred at a very low level, slightly in darkness, and was not modified by the N or C source. Silencing of NRT2.4 by specific artificial miRNA resulted in the inhibition of nitrite transport in the absence of other HANNiT (NRT2.1/NAR2 in the cell genetic background. Nitrite transport activity in the Hansenula polymorpha Δynt::URA3 Leu2 mutant was restored by expressing CrNRT2.4. These results indicate that half-size NRT2 transporters are present in photosynthetic organisms and that NRT2.4 is a HANiT.

  11. X-ray dense cellular inclusions in the cells of the green alga Chlamydomonas reinhardtii as seen by soft-x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stead, A.D.; Ford, T.W.; Page, A.M. [Univ. of London (United Kingdom); Brown, J.T.; Meyer-Ilse, W. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)


    Soft x-rays, having a greater ability to penetrate biological material than electrons, have the potential for producing images of intact, living cells. In addition, by using the so-called {open_quotes}water window{close_quotes} area of the soft x-ray spectrum, a degree of natural contrast is introduced into the image due to differential absorption of the wavelengths by compounds with a high carbon content compared to those with a greater oxygen content. The variation in carbon concentration throughout a cell therefore generates an image which is dependent upon the carbon density within the specimen. Using soft x-ray contact microscopy the authors have previously examined the green alga Chlamydomonas reinhardtii, and the most prominent feature of the cells are the numerous x-ray absorbing spheres, But they were not seen by conventional transmission electron microscopy. Similar structures have also been reported by the Goettingen group using their cryo transmission x-ray microscope at BESSY. Despite the fact that these spheres appear to occupy up to 20% or more of the cell volume when seen by x-ray microscopy, they are not visible by transmission electron microscopy. Given the difficulties and criticisms associated with soft x-ray contact microscopy, the present study was aimed at confirming the existence of these cellular inclusions and learning more of their possible chemical composition.

  12. Nitrogen-Sparing Mechanisms in Chlamydomonas Affect the Transcriptome, the Proteome, and Photosynthetic Metabolism. (United States)

    Schmollinger, Stefan; Mühlhaus, Timo; Boyle, Nanette R; Blaby, Ian K; Casero, David; Mettler, Tabea; Moseley, Jeffrey L; Kropat, Janette; Sommer, Frederik; Strenkert, Daniela; Hemme, Dorothea; Pellegrini, Matteo; Grossman, Arthur R; Stitt, Mark; Schroda, Michael; Merchant, Sabeeha S


    Nitrogen (N) is a key nutrient that limits global primary productivity; hence, N-use efficiency is of compelling interest in agriculture and aquaculture. We used Chlamydomonas reinhardtii as a reference organism for a multicomponent analysis of the N starvation response. In the presence of acetate, respiratory metabolism is prioritized over photosynthesis; consequently, the N-sparing response targets proteins, pigments, and RNAs involved in photosynthesis and chloroplast function over those involved in respiration. Transcripts and proteins of the Calvin-Benson cycle are reduced in N-deficient cells, resulting in the accumulation of cycle metabolic intermediates. Both cytosolic and chloroplast ribosomes are reduced, but via different mechanisms, reflected by rapid changes in abundance of RNAs encoding chloroplast ribosomal proteins but not cytosolic ones. RNAs encoding transporters and enzymes for metabolizing alternative N sources increase in abundance, as is appropriate for the soil environmental niche of C. reinhardtii. Comparison of the N-replete versus N-deplete proteome indicated that abundant proteins with a high N content are reduced in N-starved cells, while the proteins that are increased have lower than average N contents. This sparing mechanism contributes to a lower cellular N/C ratio and suggests an approach for engineering increased N-use efficiency.

  13. Nitrogen-Sparing Mechanisms in Chlamydomonas Affect the Transcriptome, the Proteome, and Photosynthetic Metabolism[W (United States)

    Schmollinger, Stefan; Mühlhaus, Timo; Boyle, Nanette R.; Blaby, Ian K.; Casero, David; Mettler, Tabea; Moseley, Jeffrey L.; Kropat, Janette; Sommer, Frederik; Strenkert, Daniela; Hemme, Dorothea; Pellegrini, Matteo; Grossman, Arthur R.; Stitt, Mark; Schroda, Michael; Merchant, Sabeeha S.


    Nitrogen (N) is a key nutrient that limits global primary productivity; hence, N-use efficiency is of compelling interest in agriculture and aquaculture. We used Chlamydomonas reinhardtii as a reference organism for a multicomponent analysis of the N starvation response. In the presence of acetate, respiratory metabolism is prioritized over photosynthesis; consequently, the N-sparing response targets proteins, pigments, and RNAs involved in photosynthesis and chloroplast function over those involved in respiration. Transcripts and proteins of the Calvin-Benson cycle are reduced in N-deficient cells, resulting in the accumulation of cycle metabolic intermediates. Both cytosolic and chloroplast ribosomes are reduced, but via different mechanisms, reflected by rapid changes in abundance of RNAs encoding chloroplast ribosomal proteins but not cytosolic ones. RNAs encoding transporters and enzymes for metabolizing alternative N sources increase in abundance, as is appropriate for the soil environmental niche of C. reinhardtii. Comparison of the N-replete versus N-deplete proteome indicated that abundant proteins with a high N content are reduced in N-starved cells, while the proteins that are increased have lower than average N contents. This sparing mechanism contributes to a lower cellular N/C ratio and suggests an approach for engineering increased N-use efficiency. PMID:24748044

  14. The Proteome of Copper, Iron, Zinc, and Manganese Micronutrient Deficiency in Chlamydomonas reinhardtii* (United States)

    Hsieh, Scott I.; Castruita, Madeli; Malasarn, Davin; Urzica, Eugen; Erde, Jonathan; Page, M. Dudley; Yamasaki, Hiroaki; Casero, David; Pellegrini, Matteo; Merchant, Sabeeha S.; Loo, Joseph A.


    Trace metals such as copper, iron, zinc, and manganese play important roles in several biochemical processes, including respiration and photosynthesis. Using a label-free, quantitative proteomics strategy (MSE), we examined the effect of deficiencies in these micronutrients on the soluble proteome of Chlamydomonas reinhardtii. We quantified >103 proteins with abundances within a dynamic range of 3 to 4 orders of magnitude and demonstrated statistically significant changes in ∼200 proteins in each metal-deficient growth condition relative to nutrient-replete media. Through analysis of Pearson's coefficient, we also examined the correlation between protein abundance and transcript abundance (as determined via RNA-Seq analysis) and found moderate correlations under all nutritional states. Interestingly, in a subset of transcripts known to significantly change in abundance in metal-replete and metal-deficient conditions, the correlation to protein abundance is much stronger. Examples of new discoveries highlighted in this work include the accumulation of O2 labile, anaerobiosis-related enzymes (Hyd1, Pfr1, and Hcp2) in copper-deficient cells; co-variation of Cgl78/Ycf54 and coprogen oxidase; the loss of various stromal and lumenal photosynthesis-related proteins, including plastocyanin, in iron-limited cells; a large accumulation (from undetectable amounts to over 1,000 zmol/cell) of two COG0523 domain-containing proteins in zinc-deficient cells; and the preservation of photosynthesis proteins in manganese-deficient cells despite known losses in photosynthetic function in this condition. PMID:23065468

  15. Copper response regulator1-dependent and -independent responses of the Chlamydomonas reinhardtii transcriptome to dark anoxia. (United States)

    Hemschemeier, Anja; Casero, David; Liu, Bensheng; Benning, Christoph; Pellegrini, Matteo; Happe, Thomas; Merchant, Sabeeha S


    Anaerobiosis is a stress condition for aerobic organisms and requires extensive acclimation responses. We used RNA-Seq for a whole-genome view of the acclimation of Chlamydomonas reinhardtii to anoxic conditions imposed simultaneously with transfer to the dark. Nearly 1.4 × 10(3) genes were affected by hypoxia. Comparing transcript profiles from early (hypoxic) with those from late (anoxic) time points indicated that cells activate oxidative energy generation pathways before employing fermentation. Probable substrates include amino acids and fatty acids (FAs). Lipid profiling of the C. reinhardtii cells revealed that they degraded FAs but also accumulated triacylglycerols (TAGs). In contrast with N-deprived cells, the TAGs in hypoxic cells were enriched in desaturated FAs, suggesting a distinct pathway for TAG accumulation. To distinguish transcriptional responses dependent on copper response regulator1 (CRR1), which is also involved in hypoxic gene regulation, we compared the transcriptomes of crr1 mutants and complemented strains. In crr1 mutants, ~40 genes were aberrantly regulated, reaffirming the importance of CRR1 for the hypoxic response, but indicating also the contribution of additional signaling strategies to account for the remaining differentially regulated transcripts. Based on transcript patterns and previous results, we conclude that nitric oxide-dependent signaling cascades operate in anoxic C. reinhardtii cells.

  16. Transcriptome Analysis of Manganese-deficient Chlamydomonas reinhardtii Provides Insight on the Chlorophyll Biosynthesis Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lockhart, Ainsley; Zvenigorodsky, Natasha; Pedraza, Mary Ann; Lindquist, Erika


    The biosynthesis of chlorophyll and other tetrapyrroles is a vital but poorly understood process. Recent genomic advances with the unicellular green algae Chlamydomonas reinhardtii have created opportunity to more closely examine the mechanisms of the chlorophyll biosynthesis pathway via transcriptome analysis. Manganese is a nutrient of interest for complex reactions because of its multiple stable oxidation states and role in molecular oxygen coordination. C. reinhardtii was cultured in Manganese-deplete Tris-acetate-phosphate (TAP) media for 24 hours and used to create cDNA libraries for sequencing using Illumina TruSeq technology. Transcriptome analysis provided intriguing insight on possible regulatory mechanisms in the pathway. Evidence supports similarities of GTR (Glutamyl-tRNA synthase) to its Chlorella vulgaris homolog in terms of Mn requirements. Data was also suggestive of Mn-related compensatory up-regulation for pathway proteins CHLH1 (Manganese Chelatase), GUN4 (Magnesium chelatase activating protein), and POR1 (Light-dependent protochlorophyllide reductase). Intriguingly, data suggests possible reciprocal expression of oxygen dependent CPX1 (coproporphyrinogen III oxidase) and oxygen independent CPX2. Further analysis using RT-PCR could provide compelling evidence for several novel regulatory mechanisms in the chlorophyll biosynthesis pathway.

  17. Prospects of using unicellular algae protein in biological life-support systems. [Chlorella, Chlamydomonas, Spirulina, Euglena

    Energy Technology Data Exchange (ETDEWEB)

    Antonyan, A.A.; Abakumova, I.A.; Meleshko, G.I.; Vlasova, T.F.

    The concentration, amino acid composition and biological value of proteins of unicellular algae belonging to various taxonomic groups (Chlorella, Chlamydomonas, Spirulina, Euglena) were investigated. With respect to their characteristics, these algae hold promise as components of biological life-support systems (BLSS). Indices characterizing the protein and biomass quality and biological value were calculated. Such indices as A/E (where A is an essential amino acid and E is the sum total of amino acids), anti-E/T (where anti-E is nitrogen of essential amino acids and T is its sum total), amino acid number, factor of digestibility in vitro were high enough and close to the respective parameters of the reference protein. Animal experiments showed high biological value of the algal biomass and the lack of its toxic or other adverse effects. It is suggested that the differences in the protein composition associated with various algal forms and cultivation conditions can be used to produce balanced diets by varying the portion of each form of the photoautotropic component of BLSS.

  18. Two equilibration pools of chlorophylls in the Photosystem I core antenna of Chlamydomonas reinhardtii. (United States)

    Gibasiewicz, Krzysztof; Ramesh, V M; Lin, Su; Redding, Kevin; Woodbury, Neal W; Webber, Andrew N


    Femtosecond transient absorption spectroscopy was applied for a comparative study of excitation decay in several different Photosystem I (PSI) core preparations from the green alga Chlamydomonas reinhardtii. For PSI cores with a fully interconnected network of chlorophylls, the excitation energy was equilibrated over a pool of chlorophylls absorbing at approximately 683 nm, independent of excitation wavelength [Gibasiewicz et al. J Phys Chem B 105:11498-11506, 2001; J Phys Chem B 106:6322-6330, 2002]. In preparations with impaired connectivity between chlorophylls, we have found that the spectrum of chlorophylls connected to the reaction center (i.e., with approximately 20 ps decay time) over which the excitation is equilibrated becomes excitation-wavelength-dependent. Excitation at 670 nm is finally equilibrated over chlorophylls absorbing at approximately 675 nm, whereas excitation at 695 nm or 700 nm is equilibrated over chlorophylls absorbing at approximately 683 nm. This indicates that in the vicinity of the reaction center there are two spectrally different and spatially separated pools of chlorophylls that are equally capable of effective excitation energy transfer to the reaction center. We propose that they are related to the two groups of central PSI core chlorophylls lying on the opposite sides of reaction center.

  19. Controlling expression of genes in the unicellular alga Chlamydomonas reinhardtii with a vitamin-repressible riboswitch. (United States)

    Ramundo, Silvia; Rochaix, Jean-David


    Chloroplast genomes of land plants and algae contain generally between 100 and 150 genes. These genes are involved in plastid gene expression and photosynthesis and in various other tasks. The function of some chloroplast genes is still unknown and some of them appear to be essential for growth and survival. Repressible and reversible expression systems are highly desirable for functional and biochemical characterization of these genes. We have developed a genetic tool that allows one to regulate the expression of any coding sequence in the chloroplast genome of the unicellular alga Chlamydomonas reinhardtii. Our system is based on vitamin-regulated expression of the nucleus-encoded chloroplast Nac2 protein, which is specifically required for the expression of any plastid gene fused to the psbD 5'UTR. With this approach, expression of the Nac2 gene in the nucleus and, in turn, that of the chosen chloroplast gene artificially driven by the psbD 5'UTR, is controlled by the MetE promoter and Thi4 riboswitch, which can be inactivated in a reversible way by supplying vitamin B12 and thiamine to the growth medium, respectively. This system opens interesting possibilities for studying the assembly and turnover of chloroplast multiprotein complexes such as the photosystems, the ribosome, and the RNA polymerase. It also provides a way to overcome the toxicity often associated with the expression of proteins of biotechnological interest in the chloroplast.

