WorldWideScience

Sample records for loach chameleon botia

  1. Effect of Different Fatty Acid Sources of Diet on Growth Performance of Botia Botia macracanthus Bleeker

    Directory of Open Access Journals (Sweden)

    . Sunarto

    2008-07-01

    Full Text Available Fish requires essential fatty acid for growth. Freshwater fish needs linoleat fatty acid (n-6 or combination of linoleat and a-linolenat acids (n-3.  Fish oil contains higher level of n-3, corn oil is rich of n-6, while coconut oil is rich of saturated fatty acids.  This study was conducted to determine the effect of fatty acid sources in diet on growth performance of botia Botia macracanthus. Sources of fatty acid examined were coconut oil (control, corn oil, fish oil, and corn oil + fish oil + coconut oil. The results of study show that daily growth rate of fish fed on diet containing mix of corn-coconut-fish oils (8.39% and only corn oil (8.15% was higher (p0.05.  Survival rate of fish at all treatments was similar, ranged from 90.00 to 93.33%.  Thus, the results suggested that diet containing only corn oil is suitable for botia to obtain higher growth rate and lower feed conversion rate. Keywords: fatty acid, growth performance, botia, Botia macracanthus ABSTRAK Ikan membutuhkan asam lemak essensial (EFA = Essential Fatty Acid untuk pertumbuhannya.  Ikan air tawar memerlukan asam lemak linoleat (n-6 atau gabungan asam lemak linoleat (n-6 dan alfa-linolenat (n-3.  Minyak ikan banyak mengandung asam lemak n-3, minyak jagung kaya akan asam lemak n-6, sementara minyak kelapa banyak mengandung asam lemak jenuh.  Sumber asam lemak yang diuji adalah minyak kelapa  (kontrol, minyak jagung, minyak ikan, dan minyak jagung + minyak ikan + minyak kelapa. Hasil penelitian menunjukkan bahwa laju pertumbuhan harian ikan botia yang diberi pakan yang mengandung campuran minyak jagung-kelapa-ikan (8,39% dan minyak jagung (8,15% saja lebih tinggi (p0,05.  Kelangsungan hidup ikan pada semua perlakuan relatif sama, yaitu berkisar antara 90,00-93,33%. Dengan demikian, pakan untuk ikan botia cukup mengandung minyak jagung saja untuk mendapatkan laju pertumbuhan yang tinggi dengan konversi pakan yang rendah. Kata kunci: asam lemak, kinerja pertumbuhan

  2. Camouflage Chameleons.

    Science.gov (United States)

    Housewright, Mary Kay

    1999-01-01

    Discusses an art activity that has students create pictures in which they first trace a chameleon pattern and then add camouflage to conceal the chameleon. Explains that different materials and techniques are used for students in grades k-1 and 2-5. (CMK)

  3. Derivative chameleons

    International Nuclear Information System (INIS)

    Noller, Johannes

    2012-01-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂ μ φ∂ μ φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂ μ φ∂ μ φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type

  4. Derivative chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Noller, Johannes, E-mail: johannes.noller08@imperial.ac.uk [Theoretical Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BZ (United Kingdom)

    2012-07-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂{sub μ}φ∂{sup μ}φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂{sub μ}φ∂{sup μ}φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type.

  5. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  6. Chameleon fragmentation

    International Nuclear Information System (INIS)

    Brax, Philippe; Upadhye, Amol

    2014-01-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ 4 and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments

  7. Solar Chameleons

    CERN Document Server

    Brax, Philippe

    2010-01-01

    We analyse the creation of chameleons deep inside the sun and their subsequent conversion to photons near the magnetised surface of the sun. We find that the spectrum of the regenerated photons lies in the soft X-ray region, hence addressing the solar corona problem. Moreover, these back-converted photons originating from chameleons have an intrinsic difference with regenerated photons from axions: their relative polarisations are mutually orthogonal before Compton interacting with the surrounding plasma. Depending on the photon-chameleon coupling and working in the strong coupling regime of the chameleons to matter, we find that the induced photon flux, when regenerated resonantly with the surrounding plasma, coincides with the solar flux within the soft X-ray energy range. Moreover, using the soft X-ray solar flux as a prior, we find that with a strong enough photon-chameleon coupling the chameleons emitted by the sun could lead to a regenerated photon flux in the CAST pipes, which could be within the reach...

  8. Solar chameleons

    International Nuclear Information System (INIS)

    Brax, Philippe; Zioutas, Konstantin

    2010-01-01

    We analyze the creation of chameleons deep inside the Sun (R∼0.7R sun ) and their subsequent conversion to photons near the magnetized surface of the Sun. We find that the spectrum of the regenerated photons lies in the soft x-ray region, hence addressing the solar corona problem. Moreover, these back-converted photons originating from chameleons have an intrinsic difference with regenerated photons from axions: their relative polarizations are mutually orthogonal before Compton interacting with the surrounding plasma. Depending on the photon-chameleon coupling and working in the strong coupling regime of the chameleons to matter, we find that the induced photon flux, when regenerated resonantly with the surrounding plasma, coincides with the solar flux within the soft x-ray energy range. Moreover, using the soft x-ray solar flux as a prior, we find that with a strong enough photon-chameleon coupling, the chameleons emitted by the Sun could lead to a regenerated photon flux in the CAST magnetic pipes, which could be within the reach of CAST with upgraded detector performance. Then, axion helioscopes have thus the potential to detect and identify particle candidates for the ubiquitous dark energy in the Universe.

  9. Chameleons: Reptilian Texture

    Science.gov (United States)

    Petersen, Hugh

    2009-01-01

    This article presents an art project inspired by a drawing of a chameleon the author saw in an art-supply catalog. Chameleons prove to be a good subject to highlight shape, color and texture with eigth-graders. In this project, middle- and high-school students draw a chameleon, learn how to use shapes to add to their chameleon drawing, learn how…

  10. Ellipticity Weakens Chameleon Screening

    OpenAIRE

    Burrage, Clare; Copeland, Edmund J.; Stevenson, James

    2014-01-01

    The chameleon mechanism enables a long range fifth force to be screened in dense environments when non-trivial self interactions of the field cause its mass to increase with the local density. To date, chameleon fifth forces have mainly been studied for spherically symmetric sources, however the non-linear self interactions mean that the chameleon responds to changes in the shape of the source differently to gravity. In this work we focus on ellipsoidal departures from spherical symmetry and ...

  11. Chameleon foreCAST

    OpenAIRE

    Brax, Philippe; Lindner, Axel; Zioutas, Konstantin

    2011-01-01

    Dark energy models, such as the chameleon, where the acceleration of the expansion of the universe results from the dynamics of a scalar field coupled to matter, suffer from the potential existence of a fifth force. Three known mechanisms have been proposed to restore General Relativity in the solar system and the laboratory, which are the symmetron/Damour-Polyakov effect, the Vainshtein property and the chameleon screening. Here, we propose to probe the existence of chameleons in the laborat...

  12. Chameleon induced atomic afterglow

    International Nuclear Information System (INIS)

    Brax, Philippe; Burrage, Clare

    2010-01-01

    The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When created inside an optical cavity by passing a laser beam through a constant magnetic field, chameleons are trapped between the cavity walls and form a standing wave. This effect will lead to an afterglow phenomenon even when the laser beam and the magnetic field have been turned off, and could be used to probe the interactions of the chameleon field with matter.

  13. Chameleon Induced Atomic Afterglow

    CERN Document Server

    Brax, Philippe

    2010-01-01

    The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When created inside an optical cavity by passing a laser beam through a constant magnetic field, chameleons are trapped between the cavity walls and form a standing wave. This effect will lead to an afterglow phenomenon even when the laser beam and the magnetic field have been turned off, and could be used to probe the interactions of the chameleon field with matter.

  14. Chameleon induced atomic afterglow

    International Nuclear Information System (INIS)

    Brax, Philippe

    2010-09-01

    The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When created inside an optical cavity by passing a laser beam through a constant magnetic field, chameleons are trapped between the cavity walls and form a standing wave. This effect will lead to an afterglow phenomenon even when the laser beam and the magnetic field have been turned off, and could be used to probe the interactions of the chameleon field with matter. (orig.)

  15. Chameleon induced atomic afterglow

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [CEA, IPhT, CNRS, Gif-sur-Yvette (France). Inst. de Physique Theorique; Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-09-15

    The chameleon is a scalar field whose mass depends on the density of its environment. Chameleons are necessarily coupled to matter particles and will excite transitions between atomic energy levels in an analogous manner to photons. When created inside an optical cavity by passing a laser beam through a constant magnetic field, chameleons are trapped between the cavity walls and form a standing wave. This effect will lead to an afterglow phenomenon even when the laser beam and the magnetic field have been turned off, and could be used to probe the interactions of the chameleon field with matter. (orig.)

  16. Chameleon field theories

    International Nuclear Information System (INIS)

    Khoury, Justin

    2013-01-01

    Chameleons are light scalar fields with remarkable properties. Through the interplay of self-interactions and coupling to matter, chameleon particles have a mass that depends on the ambient matter density. The manifestation of the fifth force mediated by chameleons therefore depends sensitively on their environment, which makes for a rich phenomenology. In this paper, we review two recent results on chameleon phenomenology. The first result a pair of no-go theorems limiting the cosmological impact of chameleons and their generalizations: (i) the range of the chameleon force at cosmological density today can be at most ∼Mpc; (ii) the conformal factor relating Einstein- and Jordan-frame scale factors is essentially constant over the last Hubble time. These theorems imply that chameleons have negligible effect on the linear growth of structure, and cannot account for the observed cosmic acceleration except as some form of dark energy. The second result pertains to the quantum stability of chameleon theories. We show how requiring that quantum corrections be small, so as to allow reliable predictions of fifth forces, leads to an upper bound of m −3 ) 1/3 eV for gravitational strength coupling, whereas fifth force experiments place a lower bound of m > 0.0042 eV. An improvement of less than a factor of 2 in the range of fifth force experiments could test all classical chameleon field theories whose quantum corrections are well-controlled and couple to matter with nearly gravitational strength regardless of the specific form of the chameleon potential. (paper)

  17. Chameleonic Theories: A Short Review

    Directory of Open Access Journals (Sweden)

    Andrea Zanzi

    2015-12-01

    Full Text Available In the chameleon mechanism, a field (typically scalar has a mass that depends on the matter density of the environment: the larger is the matter density, the larger is the mass of the chameleon. We briefly review some aspects of chameleonic theories. In particular, in a typical class of these theories, we discuss the lagrangian, the role of conformal transformations, the equation of motion and the thin-shell effect. We also discuss f ( R theories and chameleonic quantum gravity.

  18. Dynamics of supersymmetric chameleons

    International Nuclear Information System (INIS)

    Brax, Philippe; Davis, Anne-Christine; Sakstein, Jeremy

    2013-01-01

    We investigate the cosmological dynamics of a class of supersymmetric chameleon models coupled to cold dark matter fermions. The model includes a cosmological constant in the form of a Fayet-Illiopoulos term, which emerges at late times due to the coupling of the chameleon to two charged scalars. Supergravity corrections ensure that the supersymmetric chameleons are efficiently screened in all astrophysical objects of interest, however this does not preclude the enhancement of gravity on linear cosmological scales. We solve the modified equations for the growth of cold dark matter density perturbations in closed form in the matter era. Using this, we go on to derive the modified linear power spectrum which is characterised by two scales, the horizon size at matter-radiation equality and at the redshift when the chameleon reaches the minimum of its effective potential. We analyse the deviations from the ΛCDM predictions in the linear regime. We find that there is generically a region in the model's parameter space where the model's background cosmology coincides with that of the ΛCDM model. Furthermore, we find that characteristic deviations from ΛCDM are present on the matter power spectrum providing a clear signature of supersymmetric chameleons

  19. Dynamics of supersymmetric chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Theorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Davis, Anne-Christine; Sakstein, Jeremy, E-mail: Philippe.Brax@cea.fr, E-mail: A.C.Davis@damtp.cam.ac.uk, E-mail: J.A.Sakstein@damtp.cam.ac.uk [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2013-10-01

    We investigate the cosmological dynamics of a class of supersymmetric chameleon models coupled to cold dark matter fermions. The model includes a cosmological constant in the form of a Fayet-Illiopoulos term, which emerges at late times due to the coupling of the chameleon to two charged scalars. Supergravity corrections ensure that the supersymmetric chameleons are efficiently screened in all astrophysical objects of interest, however this does not preclude the enhancement of gravity on linear cosmological scales. We solve the modified equations for the growth of cold dark matter density perturbations in closed form in the matter era. Using this, we go on to derive the modified linear power spectrum which is characterised by two scales, the horizon size at matter-radiation equality and at the redshift when the chameleon reaches the minimum of its effective potential. We analyse the deviations from the ΛCDM predictions in the linear regime. We find that there is generically a region in the model's parameter space where the model's background cosmology coincides with that of the ΛCDM model. Furthermore, we find that characteristic deviations from ΛCDM are present on the matter power spectrum providing a clear signature of supersymmetric chameleons.

  20. Chameleon vector bosons

    International Nuclear Information System (INIS)

    Nelson, Ann E.; Walsh, Jonathan

    2008-01-01

    We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This chameleon effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints on chameleonic gauged B-L. We show that although Casimir measurements greatly constrain any B-L force much stronger than gravity with range longer than 0.1 μm, there remains an experimental window for a long-range chameleonic B-L force. Such a force could be much stronger than gravity, and long or infinite range in vacuum, but have an effective range near the surface of the earth which is less than a micron.

  1. The Czech Locative Chameleon

    Directory of Open Access Journals (Sweden)

    Tarald Taraldsen

    2007-12-01

    Full Text Available We show that under certain circumstances, the Czech locative prepositions (LOC show up as directional prepositions (DIR and vice versa, (under different circumstances the Czech DIR PPs show up as LOC. We argue that such a chameleon life of the PPs is structurally dependent.

  2. Chameleon sequences in neurodegenerative diseases

    International Nuclear Information System (INIS)

    Bahramali, Golnaz; Goliaei, Bahram; Minuchehr, Zarrin; Salari, Ali

    2016-01-01

    Chameleon sequences can adopt either alpha helix sheet or a coil conformation. Defining chameleon sequences in PDB (Protein Data Bank) may yield to an insight on defining peptides and proteins responsible in neurodegeneration. In this research, we benefitted from the large PDB and performed a sequence analysis on Chameleons, where we developed an algorithm to extract peptide segments with identical sequences, but different structures. In order to find new chameleon sequences, we extracted a set of 8315 non-redundant protein sequences from the PDB with an identity less than 25%. Our data was classified to “helix to strand (HE)”, “helix to coil (HC)” and “strand to coil (CE)” alterations. We also analyzed the occurrence of singlet and doublet amino acids and the solvent accessibility in the chameleon sequences; we then sorted out the proteins with the most number of chameleon sequences and named them Chameleon Flexible Proteins (CFPs) in our dataset. Our data revealed that Gly, Val, Ile, Tyr and Phe, are the major amino acids in Chameleons. We also found that there are proteins such as Insulin Degrading Enzyme IDE and GTP-binding nuclear protein Ran (RAN) with the most number of chameleons (640 and 405 respectively). These proteins have known roles in neurodegenerative diseases. Therefore it can be inferred that other CFP's can serve as key proteins in neurodegeneration, and a study on them can shed light on curing and preventing neurodegenerative diseases.

  3. Chameleon sequences in neurodegenerative diseases.

    Science.gov (United States)

    Bahramali, Golnaz; Goliaei, Bahram; Minuchehr, Zarrin; Salari, Ali

    2016-03-25

    Chameleon sequences can adopt either alpha helix sheet or a coil conformation. Defining chameleon sequences in PDB (Protein Data Bank) may yield to an insight on defining peptides and proteins responsible in neurodegeneration. In this research, we benefitted from the large PDB and performed a sequence analysis on Chameleons, where we developed an algorithm to extract peptide segments with identical sequences, but different structures. In order to find new chameleon sequences, we extracted a set of 8315 non-redundant protein sequences from the PDB with an identity less than 25%. Our data was classified to "helix to strand (HE)", "helix to coil (HC)" and "strand to coil (CE)" alterations. We also analyzed the occurrence of singlet and doublet amino acids and the solvent accessibility in the chameleon sequences; we then sorted out the proteins with the most number of chameleon sequences and named them Chameleon Flexible Proteins (CFPs) in our dataset. Our data revealed that Gly, Val, Ile, Tyr and Phe, are the major amino acids in Chameleons. We also found that there are proteins such as Insulin Degrading Enzyme IDE and GTP-binding nuclear protein Ran (RAN) with the most number of chameleons (640 and 405 respectively). These proteins have known roles in neurodegenerative diseases. Therefore it can be inferred that other CFP's can serve as key proteins in neurodegeneration, and a study on them can shed light on curing and preventing neurodegenerative diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Chameleon sequences in neurodegenerative diseases

    Energy Technology Data Exchange (ETDEWEB)

    Bahramali, Golnaz [Institute of Biochemistry and Biophysics, University of Tehran, Tehran (Iran, Islamic Republic of); Goliaei, Bahram, E-mail: goliaei@ut.ac.ir [Institute of Biochemistry and Biophysics, University of Tehran, Tehran (Iran, Islamic Republic of); Minuchehr, Zarrin, E-mail: minuchehr@nigeb.ac.ir [Department of Systems Biotechnology, National Institute of Genetic Engineering and Biotechnology, (NIGEB), Tehran (Iran, Islamic Republic of); Salari, Ali [Department of Systems Biotechnology, National Institute of Genetic Engineering and Biotechnology, (NIGEB), Tehran (Iran, Islamic Republic of)

    2016-03-25

    Chameleon sequences can adopt either alpha helix sheet or a coil conformation. Defining chameleon sequences in PDB (Protein Data Bank) may yield to an insight on defining peptides and proteins responsible in neurodegeneration. In this research, we benefitted from the large PDB and performed a sequence analysis on Chameleons, where we developed an algorithm to extract peptide segments with identical sequences, but different structures. In order to find new chameleon sequences, we extracted a set of 8315 non-redundant protein sequences from the PDB with an identity less than 25%. Our data was classified to “helix to strand (HE)”, “helix to coil (HC)” and “strand to coil (CE)” alterations. We also analyzed the occurrence of singlet and doublet amino acids and the solvent accessibility in the chameleon sequences; we then sorted out the proteins with the most number of chameleon sequences and named them Chameleon Flexible Proteins (CFPs) in our dataset. Our data revealed that Gly, Val, Ile, Tyr and Phe, are the major amino acids in Chameleons. We also found that there are proteins such as Insulin Degrading Enzyme IDE and GTP-binding nuclear protein Ran (RAN) with the most number of chameleons (640 and 405 respectively). These proteins have known roles in neurodegenerative diseases. Therefore it can be inferred that other CFP's can serve as key proteins in neurodegeneration, and a study on them can shed light on curing and preventing neurodegenerative diseases.

  5. Tests of chameleon gravity

    Science.gov (United States)

    Burrage, Clare; Sakstein, Jeremy

    2018-03-01

    Theories of modified gravity, where light scalars with non-trivial self-interactions and non-minimal couplings to matter—chameleon and symmetron theories—dynamically suppress deviations from general relativity in the solar system. On other scales, the environmental nature of the screening means that such scalars may be relevant. The highly-nonlinear nature of screening mechanisms means that they evade classical fifth-force searches, and there has been an intense effort towards designing new and novel tests to probe them, both in the laboratory and using astrophysical objects, and by reinterpreting existing datasets. The results of these searches are often presented using different parametrizations, which can make it difficult to compare constraints coming from different probes. The purpose of this review is to summarize the present state-of-the-art searches for screened scalars coupled to matter, and to translate the current bounds into a single parametrization to survey the state of the models. Presently, commonly studied chameleon models are well-constrained but less commonly studied models have large regions of parameter space that are still viable. Symmetron models are constrained well by astrophysical and laboratory tests, but there is a desert separating the two scales where the model is unconstrained. The coupling of chameleons to photons is tightly constrained but the symmetron coupling has yet to be explored. We also summarize the current bounds on f( R) models that exhibit the chameleon mechanism (Hu and Sawicki models). The simplest of these are well constrained by astrophysical probes, but there are currently few reported bounds for theories with higher powers of R. The review ends by discussing the future prospects for constraining screened modified gravity models further using upcoming and planned experiments.

  6. Evolution of Karyotypes in Chameleons

    Directory of Open Access Journals (Sweden)

    Michail Rovatsos

    2017-12-01

    Full Text Available The reconstruction of the evolutionary dynamics of karyotypes and sex determining systems in squamate reptiles is precluded by the lack of data in many groups including most chameleons (Squamata: Acrodonta: Chamaeleonidae. We performed cytogenetic analysis in 16 species of chameleons from 8 genera covering the phylogenetic diversity of the family and also phylogenetic reconstruction of karyotype evolution in this group. In comparison to other squamates, chameleons demonstrate rather variable karyotypes, differing in chromosome number, morphology and presence of interstitial telomeric signal (ITS. On the other hand, the location of rDNA is quite conserved among chameleon species. Phylogenetic analysis combining our new results and previously published data tentatively suggests that the ancestral chromosome number for chameleons is 2n = 36, which is the same as assumed for other lineages of the clade Iguania, i.e., agamids and iguanas. In general, we observed a tendency for the reduction of chromosome number during the evolution of chameleons, however, in Rieppeleon brevicaudatus, we uncovered a chromosome number of 2n = 62, very unusual among squamates, originating from a number of chromosome splits. Despite the presence of the highly differentiated ZZ/ZW sex chromosomes in the genus Furcifer, we did not detect any unequivocal sexual differences in the karyotypes of any other studied species of chameleons tested using differential staining and comparative genomic hybridization, suggesting that sex chromosomes in most chameleons are only poorly differentiated.

  7. A compendium of chameleon constraints

    International Nuclear Information System (INIS)

    Burrage, Clare; Sakstein, Jeremy

    2016-01-01

    The chameleon model is a scalar field theory with a screening mechanism that explains how a cosmologically relevant light scalar can avoid the constraints of intra-solar-system searches for fifth-forces. The chameleon is a popular dark energy candidate and also arises in f ( R ) theories of gravity. Whilst the chameleon is designed to avoid historical searches for fifth-forces it is not unobservable and much effort has gone into identifying the best observables and experiments to detect it. These results are not always presented for the same models or in the same language, a particular problem when comparing astrophysical and laboratory searches making it difficult to understand what regions of parameter space remain. Here we present combined constraints on the chameleon model from astrophysical and laboratory searches for the first time and identify the remaining windows of parameter space. We discuss the implications for cosmological chameleon searches and future small-scale probes.

  8. A compendium of chameleon constraints

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Sakstein, Jeremy, E-mail: clare.burrage@nottingham.ac.uk, E-mail: jeremy.sakstein@port.ac.uk [Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, 209 S. 33rd St., Philadelphia, PA 19104 (United States)

    2016-11-01

    The chameleon model is a scalar field theory with a screening mechanism that explains how a cosmologically relevant light scalar can avoid the constraints of intra-solar-system searches for fifth-forces. The chameleon is a popular dark energy candidate and also arises in f ( R ) theories of gravity. Whilst the chameleon is designed to avoid historical searches for fifth-forces it is not unobservable and much effort has gone into identifying the best observables and experiments to detect it. These results are not always presented for the same models or in the same language, a particular problem when comparing astrophysical and laboratory searches making it difficult to understand what regions of parameter space remain. Here we present combined constraints on the chameleon model from astrophysical and laboratory searches for the first time and identify the remaining windows of parameter space. We discuss the implications for cosmological chameleon searches and future small-scale probes.

  9. Cosmological dynamics of extended chameleons

    International Nuclear Information System (INIS)

    Tamanini, Nicola; Wright, Matthew

    2016-01-01

    We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at the largest distances, while structure formation is analysed at sub-horizon scales within the quasi-static approximation. The late time dynamical transition from dark matter to dark energy domination can be well described by almost all extended chameleon models considered, with no deviations from ΛCDM results at both background and perturbation levels. The results obtained in this work confirm the cosmological viability of extended chameleons as alternative dark energy models.

  10. Cosmological dynamics of extended chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Tamanini, Nicola [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Wright, Matthew, E-mail: nicola.tamanini@cea.fr, E-mail: matthew.wright.13@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom)

    2016-04-01

    We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at the largest distances, while structure formation is analysed at sub-horizon scales within the quasi-static approximation. The late time dynamical transition from dark matter to dark energy domination can be well described by almost all extended chameleon models considered, with no deviations from ΛCDM results at both background and perturbation levels. The results obtained in this work confirm the cosmological viability of extended chameleons as alternative dark energy models.

  11. Spherical collapse in chameleon models

    International Nuclear Information System (INIS)

    Brax, Ph.; Rosenfeld, R.; Steer, D.A.

    2010-01-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity

  12. Search for chameleons with CAST

    Directory of Open Access Journals (Sweden)

    V. Anastassopoulos

    2015-10-01

    Full Text Available In this work we present a search for (solar chameleons with the CERN Axion Solar Telescope (CAST. This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (βm and to photons (βγ via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of βγ≲1011 for 1<βm<106.

  13. Spherical collapse in chameleon models

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Ph. [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Rosenfeld, R. [Instituto de Física Teórica, Universidade Estadual Paulista, Rua Dr. Bento T. Ferraz, 271, 01140-070, São Paulo (Brazil); Steer, D.A., E-mail: brax@spht.saclay.cea.fr, E-mail: rosenfel@ift.unesp.br, E-mail: daniele.steer@apc.univ-paris7.fr [APC, UMR 7164, CNRS, Université Paris 7, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

    2010-08-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity.

  14. Spherical Collapse in Chameleon Models

    CERN Document Server

    Brax, Ph; Steer, D A

    2010-01-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse depends on the initial comoving size of the inhomogeneity.

  15. Search for chameleons with CAST

    DEFF Research Database (Denmark)

    Anastassopoulos, V.; Arik, M.; Aune, S.

    2015-01-01

    In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (βm) and to photons (βΥ) via the Primako eect. By reducing the X-ray detection...... energy threshold used for axions from 1 keV to 400 eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600 eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of βΥ≤1011...

  16. Search for chameleons with CAST

    CERN Document Server

    Anastassopoulos, V; Aune, S; Barth, K; Belov, A; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Christensen, F; Collar, J I; Dafni, T; Davenport, M; Desch, K; Dermenev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Garza, J G; Gazis, E N; Geralis, T; Giomataris, I; Hailey, C; Haug, F; Hasinoff, M D; Hofmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakobsen, A; Jakovčić, K; Kaminski, J; Karuza, M; Kavuk, M; Krčmar, M; Krieger, C; Krüger, A; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Luzón, G; Neff, S; Ortega, I; Papaevangelou, T; Pivovarov, M J; Raffelt, G; Riege, H; Rosu, M; Ruz, J; Savvidis, I; Solanki, S K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K; Brax, P; Lavrentyev, I; Upadhye, A

    2015-01-01

    In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter ($\\beta_{\\rm m}$) and to photons ($\\beta_{\\gamma}$) via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1$\\,$keV to 400$\\,$eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600$\\,$eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of $\\beta_{\\gamma}\\!\\lesssim\\!10^{11}$ for $1<\\beta_{\\rm m}<10^6$.

  17. Cosmological dynamics of a hybrid chameleon scenario

    OpenAIRE

    Nozari, Kourosh; Rashidi, N.

    2013-01-01

    We consider a hybrid scalar field which is non-minimally coupled to the matter and models a chameleon cosmology. By introducing an effective potential, we study the dependence of the effective potential's minimum and hybrid chameleon field's masses to the local matter density. In a dynamical system technique, we analyze the phase space of this two-field chameleon model, find its fixed points and study their stability. We show that the hybrid chameleon domination solution is a stable attractor...

  18. Effective Condition for Whole Testis Cryopreservation of Endangered Miho Spine Loach (Cobitis choii) Through the Optimization of Mud Loach (Misgurnus mizolepis) Whole Testis Cryopreservation Condition.

    Science.gov (United States)

    Kim, J J; Nam, Y K; Bang, I C; Gong, S P

      BACKGROUND: Miho spine loach (Cobitis choii) is an endangered Korean endemic fish. Whole testis cryopreservation is a good way for species preservation, but needs to the sacrifice of a large number of fish to optimize the freezing condition. Considering this limitation, a surrogate fish species was used for the protocol development. This study was to establish the effective condition for Miho spine loach whole testis cryopreservation by optimizing the conditions for whole testis cryopreservation in an allied species, mud loach (Misgurnus mizolepis). The condition for whole testis cryopreservation was optimized in mud loach first, and then the optimal condition was applied to Miho spine loach testes. The optimal condition for mud loach testis cryopreservation consists of the freezing medium containing 1.3 M dimethyl sulfoxide, 6% fetal bovine serum and 0.3 M trehalose, -1 C/min cooling rate and 26 degree C thawing temperature, which also permits effective cryopreservation of Miho spine loach testes. An effective cryopreservation condition for whole testis of the endangered Miho spine loach has been established by using mud loach as a surrogate fish.

  19. Chameleon field dynamics during inflation

    Science.gov (United States)

    Saba, Nasim; Farhoudi, Mehrdad

    By studying the chameleon model during inflation, we investigate whether it can be a successful inflationary model, wherein we employ the common typical potential usually used in the literature. Thus, in the context of the slow-roll approximations, we obtain the e-folding number for the model to verify the ability of resolving the problems of standard big bang cosmology. Meanwhile, we apply the constraints on the form of the chosen potential and also on the equation of state parameter coupled to the scalar field. However, the results of the present analysis show that there is not much chance of having the chameleonic inflation. Hence, we suggest that if through some mechanism the chameleon model can be reduced to the standard inflationary model, then it may cover the whole era of the universe from the inflation up to the late time.

  20. Chameleons with Field Dependent Couplings

    CERN Document Server

    Brax, Philippe; Mota, David F; Nunes, Nelson J; Winther, Hans A

    2010-01-01

    Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power run-away potentials and field independent couplings to matter. In this paper we investigate field-theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for E\\"ot-Wash experiments, fifth-force searches and Casimir force experiments. Requiring that the scalar-field evades gravitational tests, we find that the coupling is sensitive to a mass-scale which is of order of the Hubble scale today.

  1. Dynamical analysis of tachyonic chameleon

    Science.gov (United States)

    Banijamali, Ali; Solbi, Milad

    2017-08-01

    In the present paper we investigate tachyonic chameleon scalar field and present the phase space analysis for four different combinations of the tachyonic potential V(φ ) and the coupling function f(φ ) of the chameleon field with matter. We find some stable solution in which accelerated expansion of the universe is satisfied. In one case where both f(φ ) and V(φ ) are exponential a scaling attractor was found that can give rise to the late-time acceleration of the universe and alleviate the coincidence problem.

  2. Notes on chameleons III. The chameleons of southern Arabia

    NARCIS (Netherlands)

    Hillenius, D.

    1966-01-01

    Three chameleons have been described from southern Arabia: Chamaeleo calyptratus Duméril & Duméril, 1851; Chamaeleo calcarifer Peters, 1871 and Chamaeleo arabicus (Matschie, 1893). Chamaeleo arabicus is clearly connected with typical Chamaeleo chamaeleon by intermediate forms: Chamaeleo chamaeleon

  3. The Chameleon project in retrospective

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Heysters, P.M.; Molenkamp, Egbert

    2004-01-01

    In this paper we describe in retrospective the main results of a four year project, called Chameleon. As part of this project we developed a coarse-grained reconfigurable core for DSP algorithms in wireless devices denoted MONTIUM. After presenting the main achievements within this project we

  4. Detecting solar chameleons through radiation pressure

    CERN Document Server

    Baum, S.; Hoffmann, D.H.H.; Karuza, M.; Semertzidis, Y.K.; Upadhye, A.; Zioutas, K.

    2014-10-24

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and "fifth force" searches on Earth, one needs to screen them. One possibility is the so-called "chameleon" mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary re...

  5. Detecting chameleons through Casimir force measurements

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine; Shaw, Douglas; Mota, David F.

    2007-01-01

    The best laboratory constraints on strongly coupled chameleon fields come not from tests of gravity per se but from precision measurements of the Casimir force. The chameleonic force between two nearby bodies is more akin to a Casimir-like force than a gravitational one: The chameleon force behaves as an inverse power of the distance of separation between the surfaces of two bodies, just as the Casimir force does. Additionally, experimental tests of gravity often employ a thin metallic sheet to shield electrostatic forces; however, this sheet masks any detectable signal due to the presence of a strongly coupled chameleon field. As a result of this shielding, experiments that are designed to specifically test the behavior of gravity are often unable to place any constraint on chameleon fields with a strong coupling to matter. Casimir force measurements do not employ a physical electrostatic shield and as such are able to put tighter constraints on the properties of chameleons fields with a strong matter coupling than tests of gravity. Motivated by this, we perform a full investigation on the possibility of testing chameleon models with both present and future Casimir experiments. We find that present-day measurements are not able to detect the chameleon. However, future experiments have a strong possibility of detecting or rule out a whole class of chameleon models

  6. K-chameleon and the coincidence problem

    International Nuclear Information System (INIS)

    Wei Hao; Cai Ronggen

    2005-01-01

    In this paper we present a hybrid model of k-essence and chameleon, named as k-chameleon. In this model, due to the chameleon mechanism, the directly strong coupling between the k-chameleon field and matters (cold dark matters and baryons) is allowed. In the radiation-dominated epoch, the interaction between the k-chameleon field and background matters can be neglected; the behavior of the k-chameleon therefore is the same as that of the ordinary k-essence. After the onset of matter domination, the strong coupling between the k-chameleon and matters dramatically changes the result of the ordinary k-essence. We find that during the matter-dominated epoch, only two kinds of attractors may exist: one is the familiar K attractor and the other is a completely new, dubbed C attractor. Once the Universe is attracted into the C attractor, the fraction energy densities of the k-chameleon Ω φ and dust matter Ω m are fixed and comparable, and the Universe will undergo a power-law accelerated expansion. One can adjust the model so that the K attractor does not appear. Thus, the k-chameleon model provides a natural solution to the cosmological coincidence problem

  7. Spawning marks in spined loaches (Cobitis taenia; Cobitidae; Teleostei)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg

    2008-01-01

    Roč. 57, 1-2 (2008), s. 168-171 ISSN 0139-7893. [International Conference Loaches of the genus Cobitis and related genera. Šibenik, 24.09.2006-29.09.2006] R&D Projects: GA ČR GA206/05/2556; GA AV ČR IAA600450508 Institutional research plan: CEZ:AV0Z50450515 Keywords : freshwater fish * reproduction * autecology Subject RIV: EG - Zoology Impact factor: 0.522, year: 2008

  8. Halo modelling in chameleon theories

    Energy Technology Data Exchange (ETDEWEB)

    Lombriser, Lucas; Koyama, Kazuya [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Li, Baojiu, E-mail: lucas.lombriser@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: baojiu.li@durham.ac.uk [Institute for Computational Cosmology, Ogden Centre for Fundamental Physics, Department of Physics, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE (United Kingdom)

    2014-03-01

    We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the gravitational modification in high-density regions. Thereby, we use a mass and environment dependent chameleon spherical collapse model, the Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White halo density profile, and the halo model. Furthermore, using the spherical collapse model, we extrapolate a chameleon mass-concentration scaling relation from a ΛCDM prescription calibrated to N-body simulations. We also provide constraints on the model parameters to ensure viability on local scales. We test our description of the halo mass function and nonlinear matter power spectrum against the respective observables extracted from large-volume and high-resolution N-body simulations in the limiting case of f(R) gravity, corresponding to a vanishing Brans-Dicke parameter. We find good agreement between the two; the halo model provides a good qualitative description of the shape of the relative enhancement of the f(R) matter power spectrum with respect to ΛCDM caused by the extra attractive gravitational force but fails to recover the correct amplitude. Introducing an effective linear power spectrum in the computation of the two-halo term to account for an underestimation of the chameleon suppression at intermediate scales in our approach, we accurately reproduce the measurements from the N-body simulations.

  9. Halo modelling in chameleon theories

    International Nuclear Information System (INIS)

    Lombriser, Lucas; Koyama, Kazuya; Li, Baojiu

    2014-01-01

    We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the gravitational modification in high-density regions. Thereby, we use a mass and environment dependent chameleon spherical collapse model, the Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White halo density profile, and the halo model. Furthermore, using the spherical collapse model, we extrapolate a chameleon mass-concentration scaling relation from a ΛCDM prescription calibrated to N-body simulations. We also provide constraints on the model parameters to ensure viability on local scales. We test our description of the halo mass function and nonlinear matter power spectrum against the respective observables extracted from large-volume and high-resolution N-body simulations in the limiting case of f(R) gravity, corresponding to a vanishing Brans-Dicke parameter. We find good agreement between the two; the halo model provides a good qualitative description of the shape of the relative enhancement of the f(R) matter power spectrum with respect to ΛCDM caused by the extra attractive gravitational force but fails to recover the correct amplitude. Introducing an effective linear power spectrum in the computation of the two-halo term to account for an underestimation of the chameleon suppression at intermediate scales in our approach, we accurately reproduce the measurements from the N-body simulations

  10. Search for chameleon particles via photon regeneration

    International Nuclear Information System (INIS)

    Chou, Aaron S.; CCPP, New York U.

    2008-01-01

    We report the first results from the GammeV search for chameleon particles, which may be created via photon-photon interactions within a strong magnetic field. The chameleons are assumed to have matter effects sufficiently strong that they reflect from all solid surfaces of the apparatus, thus evading detection in our previous search for weakly-interacting axion-like particles. We implement a novel technique to create and trap the reflective particles within a jar and to detect them later via their afterglow as they slowly convert back into photons. These measurements provide the first experimental constraints on the couplings of chameleons to photons

  11. Chameleon dark energy models with characteristic signatures

    International Nuclear Information System (INIS)

    Gannouji, Radouane; Moraes, Bruno; Polarski, David; Mota, David F.; Winther, Hans A.; Tsujikawa, Shinji

    2010-01-01

    In chameleon dark energy models, local gravity constraints tend to rule out parameters in which observable cosmological signatures can be found. We study viable chameleon potentials consistent with a number of recent observational and experimental bounds. A novel chameleon field potential, motivated by f(R) gravity, is constructed where observable cosmological signatures are present both at the background evolution and in the growth rate of the perturbations. We study the evolution of matter density perturbations on low redshifts for this potential and show that the growth index today γ 0 can have significant dispersion on scales relevant for large scale structures. The values of γ 0 can be even smaller than 0.2 with large variations of γ on very low redshifts for the model parameters constrained by local gravity tests. This gives a possibility to clearly distinguish these chameleon models from the Λ-cold-dark-matter (ΛCDM) model in future high-precision observations.

  12. Chameleon Search in CAST Experiment at CERN

    CERN Document Server

    AUTHOR|(CDS)2200384; Cetin, Serkant

    Chameleons are hypothetical particles that are proposed as a scalar field to account for the accelerated expansion of the universe, the so-called `dark energy problem'. They are proposed to be produced in the high magnetic field regions inside the Sun and they propagate through or reflect from a medium with the interaction strength depending on the ambient density. The models which characterize the interaction of the chameleons provide two interaction channels: direct coupling to matter dependent on the density and coupling to electromagnetic field by Primakoff effect. CAST Experiment probes the coupling of chameleons with matter with opto-mechanical KWISP detector which is based on Fabry-Perot and Michelson interferometers. In this thesis, starting with an overview of the experimental search efforts of the CAST experiment, theoretical background of the dark energy and the chameleon mechanism will be provided. Then, the detection mechanism based on KWISP detector will be discussed and the versions of the dete...

  13. Detecting solar chameleons through radiation pressure

    CERN Document Server

    Baum, Sebastian

    2014-01-01

    Light scalar fields can drive accelerated expansion of the universe. Hence, scalars are obvious dark energy candidates. To make these models compatible with test of General Relativity in the solar system and fifth force searches on earth, one needs to screen them. One possibility is the chameleon mechanism, which renders an effective mass depending on the local energy density. If chameleons exist, they can be produced in the sun and detected on earth through their radiation pressure. We calculate the solar chameleon spectrum and the sensitivity of an experiment to be carried out at CAST, CERN, utilizing a radiation pressure sensor currently under development at INFN, Trieste. We show that such an experiment will be sensitive to a wide range of model parameters and signifies a pioneering effort searching for chameleons in unprobed paramterspace.

  14. TBCS/Chameleon Utility Trial Report

    National Research Council Canada - National Science Library

    Matthews, Michael L; Brooks, Jeremy E; Angel, Harold A

    2005-01-01

    ...)/Chameleon using participants representing command elements of a combat team. Seven participants role-played an advance to contact scenario developed by Joint Command Staff Training Centre (JCSTC) in 13 segments...

