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Sample records for hap2gcs1-dependent gamete fusion

  1. Egg CD9 protein tides correlated with sperm oscillations tune the gamete fusion ability in mammal.

    Science.gov (United States)

    Ravaux, Benjamin; Favier, Sophie; Perez, Eric; Gourier, Christine

    2018-01-23

    Mammalian fertilization involves membrane events -adhesion, fusion, sperm engulfment, membrane block to polyspermy- whose causes remain largely unknown. Recently, specific oscillations of the sperm in contact with the egg were shown to be necessary for fusion. Using a microfluidic chip to impose the venue for the encounter of two gametes allowed real-time observation of the membrane remodelling occurring at the sperm/egg interface. The spatiotemporal mapping of egg CD9 revealed that this protein concentrates at the egg/sperm interface as a result of sperm oscillations, until a CD9-rich platform is nucleated on which fusion immediately takes place. Within 2 to 5 minutes after fusion, most of the CD9 leaves the egg for the external aqueous medium. Then an egg membrane wave engulfs the sperm head in approximately 25 minutes. These results show that sperm oscillations initiate the CD9 recruitment that causes gamete fusion after which CD9 and associated proteins leave the membrane in a process likely to contribute to block polyspermy. They highlight that the gamete fusion story in mammals is an unexpected interplay between mechanical constraints and proteins. © The Author(s) (2018). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

  2. The functional domain of GCS1-based gamete fusion resides in the amino terminus in plant and parasite species.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Mori

    Full Text Available Fertilization is one of the most important processes in all organisms utilizing sexual reproduction. In a previous study, we succeeded in identifying a novel male gametic transmembrane protein GCS1 (GENERATIVE CELL SPECIFIC 1, also called HAP2 (HAPLESS 2 in the male-sterile Arabidopsis thaliana mutants, as a factor critical to gamete fusion in flowering plants. Interestingly, GCS1 is highly conserved among various eukaryotes covering plants, protists and invertebrates. Of these organisms, Chlamydomonas (green alga and Plasmodium (malaria parasite GCS1s similarly show male gametic expression and gamete fusion function. Since it is generally believed that protein factors controlling gamete fusion have rapidly evolved and different organisms utilize species-specific gamete fusion factors, GCS1 may be an ancient fertilization factor derived from the common ancestor of those organisms above. And therefore, its molecular structure and function are important to understanding the common molecular mechanics of eukaryotic fertilization. In this study, we tried to detect the central functional domain(s of GCS1, using complementation assay of Arabidopsis GCS1 mutant lines expressing modified GCS1. As a result, the positively-charged C-terminal sequence of this protein is dispensable for gamete fusion, while the highly conserved N-terminal domain is critical to GCS1 function. In addition, in vitro fertilization assay of Plasmodium berghei (mouse malaria parasite knock-in lines expressing partly truncated GCS1 showed similar results. Those findings above indicate that the extracellular N-terminus alone is sufficient for GCS1-based gamete fusion.

  3. Ocean acidification hampers sperm-egg collisions, gamete fusion, and generation of Ca2+ oscillations of a broadcast spawning bivalve, Tegillarca granosa.

    Science.gov (United States)

    Shi, Wei; Han, Yu; Guo, Cheng; Zhao, Xinguo; Liu, Saixi; Su, Wenhao; Wang, Yichen; Zha, Shanjie; Chai, Xueliang; Liu, Guangxu

    2017-09-01

    Although the effect of ocean acidification on fertilization success of marine organisms is increasingly well documented, the underlying mechanisms are not completely understood. The fertilization success of broadcast spawning invertebrates depends on successful sperm-egg collisions, gamete fusion, and standard generation of Ca 2+ oscillations. Therefore, the realistic effects of future ocean pCO 2 levels on these specific aspects of fertilization of Tegillarca granosa were investigated in the present study through sperm velocity trials, fertilization kinetics model analysis, and intracellular Ca 2+ assays, respectively. Results obtained indicated that ocean acidification significantly reduced the fertilization success of T. granosa, which could be accountable by (i) decreased sperm velocity hence reducing the probability for sperm-egg collisions; (ii) lowered probability of gamete fusion for each gamete collision event; and (iii) disrupted intracellular Ca 2+ oscillations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Mammalian gamete plasma membranes re-assessments and reproductive implications

    Science.gov (United States)

    Establishment of the diploid status occurs with the fusion of female and male gametes. Both the mammalian oocyte and spermatozoa are haploid cells surrounded with plasma membranes that are rich in various proteins playing a crucial role during fertilization. Fertilization is a complex and ordered st...

  5. Alternativní zdroje gamet

    Czech Academy of Sciences Publication Activity Database

    Čechová, Dana

    2001-01-01

    Roč. 66, č. 2 (2001), s. 151-152 ISSN 0366-0486 R&D Projects: GA ČR GV524/96/K162 Institutional research plan: CEZ:AV0Z5052915 Keywords : gametes * sperm * eggs Subject RIV: EB - Genetics ; Molecular Biology

  6. Surgical treatment of endometriosis before gamete intrafallopian ...

    African Journals Online (AJOL)

    Abstract. Objective. To determine whether active pelvic endometriosis impairs the efficacy of GIFT (gamete intrafallopian transfer) and whether prior surgical treatment of endometriosis improves the efficacy of GIFT. Design. Matched controlled retrospective study. Setting. University-based assisted reproduction programme.

  7. Fusion

    CERN Document Server

    Mahaffey, James A

    2012-01-01

    As energy problems of the world grow, work toward fusion power continues at a greater pace than ever before. The topic of fusion is one that is often met with the most recognition and interest in the nuclear power arena. Written in clear and jargon-free prose, Fusion explores the big bang of creation to the blackout death of worn-out stars. A brief history of fusion research, beginning with the first tentative theories in the early 20th century, is also discussed, as well as the race for fusion power. This brand-new, full-color resource examines the various programs currently being funded or p

  8. Intra-Family Gamete Donation: A Solution to Concerns Regarding Gamete Donation in China?

    Science.gov (United States)

    Liao, Juhong; Devolder, Katrien

    2016-09-01

    Gamete donation from third parties is controversial in China as it severs blood ties, which are considered of utmost importance in Confucian tradition. In recent years, infertile couples are increasingly demonstrating a preference for the use of gametes donated by family members to conceive children-known as "intra-family gamete donation." The main advantage of intra-family gamete donation is that it maintains blood ties between children and both parents. To date there is no practice of intra-family gamete donation in China. In this paper, we investigate intra-family adoption in China in order to illustrate that intra-family gamete donation is consistent with Confucian tradition regarding the importance of maintaining blood ties within the family. There are several specific ethical issues raised by intra-family gamete donation. It may, for example, result in consanguinity and the semblance of incest, lead to confused family relationships, and raise concerns about possible coercion of familial donors. Confucian tradition provides a new approach to understand and deal with these ethical issues in a way that Western tradition does not. As a result, we suggest intra-family gamete donation could be an acceptable solution to the problem of infertility in China. However, further discussion and open debates on the ethical issues raised by intra-family gamete donation are needed in China.

  9. Oestrogen supplementation in gamete intrafallopian transfer (GIFT ...

    African Journals Online (AJOL)

    Enrique

    2005-02-06

    Feb 6, 2005 ... intrafallopian transfer (GIFT) — a prospective randomised study. ARTICLE. Objective. To investigate the impact of oestrogen supplementation from the early luteal to the late proliferative phase on biochemical and ongoing pregnancy rates in gamete intrafallopian transfer (GIFT). Methods. Ninety-five ...

  10. Negotiating boundaries: Accessing donor gametes in India.

    Science.gov (United States)

    Widge, A; Cleland, J

    2011-01-01

    This paper documents how couples and providers access donor materials for conception in the Indian context and perceptions about using them. The objective is to facilitate understanding of critical issues and relevant concerns. A postal survey was conducted with a sample of 6000 gynaecologists and in-depth interviews were -conducted with 39 gynaecologists in four cities. Donor gametes are relatively more acceptable than a few years ago, especially if confidentiality can be -maintained, though lack of availability of donor materials is sometimes an impediment to infertility treatment. Donor sperms are usually accessed from in-house or commercial sperm banks, pathology laboratories, IVF centres, -professional donors, relatives or friends. There is scepticism about screening procedures of sperm banks. Donor eggs are usually accessed from voluntary donors, friends, relatives, egg sharing programmes, donation from other patients, advertising and commercial donors. There are several concerns regarding informed consent for using donated gametes, using -relatives and friends gametes, the unregulated use of gametes and embryos, record keeping and documentation, -unethical and corrupt practices and commercialisation. These issues need to be addressed by patients, providers and regulatory authorities by providing -information, counselling, ensuring informed consent, addressing exploitation and commercialisation, ensuring -monitoring, proper documentation and transparency.

  11. Balancing Ethical Pros and Cons of Stem Cell Derived Gametes.

    Science.gov (United States)

    Segers, Seppe; Mertes, Heidi; de Wert, Guido; Dondorp, Wybo; Pennings, Guido

    2017-07-01

    In this review we aim to provide an overview of the most important ethical pros and cons of stem cell derived gametes (SCD-gametes), as a contribution to the debate about reproductive tissue engineering. Derivation of gametes from stem cells holds promising applications both for research and for clinical use in assisted reproduction. We explore the ethical issues connected to gametes derived from embryonic stem cells (both patient specific and non-patient specific) as well as those related to gametes derived from induced pluripotent stem cells. The technology of SCD-gametes raises moral concerns of how reproductive autonomy relates to issues of embryo destruction, safety, access, and applications beyond clinical infertility.

  12. Property rights in human gametes in Australia.

    Science.gov (United States)

    White, Vanessa

    2013-03-01

    It has long been a basic tenet of the common law that there can be no property interest in human bodies or body parts. However, exceptions to the rule have been recognised from the mid-19th century and developed over time. In the early 21st century, there have been interesting developments in the common law of Australia and England, with Australian Supreme Court judges and the English Court of Appeal casting aside existing exceptions, and finding property rights in human body parts, including gametes, by relying instead on a "rational" and "logical" basis to identify property interests in human body parts.

  13. Meiosis and haploid gametes in the pathogen Trypanosoma brucei.

    Science.gov (United States)

    Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

    2014-01-20

    In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector and involves meiosis, but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human pathogens. By observing insect-derived trypanosomes during the window of peak expression of meiosis-specific genes, we identified promastigote-like (PL) cells that interacted with each other via their flagella and underwent fusion, as visualized by the mixing of cytoplasmic red and green fluorescent proteins. PL cells had a short, wide body, a very long anterior flagellum, and either one or two kinetoplasts, but only the anterior kinetoplast was associated with the flagellum. Measurement of nuclear DNA contents showed that PL cells were haploid relative to diploid metacyclics. Trypanosomes are among the earliest diverging eukaryotes, and our results support the hypothesis that meiosis and sexual reproduction are ubiquitous in eukaryotes and likely to have been early innovations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Mammalian diversity: gametes, embryos and reproduction.

    Science.gov (United States)

    Behringer, Richard R; Eakin, Guy S; Renfree, Marilyn B

    2006-01-01

    The class Mammalia is composed of approximately 4800 extant species. These mammalian species are divided into three subclasses that include the monotremes, marsupials and eutherians. Monotremes are remarkable because these mammals are born from eggs laid outside of the mother's body. Marsupial mammals have relatively short gestation periods and give birth to highly altricial young that continue a significant amount of 'fetal' development after birth, supported by a highly sophisticated lactation. Less than 10% of mammalian species are monotremes or marsupials, so the great majority of mammals are grouped into the subclass Eutheria, including mouse and human. Mammals exhibit great variety in morphology, physiology and reproduction. In the present article, we highlight some of this remarkable diversity relative to the mouse, one of the most widely used mammalian model organisms, and human. This diversity creates challenges and opportunities for gamete and embryo collection, culture and transfer technologies.

  15. Challenge testing of gametes to enhance their viability

    DEFF Research Database (Denmark)

    Callesen, Henrik

    2010-01-01

    of survival mechanism that enables them to come through the process. The details of the mechanism remain unknown but, if identified, it could have immense potential as a new way to improve the viability of embryos produced by ART. However, few publications describe systematic ways to challenge test gametes...... and then to use the results as a basis for improving gamete viability. Furthermore, new methods to monitor the reactions of gametes to such challenge tests are needed. In the present review, these two issues are discussed, as are some of the conditions necessary before a challenge test protocol can be part...

  16. 9 CFR 93.905 - Declaration and other documents for live fish, fertilized eggs, and gametes.

    Science.gov (United States)

    2010-01-01

    ... live fish, fertilized eggs, and gametes. 93.905 Section 93.905 Animals and Animal Products ANIMAL AND... for live fish, fertilized eggs, and gametes. (a) For all live fish, fertilized eggs, and gametes... fish, fertilized eggs, or gametes, the number, species, and the purpose of the importation, the name of...

  17. Chapter 1 Historical Background on Gamete and Embryo Cryopreservation.

    Science.gov (United States)

    Ali, Jaffar; AlHarbi, Naif H; Ali, Nafisa

    2017-01-01

    This chapter describes the development of the science of cryopreservation of gametes and embryos of various species including human. It attempts to record in brief the main contributions of workers in their attempts to cryopreserve gametes and embryos. The initial difficulties faced and subsequent developments and triumphs leading to present-day state of the art are given in a concise manner. The main players and their contributions are mentioned and the authors' aim is to do justice to them. This work also attempts to ensure that credit is correctly attributed for significant advances in gamete and embryo cryopreservation. In general this chapter has tried to describe the historical development of the science of cryopreservation of gametes and embryos as accurately as possible without bias or partiality.

  18. In-vitro Fertilization, Gamete Donation and Surrogacy: Perceptions ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    Most felt surrogates should not be paid. Acceptance ... Keywords: infertility, IVF, gamete donation, surrogacy, Nigeria ... The International Federation of ... of exploiting the surrogate, who is often of a lower ..... Surrogacy Arrangements Act 1985.

  19. Male gametophytic sterility. 1 - Gametic sterilities and deletions in petunia

    Energy Technology Data Exchange (ETDEWEB)

    Cornu, A.; Maizonnier, D. (Station d' Amelioration des Plantes de l' I.N.R.A., Dijon (France))

    1982-01-01

    Terminal deletions induced by ionizing radiations in Petunia are not sexually transmitted. Cytogenetic study of plants with a heterozygous deletion and their progenies shows that this lack of transmission is accompanied by a gametic semi-sterility due to the fact that gametes carrying the deleted chromosome are not viable. The interest of such a male sterility with a gametophytic determinism for the study of sporophyte-gametophyte relationships is underlined.

  20. Consequences on offspring of abnormal function in ageing gametes.

    Science.gov (United States)

    Tarín, J J; Pérez-Albalá, S; Cano, A

    2000-01-01

    The present review aims to analyse (i) the molecular, biochemical and cellular changes that accompany oocyte and sperm ageing in any of the internal or external environments where they can reside, and (ii) the consequences of the abnormal function in ageing gametes on pre- and post-implantation development and later life of offspring. This review also aims to propose and discuss cellular/molecular mechanisms framed within the 'free radical theory of ageing'. It appears that the ageing of gametes prior to fertilization may affect many molecular, biochemical and cellular pathways that may jeopardize not only pre- and post-implantation embryo/fetal development but also later life of offspring. Consequences of gamete ageing range from decreased vigour (with the concomitant decrease in intelligence, reproductive fitness and longevity) of apparently normal-looking offspring to severe congenital, epigenetic and/or genetic anomalies. All these effects may be easily prevented by efficient diffusion of both the potential risks of gamete ageing and the steps that should be taken by couples wishing to achieve pregnancy to guarantee a correct maturational synchronization of gametes at fertilization. Although in-vitro antioxidant therapy appears to protect from or retard the ageing process of gametes, it may not assure the total absence of negative effects on the resulting offspring.

  1. Cell fusion and nuclear fusion in plants.

    Science.gov (United States)

    Maruyama, Daisuke; Ohtsu, Mina; Higashiyama, Tetsuya

    2016-12-01

    Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes. Although these membranes maintain the identity of cells, they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections. Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. A Review Of Reproduction And Gamete Management In The African ...

    African Journals Online (AJOL)

    Information on the current status of reproduction and gamete management of the African Catfish, Clarias gariepinus (Burchell) a highly appreciated culturable fish species in Nigeria were reviewed. Natural and artificial reproductive behaviour as well as gonadal maturation rhythm in the highly fecund fish were documented.

  3. Artificial gametes: a systematic review of biological progress towards clinical application

    NARCIS (Netherlands)

    Hendriks, Saskia; Dancet, Eline A. F.; van Pelt, Ans M. M.; Hamer, Geert; Repping, Sjoerd

    2015-01-01

    Recent progress in the formation of artificial gametes, i.e. gametes generated by manipulation of their progenitors or of somatic cells, has led to scientific and societal discussion about their use in medically assisted reproduction (MAR). Artificial gametes could potentially help infertile men and

  4. 9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

    Science.gov (United States)

    2010-01-01

    ..., fertilized eggs, and gametes. 93.903 Section 93.903 Animals and Animal Products ANIMAL AND PLANT HEALTH... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs, and gametes. (a) Live fish, fertilized eggs, or gametes of SVC-susceptible species imported into the...

  5. Rna synthesis of perinatal female and male gametes

    International Nuclear Information System (INIS)

    Doering, R.; Hubaleck, K.

    1980-01-01

    Intensity curves of RNA synthesis in the perinatal phase of gametogenesis were established for rat fetuses and young rats by 3 H-uridine autoradiography. Gonads of male and female rat fetuses were studied on days 15 to 22 p.c. and gonads of young animals on days 1 to 7 p.n. The nuclear surface of the gametes was found to increase continuously. The number of silver grains was the same for male and female gametes up to the 18th day of fetal life, and the same applies to the silver grain density. The rate of RNA synthesis of male germ celles remained at a constant, low level throughout the study; in the female germ cells, a 10-fold increase in RNA synthesis was measured after the 19th day of fetal life. (orig./MG) [de

  6. Stem cells to gametes: how far should we go?

    Science.gov (United States)

    Whittaker, Peter

    2007-03-01

    Murine embryonic stem cells have recently been shown to be capable of differentiating in vitro into oocytes or sperm. Should these findings be duplicated using human embryonic stem cells, this would raise a number of social and ethical concerns, some specific to these particular developments, others shared with other aspects of stem cell research. This review outlines the properties of stem cells and their conversion to gametes. Concerns raised include embryo destruction, quality of gametes derived in this way, possibility for children with two male biological parents, movement towards germ line gene therapy and 'designer babies', and the future impacts on health service provisions. It is important that public discussion of some of these issues should take place.

  7. Meiosis and Haploid Gametes in the Pathogen Trypanosoma brucei

    OpenAIRE

    Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

    2014-01-01

    Summary In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence [1]. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector [2, 3] and involves meiosis [4], but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human...

  8. Motile male gametes of the araphid diatom Tabularia fasciculata search randomly for mates.

    Directory of Open Access Journals (Sweden)

    Robyn Edgar

    Full Text Available Sexuality in the marine araphid diatom Tabularia involves an unusual type of gamete, not only among diatoms but possibly in all of nature. The non-flagellated male gamete is free and vigorously motile, propelled by pseudopodia. However, the cues (if any in their search for compatible female gametes and the general search patterns to locate them are unknown. We tracked and compared male gamete movements in the presence and absence of receptive female gametes. Path linearity of male movement was not affected by presence of female gametes. Male gametes did not move towards female gametes regardless of their proximity to each other, suggesting that the detection range for a compatible mate is very small compared to known algal examples (mostly spermatozoids and that mate recognition requires (near contact with a female gamete. We therefore investigated how male gametes move to bring insight into their search strategy and found that it was consistent with the predictions of a random-walk model with changes in direction coming from an even distribution. We further investigated the type of random walk by determining the best-fit distribution on the tail of the move length distribution and found it to be consistent with a truncated power law distribution with an exponent of 2.34. Although consistent with a Lévy walk search pattern, the range of move lengths in the tail was too narrow for Lévy properties to emerge and so would be best described as Brownian motion. This is somewhat surprising because female gametes were often outnumbered by male gametes, thus contrary to the assumption that a Brownian search mode may be most optimal with an abundant target resource. This is also the first mathematically analysed search pattern of a non-flagellated protistan gamete, supporting the notion that principles of Brownian motion have wide application in biology.

  9. Two neutral alleles of improving male gamete abortion in indica-japonica hybrid rice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@It was difficult to use the pronounced heterosis of indica-japonica hybrids rice due to the panicle sterility caused by male and female gamete abortion. The female gamete abortion in most of subspecific hybrids could be solved by using an abortion-neutral gene S5-n, a wide compatibility gene. The problem of male gamete abortion indicated by distorted segregation of marker genes remained to be studied. Segregation distortion via male gamete had been reported on chromosomes 3, 7, 8, 11, and 12.

  10. Syncytin-1 and its receptor is present in human gametes

    DEFF Research Database (Denmark)

    Bjerregaard, B; Lemmen, J G; Petersen, M R

    2014-01-01

    and around the equatorial segment. The receptor ASCT-2 is expressed in the acrosomal region and in the sperm tail. Moreover, ASCT-2, but not syncytin-1, is expressed in oocytes and the mRNA level increases with increasing maturity of the oocytes. CONCLUSIONS: Syncytin and its receptor are present in human......MAIN PURPOSE AND RESEARCH QUESTION: To determine whether the true fusogen Syncytin-1 and its receptor (ASCT-2) is present in human gametes using qRT-PCR, immunoblotting and immunofluorescence. METHODS: Donated oocytes and spermatozoa, originating from a fertility center in tertiary referral...

  11. Is vitronectin the velcro that binds the gametes together?

    Science.gov (United States)

    Fusi, F M; Bernocchi, N; Ferrari, A; Bronson, R A

    1996-11-01

    Evidence has been presented that the adhesion of human spermatozoa to the oolemma is mediated by integrins recognizing the Arg-Gly-Asp sequence (RGD). Fibronectin and vitronectin, glycoproteins that contain functional RGD sequences, are both present on human spermatozoa, and integrins that recognize these ligands have been detected on spermatozoa and eggs. In this work, we studied the effects of oligopeptides specifically designed to block fibronectin or vitronectin receptors on the interaction of human spermatozoa with zona-free hamster oocytes. GRGDdSP, a peptide blocking cell attachment to fibronectin, was without effect, while GdRGDSP, which blocks both fibronectin and vitronectin receptors, significantly inhibited the binding of human spermatozoa to the oolemma of zona-free hamster eggs, in a concentration-dependent manner, over a range 1-100 microM. As these experiments suggested that a vitronectin receptor plays a role in sperm-oolemmal adhesion, we performed a series of experiments studying the effects of exogenous vitronectin, when added to spermatozoa and oocytes, on gamete interactions. Sperm-oolemmal adherence, as well as sperm aggregation, was promoted by vitronectin, over range of 2.2 nM to 1 microM, but only in the presence of calcium ions. We propose that vitronectin released during the sperm acrosome reaction is recognized by both gametes and plays a role in their adhesion.

  12. Evolution of Gamete Motility Differences I. Relation Between Swimming Speed and Pheromonal Attraction

    NARCIS (Netherlands)

    Hoekstra, Rolf F.; Janz, Robert F.; Schilstra, A.J.

    1984-01-01

    An analysis is made using population genetic models of the evolution of gamete motility differences as a consequence of a pheromonal gametic approach mechanism. A stable swimming speed dimorphism may arise via disruptive selection on swimming speed, resulting from selection favouring a high

  13. Three members of the 6-cys protein family of Plasmodium play a role in gamete fertility.

    NARCIS (Netherlands)

    Dijk, M.R. van; Schaijk, B.C.L. van; Khan, S.M.; Dooren, M.W. van; Ramesar, J.; Kaczanowski, S.; Gemert, G.J.A. van; Kroeze, H.; Stunnenberg, H.G.; Eling, W.M.C.; Sauerwein, R.W.; Waters, A.P.; Janse, C.J.

    2010-01-01

    The process of fertilization is critically dependent on the mutual recognition of gametes and in Plasmodium, the male gamete surface protein P48/45 is vital to this process. This protein belongs to a family of 10 structurally related proteins, the so called 6-cys family. To identify the role of

  14. Recent microfluidic devices for studying gamete and embryo biomechanics.

    Science.gov (United States)

    Lai, David; Takayama, Shuichi; Smith, Gary D

    2015-06-25

    The technical challenges of biomechanic research such as single cell analysis at a high monetary cost, labor, and time for just a small number of measurements is a good match to the strengths of microfluidic devices. New scientific discoveries in the fertilization and embryo development process, of which biomechanics is a major subset of interest, is crucial to fuel the continual improvement of clinical practice in assisted reproduction. The following review will highlight some recent microfluidic devices tailored for gamete and embryo biomechanics where biomimicry arises as a major theme of microfluidic device design and function, and the application of fundamental biomechanic principles are used to improve outcomes of cryopreservation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

    Science.gov (United States)

    2010-01-01

    ... of live fish, fertilized eggs, and gametes. 93.902 Section 93.902 Animals and Animal Products ANIMAL... importation of live fish, fertilized eggs, and gametes. (a) The following ports are designated as ports of entry for live fish, fertilized eggs, and gametes of SVC-susceptible species imported under this subpart...

  16. The impact of disclosure on donor gamete participants: donors, intended parents and offspring.

    Science.gov (United States)

    Greenfeld, Dorothy A

    2008-06-01

    The present review examines recent publications that provide insight into how the trend toward nonanonymity and disclosure in gamete donation impacts donors, intended parents, and their donor-conceived children. Recent findings show an increase in donor programs that offer open-identity between donors and offspring. The psychological needs of gamete donors and their attitudes toward disclosure are increasingly given consideration. Qualitative research on how parents of donor gamete offspring make decisions about disclosure reveals that even when couples initially disagree about disclosing to offspring, most ultimately come to a united disclosure decision. The literature on the impact of disclosure on donor gamete offspring has extended to include children conceived through embryo donation and children born as a result of surrogacy. The absence of genetic or gestational link between parents and their child does not have a negative impact on parent-child relationships. Parents through surrogacy tend to disclose the method of family creation to their child, whereas parents through embryo donation tend to be secretive about their child's origins. The trend toward greater openness in gamete donation has been accompanied by an increase in programs offering open-identity donation. In addition, the psychological needs of gamete donors and their attitudes toward disclosure are increasingly being given consideration. Parents of donor gamete offspring give careful thought to their disclosure decisions, and the psychological well being of donor-conceived children does not seem to be impacted by those decisions.

  17. [Gamete donation contracts: gift of life or sale of genetic material?].

    Science.gov (United States)

    Raposo, Vera Lúcia

    2012-01-01

    When science made possible to overcome the biological limitation to infertility, gamete had become a "valuable good". Therefore, lawyers are asked to define their juridical status, their modality of transference, their possible uses and the legal protection reserved to them.

  18. Epigenetic effects of methoxychlor and vinclozolin on male gametes.

    Science.gov (United States)

    Paoloni-Giacobino, Ariane

    2014-01-01

    Imprinting is an epigenetic form of gene regulation that mediates a parent-of-origin-dependent expression of the alleles of a number of genes. Imprinting, which occurs at specific sites within or surrounding the gene, called differentially methylated domains, consists in a methylation of CpGs. The appropriate transmission of genomics imprints is essential for the control of embryonic development and fetal growth. A number of endocrine disruptors (EDs) affect male reproductive tract development and spermatogenesis. It was postulated that the genetic effects of EDs might be induced by alterations in gene imprinting. We tested two EDs: methoxychlor and vinclozolin. Their administration during gestation induced in the offspring a decrease in sperm counts and significant modifications in the methylation pattern of a selection of paternally and maternally expressed canonical imprinted genes. The observation that imprinting was largely untouched in somatic cells suggests that EDs exert their damaging effects via the process of reprogramming that is unique to gamete development. Interestingly, the effects were transgenerational, although disappearing gradually from F1 to F3. A systematic analysis showed a heterogeneity in the CpG sensitivity to EDs. We propose that the deleterious effects of EDs on the male reproductive system are mediated by imprinting defects in the sperm. The reported effects of EDs on human male spermatogenesis might be mediated by analogous imprinting alterations. © 2014 Elsevier Inc. All rights reserved.

  19. Keeping mum about dad: "contracts" to protect gamete donor anonymity.

    Science.gov (United States)

    Rees, Anne

    2012-06-01

    This article considers the legal status of so-called contracts for anonymity between fertility clinics and donors of gametes that were made in the period before legislation authorising disclosure. It notes that while clinics frequently cite the existence of these "contracts" to argue against retrospective legislation authorising disclosure of the donor's identity, they may be nothing more than one-sided statements of informed consent. However, the article notes that even if an agreement between a donor and a clinic is not contractual, it does not follow that a person conceived through assisted reproductive technology has any right of access to the identity of the donor. The writer has not been able to locate examples of written promises by the clinics promising anonymity. There are written promises by the donors not to seek the identity of the recipients. These promises do not bind the resulting offspring nor do they appear to be supported by consideration. The article suggests that the basis for any individual donor to restrain a clinic from revealing their identity may be found in promissory estoppel. Nevertheless, there is no real issue in Australia concerning clinics revealing these details absent legislative authority. The issue is whether parliaments will legislate to authorise the disclosure. The article notes that it would be rare for parliaments to legislate to overturn existing legal contracts but suggests that the contract argument may not be as strong as has been thought.

  20. Natural hybridization in the sea urchin genus Pseudoboletia between species without apparent barriers to gamete recognition.

    Science.gov (United States)

    Zigler, Kirk S; Byrne, Maria; Raff, Elizabeth C; Lessios, H A; Raff, Rudolf A

    2012-06-01

    Marine species with high dispersal potential often have huge ranges and minimal population structure. Combined with the paucity of geographic barriers in the oceans, this pattern raises the question as to how speciation occurs in the sea. Over the past 20 years, evidence has accumulated that marine speciation is often linked to the evolution of gamete recognition proteins. Rapid evolution of gamete recognition proteins in gastropods, bivalves, and sea urchins is correlated with gamete incompatibility and contributes to the maintenance of species boundaries between sympatric congeners. Here, we present a counterexample to this general pattern. The sea urchins Pseudoboletia indiana and P. maculata have broad ranges that overlap in the Indian and Pacific oceans. Cytochrome oxidase I sequences indicated that these species are distinct, and their 7.3% divergence suggests that they diverged at least 2 mya. Despite this, we suspected hybridization between them based on the presence of morphologically intermediate individuals in sympatric populations at Sydney, Australia. We assessed the opportunity for hybridization between the two species and found that (1) individuals of the two species occur within a meter of each other in nature, (2) they have overlapping annual reproductive cycles, and (3) their gametes cross-fertilize readily in the laboratory and in the field. We genotyped individuals with intermediate morphology and confirmed that many were hybrids. Hybrids were fertile, and some female hybrids had egg sizes intermediate between the two parental species. Consistent with their high level of gamete compatibility, there is minimal divergence between P. indiana and P. maculata in the gamete recognition protein bindin, with a single fixed amino acid difference between the two species. Pseudoboletia thus provides a well-characterized exception to the idea that broadcast spawning marine species living in sympatry develop and maintain species boundaries through the

  1. The male gametophytic sterility. 1 - Gametic sterilities and deletions in petunia

    International Nuclear Information System (INIS)

    Cornu, A.; Maizonnier, D.

    1982-01-01

    Terminal deletions induced by ionizing radiations in Petunia are not sexually transmitted. Cytogenetic study of plants with a heterozygous deletion and their progenies shows that this lack of transmission is accompanied by a gametic semi-sterility due to the fact that gametes carrying the deleted chromosome are not viable. The interest of such a male sterility with a gametophytic determinism for the study of sporophyte-gametophyte relationships is underlined [fr

  2. Fusion energy

    International Nuclear Information System (INIS)

    Gross, R.A.

    1984-01-01

    This textbook covers the physics and technology upon which future fusion power reactors will be based. It reviews the history of fusion, reaction physics, plasma physics, heating, and confinement. Descriptions of commercial plants and design concepts are included. Topics covered include: fusion reactions and fuel resources; reaction rates; ignition, and confinement; basic plasma directory; Tokamak confinement physics; fusion technology; STARFIRE: A commercial Tokamak fusion power plant. MARS: A tandem-mirror fusion power plant; and other fusion reactor concepts

  3. Potential consequences of clinical application of artificial gametes: a systematic review of stakeholder views.

    Science.gov (United States)

    Hendriks, Saskia; Dondorp, Wybo; de Wert, Guido; Hamer, Geert; Repping, Sjoerd; Dancet, Eline A F

    2015-01-01

    Recent progress in the formation of artificial gametes, i.e. gametes generated from progenitors or somatic cells, has led to scientific and societal discussion about their use in medically assisted reproduction. In animals, live births have already been achieved using artificial gametes of varying (cell type) sources and biological research seems to be progressing steadily toward clinical application in humans. Artificial gametes could potentially help not only infertile heterosexual couples of reproductive age of which one or both partners lacks functional gametes, but also post-menopausal women and same-sex couples, to conceive a child who will be genetically related to them. But as clinical application of these new technologies may have wider societal consequences, a proactive consideration of the possible impact seems timely and important. This review aims to contribute to this by providing a systematic overview of the potential consequences of clinical application of artificial gametes anticipated by different stakeholders. The electronic database 'Medline/Pubmed' was systematically searched with medical subject heading terms (MesH) for articles published in English between January 1970 and December 2013. Articles were selected based on eligibility and reference lists of eligible studies were hand searched. The reported potential consequences of clinical application of artificial gametes were extracted from the articles and were grouped into categories by content analysis. Per category, we noted which stakeholders referred to which potential consequences, based on author affiliations and, if applicable, study participants. The systematic search yielded 2424 articles, and 84 studies were included after screening. Nine positive consequences, 21 specific consequences requiring consideration and 22 recommendations referring to clinical application of artificial gametes were documented. All positive consequences, consequences requiring consideration and

  4. Sex differences in parental care: Gametic investment, sexual selection, and social environment.

    Science.gov (United States)

    Liker, András; Freckleton, Robert P; Remeš, Vladimir; Székely, Tamás

    2015-11-01

    Male and female parents often provide different type and amount of care to their offspring. Three major drivers have been proposed to explain parental sex roles: (1) differential gametic investment by males and females that precipitates into sex difference in care, (2) different intensity of sexual selection acting on males and females, and (3) biased social environment that facilitates the more common sex to provide more care. Here, we provide the most comprehensive assessment of these hypotheses using detailed parental care data from 792 bird species covering 126 families. We found no evidence for the gametic investment hypothesis: neither gamete sizes nor gamete production by males relative to females was related to sex difference in parental care. However, sexual selection correlated with parental sex roles, because the male share in care relative to female decreased with both extra-pair paternity and frequency of male polygamy. Parental sex roles were also related to social environment, because male parental care increased with male-biased adult sex ratios (ASRs). Taken together, our results are consistent with recent theories suggesting that gametic investment is not tied to parental sex roles, and highlight the importance of both sexual selection and ASR in influencing parental sex roles. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  5. Cytological, molecular mechanisms and temperature stress regulating production of diploid male gametes in Dianthus caryophyllus L.

    Science.gov (United States)

    Zhou, Xuhong; Mo, Xijun; Gui, Min; Wu, Xuewei; Jiang, Yalian; Ma, Lulin; Shi, Ziming; Luo, Ying; Tang, Wenru

    2015-12-01

    In plant evolution, because of its key role in sexual polyploidization or whole genome duplication events, diploid gamete formation is considered as an important component in diversification and speciation. Environmental stress often triggers unreduced gamete production. However, the molecular, cellular mechanisms and adverse temperature regulating diplogamete production in carnation remain poorly understood. Here, we investigate the cytological basis for 2n male gamete formation and describe the isolation and characterization of the first gene, DcPS1 (Dianthus Caryophyllus Parallel Spindle 1). In addition, we analyze influence of temperature stress on diploid gamete formation and transcript levels of DcPS1. Cytological evidence indicated that 2n male gamete formation is attributable to abnormal spindle orientation at male meiosis II. DcPS1 protein is conserved throughout the plant kingdom and carries domains suggestive of a regulatory function. DcPS1 expression analysis show DcPS1 gene probably have a role in 2n pollen formation. Unreduced pollen formation in various cultivation was sensitive to high or low temperature which was probably regulated by the level of DcPS1 transcripts. In a broader perspective, these findings can have potential applications in fundamental polyploidization research and plant breeding programs. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  6. Expression and putative function of fibronectin and its receptor (integrin alpha(5)beta(1)) in male and female gametes during bovine fertilization in vitro.

    Science.gov (United States)

    Thys, Mirjan; Nauwynck, Hans; Maes, Dominiek; Hoogewijs, Maarten; Vercauteren, Dries; Rijsselaere, Tom; Favoreel, Herman; Van Soom, Ann

    2009-09-01

    Fibronectin (Fn) is a 440 kDa glycoprotein assumed to participate in sperm-egg interaction in human. Recently, it has been demonstrated that Fn--when present during bovine IVF--strongly inhibits sperm penetration. The present study was conducted firstly to evaluate the expression of Fn and its integrin receptor (alpha(5)beta(1)) on male and female bovine gametes using indirect immunofluorescence and secondly, to determine the function of Fn during bovine IVF. Endogenous Fn was detected underneath the zona pellucida (ZP) and integrin alpha(5) on the oolemma of cumulus-denuded oocytes. Bovine spermatozoa displayed integrin alpha(5) at their equatorial segment after acrosome reaction. We established that the main inhibitory effect of exogenously supplemented Fn was located at the sperm-oolemma binding, with a (concurrent) effect on fusion, and this can probably be attributed to the binding of Fn to spermatozoa at the equatorial segment, as shown by means of Alexa Fluor 488-conjugated Fn. Combining these results, the inhibitory effect of exogenously supplemented Fn seemed to be exerted on the male gamete by binding to the exposed integrin alpha(5)beta(1) receptor after acrosome reaction. The presence of endogenous Fn underneath the ZP together with integrin alpha(5) expression on oolemma and acrosome-reacted (AR) sperm cell surface suggests a 'velcro' interaction between the endogenous Fn ligand and corresponding receptors on both (AR) sperm cell and oolemma, initiating sperm-egg binding.

  7. Salmonid Gamete Preservation in the Snake River Basin, Annual Report 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Young, William; Kucera, Paul

    2003-07-01

    In spite of an intensive management effort, chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus mykiss) populations in the Northwest have not recovered and are currently listed as threatened species under the Endangered Species Act. In addition to the loss of diversity from stocks that have already gone extinct, decreased genetic diversity resulting from genetic drift and inbreeding is a major concern. Reduced population and genetic variability diminishes the environmental adaptability of individual species and entire ecological communities. The Nez Perce Tribe (NPT), in cooperation with Washington State University and the University of Idaho, established a germplasm repository in 1992 in order to preserve the remaining salmonid diversity in the region. The germplasm repository provides long-term storage for cryopreserved gametes. Although only male gametes can be cryopreserved, conserving the male component of genetic diversity will maintain future management options for species recovery. NPT efforts have focused on preserving salmon and steelhead gametes from the major river subbasins in the Snake River basin. However, the repository is available for all management agencies to contribute gamete samples from other regions and species. In 2002 a total of 570 viable semen samples were added to the germplasm repository. This included the gametes of 287 chinook salmon from the Lostine River, Catherine Creek, upper Grande Ronde River, Imnaha River (Lookingglass Hatchery), Lake Creek, South Fork Salmon River, Johnson Creek, Big Creek, Capehorn Creek, Marsh Creek, Pahsimeroi River (Pahsimeroi Hatchery), and upper Salmon River (Sawtooth Hatchery) and the gametes of 280 steelhead from the North Fork Clearwater River (Dworshak Hatchery), Fish Creek, Little Sheep Creek, Pahsimeroi River (Pahsimeroi Hatchery) and Snake River (Oxbow Hatchery). In addition, gametes from 60 Yakima River spring chinook and 34 Wenatchee River coho salmon were added to the

  8. A central role for P48/45 in malaria parasite male gamete fertility.

    NARCIS (Netherlands)

    Dijk, M.R. van; Janse, C.J.; Thompson, J.; Waters, A.P.; Braks, J.A.M.; Dodemont, H.J.; Stunnenberg, H.G.; Gemert, G.J.A. van; Sauerwein, R.W.; Eling, W.M.C.

    2001-01-01

    Fertilization and zygote development are obligate features of the malaria parasite life cycle and occur during parasite transmission to mosquitoes. The surface protein PFS48/45 is expressed by male and female gametes of Plasmodium falciparum and PFS48/45 antibodies prevent zygote development and

  9. [COMPARATIVE STUDY ON THE SECRET OF THE DONOR'S IDENTITY OF DONATED GAMETES].

    Science.gov (United States)

    Tisseyre, Sandrine

    2015-07-01

    French law lies down a principle of anonymity of donated gametes. This principle is ignored by English law. Moreover, English law has established, few years ago, the contrary principle: the one of transparency of the donor's identity. This study of English law reports this evolution and its consequences.

  10. Couples with non-obstructive azoospermia are interested in future treatments with artificial gametes

    NARCIS (Netherlands)

    Hendriks, S.; Hessel, M.; Mochtar, M. H.; Meissner, A.; van der Veen, F.; Repping, S.; Dancet, E. A. F.

    2016-01-01

    Would couples diagnosed with non-obstructive azoospermia (NOA) consider two future treatments with artificial gametes (AGs) as alternatives for testicular sperm extraction followed by ICSI (TESE-ICSI)? Most couples with NOA (89%) would opt for treatment with AGs before attempting TESE-ICSI and/or

  11. Salmonid Gamete Preservation in the Snake River Basin, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Robyn; Kucera, Paul A. (Nez Perce Tribe, Lapwai, ID)

    1999-03-01

    Steelhead (Oncorhynchus mykiss) and salmon (Oncorhynchus tshawytscha)populations in the Northwest are decreasing. The Nez Perce Tribe (Tribe) was funded in 1998 by the Bonneville Power Administration to coordinate gene banking of male gametes from Endangered Species Act (ESA) listed steelhead and spring and summer chinook salmon in the Snake River basin.

  12. EMP Fusion

    OpenAIRE

    KUNTAY, Isık

    2010-01-01

    This paper introduces a novel fusion scheme, called EMP Fusion, which has the promise of achieving breakeven and realizing commercial fusion power. The method is based on harnessing the power of an electromagnetic pulse generated by the now well-developed flux compression technology. The electromagnetic pulse acts as a means of both heating up the plasma and confining the plasma, eliminating intermediate steps. The EMP Fusion device is simpler compared to other fusion devices and this reduces...

  13. Limitations on the compensation of gamete donors: a public opinion survey.

    Science.gov (United States)

    Lee, Malinda S; Farland, Leslie V; Missmer, Stacey A; Ginsburg, Elizabeth S

    2017-06-01

    To determine public opinion on gamete donor compensation. Cross-sectional web-based survey. Not applicable. A nationally representative sample of 1,427 people in the United States. Not applicable. Support for the compensation of gamete donors. Of 1,427 respondents, 51 (4%) disagreed with use of IVF for any indication, and 232 (16%) believed that oocyte and/or sperm donation to be always unacceptable. Of the remaining 1,185 respondents, 953 (80%) supported and 41 (4%) opposed paying sperm donors; 1,063 (90%) supported and 24 (2%) opposed paying oocyte donors. Of respondents, 90% believed that appropriate compensation for one cycle of oocyte donation should be less than $10,000. A total of 559 (47%) supported a limit on sperm donor compensation and 544 (46%) supported a limit on oocyte donor compensation. Individuals who had personal knowledge of someone with infertility or who used assisted reproductive technology (ART), and Republicans compared with Democrats, were more likely to support limits on both oocyte and sperm donor compensation. Divorced compared with married respondents were less likely to support limits on gamete donor compensation. Men were less likely to support limits on sperm donor compensation. Most respondents in a nationally representative cohort support compensating gamete donors. Although most do not support limits on gamete donor compensation, most agree the appropriate payment for one cycle of oocyte donation is in line with former American Society for Reproductive Medicine guidelines. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Osteoclast Fusion

    DEFF Research Database (Denmark)

    Marie Julie Møller, Anaïs; Delaissé, Jean-Marie; Søe, Kent

    2017-01-01

    on the nuclearity of fusion partners. While CD47 promotes cell fusions involving mono-nucleated pre-osteoclasts, syncytin-1 promotes fusion of two multi-nucleated osteoclasts, but also reduces the number of fusions between mono-nucleated pre-osteoclasts. Furthermore, CD47 seems to mediate fusion mostly through...... individual fusion events using time-lapse and antagonists of CD47 and syncytin-1. All time-lapse recordings have been studied by two independent observers. A total of 1808 fusion events were analyzed. The present study shows that CD47 and syncytin-1 have different roles in osteoclast fusion depending...... broad contact surfaces between the partners' cell membrane while syncytin-1 mediate fusion through phagocytic-cup like structure. J. Cell. Physiol. 9999: 1-8, 2016. © 2016 Wiley Periodicals, Inc....

  15. Fusion power

    International Nuclear Information System (INIS)

    Hancox, R.

    1981-01-01

    The principles of fusion power, and its advantages and disadvantages, are outlined. Present research programmes and future plans directed towards the development of a fusion power reactor, are summarized. (U.K.)

  16. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

  17. Fusion: introduction

    International Nuclear Information System (INIS)

    Decreton, M.

    2006-01-01

    The article gives an overview and introduction to the activities of SCK-CEN's research programme on fusion. The decision to construct the ITER international nuclear fusion experiment in Cadarache is highlighted. A summary of the Belgian contributions to fusion research is given with particular emphasis on studies of radiation effects on diagnostics systems, radiation effects on remote handling sensing systems, fusion waste management and socio-economic studies

  18. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  19. Fusion Canada

    International Nuclear Information System (INIS)

    1987-07-01

    This first issue of a quarterly newsletter announces the startup of the Tokamak de Varennes, describes Canada's national fusion program, and outlines the Canadian Fusion Fuels Technology Program. A map gives the location of the eleven principal fusion centres in Canada. (L.L.)