  20. Retrograde Signaling and Photoprotection in a gun4 Mutant of Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    Cinzia Formighieri; Mauro Ceol; Giulia Bonente; Jean-David Rochaix; Roberto Bassi


    GUN4 is a regulatory subunit of Mg-chelatase involved in the control of tetrapyrrole synthesis in plants and cyanobacteria.Here,we report the first characterization of a gun4 insertion mutant of the unicellular green alga Chlamydomonas reinhardtii.The mutant contains 50% of chlorophyll as compared to wild-type and accumulates ProtolX.In contrast to the increase in LHCtranscription,the accumulation of most LHC proteins is drastically diminished,implying posttranscriptional down-regulation in the absence of transcriptional coordination.We found that 803 genes change their expression level in gun4 as compared to wild-type,by RNA-Seq,and this wide-ranging effect on transcription is apparent under physiological conditions.Besides LHCs,we identified transcripts encoding enzymes of the tetrapyrrole pathway and factors involved in signal transduction,transcription,and chromatin remodeling.Moreover,we observe perturbations in electron transport with a strongly decreased PSI-to-PSII ratio.This is accompanied by an enhanced activity of the plastid terminal oxidase (PTOX) that could have a physiological role in decreasing photosystem Ⅱ excitation pressure.

  1. Process development for hydrogen production with Chlamydomonas reinhardtii based on growth and product formation kinetics. (United States)

    Lehr, Florian; Morweiser, Michael; Rosello Sastre, Rosa; Kruse, Olaf; Posten, Clemens


    Certain strains of microalgae are long known to produce hydrogen under anaerobic conditions. In Chlamydomonas reinhardtii the oxygen-sensitive hydrogenase enzyme recombines electrons from the chloroplast electron transport chain with protons to form molecular hydrogen directly inside the chloroplast. A sustained hydrogen production can be obtained under low sulfur conditions in C. reinhardtii, reducing the net oxygen evolution by reducing the photosystem II activity and thereby overcoming the inhibition of the hydrogenases. The development of specially adapted hydrogen production strains led to higher yields and optimized biological process preconditions. So far sustainable hydrogen production required a complete exchange of the growth medium to establish sulfur-deprived conditions after biomass growth. In this work we demonstrate the transition from the biomass growth phase to the hydrogen production phase in a single batch culture only by exact dosage of sulfur. This eliminates the elaborate and energy intensive solid-liquid separation step and establishes a process strategy to proceed further versus large scale production. This strategy has been applied to determine light dependent biomass growth and hydrogen production kinetics to assess the potential of H₂ production with C. reinhardtii as a basis for scale up and further process optimization.

  2. Relief of arsenate toxicity by Cd-stimulated phytochelatin synthesis in the green alga Chlamydomonas reinhardtii. (United States)

    Kobayashi, Isao; Fujiwara, Shoko; Saegusa, Hirotaka; Inouhe, Masahiro; Matsumoto, Hiroko; Tsuzuki, Mikio


    In most photosynthetic organisms, inorganic arsenic taken up into the cells inhibits photosynthesis and cellular growth. In a green alga, Chlamydomonas reinhardtii, 0.5 mM arsenate inhibited photosynthesis almost completely within 30 min. However, in cells acclimated with a sublethal concentration (0.05 to 0.1 mM) of Cd, the inhibition of photosynthesis at 30 min after the addition of arsenate was relieved by more than 50%. The concentrations of arsenic incorporated into the cells were not significantly different between the Cd-acclimated and the non-acclimated cells. The Cd-acclimated cells accumulated Cd and synthesized phytochelatin (PC) peptides, which are known to play an important role in detoxification of heavy metals in plants. By the addition of an inhibitor of glutathione (an intermediate in the PC biosynthetic pathway) biosynthesis, buthionine sulfoximine, cells lost not only Cd tolerance but also arsenate tolerance. These results suggest that glutathione and/or PCs synthesized in Cd-acclimated cells are involved in mechanisms of arsenate tolerance.

  3. Integrated quantitative analysis of nitrogen stress response in Chlamydomonas reinhardtii using metabolite and protein profiling. (United States)

    Wase, Nishikant; Black, Paul N; Stanley, Bruce A; DiRusso, Concetta C


    Nitrogen starvation induces a global stress response in microalgae that results in the accumulation of lipids as a potential source of biofuel. Using GC-MS-based metabolite and iTRAQ-labeled protein profiling, we examined and correlated the metabolic and proteomic response of Chlamydomonas reinhardtii under nitrogen stress. Key amino acids and metabolites involved in nitrogen sparing pathways, methyl group transfer reactions, and energy production were decreased in abundance, whereas certain fatty acids, citric acid, methionine, citramalic acid, triethanolamine, nicotianamine, trehalose, and sorbitol were increased in abundance. Proteins involved in nitrogen assimilation, amino acid metabolism, oxidative phosphorylation, glycolysis, TCA cycle, starch, and lipid metabolism were elevated compared with nonstressed cultures. In contrast, the enzymes of the glyoxylate cycle, one carbon metabolism, pentose phosphate pathway, the Calvin cycle, photosynthetic and light harvesting complex, and ribosomes were reduced. A noteworthy observation was that citrate accumulated during nitrogen stress coordinate with alterations in the enzymes that produce or utilize this metabolite, demonstrating the value of comparing protein and metabolite profiles to understand complex patterns of metabolic flow. Thus, the current study provides unique insight into the global metabolic adjustments leading to lipid storage during N starvation for application toward advanced biofuel production technologies.

  4. Chlamydomonas as a model for biofuels and bio-products production. (United States)

    Scranton, Melissa A; Ostrand, Joseph T; Fields, Francis J; Mayfield, Stephen P


    Developing renewable energy sources is critical to maintaining the economic growth of the planet while protecting the environment. First generation biofuels focused on food crops like corn and sugarcane for ethanol production, and soybean and palm for biodiesel production. Second generation biofuels based on cellulosic ethanol produced from terrestrial plants, has received extensive funding and recently pilot facilities have been commissioned, but to date output of fuels from these sources has fallen well short of what is needed. Recent research and pilot demonstrations have highlighted the potential of algae as one of the most promising sources of sustainable liquid transportation fuels. Algae have also been established as unique biofactories for industrial, therapeutic, and nutraceutical co-products. Chlamydomonas reinhardtii's long established role in the field of basic research in green algae has paved the way for understanding algal metabolism and developing genetic engineering protocols. These tools are now being utilized in C. reinhardtii and in other algal species for the development of strains to maximize biofuels and bio-products yields from the lab to the field.

  5. Advances in the biotechnology of hydrogen production with the microalga Chlamydomonas reinhardtii. (United States)

    Torzillo, Giuseppe; Scoma, Alberto; Faraloni, Cecilia; Giannelli, Luca


    Biological hydrogen production is being evaluated for use as a fuel, since it is a promising substitute for carbonaceous fuels owing to its high conversion efficiency and high specific energy content. The basic advantages of biological hydrogen production over other "green" energy sources are that it does not compete for agricultural land use, and it does not pollute, as water is the only by-product of the combustion. These characteristics make hydrogen a suitable fuel for the future. Among several biotechnological approaches, photobiological hydrogen production carried out by green microalgae has been intensively investigated in recent years. A select group of photosynthetic organisms has evolved the ability to harness light energy to drive hydrogen gas production from water. Of these, the microalga Chlamydomonas reinhardtii is considered one of the most promising eukaryotic H2 producers. In this model microorganism, light energy, H2O and H2 are linked by two excellent catalysts, the photosystem 2 (PSII) and the [FeFe]-hydrogenase, in a pathway usually referred to as direct biophotolysis. This review summarizes the main advances made over the past decade as an outcome of the discovery of the sulfur-deprivation process. Both the scientific and technical barriers that need to be overcome before H2 photoproduction can be scaled up to an industrial level are examined. Actual and theoretical limits of the efficiency of the process are also discussed. Particular emphasis is placed on algal biohydrogen production outdoors, and guidelines for an optimal photobioreactor design are suggested.

  6. Recombination and Heterologous Expression of Allophycocyanin Gene in the Chloroplast of Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    Zhong-Liang SU; Kai-Xian QIAN; Cong-Ping TAN; Chun-Xiao MENG; Song QIN


    Heterogeneous expression of multiple genes in the nucleus of transgenic plants requires the introduction of an individual gene and the subsequent backcross to reconstitute multi-subunit proteins or metabolic pathways. In order to accomplish the expression of multiple genes in a single transformation event, we inserted both large and small subunits of allophycocyanin gene (apcA and apcB) into Chlamydomonas reinhardtii chloroplast expression vector, resulting in papc-S. The constructed vector was then introduced into the chloroplast of C. reinhardtii by micro-particle bombardment. Polymerase chain reaction and Southern blot analysis revealed that the two genes had integrated into the chloroplast genome. Western blot and enzyme-linked immunosorbent assay showed that the two genes from the prokaryotic cyanobacteria could be correctly expressed in the chloroplasts of C. reinhardtii. The expressed foreign protein in transformants accounted for about 2%-3% of total soluble proteins. These findings pave the way to the reconstitution of multi-subunit proteins or metabolic pathways in transgenic C. reinhardtii chloroplasts in a single transformation event.

  7. Linear systems analysis of the ciliary steering behavior associated with negative-phototaxis in Chlamydomonas reinhardtii. (United States)

    Josef, Keith; Saranak, Jureepan; Foster, Kenneth W


    In response to light stimulation Chlamydomonas reinhardtii changes the beating frequency, beating pattern, and beating synchrony of the trans and cis cilia to steer the freely-swimming cell relative to light sources. To understand the cell steering behavior the impulse responses of the beating frequency and stroke velocity of each cilium have been obtained with high temporal resolution on cells held with a micropipette. Interestingly the response of each cilium is quite different. The trans cilium responds with less delay than the cis cilium for both beating frequency and stroke velocity. For light stimulation at 2 Hz, the critical cell-rotation frequency, both responses of the trans and cis cilia are about 180 degrees out of phase. The trans-cilium beating frequency response peaks at a stimulus frequency of 5-6 Hz, higher than the cis at 1-2 Hz. The stroke velocities of the trans and cis cilia have the same stimulus-frequency response (2 Hz), but the trans cilium has a shorter delay than the cis. The times to maximum response are much shorter than the time for a rotation of the cell. The use of two different approaches that enable the trans cilium to respond ahead of the cis for both the beating frequency and stroke velocity responses suggests the importance of both responses to phototaxis. Internal cell processing responsible for the time course of the responses is proposed.

  8. Enhancement of lipid production and fatty acid profiling in Chlamydomonas reinhardtii, CC1010 for biodiesel production. (United States)

    Karpagam, R; Preeti, R; Ashokkumar, B; Varalakshmi, P


    Lipid from microalgae is one of the putative oil resources to facilitate the biodiesel production during this era of energy dissipation and environmental pollution. In this study, the key parameters such as biomass productivity, lipid productivity and lipid content were evaluated at the early stationary phase of Chlamydomonas reinhardtii, CC1010 cultivated in nutrient starved (nitrogen, phosphorous), glucose (0.05%, 0.1%, 0.15% and 0.2%) and vitamin B12 supplementation (0.001%, 0.002% and 0.003%) in Tris-Acetate-Phosphate (TAP) medium. The lipid content in nitrogen starved media was 61% which is 2.34 folds higher than nutrient sufficient TAP medium. Glucose supplementation has lead to proportional increase in biomass productivity with the increasing concentration of glucose whereas vitamin B12 supplementations had not shown any influence in lipid and biomass production. Further, fatty acid methyl ester (FAME) profiling of C. reinhardtii, CC 1010 has revealed more than 80% of total SFA (saturated fatty acid) and MUFA (mono unsaturated fatty acid) content. Quality checking parameters of biodiesel like cetane number, saponification value, iodine number and degree of unsaturation were analyzed and the biodiesel fuel properties were found to be appropriate as per the international standards, EN 14214 and ASTM D6751. Conclusively, among all the treatments, nitrogen starvation with 0.1% glucose supplementation had yielded high lipid content in C. reinhardtii, CC 1010.

  9. Ciprofloxacin toxicity and its co-metabolic removal by a freshwater microalga Chlamydomonas mexicana. (United States)

    Xiong, Jiu-Qiang; Kurade, Mayur B; Kim, Jung Rae; Roh, Hyun-Seog; Jeon, Byong-Hun


    This study evaluated the toxicity and cellular stresses of ciprofloxacin (CIP) and its co-metabolic removal in a freshwater microalga Chlamydomonas mexicana. The toxicological effects of CIP on C. mexicana were assessed by studying the growth and biochemical characteristics of the microalga including total chlorophyll, carotenoid content, malondialdehyde (MDA) and superoxide dismutase (SOD) activity. The calculated effective concentration (EC50) of CIP on C. mexicana was 65±4mgL(-1) at 96h. The growth of C. mexicana was significantly inhibited at increased concentrations of CIP, showing 36±1, 75±3. and 88±3% inhibition at 40, 60 and 100mgL(-1) CIP, respectively, compared to the control after 11days of cultivation. The total chlorophyll, carotenoid, MDA and SOD activity were significantly increased as a result of relatively high concentrations of CIP stress. C. mexicana showed 13±1% removal of CIP (2mgL(-1)) after 11days of cultivation; however, the addition of an electron donor (sodium acetate, 4gL(-1)) highly enhanced the removal of CIP (2mgL(-1)) by>3-fold after 11days. Kinetic studies showed that removal of CIP followed a first-order model (R(2) 0.94-0.97) with the apparent rate constants (k) ranging from 0.0121 to 0.079 d(-1).