  15. Supernova brightening from chameleon-photon mixing

    International Nuclear Information System (INIS)

    Burrage, C.

    2008-01-01

    Measurements of standard candles and measurements of standard rulers give an inconsistent picture of the history of the universe. This discrepancy can be explained if photon number is not conserved as computations of the luminosity distance must be modified. I show that photon number is not conserved when photons mix with chameleons in the presence of a magnetic field. The strong magnetic fields in a supernova mean that the probability of a photon converting into a chameleon in the interior of the supernova is high, this results in a large flux of chameleons at the surface of the supernova. Chameleons and photons also mix as a result of the intergalactic magnetic field. These two effects combined cause the image of the supernova to be brightened resulting in a model which fits both observations of standard candles and observations of standard rulers

  16. Stable cosmology in chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

    2018-02-01

    The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

  17. On some dynamical chameleon systems

    Science.gov (United States)

    Burkin, I. M.; Kuznetsova, O. I.

    2018-03-01

    It is now well known that dynamical systems can be categorized into systems with self-excited attractors and systems with hidden attractors. A self-excited attractor has a basin of attraction that is associated with an unstable equilibrium, while a hidden attractor has a basin of attraction that does not intersect with small neighborhoods of any equilibrium points. Hidden attractors play the important role in engineering applications because they allow unexpected and potentially disastrous responses to perturbations in a structure like a bridge or an airplane wing. In addition, complex behaviors of chaotic systems have been applied in various areas from image watermarking, audio encryption scheme, asymmetric color pathological image encryption, chaotic masking communication to random number generator. Recently, researchers have discovered the so-called “chameleon systems”. These systems were so named because they demonstrate self-excited or hidden oscillations depending on the value of parameters. The present paper offers a simple algorithm of synthesizing one-parameter chameleon systems. The authors trace the evolution of Lyapunov exponents and the Kaplan-Yorke dimension of such systems which occur when parameters change.

  18. Moduli fields as quintessence and the chameleon

    International Nuclear Information System (INIS)

    Brax, Philippe; Martin, Jerome

    2007-01-01

    We consider models where moduli fields are not stabilized and play the role of quintessence. In order to evade gravitational tests, we investigate the possibility that moduli behave as chameleon fields. We find that, for realistic moduli superpotentials, the chameleon effect is not strong enough, implying that moduli quintessence models are gravitationally ruled out. More generally, we state a no-go theorem for quintessence in supergravity whereby models either behave like a pure cosmological constant or violate gravitational tests

  19. Laboratory constraints on chameleon dark energy and power-law fields

    OpenAIRE

    Steffen, Jason H.; Upadhye, Amol; Baumbaugh, Al; Chou, Aaron S.; Mazur, Peter O.; Tomlin, Ray; Weltman, Amanda; Wester, William

    2010-01-01

    We report results from the GammeV Chameleon Afterglow Search---a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models and dark energy models not previously explored. These results exclude five orders of magnitude in the coupling of chameleons to photons covering a range of four orders of magnitude in chameleon effective mass and, for individual chameleon models, exclude betw...

  20. Lingual structural pattern of juvenile Chameleon, Chameleo chameleon

    Directory of Open Access Journals (Sweden)

    Ahmed A. El Mansi

    2017-06-01

    Full Text Available It is belong to the order Squamata, family, Chamaeleonidae. They have characteristic features of tongue protrusion during capturing prey attracts many research works and assay its velocity during protrusion. Yet little studies touched the anatomical and histological feature of the juvenile tongue and especially the middle tongue region involved in the tongue elongation, the present study aimed to focus on the histological structure of the mid-tongue and clarify its role in projection of the tongue as well as the glandular structure, keratinization of lingual epithelium and proliferation capacity of the fore-tongue region in relation with their feeding habits during the juvenile age. Juvenile Chameleo chameleon are collected from Abu Rawash, north of Giza Governorate, Egypt during summer 2015. Three juvenile developmental stages are used in the present study and categorized according to the gross morphological criteria of head, abdomen and limb lengths. The tongue and hyoid apparatus were removed and photographed. Histological, immunohistochemistry of cytokeratin and stem cell factor and scanning electronic microscopic investigations were carried out on the fore-tongue region, meanwhile only histological studies were done for the median tongue region. Morphometric assessments of number and length of lingual papillae and grades of cytokeratin and stem cell expression were done. Histologically, the dorsal lingual mucosa of the fore-tongue possessed different pattern of lingual papillae including finger-like, club, cubical, biforked and multi-branched papillae. The finger-like papillae are more abundant compared to the other types. The lamina propria of anterior median tongue pad are more glandular and exhibited abundant distribution of PAS-positive tubular glands and moderate alcian blue staining affinity of both alveolar and branched alveolar glands. There is no detected keratinization of the lingual epithelium. Stem cell factor appeared denser on

  1. Notes on Chameleons IV. A New Chameleon, from the Miocene of Fort Ternan, Kenya (Chamaeleonidae, Reptilia)

    NARCIS (Netherlands)

    Hillenius, D.

    1978-01-01

    A new, fossil chameleon is described, † Chamaeleo intermedius, found on the surface at Fort Ternan, Kenya. Most probably it eroded from a layer of fossilized lahar, close to 14 million years old. † Chamaeleo intermedius possesses characters which still occur in recent chameleons, in fact it combines

  2. Detecting solar chameleons through radiation pressure

    International Nuclear Information System (INIS)

    Baum, S.; Cantatore, G.; Hoffmann, D.H.H.; Karuza, M.; Semertzidis, Y.K.; Upadhye, A.; Zioutas, K.

    2014-01-01

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and “fifth force” searches on Earth, one needs to screen them. One possibility is the so-called “chameleon” mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on Earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary results from a force/pressure sensor, currently under development at INFN Trieste, to be mounted in the focal plane of one of the X-Ray telescopes of the CAST experiment at CERN. We show, that such an experiment signifies a pioneering effort probing uncharted chameleon parameter space

  3. The Chameleon Solid Rocket Propulsion Model

    International Nuclear Information System (INIS)

    Robertson, Glen A.

    2010-01-01

    The Khoury and Weltman (2004a and 2004b) Chameleon Model presents an addition to the gravitation force and was shown by the author (Robertson, 2009a and 2009b) to present a new means by which one can view other forces in the Universe. The Chameleon Model is basically a density-dependent model and while the idea is not new, this model is novel in that densities in the Universe to include the vacuum of space are viewed as scalar fields. Such an analogy gives the Chameleon scalar field, dark energy/dark matter like characteristics; fitting well within cosmological expansion theories. In respect to this forum, in this paper, it is shown how the Chameleon Model can be used to derive the thrust of a solid rocket motor. This presents a first step toward the development of new propulsion models using density variations verse mass ejection as the mechanism for thrust. Further, through the Chameleon Model connection, these new propulsion models can be tied to dark energy/dark matter toward new space propulsion systems utilizing the vacuum scalar field in a way understandable by engineers, the key toward the development of such systems. This paper provides corrections to the Chameleon rocket model in Robertson (2009b).

  4. Detecting solar chameleons through radiation pressure

    Energy Technology Data Exchange (ETDEWEB)

    Baum, S., E-mail: sebastian.baum@cern.ch [Uppsala Universitet, Box 516, SE 75120, Uppsala (Sweden); European Organization for Nuclear Research (CERN), Gèneve (Switzerland); Cantatore, G. [Università di Trieste, Via Valerio 2, 34127 Trieste (Italy); INFN Trieste, Padriciano 99, 34149 Trieste (Italy); Hoffmann, D.H.H. [Institut für Kernphysik, TU-Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt (Germany); Karuza, M. [INFN Trieste, Padriciano 99, 34149 Trieste (Italy); Phys. Dept. and CMNST, University of Rijeka, R. Matejcic 2, Rijeka (Croatia); Semertzidis, Y.K. [Center for Axion and Precision Physics Research (IBS), Daejeon 305-701 (Korea, Republic of); Department of Physics, KAIST, Daejeon 305-701 (Korea, Republic of); Upadhye, A. [Physics Department, University of Wisconsin–Madison, 1150 University Avenue, Madison, WI 53706 (United States); Zioutas, K., E-mail: konstantin.zioutas@cern.ch [European Organization for Nuclear Research (CERN), Gèneve (Switzerland); University of Patras, GR 26504 Patras (Greece)

    2014-12-12

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and “fifth force” searches on Earth, one needs to screen them. One possibility is the so-called “chameleon” mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on Earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary results from a force/pressure sensor, currently under development at INFN Trieste, to be mounted in the focal plane of one of the X-Ray telescopes of the CAST experiment at CERN. We show, that such an experiment signifies a pioneering effort probing uncharted chameleon parameter space.

  5. Complex rheological behaviors of loach (Misgurnus anguillicaudatus) skin mucus

    International Nuclear Information System (INIS)

    Wang, Xiang; Su, Heng; Lv, Weiyang; Du, Miao; Song, Yihu; Zheng, Qiang

    2015-01-01

    The functions and structures of biological mucus are closely linked to rheology. In this article, the skin mucus of loach (Misgurnus anguillicaudatus) was proved to be a weak hydrogel susceptible to shear rate, time, and history, exhibiting: (i) Two-region breakdown of its gel structure during oscillatory strain sweep; (ii) rate-dependent thickening followed by three-region thinning with increased shear rate, and straight thinning with decreased shear rate; and (iii) time-dependent rheopexy at low shear rates, and thixotropy at high shear rates. An interesting correlation between the shear rate- and time-dependent rheological behaviors was also revealed, i.e., the rheopexy-thixotropy transition coincided with the first-second shear thinning region transition. Apart from rheology, a structure of colloidal network was observed in loach skin mucus using transmission electron microscopy. The complex rheology was speculated to result from inter- and intracolloid structural alterations. The unique rheology associated with the colloidal network structure, which has never been previously reported in vertebrate mucus, may play a key role in the functions (e.g., flow, reannealing, lubrication, and barrier) of the mucus

  6. Complex rheological behaviors of loach (Misgurnus anguillicaudatus) skin mucus

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiang, E-mail: 11229036@zju.edu.cn; Su, Heng, E-mail: shtdyso@163.com; Lv, Weiyang, E-mail: 3090103369@zju.edu.cn; Du, Miao, E-mail: dumiao@zju.edu.cn; Song, Yihu, E-mail: s-yh0411@zju.edu.cn; Zheng, Qiang, E-mail: zhengqiang@zju.edu.cn [MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2015-01-15

    The functions and structures of biological mucus are closely linked to rheology. In this article, the skin mucus of loach (Misgurnus anguillicaudatus) was proved to be a weak hydrogel susceptible to shear rate, time, and history, exhibiting: (i) Two-region breakdown of its gel structure during oscillatory strain sweep; (ii) rate-dependent thickening followed by three-region thinning with increased shear rate, and straight thinning with decreased shear rate; and (iii) time-dependent rheopexy at low shear rates, and thixotropy at high shear rates. An interesting correlation between the shear rate- and time-dependent rheological behaviors was also revealed, i.e., the rheopexy-thixotropy transition coincided with the first-second shear thinning region transition. Apart from rheology, a structure of colloidal network was observed in loach skin mucus using transmission electron microscopy. The complex rheology was speculated to result from inter- and intracolloid structural alterations. The unique rheology associated with the colloidal network structure, which has never been previously reported in vertebrate mucus, may play a key role in the functions (e.g., flow, reannealing, lubrication, and barrier) of the mucus.

  7. Tuning the Mass of Chameleon Fields in Casimir Force Experiments

    CERN Document Server

    Brax, Ph; Davis, A C; Shaw, D J; Iannuzzi, D

    2010-01-01

    We have calculated the chameleon pressure between two parallel plates in the presence of an intervening medium that affects the mass of the chameleon field. As intuitively expected, the gas in the gap weakens the chameleon interaction mechanism with a screening effect that increases with the plate separation and with the density of the intervening medium. This phenomenon might open up new directions in the search of chameleon particles with future long range Casimir force experiments.

  8. High Tech Art: Chameleon Glass

    Science.gov (United States)

    1993-01-01

    Dichroic Glass is a technology wherein extremely thin films of metal are vacuum deposited on a glass surface. The coated glass shields spacecraft instruments from cosmic radiation and protects human vision from unfiltered sunlight in space. Because the coating process allows some wavelengths of light and color to reflect and others to pass through, a chameleon effect is produced. Murray Schwartz, a former aerospace engineer, has based his business KROMA on this NASA optical technology. He produces dichroic stained glass windows, mobiles and jewelry. The technique involves deposition of super thin layers of metal oxides applied one layer at a time in a specific order and thickness for the desired effect. His product line is unique and has been very successful.

  9. Chameleon fields, wave function collapse and quantum gravity

    International Nuclear Information System (INIS)

    Zanzi, A

    2015-01-01

    Chameleon fields are quantum (usually scalar) fields, with a density-dependent mass. In a high-density environment, the mass of the chameleon is large. On the contrary, in a small-density environment (e.g. on cosmological distances), the chameleon is very light. A model where the collapse of the wave function is induced by chameleon fields is presented. During this analysis, a Chameleonic Equivalence Principle (CEP) will be formulated: in this model, quantum gravitation is equivalent to a conformal anomaly. Further research efforts are necessary to verify whether this proposal is compatible with phenomeno logical constraints. (paper)

  10. The shape dependence of chameleon screening

    Science.gov (United States)

    Burrage, Clare; Copeland, Edmund J.; Moss, Adam; Stevenson, James A.

    2018-01-01

    Chameleon scalar fields can screen their associated fifth forces from detection by changing their mass with the local density. These models are an archetypal example of a screening mechanism, and have become an important target for both cosmological surveys and terrestrial experiments. In particular there has been much recent interest in searching for chameleon fifth forces in the laboratory. It is known that the chameleon force is less screened around non-spherical sources, but only the field profiles around a few simple shapes are known analytically. In this work we introduce a numerical code that solves for the chameleon field around arbitrary shapes with azimuthal symmetry placed in a spherical vacuum chamber. We find that deviations from spherical symmetry can increase the chameleon acceleration experienced by a test particle, and that the least screened objects are those which minimize some internal dimension. For the shapes considered in this work, keeping the mass, density and background environment fixed, the accelerations due to the source varied by a factor of ~ 3.

  11. The CHASE laboratory search for chameleon dark energy

    International Nuclear Information System (INIS)

    Steffen, Jason H.

    2010-01-01

    A scalar field is a favorite candidate for the particle responsible for dark energy. However, few theoretical means exist that can simultaneously explain the observed acceleration of the Universe and evade tests of gravity. The chameleon mechanism, whereby the properties of a particle depend upon the local environment, is one possible avenue. We present the results of the Chameleon Afterglow Search (CHASE) experiment, a laboratory probe for chameleon dark energy. CHASE marks a significant improvement other searches for chameleons both in terms of its sensitivity to the photon/chameleon coupling as well as its sensitivity to the classes of chameleon dark energy models and standard power-law models. Since chameleon dark energy is virtually indistinguishable from a cosmological constant, CHASE tests dark energy models in a manner not accessible to astronomical surveys.

  12. The CHASE laboratory search for chameleon dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason [Fermi National Accelerator Laboratory - Fermilab, P.O. Box 500, Batavia, IL 60510-5011 (United States)

    2010-07-01

    A scalar field is a favorite candidate for the particle responsible for dark energy. However, few theoretical means exist that can simultaneously explain the observed acceleration of the Universe and evade tests of gravity. The chameleon mechanism, whereby the properties of a particle depend upon the local environment, is one possible avenue. I present the results of the Chameleon Afterglow Search (CHASE) experiment, a laboratory probe for chameleon dark energy. CHASE marks a significant improvement over other searches for chameleons both in terms of its sensitivity to the photon/chameleon coupling as well as its sensitivity to the classes of chameleon dark energy models and standard power-law models. Since chameleon dark energy is virtually indistinguishable from a cosmological constant, CHASE tests dark energy models in a manner not accessible to astronomical surveys. (author)

  13. Chameleons with field-dependent couplings

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Mota, David F.; Winther, Hans A.; Nunes, Nelson J.

    2010-01-01

    Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power runaway potentials and field-independent couplings to matter. In this paper we investigate field theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for Eoet-Wash experiments, fifth-force searches and Casimir-force experiments. Requiring that the scalar field evades gravitational tests, we find that the coupling is sensitive to a mass scale which is of order of the Hubble scale today.

  14. Laboratory Constraints on Chameleon Dark Energy and Power-Law Fields

    International Nuclear Information System (INIS)

    Steffen, J. H.; Baumbaugh, A.; Chou, A. S.; Mazur, P. O.; Tomlin, R.; Wester, W.; Upadhye, A.; Weltman, A.

    2010-01-01

    We report results from a search for chameleon particles created via photon-chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of unexplored chameleon power-law and dark energy models. These results exclude 5 orders of magnitude in the coupling of chameleons to photons covering a range of 4 orders of magnitude in chameleon effective mass and, for individual models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

  15. A natural cosmological constant from chameleons

    International Nuclear Information System (INIS)

    Nastase, Horatiu; Weltman, Amanda

    2015-01-01

    We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru–Kallosh–Linde–Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the local density, patches of approximately constant scalar field potential cluster around regions of matter with density above a certain value, generating the effect of a cosmological constant on large scales. This construction addresses both the cosmological constant problem (why Λ is so small, yet nonzero) and the coincidence problem (why Λ is comparable to the matter density now)

  16. A natural cosmological constant from chameleons

    Directory of Open Access Journals (Sweden)

    Horatiu Nastase

    2015-07-01

    Full Text Available We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru–Kallosh–Linde–Trivedi (KKLT-inspired form of the potential and a particular chameleon coupling to the local density, patches of approximately constant scalar field potential cluster around regions of matter with density above a certain value, generating the effect of a cosmological constant on large scales. This construction addresses both the cosmological constant problem (why Λ is so small, yet nonzero and the coincidence problem (why Λ is comparable to the matter density now.

  17. A natural cosmological constant from chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Nastase, Horatiu, E-mail: nastase@ift.unesp.br [Instituto de Física Teórica, UNESP-Universidade Estadual Paulista, R. Dr. Bento T. Ferraz 271, Bl. II, Sao Paulo 01140-070, SP (Brazil); Weltman, Amanda, E-mail: amanda.weltman@uct.ac.za [Astrophysics, Cosmology & Gravity Center, Department of Mathematics and Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7700 (South Africa)

    2015-07-30

    We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru–Kallosh–Linde–Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the local density, patches of approximately constant scalar field potential cluster around regions of matter with density above a certain value, generating the effect of a cosmological constant on large scales. This construction addresses both the cosmological constant problem (why Λ is so small, yet nonzero) and the coincidence problem (why Λ is comparable to the matter density now)

  18. Laboratory constraints on chameleon dark energy and power-law fields

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Upadhye, Amol; Baumbaugh, Al; Chou, Aaron S.; Mazur, Peter O.; Tomlin, Ray; Weltman, Amanda; Wester, William

    2010-01-01

    We report results from the GammeV Chameleon Afterglow Search - a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models and dark energy models not previously explored. These results exclude five orders of magnitude in the coupling of chameleons to photons covering a range of four orders of magnitude in chameleon effective mass and, for individual chameleon models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

  19. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    Science.gov (United States)

    Planinsic, Gorazd; Likar, Andrej

    2012-01-01

    The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

  20. The human chameleon: Hybrid Jews in cinema

    NARCIS (Netherlands)

    Vudka, A.

    2016-01-01

    This research explores the seditious potential of hybrid Jewish figures in cinema, based on certain thinkers of post WWII French philosophy, feminist and postcolonial theories, and traditional Jewish texts, which in different ways point to a reevaluation of the "chameleon Jew" in positive terms.

  1. Higgs production as a probe of chameleon dark energy

    International Nuclear Information System (INIS)

    Brax, Philippe; Burrage, Clare; Davis, Anne-Christine; Seery, David; Weltman, Amanda

    2010-01-01

    In this paper we study various particle physics effects of a light, scalar dark energy field with chameleonlike couplings to matter. We show that a chameleon model with only matter couplings will induce a coupling to photons. In doing so, we derive the first microphysical realization of a chameleonic dark energy model coupled to the electromagnetic field strength. This analysis provides additional motivation for current and near-future tests of axionlike and chameleon particles. We find a new bound on the coupling strength of chameleons in uniformly coupled models. We also study the effect of chameleon fields on Higgs production, which is relevant for hadron colliders. These are expected to manufacture Higgs particles through weak boson fusion, or associated production with a Z or W ± . We show that, like the Tevatron, the LHC will not be able to rule out or observe chameleons through this mechanism, because gauge invariance of the low energy Lagrangian suppresses the corrections that may arise.

  2. Testing chameleon gravity with the Coma cluster

    International Nuclear Information System (INIS)

    Terukina, Ayumu; Yamamoto, Kazuhiro; Lombriser, Lucas; Bacon, David; Koyama, Kazuya; Nichol, Robert C.

    2014-01-01

    We propose a novel method to test the gravitational interactions in the outskirts of galaxy clusters. When gravity is modified, this is typically accompanied by the introduction of an additional scalar degree of freedom, which mediates an attractive fifth force. The presence of an extra gravitational coupling, however, is tightly constrained by local measurements. In chameleon modifications of gravity, local tests can be evaded by employing a screening mechanism that suppresses the fifth force in dense environments. While the chameleon field may be screened in the interior of the cluster, its outer region can still be affected by the extra force, introducing a deviation between the hydrostatic and lensing mass of the cluster. Thus, the chameleon modification can be tested by combining the gas and lensing measurements of the cluster. We demonstrate the operability of our method with the Coma cluster, for which both a lensing measurement and gas observations from the X-ray surface brightness, the X-ray temperature, and the Sunyaev-Zel'dovich effect are available. Using the joint observational data set, we perform a Markov chain Monte Carlo analysis of the parameter space describing the different profiles in both the Newtonian and chameleon scenarios. We report competitive constraints on the chameleon field amplitude and its coupling strength to matter. In the case of f(R) gravity, corresponding to a specific choice of the coupling, we find an upper bound on the background field amplitude of |f R0 | < 6 × 10 −5 , which is currently the tightest constraint on cosmological scales

  3. Odontogenesis in the Veiled Chameleon (Chamaeleo calyptratus).

    Science.gov (United States)

    Buchtová, Marcela; Zahradníček, Oldřich; Balková, Simona; Tucker, Abigail S

    2013-02-01

    Replacement teeth in reptiles and mammals develop from a successional dental lamina. In monophyodont (single generation) species such as the mouse, no successional lamina develops. We have selected a reptilian monophyodont species - the Veiled Chameleon (Chamaeleo calyptratus) - to investigate whether this is a common characteristic of species that do not have replacement teeth. Furthermore, we focus on the sequence of tooth initiation along the jaw, and tooth attachment to the bones. Embryos of the Veiled Chameleon were collected during the first 6 months of incubation (from the 5th to 24th week) at 7-day intervals. After five weeks of incubation, an epithelial thickening was present as a shallow protrusion into the mesenchyme. A week later, the epithelium elongated more deeply into the mesenchyme to form the dental lamina. The formation of all tooth germs along the jaw was initiated from the tip of the dental lamina. Development of a successional dental lamina was initiated during the pre-hatching period but this structure became markedly reduced during juvenile stages. MicroCT analysis showed the presence of a heterodont dentition in young chameleons with multicuspid teeth in the caudal jaw area and simpler monocuspid teeth rostrally. Unlike the pleurodont teeth of most reptilian species, chameleon teeth are acrodontly ankylosed to the bones of the jaw. Odontoblasts produced a layer of predentine that connected the dentine to the supporting bone, with both tooth and bone protruding out of the oral cavity and acting as a functional unit. Chameleons may provide new and useful information to study the molecular interaction at the tooth-bone interface in physiological as well as pathological conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Testing chameleon gravity with the Coma cluster

    Energy Technology Data Exchange (ETDEWEB)

    Terukina, Ayumu; Yamamoto, Kazuhiro [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Kagamiyama 1-3-1, 739-8526 (Japan); Lombriser, Lucas; Bacon, David; Koyama, Kazuya; Nichol, Robert C., E-mail: telkina@theo.phys.sci.hiroshima-u.ac.jp, E-mail: lucas.lombriser@port.ac.uk, E-mail: kazuhiro@hiroshima-u.ac.jp, E-mail: david.bacon@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: bob.nichol@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)

    2014-04-01

    We propose a novel method to test the gravitational interactions in the outskirts of galaxy clusters. When gravity is modified, this is typically accompanied by the introduction of an additional scalar degree of freedom, which mediates an attractive fifth force. The presence of an extra gravitational coupling, however, is tightly constrained by local measurements. In chameleon modifications of gravity, local tests can be evaded by employing a screening mechanism that suppresses the fifth force in dense environments. While the chameleon field may be screened in the interior of the cluster, its outer region can still be affected by the extra force, introducing a deviation between the hydrostatic and lensing mass of the cluster. Thus, the chameleon modification can be tested by combining the gas and lensing measurements of the cluster. We demonstrate the operability of our method with the Coma cluster, for which both a lensing measurement and gas observations from the X-ray surface brightness, the X-ray temperature, and the Sunyaev-Zel'dovich effect are available. Using the joint observational data set, we perform a Markov chain Monte Carlo analysis of the parameter space describing the different profiles in both the Newtonian and chameleon scenarios. We report competitive constraints on the chameleon field amplitude and its coupling strength to matter. In the case of f(R) gravity, corresponding to a specific choice of the coupling, we find an upper bound on the background field amplitude of |f{sub R0}| < 6 × 10{sup −5}, which is currently the tightest constraint on cosmological scales.

  5. Propulsion Physics Using the Chameleon Density Model

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will require a new theory of propulsion. Specifically one that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. The Chameleon Density Model (CDM) is one such model that could provide new paths in propulsion toward this end. The CDM is based on Chameleon Cosmology a dark matter theory; introduced by Khrouy and Weltman in 2004. Chameleon as it is hidden within known physics, where the Chameleon field represents a scalar field within and about an object; even in the vacuum. The CDM relates to density changes in the Chameleon field, where the density changes are related to matter accelerations within and about an object. These density changes in turn change how an object couples to its environment. Whereby, thrust is achieved by causing a differential in the environmental coupling about an object. As a demonstration to show that the CDM fits within known propulsion physics, this paper uses the model to estimate the thrust from a solid rocket motor. Under the CDM, a solid rocket constitutes a two body system, i.e., the changing density of the rocket and the changing density in the nozzle arising from the accelerated mass. Whereby, the interactions between these systems cause a differential coupling to the local gravity environment of the earth. It is shown that the resulting differential in coupling produces a calculated value for the thrust near equivalent to the conventional thrust model used in Sutton and Ross, Rocket Propulsion Elements. Even though imbedded in the equations are the Universe energy scale factor, the reduced Planck mass and the Planck length, which relates the large Universe scale to the subatomic scale.

  6. Testing Chameleon Theories with Light Propagating through a Magnetic Field

    OpenAIRE

    Brax, P.; van de Bruck, C.; Davis, A. C.; Mota, D. F.; Shaw, D. J.

    2007-01-01

    It was recently argued that the observed PVLAS anomaly can be explained by chameleon field theories in which large deviations from Newton's law can be avoided. Here we present the predictions for the dichroism and the birefringence induced in the vacuum by a magnetic field in these models. We show that chameleon particles behave very differently from standard axion-like particles (ALPs). We find that, unlike ALPs, the chameleon particles are confined within the experimental set-up. As a conse...

  7. Alpenglow: A signature for chameleons in axionlike particle search experiments

    International Nuclear Information System (INIS)

    Ahlers, M.; Lindner, A.; Ringwald, A.; Schrempp, L.; Weniger, C.

    2008-01-01

    We point out that chameleon field theories might reveal themselves as an afterglow effect in axionlike particle search experiments due to chameleon-photon conversion in a magnetic field. We estimate the parameter space which is accessible by currently available technology and find that afterglow experiments could constrain this parameter space in a way complementary to gravitational and Casimir force experiments. In addition, one could reach photon-chameleon couplings which are beyond the sensitivity of common laser polarization experiments. We also sketch the idea of a Fabry-Perot cavity with chameleons which could increase the experimental sensitivity significantly

  8. Eidinemacheilus proudlovei, a new subterranean loach from Iraqi Kurdistan (Teleostei; Nemacheilidae).

    Science.gov (United States)

    Freyhof, Jörg; Abdullah, Younis Sabir; Ararat, Korsh; Ibrahim, Hamad; Geiger, Matthias F

    2016-10-04

    Eidinemacheilus proudlovei, new species, is described from subterranean waters in the Little Zab River drainage in Iraqi Kurdistan. After the discovery of E. smithi in 1976, E. proudlovei is the second troglomorphic nemacheilid loach found in the Middle East and the second species placed in Eidinemacheilus. Eidinemacheilus proudlovei is distinguished from E. smithi by having 8+8 or 8+7 branched caudal-fin rays, no adipose keel on the caudal peduncle, enlarged jaws and a fully developed head canal system. It furthers differs substantially in its DNA barcode (>8% K2P distance) from all other nemacheilid loaches in the Middle East, Europe and Western India.

  9. Threat perception in the chameleon (Chamaeleo chameleon): evidence for lateralized eye use.

    Science.gov (United States)

    Lustig, Avichai; Keter-Katz, Hadas; Katzir, Gadi

    2012-07-01

    Chameleons are arboreal lizards with highly independent, large amplitude eye movements. In response to an approaching threat, a chameleon on a vertical pole moves so as to keep itself away from the threat. In so doing, it shifts between monocular and binocular scanning of the threat and of the environment. We analyzed eye movements in the Common chameleon, Chamaeleo chameleon, during avoidance response for lateralization, that is, asymmetry at the functional/behavioral levels. The chameleons were exposed to a threat, approaching horizontally from clockwise or anti-clockwise directions, and that could be viewed monocularly or binocularly. Our results show three broad patterns of eye use, as determined by durations spent viewing the threat and by frequency of eye shifts. Under binocular viewing, two of the patterns were found to be both side dependent, that is, lateralized and role dependent ("leading" or "following"). However, under monocular viewing, no such lateralization was detected. We discuss these findings in light of the situation not uncommon in vertebrates, of independent eye movements and a high degree of optic nerve decussation and that lateralization may well occur in organisms that are regularly exposed to critical stimuli from all spatial directions. We point to the need of further investigating lateralization at fine behavioral levels.

  10. Small scale structure formation in chameleon cosmology

    International Nuclear Information System (INIS)

    Brax, Ph.; Bruck, C. van de; Davis, A.C.; Green, A.M.

    2006-01-01

    Chameleon fields are scalar fields whose mass depends on the ambient matter density. We investigate the effects of these fields on the growth of density perturbations on sub-galactic scales and the formation of the first dark matter halos. Density perturbations on comoving scales R<1 pc go non-linear and collapse to form structure much earlier than in standard ΛCDM cosmology. The resulting mini-halos are hence more dense and resilient to disruption. We therefore expect (provided that the density perturbations on these scales have not been erased by damping processes) that the dark matter distribution on small scales would be more clumpy in chameleon cosmology than in the ΛCDM model

  11. Stability analysis in tachyonic potential chameleon cosmology

    International Nuclear Information System (INIS)

    Farajollahi, H.; Salehi, A.; Tayebi, F.; Ravanpak, A.

    2011-01-01

    We study general properties of attractors for tachyonic potential chameleon scalar-field model which possess cosmological scaling solutions. An analytic formulation is given to obtain fixed points with a discussion on their stability. The model predicts a dynamical equation of state parameter with phantom crossing behavior for an accelerating universe. We constrain the parameters of the model by best fitting with the recent data-sets from supernovae and simulated data points for redshift drift experiment generated by Monte Carlo simulations

  12. Stability analysis in tachyonic potential chameleon cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Farajollahi, H.; Salehi, A.; Tayebi, F.; Ravanpak, A., E-mail: hosseinf@guilan.ac.ir, E-mail: a.salehi@guilan.ac.ir, E-mail: ftayebi@guilan.ac.ir, E-mail: aravanpak@guilan.ac.ir [Department of Physics, University of Guilan, Rasht (Iran, Islamic Republic of)

    2011-05-01

    We study general properties of attractors for tachyonic potential chameleon scalar-field model which possess cosmological scaling solutions. An analytic formulation is given to obtain fixed points with a discussion on their stability. The model predicts a dynamical equation of state parameter with phantom crossing behavior for an accelerating universe. We constrain the parameters of the model by best fitting with the recent data-sets from supernovae and simulated data points for redshift drift experiment generated by Monte Carlo simulations.

  13. Evidence for an elastic projection mechanism in the chameleon tongue

    NARCIS (Netherlands)

    Groot, de J.H.; Leeuwen, van J.L.

    2004-01-01

    To capture prey, chameleons ballistically project their tongues as far as 1.5 body lengths with accelerations of up to 500 m s-2. At the core of a chameleon's tongue is a cylindrical tongue skeleton surrounded by the accelerator muscle. Previously, the cylindrical accelerator muscle was assumed to

  14. Systematic simulations of modified gravity: chameleon models

    International Nuclear Information System (INIS)

    Brax, Philippe; Davis, Anne-Christine; Li, Baojiu; Winther, Hans A.; Zhao, Gong-Bo

    2013-01-01

    In this work we systematically study the linear and nonlinear structure formation in chameleon theories of modified gravity, using a generic parameterisation which describes a large class of models using only 4 parameters. For this we have modified the N-body simulation code ecosmog to perform a total of 65 simulations for different models and parameter values, including the default ΛCDM. These simulations enable us to explore a significant portion of the parameter space. We have studied the effects of modified gravity on the matter power spectrum and mass function, and found a rich and interesting phenomenology where the difference with the ΛCDM paradigm cannot be reproduced by a linear analysis even on scales as large as k ∼ 0.05 hMpc −1 , since the latter incorrectly assumes that the modification of gravity depends only on the background matter density. Our results show that the chameleon screening mechanism is significantly more efficient than other mechanisms such as the dilaton and symmetron, especially in high-density regions and at early times, and can serve as a guidance to determine the parts of the chameleon parameter space which are cosmologically interesting and thus merit further studies in the future

  15. Systematic simulations of modified gravity: chameleon models

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Theorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Davis, Anne-Christine [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Li, Baojiu [Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Winther, Hans A. [Institute of Theoretical Astrophysics, University of Oslo, 0315 Oslo (Norway); Zhao, Gong-Bo, E-mail: philippe.brax@cea.fr, E-mail: a.c.davis@damtp.cam.ac.uk, E-mail: baojiu.li@durham.ac.uk, E-mail: h.a.winther@astro.uio.no, E-mail: gong-bo.zhao@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)

    2013-04-01

    In this work we systematically study the linear and nonlinear structure formation in chameleon theories of modified gravity, using a generic parameterisation which describes a large class of models using only 4 parameters. For this we have modified the N-body simulation code ecosmog to perform a total of 65 simulations for different models and parameter values, including the default ΛCDM. These simulations enable us to explore a significant portion of the parameter space. We have studied the effects of modified gravity on the matter power spectrum and mass function, and found a rich and interesting phenomenology where the difference with the ΛCDM paradigm cannot be reproduced by a linear analysis even on scales as large as k ∼ 0.05 hMpc{sup −1}, since the latter incorrectly assumes that the modification of gravity depends only on the background matter density. Our results show that the chameleon screening mechanism is significantly more efficient than other mechanisms such as the dilaton and symmetron, especially in high-density regions and at early times, and can serve as a guidance to determine the parts of the chameleon parameter space which are cosmologically interesting and thus merit further studies in the future.

  16. Schistura kampucheensis, a new species of loach from Cambodia (Teleostei: Nemacheilidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Petrtýl, M.; Chaloupková, P.; Borin, C.

    2016-01-01

    Roč. 26, č. 4 (2016), s. 353-362 ISSN 0936-9902 R&D Projects: GA ČR GA206/08/0637 Institutional support: RVO:67985904 Keywords : Schistura kampucheensis * loach Subject RIV: EG - Zoology Impact factor: 0.953, year: 2016

  17. Detecting dark energy in orbit: The cosmological chameleon

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine; Khoury, Justin; Weltman, Amanda

    2004-01-01

    We show that the chameleon scalar field can drive the current phase of cosmic acceleration for a large class of scalar potentials that are also consistent with local tests of gravity. These provide explicit realizations of a quintessence model where the quintessence scalar field couples directly to baryons and dark matter with gravitational strength. We analyze the cosmological evolution of the chameleon field and show the existence of an attractor solution with the chameleon following the minimum of its effective potential. For a wide range of initial conditions, spanning many orders of magnitude in initial chameleon energy density, the attractor is reached before nucleosynthesis. Surprisingly, the range of allowed initial conditions leading to a successful cosmology is wider than in normal quintessence. We discuss applications to the cyclic model of the universe and show how the chameleon mechanism weakens some of the constraints on cyclic potentials

  18. Visually guided avoidance in the chameleon (Chamaeleo chameleon): response patterns and lateralization.

    Science.gov (United States)

    Lustig, Avichai; Ketter-Katz, Hadas; Katzir, Gadi

    2012-01-01

    The common chameleon, Chamaeleo chameleon, is an arboreal lizard with highly independent, large-amplitude eye movements. In response to a moving threat, a chameleon on a perch responds with distinct avoidance movements that are expressed in its continuous positioning on the side of the perch distal to the threat. We analyzed body-exposure patterns during threat avoidance for evidence of lateralization, that is, asymmetry at the functional/behavioral levels. Chameleons were exposed to a threat approaching horizontally from the left or right, as they held onto a vertical pole that was either wider or narrower than the width of their head, providing, respectively, monocular or binocular viewing of the threat. We found two equal-sized sub-groups, each displaying lateralization of motor responses to a given direction of stimulus approach. Such an anti-symmetrical distribution of lateralization in a population may be indicative of situations in which organisms are regularly exposed to crucial stimuli from all spatial directions. This is because a bimodal distribution of responses to threat in a natural population will reduce the spatial advantage of predators.

  19. Visually guided avoidance in the chameleon (Chamaeleo chameleon: response patterns and lateralization.

    Directory of Open Access Journals (Sweden)

    Avichai Lustig

    Full Text Available The common chameleon, Chamaeleo chameleon, is an arboreal lizard with highly independent, large-amplitude eye movements. In response to a moving threat, a chameleon on a perch responds with distinct avoidance movements that are expressed in its continuous positioning on the side of the perch distal to the threat. We analyzed body-exposure patterns during threat avoidance for evidence of lateralization, that is, asymmetry at the functional/behavioral levels. Chameleons were exposed to a threat approaching horizontally from the left or right, as they held onto a vertical pole that was either wider or narrower than the width of their head, providing, respectively, monocular or binocular viewing of the threat. We found two equal-sized sub-groups, each displaying lateralization of motor responses to a given direction of stimulus approach. Such an anti-symmetrical distribution of lateralization in a population may be indicative of situations in which organisms are regularly exposed to crucial stimuli from all spatial directions. This is because a bimodal distribution of responses to threat in a natural population will reduce the spatial advantage of predators.

  20. Multiloop atom interferometer measurements of chameleon dark energy in microgravity

    Science.gov (United States)

    Chiow, Sheng-wey; Yu, Nan

    2018-02-01

    Chameleon field is one of the promising candidates of dark energy scalar fields. As in all viable candidate field theories, a screening mechanism is implemented to be consistent with all existing tests of general relativity. The screening effect in the chameleon theory manifests its influence limited only to the thin outer layer of a bulk object, thus producing extra forces orders of magnitude weaker than that of the gravitational force of the bulk. For pointlike particles such as atoms, the depth of screening is larger than the size of the particle, such that the screening mechanism is ineffective and the chameleon force is fully expressed on the atomic test particles. Extra force measurements using atom interferometry are thus much more sensitive than bulk mass based measurements, and indeed have placed the most stringent constraints on the parameters characterizing chameleon field. In this paper, we present a conceptual measurement approach for chameleon force detection using atom interferometry in microgravity, in which multiloop atom interferometers exploit specially designed periodic modulation of chameleon fields. We show that major systematics of the dark energy force measurements, i.e., effects of gravitational forces and their gradients, can be suppressed below all hypothetical chameleon signals in the parameter space of interest.

  1. Search for Chameleon Particles Using a Photon-Regeneration Technique

    International Nuclear Information System (INIS)

    Chou, A. S.; Wester, W.; Baumbaugh, A.; Irizarry-Valle, Y.; Mazur, P. O.; Steffen, J. H.; Tomlin, R.; Yang, X.; Yoo, J.; Gustafson, H. R.; Upadhye, A.; Weltman, A.