  20. Noninvasive imaging systems for gametes and embryo selection in IVF programs: a review.

    Science.gov (United States)

    Omidi, Marjan; Faramarzi, Azita; Agharahimi, Azam; Khalili, Mohammad Ali

    2017-09-01

    Optimizing the efficiency of the in vitro fertilization procedure by improving pregnancy rates and reducing the risks of multiple pregnancies simultaneously are the primary goals of the current assisted reproductive technology program. With the move to single embryo transfers, the need for more cost-effective and noninvasive methods for embryo selection prior to transfer is paramount. These aims require advancement in a more acquire gametes/embryo testing and selection procedures using high-tech devices. Therefore, the aim of the present review is to evaluate the efficacy of noninvasive imaging systems in the current literatures, focusing on the potential clinical application in infertile patients undergoing assisted reproductive technology treatments. In this regards, three advanced imaging systems of motile sperm organelle morphology examination, polarization microscopy and time-lapse monitoring for the best selection of the gametes and preimplantation embryos are introduced in full. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  1. Gamete and Embryo Donation and Surrogacy in Australia: The Social Context and Regulatory Framework

    Science.gov (United States)

    Hammarberg, Karin; Johnson, Louise; Petrillo, Tracey

    2011-01-01

    The social and legal acceptability of third-party reproduction varies around the world. In Australia, gamete and embryo donation and surrogacy are permitted within the regulatory framework set out by federal and state governments. The aim of this paper is to describe the social context and regulatory framework for third-party reproduction in Australia. This is a review of current laws and regulations related to third-party reproduction in Australia. Although subtle between-state differences exist, third-party reproduction is by and large a socially acceptable and legally permissible way to form a family throughout Australia. The overarching principles that govern the practice of third-party reproduction are altruism; the right of donorconceived people to be informed of their biological origins; and the provision of comprehensive counselling about the social, psychological, physical, ethical, financial and legal implications of third-party reproduction to those considering donating or receiving gametes or embryos and entering surrogacy arrangements. These principles ensure that donors are not motivated by financial gain, donor offspring can identify and meet with the person or persons who donated gametes or embryos, and prospective donors and recipients are aware of and have carefully considered the potential consequences of third-party reproduction. Australian state laws and federal guidelines prohibit commercial and anonymous third-party reproduction; mandate counselling of all parties involved in gamete and embryo donation and surrogacy arrangements; and require clinics to keep records with identifying and non- identifying information about the donor/s to allow donor-conceived offspring to trace their biological origins. PMID:24851179

  2. Gamete and Embryo Donation and Surrogacy in Australia:The Social Context and Regulatory Framework

    Directory of Open Access Journals (Sweden)

    Karin Hammarberg

    2011-01-01

    Full Text Available The social and legal acceptability of third-party reproduction varies around the world. In Australia,gamete and embryo donation and surrogacy are permitted within the regulatory framework setout by federal and state governments. The aim of this paper is to describe the social context andregulatory framework for third-party reproduction in Australia.This is a review of current laws and regulations related to third-party reproduction in Australia.Although subtle between-state differences exist, third-party reproduction is by and large a sociallyacceptable and legally permissible way to form a family throughout Australia. The overarchingprinciples that govern the practice of third-party reproduction are altruism; the right of donorconceivedpeople to be informed of their biological origins; and the provision of comprehensivecounselling about the social, psychological, physical, ethical, financial and legal implications ofthird-party reproduction to those considering donating or receiving gametes or embryos and enteringsurrogacy arrangements. These principles ensure that donors are not motivated by financial gain,donor offspring can identify and meet with the person or persons who donated gametes or embryos,and prospective donors and recipients are aware of and have carefully considered the potentialconsequences of third-party reproduction.Australian state laws and federal guidelines prohibit commercial and anonymous third-partyreproduction; mandate counselling of all parties involved in gamete and embryo donationand surrogacy arrangements; and require clinics to keep records with identifying and nonidentifyinginformation about the donor/s to allow donor-conceived offspring to trace theirbiological origins.

  3. Two-generation analysis of pollen flow across a landscape. I. Male gamete heterogeneity among females.

    Science.gov (United States)

    Smouse, P E; Dyer, R J; Westfall, R D; Sork, V L

    2001-02-01

    Gene flow is a key factor in the spatial genetic structure in spatially distributed species. Evolutionary biologists interested in microevolutionary processess and conservation biologists interested in the impact of landscape change require a method that measures the real time process of gene movement. We present a novel two-generation (parent-offspring) approach to the study of genetic structure (TwoGener) that allows us to quantify heterogeneity among the male gamete pools sampled by maternal trees scattered across the landscape and to estimate mean pollination distance and effective neighborhood size. First, we describe the model's elements: genetic distance matrices to estimate intergametic distances, molecular analysis of variance to determine whether pollen profiles differ among mothers, and optimal sampling considerations. Second, we evaluate the model's effectiveness by simulating spatially distributed populations. Spatial heterogeneity in male gametes can be estimated by phiFT, a male gametic analogue of Wright's F(ST) and an inverse function of mean pollination distance. We illustrate TwoGener in cases where the male gamete can be categorically or ambiguously determined. This approach does not require the high level of genetic resolution needed by parentage analysis, but the ambiguous case is vulnerable to bias in the absence of adequate genetic resolution. Finally, we apply TwoGener to an empirical study of Quercus alba in Missouri Ozark forests. We find that phiFT = 0.06, translating into about eight effective pollen donors per female and an effective pollination neighborhood as a circle of radius about 17 m. Effective pollen movement in Q. alba is more restricted than previously realized, even though pollen is capable of moving large distances. This case study illustrates that, with a modest investment in field survey and laboratory analysis, the TwoGener approach permits inferences about landscape-level gene movements.

  4. Three members of the 6-cys protein family of Plasmodium play a role in gamete fertility.

    Directory of Open Access Journals (Sweden)

    Melissa R van Dijk

    2010-04-01

    Full Text Available The process of fertilization is critically dependent on the mutual recognition of gametes and in Plasmodium, the male gamete surface protein P48/45 is vital to this process. This protein belongs to a family of 10 structurally related proteins, the so called 6-cys family. To identify the role of additional members of this family in Plasmodium fertilisation, we performed genetic and functional analysis on the five members of the 6-cys family that are transcribed during the gametocyte stage of P. berghei. This analysis revealed that in addition to P48/45, two members (P230 and P47 also play an essential role in the process of parasite fertilization. Mating studies between parasites lacking P230, P48/45 or P47 demonstrate that P230, like P48/45, is a male fertility factor, consistent with the previous demonstration of a protein complex containing both P48/45 and P230. In contrast, disruption of P47 results in a strong reduction of female fertility, while males remain unaffected. Further analysis revealed that gametes of mutants lacking expression of p48/45 or p230 or p47 are unable to either recognise or attach to each other. Disruption of the paralog of p230, p230p, also specifically expressed in gametocytes, had no observable effect on fertilization. These results indicate that the P. berghei 6-cys family contains a number of proteins that are either male or female specific ligands that play an important role in gamete recognition and/or attachment. The implications of low levels of fertilisation that exist even in the absence of these proteins, indicating alternative pathways of fertilisation, as well as positive selection acting on these proteins, are discussed in the context of targeting these proteins as transmission blocking vaccine candidates.

  5. Gamete and embryo donation and surrogacy in australia: the social context and regulatory framework.

    Science.gov (United States)

    Hammarberg, Karin; Johnson, Louise; Petrillo, Tracey

    2011-01-01

    The social and legal acceptability of third-party reproduction varies around the world. In Australia, gamete and embryo donation and surrogacy are permitted within the regulatory framework set out by federal and state governments. The aim of this paper is to describe the social context and regulatory framework for third-party reproduction in Australia. This is a review of current laws and regulations related to third-party reproduction in Australia. Although subtle between-state differences exist, third-party reproduction is by and large a socially acceptable and legally permissible way to form a family throughout Australia. The overarching principles that govern the practice of third-party reproduction are altruism; the right of donorconceived people to be informed of their biological origins; and the provision of comprehensive counselling about the social, psychological, physical, ethical, financial and legal implications of third-party reproduction to those considering donating or receiving gametes or embryos and entering surrogacy arrangements. These principles ensure that donors are not motivated by financial gain, donor offspring can identify and meet with the person or persons who donated gametes or embryos, and prospective donors and recipients are aware of and have carefully considered the potential consequences of third-party reproduction. Australian state laws and federal guidelines prohibit commercial and anonymous third-party reproduction; mandate counselling of all parties involved in gamete and embryo donation and surrogacy arrangements; and require clinics to keep records with identifying and non- identifying information about the donor/s to allow donor-conceived offspring to trace their biological origins.

  6. Effects of produced water on gametogenesis and gamete performance in the purple sea urchin (Stronglyocentrotus purpuratus)

    International Nuclear Information System (INIS)

    Krause, P.R.

    1993-01-01

    The author examined the effects of a chronic exposure to produced water (an oil production effluent) discharge on the gametogenesis and gamete performance of the purple sea urchin (Strongylocentrotus purpuratus) using an in situ caging experiment. Adult purple urchins were kept in benthic cages arrayed down-field from a discharging diffuser at 13 sites with distances ranging from 5m to 1,000m. Cage exposures were maintained in the field for eight weeks and each cage held 25 urchins. Gametogenesis was examined for each sex by comparing a size-independent measure of gonad mass as determined by analysis of covariance. The author found that there was a significant negative relationship between gonad mass and cage distance for both sexes, indicating that urchins living closer to the outfall produced significantly larger gonads. Gamete performance was measured through a fertilization kinetic bioassay that holds the concentration of eggs constant and varies the amount of sperm added. The proportion of eggs fertilized under each sperm concentration was determined and the response fit to a kinetics model. Significant differences were found in the fertilizability of eggs between cages. This showed a positive relationship with distance away from the outfall. The findings indicate that while adult urchins exposed to a produced water outfall produced larger gonads, they suffered a marked decreases in gamete performance

  7. Making muslim babies: Ivf and gamete donation in sunni versus shi’a islam

    Science.gov (United States)

    2006-01-01

    Medical anthropological research on science, biotechnology, and religion has focused on the “local moral worlds” of men and women as they make difficult decisions regarding their health and the beginnings and endings of human life. This paper focuses on the local moral worlds of infertile Muslims as they attempt to make, in the religiously correct fashion, Muslim babies at in vitro fertilization (IVF) clinics in Egypt and Lebanon. As early as 1980, authoritative fatwas issued from Egypt’s famed Al-Azhar University suggested that IVF and similar technologies are permissible as long as they do not involve any form of third-party donation (of sperm, eggs, embryos, or uteruses). Since the late 1990s, however, divergences in opinion over third-party gamete donation have occurred between Sunni and Shi’ite Muslims, with Iran’s leading ayatollah permitting gamete donation under certain conditions. This Iranian fatwa has had profound implications for the country of Lebanon, where a Shi’ite majority also seeks IVF services. Based on three periods of ethnographic research in Egyptian and Lebanese IVF clinics, this paper explores official and unofficial religious discourses surrounding the practice of IVF and third-party donation in the Muslim world, as well as the gender implications of gamete donation for Muslim marriages. PMID:17051430

  8. Social polyandry, parental investment, sexual selection, and evolution of reduced female gamete size.

    Science.gov (United States)

    Andersson, Malte

    2004-01-01

    Sexual selection in the form of sperm competition is a major explanation for small size of male gametes. Can sexual selection in polyandrous species with reversed sex roles also lead to reduced female gamete size? Comparative studies show that egg size in birds tends to decrease as a lineage evolves social polyandry. Here, a quantitative genetic model predicts that female scrambles over mates lead to evolution of reduced female gamete size. Increased female mating success drives the evolution of smaller eggs, which take less time to produce, until balanced by lowered offspring survival. Mean egg size is usually reduced and polyandry increased by increasing sex ratio (male bias) and maximum possible number of mates. Polyandry also increases with the asynchrony (variance) in female breeding start. Opportunity for sexual selection increases with the maximum number of mates but decreases with increasing sex ratio. It is well known that parental investment can affect sexual selection. The model suggests that the influence is mutual: owing to a coevolutionary feedback loop, sexual selection in females also shapes initial parental investment by reducing egg size. Feedback between sexual selection and parental investment may be common.

  9. Peering beneath the surface: novel imaging techniques to noninvasively select gametes and embryos for ART.

    Science.gov (United States)

    Jasensky, Joshua; Swain, Jason E

    2013-10-01

    Embryo imaging has long been a critical tool for in vitro fertilization laboratories, aiding in morphological assessment of embryos, which remains the primary tool for embryo selection. With the recent emergence of clinically applicable real-time imaging systems to assess embryo morphokinetics, a renewed interest has emerged regarding noninvasive methods to assess gamete and embryo development as a means of inferring quality. Several studies exist that utilize novel imaging techniques to visualize or quantify intracellular components of gametes and embryos with the intent of correlating localization of organelles or molecular constitution with quality or outcome. However, the safety of these approaches varies due to the potential detrimental impact of light exposure or other variables. Along with complexity of equipment and cost, these drawbacks currently limit clinical application of these novel microscopes and imaging techniques. However, as evidenced by clinical incorporation of some real-time imaging devices as well as use of polarized microscopy, some of these imaging approaches may prove to be useful. This review summarizes the existing literature on novel imaging approaches utilized to examine gametes and embryos. Refinement of some of these imaging systems may permit clinical application and serve as a means to offer new, noninvasive selection tools to improve outcomes for various assisted reproductive technology procedures.

  10. Globalization and gametes: reproductive 'tourism,' Islamic bioethics, and Middle Eastern modernity.

    Science.gov (United States)

    Inhorn, Marcia C

    2011-04-01

    'Reproductive tourism' has been defined as the search for assisted reproductive technologies (ARTs) and human gametes (eggs, sperm, embryos) across national and international borders. This article conceptualizes reproductive tourism within 'global reproscapes,' which involve the circulation of actors, technologies, money, media, ideas, and human gametes, all moving in complicated manners across geographical landscapes. Focusing on the Muslim countries of the Middle East, the article explores the Islamic 'local moral worlds' informing the movements of Middle Eastern infertile couples. The ban on third-party gamete donation in Sunni Muslim-majority countries and the recent allowance of donor technologies in the Shia Muslim-majority countries of Iran and Lebanon have led to significant movements of infertile couples across Middle Eastern national borders. In the new millennium, Iran is leading the way into this 'brave new world' of high-tech, third-party assisted conception, with Islamic bioethical discourses being used to justify various forms of technological assistance. Although the Middle East is rarely regarded in this way, it is a key site for understanding the intersection of technoscience, religious morality, and modernity, all of which are deeply implicated in the new world of reproductive tourism.

  11. Efficient computation of the inverse of gametic relationship matrix for a marked QTL

    Directory of Open Access Journals (Sweden)

    Iwaisaki Hiroaki

    2006-04-01

    Full Text Available Abstract Best linear unbiased prediction of genetic merits for a marked quantitative trait locus (QTL using mixed model methodology includes the inverse of conditional gametic relationship matrix (G-1 for a marked QTL. When accounting for inbreeding, the conditional gametic relationships between two parents of individuals for a marked QTL are necessary to build G-1 directly. Up to now, the tabular method and its adaptations have been used to compute these relationships. In the present paper, an indirect method was implemented at the gametic level to compute these few relationships. Simulation results showed that the indirect method can perform faster with significantly less storage requirements than adaptation of the tabular method. The efficiency of the indirect method was mainly due to the use of the sparseness of G-1. The indirect method can also be applied to construct an approximate G-1 for populations with incomplete marker data, providing approximate probabilities of descent for QTL alleles for individuals with incomplete marker data.

  12. Fusion neutronics

    CERN Document Server

    Wu, Yican

    2017-01-01

    This book provides a systematic and comprehensive introduction to fusion neutronics, covering all key topics from the fundamental theories and methodologies, as well as a wide range of fusion system designs and experiments. It is the first-ever book focusing on the subject of fusion neutronics research. Compared with other nuclear devices such as fission reactors and accelerators, fusion systems are normally characterized by their complex geometry and nuclear physics, which entail new challenges for neutronics such as complicated modeling, deep penetration, low simulation efficiency, multi-physics coupling, etc. The book focuses on the neutronics characteristics of fusion systems and introduces a series of theories and methodologies that were developed to address the challenges of fusion neutronics, and which have since been widely applied all over the world. Further, it introduces readers to neutronics design’s unique principles and procedures, experimental methodologies and technologies for fusion systems...

  13. The long path to pregnancy: early experience with dual anonymous gamete donation in a European in vitro fertilisation referral centre

    Directory of Open Access Journals (Sweden)

    Sills Eric

    2010-08-01

    Full Text Available Abstract Background This investigation describes features of patients undergoing in vitro fertilisation (IVF and embryo transfer (ET where both gametes were obtained from anonymous donors. Methods Gamete unsuitability or loss was confirmed in both members of seven otherwise healthy couples presenting for reproductive endocrinology consultation over a 12-month interval in Ireland. IVF was undertaken with fresh oocytes provided by anonymous donors in Ukraine; frozen sperm (anonymous donor was obtained from a licensed tissue establishment. For recipients, saline-enhanced sonography was used to assess intrauterine contour with endometrial preparation via transdermal estrogen. Results Among commissioning couples, mean±SD female and male age was 41.9 ± 3.7 and 44.6 ± 3.5 yrs, respectively. During this period, female age for non dual anonymous gamete donation IVF patients was 37.9 ± 3 yrs (p Conclusions Mean age of females undergoing dual anonymous donor gamete donation with IVF is significantly higher than the background IVF patient population. Even when neither partner is able to contribute any gametes for IVF, the clinical pregnancy rate per transfer can be satisfactory if both anonymous egg and sperm donation are used concurrently. Our report emphasises the role of pre-treatment counselling in dual anonymous gamete donation, and presents a coordinated screening and treatment approach in IVF where this option may be contemplated.

  14. Fusion Physics

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Mitsuru; Lackner, Karl; Tran, Minh Quang [eds.

    2012-09-15

    Recreating the energy production process of the Sun - nuclear fusion - on Earth in a controlled fashion is one of the greatest challenges of this century. If achieved at affordable costs, energy supply security would be greatly enhanced and environmental degradation from fossil fuels greatly diminished. Fusion Physics describes the last fifty years or so of physics and research in innovative technologies to achieve controlled thermonuclear fusion for energy production. The International Atomic Energy Agency (IAEA) has been involved since its establishment in 1957 in fusion research. It has been the driving force behind the biennial conferences on Plasma Physics and Controlled Thermonuclear Fusion, today known as the Fusion Energy Conference. Hosted by several Member States, this biennial conference provides a global forum for exchange of the latest achievements in fusion research against the backdrop of the requirements for a net energy producing fusion device and, eventually, a fusion power plant. The scientific and technological knowledge compiled during this series of conferences, as well as by the IAEA Nuclear Fusion journal, is immense and will surely continue to grow in the future. It has led to the establishment of the International Thermonuclear Experimental Reactor (ITER), which represents the biggest experiment in energy production ever envisaged by humankind.

  15. Fusion breeder

    International Nuclear Information System (INIS)

    Moir, R.W.

    1982-01-01

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs

  16. Fusion Implementation

    International Nuclear Information System (INIS)

    Schmidt, J.A.

    2002-01-01

    If a fusion DEMO reactor can be brought into operation during the first half of this century, fusion power production can have a significant impact on carbon dioxide production during the latter half of the century. An assessment of fusion implementation scenarios shows that the resource demands and waste production associated with these scenarios are manageable factors. If fusion is implemented during the latter half of this century it will be one element of a portfolio of (hopefully) carbon dioxide limiting sources of electrical power. It is time to assess the regional implications of fusion power implementation. An important attribute of fusion power is the wide range of possible regions of the country, or countries in the world, where power plants can be located. Unlike most renewable energy options, fusion energy will function within a local distribution system and not require costly, and difficult, long distance transmission systems. For example, the East Coast of the United States is a prime candidate for fusion power deployment by virtue of its distance from renewable energy sources. As fossil fuels become less and less available as an energy option, the transmission of energy across bodies of water will become very expensive. On a global scale, fusion power will be particularly attractive for regions separated from sources of renewable energy by oceans

  17. The long path to pregnancy: early experience with dual anonymous gamete donation in a European in vitro fertilisation referral centre

    LENUS (Irish Health Repository)

    Sills, Eric Scott

    2010-08-11

    Abstract Background This investigation describes features of patients undergoing in vitro fertilisation (IVF) and embryo transfer (ET) where both gametes were obtained from anonymous donors. Methods Gamete unsuitability or loss was confirmed in both members of seven otherwise healthy couples presenting for reproductive endocrinology consultation over a 12-month interval in Ireland. IVF was undertaken with fresh oocytes provided by anonymous donors in Ukraine; frozen sperm (anonymous donor) was obtained from a licensed tissue establishment. For recipients, saline-enhanced sonography was used to assess intrauterine contour with endometrial preparation via transdermal estrogen. Results Among commissioning couples, mean±SD female and male age was 41.9 ± 3.7 and 44.6 ± 3.5 yrs, respectively. During this period, female age for non dual anonymous gamete donation IVF patients was 37.9 ± 3 yrs (p < 0.001). Infertility duration was ≥3 yrs for couples enrolling in dual gamete donation, and each had ≥2 prior failed fertility treatments using native oocytes. All seven recipient couples proceeded to embryo transfer, although one patient had two transfers. Clinical pregnancy was achieved for 5\\/7 (71.4%) patients. Non-transferred cryopreserved embryos were available for all seven couples. Conclusions Mean age of females undergoing dual anonymous donor gamete donation with IVF is significantly higher than the background IVF patient population. Even when neither partner is able to contribute any gametes for IVF, the clinical pregnancy rate per transfer can be satisfactory if both anonymous egg and sperm donation are used concurrently. Our report emphasises the role of pre-treatment counselling in dual anonymous gamete donation, and presents a coordinated screening and treatment approach in IVF where this option may be contemplated.

  18. Cardiac arrest during gamete release in chum salmon regulated by the parasympathetic nerve system.

    Directory of Open Access Journals (Sweden)

    Yuya Makiguchi

    Full Text Available Cardiac arrest caused by startling stimuli, such as visual and vibration stimuli, has been reported in some animals and could be considered as an extraordinary case of bradycardia and defined as reversible missed heart beats. Variability of the heart rate is established as a balance between an autonomic system, namely cholinergic vagus inhibition, and excitatory adrenergic stimulation of neural and hormonal action in teleost. However, the cardiac arrest and its regulating nervous mechanism remain poorly understood. We show, by using electrocardiogram (ECG data loggers, that cardiac arrest occurs in chum salmon (Oncorhynchus keta at the moment of gamete release for 7.39+/-1.61 s in females and for 5.20+/-0.97 s in males. The increase in heart rate during spawning behavior relative to the background rate during the resting period suggests that cardiac arrest is a characteristic physiological phenomenon of the extraordinarily high heart rate during spawning behavior. The ECG morphological analysis showed a peaked and tall T-wave adjacent to the cardiac arrest, indicating an increase in potassium permeability in cardiac muscle cells, which would function to retard the cardiac action potential. Pharmacological studies showed that the cardiac arrest was abolished by injection of atropine, a muscarinic receptor antagonist, revealing that the cardiac arrest is a reflex response of the parasympathetic nerve system, although injection of sotalol, a beta-adrenergic antagonist, did not affect the cardiac arrest. We conclude that cardiac arrest during gamete release in spawning release in spawning chum salmon is a physiological reflex response controlled by the parasympathetic nervous system. This cardiac arrest represents a response to the gaping behavior that occurs at the moment of gamete release.

  19. Production of viable male unreduced gametes in Brassica interspecific hybrids is genotype specific and stimulated by cold temperatures

    Directory of Open Access Journals (Sweden)

    Cowling Wallace A

    2011-06-01

    Full Text Available Abstract Background Unreduced gametes (gametes with the somatic chromosome number may provide a pathway for evolutionary speciation via allopolyploid formation. We evaluated the effect of genotype and temperature on male unreduced gamete formation in Brassica allotetraploids and their interspecific hybrids. The frequency of unreduced gametes post-meiosis was estimated in sporads from the frequency of dyads or giant tetrads, and in pollen from the frequency of viable giant pollen compared with viable normal pollen. Giant tetrads were twice the volume of normal tetrads, and presumably resulted from pre-meiotic doubling of chromosome number. Giant pollen was defined as pollen with more than 1.5 × normal diameter, under the assumption that the doubling of DNA content in unreduced gametes would approximately double the pollen cell volume. The effect of genotype was assessed in five B. napus, two B. carinata and one B. juncea parents and in 13 interspecific hybrid combinations. The effect of temperature was assessed in a subset of genotypes in hot (day/night 30°C/20°C, warm (25°C/15°C, cool (18°C/13°C and cold (10°C/5°C treatments. Results Based on estimates at the sporad stage, some interspecific hybrid genotypes produced unreduced gametes (range 0.06 to 3.29% at more than an order of magnitude higher frequency than in the parents (range 0.00% to 0.11%. In nine hybrids that produced viable mature pollen, the frequency of viable giant pollen (range 0.2% to 33.5% was much greater than in the parents (range 0.0% to 0.4%. Giant pollen, most likely formed from unreduced gametes, was more viable than normal pollen in hybrids. Two B. napus × B. carinata hybrids produced 9% and 23% unreduced gametes based on post-meiotic sporad observations in the cold temperature treatment, which was more than two orders of magnitude higher than in the parents. Conclusions These results demonstrate that sources of unreduced gametes, required for the triploid

  20. Gamete types, sex determination and stable equilibria of all-hybrid populations of diploid and triploid edible frogs (Pelophylax esculentus

    Directory of Open Access Journals (Sweden)

    Christiansen Ditte G

    2009-06-01

    Full Text Available Abstract Background Triploid individuals often play a key role in speciation by hybridization. An understanding of the gamete types (ploidy and genomic content and stability of hybrid populations with triploid individuals is therefore of importance for exploring the role of hybridization in evolution. The all-hybrid populations of the edible frog, Pelophylax esculentus, are unique in their composition and genetic dynamics: Diploid (genotype LR and triploid (LLR and LRR hybrids depend on each other's different gamete contributions for successful reproduction and maintenance of the populations, as the parental genotypes P. lessonae (LL and P. ridibundus (RR are absent among adults. This study provides data and interpretations on gamete types and sex determination that are essential for understanding the function, evolutionary potential and threats of this intriguing system. Results Dissection of metamorphs from a crossing experiment confirmed that sex determination is an XX-XY system with the Y confined to the L genome. From microsatellite analysis of parents and offspring from the crossings, gamete frequencies could be deduced: Triploids of both sexes mostly made haploid gametes with the genome they had in double dose, however LLR females also made approximately 10% LL gametes by automixis. LR frogs showed much variation in their gamete production. In LRR-rich populations, their LR sperm production was sufficiently high (22% to explain the observed proportion of LRR males, the formation of which has not previously been understood. A model was constructed to calculate equilibrium genotype proportions for different population types on the basis of the gamete proportions found. These equilibria agreed well with empirical literature data. Conclusion If population differentiation with respect to genotype proportions is really driven by gamete patterns, as strongly suggested by the present study, all-hybrid populations constitute not one, but several

  1. Rapid Elimination of the Persistent Synergid through a Cell Fusion Mechanism

    KAUST Repository

    Maruyama, Daisuke

    2015-05-01

    In flowering plants, fertilization-dependent degeneration of the persistent synergid cell ensures one-on-one pairings of male and female gametes. Here, we report that the fusion of the persistent synergid cell and the endosperm selectively inactivates the persistent synergid cell in Arabidopsis thaliana. The synergid-endosperm fusion causes rapid dilution of pre-secreted pollen tube attractant in the persistent synergid cell and selective disorganization of the synergid nucleus during the endosperm proliferation, preventing attractions of excess number of pollen tubes (polytubey). The synergid-endosperm fusion is induced by fertilization of the central cell, while the egg cell fertilization predominantly activates ethylene signaling, an inducer of the synergid nuclear disorganization. Therefore, two female gametes (the egg and the central cell) control independent pathways yet coordinately accomplish the elimination of the persistent synergid cell by double fertilization. Two female gametes (the egg cell and the central cell) in flowering plants coordinately prevent attractions of excess number of pollen tubes via two mechanisms to inactivate persistent synergid cell. © 2015 Elsevier Inc.

  2. Thermonuclear fusion

    International Nuclear Information System (INIS)

    Weisse, J.

    2000-01-01

    This document takes stock of the two ways of thermonuclear fusion research explored today: magnetic confinement fusion and inertial confinement fusion. The basic physical principles are recalled first: fundamental nuclear reactions, high temperatures, elementary properties of plasmas, ignition criterion, magnetic confinement (charged particle in a uniform magnetic field, confinement and Tokamak principle, heating of magnetized plasmas (ohmic, neutral particles, high frequency waves, other heating means), results obtained so far (scale laws and extrapolation of performances, tritium experiments, ITER project), inertial fusion (hot spot ignition, instabilities, results (Centurion-Halite program, laser experiments). The second part presents the fusion reactor and its associated technologies: principle (tritium production, heat source, neutron protection, tritium generation, materials), magnetic fusion (superconducting magnets, divertor (role, principle, realization), inertial fusion (energy vector, laser adaptation, particle beams, reaction chamber, stresses, chamber concepts (dry and wet walls, liquid walls), targets (fabrication, injection and pointing)). The third chapter concerns the socio-economic aspects of thermonuclear fusion: safety (normal operation and accidents, wastes), costs (costs structure and elementary comparison, ecological impact and external costs). (J.S.)

  3. Fusion devices

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1977-01-01

    Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included

  4. Dynamics of gamete production and mating in the parasitic protist Trypanosoma brucei.

    Science.gov (United States)

    Peacock, Lori; Bailey, Mick; Gibson, Wendy

    2016-07-20

    Sexual reproduction in Plasmodium falciparum and Trypanosoma brucei occurs in the insect vector and is important in generating hybrid strains with different combinations of parental characteristics. Production of hybrid parasite genotypes depends on the likelihood of co-infection of the vector with multiple strains. In mosquitoes, existing infection with Plasmodium facilitates the establishment of a second infection, although the asynchronicity of gamete production subsequently prevents mating. In the trypanosome/tsetse system, flies become increasingly refractory to infection as they age, so the likelihood of a fly acquiring a second infection also decreases. This effectively restricts opportunities for trypanosome mating to co-infections picked up by the fly on its first feed, unless an existing infection increases the chance of successful second infection as in the Plasmodium/mosquito system. Using green and red fluorescent trypanosomes, we compared the rates of trypanosome infection and hybrid production in flies co-infected on the first feed, co-infected on a subsequent feed 18 days after emergence, or fed sequentially with each trypanosome clone 18 days apart. Infection rates were highest in the midguts and salivary glands (SG) of flies that received both trypanosome clones in their first feed, and were halved when the infected feed was delayed to day 18. In flies fed the two trypanosome clones sequentially, the second clone often failed to establish a midgut infection and consequently was not present in the SG. Nevertheless, hybrids were recovered from all three groups of infected flies. Meiotic stages and gametes were produced continuously from day 11 to 42 after the infective feed, and in sequentially infected flies, the co-occurrence of gametes led to hybrid formation. We found that a second trypanosome strain can establish infection in the tsetse SG 18 days after the first infected feed, with co-mingling of gametes and production of trypanosome hybrids

  5. ESHRE Task Force on Ethics and Law 21: genetic screening of gamete donors: ethical issues.

    Science.gov (United States)

    Dondorp, W; De Wert, G; Pennings, G; Shenfield, F; Devroey, P; Tarlatzis, B; Barri, P; Diedrich, K; Eichenlaub-Ritter, U; Tüttelmann, F; Provoost, V

    2014-07-01

    This Task Force document explores the ethical issues involved in the debate about the scope of genetic screening of gamete donors. Calls for expanded donor screening arise against the background of both occasional findings of serious but rare genetic conditions in donors or donor offspring that were not detected through present screening procedures and the advent of new genomic technologies promising affordable testing of donors for a wide range of conditions. Ethical principles require that all stakeholders' interests are taken into account, including those of candidate donors. The message of the profession should be that avoiding all risks is impossible and that testing should remain proportional.

  6. Targeting the Conserved Fusion Loop of HAP2 Inhibits the Transmission of Plasmodium berghei and falciparum

    Directory of Open Access Journals (Sweden)

    Fiona Angrisano

    2017-12-01

    Full Text Available Summary: Inhibiting transmission of Plasmodium is a central strategy in malarial eradication, and the biological process of gamete fusion during fertilization is a proven target for this approach. The lack of a structure or known molecular function of current anti-malarial vaccine targets has previously been a hindrance in the development of transmission-blocking vaccines. Structure/function studies have indicated that the conserved gamete membrane fusion protein HAP2 is a class II viral fusion protein. Here, we demonstrate that targeting a function-critical site of the fusion/cd loop with species-specific antibodies reduces Plasmodium berghei transmission in vivo by 58.9% and in vitro fertilization by up to 89.9%. A corresponding reduction in P. falciparum transmission (75.5%/36.4% reductions in intensity/prevalence is observed in complimentary field studies. These results emphasize conserved mechanisms of fusion in Apicomplexa, while highlighting an approach to design future anti-malarial transmission-blocking vaccines. : Angrisano et al. find that the HAP2 cd-loop can be targeted as an anti-malarial intervention, is immunogenic across multiple plasmodial species, can induce antibodies that specifically recognize the sexual stages of the parasitic life cycle, and can mediate transmission-blocking immunity in the lab and the field. Keywords: HAP2, malaria, transmission, fusion, vaccine

  7. Conservation of proteo-lipid nuclear membrane fusion machinery during early embryogenesis.

    Science.gov (United States)

    Byrne, Richard D; Veeriah, Selvaraju; Applebee, Christopher J; Larijani, Banafshé

    2014-01-01

    The fusogenic lipid diacylglycerol is essential for remodeling gamete and zygote nuclear envelopes (NE) during early embryogenesis. It is unclear whether upstream signaling molecules are likewise conserved. Here we demonstrate PLCγ and its activator SFK1, which co-operate during male pronuclear envelope formation, also promote the subsequent male and female pronuclear fusion. PLCγ and SFK1 interact directly at the fusion site leading to PLCγ activation. This is accompanied by a spatially restricted reduction of PtdIns(4,5)P2. Consequently, pronuclear fusion is blocked by PLCγ or SFK1 inhibition. These findings identify new regulators of events in the early embryo and suggest a conserved "toolkit" of fusion machinery drives successive NE fusion events during embryogenesis.

  8. Atomic fusion, Gerrard atomic fusion

    International Nuclear Information System (INIS)

    Gerrard, T.H.

    1980-01-01

    In the approach to atomic fusion described here the heat produced in a fusion reaction, which is induced in a chamber by the interaction of laser beams and U.H.F. electromagnetic beams with atom streams, is transferred to a heat exchanger for electricity generation by a coolant flowing through a jacket surrounding the chamber. (U.K.)

  9. Peaceful fusion

    Energy Technology Data Exchange (ETDEWEB)

    Englert, Matthias [IANUS, TU Darmstadt (Germany)

    2014-07-01

    Like other intense neutron sources fusion reactors have in principle a potential to be used for military purposes. Although the use of fissile material is usually not considered when thinking of fusion reactors (except in fusion-fission hybrid concepts) quantitative estimates about the possible production potential of future commercial fusion reactor concepts show that significant amounts of weapon grade fissile materials could be produced even with very limited amounts of source materials. In this talk detailed burnup calculations with VESTA and MCMATH using an MCNP model of the PPCS-A will be presented. We compare different irradiation positions and the isotopic vectors of the plutonium bred in different blankets of the reactor wall with the liquid lead-lithium alloy replaced by uranium. The technical, regulatory and policy challenges to manage the proliferation risks of fusion power will be addressed as well. Some of these challenges would benefit if addressed at an early stage of the research and development process. Hence, research on fusion reactor safeguards should start as early as possible and accompany the current research on experimental fusion reactors.

  10. Human DAZL, DAZ and BOULE genes modulate primordial germ cell and haploid gamete formation

    Science.gov (United States)

    Kee, Kehkooi; Angeles, Vanessa T; Flores, Martha; Nguyen, Ha Nam; Pera, Renee A Reijo

    2009-01-01

    The leading cause of infertility in men and women is quantitative and qualitative defects in human germ cell (oocyte and sperm) development. Yet, it has not been possible to examine the unique developmental genetics of human germ cell formation and differentiation due to inaccessibility of germ cells during fetal development. Although several studies have shown that germ cells can be differentiated from mouse and human embryonic stem cells, human germ cells differentiated in these studies generally did not develop beyond the earliest stages1-8. Here we used a germ cell reporter to quantitate and isolate primordial germ cells derived from both male and female hESCs. Then, by silencing and overexpressing genes that encode germ cell-specific cytoplasmic RNA-binding proteins (not transcription factors), we modulated human germ cell formation and developmental progression. We observed that human DAZL (Deleted in AZoospermia-Like) functions in primordial germ cell formation, whereas closely-related genes, DAZ and BOULE, promote later stages of meiosis and development of haploid gametes. These results are significant to the generation of gametes for future basic science and potential clinical applications. PMID:19865085

  11. Effect of gamma radiation on mutability in male gametes of Japanese quail (Coturnix coturnix japonica)

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, J [Vyskumny Ustav Chovu a Slachtenia Hydiny, Laboratorim Genetiky, Ivanka pri Dunaji (Czechoslovakia)

    1978-01-01

    An analysis of the mutability of developmental stages of male gametes of the japanese quail (Coturnix coturnix japonica), after irradiation with /sup 60/Co exposures (5.16; 15.48; and 30.96)x10/sup -2/C kg/sup -1/, i.e. 200, 600 and 1200 R, at an exposure rate of 8.59x10/sup -5/C kg/sup -1/s/sup -1/, i.e. O.33 R s/sup -1/, has shown that the rate of overall induced dominant lethality as well as the rate of mutation were highest in spermatocytes of the second order at all exposures. Starting from an exposure of 200 R the following values were found for lethal interference per 1 gamete for 1 R: spermatozoa 2.0x10/sup -3/, spermatides 1.95x10/sup -3/, spermatocytes II 6.1x10/sup -3/, spermatocytes I 4.06x10/sup -3/, spermatogonia in the process of differentiation 6.8x10/sup -3/. When analysing overall embryonic lethality, according to early and late lethality, dominant lethal mutations mainly manifested themsel--ves in the oviductal and germinal developmental periods, so that these periods can be considered as sensitive indices of genetic changes. The spermatogenic epithelium of the japanese quail was found to be greatly radioresistant since not even an exposure to 1200 R caused complete and permanent sterility.

  12. Herbicide impact on Hormosira banksii gametes measured by fluorescence and germination bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Seery, Cliff R. [Institute for Water and Environmental Resource Management, Department of Environmental Sciences, University of Technology, Sydney, Westbourne Street, Gore Hill, 2065 NSW (Australia); Gunthorpe, Leanne [Primary Industries Research Victoria (PIRVic), VIC (Australia); Ralph, Peter J. [Institute for Water and Environmental Resource Management, Department of Environmental Sciences, University of Technology, Sydney, Westbourne Street, Gore Hill, 2065 NSW (Australia)]. E-mail: peter.ralph@uts.edu.au

    2006-03-15

    The innovative bioassay described here involves chlorophyll a fluorescence measurements of gametes from the macroalgae, Hormosira banksii, where gametes (eggs) were exposed to Diuron, Irgarol and Bromacil. Response was assessed as percent inhibition from control of effective quantum yield ({delta}F/Fm') of photosystem II, herein referred to as % PSII Inhibition. This was measured with the dual-channelled pulse amplitude modulated (PAM) fluorometer, ToxY-PAM. The fluorescence bioassay was run simultaneously with an established H. banksii germination bioassay to compare sensitivity, precision, and time-to-result. The fluorescence bioassay gave highly sensitive results evidenced by EC{sub 5}s (% PSII Inhibition) for Diuron, Irgarol and Bromacil being three, four and three orders of magnitude (respectively) lower than EC{sub 5}s generated from the germination bioassays. Precision of the fluorescence bioassay was demonstrated with low coefficient of variations (<30%) for all three toxicants. With regard to time, the fluorescence bioassay gave results within 6 h, as opposed to more than 50 h for the germination bioassay. - Chlorophyll a fluorescence measurements form the basis of a macroalgal bioassay with many advantages over germination-based methods.

  13. Herbicide impact on Hormosira banksii gametes measured by fluorescence and germination bioassays

    International Nuclear Information System (INIS)

    Seery, Cliff R.; Gunthorpe, Leanne; Ralph, Peter J.

    2006-01-01

    The innovative bioassay described here involves chlorophyll a fluorescence measurements of gametes from the macroalgae, Hormosira banksii, where gametes (eggs) were exposed to Diuron, Irgarol and Bromacil. Response was assessed as percent inhibition from control of effective quantum yield (ΔF/Fm') of photosystem II, herein referred to as % PSII Inhibition. This was measured with the dual-channelled pulse amplitude modulated (PAM) fluorometer, ToxY-PAM. The fluorescence bioassay was run simultaneously with an established H. banksii germination bioassay to compare sensitivity, precision, and time-to-result. The fluorescence bioassay gave highly sensitive results evidenced by EC 5 s (% PSII Inhibition) for Diuron, Irgarol and Bromacil being three, four and three orders of magnitude (respectively) lower than EC 5 s generated from the germination bioassays. Precision of the fluorescence bioassay was demonstrated with low coefficient of variations (<30%) for all three toxicants. With regard to time, the fluorescence bioassay gave results within 6 h, as opposed to more than 50 h for the germination bioassay. - Chlorophyll a fluorescence measurements form the basis of a macroalgal bioassay with many advantages over germination-based methods

  14. Polyploidization mechanisms: temperature environment can induce diploid gamete formation in Rosa sp.

    Science.gov (United States)

    Pécrix, Yann; Rallo, Géraldine; Folzer, Hélène; Cigna, Mireille; Gudin, Serge; Le Bris, Manuel

    2011-06-01

    Polyploidy is an important evolutionary phenomenon but the mechanisms by which polyploidy arises still remain underexplored. There may be an environmental component to polyploidization. This study aimed to clarify how temperature may promote diploid gamete formation considered an essential element for sexual polyploidization. First of all, a detailed cytological analysis of microsporogenesis and microgametogenesis was performed to target precisely the key developmental stages which are the most sensitive to temperature. Then, heat-induced modifications in sporad and pollen characteristics were analysed through an exposition of high temperature gradient. Rosa plants are sensitive to high temperatures with a developmental sensitivity window limited to meiosis. Moreover, the range of efficient temperatures is actually narrow. 36 °C at early meiosis led to a decrease in pollen viability, pollen ectexine defects but especially the appearance of numerous diploid pollen grains. They resulted from dyads or triads mainly formed following heat-induced spindle misorientations in telophase II. A high temperature environment has the potential to increase gamete ploidy level. The high frequencies of diplogametes obtained at some extreme temperatures support the hypothesis that polyploidization events could have occurred in adverse conditions and suggest polyploidization facilitating in a global change context.

  15. A pharmacological study of Arabidopsis cell fusion between the persistent synergid and endosperm.

    Science.gov (United States)

    Motomura, Kazuki; Kawashima, Tomokazu; Berger, Frédéric; Kinoshita, Tetsu; Higashiyama, Tetsuya; Maruyama, Daisuke

    2018-01-29

    Cell fusion is a pivotal process in fertilization and multinucleate cell formation. A plant cell is ubiquitously surrounded by a hard cell wall, and very few cell fusions have been observed except for gamete fusions. We recently reported that the fertilized central cell (the endosperm) absorbs the persistent synergid, a highly differentiated cell necessary for pollen tube attraction. The synergid-endosperm fusion (SE fusion) appears to eliminate the persistent synergid from fertilized ovule in Arabidopsis thaliana Here, we analyzed the effects of various inhibitors on SE fusion in an in vitro culture system. Different from other cell fusions, neither disruption of actin polymerization nor protein secretion impaired SE fusion. However, transcriptional and translational inhibitors decreased the SE fusion success rate and also inhibited endosperm division. Failures of SE fusion and endosperm nuclear proliferation were also induced by roscovitine, an inhibitor of cyclin-dependent kinases (CDK). These data indicate unique aspects of SE fusion such as independence of filamentous actin support and the importance of CDK-mediated mitotic control. © 2018. Published by The Company of Biologists Ltd.

  16. Structural relationships among central cell and egg apparatus cells of barley as related to transmission of male gametes

    Directory of Open Access Journals (Sweden)

    David D. Cass

    2014-01-01

    Full Text Available Barley embryo sacs were examined using light and electron microscopy before and during fertilization. One synergid degenerates after pollination with loss of nuclear and cytoplasmic organization and cell wall material between synergid and central cell. Some wall between egg and central cell is also lost. After pollen tube discharge into the degenerate synergid, the male gametes leave the synergid entering a pocket of central cell cytoplasm separated from the synergid only by membranes. This could provide for efficient gamete transmission and possible recognition through specific membrane contacts.

  17. Cold fusion

    International Nuclear Information System (INIS)

    Suh, Suk Yong; Sung, Ki Woong; Kang, Joo Sang; Lee, Jong Jik

    1995-02-01

    So called 'cold fusion phenomena' are not confirmed yet. Excess heat generation is very delicate one. Neutron generation is most reliable results, however, the records are erratic and the same results could not be repeated. So there is no reason to exclude the malfunction of testing instruments. The same arguments arise in recording 4 He, 3 He, 3 H, which are not rich in quantity basically. An experiment where plenty of 4 He were recorded is attached in appendix. The problem is that we are trying to search cold fusion which is permitted by nature or not. The famous tunneling effect in quantum mechanics will answer it, however, the most fusion rate is known to be negligible. The focus of this project is on the theme that how to increase that negligible fusion rate. 6 figs, 4 tabs, 1512 refs. (Author)

  18. Cold fusion

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Suk Yong; Sung, Ki Woong; Kang, Joo Sang; Lee, Jong Jik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    So called `cold fusion phenomena` are not confirmed yet. Excess heat generation is very delicate one. Neutron generation is most reliable results, however, the records are erratic and the same results could not be repeated. So there is no reason to exclude the malfunction of testing instruments. The same arguments arise in recording {sup 4}He, {sup 3}He, {sup 3}H, which are not rich in quantity basically. An experiment where plenty of {sup 4}He were recorded is attached in appendix. The problem is that we are trying to search cold fusion which is permitted by nature or not. The famous tunneling effect in quantum mechanics will answer it, however, the most fusion rate is known to be negligible. The focus of this project is on the theme that how to increase that negligible fusion rate. 6 figs, 4 tabs, 1512 refs. (Author).

  19. Laser fusion

    International Nuclear Information System (INIS)

    Ashby, D.E.T.F.

    1976-01-01

    A short survey is given on laser fusion its basic concepts and problems and the present theoretical and experimental methods. The future research program of the USA in this field is outlined. (WBU) [de

  20. Fusion energy

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The efforts of the Chemical Technology Division in fusion energy include the areas of fuel handling, processing, and containment. Current studies are concerned largely with the development of vacuum pumps for fusion reactors and experiments and with development and evaluation of techniques for recovering tritium from solid or liquid breeding blankets. In addition, a small effort is devoted to support of the ORNL design of a major Tokamak experiment, The Next Step (TNS)

  1. Laser fusion

    International Nuclear Information System (INIS)

    Key, M.H.; Oxford Univ.

    1990-04-01

    The use of lasers to drive implosions for the purpose of inertially confined fusion is an area of intense activity where progress compares favourably with that made in magnetic fusion and there are significant prospects for future development. In this brief review the basic concept is summarised and the current status is outlined both in the area of laser technology and in the most recent results from implosion experiments. Prospects for the future are also considered. (author)

  2. Nuclear fusion

    International Nuclear Information System (INIS)

    Al-zaelic, M.M.