  10. Toxicity of atrazine and its bioaccumulation and biodegradation in a green microalga, Chlamydomonas mexicana. (United States)

    Kabra, Akhil N; Ji, Min-Kyu; Choi, Jaewon; Kim, Jung Rae; Govindwar, Sanjay P; Jeon, Byong-Hun


    This study evaluated the toxicity of herbicide atrazine, along with its bioaccumulation and biodegradation in the green microalga Chlamydomonas mexicana. At low concentration (10 μg L(-1)), atrazine had no profound effect on the microalga, while higher concentrations (25, 50, and 100 μg L(-1)) imposed toxicity, leading to inhibition of cell growth and chlorophyll a accumulation by 22 %, 33 %, and 36 %, and 13 %, 24 %, and 27 %, respectively. Atrazine 96-h EC50 for C. mexicana was estimated to be 33 μg L(-1). Microalga showed a capability to accumulate atrazine in the cell and to biodegrade the cell-accumulated atrazine resulting in 14-36 % atrazine degradation at 10-100 μg L(-1). Increasing atrazine concentration decreased the total fatty acids (from 102 to 75 mg g(-1)) and increased the unsaturated fatty acid content in the microalga. Carbohydrate content increased gradually with the increase in atrazine concentration up to 15 %. This study shows that C. mexicana has the capability to degrade atrazine and can be employed for the remediation of atrazine-contaminated streams.

  11. An organelle K+ channel is required for osmoregulation in Chlamydomonas reinhardtii. (United States)

    Xu, Feifei; Wu, Xiaoan; Jiang, Lin-Hua; Zhao, Hucheng; Pan, Junmin


    Fresh water protozoa and algae face hypotonic challenges in their living environment. Many of them employ a contractile vacuole system to uptake excessive water from the cytoplasm and expel it to the environment to achieve cellular homeostasis. K(+), a major osmolyte in contractile vacuole, is predicted to create higher osmolarity for water influx. Molecular mechanisms for K(+) permeation through the plasma membrane have been well studied. However, how K(+) permeates organelles such as the contractile vacuole is not clear. Here, we show that the six-transmembrane K(+) channel KCN11 in Chlamydomonas is exclusively localized to contractile vacuole. Ectopic expression of KCN11 in HEK293T cells results in voltage-gated K(+) channel activity. Disruption of the gene or mutation of key residues for K(+) permeability of the channel leads to dysfunction of cell osmoregulation in very hypotonic conditions. The contractile cycle is inhibited in the mutant cells with a slower rate of contractile vacuole swelling, leading to cell death. These data demonstrate a new role for six-transmembrane K(+) channels in contractile vacuole functioning and provide further insights into osmoregulation mediated by the contractile vacuole.

  12. The Unicellular Green Alga Chlamydomonas reinhardtii as an Experimental System to Study Chloroplast RNA Metabolism (United States)

    Nickelsen, J.; Kück, U.

    Chloroplasts are typical organelles of photoautotrophic eukaryotic cells which drive a variety of functions, including photosynthesis. For many years the unicellular green alga Chlamydomonas reinhardtii has served as an experimental organism for studying photosynthetic processes. The recent development of molecular tools for this organism together with efficient methods of genetic analysis and the availability of many photosynthesis mutants has now made this alga a powerful model system for the analysis of chloroplast biogenesis. For example, techniques have been developed to transfer recombinant DNA into both the nuclear and the chloroplast genome. This allows both complementation tests and analyses of gene functions in vivo. Moreover, site-specific DNA recombinations in the chloroplast allow targeted gene disruption experiments which enable a "reverse genetics" to be performed. The potential of the algal system for the study of chloroplast biogenesis is illustrated in this review by the description of regulatory systems of gene expression involved in organelle biogenesis. One example concerns the regulation of trans-splicing of chloroplast mRNAs, a process which is controlled by both multiple nuclear- and chloroplast-encoded factors. The second example involves the stabilization of chloroplast mRNAs. The available data lead us predict distinct RNA elements, which interact with trans-acting factors to protect the RNA against nucleolytic attacks.

  13. Mutagenesis of Ser24 of cytochrome b559 α subunit affects PSⅡ activities in Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    MA JingJing; LI LiangBi; JING YuXiang; KUANG TingYun


    In order to study the functions of cytochrome b559 (Cyt b559) in photosystem two (PSⅡ) activity, mutant S24F of Chlamydomonas reinhardtii was constructed using site directed mutagenesis, in which Serine24 (Ser24) locating downstream of Histidine23 (His23) in c subunit of Cyt b559 was replaced by Phenylalanine (Phe). Physiological and biochemical analysis showed that mutant S24F could be grown photoautotrophically or photoheterotrophically. However, their growth rate was slower either on HSM or TAP medium than that of the control; Analysis of PSⅡ activity revealed that its oxygen evolution was about 71% of wild type (WT); The Photochemical efficiency of PSll (Fv/Fm) of S24F was reduced 0.23 compared with WT; S24F was more sensitive to strong light irradiance than the wild type; Furthermore,SDS-PAGE and Western-blotting analysis indicated that the expression levels of c subunit of Cyt b559,LHCⅡ and PsbO of S24F were a little less than those of the wild type. Overall, these data suggests that Ser24 plays a significant role in making Cyt b559 structure maintain PSⅡ complex activity of oxygen evolution although it is not directly bound to heme group.

  14. Phosphoribulokinase from Chlamydomonas reinhardtii: a Benson-Calvin cycle enzyme enslaved to its cysteine residues. (United States)

    Thieulin-Pardo, Gabriel; Remy, Thérèse; Lignon, Sabrina; Lebrun, Régine; Gontero, Brigitte


    Phosphoribulokinase (PRK) in the green alga Chlamydomonas reinhardtii is a finely regulated and well-studied enzyme of the Benson-Calvin cycle. PRK can form a complex with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the small chloroplast protein CP12. This study aimed to determine the molecular determinants on PRK involved in the complex and the mechanism of action of a recently described novel regulation of PRK that involves glutathionylation. A combination of mass spectrometry, mutagenesis and activity analyses showed that Cys16, besides its role as the binding site of ATP, was also the site for S-glutathionylation. Previous kinetic analysis of the C55S mutant showed that in the oxidized inactive form of PRK, this residue formed a disulfide bridge with the Cys16 residue. This is the only bridge reported for PRK in the literature. Our data show for the first time that a disulfide bridge between Cys243 and Cys249 on PRK is required to form the PRK-GAPDH-CP12 complex. These results uncover a new mechanism for the PRK-GAPDH-CP12 formation involving a thiol disulfide exchange reaction with CP12 and identify Cys16 of PRK as a target of glutathionylation acting against oxidative stress. Although Cys16 is the key residue involved in binding ATP and acting as a defense against oxidative damage, the formation of the algal ternary complex requires the formation of another disulfide bridge on PRK involving Cys243 and Cys249.

  15. Integration of carbon assimilation modes with photosynthetic light capture in the green alga Chlamydomonas reinhardtii. (United States)

    Berger, Hanna; Blifernez-Klassen, Olga; Ballottari, Matteo; Bassi, Roberto; Wobbe, Lutz; Kruse, Olaf


    The unicellular green alga Chlamydomonas reinhardtii is capable of using organic and inorganic carbon sources simultaneously, which requires the adjustment of photosynthetic activity to the prevailing mode of carbon assimilation. We obtained novel insights into the regulation of light-harvesting at photosystem II (PSII) following altered carbon source availability. In C. reinhardtii, synthesis of PSII-associated light-harvesting proteins (LHCBMs) is controlled by the cytosolic RNA-binding protein NAB1, which represses translation of particular LHCBM isoform transcripts. This mechanism is fine-tuned via regulation of the nuclear NAB1 promoter, which is activated when linear photosynthetic electron flow is restricted by CO(2)-limitation in a photoheterotrophic context. In the wild-type, accumulation of NAB1 reduces the functional PSII antenna size, thus preventing a harmful overexcited state of PSII, as observed in a NAB1-less mutant. We further demonstrate that translation control as a newly identified long-term response to prolonged CO(2)-limitation replaces LHCII state transitions as a fast response to PSII over-excitation. Intriguingly, activation of the long-term response is perturbed in state transition mutant stt7, suggesting a regulatory link between the long- and short-term response. We depict a regulatory circuit operating on distinct timescales and in different cellular compartments to fine-tune light-harvesting in photoheterotrophic eukaryotes.

  16. Towards elucidation of the toxic mechanism of copper on the model green alga Chlamydomonas reinhardtii. (United States)

    Jiang, Yongguang; Zhu, Yanli; Hu, Zhangli; Lei, Anping; Wang, Jiangxin


    Toxic effects of copper on aquatic organisms in polluted water bodies have garnered particular attention in recent years. Microalgae play an important role in aquatic ecosystems, and they are sensitive to heavy metal pollution. Thus, it is important to clarify the mechanism of copper toxicity first for ecotoxicology studies. In this study, the physiological, biochemical and gene expression characteristics of a model green microalga, Chlamydomonas reinhardtii, with 0, 50, 150 and 250 μM copper treatments were investigated. The response of C. reinhardtii to copper stress was significantly shown at a dose dependent manner. Inhibition of cell growth and variation of total chlorophyll content were observed with copper treatments. The maximum photochemical efficiency of PSII, actual photochemical efficiency of PSII and photochemical quenching value decreased in the 250 μM copper treatment with minimum values equal to 28, 24 and 60 % of the control values respectively. The content of lipid peroxidation biomarker malondialdehyde with copper treatments increased with a maximum value sevenfold higher than the control value. Inhibition of cell growth and photosynthesis was ascribed to peroxidation of membrane lipids. The glutathione content and activities of antioxidant enzymes, glutathione S-transferase, glutathione peroxidase, superoxide dismutase and peroxidase were induced by copper. Interestingly, the expression of antioxidant genes and the photosynthetic gene decreased in most copper treatments. In conclusion, oxidative stress caused by production of excess reactive oxidative species might be the major mechanism of copper toxicity on C. reinhardtii.

  17. Phytotoxicity of 15 common pharmaceuticals on the germination of Lactuca sativa and photosynthesis of Chlamydomonas reinhardtii. (United States)

    Pino, Ma Rosa; Muñiz, Selene; Val, Jonatan; Navarro, Enrique


    Pharmaceuticals reach terrestrial environments through the application of treated wastewaters and biosolids to agricultural soils. We have investigated the toxicity of 15 common pharmaceuticals, classified as nonsteroidal anti-inflammatory drugs (NSAIDs), blood lipid-lowering agents, β-blockers and antibiotics, in two photosynthetic organisms. Twelve pharmaceuticals caused inhibitory effects on the radicle and hypocotyl elongation of Lactuca sativa seeds. The EC50 values obtained were in the range of 170-5656 mg L(-1) in the case of the radicle and 188-4558 mg L(-1) for the hypocotyl. Propranolol was the most toxic drug for both root and hypocotyl elongation, followed by the NSAIDs, then gemfibrozil and tetracycline. Other effects, such as root necrosis, inhibition of root growth and curly hairs, were detected. However, even at the highest concentrations tested (3000 mg L(-1)), seed germination was not affected. NSAIDs decreased the photosynthetic yield of Chlamydomonas reinhardtii, but only salicylic acid showed EC50 values below 1000 mg L(-1). The first effects detected at low concentrations, together with the concentrations found in environmental samples, indicate that the use of biosolids and wastewaters containing pharmaceuticals should be regulated and their compositions assessed in order to prevent medium- and long-term impacts on agricultural soils and crops.

  18. Genetic Analysis of the Chlamydomonas Reinhardtii I-Crei Mobile Intron Homing System in Escherichia Coli (United States)

    Seligman, L. M.; Stephens, K. M.; Savage, J. H.; Monnat-Jr., R. J.


    We have developed and used a genetic selection system in Escherichia coli to study functional requirements for homing site recognition and cleavage by a representative eukaryotic mobile intron endonuclease. The homing endonuclease, I-CreI, was originally isolated from the chloroplast of the unicellular green alga Chlamydomonas reinhardtii. I-CreI homing site mutants contained base pair substitutions or single base deletions that altered the rate of homing site cleavage and/or product release. I-CreI endonuclease mutants fell into six phenotypic classes that differed in in vivo activity, toxicity or genetic dominance. Inactivating mutations clustered in the N-terminal 60% of the I-CreI amino acid sequence, and two frameshift mutations were isolated that resulted in premature translation termination though retained partial activity. These mutations indicate that the N-terminal two-thirds of the I-CreI endonuclease is sufficient for homing site recognition and cleavage. Substitution mutations altered in four potential active site residues were examined: D20N, Q47H or R70A substitutions inactivated endonuclease activity, whereas S22A did not. The genetic approach we have taken complements phylogenetic and structural studies of mobile intron endonucleases and has provided new information on the mechanistic basis of I-CreI homing site recognition and cleavage. PMID:9409828

  19. An omics based assessment of cadmium toxicity in the green alga Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Jamers, An; Blust, Ronny; De Coen, Wim [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Griffin, Julian L. [Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 2QA (United Kingdom); Jones, Oliver A.H., E-mail: [School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne, VIC 3001 (Australia)


    The effects of cadmium were assessed in the freshwater alga Chlamydomonas reinhardtii. Algae were exposed to concentrations of 0, 8.1 or 114.8 {mu}M of cadmium and growth rates, gene transcription and metabolite profiles were examined after 48 and 72 h of exposure. In algae exposed to 8.1 {mu}M Cd, several genes were differentially transcribed after 48 h but no adverse growth related effects were detected. A transient effect on both gene transcription patterns and metabolite profiles could be discerned after 48 h of exposure but the majority of these changes disappeared after 72 h. In contrast, all effects were more pronounced at the 114.8 {mu}M cadmium exposure. Here growth was clearly reduced and transcription of a large number of genes involved in oxidative stress defense mechanisms was differentially increased. Metabolites involved in the glutathione synthesis pathway (an important antioxidant defense) were also affected but the effects of cadmium were found to be more pronounced at the transcript level than in the metabolome, suggesting that the former exhibits greater sensitivity toward cadmium exposure.