    2009-01-01

    We report the first results from the GammeV search for chameleon particles, which may be created via photon-photon interactions within a strong magnetic field. Chameleons are hypothesized scalar fields that could explain the dark energy problem. We implement a novel technique to create and trap the reflective particles within a jar and to detect them later via their afterglow as they slowly convert back into photons. These measurements provide the first experimental constraints on the couplings of chameleons to photons

  2. Testing chameleon theories with light propagating through a magnetic field

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine; Mota, David F.; Shaw, Douglas

    2007-01-01

    It was recently argued that the observed PVLAS anomaly can be explained by chameleon field theories in which large deviations from Newton's law can be avoided. Here we present the predictions for the dichroism and the birefringence induced in the vacuum by a magnetic field in these models. We show that chameleon particles behave very differently from standard axionlike particles (ALPs). We find that, unlike ALPs, the chameleon particles are confined within the experimental setup. As a consequence, the birefringence is always bigger than the dichroism in PVLAS-type experiments

  3. Longevity in Calumma parsonii, the World's largest chameleon.

    Science.gov (United States)

    Tessa, Giulia; Glaw, Frank; Andreone, Franco

    2017-03-01

    Large body size of ectothermic species can be correlated with high life expectancy. We assessed the longevity of the World's largest chameleon, the Parson's chameleon Calumma parsonii from Madagascar by using skeletochronology of phalanges taken from preserved specimens held in European natural history museums. Due to the high bone resorption we can provide only the minimum age of each specimen. The highest minimum age detected was nine years for a male and eight years for a female, confirming that this species is considerably long living among chameleons. Our data also show a strong correlation between snout-vent length and estimated age. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Nanocomposite tribological coatings with 'chameleon' surface adaptation

    International Nuclear Information System (INIS)

    Voevodin, A.A.; Fitz, T.A.; Hu, J.J.; Zabinski, J.S.

    2002-01-01

    Nanocomposite tribological coatings were designed to respond to changing environmental conditions by self-adjustment of their surface properties to maintain good tribological performance in any environment. These smart coatings have been dubbed 'chameleon' because, analogous to a chameleon changing its skin color to avoid predators, the coating changes its 'skin' chemistry and structure to avoid wear. The concept was originally developed using WC, diamondlike carbon, and WS 2 material combination for adaptation to a humid/dry environment cycling. In order to address temperature variation, nanocomposite coatings made of yttria-stabilized zirconia (YSZ) in a gold matrix were developed with encapsulated nanosized reservoirs of MoS 2 and diamondlike carbon (DLC). Coatings were produced using a combination of laser ablation and magnetron sputtering. They were characterized by x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy, x-ray energy dispersive spectroscopy, and micro-Raman spectroscopy. Results were correlated with mechanical and tribological characterization. Coating hardness was evaluated using nanoindentation, while coating adhesion and toughness were estimated using scratch and Vickers indentation tests. Friction and wear endurance measurements of YSZ/Au/MoS 2 /DLC coatings against steel and Si 3 N 4 balls were performed at room temperature in controlled humidity air, dry nitrogen, and vacuum environments, as well as at 500 deg. C in air. Depending on the environment, coating friction surface changed its chemistry and structure between (i) graphitic carbon for sliding in humid air [coating friction coefficients (c.o.f. 0.10-0.15)], (ii) hexagonal MoS 2 for sliding in dry N 2 and vacuum (c.o.f. 0.02-0.05), and (iii) metallic Au for sliding in air at 500 deg. C (c.o.f. 0.10-0.20). The unique coating skin adaptation realized with YSZ/Au/MoS 2 /DLC and WC/DLC/WS composites proves a universal applicability of the chameleon design

  5. COSMOLOGY OF CHAMELEONS WITH POWER-LAW COUPLINGS

    International Nuclear Information System (INIS)

    Mota, David F.; Winther, Hans A.

    2011-01-01

    In chameleon field theories, a scalar field can couple to matter with gravitational strength and still evade local gravity constraints due to a combination of self-interactions and the couplings to matter. Originally, these theories were proposed with a constant coupling to matter; however, the chameleon mechanism also extends to the case where the coupling becomes field dependent. We study the cosmology of chameleon models with power-law couplings and power-law potentials. It is found that these generalized chameleons, when viable, have a background expansion very close to ΛCDM, but can in some special cases enhance the growth of the linear perturbations at low redshifts. For the models we consider, it is found that this region of the parameter space is ruled out by local gravity constraints. Imposing a coupling to dark matter only, the local constraints are avoided, and it is possible to have observable signatures on the linear matter perturbations.

  6. Chameleon halo modeling in f(R) gravity

    International Nuclear Information System (INIS)

    Li Yin; Hu, Wayne

    2011-01-01

    We model the chameleon effect on cosmological statistics for the modified gravity f(R) model of cosmic acceleration. The chameleon effect, required to make the model compatible with local tests of gravity, reduces force enhancement as a function of the depth of the gravitational potential wells of collapsed structure and so is readily incorporated into a halo model by including parameters for the chameleon mass threshold and rapidity of transition. We show that the abundance of halos around the chameleon mass threshold is enhanced by both the merging from below and the lack of merging to larger masses. This property also controls the power spectrum in the nonlinear regime and we provide a description of the transition to the linear regime that is valid for a wide range of f(R) models.

  7. Photonic crystals cause active colour change in chameleons

    Science.gov (United States)

    Teyssier, Jérémie; Saenko, Suzanne V.; van der Marel, Dirk; Milinkovitch, Michel C.

    2015-03-01

    Many chameleons, and panther chameleons in particular, have the remarkable ability to exhibit complex and rapid colour changes during social interactions such as male contests or courtship. It is generally interpreted that these changes are due to dispersion/aggregation of pigment-containing organelles within dermal chromatophores. Here, combining microscopy, photometric videography and photonic band-gap modelling, we show that chameleons shift colour through active tuning of a lattice of guanine nanocrystals within a superficial thick layer of dermal iridophores. In addition, we show that a deeper population of iridophores with larger crystals reflects a substantial proportion of sunlight especially in the near-infrared range. The organization of iridophores into two superposed layers constitutes an evolutionary novelty for chameleons, which allows some species to combine efficient camouflage with spectacular display, while potentially providing passive thermal protection.

  8. Chameleon scalar fields in relativistic gravitational backgrounds

    International Nuclear Information System (INIS)

    Tsujikawa, Shinji; Tamaki, Takashi; Tavakol, Reza

    2009-01-01

    We study the field profile of a scalar field φ that couples to a matter fluid (dubbed a chameleon field) in the relativistic gravitational background of a spherically symmetric spacetime. Employing a linear expansion in terms of the gravitational potential Φ c at the surface of a compact object with a constant density, we derive the thin-shell field profile both inside and outside the object, as well as the resulting effective coupling with matter, analytically. We also carry out numerical simulations for the class of inverse power-law potentials V(φ) = M 4+n φ −n by employing the information provided by our analytical solutions to set the boundary conditions around the centre of the object and show that thin-shell solutions in fact exist if the gravitational potential Φ c is smaller than 0.3, which marginally covers the case of neutron stars. Thus the chameleon mechanism is present in the relativistic gravitational backgrounds, capable of reducing the effective coupling. Since thin-shell solutions are sensitive to the choice of boundary conditions, our analytic field profile is very helpful to provide appropriate boundary conditions for Φ c ∼< O(0.1)

  9. Chameleon scalar fields in relativistic gravitational backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Tsujikawa, Shinji [Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Tamaki, Takashi [Department of Physics, Waseda University, Okubo 3-4-1, Tokyo 169-8555 (Japan); Tavakol, Reza, E-mail: shinji@rs.kagu.tus.ac.jp, E-mail: tamaki@gravity.phys.waseda.ac.jp, E-mail: r.tavakol@qmul.ac.uk [Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London, London E1 4NS (United Kingdom)

    2009-05-15

    We study the field profile of a scalar field {phi} that couples to a matter fluid (dubbed a chameleon field) in the relativistic gravitational background of a spherically symmetric spacetime. Employing a linear expansion in terms of the gravitational potential {Phi}{sub c} at the surface of a compact object with a constant density, we derive the thin-shell field profile both inside and outside the object, as well as the resulting effective coupling with matter, analytically. We also carry out numerical simulations for the class of inverse power-law potentials V({phi}) = M{sup 4+n}{phi}{sup -n} by employing the information provided by our analytical solutions to set the boundary conditions around the centre of the object and show that thin-shell solutions in fact exist if the gravitational potential {Phi}{sub c} is smaller than 0.3, which marginally covers the case of neutron stars. Thus the chameleon mechanism is present in the relativistic gravitational backgrounds, capable of reducing the effective coupling. Since thin-shell solutions are sensitive to the choice of boundary conditions, our analytic field profile is very helpful to provide appropriate boundary conditions for {Phi}{sub c}{approx}

  10. Combined use of Azolla and loach suppressed paddy weeds and increased organic rice yield: second season results

    Directory of Open Access Journals (Sweden)

    Weiguo Cheng

    2015-01-01

    Full Text Available Organic farming uses alternatives to agricultural chemicals such as synthetic fertilizers and pesticides. The primary challenge in organic rice farming is controlling weeds without using herbicides and improving rice yield without chemical fertilizers. In our previous paper entitled as combined use of Azolla and loach suppressed weed Monochoria vaginalis and increased rice yield without agrochemicals, we reported the first year rice growth season results from an in situ container experiment. The experiment was designed with 4 treatments—control (with neither Azolla nor loach, Azolla (Azolla alone, loach (loach alone, and Az+Lo (combined Azolla and loach—with 3 replications each. The first year results showed that combined use of Azolla and loach was successful in weed suppression and increase in rice yield in 2012. In this paper, we report the second year results from the continuous container experiment in 2013. M.vaginalis emergences were very low in second year rice growth season on all treatments. Compared first year, the rice yields decreased in second year on all treatments due to different weather condition and with or without organic soybean oil cake application between two rice growth seasons. The second year results also showed the raising loach had a stronger effect to increase tiller and panicle numbers, and spikelet number per panicle, then improve rice yields to 2.3 times than control. The Azolla residues left from first year have weaker effect on rice growth and yield, but increase soil organic matter accumulation at second year. The two years study indicated that combined use of Azolla and loach can meet two of the greatest challenges in organic rice production: providing effective weed control and improving rice nutrition without agrochemicals.

  11. Cosmic history of chameleonic dark matter in F (R ) gravity

    Science.gov (United States)

    Katsuragawa, Taishi; Matsuzaki, Shinya

    2018-03-01

    We study the cosmic history of the scalaron in F (R ) gravity with constructing the time evolution of the cosmic environment and discuss the chameleonic dark matter based on the chameleon mechanism in the early and current Universe. We then find that the scalaron can be a dark matter. We also propose an interesting possibility that the F (R ) gravity can address the coincidence problem.

  12. Analysis of Different Ploidy and Parent–Offspring Genomic DNA Methylation in the Loach Misgurnus anguillicaudatus

    Directory of Open Access Journals (Sweden)

    He Zhou

    2016-08-01

    Full Text Available In this study, we selected natural polyploidy loach (diploid, triploid and tetraploid and hybrid F1 generation obverse cross (4 × 2 and inverse cross (2 × 4 by diploids and tetraploids as the research model. The MSAP (methylation-sensitive amplified polymorphism reaction system was established by our laboratory to explore methylation levels and pattern diversification features at the whole genome level of the polyploidy loach. The results showed that the total methylation and full methylation rates decreased on increased ploidy individuals; moreover, the hemimethylation rate showed no consistent pattern. Compared with diploid loach, the methylation patterns of tetraploid sites changed 68.17%, and the methylation patterns of triploid sites changed 73.05%. The proportion of hypermethylation genes is significantly higher than the proportion of demethylation genes. The methylation level of reciprocal cross F1 generation is lower than the male diploid and higher than the female tetraploid. The hemimethylation and total methylation rate of the cross hybrid F1 generation is significantly higher than the orthogonal F1 generation (p < 0.01. After readjusting, the methylation pattern of genome DNA of reciprocal hybrids changed 69.59% and 72.83%, respectively.

  13. Analysis of Different Ploidy and Parent–Offspring Genomic DNA Methylation in the Loach Misgurnus anguillicaudatus

    Science.gov (United States)

    Zhou, He; Ma, Tian-Yu; Zhang, Rui; Xu, Qi-Zheng; Shen, Fu; Qin, Yan-Jie; Xu, Wen; Wang, Yuan; Li, Ya-Juan

    2016-01-01

    In this study, we selected natural polyploidy loach (diploid, triploid and tetraploid) and hybrid F1 generation obverse cross (4 × 2) and inverse cross (2 × 4) by diploids and tetraploids as the research model. The MSAP (methylation-sensitive amplified polymorphism) reaction system was established by our laboratory to explore methylation levels and pattern diversification features at the whole genome level of the polyploidy loach. The results showed that the total methylation and full methylation rates decreased on increased ploidy individuals; moreover, the hemimethylation rate showed no consistent pattern. Compared with diploid loach, the methylation patterns of tetraploid sites changed 68.17%, and the methylation patterns of triploid sites changed 73.05%. The proportion of hypermethylation genes is significantly higher than the proportion of demethylation genes. The methylation level of reciprocal cross F1 generation is lower than the male diploid and higher than the female tetraploid. The hemimethylation and total methylation rate of the cross hybrid F1 generation is significantly higher than the orthogonal F1 generation (p < 0.01). After readjusting, the methylation pattern of genome DNA of reciprocal hybrids changed 69.59% and 72.83%, respectively. PMID:27556458

  14. Stone loaches of Choman River system, Kurdistan, Iran (Teleostei: Cypriniformes: Nemacheilidae).

    Science.gov (United States)

    Kamangar, Barzan Bahrami; Prokofiev, Artem M; Ghaderi, Edris; Nalbant, Theodore T

    2014-01-20

    For the first time, we present data on species composition and distributions of nemacheilid loaches in the Choman River basin of Kurdistan province, Iran. Two genera and four species are recorded from the area, of which three species are new for science: Oxynoemacheilus kurdistanicus, O. zagrosensis, O. chomanicus spp. nov., and Turcinoemacheilus kosswigi Băn. et Nalb. Detailed and illustrated morphological descriptions and univariate and multivariate analysis of morphometric and meristic features are for each of these species. Forty morphometric and eleven meristic characters were used in multivariate analysis to select characters that could discriminate between the four loach species. Discriminant Function Analysis revealed that sixteen morphometric measures and five meristic characters have the most variability between the loach species. The dendrograms based on cluster analysis of Mahalanobis distances of morphometrics and a combination of both characters confirmed two distinct groups: Oxynoemacheilus spp. and T. kosswigi. Within Oxynoemacheilus, O. zagrosensis and O. chomanicus are more similar to one other rather to either is to O. kurdistanicus.

  15. Constraining chameleon field theories using the GammeV afterglow experiments

    International Nuclear Information System (INIS)

    Upadhye, A.; Steffen, J. H.; Weltman, A.

    2010-01-01

    The GammeV experiment has constrained the couplings of chameleon scalar fields to matter and photons. Here, we present a detailed calculation of the chameleon afterglow rate underlying these constraints. The dependence of GammeV constraints on various assumptions in the calculation is studied. We discuss the GammeV-CHameleon Afterglow SEarch, a second-generation GammeV experiment, which will improve upon GammeV in several major ways. Using our calculation of the chameleon afterglow rate, we forecast model-independent constraints achievable by GammeV-CHameleon Afterglow SEarch. We then apply these constraints to a variety of chameleon models, including quartic chameleons and chameleon dark energy models. The new experiment will be able to probe a large region of parameter space that is beyond the reach of current tests, such as fifth force searches, constraints on the dimming of distant astrophysical objects, and bounds on the variation of the fine structure constant.

  16. How to avoid a swift kick in the chameleons

    International Nuclear Information System (INIS)

    Padilla, Antonio; Stefanyszyn, David; Wilson, Toby; Platts, Emma; Walters, Anthony; Weltman, Amanda

    2016-01-01

    Recently, it was argued that the conformal coupling of the chameleon to matter fields created an issue for early universe cosmology. As standard model degrees of freedom become non-relativistic in the early universe, the chameleon is attracted towards a ''surfing'' solution, so that it arrives at the potential minimum with too large a velocity. This leads to rapid variations in the chameleon's mass and excitation of high energy modes, casting doubts on the classical treatment at Big Bang Nucleosynthesis. Here we present the DBI chameleon, a consistent high energy modification of the chameleon theory that dynamically renders it weakly coupled to matter during the early universe thereby eliminating the adverse effects of the 'kicks'. This is done without any fine tuning of the coupling between the chameleon and matter fields, and retains its screening ability in the solar system. We demonstrate this explicitly with a combination of analytic and numerical results

  17. How to avoid a swift kick in the chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, Antonio; Stefanyszyn, David; Wilson, Toby [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Platts, Emma; Walters, Anthony; Weltman, Amanda, E-mail: antonio.padilla@nottingham.ac.uk, E-mail: pltemm002@myuct.ac.za, E-mail: ppxds1@nottingham.ac.uk, E-mail: tony.walters@uct.ac.za, E-mail: amanda.weltman@uct.ac.za, E-mail: toby.wilson@nottingham.ac.uk [Astrophysics, Cosmology and Gravity Centre, Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)

    2016-03-01

    Recently, it was argued that the conformal coupling of the chameleon to matter fields created an issue for early universe cosmology. As standard model degrees of freedom become non-relativistic in the early universe, the chameleon is attracted towards a ''surfing'' solution, so that it arrives at the potential minimum with too large a velocity. This leads to rapid variations in the chameleon's mass and excitation of high energy modes, casting doubts on the classical treatment at Big Bang Nucleosynthesis. Here we present the DBI chameleon, a consistent high energy modification of the chameleon theory that dynamically renders it weakly coupled to matter during the early universe thereby eliminating the adverse effects of the 'kicks'. This is done without any fine tuning of the coupling between the chameleon and matter fields, and retains its screening ability in the solar system. We demonstrate this explicitly with a combination of analytic and numerical results.

  18. Artificial chameleon skin that controls spectral radiation: Development of Chameleon Cool Coating (C3).

    Science.gov (United States)

    Gonome, Hiroki; Nakamura, Masashi; Okajima, Junnosuke; Maruyama, Shigenao

    2018-01-19

    Chameleons have a diagnostic thermal protection that enables them to live under various conditions. Our developed special radiative control therefore is inspired by the chameleon thermal protection ability by imitating its two superposed layers as two pigment particles in one coating layer. One particle imitates a chameleon superficial surface for color control (visible light), and another particle imitates a deep surface to reflect solar irradiation, especially in the near-infrared region. Optical modeling allows us to optimally design the particle size and volume fraction. Experimental evaluation shows that the desired spectral reflectance, i.e., low in the VIS region and high in NIR region, can be achieved. Comparison between the measured and calculated reflectances shows that control of the particle size and dispersion/aggregation of particle cloud is important in improving the thermal-protection performance of the coating. Using our developed coating, the interior temperature decreases and the cooling load is reduced while keeping the dark tone of the object.

  19. Lateralization of visually guided detour behaviour in the common chameleon, Chamaeleo chameleon, a reptile with highly independent eye movements.

    Science.gov (United States)

    Lustig, Avichai; Ketter-Katz, Hadas; Katzir, Gadi

    2013-11-01

    Chameleons (Chamaeleonidae, reptilia), in common with most ectotherms, show full optic nerve decussation and sparse inter-hemispheric commissures. Chameleons are unique in their capacity for highly independent, large-amplitude eye movements. We address the question: Do common chameleons, Chamaeleo chameleon, during detour, show patterns of lateralization of motion and of eye use that differ from those shown by other ectotherms? To reach a target (prey) in passing an obstacle in a Y-maze, chameleons were required to make a left or a right detour. We analyzed the direction of detours and eye use and found that: (i) individuals differed in their preferred detour direction, (ii) eye use was lateralized at the group level, with significantly longer durations of viewing the target with the right eye, compared with the left eye, (iii) during left side, but not during right side, detours the durations of viewing the target with the right eye were significantly longer than the durations with the left eye. Thus, despite the uniqueness of chameleons' visual system, they display patterns of lateralization of motion and of eye use, typical of other ectotherms. These findings are discussed in relation to hemispheric functions. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Nanocomposite tribological coatings with "chameleon" surface adaptation

    Science.gov (United States)

    Voevodin, A. A.; Fitz, T. A.; Hu, J. J.; Zabinski, J. S.

    2002-07-01

    Nanocomposite tribological coatings were designed to respond to changing environmental conditions by self-adjustment of their surface properties to maintain good tribological performance in any environment. These smart coatings have been dubbed "chameleon" because, analogous to a chameleon changing its skin color to avoid predators, the coating changes its "skin" chemistry and structure to avoid wear. The concept was originally developed using WC, diamondlike carbon, and WS2 material combination for adaptation to a humid/dry environment cycling. In order to address temperature variation, nanocomposite coatings made of yttria-stabilized zirconia (YSZ) in a gold matrix were developed with encapsulated nanosized reservoirs of MoS2 and diamondlike carbon (DLC). Coatings were produced using a combination of laser ablation and magnetron sputtering. They were characterized by x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy, x-ray energy dispersive spectroscopy, and micro-Raman spectroscopy. Results were correlated with mechanical and tribological characterization. Coating hardness was evaluated using nanoindentation, while coating adhesion and toughness were estimated using scratch and Vickers indentation tests. Friction and wear endurance measurements of YSZ/Au/MoS2/DLC coatings against steel and Si3N4 balls were performed at room temperature in controlled humidity air, dry nitrogen, and vacuum environments, as well as at 500 degC in air. Depending on the environment, coating friction surface changed its chemistry and structure between (i) graphitic carbon for sliding in humid air [coating friction coefficients (c.o.f. 0.10-0.15)], (ii) hexagonal MoS2 for sliding in dry N2 and vacuum (c.o.f. 0.02-0.05), and (iii) metallic Au for sliding in air at 500 degC (c.o.f. 0.10-0.20). The unique coating skin adaptation realized with YSZ/Au/MoS2/DLC and WC/DLC/WS composites proves a universal applicability of the chameleon design concept

  1. A network biology approach to understanding the importance of chameleon proteins in human physiology and pathology.

    Science.gov (United States)

    Bahramali, Golnaz; Goliaei, Bahram; Minuchehr, Zarrin; Marashi, Sayed-Amir

    2017-02-01

    Chameleon proteins are proteins which include sequences that can adopt α-helix-β-strand (HE-chameleon) or α-helix-coil (HC-chameleon) or β-strand-coil (CE-chameleon) structures to operate their crucial biological functions. In this study, using a network-based approach, we examined the chameleon proteins to give a better knowledge on these proteins. We focused on proteins with identical chameleon sequences with more than or equal to seven residues long in different PDB entries, which adopt HE-chameleon, HC-chameleon, and CE-chameleon structures in the same protein. One hundred and ninety-one human chameleon proteins were identified via our in-house program. Then, protein-protein interaction (PPI) networks, Gene ontology (GO) enrichment, disease network, and pathway enrichment analyses were performed for our derived data set. We discovered that there are chameleon sequences which reside in protein-protein interaction regions between two proteins critical for their dual function. Analysis of the PPI networks for chameleon proteins introduced five hub proteins, namely TP53, EGFR, HSP90AA1, PPARA, and HIF1A, which were presented in four PPI clusters. The outcomes demonstrate that the chameleon regions are in critical domains of these proteins and are important in the development and treatment of human cancers. The present report is the first network-based functional study of chameleon proteins using computational approaches and might provide a new perspective for understanding the mechanisms of diseases helping us in developing new medical therapies along with discovering new proteins with chameleon properties which are highly important in cancer.

  2. Search for Chameleon Scalar Fields with the Axion Dark Matter Experiment

    International Nuclear Information System (INIS)

    Rybka, G.; Hotz, M.; Rosenberg, L. J; Asztalos, S. J.; Carosi, G.; Hagmann, C.; Kinion, D.; van Bibber, K.; Hoskins, J.; Martin, C.; Sikivie, P.; Tanner, D. B.; Bradley, R.; Clarke, J.

    2010-01-01

    Scalar fields with a 'chameleon' property, in which the effective particle mass is a function of its local environment, are common to many theories beyond the standard model and could be responsible for dark energy. If these fields couple weakly to the photon, they could be detectable through the afterglow effect of photon-chameleon-photon transitions. The ADMX experiment was used in the first chameleon search with a microwave cavity to set a new limit on scalar chameleon-photon coupling β γ excluding values between 2x10 9 and 5x10 14 for effective chameleon masses between 1.9510 and 1.9525 μeV.

  3. Quantitative PCR Assays for Detecting Loach Minnow (Rhinichthys cobitis and Spikedace (Meda fulgida in the Southwestern United States.

    Directory of Open Access Journals (Sweden)

    Joseph C Dysthe

    Full Text Available Loach minnow (Rhinichthys cobitis and spikedace (Meda fulgida are legally protected with the status of Endangered under the U.S. Endangered Species Act and are endemic to the Gila River basin of Arizona and New Mexico. Efficient and sensitive methods for monitoring these species' distributions are critical for prioritizing conservation efforts. We developed quantitative PCR assays for detecting loach minnow and spikedace DNA in environmental samples. Each assay reliably detected low concentrations of target DNA without detection of non-target species, including other cyprinid fishes with which they co-occur.

  4. Genetic diversity and phylogenetic relationships of spined loaches (genus Cobitis) in Croatia based on mtDNA and allozyme analyses

    Czech Academy of Sciences Publication Activity Database

    Buj, I.; Podnar, M.; Mrakovčić, M.; Choleva, Lukáš; Šlechtová, Věra; Tvrtković, N.; Ćaleta, M.; Mustafić, P.; Marčić, Z.; Zanella, D.; Brigić, A.

    2008-01-01

    Roč. 57, 1-2 (2008), s. 71-82 ISSN 0139-7893. [International Conference Loaches of the genus Cobitis and related genera. Šibenik, 24.09.2006-29.09.2006] R&D Projects: GA ČR GP206/05/P586; GA ČR GA206/06/1763; GA MŠk LC06073 Grant - others:UK Praha(CZ) 187/2005 B BIO Institutional research plan: CEZ:AV0Z50450515 Keywords : Cobitidae loaches * Danube watershed * Adriatic watershed Subject RIV: EG - Zoology Impact factor: 0.522, year: 2008

  5. Cosmic web and environmental dependence of screening: Vainshtein vs. chameleon

    Energy Technology Data Exchange (ETDEWEB)

    Falck, Bridget; Koyama, Kazuya; Zhao, Gong-Bo, E-mail: bridget.falck@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: gong-bo.zhao@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, Portsmouth (United Kingdom)

    2015-07-01

    Theories which modify general relativity to explain the accelerated expansion of the Universe often use screening mechanisms to satisfy constraints on Solar System scales. We investigate the effects of the cosmic web and the local environmental density of dark matter halos on the screening properties of the Vainshtein and chameleon screening mechanisms. We compare the cosmic web morphology of dark matter particles, mass functions of dark matter halos, mass and radial dependence of screening, velocity dispersions and peculiar velocities, and environmental dependence of screening mechanisms in f(R) and nDGP models. Using the ORIGAMI cosmic web identification routine we find that the Vainshtein mechanism depends on the cosmic web morphology of dark matter particles, since these are defined according to the dimensionality of their collapse, while the chameleon mechanism shows no morphology dependence. The chameleon screening of halos and their velocity dispersions depend on halo mass, and small halos and subhalos can be environmentally screened in the chameleon mechanism. On the other hand, the screening of halos in the Vainshtein mechanism does not depend on mass nor environment, and their velocity dispersions are suppressed. The peculiar velocities of halos in the Vainshtein mechanism are enhanced because screened objects can still feel the fifth force generated by external fields, while peculiar velocities of chameleon halos are suppressed when the halo centers are screened.

  6. Cosmic web and environmental dependence of screening: Vainshtein vs. chameleon

    International Nuclear Information System (INIS)

    Falck, Bridget; Koyama, Kazuya; Zhao, Gong-Bo

    2015-01-01

    Theories which modify general relativity to explain the accelerated expansion of the Universe often use screening mechanisms to satisfy constraints on Solar System scales. We investigate the effects of the cosmic web and the local environmental density of dark matter halos on the screening properties of the Vainshtein and chameleon screening mechanisms. We compare the cosmic web morphology of dark matter particles, mass functions of dark matter halos, mass and radial dependence of screening, velocity dispersions and peculiar velocities, and environmental dependence of screening mechanisms in f(R) and nDGP models. Using the ORIGAMI cosmic web identification routine we find that the Vainshtein mechanism depends on the cosmic web morphology of dark matter particles, since these are defined according to the dimensionality of their collapse, while the chameleon mechanism shows no morphology dependence. The chameleon screening of halos and their velocity dispersions depend on halo mass, and small halos and subhalos can be environmentally screened in the chameleon mechanism. On the other hand, the screening of halos in the Vainshtein mechanism does not depend on mass nor environment, and their velocity dispersions are suppressed. The peculiar velocities of halos in the Vainshtein mechanism are enhanced because screened objects can still feel the fifth force generated by external fields, while peculiar velocities of chameleon halos are suppressed when the halo centers are screened

  7. The contributions of the music of George Fenton to the fi lms of Ken Loach

    OpenAIRE

    Sofía López Hernández

    2018-01-01

    Ken Loach is a high profile British film director. Since the mid 1960’s, he has made numerous films for cinema and television. There is already a lot written about his way of filming and yet very little is written about the music for his films. To be able to get inside the music of Ken Loach’s films, we must first talk about George Fenton as he has been Loach’s usual composer since 1994. The object of this article is to fill this gap: to discover what musical characteristics Fenton contri...

  8. The contributions of the music of George Fenton to the fi lms of Ken Loach

    Directory of Open Access Journals (Sweden)

    Sofía López Hernández

    2018-01-01

    Full Text Available Ken Loach is a high profile British film director. Since the mid 1960’s, he has made numerous films for cinema and television. There is already a lot written about his way of filming and yet very little is written about the music for his films. To be able to get inside the music of Ken Loach’s films, we must first talk about George Fenton as he has been Loach’s usual composer since 1994. The object of this article is to fill this gap: to discover what musical characteristics Fenton contributes to Loach’s cinema.

  9. Schistura maculosa, a new species of loach (Teleostei: Nemacheilidae) from Mizoram, northeastern India.

    Science.gov (United States)

    Lalronunga, Samuel; Lalnuntluanga; Lalramliana

    2013-01-01

    Schistura maculosa, a new species of loach, is described from Tuingo and Pharsih Rivers, tributaries of Tuivai River (Barak drainage) in Mizoram, northeastern India. It is distinguished from other closely related Schistura species in having an axillary pelvic lobe; an incomplete lateral line; 20-30 narrow black bars on the body; 3-4 rows of black spots horizontally across the dorsal-fin; a slightly emarginate caudal-fin, with 5-7 rows of black spots more or less regularly arranged vertically on rays across the fin, and 8+8 branched caudal-fin rays.

  10. Futebol, Cultura e Utopia: uma leitura de À procura de Eric, de Ken Loach

    OpenAIRE

    André Luís Reis Fernandes

    2016-01-01

    O presente trabalho tem como objetivo analisar o filme À procura de Eric(2009), do cineasta inglês Ken Loach. A análise procura fundamentar de que forma a narrativa do filme apresenta aspectos formais e conceituais que permitam aproximar os elementos constitutivos do jogo de futebol com possibilidades de explicações do mundo da pós-modernidade pautadas pelo materialismo histórico. Para tal, será necessário compreender a noção de Mapeamento Cognitivo, de Fredric Jameson, visando delimitar de q...

  11. Strongly Coupled Chameleons and the Neutronic Quantum Bouncer

    International Nuclear Information System (INIS)

    Brax, Philippe; Pignol, Guillaume

    2011-01-01

    We consider the potential detection of chameleons using bouncing ultracold neutrons. We show that the presence of a chameleon field over a planar plate would alter the energy levels of ultracold neutrons in the terrestrial gravitational field. When chameleons are strongly coupled to nuclear matter, β > or approx. 10 8 , we find that the shift in energy levels would be detectable with the forthcoming GRANIT experiment, where a sensitivity of the order of 1% of a peV is expected. We also find that an extremely large coupling β > or approx. 10 11 would lead to new bound states at a distance of order 2 μm, which is already ruled out by previous Grenoble experiments. The resulting bound, β 11 , is already 3 orders of magnitude better than the upper bound, β 14 , from precision tests of atomic spectra.

  12. Detecting chameleons: The astronomical polarization produced by chameleonlike scalar fields

    International Nuclear Information System (INIS)

    Burrage, Clare; Davis, Anne-Christine; Shaw, Douglas J.

    2009-01-01

    We show that a coupling between chameleonlike scalar fields and photons induces linear and circular polarization in the light from astrophysical sources. In this context chameleonlike scalar fields include those of the Olive-Pospelov (OP) model, which describes a varying fine structure constant. We determine the form of this polarization numerically and give analytic expressions in two useful limits. By comparing the predicted signal with current observations we are able to improve the constraints on the chameleon-photon coupling and the coupling in the OP model by over 2 orders of magnitude. It is argued that, if observed, the distinctive form of the chameleon induced circular polarization would represent a smoking gun for the presence of a chameleon. We also report a tentative statistical detection of a chameleonlike scalar field from observations of starlight polarization in our galaxy.

  13. A proposed experimental search for chameleons using asymmetric parallel plates

    International Nuclear Information System (INIS)

    Burrage, Clare; Copeland, Edmund J.; Stevenson, James A.

    2016-01-01

    Light scalar fields coupled to matter are a common consequence of theories of dark energy and attempts to solve the cosmological constant problem. The chameleon screening mechanism is commonly invoked in order to suppress the fifth forces mediated by these scalars, sufficiently to avoid current experimental constraints, without fine tuning. The force is suppressed dynamically by allowing the mass of the scalar to vary with the local density. Recently it has been shown that near future cold atoms experiments using atom-interferometry have the ability to access a large proportion of the chameleon parameter space. In this work we demonstrate how experiments utilising asymmetric parallel plates can push deeper into the remaining parameter space available to the chameleon.

  14. Neutron stars in screened modified gravity: Chameleon versus dilaton

    Science.gov (United States)

    Brax, Philippe; Davis, Anne-Christine; Jha, Rahul

    2017-04-01

    We consider the scalar field profile around relativistic compact objects such as neutron stars for a range of modified gravity models with screening mechanisms of the chameleon and Damour-Polyakov types. We focus primarily on inverse power law chameleons and the environmentally dependent dilaton as examples of both mechanisms. We discuss the modified Tolman-Oppenheimer-Volkoff equation and then implement a relaxation algorithm to solve for the scalar profiles numerically. We find that chameleons and dilatons behave in a similar manner and that there is a large degeneracy between the modified gravity parameters and the neutron star equation of state. This is exemplified by the modifications to the mass-radius relationship for a variety of model parameters.

  15. A proposed experimental search for chameleons using asymmetric parallel plates

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare; Copeland, Edmund J.; Stevenson, James A., E-mail: Clare.Burrage@nottingham.ac.uk, E-mail: ed.copeland@nottingham.ac.uk, E-mail: james.stevenson@nottingham.ac.uk [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom)

    2016-08-01

    Light scalar fields coupled to matter are a common consequence of theories of dark energy and attempts to solve the cosmological constant problem. The chameleon screening mechanism is commonly invoked in order to suppress the fifth forces mediated by these scalars, sufficiently to avoid current experimental constraints, without fine tuning. The force is suppressed dynamically by allowing the mass of the scalar to vary with the local density. Recently it has been shown that near future cold atoms experiments using atom-interferometry have the ability to access a large proportion of the chameleon parameter space. In this work we demonstrate how experiments utilising asymmetric parallel plates can push deeper into the remaining parameter space available to the chameleon.

  16. Quantitative PCR assays for detecting loach minnow (Rhinichthys cobitis) and spikedace (Meda fulgida) in the southwestern United States

    Science.gov (United States)

    Joseph C. Dysthe; Kellie J. Carim; Yvette M. Paroz; Kevin S. McKelvey; Michael K. Young; Michael K. Schwartz

    2016-01-01

    Loach minnow (Rhinichthys cobitis) and spikedace (Meda fulgida) are legally protected with the status of Endangered under the U.S. Endangered Species Act and are endemic to the Gila River basin of Arizona and New Mexico. Efficient and sensitive methods for monitoring these species’ distributions are critical for prioritizing conservation efforts. We developed...

  17. The complete mitochondrial transcript of the red tail loach Yasuhikotakia modesta as assembled from RNAseq (Teleostei: Botiidae)

    Czech Academy of Sciences Publication Activity Database

    Grau, J. H.; Hilgers, L.; Altmüller, J.; Šlechtová, Vendula; Bohlen, Jörg

    2017-01-01

    Roč. 2, č. 1 (2017), s. 46-47 ISSN 2380-2359 R&D Projects: GA ČR GA13-37277S Institutional support: RVO:67985904 Keywords : Yasuhikotakia modesta * loach * Botiidae Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3)

  18. f(R) gravity and chameleon theories

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine; Shaw, Douglas J.

    2008-01-01

    We analyze f(R) modifications of Einstein's gravity as dark energy models in the light of their connection with chameleon theories. Formulated as scalar-tensor theories, the f(R) theories imply the existence of a strong coupling of the scalar field to matter. This would violate all experimental gravitational tests on deviations from Newton's law. Fortunately, the existence of a matter dependent mass and a thin-shell effect allows one to alleviate these constraints. The thin-shell condition also implies strong restrictions on the cosmological dynamics of the f(R) theories. As a consequence, we find that the equation of state of dark energy is constrained to be extremely close to -1 in the recent past. We also examine the potential effects of f(R) theories in the context of the Eoet-wash experiments. We show that the requirement of a thin shell for the test bodies is not enough to guarantee a null result on deviations from Newton's law. As long as dark energy accounts for a sizeable fraction of the total energy density of the Universe, the constraints that we deduce also forbid any measurable deviation of the dark energy equation of state from -1. All in all, we find that both cosmological and laboratory tests imply that f(R) models are almost coincident with a ΛCDM model at the background level.

  19. Effect of microinjections of subunits of cAMP-dependent protein kinase on development, proliferation, and RNA synthesis in early embryos of the loach Misgurnus fossilis L

    International Nuclear Information System (INIS)

    Glukhov, A.I.; Benyumov, A.O.; Nesterova, M.V.; Severin, E.S.; Gazaryan, K.G.

    1986-01-01

    The effect of the catalytic and regulatory subunits of cAMP-dependent protein kinase type II on development, proliferation, and RNA synthesis was studied in loach embryos. It was found that injection of the catalytic subunit in a physiological concentration leads to a disturbance in the course of development and inhibits proliferation and RNA synthesis in the embryos. An increase in the concentration of this protein above the physiological level leads to death of the embryos in the first hours of development. Injection of the regulatory subunit stimulated the incorporation of labeled uridine into the acid-insoluble fraction of the embryos, beginning with the gastrula stage. The cell nuclei of loach embryos injected with subunits of protein kinase type II were transplanted into activated loach egg cells: subunits of protein kinase type I had no effect on the ability of nuclei of undetermined loach embryo cells to provide de novo development and their effect was reversible

  20. Accurate modeling of complete functional RF blocks: CHAMELEON RF

    NARCIS (Netherlands)

    Janssen, H.H.J.M.; Niehof, J.; Schilders, W.H.A.; Ciuprina, G.; Ioan, D.

    2007-01-01

    Next-generation nano-scale RF-IC designs have an unprecedented complexity and performance that will inevitably lead to costly re-spins and loss of market opportunities. In order to cope with this, the aim of the European Framework 6 CHAMELEON RF project is to develop methodologies and prototype

  1. Chameleon field and the late time acceleration of the Universe

    Indian Academy of Sciences (India)

    Chameleon field and the late time acceleration of the Universe. NARAYAN BANERJEE1,∗, SUDIPTA DAS2 and KOYEL GANGULY3. 1IISER-Kolkata, Mohanpur Campus, P.O. BCKV Main Office, District Nadia 741 252,. India. 2Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019, India.

  2. Constraining chameleon field theories using the GammeV afterglow experiments

    International Nuclear Information System (INIS)

    Upadhye, A.; Steffen, J.H.; Weltman, A.

    2009-01-01

    The GammeV experiment has constrained the couplings of chameleon scalar fields to matter and photons. Here we present a detailed calculation of the chameleon afterglow rate underlying these constraints. The dependence of GammeV constraints on various assumptions in the calculation is studied. We discuss GammeV-CHASE, a second-generation GammeV experiment, which will improve upon GammeV in several major ways. Using our calculation of the chameleon afterglow rate, we forecast model-independent constraints achievable by GammeV-CHASE. We then apply these constraints to a variety of chameleon models, including quartic chameleons and chameleon dark energy models. The new experiment will be able to probe a large region of parameter space that is beyond the reach of current tests, such as fifth force searches, constraints on the dimming of distant astrophysical objects, and bounds on the variation of the fine structure constant.