    2013-01-01

    Nuclear fusion can be relied on to solve the global energy crisis if the process of limiting the heat produced by the fusion reaction (Plasma) is successful. Currently scientists are progressively working on this aspect whereas there are two methods to limit the heat produced by fusion reaction, the two methods are auto-restriction using laser beam and magnetic restriction through the use of magnetic fields and research is carried out to improve these two methods. It is expected that at the end of this century the nuclear fusion energy will play a vital role in overcoming the global energy crisis and for these reasons, acquiring energy through the use of nuclear fusion reactors is one of the most urge nt demands of all mankind at this time. The conclusion given is that the source of fuel for energy production is readily available and inexpensive ( hydrogen atoms) and whole process is free of risks and hazards, especially to general health and the environment . Nuclear fusion importance lies in the fact that energy produced by the process is estimated to be about four to five times the energy produced by nuclear fission. (author)

  3. Salmonid Gamete Preservation in the Snake River Basin, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Robyn; Kucera, Paul

    2002-06-01

    Steelhead (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytscha) populations in the Northwest are decreasing. Genetic diversity is being lost at an alarming rate. Along with reduced population and genetic variability, the loss of biodiversity means a diminished environmental adaptability. The Nez Perce Tribe (Tribe) strives to ensure availability of genetic samples of the existing male salmonid population by establishing and maintaining a germplasm repository. The sampling strategy, initiated in 1992, has been to collect and preserve male salmon and steelhead genetic diversity across the geographic landscape by sampling within the major river subbasins in the Snake River basin, assuming a metapopulation structure existed historically. Gamete cryopreservation conserves genetic diversity in a germplasm repository, but is not a recovery action for listed fish species. The Tribe was funded in 2001 by the Bonneville Power Administration (BPA) and the U.S. Fish and Wildlife Service Lower Snake River Compensation Plan (LSRCP) to coordinate gene banking of male gametes from Endangered Species Act (ESA) listed steelhead and spring and summer chinook salmon in the Snake River basin. In 2001, a total of 398 viable chinook salmon semen samples from the Lostine River, Catherine Creek, upper Grande Ronde River, Lookingglass Hatchery (Imnaha River stock), Lake Creek, the South Fork Salmon River weir, Johnson Creek, Big Creek, Capehorn Creek, Marsh Creek, Pahsimeroi Hatchery, and Sawtooth Hatchery (upper Salmon River stock) were cryopreserved. Also, 295 samples of male steelhead gametes from Dworshak Hatchery, Fish Creek, Grande Ronde River, Little Sheep Creek, Pahsimeroi Hatchery and Oxbow Hatchery were also cryopreserved. The Grande Ronde chinook salmon captive broodstock program stores 680 cryopreserved samples at the University of Idaho as a long-term archive, half of the total samples. A total of 3,206 cryopreserved samples from Snake River basin steelhead and

  4. Reproductive and therapeutic cloning, germline therapy, and purchase of gametes and embryos: comments on Canadian legislation governing reproduction technologies

    Science.gov (United States)

    Bernier, L; Gregoire, D

    2004-01-01

    In this article the three main topics covered in the new legislation are commented on: cloning, germline therapy, and purchase of gametes and embryos. Some important issues also covered in the new legislation, such as privacy and access to information, data protection, identity of donors, and inspection, will not be addressed. PMID:15574437

  5. Cryopreservation of Adult Male Spring and Summer Chinook Salmon Gametes in the Snake River Basin, 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Faurot, Dave; Kucera, Paul A.; Armstrong, Robyn D. (Nez Perce Tribe, Lapwai, ID)

    1998-06-01

    Chinook salmon populations in the Northwest are decreasing in number. The Nez Perce Tribe was funded in 1997 by the Bonneville Power Administration to coordinate and initiate gene banking of adult male gametes from Endangered Species Act (ESA) listed spring and summer chinook salmon in the Snake River basin.

  6. Oocyte banking for anticipated gamete exhaustion (AGE) is a preventive intervention, neither social nor nonmedical.

    Science.gov (United States)

    Stoop, Dominic; van der Veen, Fulco; Deneyer, Michel; Nekkebroeck, Julie; Tournaye, Herman

    2014-05-01

    The scope of female fertility preservation through cryopreservation of oocytes or ovarian cortex has widened from mainly oncological indications to a variety of fertility-threatening conditions. So far, no specific universally accepted denomination name has been given to cryopreservation of oocytes or ovarian cortex for the prevention of age-related fertility decline. We argue that the commonly used phrases 'social' and 'nonmedical freezing' to denote the indication for cryopreservation are not entirely correct. We suggest 'AGE banking', as this has not only the advantage of being catchy but also depicts the exact indication for the strategy, anticipated gamete exhaustion. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Cold fusion

    International Nuclear Information System (INIS)

    Koster, J.

    1989-01-01

    In this contribution the author the phenomenom of so-called cold fusion, inspired by the memorable lecture of Moshe Gai on his own search for this effect. Thus much of what follows was presented by Dr. Gai; the rest is from independent reading. What is referred to as cold fusion is of course the observation of possible products of deuteron-deuteron (d-d) fusion within deuterium-loaded (dentended) electrodes. The debate over the two vanguard cold fusion experiments has raged under far more public attention than usually accorded new scientific phenomena. The clamor commenced with the press conference of M. Fleishmann and S. Pons on March 23, 1989 and the nearly simultaneous wide circulation of a preprint of S. Jones and collaborators. The majority of work attempting to confirm these observations has at the time of this writing yet to appear in published form, but contributions to conferences and electronic mail over computer networks were certainly filled with preliminary results. To keep what follows to a reasonable length the author limit this discussion to the searches for neutron (suggested by ref. 2) or for excessive heat production (suggested by ref. 1), following a synopsis of the hypotheses of cold fusion

  8. Collection of gametes from live axolotl, Ambystoma mexicanum, and standardization of in vitro fertilization.

    Science.gov (United States)

    Mansour, N; Lahnsteiner, F; Patzner, R A

    2011-01-15

    This study established the first protocol for collection of gametes from live axolotl, Ambystoma mexicanum, by gentle abdominal massage and in vitro fertilization. To stimulate spermiation and ovulation, human chorionic gonadotrophin (hCG) and Ovopel pellets, which are commercially used to stimulate spawning in fish, were tested. The hCG was more effective than Ovopel pellets and yielded a higher semen volume in the injected males and a shorter response time in the females. Collected semen by this method was already motile and fertile. Fertile eggs could be collected in 3-4 successive collection times after the female has started the typical spawning behaviour. The fertilization condition that yielded the highest hatching rate was mixing semen with eggs before the addition of a fertilization saline solution (20 mmol/l NaCl, 1 mmol/l KCl, 1 mmol/l Mg(2)SO(4), 1 mmol Ca(2)Cl, 3 mmol NaHCO(3), 10 mmol/l Tris, pH 8.5 - Osmolality = 65 mosmol/kg). When the pH of the fertilization solution was increased to ≥ 10, the hatching rate was significantly increased. The use of fertilization solutions with osmolalities of ≥ 150 and ≥ 182 were accompanied with a significant decrease in hatching rates and the appearance of deformed larvae, respectively. In conclusion, a reliable protocol for gamete collection from live axolotl is established as a laboratory model of in vitro fertilization for urodele amphibians. This protocol may be transferable to endangered urodeles. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Comparative study of the germination of Ulva prolifera gametes on various substrates

    Science.gov (United States)

    Geng, Huixia; Yan, Tian; Zhou, Mingjiang; Liu, Qing

    2015-09-01

    Since 2007, massive green tides have occurred every summer in the southern Yellow Sea (YS), China. They have caused severe ecological consequences and huge economic losses. Ulva prolifera originated from Subei Shoal of the YS was confirmed as causative species of the green tides. The Porphyra yezoensis aquaculture rafts in the Subei Shoal have been highly suspected to be the "seed bed" of the green tides, because U. prolifera abundantly fouled the Porphyra yezoensis aquaculture facilities. Besides, various habitats of aquaculture ponds along the Jiangsu coastline and mudflat in the Subei Shoal were proposed to be possible sources of green tides. To understand the "seed" of the green tides in the southern YS and mitigate the original biomass of the green tide, various materials used as substrates for the germination of U. prolifera gametes were tested in this study. Culture experiments showed the following: 1) materials used in the P. yezoensis rafts (plastic, bamboo, jute rope, plastic rope, nylon netting, and plastic netting) displayed a significantly higher germination rate than those associated with mudflats and aquaculture ponds (mud, sand and rock); 2) plastics were the best substrates for the germination of U. prolifera gametes; 3) poor germination was found on old fronds of U. prolifera,, and rubber showed inhibitory effect on germination. The success in germination on P. yezoensis rafts related materials supports the notion that these mariculture structures may be involved in acting as a seed bed for green tide macroalgae. The lack of germination on rubber surfaces may suggest one way to limit the proliferation of early stages of U. prolifera.

  10. Effects of an oil production effluent on gametogenesis and gamete performance in the purple sea urchin (Strongylocentrotus purpuratus Stimpson)

    International Nuclear Information System (INIS)

    Krause, P.R.

    1994-01-01

    Adult organisms subjected to chronic discharges from a point source of pollution may exhibit several sublethal responses. One such response is the impairment of gamete production. This may be expressed in the amount and/or quality of gametes produced by adults. In this study the effects of chronic exposure to produced water (an oil production effluent) on the gametogenesis and gamete performance of the purple sea urchin (Strongylocentrotus purpuratus Stimpson) were examined using an in situ caging experiment. Adult purple sea urchins were kept in benthic cages arrayed down-field from a discharging diffuser at 13 sites, with distances ranging from 5 to 1,000 m. Cage exposures were maintained in the field for eight weeks, and each cage held 25 animals. Gametogenesis was examined for each sex by comparing a size-independent measure of relative gonads ass as determined by analysis of covariance. Results showed that there was a significant negative relationship between these estimates of relative gonad mass and distance from the outfall for both sexes, indicating that sea urchins living closer to the outfall produced significantly larger gonads. Gamete performance was measured through a fertilization kinetics bioassay that held the concentration of eggs constant and varied the amount of sperm added. The proportion of eggs fertilized under each sperm concentration was determined and the response fit to a model of fertilizability showed a positive relationship with distance away from the outfall. These findings indicate that although adult sea urchins exposed to a produced water outfall exhibit larger gonads, they suffer a marked decrease in a gamete performance

  11. Fusion events

    International Nuclear Information System (INIS)

    Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.

    1998-01-01

    The fusion reactions between low energy heavy ions have a very high cross section. First measurements at energies around 30-40 MeV/nucleon indicated no residue of either complete or incomplete fusion, thus demonstrating the disappearance of this process. This is explained as being due to the high amount o energies transferred to the nucleus, what leads to its total dislocation in light fragments and particles. Exclusive analyses have permitted to mark clearly the presence of fusion processes in heavy systems at energies above 30-40 MeV/nucleon. Among the complete events of the Kr + Au reaction at 60 MeV/nucleon the majority correspond to binary collisions. Nevertheless, for the most considerable energy losses, a class of events do occur for which the detected fragments appears to be emitted from a unique source. These events correspond to an incomplete projectile-target fusion followed by a multifragmentation. Such events were singled out also in the reaction Xe + Sn at 50 MeV/nucleon. For the events in which the energy dissipation was maximal it was possible to isolate an isotropic group of events showing all the characteristics of fusion nuclei. The fusion is said to be incomplete as pre-equilibrium Z = 1 and Z = 2 particles are emitted. The cross section is of the order of 25 mb. Similar conclusions were drown for the systems 36 Ar + 27 Al and 64 Zn + nat Ti. A cross section value of ∼ 20 mb was determined at 55 MeV/nucleon in the first case, while the measurement of evaporation light residues in the last system gave an upper limit of 20-30 mb for the cross section at 50 MeV/nucleon

  12. Nuclear fusion

    International Nuclear Information System (INIS)

    Huber, H.

    1978-01-01

    A comprehensive survey is presented of the present state of knowledge in nuclear fusion research. In the first part, potential thermonuclear reactions, basic energy balances of the plasma (Lawson criterion), and the main criteria to be observed in the selection of appropriate thermonuclear reactions are dealt with. This is followed by a discussion of the problems encountered in plasma physics (plasma confinement and heating, transport processes, plasma impurities, plasma instabilities and plasma diagnostics) and by a consideration of the materials problems involved, such as material of the first wall, fuel inlet and outlet, magnetic field generation, as well as repair work and in-service inspections. Two main methods have been developed to tackle these problems: reactor concepts using the magnetic pinch (stellarator, Tokamak, High-Beta reactors, mirror machines) on the one hand, and the other concept using the inertial confinement (laser fusion reactor). These two approaches and their specific problems as well as past, present and future fusion experiments are treated in detail. The last part of the work is devoted to safety and environmental aspects of the potential thermonuclear aspects of the potential thermonuclear reactor, discussing such problems as fusion-specific hazards, normal operation and potential hazards, reactor incidents, environmental pollution by thermal effluents, radiological pollution, radioactive wastes and their disposal, and siting problems. (orig./GG) [de

  13. Short fusion

    CERN Multimedia

    2002-01-01

    French and UK researchers are perfecting a particle accelerator technique that could aid the quest for fusion energy or make X-rays that are safer and produce higher-resolution images. Led by Dr Victor Malka from the Ecole Nationale Superieure des Techniques Avancees in Paris, the team has developed a better way of accelerating electrons over short distances (1 page).

  14. Magnetic fusion

    International Nuclear Information System (INIS)

    2002-01-01

    This document is a detailed lecture on thermonuclear fusion. The basic physics principles are recalled and the technological choices that have led to tokamaks or stellarators are exposed. Different aspects concerning thermonuclear reactors such as safety, economy and feasibility are discussed. Tore-supra is described in details as well as the ITER project

  15. Cold fusion

    International Nuclear Information System (INIS)

    Seo, Suk Yong; You, Jae Jun

    1996-01-01

    Nearly every technical information is chased in the world. All of them are reviewed and analyzed. Some of them are chosen to study further more to review every related documents. And a probable suggestion about the excitonic process in deuteron absorbed condensed matter is proposed a way to cold fusion. 8 refs. (Author)

  16. Salmonid Gamete Preservation in the Snake River Basin : 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Robyn; Kucera, Paul A. [Nez Perce Tribe. Dept. of Fisheries Resource Management, Lapwai, ID (US)

    2001-06-01

    Steelhead (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytscha) populations in the Northwest are decreasing. Genetic diversity is being lost at an alarming rate. The Nez Perce Tribe (Tribe) strives to ensure availability of genetic samples of the existing male salmonid population by establishing and maintaining a germplasm repository. The sampling strategy, initiated in 1992, has been to collect and preserve male salmon and steelhead genetic diversity across the geographic landscape by sampling within the major river subbasins in the Snake River basin, assuming a metapopulation structure existed historically. Gamete cryopreservation conserves genetic diversity in a germplasm repository, but is not a recovery action for listed fish species. The Tribe was funded in 2000 by the Bonneville Power Administration (BPA) and the U.S. Fish and Wildlife Service Lower Snake River Compensation Plan (LSRCP) to coordinate gene banking of male gametes from Endangered Species Act listed steelhead and spring and summer chinook salmon in the Snake River basin. In 2000, a total of 349 viable chinook salmon semen samples from the Lostine River, Catherine Creek, upper Grande Ronde River, Lookingglass Hatchery (Imnaha River stock), Rapid River Hatchery, Lake Creek, the South Fork Salmon River weir, Johnson Creek, Big Creek, Capehorn Creek, Marsh Creek, Pahsimeroi Hatchery, and Sawtooth Hatchery (upper Salmon River stock) were cryopreserved. Also, 283 samples of male steelhead gametes from Dworshak Hatchery, Fish Creek, Grande Ronde River, Imnaha River, Little Sheep Creek, Pahsimeroi Hatchery and Oxbow Hatchery were also cryopreserved. The Tribe acquired 5 frozen steelhead samples from the Selway River collected in 1994 and 15 from Fish Creek sampled in 1993 from the U.S. Geological Survey, for addition into the germplasm repository. Also, 590 cryopreserved samples from the Grande Ronde chinook salmon captive broodstock program are being stored at the University of Idaho as

  17. Cold fusion, Alchemist's dream

    International Nuclear Information System (INIS)

    Clayton, E.D.

    1989-09-01

    In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D 2 molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D 2 fusion at low energies; fusion of deuterons into 4 He; secondary D+T fusion within the hydrogenated metal lattice; 3 He to 4 He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of 3 He/ 4 He

  18. Magnetic fusion; La fusion magnetique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This document is a detailed lecture on thermonuclear fusion. The basic physics principles are recalled and the technological choices that have led to tokamaks or stellarators are exposed. Different aspects concerning thermonuclear reactors such as safety, economy and feasibility are discussed. Tore-supra is described in details as well as the ITER project.

  19. Examination of relaxin and its receptors expression in pig gametes and embryos

    Directory of Open Access Journals (Sweden)

    Bathgate Ross A

    2011-01-01

    Full Text Available Abstract Background Relaxin is a small peptide also known as pregnancy hormone in many mammals. It is synthesized by both male and female tissues, and its secretions are found in various body fluids such as plasma serum, ovarian follicular fluid, utero-oviduct secretions, and seminal plasma of many mammals, including pigs. However, the presence and effects of relaxin in porcine gametes and embryos are still not well-known. The purpose of this study was to assess the presence of relaxin and its receptors RXFP1 and RXFP2 in pig gametes and embryos. Methods Immature cumulus-oocyte complexes (COCs were aspirated from sows' ovaries collected at the abattoir. After in vitro-maturation, COCs were in vitro-fertilized and cultured. For studies, immature and mature COCs were separately collected, and oocytes were freed from their surrounding cumulus cells. Denuded oocytes, cumulus cells, mature boar spermatozoa, zygotes, and embryos (cleaved and blastocysts were harvested for temporal and spatial gene expression studies. Sections of ovary, granulosa and neonatal porcine uterine cells were also collected to use as controls. Results Using both semi-quantitative and quantitative PCRs, relaxin transcripts were not detected in all tested samples, while RXFP1 and RXFP2 mRNA were present. Both receptor gene products were found at higher levels in oocytes compared to cumulus cells, irrespective of the maturation time. Cleaved-embryos contained higher levels of RXFP2 mRNA, whereas, blastocysts were characterized by a higher RXFP1 mRNA content. Using western-immunoblotting or in situ immunofluorescence, relaxin and its receptor proteins were detected in all samples. Their fluorescence intensities were consistently more important in mature oocytes than immature ones. The RXFP1 and RXFP2 signal intensities were mostly located in the plasma membrane region, while the relaxin ones appeared homogeneously distributed within the oocytes and embryonic cells. Furthermore

  20. Splenogonadal Fusion

    Directory of Open Access Journals (Sweden)

    Sung-Lang Chen

    2008-11-01

    Full Text Available Splenogonadal fusion (SGF is a rare congenital non-malignant anomaly characterized by fusion of splenic tissue to the gonad, and can be continuous or discontinuous. Very few cases have been diagnosed preoperatively, and many patients who present with testicular swelling undergo unnecessary orchiectomy under the suspicion of testicular neoplasm. A 16-year-old boy presented with a left scrotal mass and underwent total excision of a 1.6-cm tumor without damaging the testis, epididymis or its accompanying vessels. Pathologic examination revealed SFG (discontinuous type. If clinically suspected before surgery, the diagnosis may be confirmed by Tc-99m sulfur colloid imaging, which shows uptake in both the spleen and accessory splenic tissue within the scrotum. Frozen section should be considered if there remains any doubt regarding the diagnosis during operation.

  1. Laser fusion

    International Nuclear Information System (INIS)

    Eliezer, S.

    1982-02-01

    In this paper, the physics of laser fusion is described on an elementary level. The irradiated matter consists of a dense inner core surrounded by a less dense plasma corona. The laser radiation is mainly absorbed in the outer periphery of the plasma. The absorbed energy is transported inward to the ablation surface where plasma flow is created. Due to this plasma flow, a sequence of inward going shock waves and heat waves are created, resulting in the compression and heating of the core to high density and temperature. The interaction physics between laser and matter leading to thermonuclear burn is summarized by the following sequence of events: Laser absorption → Energy transport → Compression → Nuclear Fusion. This scenario is shown in particular for a Nd:laser with a wavelength of 1 μm. The wavelength scaling of the physical processes is also discussed. In addition to the laser-plasma physics, the Nd high power pulsed laser is described. We give a very brief description of the oscillator, the amplifiers, the spatial filters, the isolators and the diagnostics involved. Last, but not least, the concept of reactors for laser fusion and the necessary laser system are discussed. (author)

  2. Fusion spectroscopy

    International Nuclear Information System (INIS)

    Peacock, N.J.

    1995-09-01

    This article traces developments in the spectroscopy of high temperature laboratory plasma used in controlled fusion research from the early 1960's until the present. These three and a half decades have witnessed many orders of magnitude increase in accessible plasma parameters such as density and temperature as well as particle and energy confinement timescales. Driven by the need to interpret the radiation in terms of the local plasma parameters, the thrust of fusion spectroscopy has been to develop our understanding of (i) the atomic structure of highly ionised atoms, usually of impurities in the hydrogen isotope fuel; (ii) the atomic collision rates and their incorporation into ionization structure and emissivity models that take into account plasma phenomena like plasma-wall interactions, particle transport and radiation patterns; (iii) the diagnostic applications of spectroscopy aided by increasingly sophisticated characterisation of the electron fluid. These topics are discussed in relation to toroidal magnetically confined plasmas, particularly the Tokamak which appears to be the most promising approach to controlled fusion to date. (author)

  3. "I am Your Mother and Your Father!" In Vitro Derived Gametes and the Ethics of Solo Reproduction.

    Science.gov (United States)

    Cutas, Daniela; Smajdor, Anna

    2017-12-01

    In this paper, we will discuss the prospect of human reproduction achieved with gametes originating from only one person. According to statements by a minority of scientists working on the generation of gametes in vitro, it may become possible to create eggs from men's non-reproductive cells and sperm from women's. This would enable, at least in principle, the creation of an embryo from cells obtained from only one individual: 'solo reproduction'. We will consider what might motivate people to reproduce in this way, and the implications that solo reproduction might have for ethics and policy. We suggest that such an innovation is unlikely to revolutionise reproduction and parenting. Indeed, in some respects it is less revolutionary than in vitro fertilisation as a whole. Furthermore, we show that solo reproduction with in vitro created gametes is not necessarily any more ethically problematic than gamete donation-and probably less so. Where appropriate, we draw parallels with the debate surrounding reproductive cloning. We note that solo reproduction may serve to perpetuate reductive geneticised accounts of reproduction, and that this may indeed be ethically questionable. However, in this it is not unique among other technologies of assisted reproduction, many of which focus on genetic transmission. It is for this reason that a ban on solo reproduction might be inconsistent with continuing to permit other kinds of reproduction that also bear the potential to strengthen attachment to a geneticised account of reproduction. Our claim is that there are at least as good reasons to pursue research towards enabling solo reproduction, and eventually to introduce solo reproduction as an option for fertility treatment, as there are to do so for other infertility related purposes.

  4. Does selection for gamete dispersal and capture lead to a sex difference in clump water-holding capacity?

    Science.gov (United States)

    Moore, Jonathan D; Kollar, Leslie M; McLetchie, D Nicholas

    2016-08-01

    Differences in male and female reproductive function can lead to selection for sex-specific gamete dispersal and capture traits. These traits have been explored from shoot to whole plant levels in wind-pollinated species. While shoot traits have been explored in water-fertilized species, little is known about how whole plant morphology affects gamete dispersal and capture. We used the dioecious, water-fertilized plant Bryum argenteum to test for differences in clump morphology and water-holding characteristics consistent with divergent selection. We hypothesized that sex-specific clump morphology, arising at maturity, produces relatively low male water-holding capacity for gamete dispersal and high female capacity for gamete capture. We measured isolated young shoot and clump water-holding capacity and clump morphological characteristics on greenhouse-grown plants. Young shoot capacity was used to predict clump capacity, which was compared with actual clump capacity. Young male shoots held more water per unit length, and male clumps had higher shoot density, which extrapolated to higher clump water-holding capacity. However, female clumps held more water and were taller with more robust shoots. Actual clump capacity correlated positively with clump height and shoot cross-sectional area. The sex difference in actual clump capacity and its unpredictability from younger shoots are consistent with our hypothesis that males should hold less water than females to facilitate sexual reproduction. These results provide conceptual connections to other plant groups and implications for connecting divergent selection to female-biased sex ratios in B. argenteum and other bryophytes. © 2016 Botanical Society of America.

  5. Influences of DMP on the fertilization process and subsequent embryogenesis of abalone (Haliotis diversicolor supertexta by gametes exposure.

    Directory of Open Access Journals (Sweden)

    Jin Zhou

    Full Text Available Di-methyl phthalate (DMP, a typical endocrine disrupting chemical (EDC, is ubiquitously distributed in aquatic environments; yet studies regarding its impact on gametes and the resulting effects on embryogenesis in marine gastropods are relatively scarce. In this study, the influences of DMP on the gametes and subsequent developmental process of abalone (Haliotis diversicolor supertexta, a representative marine benthic gastropod were assessed. Newborn abalone eggs and sperm were exposed separately to different DMP concentrations (1, 10 or 100 ppb for 60 min. At the end-point of exposure, the DMP-treated eggs and sperm were collected for analysis of their ultra-structures, ATPase activities and total lipid levels, and the fertilized gametes (embryos were collected to monitor related reproductive parameters (fertilization rate, abnormal development rate and hatching success rate. Treatment with DMP did not significantly alter the structure or total lipid content of eggs at any of the doses tested. Hatching failures and morphological abnormalities were only observed with the highest dose of DMP (100 ppb. However, DMP exposure did suppress sperm ATPase activities and affect the morphological character of their mitochondria. DMP-treated sperm exhibited dose-dependent decreases in fertilization efficiency, morphogenesis and hatchability. Relatively obvious toxicological effects were observed when both sperm and eggs were exposed to DMP. Furthermore, RT-PCR results indicate that treatment of gametes with DMP changed the expression patterns of physiologically-regulated genes (cyp3a, 17β-HSD-11 and 17β-HSD-12 in subsequent embryogenesis. Taken together, this study proofed that pre-fertilization exposure of abalone eggs, sperm or both to DMP adversely affects the fertilization process and subsequent embryogenesis.

  6. Gamete donors' reasons for, and expectations and experiences of, registration with a voluntary donor linking register.

    Science.gov (United States)

    Blyth, Eric; Crawshaw, Marilyn; Frith, Lucy; van den Akker, Olga

    2017-12-01

    This paper reports on a study of the views and experiences of 21 sperm donors and five egg donors registered with UK DonorLink (UKDL), a voluntary DNA-based contact register established to facilitate contact between adults who wish to identify and locate others to whom they are genetically related following donor conception. Specifically, the paper examines donors' reasons for searching for, or making information about themselves available to donor-conceived offspring. Their expectations of registration with UKDL, experiences of being registered and finally, the experiences of those who had contacted donor-conceived offspring and other genetic relatives are investigated. While most respondents reported largely positive experiences of registration, the study found significant issues relating to concerns about donation, DNA testing, possible linking with offspring and expectations of any relationship that might be established with offspring that have implications for support, mediation and counselling. Research that puts the experiences, perceptions and interests of gamete donors as the central focus of study is a relatively recent phenomenon. This study contributes to this debate and highlights directions for future research in this area.

  7. Vertical transmission of Prunus necrotic ringspot virus: hitch-hiking from gametes to seedling.

    Science.gov (United States)

    Amari, Khalid; Burgos, Lorenzo; Pallás, Vicente; Sánchez-Pina, Maria Amelia

    2009-07-01

    The aim of this work was to follow Prunus necrotic ringspot virus (PNRSV) infection in apricot reproductive tissues and transmission of the virus to the next generation. For this, an analysis of viral distribution in apricot reproductive organs was carried out at different developmental stages. PNRSV was detected in reproductive tissues during gametogenesis. The virus was always present in the nucellus and, in some cases, in the embryo sac. Studies within infected seeds at the embryo globular stage revealed that PNRSV infects all parts of the seed, including embryo, endosperm and testa. In the torpedo and bent cotyledon developmental stages, high concentrations of the virus were detected in the testa and endosperm. At seed maturity, PNRSV accumulated slightly more in the embryo than in the cotyledons. In situ hybridization showed the presence of PNRSV RNA in embryos obtained following hand-pollination of virus-free pistils with infected pollen. Interestingly, tissue-printing from fruits obtained from these pistils showed viral RNA in the periphery of the fruits, whereas crosses between infected pistils and infected pollen resulted in a total invasion of the fruits. Taken together, these results shed light on the vertical transmission of PNRSV from gametes to seedlings.

  8. Postmating sexual conflict and female control over fertilization during gamete interaction.

    Science.gov (United States)

    Firman, Renée C

    2018-06-01

    Males and females rarely have identical evolutionary interests over reproduction, and when the fitness of both sexes is dependent upon paternity outcomes, sexual conflict over fertilization is inevitable. In internal fertilizers, the female tract is a formidable selective force on the number and integrity of sperm that reach the egg. Selection on sperm quality is intensified when females mate multiply and rival males are forced to compete for fertilizations. While male adaptations to sperm competition have been well documented (e.g., increased sperm fertilizing capacity), much less attention has been given to the evolutionary consequences of postmating sexual conflict for egg form and function. Specifically, increased sperm competitiveness can be detrimental by giving rise to an elevation in reproductive failure resulting from polyspermy. Spanning literature on both internal and external fertilizers, in this review I discuss how females respond to sperm competition via fertilization barriers that mediate sperm entry. These findings, which align directly with sexual conflict theory, indicate that females have greater control over fertilization than has previously been appreciated. I then consider the implications of gametic sexual conflict in relation to the development of reproductive isolation and speculate on potential mechanisms accounting for "egg defensiveness." Finally, I discuss the functional significance of egg defensiveness for both the sexes, and sperm selection for females. © 2018 New York Academy of Sciences.

  9. Strategies for locating the female gamete: the importance of measuring sperm trajectories in three spatial dimensions

    Science.gov (United States)

    Guerrero, Adán; Carneiro, Jorge; Pimentel, Arturo; Wood, Christopher D.; Corkidi, Gabriel; Darszon, Alberto

    2011-01-01

    The spermatozoon must find its female gamete partner and deliver its genetic material to generate a new individual. This requires that the spermatozoon be motile and endowed with sophisticated swimming strategies to locate the oocyte. A common strategy is chemotaxis, in which spermatozoa detect and follow a gradient of chemical signals released by the egg and its associated structures. Decoding the female gamete’s positional information is a process that spermatozoa undergo in a three-dimensional (3D) space; however, due to their speed and small size, this process has been studied almost exclusively in spermatozoa restricted to swimming in two dimensions (2D). This review examines the relationship between the mechanics of sperm propulsion and the physiological function of these cells in 3D. It also considers whether it is possible to derive all the 3D sperm swimming characteristics by extrapolating from 2D measurements. It is concluded that full insight into flagellar beat dynamics, swimming paths and chemotaxis under physiological conditions will eventually require quantitative imaging of flagellar form, ion flux changes, cell trajectories and modelling of free-swimming spermatozoa in 3D. PMID:21642645

  10. Arabidopsis female gametophyte gene expression map reveals similarities between plant and animal gametes.

    Science.gov (United States)

    Wuest, Samuel E; Vijverberg, Kitty; Schmidt, Anja; Weiss, Manuel; Gheyselinck, Jacqueline; Lohr, Miriam; Wellmer, Frank; Rahnenführer, Jörg; von Mering, Christian; Grossniklaus, Ueli

    2010-03-23

    The development of multicellular organisms is controlled by differential gene expression whereby cells adopt distinct fates. A spatially resolved view of gene expression allows the elucidation of transcriptional networks that are linked to cellular identity and function. The haploid female gametophyte of flowering plants is a highly reduced organism: at maturity, it often consists of as few as three cell types derived from a common precursor [1, 2]. However, because of its inaccessibility and small size, we know little about the molecular basis of cell specification and differentiation in the female gametophyte. Here we report expression profiles of all cell types in the mature Arabidopsis female gametophyte. Differentially expressed posttranscriptional regulatory modules and metabolic pathways characterize the distinct cell types. Several transcription factor families are overrepresented in the female gametophyte in comparison to other plant tissues, e.g., type I MADS domain, RWP-RK, and reproductive meristem transcription factors. PAZ/Piwi-domain encoding genes are upregulated in the egg, indicating a role of epigenetic regulation through small RNA pathways-a feature paralleled in the germline of animals [3]. A comparison of human and Arabidopsis egg cells for enrichment of functional groups identified several similarities that may represent a consequence of coevolution or ancestral gametic features. 2010 Elsevier Ltd. All rights reserved.

  11. Expression and localization of tubulin cofactors TBCD and TBCE in human gametes.

    Science.gov (United States)

    Jiménez-Moreno, Victoria; Agirregoitia, Ekaitz

    2017-06-01

    The tubulin cofactors TBCD and TBCE play an essential role in regulation of the microtubule dynamics in a wide variety of somatic cells, but little information is known about the expression of these cofactors in human sperm and oocytes. In this study, we focused on the investigation of the presence of, and the differential distribution of, the tubulin cofactors TBCD and TBCE in human sperm and during human oocyte maturation. We performed expression assays for TBCD and TBCE by reverse transcription-polymerase chain reaction (RT-PCR), western blot and immunofluorescence and verified the presence of both cofactors in human gametes. TBCD and TBCE were located mainly in the middle region and in the tail of the sperm while in the oocyte the localization was cytosolic. The mRNA of both tubulin cofactors were present in the human oocytes but not in sperm cells. This finding gives a first insight into where TBCD and TBCE could carry out their function in the continuous changes that the cytoskeleton experiences during gametogenesis and also prior to fertilization.

  12. Regulating Gamete Donation in the U.S.: Ethical, Legal and Social Implications

    Directory of Open Access Journals (Sweden)

    Maya Sabatello

    2015-07-01

    Full Text Available This article explores the practice of gamete donation in the U.S. having in mind the larger question of what do we as a society owe children born as a result (donor-conceived children. Do recipient-parents have a duty to tell their donor-conceived child about his/her genetic origins? Should the identity of the donor be disclosed or remain anonymous? Does the child have a right to know her conception story and to receive information, including identifying information, about the donor? Furthermore, if a donor-conceived child has a right to know, who has the duty to tell her/him about it? The Article underscores the ethical, legal and social dilemmas that arise, comparing and contrasting with international developments in this arena. It highlights the market-based and more specific medical justifications for regulating this field, explores the emerging so-called right of the child to know his/her genetic origins (“the right to know”, and considers the challenges such a right evokes to existing legal culture and principles of medical ethics in the U.S. as well as other broader societal implications of such a right.

  13. Regulating Gamete Donation in the U.S.: Ethical, Legal and Social Implications.

    Science.gov (United States)

    Sabatello, Maya

    2015-09-01

    This article explores the practice of gamete donation in the U.S. having in mind the larger question of what do we as a society owe children born as a result (donor-conceived children). Do recipient-parents have a duty to tell their donor-conceived child about his/her genetic origins? Should the identity of the donor be disclosed or remain anonymous? Does the child have a right to know her conception story and to receive information, including identifying information, about the donor? Furthermore, if a donor-conceived child has a right to know, who has the duty to tell her/him about it? The Article underscores the ethical, legal and social dilemmas that arise, comparing and contrasting with international developments in this arena. It highlights the market-based and more specific medical justifications for regulating this field, explores the emerging so-called right of the child to know his/her genetic origins ("the right to know"), and considers the challenges such a right evokes to existing legal culture and principles of medical ethics in the U.S. as well as other broader societal implications of such a right.

  14. The Role of Peroxisome Proliferator-Activated Receptors in the Development and Physiology of Gametes and Preimplantation Embryos

    Directory of Open Access Journals (Sweden)

    Jaou-Chen Huang

    2008-01-01

    Full Text Available In several species, a family of nuclear receptors, the peroxisome proliferator-activated receptors (PPARs composed of three isotypes, is expressed in somatic cells and germ cells of the ovary as well as the testis. Invalidation of these receptors in mice or stimulation of these receptors in vivo or in vitro showed that each receptor has physiological roles in the gamete maturation or the embryo development. In addition, synthetic PPARγ ligands are recently used to induce ovulation in women with polycystic ovary disease. These results reveal the positive actions of PPAR in reproduction. On the other hand, xenobiotics molecules (in herbicides, plasticizers, or components of personal care products, capable of activating PPAR, may disrupt normal PPAR functions in the ovary or the testis and have consequences on the quality of the gametes and the embryos. Despite the recent data obtained on the biological actions of PPARs in reproduction, relatively little is known about PPARs in gametes and embryos. This review summarizes the current knowledge on the expression and the function of PPARs as well as their partners, retinoid X receptors (RXRs, in germ cells and preimplantation embryos. The effects of natural and synthetic PPAR ligands will also be discussed from the perspectives of reproductive toxicology and assisted reproductive technology.

  15. Consecutive five-year analysis of paternal and maternal gene flow and contributions of gametic heterogeneities to overall genetic composition of dispersed seeds of Pinus densiflora (Pinaceae).

    Science.gov (United States)

    Iwaizumi, Masakazu G; Takahashi, Makoto; Isoda, Keiya; Austerlitz, Frédéric

    2013-09-01

    Genetic variability in monoecious woody plant populations results from the assemblage of individuals issued from asymmetrical male and female reproductive functions, produced during spatially and temporarily heterogeneous reproductive and dispersal events. Here we investigated the dispersal patterns and levels of genetic diversity and differentiation of both paternal and maternal gametes in a natural population of Pinus densiflora at the multiple-year scale as long as five consecutive years. • We analyzed the paternity and maternity for 1576 seeds and 454 candidate adult trees using nuclear DNA polymorphisms of diploid biparental embryos and haploid maternal megagametophytes at eight microsatellite loci. • Despite the low levels of genetic differentiation among gamete groups, a two-way AMOVA analysis showed that the parental origin (paternal vs. maternal gametes), the year of gamete production and their interaction had significant effects on the genetic composition of the seeds. While maternal gamete groups showed a significant FST value across the 5 years, this was not true for their paternal counterparts. Within the population, we found that the relative reproductive contributions of the paternal vs. the maternal parent differed among adult trees, the maternal contributions showing a larger year-to-year fluctuation. • The overall genetic variability of dispersed seeds appeared to result from two sources of heterogeneity: the difference between paternal and maternal patterns of reproduction and gamete dispersal and year-to-year heterogeneity of reproduction of adult trees, especially in their maternal reproduction.

  16. Conundrums with penumbras: the right to privacy encompasses non-gamete providers who create preembryos with the intent to become parents.

    Science.gov (United States)

    Dillon, Lainie M C

    2003-05-01

    To date, five state high courts have resolved disputes over frozen preembryos. These disputes arose during divorce proceedings between couples who had previously used assisted reproduction and cryopreserved excess preembryos. In each case, one spouse wished to have the preembryos destroyed, while the other wanted to be able to use or donate them in the future. The parties in these cases invoked the constitutional right to privacy to argue for dispositional control over the preembryos; two of the five cases were resolved by relying on this right. The constitutional right to privacy protects intimate decisions involving procreation, marriage, and family life. However, when couples use donated sperm or ova to create preembryos, a unique circumstance arises: one spouse--the gamete provider--is genetically related to the preembryos and the other is not. If courts resolve frozen preembryo disputes that involve non-gamete providers based on the constitutional right to privacy, they should find that the constitutional right to privacy encompasses the interests of both gamete and non-gamete providers. Individuals who create preembryos with the intent to become a parent have made an intimate decision involving procreation, marriage, and family life that falls squarely within the the right to privacy. In such cases, the couple together made the decision to create a family through the use of assisted reproduction, and the preembryos would not exist but for that joint decision. Therefore, gamete and non-gamete providers should be afforded equal constitutional protection in disputes over frozen preembryos.

  17. Fusion Machines

    International Nuclear Information System (INIS)

    Weynants, R.R.

    2004-01-01

    A concise overview is given of the principles of inertial and magnetic fusion, with an emphasis on the latter in view of the aim of this summer school. The basis of magnetic confinement in mirror and toroidal geometry is discussed and applied to the tokamak concept. A brief discussion of the reactor prospects of this configuration identifies which future developments are crucial and where alternative concepts might help in optimising the reactor design. The text also aims at introducing the main concepts encountered in tokamak research that will be studied and used in the subsequent lectures

  18. Fusion Canada issue 10

    International Nuclear Information System (INIS)

    1990-02-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on Fusion Materials Research, ITER physics research, fusion performance record at JET, and design options for reactor building. 4 figs

  19. Mating behaviour and gamete release in gilthead seabream (Sparus aurata, Linnaeus 1758) held in captivity

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra-Zatarain, Z.; Duncan, N.

    2015-07-01

    The present study aimed to describe the reproductive behaviour of gilthead seabream (Sparus aurata) in captivity. Twenty-four mature gilthead seabream, divided in two tanks, were utilized for the present study. Reproductive behaviour was recorded using submersibles cameras. A total of 67 spawning events were analysed. The mean duration time that gilthead seabream spent spawning was 54 ± 4 min/day, during which mean number of individual spawning events was 5.6 ± 0.2. The mean volume of eggs produced by both broodstocks was 405 ± 13.4 mL with a fertilization rate of 91.6 ± 0.4%. The reproductive behaviour began with a schooling behaviour and then forming light aggregations. From an aggregation or an encounter while swimming freely a female initiated a spawning rush followed by one or more males to gametes liberation. The spawning rush was brief, 1.6 ± 0.5 sec, over an approximately 1.7 ± 0.2 m distance from the tank bottom to the water surface. Pair spawning, between a single female and male, was the most common (71.6%). Group spawning was less common and involved a single female spawning with two males (22.5%) or three males (4.9%). Spawning rushes involving more than one female were not observed. Gilthead seabream in the present study presented a tendency to pair spawn and eggs collected as a “spawn” were actually the sum of many separate spawning events over a short time period. This is the first description of gilthead seabream spawning and the findings help to understand microsatellite based observations of spawning kinetics. (Author)

  20. Expression of a type B RIFIN in Plasmodium falciparum merozoites and gametes

    Directory of Open Access Journals (Sweden)

    Mwakalinga Steven B

    2012-12-01

    Full Text Available Abstract Background The ability of Plasmodium falciparum to undergo antigenic variation, by switching expression among protein variants encoded by multigene families, such as var, rif and stevor, is key to the survival of this parasite in the human host. The RIFIN protein family can be divided into A and B types based on the presence or absence of a 25 amino acid motif in the semi-conserved domain. A particular type B RIFIN, PF13_0006, has previously been shown to be strongly transcribed in the asexual and sexual stages of P. falciparum in vitro. Methods Antibodies to recombinant PF13_0006 RIFIN were used in immunofluorescence and confocal imaging of 3D7 parasites throughout the asexual reproduction and sexual development to examine the expression of PF13_0006. Furthermore, reactivity to recombinant PF13_0006 was measured in plasma samples collected from individuals from both East and West African endemic areas. Results The PF13_0006 RIFIN variant appeared expressed by both released merozoites and gametes after emergence. 7.4% and 12.1% of individuals from East and West African endemic areas, respectively, carry plasma antibodies that recognize recombinant PF13_0006, where the antibody responses were more common among older children. Conclusions The stage specificity of PF13_0006 suggests that the diversity of RIFIN variants has evolved to provide multiple specialized functions in different stages of the parasite life cycle. These data also suggest that RIFIN variants antigenically similar to PF13_0006 occur in African parasite populations.

  1. Azadirachtin effects on mating success, gametic abnormalities and progeny survival in Drosophila melanogaster (Diptera).

    Science.gov (United States)

    Oulhaci, Chemseddine M; Denis, Béatrice; Kilani-Morakchi, Samira; Sandoz, Jean-Christophe; Kaiser, Laure; Joly, Dominique; Aribi, Nadia

    2018-01-01

    Azadirachtin is a prominent natural pesticide and represents an alternative to conventional insecticides. It has been successfully used against insect pests. However, its effects on reproduction require further analysis. Here we investigated lethal and sublethal effects of azadirachtin, on treated adults in a model insect, Drosophila melanogaster (Meigen). Dose-mortality relationships as well as several parameters of reproduction (mating, spermatogenesis, oogenesis and fertility) were examined. Neem-Azal, a commercial formulation of azadirachtin, applied topically on newly emerged adults, increased mortality with a positive dose-dependent relationship. The LD 50 (0.63 μg) was determined 24 h after treatment using a non-linear regression. Adults surviving this dose had a mating success that was divided by 3 and a progeny production reduced by half when males were treated, and even more when females were treated. When combining probability of survival, of mating and reduced progeny, it appeared that LD 50 induced a 98% reduction in reproductive rates. Reduced progeny was partially explained by the effect of adult treatment on gametes number and abnormalities. The number of cysts and the apical nuclei positions within the cysts decreased by 29.7% and 20%, respectively, in males. In females, the number of oocytes per ovary and the volume of basal oocytes also decreased by 16.1% and 32.4%, respectively. Azadirachtin causes significant toxic effects in both sexes and decreases the fecundity and fertility of D. melanogaster. Females are more sensitive to azadirachtin. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Selling blood and gametes during tough economic times: insights from Google search.

    Science.gov (United States)

    Wu, Jonathan A; Ngo, Tin C; Rothman, Cappy; Breyer, Benjamin N; Eisenberg, Michael L

    2015-10-01

    To use Google Insights search volume and publicly available economic indicators to test the hypothesis that sperm, egg, and blood donations increase during economic downturns and to demonstrate the feasibility of using Google search volume data to predict national trends in actual sperm, egg, and blood donations rates. Cross-correlation statistical analysis comparing Google search data for terms relating to blood, egg, and sperm donations with various economic indicators including the S&P 500 closing values, gross domestic product (GDP), the U.S. Index of Leading Indicators (U.S. Leading Index), gross savings rate, mortgage interest rates, unemployment rate, and consumer price index (CPI) from 2004-2011. A secondary analysis determined the Pearson correlation coefficient between Google search data with actual sperm, egg, and blood donation volume in the U.S. as measured by California Cryobank, the National Assisted Reproductive Technology Surveillance System, and the National Blood Collection and Utilization Survey, respectively. Significance of cross-correlation and Pearson correlation analysis as indicated by p value. There were several highly significant cross-correlation relationships between search volume and various economic indicators. Correlation between Google search volume for the term 'sperm donation,' 'egg donation,' and 'blood donation' with actual number of sperm, egg and blood donations in the United States demonstrated Pearson correlation coefficients of 0.2 (p > 0.10), -0.1 (p > 0.10), and 0.07 (p > 0.10), respectively. Temporal analysis showed an improved correlation coefficient of 0.9 (p Google search volume. Google search volume data for search terms relating to sperm, egg, and blood donation increase during economic downturns. This finding suggests gamete and bodily fluid donations are influenced by market forces like other commodities. Google search may be useful for predicting blood donation trends but is more limited in predicting actual

  3. Revitalizing Fusion via Fission Fusion

    Science.gov (United States)

    Manheimer, Wallace

    2001-10-01

    Existing tokamaks could generate significant nuclear fuel. TFTR, operating steady state with DT might generate enough fuel for a 300 MW nuclear reactor. The immediate goals of the magnetic fusion program would necessarily shift from a study of advanced plasma regimes in larger sized devices, to mostly known plasmas regimes, but at steady state or high duty cycle operation in DT plasmas. The science and engineering of breeding blankets would be equally important. Follow on projects could possibly produce nuclear fuel in large quantity at low price. Although today there is strong opposition to nuclear power in the United States, in a 21st century world of 10 billion people, all of whom will demand a middle class life style, nuclear energy will be important. Concern over greenhouse gases will also drive the world toward nuclear power. There are studies indicating that the world will need 10 TW of carbon free energy by 2050. It is difficult to see how this can be achieved without the breeding of nuclear fuel. By using the thorium cycle, proliferation risks are minimized. [1], [2]. 1 W. Manheimer, Fusion Technology, 36, 1, 1999, 2.W. Manheimer, Physics and Society, v 29, #3, p5, July, 2000

  4. Catalysed fusion

    CERN Document Server

    Farley, Francis

    2012-01-01

    A sizzling romance and a romp with subatomic particles at CERN. Love, discovery and adventure in the city where nations meet and beams collide. Life in a large laboratory. As always, the challenges are the same. Who leads? Who follows? Who succeeds? Who gets the credit? Who gets the women or the men? Young Jeremy arrives in CERN and joins the quest for green energy. Coping with baffling jargon and manifold dangers, he is distracted by radioactive rats, lovely ladies and an unscrupulous rival. Full of doubts and hesitations, he falls for a dazzling Danish girl, who leads him astray. His brilliant idea leads to a discovery and a new route to cold fusion. But his personal life is scrambled. Does it bring fame or failure? Tragedy or triumph?