  20. Characterization of a Native Algae Species Chlamydomonas debaryana: Strain Selection, Bioremediation Ability, and Lipid Characterization

    Directory of Open Access Journals (Sweden)

    Bo Zhang


    Full Text Available Native microalgal species may offer a favorable combination of both wastewater treatment and biofuel production. In this research, a green microalgae, Chlamydomonas debaryana, was isolated from a local lagoon, screened for its lipid content using flow cytometry, and further identified with microscopic observations and DNA sequence analysis. When using swine wastewater as a medium, the biomass yields were between 0.6 and 1.62 g/L, giving a median value of 1.11 g/L. By increasing mass transfer rates and providing sufficient light intensity, the microalgal growth was intrinsically enhanced. The growth of C. debaryana reduced most nutritional contents of the wastewater except iron. When combining the microalgal growth and nutrient removal, C. debaryana was able to utilize 1.3 to 1.6×103 mg COD (chemical oxygen demand/g biomass, 55 to 90 ppm ammonia/g biomass, and 48 to 89 ppm phosphorous/g biomass, The lipid content of C. debaryana was 19.9 ± 4.3% of cell dry weight. The transesterified microalgal oil mostly consisted of 14 kinds of fatty acids, ranging from C5 to C22, which can be refined into renewable jet fuel or used as sources of omega-3 and omega-6 fatty acids.

  1. The Chlamydomonas reinhardtii alternative oxidase 1 is regulated by heat stress. (United States)

    Zalutskaya, Zhanneta; Lapina, Tatiana; Ermilova, Elena


    The alternative oxidase (AOX) is a non-energy conserving terminal oxidase that has emerged as an important mitochondrial component of the cell stress responses. Although the most studied abiotic condition in relation to Chlamydomonas reinhardtii is high temperature, changes in AOX capacity of the alga were studied only under oxidative stress and cold. To examine whether elevated temperatures affected AOX1 expression, we applied quantitative real-time PCR and pharmaceutical approaches. In this work, we demonstrated a sharp increase in AOX1 transcript and protein abundance under heat stress. Furthermore, C. reinhardtii cells displayed a large increase in alternative respiration in response to high temperature. Feeding with the protein kinase inhibitor staurosporine strongly retarded the AOX1 transcription. Finally, the addition of the calcium chelator EGTA prevented heat-induced AOX1 expression. Together, our results imply that heat-inducible Ca(2+) influx and protein kinase(s) may mediate AOX1 expression at elevated temperatures. Characterization of heat-induced AOX1 regulation in the green alga C. reinhardtii provides a framework for a more complete understanding of the function of this conserved protein.

  2. Trophic transfer of gold nanoparticles from Euglena gracilis or Chlamydomonas reinhardtii to Daphnia magna. (United States)

    Lee, Woo-Mi; Yoon, Sung-Ji; Shin, Yu-Jin; An, Youn-Joo


    Understanding the trophic transfer of nanoparticles (NPs) is important because NPs are small enough to easily penetrate into organisms. In this study, we evaluated the trophic transfer of gold NPs (AuNPs) within the aquatic food chain. We observed AuNPs transfer from 2 species of primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna). Also, bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. The reasons for the difference in Au accumulation may be the physical structure of these organisms, and the surface area that is available for interaction with NPs. C. reinhardtii has a cell wall that may act as a barrier to the penetration of NPs. The size of E. gracilis is larger than that of C. reinhardtii. This study demonstrates the trophic transfer of AuNPs from a general producer to a consumer in an aquatic environment.

  3. A small multifunctional pentatricopeptide repeat protein in the chloroplast of Chlamydomonas reinhardtii. (United States)

    Jalal, Abdullah; Schwarz, Christian; Schmitz-Linneweber, Christian; Vallon, Olivier; Nickelsen, Jörg; Bohne, Alexandra-Viola


    Organellar biogenesis is mainly regulated by nucleus-encoded factors, which act on various steps of gene expression including RNA editing, processing, splicing, stabilization, and translation initiation. Among these regulatory factors, pentatricopeptide repeat (PPR) proteins form the largest family of RNA binding proteins, with hundreds of members in flowering plants. In striking contrast, the genome of the unicellular green alga Chlamydomonas reinhardtii encodes only 14 such proteins. In this study, we analyzed PPR7, the smallest and most highly expressed PPR protein in C. reinhardtii. Green fluorescent protein-based localization and gel-filtration analysis revealed that PPR7 forms a part of a high-molecular-weight ribonucleoprotein complex in the chloroplast stroma. RIP-chip analysis of PPR7-bound RNAs demonstrated that the protein associates with a diverse set of chloroplast transcripts in vivo, i.e. rrnS, psbH, rpoC2, rbcL, atpA, cemA-atpH, tscA, and atpI-psaJ. Furthermore, the investigation of PPR7 RNAi strains revealed that depletion of PPR7 results in a light-sensitive phenotype, accompanied by altered levels of its target RNAs that are compatible with the defects in their maturation or stabilization. PPR7 is thus an unusual type of small multifunctional PPR protein, which interacts, probably in conjunction with other RNA binding proteins, with numerous target RNAs to promote a variety of post-transcriptional events.

  4. Identification of regulatory network hubs that control lipid metabolism in Chlamydomonas reinhardtii. (United States)

    Gargouri, Mahmoud; Park, Jeong-Jin; Holguin, F Omar; Kim, Min-Jeong; Wang, Hongxia; Deshpande, Rahul R; Shachar-Hill, Yair; Hicks, Leslie M; Gang, David R


    Microalgae-based biofuels are promising sources of alternative energy, but improvements throughout the production process are required to establish them as economically feasible. One of the most influential improvements would be a significant increase in lipid yields, which could be achieved by altering the regulation of lipid biosynthesis and accumulation. Chlamydomonas reinhardtii accumulates oil (triacylglycerols, TAG) in response to nitrogen (N) deprivation. Although a few important regulatory genes have been identified that are involved in controlling this process, a global understanding of the larger regulatory network has not been developed. In order to uncover this network in this species, a combined omics (transcriptomic, proteomic and metabolomic) analysis was applied to cells grown in a time course experiment after a shift from N-replete to N-depleted conditions. Changes in transcript and protein levels of 414 predicted transcription factors (TFs) and transcriptional regulators (TRs) were monitored relative to other genes. The TF and TR genes were thus classified by two separate measures: up-regulated versus down-regulated and early response versus late response relative to two phases of polar lipid synthesis (before and after TAG biosynthesis initiation). Lipidomic and primary metabolite profiling generated compound accumulation levels that were integrated with the transcript dataset and TF profiling to produce a transcriptional regulatory network. Evaluation of this proposed regulatory network led to the identification of several regulatory hubs that control many aspects of cellular metabolism, from N assimilation and metabolism, to central metabolism, photosynthesis and lipid metabolism.

  5. The response of Chlamydomonas reinhardtii to nitrogen deprivation: a systems biology analysis. (United States)

    Park, Jeong-Jin; Wang, Hongxia; Gargouri, Mahmoud; Deshpande, Rahul R; Skepper, Jeremy N; Holguin, F Omar; Juergens, Matthew T; Shachar-Hill, Yair; Hicks, Leslie M; Gang, David R


    Drastic alteration in macronutrients causes large changes in gene expression in the photosynthetic unicellular alga Chlamydomonas reinhardtii. Preliminary data suggested that cells follow a biphasic response to this change hinging on the initiation of lipid accumulation, and we hypothesized that drastic repatterning of metabolism also followed this biphasic modality. To test this hypothesis, transcriptomic, proteomic, and metabolite changes that occur under nitrogen (N) deprivation were analyzed. Eight sampling times were selected covering the progressive slowing of growth and induction of oil synthesis between 4 and 6 h after N deprivation. Results of the combined, systems-level investigation indicated that C. reinhardtii cells sense and respond on a large scale within 30 min to a switch to N-deprived conditions turning on a largely gluconeogenic metabolic state, which then transitions to a glycolytic stage between 4 and 6 h after N depletion. This nitrogen-sensing system is transduced to carbon- and nitrogen-responsive pathways, leading to down-regulation of carbon assimilation and chlorophyll biosynthesis, and an increase in nitrogen metabolism and lipid biosynthesis. For example, the expression of nearly all the enzymes for assimilating nitrogen from ammonium, nitrate, nitrite, urea, formamide/acetamide, purines, pyrimidines, polyamines, amino acids and proteins increased significantly. Although arginine biosynthesis enzymes were also rapidly up-regulated, arginine pool size changes and isotopic labeling results indicated no increased flux through this pathway.

  6. Coordinated Regulation of Gene Expression for Carotenoid Metabolism in Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    Tian-Hu Sun; Cheng-Qian Liu; Yuan-Yuan Hui; Wen-Kai Wu; Zhi-Gang Zhou; Shan Lu


    Carotenoids are important plant pigments for both light harvesting and photooxidation protection.Using the model system of the unicellular green alga Chlamydomonas reinhardtii,we characterized the regulation of gene expression for carotenoid metabolism by quantifying changes in the transcript abundance of dxs,dxr and ipi in the plastidic methylerythritol phosphate pathway and of ggps,psy,pds,lcyb and bchy,directly involved in carotenoid metabolism,under different photoperiod,light and metabolite treatments.The expression of these genes fluctuated with light/dark shifting.Light treatment also promoted the accumulation of transcripts of all these genes.Of the genes studied,dxs,ggps and lcyb displayed the typical circadian pattern by retaining a rhythmic fluctuation of transcript abundance under both constant light and constant dark entrainments.The expression of these genes could also be regulated by metabolic intermediates.For example,ggps was significantly suppressed by a geranylgeranyl pyrophosphate supplement and ipi was upregulated by isopentenyl pyrophosphate.Furthermore,CrOr,a C.reinhardtii homolog of the recently characterized Or gene that accounts for carotenoid accumulation,also showed co-expression with carotenoid biosynthetic genes such as pds and lcyb.Our data suggest a coordinated regulation on carotenoid metabolism in C.reinhardtii at the transcriptional level.

  7. Virtual reality for intelligent and interactive operating, training, and visualization systems (United States)

    Freund, Eckhard; Rossmann, Juergen; Schluse, Michael


    Virtual Reality Methods allow a new and intuitive way of communication between man and machine. The basic idea of Virtual Reality (VR) is the generation of artificial computer simulated worlds, which the user not only can look at but also can interact with actively using data glove and data helmet. The main emphasis for the use of such techniques at the IRF is the development of a new generation of operator interfaces for the control of robots and other automation components and for intelligent training systems for complex tasks. The basic idea of the methods developed at the IRF for the realization of Projective Virtual Reality is to let the user work in the virtual world as he would act in reality. The user actions are recognized by the Virtual reality System and by means of new and intelligent control software projected onto the automation components like robots which afterwards perform the necessary actions in reality to execute the users task. In this operation mode the user no longer has to be a robot expert to generate tasks for robots or to program them, because intelligent control software recognizes the users intention and generated automatically the commands for nearly every automation component. Now, Virtual Reality Methods are ideally suited for universal man-machine-interfaces for the control and supervision of a big class of automation components, interactive training and visualization systems. The Virtual Reality System of the IRF-COSIMIR/VR- forms the basis for different projects starting with the control of space automation systems in the projects CIROS, VITAL and GETEX, the realization of a comprehensive development tool for the International Space Station and last but not least with the realistic simulation fire extinguishing, forest machines and excavators which will be presented in the final paper in addition to the key ideas of this Virtual Reality System.

  8. A Study on Immersion of Hand Interaction for Mobile Platform Virtual Reality Contents


    Seunghun Han; Jinmo Kim


    This study proposes gaze-based hand interaction, which is helpful for improving the user’s immersion in the production process of virtual reality content for the mobile platform, and analyzes efficiency through an experiment using a questionnaire. First, three-dimensional interactive content is produced for use in the proposed interaction experiment while presenting an experiential environment that gives users a high sense of immersion in the mobile virtual reality environment. This is design...

  9. Virtual reality and the CAVE: Taxonomy, interaction challenges and research directions


    Muhanna A. Muhanna


    One of the main goals of virtual reality is to provide immersive environments that take participants away from the real life into a virtual one. Many investigators have been interested in bringing new technologies, devices, and applications to facilitate this goal. Few, however, have focused on the specific human–computer interaction aspects of such environments. In this article we present our literature review of virtual reality and the Cave Automated Virtual Environment (CAVE). In particula...

  10. Utilizing virtual and augmented reality for educational and clinical enhancements in neurosurgery. (United States)

    Pelargos, Panayiotis E; Nagasawa, Daniel T; Lagman, Carlito; Tenn, Stephen; Demos, Joanna V; Lee, Seung J; Bui, Timothy T; Barnette, Natalie E; Bhatt, Nikhilesh S; Ung, Nolan; Bari, Ausaf; Martin, Neil A; Yang, Isaac


    Neurosurgery has undergone a technological revolution over the past several decades, from trephination to image-guided navigation. Advancements in virtual reality (VR) and augmented reality (AR) represent some of the newest modalities being integrated into neurosurgical practice and resident education. In this review, we present a historical perspective of the development of VR and AR technologies, analyze its current uses, and discuss its emerging applications in the field of neurosurgery.