  3. Towards a UV completion of chameleons in string theory

    International Nuclear Information System (INIS)

    Hinterbichler, Kurt; Khoury, Justin; Nastase, Horatiu

    2011-01-01

    Full text: Chameleons are scalar fields that couple directly to ordinary matter with gravitational strength, thus effectively modifying the gravitational interaction, but which nevertheless evade the stringent constraints on tests of gravity because of properties they acquire in the presence of high ambient matter density. In the original formulation, one could simply describe the modification as the scalar mass depending on the matter density, but in the general set-up one can have a more complicated description. In any case, chameleon theories were originally constructed in a bottom-up, phenomenological fashion, with potentials and matter couplings designed to hide the scalar from experiments. We now show that it is in general possible for chameleons to arise in string and supergravity theories, as the volume modulus (for extra dimensions). We consider as a general chameleon set-up a potential for the volume modulus with a minimum, i.e. stabilized, and an exponentially increasing form on the side of large volume. We show that in fact the scenario proposed within string theory by Kachru, Kallosh, Linde and Trivedi (KKLT) is of this type, provided we change the sign of the exponent a in the superpotential W = W 0 + Ae iap (such a change has been considered before even within the KKLT scenario, and also in general compactifications). We show that these chameleon models satisfy Earth and astrophysical constraints, thus finding experimental constraints on the parameters of the potential, both for the general case, and for KKLT. For the KKLT potential, the constraints imply a KK scale (for the extra dimensions) of about 10 11 GeV , and the constant term in the superpotential of about 10 -30 M P 3 . (author)

  4. Towards a UV completion of chameleons in string theory

    Energy Technology Data Exchange (ETDEWEB)

    Hinterbichler, Kurt; Khoury, Justin [University of Pennsylvania, PA (United States); Nastase, Horatiu [Instituto de Fisica Teorica (IFT/UNESP), SP (Brazil)

    2011-07-01

    Full text: Chameleons are scalar fields that couple directly to ordinary matter with gravitational strength, thus effectively modifying the gravitational interaction, but which nevertheless evade the stringent constraints on tests of gravity because of properties they acquire in the presence of high ambient matter density. In the original formulation, one could simply describe the modification as the scalar mass depending on the matter density, but in the general set-up one can have a more complicated description. In any case, chameleon theories were originally constructed in a bottom-up, phenomenological fashion, with potentials and matter couplings designed to hide the scalar from experiments. We now show that it is in general possible for chameleons to arise in string and supergravity theories, as the volume modulus (for extra dimensions). We consider as a general chameleon set-up a potential for the volume modulus with a minimum, i.e. stabilized, and an exponentially increasing form on the side of large volume. We show that in fact the scenario proposed within string theory by Kachru, Kallosh, Linde and Trivedi (KKLT) is of this type, provided we change the sign of the exponent a in the superpotential W = W{sub 0} + Ae{sup iap} (such a change has been considered before even within the KKLT scenario, and also in general compactifications). We show that these chameleon models satisfy Earth and astrophysical constraints, thus finding experimental constraints on the parameters of the potential, both for the general case, and for KKLT. For the KKLT potential, the constraints imply a KK scale (for the extra dimensions) of about 10{sup 11}GeV , and the constant term in the superpotential of about 10{sup -30}M{sub P}{sup 3}. (author)

  5. Strongly coupled chameleon fields: Possible test with a neutron Lloyd's mirror interferometer

    International Nuclear Information System (INIS)

    Pokotilovski, Yu.N.

    2013-01-01

    The consideration of possible neutron Lloyd's mirror interferometer experiment to search for strongly coupled chameleon fields is presented. The chameleon scalar fields were proposed to explain the acceleration of expansion of the Universe. The presence of a chameleon field results in a change of a particle's potential energy in vicinity of a massive body. This interaction causes a phase shift of neutron waves in the interferometer. The sensitivity of the method is estimated

  6. Strongly coupled chameleon fields: Possible test with a neutron Lloyd's mirror interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Pokotilovski, Yu.N., E-mail: pokot@nf.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation)

    2013-02-26

    The consideration of possible neutron Lloyd's mirror interferometer experiment to search for strongly coupled chameleon fields is presented. The chameleon scalar fields were proposed to explain the acceleration of expansion of the Universe. The presence of a chameleon field results in a change of a particle's potential energy in vicinity of a massive body. This interaction causes a phase shift of neutron waves in the interferometer. The sensitivity of the method is estimated.

  7. Notes on chameleons V. The chameleons of North Africa and adjacent countries, Chamaeleo chamaeleon (Linnaeus) (Sauria: Chamaeleonidae)

    NARCIS (Netherlands)

    Hillenius, D.

    1978-01-01

    The regional variation of Chamaeleo chamaeleon is conspicuous, as might be expected, considering the wide distribution. This paper mainly deals with the chameleons of the Mediterranean populations. Though the range of variation per region is rather large, some clear clines can be discerned. In

  8. Alpenglow. A signature for chameleons in axion-like particle search experiments

    International Nuclear Information System (INIS)

    Ahlers, M.; Lindner, A.; Ringwald, A.; Schrempp, L.; Weniger, C.

    2007-10-01

    We point out that chameleon field theories might reveal themselves as an ''afterglow'' effect in axion-like particle search experiments due to chameleon-photon conversion in a magnetic field. We estimate the parameter space which is accessible by currently available technology and find that afterglow experiments could constrain this parameter space in a way complementary to gravitational and Casimir force experiments.In addition, one could reach photon-chameleon couplings which are beyond the sensitivity of common laser polarization experiments. We also sketch the idea of a Fabry-Perot cavity with chameleons which could increase the experimental sensitivity significantly. (orig.)

  9. Alpenglow. A signature for chameleons in axion-like particle search experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers, M.; Lindner, A.; Ringwald, A.; Schrempp, L.; Weniger, C.

    2007-10-15

    We point out that chameleon field theories might reveal themselves as an ''afterglow'' effect in axion-like particle search experiments due to chameleon-photon conversion in a magnetic field. We estimate the parameter space which is accessible by currently available technology and find that afterglow experiments could constrain this parameter space in a way complementary to gravitational and Casimir force experiments.In addition, one could reach photon-chameleon couplings which are beyond the sensitivity of common laser polarization experiments. We also sketch the idea of a Fabry-Perot cavity with chameleons which could increase the experimental sensitivity significantly. (orig.)

  10. Oxynoemacheilus zarzianus, a new loach from the Lesser Zab River drainage in Iraqi Kurdistan (Teleostei: Nemacheilidae).

    Science.gov (United States)

    Freyhof, Jörg; Geiger, Matthias

    2017-06-02

    Oxynoemacheilus zarzianus, new species, is described from the Lesser Zab River drainage, a tributary of the lower Tigris. It is distinguished from other Oxynoemacheilus species in the Tigris drainage by having a slightly emarginate caudal fin, no suborbital groove in males, a complete lateral line, the posterior process of the bony air-bladder capsule directed posteriorly, the flank and posterior part of back covered by scales, short barbels and a deep caudal peduncle. It is the fourth Oxynoemacheilus species known from the Lesser Zab drainage, where such loaches seem to be highly isolated in headwaters. Oxynoemacheilus species diversity in the Euphrates and Tigris drainage is exceptional high. Today 22 species are known from the entire Euphrates and Tigris drainage and 15 from the Tigris drainage alone.

  11. Transient expression and activity of human DNA polymerase iota in loach embryos.

    Science.gov (United States)

    Makarova, Irina V; Kazakov, Andrey A; Makarova, Alena V; Khaidarova, Nella V; Kozikova, Larisa V; Nenasheva, Valentina V; Gening, Leonid V; Tarantul, Vyacheslav Z; Andreeva, Ludmila E

    2012-02-01

    Human DNA polymerase iota (Pol ι) is a Y-family DNA polymerase with unusual biochemical properties and not fully understood functions. Pol ι preferentially incorporates dGTP opposite template thymine. This property can be used to monitor Pol ι activity in the presence of other DNA polymerases, e.g. in cell extracts of tissues and tumors. We have now confirmed the specificity and sensitivity of the method of Pol ι activity detection in cell extracts using an animal model of loach Misgurnus fossilis embryos transiently expressing human Pol ι. The overexpression of Pol ι was shown to be accompanied by an increase in abnormalities in development and the frequency of pycnotic nuclei in fish embryos. Further analysis of fish embryos with constitutive or regulated Pol ι expression may provide insights into Pol ι functions in vertebrate animals.

  12. Relating lateralization of eye use to body motion in the avoidance behavior of the chameleon (Chamaeleo chameleon).

    Science.gov (United States)

    Lustig, Avichai; Ketter-Katz, Hadas; Katzir, Gadi

    2013-01-01

    Lateralization is mostly analyzed for single traits, but seldom for two or more traits while performing a given task (e.g. object manipulation). We examined lateralization in eye use and in body motion that co-occur during avoidance behaviour of the common chameleon, Chamaeleo chameleon. A chameleon facing a moving threat smoothly repositions its body on the side of its perch distal to the threat, to minimize its visual exposure. We previously demonstrated that during the response (i) eye use and body motion were, each, lateralized at the tested group level (N = 26), (ii) in body motion, we observed two similar-sized sub-groups, one exhibiting a greater reduction in body exposure to threat approaching from the left and one--to threat approaching from the right (left- and right-biased subgroups), (iii) the left-biased sub-group exhibited weak lateralization of body exposure under binocular threat viewing and none under monocular viewing while the right-biased sub-group exhibited strong lateralization under both monocular and binocular threat viewing. In avoidance, how is eye use related to body motion at the entire group and at the sub-group levels? We demonstrate that (i) in the left-biased sub-group, eye use is not lateralized, (ii) in the right-biased sub-group, eye use is lateralized under binocular, but not monocular viewing of the threat, (iii) the dominance of the right-biased sub-group determines the lateralization of the entire group tested. We conclude that in chameleons, patterns of lateralization of visual function and body motion are inter-related at a subtle level. Presently, the patterns cannot be compared with humans' or related to the unique visual system of chameleons, with highly independent eye movements, complete optic nerve decussation and relatively few inter-hemispheric commissures. We present a model to explain the possible inter-hemispheric differences in dominance in chameleons' visual control of body motion during avoidance.

  13. Relating lateralization of eye use to body motion in the avoidance behavior of the chameleon (Chamaeleo chameleon.

    Directory of Open Access Journals (Sweden)

    Avichai Lustig

    Full Text Available Lateralization is mostly analyzed for single traits, but seldom for two or more traits while performing a given task (e.g. object manipulation. We examined lateralization in eye use and in body motion that co-occur during avoidance behaviour of the common chameleon, Chamaeleo chameleon. A chameleon facing a moving threat smoothly repositions its body on the side of its perch distal to the threat, to minimize its visual exposure. We previously demonstrated that during the response (i eye use and body motion were, each, lateralized at the tested group level (N = 26, (ii in body motion, we observed two similar-sized sub-groups, one exhibiting a greater reduction in body exposure to threat approaching from the left and one--to threat approaching from the right (left- and right-biased subgroups, (iii the left-biased sub-group exhibited weak lateralization of body exposure under binocular threat viewing and none under monocular viewing while the right-biased sub-group exhibited strong lateralization under both monocular and binocular threat viewing. In avoidance, how is eye use related to body motion at the entire group and at the sub-group levels? We demonstrate that (i in the left-biased sub-group, eye use is not lateralized, (ii in the right-biased sub-group, eye use is lateralized under binocular, but not monocular viewing of the threat, (iii the dominance of the right-biased sub-group determines the lateralization of the entire group tested. We conclude that in chameleons, patterns of lateralization of visual function and body motion are inter-related at a subtle level. Presently, the patterns cannot be compared with humans' or related to the unique visual system of chameleons, with highly independent eye movements, complete optic nerve decussation and relatively few inter-hemispheric commissures. We present a model to explain the possible inter-hemispheric differences in dominance in chameleons' visual control of body motion during avoidance.

  14. A newly discovered population of the Balkan spiny loach Sabanejewia balcanica (Karaman, 1922) in the River Jihlava, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Halačka, Karel; Muška, Milan; Mendel, Jan; Vetešník, Lukáš

    2017-01-01

    Roč. 66, č. 3 (2017), s. 163-166 ISSN 0139-7893 R&D Projects: GA ČR GA13-12580S Institutional support: RVO:68081766 ; RVO:60077344 Keywords : loaches * rare native species * sequence analysis * NATURA 2000 Subject RIV: EG - Zoology; EG - Zoology (BC-A) OBOR OECD: Zoology; Zoology (BC-A) Impact factor: 0.739, year: 2016

  15. Effect of loach consumption on the reproduction of giant water bug Kirkaldyia deyrolli: dietary selection, reproductive performance, and nutritional evaluation

    OpenAIRE

    Ohba, Shin-ya; Izumi, Yohei; Tsumuki, Hisaaki

    2012-01-01

    Rice fields provide major habitats for lentic aquatic insects including the giant water bug Kirkaldyia (=Lethocerus) deyrolli (Heteroptera: Belostomatidae) in Japan. Previous researchers have emphasized that conserving populations of the frogs, Hyla japonicus and Rana nigromaculata, is very important for preserving K. deyrolli because these frogs were found to be a major component of the diet of K. deyrolli adults. However, these previous studies were carried out in rice fields with no loache...

  16. Dynamics of tandemly repeated DNA sequences during evolution of diploid and tetraploid botiid loaches (Teleostei: Cobitoidea: Botiidae)

    Czech Academy of Sciences Publication Activity Database

    Sember, Alexandr; Bohlen, Jörg; Šlechtová, Vendula; Altmanová, Marie; Pelikánová, Šárka; Ráb, Petr

    2018-01-01

    Roč. 13, č. 3 (2018), č. článku e0195054. E-ISSN 1932-6203 R&D Projects: GA ČR GA13-37277S; GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : polyploidization * loach Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 2.806, year: 2016

  17. A Ploidy Difference Represents an Impassable Barrier for Hybridisation in Animals. Is There an Exception among Botiid Loaches (Teleostei: Botiidae?

    Directory of Open Access Journals (Sweden)

    Jörg Bohlen

    Full Text Available One of the most efficient mechanisms to keep animal lineages separate is a difference in ploidy level (number of whole genome copies, since hybrid offspring from parents with different ploidy level are functionally sterile. In the freshwater fish family Botiidae, ploidy difference has been held responsible for the separation of its two subfamilies, the evolutionary tetraploid Botiinae and the diploid Leptobotiinae. Diploid and tetraploid species coexist in the upper Yangtze, the Pearl River and the Red River basins in China. Interestingly, the species 'Botia' zebra from the Pearl River basin combines a number of morphological characters that otherwise are found in the diploid genus Leptobotia with morphological characters of the tetraploid genus Sinibotia, therefore the aim of the present study is to test weather 'B.' zebra is the result of a hybridisation event between species from different subfamilies with different ploidy level. A closer morphological examination indeed demonstrates a high similarity of 'B.' zebra to two co-occurring species, the diploid Leptobotia guilinensis and the tetraploid Sinibotia pulchra. These two species thus could have been the potential parental species in case of a hybrid origin of 'B.' zebra. The morphologic analysis further reveals that 'B.' zebra bears even the diagnostic characters of the genera Leptobotia (Leptobotiinae and Sinibotia (Botiinae. In contrast, a comparison of six allozyme loci between 'B.' zebra, L. guilinensis and S. pulchra showed only similarities between 'B.' zebra and S. pulchra, not between 'B.' zebra and L. guilinensis. Six specimens of 'B.' zebra that were cytogenetically analysed were tetraploid with 4n = 100. The composition of the karyotype (18% metacentric, 18% submetacentric, 36% subtelocentric and 28% acrocentric chromosomes differs from those of L. guilinensis (12%, 24%, 20% and 44% and S. pulchra (20%, 26%, 28% and 26%, and cannot be obtained by any combination of genomes from

  18. Time-delayed chameleon: Analysis, synchronization and FPGA implementation

    Science.gov (United States)

    Rajagopal, Karthikeyan; Jafari, Sajad; Laarem, Guessas

    2017-12-01

    In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware-software co-simulation and the results are presented.

  19. Manipulators inspired by the tongue of the chameleon

    International Nuclear Information System (INIS)

    Debray, Alexis

    2011-01-01

    Chameleons have developed a specialized ballistic tongue which elongates more than six times its rest length at speeds higher than 3.5 m s -1 and accelerations 350 m s -2 , with a highly flexible mobile part, and which applies no continuous force during forward motion. These characteristics are possible because this tongue consists of two highly specialized systems, an ejection system for the forward motion and an accordion-like system for the retraction. Four manipulators inspired by the tongue of the chameleon and based on this design have been developed, resulting in three characteristics similar to the tongue of the chameleon: extensibility of the manipulator, flexibility of the mobile part, and absence of continuous force during the forward motion. The first manipulator mimics the basic mechanism of the tongue of the chameleon and reproduced its basic performances. A second manipulator performs a catching function at a speed of 3.5 m s -1 with an acceleration of 573 m s -2 while elongating seven times its rest length. The design of this manipulator is such that the dc motor used for retraction applies a torque 25 times its rated torque. Moreover, during the retraction, the mobile part of the manipulator moves due to its own inertia, allowing the dc motor to rotate at full velocity. In another manipulator, the addition of an elastomer in the mobile part allows for control of the retraction velocity. A model for these two manipulators compares well with the experimental data. Finally, the addition of wings on the mobile part allows us to take the advantage of aerodynamic effects, which is unusual for manipulators.

  20. Manipulators inspired by the tongue of the chameleon.

    Science.gov (United States)

    Debray, Alexis

    2011-06-01

    Chameleons have developed a specialized ballistic tongue which elongates more than six times its rest length at speeds higher than 3.5 m s(-1) and accelerations 350 m s(-2), with a highly flexible mobile part, and which applies no continuous force during forward motion. These characteristics are possible because this tongue consists of two highly specialized systems, an ejection system for the forward motion and an accordion-like system for the retraction. Four manipulators inspired by the tongue of the chameleon and based on this design have been developed, resulting in three characteristics similar to the tongue of the chameleon: extensibility of the manipulator, flexibility of the mobile part, and absence of continuous force during the forward motion. The first manipulator mimics the basic mechanism of the tongue of the chameleon and reproduced its basic performances. A second manipulator performs a catching function at a speed of 3.5 m s(-1) with an acceleration of 573 m s(-2) while elongating seven times its rest length. The design of this manipulator is such that the dc motor used for retraction applies a torque 25 times its rated torque. Moreover, during the retraction, the mobile part of the manipulator moves due to its own inertia, allowing the dc motor to rotate at full velocity. In another manipulator, the addition of an elastomer in the mobile part allows for control of the retraction velocity. A model for these two manipulators compares well with the experimental data. Finally, the addition of wings on the mobile part allows us to take the advantage of aerodynamic effects, which is unusual for manipulators.

  1. Manipulators inspired by the tongue of the chameleon

    Energy Technology Data Exchange (ETDEWEB)

    Debray, Alexis, E-mail: debray.alexis@canon.co.jp [Canon Incorporation, 3-30-2, Shimomaruko, Ohta-ku, Tokyo 146-8501 (Japan)

    2011-06-15

    Chameleons have developed a specialized ballistic tongue which elongates more than six times its rest length at speeds higher than 3.5 m s{sup -1} and accelerations 350 m s{sup -2}, with a highly flexible mobile part, and which applies no continuous force during forward motion. These characteristics are possible because this tongue consists of two highly specialized systems, an ejection system for the forward motion and an accordion-like system for the retraction. Four manipulators inspired by the tongue of the chameleon and based on this design have been developed, resulting in three characteristics similar to the tongue of the chameleon: extensibility of the manipulator, flexibility of the mobile part, and absence of continuous force during the forward motion. The first manipulator mimics the basic mechanism of the tongue of the chameleon and reproduced its basic performances. A second manipulator performs a catching function at a speed of 3.5 m s{sup -1} with an acceleration of 573 m s{sup -2} while elongating seven times its rest length. The design of this manipulator is such that the dc motor used for retraction applies a torque 25 times its rated torque. Moreover, during the retraction, the mobile part of the manipulator moves due to its own inertia, allowing the dc motor to rotate at full velocity. In another manipulator, the addition of an elastomer in the mobile part allows for control of the retraction velocity. A model for these two manipulators compares well with the experimental data. Finally, the addition of wings on the mobile part allows us to take the advantage of aerodynamic effects, which is unusual for manipulators.

  2. Smart Nanocomposite Coatings with Chameleon Surface Adaptation in Tribological Applications

    Science.gov (United States)

    Voevodin, A. A.; Zabinski, J. S.

    Smart nanocomposite tribological coatings were designed to respond to changing environmental conditions by self-adjustment of their surface properties to maintain good tribological performance in any environment. These coatings have been dubbed "chameleon" because of their ability to change their surface chemistry and structure to avoid wear. The first "chameleon" coatings were made of WC, WS2, and DLC; these coatings provided superior mechanical toughness and performance in dry/humid environmental cycling. In order to address temperature variation, the second generation of "chameleon" coatings were made of yttria stabilized zirconia (YSZ) in a gold matrix with encapsulated nano-sized reservoirs of MoS2 and DLC. High temperature lubrication with low melting point glassy ceramic phases was also explored. All coatings were produced using a combination of laser ablation and magnetron sputtering. They were thoroughly characterized by various analytical, mechanical, and tribological methods. Coating toughness was remarkably enhanced by activation of a grain boundary sliding mechanism. Friction and wear endurance measurements were performed in controlled humidity air, dry nitrogen, and vacuum environments, as well as at 500-600 °C in air. Unique friction and wear performance in environmental cycling was demonstrated.

  3. Evidence for Adaptation to the Tibetan Plateau Inferred from Tibetan Loach Transcriptomes.

    Science.gov (United States)

    Wang, Ying; Yang, Liandong; Zhou, Kun; Zhang, Yanping; Song, Zhaobin; He, Shunping

    2015-10-09

    Triplophysa fishes are the primary component of the fish fauna on the Tibetan Plateau and are well adapted to the high-altitude environment. Despite the importance of Triplophysa fishes on the plateau, the genetic mechanisms of the adaptations of these fishes to this high-altitude environment remain poorly understood. In this study, we generated the transcriptome sequences for three Triplophysa fishes, that is, Triplophysa siluroides, Triplophysa scleroptera, and Triplophysa dalaica, and used these and the previously available transcriptome and genome sequences from fishes living at low altitudes to identify potential genetic mechanisms for the high-altitude adaptations in Triplophysa fishes. An analysis of 2,269 orthologous genes among cave fish (Astyanax mexicanus), zebrafish (Danio rerio), large-scale loach (Paramisgurnus dabryanus), and Triplophysa fishes revealed that each of the terminal branches of the Triplophysa fishes had a significantly higher ratio of nonsynonymous to synonymous substitutions than that of the branches of the fishes from low altitudes, which provided consistent evidence for genome-wide rapid evolution in the Triplophysa genus. Many of the GO (Gene Ontology) categories associated with energy metabolism and hypoxia response exhibited accelerated evolution in the Triplophysa fishes compared with the large-scale loach. The genes that exhibited signs of positive selection and rapid evolution in the Triplophysa fishes were also significantly enriched in energy metabolism and hypoxia response categories. Our analysis identified widespread Triplophysa-specific nonsynonymous mutations in the fast evolving genes and positively selected genes. Moreover, we detected significant evidence of positive selection in the HIF (hypoxia-inducible factor)-1A and HIF-2B genes in Triplophysa fishes and found that the Triplophysa-specific nonsynonymous mutations in the HIF-1A and HIF-2B genes were associated with functional changes. Overall, our study provides

  4. Transcriptomic Analysis of Compromise Between Air-Breathing and Nutrient Uptake of Posterior Intestine in Loach (Misgurnus anguillicaudatus), an Air-Breathing Fish.

    Science.gov (United States)

    Huang, Songqian; Cao, Xiaojuan; Tian, Xianchang

    2016-08-01

    Dojo loach (Misgurnus anguillicaudatus) is an air-breathing fish species by using its posterior intestine to breathe on water surface. So far, the molecular mechanism about accessory air-breathing in fish is seldom addressed. Five cDNA libraries were constructed here for loach posterior intestines form T01 (the initial stage group), T02 (mid-stage of normal group), T03 (end stage of normal group), T04 (mid-stage of air-breathing inhibited group), and T05 (the end stage of air-breathing inhibited group) and subjected to perform RNA-seq to compare their transcriptomic profilings. A total of 92,962 unigenes were assembled, while 37,905 (40.77 %) unigenes were successfully annotated. 2298, 1091, and 3275 differentially expressed genes (fn1, ACE, EGFR, Pxdn, SDF, HIF, VEGF, SLC2A1, SLC5A8 etc.) were observed in T04/T02, T05/T03, and T05/T04, respectively. Expression levels of many genes associated with air-breathing and nutrient uptake varied significantly between normal and intestinal air-breathing inhibited group. Intraepithelial capillaries in posterior intestines of loaches from T05 were broken, while red blood cells were enriched at the surface of intestinal epithelial lining with 241 ± 39 cells per millimeter. There were periodic acid-schiff (PAS)-positive epithelial mucous cells in posterior intestines from both normal and air-breathing inhibited groups. Results obtained here suggested an overlap of air-breathing and nutrient uptake function of posterior intestine in loach. Intestinal air-breathing inhibition in loach would influence the posterior intestine's nutrient uptake ability and endothelial capillary structure stability. This study will contribute to our understanding on the molecular regulatory mechanisms of intestinal air-breathing in loach.

  5. La inmigración y la ciudadanía según Ken Loach

    Directory of Open Access Journals (Sweden)

    María del Carmen Rodríguez Rodríguez

    2015-04-01

    Full Text Available Tomando como referencia una producción cinematográfica particular, la del cineasta británico Ken Loach (Nuneaton, 1936, se aborda en este artículo el tema de la inmigración reflejado en dos de sus películas: Pan y Rosas (2000 y Solo un beso (2004. Cuestiones como la inmigración ilegal, las segundas generaciones inmigrantes, la multiculturalidad, la adaptación y el mestizaje (dentro de un contexto anglosajón son algunos de los temas que se tratan en estos filmes y que sacan a relucir la problemática que conlleva el concepto de ciudadanía en la actualidad. Desde una perspectiva fundamentalmente (aunque no solo económica en Pan y Rosas y cultural en Solo un beso, se observan los mecanismos de inclusión y exclusión que configuran la posición del inmigrante en la sociedad contemporánea. El análisis detallado de las escenas, diálogos y personajes de las citadas películas intentará recoger el discurso crítico de este realizador, prestando atención a las cuestiones más significativas desde un punto de vista sociológico. 

  6. Microornamentation of leaf chameleons (Chamaeleonidae: Brookesia, Rhampholeon, and Rieppeleon)--with comments on the evolution of microstructures in the Chamaeleonidae.

    Science.gov (United States)

    Riedel, Jendrian; Böhme, Wolfgang; Bleckmann, Horst; Spinner, Marlene

    2015-02-01

    Chameleons (Chamaeleonidae) feature many adaptations to their arboreal lifestyle, including zygodactylous feet, a prehensile tail, and epidermal microstructures. In arboreal tree chameleons, the substrate-contacting site of the feet and tail is covered by microscopic hair-like structures (setae) of 6-20 µm length. Their friction enhancing function has been shown in recent studies. Leaf chameleons and one representative of the tree chameleons (Chamaeleo namaquensis) secondarily have become ground-dwelling. Because leaf chameleons are paraphyletic, one could expect that in the three leaf chameleon genera Brookesia, Rhampholeon, and Rieppeleon and the tree chameleon Ch. namaquensis, epidermis has adapted independently to terrestrial locomotion. Using scanning electron microscopy, we investigated the substrate-contacting surfaces of the feet (subdigital) of 17 leaf chameleon species and five tree chameleon species that have not yet been examined. Additionally, surfaces not involved in locomotion, the flanks (dorsolateral), and scale interstices, were examined. Although the subdigital microstructures in leaf chameleons are more diverse than in tree chameleons, we found some features across the genera. The subdigital microornamentation of Rhampholeon spinosus consists of long thin setae and spines, comparable to those of tree chameleons. All other Rhampholeon species have spines or short but broad setae. Rh. spectrum had tooth-like structures instead of setae. Subdigital scales of Brookesia have either thorns or conical scale-tops in the center and feature honeycomb microstructures. In Rieppeleon, subdigital scales have a thorn. Scale surfaces are covered by honeycombs and short hair-like structures (spines). As subdigital scales with a thorn in the center and honeycomb microstructures were also found in the terrestrial tree chameleon Ch. namaquensis, one can assume that this geometry is a convergent adaptation to terrestrial locomotion. Despite the great number of

  7. On the anomalous afterglow seen in a chameleon afterglow search

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Baumbaugh, Alan; Chou, Aaron S.; Tomlin, Ray; Upadhye, Amol

    2012-01-01

    We present data from our investigation of the anomalous orange-colored afterglow that was seen in the GammeV Chameleon Afterglow Search (CHASE). These data include information about the broadband color of the observed glow, the relationship between the glow and the temperature of the apparatus, and other data taken prior to, and during the science operations of CHASE. While differing in several details, the generic properties of the afterglow from CHASE are similar to luminescence seen in some vacuum compounds. Contamination from this, or similar, luminescent signatures will likely impact the design of implementation of future experiments involving single photon detectors and high intensity light sources in a cryogenic environment.

  8. Interacting HDE and NADE in Brans-Dicke chameleon cosmology

    International Nuclear Information System (INIS)

    Sheykhi, Ahmad; Jamil, Mubasher

    2011-01-01

    Motivated by the recent work of one of us Setare and Jamil (2010) , we generalize this work to the case where the pressureless dark matter and the holographic dark energy do not conserve separately but interact with each other. We investigate the cosmological applications of interacting holographic dark energy in Brans-Dicke theory with chameleon scalar field which is non-minimally coupled to the matter field. We find out that in this model the phantom crossing can be constructed if the model parameters are chosen suitably. We also perform the study for the new agegraphic dark energy model and calculate some relevant cosmological parameters and their evolution.

  9. Effect of the chameleon scalar field on brane cosmological evolution

    Science.gov (United States)

    Bisabr, Y.; Ahmadi, F.

    2017-11-01

    We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.

  10. Observational constraints on tachyonic chameleon dark energy model

    Science.gov (United States)

    Banijamali, A.; Bellucci, S.; Fazlpour, B.; Solbi, M.

    2018-03-01

    It has been recently shown that tachyonic chameleon model of dark energy in which tachyon scalar field non-minimally coupled to the matter admits stable scaling attractor solution that could give rise to the late-time accelerated expansion of the universe and hence alleviate the coincidence problem. In the present work, we use data from Type Ia supernova (SN Ia) and Baryon Acoustic oscillations to place constraints on the model parameters. In our analysis we consider in general exponential and non-exponential forms for the non-minimal coupling function and tachyonic potential and show that the scenario is compatible with observations.

  11. Interacting HDE and NADE in Brans-Dicke chameleon cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Sheykhi, Ahmad, E-mail: sheykhi@mail.uk.ac.i [Department of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: mjamil@camp.nust.edu.p [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, H-12, Islamabad (Pakistan)

    2011-01-03

    Motivated by the recent work of one of us Setare and Jamil (2010) , we generalize this work to the case where the pressureless dark matter and the holographic dark energy do not conserve separately but interact with each other. We investigate the cosmological applications of interacting holographic dark energy in Brans-Dicke theory with chameleon scalar field which is non-minimally coupled to the matter field. We find out that in this model the phantom crossing can be constructed if the model parameters are chosen suitably. We also perform the study for the new agegraphic dark energy model and calculate some relevant cosmological parameters and their evolution.

  12. Effect of the chameleon scalar field on brane cosmological evolution

    Directory of Open Access Journals (Sweden)

    Y. Bisabr

    2017-11-01

    Full Text Available We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.

  13. GROWTH RESPONSE OF CLOWN LOACH (Chromobotia macracanthus Bleeker 1852 JUVENILES IMMERSED IN WATER CONTAINING RECOMBINANT GROWTH HORMONE

    Directory of Open Access Journals (Sweden)

    Asep Permana

    2015-12-01

    Full Text Available The main problem in the culture of clown loach (Chromobotia macracanthus is the slow growth rate, which takes about six months to reach its market size (two inches total body length. Slow growth eventually cause a long production time and increase the production costs. An alternative solution can be proposed in order to enhance the growth is by using recombinant growth hormone. The aim of this study was to determine the immersion dose of recombinant Epinephelus lanceolatus growth hormone (rElGH which can generate the highest growth in clown loach. Larvae at seven day after hatching were hyperosmotic treated with NaCl 2.0% for one minute, then immersed for one hour in water containing 0.3% NaCl, 0.01% bovine serum albumin (BSA, and different doses of rElGH, namely: 0.12 (treatment A, 1.2 (B, 12 (C, and 120 mg/L (D. As control, fish were immersed in water without rElGH and NaCl (control-1, water containing 0.3% NaCl and 0.01% BSA (control-2, and 0.3% NaCl water (control-3. Each treatment was replicated three times. The results showed that clown loach juveniles in treatment B, C, and D had longer total body length (P0.05. In addition, the percentage of large size juveniles increased approximately 5% in treatment B, almost the same as in the medium size, while the small size were decrease compared to the control-1. Thus, the best immersion dose of rElGH was 1.2 mg/L water.

  14. Characterization of Metarhizium viride Mycosis in Veiled Chameleons (Chamaeleo calyptratus), Panther Chameleons (Furcifer pardalis), and Inland Bearded Dragons (Pogona vitticeps).

    Science.gov (United States)

    Schmidt, Volker; Klasen, Linus; Schneider, Juliane; Hübel, Jens; Pees, Michael

    2017-03-01

    Metarhizium viride has been associated with fatal systemic mycoses in chameleons, but subsequent data on mycoses caused by this fungus in reptiles are lacking. The aim of this investigation was therefore to obtain information on the presence of M. viride in reptiles kept as pets in captivity and its association with clinical signs and pathological findings as well as improvement of diagnostic procedures. Beside 18S ribosomal DNA (rDNA) (small subunit [SSU]) and internal transcribed spacer region 1 (ITS-1), a fragment of the large subunit (LSU) of 28S rDNA, including domain 1 (D1) and D2, was sequenced for the identification of the fungus and phylogenetic analysis. Cultural isolation and histopathological examinations as well as the pattern of antifungal drug resistance, determined by using agar diffusion testing, were additionally used for comparison of the isolates. In total, 20 isolates from eight inland bearded dragons ( Pogona vitticeps ), six veiled chameleons ( Chamaeleo calyptratus ), and six panther chameleons ( Furcifer pardalis ) were examined. Most of the lizards suffered from fungal glossitis, stomatitis, and pharyngitis or died due to visceral mycosis. Treatment with different antifungal drugs according to resistance patterns in all three different lizard species was unsuccessful. Sequence analysis resulted in four different genotypes of M. viride based on differences in the LSU fragment, whereas the SSU and ITS-1 were identical in all isolates. Sequence analysis of the SSU fragment revealed the first presentation of a valid large fragment of the SSU of M. viride According to statistical analysis, genotypes did not correlate with differences in pathogenicity, antifungal susceptibility, or species specificity. Copyright © 2017 American Society for Microbiology.

  15. Hidden in the light: Magnetically induced afterglow from trapped chameleon fields

    International Nuclear Information System (INIS)

    Gies, Holger; Mota, David F.; Shaw, Douglas J.

    2008-01-01

    We propose an afterglow phenomenon as a unique trace of chameleon fields in optical experiments. The vacuum interaction of a laser pulse with a magnetic field can lead to a production and subsequent trapping of chameleons in the vacuum chamber, owing to their mass dependence on the ambient matter density. Magnetically induced reconversion of the trapped chameleons into photons creates an afterglow over macroscopic timescales that can conveniently be searched for by current optical experiments. We show that the chameleon parameter range accessible to available laboratory technology is comparable to scales familiar from astrophysical stellar energy-loss arguments. We analyze quantitatively the afterglow properties for various experimental scenarios and discuss the role of potential background and systematic effects. We conclude that afterglow searches represent an ideal tool to aim at the production and detection of cosmologically relevant scalar fields in the laboratory

  16. The Chameleon Syndrome: A Social Psychological Dimension of the Female Sex Role

    Science.gov (United States)

    Rosen, Bernard C.; Aneshensel, Carol S.

    1976-01-01

    This study assesses the incidence and social correlates of the female form of the Chameleon Syndrome--an accommodative response to an environment perceived as hostile to inappropriate sex role behavior--among a sample of 3200 American adolescents. (Author)

  17. Chameleon gravity, electrostatics, and kinematics in the outer galaxy

    International Nuclear Information System (INIS)

    Pourhasan, R.; Mann, R.B.; Afshordi, N.; Davis, A.C.

    2011-01-01

    Light scalar fields are expected to arise in theories of high energy physics (such as string theory), and find phenomenological motivations in dark energy, dark matter, or neutrino physics. However, the coupling of light scalar fields to ordinary (or dark) matter is strongly constrained from laboratory, solar system, and astrophysical tests of the fifth force. One way to evade these constraints in dense environments is through the chameleon mechanism, where the field's mass steeply increases with ambient density. Consequently, the chameleonic force is only sourced by a thin shell near the surface of dense objects, which significantly reduces its magnitude. In this paper, we argue that thin-shell conditions are equivalent to ''conducting'' boundary conditions in electrostatics. As an application, we use the analogue of the method of images to calculate the back-reaction (or self-force) of an object around a spherical gravitational source. Using this method, we can explicitly compute the violation of the equivalence principle in the outskirts of galactic haloes (assuming an NFW dark matter profile): Intermediate mass satellites can be slower than their larger/smaller counterparts by as much as 10% close to a thin shell

  18. Chameleon gravity, electrostatics, and kinematics in the outer galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Pourhasan, R.; Mann, R.B. [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Afshordi, N. [Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5 (Canada); Davis, A.C., E-mail: r2pourhasan@uwaterloo.ca, E-mail: nafshordi@perimeterinstitute.ca, E-mail: rbmann@sciborg.uwaterloo.ca, E-mail: A.C.Davis@damtp.cam.ac.uk [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, Cambridge CB3 0WA (United Kingdom)

    2011-12-01

    Light scalar fields are expected to arise in theories of high energy physics (such as string theory), and find phenomenological motivations in dark energy, dark matter, or neutrino physics. However, the coupling of light scalar fields to ordinary (or dark) matter is strongly constrained from laboratory, solar system, and astrophysical tests of the fifth force. One way to evade these constraints in dense environments is through the chameleon mechanism, where the field's mass steeply increases with ambient density. Consequently, the chameleonic force is only sourced by a thin shell near the surface of dense objects, which significantly reduces its magnitude. In this paper, we argue that thin-shell conditions are equivalent to ''conducting'' boundary conditions in electrostatics. As an application, we use the analogue of the method of images to calculate the back-reaction (or self-force) of an object around a spherical gravitational source. Using this method, we can explicitly compute the violation of the equivalence principle in the outskirts of galactic haloes (assuming an NFW dark matter profile): Intermediate mass satellites can be slower than their larger/smaller counterparts by as much as 10% close to a thin shell.

  19. Compatibility of the Chameleon-Field Model with Fifth-Force Experiments, Cosmology, and PVLAS and CAST Results

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine

    2007-01-01

    We analyze the PVLAS results using a chameleon field whose properties depend on the environment. We find that, assuming a runaway bare potential V(φ) and a universal coupling to matter, the chameleon potential is such that the scalar field can act as dark energy. Moreover, the chameleon-field model is compatible with the CERN Axion Solar Telescope results, fifth-force experiments, and cosmology

  20. Conceptual Kinematic Design and Performance Evaluation of a Chameleon-Like Service Robot for Space Stations

    Directory of Open Access Journals (Sweden)

    Marco Ceccarelli

    2015-03-01

    Full Text Available In this paper a conceptual kinematic design of a chameleon-like robot with proper mobility capacity is presented for service applications in space stations as result of design considerations with biomimetic inspiration by looking at chameleons. Requirements and characteristics are discussed with the aim to identify design problems and operation features. A study of feasibility is described through performance evaluation by using simulations for a basic operation characterization.