  5. Fusion cuisine

    DEFF Research Database (Denmark)

    Peters, Chris; Broersma, Marcel

    2018-01-01

    JJournalism studies as an academic field is characterized by multidisciplinarity. Focusing on one object of study, journalism and the news, it established itself by integrating and synthesizing approaches from established disciplines – a tendency that lives on today. This constant gaze to the out......JJournalism studies as an academic field is characterized by multidisciplinarity. Focusing on one object of study, journalism and the news, it established itself by integrating and synthesizing approaches from established disciplines – a tendency that lives on today. This constant gaze...... to the outside for conceptual inspiration and methodological tools lends itself to a journalism studies that is a fusion cuisine of media, communication, and related scholarship. However, what happens when this object becomes as fragmented and multifaceted as the ways we study it? This essay addresses...

  6. Evidence for participation of GCS1 in fertilization of the starlet sea anemone Nematostella vectensis: Implication of a common mechanism of sperm–egg fusion in plants and animals

    Energy Technology Data Exchange (ETDEWEB)

    Ebchuqin, Eerdundagula; Yokota, Naoto; Yamada, Lixy [Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Sugashima, Toba 517-0004 (Japan); Yasuoka, Yuuri [Marine Genomics Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495 (Japan); Akasaka, Mari [Laboratory of Molecular Genetics, Graduate School of Science, Nagoya University, Chikusa-ku, Furo-cho, Nagoya 464-8602 (Japan); Arakawa, Mio; Deguchi, Ryusaku [Department of Biology, Miyagi University of Education, Sendai, Miyagi 980-0845 (Japan); Mori, Toshiyuki [Waseda Institute for Advanced Study, Waseda University, Shinjuku, Tokyo 169-8050 (Japan); Sawada, Hitoshi, E-mail: hsawada@bio.nagoya-u.ac.jp [Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Sugashima, Toba 517-0004 (Japan)

    2014-09-05

    Highlights: • GCS1 is a sperm transmembrane protein that is essential for gamete fusion in flowering plants. • The GCS1 gene is present not only in angiosperms but also in unicellular organisms and animals. • NvGCS1 gene is expressed in the testis and GCS1 protein exists in sperm of a sea anemone. • Anti-GCS1 antibodies inhibited the fertilization, showing the participation in fertilization. - Abstract: It has been reported that GCS1 (Generative Cell Specific 1) is a transmembrane protein that is exclusively expressed in sperm cells and is essential for gamete fusion in flowering plants. The GCS1 gene is present not only in angiosperms but also in unicellular organisms and animals, implying the occurrence of a common or ancestral mechanism of GCS1-mediated gamete fusion. In order to elucidate the common mechanism, we investigated the role of GCS1 in animal fertilization using a sea anemone (Cnidaria), Nematostella vectensis. Although the existence of the GCS1 gene in N. vectensis has been reported, the expression of GCS1 in sperm and the role of GCS1 in fertilization are not known. In this study, we showed that the GCS1 gene is expressed in the testis and that GCS1 protein exists in sperm by in situ hybridization and proteomic analysis, respectively. Then we made four peptide antibodies against the N-terminal extracellular region of NvGCS1. These antibodies specifically reacted to NvGCS1 among sperm proteins on the basis of Western analysis and potently inhibited fertilization in a concentration-dependent manner. These results indicate that sperm GCS1 plays a pivotal role in fertilization, most probably in sperm–egg fusion, in a starlet sea anemone, suggesting a common gamete-fusion mechanism shared by eukaryotic organisms.

  7. Towards nuclear fusion reactors

    International Nuclear Information System (INIS)

    1993-11-01

    The results of nuclear fusion researches in JAERI are summarized. In this report, following themes are collected: the concept of fusion reactor (including ITER), fusion reactor safety, plasma confinement, fusion reactor equipment, and so on. Includes glossary. (J.P.N.)

  8. Fusion Canada issue 28

    International Nuclear Information System (INIS)

    1995-06-01

    A short bulletin from the National Fusion Program highlighting in this issue the Canada - US fusion meeting in Montreal, fusion breeder work in Chile, new management at CFFTP, fast electrons in tokamaks: new data from TdeV, a program review of CCFM and Velikhov to address Montreal fusion meeting. 1 fig

  9. Fusion systems engineering

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Summaries of research are included for each of the following topics: (1) fusion reactor systems studies, (2) development of blanket processing technology for fusion reactors, (3) safety studies of fusion concepts, (4) the MACK/MACKLIB system for nuclear response functions, and (5) energy storage and power supply systems for fusion reactors

  10. The Effect of Filamentous Turf Algal Removal on the Development of Gametes of the Coral Orbicella annularis

    Science.gov (United States)

    Cetz-Navarro, Neidy P.; Carpizo-Ituarte, Eugenio J.; Espinoza-Avalos, Julio; Chee-Barragán, Guillermina

    2015-01-01

    Macroalgae and filamentous turf algae (FTA) are abundant on degraded coral reefs, and the reproductive responses of corals may indicate sub-lethal stress under these conditions. The percentage of gametogenic stages (PGS) and the maximum diameter of eggs (MDE; or egg size) of Orbicella annularis were used to evaluate the effect of long- (7–10 months) and short-term (2.5 months) FTA removal (treatments T1 and T2, respectively) at both the beginning (May) and the end (August) of gametogenesis. Ramets (individual lobes of a colony) surrounded by FTA (T3) or crustose coralline algae (CCA; T4) were used as controls. The removal of FTA enhanced the development of gametes (i.e., a larger and higher percentage of mature gametes (PMG)) of O. annularis for T1 vs. T3 ramets in May and T1 and T2 vs. T3 ramets in August. Similar values of PGS and MDE between gametes from T3 and T4 in both May and August were unexpected because a previous study had shown that the same ramets of T4 (with higher tissue thickness, chlorophyll a cm-2 and zooxanthellae density and lower mitotic index values) were less stressed than ramets of T3. Evaluating coral stress through reproduction can reveal more sensitive responses than other biological parameters; within reproductive metrics, PGS can be a better stress indicator than egg size. The presence of turf algae strongly impacted the development of gametes and egg size (e.g., PMG in ramets with FTA removal increased almost twofold in comparison with ramets surrounded by FTA in August), most likely exerting negative chronic effects in the long run due to the ubiquity and permanence of turf algae in the Caribbean. These algae can be considered a stressor that affects coral sexual reproduction. Although the effects of turf algae on O. annularis are apparently less severe than those of other stressors, the future of this species is uncertain because of the combined impacts of these effects, the decline of O. annularis populations and the almost

  11. Hormonal induction of gamete release, and in-vitro fertilisation, in the critically endangered Southern Corroboree Frog, Pseudophryne corroboree

    Directory of Open Access Journals (Sweden)

    Silla Aimee J

    2010-11-01

    Full Text Available Abstract Background Conservation Breeding Programs (CBP's are playing an important role in the protection of critically endangered anuran amphibians, but for many species recruitment is not successful enough to maintain captive populations, or provide individuals for release. In response, there has been an increasing focus on the use of Assisted Reproductive Technologies (ART, including the administration of reproductive hormones to induce gamete release followed by in vitro fertilisation. The objective of this study was to test the efficacy of two exogenous hormones to induce gamete release, for the purpose of conducting in vitro fertilisation (IVF, in one of Australia's most critically endangered frog species, Pseudophryne corroboree. Methods Male frogs were administered a single dose of either human chorionic gonadotropin (hCG or luteinizing hormone-releasing hormone (LHRHa, while female frogs received both a priming and ovulatory dose of LHRHa. Spermiation responses were evaluated at 3, 7, 12, 24, 36, 48, 60 and 72 h post hormone administration (PA, and sperm number and viability were quantified using fluorescent microscopy. Ovulation responses were evaluated by stripping females every 12 h PA for 5 days. Once gametes were obtained, IVF was attempted by combining spermic urine with oocytes in a dilute solution of simplified amphibian ringer (SAR. Results Administration of both hCG and LHRHa induced approximately 80% of males to release sperm over 72 h. Peak sperm release occurred at 12 h PA for hCG treated males and 36 h PA for LHRHa treated males. On average, LHRHa treated males released a significantly higher total number of live sperm, and a higher concentration of sperm, over a longer period. In female frogs, administration of LHRHa induced approximately 30% of individuals to release eggs. On average, eggs were released between 24 and 48 h PA, with a peak in egg release at 36 h PA. IVF resulted in a moderate percentage (54.72% of eggs

  12. The effect of filamentous turf algal removal on the development of gametes of the coral Orbicella annularis.

    Directory of Open Access Journals (Sweden)

    Neidy P Cetz-Navarro

    Full Text Available Macroalgae and filamentous turf algae (FTA are abundant on degraded coral reefs, and the reproductive responses of corals may indicate sub-lethal stress under these conditions. The percentage of gametogenic stages (PGS and the maximum diameter of eggs (MDE; or egg size of Orbicella annularis were used to evaluate the effect of long- (7-10 months and short-term (2.5 months FTA removal (treatments T1 and T2, respectively at both the beginning (May and the end (August of gametogenesis. Ramets (individual lobes of a colony surrounded by FTA (T3 or crustose coralline algae (CCA; T4 were used as controls. The removal of FTA enhanced the development of gametes (i.e., a larger and higher percentage of mature gametes (PMG of O. annularis for T1 vs. T3 ramets in May and T1 and T2 vs. T3 ramets in August. Similar values of PGS and MDE between gametes from T3 and T4 in both May and August were unexpected because a previous study had shown that the same ramets of T4 (with higher tissue thickness, chlorophyll a cm-2 and zooxanthellae density and lower mitotic index values were less stressed than ramets of T3. Evaluating coral stress through reproduction can reveal more sensitive responses than other biological parameters; within reproductive metrics, PGS can be a better stress indicator than egg size. The presence of turf algae strongly impacted the development of gametes and egg size (e.g., PMG in ramets with FTA removal increased almost twofold in comparison with ramets surrounded by FTA in August, most likely exerting negative chronic effects in the long run due to the ubiquity and permanence of turf algae in the Caribbean. These algae can be considered a stressor that affects coral sexual reproduction. Although the effects of turf algae on O. annularis are apparently less severe than those of other stressors, the future of this species is uncertain because of the combined impacts of these effects, the decline of O. annularis populations and the almost

  13. Fusion systems engineering

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Research during this report period has covered the following areas: (1) fusion reactor systems studies, (2) development of blanket processing technology for fusion reactors, (3) safety studies of fusion concepts, (4) MACKLIB-IV, a new library of nuclear response functions, (5) energy storage and power supply requirements for commercial fusion reactors, (6) blanket/shield design evaluation for commercial fusion reactors, and (7) cross section measurements, evaluations, and techniques

  14. Fusion fuel and renewables

    International Nuclear Information System (INIS)

    Entler, Slavomir

    2015-01-01

    It is shown that fusion fuel meets all aspects applied when defining renewables. A table of definitions of renewables is presented. The sections of the paper are as follows: An industrial renewable source; Nuclear fusion; Current situation in research; Definitions of renewable sources; Energy concept of nuclear fusion; Fusion fuel; Natural energy flow; Environmental impacts; Fusion fuel assessment; Sustainable power; and Energy mix from renewables. (P.A.)

  15. Cold fusion

    International Nuclear Information System (INIS)

    Bush, R.T.

    1991-01-01

    The transmission resonance model (TRM) is combined with some electrochemistry of the cathode surface and found to provide a good fit to new data on excess heat. For the first time, a model for cold fusion not only fits calorimetric data but also predicts optimal trigger points. This suggests that the model is meaningful and that the excess heat phenomenon claimed by Fleischmann and Pons is genuine. A crucial role is suggested for the overpotential and, in particular, for the concentration overpotential, i.e., the hydrogen overvoltage. Self-similar geometry, or scale invariance, i.e., a fractal nature, is revealed by the relative excess power function. Heat bursts are predicted with a scale invariance in time, suggesting a possible link between the TRM and chaos theory. The model describes a near-surface phenomenon with an estimated excess power yield of ∼1 kW/cm 3 Pd, as compared to 50 W/cm 3 of reactor core for a good fission reactor. Transmission resonance-induced nuclear transmutation, a new type of nuclear reaction, is strongly suggested with two types emphasized: transmission resonance-induced neutron transfer reactions yielding essentially the same end result as Teller's hypothesized catalytic neutron transfer and a three-body reaction promoted by standing de Broglie waves. In this paper suggestions for the anomalous production of heat, particles, and radiation are given

  16. Fusion energy

    International Nuclear Information System (INIS)

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the MaxPlanck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989--1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R ampersand D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R ampersand D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase

  17. Protection against de novo methylation is instrumental in maintaining parent-of-origin methylation inherited from the gametes.

    Science.gov (United States)

    Proudhon, Charlotte; Duffié, Rachel; Ajjan, Sophie; Cowley, Michael; Iranzo, Julian; Carbajosa, Guillermo; Saadeh, Heba; Holland, Michelle L; Oakey, Rebecca J; Rakyan, Vardhman K; Schulz, Reiner; Bourc'his, Déborah

    2012-09-28

    Identifying loci with parental differences in DNA methylation is key to unraveling parent-of-origin phenotypes. By conducting a MeDIP-Seq screen in maternal-methylation free postimplantation mouse embryos (Dnmt3L-/+), we demonstrate that maternal-specific methylation exists very scarcely at midgestation. We reveal two forms of oocyte-specific methylation inheritance: limited to preimplantation, or with longer duration, i.e. maternally imprinted loci. Transient and imprinted maternal germline DMRs (gDMRs) are indistinguishable in gametes and preimplantation embryos, however, de novo methylation of paternal alleles at implantation delineates their fates and acts as a major leveling factor of parent-inherited differences. We characterize two new imprinted gDMRs, at the Cdh15 and AK008011 loci, with tissue-specific imprinting loss, again by paternal methylation gain. Protection against demethylation after fertilization has been emphasized as instrumental in maintaining parent-of-origin methylation inherited from the gametes. Here we provide evidence that protection against de novo methylation acts as an equal major pivot, at implantation and throughout life. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Induced pluripotent stem cell-derived gamete-associated proteins incite rejection of induced pluripotent stem cells in syngeneic mice.

    Science.gov (United States)

    Kim, Eun-Mi; Manzar, Gohar; Zavazava, Nicholas

    2017-06-01

    The safety of induced pluripotent stem cells (iPSCs) in autologous recipients has been questioned after iPSCs, but not embryonic stem cells (ESCs), were reported to be rejected in syngeneic mice. This important topic has remained controversial because there has not been a mechanistic explanation for this phenomenon. Here, we hypothesize that iPSCs, but not ESCs, readily differentiate into gamete-forming cells that express meiotic antigens normally found in immune-privileged gonads. Because peripheral blood T cells are not tolerized to these antigens in the thymus, gamete-associated-proteins (GAPs) sensitize T cells leading to rejection. Here, we provide evidence that GAPs expressed in iPSC teratomas, but not in ESC teratomas, are responsible for the immunological rejection of iPSCs. Furthermore, silencing the expression of Stra8, 'the master regulator of meiosis', in iPSCs, using short hairpin RNA led to significant abrogation of the rejection of iPSCs, supporting our central hypothesis that GAPs expressed after initiation of meiosis in iPSCs were responsible for rejection. In contrast to iPSCs, iPSC-derivatives, such as haematopoietic progenitor cells, are able to engraft long-term into syngeneic recipients because they no longer express GAPs. Our findings, for the first time, provide a unifying explanation of why iPSCs, but not ESCs, are rejected in syngeneic recipients, ending the current controversy on the safety of iPSCs and their derivatives. © 2017 John Wiley & Sons Ltd.

  19. Genetic mapping of centromeres in the nine Citrus clementina chromosomes using half-tetrad analysis and recombination patterns in unreduced and haploid gametes.

    Science.gov (United States)

    Aleza, Pablo; Cuenca, José; Hernández, María; Juárez, José; Navarro, Luis; Ollitrault, Patrick

    2015-03-08

    Mapping centromere locations in plant species provides essential information for the analysis of genetic structures and population dynamics. The centromere's position affects the distribution of crossovers along a chromosome and the parental heterozygosity restitution by 2n gametes is a direct function of the genetic distance to the centromere. Sexual polyploidisation is relatively frequent in Citrus species and is widely used to develop new seedless triploid cultivars. The study's objectives were to (i) map the positions of the centromeres of the nine Citrus clementina chromosomes; (ii) analyse the crossover interference in unreduced gametes; and (iii) establish the pattern of genetic recombination in haploid clementine gametes along each chromosome and its relationship with the centromere location and distribution of genic sequences. Triploid progenies were derived from unreduced megagametophytes produced by second-division restitution. Centromere positions were mapped genetically for all linkage groups using half-tetrad analysis. Inference of the physical locations of centromeres revealed one acrocentric, four metacentric and four submetacentric chromosomes. Crossover interference was observed in unreduced gametes, with variation seen between chromosome arms. For haploid gametes, a strong decrease in the recombination rate occurred in centromeric and pericentromeric regions, which contained a low density of genic sequences. In chromosomes VIII and IX, these low recombination rates extended beyond the pericentromeric regions. The genomic region corresponding to a genetic distance recombination pattern along each chromosome. However, regions with low recombination rates extended beyond the pericentromeric regions of some chromosomes into areas richer in genic sequences. The persistence of strong linkage disequilibrium between large numbers of genes promotes the stability of epistatic interactions and multilocus-controlled traits over successive generations but

  20. Fusion technology: The Iter fusion experiment

    International Nuclear Information System (INIS)

    Dietz, K.J.

    1994-01-01

    Plans for the Iter international fusion experiment, in which the European Union, Japan, Canada, Russia, Sweden, Switzerland, and the USA cooperate, were begun in 1985, and construction work started in early 1994. These activities serve for the preparation of the design and construction documents for a research reactor in which a stable fusion plasma is to be generated. This is to be the basis for the construction of a fusion reactor for electricity generation. Preparatory work was performed in the Tokamak experiments with JET and TFTR. The fusion power of 1.5 GW will be attained, thus enabling Iter to keep a deuterium-tritium plasma burning. (orig.) [de

  1. Couples with non-obstructive azoospermia are interested in future treatments with artificial gametes.

    Science.gov (United States)

    Hendriks, S; Hessel, M; Mochtar, M H; Meissner, A; van der Veen, F; Repping, S; Dancet, E A F

    2016-08-01

    Would couples diagnosed with non-obstructive azoospermia (NOA) consider two future treatments with artificial gametes (AGs) as alternatives for testicular sperm extraction followed by ICSI (TESE-ICSI)? Most couples with NOA (89%) would opt for treatment with AGs before attempting TESE-ICSI and/or after failed TESE-ICSI. Couples with NOA who undergo TESE-ICSI have a 25% chance of conceiving a child. Two future treatments that are being developed are 'ICSI with artificial sperm formed from somatic cells' (ICSI with AGs) and 'natural conception after autotransplantation of in vitro proliferated spermatogonial stem cells' (natural conception with AGs). It is unknown what treatment preferences patients have. A cross-sectional survey conducted in 2012-2013, addressing all 921 couples diagnosed with NOA and treated with TESE-ICSI in Dutch fertility clinics between 2007 and 2012. The coded questionnaires were sent by mail and followed up with two reminders. We developed the questionnaire based on a literature review and previous qualitative interviews, and included treatment preference and the valuation of nine treatment characteristics. We assessed reliability of the questionnaires and calculated mean importance scores (MISs: 0-10) of each treatment characteristic. We assessed which patient and treatment characteristics were associated with a couple's hypothetical treatment preference using binominal regression. The vast majority (89%) of the 494 responding couples (response rate: 54%) would potentially opt for AGs as a first and/or a last resort treatment option. More specifically, as a first treatment couples were likely (67%) to prefer natural conception with AGs over TESE-ICSI and less likely to prefer ICSI with AGs over TESE-ICSI (34%). After failed TESE-ICSI, the majority of couples (75%) would want to attempt ICSI with AGs as a last resort option. The most important characteristics of treatment were safety for children (MIS: 8.2), pregnancy rates (MIS: 7.7) and

  2. Review of fusion synfuels

    International Nuclear Information System (INIS)

    Fillo, J.A.

    1980-01-01

    Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high-temperature electrolysis of approx. 50 to 65% are projected for fusion reactors using high-temperatures blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion

  3. Barriers to fusion

    International Nuclear Information System (INIS)

    Berriman, A.C.; Butt, R.D.; Dasgupta, M.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

    1999-01-01

    The fusion barrier is formed by the combination of the repulsive Coulomb and attractive nuclear forces. Recent research at the Australian National University has shown that when heavy nuclei collide, instead of a single fusion barrier, there is a set of fusion barriers. These arise due to intrinsic properties of the interacting nuclei such deformation, rotations and vibrations. Thus the range of barrier energies depends on the properties of both nuclei. The transfer of matter between nuclei, forming a neck, can also affect the fusion process. High precision data have been used to determine fusion barrier distributions for many nuclear reactions, leading to new insights into the fusion process

  4. Fusion reactor design studies

    International Nuclear Information System (INIS)

    Emmert, G.A.; Kulcinski, G.L.; Santarius, J.F.

    1990-01-01

    This report discusses the following topics on the ARIES tokamak: systems; plasma power balance; impurity control and fusion ash removal; fusion product ripple loss; energy conversion; reactor fueling; first wall design; shield design; reactor safety; and fuel cost and resources

  5. Laser fusion: an overview

    International Nuclear Information System (INIS)

    Boyer, K.

    1975-01-01

    The laser fusion concept is described along with developments in neodymium and carbon dioxide lasers. Fuel design and fabrication are reviewed. Some spin-offs of the laser fusion program are discussed. (U.S.)

  6. Fusion Canada issue 23

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-01-01

    A short bulletin from the National Fusion Program highlighting in this issue TdeV tokamak updates, fusion research in Korea, CCFM program review, TdeV divertor plasma, and CFFTP program review. 4 figs.

  7. Fusion Canada issue 27

    International Nuclear Information System (INIS)

    1995-03-01

    A short bulletin from the National Fusion Program highlighting in this issue ITER reactor siting, a major upgrade for TdeV tokamak, Ceramic Breeders: new tritium mapping technique and Joint Fusion Symposium. 2 figs

  8. Fusion Canada issue 20

    International Nuclear Information System (INIS)

    1993-03-01

    Fusion Canada's publication of the National Fusion Program. Included in this issue is the CFFTP Industrial Impact Study, CCFM/TdeV Update:helium pumping, research funds, and deuterium in beryllium - high temperature behaviour. 3 figs

  9. Fusion Canada issue 23

    International Nuclear Information System (INIS)

    1994-01-01

    A short bulletin from the National Fusion Program highlighting in this issue TdeV tokamak updates, fusion research in Korea, CCFM program review, TdeV divertor plasma, and CFFTP program review. 4 figs

  10. Canada's Fusion Program

    International Nuclear Information System (INIS)

    Jackson, D. P.

    1990-01-01

    Canada's fusion strategy is based on developing specialized technologies in well-defined areas and supplying these technologies to international fusion projects. Two areas are specially emphasized in Canada: engineered fusion system technologies, and specific magnetic confinement and materials studies. The Canadian Fusion Fuels Technology Project focuses on the first of these areas. It tritium and fusion reactor fuel systems, remote maintenance and related safety studies. In the second area, the Centre Canadian de fusion magnetique operates the Tokamak de Varennes, the main magnetic fusion device in Canada. Both projects are partnerships linking the Government of Canada, represented by Atomic Energy of Canada Limited, and provincial governments, electrical utilities, universities and industry. Canada's program has extensive international links, through which it collaborates with the major world fusion programs, including participation in the International Thermonuclear Experimental Reactor project

  11. Fusion systems engineering

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Information is given on each of the following topics: (1) fusion reactor systems studies, (2) development of blanket processing technology for fusion reactors, (3) safety studies of CTR concepts, and (4) cross section measurements and techniques

  12. Fusion Canada issue 6

    International Nuclear Information System (INIS)

    1989-02-01

    A short bulletin from the National Fusion Program. Included in this issue is a funding report for CFFTP, a technical update for Tokamak de Varennes and a network for university research by the National Fusion Program. 4 figs

  13. Fusion Canada issue 18

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-08-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on the ITER agreement signed with the EDA, the robotic maintenance for NET, the CFFTP Fusion Pilot Study, the new IEA joint programs on environment, safety and economic aspects of fusion power, and a review by the CCFM advisory committee. 3 figs.

  14. User's perspective on fusion

    International Nuclear Information System (INIS)

    Ashworth, C.P.

    1976-01-01

    The need in fusion, from the electric utilities viewpoint, is for fusion to be a real option, not huge, complicated nuclear plants costing $10 billion each and requiring restructuring the energy industry to provide and use them. A course for future fusion reactor work in order to be a real option is discussed. The advantages of alternate concepts to the tokamak are presented

  15. Fusion Canada issue 17

    International Nuclear Information System (INIS)

    1992-05-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on increased funding for the Canadian Fusion Program, news of the compact Toroid fuelling gun, an update on Tokamak de Varennes, the Canada - U.S. fusion meeting, measurements of plasma flow velocity, and replaceable Tokamak divertors. 4 figs

  16. Fusion Canada issue 18

    International Nuclear Information System (INIS)

    1992-08-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on the ITER agreement signed with the EDA, the robotic maintenance for NET, the CFFTP Fusion Pilot Study, the new IEA joint programs on environment, safety and economic aspects of fusion power, and a review by the CCFM advisory committee. 3 figs

  17. CO2-laser fusion

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

  18. Fusion Canada issue 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-11-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on availability of Canadian Tritium, an ITER update, a CCFM update on Tokamak and the new team organization, an international report on Fusion in Canada and a Laser Fusion Project at the University of Toronto. 3 figs.

  19. Heavy ion fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1986-01-01

    This report on the International Symposium on Heavy Ion Fusion held May 27-29, 1986 summarizes the problems and achievements in the areas of targets, accelerators, focussing, reactor studies, and system studies. The symposium participants recognize that there are large uncertainties in Heavy Ion Fusion but many of them are also optimistic that HIF may ultimately be the best approach to fusion

  20. Fusion Canada issue 17

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-05-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on increased funding for the Canadian Fusion Program, news of the compact Toroid fuelling gun, an update on Tokamak de Varennes, the Canada - U.S. fusion meeting, measurements of plasma flow velocity, and replaceable Tokamak divertors. 4 figs.

  1. Fusion Canada issue 25

    International Nuclear Information System (INIS)

    1994-08-01

    A short bulletin from the National Fusion Program highlighting in this issue an economic impact study of the Canadian site for ITER, Harvey Skarsgard: fusion pioneer retires, NFP: Phillips and Holtslander exchange roles, Europe's fusion funding proposals and an update of CCFM/TdeV. 1 fig

  2. Fusion reactors - types - problems

    International Nuclear Information System (INIS)

    Schmitter, K.H.

    1979-07-01

    A short account is given of the principles of fusion reactions and of the expected advantages of fusion reactors. Descriptions are presented of various Tokamak experimental devices being developed in a number of countries and of some mirror machines. The technical obstacles to be overcome before a fusion reactor could be self-supporting are discussed. (U.K.)

  3. Cold fusion research

    International Nuclear Information System (INIS)

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy

  4. Fusion Canada issue 9

    International Nuclear Information System (INIS)

    1989-11-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on availability of Canadian Tritium, an ITER update, a CCFM update on Tokamak and the new team organization, an international report on Fusion in Canada and a Laser Fusion Project at the University of Toronto. 3 figs

  5. Occurrence of 2n gametes in the F1 hybrids of Oriental x Asiatic lilies (Lilium): Relevance to intergenomic recombination and backcrossing

    NARCIS (Netherlands)

    Barba Gonzalez, R.; Lim, K.B.; Ramanna, M.S.; Visser, R.G.F.; Tuyl, van J.M.

    2005-01-01

    Cytological modes of the origin of 2n gametes were investigated in six different genotypes of F1 hybrids between Oriental and Asiatic (OA) lilies (Lilium, 2n = 2x = 24). Chromosome pairing between the parental genomes was very low, the average frequency range from 0.3 to 1.2 bivalents per cell among

  6. Influence of gametal release method and larval initial density in the culture of the sea urchin Paracentrotus lividus

    Directory of Open Access Journals (Sweden)

    Sílvia C. Gonçalves

    2014-06-01

    Full Text Available The gonads of sea urchins have increased interest for human consumption, as a culinary delicacy worldwide. In Europe, the species Paracentrotus lividus was identified as an ideal candidate to meet the growing demand for this product, due to its high gonadosomatic index and easy access. However, the current commercial model, based on the exploitation its natural populations, may be unsustainable. Therefore, its production in aquaculture would be beneficial to avoid depletion of natural stocks of these organisms. The present study sought to develop a culture system for Paracentrotus lividus in aquaculture, which would allow maintaining the early embryonic and larval stages of this animal. A trial was set using 3 gametal release methods (due to stress induced by capture and by injecting 0.125M and 0.250M of potassium chloride and 3 densities of sea urchin embryos (530 embryos/L, 1000 embryos/L and 2000 embryos/L, using 5 replicate individual culture tanks for each combined factor. The embryos were obtained by adding gametes to sea water, in a proportion 1 egg : 100 spermatozoids, and by discarding unfertilized floating eggs by decantation. Afterwards, the embryos were transferred to a culture system composed by cylindrical-conical plastic tanks of 2L. These were decontaminated and filled with 0.750L of sea water, continuously aerated through a sterile pipette of 3mL. These tanks were placed on metal shelves, artificially illuminated with daylight fluorescent lamps (18w/765, 400Lux and maintained at 22°C. The larvae were fed each 2 days, with a mixture of microalgae Tetraselmis chuii, Phaeodactylum tricornumtum and Thalassiosira weliflogii at a concentration of 800-1000 microalgae/mL, adding 15µL, 50µL and 30µL to each individual tank, respectively for each of the initial larval densities introduced. There was an influence of the factor initial larval density in the mortality rate, wherein the number of larvae that died during the trial was much

  7. First llama (Lama glama) pregnancy obtained after in vitro fertilization and in vitro culture of gametes from live animals.

    Science.gov (United States)

    Trasorras, V; Baca Castex, C; Alonso, A; Giuliano, S; Santa Cruz, R; Arraztoa, C; Chaves, G; Rodríguez, D; Neild, D; Miragaya, M

    2014-07-01

    The aim of this study was to evaluate the developmental competence and pregnancy rate of llama hatched blastocysts produced in vitro using gametes from live animals and two different culture conditions. Fifteen adult females were superstimulated with 1500 IU of eCG, eleven (73%) responded to the treatment and were used as oocyte donors. Follicular aspiration was conducted by flank laparotomy. Semen collections were performed under general anesthesia by electroejaculation of the male. Sixty-six COCs were recovered from 77 aspirated follicles (86% recovery) and were randomly placed in Fertil-TALP microdroplets with the sperm suspension (20 × 10(6)live spermatozoa/ml). After 24 h, they were placed in SOFaa medium supplemented with FCS and randomly assigned to one of two culture conditions. Culture condition 1 (CC1) consisted of 6 days of culture (n=28) and culture condition 2 (CC2) consisted of renewing the culture medium every 48 h (n=35). In CC1, the blastocyst rate was 36% (10/28) and the hatched blastocyst rate was 28% (8/28) whereas in CC2, the blastocyst rate was 34% (12/35) and the hatched blastocyst rate was 20% (7/35) (p>0.05). No pregnancies were obtained after embryo transfer (ET) of CC1 blastocysts (0/8) while one pregnancy was obtained (1/7) after transferring a hatched blastocyst from CC2. Forty-two days after the ET, the pregnancy was lost. This study represents the first report of a pregnancy in the llama after intrauterine transfer of embryos produced by in vitro fertilization using gametes from live animals. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effects of water pH on gamete activation, embryonic development, and larval normality in Prochilodus lineatus

    Directory of Open Access Journals (Sweden)

    Eduardo Antônio Sanches

    2015-08-01

    Full Text Available We investigated the effects of breeding water pH on the spermatic motility, artificial fertilization, and initial development of offspring in curimba, Prochilodus lineatus. After hormonal induction, we conducted gamete activation, artificial fertilization, and embryo incubation in water with pH values of 4.43 ± 0.13, 5.82 ± 0.14, 7.37 ± 0.10, 8.21 ± 0.06, and 9.57 ± 0.16. When the water pH was 6.65, spermatic motility was maintained for ?25.21 s (P < 0.05. The highest fertilization rates (P < 0.05 were obtained when the water pH ranged from 5.82 ± 0.14 to 8.21 ± 0.06, and the highest hatching rates (P < 0.05 were observed when the water pH was 7.37 ± 0.10. A water pH of between 7.37 ± 0.10 and 8.21 ± 0.06 resulted in more complete formation of the perivitelline space (P < 0.05; additionally, embryos incubated in alkaline waters produced a higher percentage of normal larvae (P < 0.05, despite increased mortality levels. Our results indicate that the pH of the water used for gamete activation, artificial oocyte fertilization, and incubation of eggs and larvae of P. lineatus should be ~7, in order to promote successful breeding and normal larval production.

  9. Viral membrane fusion

    International Nuclear Information System (INIS)

    Harrison, Stephen C.

    2015-01-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism

  10. Viral membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Stephen C., E-mail: harrison@crystal.harvard.edu

    2015-05-15

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

  11. Fusion technology 1992

    International Nuclear Information System (INIS)

    Ferro, C.; Gasparatto, M.; Knoepfel, H.

    1993-01-01

    The aim of the biennial series of symposia on the title subject, organized by the European Fusion Laboratories, is the exchange of information on the design, construction and operation of fusion experiments and on the technology being developed for the next step devices and fusion reactors. The coverage of the volume includes the technological aspects of fusion reactors in relation to new developments, this forming a guideline for the definition of future work. These proceedings comprise three volumes and contain both the invited lectures and contributed papers presented at the symposium which was attended by 569 participants from around the globe. The 343 papers, including 12 invited papers, characterize the increasing interest of industry in the fusion programme, giving a broad and current overview on the progress and trends fusion technology is experiencing now, as well as indicating the future for fusion devices

  12. Economics of fusion research

    International Nuclear Information System (INIS)

    1977-01-01

    This report provides the results of a study of methods of economic analysis applied to the evaluation of fusion research. The study recognizes that a hierarchy of economic analyses of research programs exists: standard benefit-cost analysis, expected value of R and D information, and expected utility analysis. It is shown that standard benefit-cost analysis, as commonly applied to research programs, is inadequate for the evaluation of a high technology research effort such as fusion research. A methodology for performing an expected value analysis is developed and demonstrated and an overview of an approach to perform an expected utility analysis of fusion research is presented. In addition, a potential benefit of fusion research, not previously identified, is discussed and rough estimates of its magnitude are presented. This benefit deals with the effect of a fusion research program on optimal fossil fuel consumption patterns. The results of this study indicate that it is both appropriate and possible to perform an expected value analysis of fusion research in order to assess the economics of a fusion research program. The results indicate further that the major area of benefits of fusion research is likely due to the impact of a fusion research program on optimal fossil fuel consumption patterns and it is recommended that this benefit be included in future assessments of fusion research economics

  13. Economics of fusion research

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1977-10-15

    This report provides the results of a study of methods of economic analysis applied to the evaluation of fusion research. The study recognizes that a hierarchy of economic analyses of research programs exists: standard benefit-cost analysis, expected value of R and D information, and expected utility analysis. It is shown that standard benefit-cost analysis, as commonly applied to research programs, is inadequate for the evaluation of a high technology research effort such as fusion research. A methodology for performing an expected value analysis is developed and demonstrated and an overview of an approach to perform an expected utility analysis of fusion research is presented. In addition, a potential benefit of fusion research, not previously identified, is discussed and rough estimates of its magnitude are presented. This benefit deals with the effect of a fusion research program on optimal fossil fuel consumption patterns. The results of this study indicate that it is both appropriate and possible to perform an expected value analysis of fusion research in order to assess the economics of a fusion research program. The results indicate further that the major area of benefits of fusion research is likely due to the impact of a fusion research program on optimal fossil fuel consumption patterns and it is recommended that this benefit be included in future assessments of fusion research economics.

  14. Recycling fusion materials

    International Nuclear Information System (INIS)

    Ooms, L.

    2005-01-01

    The inherent safety and environmental advantages of fusion power in comparison with other energy sources play an important role in the public acceptance. No waste burden for future generations is therefore one of the main arguments to decide for fusion power. The waste issue has thus been studied in several documents and the final conclusion of which it is stated that there is no permanent disposal waste needed if recycling is applied. But recycling of fusion reactor materials is far to be obvious regarding mostly the very high specific activity of the materials to be handled, the types of materials and the presence of tritium. The main objective of research performed by SCK-CEN is to study the possible ways of recycling fusion materials and analyse the challenges of the materials management from fusion reactors, based on current practices used in fission reactors and the requirements for the manufacture of fusion equipment

  15. The controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2014-01-01

    After some generalities on particle physics, and on fusion and fission reactions, the author outlines that the fission reaction is easier to obtain than the fusion reaction, evokes the fusion which takes place in stars, and outlines the difficulty to manage and control this reaction: one of its application is the H bomb. The challenge is therefore to find a way to control this reaction and make it a steady and continuous source of energy. The author then presents the most promising way: the magnetic confinement fusion. He evokes its main issues, the already performed experiments (tokamak), and gives a larger presentation of the ITER project. Then, he evokes another way, the inertial confinement fusion, and the two main experimental installations (National Ignition Facility in Livermore, and the Laser Megajoule in Bordeaux). Finally, he gives a list of benefits and drawbacks of an industrial nuclear fusion

  16. Laser fusion overview

    International Nuclear Information System (INIS)

    Nuckolls, J.

    1976-01-01

    Because of recent breakthroughs in the target area, and in the glass laser area, the scientific feasibility of laser fusion--and of inertial fusion--may be demonstrated in the early 1980's. Then the development in that time period of a suitable laser (or storage ring or other driving source) would make possible an operational inertial fusion reactor in this century. These are roughly the same time scales as projected by the Tokamak magnetic confinement approach. It thus appears that the 15-20 year earlier start by magnetic confinement fusion may be overcome. Because inertial confinement has been demonstrated, and inertial fusion reactors may operate on smaller scales than Tokamaks, laser fusion may have important technical and economic advantages

  17. Synthetic fuels and fusion

    Energy Technology Data Exchange (ETDEWEB)

    Fillo, J A; Powell, J; Steinberg, M [Brookhaven National Lab., Upton, NY (USA)

    1981-03-01

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. equal to 40-60% and hydrogen production efficiencies by high temperature electrolysis of approx. equal to 50-70% are projected for fusion reactors using high temperature blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long-term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  18. Magnetic-fusion program

    International Nuclear Information System (INIS)

    1980-08-01

    In February 1980, the Director of Energy Research requested that the Energy Research Advisory Board (ERAB) review the Department of Energy (DOE) Magnetic Fusion Program. Of particular concern to the DOE was the judicious choice of the next major steps toward demonstration of economic power production from fusion. Of equal concern was the overall soundness of the DOE Magnetic Fusion Program: its pace, scope, and funding profiles. Their finding and recommendations are included

  19. Magnetic fusion technology

    CERN Document Server

    Dolan, Thomas J

    2014-01-01

    Magnetic Fusion Technology describes the technologies that are required for successful development of nuclear fusion power plants using strong magnetic fields. These technologies include: ? magnet systems, ? plasma heating systems, ? control systems, ? energy conversion systems, ? advanced materials development, ? vacuum systems, ? cryogenic systems, ? plasma diagnostics, ? safety systems, and ? power plant design studies. Magnetic Fusion Technology will be useful to students and to specialists working in energy research.

  20. Status of fusion maintenance

    International Nuclear Information System (INIS)

    Fuller, G.M.

    1984-01-01

    Effective maintenance will be an essential ingredient in determining fusion system productivity. This level of productivity will result only after close attention is paid to the entire system as an entity and appropriate integration of the elements is made. The status of fusion maintenance is reviewed in the context of the entire system. While there are many challenging developmental tasks ahead in fusion maintenance, the required technologies are available in several high-technology industries, including nuclear fission

  1. Membrane fusion and exocytosis.

    Science.gov (United States)

    Jahn, R; Südhof, T C

    1999-01-01

    Membrane fusion involves the merger of two phospholipid bilayers in an aqueous environment. In artificial lipid bilayers, fusion proceeds by means of defined transition states, including hourglass-shaped intermediates in which the proximal leaflets of the fusing membranes are merged whereas the distal leaflets are separate (fusion stalk), followed by the reversible opening of small aqueous fusion pores. Fusion of biological membranes requires the action of specific fusion proteins. Best understood are the viral fusion proteins that are responsible for merging the viral with the host cell membrane during infection. These proteins undergo spontaneous and dramatic conformational changes upon activation. In the case of the paradigmatic fusion proteins of the influenza virus and of the human immunodeficiency virus, an amphiphilic fusion peptide is inserted into the target membrane. The protein then reorients itself, thus forcing the fusing membranes together and inducing lipid mixing. Fusion of intracellular membranes in eukaryotic cells involves several protein families including SNAREs, Rab proteins, and Sec1/Munc-18 related proteins (SM-proteins). SNAREs form a novel superfamily of small and mostly membrane-anchored proteins that share a common motif of about 60 amino acids (SNARE motif). SNAREs reversibly assemble into tightly packed helical bundles, the core complexes. Assembly is thought to pull the fusing membranes closely together, thus inducing fusion. SM-proteins comprise a family of soluble proteins that bind to certain types of SNAREs and prevent the formation of core complexes. Rab proteins are GTPases that undergo highly regulated GTP-GDP cycles. In their GTP form, they interact with specific proteins, the effector proteins. Recent evidence suggests that Rab proteins function in the initial membrane contact connecting the fusing membranes but are not involved in the fusion reaction itself.

  2. Fusion facility siting considerations

    International Nuclear Information System (INIS)

    Bussell, G.T.

    1985-01-01

    Inherent in the fusion program's transition from hydrogen devices to commercial power machines is a general increase in the size and scope of succeeding projects. This growth will lead to increased emphasis on safety, environmental impact, and the external effects of fusion in general, and of each new device in particular. A critically important consideration in this regard is site selection. The purpose of this paper is to examine major siting issues that may affect the economics, safety, and environmental impact of fusion

  3. Fusion research principles

    CERN Document Server

    Dolan, Thomas James

    2013-01-01

    Fusion Research, Volume I: Principles provides a general description of the methods and problems of fusion research. The book contains three main parts: Principles, Experiments, and Technology. The Principles part describes the conditions necessary for a fusion reaction, as well as the fundamentals of plasma confinement, heating, and diagnostics. The Experiments part details about forty plasma confinement schemes and experiments. The last part explores various engineering problems associated with reactor design, vacuum and magnet systems, materials, plasma purity, fueling, blankets, neutronics

  4. Nuclear fusion power

    International Nuclear Information System (INIS)

    Dinghee, D.A.

    1983-01-01

    In this chapter, fusion is compared with other inexhaustible energy sources. Research is currently being conducted both within and outside the USA. The current confinement principles of thermonuclear reactions are reveiwed with the discussion of economics mainly focusing on the magnetic confinement concepts. Environmental, health and safety factors are of great concern to the public and measures are being taken to address them. The magnetic fusion program logic and the inertial fusion program logic are compared

  5. Inertial confinement fusion (ICF)

    International Nuclear Information System (INIS)

    Nuckolls, J.

    1977-01-01

    The principal goal of the inertial confinement fusion program is the development of a practical fusion power plant in this century. Rapid progress has been made in the four major areas of ICF--targets, drivers, fusion experiments, and reactors. High gain targets have been designed. Laser, electron beam, and heavy ion accelerator drivers appear to be feasible. Record-breaking thermonuclear conditions have been experimentally achieved. Detailed diagnostics of laser implosions have confirmed predictions of the LASNEX computer program. Experimental facilities are being planned and constructed capable of igniting high gain fusion microexplosions in the mid 1980's. A low cost long lifetime reactor design has been developed

  6. Inertial fusion energy

    International Nuclear Information System (INIS)

    Decroisette, M.; Andre, M.; Bayer, C.; Juraszek, D.; Le Garrec, B.; Deutsch, C.; Migus, A.

    2005-01-01

    We first recall the scientific basis of inertial fusion and then describe a generic fusion reactor with the different components: the driver, the fusion chamber, the material treatment unit, the target factory and the turbines. We analyse the options proposed at the present time for the driver and for target irradiation scheme giving the state of art for each approach. We conclude by the presentation of LMJ (laser Megajoule) and NIF (national ignition facility) projects. These facilities aim to demonstrate the feasibility of laboratory DT ignition, first step toward Inertial Fusion Energy. (authors)

  7. Laser fusion program overview

    International Nuclear Information System (INIS)

    Emmett, J.L.

    1977-01-01

    This program is structured to proceed through a series of well defined fusion milestones to proof of the scientific feasibility, of laser fusion with the Shiva Nova system. Concurrently, those key technical areas, such as advanced lasers, which are required to progress beyond proof of feasibility, are being studied. We have identified and quantified the opportunities and key technical issues in military applications, such as weapons effects simulations, and in civilian applications, such as central-station electric power production. We summarize the current status and future plans for the laser fusion program at LLL, emphasizing the civilian applications of laser fusion

  8. Frontiers in fusion research

    CERN Document Server

    Kikuchi, Mitsuru

    2011-01-01

    Frontiers in Fusion Research provides a systematic overview of the latest physical principles of fusion and plasma confinement. It is primarily devoted to the principle of magnetic plasma confinement, that has been systematized through 50 years of fusion research. Frontiers in Fusion Research begins with an introduction to the study of plasma, discussing the astronomical birth of hydrogen energy and the beginnings of human attempts to harness the Sun's energy for use on Earth. It moves on to chapters that cover a variety of topics such as: * charged particle motion, * plasma kinetic theory, *

  9. Fusion of Nonionic Vesicles

    DEFF Research Database (Denmark)

    Bulut, Sanja; Oskolkova, M. Z.; Schweins, R.