  11. Extended Endoscopic Endonasal Approaches for Cerebral Aneurysms: Anatomical, Virtual Reality and Morphometric Study


    Alberto Di Somma; Matteo de Notaris; Vita Stagno; Luis Serra; Joaquim Enseñat; Isam Alobid; Joan San Molina; Joan Berenguer; Paolo Cappabianca; Alberto Prats-Galino


    Introduction. The purpose of the present contribution is to perform a detailed anatomic and virtual reality three-dimensional stereoscopic study in order to test the effectiveness of the extended endoscopic endonasal approaches for selected anterior and posterior circulation aneurysms. Methods. The study was divided in two main steps: (1) simulation step, using a dedicated Virtual Reality System (Dextroscope, Volume Interactions); (2) dissection step, in which the feasibility to reach specifi...

  12. A Distributed Architecture for Collaborative Teleoperation using Virtual Reality and Web Platforms



    International audience; Augmented Reality (AR) can provide to a Human Operator (HO) a real help to achieve complex tasks, such as remote control of robots and cooperative teleassistance. Using appropriate augmentations, the HO can interact faster, safer and easier with the remote real world. In this paper, we present an extension of an existing distributed software and network architecture for collaborative teleoperation based on networked human-scaled mixed reality and mobile platform. The f...

  13. Computer Vision Assisted Virtual Reality Calibration (United States)

    Kim, W.


    A computer vision assisted semi-automatic virtual reality (VR) calibration technology has been developed that can accurately match a virtual environment of graphically simulated three-dimensional (3-D) models to the video images of the real task environment.

  14. ARLearn: augmented reality meets augmented virtuality

    NARCIS (Netherlands)

    Ternier, Stefaan; Klemke, Roland; Kalz, Marco; Van Ulzen, Patricia; Specht, Marcus


    Ternier, S., Klemke, R., Kalz, M., Van Ulzen, P., & Specht, M. (2012). ARLearn: augmented reality meets augmented virtuality [Special issue]. Journal of Universal Computer Science - Technology for learning across physical and virtual spaces, 18(15), 2143-2164.

  15. Augmented Reality Simulations on Handheld Computers (United States)

    Squire, Kurt; Klopfer, Eric


    Advancements in handheld computing, particularly its portability, social interactivity, context sensitivity, connectivity, and individuality, open new opportunities for immersive learning environments. This article articulates the pedagogical potential of augmented reality simulations in environmental engineering education by immersing students in…

  16. Handbook for evaluation studies in virtual reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore; Koeffel, Christina


    Virtual reality (VR) applications are spreading and attract industries since VR technologies are becoming more affordable, powerful and robust. VR applications inherently call for human-computer interaction, which in turn calls for system and usability evaluations, typically through measurement...

  17. Den lidt for virkelige reality

    Directory of Open Access Journals (Sweden)

    Lars Holmgaard Christensen


    Full Text Available En vigtig dimension i de store reality koncepter som Robinson Ekspe- ditionen, Big Brother og Baren er deres høje grad af (interaktivitet, som bliver formidlet gennem andre medier. Artiklen behandler det dis- kussionsforum, som TV3 oprettede i forbindelse med Robinson Ekspe- ditionen 2000. Det spiller en særlig rolle, at kommunikationen foregår i et offentligt rum i regi af TV3, og debattørerne udfolder en opmærksom- hedsvækkende diskurs, som har en fornærmende og rituel karakter i forhold til de deltagende personer i Robinson Ekspeditionen. Over tid opstår der imidlertid en mere dialogisk samtaleform mellem de aktive personer i gruppen. Afslutningsvist diskuteres, om de aktive seeres indlæg kan formidles i en interaktiv form i forhold til selve tv-teksten. Det giver dog visse problemer at videreformidle de underholdende, men fornærmende indlæg direkte i tv’s offentlige rum.

  18. Augmented Reality Repair Guidance System

    Directory of Open Access Journals (Sweden)

    Sidharth Bhatia


    Full Text Available The daily life of a common man revolves around various forms of appliances/gadgets he uses throughout the day such as a mobile phone, laptop, printer, microwave oven, washing machine, etc. Although these appliances/gadgets are taken by most of the people for granted, the problem occurs when any of these things do not work as they are expected to. Getting them to the repair shops for every small glitch is expensive as well as time consuming. Although most of the companies which produce these appliances/gadgets do supply them with basic manuals, which deal with how to solve these minor issues, but reading them and at the same time repairing the corresponding appliance/gadget can be a frustrating task at times. These problems can be reduced to a large extent if some kind of live guidance is available. In this paper we propose a method to do so with the help of an augmented reality based system that will guide the user to carry out small scale repair jobs on these gadgets. All that is required is a decent webcam and a computing device, with a processor of 1 GHz or more and a display screen.

  19. Digital Augmented Reality Audio Headset

    Directory of Open Access Journals (Sweden)

    Jussi Rämö


    Full Text Available Augmented reality audio (ARA combines virtual sound sources with the real sonic environment of the user. An ARA system can be realized with a headset containing binaural microphones. Ideally, the ARA headset should be acoustically transparent, that is, it should not cause audible modification to the surrounding sound. A practical implementation of an ARA mixer requires a low-latency headphone reproduction system with additional equalization to compensate for the attenuation and the modified ear canal resonances caused by the headphones. This paper proposes digital IIR filters to realize the required equalization and evaluates a real-time prototype ARA system. Measurements show that the throughput latency of the digital prototype ARA system can be less than 1.4 ms, which is sufficiently small in practice. When the direct and processed sounds are combined in the ear, a comb filtering effect is brought about and appears as notches in the frequency response. The comb filter effect in speech and music signals was studied in a listening test and it was found to be inaudible when the attenuation is 20 dB. Insert ARA headphones have a sufficient attenuation at frequencies above about 1 kHz. The proposed digital ARA system enables several immersive audio applications, such as a virtual audio tourist guide and audio teleconferencing.

  20. Protective Measurement and Quantum Reality (United States)

    Gao, Shan


    1. Protective measurements: an introduction Shan Gao; Part I. Fundamentals and Applications: 2. Protective measurements of the wave function of a single system Lev Vaidman; 3. Protective measurement, postselection and the Heisenberg representation Yakir Aharonov and Eliahu Cohen; 4. Protective and state measurement: a review Gennaro Auletta; 5. Determination of the stationary basis from protective measurement on a single system Lajos Diósi; 6. Weak measurements, the energy-momentum tensor and the Bohm approach Robert Flack and Basil J. Hiley; Part II. Meanings and Implications: 7. Measurement and metaphysics Peter J. Lewis; 8. Protective measurements and the explanatory gambit Michael Dickson; 9. Realism and instrumentalism about the wave function: how should we choose? Mauro Dorato and Frederico Laudisa; 10. Protective measurements and the PBR theorem Guy Hetzroni and Daniel Rohrlich; 11. The roads not taken: empty waves, waveform collapse and protective measurement in quantum theory Peter Holland; 12. Implications of protective measurements on de Broglie-Bohm trajectories Aurelien Drezet; 13. Entanglement, scaling, and the meaning of the wave function in protective measurement Maximilian Schlosshauer and Tangereen V. B. Claringbold; 14. Protective measurements and the nature of the wave function within the primitive ontology approach Vincent Lam; 15. Reality and meaning of the wave function Shan Gao; Index.

  1. Water-friendly virtual reality pain control during wound care. (United States)

    Hoffman, Hunter G; Patterson, David R; Magula, Jeff; Carrougher, Gretchen J; Zeltzer, Karen; Dagadakis, Stephen; Sharar, Sam R


    Recent research suggests that entering an immersive virtual environment can serve as a powerful nonpharmacologic analgesic for severe burn pain. The present case study describes an attempt to use water-friendly virtual reality (VR) technology with a burn patient undergoing wound care in a hydrotherapy tub. The patient was a 40-year-old male with 19% total body surface area deep flame/flash burns to his legs, neck, back, and buttocks. The virtual reality treatment decreased the patient's sensory and affective pain ratings and decreased the amount of time spent thinking about his pain during wound care. We believe that VR analgesia works by drawing attention away from the wound care, leaving less attention available to process incoming pain signals. The water-friendly VR helmet dramatically increases the number of patients with severe burns that could potentially be treated with VR (see

  2. Virtual Reality: An Efficient Way in GIS Classroom Teaching

    Directory of Open Access Journals (Sweden)

    Jiangfan Feng


    Full Text Available Although geographic information system (GIS education has been spread widely, it becomes increasingly apparent that two-dimensional maps cannot be precisely present multidimensional and dynamic spatial phenomena. It seems that merging GIS and Virtual Reality (VR is a way to deal with these issues in terms of GIS classroom teaching. Virtual learning environment is the simulation of teaching method, thinking model, cognition manner and control means in the actual learning environment. This paper introduces virtual reality technology and the necessity of applying in GIS education and instruction, which explain the basic method and achieving a way of VR technology applying in the GIS classroom teaching with the instance of VR. The purpose of this paper is to analyze the application of virtual realistic learning environment for GIS education and establish a classroom teaching model accordingly.

  3. Augmented Reality Based Doppler Lidar Data Visualization: Promises and Challenges (United States)

    Cherukuru, N. W.; Calhoun, R.


    Augmented reality (AR) is a technology in which the enables the user to view virtual content as if it existed in real world. We are exploring the possibility of using this technology to view radial velocities or processed wind vectors from a Doppler wind lidar, thus giving the user an ability to see the wind in a literal sense. This approach could find possible applications in aviation safety, atmospheric data visualization as well as in weather education and public outreach. As a proof of concept, we used the lidar data from a recent field campaign and developed a smartphone application to view the lidar scan in augmented reality. In this paper, we give a brief methodology of this feasibility study, present the challenges and promises of using AR technology in conjunction with Doppler wind lidars.

  4. A Standalone Markerless 3D Tracker for Handheld Augmented Reality

    CERN Document Server

    Lima, Joao Paulo; Kelner, Judith


    This paper presents an implementation of a markerless tracking technique targeted to the Windows Mobile Pocket PC platform. The primary aim of this work is to allow the development of standalone augmented reality applications for handheld devices based on natural feature tracking. In order to achieve this goal, a subset of two computer vision libraries was ported to the Pocket PC platform. They were also adapted to use fixed point math, with the purpose of improving the overall performance of the routines. The port of these libraries opens up the possibility of having other computer vision tasks being executed on mobile platforms. A model based tracking approach that relies on edge information was adopted. Since it does not require a high processing power, it is suitable for constrained devices such as handhelds. The OpenGL ES graphics library was used to perform computer vision tasks, taking advantage of existing graphics hardware acceleration. An augmented reality application was created using the implement...

  5. Teaching and Learning in the Mixed-Reality Science Classroom (United States)

    Tolentino, Lisa; Birchfield, David; Megowan-Romanowicz, Colleen; Johnson-Glenberg, Mina C.; Kelliher, Aisling; Martinez, Christopher


    As emerging technologies become increasingly inexpensive and robust, there is an exciting opportunity to move beyond general purpose computing platforms to realize a new generation of K-12 technology-based learning environments. Mixed-reality technologies integrate real world components with interactive digital media to offer new potential to combine best practices in traditional science learning with the powerful affordances of audio/visual simulations. This paper introduces the realization of a learning environment called SMALLab, the Situated Multimedia Arts Learning Laboratory. We present a recent teaching experiment for high school chemistry students. A mix of qualitative and quantitative research documents the efficacy of this approach for students and teachers. We conclude that mixed-reality learning is viable in mainstream high school classrooms and that students can achieve significant learning gains when this technology is co-designed with educators.

  6. ChemPreview: an augmented reality-based molecular interface. (United States)

    Zheng, Min; Waller, Mark P


    Human computer interfaces make computational science more comprehensible and impactful. Complex 3D structures such as proteins or DNA are magnified by digital representations and displayed on two-dimensional monitors. Augmented reality has recently opened another door to access the virtual three-dimensional world. Herein, we present an augmented reality application called ChemPreview with the potential to manipulate bio-molecular structures at an atomistic level. ChemPreview is available at, and is built on top of the Meta 1 platform ChemPreview can be used to interact with a protein in an intuitive way using natural hand gestures, thereby making it appealing to computational chemists or structural biologists. The ability to manipulate atoms in real world could eventually provide new and more efficient ways of extracting structural knowledge, or designing new molecules in silico.

  7. Visualization of Vector Field by Virtual Reality (United States)

    Kageyama, A.; Tamura, Y.; Sato, T.

    A visualization software program is developed in order to analyze three dimensional vector fields by means of today's advanced virtual reality technology. This program enables simulation researchers to interactively visualize stream lines, tracer particle motions, isosurfaces, etc.~with stereo view. The program accepts any kind of vector fields on structured mesh as an input data. A virtual reality hardware system, on which the program operates, and details of the program are described.

  8. Virtual Reality in the Medical Field


    Motomatsu, Haruka


    The objective is to analyze the use of the emerging 3D computer technology of VirtualReality in the use of relieving pain in physically impaired conditions such as burn victims,amputees, and phantom limb patients, during therapy and medical procedures. Virtualtechnology generates a three dimensional visual virtual world in which enables interaction.Comparison will be made between the emerging technology of the Virtual Reality and methodsusually used, which are the use of medicine. Medicine ha...