  1. The effects of two free-floating plants (Eichhornia crassipes and Pistia stratiotes on the burrow morphology and water quality characteristics of pond loach (Misgurnus anguillicaudatus habitat

    Directory of Open Access Journals (Sweden)

    Jinqing Wang

    2018-01-01

    Full Text Available Loach exhibit conspicuous drilling behaviors in the mud of shallow waters, yet their burrow morphology and the factors affecting this behavior have received little attention. We characterized the burrow morphology and water quality of the pond loach Misgurnus anguillicaudatus in three scenarios: in tanks without plants, tanks with the free-floating plant water hyacinth Eichhornia crassipes, and tanks with water lettuce Pistia stratiotes. Water hyacinth effectively removed water TN, COD, NO3-N and NH4-N, and water lettuce removed water TP and NH4-N. Water hyacinth and water lettuce markedly reduced water turbidity and DO, increased TOC and EC. Water hyacinth purified water more effectively than water lettuce, providing a suitable habitat for loach feeding, living and burrowing. The burrow structures were V-shaped, Y-shaped, inverted L-shaped, or complicated dendritic networks composed of multiple V shapes. The hyacinth treatment was characterized by the greatest burrow volume, length, depth, and structural complexity, but the opening size was reduced by dense root mat coverage. Burrows in the water lettuce treatment were characterized by intermediate volume, length, branches and sinuosity, but they had the largest opening and pit size. The control treatment had a flat bottom with the smallest, shortest burrows. This study indicates that free-floating plants improve habitat suitability and change burrow morphology and may be used to improve loach breeding methods.

  2. Disseminated Mycosis in Veiled Chameleons (Chamaeleo calyptratus) Caused by Chamaeleomyces granulomatis, a New Fungus Related to Paecilomyces viridis

    DEFF Research Database (Denmark)

    Sigler, Lynne; Gibas, Connie Fe C.; Kokotovic, Branko

    2010-01-01

    An outbreak of disseminated granulomatous disease occurred in a group of veiled chameleons (Chamaeleo calyptratus) in a zoo collection. An adult female and six offspring developed large granulomas in multiple organs and were euthanized. At necropsy, roughly spherical yellow-to-white nodules 1 to 3...... of morphology results to represent Paecilomyces viridis, a species known only from one outbreak of fatal mycosis in carpet chameleons (Furcifer lateralis). Data obtained from morphological studies and from phylogenetic analyses of nuclear ribosomal rRNA (rDNA) sequence data revealed the Danish chameleon....... Chamaeleomyces species appear to be rare but aggressive pathogens of chameleons....

  3. A first possible chameleon from the late Miocene of India (the hominoid site of Haritalyangar): a tentative evidence for an Asian dispersal of chameleons.

    Science.gov (United States)

    Sankhyan, Anek R; Čerňanský, Andrej

    2016-12-01

    Miocene rare fossils from India, tentatively attributed to chameleons, are described for the first time. The material consists of a fragment of the left squamosal and an element interpreted as a posterodorsal process of the parietal. The specimens come from a late Miocene site of the Nagri Formation (Middle Siwaliks, ~ 9 Mya) at Haritalyangar, North India. This material presents a possible evidence for a chameleon dispersal to Asia. Based on molecular data, the dispersion of an Asian chamaeleonid lineage from Africa to Arabia/Asia is dated at approximately 13 Mya and its diversification in situ at around 6-8 Mya. However, till now, no Miocene-age fossil record has been described to support crown chamaeleonid presence in this area. The material described herein is very fragmented. If correctly allocated, the Haritalyangar chameleons show the oldest known occurrence of this clade in India, at least approximately 9 Mya ago.

  4. Molecular cloning, expression analysis and miRNA prediction of vascular endothelial growth factor A (VEGFAa and VEGFAb) in pond loach Misgurnus anguillicaudatus, an air-breathing fish.

    Science.gov (United States)

    Luo, Weiwei; Liang, Xiao; Huang, Songqian; Cao, Xiaojuan

    2016-12-01

    Vascular endothelial growth factor A (VEGFA) is the most studied and the best characterized member of the VEGF family and is a key regulator of angiogenesis via its ability to affect the proliferation, migration, and differentiation of endothelial cells. In this study, the full-length cDNAs encoding VEGFAa and VEGFAb from pond loach, Misgurnus anguillicaudatus, were isolated. The VEGFAa is constituted by an open reading frame (ORF) of 570bp encoding for a peptide of 189 amino acid residues, a 639bp 5'-untranslated region (UTR) and a 2383bp 3' UTR. The VEGFAb is constituted by an ORF of 687bp encoding for a peptide of 228 amino acid residues, a 560bp 5' UTR and a 1268bp 3' UTR. Phylogenetic analysis indicated that the VEGFAa and VEGFAb of pond loach were conserved in vertebrates. Expression levels of VEGFAa and VEGFAb were detected by RT-qPCR at different development stages of pond loach and in different tissues of 6-month-old, 12-month-old and 24-month-old pond loach. Moreover, eight predicted miRNAs (miR-200, miR-29, miR-218, miR-338, miR-103, miR-15, miR-17 and miR-223) targeting VEGFAa and VEGFAb were validated by an intestinal air-breathing inhibition experiment. This study will be of value for further studies into the function of VEGFA and its corresponding miRNAs, which will shed a light on the vascularization and accessory air-breathing process in pond loach. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Gauss-Bonnet chameleon mechanism of dark energy

    International Nuclear Information System (INIS)

    Ito, Yusaku; Nojiri, Shin'ichi

    2009-01-01

    As a model of the current accelerated expansion of the Universe, we consider a model of the scalar-Einstein-Gauss-Bonnet gravity. This model includes the propagating scalar modes, which might give a large correction to the Newton law. In order to avoid this problem, we propose an extension of the chameleon mechanism where the scalar mode becomes massive due to the coupling with the Gauss-Bonnet term. Since the Gauss-Bonnet invariant does not vanish near the Earth or in the Solar System, even in the vacuum, the scalar mode is massive even in the vacuum and the correction to the Newton law could be small. We also discuss the possibility that the model could describe simultaneously the inflation in the early Universe, in addition to the current accelerated expansion.

  6. Chameleon's behavior of modulable nonlinear electrical transmission line

    Science.gov (United States)

    Togueu Motcheyo, A. B.; Tchinang Tchameu, J. D.; Fewo, S. I.; Tchawoua, C.; Kofane, T. C.

    2017-12-01

    We show that modulable discrete nonlinear transmission line can adopt Chameleon's behavior due to the fact that, without changing its appearance structure, it can become alternatively purely right or left handed line which is different to the composite one. Using a quasidiscrete approximation, we derive a nonlinear Schrödinger equation, that predicts accurately the carrier frequency threshold from the linear analysis. It appears that the increasing of the linear capacitor in parallel in the series branch induced the selectivity of the filter in the right-handed region while it increases band pass filter in the left-handed region. Numerical simulations of the nonlinear model confirm the forward wave in the right handed line and the backward wave in the left handed one.

  7. Sexual Dimorphism in Bite Performance Drives Morphological Variation in Chameleons

    Science.gov (United States)

    da Silva, Jessica M.; Herrel, Anthony; Measey, G. John; Tolley, Krystal A.

    2014-01-01

    Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal’s foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal’s performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open- or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and

  8. Sexual dimorphism in bite performance drives morphological variation in chameleons.

    Directory of Open Access Journals (Sweden)

    Jessica M da Silva

    Full Text Available Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open- or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive

  9. Sexual dimorphism in bite performance drives morphological variation in chameleons.

    Science.gov (United States)

    da Silva, Jessica M; Herrel, Anthony; Measey, G John; Tolley, Krystal A

    2014-01-01

    Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open- or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and

  10. Comparative musculoskeletal anatomy of chameleon limbs, with implications for the evolution of arboreal locomotion in lizards and for teratology.

    Science.gov (United States)

    Molnar, Julia L; Diaz, Raul E; Skorka, Tautis; Dagliyan, Grant; Diogo, Rui

    2017-09-01

    Chameleon species have recently been adopted as models for evo-devo and macroevolutionary processes. However, most anatomical and developmental studies of chameleons focus on the skeleton, and information about their soft tissues is scarce. Here, we provide a detailed morphological description based on contrast enhanced micro-CT scans and dissections of the adult phenotype of all the forelimb and hindlimb muscles of the Veiled Chameleon (Chamaeleo calyptratus) and compare these muscles with those of other chameleons and lizards. We found the appendicular muscle anatomy of chameleons to be surprisingly conservative considering the remarkable structural and functional modifications of the limb skeleton, particularly the distal limb regions. For instance, the zygodactyl autopodia of chameleons are unique among tetrapods, and the carpals and tarsals are highly modified in shape and number. However, most of the muscles usually present in the manus and pes of other lizards are present in the same configuration in chameleons. The most obvious muscular features related to the peculiar opposable autopodia of chameleons are: (1) presence of broad, V-shaped plantar and palmar aponeuroses, and absence of intermetacarpales and intermetatarsales, between the digits separated by the cleft in each autopod; (2) oblique orientation of the superficial short flexors originating from these aponeuroses, which may allow these muscles to act as powerful adductors of the "super-digits"; and (3) well-developed abductor digiti minimi muscles and abductor pollicis/hallucis brevis muscles, which may act as powerful abductors of the "super-digits." © 2017 Wiley Periodicals, Inc.

  11. Female heterogamety in Madagascar chameleons (Squamata: Chamaeleonidae: Furcifer): differentiation of sex and neo-sex chromosomes

    Science.gov (United States)

    Rovatsos, Michail; Pokorná, Martina Johnson; Altmanová, Marie; Kratochvíl, Lukáš

    2015-01-01

    Amniotes possess variability in sex determining mechanisms, however, this diversity is still only partially known throughout the clade and sex determining systems still remain unknown even in such a popular and distinctive lineage as chameleons (Squamata: Acrodonta: Chamaeleonidae). Here, we present evidence for female heterogamety in this group. The Malagasy giant chameleon (Furcifer oustaleti) (chromosome number 2n = 22) possesses heteromorphic Z and W sex chromosomes with heterochromatic W. The panther chameleon (Furcifer pardalis) (2n = 22 in males, 21 in females), the second most popular chameleon species in the world pet trade, exhibits a rather rare Z1Z1Z2Z2/Z1Z2W system of multiple sex chromosomes, which most likely evolved from W-autosome fusion. Notably, its neo-W chromosome is partially heterochromatic and its female-specific genetic content has expanded into the previously autosomal region. Showing clear evidence for genotypic sex determination in the panther chameleon, we resolve the long-standing question of whether or not environmental sex determination exists in this species. Together with recent findings in other reptile lineages, our work demonstrates that female heterogamety is widespread among amniotes, adding another important piece to the mosaic of knowledge on sex determination in amniotes needed to understand the evolution of this important trait. PMID:26286647

  12. Cold-shock eliminates female nucleus in fertilized eggs to induce androgenesis in the loach (Misgurnus anguillicaudatus, a teleost fish

    Directory of Open Access Journals (Sweden)

    Morishima Kagayaki

    2011-11-01

    Full Text Available Abstract Background Androgenesis (all-male inheritance is generally induced by means of irradiating the eggs to inactivate the maternal genome, followed by fertilization with normal sperm. In fish, the conventional technique for induced androgenesis has been applied for rapid fixation to traits, recovery of cryopreserved genotypes, sex-control, etc. A new method of androgenesis that eliminates the need to irradiate the egg was proposed using the loach, Misgurnus anguillicaudatus (a teleost fish. Results When the eggs of wild-type females were fertilized with sperm of albino or orange phenotype males and cold-shocked at 0 to 3°C for 60 min duration just after fertilization, generally more than 30% (with a peak of 100% of the hatched progeny were androgenotes. While a few of them were the normal diploid, most of them turned out to be abnormal haploid. All-male inheritance was verified by the expression of the recessive color trait (albino or orange and microsatellite genotypes comprising only paternally derived alleles. Nuclear behavior after the cold-shock treatment was traced by microscopic observation of DAPI (4'6-diamidino-2-phenylindole-stained samples and hematoxylin-eosin stained histological sections, and the extrusion of egg (maternal nucleus was observed in eggs treated in the optimum timing. Conclusion In this paper, we demonstrate that cold-shock treatment (at 0 and 3°C of loach eggs for 60 min just after fertilization successfully induces androgenetic haploid development. The most likely mechanism of cold-shock induced androgenesis is an elimination of the egg nucleus together along with the second polar body and subsequent development of a decondensed sperm nucleus or male pronucleus.

  13. Cloning of three heat shock protein genes (HSP70, HSP90α and HSP90β) and their expressions in response to thermal stress in loach (Misgurnus anguillicaudatus) fed with different levels of vitamin C.

    Science.gov (United States)

    Yan, Jie; Liang, Xiao; Zhang, Yin; Li, Yang; Cao, Xiaojuan; Gao, Jian

    2017-07-01

    Heat shock protein 70 (HSP70) and 90 (HSP90) are the most broadly studied proteins in HSP families. They play key roles in cells as molecular chaperones, in response to stress conditions such as thermal stress. In this study, full-length cDNA sequences of HSP70, HSP90α and HSP90β from loach Misgurnus anguillicaudatus were cloned. The full-length cDNA of HSP70 in loach was 2332bp encoding 644 amino acids, while HSP90α and HSP90β were 2586bp and 2678bp in length, encoding 729 and 727 amino acids, respectively. The deduced amino acid sequences of HSP70 in loach shared the highest identity with those of Megalobrama amblycephala and Cyprinus carpio. The deduced amino acid sequences of HSP90α and HSP90β in loach both shared the highest identity with those of M. amblycephala. Their mRNA tissue expression results showed that the maximum expressions of HSP70, HSP90α and HSP90β were respectively present in the intestine, brain and kidney of loach. Quantitative real-time PCR was employed to analyze the temporal expressions of HSP70, HSP90α and HSP90β in livers of loaches fed with different levels of vitamin C under thermal stress. Expression levels of the three HSP genes in loach fed the diet without vitamin C supplemented at 0 h of thermal stress were significantly lower than those at 2 h, 6 h, 12 h and 24 h of thermal stress. It indicated that expressions of the three HSP genes were sensitive to thermal stress in loach. The three HSP genes in loaches fed with 1000 mg/kg vitamin C expressed significantly lower than other vitamin C groups at many time points of thermal stress, suggesting 1000 mg/kg dietary vitamin C might decrease the body damages caused by the thermal stress. This study will be of value for further studies into thermal stress tolerance in loach. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Subdigital setae of chameleon feet: friction-enhancing microstructures for a wide range of substrate roughness.

    Science.gov (United States)

    Spinner, Marlene; Westhoff, Guido; Gorb, Stanislav N

    2014-06-27

    Hairy adhesive systems of microscopic setae with triangular flattened tips have evolved convergently in spiders, insects and arboreal lizards. The ventral sides of the feet and tails in chameleons are also covered with setae. However, chameleon setae feature strongly elongated narrow spatulae or fibrous tips. The friction enhancing function of these microstructures has so far only been demonstrated in contact with glass spheres. In the present study, the frictional properties of subdigital setae of Chamaeleo calyptratus were measured under normal forces in the physical range on plane substrates having different roughness. We showed that chameleon setae maximize friction on a wide range of substrate roughness. The highest friction was measured on asperities of 1 μm. However, our observations of the climbing ability of Ch. calyptratus on rods of different diameters revealed that also claws and grasping feet are additionally responsible for the force generation on various substrates during locomotion.

  15. The scaling of tongue projection in the veiled chameleon, Chamaeleo calyptratus.

    Science.gov (United States)

    Herrel, Anthony; Redding, Chrystal L; Meyers, J Jay; Nishikawa, Kiisa C

    2014-08-01

    Within a year of hatching, chameleons can grow by up to two orders of magnitude in body mass. Rapid growth of the feeding mechanism means that bones, muscles, and movements change as chameleons grow while needing to maintain function. A previous morphological study showed that the musculoskeletal components of the feeding apparatus grow with negative allometry relative to snout-vent length (SVL) in chameleons. Here, we investigate the scaling of prey capture kinematics and muscle physiological cross-sectional area in the veiled chameleon, Chamaeleo calyptratus. The chameleons used in this study varied in size from approximately 3 to 18 cm SVL (1-200 g). Feeding sequences of 12 chameleons of different sizes were filmed and the timing of movements and the displacements and velocities of the jaws, tongue, and the hyolingual apparatus were quantified. Our results show that most muscle cross-sectional areas as well as tongue and hyoid mass scaled with isometry relative to mandible length, yet with negative allometry relative to SVL. Durations of movement also scaled with negative allometry relative to SVL and mandible length. Distances and angles generally scaled as predicted under geometric similarity (slopes of 1 and 0, respectively), while velocities generally scaled with slopes greater than 0 relative to SVL and mandible length. These data indicate that the velocity of jaw and tongue movements is generally greater in adults compared to juveniles. The discrepancy between the scaling of cross-sectional areas versus movements suggests changes in the energy storage and release mechanisms implicated in tongue projection. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. Attractors, statefinders and observational measurement for chameleonic Brans-Dicke cosmology

    International Nuclear Information System (INIS)

    Farajollahi, Hossein; Salehi, Amin

    2010-01-01

    We investigate chameleonic Brans-Dicke model applied to the FRW universes. A framework to study stability and attractor solutions in the phase space is developed for the model. We show that depending on the matter field and stability conditions, it is possible to realize phantom-like behavior without introducing phantom filed in the model while the stability is fulfilled and phantom crossing occurs. The statefinder parameters to the model for different kinds of matter interacting with the chameleon scalar field are studied. We also compare our model with present day observations

  17. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon

    OpenAIRE

    Takenaka, Naomi; Yokoyama, Shozo

    2007-01-01

    At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (λmax’s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76–86%, 14–24%, and ...

  18. Attractors, statefinders and observational measurement for chameleonic Brans-Dicke cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Farajollahi, Hossein; Salehi, Amin, E-mail: hosseinf@guilan.ac.ir, E-mail: a.salehi@guilan.ac.ir [Department of Physics, University of Guilan, Rasht (Iran, Islamic Republic of)

    2010-11-01

    We investigate chameleonic Brans-Dicke model applied to the FRW universes. A framework to study stability and attractor solutions in the phase space is developed for the model. We show that depending on the matter field and stability conditions, it is possible to realize phantom-like behavior without introducing phantom filed in the model while the stability is fulfilled and phantom crossing occurs. The statefinder parameters to the model for different kinds of matter interacting with the chameleon scalar field are studied. We also compare our model with present day observations.

  19. γ parameter and Solar System constraint in chameleon-Brans-Dicke theory

    International Nuclear Information System (INIS)

    Saaidi, Kh.; Mohammadi, A.; Sheikhahmadi, H.

    2011-01-01

    The post Newtonian parameter is considered in the chameleon-Brans-Dicke model. In the first step, the general form of this parameter and also effective gravitational constant is obtained. An arbitrary function for f(Φ), which indicates the coupling between matter and scalar field, is introduced to investigate validity of solar system constraint. It is shown that the chameleon-Brans-Dicke model can satisfy the solar system constraint and gives us an ω parameter of order 10 4 , which is in comparable to the constraint which has been indicated in [19].

  20. Madeleine de Scudéry’s animal sublime, or of chameleons

    OpenAIRE

    Duggan, Anne E.

    2016-01-01

    Drawing from Erica Harth’s work, animal studies, and ecofeminism, I explore the ways in which Scudéry engages in the important seventeenth-century debates over animal reason. Her engagement in these debates is significant: it foregrounds the fact that René Descartes’s conception of the animal-as-machine was immediately challenged by his contemporaries. In her “Story of Two Chameleons,” Scudéry challenges early modern moral and especially scientific representations of the chameleon, which l...

  1. Morphometric analysis of chameleon fossil fragments from the Early Pliocene of South Africa: a new piece of the chamaeleonid history.

    Science.gov (United States)

    Dollion, Alexis Y; Cornette, Raphaël; Tolley, Krystal A; Boistel, Renaud; Euriat, Adelaïde; Boller, Elodie; Fernandez, Vincent; Stynder, Deano; Herrel, Anthony

    2015-02-01

    The evolutionary history of chameleons has been predominantly studied through phylogenetic approaches as the fossil register of chameleons is limited and fragmented. The poor state of preservation of these fossils has moreover led to the origin of numerous nomen dubia, and the identification of many chameleon fossils remains uncertain. We here examine chameleon fossil fragments from the Early Pliocene Varswater formation, exposed at the locality of Langebaanweg "E" Quarry along the southwestern coast of South Africa. Our aim was to explore whether these fossil fragments could be assigned to extant genera. To do so, we used geometric morphometric approaches based on microtomographic imaging of extant chameleons as well as the fossil fragments themselves. Our study suggests that the fossils from this deposit most likely represent at least two different forms that may belong to different genera. Most fragments are phenotypically dissimilar from the South African endemic genus Bradypodion and are more similar to other chameleon genera such as Trioceros or Kinyongia. However, close phenetic similarities between some of the fragments and the Seychelles endemic Archaius or the Madagascan genus Furcifer suggest that some of these fragments may not contain enough genus-specific information to allow correct identification. Other fragments such as the parietal fragments appear to contain more genus-specific information, however. Although our data suggest that the fossil diversity of chameleons in South Africa was potentially greater than it is today, this remains to be verified based on other and more complete fragments.

  2. An Analysis of Failure Handling in Chameleon, A Framework for Supporting Cost-Effective Fault Tolerant Services

    Science.gov (United States)

    Haakensen, Erik Edward

    1998-01-01

    The desire for low-cost reliable computing is increasing. Most current fault tolerant computing solutions are not very flexible, i.e., they cannot adapt to reliability requirements of newly emerging applications in business, commerce, and manufacturing. It is important that users have a flexible, reliable platform to support both critical and noncritical applications. Chameleon, under development at the Center for Reliable and High-Performance Computing at the University of Illinois, is a software framework. for supporting cost-effective adaptable networked fault tolerant service. This thesis details a simulation of fault injection, detection, and recovery in Chameleon. The simulation was written in C++ using the DEPEND simulation library. The results obtained from the simulation included the amount of overhead incurred by the fault detection and recovery mechanisms supported by Chameleon. In addition, information about fault scenarios from which Chameleon cannot recover was gained. The results of the simulation showed that both critical and noncritical applications can be executed in the Chameleon environment with a fairly small amount of overhead. No single point of failure from which Chameleon could not recover was found. Chameleon was also found to be capable of recovering from several multiple failure scenarios.

  3. Force sensor for chameleon and Casimir force experiments with parallel-plate configuration

    NARCIS (Netherlands)

    Almasi, A.; Brax, P.; Iannuzzi, D.; Sedmik, R.

    2015-01-01

    The search for non-Newtonian forces has been pursued following many different paths. Recently it was suggested that hypothetical chameleon interactions, which might explain the mechanisms behind dark energy, could be detected in a high-precision force measurement. In such an experiment, interactions

  4. Effect of a chameleon scalar field on the cosmic microwave background

    International Nuclear Information System (INIS)

    Davis, Anne-Christine; Schelpe, Camilla A. O.; Shaw, Douglas J.

    2009-01-01

    We show that a direct coupling between a chameleonlike scalar field and photons can give rise to a modified Sunyaev-Zel'dovich (SZ) effect in the cosmic microwave background (CMB). The coupling induces a mixing between chameleon particles and the CMB photons when they pass through the magnetic field of a galaxy cluster. Both the intensity and the polarization of the radiation are modified. The degree of modification depends strongly on the properties of the galaxy cluster such as magnetic field strength and electron number density. Existing SZ measurements of the Coma cluster enable us to place constraints on the photon-chameleon coupling. The constrained conversion probability in the cluster is P Coma (204 GHz) -5 at 95% confidence, corresponding to an upper bound on the coupling strength of g eff (cell) -8 GeV -1 or g eff (Kolmo) -10 GeV -1 , depending on the model that is assumed for the cluster magnetic field structure. We predict the radial profile of the chameleonic CMB intensity decrement. We find that the chameleon effect extends farther toward the edges of the cluster than the thermal SZ effect. Thus we might see a discrepancy between the x-ray emission data and the observed SZ intensity decrement. We further predict the expected change to the CMB polarization arising from the existence of a chameleonlike scalar field. These predictions could be verified or constrained by future CMB experiments.

  5. Comprehensive high-accuracy modeling of electromagnetic effects in complete nanoscale RF blocks: CHAMELEON RF

    NARCIS (Netherlands)

    Niehof, J.; Janssen, H.H.J.M.; Schilders, W.H.A.

    2006-01-01

    Next-generation nano-scale RFIC designs have an unprecedented complexity and performance that will inevitably lead to costly re-spins and loss of market opportunities. In order to cope with this, the aim of the European Framework 6 CHAMELEON RF project is to develop methodologies and prototype tools

  6. The Populist Chameleon: The People's Party, Huey Long, George Wallace, and the Populist Argumentative Frame

    Science.gov (United States)

    Lee, Michael J.

    2006-01-01

    This essay argues that a sustained form can be located in the complicated history of populist rhetoric. Despite its chameleonic qualities, the advancement of populism is constituted by alterations in the focus and content, not the structure, of populist activism. This structure, or what I term its argumentative frame, positions a virtuous people…

  7. Selection for Social Signalling Drives the Evolution of Chameleon Colour Change

    Science.gov (United States)

    Stuart-Fox, Devi; Moussalli, Adnan

    2008-01-01

    Rapid colour change is a remarkable natural phenomenon that has evolved in several vertebrate and invertebrate lineages. The two principal explanations for the evolution of this adaptive strategy are (1) natural selection for crypsis (camouflage) against a range of different backgrounds and (2) selection for conspicuous social signals that maximise detectability to conspecifics, yet minimise exposure to predators because they are only briefly displayed. Here we show that evolutionary shifts in capacity for colour change in southern African dwarf chameleons (Bradypodion spp.) are associated with increasingly conspicuous signals used in male contests and courtship. To the chameleon visual system, species showing the most dramatic colour change display social signals that contrast most against the environmental background and amongst adjacent body regions. We found no evidence for the crypsis hypothesis, a finding reinforced by visual models of how both chameleons and their avian predators perceive chameleon colour variation. Instead, our results suggest that selection for conspicuous social signals drives the evolution of colour change in this system, supporting the view that transitory display traits should be under strong selection for signal detectability. PMID:18232740

  8. Lifelong Learning as a Chameleonic Concept and Versatile Practice: Y2K Perspectives and Trends

    Science.gov (United States)

    Grace, Andre P.

    2004-01-01

    This essay focuses on contemporary lifelong-learning discourse as it was reflected in deliberations during three events held in Australia, Canada and the UK during 2000-01. Through the dialogical lenses of these Y2K events that brought together an array of international participants, it examines lifelong learning as a chameleonic concept and…

  9. Selection for social signalling drives the evolution of chameleon colour change.

    Directory of Open Access Journals (Sweden)

    Devi Stuart-Fox

    2008-01-01

    Full Text Available Rapid colour change is a remarkable natural phenomenon that has evolved in several vertebrate and invertebrate lineages. The two principal explanations for the evolution of this adaptive strategy are (1 natural selection for crypsis (camouflage against a range of different backgrounds and (2 selection for conspicuous social signals that maximise detectability to conspecifics, yet minimise exposure to predators because they are only briefly displayed. Here we show that evolutionary shifts in capacity for colour change in southern African dwarf chameleons (Bradypodion spp. are associated with increasingly conspicuous signals used in male contests and courtship. To the chameleon visual system, species showing the most dramatic colour change display social signals that contrast most against the environmental background and amongst adjacent body regions. We found no evidence for the crypsis hypothesis, a finding reinforced by visual models of how both chameleons and their avian predators perceive chameleon colour variation. Instead, our results suggest that selection for conspicuous social signals drives the evolution of colour change in this system, supporting the view that transitory display traits should be under strong selection for signal detectability.

  10. Kinyongia asheorum sp n., a new montane chameleon from the Nyiro Range, northern Kenya (Squamata: Chamaeleonidae)

    Czech Academy of Sciences Publication Activity Database

    Nečas, P.; Sindaco, R.; Kořený, L.; Kopečná, J.; Malonza, P. K.; Modrý, David

    -, č. 2028 (2009), s. 41-50 ISSN 1175-5326 R&D Projects: GA ČR GA524/03/1548; GA ČR GA206/03/1544 Institutional research plan: CEZ:AV0Z60220518 Keywords : Kinyongia asheorum sp n, * new montane chameleon * Kenya Subject RIV: EG - Zoology Impact factor: 0.891, year: 2009

  11. Chameleon-photon mixing in a primordial magnetic field

    International Nuclear Information System (INIS)

    Schelpe, Camilla A. O.

    2010-01-01

    The existence of a sizable, O(10 -10 -10 -9 G), cosmological magnetic field in the early Universe has been postulated as a necessary step in certain formation scenarios for the large-scale O(μG) magnetic fields found in galaxies and galaxy clusters. If this field exists then it may induce significant mixing between photons and axion-like particles (ALPs) in the early Universe. The resonant conversion of photons into ALPs in a primordial magnetic field has been studied elsewhere by Mirizzi, Redondo and Sigl (2009). Here we consider the nonresonant mixing between photons and scalar ALPs with masses much less than the plasma frequency along the path, with specific reference to the chameleon scalar field model. The mixing would alter the intensity and polarization state of the cosmic microwave background (CMB) radiation. We find that the average modification to the CMB polarization modes is negligible. However the average modification to the CMB intensity spectrum is more significant and we compare this to high-precision measurements of the CMB monopole made by the far infrared absolute spectrophotometer on board the COBE satellite. The resulting 95% confidence limit on the scalar-photon conversion probability in the primordial field (at 100 GHz) is P γ↔φ -2 . This corresponds to a degenerate constraint on the photon-scalar coupling strength, g eff , and the magnitude of the primordial magnetic field. Taking the upper bound on the strength of the primordial magnetic field derived from the CMB power spectra, B λ ≤5.0x10 -9 G, this would imply an upper bound on the photon-scalar coupling strength in the range g eff -13 GeV -1 to g eff -14 GeV -1 , depending on the power spectrum of the primordial magnetic field.

  12. A unique life history among tetrapods: an annual chameleon living mostly as an egg.

    Science.gov (United States)

    Karsten, Kristopher B; Andriamandimbiarisoa, Laza N; Fox, Stanley F; Raxworthy, Christopher J

    2008-07-01

    The approximately 28,300 species of tetrapods (four-limbed vertebrates) almost exclusively have perennial life spans. Here, we report the discovery of a remarkable annual tetrapod from the arid southwest of Madagascar: the chameleon Furcifer labordi, with a posthatching life span of just 4-5 months. At the start of the active season (November), an age cohort of hatchlings emerges; larger juveniles or adults are not present. These hatchlings grow rapidly, reach sexual maturity in less than 2 months, and reproduce in January-February. After reproduction, senescence appears, and the active season concludes with population-wide adult death. Consequently, during the dry season, the entire population is represented by developing eggs that incubate for 8-9 months before synchronously hatching at the onset of the following rainy season. Remarkably, this chameleon spends more of its short annual life cycle inside the egg than outside of it. Our review of tetrapod longevity (>1,700 species) finds no others with such a short life span. These findings suggest that the notorious rapid death of chameleons in captivity may, for some species, actually represent the natural adult life span. Consequently, a new appraisal may be warranted concerning the viability of chameleon breeding programs, which could have special significance for species of conservation concern. Additionally, because F. labordi is closely related to other perennial species, this chameleon group may prove also to be especially well suited for comparative studies that focus on life history evolution and the ecological, genetic, and/or hormonal determinants of aging, longevity, and senescence.

  13. Different Histories, Different Destinies‒Impact of Evolutionary History and Population Genetic Structure on Extinction Risk of the Adriatic Spined Loaches (Genus Cobitis; Cypriniformes, Actinopterygii.

    Directory of Open Access Journals (Sweden)

    Ivana Buj

    Full Text Available The region of Balkans is often considered as an ichthyologic "hot spot", with a great number of species and high portion of endemics living in fresh waters in a relatively small area. The Adriatic watershed in Croatia and Herzegovina is inhabited by six spined loach species (genus Cobitis whose extinction risk estimations were based solely on their extent of occurrence (and/or area of occupancy and its fragmentation, and conservation proposals do not consider diversity below species level. In this investigation we employed molecular genetic methods to describe present genetic structure of the Adriatic spined loaches and reveal their demographic history. The divergence of the Adriatic lineages inside the genus Cobitis started in Miocene and lasted until Pleistocene epoch. Geological events responsible for shaping recent diversity of spined loaches in the Adriatic basin are: the Dinarid Mountains upwelling, the evolution of Dinaric Lake system, local tectonic activity, river connections during glaciations and differences in sea level. Even though all the investigated species inhabit karstic rivers located in the same geographic area and that were subject of similar geological events, the results obtained reveal great differences in their genetic diversity and structure and point out the necessity of different conservation measures to ensure their future viability. High level of genetic polymorphism is characteristic for species located more to the south. Two species comprised of more than one population have completely different intraspecific structure; populations of C. illyrica are genetically distinct and represent separate evolutionary significant units, whereas intraspecific structure of C. narentana corresponds to metapopulational pattern. Without population genetic data, evolutionary significant units could be easily misidentified. Furthermore, the obtained results affirm that population genetic measurements are able to detect differences

  14. Lateral mobility of plasma membrane proteins in dividing eggs of the loach (Misgurnus fossilis): Regional differences and changes during the cell cycle.

    Science.gov (United States)

    Bozhkova, V P; Budayova, M; Kvasnicka, P; Cigankova, N; Chorvat, D

    1994-12-01

    Regional differences in lateral diffusion rates of fluorescence-labeled proteins have been studied in the plasma membrane of dividing eggs of the loach (Misgurnus fossilis) by fluorescence recovery after photobleaching (FRAP). Apparent animal-vegetal differences in fluorescence intensity, lateral diffusion coefficients, and fractions of mobile proteins have been found, with all these quantities being higher in the animal pole region than in the yolk region. Cyclic changes in protein diffusion coefficients and mobile fractions during the first few cell cycles have also been recorded. Soon after the end of a cleavage, the diffusion coefficient reaches its minimal value and increases rapidly before the next cleavage.

  15. CUTANEOUS SQUAMOUS CELL CARCINOMA IN A PANTHER CHAMELEON (FURCIFER PARDALIS) AND TREATMENT WITH CARBOPLATIN IMPLANTABLE BEADS.

    Science.gov (United States)

    Johnson, James G; Naples, Lisa M; Chu, Caroline; Kinsel, Michael J; Flower, Jennifer E; Van Bonn, William G

    2016-09-01

    A 3-yr-old male panther chameleon (Furcifer pardalis) presented with bilateral raised crusted skin lesions along the lateral body wall that were found to be carcinoma in situ and squamous cell carcinoma. Similar lesions later developed on the caudal body wall and tail. A subcutaneous implantable carboplatin bead was placed in the first squamous cell carcinoma lesion identified. Additional new lesions sampled were also found to be squamous cell carcinomas, and viral polymerase chain reaction was negative for papillomaviruses and herpesviruses. Significant skin loss would have resulted from excision of all the lesions, so treatment with only carboplatin beads was used. No adverse effects were observed. Lesions not excised that were treated with beads decreased in size. This is the first description of cutaneous squamous cell carcinoma and treatment with carboplatin implantable beads in a panther chameleon.

  16. A signature for chameleons in axion-like particle search experiments

    Energy Technology Data Exchange (ETDEWEB)

    Weniger, Christoph [DESY Hamburg (Germany)

    2008-07-01

    Scalar-Tensor theories are well known and viable generalizations of General Relativity. In recent publications, it was shown that these theories can satisfy all astronomical bounds even if the scalar field couples to matter much stronger than gravity. This is due to the fact that the effective mass of the scalar field strongly depends on the density of the ambient matter. We point out that these strongly coupled fields, which were dubbed chameleons, might reveal themselves as an aefterglow'' effect in axion-like particle search experiments due to chameleon photon conversion in a magnetic field. We estimate the parameter space which is accessible by currently available technology and find that afterglow experiments could constrain this parameter space in a way complementary to gravitational and Casimir force experiments.

  17. Evolution of the Brans—Dicke Parameter in Generalized Chameleon Cosmology

    International Nuclear Information System (INIS)

    Jamil, Mubasher; Momeni, D.

    2011-01-01

    Motivated by an earlier study of Sahoo and Singh [Mod. Phys. Lett. A 17 (2002) 2409], we investigate the time dependence of the Brans-Dicke parameter ω(t) for an expanding Universe in the generalized Brans-Dicke Chameleon cosmology, and obtain an explicit dependence of ω(t) in different expansion phases of the Universe. Also, we discuss how the observed accelerated expansion of the observable Universe can be accommodated in the present formalism. (geophysics, astronomy, and astrophysics)

  18. Stability analysis and observational measurement in chameleonic generalised Brans-Dicke cosmology

    International Nuclear Information System (INIS)

    Farajollahi, Hossein; Salehi, Amin

    2011-01-01

    We investigate the dynamics of the chameleonic Generalised Brans-Dicke model in flat FRW cosmology. In a new approach, a framework to study stability and attractor solutions in the phase space for the model is developed by simultaneously best fitting the stability and model parameters with the observational data. The results show that for an accelerating universe the phantom crossing does not occur in the past and near future

  19. The incidence and antibiotic resistance of Salmonella species isolated from cloacae of captive veiled chameleons

    Directory of Open Access Journals (Sweden)

    Silvia Barazorda Romero

    2015-01-01

    Full Text Available Salmonella can be present in the intestinal flora of captive reptiles without clinical disease or it can cause life threatening morbidity. The presence of certain species of Salmonella in reptiles is consistent with them being the source of contamination in some cases of human disease. Thus, Salmonella positive animals can be a potential public health concern even more when strains acquire resistance to antibiotics. The nature and extent of Salmonella harboured by different species of reptiles commonly kept in captivity are not known. The aims of this study were to analyse the incidence of Salmonella species in cloacae as an indicator of the intestinal flora in a cohort of healthy captive bred female veiled chameleons. A cloacal sample was taken from each of fifteen healthy captive bred, adult female veiled chameleons that were housed at a teaching and research clinic. Salmonella isolates were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and positive cases were serotyped by slide agglutination test. Salmonella organisms were detected in 12 chameleons. Eighty percent of chameleons harboured 1 of 4 subspecies and serovars of Salmonella. All strains belonged to the species enterica, predominantly subspecies enterica (91.7 % and were distributed among 4 different serovars: S. Ago (58.3 %, S. Blijdorp (16.7 %, S. Tennessee (16.7 % and S. IV 45:g,z51:- (8.3 %. Antibiotic resistance to streptomycin was detected in one of 12 Salmonella strains: S. IV 45:g,z51:-. Our study extended the list of Salmonella found in healthy captive animals and included serovars S. Tennessee and S. IV 45:g,z51:- that have been associated with morbidity in humans.

  20. How CMB and large-scale structure constrain chameleon interacting dark energy

    International Nuclear Information System (INIS)

    Boriero, Daniel; Das, Subinoy; Wong, Yvonne Y.Y.

    2015-01-01

    We explore a chameleon type of interacting dark matter-dark energy scenario in which a scalar field adiabatically traces the minimum of an effective potential sourced by the dark matter density. We discuss extensively the effect of this coupling on cosmological observables, especially the parameter degeneracies expected to arise between the model parameters and other cosmological parameters, and then test the model against observations of the cosmic microwave background (CMB) anisotropies and other cosmological probes. We find that the chameleon parameters α and β, which determine respectively the slope of the scalar field potential and the dark matter-dark energy coupling strength, can be constrained to α < 0.17 and β < 0.19 using CMB data and measurements of baryon acoustic oscillations. The latter parameter in particular is constrained only by the late Integrated Sachs-Wolfe effect. Adding measurements of the local Hubble expansion rate H 0 tightens the bound on α by a factor of two, although this apparent improvement is arguably an artefact of the tension between the local measurement and the H 0 value inferred from Planck data in the minimal ΛCDM model. The same argument also precludes chameleon models from mimicking a dark radiation component, despite a passing similarity between the two scenarios in that they both delay the epoch of matter-radiation equality. Based on the derived parameter constraints, we discuss possible signatures of the model for ongoing and future large-scale structure surveys

  1. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon.

    Science.gov (United States)

    Takenaka, Naomi; Yokoyama, Shozo

    2007-09-01

    At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (lambda(max)'s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76-86%, 14-24%, and 10% of the spectral difference between them could be explained by amino acid differences in transmembrane (TM) helices I-IV, V-VII, and amino acid interactions between the two segments, respectively. Evolutionary and mutagenesis analyses revealed that the lambda(max)'s of the gecko and chameleon pigments diverged from each other not only by S49A (serine to alanine replacement at residue 49), S49F (serine to phenylalanine), L52M (leucine to methionine), D83N (aspartic acid to asparagine), M86T (methionine to threonine), and T97A (threonine to alanine) but also by other amino acid replacements that cause minor lambda(max)-shifts individually.