    2010-01-01

    We present an experimental study of vesicle fusion using light and neutron scattering to monitor fusion events. Vesicles are reproducibly formed with an extrusion procedure using an single amphiphile triethylene glycol mono-n-decyl ether in water. They show long-term stability for temperatures ar...... a barrier to fusion changing from 15 k(B)T at T = 26 degrees C to 10k(H) T at T = 35 degrees C. These results are compatible with the theoretical predictions using the stalk model of vesicle fusion....

  10. Fusion reactor safety

    International Nuclear Information System (INIS)

    1987-12-01

    Nuclear fusion could soon become a viable energy source. Work in plasma physics, fusion technology and fusion safety is progressing rapidly in a number of Member States and international collaboration continues on work aiming at the demonstration of fusion power generation. Safety of fusion reactors and technological and radiological aspects of waste management are important aspects in the development and design of fusion machines. In order to provide an international forum to review and discuss the status and the progress made since 1983 in programmes related to operational safety aspects of fusion reactors, their waste management and decommissioning concepts, the IAEA had organized the Technical Committee on ''Fusion Reactor Safety'' in Culham, 3-7 November 1986. All presentations of this meeting were divided into four sessions: 1. Statements on National-International Fusion Safety Programmes (5 papers); 2. Operation and System Safety (15 papers); 3. Waste Management and Decommissioning (5 papers); 4. Environmental Impacts (6 papers). A separate abstract was prepared for each of these 31 papers. Refs, figs, tabs

  11. Magnetic fusion reactor economics

    International Nuclear Information System (INIS)

    Krakowski, R.A.

    1995-01-01

    An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission → fusion. The present projections of the latter indicate that capital costs of the fusion ''burner'' far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ''implementation-by-default'' plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify the contemporary vision for fusion power. Competitive fusion power in this context will require a significant broadening of an overly focused program to explore the physics and simbiotic technologies leading to more compact, simplified, and efficient plasma-confinement configurations that reside at the heart of an attractive fusion power plant

  12. Incomplete fusion studies

    International Nuclear Information System (INIS)

    Singh, B.P.

    2011-01-01

    In order to study the incomplete fusion reaction dynamics at energies ≅ 4-7 MeV/nucleon, several experiments have been carried out using accelerator facilities available in India. The measurements presented here cover a wide range of projectile-target combinations and enhance significantly our knowledge about incomplete fusion reaction dynamics. Here, the three sets of measurements have been presented; (i) excitation functions, (ii) forward recoil range distributions and (iii) the spin distributions. The first evidence of these reactions has been obtained from the measurement and analysis of excitation functions for xn/αxn/2αxn-channels. The measured excitation functions have been analyzed within the framework of compound nucleus model. The results obtained indicate the occurrence of fusion incompleteness at low beam energies. However, in order to determine the relative contribution of complete and incomplete fusion reaction processes, the recoil range distributions of the heavy residues have also been measured and analyzed within the framework of breakup fusion model which confirmed the fusion incompleteness in several heavy ion reactions involving α-emitting reaction channels. Further, in order to study the role of l-values in these reactions the spin distributions of the residues populated in case of complete and incomplete channels have been measured and are found to be distinctly different. The analysis of the data on spin distribution measurements indicate that the mean values of driving input angular momenta associated with direct-α-emitting (incomplete fusion) channels are higher than that observed for fusion-evaporation xn or α-emitting (complete fusion) channels, and is found to increase with direct α-multiplicity in the forward cone. One of the important conclusions drawn in the present work is that, there is significant incomplete fusion contribution even at energies slightly above the barrier. Further, the projectile structure has been found to

  13. Linkage analysis for the gametic lethal gene of a rice variety 'Koshihikari' and the semi-dwarfing gene induced in 'Koshihikari'

    International Nuclear Information System (INIS)

    Tomita, M.; Tanisaka, T.; Okumoto, Y.; Yamagata, H.

    1990-01-01

    Full text: 'Koshihikari', a Japanese tall variety, is now most widely cultivated in Japan because of its good quality and taste, but is extremely poor in lodging resistance. In order to create a semi-dwarf 'Koshihikari', large scale mutation breeding was carried out at Hokuriku Agricultural Experiment Station, resulting in the production of an excellent semi-dwarf mutant strain 'Hokuriku 100'. It has extensively been used as cross parent. Genetic analyses revealed that the semi-dwarfness of 'Hokuriku 100' is controlled by two mutant genes, a recessive semi-dwarfness gene sd(t) and a non-gametic lethal gene lt m mutated from the genetic lethal gene of 'Koshihikari' lt, which would cause abortion of both male and female gametes when it occurs together with sd(t). Further analyses led to conclude that It is located on chromosome 9, sd(t) on chromosome 10. (author)

  14. Mirror fusion--fission hybrids

    International Nuclear Information System (INIS)

    Lee, J.D.

    1978-01-01

    The fusion-fission concept and the mirror fusion-fission hybrid program are outlined. Magnetic mirror fusion drivers and blankets for hybrid reactors are discussed. Results of system analyses are presented and a reference design is described

  15. How parents whose children have been conceived with donor gametes make their disclosure decision: contexts, influences, and couple dynamics.

    Science.gov (United States)

    Shehab, Dena; Duff, Julia; Pasch, Lauri A; Mac Dougall, Kirstin; Scheib, Joanna E; Nachtigall, Robert D

    2008-01-01

    To describe parents' disclosure decision-making process. In-depth ethnographic interviews. Participants were recruited from 11 medical infertility practices and 1 sperm bank in Northern California. One hundred forty-one married couples who had conceived a child using donor gametes (62 with donor sperm, 79 with donor oocytes). Husbands and wives were interviewed together and separately. Thematic analysis of interview transcripts. Ninety-five percent of couples came to a united disclosure decision, some "intuitively," but most after discussions influenced by the couples' local sociopolitical environment, professional opinion, counseling, religious and cultural background, family relationships, and individual personal, psychological, and ethical beliefs. Couples who were not initially in agreement ultimately came to a decision after one partner deferred to the wishes or opinions of the other. Deferral could reflect the result of a prior agreement, one partner's recognition of the other's experiential or emotional expertise, or direct persuasion. In disclosing couples, men frequently deferred to their wives, whereas, in nondisclosing couples, women always deferred to their husbands. Although the majority of couples were in initial agreement about disclosure, for many the disclosure decision was a complex, negotiated process reflecting a wide range of influences and contexts.

  16. Restoration of critically endangered elkhorn coral (Acropora palmata populations using larvae reared from wild-caught gametes

    Directory of Open Access Journals (Sweden)

    Valérie F. Chamberland

    2015-07-01

    Full Text Available Elkhorn coral (Acropora palmata populations provide important ecological functions on shallow Caribbean reefs, many of which were lost when a disease reduced their abundance by more than 95% beginning in the mid-1970s. Since then, a lack of significant recovery has prompted rehabilitation initiatives throughout the Caribbean. Here, we report the first successful outplanting and long-term survival of A. palmata settlers reared from gametes collected in the field. A. palmata larvae were settled on clay substrates (substrate units and either outplanted on the reef two weeks after settlement or kept in a land-based nursery. After 2.5 years, the survival rate of A. palmata settlers outplanted two weeks after settlement was 6.8 times higher (3.4% than that of settlers kept in a land-based nursery (0.5%. Furthermore, 32% of the substrate units on the reef still harbored one or more well-developed recruit compared to 3% for substrate units kept in the nursery. In addition to increasing survival, outplanting A. palmata settlers shortly after settlement reduced the costs to produce at least one 2.5-year-old A. palmata individual from $325 to $13 USD. Thus, this study not only highlights the first successful long-term rearing of this critically endangered coral species, but also shows that early outplanting of sexually reared coral settlers can be more cost-effective than the traditional approach of nursery rearing for restoration efforts aimed at rehabilitating coral populations.

  17. Control of DEMETER DNA demethylase gene transcription in male and female gamete companion cells in Arabidopsis thaliana.

    Science.gov (United States)

    Park, Jin-Sup; Frost, Jennifer M; Park, Kyunghyuk; Ohr, Hyonhwa; Park, Guen Tae; Kim, Seohyun; Eom, Hyunjoo; Lee, Ilha; Brooks, Janie S; Fischer, Robert L; Choi, Yeonhee

    2017-02-21

    The DEMETER (DME) DNA glycosylase initiates active DNA demethylation via the base-excision repair pathway and is vital for reproduction in Arabidopsis thaliana DME-mediated DNA demethylation is preferentially targeted to small, AT-rich, and nucleosome-depleted euchromatic transposable elements, influencing expression of adjacent genes and leading to imprinting in the endosperm. In the female gametophyte, DME expression and subsequent genome-wide DNA demethylation are confined to the companion cell of the egg, the central cell. Here, we show that, in the male gametophyte, DME expression is limited to the companion cell of sperm, the vegetative cell, and to a narrow window of time: immediately after separation of the companion cell lineage from the germline. We define transcriptional regulatory elements of DME using reporter genes, showing that a small region, which surprisingly lies within the DME gene, controls its expression in male and female companion cells. DME expression from this minimal promoter is sufficient to rescue seed abortion and the aberrant DNA methylome associated with the null dme-2 mutation. Within this minimal promoter, we found short, conserved enhancer sequences necessary for the transcriptional activities of DME and combined predicted binding motifs with published transcription factor binding coordinates to produce a list of candidate upstream pathway members in the genetic circuitry controlling DNA demethylation in gamete companion cells. These data show how DNA demethylation is regulated to facilitate endosperm gene imprinting and potential transgenerational epigenetic regulation, without subjecting the germline to potentially deleterious transposable element demethylation.

  18. The fusion reactor

    International Nuclear Information System (INIS)

    Brennan, M.H.

    1974-01-01

    Basic principles of the fusion reactor are outlined. Plasma heating and confinement schemes are described. These confinement systems include the linear Z pinch, magnetic mirrors and Tokamaks. A fusion reactor is described and a discussion is given of its environmental impact and its fuel situation. (R.L.)

  19. Fusion Canada issue 8

    International Nuclear Information System (INIS)

    1989-08-01

    A short bulletin from the National Fusion Program. Included in this issue are Canada-ITER contributions, NET Fuel Processing Loop, Bilateral Meeting for Canada-Europe, report from Tokamak de Varennes and a report from the University of Toronto on materials research for Fusion Reactors. 3 figs

  20. Fusion Canada issue 15

    International Nuclear Information System (INIS)

    1991-10-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on the 1996 IAEA Fusion Conference site, operations at the Tokamak de Varennes including divertor pumping of impurities and pumping of carbon monoxide and methane, a discussion of the CFFTP and it's role. 1 fig

  1. Energy by nuclear fusion

    International Nuclear Information System (INIS)

    Buende, R.; Daenner, W.; Herold, H.; Raeder, J.

    1976-12-01

    This report reviews the state of knowledge in a number of fields of fusion research up to autumn 1976. Section 1 gives a very brief presentation of the elementary fusion reactions, the energies delivered by them and the most basic energy balances leading to Lawson-type diagrams. Section 2 outlines the reserves and cost of lithium and deuterium, gives estimates of the total energy available from DT fusion and comments on production technology, availlability and handling of the fuels. In section 3 a survey is given of the different concepts of magnetic confinement (stellarators, tokamaks, toroidal pinches, mirror machines, two-component plasmas), of confinement by walls, gas blankets and imploding liners and, finally, of the concepts of interial confinement (laser fusion, beam fusion). The reactors designed or outlined on the basis of the tokamak, high-β, mirror, and laser fusion concepts are presented in section 4, which is followed in section 5 by a discussion of the key problems of fusion power plants. The present-day knowledge of the cost structure of fusion power plants and the sensitivity of this structure with respect to the physical and technical assumptions made is analysed in section 6. Section 7 and 8 treat the aspects of safety and environment. The problems discussed include the hazard potentials of different designs (radiological, toxicological, and with respect to stored energies), release of radioactivity, possible kinds of malfunctioning, and the environmental impact of waste heat, radiation and radioactive waste (orig.) [de

  2. Fusion helps diversification

    NARCIS (Netherlands)

    Liang, S.; Ren, Z.; de Rijke, M.

    2014-01-01

    A popular strategy for search result diversification is to first retrieve a set of documents utilizing a standard retrieval method and then rerank the results. We adopt a different perspective on the problem, based on data fusion. Starting from the hypothesis that data fusion can improve performance

  3. Fusion Canada issue 22

    International Nuclear Information System (INIS)

    1993-10-01

    A short bulletin from the National Fusion Program highlighting in this issue a bi-lateral meeting between Canada and Japan, water and hydrogen detritiation, in-situ tokamak surface analysis, an update of CCFM/TdeV and tritium accounting Industry guidance in Fusion, fast probe for plasma-surface interaction. 4 figs

  4. International fusion research council

    International Nuclear Information System (INIS)

    Belozerov, A.N.

    1977-01-01

    A brief history of the International Fusion Research Council (IFRC) is given and the minutes of the 1976 meeting in Garching are summarized. At the Garching meeting, the IFRC evaluated the quality of papers presented at recent IAEA conferences on plasma physics and controlled thermonuclear research, and made recommendations on the organization and timing of future meetings on nuclear fusion

  5. Fusion Canada issue 15

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-10-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on the 1996 IAEA Fusion Conference site, operations at the Tokamak de Varennes including divertor pumping of impurities and pumping of carbon monoxide and methane, a discussion of the CFFTP and it`s role. 1 fig.

  6. Magnetic Fusion Program Plan

    International Nuclear Information System (INIS)

    1985-02-01

    This Plan reflects the present conditions of the energy situation and is consistent with national priorities for the support of basic and applied research. It is realistic in taking advantage of the technical position that the United States has already established in fusion research to make cost-effective progress toward the development of fusion power as a future energy option

  7. Fusion Canada issue 8

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-08-01

    A short bulletin from the National Fusion Program. Included in this issue are Canada-ITER contributions, NET Fuel Processing Loop, Bilateral Meeting for Canada-Europe, report from Tokamak de Varennes and a report from the University of Toronto on materials research for Fusion Reactors. 3 figs.

  8. Sensor Data Fusion

    DEFF Research Database (Denmark)

    Plascencia, Alfredo; Stepán, Petr

    2006-01-01

    The main contribution of this paper is to present a sensor fusion approach to scene environment mapping as part of a Sensor Data Fusion (SDF) architecture. This approach involves combined sonar array with stereo vision readings.  Sonar readings are interpreted using probability density functions...

  9. Coatings for laser fusion

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.

    1981-01-01

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors

  10. Fusion reactor materials

    International Nuclear Information System (INIS)

    Sethi, V.K.; Scholz, R.; Nolfi, F.V. Jr.; Turner, A.P.L.

    1980-01-01

    Data are given for each of the following areas: (1) effects of irradiation on fusion reactor materials, (2) hydrogen permeation and materials behavior in alloys, (3) carbon coatings for fusion applications, (4) surface damage of TiB 2 coatings under energetic D + and 4 He + irradiations, and (5) neutron dosimetry

  11. The IGNITEX fusion project

    International Nuclear Information System (INIS)

    Carrera, R.

    1987-01-01

    The author discusses the recently proposed fusion ignition experiment, IGNITEX. He emphasizes the basic ideas of this concept rather than the specific details of the physics and engineering aspects of the experiment. This concept is a good example of the importance of maintaining an adequate balance between the basic scientific progress in fusion physics and the new technologies that are becoming available in order to make fusion work. The objective of the IGNITEX project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. Being able to study this not-yet-produced regime of plasma operation is essential to fusion research. Two years after the fission nuclear reaction was discovered, a non-self-sustained fission reaction was produced in a laboratory, and in one more year a self-sustained reaction was achieved at the University of Chicago. However, after almost forty years of fusion research, a self-sustained fusion reaction has yet not been produced in a laboratory experiment. This fact indicates the greater difficulty of the fusion experiment. Because of the difficulty involved in the production of a self-sustained fusion reaction, it is necessary to propose such an experiment with maximum ignition margins, maximum simplicity, and minimum financial risk

  12. Controlled thermonuclear fusion

    CERN Document Server

    Bobin, Jean Louis

    2014-01-01

    The book is a presentation of the basic principles and main achievements in the field of nuclear fusion. It encompasses both magnetic and inertial confinements plus a few exotic mechanisms for nuclear fusion. The state-of-the-art regarding thermonuclear reactions, hot plasmas, tokamaks, laser-driven compression and future reactors is given.

  13. Fusion Power Deployment

    International Nuclear Information System (INIS)

    Schmidt, J.A.; Ogden, J.M.

    2002-01-01

    Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment

  14. Fusion Canada issue 4

    International Nuclear Information System (INIS)

    1988-05-01

    A short bulletin from the National Fusion Program. Included in this issue is a technical update on Tokamak de Varennes, a report on the Beatrix II Breeding Materials Test Program, the Tritium glovebox system for UPM, Saudi Arabia, a broad update of the Canadian Fusion Fuels Technology Project is also included. 1 fig

  15. Fusion Canada issue 12

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-10-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on Darlington`s Tritium Removal Facility, work at universities on Deuterium Diffusivity in Beryllium, Fusion Studies, confinement research and the operation of divertors at Tokamak de Varennes. 5 figs.

  16. Fusion Canada issue 22

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-10-01

    A short bulletin from the National Fusion Program highlighting in this issue a bi-lateral meeting between Canada and Japan, water and hydrogen detritiation, in-situ tokamak surface analysis, an update of CCFM/TdeV and tritium accounting Industry guidance in Fusion, fast probe for plasma-surface interaction. 4 figs.

  17. Fusion Canada issue 4

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-05-01

    A short bulletin from the National Fusion Program. Included in this issue is a technical update on Tokamak de Varennes, a report on the Beatrix II Breeding Materials Test Program, the Tritium glovebox system for UPM, Saudi Arabia, a broad update of the Canadian Fusion Fuels Technology Project is also included. 1 fig.

  18. Fusion Canada issue 19

    International Nuclear Information System (INIS)

    1992-12-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on the IAEA Plasma Biasing Meeting, the new IEA program -Nuclear Technology of Fusion reactors, TFTR tritium purification system, an update by CCFM on machine additions and modifications, and news of a new compact Toroid injector at the University of Saskatchewan. 1 fig

  19. Fusion Canada issue 14

    International Nuclear Information System (INIS)

    1991-05-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on a fusion cooperation agreement between Japan and Canada, an update at Tokamak de Varennes on plasma biasing experiments and boronization tests and a collaboration between Canada and the U.S. on a compact toroid fuelling gun. 4 figs

  20. Fusion Canada issue 12

    International Nuclear Information System (INIS)

    1990-10-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on Darlington's Tritium Removal Facility, work at universities on Deuterium Diffusivity in Beryllium, Fusion Studies, confinement research and the operation of divertors at Tokamak de Varennes. 5 figs

  1. Controlled Nuclear Fusion.

    Science.gov (United States)

    Glasstone, Samuel

    This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature…

  2. Industry's role in inertial fusion

    International Nuclear Information System (INIS)

    Glass, A.J.

    1983-01-01

    This paper is an address to the Tenth Symposium on Fusion Engineering. The speaker first addressed the subject of industry's role in inertial fusion three years earlier in 1980, outlining programs that included participation in the Shiva construction project, and the industrial participants' program set up in the laser fusion program to bring industrial scientists and engineers into the laboratory to work on laser fusion. The speaker is now the president of KMS Fusion, Inc., the primary industrial participant in the inertial fusion program. The outlook for fusion energy and the attitude of the federal government toward the fusion program is discussed

  3. Towards fusion power

    International Nuclear Information System (INIS)

    Venkataraman, G.

    1975-01-01

    An attempt has been made to present general but broad review of the recent developments in the field of plasma physics and its application to fusion power. The first chapter describes the fusion reactions and fusion power systems. The second chapter deals in detail with production and behaviour of plasma, screening, oscillations, instability, energy losses, temperature effects, etc. Magnetic confinements, including pinch systems, toroidal systems such as Tokamac and stellarator, minor machine, etc. are discussed in detail in chapter III. Laser produced plasma, laser implosion and problems associated with it and future prospects are explained in chapter IV. Chapter V is devoted entirely to the various aspects of hybrid systems. The last chapter throws light on problems of fusion technology, such as plasma heating, vacuum requirements, radiation damage, choice of materials, blanket problems, hazards of fusion reactions, etc. (K.B.)

  4. Fusion fuel blanket technology

    International Nuclear Information System (INIS)

    Hastings, I.J.; Gierszewski, P.

    1987-05-01

    The fusion blanket surrounds the burning hydrogen core of a fusion reactor. It is in this blanket that most of the energy released by the nuclear fusion of deuterium-tritium is converted into useful product, and where tritium fuel is produced to enable further operation of the reactor. As fusion research turns from present short-pulse physics experiments to long-burn engineering tests in the 1990's, energy removal and tritium production capabilities become important. This technology will involve new materials, conditions and processes with applications both to fusion and beyond. In this paper, we introduce features of proposed blanket designs and update and status of international research. In focusing on the Canadian blanket technology program, we discuss the aqueous lithium salt blanket concept, and the in-reactor tritium recovery test program

  5. Decomposition of incomplete fusion

    International Nuclear Information System (INIS)

    Sobotka, L.B.; Sarantities, D.G.; Stracener, D.W.; Majka, Z.; Abenante, V.; Semkow, T.M.; Hensley, D.C.; Beene, J.R.; Halbert, M.L.

    1989-01-01

    The velocity distribution of fusion-like products formed in the reaction 701 MeV 28 Si+ 100 Mo is decomposed into 26 incomplete fusion channels. The momentum deficit of the residue per nonevaporative mass unit is approximately equal to the beam momentum per nucleon. The yields of the incomplete fusion channels correlate with the Q-value for projectile fragmentation rather than that for incomplete fusion. The backward angle multiplicities of light particles and heavy ions increase with momentum transfer, however, the heavy ion multiplicities also depend on the extent of the fragmentation of the incomplete fusion channel. These data indicate that at fixed linear momentum transfer, increased fragmentation of the unfused component is related to a reduced transferred angular momentum. 22 refs., 6 figs., 1 tab

  6. Nuclear fusion: The issues

    International Nuclear Information System (INIS)

    Griffin, R.D.

    1993-01-01

    The taming of fusion energy, has proved one of the most elusive quests of modern science. For four decades, the United States has doggedly pursued energy's holy grail, pumping more than $9 billion into research and reactor prototypes. This year, the federal government is slated to spend $339 million on fusion, more than the combined amount the government will spend for research on oil, natural gas, solar power, wind power, geothermal energy, biofuels and conservation. This article summarizes the technical, political in terms of international cooperation, economic, planning, etc. issues surrounding the continued development of fusion as a possible power source for the next century. Brief descriptions of how fusion works and of the design of a tokamak fusion machine are included

  7. Fusion safety data base

    International Nuclear Information System (INIS)

    Laats, E.T.; Hardy, H.A.

    1983-01-01

    The purpose of this Fusion Safety Data Base Program is to provide a repository of data for the design and development of safe commercial fusion reactors. The program is sponsored by the United States Department of Energy (DOE), Office of Fusion Energy. The function of the program is to collect, examine, permanently store, and make available the safety data to the entire US magnetic-fusion energy community. The sources of data will include domestic and foreign fusion reactor safety-related research programs. Any participant in the DOE Program may use the Data Base Program from his terminal through user friendly dialog and can view the contents in the form of text, tables, graphs, or system diagrams

  8. Compact fusion reactors

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  9. Some fusion perspectives

    International Nuclear Information System (INIS)

    McNally, J.R. Jr.

    1977-01-01

    Some of the concepts of nuclear fusion reactions, advanced fusion fuels, environmental impacts, etc., are explored using the following general outline: I. Principles of Fusion (Nuclear Fuels and Reactions, Lawson Condition, n tau vs T, Nuclear Burn Characteristics); II. Magnetic Mirror Possibilities (the Ion Layer and Electron Layer, Exponential Build-up at MeV energies, Lorentz trapping at GeV energies); III. Pellet Fuel Fusion Prospects (Advanced Pellet Fuel Fusion Prospects, Burn Characteristics and Applications, Excitation-heating Prospects for Runaway Ion Temperatures). Inasmuch as the outline is very skeletal, a significant research and development effort may be in order to evaluate these prospects in more detail and hopefully ''harness the H-bomb'' for peaceful applications, the author concludes. 28 references

  10. Investigations of image fusion

    Science.gov (United States)

    Zhang, Zhong

    1999-12-01

    The objective of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a single image which is more suitable for the purpose of human visual perception or further image processing tasks. In this thesis, a region-based fusion algorithm using the wavelet transform is proposed. The identification of important features in each image, such as edges and regions of interest, are used to guide the fusion process. The idea of multiscale grouping is also introduced and a generic image fusion framework based on multiscale decomposition is studied. The framework includes all of the existing multiscale-decomposition- based fusion approaches we found in the literature which did not assume a statistical model for the source images. Comparisons indicate that our framework includes some new approaches which outperform the existing approaches for the cases we consider. Registration must precede our fusion algorithms. So we proposed a hybrid scheme which uses both feature-based and intensity-based methods. The idea of robust estimation of optical flow from time- varying images is employed with a coarse-to-fine multi- resolution approach and feature-based registration to overcome some of the limitations of the intensity-based schemes. Experiments show that this approach is robust and efficient. Assessing image fusion performance in a real application is a complicated issue. In this dissertation, a mixture probability density function model is used in conjunction with the Expectation- Maximization algorithm to model histograms of edge intensity. Some new techniques are proposed for estimating the quality of a noisy image of a natural scene. Such quality measures can be used to guide the fusion. Finally, we study fusion of images obtained from several copies of a new type of camera developed for video surveillance. Our techniques increase the capability and reliability of the surveillance system and provide an easy way to obtain 3-D

  11. US fusion community discussion on fusion strategies

    International Nuclear Information System (INIS)

    Marton, W.A.

    1998-01-01

    On April 26 - May 1, 1998, a US Fusion Community Forum for Major Next-Step Experiments was held at Madison, Wisconsin, USA. Both the Single Integrated Step strategy and the Multiple Machine strategy have substantial support from the about 180 scientists and engineers who participated

  12. Materials for fusion reactors

    International Nuclear Information System (INIS)

    Ehrlich, K.; Kaletta, D.

    1978-03-01

    The following report describes five papers which were given during the IMF seminar series summer 1977. The purpose of this series was to discuss especially the irradiation behaviour of materials intended for the first wall of future fusion reactors. The first paper deals with the basic understanding of plasma physics relating to the fusion reactor and presents the current state of art of fusion technology. The next two talks discuss the metals intended for the first wall and structural components of a fusion reactor. Since 14 MeV neutrons play an important part in the process of irradiation damage their role is discussed in detail. The question which machines are presently available to simulate irradiation damage under conditions similar to the ones found in a fusion reactor are investigated in the fourth talk which also presents the limitations of the different methods of simulation. In this context also discussed is the importance future intensive neutron sources and materials test reactors will have for this problem area. The closing paper has as a theme the review of the present status of research of metallic and non-metallic materials in view of the quite different requirements for different fusion systems; a closing topic is the world supply on rare materials required for fusion reactors. (orig) [de

  13. Fusion research in Hungary

    International Nuclear Information System (INIS)

    Zoletnik, S.

    2004-01-01

    Hungarian fusion research started in the 1970s, when the idea of installing a small tokamak experiment emerged. In return to computer equipment a soviet tokamak was indeed sent to Hungary and started to operate as MT-1 at the Central Research Institute for Physics (KFKI) in 1979. Major research topics included diagnostic development, edge plasma studies and investigation of disruptions. Following a major upgrade in 1992 (new vacuum vessel, active position control and PC network based data acquisition system) the MT-1M tokamak was used for the study of transport processes with trace impurity injection, micropellet ablation studies, X-ray tomography and laser blow-off diagnostic development. Although funding ceased in the middle of the 90's the group was held alive by collaborations with EU fusion labs: FZ -Juelich, IPP-Garching and CRPP-EPFL Lausanne. In 1998 the machine was dismantled due to reorganization of the Hungarian Academy of Sciences. New horizons opened to fusion research from 1999, when Hungary joined EURATOM and a fusion Association was formed. Since then fusion physics studies are done in collaboration with major EU fusion laboratories, Hungarian researchers also play an active role in JET diagnostics upgrade and ITER design. Major topics are pellet ablation studies, plasma turbulence diagnosis using Beam Emission Spectroscopy and other techniques, tomography and plasma diagnostics using various neutral beams. In fusion relevant technology R and D Hungary has less records. Before joining EURATOM some materials irradiation studies were done at the Budapest Research Reactor at KFKI-AEKI. The present day fusion technology programme focuses still on irradiation studies, nuclear material database and electromagnetic testing techniques. Increasing the fusion technology research activities is a difficult task, as the competition in Hungarian industry is very strong and the interest of organizations in long-term investments into R and D is rather weak and

  14. Mirror fusion reactors

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Conceptual design studies were made of fusion reactors based on the three current mirror-confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fuel for fission reactors. We have designed a large commercial hybrid and a small pilot-plant hybrid based on standard mirror confinement. Tandem mirror designs include a commercial 1000-MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single-cell pilot plant

  15. Mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Moir, R.W.

    1978-01-01

    We have carried out conceptual design studies of fusion reactors based on the three current mirror confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fission fuel for fission reactors. We have designed a large commercial hybrid based on standard mirror confinement, and also a small pilot plant hybrid. Tandem mirror designs include a commercial 1000 MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single cell pilot plant

  16. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    Decreton, M.

    2002-01-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed

  17. Remote sensing image fusion

    CERN Document Server

    Alparone, Luciano; Baronti, Stefano; Garzelli, Andrea

    2015-01-01

    A synthesis of more than ten years of experience, Remote Sensing Image Fusion covers methods specifically designed for remote sensing imagery. The authors supply a comprehensive classification system and rigorous mathematical description of advanced and state-of-the-art methods for pansharpening of multispectral images, fusion of hyperspectral and panchromatic images, and fusion of data from heterogeneous sensors such as optical and synthetic aperture radar (SAR) images and integration of thermal and visible/near-infrared images. They also explore new trends of signal/image processing, such as

  18. Beam dancer fusion device

    International Nuclear Information System (INIS)

    Maier, H.B.

    1984-01-01

    To accomplish fusion of two or more fusion fuel elements numerous minute spots of energy or laser light are directed to a micro target area, there to be moved or danced about by a precision mechanical controlling apparatus at the source of the laser light or electromagnetic energy beams, so that merging and coinciding patterns of light or energy beams can occur around the area of the fuel atoms or ions. The projecting of these merging patterns may be considered as target searching techniques to locate responsive clusters of fuel elements and to compress such elements into a condition in which fusion may occur. Computerized programming may be used

  19. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    Decreton, M.

    2001-01-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the behaviour of fusion reactor materials and components during and after irradiation. Ongoing projects include: the study of the mechanical behaviour of structural materials under neutron irradiation; the investigation of the characteristics of irradiated first wall material such as beryllium; the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; and the study of dismantling and waste disposal strategy for fusion reactors. Progress and achievements in these areas in 2000 are discussed

  20. Japanese fusion research

    International Nuclear Information System (INIS)

    Uchida, T.

    1987-01-01

    The Japan experience during thirty years in nuclear fusion research is reported, after attending the 1st Geneva Conference in 1955, Osaka University, immedeately began linear pinch study using capacitor bank discharge. Subsequently to his trial several groups were organized to ward fusion R and D at universities in Tokyo, Nagoya, Kyoto, Sendai and son on. Based upon the recommendation of Japan Science Council, Institut of Plasma Physics (IPP) was established at Nagoya University in 1961 When the 1st International Conference on Plasma Physics and Controlled Nuclear Fusion Research was held in Saltzburg. The gloomy Bohm barrier had stood in front of many of experiments at that time. (author) [pt

  1. Regulation of membrane fusion and secretory events in the sea urchin embryo

    International Nuclear Information System (INIS)

    Roe, J.L.

    1990-01-01

    Membrane fusion and secretory events play a key role in fertilization and early development in the sea urchin embryo. To investigate the mechanism of membrane fusion, the effect of inhibitors of metalloendoprotease activity was studied on two model systems of cell fusion; fertilization and spiculogenesis by primary mesenchyme cells in the embryo. Both the zinc chelator, 1,10-phenanthroline, and peptide metalloprotease substrates were found to inhibit both fertilization and gamete fusion, while peptides that are not substrates of metalloproteases did not affect either process. Primary mesenchyme cells form the larval skeleton in the embryo by deposition of mineral and an organic matrix into a syncytial cavity formed by fusion of filopodia of these cells. Metalloprotease inhibitors were found to inhibit spiculogenesis both in vivo and in cultures of isolated primary mesenchyme cells, and the activity of a metalloprotease of the appropriate specificity was found in the primary mesenchyme cells. These two studies implicate the activity of a metalloprotease in a necessary step in membrane fusion. Following fertilization, exocytosis of the cortical granules results in the formation of the fertilization envelope and the hyaline layer, that surround the developing embryo. The hatching enzyme is secreted by the blastula stage sea urchin embryo, which proteolyzes the fertilization envelope surrounding the embryo, allowing the embryo to hatch. Using an assay that measures 125 I-fertilization envelope degradation, the hatching enzyme was identified as a 33 kDa metalloprotease, and was purified by ion-exchange and affinity chromatography from the hatching media of Strongylocentrotus purpuratus embryos. The hatching enzyme showed a substrate preference for only a minor subset of fertilization envelope proteins

  2. Inertial thermonuclear fusion by laser

    International Nuclear Information System (INIS)

    Watteau, J.P.

    1993-12-01

    The principles of deuterium tritium (DT) magnetic or inertial thermonuclear fusion are given. Even if results would be better with heavy ions beams, most of the results on fusion are obtained with laser beams. Technical and theoretical aspects of the laser fusion are presented with an extrapolation to the future fusion reactor. (A.B.). 34 refs., 17 figs

  3. Inertial fusion commercial power plants

    International Nuclear Information System (INIS)

    Logan, B.G.

    1994-01-01

    This presentation discusses the motivation for inertial fusion energy, a brief synopsis of five recently-completed inertial fusion power plant designs, some general conclusions drawn from these studies, and an example of an IFE hydrogen synfuel plant to suggest that future fusion studies consider broadening fusion use to low-emission fuels production as well as electricity

  4. Why and how of fusion

    International Nuclear Information System (INIS)

    Miley, G.H.

    1977-01-01

    The potential advantages of fusion power are listed. The approaches to plasma containment are mentioned and the status of the fusion program is described. The ERDA and EPRI programs are discussed. The Fusion Energy Foundation's activities are mentioned. Fusion research at the U. of Ill. is described briefly

  5. The specification and global reprogramming of histone epigenetic marks during gamete formation and early embryo development in C. elegans.

    Directory of Open Access Journals (Sweden)

    Mark Samson

    2014-10-01

    Full Text Available In addition to the DNA contributed by sperm and oocytes, embryos receive parent-specific epigenetic information that can include histone variants, histone post-translational modifications (PTMs, and DNA methylation. However, a global view of how such marks are erased or retained during gamete formation and reprogrammed after fertilization is lacking. To focus on features conveyed by histones, we conducted a large-scale proteomic identification of histone variants and PTMs in sperm and mixed-stage embryo chromatin from C. elegans, a species that lacks conserved DNA methylation pathways. The fate of these histone marks was then tracked using immunostaining. Proteomic analysis found that sperm harbor ∼2.4 fold lower levels of histone PTMs than embryos and revealed differences in classes of PTMs between sperm and embryos. Sperm chromatin repackaging involves the incorporation of the sperm-specific histone H2A variant HTAS-1, a widespread erasure of histone acetylation, and the retention of histone methylation at sites that mark the transcriptional history of chromatin domains during spermatogenesis. After fertilization, we show HTAS-1 and 6 histone PTM marks distinguish sperm and oocyte chromatin in the new embryo and characterize distinct paternal and maternal histone remodeling events during the oocyte-to-embryo transition. These include the exchange of histone H2A that is marked by ubiquitination, retention of HTAS-1, removal of the H2A variant HTZ-1, and differential reprogramming of histone PTMs. This work identifies novel and conserved features of paternal chromatin that are specified during spermatogenesis and processed in the embryo. Furthermore, our results show that different species, even those with diverged DNA packaging and imprinting strategies, use conserved histone modification and removal mechanisms to reprogram epigenetic information.

  6. Fusion in the energy system

    DEFF Research Database (Denmark)

    Fusion energy is the fundamental energy source of the Universe, as the energy of the Sun and the stars are produced by fusion of e.g. hydrogen to helium. Fusion energy research is a strongly international endeavor aiming at realizing fusion energy production in power plants on Earth. Reaching...... of integration into the future electricity system and socio-economic studies of fusion energy will be presented, referring to the programme of Socio-Economic Research on Fusion (SERF) under the European Fusion Energy Agreement (EFDA)....

  7. Fusion-power demonstration

    International Nuclear Information System (INIS)

    Henning, C.D.; Logan, B.G.; Carlson, G.A.; Neef, W.S.; Moir, R.W.; Campbell, R.B.; Botwin, R.; Clarkson, I.R.; Carpenter, T.J.

    1983-01-01

    As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment

  8. International aspects of fusion

    International Nuclear Information System (INIS)

    Stacey, W.M. Jr.

    1979-12-01

    International collaborative efforts in magnetic confinement fusion in which the USA is involved are reviewed. These efforts are carried under the auspices of international agencies and through bilateral agreements

  9. Magnetic fusion energy

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The efforts of the Chemical Technology Division in the area of fusion energy include fuel handling, processing, and containment. These studies are closely coordinated with the ORNL Fusion Energy Division. Current experimental studies are concerned with the development of vacuum pumps for fusion reactors, the evaluation and development of techniques for recovering tritium (fuel) from either solid or liquid lithium containing blankets, and the use of deep beds of sorbents as roughing pumps and/or transfer operations. In addition, a small effort is devoted to the support of the ORNL design of The Next Step (TNS) in tokamak reactor development. The more applied studies--vacuum pump development and TNS design--are funded by the DOE/Magnetic Fusion Energy, and the more fundamental studies--blanket recovery and sorption in deep beds--are funded by the DOE/Basic Energy Sciences

  10. Fusion technology programme

    International Nuclear Information System (INIS)

    Finken, D.

    1984-04-01

    KfK participates to the Fusion Technology Programme of the European Community. Most of the work in progress addresses the Next European Torus (NET) and the long term technology aspects as defined in the 82/86 programme. A minor part serves to preparation of future contributions and to design studies on fusion concepts in a wider perspective. The Fusion Technology Programme of Euratom covers mainly aspects of nuclear engineering. Plasma engineering, heating, refueling and vacuum technology are at present part of the Physics Programme. In view of NET, integration of the different areas of work will be mandatory. KfK is therefore prepared to address technical aspects beyond the actual scope of the physics experiments. The technology tasks are reported project wise under title and code of the Euratom programme. Most of the projects described here are shared with other European fusion laboratories as indicated in the table annexed to this report. (orig./GG)

  11. Fusion-breeder program

    International Nuclear Information System (INIS)

    Moir, R.W.

    1982-01-01

    The various approaches to a combined fusion-fission reactor for the purpose of breeding 239 Pu and 233 U are described. Design aspects and cost estimates for fuel production and electricity generation are discussed

  12. Cold nuclear fusion device

    International Nuclear Information System (INIS)

    Ogino, Shinji.

    1991-01-01

    Selection of cathode material is a key to the attainment of cold nuclear fusion. However, there are only few reports on the cathode material at present and an effective development has been demanded. The device comprises an anode and a cathode and an electrolytic bath having metal salts dissolved therein and containing heavy water in a glass container. The anode is made of gold or platinum and the cathode is made of metals of V, Sr, Y, Nb, Hf or Ta, and a voltage of 3-25V is applied by way of a DC power source between them. The metal comprising V, Sr, Y, Nb, Hf or Ta absorbs deuterium formed by electrolysis of heavy water effectively to cause nuclear fusion reaction at substantially the same frequency and energy efficiency as palladium and titanium. Accordingly, a cold nuclear fusion device having high nuclear fusion generation frequency can be obtained. (N.H.)

  13. Cell fusions in mammals

    DEFF Research Database (Denmark)

    Larsson, Lars-Inge; Bjerregaard, Bolette; Talts, Jan Fredrik

    2008-01-01

    Cell fusions are important to fertilization, placentation, development of skeletal muscle and bone, calcium homeostasis and the immune defense system. Additionally, cell fusions participate in tissue repair and may be important to cancer development and progression. A large number of factors appear...... to regulate cell fusions, including receptors and ligands, membrane domain organizing proteins, proteases, signaling molecules and fusogenic proteins forming alpha-helical bundles that bring membranes close together. The syncytin family of proteins represent true fusogens and the founding member, syncytin-1......, has been documented to be involved in fusions between placental trophoblasts, between cancer cells and between cancer cells and host ells. We review the literature with emphasis on the syncytin family and propose that syncytins may represent universal fusogens in primates and rodents, which work...

  14. Fusion Canada issue 11

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-06-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on operation at Tokamak de Varennes, CRITIC irradiations at AECL, Tritium systems at TFTR, physics contribution at ITER. 4 figs.

  15. Fusion technology (FT)

    International Nuclear Information System (INIS)

    1978-01-01

    The annual report of tha fusion technology (FT) working group discusses the projects carried out by the participating institutes in the fields of 1) fuel injection and plasma heating, 2) magnetic field technology, and 3) systems investigations. (HK) [de

  16. Fusion technology development

    International Nuclear Information System (INIS)

    1979-08-01

    This report includes information on the following chapters: (1) conceptual design studies, (2) magnetics, (3) plasma heating, fueling, and exhaust, (4) materials for fusion reactors, (5) alternate applications, and (6) environment and safety

  17. Fusion reactor materials

    International Nuclear Information System (INIS)

    Rowcliffe, A.F.; Burn, G.L.; Knee', S.S.; Dowker, C.L.

    1994-02-01

    This is the fifteenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; Special purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the U.S. Department of Energy. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide

  18. Fusion cost normalization

    International Nuclear Information System (INIS)

    Schulte, S.C.; Willke, T.L.

    1978-01-01

    The categorization and accounting methods described in this paper provide a common format that can be used to assess the economic character of magnetically confined fusion reactor design concepts. The format was developed with assistance from the fusion economics community, thus ensuring that the methods meet with the approval of potential users. The format will aid designers in the preparation of design concept cost estimates and also provide policy makers with a tool to assist in appraising which design concepts may be economically promising. Adherence to the format when evaluating prospective fusion reactor design concepts will result in the identification of the more promising concepts, thus enabling the fusion power alternatives with better economic potential to be quickly and efficiently developed

  19. Complimentary Advanced Fusion Exploration

    National Research Council Canada - National Science Library

    Alford, Mark G; Jones, Eric C; Bubalo, Adnan; Neumann, Melissa; Greer, Michael J

    2005-01-01

    .... The focus areas were in the following regimes: multi-tensor homographic computer vision image fusion, out-of-sequence measurement and track data handling, Nash bargaining approaches to sensor management, pursuit-evasion game theoretic modeling...

  20. Fusion plasma physics

    CERN Document Server

    Stacey, Weston M

    2012-01-01

    This revised and enlarged second edition of the popular textbook and reference contains comprehensive treatments of both the established foundations of magnetic fusion plasma physics and of the newly developing areas of active research. It concludes with a look ahead to fusion power reactors of the future. The well-established topics of fusion plasma physics -- basic plasma phenomena, Coulomb scattering, drifts of charged particles in magnetic and electric fields, plasma confinement by magnetic fields, kinetic and fluid collective plasma theories, plasma equilibria and flux surface geometry, plasma waves and instabilities, classical and neoclassical transport, plasma-materials interactions, radiation, etc. -- are fully developed from first principles through to the computational models employed in modern plasma physics. The new and emerging topics of fusion plasma physics research -- fluctuation-driven plasma transport and gyrokinetic/gyrofluid computational methodology, the physics of the divertor, neutral ...

  1. Fusion power demonstration

    International Nuclear Information System (INIS)

    Henning, C.D.; Logan, B.G.

    1983-01-01

    As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment

  2. Optical Fiber Fusion Splicing

    CERN Document Server

    Yablon, Andrew D

    2005-01-01

    This book is an up-to-date treatment of optical fiber fusion splicing incorporating all the recent innovations in the field. It provides a toolbox of general strategies and specific techniques that the reader can apply when optimizing fusion splices between novel fibers. It specifically addresses considerations important for fusion splicing of contemporary specialty fibers including dispersion compensating fiber, erbium-doped gain fiber, polarization maintaining fiber, and microstructured fiber. Finally, it discusses the future of optical fiber fusion splicing including silica and non-silica based optical fibers as well as the trend toward increasing automation. Whilst serving as a self-contained reference work, abundant citations from the technical literature will enable readers to readily locate primary sources.

  3. Controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Sakanaka, P.H.

    1984-01-01

    A simplified review on the status of the controlled thermonuclear fusion research aiming to present the motivation, objective, necessary conditions and adopted methods to reach the objective. (M.C.K.) [pt

  4. Fusion safety program plan

    International Nuclear Information System (INIS)

    Crocker, J.G.; Holland, D.F.; Herring, J.S.

    1980-09-01

    The program plan consists of research that has been divided into 13 different areas. These areas focus on the radioactive inventories that are expected in fusion reactors, the energy sources potentially available to release a portion of these inventories, and analysis and design techniques to assess and ensure that the safety risks associated with operation of magnetic fusion facilities are acceptably low. The document presents both long-term program requirements that must be fulfilled as part of the commercialization of fusion power and a five-year plan for each of the 13 different program areas. Also presented is a general discussion of magnetic fusion reactor safety, a method for establishing priorities in the program, and specific priority ratings for each task in the five-year plan

  5. Fusion Revisits CERN

    CERN Multimedia

    2001-01-01

    It's going to be a hot summer at CERN. At least in the Main Building, where from 13 July to 20 August an exhibition is being hosted on nuclear fusion, the energy of the Stars. Nuclear fusion is the engine driving the stars but also a potential source of energy for mankind. The exhibition shows the different nuclear fusion techniques and research carried out on the subject in Europe. Inaugurated at CERN in 1993, following collaboration between Lausanne's CRPP-EPFL and CERN, with input from Alessandro Pascolini of Italy's INFN, this exhibition has travelled round Europe before being revamped and returning to CERN. 'Fusion, Energy of the Stars', from 13 July onwards, Main Building

  6. Fusion Simulation Program

    International Nuclear Information System (INIS)

    Greenwald, Martin

    2011-01-01

    Many others in the fusion energy and advanced scientific computing communities participated in the development of this plan. The core planning team is grateful for their important contributions. This summary is meant as a quick overview the Fusion Simulation Program's (FSP's) purpose and intentions. There are several additional documents referenced within this one and all are supplemental or flow down from this Program Plan. The overall science goal of the DOE Office of Fusion Energy Sciences (FES) Fusion Simulation Program (FSP) is to develop predictive simulation capability for magnetically confined fusion plasmas at an unprecedented level of integration and fidelity. This will directly support and enable effective U.S. participation in International Thermonuclear Experimental Reactor (ITER) research and the overall mission of delivering practical fusion energy. The FSP will address a rich set of scientific issues together with experimental programs, producing validated integrated physics results. This is very well aligned with the mission of the ITER Organization to coordinate with its members the integrated modeling and control of fusion plasmas, including benchmarking and validation activities. (1). Initial FSP research will focus on two critical Integrated Science Application (ISA) areas: ISA1, the plasma edge; and ISA2, whole device modeling (WDM) including disruption avoidance. The first of these problems involves the narrow plasma boundary layer and its complex interactions with the plasma core and the surrounding material wall. The second requires development of a computationally tractable, but comprehensive model that describes all equilibrium and dynamic processes at a sufficient level of detail to provide useful prediction of the temporal evolution of fusion plasma experiments. The initial driver for the whole device model will be prediction and avoidance of discharge-terminating disruptions, especially at high performance, which are a critical

  7. The fusion dilemma

    International Nuclear Information System (INIS)

    Carruthers, R.