  9. Virtual Reality: immersed in the structural world


    McCabe, Aimee; McPolin, Daniel


    Virtual reality is a rapidly emerging technology, driven by the computer gaming industry. The maturity of the concept, combined with modern hardware, is delivering an experience which offers a useful commercial tool for industry and educators. This article discusses the uses of virtual reality within structural engineering and provides an understanding of how it can be incorporated easily and efficiently for design purposes and beyond.

  10. Voyeurismo Televisivo, Reality Shows e Brasilidade Televisiva


    Suzana Kilpp


    In the last years we watched a boom of reality shows in the media and also in the academic production specialized in this subject. It remains, however, a epistemological gap related to the aesthetic and techniques (which are related to the televisions grammars) that TV uses in these programs to enunciate ethics directions to its own voyeurism, that goes far beyond reality shows, having repercussions on social imaginary of transparency and surveillance, and the redesign of public and private s...

  11. The Development of Mobile Augmented Reality (United States)


    This chapter provides a high-level overview of fifteen years of augmented reality research that was sponsored by the U.S. Office of Naval Research...years by a number of university and industrial research laboratories. It laid the groundwork for the development of many commercial mobile augmented ... reality (AR) applications that are currently available for smartphones and tablets. Furthermore, it helped shape a number of ongoing research activities in mobile AR.

  12. Augmented REality Sandtables (ARESs) Impact on Learning (United States)


    ARL-CR-0803 ● JULY 2016 US Army Research Laboratory Augmented REality Sandtable’s (ARES’s) Impact on Learning by Tarah N...REality Sandtable’s (ARES’s) Impact on Learning by Tarah N Schmidt-Daly, Jennifer M Riley, Kelly S Hale, David Yacht, and Jack Hart Design...Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time


    Wender, Regina; Hoffman, Hunter G; Hunner, Harley H; Seibel, Eric J; Patterson, David R; Sharar, Sam R


    Despite medication with opioids and other powerful pharmacologic pain medications, most patients rate their pain during severe burn wound care as severe to excruciating. Excessive pain is a widespread medical problem in a wide range of patient populations. Immersive virtual reality (VR) distraction may help reduce pain associated with medical procedures. Recent research manipulating immersiveness has shown that a high tech VR helmet reduces pain more effectively than a low tech VR helmet. The present study explores the effect of interactivity on the analgesic effectiveness of virtual reality. Using a double blind design, in the present study, twenty-one volunteers were randomly assigned to one of two groups, and received a thermal pain stimulus during either interactive VR, or during non-interactive VR. Subjects in both groups individually glided through the virtual world, but one group could look around and interact with the environment using the trackball, whereas participants in the other group had no trackball. Afterwards, each participant provided subjective 0-10 ratings of cognitive, sensory and affective components of pain, and the amount of fun during the pain stimulus. Compared to the non-interactive VR group, participants in the interactive VR group showed 75% more reduction in pain unpleasantness (p virtual reality.

  14. Performance on a virtual reality angled laparoscope task correlates with spatial ability of trainees. (United States)

    Rosenthal, Rachel; Hamel, Christian; Oertli, Daniel; Demartines, Nicolas; Gantert, Walter A


    The aim of the present study was to investigate whether trainees' performance on a virtual reality angled laparoscope navigation task correlates with scores obtained on a validated conventional test of spatial ability. 56 participants of a surgery workshop performed an angled laparoscope navigation task on the Xitact LS 500 virtual reality Simulator. Performance parameters were correlated with the score of a validated paper-and-pencil test of spatial ability. Performance at the conventional spatial ability test significantly correlated with performance at the virtual reality task for overall task score (p travel speed (p = 0.947). In conclusion, trainees' performance in a standardized virtual reality camera navigation task correlates with their innate spatial ability. This VR session holds potential to serve as an assessment tool for trainees.

  15. Operating Room Performance Improves after Proficiency-Based Virtual Reality Cataract Surgery Training

    DEFF Research Database (Denmark)

    Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Kjærbo, Hadi


    PURPOSE: To investigate the effect of virtual reality proficiency-based training on actual cataract surgery performance. The secondary purpose of the study was to define which surgeons benefit from virtual reality training. DESIGN: Multicenter masked clinical trial. PARTICIPANTS: Eighteen cataract...... surgeons with different levels of experience. METHODS: Cataract surgical training on a virtual reality simulator (EyeSi) until a proficiency-based test was passed. MAIN OUTCOME MEASURES: Technical performance in the operating room (OR) assessed by 3 independent, masked raters using a previously validated...... task-specific assessment tool for cataract surgery (Objective Structured Assessment of Cataract Surgical Skill). Three surgeries before and 3 surgeries after the virtual reality training were video-recorded, anonymized, and presented to the raters in random order. RESULTS: Novices (non...

  16. 衣藻有性生殖的分子机制%Molecular Mechanism of Chlamydomonas Mating

    Institute of Scientific and Technical Information of China (English)

    李修岭; 李夜光


    衣藻作为分子生物学研究的模式材料,被广泛用于植物光合作用、鞭毛组装与功能、细胞周期与节律、细胞信号传导与光感受、细胞识别等重要生物学过程的研究,而且衣藻有性生殖的分子机制与人类某些疾病的发生机制存在联系.该文对国内外近年来有关莱茵衣藻在有性生殖过程中凝集素的动态分布,包括鞭毛粘连、补充、传递、脱粘连、凝集素合成的正调节,以及与性凝集素行为有关的基因研究进展进行综述,以阐明衣藻有性生殖的分子机制,为人类的疾病研究提供参考.%As a model organism for studying photosynthesis of plant,flagella assembly and function,cell cycle and circadian rhythms,signal transduction,light perception and cell recognition,Chlamydomonas has been investigated widely.This review reported the advances in molecular mechanism of Chlamydomonas reinhardtii mating.We focused on adhension,tipping,disadhension and regulation of synthesis of sex agglutinins as well as some genes related with adhension of agglutinins.The molecular mechanism of Chlamydomonas mating might provide reference to the study of some human diseases.

  17. Filling Knowledge Gaps in Biological Networks: integrating global approaches to understand H2 metabolism in Chlamydomonas reinhardtii - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Posewitz, Matthew C


    The green alga Chlamydomonas reinhardtii (Chlamydomonas) has numerous genes encoding enzymes that function in fermentative pathways. Among these genes, are the [FeFe]-hydrogenases, pyruvate formate lyase, pyruvate ferredoxin oxidoreductase, acetate kinase, and phosphotransacetylase. We have systematically undertaken a series of targeted mutagenesis approaches to disrupt each of these key genes and omics techniques to characterize alterations in metabolic flux. Funds from DE-FG02-07ER64423 were specifically leveraged to generate mutants with disruptions in the genes encoding the [FeFe]-hydrogenases HYDA1 and HYDA2, pyruvate formate lyase (PFL1), and in bifunctional alcohol/aldehyde alcohol dehydrogenase (ADH1). Additionally funds were used to conduct global transcript profiling experiments of wildtype Chlamydomonas cells, as well as of the hydEF-1 mutant, which is unable to make H2 due to a lesion in the [FeFe]-hydrogenase biosynthetic pathway. In the wildtype cells, formate, acetate and ethanol are the dominant fermentation products with traces of CO2 and H2 also being produced. In the hydEF-1 mutant, succinate production is increased to offset the loss of protons as a terminal electron acceptor. In the pfl-1 mutant, lactate offsets the loss of formate production, and in the adh1-1 mutant glycerol is made instead of ethanol. To further probe the system, we generated a double mutant (pfl1-1 adh1) that is unable to synthesize both formate and ethanol. This strain, like the pfl1 mutants, secreted lactate, but also exhibited a significant increase in the levels of extracellular glycerol, acetate, and intracellular reduced sugars, and a decline in dark, fermentative H2 production. Whereas wild-type Chlamydomonas fermentation primarily produces formate and ethanol, the double mutant performs a complete rerouting of the glycolytic carbon to lactate and glycerol. Lastly, transcriptome data have been analysed for both the wildtype and hydEF-1, that correlate with our

  18. [Virtual reality therapy in anxiety disorders]. (United States)

    Mitrousia, V; Giotakos, O


    During the last decade a number of studies have been conducted in order to examine if virtual reality exposure therapy can be an alternative form of therapy for the treatment of mental disorders and particularly for the treatment of anxiety disorders. Imaginal exposure therapy, which is one of the components of Cognitive Behavioral Therapy, cannot be easily applied to all patients and in cases like those virtual reality can be used as an alternative or a supportive psychotherapeutic technique. Most studies using virtual reality have focused on anxiety disorders, mainly in specific phobias, but some extend to other disorders such as eating disorders, drug dependence, pain control and palliative care and rehabilitation. Main characteristics of virtual reality therapy are: "interaction", "immersion", and "presence". High levels of "immersion" and "presence" are associated with increased response to exposure therapy in virtual environments, as well as better therapeutic outcomes and sustained therapeutic gains. Typical devices that are used in order patient's immersion to be achieved are the Head-Mounted Displays (HMD), which are only for individual use, and the computer automatic virtual environment (CAVE), which is a multiuser. Virtual reality therapy's disadvantages lie in the difficulties that arise due to the demanded specialized technology skills, devices' cost and side effects. Therapists' training is necessary in order for them to be able to manipulate the software and the hardware and to adjust it to each case's needs. Devices' cost is high but as technology continuously improves it constantly decreases. Immersion during virtual reality therapy can induce mild and temporary side effects such as nausea, dizziness or headache. Until today, however, experience shows that virtual reality offers several advantages. Patient's avoidance to be exposed in phobic stimuli is reduced via the use of virtual reality since the patient is exposed to them as many times as he

  19. Antioxidant therapy: myth or reality?

    Energy Technology Data Exchange (ETDEWEB)

    Nunez-Selles, Alberto J. [Center of Pharmaceutical Chemistry, Havana (Cuba)]. E-mail:


    New terms such as oxidative stress, antioxidant products or pro-oxidant risks are becoming familiar and an increasing number of international scientific conferences and the publication of thousands of scientific articles is an indication of the growing interest that the subject awakens. The most publicized example is perhaps the French paradox, based on the apparent compatibility of a high fat diet with a low incidence of coronary atherosclerosis attributed to the regular consumption, by the French, of red wine and/or grape juice. Flavonoids, and other phenolic substances contained in red wine, are assigned with antioxidant properties, which lower the oxidation of low density lipoproteins and consequently, the risk of atherogenic diseases. Other examples are the aging process and its correlation with an increase of free radicals, and the correlation between the initiation and promotion of cancer and tissue injury by free radicals, which has induced the intake of antioxidant products as chemical factors that prevent the onset of the disease. Currently, the incidence of oxidative stress on the onset and evolution of more than 100 diseases is claimed by several researchers. All these are 'realities', which on the other hand, are lacking of more clinical evidence, are considered by both physicians and health regulatory bodies, either as 'myths' or of 'secondary' importance. In the attempts to destroy those myths, results of chemical, pre-clinical, and clinical works with a crude extract of mango (Mangifera indica L.) stem bark, which has been developed in Cuba, are reviewed, with a strong experimental evidence of its antioxidant, anti-inflammatory and immunomodulatory properties. (author)

  20. Reflective and refractive objects for mixed reality. (United States)

    Knecht, Martin; Traxler, Christoph; Winklhofer, Christoph; Wimmer, Michael


    In this paper, we present a novel rendering method which integrates reflective or refractive objects into a differential instant radiosity (DIR) framework usable for mixed-reality (MR) applications. This kind of objects are very special from the light interaction point of view, as they reflect and refract incident rays. Therefore they may cause high-frequency lighting effects known as caustics. Using instant-radiosity (IR) methods to approximate these high-frequency lighting effects would require a large amount of virtual point lights (VPLs) and is therefore not desirable due to real-time constraints. Instead, our approach combines differential instant radiosity with three other methods. One method handles more accurate reflections compared to simple cubemaps by using impostors. Another method is able to calculate two refractions in real-time, and the third method uses small quads to create caustic effects. Our proposed method replaces parts in light paths that belong to reflective or refractive objects using these three methods and thus tightly integrates into DIR. In contrast to previous methods which introduce reflective or refractive objects into MR scenarios, our method produces caustics that also emit additional indirect light. The method runs at real-time frame rates, and the results show that reflective and refractive objects with caustics improve the overall impression for MR scenarios.

  1. [Dengue vaccines. A reality for Argentina?]. (United States)

    Orellano, Pablo W; Salomón, Oscar D


    Dengue outbreaks have occurred yearly in Argentina since 1998. A number of candidate vaccines have been tested in endemic countries. The most advanced one was licensed in three countries of Latin America for children over 9 years of age. In the present article the benefits and drawbacks of these vaccines as well as the challenges for the implementation of a vaccination strategy in Argentina are discussed. Furthermore, a risk stratification strategy with new criteria and a multidisciplinary vision is suggested as a possible path for the assessment of the pertinence of a vaccination program in areas showing the highest risk of dengue transmission and/or for people at the greatest risk of developing severe dengue. It is also suggested that the definition regarding the status of endemicity should take into account the local realities. Finally, this paper proposes a broad discussion on the evidences, the expected impact and instrumental aspects that would be involved in the incorporation of a dengue vaccine, marketed or in development, into the national immunization program, and especially which subpopulation should be targeted for the immunization strategy to be cost-effective.