  2. PREPARING OF THE CHAMELEON COATING BY THE ION JET DEPOSITION METHOD

    Directory of Open Access Journals (Sweden)

    Jakub Skocdopole

    2017-07-01

    Full Text Available Preparation of chameleon coatings using an Ionized Jet Deposition (IJD technique is reported in the present paper. IJD is a new flexible method for thin film deposition developed by Noivion, Srl. The chameleon coatings are thin films characterised by a distinct change of their tribological properties according to the external conditions. The deposited films of SiC and TiN materials were examined by the Raman spectroscopy, SEM and XPS. The results of the Raman spectroscopy have proved an amorphous structure of SiC films. The data from XPS on TiN films have shown that the films are heavily oxidized, but also prove that the films are composed of TiN and pure Ti. The SEM provided information about the size of grains and particles constituting the deposited films, which is important for tribological properties of the films. Deposition of the chameleon coating is very complex problem and IJD could be ideal method for preparation of this coating.

  3. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon

    Science.gov (United States)

    Takenaka, Naomi; Yokoyama, Shozo

    2009-01-01

    At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (λmax’s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76–86%, 14–24%, and 10% of the spectral difference between them could be explained by amino acid differences in transmembrane (TM) helices I~IV, V~VII, and amino acid interactions between the two segments, respectively. Evolutionary and mutagenesis analyses revealed that the λmax’s of the gecko and chameleon pigments diverged from each other not only by S49A (serine to alanine replacement at residue 49), S49F (serine to phenylalanine), L52M (leucine to methionine), D83N (aspartic acid to asparagine), M86T (methionine to thereonine), and T97A (threonine to alanine) but also by other amino acid replacements that cause minor λmax-shifts individually. PMID:17590287

  4. Diet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii

    Science.gov (United States)

    Kraus, Fred; Medeiros, Arthur; Preston, David; Jarnevich, Catherine S.; Rodda, Gordon H.

    2012-01-01

    We summarize information on current distribution of the invasive lizard Chamaeleo jacksonii and predict its potential distribution in the Hawaiian Islands. Potential distribution maps are based on climate models developed from known localities in its native range and its Hawaiian range. We also present results of analysis of stomach contents of a sample of 34 chameleons collected from native, predominantly dryland, forest on Maui. These data are the first summarizing prey range of this non-native species in an invaded native-forest setting. Potential distribution models predict that the species can occur throughout most of Hawaii from sea level to >2,100 m elevation. Important features of this data set are that approximately one-third of the diet of these lizards is native insects, and the lizards are consuming large numbers of arthropods each day. Prey sizes span virtually the entire gamut of native Hawaiian arthropod diversity, thereby placing a large number of native species at risk of predation. Our dietary results contrast with expectations for most iguanian lizards and support suggestions that chameleons comprise a third distinct foraging-mode category among saurians. The combination of expanding distribution, large potential range size, broad diet, high predation rates, and high densities of these chameleons imply that they may well become a serious threat to some of the Hawaiian fauna.

  5. Chameleon-Inspired Mechanochromic Photonic Films Composed of Non-Close-Packed Colloidal Arrays.

    Science.gov (United States)

    Lee, Gun Ho; Choi, Tae Min; Kim, Bomi; Han, Sang Hoon; Lee, Jung Min; Kim, Shin-Hyun

    2017-11-28

    Chameleons use a non-close-packed array of guanine nanocrystals in iridophores to develop and tune skin colors in the full visible range. Inspired by the biological process uncovered in panther chameleons, we designed photonic films containing a non-close-packed face-centered-cubic array of silica particles embedded in an elastomer. The non-close-packed array is formed by interparticle repulsion exerted by solvation layers on the particle surface, which is rapidly captured in the elastomer by photocuring of the dispersion medium. The artificial skin exhibits a structural color that shifts from red to blue under stretching or compression. The separation between inelastic particles enables tuning without experiencing significant rearrangement of particles, providing elastic deformation and reversible color change, as chameleons do. The simple fabrication procedure consists of film casting and UV irradiation, potentially enabling the continuous high-throughput production. The mechanochromic property of the photonic films enables the visualization of deformation or stress with colors, which is potentially beneficial for various applications, including mechanical sensors, sound-vision transformers, and color display.

  6. A Phylogeographic Assessment of the Malagasy Giant Chameleons (Furcifer verrucosus and Furcifer oustaleti.

    Directory of Open Access Journals (Sweden)

    Antonia M Florio

    Full Text Available The Malagasy giant chameleons (Furcifer oustaleti and Furcifer verrucosus are sister species that are both broadly distributed in Madagascar, and also endemic to the island. These species are also morphologically similar and, because of this, have been frequently misidentified in the field. Previous studies have suggested that cryptic species are nested within this chameleon group, and two subspecies have been described in F. verrucosus. In this study, we utilized a phylogeographic approach to assess genetic diversification within these chameleons. This was accomplished by (1 identifying clades within each species supported by both mitochondrial and nuclear DNA, (2 assessing divergence times between clades, and (3 testing for niche divergence or conservatism. We found that both F. oustaleti and F. verrucosus could be readily identified based on genetic data, and within each species, there are two well-supported clades. However, divergence times are not contemporary and spatial patterns are not congruent. Diversification within F. verrucosus occurred during the Plio-Pleistocene, and there is evidence for niche divergence between a southwestern and southeastern clade, in a region of Madagascar that shows no obvious landscape barriers to dispersal. Diversification in F. oustaleti occurred earlier in the Pliocene or Miocene, and niche conservatism is supported with two genetically distinct clades separated at the Sofia River in northwestern Madagascar. Divergence within F. verrucosus is most consistent with patterns expected from ecologically mediated speciation, whereas divergence in F. oustaleti most strongly matches the patterns expected from the riverine barrier hypothesis.

  7. Comparison of spermatozoa parameters, fine structures, and energy-related factors among tetraploid, hyper-tetraploid, and hyper-triploid loaches (Misgurnus anguillicaudatus).

    Science.gov (United States)

    Zhao, Yan; Saito, Taiju; Pšenička, Martin; Fujimoto, Takafumi; Arai, Katsutoshi

    2014-04-01

    To evaluate the influence of ploidy elevation and aneuploidy on spermatozoa in the loach Misgurnus anguillicaudatus, we investigated some parameters (motility, concentration, and viability), fine structures (gross morphology, head size, and flagellum length), and energy-related biochemical factors (volume of mitochondrial mass per cell and ATP content) in diploid, hyper-diploid, and hexaploid-range spermatozoa produced in natural tetraploid, hyper-tetraploid, and hyper-triploid male loaches, respectively. Diploid spermatozoa exhibited vigorous movement and sufficient duration of motility similar to those in haploid spermatozoa. They had longer flagella, higher numbers and larger volume of mitochondria, and higher ATP content than haploid spermatozoa of wild-type diploids. No differences were observed in parameters and morphological characteristics between diploid and hyper-diploid spermatozoa. In contrast, the hexaploid-range spermatozoa of hyper-triploid males exhibited poor progressive motility in spite of a higher ATP content of spermatozoa. Spermatozoa with no flagella (36.0%) or multiple flagella (18.6%) were also observed in hyper-triploids. Ratios of head to flagellum length in hexaploid-range spermatozoa were significantly different from those of haploid spermatozoa. In addition to the normal 9+2 microtubule structure of the flagellum, an abnormal 9+1 microtubule structure was also observed in the spermatozoa of hyper-triploids. © 2014 Wiley Periodicals, Inc.

  8. Combining morphology and genetics in resolving taxonomy--a systematic revision of spined loaches (Genus Cobitis; Cypriniformes, Actinopterygii in the Adriatic watershed.

    Directory of Open Access Journals (Sweden)

    Ivana Buj

    Full Text Available Taxonomic investigation of spined loaches from Dalmatia and Herzegovina was conducted on specimens from 14 localities. The results of the detailed morphological investigations were combined with genetic data (based on one mitochondrial and two nuclear genes in order to resolve the taxonomic status of each Cobitis population. Among the investigated features of external morphology, the appearance of spots on the caudal fin base turned out to have the greatest diagnostic value. Furthermore, the number of branched fin rays enabled the discrimination of several species. No morphometric character alone could ensure determination of any Cobitis species. Nevertheless, groups of populations that are more similar in their body shapes correspond to mitochondrial phylogenetic lineages. Based on molecular genetic markers, Dalmatian and Herzegovinian spined loaches form independent lineages inside the Adriatic phylogenetic group. Mitochondrial DNA phylogenetic reconstruction revealed six monophyletic lineages, corresponding to six species distributed in the investigated area. The population distributed in Mostarsko blato karstic field in Bosnia and Herzegovina is described as a new species based on a unique combination of morphological characters: a single triangular Canestrini scale; usually 51/2 branched anal fin rays, 61/2 branched dorsal fin rays, 14 branched caudal fin rays; no spots in the surface pigmentation layer on the caudal fin base; scales on the body very small.

  9. High-Throughput Sequencing Identifies MicroRNAs from Posterior Intestine of Loach (Misgurnus anguillicaudatus) and Their Response to Intestinal Air-Breathing Inhibition.

    Science.gov (United States)

    Huang, Songqian; Cao, Xiaojuan; Tian, Xianchang; Wang, Weimin

    2016-01-01

    MicroRNAs (miRNAs) exert important roles in animal growth, immunity, and development, and regulate gene expression at the post-transcriptional level. Knowledges about the diversities of miRNAs and their roles in accessory air-breathing organs (ABOs) of fish remain unknown. In this work, we used high-throughput sequencing to identify known and novel miRNAs from the posterior intestine, an important ABO, in loach (Misgurnus anguillicaudatus) under normal and intestinal air-breathing inhibited conditions. A total of 204 known and 84 novel miRNAs were identified, while 47 miRNAs were differentially expressed between the two small RNA libraries (i.e. between the normal and intestinal air-breathing inhibited group). Potential miRNA target genes were predicted by combining our transcriptome data of the posterior intestine of the loach under the same conditions, and then annotated using COG, GO, KEGG, Swissprot and Nr databases. The regulatory networks of miRNAs and their target genes were analyzed. The abundances of nine known miRNAs were validated by qRT-PCR. The relative expression profiles of six known miRNAs and their eight corresponding target genes, and two novel potential miRNAs were also detected. Histological characteristics of the posterior intestines in both normal and air-breathing inhibited group were further analyzed. This study contributes to our understanding on the functions and molecular regulatory mechanisms of miRNAs in accessory air-breathing organs of fish.

  10. New holographic reconstruction of scalar-field dark-energy models in the framework of chameleon Brans-Dicke cosmology

    International Nuclear Information System (INIS)

    Chattopadhyay, Surajit; Pasqua, Antonio; Khurshudyan, Martiros

    2014-01-01

    Motivated by the work of Yang et al. (Mod. Phys. Lett. A 26:191, 2011), we report on a study of the new holographic dark energy (NHDE) model with energy density given by ρ D = (3φ 2 )/(4ω)(μH 2 + νH) in the framework of chameleon Brans-Dicke cosmology. We have studied the correspondence between the quintessence, the DBI-essence, and the tachyon scalar-field models with the NHDE model in the framework of chameleon Brans-Dicke cosmology. Deriving an expression of the Hubble parameter H and, accordingly, ρ D in the context of chameleon Brans-Dicke chameleon cosmology, we have reconstructed the potentials and dynamics for these scalar-field models. Furthermore, we have examined the stability for the obtained solutions of the crossing of the phantom divide under a quantum correction of massless conformally invariant fields, and we have seen that the quantum correction could be small when the phantom crossing occurs and the obtained solutions of the phantom crossing could be stable under the quantum correction. It has also been noted that the potential increases as the matter. chameleon coupling gets stronger with the evolution of the universe. (orig.)

  11. New holographic reconstruction of scalar-field dark-energy models in the framework of chameleon Brans-Dicke cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, Surajit [Pailan College of Management and Technology, Kolkata (India); Pasqua, Antonio [University of Trieste, Department of Physics, Trieste (Italy); Khurshudyan, Martiros [Yerevan State University, Department of Theoretical Physics, Yerevan (Armenia); Potsdam-Golm Science Park, Max Planck Institute of Colloids and Interfaces, Potsdam (Germany)

    2014-09-15

    Motivated by the work of Yang et al. (Mod. Phys. Lett. A 26:191, 2011), we report on a study of the new holographic dark energy (NHDE) model with energy density given by ρ{sub D} = (3φ{sup 2})/(4ω)(μH{sup 2} + νH) in the framework of chameleon Brans-Dicke cosmology. We have studied the correspondence between the quintessence, the DBI-essence, and the tachyon scalar-field models with the NHDE model in the framework of chameleon Brans-Dicke cosmology. Deriving an expression of the Hubble parameter H and, accordingly, ρ{sub D} in the context of chameleon Brans-Dicke chameleon cosmology, we have reconstructed the potentials and dynamics for these scalar-field models. Furthermore, we have examined the stability for the obtained solutions of the crossing of the phantom divide under a quantum correction of massless conformally invariant fields, and we have seen that the quantum correction could be small when the phantom crossing occurs and the obtained solutions of the phantom crossing could be stable under the quantum correction. It has also been noted that the potential increases as the matter. chameleon coupling gets stronger with the evolution of the universe. (orig.)

  12. How CMB and large-scale structure constrain chameleon interacting dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Boriero, Daniel [Fakultät für Physik, Universität Bielefeld, Universitätstr. 25, Bielefeld (Germany); Das, Subinoy [Indian Institute of Astrophisics, Bangalore, 560034 (India); Wong, Yvonne Y.Y., E-mail: boriero@physik.uni-bielefeld.de, E-mail: subinoy@iiap.res.in, E-mail: yvonne.y.wong@unsw.edu.au [School of Physics, The University of New South Wales, Sydney NSW 2052 (Australia)

    2015-07-01

    We explore a chameleon type of interacting dark matter-dark energy scenario in which a scalar field adiabatically traces the minimum of an effective potential sourced by the dark matter density. We discuss extensively the effect of this coupling on cosmological observables, especially the parameter degeneracies expected to arise between the model parameters and other cosmological parameters, and then test the model against observations of the cosmic microwave background (CMB) anisotropies and other cosmological probes. We find that the chameleon parameters α and β, which determine respectively the slope of the scalar field potential and the dark matter-dark energy coupling strength, can be constrained to α < 0.17 and β < 0.19 using CMB data and measurements of baryon acoustic oscillations. The latter parameter in particular is constrained only by the late Integrated Sachs-Wolfe effect. Adding measurements of the local Hubble expansion rate H{sub 0} tightens the bound on α by a factor of two, although this apparent improvement is arguably an artefact of the tension between the local measurement and the H{sub 0} value inferred from Planck data in the minimal ΛCDM model. The same argument also precludes chameleon models from mimicking a dark radiation component, despite a passing similarity between the two scenarios in that they both delay the epoch of matter-radiation equality. Based on the derived parameter constraints, we discuss possible signatures of the model for ongoing and future large-scale structure surveys.

  13. High-Throughput Sequencing Identifies MicroRNAs from Posterior Intestine of Loach (Misgurnus anguillicaudatus and Their Response to Intestinal Air-Breathing Inhibition.

    Directory of Open Access Journals (Sweden)

    Songqian Huang

    Full Text Available MicroRNAs (miRNAs exert important roles in animal growth, immunity, and development, and regulate gene expression at the post-transcriptional level. Knowledges about the diversities of miRNAs and their roles in accessory air-breathing organs (ABOs of fish remain unknown. In this work, we used high-throughput sequencing to identify known and novel miRNAs from the posterior intestine, an important ABO, in loach (Misgurnus anguillicaudatus under normal and intestinal air-breathing inhibited conditions. A total of 204 known and 84 novel miRNAs were identified, while 47 miRNAs were differentially expressed between the two small RNA libraries (i.e. between the normal and intestinal air-breathing inhibited group. Potential miRNA target genes were predicted by combining our transcriptome data of the posterior intestine of the loach under the same conditions, and then annotated using COG, GO, KEGG, Swissprot and Nr databases. The regulatory networks of miRNAs and their target genes were analyzed. The abundances of nine known miRNAs were validated by qRT-PCR. The relative expression profiles of six known miRNAs and their eight corresponding target genes, and two novel potential miRNAs were also detected. Histological characteristics of the posterior intestines in both normal and air-breathing inhibited group were further analyzed. This study contributes to our understanding on the functions and molecular regulatory mechanisms of miRNAs in accessory air-breathing organs of fish.

  14. De novo assembly of mud loach (Misgurnus anguillicaudatus skin transcriptome to identify putative genes involved in immunity and epidermal mucus secretion.

    Directory of Open Access Journals (Sweden)

    Yong Long

    Full Text Available Fish skin serves as the first line of defense against a wide variety of chemical, physical and biological stressors. Secretion of mucus is among the most prominent characteristics of fish skin and numerous innate immune factors have been identified in the epidermal mucus. However, molecular mechanisms underlying the mucus secretion and immune activities of fish skin remain largely unclear due to the lack of genomic and transcriptomic data for most economically important fish species. In this study, we characterized the skin transcriptome of mud loach using Illumia paired-end sequencing. A total of 40364 unigenes were assembled from 86.6 million (3.07 gigabases filtered reads. The mean length, N50 size and maximum length of assembled transcripts were 387, 611 and 8670 bp, respectively. A total of 17336 (43.76% unigenes were annotated by blast searches against the NCBI non-redundant protein database. Gene ontology mapping assigned a total of 108513 GO terms to 15369 (38.08% unigenes. KEGG orthology mapping annotated 9337 (23.23% unigenes. Among the identified KO categories, immune system is the largest category that contains various components of multiple immune pathways such as chemokine signaling, leukocyte transendothelial migration and T cell receptor signaling, suggesting the complexity of immune mechanisms in fish skin. As for mucin biosynthesis, 37 unigenes were mapped to 7 enzymes of the mucin type O-glycan biosynthesis pathway and 8 members of the polypeptide N-acetylgalactosaminyltransferase family were identified. Additionally, 38 unigenes were mapped to 23 factors of the SNARE interactions in vesicular transport pathway, indicating that the activity of this pathway is required for the processes of epidermal mucus storage and release. Moreover, 1754 simple sequence repeats (SSRs were detected in 1564 unigenes and dinucleotide repeats represented the most abundant type. These findings have laid the foundation for further understanding

  15. De novo assembly of mud loach (Misgurnus anguillicaudatus) skin transcriptome to identify putative genes involved in immunity and epidermal mucus secretion.

    Science.gov (United States)

    Long, Yong; Li, Qing; Zhou, Bolan; Song, Guili; Li, Tao; Cui, Zongbin

    2013-01-01

    Fish skin serves as the first line of defense against a wide variety of chemical, physical and biological stressors. Secretion of mucus is among the most prominent characteristics of fish skin and numerous innate immune factors have been identified in the epidermal mucus. However, molecular mechanisms underlying the mucus secretion and immune activities of fish skin remain largely unclear due to the lack of genomic and transcriptomic data for most economically important fish species. In this study, we characterized the skin transcriptome of mud loach using Illumia paired-end sequencing. A total of 40364 unigenes were assembled from 86.6 million (3.07 gigabases) filtered reads. The mean length, N50 size and maximum length of assembled transcripts were 387, 611 and 8670 bp, respectively. A total of 17336 (43.76%) unigenes were annotated by blast searches against the NCBI non-redundant protein database. Gene ontology mapping assigned a total of 108513 GO terms to 15369 (38.08%) unigenes. KEGG orthology mapping annotated 9337 (23.23%) unigenes. Among the identified KO categories, immune system is the largest category that contains various components of multiple immune pathways such as chemokine signaling, leukocyte transendothelial migration and T cell receptor signaling, suggesting the complexity of immune mechanisms in fish skin. As for mucin biosynthesis, 37 unigenes were mapped to 7 enzymes of the mucin type O-glycan biosynthesis pathway and 8 members of the polypeptide N-acetylgalactosaminyltransferase family were identified. Additionally, 38 unigenes were mapped to 23 factors of the SNARE interactions in vesicular transport pathway, indicating that the activity of this pathway is required for the processes of epidermal mucus storage and release. Moreover, 1754 simple sequence repeats (SSRs) were detected in 1564 unigenes and dinucleotide repeats represented the most abundant type. These findings have laid the foundation for further understanding the secretary

  16. Molecular evidence of cryptic diversity in Paracaryophyllaeus (Cestoda: Caryophyllidea), parasites of loaches (Cobitidae) in Eurasia, including description of P. vladkae n. sp.

    Science.gov (United States)

    Scholz, Tomáš; Oros, Mikuláš; Bazsalovicsová, Eva; Brabec, Jan; Waeschenbach, Andrea; Xi, Bing-Wen; Aydoğdu, Ali; Besprozvannykh, Vladimir; Shimazu, Takeshi; Králová-Hromadová, Ivica; Littlewood, D Timothy J

    2014-12-01

    Molecular phylogenetic analysis of an extensive collection of monozoic tapeworms of the genus Paracaryophyllaeus Kulakovskaya, 1961 (Cestoda: Caryophyllidea), parasites of loaches (Cypriniformes: Cobitidae) in Eurasia, has revealed cryptic species diversity within this long-time monotypic genus, especially in the Paracaryophyllaeus gotoi (Motomura, 1927) species complex [syn. Paracaryophyllaeus dubininorum (Kulakovskaya, 1961); type species]. Three independent, well-supported clades were discovered on the basis of molecular data: (i) specimens from Misgurnus anguillicaudatus and Cobitis lutheri from China, Russian Far East and Japan - called herein P. cf. gotoi 1, which may be conspecific with P. gotoi (Motomura, 1927), although in the absence of sequence data for P. gotoi from its type locality (basin of the River Kumkan in Korea), no certain inferences about their identity can currently be made; (ii) specimens from M. anguillicaudatus from China and Japan - P. cf. gotoi 2, which are morphologically indistinguishable from those of P. cf. gotoi 1; and (iii) morphologically distinct tapeworms from the endemic loach Cobitis bilseli from southwestern Turkey (Beyşehir Lake), which are described herein as a new species. Paracaryophyllaeus vladkae Scholz, Oros and Aydoğdu n. sp. differs from the remaining species of the genus in the following characteristics: the testes begin anterior to the first vitelline follicles (versus posterior), the body is short and robust (versus more elongate and slender), and the scolex is wide, rounded or apically tapered (versus claviform to truncate). Species composition of the genus, host specificity of species and geographical distribution are briefly discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Chameleon Effect, the Range of Values Hypothesis and Reproducing the EPR-Bohm Correlations

    Science.gov (United States)

    Accardi, Luigi; Khrennikov, Andrei

    2007-02-01

    We present a detailed analysis of assumptions that J. Bell used to show that local realism contradicts QM. We find that Bell's viewpoint on realism is nonphysical, because it implicitly assume that observed physical variables coincides with ontic variables (i.e., these variables before measurement). The real physical process of measurement is a process of dynamical interaction between a system and a measurement device. Therefore one should check the adequacy of QM not to "Bell's realism," but to adaptive realism (chameleon realism). Dropping Bell's assumption we are able to construct a natural representation of the EPR-Bohm correlations in the local (adaptive) realistic approach.

  18. Expanding horizons with Chameleon: team Missouri's innovative home automation system

    Energy Technology Data Exchange (ETDEWEB)

    Glass, B. [Department of Computer Engineering, Missouri University of Science and Technology, 1401 Pine Street, Rolla, MO 65409 (United States); Brannon, B. [Department of Electrical Engineering, Missouri University of Science and Technology, 1401 Pine Street, Rolla, MO 65409 (United States); Grantham, K. [Department of Engineering Management, Missouri University of Science and Technology, 1401 Pine Street, Rolla, MO 65409 (United States); Baur, S. [Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, 1401 Pine Street, Rolla, MO 65409 (United States)

    2010-06-15

    Team Missouri's 2009 Solar Decathlon entry featured a revolutionary home automation system, Chameleon, promoting both convenience and energy savings. This was accomplished using the typical controls of a convenience based automation system, while maintaining user set points, such as a home's ambient temperature, in the most energy efficient manner. Environmental features of the system include controls for space heating, ventilation and air conditioning, lighting, windows, shades, appliances, indoor air quality, as well as indoor and outdoor irrigation. Further analysis and refinement to the prototype system displayed at the competition is also presented in this paper. (authors)

  19. Expanding Horizons with Chameleon: Team Missouri’s Innovative Home Automation System

    Directory of Open Access Journals (Sweden)

    Bryan Glass

    2010-06-01

    Full Text Available Team Missouri’s 2009 Solar Decathlon entry featured a revolutionary home automation system, Chameleon, promoting both convenience and energy savings. This was accomplished using the typical controls of a convenience based automation system, while maintaining user set points, such as a home’s ambient temperature, in the most energy efficient manner. Environmental features of the system include controls for home heating, ventilation and air conditioning, lighting, windows, shades, appliances, indoor air quality, as well as indoor and outdoor irrigation. Further analysis and refinement to the prototype system displayed at the competition is also presented in this paper.

  20. Avoidance of a moving threat in the common chameleon (Chamaeleo chamaeleon): rapid tracking by body motion and eye use.

    Science.gov (United States)

    Lev-Ari, Tidhar; Lustig, Avichai; Ketter-Katz, Hadas; Baydach, Yossi; Katzir, Gadi

    2016-08-01

    A chameleon (Chamaeleo chamaeleon) on a perch responds to a nearby threat by moving to the side of the perch opposite the threat, while bilaterally compressing its abdomen, thus minimizing its exposure to the threat. If the threat moves, the chameleon pivots around the perch to maintain its hidden position. How precise is the body rotation and what are the patterns of eye movement during avoidance? Just-hatched chameleons, placed on a vertical perch, on the side roughly opposite to a visual threat, adjusted their position to precisely opposite the threat. If the threat were moved on a horizontal arc at angular velocities of up to 85°/s, the chameleons co-rotated smoothly so that (1) the angle of the sagittal plane of the head relative to the threat and (2) the direction of monocular gaze, were positively and significantly correlated with threat angular position. Eye movements were role-dependent: the eye toward which the threat moved maintained a stable gaze on it, while the contralateral eye scanned the surroundings. This is the first description, to our knowledge, of such a response in a non-flying terrestrial vertebrate, and it is discussed in terms of possible underlying control systems.

  1. The Wanderer, the Chameleon, and the Warrior: Experiences of Doctoral Students of Color Developing a Research Identity in Educational Administration

    Science.gov (United States)

    Murakami-Ramalho, Elizabeth; Piert, Joyce; Militello, Matthew

    2008-01-01

    In this article, the authors use their personal narratives and collaborative portraits as methods to shed light on the complexities of developing a research identity while journeying through a doctoral program. Using the metaphors of a wanderer, a chameleon, and a warrior, their narratives represent portraits of experiences faced by doctoral…

  2. Age-related changes in the tooth-bone interface area of acrodont dentition in the chameleon

    Czech Academy of Sciences Publication Activity Database

    Dosedělová, Hana; Štěpánková, K.; Zikmund, T.; Lesot, H.; Kaiser, J.; Novotný, K.; Štembírek, Jan; Knotek, Z.; Zahradníček, Oldřich; Buchtová, Marcela

    2016-01-01

    Roč. 229, č. 3 (2016), s. 356-368 ISSN 0021-8782 R&D Projects: GA ČR GB14-37368G; GA ČR(CZ) GP14-29273P Institutional support: RVO:67985904 ; RVO:68378041 Keywords : Chamaeleo-cylyptratus * tongue projection * veiled chameleon Subject RIV: EA - Cell Biology Impact factor: 2.182, year: 2016

  3. Genetic differentiation of two diploid-polyploid complexes of spined loach, genus Cobitis (Cobitidae), in the Czech Republic, involving C. taenia, C. elongatoides and C. spp.: allozyme interpopulation and interspecific differences

    Czech Academy of Sciences Publication Activity Database

    Šlechtová, Věra; Lusková, Věra; Šlechta, Vlastimil; Lusk, Stanislav; Halačka, Karel; Bohlen, Jörg

    2000-01-01

    Roč. 49, Suppl. 1 (2000), s. 67-78 ISSN 0139-7893. [Loaches of the genus Cobitis and related genera. Brno, 31.05.1999-03.06.1999] R&D Projects: GA ČR(CZ) GA206/97/0684; GA AV ČR(CZ) KSK2005601 Keywords : Cobitis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.240, year: 2000

  4. Age-related changes in the tooth-bone interface area of acrodont dentition in the chameleon.

    Science.gov (United States)

    Dosedělová, Hana; Štěpánková, Kateřina; Zikmund, Tomáš; Lesot, Herve; Kaiser, Jozef; Novotný, Karel; Štembírek, Jan; Knotek, Zdeněk; Zahradníček, Oldřich; Buchtová, Marcela

    2016-09-01

    Chameleon teeth develop as individual structures at a distance from the developing jaw bone during the pre-hatching period and also partially during the post-hatching period. However, in the adult, all teeth are fused together and tightly attached to the jaw bone by mineralized attachment tissue to form one functional unit. Tooth to bone as well as tooth to tooth attachments are so firm that if injury to the oral cavity occurs, several neighbouring teeth and pieces of jaw can be broken off. We analysed age-related changes in chameleon acrodont dentition, where ankylosis represents a physiological condition, whereas in mammals, ankylosis only occurs in a pathological context. The changes in hard-tissue morphology and mineral composition leading to this fusion were analysed. For this purpose, the lower jaws of chameleons were investigated using X-ray micro-computed tomography, laser-induced breakdown spectroscopy and microprobe analysis. For a long time, the dental pulp cavity remained connected with neighbouring teeth and also to the underlying bone marrow cavity. Then, a progressive filling of the dental pulp cavity by a mineralized matrix occurred, and a complex network of non-mineralized channels remained. The size of these unmineralized channels progressively decreased until they completely disappeared, and the dental pulp cavity was filled by a mineralized matrix over time. Moreover, the distribution of calcium, phosphorus and magnesium showed distinct patterns in the different regions of the tooth-bone interface, with a significant progression of mineralization in dentin as well as in the supporting bone. In conclusion, tooth-bone fusion in chameleons results from an enhanced production of mineralized tissue during post-hatching development. Uncovering the developmental processes underlying these outcomes and performing comparative studies is necessary to better understand physiological ankylosis; for that purpose, the chameleon can serve as a useful model

  5. Eastward from Africa: palaeocurrent-mediated chameleon dispersal to the Seychelles islands.

    Science.gov (United States)

    Townsend, Ted M; Tolley, Krystal A; Glaw, Frank; Böhme, Wolfgang; Vences, Miguel

    2011-04-23

    Madagascar and the Seychelles are Gondwanan remnants currently isolated in the Indian Ocean. In the Late Cretaceous, these islands were joined with India to form the Indigascar landmass, which itself then split into its three component parts around the start of the Tertiary. This history is reflected in the biota of the Seychelles, which appears to contain examples of both vicariance- and dispersal-mediated divergence from Malagasy or Indian sister taxa. One lineage for which this has been assumed but never thoroughly tested is the Seychellean tiger chameleon, a species assigned to the otherwise Madagascar-endemic genus Calumma. We present a multi-locus phylogenetic study of chameleons, and find that the Seychellean species is actually the sister taxon of a southern African clade and requires accomodation in its own genus as Archaius tigris. Divergence dating and biogeographic analyses indicate an origin by transoceanic dispersal from Africa to the Seychelles in the Eocene-Oligocene, providing, to our knowledge, the first such well-documented example and supporting novel palaeocurrent reconstructions.

  6. Chameleonic dilaton, nonequivalent frames, and the cosmological constant problem in quantum string theory

    International Nuclear Information System (INIS)

    Zanzi, Andrea

    2010-01-01

    The chameleonic behavior of the string theory dilaton is suggested. Some of the possible consequences of the chameleonic string dilaton are analyzed in detail. In particular, (1) we suggest a new stringy solution to the cosmological constant problem and (2) we point out the nonequivalence of different conformal frames at the quantum level. In order to obtain these results, we start taking into account the (strong coupling) string loop expansion in the string frame (S-frame), therefore the so-called form factors are present in the effective action. The correct dark energy scale is recovered in the Einstein frame (E-frame) without unnatural fine-tunings and this result is robust against all quantum corrections, granted that we assume a proper structure of the S-frame form factors in the strong coupling regime. At this stage, the possibility still exists that a certain amount of fine-tuning may be required to satisfy some phenomenological constraints. Moreover in the E-frame, in our proposal, all the interactions are switched off on cosmological length scales (i.e., the theory is IR-free), while higher derivative gravitational terms might be present locally (on short distances) and it remains to be seen whether these facts clash with phenomenology. A detailed phenomenological analysis is definitely necessary to clarify these points.

  7. Using an InGrid Detector to Search for Solar Chameleons with CAST

    CERN Document Server

    Desch, Klaus; Krieger, Christoph; Lupberger, Michael

    2015-01-01

    We report on the construction, operation experience, and preliminary background measurements of an InGrid detector, i.e. a MicroMegas detector with CMOS pixel readout. The detector was mounted in the focal plane of the Abrixas X-Ray telescope at the CAST experiment at CERN. The detector is sensitive to soft X-Rays in a broad energy range (0.3--10 keV) and thus enables the search for solar chameleons. Smooth detector operation during CAST data taking in autumn 2014 has been achieved. Preliminary analysis of background data indicates a background rate of $1-5\\times 10^{-5}\\,\\mathrm{keV}^{-1}\\mathrm{cm}^{-2}\\mathrm{s}^{-1}$ above 2 keV and $\\sim 3\\times 10^{-4}\\,\\mathrm{keV}^{-1}\\mathrm{cm}^{-2}\\mathrm{s}^{-1}$ around 1 keV. An expected limit of $\\beta_\\gamma \\lesssim 5\\times 10^{10}$ on the chameleon photon coupling is estimated in case of absence of an excess in solar tracking data. We also discuss the prospects for future operation of the detector.

  8. Chameleons communicate with complex colour changes during contests: different body regions convey different information.

    Science.gov (United States)

    Ligon, Russell A; McGraw, Kevin J

    2013-01-01

    Many animals display static coloration (e.g. of feathers or fur) that can serve as a reliable sexual or social signal, but the communication function of rapidly changing colours (as in chameleons and cephalopods) is poorly understood. We used recently developed photographic and mathematical modelling tools to examine how rapid colour changes of veiled chameleons Chamaeleo calyptratus predict aggressive behaviour during male-male competitions. Males that achieved brighter stripe coloration were more likely to approach their opponent, and those that attained brighter head coloration were more likely to win fights; speed of head colour change was also an important predictor of contest outcome. This correlative study represents the first quantification of rapid colour change using organism-specific visual models and provides evidence that the rate of colour change, in addition to maximum display coloration, can be an important component of communication. Interestingly, the body and head locations of the relevant colour signals map onto the behavioural displays given during specific contest stages, with lateral displays from a distance followed by directed, head-on approaches prior to combat, suggesting that different colour change signals may evolve to communicate different information (motivation and fighting ability, respectively).

  9. Interactions between Biliverdin, Oxidative Damage, and Spleen Morphology after Simulated Aggressive Encounters in Veiled Chameleons.

    Directory of Open Access Journals (Sweden)

    Michael W Butler

    Full Text Available Stressors frequently increase oxidative damage--unless organisms simultaneously mount effective antioxidant responses. One putative mitigative mechanism is the use of biliverdin, an antioxidant produced in the spleen during erythrocyte degradation. We hypothesized that both wild and captive-bred male veiled chameleons (Chamaeleo calyptratus, which are highly aggressive to conspecifics, would respond to agonistic displays with increased levels of oxidative damage, but that increased levels of biliverdin would limit this increase. We found that even just visual exposure to a potential combatant resulted in decreased body mass during the subsequent 48-hour period, but that hematocrit, biliverdin concentration in the bile, relative spleen size, and oxidative damage in plasma, liver, and spleen were unaffected. Contrary to our predictions, we found that individuals with smaller spleens exhibited greater decreases in hematocrit and higher bile biliverdin concentrations, suggesting a revision to the idea of spleen-dependent erythrocyte processing. Interestingly, individuals with larger spleens had reduced oxidative damage in both the liver and spleen, demonstrating the spleen's importance in modulating oxidative damage. We also uncovered differences in spleen size and oxidative damage between wild and captive-bred chameleons, highlighting environmentally dependent differences in oxidative physiology. Lastly, we found no relationship between oxidative damage and biliverdin concentration, calling into question biliverdin's antioxidant role in this species.

  10. Skin pattern structure and function of juvenile ages of Chameleo chameleon

    Directory of Open Access Journals (Sweden)

    Yosra A. Fouda

    2017-03-01

    Full Text Available Little is known about the skin structure of juvenile chameleon especially its sensory function of their integumentary structure. Fifteen juvenile Chameleo chameleon are collected from Abu Rawash, Northern area of Giza, Egypt during Summer of 2015. It is belong to the order Squamata, family, Chamaeleonidae. Three ages are used in the present study and categorized according to the morphological criteria of head, abdomen and limb lengths. Dorsal abdominal surfaces are covered with abdominal scales of varying sizes either conical or elliptical-structures, regularly arranged in rows and imbricated with each other. Each scale possessed one cylindrical lenticular epidermal sense organ containing heavy sensillia. Histologically, the scales are characterized by wider conical surfaces and intermingled with another one by hinge region. The epidermal layer of outer scale surface is composed of five-layered stratified squamous epithelium including the stratum germinativum, intermediate zone of stratum spinosum and granulosum, α-keratin layer, β-keratin layer and outer superficial Oberhaütchen. Melanosomes are abundant in the intermediate zone as well as in the peripheral dermal layer underneath stratum germinativum layer. The melanosomes possessed long cellular processes with their content of melanin granules underneath the epidermis. The dermis is composed of upper collagenous and inner compact layer. Semithin sections revealed the presence of fibroblast cells, collagenous fibrils, nerve axons, melanosomes and mast cells in the connective tissue core. Increased immunoreaction of cytokeratin is observed in the epidermal layers of G3; meanwhile, an increased proliferation of epidermal and dermal cells was detected in G1. Transmission electron microscopy exhibited striking formation of dermal sense organs containing neuronal cells of both oligodendrocytes and Schwann cells with myelinated and unmyelinated nerve axons ensheathed externally by thin

  11. A sensitive search for dark energy through chameleon scalar fields using neutron interferometry

    International Nuclear Information System (INIS)

    Snow, W M; Li, K; Skavysh, V; Arif, M; Huber, M; Heacock, B; Young, A R; Pushin, D

    2015-01-01

    The physical origin of the dark energy, which is postulated to cause the accelerated expansion rate of the universe, is one of the major open questions of cosmology. A large subset of theories postulate the existence of a scalar field with a nonlinear coupling to matter chosen so that the effective range and/or strength of the field is greatly suppressed unless the source is placed in vacuum. We describe a measurement using neutron interferometry which can place a stringent upper bound on chameleon fields proposed as a solution to the problem of the origin of dark energy of the universe in the regime with a strongly-nolinear coupling term. In combination with other experiments searching for exotic short-range forces and laser-based measurements, slow neutron experiments are capable of eliminating this and many similar types of scalar-field-based dark energy models by laboratory experiments

  12. Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field

    International Nuclear Information System (INIS)

    Setare, M.R.; Jamil, Mubasher

    2010-01-01

    We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter α (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.

  13. Chameleonic contribution to the Sunyaev-Zel'dovich radial profile of the Coma cluster

    International Nuclear Information System (INIS)

    Davis, Anne-Christine; Schelpe, Camilla A. O.; Shaw, Douglas J.

    2011-01-01

    We constrain the chameleonic Sunyaev-Zel'dovich (CSZ) effect in the Coma cluster from measurements of the Coma radial profile presented in the WMAP 7-year results. The CSZ effect arises from the interaction of a scalar (or pseudoscalar) particle with the cosmic microwave background in the magnetic field of galaxy clusters. We combine this radial profile data with SZ measurements towards the center of the Coma cluster in different frequency bands, to find ΔT SZ,RJ (0)=-410±50 μK and ΔT CSZ 204 GHz (0) > or approx. -50 μK (at 95% confidence) for the thermal SZ and CSZ effects in the cluster, respectively. This leads to an estimated bound on the photon to scalar (or pseudoscalar) coupling strength of g eff -10 GeV -1 .

  14. Modified Holographic Ricci Dark Energy in Chameleon Brans–Dicke Cosmology and Its Thermodynamic Consequence

    International Nuclear Information System (INIS)

    Jawad, A.; Chattopadhyay, S.; Bhattacharya, S.; Pasqua, A.

    2015-01-01

    The objective of this paper is to discuss the Chameleon Brans–Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n. (paper)

  15. Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field

    Energy Technology Data Exchange (ETDEWEB)

    Setare, M.R., E-mail: rezakord@ipm.i [Department of Science of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: mjamil@camp.edu.p [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, Rawalpindi 46000 (Pakistan)

    2010-06-07

    We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter {alpha} (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.

  16. Modified Holographic Ricci Dark Energy in Chameleon Brans-Dicke Cosmology and Its Thermodynamic Consequence

    Science.gov (United States)

    Jawad, A.; Chattopadhyay, S.; Bhattacharya, S.; Pasqua, A.