    1981-01-01

    The present position in fusion research is reviewed and discussed with relation to the requirements of an economic reactor. Meeting these requirements calls for a mission-oriented project of interdisciplinary character whose timely evolution from one with a research orientation, is a challenging management problem. The cost-effectiveness of future expenditure on fusion research is dependent upon acknowledging this challenge and realistically facing the difficult tasks which it presents. (U.K.)

  8. Possible fusion reactor

    International Nuclear Information System (INIS)

    Yoshikawa, S.

    1976-05-01

    A scheme to improve performance characteristics of a tokamak-type fusion reactor is proposed. Basically, the tokamak-type plasma could be moved around so that the plasma could be heated by compression, brought to the region where the blanket surrounds the plasma, and moved so as to keep wall loading below the acceptable limit. This idea should be able to help to economize a fusion reactor

  9. Fusion power plant economics

    International Nuclear Information System (INIS)

    Miller, R.L.

    1996-01-01

    The rationale, methodology, and updated comparative results of cost projections for magnetic-fusion-energy central-station electric power plants are considered. Changing market and regulatory conditions, particularly in the U.S., prompt fundamental reconsideration of what constitutes a competitive future energy-source technology and has implications for the direction and emphasis of appropriate near-term research and development programs, for fusion and other advanced generation systems. 36 refs., 2 figs., 2 tabs

  10. Sonoluminescence and bubble fusion

    OpenAIRE

    Arakeri, Vijay H

    2003-01-01

    Sonoluminescence (SL), the phenomenon of light emission from nonlinear motion of a gas bubble, involves an extreme degree of energy focusing. The conditions within the bubble during the last stages of the nearly catastrophic implosion are thought to parallel the efforts aimed at developing inertial confinement fusion. A limited review on the topic of SL and its possible connection to bubble nuclear fusion is presented here. The emphasis is on looking for a link between the various forms o...

  11. Fusion reactor materials

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The following topics are briefly discussed: (1) surface blistering studies on fusion reactor materials, (2) TFTR design support activities, (3) analysis of samples bombarded in-situ in PLT, (4) chemical sputtering effects, (5) modeling of surface behavior, (6) ion migration in glow discharge tube cathodes, (7) alloy development for irradiation performance, (8) dosimetry and damage analysis, and (9) development of tritium migration in fusion devices and reactors

  12. Bringing together fusion research

    International Nuclear Information System (INIS)

    Leiser, M.

    1982-01-01

    The increasing involvement of the IAEA in fusion, together with the growing efforts devoted to this area, are described. The author puts forward the idea that one of the most important aspects of this involvement is in providing a world-wide forum for scientists. The functions of the IFRC (International Fusion Research Council) as an advisory group are outlined, and the role played by IFRC in the definition and objectives of INTOR (International Tokamak Reactor) are briefly described

  13. Fusion Canada issue 13

    International Nuclear Information System (INIS)

    1991-01-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on Canada's plans to participate in the Engineering Design Activities (EDA), bilateral meetings with Canada and the U.S., committee meeting with Canada-Europe, an update at Tokamak de Varennes on Plasma Biasing experiments and boronized graphite tests, fusion materials research at the University of Toronto using a dual beam accelerator and a review of the CFFTP and the CCFM. 2 figs

  14. Conference on Norwegian fusion research

    International Nuclear Information System (INIS)

    The question of instituting a systematic research programme in Norway on aspects of thermonuclear and plasma physics has been raised. The conference here reported was intended to provide basic information on the status of fusion research internationally and to discuss a possible Norwegian programme. The main contributions covered the present status of fusion research, international cooperation, fusion research in small countries and minor laboratories, fusion research in Denmark and Sweden, and a proposed fusion experiment in Bergen. (JIW)

  15. Status of fusion technology

    International Nuclear Information System (INIS)

    Mohan, Ashok

    1978-01-01

    The current status of fusion technology is surveyed. Limited reserves of fossil fuel and dangers of proliferation from nuclear reactors have brought into focus the need to develop an optional energy source. Fusion is being looked upon as an optional energy source which is free from environmental hazards unlike fossil fuels and nuclear reactors. Investments in R and D of fusion energy have increased rapidly in USA, Japan, USSR and European countries. Out of the various fusion fuels known, a mixture of D and T is widely chosen. The main problem in fusion technology is the confinement of plasma for a time sufficient to start the fusion reaction. This can be done magnetically or inertially. The three approaches to magnetic confinement are : (1) tokamak, (2) mirror and (3) pinch. Inertial confinement makes use of lasers or electron beams or ion beams. Both the methods of confinement i.e. magnetic and inertial have problems which are identified and their nature is discussed. (M.G.B.)

  16. Energy from inertial fusion

    International Nuclear Information System (INIS)

    1995-03-01

    This book contains 22 articles on inertial fusion energy (IFE) research and development written in the framework of an international collaboration of authors under the guidance of an advisory group on inertial fusion energy set up in 1991 to advise the IAEA. It describes the actual scientific, engineering and technological developments in the field of inertial confinement fusion (ICF). It also identifies ways in which international co-operation in ICF could be stimulated. The book is intended for a large audience and provides an introduction to inertial fusion energy and an overview of the various technologies needed for IFE power plants to be developed. It contains chapters on (i) the fundamentals of IFE; (ii) inertial confinement target physics; (iii) IFE power plant design principles (requirements for power plant drivers, solid state laser drivers, gas laser drivers, heavy ion drivers, and light ion drivers, target fabrication and positioning, reaction chamber systems, power generation and conditioning and radiation control, materials management and target materials recovery), (iv) special design issues (radiation damage in structural materials, induced radioactivity, laser driver- reaction chamber interfaces, ion beam driver-reaction chamber interfaces), (v) inertial fusion energy development strategy, (vi) safety and environmental impact, (vii) economics and other figures of merit; (viii) other uses of inertial fusion (both those involving and not involving implosions); and (ix) international activities. Refs, figs and tabs

  17. Perspectives of fusion power

    International Nuclear Information System (INIS)

    Jensen, V.O.

    1984-01-01

    New and practically inexhaustible sources of energy must be developed for the period when oil, coal and uranium will become scarce and expensive. Nuclear fusion holds great promise as one of these practically inexhaustible energy sources. Based on the deuteriumtritium reaction with tritium obtained from naturally occuring lithium, which is also widely available in Europe, the accessible energy resources in the world are 3.10 12 to 3.10 16 toe; based on the deuterium-deuterium reaction, the deuterium content of the oceans corresponds to 10 20 toe. It is presently envisaged that in order to establish fusion as a large-scale energy source, three major thresholds must be reached: - Scientific feasibility, - Technical feasibility, i.e. the proof that the basic technical problems of the fusion reactor can be solved. - Commercial feasibility, i.e. proof that fusion power reactors can be built on an industrial scale, can be operated reliably and produce usable energy at prices competitive with other energy sources. From the above it is clear that the route to commercial fusion will be long and costly and involve the solution of extremely difficult technical problems. In view of the many steps which have to be taken, it appears unlikely that commercial fusion power will be in general use within the next 50 years and by that time world-wide expenditure on research, development and demonstration may well have exceeded 100 Bio ECU. (author)

  18. Controlled thermonuclear fusion: research on magnetic fusion

    International Nuclear Information System (INIS)

    Paris, P.J.

    1988-12-01

    Recent progress in thermonuclear fusion research indicates that the scientists' schedule for the demonstration of the scientific feasibility will be kept and that break-even will be attained in the course of the next decade. To see the implementation of ignition, however, the generation of future experiments must be awaited. These projects are currently under study. With technological research going on in parallel, they should at the same time contribute to the design of a reactor. Fusion reactors will be quite different from the fission nuclear reactors we know, and the waste of the plants will also be of a different nature. It is still too early to define the precise design of a fusion reactor. On the basis of a toric machine concept like that of the tokamak, we can, however, envisage that the problems with which we are confronted will be solved one after the other. As we have just seen, these will be the objectives of the future experimental installations where ignition will be possible and where the flux of fast neutrons will be so strong that they will allow the study of low-activation materials which will be used in the structure of the reactor. But this is also a task in which from now onwards numerous laboratories in Europe and in the world participate. The works are in fact punctiform, and often the mutual incidences can only be determined by an approach simulated by numerical codes. (author) 19 figs., 6 tabs., 8 refs

  19. Advanced fusion reactor

    International Nuclear Information System (INIS)

    Tomita, Yukihiro

    2003-01-01

    The main subjects on fusion research are now on D-T fueled fusion, mainly due to its high fusion reaction rate. However, many issues are still remained on the wall loading by the 14 MeV neutrons. In the case of D-D fueled fusion, the neutron wall loading is still remained, though the technology related to tritium breeding is not needed. The p- 6 Li and p- 11 B fueled fusions are not estimated to be the next generation candidate until the innovated plasma confinement technologies come in useful to achieve the high performance plasma parameters. The fusion reactor of D- 3 He fuels has merits on the smaller neutron wall loading and tritium handling. However, there are difficulties on achieving the high temperature plasma more than 100 keV. Furthermore the high beta plasma is needed to decrease synchrotron radiation loss. In addition, the efficiency of the direct energy conversion from protons coming out from fusion reaction is one of the key parameters in keeping overall power balance. Therefore, open magnetic filed lines should surround the plasma column. In this paper, we outlined the design of the commercial base reactor (ARTEMIS) of 1 GW electric output power configured by D- 3 He fueled FRC (Field Reversed Configuration). The ARTEMIS needs 64 kg of 3 He per a year. On the other hand, 1 million tons of 3 He is estimated to be in the moon. The 3 He of about 10 23 kg are to exist in gaseous planets such as Jupiter and Saturn. (Y. Tanaka)

  20. Ion beam inertial fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1995-01-01

    About twenty years ago, A. W. Maschke of Brookhaven National Laboratory and R. L. Martin of Argonne National Laboratory recognized that the accelerators that have been developed for high energy and nuclear physics are, in many ways, ideally suited to the requirements of inertial fusion power production. These accelerators are reliable, they have a long operating life, and they can be efficient. Maschke and Martin noted that they can focus ion beams to small focal spots over distances of many meters and that they can readily operate at the high pulse repetition rates needed for commercial power production. Fusion, however, does impose some important new constraints that are not important for high energy or nuclear physics applications. The most challenging new constraint from a scientific standpoint is the requirement that the accelerator deliver more than 10 14 W of beam power to a small quantity (less than 100 mg) of matter. The most challenging constraint from an engineering standpoint is accelerator cost. Maschke showed theoretically that accelerators could produce adequate work. Heavy-ion fusion is widely recognized to be a promising approach to inertial fusion power production. It provides an excellent opportunity to apply methods and technology developed for basic science to an important societal need. The pulsed-power community has developed a complementary, parallel approach to ion beam fusion known as light-ion fusion. The talk will discuss both heavy-ion and light-ion fusion. It will explain target physics requirements and show how they lead to constraints on the usual accelerator parameters such as kinetic energy, current, and emittance. The talk will discuss experiments that are presently underway, specifically experiments on high-current ion sources and injectors, pulsed-power machines recirculating induction accelerators, and transverse beam combining. The talk will give a brief description of a proposed new accelerator called Elise

  1. Fusion Canada issue 29

    International Nuclear Information System (INIS)

    1995-10-01

    A short bulletin from the National Fusion Program highlighting in this issue Canada-Europe Accords: 5 year R and D collaboration for the International Thermonuclear Experimental Reactor (ITER) AECL is designated to arrange and implement the Memorandum of Understanding (MOU) and the ITER Engineering Design Activities (EDA) while EUROTAM is responsible for operating Europe's Fusion R and D programs plus MOU and EDA. The MOU includes tokamaks, plasma physics, fusion technology, fusion fuels and other approaches to fusion energy (as alternatives to tokamaks). STOR-M Tokamak was restarted at the University of Saskatchewan following upgrades to the plasma chamber to accommodate the Compact Toroid (CT) injector. The CT injector has a flexible attachment thus allowing for injection angle adjustments. Real-time video images of a single plasma discharge on TdeV showing that as the plasma density increases, in a linear ramp divertor, the plasma contact with the horizontal plate decreases while contact increases with the oblique plate. Damage-resistant diffractive optical elements (DOE) have been developed for Inertial Confinement Fusion (ICF) research by Gentac Inc. and the National Optics Institute, laser beam homogeniser and laser harmonic separator DOE can also be made using the same technology. Studies using TdeV indicate that a divertor will be able to pump helium from the tokamak with a detached-plasma divertor but helium extraction performance must first be improved, presently the deuterium:helium retention radio-indicates that in order to pump enough helium through a fusion reactor, too much deuterium-tritium fuel would be pumped out. 2 fig

  2. Advanced fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Yukihiro [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2003-04-01

    The main subjects on fusion research are now on D-T fueled fusion, mainly due to its high fusion reaction rate. However, many issues are still remained on the wall loading by the 14 MeV neutrons. In the case of D-D fueled fusion, the neutron wall loading is still remained, though the technology related to tritium breeding is not needed. The p-{sup 6}Li and p-{sup 11}B fueled fusions are not estimated to be the next generation candidate until the innovated plasma confinement technologies come in useful to achieve the high performance plasma parameters. The fusion reactor of D-{sup 3}He fuels has merits on the smaller neutron wall loading and tritium handling. However, there are difficulties on achieving the high temperature plasma more than 100 keV. Furthermore the high beta plasma is needed to decrease synchrotron radiation loss. In addition, the efficiency of the direct energy conversion from protons coming out from fusion reaction is one of the key parameters in keeping overall power balance. Therefore, open magnetic filed lines should surround the plasma column. In this paper, we outlined the design of the commercial base reactor (ARTEMIS) of 1 GW electric output power configured by D-{sup 3}He fueled FRC (Field Reversed Configuration). The ARTEMIS needs 64 kg of {sup 3}He per a year. On the other hand, 1 million tons of {sup 3}He is estimated to be in the moon. The {sup 3}He of about 10{sup 23} kg are to exist in gaseous planets such as Jupiter and Saturn. (Y. Tanaka)

  3. [Case Reports] Successful pregnancy foilowing gamete intrafallopian transfer in a patient with a transverse vaginal septum: case report

    OpenAIRE

    Ami, Kazumi; Tsuji, Isao; Watanabe, Yo; Fujinami, Nahoko; Miyazaki, Ayako; Hoshiai, Hiroshi

    2010-01-01

    [Abstract] Transverse vaginal septa (TVSs) are rare congenital, obstructive vaginal anomalies resulting from a defect of vertical fusion during embryogenesis of the vagina and are generally diagnosed at the time of pregnancy in association with obstetric complications. TVSs also contribute to infertility. Surgical treatment, such as resection or fenestration of the TVS, is generally indicated. However, the optimal treatment of infertile patients with TVS has not been established, and few case...

  4. Multiple and asymmetrical origin of polyploid dog rose hybrids (Rosa L. sect. Caninae (DC.) Ser.) involving unreduced gametes.

    Science.gov (United States)

    Herklotz, V; Ritz, C M

    2017-08-01

    Polyploidy and hybridization are important factors for generating diversity in plants. The species-rich dog roses ( Rosa sect. Caninae ) originated by allopolyploidy and are characterized by unbalanced meiosis producing polyploid egg cells (usually 4 x ) and haploid sperm cells (1 x ). In extant natural stands species hybridize spontaneously, but the extent of natural hybridization is unknown. The aim of the study was to document the frequency of reciprocal hybridization between the subsections Rubigineae and Caninae with special reference to the contribution of unreduced egg cells (5 x ) producing 6 x offspring after fertilization with reduced (1 x ) sperm cells. We tested whether hybrids arose by independent multiple events or via a single or few incidences followed by a subsequent spread of hybrids. Population genetics of 45 mixed stands of dog roses across central and south-eastern Europe were analysed using microsatellite markers and flow cytometry. Hybrids were recognized by the presence of diagnostic alleles and multivariate statistics were used to display the relationships between parental species and hybrids. Among plants classified to subsect. Rubigineae , 32 % hybridogenic individuals were detected but only 8 % hybrids were found in plants assigned to subsect. Caninae . This bias between reciprocal crossings was accompanied by a higher ploidy level in Rubigineae hybrids, which originated more frequently by unreduced egg cells. Genetic patterns of hybrids were strongly geographically structured, supporting their independent origin. The biased crossing barriers between subsections are explained by the facilitated production of unreduced gametes in subsect. Rubigineae . Unreduced egg cells probably provide the highly homologous chromosome sets required for correct chromosome pairing in hybrids. Furthermore, the higher frequency of Rubigineae hybrids is probably influenced by abundance effects because the plants of subsect. Caninae are much more abundant

  5. Myoblast fusion in Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Haralalka, Shruti [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Abmayr, Susan M., E-mail: sma@stowers.org [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, MO 66160 (United States)

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  6. Fusion, magnetic confinement

    International Nuclear Information System (INIS)

    Berk, H.L.

    1992-01-01

    An overview is presented of the principles of magnetic confinement of plasmas for the purpose of achieving controlled fusion conditions. Sec. 1 discusses the different nuclear fusion reactions which can be exploited in prospective fusion reactors and explains why special technologies need to be developed for the supply of tritium or 3 He, the probable fuels. In Sec. 2 the Lawson condition, a criterion that is a measure of the quality of confinement relative to achieving fusion conditions, is explained. In Sec. 3 fluid equations are used to describe plasma confinement. Specific confinement configurations are considered. In Sec. 4 the orbits of particle sin magneti and electric fields are discussed. In Sec. 5 stability considerations are discussed. It is noted that confinement systems usually need to satisfy stability constraints imposed by ideal magnetohydrodynamic (MHD) theory. The paper culminates with a summary of experimental progress in magnetic confinement. Present experiments in tokamaks have reached the point that the conditions necessary to achieve fusion are being satisfied

  7. Fusion technology programme

    International Nuclear Information System (INIS)

    Finken, D.

    1986-05-01

    In 1982, KfK joined the fusion programme of EURATOM as a further association introducing its experience in nuclear technology. KfK closely cooperates with IPP Garching, the two institutions forming a research unit aiming at planning and realization of future development steps of fusion. KfK has combined its forces in the Nuclear Fusion Project (PKF) with participation of several KfK departments to the project tasks. Previous work of KfK in magnetic fusion has addressed mainly superconducting magnets, plasma heating by cluster ions and studies on structural materials. At present, emphasis of our work has concentrated increasingly on the nuclear part, i.e. the first wall and blanket structures and the elements of the tritium extraction and purification system. Associated to this component development are studies of remote maintenance and safety. Most of the actual work addresses NET, the next step to a demonstration of fusion feasibility. NET is supposed to follow JET, the operating plasma physics experiment of Euratom, on the 1990's. Detailed progress of the work in the past half year is described in this report. (orig./GG)

  8. Challenges of nuclear fusion

    International Nuclear Information System (INIS)

    Kunkel, W.B.

    1987-01-01

    After 30 years of research and development in many countries, the magnetic confinement fusion experiments finally seem to be getting close to the original first goal: the point of ''scientific break-even''. Plans are being made for a generation of experiments and tests with actual controlled thermonuclear fusion conditions. Therefore engineers and material scientists are hard at work to develop the required technology. In this paper the principal elements of a generic fusion reactor are described briefly to introduce the reader to the nature of the problems at hand. The main portion of the presentation summarises the recent advances made in this field and discusses the major issues that still need to be addressed in regard to materials and technology for fusion power. Specific examples are the problems of the first wall and other components that come into direct contact with the plasma, where both lifetime and plasma contamination are matters of concern. Equally challenging are the demands on structural materials and on the magnetic-field coils, particularly in connection with the neutron-radiation environment of fusion reactors. Finally, the role of ceramics must be considered, both for insulators and for fuel breeding purposes. It is evident that we still have a formidable task before us, but at this point none of the problems seem to be insoluble. (author)

  9. The need for fusion

    International Nuclear Information System (INIS)

    Llewellyn Smith, Chris

    2005-01-01

    World energy use is predicted to double in the next 40 years. Currently 80% is provided by burning fossil fuels, but this is not sustainable indefinitely because (i) it is driving climate change, and (ii) fossil fuels will eventually be exhausted (starting with oil). The resulting potential energy crisis requires increased investment in energy research and development (which is currently very small on the scale of the $3 trillion p.a. energy market, and falling). The wide portfolio of energy work that should be supported must include fusion, which is one of the very few options that are capable in principle of supplying a large fraction of need. The case for fusion has been strengthened by recent advances in plasma physics and fusion technology that are reflected in the forthcoming European Fusion Power Plant Conceptual Study, which addresses safety and cost issues. The big questions are - How can we deliver fusion power as fast as possible? How long is it likely to take? I argue for a fast track programme, and describe a fast-track model developed at Culham, which is intended to stimulate debate on the way ahead and the resources that are needed

  10. Myoblast fusion in Drosophila

    International Nuclear Information System (INIS)

    Haralalka, Shruti; Abmayr, Susan M.

    2010-01-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  11. Material for fusion reactor

    International Nuclear Information System (INIS)

    Abhishek, Anuj; Ranjan, Prem

    2011-01-01

    To make nuclear fusion power a reality, the scientists are working restlessly to find the materials which can confine the power generated by the fusion of two atomic nuclei. A little success in this field has been achieved, though there are still miles to go. Fusion reaction is a special kind of reaction which must occur at very high density and temperature to develop extremely large amount of energy, which is very hard to control and confine within using the present techniques. As a whole it requires the physical condition that rarely exists on the earth to carry out in an efficient manner. As per the growing demand and present scenario of the world energy, scientists are working round the clock to make effective fusion reactions to real. In this paper the work presently going on is considered in this regard. The progress of the Joint European Torus 2010, ITER 2005, HiPER and minor works have been studied to make the paper more object oriented. A detailed study of the technological and material requirement has been discussed in the paper and a possible suggestion is provided to make a contribution in the field of building first ever nuclear fusion reactor

  12. The gametic synapse

    DEFF Research Database (Denmark)

    Macaulay, Angus D.; Gilbert, Isabelle; Caballero, Julieta

    2014-01-01

    Even after several decades of quiescent storage in the ovary, the female germ cell is capable of reinitiating transcription to build the reserves that are essential to support early embryonic development. In the current model of mammalian oogenesis, there exists bilateral communication between th...

  13. Coatings for fusion reactor environments

    International Nuclear Information System (INIS)

    Mattox, D.M.

    1979-01-01

    The internal surfaces of a tokamak fusion reactor control the impurity injection and gas recycling into the fusion plasma. Coating of internal surfaces may provide a desirable and possibly necessary design flexibility for achieving the temperatures, ion densities and containment times necessary for net energy production from fusion reactions to take place. In this paper the reactor environments seen by various componentare reviewed along with possible materials responses. Characteristics of coating-substrate systems, important to fusion applications, are delineated and the present status of coating development for fusion applications is reviewed. Coating development for fusion applications is just beginning and poses a unique and important challenge for materials development

  14. Fusion: Energy for the future

    International Nuclear Information System (INIS)

    1991-05-01

    Fusion, which occurs in the sun and the stars, is a process of transforming matter into energy. If we can harness the fusion process on Earth, it opens the way to assuring that future generations will not want for heat and electric power. The purpose of this booklet is to introduce the concept of fusion energy as a viable, environmentally sustainable energy source for the twenty-first century. The booklet presents the basic principles of fusion, the global research and development effort in fusion, and Canada's programs for fusion research and development

  15. Vacuum engineering for fusion research and fusion reactors

    International Nuclear Information System (INIS)

    Pittenger, L.C.

    1976-01-01

    The following topics are described: (1) surface pumping by cryogenic condensation, (2) operation of large condensing cryopumps, (3) pumping for large fusion experiments, and (4) vacuum technology for fusion reactors

  16. Controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Trocheris, M.

    1975-01-01

    An outline is given of the present position of research into controlled fusion. After a brief reminder of the nuclear reactions of fusion and the principle of their use as a source of energy, the results obtained by the method of magnetic confinement are summarized. Among the many solutions that have been imagined and tried out to achieve a magnetic containing vessel capable of holding the thermonuclear plasma, the devices of the Tokamak type have a good lead and that is why they are described in greater detail. An idea is then given of the problems that arise when one intends conceiving the thermonuclear reactor based on the principle of the Tokamaks. The last section deals with fusion by lasers which is a new and most attractive alternative, at least from the viewpoint of basis physics. The report concludes with an indication of the stages to be passed through to reach production of energy on an industrial scale [fr

  17. Peaceful Uses of Fusion

    Science.gov (United States)

    Teller, E.

    1958-07-03

    Applications of thermonuclear energy for peaceful and constructive purposes are surveyed. Developments and problems in the release and control of fusion energy are reviewed. It is pointed out that the future of thermonuclear power reactors will depend upon the construction of a machine that produces more electric energy than it consumes. The fuel for thermonuclear reactors is cheap and practically inexhaustible. Thermonuclear reactors produce less dangerous radioactive materials than fission reactors and, when once brought under control, are not as likely to be subject to dangerous excursions. The interaction of the hot plasma with magnetic fields opens the way for the direct production of electricity. It is possible that explosive fusion energy released underground may be harnessed for the production of electricity before the same feat is accomplished in controlled fusion processes. Applications of underground detonations of fission devices in mining and for the enhancement of oil flow in large low-specific-yield formations are also suggested.

  18. Ceramics for fusion applications

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1987-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al 2 O 3 , MgAl 2 O 4 , BeO, Si 3 N 4 and SiC are currently under study for fusion applications, and results to date show widely-varying responses to the fusion environment. Materials can be identified today that will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications. (author)

  19. Inverse fusion PCR cloning.

    Directory of Open Access Journals (Sweden)

    Markus Spiliotis

    Full Text Available Inverse fusion PCR cloning (IFPC is an easy, PCR based three-step cloning method that allows the seamless and directional insertion of PCR products into virtually all plasmids, this with a free choice of the insertion site. The PCR-derived inserts contain a vector-complementary 5'-end that allows a fusion with the vector by an overlap extension PCR, and the resulting amplified insert-vector fusions are then circularized by ligation prior transformation. A minimal amount of starting material is needed and experimental steps are reduced. Untreated circular plasmid, or alternatively bacteria containing the plasmid, can be used as templates for the insertion, and clean-up of the insert fragment is not urgently required. The whole cloning procedure can be performed within a minimal hands-on time and results in the generation of hundreds to ten-thousands of positive colonies, with a minimal background.

  20. Laser for fusion energy

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1995-01-01

    Solid state lasers have proven to be very versatile tools for the study and demonstration of inertial confinement fusion principles. When lasers were first contemplated to be used for the compression of fusion fuel in the late 1950s, the laser output energy levels were nominally one joule and the power levels were 10 3 watts (pulse duration's of 10 -3 sec). During the last 25 years, lasers optimized for fusion research have been increased in power to typically 100,000 joules with power levels approaching 10 14 watts. As a result of experiments with such lasers at many locations, DT target performance has been shown to be consistent with high gain target output. However, the demonstration of ignition and gain requires laser energies of several megajoules. Laser technology improvements demonstrated over the past decade appear to make possible the construction of such multimegajoule lasers at affordable costs. (author)

  1. Ceramics for fusion applications

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1986-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle, and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al 2 O 3 , MgAl 2 O 4 , BeO, Si 3 N 4 and SiC are currently under study for fusion applications, and results to date show widely-varying response to the fusion environment. Materials can be identified today which will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications

  2. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed.

  3. Fusion reactor wastes

    International Nuclear Information System (INIS)

    Young, J.R.

    1976-01-01

    The fusion reactor currently is being developed as a clean source of electricity with an essentially infinite source of fuel. These reactors are visualized as using a fusion reaction to generate large quantities of high temperature energy which can be used as process heat or for the generation of electricity. The energy would be created primarily as the kinetic energy of neutrons or other reaction products. Neutron energy could be converted to high-temperature heat by moderation and capture of the neutrons. The energy of other reaction products could be converted to high-temperature heat by capture, or directly to electricity by direct conversion electrostatic equipment. An analysis to determine the wastes released as a result of operation of fusion power plants is presented

  4. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.; Sessler, A.M.

    1980-01-01

    Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion-source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at. (Auth.)

  5. On impact fusion

    International Nuclear Information System (INIS)

    Winterberg, F.

    1997-01-01

    Impact fusion is a promising, but much less developed road towards inertial confinement fusion. It offers an excellent solution to the so-called stand-off problem for thermonuclear microexplosions but is confronted with the challenge to accelerate macroscopic particles to the needed high velocities of 10 2 -10 3 km/s. To reach these velocities, two ways have been studied in the past. The electric acceleration of a beam of microparticles, with the particles as small as large clusters, and the magnetic acceleration of gram-size ferromagnetic or superconducting projectiles. For the generation of an intense burst of soft X-rays used for the indirect drive, impact fusion may offer new promising possibilities

  6. Fusion research at ORNL

    International Nuclear Information System (INIS)

    1982-03-01

    The ORNL Fusion Program includes the experimental and theoretical study of two different classes of magnetic confinement schemes - systems with helical magnetic fields, such as the tokamak and stellarator, and the ELMO Bumpy Torus (EBT) class of toroidally linked mirror systems; the development of technologies, including superconducting magnets, neutral atomic beam and radio frequency (rf) heating systems, fueling systems, materials, and diagnostics; the development of databases for atomic physics and radiation effects; the assessment of the environmental impact of magnetic fusion; and the design of advanced demonstration fusion devices. The program involves wide collaboration, both within ORNL and with other institutions. The elements of this program are shown. This document illustrates the program's scope; and aims by reviewing recent progress

  7. Canadian fusion program

    International Nuclear Information System (INIS)

    Brown, T.S.

    1982-06-01

    The National Research Council of Canada is establishing a coordinated national program of fusion research and development that is planned to grow to a total annual operating level of about $20 million in 1985. The long-term objective of the program is to put Canadian industry in a position to manufacture sub-systems and components of fusion power reactors. In the near term the program is designed to establish a minimum base of scientific and technical expertise sufficient to make recognized contributions and thereby gain access to the international effort. The Canadian program must be narrowly focussed on a few specializations where Canada has special indigenous skills or technologies. The programs being funded are the Tokamak de Varennes, the Fusion Fuels Technology Project centered on tritium management, and high-power gas laser technology and associated diagnostic instrumentation

  8. Ceramics for fusion devices

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1984-01-01

    Ceramics are required for a number of applications in fusion devices, among the most critical of which are magnetic coil insulators, windows for RF heating systems, and structural uses. Radiation effects dominate consideration of candidate materials, although good pre-irradiation properties are a requisite. Materials and components can be optimized by careful control of chemical and microstructural content, and application of brittle material design and testing techniques. Future directions for research and development should include further extension of the data base in the areas of electrical, structural, and thermal properties; establishment of a fission neutron/fusion neutron correlation including transmutation gas effects; and development of new materials tailored to meet the specific needs of fusion reactors

  9. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.; Sessler, A.M.

    1980-07-01

    Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at

  10. Alternate laser fusion drivers

    International Nuclear Information System (INIS)

    Pleasance, L.D.

    1979-11-01

    One objective of research on inertial confinement fusion is the development of a power generating system based on this concept. Realization of this goal will depend on the availability of a suitable laser or other system to drive the power plant. The primary laser systems used for laser fusion research, Nd 3+ : Glass and CO 2 , have characteristics which may preclude their use for this application. Glass lasers are presently perceived to be incapable of sufficiently high average power operation and the CO 2 laser may be limited by and issues associated with target coupling. These general perceptions have encouraged a search for alternatives to the present systems. The search for new lasers has been directed generally towards shorter wavelengths; most of the new lasers discovered in the past few years have been in the visible and ultraviolet region of the spectrum. Virtually all of them have been advocated as the most promising candidate for a fusion driver at one time or another

  11. Neutrons and fusion

    International Nuclear Information System (INIS)

    Maynard, C.W.

    1976-01-01

    The production of energy from fusion reactions does not require neutrons in the fundamental sense that they are required in a fission reactor. Nevertheless, the dominant fusion reaction, that between deuterium and tritium, yields a 14 MeV neutron. To contrast a fusion reactor based on this reaction with the fission case, 3 x 10 20 such neutrons produced per gigawatt of power. This is four times as many neutrons as in an equivalent fission reactor and they carry seven times the energy of the fission neutrons. Thus, they dominate the energy recovery problem and create technological problems comparable to the original plasma confinement problem as far as a practical power producing device is concerned. Further contrasts of the fusion and fission cases are presented to establish the general role of neutrons in fusion devices. Details of the energy deposition processes are discussed and those reactions necessary for producing additional tritium are outlined. The relatively high energy flux with its large intensity will activate almost any materials of which the reactor may be composed. This activation is examined from the point of view of decay heat, radiological safety, and long-term storage. In addition, a discussion of the deleterious effects of neutron interactions on materials is given in some detail; this includes the helium and hydrogen producing reactions and displacement rate of the lattice atoms. The various materials that have been proposed for structural purposes, for breeding, reflecting, and moderating neutrons, and for radiation shielding are reviewed from the nuclear standpoint. The specific reactions of interest are taken up for various materials and finally a report is given on the status and prospects of data for fusion studies

  12. Insulators for fusion applications

    International Nuclear Information System (INIS)

    1987-04-01

    Design studies for fusion devices and reactors have become more detailed in recent years and with this has come a better understanding of requirements and operating conditions for insulators in these machines. Ceramic and organic insulators are widely used for many components of fusion devices and reactors namely: radio frequency (RF) energy injection systems (BeO, Al 2 O 3 , Mg Al 2 O 4 , Si 3 N 4 ); electrical insulation for the torus structure (SiC, Al 2 O 3 , MgO, Mg Al 2 O 4 , Si 4 Al 2 O 2 N 6 , Si 3 N 4 , Y 2 O 3 ); lightly-shielded magnetic coils (MgO, MgAl 2 O 4 ); the toroidal field coil (epoxies, polyimides), neutron shield (B 4 C, TiH 2 ); high efficiency electrical generation; as well as the generation of very high temperatures for high efficiency hydrogen production processes (ZrO 2 and Al 2 O 3 - mat, graphite and carbon - felt). Timely development of insulators for fusion applications is clearly necessary. Those materials to be used in fusion machines should show high resistance to radiation damage and maintain their structural integrity. Now the need is urgent for a variety of radiation resistant materials, but much effort in these areas is required for insulators to be considered seriously by the design community. This document contains 14 papers from an IAEA meeting. It was the objective of this meeting to identify existing problems in analysing various situations of applications and requirements of electrical insulators and ceramics in fusion and to recommend strategies and different stages of implementation. This meeting was endorsed by the International Fusion Research Council

  13. International fusion research

    International Nuclear Information System (INIS)

    Pease, R.S.

    1983-01-01

    Nuclear energy of the light elements deuterium and lithium can be released if the 100 MK degree temperature required for deuterium-tritium thermonuclear fusion reactions can be achieved together with sufficient thermal insulation for a net energy yield. Progress of world-wide research shows good prospect for these physical conditions being achieved by the use of magnetic field confinement and of rapidly developing heating methods. Tokamak systems, alternative magnetic systems and inertial confinement progress are described. International co-operation features a number of bilateral agreements between countries: the Euratom collaboration which includes the Joint European Torus, a joint undertaking of eleven Western European nations of Euratom, established to build and operate a major confinement experiment; the development of co-operative projects within the OECD/IEA framework; the INTOR workshop, a world-wide study under IAEA auspices of the next major step in fusion research which might be built co-operatively; and assessments of the potential of nuclear fusion by the IAEA and the International Fusion Research Council. The INTOR (International Tokamak Reactor) studies have outlined a major plant of the tokamak type to study the engineering and technology of fusion reactor systems, which might be constructed on a world-wide basis to tackle and share the investment risks of the developments which lie ahead. This paper summarizes the recent progress of research on controlled nuclear fusion, featuring those areas where international co-operation has played an important part, and describes the various arrangements by which this international co-operation is facilitated. (author)

  14. Intense fusion neutron sources

    International Nuclear Information System (INIS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-01-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 10 15 -10 21 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 10 20 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  15. Intense fusion neutron sources

    Science.gov (United States)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  16. Confinement inertial fusion. Power reactors of nuclear fusion by lasers

    International Nuclear Information System (INIS)

    Velarde, G.; Ahnert, C.; Aragones, J.M.; Leira, G; Martinez-Val, J.M.

    1980-01-01

    The energy crisis and the need of the nuclear fusion energy are analized. The nuclear processes in the laser interation with the ablator material are studied, as well as the thermohydrodinamic processes in the implossion, and the neutronics of the fusion. The fusion reactor components are described and the economic and social impact of its introduction in the future energetic strategies.(author)

  17. Nuclear fusion: Pursuing the Soft [Symposium on fusion technology] option

    International Nuclear Information System (INIS)

    Kenward, M.

    1991-01-01

    Fusion research has come a long way since the fusion community held the first Symposium on fusion technology (Soft) in Britain 30 years ago. Some of the recent achievements of the Jet project are reported from this year's symposium, the 16th in the series, held in London at the beginning of September. (author)

  18. Fusion Energy Update

    International Nuclear Information System (INIS)

    Whitson, M.O.

    1982-01-01

    Fusion Energy Update (CFU) provides monthly abstracting and indexing coverage of current scientific and technical reports, journal articles, conference papers and proceedings, books, patents, theses, and monographs for all sources on fusion energy. All information announced in CFU, plus additional backup information, is included in the energy information data base of the Department of Energy's Technical Information Center. The subject matter covered by CFU includes plasma physics, the physics and engineering of blankets, magnet coils and fields, power supplies and circuitry, cooling systems, fuel systems, radiation hazards, power conversion systems, inertial confinement systems, and component development and testing

  19. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    Decreton, M.

    2000-01-01

    SCK-CEN's research and development programme on fusion reactor materials includes: (1) the study of the mechanical behaviour of structural materials under neutron irradiation (including steels, inconel, molybdenum, chromium); (2) the determination and modelling of the characteristics of irradiated first wall materials such as beryllium; (3) the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; (4) the study of the dismantling and waste disposal strategy for fusion reactors.; (5) a feasibility study for the testing of blanket modules under neutron radiation. Main achievements in these topical areas in the year 1999 are summarised

  20. Vacuum fusion of uranium

    International Nuclear Information System (INIS)

    Stohr, J.A.

    1957-01-01

    After having outlined that vacuum fusion and moulding of uranium and of its alloys have some technical and economic benefits (vacuum operations avoid uranium oxidation and result in some purification; precision moulding avoids machining, chip production and chemical reprocessing of these chips; direct production of the desired shape is possible by precision moulding), this report presents the uranium fusion unit (its low pressure enclosure and pumping device, the crucible-mould assembly, and the MF supply device). The author describes the different steps of cast production, and briefly comments the obtained results

  1. Pulsed power for fusion

    International Nuclear Information System (INIS)

    Martin, T.H.

    1976-01-01

    A review which traces the development of high power pulsed accelerators from the original inception at the Atomic Weapons Research Establishment, Aldermaston, England, for Bremsstrahlung output, through the low impedance accelerators, to the double-sided accelerators for fusion will be given. Proto II is presently being assembled at Sandia and preliminary testing on the Marx has been completed. Examples of various techniques will be shown from Sandia accelerators. Requirements for accelerators capable of achieving fusion levels will be developed and problem areas outlined. The diode insulator flashover problem presently limits the maximum current available from the accelerators

  2. Atomic data for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A. (eds.); Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

  3. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Carlson, G.A.; Schultz, K.R.; Smith, A.C. Jr.

    1978-01-01

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

  4. Thermonuclear fusion power

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, B

    1977-01-01

    The present state and future possibilities of controlled-nuclear-fusion research are reviewed, including basic concepts and problems, as well as various approaches based on magnetic- and nonmagnetic-confinement schemes. Considerable progress has so far been made in both plasma physics and fusion-reactor technology, and a closer relationship has been established between theory and experiments. Still, none of the present approaches will, for certain, lead to the final solution of a full-scale reactor. Intensified work along broad lines, with emphasis also on basic research and new ideas, is necessary for future success.

  5. The European Fusion Programme

    International Nuclear Information System (INIS)

    Palumbo, D.

    1983-01-01

    The European Fusion Programme is coordinated by Euratom and represents a long term cooperative project of Member States of the European Communities in the field of fusion, designed to lead to the joint construction of prototypes. The main lines of the programme proposed for 1982 to 1986 are: (1) the continuation of a strong effort on tokamaks with emphasis on JET construction, operation and upgrading, (2) conceptual design of NET and development of the related technology, and (3) further work on two alternative magnetic confinement systems. The current status and future plans for this programme are discussed in the paper. (author)

  6. Atomic data for fusion

    International Nuclear Information System (INIS)

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A.; Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research

  7. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on fusion reactor materials includes: (1) the study of the mechanical behaviour of structural materials under neutron irradiation (including steels, inconel, molybdenum, chromium); (2) the determination and modelling of the characteristics of irradiated first wall materials such as beryllium; (3) the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; (4) the study of the dismantling and waste disposal strategy for fusion reactors.; (5) a feasibility study for the testing of blanket modules under neutron radiation. Main achievements in these topical areas in the year 1999 are summarised.

  8. Advanced fusion concepts program

    International Nuclear Information System (INIS)

    Dove, W.F.

    1978-01-01

    While the prospects for the eventual development of a tokamak-based fusion reactor appear promising at the present time, the Department of Energy maintains a vigorous program in alternate magnetic fusion concepts. Several of the concepts presently supported include the toroidal reversed field pinch, Tormac, Elmo Bumpy Torus, and various linear options. Recent technical accomplishments and program evaluations indicate that the possibility now exists for undertaking the next development stage, a proof-of-principle experiment, for a few of the most promising alternate concepts

  9. Fusion welding process

    Science.gov (United States)

    Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

    1983-01-01

    A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

  10. Fusion technology programme

    International Nuclear Information System (INIS)

    Finken, D.

    1985-05-01

    In the current Fusion Technology Programme of the European Community the KfK association is working at present on 16 R and D contracts. Most of the work is strongly oriented towards the Next European Torus. Direct support to NET is given by three KfK delegates being member of the NET study group. In addition to the R and D contracts the association is working on 11 NET study contracts. Though KfK contributes to all areas defined in fusion technology, the main emphasis is put on superconducting magnet and breeding blanket development. Other important fields are tritium technology, materials research, and remote handling. (orig./GG)

  11. Cold fusion in perspective

    International Nuclear Information System (INIS)

    Sanford, L.

    1989-01-01

    Since early April a great deal of excitement has been created over the Fleischmann/Pons cold fusion experiment, which if it performs as advertised, could turn out to be mankind's best hope of heading off the energy crisis scheduled for early in the next century. Dozens of groups around the world are now attempting to duplicate the experiment to see if Fleischmann and Pons' discovery is an experimental mistake, an unknown electrochemical effect or a new kind of fusion reaction. This article puts the experiment into the perspective of today and looks at how it might affect the energy scene tomorrow if it should turn out to be commercially exploitable. (author)

  12. Multisensor data fusion algorithm development

    Energy Technology Data Exchange (ETDEWEB)

    Yocky, D.A.; Chadwick, M.D.; Goudy, S.P.; Johnson, D.K.

    1995-12-01

    This report presents a two-year LDRD research effort into multisensor data fusion. We approached the problem by addressing the available types of data, preprocessing that data, and developing fusion algorithms using that data. The report reflects these three distinct areas. First, the possible data sets for fusion are identified. Second, automated registration techniques for imagery data are analyzed. Third, two fusion techniques are presented. The first fusion algorithm is based on the two-dimensional discrete wavelet transform. Using test images, the wavelet algorithm is compared against intensity modulation and intensity-hue-saturation image fusion algorithms that are available in commercial software. The wavelet approach outperforms the other two fusion techniques by preserving spectral/spatial information more precisely. The wavelet fusion algorithm was also applied to Landsat Thematic Mapper and SPOT panchromatic imagery data. The second algorithm is based on a linear-regression technique. We analyzed the technique using the same Landsat and SPOT data.

  13. Atomic physics issues in fusion

    International Nuclear Information System (INIS)

    Post, D.E.

    1982-01-01

    Atomic physics issues have played a large role in controlled fusion research. A general introduction to the present role of atomic processes in both inertial and magnetic controlled fusion work is presented. (Auth.)

  14. Bringing fusion electric power closer

    International Nuclear Information System (INIS)

    Kintner, E.

    1977-01-01

    A review of the controlled fusion research program is given. The tokamak research program is described. Beam injection heating, control systems, and the safety of fusion reactors are topics that are also discussed

  15. Fusion technology status and requirements

    International Nuclear Information System (INIS)

    Thomassen, K.I.

    1982-01-01

    This paper summarizes the status of fusion technology and discusses the requirements to be met in order to build a demonstration fusion plant. Strategies and programmatic considerations in pursuing engineering feasibility are also outlined

  16. The quest for fusion energy

    International Nuclear Information System (INIS)

    Johnson, J.L.

    1997-10-01

    A brief history of the magnetic fusion program from the point of view of a stellarator enthusiast who worked at a major tokamak laboratory. The reason that success in the magnetic fusion energy program is essential is presented. (author)

  17. Prospect for inertial fusion energy

    International Nuclear Information System (INIS)

    Yamanaka, C.

    1994-01-01

    This paper presents recent inertial fusion experiments at Osaka. The inertial fusion energy reactor used for these experiments was designed according to some principles based on environmental, social and safety considerations. (TEC). 1 fig., 1 ref

  18. Accelerator and fusion research division

    International Nuclear Information System (INIS)

    1992-12-01

    This report contains brief discussions on research topics in the following area: Heavy-Ion Fusion Accelerator Research; Magnetic Fusion Energy; Advanced Light Source; Center for Beam Physics; Superconducting Magnets; and Bevalac Operations

  19. Fusion engineering device design description

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.

  20. Fusion Engineering Device design description

    International Nuclear Information System (INIS)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein

  1. Fusion reactor development: A review

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    This paper is a review of the current prospects for fusion reactor development based upon the present status in plasma physics research, fusion technology development and reactor conceptual design for the tokamak magnetic confinement concept. Recent advances in tokamak plasma research and fusion technology development are summarized. The direction and conclusions of tokamak reactor conceptual design are discussed. The status of alternate magnetic confinement concept research is reviewed briefly. A feasible timetable for the development of fusion reactors is presented

  2. Fusion engineering device design description

    International Nuclear Information System (INIS)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein

  3. Graphite for fusion energy applications

    International Nuclear Information System (INIS)

    Eatherly, W.P.; Clausing, R.E.; Strehlow, R.A.; Kennedy, C.R.; Mioduszewski, P.K.