  2. Neuronavigation surgery in China: reality and prospects

    Institute of Scientific and Technical Information of China (English)

    WU Jin-song; LU Jun-feng; GONG Xiu; MAO Ying; ZHOU Liang-fu


    Objective To review the history,development,and reality of neuronavigation surgery in China and to discuss the future of neuronavigation surgery.Data sources PubMed,the China Knowledge Resource Integrated Database,and the VIP Database for Chinese Technical Periodicals were searched for papers published from 1995 to the present with the key words "neuronavigation,""functional navigation," "image-guided," and "stereotaxy." Articles were reviewed for additional citations,and some information was gathered from Web searches.Study selection Articles related to neuronavigation surgery in China were selected,with special attention to application to brain tumors.Results Since the introduction of neurosurgical navigation to China in 1997,this core technique in minimally invasive neurosurgery has seen rapid development.This development has ranged from brain structural localization to functional brain mapping,from static digital models of the brain to dynamic brain-shift compensation models,and from preoperative image-guided surgery to intraoperative real-time image-guided surgery,and from application of imported equipment and technology to use of equipment and technology that possess Chinese independent intellectual property rights.Conclusions The development and application of neuronavigation techniques have made neurological surgeries in China more safe,precise and effective,and less invasive,and promoted the quality of Chinese neurosurgical practice to the rank of the most advance and excellence in the world.

  3. Evaluating User Experience of Augmented Reality Eyeglasses. (United States)

    Gamberini, Luciano; Orso, Valeria; Beretta, Andrea; Jacucci, Giulio; Spagnolli, Anna; Rimondi, Romina


    Augmented reality based applications have been experimented with in various contexts. Typically, the interaction is supported by handled devices, which, in specific scenarios, may hinder the interaction and spoil the experience of use, as the user is forced to hold the device and to keep her eyes on it at all times. The recent launch on the market of light-weight, unobtrusive head-mounted displays may change this circumstance. Nevertheless, investigations are needed to understand if such head-worn devices effectively outperform handheld devices in terms of comfort and pleasant experience of use. Here we present two experiments aimed at assessing the comfort of wearing a head-worn, see-through AR viewer in both a controlled and a natural setting. Besides the comfort of wearing the device, aspects related to the user experience were also investigated in the field evaluation. Our findings suggest that the head-mounted display examined is comfortable to wear regardless of the context of use. Interestingly in the field trails, participants did not express concern for the impression they would have made on other people and the experience of use was overall pleasant. Possible issues related to visual fatigue emerged.

  4. Scalar Implicatures: The Psychological Reality of Scales. (United States)

    de Carvalho, Alex; Reboul, Anne C; Van der Henst, Jean-Baptiste; Cheylus, Anne; Nazir, Tatjana


    Scalar implicatures, the phenomena where a sentence like "The pianist played some Mozart sonatas" is interpreted, as "The pianist did not play all Mozart sonatas" have been given two different analyses. Neo-Griceans (NG) claim that this interpretation is based on lexical scales (e.g., ), where the stronger term (e.g., all) implies the weaker term (e.g., some), but the weaker term (e.g., some) implicates the negation of the stronger term (i.e., some = not all). Post-Griceans (PG) deny that this is the case and offer a context-based inferential account for scalar implicatures. While scalar implicatures have been extensively investigated, with results apparently in favor of PG accounts, the psychological reality of lexical scales has not been put to the test. This is what we have done in the present experiment, with a lexical decision task using lexical scales in a masked priming paradigm. While PG accounts do not attribute any role for lexical scales in the computation of scalar implicatures, NG accounts suggest that lexical scales are the core mechanism behind the computation of scalar implicatures, and predict that weaker terms in a scale should prime stronger terms more than the reverse because stronger words are necessary to the interpretation of weaker words, while stronger words can be interpreted independently of weaker words. Our results provided evidence in favor of the psychological existence of scales, leading to the first clear experimental support for the NG account.

  5. Lecture programme The reality of science today

    CERN Multimedia


    What are the new challenges and realities facing scientific research? What is its place in society today? To answer these questions, the History and Philosophy of Sciences Unit of Geneva University, in collaboration with ASPERA, the European network for astroparticle physics research, has organised a programme of lectures entitled La réalité de la science d’aujourd’hui, enjeux et défis de la diversité. This series of lectures will provide researchers and members of the public with a snapshot of the state of science today from the perspective of laboratories and institutes, and on subjects such as funding policy and technological and legal impact. The first lecture will be given by science historian Dominique Pestre (EHESS & Centre Koyré, Paris), renowned for his contributions to the analysis of science past and present, and notably one of the authors of the work "History of CERN". He will discuss the modern methods of producing scientific knowledge which have been develop...

  6. Simulating hemispatial neglect with virtual reality

    Directory of Open Access Journals (Sweden)

    Yoshizawa Makoto


    Full Text Available Abstract Background Hemispatial neglect is a cognitive disorder defined as a lack of attention for stimuli contra-lateral to the brain lesion. The assessment is traditionally done with basic pencil and paper tests and the rehabilitation programs are generally not well adapted. We propose a virtual reality system featuring an eye-tracking device for a better characterization of the neglect that will lead to new rehabilitation techniques. Methods This paper presents a comparison of eye-gaze patterns of healthy subjects, patients and healthy simulated patients on a virtual line bisection test. The task was also executed with a reduced visual field condition hoping that fewer stimuli would limit the neglect. Results We found that patients and healthy simulated patients had similar eye-gaze patterns. However, while the reduced visual field condition had no effect on the healthy simulated patients, it actually had a negative impact on the patients. We discuss the reasons for these differences and how they relate to the limitations of the neglect simulation. Conclusion We argue that with some improvements the technique could be used to determine the potential of new rehabilitation techniques and also help the rehabilitation staff or the patient's relatives to better understand the neglect condition.

  7. The path to triacylglyceride obesity in the sta6 strain of Chlamydomonas reinhardtii. (United States)

    Goodenough, Ursula; Blaby, Ian; Casero, David; Gallaher, Sean D; Goodson, Carrie; Johnson, Shannon; Lee, Jae-Hyeok; Merchant, Sabeeha S; Pellegrini, Matteo; Roth, Robyn; Rusch, Jannette; Singh, Manmilan; Umen, James G; Weiss, Taylor L; Wulan, Tuya


    When the sta6 (starch-null) strain of the green microalga Chlamydomonas reinhardtii is nitrogen starved in acetate and then "boosted" after 2 days with additional acetate, the cells become "obese" after 8 days, with triacylglyceride (TAG)-filled lipid bodies filling their cytoplasm and chloroplasts. To assess the transcriptional correlates of this response, the sta6 strain and the starch-forming cw15 strain were subjected to RNA-Seq analysis during the 2 days prior and 2 days after the boost, and the data were compared with published reports using other strains and growth conditions. During the 2 h after the boost, ∼425 genes are upregulated ≥2-fold and ∼875 genes are downregulated ≥2-fold in each strain. Expression of a small subset of "sensitive" genes, encoding enzymes involved in the glyoxylate and Calvin-Benson cycles, gluconeogenesis, and the pentose phosphate pathway, is responsive to culture conditions and genetic background as well as to boosting. Four genes-encoding a diacylglycerol acyltransferase (DGTT2), a glycerol-3-P dehydrogenase (GPD3), and two candidate lipases (Cre03.g155250 and Cre17.g735600)-are selectively upregulated in the sta6 strain. Although the bulk rate of acetate depletion from the medium is not boost enhanced, three candidate acetate permease-encoding genes in the GPR1/FUN34/YaaH superfamily are boost upregulated, and 13 of the "sensitive" genes are strongly responsive to the cell's acetate status. A cohort of 64 autophagy-related genes is downregulated by the boost. Our results indicate that the boost serves both to avert an autophagy program and to prolong the operation of key pathways that shuttle carbon from acetate into storage lipid, the combined outcome being enhanced TAG accumulation, notably in the sta6 strain.

  8. The Path to Triacylglyceride Obesity in the sta6 Strain of Chlamydomonas reinhardtii (United States)

    Blaby, Ian; Casero, David; Gallaher, Sean D.; Goodson, Carrie; Johnson, Shannon; Lee, Jae-Hyeok; Merchant, Sabeeha S.; Pellegrini, Matteo; Roth, Robyn; Rusch, Jannette; Singh, Manmilan; Umen, James G.; Weiss, Taylor L.; Wulan, Tuya


    When the sta6 (starch-null) strain of the green microalga Chlamydomonas reinhardtii is nitrogen starved in acetate and then “boosted” after 2 days with additional acetate, the cells become “obese” after 8 days, with triacylglyceride (TAG)-filled lipid bodies filling their cytoplasm and chloroplasts. To assess the transcriptional correlates of this response, the sta6 strain and the starch-forming cw15 strain were subjected to RNA-Seq analysis during the 2 days prior and 2 days after the boost, and the data were compared with published reports using other strains and growth conditions. During the 2 h after the boost, ∼425 genes are upregulated ≥2-fold and ∼875 genes are downregulated ≥2-fold in each strain. Expression of a small subset of “sensitive” genes, encoding enzymes involved in the glyoxylate and Calvin-Benson cycles, gluconeogenesis, and the pentose phosphate pathway, is responsive to culture conditions and genetic background as well as to boosting. Four genes—encoding a diacylglycerol acyltransferase (DGTT2), a glycerol-3-P dehydrogenase (GPD3), and two candidate lipases (Cre03.g155250 and Cre17.g735600)—are selectively upregulated in the sta6 strain. Although the bulk rate of acetate depletion from the medium is not boost enhanced, three candidate acetate permease-encoding genes in the GPR1/FUN34/YaaH superfamily are boost upregulated, and 13 of the “sensitive” genes are strongly responsive to the cell's acetate status. A cohort of 64 autophagy-related genes is downregulated by the boost. Our results indicate that the boost serves both to avert an autophagy program and to prolong the operation of key pathways that shuttle carbon from acetate into storage lipid, the combined outcome being enhanced TAG accumulation, notably in the sta6 strain. PMID:24585881

  9. Hydrogen production by Chlamydomonas reinhardtii: an elaborate interplay of electron sources and sinks

    Energy Technology Data Exchange (ETDEWEB)

    Hemschemeier, A; Happe, T. [Ruhr Univ Bochum, AG Photobiotechnol, Lehrstuhl Biochem Pflanzen, Fak Biol, D-44780 Bochum (Germany); Fouchard, S [Univ Nantes, CNRS, Lab GEPEA, UMR 6144, F-44602 St Nazaire (France); Cournac, L; Peltier, G. [CEA Cadarache, DSV, IBEB, SBVME, Lab Bioenerget et Biotechnol Bacteries et Microalgues, CEA-CNRS-Univ Aix Marseille, UMR 6191, F-13108 St Paul Les Durance (France)


    The unicellular green alga Chlamydomonas reinhardtii possesses a [FeFe]-hydrogenase HydA1 (EC, which is coupled to the photosynthetic electron transport chain. Large amounts of H{sub 2} are produced in a light-dependent reaction for several days when C. reinhardtii cells are deprived of sulfur. Under these conditions, the cells drastically change their physiology from aerobic photosynthetic growth to an anaerobic resting state. The understanding of the underlying physiological processes is not only important for getting further insights into the adaptability of photosynthesis, but will help to optimize the biotechnological application of algae as H{sub 2} producers. Two of the still most disputed questions regarding H{sub 2} generation by C. reinhardtii concern the electron source for H{sub 2} evolution and the competition of the hydrogenase with alternative electron sinks. We analyzed the H{sub 2} metabolism of S-depleted C. reinhardtii cultures utilizing a special mass spectrometer setup and investigated the influence of photosystem II (PSII)- or ribulose-bisphosphate-carboxylase/oxygenase (Rubisco)-deficiency. We show that electrons for H{sub 2}-production are provided both by PSII activity and by a non-photochemical plastoquinone reduction pathway, which is dependent on previous PSII activity. In a Rubisco-deficient strain, which produces H{sub 2} also in the presence of sulfur, H{sub 2} generation seems to be the only significant electron sink for PSII activity and rescues this strain at least partially from a light-sensitive phenotype.The latter indicates that the down-regulation of assimilatory pathways in S-deprived C. reinhardtii cells is one of the important prerequisites for a sustained H{sub 2} evolution. (authors)

  10. A novel screening protocol for the isolation of hydrogen producing Chlamydomonas reinhardtii strains

    Directory of Open Access Journals (Sweden)

    Happe Thomas


    Full Text Available Abstract Background Sealed Chlamydomonas reinhardtii cultures evolve significant amounts of hydrogen gas under conditions of sulfur depletion. However, the eukaryotic green alga goes through drastic metabolic changes during this nutritional stress resulting in cell growth inhibition and eventually cell death. This study aimed at isolating C. reinhardtii transformants which produce hydrogen under normal growth conditions to allow a continuous hydrogen metabolism without the stressful impact of nutrient deprivation. Results To achieve a steady photobiological hydrogen production, a screening protocol was designed to identify C. reinhardtii DNA insertional mutagenesis transformants with an attenuated photosynthesis to respiration capacity ratio (P/R ratio. The screening protocol entails a new and fast method for mutant strain selection altered in their oxygen production/consumption balance. Out of 9000 transformants, four strains with P/R ratios varying from virtually zero to three were isolated. Strain apr1 was found to have a slightly higher respiration rate and a significantly lower photosynthesis rate than the wild type. Sealed cultures of apr1 became anaerobic in normal growth medium (TAP under moderate light conditions and induced [FeFe]-hydrogenase activity, yet without significant hydrogen gas evolution. However, Calvin-Benson cycle inactivation of anaerobically adapted apr1 cells in the light led to a 2-3-fold higher in vivo hydrogen production than previously reported for the sulfur-deprived C. reinhardtii wild type. Conclusion Attenuated P/R capacity ratio in microalgal mutants constitutes a platform for achieving steady state photobiological hydrogen production. Using this platform, algal hydrogen metabolism can be analyzed without applying nutritional stress. Furthermore, these strains promise to be useful for biotechnological hydrogen generation, since high in vivo hydrogen production rates are achievable under normal growth

  11. Sulphate, more than a nutrient, protects the microalga Chlamydomonas moewusii from cadmium toxicity. (United States)

    Mera, Roi; Torres, Enrique; Abalde, Julio


    Sulphur is an essential macroelement that plays important roles in living organisms. The thiol rich sulphur compounds, such as cysteine, γ-Glu-Cys, glutathione and phytochelatins participate in the tolerance mechanisms against cadmium toxicity. Plants, algae, yeasts and most prokaryotes cover their demand for reduced sulphur by reduction of inorganic sulphate. The aim of this study was to investigate, using a bifactorial experimental design, the effect of different sulphate concentrations in the nutrient solution on cadmium toxicity in the freshwater microalga Chlamydomonas moewusii. Cell growth, kinetic parameters of sulphate utilization and intracellular concentrations of low-molecular mass thiol compounds were determined. A mathematical model to describe the growth of this microalga based on the effects of sulphate and cadmium was obtained. An ANOVA revealed an interaction between them, 16% of the effect sizes was explained by this interaction. A higher amount of sulphate in the culture medium allowed a higher cadmium tolerance due to an increase in the thiol compound biosynthesis. The amount of low-molecular mass thiol compounds, mainly phytochelatins, synthesized by this microalga was significantly dependent on the sulphate and cadmium concentrations; the higher phytochelatin content was obtained in cultures with 4 mg Cd/L and 1mM sulphate. The maximum EC50 value (based on nominal cadmium concentration) reached for this microalga was 4.46 ± 0.42 mg Cd/L when the sulphate concentration added to the culture medium was also 1mM. An increase in the sulphate concentration, in deficient environments, could alleviate the toxic effect of this metal; however, a relative excess is also negative. The results obtained showed a substrate inhibition for this nutrient. An uncompetitive model for sulphate was chosen to establish the mathematical model that links both factors.