    2015-04-01

    The objective of this paper is to discuss the Chameleon Brans-Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n. The financial Supported from Department of Science and Technology, Govt. of India under Project Grant No. SR/FTP/PS-167/2011 is thankfully acknowledged by SC

  17. Experimental evidence for friction-enhancing integumentary modifications of chameleons and associated functional and evolutionary implications

    Science.gov (United States)

    Khannoon, Eraqi R.; Endlein, Thomas; Russell, Anthony P.; Autumn, Kellar

    2014-01-01

    The striking morphological convergence of hair-like integumentary derivatives of lizards and arthropods (spiders and insects) demonstrates the importance of such features for enhancing purchase on the locomotor substrate. These pilose structures are responsible for the unique tractive abilities of these groups of animals, enabling them to move with seeming ease on overhanging and inverted surfaces, and to traverse inclined smooth substrates. Three groups of lizards are well known for bearing adhesion-promoting setae on their digits: geckos, anoles and skinks. Similar features are also found on the ventral subdigital and distal caudal skin of chameleons. These have only recently been described in any detail, and structurally and functionally are much less well understood than are the setae of geckos and anoles. The seta-like structures of chameleons are not branched (a characteristic of many geckos), nor do they terminate in spatulate tips (which is characteristic of geckos, anoles and skinks). They are densely packed and have attenuated blunt, globose tips or broad, blade-like shafts that are flattened for much of their length. Using a force transducer, we tested the hypothesis that these structures enhance friction and demonstrate that the pilose skin has a greater frictional coefficient than does the smooth skin of these animals. Our results are consistent with friction being generated as a result of side contact of the integumentary filaments. We discuss the evolutionary and functional implications of these seta-like structures in comparison with those typical of other lizard groups and with the properties of seta-mimicking synthetic structures. PMID:24285195

  18. Sequential fragmentation of Pleistocene forests in an East Africa biodiversity hotspot: chameleons as a model to track forest history.

    Directory of Open Access Journals (Sweden)

    G John Measey

    Full Text Available The Eastern Arc Mountains (EAM is an example of naturally fragmented tropical forests, which contain one of the highest known concentrations of endemic plants and vertebrates. Numerous paleo-climatic studies have not provided direct evidence for ancient presence of Pleistocene forests, particularly in the regions in which savannah presently occurs. Knowledge of the last period when forests connected EAM would provide a sound basis for hypothesis testing of vicariance and dispersal models of speciation. Dated phylogenies have revealed complex patterns throughout EAM, so we investigated divergence times of forest fauna on four montane isolates in close proximity to determine whether forest break-up was most likely to have been simultaneous or sequential, using population genetics of a forest restricted arboreal chameleon, Kinyongia boehmei.We used mitochondrial and nuclear genetic sequence data and mutation rates from a fossil-calibrated phylogeny to estimate divergence times between montane isolates using a coalescent approach. We found that chameleons on all mountains are most likely to have diverged sequentially within the Pleistocene from 0.93-0.59 Ma (95% HPD 0.22-1.84 Ma. In addition, post-hoc tests on chameleons on the largest montane isolate suggest a population expansion ∼182 Ka.Sequential divergence is most likely to have occurred after the last of three wet periods within the arid Plio-Pleistocene era, but was not correlated with inter-montane distance. We speculate that forest connection persisted due to riparian corridors regardless of proximity, highlighting their importance in the region's historic dispersal events. The population expansion coincides with nearby volcanic activity, which may also explain the relative paucity of the Taita's endemic fauna. Our study shows that forest chameleons are an apposite group to track forest fragmentation, with the inference that forest extended between some EAM during the Pleistocene 1

  19. The experimental results on the quality of clustering diverse set of data using a modified algorithm chameleon

    Directory of Open Access Journals (Sweden)

    Татьяна Борисовна Шатовская

    2015-03-01

    Full Text Available In this work results of modified Chameleon algorithm are discussed. Hierarchical multilevel algorithms consist of several stages: building the graph, coarsening, partitioning, recovering. Exploring of clustering quality for different data sets with different combinations of algorithms on different stages of the algorithm is the main aim of the article. And also aim is improving the construction phase through the optimization algorithm of choice k in the building the graph k-nearest neighbors

  20. Chronic liver disease and subchronic nephritis in a male warty chameleon (Furcifer verrucosus with transient hyperglycaemia – case report

    Directory of Open Access Journals (Sweden)

    Zdeněk Knotek

    2011-01-01

    Full Text Available A two-year old male warty chameleon (Furcifer verrucosus weighing 160 g was presented for veterinary examination following 4 weeks of decreased ability to catch insects with the tongue and difficulty in swallowing the prey. Non-invasive endoscopy did not reveal any macroscopic changes of the oral cavity mucosa or the cranial part of the esophagus. Dorsoventral and laterolateral plain and contrast radiographs revealed enlargement of the medial part of the liver without any visible abnormalities in the regions of the esophagus, stomach or small intestine. Abnormalities in the plasma chemistry profile included transient hyperglycaemia (52.68–57.18 mmol/l and hyperuricaemia (452.70–622.20 μmol/l. The chameleon was examined at 7, 20 and 22 weeks after initial examination. Its body weight decreased to 120 g. A blood profile revealed normoglycaemia (16.37–10.22 mmol/l and hyperphosphataemia (2.92–3.06 mmol/l at the last three examinations. The chameleon died suddenly 33 days after the final examination. Necropsy revealed the presence of a large liver cyst, filled with fluid. The liver had lost all of its normal structure. The kidneys showed a large area with fibrosis and multiple uric acid tophi. The post mortem findings were defined as liver with fatty degeneration and moderate fibrotic changes with large cyst, subchronic nephritis with uric acid tophi, and mineralization in the myocardium. This paper describes the first documented case of transient hyperglycaemia in a warty chameleon (Furcifer verrucosus associated with chronic liver disease and subchronic nephritis.

  1. Life-history and ecological distribution of chameleons (Reptilia, Chamaeleonidae) from the rain forests of Nigeria: conservation implications

    OpenAIRE

    Akani, G. C.; Ogbalu, O. K.; Luiselli, L.

    2001-01-01

    Five species of chameleons were observed in the continuous forest zone of southern Nigeria: Chamaeleo gracilis gracilis Hallowell, 1842, Chamaeleo owenii Gray, 1831, Chamaeleo cristatus Stutchbury, 1837, Chamaeleo wiedersheimi Nieden, 1910, and Rhampholeon spectrum (Bucholz 1874). Many original locality records are presented for each species. One species is apparently rare and confined to montane habitats (C. wiedersheimi), another species is relatively common and its habitat is generalist (C...

  2. The first Chameleon transcriptome: comparative genomic analysis of the OXPHOS system reveals loss of COX8 in Iguanian lizards.

    Science.gov (United States)

    Bar-Yaacov, Dan; Bouskila, Amos; Mishmar, Dan

    2013-01-01

    Recently, we found dramatic mitochondrial DNA divergence of Israeli Chamaeleo chamaeleon populations into two geographically distinct groups. We aimed to examine whether the same pattern of divergence could be found in nuclear genes. However, no genomic resource is available for any chameleon species. Here we present the first chameleon transcriptome, obtained using deep sequencing (SOLiD). Our analysis identified 164,000 sequence contigs of which 19,000 yielded unique BlastX hits. To test the efficacy of our sequencing effort, we examined whether the chameleon and other available reptilian transcriptomes harbored complete sets of genes comprising known biochemical pathways, focusing on the nDNA-encoded oxidative phosphorylation (OXPHOS) genes as a model. As a reference for the screen, we used the human 86 (including isoforms) known structural nDNA-encoded OXPHOS subunits. Analysis of 34 publicly available vertebrate transcriptomes revealed orthologs for most human OXPHOS genes. However, OXPHOS subunit COX8 (Cytochrome C oxidase subunit 8), including all its known isoforms, was consistently absent in transcriptomes of iguanian lizards, implying loss of this subunit during the radiation of this suborder. The lack of COX8 in the suborder Iguania is intriguing, since it is important for cellular respiration and ATP production. Our sequencing effort added a new resource for comparative genomic studies, and shed new light on the evolutionary dynamics of the OXPHOS system.

  3. Search for chameleons with an InGrid based X-ray detector at the CAST experiment

    Energy Technology Data Exchange (ETDEWEB)

    Desch, Klaus; Kaminski, Jochen; Krieger, Christoph; Schmidt, Sebastian [Physikalisches Institut, Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany)

    2016-07-01

    The CERN Axion Solar Telescope (CAST) searches for axions and also other exotic particles emerging from the Sun. Chameleons, for example, are part of Dark Energy theories. Like Axions they can be converted into soft X-ray photons in a high magnetic field and should result in an X-ray spectrum peaking below 1 keV. Because of their low energy and weak coupling, detectors with low energy threshold and low background rates are mandatory. Both requirements are met by an X-ray detector based on the combination of a Micromegas gas amplification stage with a highly integrated pixel chip which allows to make full use of the Micromegas structure's granularity. It has been demonstrated that these devices can detect even single electrons. Thus, allowing for a topological background suppression as well as for detection of low energy X-ray photons creating only very few primary electrons. After the detection threshold had been evaluated to be low enough to allow for the detection of the carbon K{sub α} line at 277 eV, the detector was mounted at one of CAST's X-ray telescopes and installed along with its infrastructure in 2014. During data taking until end of 2015 background rates of less than 10{sup -4} keV/(cm{sup 2}.s) have been achieved below 2 keV. First preliminary results of the ongoing chameleon analysis and possibly an improved limit for solar chameleons are presented.

  4. Life-history and ecological distribution of chameleons (Reptilia, Chamaeleonidae from the rain forests of Nigeria: conservation implications

    Directory of Open Access Journals (Sweden)

    Akani, G. C.

    2001-12-01

    Full Text Available Five species of chameleons were observed in the continuous forest zone of southern Nigeria: Chamaeleo gracilis gracilis Hallowell, 1842, Chamaeleo owenii Gray, 1831, Chamaeleo cristatus Stutchbury, 1837, Chamaeleo wiedersheimi Nieden, 1910, and Rhampholeon spectrum (Bucholz 1874. Many original locality records are presented for each species. One species is apparently rare and confined to montane habitats (C. wiedersheimi, another species is relatively common and its habitat is generalist (C. gracilis, and the other three species are vulnerable and limited to specific micro-habitats. Female R. spectrum had clutch sizes of two eggs each and exhibited a prolonged reproductive season with oviposition likely occurring during the late phase of the dry season. Females of both C. cristatus (clutch sizes: 11-14 eggs and C. owenii (clutch sizes: 15-19 eggs have a shorter reproductive season with oviposition occurring most probably at the interphase between the end of the wet season and the onset of the dry season, and female C. gracilis (clutch sizes: 14-23 eggs appeared to exhibit two distinct oviposition periods (one at the interphase between the end of the wet season and the onset of the dry season, and one at the peak phase of the dry season. Diets of four sympatric species of chameleons consisted almost exclusively of arthropods. There were significant inter-group differences at either intra-specific level (with the females of the two best studied species, i.e. R. spectrum and C. gracilis, having a wider food niche breadth than males or inter-specific level (with a continuum of dietary specialization from the less generalist (C. cristatus to the more generalist (C. gracilis. However, ‘thread-trailing’ experiments indicated that activity patterns of Nigerian chameleons were relatively similar among species. The overall abundance of chameleons (as estimated from the number of specimens observed in the time unit of field effort was relatively

  5. El cine como verdad rev(belada: Ken Loach; una reflexión sobre los años que forjaron el discurso naturalista del cineasta/ Cinema as rev(bealed truth: Ken Loach; a reflection over the years that forged the filmmaker’s naturalist speech

    Directory of Open Access Journals (Sweden)

    Mercedes Miguel Borrás

    2015-07-01

    Full Text Available La sabiduría que se desprende al contemplar el cine de Ken Loach, su depurado estilo naturalista, es fruto de un largo recorrido caracterizado por la coherencia y honestidad. Un cineasta que lleva más de medio siglo dejando huellas de su humanismo, dando voz a los desheredados. ¿De dónde procede su mirada? ¿Cuál es la sustancia expresiva de la que se nutre su discurso? Detenemos nuestra atención en los filmes realizados en la primera etapa de su carrera (1964-1990, pues es cuando se percibe con mayor fuerza el deseo de Loach de penetrar en la realidad con un lenguaje tan riguroso que el pensamiento parece inscribirse en la película, “un cine de confesión, de ensayo”. Una mirada, que se rebela contra un orden y una sociedad injustos, y engendra emociones insospechadas, convocando a la ternura, pero al mismo tiempo hace que nos cuestionemos lo que se nos está contando. Un cine puro, directo, sin concesiones, que reduce al mínimo los recursos. Una verdad a la que se accede de forma natural, una verdad revelada. En el calidoscopio de realidades presentes en un mismo acontecimiento, que el cine (por su naturaleza indicial e icónica es capaz de mostrar, radica esa sustancia expresiva. The Wisdom that emerges when we watch Ken Loach’s films, his refined naturalistic style, is the result of a long journey marked by consistency and honesty. A filmmaker who spend more than half a century leaving traces of their humanism, giving voice to the dispossessed. Where is the origin of the way of his looking? What is the expressive substance that nourishes his speech? We hold our attention on the films made in the first stage of his career (1964-1990, as it is when we perceive the desire of the filmmaker to penetrate in the reality with such a rigorous language that the thinking seems to enroll in the film... a cinema of confession and essay. A look, that always rebels against an order and a inherently and unjust society, and generates unexpected

  6. Solar system and equivalence principle constraints on f(R) gravity by the chameleon approach

    International Nuclear Information System (INIS)

    Capozziello, Salvatore; Tsujikawa, Shinji

    2008-01-01

    We study constraints on f(R) dark energy models from solar system experiments combined with experiments on the violation of the equivalence principle. When the mass of an equivalent scalar field degree of freedom is heavy in a region with high density, a spherically symmetric body has a thin shell so that an effective coupling of the fifth force is suppressed through a chameleon mechanism. We place experimental bounds on the cosmologically viable models recently proposed in the literature that have an asymptotic form f(R)=R-λR c [1-(R c /R) 2n ] in the regime R>>R c . From the solar system constraints on the post-Newtonian parameter γ, we derive the bound n>0.5, whereas the constraints from the violations of the weak and strong equivalence principles give the bound n>0.9. This allows a possibility to find the deviation from the Λ-cold dark matter (ΛCDM) cosmological model. For the model f(R)=R-λR c (R/R c ) p with 0 -10 , which shows that this model is hardly distinguishable from the ΛCDM cosmology

  7. Revisiting chameleon gravity: Thin-shell and no-shell fields with appropriate boundary conditions

    International Nuclear Information System (INIS)

    Tamaki, Takashi; Tsujikawa, Shinji

    2008-01-01

    We derive analytic solutions of a chameleon scalar field φ that couples to a nonrelativistic matter in the weak gravitational background of a spherically symmetric body, paying particular attention to a field mass m A inside of the body. The standard thin-shell field profile is recovered by taking the limit m A r c →∞, where r c is a radius of the body. We show the existence of ''no-shell'' solutions where the field is nearly frozen in the whole interior of the body, which does not necessarily correspond to the 'zero-shell' limit of thin-shell solutions. In the no-shell case, under the condition m A r c >>1, the effective coupling of φ with matter takes the same asymptotic form as that in the thin-shell case. We study experimental bounds coming from the violation of equivalence principle as well as solar-system tests for a number of models including f(R) gravity and find that the field is in either the thin-shell or the no-shell regime under such constraints, depending on the shape of scalar-field potentials. We also show that, for the consistency with local gravity constraints, the field at the center of the body needs to be extremely close to the value φ A at the extremum of an effective potential induced by the matter coupling.

  8. Effects of incubation temperature on growth and performance of the veiled chameleon (Chamaeleo calyptratus).

    Science.gov (United States)

    Andrews, Robin M

    2008-10-01

    I evaluated the effect of incubation temperature on phenotypes of the veiled chameleon, Chamaeleo calyptratus. I chose this species for study because its large clutch size (30-40 eggs or more) allows replication within clutches both within and among experimental treatments. The major research objectives were (1) to assess the effect of constant low, moderate, and high temperatures on embryonic development, (2) to determine whether the best incubation temperature for embryonic development also produced the "best" hatchlings, and (3) to determine how a change in incubation temperature during mid-development would affect phenotype. To meet these objectives, I established five experimental temperature regimes and determined egg survival and incubation length and measured body size and shape, selected body temperatures, and locomotory performance of lizards at regular intervals from hatching to 90 d, or just before sexual maturity. Incubation temperature affected the length of incubation, egg survival, and body mass, but did not affect sprint speed or selected body temperature although selected body temperature affected growth in mass independently of treatment and clutch. Incubation at moderate temperatures provided the best conditions for both embryonic and post-hatching development. The highest incubation temperatures were disruptive to development; eggs had high mortality, developmental rate was low, and hatchlings grew slowly. Changes in temperature during incubation increased the among-clutch variance in incubation length relative to that of constant temperature treatments. Copyright 2008 Wiley-Liss, Inc.

  9. A new species of Choleoeimeria (Apicomplexa: Eimeriidae) from Meller's chameleon, Trioceros melleri (Sauria: Chamaeleonidae).

    Science.gov (United States)

    McAllister, Chris T

    2012-10-01

    A captive specimen of Meller's chameleon, Trioceros melleri (Gray), originally from Tanzania and housed at the Oklahoma City Zoological Park Herpetarium, Oklahoma County, Oklahoma, was found to be passing an undescribed species of Choleoeimeria in its feces. Oocysts of Choleoeimeria steveuptoni n. sp. were cylindroidal, 38.5 × 17.8 (36-42 × 17-19) µm with a bilayered wall and a shape index (length/width) of 2.2. A micropyle and oocyst residuum were absent, but a fragmented polar granule was often present. Ovoidal sporocysts were composed of 2 valves joined by a suture and measured 11.3 × 9.1 (11-12 × 9-10) µm; shape index of 1.3. Stieda, sub-Stieda, and para-Stieda bodies were absent. The sporocyst residuum consists of multiple globules dispersed along the perimeter of the sporocyst and between sporozoites. Sporozoites were elongate, 13.1 × 2.9 (12-15 × 2.6-3.2) µm with an elongate posterior refractile body. The new species represents the second coccidian documented from this lizard.

  10. A new species of Choleoeimeria (apicomplexa: eimeriidae) from oustalet's chameleon, Furcifer oustaleti (Sauria: Chamaeleonidae).

    Science.gov (United States)

    McAllister, Chris T

    2012-02-01

    One of three (33%) captive specimens of Oustalet's chameleon, Furcifer oustaleti (Mocquard) originally from Madagascar and housed at the Oklahoma City Zoological Park Herpetarium, Oklahoma County, Oklahoma, USA, was found to be passing an undescribed species of Choleoeimeria in its faeces. Oocysts of Choleoeimeria fischeri sp. n. were cylindroidal, 30.3 x 16.8 (28-34 x 15-18) microm, with a smooth, bilayered wall and a length/width ratio (L/W) of 1.8. A micropyle and oocyst residuum was absent but a fragmented polar granule was often present. Sporocysts were ovoidal, 9.6 x 8.0 (9-10 x 7-9) jm, with an L/W of 1.2. Stieda, sub-Stieda, and para-Stieda bodies were absent. The sporocyst residuum consists of large globules dispersed between sporozoites. Sporozoites were elongate, 8.6 x 2.9 (8-10 x 2-3) microm, with an elongate posterior refractile body. The new species represents the second coccidian described from this lizard.

  11. An Access Control Protocol for Wireless Sensor Network Using Double Trapdoor Chameleon Hash Function

    Directory of Open Access Journals (Sweden)

    Tejeshwari Thakur

    2016-01-01

    Full Text Available Wireless sensor network (WSN, a type of communication system, is normally deployed into the unattended environment where the intended user can get access to the network. The sensor nodes collect data from this environment. If the data are valuable and confidential, then security measures are needed to protect them from the unauthorized access. This situation requires an access control protocol (ACP in the design of sensor network because of sensor nodes which are vulnerable to various malicious attacks during the authentication and key establishment and the new node addition phase. In this paper, we propose a secured ACP for such WSN. This protocol is based on Elliptic Curve Discrete Log Problem (ECDLP and double trapdoor chameleon hash function which secures the WSN from malicious attacks such as node masquerading attack, replay attack, man-in-the-middle attack, and forgery attacks. Proposed ACP has a special feature known as session key security. Also, the proposed ACP is more efficient as it requires only one modular multiplication during the initialization phase.

  12. Cluster abundance in chameleon f ( R ) gravity I: toward an accurate halo mass function prediction

    Energy Technology Data Exchange (ETDEWEB)

    Cataneo, Matteo; Rapetti, David [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Lombriser, Lucas [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Li, Baojiu, E-mail: matteoc@dark-cosmology.dk, E-mail: drapetti@dark-cosmology.dk, E-mail: llo@roe.ac.uk, E-mail: baojiu.li@durham.ac.uk [Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2016-12-01

    We refine the mass and environment dependent spherical collapse model of chameleon f ( R ) gravity by calibrating a phenomenological correction inspired by the parameterized post-Friedmann framework against high-resolution N -body simulations. We employ our method to predict the corresponding modified halo mass function, and provide fitting formulas to calculate the enhancement of the f ( R ) halo abundance with respect to that of General Relativity (GR) within a precision of ∼< 5% from the results obtained in the simulations. Similar accuracy can be achieved for the full f ( R ) mass function on the condition that the modeling of the reference GR abundance of halos is accurate at the percent level. We use our fits to forecast constraints on the additional scalar degree of freedom of the theory, finding that upper bounds competitive with current Solar System tests are within reach of cluster number count analyses from ongoing and upcoming surveys at much larger scales. Importantly, the flexibility of our method allows also for this to be applied to other scalar-tensor theories characterized by a mass and environment dependent spherical collapse.

  13. Stroke Chameleons Manifesting as Distinct Radial Neuropathies: Expertise Can Hasten the Diagnosis

    Directory of Open Access Journals (Sweden)

    Fabrício Diniz de Lima

    2017-12-01

    Full Text Available Objective: Stroke chameleons encompass an atypical group of syndromes that do not initially appear to be cerebrovascular accidents. The objective of this study was to report patients with different lesions of central origin clinically presenting as wrist drop and with a semiology similar to that produced by peripheral lesions of the radial nerve at different topographical levels. Methods: This is a case series study of patients presenting with wrist drop during the acute phase of stroke who were assessed by clinical examination and CT and MRI brain scans. Results: Three cases presenting as monoparesis were evaluated. In all patients, the MRI revealed restricted diffusion in the pre- and post-central gyrus. Electromyography showed that the functionality of the radial, median, and ulnar nerves were intact in all three cases. The monoparesis resolved completely within 1 month of rehabilitation therapy, and no evidence of recurrent or new events was reported during the 6-month follow-up after stenting. Conclusion: The central message of this study is that when acute onset symptoms are present in a relatively old patient with vascular risk factors, stroke should be considered as the possible aetiology until proven otherwise, and the appropriate steps should be taken to avoid a delay in the treatment and to improve outcomes.

  14. Microsatellite Markers for the Chameleon Grasshopper (Kosciuscola tristis (Orthoptera: Acrididae, an Australian Alpine Specialist

    Directory of Open Access Journals (Sweden)

    Ange-Marie Risterucci

    2012-09-01

    Full Text Available A set of polymorphic loci was characterised using an enrichment library for the Australian alpine specialist, the chameleon grasshopper (Kosciuscola tristis, an atypical grasshopper known for its remarkable temperature-controlled colour change. The number of alleles per locus ranged from three to 20 and observed heterozygosity from 0.16 to 0.76. These are the first microsatellite markers for a non-endangered Australian alpine animal and will inform questions of gene flow across the sky islands of this unique and threatened region.

  15. First report of Rhabdias (Nematoda: Rhabdiasoidea from lungs of montane chameleons in Cameroon: description of two new species and notes on biology

    Directory of Open Access Journals (Sweden)

    Lhermitte-Vallarino N.

    2008-12-01

    Full Text Available The lung nematodes of the genus Rhabdias parasitic in chameleons were previously only known from east Africa and Madagascar. Two new species are described from Cameroon: i Rhabdias okuensis n. sp., type-host Chamaeleo (Trioceros quadricornis gracilior, from Mont Oku, is frequent; it resembles R. jarki from Burundi, with a short buccal capsule and a long, thin oesophagus, and is distinguished by its large cervical vesicle and cephalic characters (mouth aperture, papillae. The female parasites are hermaphroditic (spermatozoa identified and they pierce the lung wall and induce lesions, as R. jarki. In the same locality, another chameleon, C. (T. w. wiedersheimi also harbours R. okuensis, as demonstrated with the 12S rDNA and coxI gene sequences. ii R. cristati n. sp., type-host C. (T. cristatus, from Mount Cameroon, is described from one heavily infected specimen; it resembles R. chamaeleonis from East Africa, and is distinguished by the large buccal capsule and the thick apex of the intestine. The free-living phase, studied in R. okuensis, presents characters of other Rhabdias from chameleons: heterogony, development of larvae through matricidal endotoky, infective larval stages with a thick, rounded caudal extremity, exuvium transformed into a thick cuticular sheeth. Each free-living female produces one larva, as in other African Rhabdias, whereas the female of R. gemellipara, a parasite of a Malagasy chameleon, produces two larvae.

  16. Insights into chameleons of the genus Trioceros (Squamata: Chamaeleonidae) in Cameroon, with the resurrection of Chamaleon serratus Mertens, 1922

    Czech Academy of Sciences Publication Activity Database

    Barej, M. F.; Ineich, I.; Gvoždík, Václav; Lhermitte-Vallarino, N.; Gonwouo, N.L.; Le Breton, M.; Bott, U.; Schmitz, A.

    2010-01-01

    Roč. 57, č. 2 (2010), s. 211-229 ISSN 2190-7307 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : Chameleon serratus * Cameroon * insights Subject RIV: EG - Zoology

  17. Detecting cryptic speciation in the widespread and morphologically conservative carpet chameleon (Furcifer lateralis) of Madagascar.

    Science.gov (United States)

    Florio, A M; Ingram, C M; Rakotondravony, H A; Louis, E E; Raxworthy, C J

    2012-07-01

    Species delimitation within recently evolved groups can be challenging because species may be difficult to distinguish morphologically. Following the General Lineage Concept, we apply a multiple evidence approach to assess species limits within the carpet chameleon Furcifer lateralis, which is endemic to Madagascar and exported in large numbers for the pet trade. Cryptic speciation within F. lateralis was considered likely because this species (1) has a vast distribution, (2) occupies exceptionally diverse habitats and (3) exhibits subtle regional differences in morphology. Phylogenetic trees reconstructed using nuclear and mitochondrial genes recovered three well-supported clades corresponding with geography. Morphological results based on canonical variates analysis show that these clades exhibit subtle differences in head casque morphology. Ecological niche modelling results found that these phylogenetic groups also occupy unique environmental space and exhibit patterns of regional endemism typical of other endemic reptiles. Combined, our findings provide diverse yet consistent evidence for the existence of three species. Consequently, we elevate the subspecies F. lateralis major to species rank and name a new species distributed in northern and western Madagascar. Initial ecological divergence, associated with speciation of F. lateralis in humid eastern habitat, fits the Ecographic Constraint model for species diversification in Madagascar. By contrast, the second speciation event provides some support for the Riverine Barrier model, with the Mangoky River possibly causing initial isolation between species. These findings thus support two contrasting models of speciation within closely related species and demonstrate the utility of applying a combined-evidence approach for detecting cryptic speciation. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  18. Hyperfine interaction in the Autler-Townes effect: The formation of bright, dark, and chameleon states

    Science.gov (United States)

    Kirova, T.; Cinins, A.; Efimov, D. K.; Bruvelis, M.; Miculis, K.; Bezuglov, N. N.; Auzinsh, M.; Ryabtsev, I. I.; Ekers, A.

    2017-10-01

    This paper is devoted to clarifying the implications of hyperfine (HF) interaction in the formation of adiabatic (i.e., "laser-dressed") states and their expression in the Autler-Townes (AT) spectra. We first use the Morris-Shore model [J. R. Morris and B. W. Shore, Phys. Rev. A 27, 906 (1983), 10.1103/PhysRevA.27.906] to illustrate how bright and dark states are formed in a simple reference system where closely spaced energy levels are coupled to a single state with a strong laser field with the respective Rabi frequency ΩS. We then expand the simulations to realistic hyperfine level systems in Na atoms for a more general case when non-negligible HF interaction can be treated as a perturbation in the total system Hamiltonian. A numerical analysis of the adiabatic states that are formed by coupling of the 3 p3 /2 and 4 d5 /2 states by the strong laser field and probed by a weak laser field on the 3 s1 /2-3 p3 /2 transition yielded two important conclusions. Firstly, the perturbation introduced by the HF interaction leads to the observation of what we term "chameleon" states—states that change their appearance in the AT spectrum, behaving as bright states at small to moderate ΩS, and fading from the spectrum similarly to dark states when ΩS is much larger than the HF splitting of the 3 p3 /2 state. Secondly, excitation by the probe field from two different HF levels of the ground state allows one to address orthogonal sets of adiabatic states; this enables, with appropriate choice of ΩS and the involved quantum states, a selective excitation of otherwise unresolved hyperfine levels in excited electronic states.

  19. Static structure of chameleon dark matter as an explanation of dwarf spheroidal galaxy cores

    Science.gov (United States)

    Chanda, Prolay Krishna; Das, Subinoy

    2017-04-01

    We propose a novel mechanism that explains the cored dark matter density profile in recently observed dark matter rich dwarf spheroidal galaxies. In our scenario, dark matter particle mass decreases gradually as a function of distance towards the center of a dwarf galaxy due to its interaction with a chameleon scalar. At closer distance towards the Galactic center the strength of attractive scalar fifth force becomes much stronger than gravity and is balanced by the Fermi pressure of the dark matter cloud; thus, an equilibrium static configuration of the dark matter halo is obtained. Like the case of soliton star or fermion Q-star, the stability of the dark matter halo is obtained as the scalar achieves a static profile and reaches an asymptotic value away from the Galactic center. For simple scalar-dark matter interaction and quadratic scalar self-interaction potential, we show that dark matter behaves exactly like cold dark matter (CDM) beyond a few kpc away from the Galactic center but at closer distance it becomes lighter and Fermi pressure cannot be ignored anymore. Using Thomas-Fermi approximation, we numerically solve the radial static profile of the scalar field, fermion mass and dark matter energy density as a function of distance. We find that for fifth force mediated by an ultralight scalar, it is possible to obtain a flattened dark matter density profile towards the Galactic center. In our scenario, the fifth force can be neglected at distance r ≥1 kpc from the Galactic center and dark matter can be simply treated as heavy nonrelativistic particles beyond this distance, thus reproducing the success of CDM at large scales.

  20. The Santiago-Harvard-Edinburgh-Durham void comparison - I. SHEDding light on chameleon gravity tests

    Science.gov (United States)

    Cautun, Marius; Paillas, Enrique; Cai, Yan-Chuan; Bose, Sownak; Armijo, Joaquin; Li, Baojiu; Padilla, Nelson

    2018-05-01

    We present a systematic comparison of several existing and new void-finding algorithms, focusing on their potential power to test a particular class of modified gravity models - chameleon f(R) gravity. These models deviate from standard general relativity (GR) more strongly in low-density regions and thus voids are a promising venue to test them. We use halo occupation distribution (HOD) prescriptions to populate haloes with galaxies, and tune the HOD parameters such that the galaxy two-point correlation functions are the same in both f(R) and GR models. We identify both three-dimensional (3D) voids and two-dimensional (2D) underdensities in the plane of the sky to find the same void abundance and void galaxy number density profiles across all models, which suggests that they do not contain much information beyond galaxy clustering. However, the underlying void dark matter density profiles are significantly different, with f(R) voids being more underdense than GR ones, which leads to f(R) voids having a larger tangential shear signal than their GR analogues. We investigate the potential of each void finder to test f(R) models with near-future lensing surveys such as EUCLID and LSST. The 2D voids have the largest power to probe f(R) gravity, with an LSST analysis of tunnel (which is a new type of 2D underdensity introduced here) lensing distinguishing at 80 and 11σ (statistical error) f(R) models with parameters, |fR0| = 10-5 and 10-6, from GR.

  1. GPGPU accelerated Krylov methods for compact modeling of on-chip passive integrated structures within the Chameleon-RF workflow

    Directory of Open Access Journals (Sweden)

    Sebastian Gim

    2012-11-01

    Full Text Available Continued device scaling into the nanometer region and high frequencies of operation well into the multi-GHz region has given rise to new effects that previously had negligible impact but now present greater challenges and unprecedented complexity to designing successful mixed-signal silicon. The Chameleon-RF project was conceived to address these challenges. Creative use of domain decomposition, multi grid techniques or reduced order modeling techniques (ROM can be selectively applied at all levels of the process to efficiently prune down degrees of freedom (DoFs. However, the simulation of complex systems within a reasonable amount of time remains a computational challenge. This paper presents work done in the incorporation of GPGPU technology to accelerate Krylov based algorithms used for compact modeling of on-chip passive integrated structures within the workflow of the Chameleon-RF project. Based upon insight gained from work done above, a novel GPGPU accelerated algorithm was developed for the Krylov ROM (kROM methods and is described here for the benefit of the wider community.

  2. Impact of temperature on performance in two species of South African dwarf chameleon, Bradypodion pumilum and B. occidentale.

    Science.gov (United States)

    Segall, Marion; Tolley, Krystal A; Vanhooydonck, Bieke; Measey, G John; Herrel, Anthony

    2013-10-15

    Temperature is an extrinsic factor that influences reptile behavior because of its impact on reptile physiology. Understanding the impact of temperature on performance traits is important as it may affect the ecology and fitness of ectothermic animals such as reptiles. Here, we examined the temperature dependence of performance in two species of South African dwarf chameleon (Bradypodion): one adapted to a semi-arid environment and one to a mesic environment. Ecologically relevant performance traits were tested at different temperatures to evaluate their thermal dependence, and temperature-performance breadths for 80% and 90% of each performance trait were calculated. Our results show distinct differences in the thermal dependence of speed- versus force-related performance traits. Moreover, our results show that the semi-arid species is better adapted to higher temperatures and as such has a better chance of coping with the predicted increases in environmental temperature. The mesic area-adapted species seems to be more sensitive to an increase in temperature and could therefore potentially be threatened by the predicted future climate change. However, further studies investigating the potential for acclimation in chameleons are needed to better understand how animals may respond to future climate change.

  3. Reappraisal of the specific status of Rhabdias (Nematoda: Rhabdiasoidea from Malagasy chameleons in the Paris Museum collection

    Directory of Open Access Journals (Sweden)

    Lhermitte-Vallarino N.

    2009-06-01

    Full Text Available To date Rhabdias gemellipara is the only species described from Malagasy chameleons, but heterogeneity of the material had been suspected. 11 samples of Rhabdias parasites present in the Paris Natural History Museum collection were examined. The size and shape of the buccal capsule, shape and length of the oesophagus, shape of the apical region of the intestine, extent of the genital tract and structure of the cuticular vesicle led to the distinction of five species. Rhabdias rabetafikae n. sp. parasitises Calumma cucullatum in the northeastern region (Cap Machoual. In the eastern region, R. nasutum n. sp. is parasitic in C. nasutum, and R. brevicorne n. sp. in C. brevicorne. All three species are similar in size to the African species parasitic in chameleons from which they can be distinguished by several characters. The small species, R. gemellipara, type host C. parsonii from the eastern region, was also found in C. brevicorne from the same geographic region. In the central region, Rhabdias sp., equally collected from C. brevicorne, is distinguished from R. gemellipara by a laterally flattened buccal capsule. All Malagasy species are hermaphrodites. Throughout the worm’s life spermatozoids are formed intermittently in a band of cells situated at 1-2 mm from the extremity of the ovaries; they migrate in the ovaries and accumulate in the oviducts.

  4. Urns and Chameleons: two metaphors for two different types of measurements

    International Nuclear Information System (INIS)

    Accardi, Luigi

    2013-01-01

    -existent properties' (urn metaphor) and measurements consisting in reading 'a response to an interaction' (chameleon metaphor). The non-trivial point is that one can prove that, while the urn scheme cannot lead to empirical data outside of classic probability, response based measurements can give rise to non classical statistics. The talk will include entirely classical examples of non classical statistics and potential applications to economic, sociological or biomedical phenomena

  5. Discovery of a Giant Chameleon-Like Lizard (Anolis) on Hispaniola and Its Significance to Understanding Replicated Adaptive Radiations.

    Science.gov (United States)

    Mahler, D Luke; Lambert, Shea M; Geneva, Anthony J; Ng, Julienne; Hedges, S Blair; Losos, Jonathan B; Glor, Richard E

    2016-09-01

    We report a new chameleon-like Anolis species from Hispaniola that is ecomorphologically similar to congeners found only on Cuba. Lizards from both clades possess short limbs and a short tail and utilize relatively narrow perches, leading us to recognize a novel example of ecomorphological matching among islands in the well-known Greater Antillean anole radiation. This discovery supports the hypothesis that the assembly of island faunas can be substantially deterministic and highlights the continued potential for basic discovery to reveal new insights in well-studied groups. Restricted to a threatened band of midelevation transitional forest near the border of the Dominican Republic and Haiti, this new species appears to be highly endangered.

  6. Rivaling the World's Smallest Reptiles: Discovery of Miniaturized and Microendemic New Species of Leaf Chameleons (Brookesia) from Northern Madagascar

    Science.gov (United States)

    Glaw, Frank; Köhler, Jörn; Townsend, Ted M.; Vences, Miguel

    2012-01-01

    Background One clade of Malagasy leaf chameleons, the Brookesia minima group, is known to contain species that rank among the smallest amniotes in the world. We report on a previously unrecognized radiation of these miniaturized lizards comprising four new species described herein. Methodology/Principal Findings The newly discovered species appear to be restricted to single, mostly karstic, localities in extreme northern Madagascar: Brookesia confidens sp. n. from Ankarana, B. desperata sp. n. from Forêt d'Ambre, B. micra sp. n. from the islet Nosy Hara, and B. tristis sp. n. from Montagne des Français. Molecular phylogenetic analyses based on one mitochondrial and two nuclear genes of all nominal species in the B. minima group congruently support that the four new species, together with B. tuberculata from Montagne d'Ambre in northern Madagascar, form a strongly supported clade. This suggests that these species have diversified in geographical proximity in this small area. All species of the B. minima group, including the four newly described ones, are characterized by very deep genetic divergences of 18–32% in the ND2 gene and >6% in the 16S rRNA gene. Despite superficial similarities among all species of this group, their status as separate evolutionary lineages is also supported by moderate to strong differences in external morphology, and by clear differences in hemipenis structure. Conclusion/Significance The newly discovered dwarf chameleon species represent striking cases of miniaturization and microendemism and suggest the possibility of a range size-body size relationship in Malagasy reptiles. The newly described Brookesia micra reaches a maximum snout-vent length in males of 16 mm, and its total length in both sexes is less than 30 mm, ranking it among the smallest amniote vertebrates in the world. With a distribution limited to a very small islet, this species may represent an extreme case of island dwarfism. PMID:22348069

  7. Rivaling the world's smallest reptiles: discovery of miniaturized and microendemic new species of leaf chameleons (Brookesia from northern Madagascar.

    Directory of Open Access Journals (Sweden)

    Frank Glaw

    Full Text Available BACKGROUND: One clade of Malagasy leaf chameleons, the Brookesia minima group, is known to contain species that rank among the smallest amniotes in the world. We report on a previously unrecognized radiation of these miniaturized lizards comprising four new species described herein. METHODOLOGY/PRINCIPAL FINDINGS: The newly discovered species appear to be restricted to single, mostly karstic, localities in extreme northern Madagascar: Brookesia confidens sp. n. from Ankarana, B. desperata sp. n. from Forêt d'Ambre, B. micra sp. n. from the islet Nosy Hara, and B. tristis sp. n. from Montagne des Français. Molecular phylogenetic analyses based on one mitochondrial and two nuclear genes of all nominal species in the B. minima group congruently support that the four new species, together with B. tuberculata from Montagne d'Ambre in northern Madagascar, form a strongly supported clade. This suggests that these species have diversified in geographical proximity in this small area. All species of the B. minima group, including the four newly described ones, are characterized by very deep genetic divergences of 18-32% in the ND2 gene and >6% in the 16S rRNA gene. Despite superficial similarities among all species of this group, their status as separate evolutionary lineages is also supported by moderate to strong differences in external morphology, and by clear differences in hemipenis structure. CONCLUSION/SIGNIFICANCE: The newly discovered dwarf chameleon species represent striking cases of miniaturization and microendemism and suggest the possibility of a range size-body size relationship in Malagasy reptiles. The newly described Brookesia micra reaches a maximum snout-vent length in males of 16 mm, and its total length in both sexes is less than 30 mm, ranking it among the smallest amniote vertebrates in the world. With a distribution limited to a very small islet, this species may represent an extreme case of island dwarfism.