    1987-03-01

    Graphite is in widespread and beneficial use in present fusion energy devices. This report reflects the view of graphite materials scientists on using graphite in fusion devices. Graphite properties are discussed with emphasis on application to fusion reactors. This report is intended to be introductory and descriptive and is not intended to serve as a definitive information source

  4. Fusion reactor radioactive waste management

    International Nuclear Information System (INIS)

    Kaser, J.D.; Postma, A.K.; Bradley, D.J.

    1976-01-01

    Quantities and compositions of non-tritium radioactive waste are estimated for some current conceptual fusion reactor designs, and disposal of large amounts of radioactive waste appears necessary. Although the initial radioactivity of fusion reactor and fission reactor wastes are comparable, the radionuclides in fusion reactor wastes are less hazardous and have shorter half-lives. Areas requiring further research are discussed

  5. Hugging fusion and related topics

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    An important problem related to the synthesis of very heavy nuclides by fusion of two heavy-ions is the extra push effect. To avoid it, we propose a hugging fusion, which is the fusion of two well-deformed heavy-ions. (author)

  6. Bubble fusion: Preliminary estimates

    International Nuclear Information System (INIS)

    Krakowski, R.A.

    1995-01-01

    The collapse of a gas-filled bubble in disequilibrium (i.e., internal pressure much-lt external pressure) can occur with a significant focusing of energy onto the entrapped gas in the form of pressure-volume work and/or acoustical shocks; the resulting heating can be sufficient to cause ionization and the emission of atomic radiations. The suggestion that extreme conditions necessary for thermonuclear fusion to occur may be possible has been examined parametrically in terms of the ratio of initial bubble pressure relative to that required for equilibrium. In this sense, the disequilibrium bubble is viewed as a three-dimensional ''sling shot'' that is ''loaded'' to an extent allowed by the maximum level of disequilibrium that can stably be achieved. Values of this disequilibrium ratio in the range 10 -5 --10 -6 are predicted by an idealized bubble-dynamics model as necessary to achieve conditions where nuclear fusion of deuterium-tritium might be observed. Harmonic and aharmonic pressurizations/decompressions are examined as means to achieve the required levels of disequilibrium required to create fusion conditions. A number of phenomena not included in the analysis reported herein could enhance or reduce the small levels of nuclear fusions predicted

  7. Fusion technology 1998

    International Nuclear Information System (INIS)

    Beaumont, B.; Libeyre, P.; Gentile, B. de; Tonon, G.

    1998-01-01

    The Symposium On Fusion Technology (SOFT) is held every two years with the objective to set the stage for the exchange of information on the design, construction and operation of fusion experiments and on the technology which is being developed for the next step devices and fusion reactors. By decision of the International Organizing Committee, the 20. SOFT includes invited talks, and oral and poster contributions in the following topics: plasma facing components, plasma heating and current drive, plasma engineering and control, experimental systems and diagnostics, magnets and power supplies, fuel technologies, remote operation, blanket and shield technologies, safety and environment, and system engineering and future devices. This symposium differs from the previous ones of this series by the way the present proceedings are produced. In order to have the written material available to the participants and the community at the nearest to the conference event, the papers have been collected 2 months in advance and printed in the present books. The goal was to deliver them to each participant upon arrival to the conference centre. These books contain all the papers corresponding to poster presentation, and the abstracts of the oral contributions and invited papers. The papers corresponding to these presentations, both oral and invited, will be published in 1999, after a standard review process, in a supplement of Fusion Engineering and Design. (author)

  8. Fusion of biological membranes

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 64; Issue 6. Fusion of biological membranes. K Katsov M Müller M Schick. Invited Talks:- Topic 11. Biologically motivated problems (protein-folding models, dynamics at the scale of the cell; biological networks, evolution models, etc.) Volume 64 Issue 6 June 2005 pp ...

  9. Future with fusion power

    International Nuclear Information System (INIS)

    Hirschfeld, F.

    1977-01-01

    This article reviews several current approaches to the development of nuclear fusion power sources by the year 2000. First mentioned is the only project to develop a nonpolluting, radiation-free source by using only natural and nonradioactive isotopes (nuclei of deuterium, helium 3 and boron) as ''advanced'' fuels. This system will also be capable of direct conversion of the released energy into electricity. Next described is the PACER concept, in which thermonuclear burning of deuterium occurs in fusion explosion taking place underground (e.g., in a salt dome). The released energy is absorbed in high-pressure steam which is then piped to a surface heat exchanger to provide steam for a turbogenerator. After filtration, the steam is returned. The PACER system also produces fissionable fuel. The balance of the article reviews three ''magnetic fusion'' approaches. Tokamak, mirror and theta pinch systems utilize magnetic fields to confine a plasma for either pulsed or steady-state operation. The tokamak and theta pinch are toroidal in shape, while the mirror can be thought of as a magnetic field configuration of roughly tubular shape that confines the plasma by means of higher fields at the ends than at its center. The tokamak approach accounts for about 65 percent of the magnetic fusion research and development, while theta pinches and mirrors represent about 15 percent each. Refs

  10. Fusion Canada issue 7

    International Nuclear Information System (INIS)

    1989-05-01

    A short bulletin from the National Fusion Program. Included in this issue are CFFTP highlights on the Karlsruhe Isotope Separation System, a report on ITER tritium process systems, an experimental update on Tokamak de Varennes and Canada-U.S. bilateral technical collaboration topics. 2 figs

  11. Charged particle fusion targets

    International Nuclear Information System (INIS)

    Bangerter, R.O.; Meeker, D.J.

    1977-01-01

    The power, voltage, energy and other requirements of electron and ion beam fusion targets are reviewed. Single shell, multiple shell and magnetically insulated target designs are discussed. Questions of stability are also considered. In particular, it is shown that ion beam targets are stabilized by an energy spread in the ion beam

  12. Mars manned fusion spaceship

    International Nuclear Information System (INIS)

    Hedrick, J.; Buchholtz, B.; Ward, P.; Freuh, J.; Jensen, E.

    1991-01-01

    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium. Helium can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system

  13. Magnetic fusion energy

    International Nuclear Information System (INIS)

    McNamara, B.

    1977-01-01

    A brief review of fusion research during the last 20 years is given. Some highlights of theoretical plasma physics are presented. The role that computational plasma physics is playing in analyzing and understanding the experiments of today is discussed. The magnetic mirror program is reviewed

  14. Fusion development and technology

    International Nuclear Information System (INIS)

    Montgomery, D.B.

    1991-01-01

    This report discusses the following topics: superconducting magnet technology high field superconductors; advanced magnetic system and divertor development; poloidal field coils; gyrotron development; commercial reactor studies -- Aries; ITER physics; ITER superconducting PF scenario and magnet analysis; and safety, environmental and economic factors in fusion development

  15. Cold fusion - todays situation

    International Nuclear Information System (INIS)

    Malmqvist, K.

    1993-01-01

    A brief review of the history of cold fusion is given. It is noted that it is not possible to draw any definite conclusions about all the experimental and theoretical details, but that some of the results presented do not seem to be reached according to the normal scientific methods. 6 figs

  16. Fusion energy studies

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The following topics are considered: (1) cryosorption vacuum pumping for fusion reactors, (2) TNS support studies, (3) tritium recovery from irradiated Li-Al and SAP, (4) actinide oxides, nitrides, and carbides, and (5) transition metal-actinide-C phase equilibria

  17. Fusion technology programme

    International Nuclear Information System (INIS)

    Finken, D.

    1985-10-01

    KfK is involved in the European Fusion Programme predominantly in the NET and Fusion Technology part. The following fields of activity are covered: Studies for NET, alternative confinement concepts, and needs and issues of integral testing. Research on structural materials. Development of superconducting magnets. Gyrotron development (part of the Physics Programme). Nuclear technology (breeding materials, blanket design, tritium technology, safety and environmental aspects of fusion, remote maintenance). Reported here are status and results of work under contracts with the CEC within the NET and Technology Programme. The aim of the major part of this R and D work is the support of NET, some areas (e.g. materials, safety and environmental impact, blanket design) have a wider scope and address problems of a demonstration reactor. In the current working period, several new proposals have been elaborated to be implemented into the 85/89 Euratom Fusion Programme. New KfK contributions relate to materials research (dual beam and fast reactor irradiations, ferritic steels), to blanket engineering (MHD-effects) and to safety studies (e.g. magnet safety). (orig./GG)

  18. Research into thermonuclear fusion

    International Nuclear Information System (INIS)

    Schumacher, U.

    1989-01-01

    The experimental and theoretical studies carried out in close international cooperation in the field of thermonuclear fusion by magnetic plasma confinement have achieved such progress towards higher plasma temperatures and densities, longer confinement times and, thus, increased fusion product, that emphasis now begins to be shifted from problems of physics to those of technology as a next major step is being prepared towards a large international project (ITER) to achieve thermonuclear burning. The generation and maintenance of a burning fusion plasma in an experimental physics phase will be followed by a phase of technical materials studies at high fluxes of fusion neutrons. These goals have been pursued since 1983 by an international study group at Garching working on the design of a Next European Torus (NET). Since May 1988, an international study group comprising ten experts each from the USSR, USA, Japan, and the European Community has begun to work on a design draft of ITER (International Thermonuclear Experimental Reactor) in Garching under the auspices of IAEA. (orig.) [de

  19. Fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  20. Fusion Canada issue 21

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-08-01

    A short bulletin from the National Fusion Program highlighting in this issue Europe proposes Canada`s participation in ITER, tritium for JET, CCFM/TdeV-Tokamak helium pumping and TdeV update, ITER-related R and D at CFFTP, ITER Deputy Director visits Canada, NFP Director to Chair IFRC, Award for Akira Hirose. 3 figs.

  1. Advanced lasers for fusion

    International Nuclear Information System (INIS)

    Krupke, W.F.; George, E.V.; Haas, R.A.

    1979-01-01

    Laser drive systems' performance requirements for fusion reactors are developed following a review of the principles of inertial confinement fusion and of the technical status of fusion research lasers (Nd:glass; CO 2 , iodine). These requirements are analyzed in the context of energy-storing laser media with respect to laser systems design issues: optical damage and breakdown, medium excitation, parasitics and superfluorescence depumping, energy extraction physics, medium optical quality, and gas flow. Three types of energy-storing laser media of potential utility are identified and singled out for detailed review: (1) Group VI atomic lasers, (2) rare earth solid state hybrid lasers, and (3) rare earth molecular vapor lasers. The use of highly-radiative laser media, particularly the rare-gas monohalide excimers, are discussed in the context of short pulse fusion applications. The concept of backward wave Raman pulse compression is considered as an attractive technique for this purpose. The basic physics and device parameters of these four laser systems are reviewed and conceptual designs for high energy laser systems are presented. Preliminary estimates for systems efficiencies are given. (Auth.)

  2. International fusion og spaltning

    DEFF Research Database (Denmark)

    Hansen, Lone L.

    Bogen analyserer de nye muligheder fra 2007 i europæisk ret med hensyn til fusion eller spaltning mellem aktieselskaber og anpartsselskaber med hjemsted i forskellige europæiske lande. Bogen gennemgår de nye muligheder for strukturændringer, der herved er opstået mulighed for, og den sætter fokus...

  3. Fusion program overview

    International Nuclear Information System (INIS)

    Clarke, J.F.

    1983-01-01

    There has been and continues to be a perceived need for the fusion energy option in our energy future. The National Energy Plan states that ''the Federal Government recognizes a direct responsibility to demonstrate the scientific and engineering feasibility of fusion''. The goal of the program, in exercising this responsibility, is to develop the knowledge base upon which decisions on the commercial feasibility of fusion will be made after the conclusion of the present scientific feasibility phase of the program. The strategy is to preceed sequentially through a product definition phase, to the product development phase. Product definition is the identification of an attractive fusion reactor concept supported by a sound base of scientific and technological information. Product development is the further refinement of scientific, technological and engineering information base of the selected concept to provide a firm basis for commercial application. Each of these phases will be discussed with special emphasis on the relationship between the annual appropriation process and the influence of external forces on the pace of the program. This discussion will include the use of international cooperation to maintain and extend program scope. Further discussion will cover the important scientific and technological advances of the last few years and the way in which they have influenced the development of our management strategy to maximize our resources

  4. Fusion Canada issue 16

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-01-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on Ontario Hydro`s contract for tritium supply from Germany, a CCFM update on plasma biasing, divertor operation, radiofrequency plasma current drive and the plasma heating system for the Tokamak de Varennes, and an agreement for ITER engineering design activities. 5 figs.

  5. Rencontre on fusion technology

    International Nuclear Information System (INIS)

    Read, S.F.J.

    1979-02-01

    This report of a rencontre held to consider the technology of magnetic confinement fusion devices gives the agenda for the meeting and lists those topics which were identified as areas of research. These topics included materials, tritium, structures and heat transfer, neutronics and nuclear data, and corrosion problems. (UK)

  6. Bouillabaisse sushi fusion power

    CERN Multimedia

    2004-01-01

    "If avant-garde cuisine is any guide, Japanese-French fusion does not work all that well. And the interminable discussions over the International Thermonuclear Experimental Reactor (ITER) suggest that what is true of cooking is true of physics" (1 page)

  7. Status of inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.

    1987-04-01

    The technology advancement to high-power beams has also given birth to new technologies. That class of Free Electron Lasers that employs rf linacs, synchrotrons, and storage rings - although the use the tools of High Energy Physics (HEP) - was developed well behind the kinetic energy frontier. The induction linac, however, is something of an exception; it was born directly from the needs of the magnetic fusion program, and was not motivated by a high-energy physics application. The heavy-ion approach to inertial fusion starts with picking from the rich menu of accelerator technologies those that have, ab initio, the essential ingredients needed for a power plant driver: multigap acceleration - which leads to reliability/lifetime; electrical efficiency; repetition rate; and beams that can be reliably focused over a suitably long distance. The report describes the programs underway in Heavy Ion Fusion Accelerator Research as well as listing expected advances in driver, target, and beam quality areas in the inertial fusion power program

  8. Fusion reactor materials

    International Nuclear Information System (INIS)

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics

  9. Fusion meets electronics

    Czech Academy of Sciences Publication Activity Database

    Řípa, Milan

    2011-01-01

    Roč. 1, č. 2 (2011), s. 8-8 ISSN 1818-5355 Institutional research plan: CEZ:AV0Z20430508 Keywords : fusion * AMPER 2011 * ITER * COMPASS * IPP * CR Subject RIV: BL - Plasma and Gas Discharge Physics http://www.jet.efda.org/ multimedia /newsletter/current/

  10. Fusion Canada issue 21

    International Nuclear Information System (INIS)

    1993-08-01

    A short bulletin from the National Fusion Program highlighting in this issue Europe proposes Canada's participation in ITER, tritium for JET, CCFM/TdeV-Tokamak helium pumping and TdeV update, ITER-related R and D at CFFTP, ITER Deputy Director visits Canada, NFP Director to Chair IFRC, Award for Akira Hirose. 3 figs

  11. Fusion Canada issue 7

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-05-01

    A short bulletin from the National Fusion Program. Included in this issue are CFFTP highlights on the Karlsruhe Isotope Separation System, a report on ITER tritium process systems, an experimental update on Tokamak de Varennes and Canada-U.S. bilateral technical collaboration topics. 2 figs.

  12. Controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Rebut, P.H.

    1992-01-01

    The author gives a chronological account of the research about thermonuclear fusion and presents the principle of JET thermonuclear reactor based upon the magnetic confinement. The problems of heating and confining a thermonuclear plasma may be regarded as solved. They make possible the definition of the size and geometry needed to realize a next-step tokamak (ITER, NET projects)

  13. Fusion Canada issue 26

    International Nuclear Information System (INIS)

    1994-11-01

    A short bulletin from the National Fusion Program highlighting in this issue tritium supply for Japanese research, Canada to host the 1995 IAEA Conference on Tritium, studies on the tokamak divertor and edge plasma studies, a tritium field release study, erosion studies on plasma facing materials, G. Pacher returns to CCFM and an update on CCFM/TdeV

  14. Fusion target design

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1978-01-01

    Most detailed fusion target design is done by numerical simulation using large computers. Although numerical simulation is briefly discussed, this lecture deals primarily with the way in which basic physical arguments, driver technology considerations and economical power production requirements are used to guide and augment the simulations. Physics topics discussed include target energetics, preheat, stability and symmetry. A specific design example is discussed

  15. Fusion Canada issue 16

    International Nuclear Information System (INIS)

    1992-01-01

    A short bulletin from the National Fusion Program. Included in this issue is a report on Ontario Hydro's contract for tritium supply from Germany, a CCFM update on plasma biasing, divertor operation, radiofrequency plasma current drive and the plasma heating system for the Tokamak de Varennes, and an agreement for ITER engineering design activities. 5 figs

  16. Fusion Canada issue 24

    International Nuclear Information System (INIS)

    1994-04-01

    A short bulletin from the National Fusion Program highlighting in this issue the opening of the Garching ITER site, a CCFM/TdeV update,a tritium release field test, measuring radial profile of plasma current density on TdeV, power supplies for TdeV, 5th International Tritium Technology conference, and 1994 basic tritium course. 4 figs

  17. Plasma nuclear fusion method

    International Nuclear Information System (INIS)

    Yamazaki, Shunpei; Miyanaga, Shoji; Wakaizumi, Kazuhiro; Takemura, Yasuhiko.

    1990-01-01

    Nuclear fusion reactions are attained by plasma gas phase reactions using magnetic fields and microwaves, and the degree of the reactions is controlled. That is, deuterium (D 2 ) is introduced into a plasma container by utilizing the resonance of microwaves capable of generating plasmas at high density higher by more than 10 - 10 3 times as compared with the high frequency and magnetic fields, and an electric energy is applied to convert gaseous D 2 into plasmas and nuclear fusion is conducted. Further, the deuterium ions in the plasmas are attracted to a surface of a material causing nuclear fusion under a negatively biased electric field from the outside (typically represented by Pd or Ti). Then, deuterium nuclei (d) or deuterium ions collide to the surface of the cathode on the side of palladium to conduct nuclear reaction at the surface or the inside (vicinity) thereof. However, a DC bias is applied as an external bias with the side of the palladium being negative. The cold nuclear fusion was demonstrated by placing a neutron counter in the vicinity of the container and confirming neutrons generated there. (I.S.)

  18. Controlled nuclear fusion apparatus

    International Nuclear Information System (INIS)

    Bussard, R.W.; Coppi, B.

    1982-01-01

    A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. Thermonuclear ignition of the plasma is obtained by feeding neutral fusible gas into the plasma in a controlled manner such that charged particle heating produced by the fusion reaction is utilized to bootstrap the device to a region of high temperatures and high densities wherein charged particle heating is sufficient to overcome radiation and thermal conductivity losses. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time. A series of potentially disposable and replaceable central core regions are disclosed for a large-scale economical electrical power generating plant

  19. lysosome tethering and fusion

    Indian Academy of Sciences (India)

    AMIT TULI

    LYSOSOME. MTOC. LATE ENDOSOME. Arl8b promotes the assembly of the HOPS complex on the lysosomes to mediate late endosome-lysosome fusion and cargo delivery to lysosomes. Khatter D et al., J Cell Science 2015. Khatter D et al., Cellular Logistics 2015 ...

  20. Controlled thermonuclear fusion reactors

    International Nuclear Information System (INIS)

    Walstrom, P.L.

    1976-01-01

    Controlled production of energy by fusion of light nuclei has been the goal of a large portion of the physics community since the 1950's. In order for a fusion reaction to take place, the fuel must be heated to a temperature of 100 million degrees Celsius. At this temperature, matter can exist only in the form of an almost fully ionized plasma. In order for the reaction to produce net power, the product of the density and energy confinement time must exceed a minimum value of 10 20 sec m -3 , the so-called Lawson criterion. Basically, two approaches are being taken to meet this criterion: inertial confinement and magnetic confinement. Inertial confinement is the basis of the laser fusion approach; a fuel pellet is imploded by intense laser beams from all sides and ignites. Magnetic confinement devices, which exist in a variety of geometries, rely upon electromagnetic forces on the charged particles of the plasma to keep the hot plasma from expanding. Of these devices, the most encouraging results have been achieved with a class of devices known as tokamaks. Recent successes with these devices have given plasma physicists confidence that scientific feasibility will be demonstrated in the next generation of tokamaks; however, an even larger effort will be required to make fusion power commercially feasible. As a result, emphasis in the controlled thermonuclear research program is beginning to shift from plasma physics to a new branch of nuclear engineering which can be called fusion engineering, in which instrumentation and control engineers will play a major role. Among the new problem areas they will deal with are plasma diagnostics and superconducting coil instrumentation

  1. Accelerators for heavy ion fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1985-10-01

    Large fusion devices will almost certainly produce net energy. However, a successful commercial fusion energy system must also satisfy important engineering and economic constraints. Inertial confinement fusion power plants driven by multi-stage, heavy-ion accelerators appear capable of meeting these constraints. The reasons behind this promising outlook for heavy-ion fusion are given in this report. This report is based on the transcript of a talk presented at the Symposium on Lasers and Particle Beams for Fusion and Strategic Defense at the University of Rochester on April 17-19, 1985

  2. Commercial application of laser fusion

    International Nuclear Information System (INIS)

    Booth, L.A.

    1976-01-01

    The fundamentals of laser-induced fusion, some laser-fusion reactor concepts, and attendant means of utilizing the thermonuclear energy for commercial electric power generation are discussed. Theoretical fusion-pellet microexplosion energy release characteristics are described and the effects of pellet design options on pellet-microexplosion characteristics are discussed. The results of analyses to assess the engineering feasibility of reactor cavities for which protection of cavity components is provided either by suitable ablative materials or by diversion of plasmas by magnetic fields are presented. Two conceptual laser-fusion electric generating stations, based on different laser-fusion reactor concepts, are described

  3. Prospects for alternative Fusion Fuels

    International Nuclear Information System (INIS)

    Glancy, J.

    1986-01-01

    The author has worked on three different magnetic confinement concepts for alternate fusion fueled reactors: tokamaks; tanden mirrors, and reversed field pinches. The focus of this article is on prospects for alternate fusion fuels as the author sees them relative to the other choices: increased numbers of coal plants, fission reactors, renewables, and D-T fusion. Discussion is limited on the consideration of alternate fusion fuels to the catalyzed deuterium-deuterium fuel cycle. Reasons for seeking an alternate energy source are cost, a more secure fuel supply, environmental impact and safety. The technical risks associated with development of fusion are examined briefly

  4. Directions for improved fusion reactors

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Delene, J.G.

    1986-01-01

    Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. A generic fusion physics/engineering/costing model is used to provide a quantiative basis for these arguments for specific fusion concepts

  5. Risk considerations for fusion energy

    International Nuclear Information System (INIS)

    Kazimi, M.S.

    1983-01-01

    An assessment is made of the public and occupational health effects implied in the utilization of fusion reactors as a source of electricity. Three conceptual designs for TOKAMAK fusion reactors are used in the assessment. It was assumed in this analysis that a fusion plant will release 10 Ci/day of tritium to the atmosphere. Risk from waste management and accidents are estimated relative to risk of LWR's energy cycle. Comparison of the fusion occupational and public risk from coal, LWR, solar thermal and solar-photovoltaic plants has been undertaken. It is concluded that, compared to other fuel cycles, fusion can potentially have a favorable position with respect to risk

  6. Fusion research activities in China

    International Nuclear Information System (INIS)

    Deng Xiwen

    1998-01-01

    The fusion program in China has been executed in most areas of magnetic confinement fusion for more than 30 years. Basing on the situation of the power supply requirements of China, the fusion program is becoming an important and vital component of the nuclear power program in China. This paper reviews the status of fusion research and next step plans in China. The motivation and goal of the Chinese fusion program is explained. Research and development on tokamak physics and engineering in the southwestern institute of physics (SWIP) and the institute of plasma physics of Academic Sinica (ASIPP) are introduced. A fusion breeder program and a pure fusion reactor design program have been supported by the state science and technology commission (SSTC) and the China national nuclear corporation (CNNC), respectively. Some features and progress of fusion reactor R and D activities are reviewed. Non fusion applications of plasma science are an important part of China fusion research; a brief introduction about this area is given. Finally, an introductional collaboration network on fusion research activities in China is reported. (orig.)

  7. Cell fusion by ionizing radiation

    International Nuclear Information System (INIS)

    Khair, M.B.

    1993-08-01

    The relevance and importance of cell fusion are illustrated by the notion that current interest in this phenomenon is shared by scientists in quite varied disciplines. The diversity of cellular membrane fusion phenomena could provoke one to think that there must be a multitude of mechanisms that can account for such diversity. But, in general, the mechanism for the fusion reaction itself could be very similar in many, or even all, cases. Cell fusion can be induced by several factors such as virus Sendai, polyethylene glycol, electric current and ionizing radiation. This article provides the reader with short view of recent progress in research on cell fusion and gives some explanations about fusion mechanisms. This study shows for the first time, the results of the cell fusion induced by ionizing radiations that we have obtained in our researches and the work performed by other groups. (author). 44 refs

  8. 50 years of fusion research

    Science.gov (United States)

    Meade, Dale

    2010-01-01

    Fusion energy research began in the early 1950s as scientists worked to harness the awesome power of the atom for peaceful purposes. There was early optimism for a quick solution for fusion energy as there had been for fission. However, this was soon tempered by reality as the difficulty of producing and confining fusion fuel at temperatures of 100 million °C in the laboratory was appreciated. Fusion research has followed two main paths—inertial confinement fusion and magnetic confinement fusion. Over the past 50 years, there has been remarkable progress with both approaches, and now each has a solid technical foundation that has led to the construction of major facilities that are aimed at demonstrating fusion energy producing plasmas.

  9. The fusion-fission hybrid

    International Nuclear Information System (INIS)

    Teller, E.

    1985-01-01

    As the history of the development of fusion energy shows, a sustained controlled fusion reaction is much more difficult to produce than rapid uncontrolled release of fusion energy. Currently, the ''magnetic bottle'' technique shows sufficient progress that it might applied for the commercial fuel production of /sup 233/U, suitable for use in fission reactors, by developing a fusion-fission hybrid. Such a device would consist of a fusion chamber core surrounded by a region containing cladded uranium pellets cooled by helium, with lithium salts also present to produce tritium to refuel the fusion process. Successful development of this hybrid might be possible within 10 y, and would provide both experience and funds for further development of controlled fusion energy

  10. Inertial Fusion Energy

    Energy Technology Data Exchange (ETDEWEB)

    Mima, K

    2012-09-15

    In 1917, Albert Einstein suggested the theory of stimulated emission of light that led to the development of the laser. The first laser, based on Einstein's theory, was demonstrated by the Maiman experiment in 1960. In association with the invention and developments of the laser, N.G. Basov, A. Prokorov and C.H. Towns received the Nobel prize for physics in 1963. On the other hand, it had been recognized that nuclear fusion energy is the energy source of our universe. It is the origin of the energy in our sun and in the stars. Right after the laser oscillation experiment, it was suggested by J. Nuckolls, E. Teller and S. Colgate in the USA and A. Sakharov in the USSR that nuclear fusion induced by lasers be used to solve the energy problem. Following the suggestion, the pioneering works for heating plasmas to a thermonuclear temperature with a laser were published by N. Basov, O.N. Krohin, J.M. Dawson, C.R. Kastler, H. Hora, F. Flux and S. Eliezer. The new concept of fusion ignition and burn by laser 'implosion' was proposed by J. Nuckolls, which extended the spherically imploding shock concept discovered by G. Guderley to the laser fusion concept. Since then, laser fusion research has started all over the world. For example, many inertial fusion energy (IFE) facilities have been constructed for investigating implosion physics: Lasers: GEKKO I, GEKKO II, GEKKO IV, GEKKO MII and GEKKO xII at ILE, Osaka University, Japan; JANUS, CYCLOPS, ARUGUS, SHIVA and NOVA at Lawrence Livermore National Laboratory (LLNL), USA; OMEGA at the Laboratory for Laser Energetics (LLE), University of Rochester, USA; PHEBUS at Limeil, Paris, France; the ASTERIx iodine laser at the Max-Planck-Institut fuer Plasmaphysik (IPP), Garching, Germany; MPI, GLECO at the Laboratoire d'Utilisation des Lasers Intenses (LULI), ecole Polytecnique, France; HELIOS at Los Alamos National Laboratory, USA; Shengan II at the Shanghai Institute of Optics and Fine Mechanics, China; VULCAN at the Rutherford

  11. Muon nuclear fusion and low temperature nuclear fusion

    International Nuclear Information System (INIS)

    Nagamine, Kanetada

    1990-01-01

    Low temperature (or normal temperature) nuclear fusion is one of the phenomena causing nuclear fusion without requiring high temperature. In thermal nuclear fusion, the Coulomb barrier is overcome with the help of thermal energy, but in the low temperature nuclear fusion, the Coulomb barrier is neutralized by the introduction of the particles having larger mass than electrons and negative charges, at this time, if two nuclei can approach to the distance of 10 -13 cm in the neutral state, the occurrence of nuclear fusion reaction is expected. As the mass of the particles is heavier, the neutral region is smaller, and nuclear fusion is easy to occur. The particles to meet this purpose are the electrons within substances and muons. The research on muon nuclear fusion became suddenly active in the latter half of 1970s, the cause of which was the discovery of the fact that the formation of muons occurs resonantly rapidly in D-T and D-D systems. Muons are the unstable elementary particles having the life of 2.2 μs, and they can have positive and negative charges. In the muon catalyzed fusion, the muons with negative charge take part. The principle of the muon catalyzed fusion, its present status and future perspective, and the present status of low temperature nuclear fusion are reported. (K.I.)

  12. Fusion reactor problems

    International Nuclear Information System (INIS)

    Carruthers, R.

    It is pointed out that plasma parameters for a fusion reactor have been fairly accurately defined for many years, and the real plasma physics objective must be to find the means of achieving and maintaining these specifiable parameters. There is good understanding of the generic technological problems: breading blankets and shields, radiation damage, heat transfer and methods of magnet design. The required plasma parameters for fusion self-heated reactors are established at ntausub(E) approximately 2.10 14 cm -3 sec, plasma radius 1.5 to 3 m, wall loading 5 to 10 MW cm -2 , temperature 15 keV. Within this model plasma control by quasi-steady burn as a key problem is studied. It is emphasized that the future programme must interact more closely with engineering studies and should concentrate upon research which is relevant to reactor plasmas. (V.P.)

  13. Fusion technology programme

    International Nuclear Information System (INIS)

    Finken, D.

    1984-10-01

    The KfK-Association has continued work on 17 R and D contracts of the Fusion Technology Programme. An effort of 94 manyears per year is at present contributed by 10 KfK departments, covering all aereas defined in the Fusion Technology Programme. The dominant part of the work is directed towards the need of the NET design or supporting experiments. Some additional effort addresses long term technological issues and system studies relevant to DEMO or confinement schemes alternative to tokamaks. Direct contribution to the NET team has increased by augmentation of NET study contracts and delegation of personnel, three KfK delegates being at present members of the NET team. In reverse, specifications and design guidelines worked out by NET have started to have an impact on the current R and D-work in the laboratory. (orig./GG)

  14. Fluorination by fusion

    International Nuclear Information System (INIS)

    Gray, J.H.

    1986-01-01

    LECO crucibles and incinerator ash are two waste categories that cannot be discarded due to the presence of insoluble transuranics. Current chemical processing methods are not too effective, requiring a number of repeated operations in order to dissolve more than half the transuranics. An alternate dissolution approach has been developed involving the use of ammonium bifluoride. Low temperature fusion of the waste with ammonium bifluoride is followed by dissolution of the fused material in boiling nitric acid solutions. Greater than 60% of the transuranics contained in LECO crucibles and greater than 95% of the transuranics mixed with the incinerator ash are dissolved after a single fusion and dissolution step. Fluorination of the transuranics along with other impurities appears to render the waste material soluble in nitric acid

  15. Fusion pumped laser

    Science.gov (United States)

    Pappas, D.S.

    1987-07-31

    The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

  16. Pulsed fusion reactors

    International Nuclear Information System (INIS)

    1975-01-01

    This summer school specialized in examining specific fusion center systems. Papers on scientific feasibility are first presented: confinement of high-beta plasma, liners, plasma focus, compression and heating and the use of high power electron beams for thermonuclear reactors. As for technological feasibility, lectures were on the theta-pinch toroidal reactors, toroidal diffuse pinch, electrical engineering problems in pulsed magnetically confined reactors, neutral gas layer for heat removal, the conceptual design of a series of laser fusion power plants with ''Saturn'', implosion experiments and the problem of the targets, the high brightness lasers for plasma generation, and topping and bottoming cycles. Some problems common to pulsed reactors were examined: energy storage and transfer, thermomechanical and erosion effects in the first wall and blanket, the problems of tritium production, radiation damage and neutron activation in blankets, and the magnetic and inertial confinement

  17. Experiments in cold fusion

    International Nuclear Information System (INIS)

    Palmer, E.P.

    1986-01-01

    The work of Steve Jones and others in muon-catalyzed cold fusion of deuterium and hydrogen suggests the possibility of such fusion catalyzed by ions, or combinations of atoms, or more-or-less free electrons in solid and liquid materials. A hint that this might occur naturally comes from the heat generated in volcanic action in subduction zones on the earth. It is questionable whether the potential energy of material raised to the height of a midocean ridge and falling to the depth of an ocean trench can produce the geothermal effects seen in the volcanoes of subduction zones. If the ridge, the trench, the plates, and the asthenosphere are merely visible effects of deeper density-gradient driven circulations, it is still uncertain that observed energy-concentration effects fit the models

  18. Fusion through the NET

    International Nuclear Information System (INIS)

    Spears, B.

    1987-01-01

    The paper concerns the next generation of fusion machines which are intended to demonstrate the technical viability of fusion. In Europe, the device that will follow on from JET is known as NET - the Next European Torus. If the design programme for NET proceeds, Europe could start to build the machine in 1994. The present JET programme hopes to achieve breakeven in the early 1990's. NET hopes to reach ignition in the next century, and so lay the foundation for a demonstration reactor. A description is given of the technical specifications of the components of NET, including: the first wall, the divertors to protect the wall, the array of magnets that provide the fields containing the plasma, the superconducting magnets, and the shield of the machine. NET's research programme is briefly outlined, including the testing programme to optimise conditions in the machine to achieve ignition, and its safety work. (U.K.)

  19. Heavy ion fusion III

    International Nuclear Information System (INIS)

    Hammer, D.; Max, C.; Perkins, F.; Rosenbluth, M.

    1987-03-01

    This report updates Heavy Ion Fusion, JSR-82-302, dated January, 1983. During the last four years, program management and direction has been changed and the overall Inertial Confinement Program has been reviewed. This report therefore concentrates on accelerator physics issues, how the program has addressed those issues during the last four years, and how it will be addressing them in the future. 8 refs., 3 figs

  20. Alternative fusion concepts

    International Nuclear Information System (INIS)

    Rostagni, G.

    1981-01-01

    The paper reports the discussions and statements made by the participants on the actual state and future of five different approaches on the fusion concept; they are the following: bumpy torus, reversed-field pinch, open-ended configurations, compact toroids and stellarators. Tables show for each concept parameters that represent the achieved results; data expected for future devices and extrapolations on reactor requirements are included

  1. Fusion development and technology

    International Nuclear Information System (INIS)

    Montgomery, D.B.

    1992-01-01

    This report discusses the following: superconducting magnet technology; high field superconductors; advanced magnetic system and divertor development; poloidal field coils; gyrotron development; commercial reactor studies--aries; ITER physics: alpha physics and alcator R ampersand D for ITER; lower hybrid current drive and heating in the ITER device; ITER superconducting PF scenario and magnet analysis; ITER systems studies; and safety, environmental and economic factors in fusion development

  2. (Fusion energy research)

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, C.A. (ed.)

    1988-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices (FY88); tokamak fusion test reactor; Princeton beta Experiment-Modification; S-1 Spheromak; current drive experiment; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical plasma; tokamak modeling; compact ignition tokamak; international thermonuclear experimental reactor; Engineering Department; Project Planning and Safety Office; quality assurance and reliability; and technology transfer.

  3. Fusion impulse containment

    International Nuclear Information System (INIS)

    Bohachevsky, I.O.

    1979-01-01

    The characteristics of impact fusion energy releases are not known sufficiently well to examine in detail specific containment vessel concepts or designs. Therefore it appears appropriate to formulate the impulse containment problem in general and to derive results in the form of explicit expressions from which magnitude estimates and parametric dependencies (trends) can be inferred conveniently and rapidly. In the following presentation we carry out this task using assumptions and approximations that are required to perform the analysis

  4. Nuclear fusion system

    International Nuclear Information System (INIS)

    Dow, W.G.

    1981-01-01

    The invention pertains to the method and apparatus for the confining of a stream of fusible positive ions at values of density and high average kinetic energy, primarily of tightly looping motions, to produce nuclear fusion at a useful rate; more or less intimately mixed with the fusible ions will be lowerenergy electrons at about equal density, introduced solely for the purpose of neutralizing the positive space charge of the ions

  5. [Fusion energy research

    International Nuclear Information System (INIS)

    Phillips, C.A.

    1988-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices (FY88); tokamak fusion test reactor; Princeton beta Experiment-Modification; S-1 Spheromak; current drive experiment; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical plasma; tokamak modeling; compact ignition tokamak; international thermonuclear experimental reactor; Engineering Department; Project Planning and Safety Office; quality assurance and reliability; and technology transfer

  6. Fusion-fission dynamics

    International Nuclear Information System (INIS)

    Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

    1992-01-01

    Classical dynamical calculations of the heavy ion induced fission processes have been performed for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus. As a result prescission lifetimes were obtained and compared with the experimental values. The comparison between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. (orig.)

  7. Fusion propulsion systems

    International Nuclear Information System (INIS)

    Haloulakos, V.E.; Bourque, R.F.

    1989-01-01

    The continuing and expanding national efforts in both the military and commercial sectors for exploration and utilization of space will require launch, assembly in space, and orbital transfer of large payloads. The currently available delivery systems, utilizing various forms of chemical propulsion, do not have the payload capacity to fulfill the planned missions. National planning documents such as Air Force Project Forecast II and the National Commission on Space Report to the President contain numerous missions and payload delivery schedules that are beyond the present capabilities of the available systems, such as the Space Shuttle and the Expendable Launch Vehicles (ELVs). The need, therefore, is very pressing to design, develop, and deploy propulsion systems that offer a quantum level increase in delivered performance. One such potential system is fusion propulsion. This paper summarizes the result of an Air Force Astronautics Laboratory (AFAL) sponsored study of fusion propulsion conducted by the McDonnell Douglas Astronautics Company (MDAC), and its subcontractor General Atomics This study explored the potential of fusion propulsion for Air Force missions. Fusion fuels and existing confinement concepts were evaluated according to elaborate criteria. Two fuels, deuterium-tritium and deuterium-helium 3 (D- 3 He) were considered worthy of further consideration. D- 3 He was selected as the most attractive for this Air Force study. The colliding translating compact torus confinement concept was evaluated in depth and found to possibly possess the low mass and compactness required. Another possible concept is inertial confinement with the propellant surrounding the target. 5 refs., 5 figs., 8 tabs

  8. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    Moons, F.

    1998-01-01

    SCK-CEN's programme on fusion reactor materials includes studies (1) to investigate fracture mechanics of neutron-irradiated beryllium; (2) to describe the helium behaviour in irradiated beryllium at atomic scale; (3) to define the kinetics of beryllium reacting with air or steam; (3) to perform a feasibility study for the testing of integrated blanket modules under neutron irradiation. Progress and achievements in 1997 are reported

  9. Automating ASW fusion

    OpenAIRE

    Pabelico, James C.

    2011-01-01

    Approved for public release; distribution is unlimited. This thesis examines ASW eFusion, an anti-submarine warfare (ASW) tactical decision aid (TDA) that utilizes Kalman filtering to improve battlespace awareness by simplifying and automating the track management process involved in anti-submarine warfare (ASW) watchstanding operations. While this program can currently help the ASW commander manage uncertainty and make better tactical decisions, the program has several limitations. Comman...

  10. Fusion reactor critical issues

    International Nuclear Information System (INIS)

    1987-11-01

    The document summarizes the results of a series of INTOR-related meetings organized by the IAEA in 1985-1986 with the following topics: Impurity control modelling, non-inductive current-drive, confinement in tokamaks with intense heating and DEMO requirements. These results are useful to the specialists involved in research on large fusion machines or in the design activity on the next generation tokamaks. Refs, figs and tabs

  11. Inertial confinement fusion

    International Nuclear Information System (INIS)

    Nuckolls, J.H.; Wood, L.L.

    1988-01-01

    Edward Teller has been a strong proponent of harnessing nuclear explosions for peaceful purposes. There are two approaches: Plowshare, which utilizes macro- explosions, and inertial confinement fusion, which utilizes microexplosions. The development of practical fusion power plants is a principal goal of the inertial program. It is remarkable that Teller's original thermonuclear problem, how to make super high yield nuclear explosions, and the opposite problem, how to make ultra low yield nuclear explosions, may both be solved by Teller's radiation implosion scheme. This paper reports on the essential physics of these two thermonuclear domains, which are separated by nine orders of magnitude in yield, provided by Teller's similarity theorem and its exceptions. Higher density makes possible thermonuclear burn of smaller masses of fuel. The leverage is high: the scale of the explosion diminishes with the square of the increase in density. The extraordinary compressibility of matter, first noticed by Teller during the Los Alamos atomic bomb program, provides an almost incredible opportunity to harness fusion. The energy density of thermonuclear fuels isentropically compressed to super high-- -densities---even to ten thousand times solid density---is small compared to the energy density at thermonuclear ignition temperatures. In small masses of fuel imploded to these super high matter densities, the energy required to achieve ignition may be greatly reduced by exploiting thermonuclear propagation from a relatively small hot spot

  12. Heavy ion fusion

    International Nuclear Information System (INIS)

    Hofmann, Ingo

    1993-01-01

    With controlled thermonuclear fusion holding out the possibility of a prolific and clean new source of energy, the goal remains elusive after many years of continual effort. While the conventional Tokamak route with magnetic confinement continues to hit the headlines, other alternatives are now becoming competitive. One possible solution is to confine the thermonuclear fuel pellet by high power beams. Current research and perspectives for future work in such inertial confinement was the subject of the 'Prospects for Heavy Ion Fusion' European Research Conference held in Aghia Pelaghia, Crete, last year. Its main focus was on the potential of heavy ion accelerators as well as recent advances in target physics with high power lasers and light ion beams. Carlo Rubbia declared that high energy accelerators, with their high efficiency, are the most promising approach to economical fusion energy production. However the need for cost saving in the driver accelerator requires new ideas in target design tailored to the particularities of heavy ion beams, which need to be pushed to the limits of high current and phase space density at the same time

  13. The light controlled fusion

    International Nuclear Information System (INIS)

    Gong, BingXin

    2013-01-01

    Highlights: • This is a new technique for controlled fusion. • There will be an attraction force between the two oscillating nuclei. • The attraction force is greater than the Coulomb repulsion between the two nuclei. • The kinetic energy and the density of the two nuclei can be controlled. • The electric vector and the frequency of the light can be controlled. - Abstract: This is a new technique for controlled fusion. When two nuclei are colliding with each other, light, whose the frequency is higher than the minimal threshold frequency of lithium, will be aimed directly at the two nuclei, the two nuclei will perform the simple harmonic oscillation, the charged particle’s simple harmonic oscillation can be considered as an oscillating electric dipole, and the two oscillating nuclei will radiate the electromagnetic wave. Either of the two oscillating electric dipoles will attract each other, or they will repulse each other. There will be an attraction force between the two oscillating nuclei. When the attraction force is greater than the Coulomb repulsion between the two nuclei, the two nuclei will fuse together. Where the kinetic energy and the density of the two nuclei can be controlled, the electric vector and the frequency of the light can be controlled also and, therefore, the fusion can be controlled

  14. Future of fusion implementation

    International Nuclear Information System (INIS)

    Beardsworth, E.; Powell, J.R.

    1978-01-01

    For fusion to become available for commercial use in the 21st century, R and D must be undertaken now. But it is hard to justify these expenditures with a cost/benefit oriented assessment methodology, because of both the time-frame and the uncertainty of the future benefits. Focusing on the factors most relevant for current consideration of fusion's commercial prospects, i.e., consumption levels and the outcomes for fission, solar, and coal, many possible futures of the US energy system are posited and analyzed under various assumptions about costs. The Reference Energy System approach was modified to establish both an appropriate degree of detail and explicit time dependence, and a computer code used to organize the relevant data and to perform calculations of system cost (annual and discounted present value), resource use, and residuals that are implied by the consumptions levels and technology mix in each scenario. Not unreasonable scenarios indicate benefits in the form of direct cost savings, which may well exceed R and D costs, which could be attributed to the implementation of fusion

  15. Jazz-Philosophy Fusion

    Directory of Open Access Journals (Sweden)

    James Tartaglia

    2016-07-01

    Full Text Available In this paper I describe and provide a justification for the fusion of jazz music and philosophy which I have developed; the justification is provided from the perspectives of both jazz and philosophy. I discuss two of my compositions, based on philosophical ideas presented by Schopenhauer and Derek Parfit respectively; links to sound files are provided. The justification emerging from this discussion is that philosophy produces ‘non-argumentative effects’ which provide suitable material for artistic expression and exploration. These effects – which are often emotional – are under-recognised in philosophy, but they do important philosophical work in demarcating the kinds of truths we want to discover, and in sustaining our search for them. Jazz-Philosophy Fusion can help to increase metaphilosophical self-consciousness about these effects, while also helping to counteract any undue persuasive force they may achieve. Jazz is a particularly suitable medium because it has independently developed a concern with philosophical ideas; because of strong parallels between jazz and philosophy which explain their mutual openness to fusions, and because improvisation very effectively facilitates the direct audience engagement essential to inducing these effects.

  16. Solenoidal fusion system

    International Nuclear Information System (INIS)

    Linlor, W.I.

    1980-01-01

    This invention discloses apparatus and methods to produce nuclear fusion utilizing fusible material in the form of high energy ion beams confined in magnetic fields. For example, beams of deuterons and tritons are injected in the same direction relative to the axis of a vacuum chamber. The ion beams are confined by the magnetic fields of long solenoids. The products of the fusion reactions, such as neutrons and alpha particles, escape to the wall surrounding the vacuum chamber, producing heat. The momentum of the deuterons is approximately equal to the momentum of the tritons, so that both types of ions follow the same path in the confining magnetic field. The velocity of the deuteron is sufficiently greater than the velocity of the triton so that overtaking collisions occur at a relative velocity which produces a high fusion reaction cross section. Electrons for space charge neutralization are obtained by ionization of residual gas in the vacuum chamber, and additionally from solid material (Irradiated with ultra-violet light or other energetic radiation) adjacent to the confinement region. For start-up operation, injected high-energy molecular ions can be dissociated by intense laser beam, producing trapping via change of charge state. When sufficiently intense deuteron and triton beams have been produced, the laser beam can be removed, and subsequent change of charge state can be achieved by collisions

  17. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Fessenden, T.J.; Friedman, A.