  12. High yield secretion of recombinant proteins from the microalga Chlamydomonas reinhardtii. (United States)

    Ramos-Martinez, E M; Fimognari, L; Sakuragi, Y


    Microalga-based biomanufacturing of recombinant proteins is attracting growing attention due to its advantages in safety, metabolic diversity, scalability, and sustainability. Secretion of recombinant proteins can accelerate the use of microalgal platforms by allowing post-translational modifications and easy recovery of products from the culture media. However, currently, the yields of secreted recombinant proteins are low, which hampers the commercial application of this strategy. This study aimed at expanding the genetic tools for enhancing secretion of recombinant proteins in Chlamydomonas reinhardtii, a widely used green microalga as a model organism and a potential industrial biotechnology platform. We demonstrated that the putative signal sequence from C. reinhardtii gametolysin can assist the secretion of the yellow fluorescent protein Venus into the culture media. In order to increase the secretion yields, Venus was C-terminally fused with synthetic glycomodules comprised of tandem serine (Ser) and proline (Pro) repeats of 10 and 20 units [hereafter (SP)n, wherein n=10 or 20]. The yields of the (SP)n-fused Venus were higher than Venus without the glycomodule by up to 12 folds, with the maximum yield of 15 mg L(-1) . Moreover, the presence of the glycomodules confererred an enhanced proteolytic protein stability. The Venus-(SP)n proteins were shown to be glycosylated, and a treatment of the cells with Brefeldin A led to a suggestion that glycosylation of the (SP)n glycomodules starts in the endoplasmic reticulum (ER). Taken together, the results demonstrate the utility of the gametolysin signal sequence and (SP)n glycomodule to promote a more efficient biomanufacturing of microalgae-based recombinant proteins. This article is protected by copyright. All rights reserved.

  13. Tying Down Loose Ends in the Chlamydomonas Genome: Functional Significance of Abundant Upstream Open Reading Frames

    Directory of Open Access Journals (Sweden)

    Frederick R. Cross


    Full Text Available The Chlamydomonas genome has been sequenced, assembled, and annotated to produce a rich resource for genetics and molecular biology in this well-studied model organism. The annotated genome is very rich in open reading frames upstream of the annotated coding sequence (‘uORFs’: almost three quarters of the assigned transcripts have at least one uORF, and frequently more than one. This is problematic with respect to the standard ‘scanning’ model for eukaryotic translation initiation. These uORFs can be grouped into three classes: class 1, initiating in-frame with the coding sequence (CDS (thus providing a potential in-frame N-terminal extension; class 2, initiating in the 5′ untranslated sequences (5UT and terminating out-of-frame in the CDS; and class 3, initiating and terminating within the 5UT. Multiple bioinformatics criteria (including analysis of Kozak consensus sequence agreement and BLASTP comparisons to the closely related Volvox genome, and statistical comparison to cds and to random sequence controls indicate that of ∼4000 class 1 uORFs, approximately half are likely in vivo translation initiation sites. The proposed resulting N-terminal extensions in many cases will sharply alter the predicted biochemical properties of the encoded proteins. These results suggest significant modifications in ∼2000 of the ∼20,000 transcript models with respect to translation initiation and encoded peptides. In contrast, class 2 uORFs may be subject to purifying selection, and the existent ones (surviving selection are likely inefficiently translated. Class 3 uORFs are found in more than half of transcripts, frequently multiple times per transcript; however, they are remarkably similar to random sequence expectations with respect to size, number, and composition, and therefore may in most cases be selectively neutral.

  14. Structure, circadian regulation and bioinformatic analysis of the unique sigma factor gene in Chlamydomonas reinhardtii. (United States)

    Carter, Matthew L; Smith, Annette C; Kobayashi, Hirokazu; Purton, Saul; Herrin, David L


    In higher plants, the transcription of plastid genes is mediated by at least two types of RNA polymerase (RNAP); a plastid-encoded bacterial RNAP in which promoter specificity is conferred by nuclear-encoded sigma factors, and a nuclear-encoded phage-like RNAP. Green algae, however, appear to possess only the bacterial enzyme. Since transcription of much, if not most, of the chloroplast genome in Chlamydomonas reinhardtii is regulated by the circadian clock and the nucleus, we sought to identify sigma factor genes that might be responsible for this regulation. We describe a nuclear gene (RPOD) that is predicted to encode an 80 kDa protein that, in addition to a predicted chloroplast transit peptide at the N-terminus, has the conserved motifs (2.1- 4.2) diagnostic of bacterial sigma-70 factors. We also identified two motifs not previously recognized for sigma factors, adjacent PEST sequences and a leucine zipper, both suggested to be involved in protein-protein interactions. PEST sequences were also found in approximately 40% of sigma factors examined, indicating they may be of general significance. Southern blot hybridization and BLAST searches of the genome and EST databases suggest that RPODmay be the only sigma factor gene in C. reinhardtii. The levels of RPODmRNA increased 2- 3-fold in the mid-to-late dark period of light-dark cycling cells, just prior to, or coincident with, the peak in chloroplast transcription. Also, the dark-period peak in RPOD mRNA persisted in cells shifted to continuous light or continuous dark for at least one cycle, indicating that RPODis under circadian clock control. These results suggest that regulation of RPODexpression contributes to the circadian clock's control of chloroplast transcription.

  15. The RoboCup Mixed Reality League - A Case Study (United States)

    Gerndt, Reinhard; Bohnen, Matthias; da Silva Guerra, Rodrigo; Asada, Minoru

    In typical mixed reality systems there is only a one-way interaction from real to virtual. A human user or the physics of a real object may influence the behavior of virtual objects, but real objects usually cannot be influenced by the virtual world. By introducing real robots into the mixed reality system, we allow a true two-way interaction between virtual and real worlds. Our system has been used since 2007 to implement the RoboCup mixed reality soccer games and other applications for research and edutainment. Our framework system is freely programmable to generate any virtual environment, which may then be further supplemented with virtual and real objects. The system allows for control of any real object based on differential drive robots. The robots may be adapted for different applications, e.g., with markers for identification or with covers to change shape and appearance. They may also be “equipped” with virtual tools. In this chapter we present the hardware and software architecture of our system and some applications. The authors believe this can be seen as a first implementation of Ivan Sutherland’s 1965 idea of the ultimate display: “The ultimate display would, of course, be a room within which the computer can control the existence of matter …” (Sutherland, 1965, Proceedings of IFIPS Congress 2:506-508).

  16. Just enough reality: a kinder gentler approach to stereo (United States)

    Siegel, Mel


    We demonstrate that the binocular perspective disparity generated by an interocular separation that is only a few percent of the nominal 65 mm human interocular separation is still enough to stimulate depth perception. This perception, which we call microstereopsis, has a 'kinder gentler' character than the stark and stressful stimulus presented by geometrically correct virtual reality displays. Microstereopsis stimulates 'just enough reality:' enough to resolve the depth ambiguity in flat images, but not so much reality that it hurts. We observe that whereas crosstalk between left and right image channels is normally perceived as ghosting, with microstereopsis it is perceived as blur in the foreground and background. Since ghosting is objectionable, whereas blur that looks like depth-of-focus in not objectionable, this relaxes the requirement for a high contrast ratio between on and off states of the stereo view multiplexer. This relaxation in turn suggest possibilities for zoneless autostereoscopic displays. We propose a realization based on an electronically toggled louvre filter using suspended particle display technology.

  17. Invariant-Based Augmented Reality on Mobile Phones

    Directory of Open Access Journals (Sweden)

    Jie Shen


    Full Text Available A calibration-free augmented reality based on affine invariant is firstly formulated by tensor method. This approach does not use the calibration parameters of the camera and the 3D locations of the environment’s object, and can realize the augmentation of virtual objects. Meanwhile, a new approach to resolving occlusion problem in augmented reality is presented. Based on an arm-optimized implementation of  the Scale Invariant Feature Transform (SIFT algorithm developed by David Lowe and Random Sample Consensus (RANSAC algorithm, the point correspondences in any two views are determined. According to the invariant for two views and these point correspondences, the occluding contours can be transferred to any views, so the occlusion is resolved. Some typical experiments show that the approach of invariant-based augmented reality is feasible on mobile phones. 

  18. Evaluating Virtual Reality and Augmented Reality Training for Industrial Maintenance and Assembly Tasks (United States)

    Gavish, Nirit; Gutiérrez, Teresa; Webel, Sabine; Rodríguez, Jorge; Peveri, Matteo; Bockholt, Uli; Tecchia, Franco


    The current study evaluated the use of virtual reality (VR) and augmented reality (AR) platforms, developed within the scope of the SKILLS Integrated Project, for industrial maintenance and assembly (IMA) tasks training. VR and AR systems are now widely regarded as promising training platforms for complex and highly demanding IMA tasks. However,…

  19. Bioinformatic Analysis of the Nitrate Reductase Gene in Antartic Ice Algae Chlamydomonas sp. ICE-L%南极衣藻Chlamydomonas sp.ICE-L硝酸还原酶基因的生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    林敏卓; 刘晨临; 黄晓航; 杨平平


    Nitrate reductase (NR) plays an important role in the abiotic stress adaptation in plants by regulating nitrogen metabolism. A nitrate reductase (NR) gene of Antarctic ice algae, Chlamydomonas sp. ICE-L, was identified from the cDNA library and sequenced. The encoded protein sequence of NR gene was investigated by bioinformatic analysis. Through sequence alignment the active sites of ICE-L NR protein sequence which may related to stress acclimation was identified. In addition, the tertiary structure of ICE- L NR protein sequence was predicted. The full-length of Chlamydomonas ICE-L NR gene contained an open reading frame of 2,589 bp encoding a nitrate reductase of 863 amino acids. Phylogenetic analysis showed that the gene was homologous to known green algae NRs with identity of 63%, 61%, 60% and 54% to Volvox carteri, Chlamydomonas reinhardtii, Dunaliella tertiolecta and Chlorella vulgaris respectively. The functional prediction analysis revealed that NR gene sequence has 3 different functional domains which was similar to higher plant. This bioinformatic analysis about NR gene of ICE- L will help us further understand and deeply expand the recearch on the acclimatizing mechanism of Antarctic ice alga Chlamydomonas in the extreme environment from the angle of NR gene.%硝酸还原酶(NR)除调节植物的氮代谢外,在植物的各种非生物胁迫的适应过程中也发挥着重要的作用.从南极冰藻Chlamydomonas sp.ICE-L的cDNA文库中筛选到了硝酸还原酶的全长基因,对其进行测序并对其编码的蛋白序列进行了生物信息学分析,构建了NR的系统进化树,通过多序列比对探讨了可能与该酶逆境适应性相关的活性位点,并对该蛋白进行了三级结构预测分析.结果显示,NR基因的编码区长2 589 bp,编码863个氨基酸.在以氨基酸序列构建的系统进化树中,南极衣藻的NR序列和其他绿藻类的聚在一起,与团藻、莱茵衣藻、杜氏盐藻和小球藻

  20. Communicating amidst reality: Ezekiel�s communication as a response to his reality

    Directory of Open Access Journals (Sweden)

    Johan Serfontein


    Full Text Available The reality of exile was the backdrop of Ezekiel�s prophecies (communication. He respondedto this reality with a word that he claimed he received from YHWH. This word he crafted intoa powerful piece of communication that appealed, with the help of metaphors and images, tothe imaginations of his audience. These imaginations of the future in the end seed the newpossibilities that became their new reality. The question would be if Ezekiel�s communicationprocess could be helpful to leaders who find themselves in a new modern-day reality wherethey are struggling to lead.Intradisciplinary and/or interdisciplinary implications: Prophetic criticism usually staysclear of practical issues like leadership, communication and change. This article attempts toconstruct a communication model from the prophet Ezekiel�s communication that can helpmodern-day leaders to communicate amidst their reality. It aids in bridging the divide thatexists between Practical Theology and Old Testament Biblical Studies.