    1991-01-01

    This report describes the research status in the following areas of research in the field of heavy ion inertial fusion: (1) RF accelerators, storage rings, and synchrotrons; (2) induction linacs; (3) recirculation induction accelerator approach; (4) a new accelerator concept, the ''Mirrortron''; (5) general issues of transport, including beam merging, production of short, fat quadrupoles with nearly linear focusing, calculations of beam behaviour in image fields; 3-D electrostatic codes on drift compression with misalignments and transport around bends; (6) injectors, ion sources and RFQs, a.o., on the development of a 27 MHz RFQ to be used for the low energy portion of a new injector for all ions up to Uranium, and the development of a 2 MV carbon ion injector to provide 16 C + beams of 0.5 A each for ILSE; (7) beam transport from accelerator to target, reporting, a.o., the feasibility to suppress third-order aberrations; while Particle-in-Cell simulations on the propagation of a non-neutral ion beam in a low density gas identified photo-ionization by thermal X-rays from the target as an important source of defocusing; (9) heavy ion target studies; (10) reviewing experience with laser drivers; (11) ion cluster stopping and muon catalyzed fusion; (12) heavy ion systems, including the option of a fusion-fission burner. 1 tab

  18. Fusion research at Culham site

    International Nuclear Information System (INIS)

    Tolonen, P.; Toppila, T.

    1998-01-01

    One of the many targets on the Finnish Nuclear Society (ATS) excursion to England was the Culham fusion research site. The site has divided into two parts. One of them is UKAEA Fusion with small scale fusion reactors and 200 employees. UKAEA has 3 fusion reactors at Culham site. One of is the START (Small Tight Aspect Ratio Tokamak) which was operational since 1991 but is today already out of operation. UKAEA has been operating a JET-like tokamak fusion reactor COMPASS-D since 1989. The latest of three reactors is MAST (Mega Amp Spherical Tokamak), which is still under construction. The first plasma will take place in the end of 1998. Another part of Culham site is JET (Joint European Torus), an all-European fusion undertaking with 350 employees. 150 of them are from various European countries and the rest 200 are employed by UKAEA. JET is the biggest fusion reactor ever and it represents the latest step in world wide fusion programme. In October 1997 JET achieved a world record in fusion power and energy. JET produced 16,1 MW power for 1 s and totally 21,7 MJ energy. This is the closest attempt to achieve break-even conditions. The next step in world wide fusion programme will be international ITER-reactor. This undertaking has some financial problems, since United States has taken distance to magnetic fusion research and moved closer to inertial fusion with funding of US Department of Defence. The planned reactor, however, is physically twice as big as JET. The step after this phase will be DEMO, which is purposed to produce fusion energy. According to our hosts in Culham this phase is 40 years ahead. (author)

  19. Evidence of parasexual activity in "asexual amoebae" Cochliopodium spp. (Amoebozoa): extensive cellular and nuclear fusion.

    Science.gov (United States)

    Tekle, Yonas I; Anderson, O Roger; Lecky, Ariel F

    2014-09-01

    The majority of microbial eukaryotes have long been considered asexual, though new evidence indicates sex, or sexual-like (parasexual) behaviors that deviate from the usual union of two gametes, among other variant aspects. Over a dozen amoebozoans are implicated to have sexual stages. However, the exact mechanism by which sex occurs in these lineages remains elusive. This is mainly due to the diverse quality and cryptic nature of their life cycle. In this study we present evidence of some previously unreported aspects of the life cycle of an amoeba, Cochliopodium, that undergoes unusual intraspecific interactions using light microscopy and immunocytochemistry. Similar to other amoebozoans, Cochliopodium, is considered asexual with no published reports of sex or parasexuality. We also investigated environmental conditions that govern the observed intraspecific interactions. Both light microscopic and immunocytochemistry evidence demonstrates Cochliopodium undergoes cellular fusion (plasmogamy) and nuclear fusion (karyogamy). Large plasmodia eventually undergo karyogamy and contain large fused, polyploid, nuclei. These are observed to fragment, subsequently, by karyotomy (nuclear fission) and cytoplasmic fission to yield uninucleated amoebae. This process could lead to a non-meiotic, parasexual exchange of chromosomes in Cochliopodium. These findings strongly suggest that Cochliopodium is involved in parasexual activity and should no longer be considered strictly asexual. Copyright © 2014 Elsevier GmbH. All rights reserved.

  20. Impaired gamete production and viability in Atlantic croaker collected throughout the 20,000 km(2) hypoxic region in the northern Gulf of Mexico.

    Science.gov (United States)

    Thomas, Peter; Rahman, Md Saydur; Picha, Matthew E; Tan, Wenxian

    2015-12-15

    The long-term impacts of recent marked increases in the incidence and extent of hypoxia (dissolved oxygen Gulf of Mexico. Potential fecundity was significantly lower in croaker collected throughout the ~20,000 km(2) hypoxic region than in croaker from normoxic sites. In vitro bioassays of gamete viability showed reductions in oocyte maturation and sperm motility in croaker collected from the hypoxic sites in response to reproductive hormones which were accompanied by decreases in gonadal levels of membrane progestin receptor alpha, the receptor regulating these processes. The finding that environmental hypoxia exposure reduces oocyte viability in addition to decreasing oocyte production in croaker suggests that fecundity estimates need to be adjusted to account for the decrease in oocyte maturation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Inertial fusion energy; L'energie de fusion inertielle

    Energy Technology Data Exchange (ETDEWEB)

    Decroisette, M.; Andre, M.; Bayer, C.; Juraszek, D. [CEA Bruyeres-le-Chatel, Dir. des Systemes d' Information (CEA/DIF), 91 (France); Le Garrec, B. [CEA Centre d' Etudes Scientifiques et Techniques d' Aquitaine, 33 - Le Barp (France); Deutsch, C. [Paris-11 Univ., 91 - Orsay (France); Migus, A. [Institut d' Optique Centre scientifique, 91 - Orsay (France)

    2005-07-01

    We first recall the scientific basis of inertial fusion and then describe a generic fusion reactor with the different components: the driver, the fusion chamber, the material treatment unit, the target factory and the turbines. We analyse the options proposed at the present time for the driver and for target irradiation scheme giving the state of art for each approach. We conclude by the presentation of LMJ (laser Megajoule) and NIF (national ignition facility) projects. These facilities aim to demonstrate the feasibility of laboratory DT ignition, first step toward Inertial Fusion Energy. (authors)

  2. Recent fusion research in the National Institute for Fusion Science

    International Nuclear Information System (INIS)

    Komori, Akio; Sakakibara, Satoru; Sagara, Akio; Horiuchi, Ritoku; Yamada, Hiroshi; Takeiri, Yasuhiko

    2011-01-01

    The National Institute for Fusion Science (NIFS), which was established in 1989, promotes academic approaches toward the exploration of fusion science for steady-state helical reactor and realizes the establishment of a comprehensive understanding of toroidal plasmas as an inter-university research organization and a key center of worldwide fusion research. The Large Helical Device (LHD) Project, the Numerical Simulation Science Project, and the Fusion Engineering Project are organized for early realization of net current free fusion reactor, and their recent activities are described in this paper. The LHD has been producing high-performance plasmas comparable to those of large tokamaks, and several new findings with regard to plasma physics have been obtained. The numerical simulation science project contributes understanding and systemization of the physical mechanisms of plasma confinement in fusion plasmas and explores complexity science of a plasma for realization of the numerical test reactor. In the fusion engineering project, the design of the helical fusion reactor has progressed based on the development of superconducting coils, the blanket, fusion materials and tritium handling. (author)

  3. Influence of spawning procedure on gametes fertilization success in Salminus hilarii Valenciennes, 1850 (Teleostei: Characidae: Implications for the conservation of this species

    Directory of Open Access Journals (Sweden)

    Renato M. Honji

    Full Text Available Artificial reproduction and gamete fertilization were evaluated in Salminus hilarii wild and domesticated broodstocks. Wild and domesticated broodstocks were artificially induced to reproduction using a carp pituitary treatment. Four groups were considered: Group 1 (G1, fish caught in the wild maintained for three years in the same conditions as the domesticated broodstocks and spawned naturally; Group 2 (G2, broodstock born and raised in captivity and spawned naturally; Group 3 (G3, wild broodstocks, which were manually stripped for gamete collection and dry fertilization; and Group 4 (G4, domesticated males and females, also manually stripped. Oocytes, eggs, and larvae were sampled at different time intervals throughout embryonic development. Yolk sac absorption occurred approximately 24-29 h after hatching. Twenty-six h after hatching, the larvae mouths opened. Cannibalism was identified just 28-30 h after hatching. There was no morphological difference in embryonic development among all groups. The number of released eggs per gram of female was: G1: 83.3 ± 24.5 and G2: 103.8 ± 37.4; however, the fertilization success was lower in G2 (42.0 ± 6.37 % compared with G1 (54.7 ± 3.02% (P = 0.011. Hand-stripping of oocytes was not successful and the fertilization rate was zero. The reproduction of this species in captivity is viable, but it is necessary to improve broodstock management to enhance fertilization rates and obtain better fingerling production for restocking programs.

  4. [Image fusion in medical radiology].

    Science.gov (United States)

    Burger, C

    1996-07-20

    Image fusion supports the correlation between images of two or more studies of the same organ. First, the effect of differing geometries during image acquisitions, such as a head tilt, is compensated for. As a consequence, congruent images can easily be obtained. Instead of merely putting them side by side in a static manner and burdening the radiologist with the whole correlation task, image fusion supports him with interactive visualization techniques. This is especially worthwhile for small lesions as they can be more precisely located. Image fusion is feasible today. Easy and robust techniques are readily available, and furthermore DICOM, a rapidly evolving data exchange standard, diminishes the once severe compatibility problems for image data originating from systems of different manufacturers. However, the current solutions for image fusion are not yet established enough for a high throughput of fusion studies. Thus, for the time being image fusion is most appropriately confined to clinical research studies.

  5. Intitutional constraints to fusion commercialization

    International Nuclear Information System (INIS)

    1979-10-01

    The major thrust of this report is that the long time frame associated with the development of commercial fusion systems in the context of the commercialization and institutional history of an allied technology, fission-power, suggests that fusion commercialization will not occur without active and broad-based support on the part of the Nation's political leaders. Its key recommendation is that DOE fusion planners devote considerable resources to analytical efforts aimed at determining the need for fusion and the timing of that need, in order to convince policymakers that they need do more than preserve fusion as an option for application at some indefinite point in the future. It is the thesis of the report that, in fact, an act of political vision on the part of the Nation's leaders will be required to accomplish fusion commercialization

  6. Fusion power and its prospects

    International Nuclear Information System (INIS)

    Kammash, T.

    1981-01-01

    Recent progress in research towards the development of fusion power is reviewed. In the magnetic approach, the impressive advances made in Tokamak research in the past few years have bolstered the confidence that experimental Tokamak devices currently under construction will demonstrate the break-even condition or scientific feasibility of fusion power. Exciting and innovative ideas in mirror magnetic confinement are expected to culminate in high-Q devices which will make open-ended confinement a serious contender for fusion reactors. In the inertial confinement approach, conflicting pellet temperature requirements have placed severe constraints on useful laser intensities and wavelengths for laser-driven fusion. Relativistic electron beam fusion must solve critical focusing and pellet coupling problems, and the newly proposed heavy ion beam fusion, though feasible and attractive in principle, requires very high energy particles for which the accelerator technology may not be available for some time to come

  7. Fusion power: the transition from fundamental science to fusion reactor engineering

    International Nuclear Information System (INIS)

    Post, R.F.

    1975-01-01

    The historical development of fusion research is outlined. The basics of fusion power along with fuel cost and advantages of fusion are discussed. Some quantitative requirements for fusion power are described. (MOW)

  8. Weaving Hilbert space fusion frames

    OpenAIRE

    Neyshaburi, Fahimeh Arabyani; Arefijamaal, Ali Akbar

    2018-01-01

    A new notion in frame theory, so called weaving frames has been recently introduced to deal with some problems in signal processing and wireless sensor networks. Also, fusion frames are an important extension of frames, used in many areas especially for wireless sensor networks. In this paper, we survey the notion of weaving Hilbert space fusion frames. This concept can be had potential applications in wireless sensor networks which require distributed processing using different fusion frames...

  9. ALKALI FUSION OF ROSETTA ZIRCON

    International Nuclear Information System (INIS)

    DAHER, A.

    2008-01-01

    The decomposition of Rosetta zircon by fusion with different types of alkalis has been investigated. These alkalis include sodium hydroxide, potassium hydroxide and eutectic mixture of both. The influences of the reaction temperature, zircon to alkalis ratio, fusion time and the stirring of the reactant on the fusion reaction have been evaluated. The obtained results favour the decomposition of zircon with the eutectic alkalis mixture by a decomposition efficiency of 96% obtained at 500 0 C after one hour

  10. High Level Information Fusion (HLIF) with nested fusion loops

    Science.gov (United States)

    Woodley, Robert; Gosnell, Michael; Fischer, Amber

    2013-05-01

    Situation modeling and threat prediction require higher levels of data fusion in order to provide actionable information. Beyond the sensor data and sources the analyst has access to, the use of out-sourced and re-sourced data is becoming common. Through the years, some common frameworks have emerged for dealing with information fusion—perhaps the most ubiquitous being the JDL Data Fusion Group and their initial 4-level data fusion model. Since these initial developments, numerous models of information fusion have emerged, hoping to better capture the human-centric process of data analyses within a machine-centric framework. 21st Century Systems, Inc. has developed Fusion with Uncertainty Reasoning using Nested Assessment Characterizer Elements (FURNACE) to address challenges of high level information fusion and handle bias, ambiguity, and uncertainty (BAU) for Situation Modeling, Threat Modeling, and Threat Prediction. It combines JDL fusion levels with nested fusion loops and state-of-the-art data reasoning. Initial research has shown that FURNACE is able to reduce BAU and improve the fusion process by allowing high level information fusion (HLIF) to affect lower levels without the double counting of information or other biasing issues. The initial FURNACE project was focused on the underlying algorithms to produce a fusion system able to handle BAU and repurposed data in a cohesive manner. FURNACE supports analyst's efforts to develop situation models, threat models, and threat predictions to increase situational awareness of the battlespace. FURNACE will not only revolutionize the military intelligence realm, but also benefit the larger homeland defense, law enforcement, and business intelligence markets.

  11. An electrolytic route to fusion?

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    A patent has been granted by the Swedish Patent Authority for a new process to initiate and control energy generation through fusion reactions of hydrogen. According to the patent-holder, the Swedish company AB Technology Development, the fusion power process could be available for commercial applications within 4-5 years if laboratory and pilot plant tests prove successful. The new process employs a high voltage discharge in heavy water to create conditions under which, according to the patent holder, a high probability of fusion is achieved without the extraordinary high temperatures required in a conventional fusion reactor. (author)

  12. Radioisotope production in fusion reactors

    International Nuclear Information System (INIS)

    Engholm, B.A.; Cheng, E.T.; Schultz, K.R.

    1986-01-01

    Radioisotope production in fusion reactors is being investigated as part of the Fusion Applications and Market Evaluation (FAME) study. /sup 60/Co is the most promising such product identified to date, since the /sup 60/Co demand for medical and food sterilization is strong and the potential output from a fusion reactor is high. Some of the other radioisotopes considered are /sup 99/Tc, /sup 131/l, several Eu isotopes, and /sup 210/Po. Among the stable isotopes of interest are /sup 197/Au, /sup 103/Rh and Os. In all cases, heat or electricity can be co-produced from the fusion reactor, with overall attractive economics

  13. Results of nuclear fusion development

    International Nuclear Information System (INIS)

    Yamamoto, Kenzo

    1975-01-01

    Compared with the nuclear fission research which followed that in advanced countries, Japan has treaded on its own track in nuclear fusion development; in the former, she had been far behind other leading countries. Characteristic of the efforts in Japan is the collaboration with educational institutions. Works are now carried out mainly in Tokamak plasma confinement, though other means being studied simultaneously. The nation's fusion research program is the realization of a fusion reactor at the turn of the present century, based on the world-level results attained with Tokamak. Past developments in the nuclear fusion research, the current status, and aspects for the future are discribed. (Mori, K.)

  14. Stockpile tritium production from fusion

    International Nuclear Information System (INIS)

    Lokke, W.A.; Fowler, T.K.

    1986-01-01

    A fusion breeder holds the promise of a new capability - ''dialable'' reserve capacity at little additional cost - that offers stockpile planners a new way to deal with today's uncertainties in forecasting long range needs. Though still in the research stage, fusion can be developed in time to meet future military requirements. Much of the necessary technology will be developed by the ongoing magnetic fusion energy program. However, a specific program to develop the nuclear technology required for materials production is needed if fusion is to become a viable option for a new production complex around the turn of the century

  15. Economic potential of inertial fusion

    International Nuclear Information System (INIS)

    Nuckolls, J.H.

    1984-04-01

    Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents

  16. Synchrotron radiation and fusion materials

    International Nuclear Information System (INIS)

    Nielsen, S.F.

    2009-01-01

    The development of fusion energy is approaching a stage where the capabilities of materials will be dictating the further progress and the time scale for the attainment of fusion power. EU has therefore funded the Fusion Energy Materials Science project Coordination Action (FEMaS - CA) with the intension to utilise the know-how in the materials community to help overcome the material science problems with the fusion related materials. The FEMaS project and some of the possible applications of synchrotron radiation for materials characterisation are described in this paper. (au)

  17. Cold nuclear fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tsyganov, E.N., E-mail: edward.tsyganov@coldfusion-power.com [Cold Fusion Power, International (United States); Bavizhev, M.D. [LLC “Radium”, Moscow (Russian Federation); Buryakov, M.G. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation); Dabagov, S.B. [RAS P.N. Lebedev Physical Institute, Leninsky pr. 53, 119991 Moscow (Russian Federation); National Research Nuclear University MEPhI, Kashirskoe shosse 31, 115409 Moscow (Russian Federation); Golovatyuk, V.M.; Lobastov, S.P. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation)

    2015-07-15

    If target deuterium atoms were implanted in a metal crystal in accelerator experiments, a sharp increase in the probability of DD-fusion reaction was clearly observed when compared with the reaction’s theoretical value. The electronic screening potential, which for a collision of free deuterium atoms is about 27 eV, reached 300–700 eV in the case of the DD-fusion in metallic crystals. These data leads to the conclusion that a ban must exist for deuterium atoms to be in the ground state 1s in a niche filled with free conduction electrons. At the same time, the state 2p whose energy level is only 10 eV above that of state 1s is allowed in these conditions. With anisotropy of 2p, 3p or above orbitals, their spatial positions are strictly determined in the lattice coordinate system. When filling out the same potential niches with two deuterium atoms in the states 2p, 3p or higher, the nuclei of these atoms can be permanently positioned without creating much Coulomb repulsion at a very short distance from each other. In this case, the transparency of the potential barrier increases dramatically compared to the ground state 1s for these atoms. The probability of the deuterium nuclei penetrating the Coulomb barrier by zero quantum vibration of the DD-system also increases dramatically. The so-called cold nuclear DD-fusion for a number of years was registered in many experiments, however, was still rejected by mainstream science for allegedly having no consistent scientific explanation. Finally, it received the validation. Below, we outline the concept of this explanation and give the necessary calculations. This paper also considers the further destiny of the formed intermediate state of {sup 4}He{sup ∗}.

  18. Fusion technology projects

    International Nuclear Information System (INIS)

    Elen, J.D.

    1985-11-01

    The current status of the European Fusion File project (EFF) is reviewed. Some new tools for the nuclear-data evaluation and the processing are discussed. A method description and users manual for the toroidal-geometry neutronic program system FURNACE has been published. Calculations with FURNACE have been started to obtain the effective tritium breeding ratio and the distribution of the nuclear heat for the 17 Li 83 Pb blanket in the NET II torus geometry. The results of several experiments are reported: tensile tests on vanadium alloy V5%Ti doped with boron; creep embrittlement of stainless steel type 316; critical current test of a composite niobium-tin superconductor

  19. The laser thermonuclear fusion

    International Nuclear Information System (INIS)

    Coutant, J.; Dautray, R.; Decroisette, M.; Watteau, J.P.

    1987-01-01

    Principle of the thermonuclear fusion by inertial confinement: required characteristics of the deuterium-tritium plasma and of the high power lasers to be used Development of high power lasers: active media used; amplifiers; frequency conversion; beam quality; pulse conditioning; existing large systems. The laser-matter interaction: collision and collective interaction of the laser radiation with matter; transport of the absorbed energy; heating and compression of deuterium-tritium; diagnoses and their comparison with the numerical simulation of the experiment; performances. Conclusions: difficulties to overcome; megajoule lasers; other energy source: particles beams [fr

  20. The future of fusion

    International Nuclear Information System (INIS)

    Sheffield, John

    2001-01-01

    The population of the world is increasing, mainly in the developing world, and is projected to saturate within about 100 years at up to twice the present population of 6 billion people (Bos et al., World Population Projections: 1994-95 Edition, Published for the World Bank). Studies (Goldemberg and Johansson (Eds.), Energy as an Instrument for Socio-Economic Development United Nations Development Programme, New York, 1995, p. 9; United Nations Statistical Yearbooks, 10th issue; 1965; 20th issue; 1975, 22nd issue, 1977; 32nd issue, 1987; and 39th issue 1994, United Nations Publications; Sheffield, J. Technol. Forecasting Social Change 59 (1998) 55.) show that, historically, the population growth rate has varied inversely as the annual per capita energy use in most parts of the developing world, where per capita energy use is typically less than 1 t of oil equivalent energy per year. However, in areas with more than 2-3 t of oil equivalent of energy use per year per person, the growth rate is around zero. If this trend continues, a stable world population will require, allowing for energy efficiency improvements, some 2-3 times the present annual energy use. There is an abundance of energy in the world both exploited and potential to meet this need - fossil, fission, and renewables - but it is not evenly distributed, some are costly, and there are issues of environmental pollution in present use, that may limit use. Fusion energy is a potential longer-term source with attractive environmental features. It is the least-developed energy option and still faces a challenging development path, but there are many areas of the world that would benefit hugely from its deployment from the later part of the 21st century onward, and it is important to consider how it might be deployed. Most fusion power plant options considered today show an economy of scale, owing to the fixed distance needed for shielding fusion neutrons, tritium breeding and handling the heat loads. One

  1. Achievement of solid-state plasma fusion ('Cold-Fusion')

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Zhang, Yue-Chang

    1995-01-01

    Using a 'QMS' (Quadrupole Mass Spectrometer), the authors detected a significantly large amount (10 20 -10 21 [cm -3 ]) of helium ( 2 4 He), which was concluded to have been produced by a deuterium nuclear reaction within a host solid. These results were found to be fully repeatable and supported the authors' proposition that solid state plasma fusion ('Cold Fusion') can be generated in energetic deuterium Strongly Coupled Plasma ('SC-plasma'). This fusion reaction is thought to be sustained by localized 'Latticequake' in a solid-state media with the deuterium density equivalent to that of the host solid. While exploring this basic proposition, the characteristic differences when compared with ultra high temperature-state plasma fusion ('Hot Fusion') are clarified. In general, the most essential reaction product in both types of the deuterium plasma fusion is considered to be helium, irrespective of the 'well-known and/or unknown reactions', which is stored within the solid-state medium in abundance as a 'Residual Product', but which generally can not enter into nor be released from host-solid at a room temperature. Even measuring instruments with relatively poor sensitivity should be able to easily detect such residual helium. An absence of residual helium means that no nuclear fusion reaction has occurred, whereas its presence provides crucial evidence that nuclear fusion has, in fact, occurred in the solid. (author)

  2. Fusion energy 2000. Fusion energy 1998 (2001 Edition). Proceedings

    International Nuclear Information System (INIS)

    2001-01-01

    This CD-ROM contains the Proceedings of 18th International Conference on Fusion Energy. It also contains an updated version of the Fusion Energy Conference 1998 Proceedings (38 additional papers included) as well as information on how to use this CD-ROM. The 18th International Atomic Energy Agency Fusion Energy Conference (FEC-2000) was held in Sorrento, Italy, 4-10 October 2000. 573 participants from over thirty countries and three international organizations took part in this Conference. The Conference was organized by the IAEA in co-operation with the Italian National Agency for New Technology, Energy and Environment (ENEA). Around 400 papers were presented in 22 oral and 8 poster sessions on magnetic confinement experiments, inertial fusion energy, plasma heating and current drive, ITER engineering design activities, magnetic confinement theory, innovative concepts, fusion technology, and safety and environment aspects. The 17th International Atomic Energy Agency (IAEA) Fusion Energy Conference was held in Yokohama, Japan, 19-24 October 1999. This 6-day conference, which was attended by 835 participants from over 30 countries and two international organizations, was organized by the IAEA in co-operation with the Japan Atomic Energy Research Institute (JAERI). More than 360 papers plus 5 summary talks were presented in 23 oral and 8 poster sessions on magnetic confinement and experiments, inertial fusion energy, plasma heating and current drive, ITER engineering design activities, magnetic confinement theory, innovative concepts and fusion technology

  3. Muon-catalyzed fusion: A new direction in fusion research

    International Nuclear Information System (INIS)

    Jones, S.E.

    1986-01-01

    In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored

  4. Muon-catalyzed fusion: a new direction in fusion research

    International Nuclear Information System (INIS)

    Jones, S.E.

    1986-01-01

    In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored

  5. Circumferential fusion improves outcome in comparison with instrumented posterolateral fusion

    DEFF Research Database (Denmark)

    Videbaek, Tina S; Christensen, Finn B; Soegaard, Rikke

    2006-01-01

    with respect to all four DPQ categories: daily activities, work/leisure, anxiety/depression, and social interest. The Oswestry Disability Index supported these results (P ...STUDY DESIGN: Prospective randomized clinical study with a 5- to 9-year follow-up period. OBJECTIVE: The aim of the present study was to analyze the long-term outcome with respect to functional disability, pain, and general health of patients treated by means of circumferential lumbar fusion...... in comparison with those treated by means of instrumented posterolateral lumbar fusion. SUMMARY OF BACKGROUND DATA: Circumferential fusion has become a common procedure in lumbar spinal fusion both as a primary and salvage procedure. However, the claimed advantages of circumferential fusion over conventional...

  6. Culham: fusion and commerce

    International Nuclear Information System (INIS)

    Herman, R.

    1976-01-01

    An overview is given of present day work at the UKAEA research establishment at Culham. This consists not only of research into the practical and theoretical problems of nuclear fusion but also contract work for commercial companies and government agencies. This latter type of work includes studies on the effect of lightening striking aircraft, work on electrostatic hazards in oil tankers and potential uses of lasers in industrial processes such as cutting, drilling and welding. The six toroidal confinement devices at present at Culham are described. Reference is made to the superconducting levitron which is of the toroidal multipole type, two stellarators TORSO and CLEO, the reversed field pinch configuration Zeta experiment and the two tokamaks TOSCA and DITE. Work on such complex machines needs substantial support in engineering and computational skills, and these are also provided by groups at Culham. Research is already under way into overcoming the difficulties of an actual reactor system such as extracting energy from the neutrons coming out of the plasma, and the long term effects of neutron irradiation on cell modules for fusion reactor blankets. (U.K.)

  7. Utility requirements for fusion

    International Nuclear Information System (INIS)

    Vondrasek, R.J.

    1982-02-01

    This report describes work done and results obtained during performance of Task 1 of a study of Utility Requirements and Criteria for Fusion Options. The work consisted of developing a list of utility requirements for fusion optics containing definition of the requirements and showing their relative importance to the utility industry. The project team members developed a preliminary list which was refined by discussions and literature searches. The refined list was recast as a questionnaire which was sent to a substantial portion of the utility industry in this country. Forty-three questionnaire recipients responded including thirty-two utilities. A workshop was held to develop a revised requirements list using the survey responses as a major input. The list prepared by the workshop was further refined by a panel consisting of vice presidents of the three project team firms. The results of the study indicate that in addition to considering the cost of energy for a power plant, utilities consider twenty-three other requirements. Four of the requirements were judged to be vital to plant acceptability: Plant Capital Cost, Financial Liability, Plant Safety and Licensability

  8. Collaborations in fusion research

    International Nuclear Information System (INIS)

    Barnes, D.; Davis, S.; Roney, P.

    1995-01-01

    This paper reviews current experimental collaborative efforts in the fusion community and extrapolates to operational scenarios for the Tokamak Physics Experiment (TPX) and the International Thermonuclear Experimental Reactor (ITER). Current requirements, available technologies and tools, and problems, issues and concerns are discussed. This paper specifically focuses on the issues that apply to experimental operational collaborations. Special requirements for other types of collaborations, such as theoretical or design and construction efforts, will not be addressed. Our current collaborative efforts have been highly successful, even though the tools in use will be viewed as primitive by tomorrow's standards. An overview of the tools and technologies in today's collaborations can be found in the first section of this paper. The next generation of fusion devices will not be primarily institutionally based, but will be national (TPX) and international (ITER) in funding, management, operation and in ownership of scientific results. The TPX will present the initial challenge of real-time remotely distributed experimental data analysis for a steady state device. The ITER will present new challenges with the possibility of several remote control rooms all participating in the real-time operation of the experimental device. A view to the future of remote collaborations is provided in the second section of this paper

  9. Compact magnetic fusion systems

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.

    1983-12-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak/sup 1/ and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics.

  10. Compact magnetic fusion systems

    International Nuclear Information System (INIS)

    Linford, R.K.

    1983-01-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak 1 and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics

  11. Clean steels for fusion

    International Nuclear Information System (INIS)

    Gelles, D.S.

    1995-03-01

    Fusion energy production has an inherent advantage over fission: a fuel supply with reduced long term radioactivity. One of the leading candidate materials for structural applications in a fusion reactor is a tungsten stabilized 9% chromium Martensitic steel. This alloy class is being considered because it offers the opportunity to maintain that advantage in the reactor structure as well as provide good high temperature strength and radiation induced swelling and embrittlement resistance. However, calculations indicate that to obtain acceptable radioactivity levels within 500 years after service, clean steel will be required because the niobium impurity levels must be kept below about 2 appm and nickel, molybdenum, nitrogen, copper, and aluminum must be intentionally restricted. International efforts are addressing the problems of clean steel production. Recently, a 5,000 kg heat was vacuum induction melted in Japan using high purity commercial raw materials giving niobium levels less than 0.7 appm. This paper reviews the need for reduced long term radioactivity, defines the advantageous properties of the tungsten stabilized Martensitic steel class, and describes the international efforts to produce acceptable clean steels

  12. Fusion energy division computer systems network

    International Nuclear Information System (INIS)

    Hammons, C.E.

    1980-12-01

    The Fusion Energy Division of the Oak Ridge National Laboratory (ORNL) operated by Union Carbide Corporation Nuclear Division (UCC-ND) is primarily involved in the investigation of problems related to the use of controlled thermonuclear fusion as an energy source. The Fusion Energy Division supports investigations of experimental fusion devices and related fusion theory. This memo provides a brief overview of the computing environment in the Fusion Energy Division and the computing support provided to the experimental effort and theory research

  13. Fusion energy. What Canada can do

    International Nuclear Information System (INIS)

    Weller, J.A.

    1988-01-01

    As Canada's fusion programs have grown, Canadian capabilities in fusion science and technology have grown and matured with them. The fusion capabilities described in this booklet have come from a coordinated national effort. The Government of Canada is committed to continuing its fusion energy program, and to supporting global fusion efforts. These first pages provide an overview of Canada's fusion work and its underlying basis of science and technology

  14. Data fusion qualitative sensitivity analysis

    International Nuclear Information System (INIS)

    Clayton, E.A.; Lewis, R.E.

    1995-09-01

    Pacific Northwest Laboratory was tasked with testing, debugging, and refining the Hanford Site data fusion workstation (DFW), with the assistance of Coleman Research Corporation (CRC), before delivering the DFW to the environmental restoration client at the Hanford Site. Data fusion is the mathematical combination (or fusion) of disparate data sets into a single interpretation. The data fusion software used in this study was developed by CRC. The data fusion software developed by CRC was initially demonstrated on a data set collected at the Hanford Site where three types of data were combined. These data were (1) seismic reflection, (2) seismic refraction, and (3) depth to geologic horizons. The fused results included a contour map of the top of a low-permeability horizon. This report discusses the results of a sensitivity analysis of data fusion software to variations in its input parameters. The data fusion software developed by CRC has a large number of input parameters that can be varied by the user and that influence the results of data fusion. Many of these parameters are defined as part of the earth model. The earth model is a series of 3-dimensional polynomials with horizontal spatial coordinates as the independent variables and either subsurface layer depth or values of various properties within these layers (e.g., compression wave velocity, resistivity) as the dependent variables

  15. Magnetic fusion energy. Part VI

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The first chapter of this part describes briefly the DOE policy for fusion energy. Subsequent chapters include: FY 1980 overview - activities of the Office of Fusion Energy; subactivity descriptions (confinement systems, development and technology, applied plasma physics, and reactor projects); field activities (DOE laboratories, educational institutions, nonprofit organizations, and commercial firms); commercialization; environmental implications; regional activities; and international programs

  16. Tritium-assisted fusion breeders

    International Nuclear Information System (INIS)

    Greenspan, E.; Miley, G.H.

    1983-08-01

    This report undertakes a preliminary assessment of the prospects of tritium-assisted D-D fuel cycle fusion breeders. Two well documented fusion power reactor designs - the STARFIRE (D-T fuel cycle) and the WILDCAT (Cat-D fuel cycle) tokamaks - are converted into fusion breeders by replacing the fusion electric blankets with 233 U producing fission suppressed blankets; changing the Cat-D fuel cycle mode of operation by one of the several tritium-assisted D-D-based modes of operation considered; adjusting the reactor power level; and modifying the resulting plant cost to account for the design changes. Three sources of tritium are considered for assisting the D-D fuel cycle: tritium produced in the blankets from lithium or from 3 He and tritium produced in the client fission reactors. The D-D-based fusion breeders using tritium assistance are found to be the most promising economically, especially the Tritium Catalyzed Deuterium mode of operation in which the 3 He exhausted from the plasma is converted, by neutron capture in the blanket, into tritium which is in turn fed back to the plasma. The number of fission reactors of equal thermal power supported by Tritium Catalyzed Deuterium fusion breeders is about 50% higher than that of D-T fusion breeders, and the profitability is found to be slightly lower than that of the D-T fusion breeders

  17. Cellulose binding domain fusion proteins

    Science.gov (United States)

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1998-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  18. Laser-induced nuclear fusion

    International Nuclear Information System (INIS)

    Jablon, Claude

    1977-01-01

    Research programs on laser-induced thermonuclear fusion in the United States, in Europe and in USSR are reviewed. The principle of the fusion reactions induced is explained, together with the theoretical effects of the following phenomena: power and type of laser beams, shape and size of the solid target, shock waves, and laser-hydrodynamics coupling problems [fr

  19. The assessment of fusion power

    International Nuclear Information System (INIS)

    Bickerton, Roy

    1990-01-01

    It is argued that the recent 'Science and Technology Options Assessments' of fusion power produced for the European Parliament is incorrecta and misleading. The report takes no account of the complex organizational structure of the European fusion programme, it misrepresents history, and it presents incomprehensible graphical evidence and criteria which are narrowly-based and largely platitudinous. (author)

  20. Magnetic fusion program summary document

    International Nuclear Information System (INIS)

    1979-04-01

    This document outlines the current and planned research, development, and commercialization (RD and C) activities of the Offic of Fusion Energy under the Assistant Secretary for Energy Technology, US Department of Energy (DOE). The purpose of this document is to explain the Office of Fusion Energy's activities to Congress and its committees and to interested members of the public

  1. Fusion Policy Advisory Committee (FPAC)

    International Nuclear Information System (INIS)

    1990-09-01

    This document is the final report of the Fusion Policy Advisory Committee. The report conveys the Committee's views on the matters specified by the Secretary in his charge and subsequent letters to the Committee, and also satisfies the provisions of Section 7 of the Magnetic Fusion Energy Engineering Act of 1980, Public Law 96-386, which require a triennial review of the conduct of the national Magnetic Fusion Energy program. Three sub-Committee's were established to address the large number of topics associated with fusion research and development. One considered magnetic fusion energy, a second considered inertial fusion energy, and the third considered issues common to both. For many reasons, the promise of nuclear fusion as a safe, environmentally benign, and affordable source of energy is bright. At the present state of knowledge, however, it is uncertain that this promise will become reality. Only a vigorous, well planned and well executed program of research and development will yield the needed information. The Committee recommends that the US commit to a plan that will resolve this critically important issue. It also outlines the first steps in a development process that will lead to a fusion Demonstration Power Plant by 2025. The recommended program is aggressive, but we believe the goal is reasonable and attainable. International collaboration at a significant level is an important element in the plan

  2. Cold nuclear fusion. Germany 2012

    Energy Technology Data Exchange (ETDEWEB)

    Petrescu, Florian Ion

    2012-07-01

    Nuclear fusion is the process by which two or more atomic nuclei join together, or ''fuse'', to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to energy which is released. The binding energy of the resulting nucleus is greater than the binding energy of each of the nuclei that fused to produce it. Fusion is the process that powers active stars. Creating the required conditions for fusion on Earth is very difficult, to the point that it has not been accomplished at any scale for protium, the common light isotope of hydrogen that undergoes natural fusion in stars. In nuclear weapons, some of the energy released by an atomic bomb (fission bomb) is used for compressing and heating a fusion fuel containing heavier isotopes of hydrogen, and also sometimes lithium, to the point of ''ignition''. At this point, the energy released in the fusion reactions is enough to briefly maintain the reaction. Fusion-based nuclear power experiments attempt to create similar conditions using far lesser means, although to date these experiments have failed to maintain conditions needed for ignition long enough for fusion to be a viable commercial power source.

  3. Civilian applications of laser fusion

    International Nuclear Information System (INIS)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1978-01-01

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. We have found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser fusion studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented

  4. The status of cold fusion

    Science.gov (United States)

    Storms, E.

    This report attempts to update the status of the phenomenon of cold fusion. The new field is continuing to grow as a variety of nuclear reactions are discovered to occur in a variety of chemical environments at modest temperatures. However, it must be cautioned that most scientists consider cold fusion as something akin to UFO's, ESP, and numerology.

  5. Fusion Power measurement at ITER

    Energy Technology Data Exchange (ETDEWEB)

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

    2015-07-01

    Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

  6. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...

  7. Fusion-bonded fluidic interconnects

    NARCIS (Netherlands)

    Fazal, I.; Elwenspoek, Michael Curt

    2008-01-01

    A new approach to realize fluidic interconnects based on the fusion bonding of glass tubes with silicon is presented. Fusion bond strength analyses have been carried out. Experiments with plain silicon wafers and coated with silicon oxide and silicon nitride are performed. The obtained results are

  8. Kaliski's explosive driven fusion experiments

    International Nuclear Information System (INIS)

    Marshall, J.

    1979-01-01

    An experiment performed by a group in Poland on the production of DD fusion neutrons by purely explosive means is discussed. A method for multiplying shock velocities ordinarily available from high explosives by a factor of ten is described, and its application to DD fusion experiments is discussed

  9. Particle-induced thermonuclear fusion

    International Nuclear Information System (INIS)

    Salisbury, W.W.

    1980-01-01

    A nuclear fusion process for igniting a nuclear fusion pellet in a manner similar to that proposed for laser beams uses, an array of pulsed high energy combined particle beams, focused to bombard the pellet for isentropically compressing it to a Fermi-degenerate state by thermal blow-off and balanced beam momentum transfer. (author)

  10. Fusion characterization of biomass ash

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang

    2016-01-01

    The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two...... stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, Tm, is proposed to represent the severe melting temperature of biomass ash. The fusion...... characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates....

  11. Fusion as an energy option

    International Nuclear Information System (INIS)

    Steiner, D.

    1976-01-01

    The environmental issues, alternative fusion fuels, the economic potential, and the time scale of fusion power are assessed. It is common for the advocate of a long-term energy source to claim his source (fission, fusion, solar, etc.) as the ultimate solution to man's energy needs. The author does not believe that such a stance will lead to a rational energy policy. Dr. Steiner encourages a long-term energy policy that has as its goal the development of fission breeders, fusion, and solar energy--not be totally reliant on a single source. He does advocate vigorous funding for fusion, not because it is a guarantee for ''clean, limitless, and cheap power,'' but because it may provide an important energy option for the next century

  12. Future directions in fusion research

    International Nuclear Information System (INIS)

    Clarke, J.F.

    1987-01-01

    The author discusses his analysis to quantify the priority of fusion R and D in the United States. The conclusion is that this priority has been essentially constant for 35 years with only two exceptions. He identifies four basic problems that must be solved. These problems are: to improve the scientific understanding of confinement concepts if we are going to have an energy source that can be utilized some day; to understand the physics of burning plasmas; to develop the materials for fusion use to realize the environmental potential of fusion; and to develop fusion nuclear technology. A response to these problems is given, based on the author's argument for international collaboration in fusion research

  13. Magnetic fusion energy and computers

    International Nuclear Information System (INIS)

    Killeen, J.

    1982-01-01

    The application of computers to magnetic fusion energy research is essential. In the last several years the use of computers in the numerical modeling of fusion systems has increased substantially. There are several categories of computer models used to study the physics of magnetically confined plasmas. A comparable number of types of models for engineering studies are also in use. To meet the needs of the fusion program, the National Magnetic Fusion Energy Computer Center has been established at the Lawrence Livermore National Laboratory. A large central computing facility is linked to smaller computer centers at each of the major MFE laboratories by a communication network. In addition to providing cost effective computing services, the NMFECC environment stimulates collaboration and the sharing of computer codes among the various fusion research groups

  14. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  15. Is there hope for fusion?

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1990-01-01

    From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025--2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 4 figs., 3 tabs

  16. The scientific status of fusion

    International Nuclear Information System (INIS)

    Crandall, D.H.

    1989-01-01

    The development of fusion energy has been a large-scale scientific undertaking of broad interest. The magnetic plasma containment in tokamaks and the laser-drive ignition of microfusion capsules appear to be scientifically feasible sources of energy. These concepts are bounded by questions of required intensity in magnetid field and plasma currents or in drive energy and, for both concepts, by issues of plasma stability and energy transport. The basic concept and the current scientific issues are described for magnetic fusion and for the interesting, but likely infeasible, muon-catalyzed fusion concept. Inertial fusion is mentioned, qualitatively, to complete the context. For magnetic fusion, the required net energy production within the plasma may be accomplished soon, but the more useful goal of self-sustained plasma ignition requires a new device of somewhat uncertain (factor of 2) cost and size. (orig.)

  17. World progress toward fusion energy

    International Nuclear Information System (INIS)

    Davies, N.A.

    1989-01-01

    The author discusses international progress in fusion research during the last three years. Much of the technical progress has been achieved through international collaboration in magnetic fusion research. This progress has stimulated political interest in a multinational effort, aimed at designing and possibly constructing the world's first experimental fusion reactor. This interest was reflected in recent summit-level discussions involving President Mitterand, General Secretary Gorbachev, and President Reagan. Most recently, the European Community (EC), Japan, the United States, and the U.S.S.R. have decided to begin serious preparation for taking the next step toward practical fusion energy. These parties have agreed to begin the design and supporting R and D for an International Thermonuclear Experimental Reactor (ITER) under the auspices of the International Atomic Energy Agency (IAEA). The initiation of this international program to prepare for a fusion test reactor is discussed

  18. Preparation of GST Fusion Proteins.

    Science.gov (United States)

    Einarson, Margret B; Pugacheva, Elena N; Orlinick, Jason R

    2007-04-01

    INTRODUCTIONThis protocol describes the preparation of glutathione-S-transferase (GST) fusion proteins, which have had a wide range of applications since their introduction as tools for synthesis of recombinant proteins in bacteria. GST was originally selected as a fusion moiety because of several desirable properties. First and foremost, when expressed in bacteria alone, or as a fusion, GST is not sequestered in inclusion bodies (in contrast to previous fusion protein systems). Second, GST can be affinity-purified without denaturation because it binds to immobilized glutathione, which provides the basis for simple purification. Consequently, GST fusion proteins are routinely used for antibody generation and purification, protein-protein interaction studies, and biochemical analysis.

  19. Fusion - 2050 perspective (in Polish)

    CERN Document Server

    Romaniuk, R S

    2013-01-01

    The results of strongly exothermic reaction of thermonuclear fusion between nuclei of deuterium and tritium are: helium nuclei and neutrons, plus considerable kinetic energy of neutrons of over 14 MeV. DT nuclides synthesis reaction is probably not the most favorable one for energy production, but is the most advanced technologically. More efficient would be possibly aneutronic fusion. The EU by its EURATOM agenda prepared a Road Map for research and implementation of Fusion as a commercial method of thermonuclear energy generation in the time horizon of 2050.The milestones on this road are tokomak experiments JET, ITER and DEMO, and neutron experiment IFMIF. There is a hope, that by engagement of the national government, and all research and technical fusion communities, part of this Road Map may be realized in Poland. The infrastructure build for fusion experiments may be also used for material engineering research, chemistry, biomedical, associated with environment protection, power engineering, security, ...

  20. World progress toward fusion energy

    International Nuclear Information System (INIS)

    Clarke, J.F.

    1989-09-01

    This paper will describe the progress in fusion science and technology from a world perspective. The paper will cover the current technical status, including the understanding of fusion's economic, environmental, and safety characteristics. Fusion experiments are approaching the energy breakeven condition. An energy gain (Q) of 30 percent has been achieved in magnetic confinement experiments. In addition, temperatures required for an ignited plasma (Ti = 32 KeV) and energy confinements about 75 percent of that required for ignition have been achieved in separate experiments. Two major facilities have started the experimental campaign to extend these results and achieve or exceed Q = 1 plasma conditions by 1990. Inertial confinement fusion experiments are also approaching thermonuclear conditions and have achieved a compression factor 100-200 times liquid D-T. Because of this progress, the emphasis in fusion research is turning toward questions of engineering feasibility. Leaders of the major fusion R and D programs in the European Community (EC), Japan, the United States, and the U.S.S.R. have agreed on the major steps that are needed to reach the point at which a practical fusion system can be designed. The United States is preparing for an experiment to address the last unexplored scientific issue, the physics of an ignited plasma, during the late 1990's. The EC, Japan, U.S.S.R., and the United States have joined together under the auspices of the International Atomic Energy Agency (IAEA) to jointly design and prepare the validating R and D for an international facility, the International Thermonuclear Experimental Reactor (ITER), to address all the remaining scientific issues and to explore the engineering technology of fusion around the turn of the century. In addition, a network of international agreements have been concluded between these major parties and a number of smaller fusion programs, to cooperate on resolving a complete spectrum of fusion science and