  8. Mitochondrial DNA variation, but not nuclear DNA, sharply divides morphologically identical chameleons along an ancient geographic barrier.

    Directory of Open Access Journals (Sweden)

    Dan Bar Yaacov

    Full Text Available The Levant is an important migration bridge, harboring border-zones between Afrotropical and palearctic species. Accordingly, Chameleo chameleon, a common species throughout the Mediterranean basin, is morphologically divided in the southern Levant (Israel into two subspecies, Chamaeleo chamaeleon recticrista (CCR and C. c. musae (CCM. CCR mostly inhabits the Mediterranean climate (northern Israel, while CCM inhabits the sands of the north-western Negev Desert (southern Israel. AFLP analysis of 94 geographically well dispersed specimens indicated moderate genetic differentiation (PhiPT = 0.097, consistent with the classical division into the two subspecies, CCR and CCM. In contrast, sequence analysis of a 637 bp coding mitochondrial DNA (mtDNA fragment revealed two distinct phylogenetic clusters which were not consistent with the morphological division: one mtDNA cluster consisted of CCR specimens collected in regions northern of the Jezreel Valley and another mtDNA cluster harboring specimens pertaining to both the CCR and CCM subspecies but collected southern of the Jezreel Valley. AMOVA indicated clear mtDNA differentiation between specimens collected northern and southern to the Jezreel Valley (PhiPT = 0.79, which was further supported by a very low coalescent-based estimate of effective migration rates. Whole chameleon mtDNA sequencing (∼17,400 bp generated from 11 well dispersed geographic locations revealed 325 mutations sharply differentiating the two mtDNA clusters, suggesting a long allopatric history further supported by BEAST. This separation correlated temporally with the existence of an at least 1 million year old marine barrier at the Jezreel Valley exactly where the mtDNA clusters meet. We discuss possible involvement of gender-dependent life history differences in maintaining such mtDNA genetic differentiation and suggest that it reflects (ancient local adaptation to mitochondrial-related traits.

  9. A phylogenetic review of the African leaf chameleons: genus Rhampholeon (Chamaeleonidae): the role of vicariance and climate change in speciation.

    Science.gov (United States)

    Matthee, Conrad A; Tilbury, Colin R; Townsend, Ted

    2004-09-22

    The phylogenetic associations among 13 currently recognized African leaf chameleon species were investigated by making use of mitochondrial and nuclear DNA sequence data (44 taxa and 4145 characters). The gene tree indicates two divergent clades within Rhampholeon; this finding is congruent with previous morphological suggestions. The first clade (I) comprises three taxa (R. kerstenii, R. brevicaudatus and R. brachyurus) and is widely distributed in lowland forest and or non-forest biomes. The second clade (II) comprises the remaining Rhampholeon species and can be subdivided into three subclades. By contrast, most taxa belonging to clade II are confined to relict montane forest biotopes. Based on geographical, morphological and molecular evidence, it is suggested that the taxonomy of Rhampholeon be revised to include two genera (Rieppeleon and Rhampholeon) and three subgenera (Rhampholeon, Bicuspis and Rhinodigitum). There is a close correlation between geographical distribution and phylogenetic relatedness among Rhampholeon taxa, indicating that vicariance and climate change were possibly the most influential factors driving speciation in the group. A relaxed Bayesian clock suggests that speciation times coincided both with the northern movement of Africa, which caused the constriction of the pan African forest, and to rifting in east Africa ca. 20 Myr ago. Subsequent speciation among taxa was probably the result of gradual desiccation of forests between 20 and 5 Myr ago.

  10. GENETIC DIFFERENTIATION AMONG POPULATIONS OF Chromobotia macracanthus BLEEKER FROM SUMATRA AND KALIMANTAN BASED ON SEQUENCING GENE OF MTDNA CYTOCHROME B AND NUCLEUS DNA RAG2

    Directory of Open Access Journals (Sweden)

    Sudarto Sudarto

    2008-12-01

    Full Text Available Research on genetic differentiation among populations of Chromobotia macracanthus Bleeker from Sumatra, based on sequencing gene of mtDNA Cytochrome b and nucleus DNA RAG2 has been done. The objectives of the study were to obtain the representation of genetic differentiation among population of clown loach fishes or botia (Chromobotia macracanthus from Sumatra and Kalimantan and to estimate the time divergence of both population group of botia. Samples of botia population were taken from 3 rivers in Sumatra namely Batanghari, Musi, and Tulang Bawang and one river from Kalimantan namely Kapuas. The genetic analysis was based on the sequencing of mtDNA Cytochrome b and nucleus DNA RAG2. The statistical analysis was done by using APE package on R language. The parameters observed were: nucleotide diversity, genetic distance, and neighbor-joining tree. The result showed that the highest nucleotide diversity was fish population of Musi, while the other two populations, Tulang Bawang (Sumatra and Kapuas (Kalimantan, were considered as the lowest genetic diversity especially based on nucleus DNA RAG2 sequencing. Based on mtDNA Cytochrome-b sequencing, the most distinct population among those populations based on genetic distance were fish populations of Musi and Kapuas. According to the result of neighbor-joining tree analysis, the populations of botia were classified into two groups namely group of Sumatra and group of Kalimantan. The estimation of time divergence among group of population of Sumatra and Kalimantan based on mtDNA Cytochrome b was about 9.25—9.46 million years (Miocene era. The high genetic differences between groups of Sumatra and Kalimantan suggested that the effort of restocking botia from Sumatra into Kalimantan has to be done carefully, because it may disturb the gene originality of both botia populations.

  11. Morphological and biological study of Rhabdias spp. (Nematoda from african chameleons with description of a new species

    Directory of Open Access Journals (Sweden)

    Lhermitte-Vallarino N.

    2004-03-01

    Full Text Available Lung-dwelling females of Rhabdias (Rhabdiasidae, and possible migrating ceolomic young females were searched for in 46 chameleons, belonging to seven species. Rhabdias chamaeleonis, the single species identified to date in Africa, was found in Chamaeleo (Trioceros johnstoni and C. (T. hoehnelii, and redescribed ; the sizes of the buccal capsule and oesophagus were stable compared to the length of the female parasites, which varied from 6 mm to 22 mm in length. A second species, R. jarki n, sp., was identified from one C. (T. johnstoni ; it differed from R. chamaeleonis in the shape of anterior region, the longer and slender oesophagus (ratio bulb diameter-body diameter at that level about 1/5 instead of 1/2, the arrangement of the head papillae, the shape of the buccal capsule, and the anatomy of the genital apparatus : one of the ovaries (the anterior or posterior one according to the specimen had a band of small cells, among larger ovocytes of the synapsis zone, which were likely to generate the spermatozoa present in the oviducts, whereas these two elements were absent from R. chamaeleonis. The parasitic females of R. jarki thus appeared to be hermaphroditic, whereas those of R. chamaeleonis appeared to be parthenogenetic. The free living phase of these Rhabdias species was heterogonic. The infective larva of R. chamaeleonis was 360-590 µm long, unmotile and at third stage inside the maternal cuticle. The free-living male of R. jarki was described. The numerous infective larvae recovered from cultures of unidentified Rhabdias were all in maternal cuticle (one larva/female instead of two as in R. gemellipara from Calumma parsonii, from Madagascar and two kinds of larvae were identified, R. chamaeleonis and larvae 700-900 µm long provisionally identified to R. jarki. The behaviour of infective larvae and a few successful infections of insects suggest that, in the field, insect transport hosts are involved in transmission and in preventing

  12. The Veiled Chameleon (Chamaeleo calyptratus Duméril and Duméril 1851): A Model for Studying Reptile Body Plan Development and Evolution.

    Science.gov (United States)

    Diaz, Raul E; Anderson, Christopher V; Baumann, Diana P; Kupronis, Richard; Jewell, David; Piraquive, Christina; Kupronis, Jill; Winter, Kristy; Bertocchini, Federica; Trainor, Paul A

    2015-08-26

    Vertebrate model organisms have facilitated the discovery and exploration of morphogenetic events and developmental pathways that underpin normal and pathological embryological events. In contrast to amniotes such as Mus musculus (Mammalia) and Gallus gallus (Aves), our understanding of early patterning and developmental events in reptiles (particularly nonavians) remains weak. Squamate reptiles (lizards, snakes, and amphisbaenians) comprise approximately one-third of all living amniotes. But studies of early squamate development have been limited because, in most members of this lineage, embryo development at the time of oviposition is very advanced (limb bud stages and older). In many cases, squamates give birth to fully developed offspring. However, in the veiled chameleon (Chamaeleo calyptratus), embryos have progressed only to a primitive pregastrula stage at the time of oviposition. Furthermore, the body plan of the veiled chameleon is highly specialized for climbing in an arboreal environment. It possesses an entire suite of skeletal and soft anatomical modifications, including cranioskeletal ornamentation, lingual anatomy and biomechanics for projection, autopodial clefting for grasping, adaptations for rapid integumental color changes, a prehensile tail with a lack of caudal autotomy, the loss of the tympanum in the middle ear, and the acquisition of turreted eyes. Thus, C. calyptratus is an important model organism for studying the role of ecological niche specialization, as well as genetic and morphological evolution within an adaptive framework. More importantly, this species is easily bred in captivity, with only a small colony (<10 individuals) needed to obtain hundreds of embryos every year. © 2015 Cold Spring Harbor Laboratory Press.

  13. Alternative Mating Tactics in Male Chameleons (Chamaeleo chamaeleon) Are Evident in Both Long-Term Body Color and Short-Term Courtship Pattern

    Science.gov (United States)

    Keren-Rotem, Tammy; Levy, Noga; Wolf, Lior; Bouskila, Amos; Geffen, Eli

    2016-01-01

    Alternative mating tactics in males of various taxa are associated with body color, body size, and social status. Chameleons are known for their ability to change body color following immediate environmental or social stimuli. In this study, we examined whether the differential appearance of male common chameleon during the breeding season is indeed an expression of alternative mating tactics. We documented body color of males and used computer vision techniques to classify images of individuals into discrete color patterns associated with seasons, individual characteristics, and social contexts. Our findings revealed no differences in body color and color patterns among males during the non-breeding season. However, during the breeding season males appeared in several color displays, which reflected body size, social status, and behavioral patterns. Furthermore, smaller and younger males resembled the appearance of small females. Consequently, we suggest that long-term color change in males during the breeding season reflects male alternative mating tactics. Upon encounter with a receptive female, males rapidly alter their appearance to that of a specific brief courtship display, which reflects their social status. The females, however, copulated indiscriminately in respect to male color patterns. Thus, we suggest that the differential color patterns displayed by males during the breeding season are largely aimed at inter-male signaling. PMID:27409771

  14. Alternative Mating Tactics in Male Chameleons (Chamaeleo chamaeleon Are Evident in Both Long-Term Body Color and Short-Term Courtship Pattern.

    Directory of Open Access Journals (Sweden)

    Tammy Keren-Rotem

    Full Text Available Alternative mating tactics in males of various taxa are associated with body color, body size, and social status. Chameleons are known for their ability to change body color following immediate environmental or social stimuli. In this study, we examined whether the differential appearance of male common chameleon during the breeding season is indeed an expression of alternative mating tactics. We documented body color of males and used computer vision techniques to classify images of individuals into discrete color patterns associated with seasons, individual characteristics, and social contexts. Our findings revealed no differences in body color and color patterns among males during the non-breeding season. However, during the breeding season males appeared in several color displays, which reflected body size, social status, and behavioral patterns. Furthermore, smaller and younger males resembled the appearance of small females. Consequently, we suggest that long-term color change in males during the breeding season reflects male alternative mating tactics. Upon encounter with a receptive female, males rapidly alter their appearance to that of a specific brief courtship display, which reflects their social status. The females, however, copulated indiscriminately in respect to male color patterns. Thus, we suggest that the differential color patterns displayed by males during the breeding season are largely aimed at inter-male signaling.

  15. The Paradox of Health Policy: Revealing the True Colours of This ‘Chameleon Concept’ Comment on “The Politics and Analytics of Health Policy”

    Directory of Open Access Journals (Sweden)

    Mark Exworthy

    2014-06-01

    Full Text Available Health policy has been termed a ‘chameleon concept’, referring to its ability to take on different forms of disciplinarity as well as different roles and functions. This paper extends Paton’s analysis by exploring the paradox of health policy as a field of academic inquiry—sitting across many of the boundaries of social science but also marginalised by them. It situates contemporary approaches within disciplinary traditions, explaining its inter- and multi-disciplinary character. It also presents a ‘way of seeing’ health policy in terms of three axes: central/local, profession/management, and health/healthcare. The paper concludes with a call for a new research agenda which recognises health policy’s pedigree but also one which carves a distinctive future of relevance and rigour.

  16. Contributions to the herpetofauna of the Albertine Rift: Two new species of chameleon (Sauria: Chamaeleonidae) from an isolated montane forest, south eastern Democratic Republic of Congo.

    Science.gov (United States)

    Tilbury, Colin R; Tolley, Krystal A

    2015-01-13

    Two new species of chameleons from the genera Rhampholeon and Kinyongia are described from an isolated montane forest remnant situated toward the southern end of the Albertine Rift bordering Lake Tanganyika. The closest known localities of species from these genera are 200km and 400km to the north respectively, separated by large intervening tracts of lowland savannah and Brachystegia (Miombo) woodland - habitats not normally inhabited by species of these genera. Rhampholeon hattinghi sp. nov. and Kinyongia mulyai sp. nov. bear superficial resemblances to previously described species (Rh. boulengeri Steindachner and K. adolfifriderici  (Sternfeld)). Rhampholeon hattinghi sp. nov. has a relatively smooth supra-orbital ridge, deep axillary but absent inguinal mite pockets, prominent white spots on the base of the tail and a uniquely derived hemipenal morphology with billowing parasulcal evaginations. Like K. adolfifriderici, Kinyongia mulyai sp. nov. is devoid of a rostral appendage but differs in having a longer and narrower head, a higher upper labial scale count and by the absence of a dorsal crest in the male. To place these new chameleons within the context of their respective genera, Bayesian and maximum likelihood phylogenetic analyses were carried out utilising two mitochondrial (ND2 and 16S) and one nuclear marker (RAG1).  Both chameleons were found to have morphological features that distinguish them from other congeners. Based on phylogenetic analysis they are clearly separate evolutionary lineages and are described as new species. 

  17. Interlanguage as Chameleon.

    Science.gov (United States)

    Tarone, Elaine

    1979-01-01

    Explores the validity of Labov's (1969) "Observer Paradox," and the five axioms describing the problems involved in linguistic research, for interlanguage research. Methodological remedies are suggested. (AM)

  18. University Presidents: Academic Chameleons

    Science.gov (United States)

    Buxton, Thomas H.; And Others

    1976-01-01

    Sampling the opinions of at least one college or university president in each state and at schools of all sizes, the authors measure the degree of job satisfaction experienced by presidents. (Editor/LBH)

  19. Chameleons in the Community

    Science.gov (United States)

    Haydon, Caroline

    1978-01-01

    Home visiting is clearly here to stay. More and more authorities are trying it out as a way of bringing home and school closer together. Yet it's an idea that embraces a wide variety of approaches, styles and attitudes. Reports on three of the early pioneering projects in Birmingham, Liverpool and Leicester. (Editor)

  20. HYBRIDIZATION AND CHAMELEONIC JOURNALISM

    Directory of Open Access Journals (Sweden)

    Adriana Schryver Kurtz

    2016-12-01

    Full Text Available O texto aborda a crescente hibridização entre o Jornalismo e demais formatos midiáticos como resultado natural de um processo que já está na própria raiz da comunicação enquanto atividade histórica. A lógica interna e as potencialidades estéticas e discursivas do fenômeno são analisadas a partir das convergências entre jornalismo e cinema. Para tanto, utiliza o falso documentário Zelig (1983, texto fílmico de Woody Allen, híbrido por natureza, postulado como um microcosmo rico em pistas e sugestões para refletir sobre a fusão entre conteúdos informativos e não informativos.   PALAVRAS-CHAVE: Hibridização; Jornalismo; Cinema; Zelig.       ABSTRACT The text discusses the growing hybridization between journalism and other media formats as a natural result of a process that is already in the very root of communication while historical activity. The internal logic and the aesthetic and discursive potential of the phenomenon are analyzed through the convergences between journalism and cinema. Therefore, uses the mockumentary Zelig (1983, filmic text of Woody Allen, hybrid by nature, postulated as a microcosm rich in clues and suggestions to reflect about the merger between informative and uninformative content.      KEYWORDS: Hybridization; Journalism; Cinema; Zelig.     RESUMEN El texto aborda la creciente hibridación entre el periodismo y otros formatos de medios como um resultado natural de un proceso que ya está en la raíz misma de la comunicación mientras actividad histórica. Se analizan la lógica interna y el potencial estético y discursivo del fenómeno a través de las convergencias entre el periodismo y el cine. Para ello, utiliza el falso documental Zelig (1983, texto fílmico de Woody Allen, híbrido en su naturaleza, postulado como un microcosmos rico en pistas y sugerencias para reflexionar sobre la fusión entre contenidos informativos y no informativos.      PALABRAS CLAVE: Hibridación; Periodismo; Cine; Zelig. Arquivamento e preservação de longo prazo do arquivo em: OpenDepot / Edina (The University of Edinburgh:  em processo de inclusão/indexação SSOAR-GESIS – Leibniz-Institut (Alemanha:  HAL (França: em processo de inclusão/indexação

  1. The Chameleon's Revenge

    DEFF Research Database (Denmark)

    Gundersen, Eline Busck

    2011-01-01

    Response-dependence theses are usually formulated in terms of a priori true biconditionals of roughly the form ‘something, x, falls under the concept ‘F’ « x would elicit response R from subjects S under conditions C’. Such formulations are vulnerable to conditional fallacy problems; counterexamp...

  2. Calixarenes, chemical chameleons

    NARCIS (Netherlands)

    van Dienst, E.S.; van Dienst, Erik; Iwema bakker, W.I.; Iwema Bakker, Wouter I.; Engbersen, Johannes F.J.; Verboom, Willem; Reinhoudt, David

    1993-01-01

    Methods for the synthesis of selectivety functionalized calix[4]arenes have been developed. These functionalized calix[4]arenes have been coupled to cavitands and cyclodextrins. A number of practical applications of calix[4]arenes are described.

  3. The Chameleon Workforce

    DEFF Research Database (Denmark)

    Marfelt, Mikkel Mouritz

    , cultural, professional, etc.). This PhD dissertation studies this phenomenon, ‘a diverse workforce’, in a large Scandinavian pharmaceutical company. The dissertation follows the Diverse and Global Workforce (DGW) project, a ‘headquarter centric’ and strategic corporate initiative to address the rapid......Due to advancements in technology and the expansion of companies onto a global level, organizations have become increasingly aware of the need to understand and manage diverse workforces; that is, the need to understand and manage differences among employees across borders (such as geographical...... global expansion of the company workforce....

  4. A new species of Chameleon (Sauria: Chamaeleonidae: Kinyongia highlights the biological affinities between the Southern Highlands and Eastern Arc Mountains of Tanzania

    Directory of Open Access Journals (Sweden)

    Michele Menegon

    2015-12-01

    Full Text Available A new species of chameleon is described from the Livingstone and Udzungwa Mountains of Tanzania. The new species is morphologically most similar to Kinyongia vanheygeni. Furthermore, a single, short rostral appendage shows the species similarity to other Eastern Arc endemic Kinyongia species (e.g. K. uthmoelleri, K. oxyrhina, K. magomberae and K. tenuis. Females of all these species lack any rostral ornamentation and are all very similar morphologically. Males of the new species, on which the morphological diagnosis is based, can be distinguished from other Kinyongia by a shorter rostral appendage that bifurcates at the tip. They are easily distinguished from K. vanheygeni, otherwise the most similar species, by differences in head scalation and the length and shape of the rostral appendage. The new species is associated with montane rainforest and is known from only four forest fragments of which two are in the Udzungwa and two in the Livingstone Mountains. Phylogenetically, the new species is sister to K. tenuis and K. magomberae, which together, form a clade that also contains K. oxyrhina. The disjunct distribution of the new species, in the Livingstone and Udzungwa mountains, stretches across the ‘Makambako Gap’ which is a putative biogeographical barrier separating the distinct faunas of the Southern highlands and Eastern Arc Mountains. Evidence from this species however, points to potentially closer biological affinities between the Livingstone and Udzungwa mountains.

  5. Two new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from the flap-necked chameleon Chamaeleo dilepis (Sauria: Chamaeleonidae) in the Republic of Namibia.

    Science.gov (United States)

    McAllister, Chris T

    2012-09-01

    Two new species of Isospora Schneider, 1881 from flap-necked chameleons Chamaeleo dilepis Leach are described from the faeces of specimens collected in the Republic of Namibia. Oöcysts of Isospora freedi n. sp. from one of four (25%) C. dilepis collected in the East Caprivi District are spherical to subspherical, with a smooth, colourless, bilayered wall, measure 23.7 × 21.2 μm and have a length/width (L/W) ratio of 1.1. The micropyle and the oöcyst residuum are absent but a polar granule is sometimes present. Sporocysts are ovoidal to ellipsoidal and 13.9 × 10.3 μm in size with prominent Stieda and sub-Stieda bodies; and the sporocyst residuum is composed of a compact mass of large globules. The sporozoites contain anterior and posterior refractile bodies with a nucleus between them. Oöcysts of Isopora mandelai n. sp. from three of seven (43%) C. dilepis collected in the Outjo District are ellipsoidal to cylindroidal, with a smooth, colourless, bilayered wall, measure 36.9 × 31.0 μm and have an L/W ratio of 1.2. The micropyle, oöcyst residuum and polar granule are absent. Sporocysts are ovoidal to ellipsoidal, 15.3 × 11.1 μm in size and contain Stieda and sub-Stieda bodies; and the non-membranous sporocyst residuum is composed of granules of various sizes. The sporozoites contain anterior and posterior refractile bodies with a nucleus between them. These two new taxa represent the third and fourth coccidian species reported from C. dilepis.

  6. The Length-Weight, Length-Length Relationship and Condition Factor of Angora Loach, Oxynoemacheilus angorae (Steindachner, 1897 Inhabiting Kılıçözü Stream in Kızılırmak River Basin (Central Anatolia-Turkey

    Directory of Open Access Journals (Sweden)

    Okan Yazıcıoğlu

    2016-12-01

    Full Text Available In this study, length-weight relationship (LWR, length- length relationship (LLR and condition factor (K of Angora loach, Oxynoemacheilus angorae were determined. A total of 103 specimens were sampled from Kılıçözü Stream in 2014. The length and weight of specimens were ranged 3.5-9.8 cm and 0.38-6.58 g, respectively. Length-weight relationships for female, male and all samples were found as W= 0.01056.TL2.896 (r²= 0.923, W= 0.00963.TL2.940 (r²= 0.978 and W= 0.00987.TL2.929 (r²= 0.963, respectively. LWRs indicated an isometric growth in female, male and all samples. The values of Fulton’s condition factor (K ranged from 0.699 to 1.246 for females and from 0.654 to 1.072 for males. All length-length relationships were statistically significant.

  7. Parallel solution of the time-dependent Ginzburg-Landau equations and other experiences using BlockComm-Chameleon and PCN on the IBM SP, Intel iPSC/860, and clusters of workstations

    International Nuclear Information System (INIS)

    Coskun, E.

    1995-09-01

    Time-dependent Ginzburg-Landau (TDGL) equations are considered for modeling a thin-film finite size superconductor placed under magnetic field. The problem then leads to the use of so-called natural boundary conditions. Computational domain is partitioned into subdomains and bond variables are used in obtaining the corresponding discrete system of equations. An efficient time-differencing method based on the Forward Euler method is developed. Finally, a variable strength magnetic field resulting in a vortex motion in Type II High T c superconducting films is introduced. The authors tackled the problem using two different state-of-the-art parallel computing tools: BlockComm/Chameleon and PCN. They had access to two high-performance distributed memory supercomputers: the Intel iPSC/860 and IBM SP1. They also tested the codes using, as a parallel computing environment, a cluster of Sun Sparc workstations

  8. [Chameleon spondylodiscitis : Challenge for geriatricians].

    Science.gov (United States)

    Hofmann, Werner

    2018-06-01

    The incidence of spondylodiscitis is increasing and attributable to an aging population with multimorbidities. Spondylodiscitis represents a life-threatening disease. Typical clinical manifestations often involve nonspecific symptoms with back pain; however, due to the frequent absence of fever the disease is often overlooked. Pathogen detection and spinal imaging with magnetic resonance imaging (MRI) are essential for the diagnosis. Identification of the causative pathogen is particularly important for initiating targeted antibiotic treatment. Debridement and stabilization are the mainstays of surgical management, even though foreign material must be implanted into the focus of inflammation.

  9. The Action Researcher as Chameleon.

    Science.gov (United States)

    Hadfield, Mark; Bennett, Steve

    1995-01-01

    Describes a project that trained institutional policymakers in action research regarding problems in developing training policies about young people's needs, examining attempts to collaborate and dialog with stakeholders and discussing how project members became enmeshed in complex sets of relationships calling for construction of dialog in…

  10. Chameleon Chasing II: A Replication.

    Science.gov (United States)

    Newsom, Doug A.; And Others

    1993-01-01

    Replicates a 1972 survey of students, educators, and Public Relations Society of America members regarding who the public relations counselor really serves. Finds that, in 1992, most respondents thought primary responsibility was to the client, then to the client's relevant publics, then to self, then to society, and finally to media. Compares…

  11. Evolution of Karyotypes in Chameleons

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Altmanová, M.; Johnson Pokorná, Martina; Velenský, P.; Baca, A. S.; Kratochvíl, L.

    2017-01-01

    Roč. 8, č. 12 (2017), č. článku 382. ISSN 2073-4425 Institutional support: RVO:67985904 Keywords : karyotype evolution * ITS * rDNA Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 3.600, year: 2016

  12. Schistura udomritthiruji, a new loach from southern Thailand (Cypriniformes: Nemacheilidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2009-01-01

    Roč. 20, č. 4 (2009), s. 319-324 ISSN 0936-9902 R&D Projects: GA ČR GA206/08/0637; GA ČR GA206/05/2556; GA AV ČR IAA600450508; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : Cypriniformes * Nemacheilidae * Schistura udomritthuji Subject RIV: EG - Zoology Impact factor: 0.940, year: 2009

  13. Loaches and the environment in two provinces in Northern Vietnam

    Czech Academy of Sciences Publication Activity Database

    Petrtýl, M.; Bohlen, Jörg; Kalous, L.; Bui, A.T.; Chaloupková, P.

    2011-01-01

    Roč. 60, č. 4 (2011), 368-374 ISSN 0139-7893 R&D Projects: GA ČR GA206/05/2556; GA ČR GA206/08/0637 Grant - others:MZe(CZ) 29/Mze/B/08-10 Institutional research plan: CEZ:AV0Z50450515 Keywords : biodiversity * conservation * Teleostei Subject RIV: EG - Zoology Impact factor: 0.554, year: 2011

  14. Gene expression profiles of fin regeneration in loach (Paramisgurnus dabryanu).

    Science.gov (United States)

    Li, Li; He, Jingya; Wang, Linlin; Chen, Weihua; Chang, Zhongjie

    2017-11-01

    Teleost fins can regenerate accurate position-matched structure and function after amputation. However, we still lack systematic transcriptional profiling and methodologies to understand the molecular basis of fin regeneration. After histological analysis, we established a suppression subtraction hybridization library containing 418 distinct sequences expressed differentially during the process of blastema formation and differentiation in caudal fin regeneration. Genome ontology and comparative analysis of differential distribution of our data and the reference zebrafish genome showed notable subcategories, including multi-organism processes, response to stimuli, extracellular matrix, antioxidant activity, and cell junction function. KEGG pathway analysis allowed the effective identification of relevant genes in those pathways involved in tissue morphogenesis and regeneration, including tight junction, cell adhesion molecules, mTOR and Jak-STAT signaling pathway. From relevant function subcategories and signaling pathways, 78 clones were examined for further Southern-blot hybridization. Then, 17 genes were chosen and characterized using semi-quantitative PCR. Then 4 candidate genes were identified, including F11r, Mmp9, Agr2 and one without a match to any database. After real-time quantitative PCR, the results showed obvious expression changes in different periods of caudal fin regeneration. We can assume that the 4 candidates, likely valuable genes associated with fin regeneration, deserve additional attention. Thus, our study demonstrated how to investigate the transcript profiles with an emphasis on bioinformatics intervention and how to identify potential genes related to fin regeneration processes. The results also provide a foundation or knowledge for further research into genes and molecular mechanisms of fin regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Reviews Equipment: Chameleon Nano Flakes Book: Requiem for a Species Equipment: Laser Sound System Equipment: EasySense VISION Equipment: UV Flash Kit Book: The Demon-Haunted World Book: Nonsense on Stilts Book: How to Think about Weird Things Web Watch

    Science.gov (United States)

    2011-03-01

    WE RECOMMEND Requiem for a Species This book delivers a sober message about climate change Laser Sound System Sound kit is useful for laser demonstrations EasySense VISION Data Harvest produces another easy-to-use data logger UV Flash Kit Useful equipment captures shadows on film The Demon-Haunted World World-famous astronomer attacks pseudoscience in this book Nonsense on Stilts A thought-provoking analysis of hard and soft sciences How to Think about Weird Things This book explores the credibility of astrologers and their ilk WORTH A LOOK Chameleon Nano Flakes Product lacks good instructions and guidelines WEB WATCH Amateur scientists help out researchers with a variety of online projects

  16. Odontogenesis in the Veiled Chameleon (Chamaeleo calyptratus)

    Czech Academy of Sciences Publication Activity Database

    Buchtová, Marcela; Zahradníček, Oldřich; Balková, Simona; Tucker, A. S.

    2013-01-01

    Roč. 58, č. 2 (2013), s. 118-133 ISSN 0003-9969 R&D Projects: GA AV ČR KJB601110910; GA ČR(CZ) GAP305/12/1766 Institutional support: RVO:67985904 ; RVO:68378041 Keywords : dental lamina * tooth attachment * heterodont dentition * cytokeratin Subject RIV: FF - HEENT, Dentistry Impact factor: 1.880, year: 2013

  17. The School Psychologist as a Chameleon

    Science.gov (United States)

    Weininger, Otto

    1971-01-01

    This paper reviews very briefly some of the comprehensive views of the functions of the school psychologists, presents some suggestions which have been made in recent years for the training of school psychological personnel, and discusses the complex interrelationships between the psychologist and all those people and variables which make up his…

  18. Extending applicability of bimetric theory: chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Uzan, Jean-Philippe

    2018-02-01

    This article extends bimetric formulations of massive gravity to make the mass of the graviton to depend on its environment. This minimal extension offers a novel way to reconcile massive gravity with local tests of general relativity without invoking the Vainshtein mechanism. On cosmological scales, it is argued that the model is stable and that it circumvents the Higuchi bound, hence relaxing the constraints on the parameter space. Moreover, with this extension the strong coupling scale is also environmentally dependent in such a way that it is kept sufficiently higher than the expansion rate all the way up to the very early universe, while the present graviton mass is low enough to be phenomenologically interesting. In this sense the extended bigravity theory serves as a partial UV completion of the standard bigravity theory. This extension is very generic and robust and a simple specific example is described.

  19. Inflammatory carcinoma of breast: The chameleon

    Directory of Open Access Journals (Sweden)

    Indranil Chakrabarti

    2017-01-01

    Full Text Available Inflammatory breast carcinoma is an extremely rare, rapidly progressive breast carcinoma which is a great masquerader and often is mistaken as an inflammatory lesion. This leads to the delay in diagnosis. Here, we report such a case where the mistaken clinical diagnosis led to it being treated with antibiotics. However, fine-needle aspiration cytology of the case saved the day. Histopathological confirmation followed by multimodal therapy was rendered, and the patient responded well to the treatment. Thus, awareness and recognition of this rare entity, which mimics various inflammatory and nonmalignant causes, is of paramount importance for the doctors and patients alike.

  20. Chameleon or Phoenix: The Metamorphosis of TAFE.

    Science.gov (United States)

    Anderson, Damon

    1998-01-01

    Examines aspects of the history of technical and vocational education (TAFE) in Australia: technical education system in Victoria; dissolution of the binary system in higher education; and new instructional discourses and practices shaping TAFE. Speculates on the potential reemergence of the binary system and future prospects for TAFE. (SK)

  1. The Chameleon Architecture for Streaming DSP Applications

    NARCIS (Netherlands)

    Bergmann, N.; Smit, Gerardus Johannes Maria; Kokkeler, Andre B.J.; Platzner, M.; Wolkotte, P.T.; Teich, J.; Holzenspies, P.K.F.; van de Burgwal, M.D.; Heysters, P.M.

    2007-01-01

    We focus on architectures for streaming DSP applications such as wireless baseband processing and image processing. We aim at a single generic architecture that is capable of dealing with different DSP applications. This architecture has to be energy efficient and fault tolerant. We introduce a

  2. The Chameleon Architecture for Streaming DSP Applications

    Directory of Open Access Journals (Sweden)

    André B. J. Kokkeler

    2007-02-01

    Full Text Available We focus on architectures for streaming DSP applications such as wireless baseband processing and image processing. We aim at a single generic architecture that is capable of dealing with different DSP applications. This architecture has to be energy efficient and fault tolerant. We introduce a heterogeneous tiled architecture and present the details of a domain-specific reconfigurable tile processor called Montium. This reconfigurable processor has a small footprint (1.8 mm2 in a 130 nm process, is power efficient and exploits the locality of reference principle. Reconfiguring the device is very fast, for example, loading the coefficients for a 200 tap FIR filter is done within 80 clock cycles. The tiles on the tiled architecture are connected to a Network-on-Chip (NoC via a network interface (NI. Two NoCs have been developed: a packet-switched and a circuit-switched version. Both provide two types of services: guaranteed throughput (GT and best effort (BE. For both NoCs estimates of power consumption are presented. The NI synchronizes data transfers, configures and starts/stops the tile processor. For dynamically mapping applications onto the tiled architecture, we introduce a run-time mapping tool.

  3. The Chameleon Architecture for Streaming DSP Applications

    Directory of Open Access Journals (Sweden)

    Heysters PaulM

    2007-01-01

    Full Text Available We focus on architectures for streaming DSP applications such as wireless baseband processing and image processing. We aim at a single generic architecture that is capable of dealing with different DSP applications. This architecture has to be energy efficient and fault tolerant. We introduce a heterogeneous tiled architecture and present the details of a domain-specific reconfigurable tile processor called Montium. This reconfigurable processor has a small footprint (1.8 mm2 in a 130 nm process, is power efficient and exploits the locality of reference principle. Reconfiguring the device is very fast, for example, loading the coefficients for a 200 tap FIR filter is done within 80 clock cycles. The tiles on the tiled architecture are connected to a Network-on-Chip (NoC via a network interface (NI. Two NoCs have been developed: a packet-switched and a circuit-switched version. Both provide two types of services: guaranteed throughput (GT and best effort (BE. For both NoCs estimates of power consumption are presented. The NI synchronizes data transfers, configures and starts/stops the tile processor. For dynamically mapping applications onto the tiled architecture, we introduce a run-time mapping tool.

  4. Hyperchaotic Chameleon: Fractional Order FPGA Implementation

    Directory of Open Access Journals (Sweden)

    Karthikeyan Rajagopal

    2017-01-01

    Full Text Available There are many recent investigations on chaotic hidden attractors although hyperchaotic hidden attractor systems and their relationships have been less investigated. In this paper, we introduce a hyperchaotic system which can change between hidden attractor and self-excited attractor depending on the values of parameters. Dynamic properties of these systems are investigated. Fractional order models of these systems are derived and their bifurcation with fractional orders is discussed. Field programmable gate array (FPGA implementations of the systems with their power and resource utilization are presented.

  5. Do dwarf chameleons ( Bradypodion ) show developmental plasticity?

    African Journals Online (AJOL)

    It has been hypothesized that B. melanocephalum and B. thamnobates may be phenotypically plastic populations of the same species, since environmental conditions, the driving force behind developmental plasticity, varies between the distributions of these two allopatric taxa.We raised juveniles of both species under ...

  6. If Only Cultural Chameleons Could Fly Too

    DEFF Research Database (Denmark)

    Blasco, Maribel; Feldt, Liv Egholm; Jakobsen, Michael

    2012-01-01

    The article offers a critique of the concept of cultural intelligence (CQ) from a semiotic perspective. It addresses three assumptions that underpin the CQ concept: that CQ exists, that conflict and misunderstandings are antithetical to CQ and that metacognition involves a cultural dimension. The...

  7. Lymphogranuloma venereum: "a clinical and histopathological chameleon?".

    Science.gov (United States)

    Tchernev, Georgi; Salaro, Cristina; Costa, Mariana Carvalho; Patterson, James W; Nenoff, Pietro

    2010-01-01

    Lymphogranuloma venereum is an infection caused by a variety of the bacterium Chlamydia trachomatis. Both genital and extragenital manifestations of the disease can cause serious differential diagnostic difficulties, indirectly leading to progression and dissemination of the infection. This work describes cases of patients with lymphogranuloma venereum showing atypical clinical and/or histopathological findings. It also focuses on alternative therapeutic approaches, such as surgical excision at stage 1, that may lead to a positive outcome. It is not completely clear whether histopathological findings of lymphogranuloma venereum can reveal progression or changes in the course of the disease over time, as is the case in other diseases. We conclude that both clinical and histopathological observations in a larger number of patients are needed in order to further evaluate the findings presented in this article.

  8. Notes on Chameleons I. Comparative cytology: aid and new complications in Chameleon-taxonomy

    NARCIS (Netherlands)

    Hillenius, D.

    1963-01-01

    1. Comparison is made between the subdivision of the genus Chamaeleo in groups of species based on cytological considerations (MATTHEY & VAN BRINK) and the subdivision of this genus in groups based on taxonomical considerations (HILLENIUS). Both subdivisions were developed independently from each

  9. Relative profile analysis of molecular markers for identification and genetic discrimination of loaches (Pisces, Nemacheilidae).

    Science.gov (United States)

    Patil, Tejas Suresh; Tamboli, Asif Shabodin; Patil, Swapnil Mahadeo; Bhosale, Amrut Ravindra; Govindwar, Sanjay Prabhu; Muley, Dipak Vishwanathrao

    2016-01-01

    Genus Nemacheilus, Nemachilichthys and Schistura belong to the family Nemacheilidae of the order Cypriniformes. The present investigation was undertaken to observe genetic diversity, phylogenetic relationship and to develop a molecular-based tool for taxonomic identification. For this purpose, four different types of molecular markers were utilized in which 29 random amplified polymorphic DNA (RAPD), 25 inter-simple sequence repeat (ISSR) markers, and 10 amplified fragment length polymorphism (AFLP) marker sets were screened and mitochondrial COI gene was sequenced. This study added COI barcodes for the identification of Nemacheilus anguilla, Nemachilichthys rueppelli and Schistura denisoni. RAPD showed higher polymorphism (100%) than the ISSR (93.75-100%) and AFLP (93.86-98.96%). The polymorphic information content (PIC), heterozygosity, multiplex ratio, and gene diversity was observed highest for AFLP primers, whereas the major allele frequency was observed higher for RAPD (0.5556) and lowest for AFLP (0.1667). The COI region of all individuals was successfully amplified and sequenced, which gave a 100% species resolution. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  10. Nemacheilus Paucimaculatus, a new species of loach from the Southern Malay Peninsula (Teleostei: Nemacheilidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2011-01-01

    Roč. 59, č. 2 (2011), 201-204 ISSN 0217-2445 R&D Projects: GA ČR GA206/08/0637; GA ČR GA206/05/2556; GA AV ČR IAA600450508 Institutional research plan: CEZ:AV0Z50450515 Keywords : Cobitoidea * Malaysia * Johor Subject RIV: EG - Zoology Impact factor: 1.467, year: 2011

  11. A new genus and two new species of loaches (Teleostei: Nemacheilidae) from Myanmar

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2011-01-01

    Roč. 22, č. 1 (2011), 1-10 ISSN 0936-9902 R&D Projects: GA ČR GA206/08/0637; GA ČR GA206/05/2556; GA AV ČR IAA600450508 Institutional research plan: CEZ:AV0Z50450515 Keywords : Schist ore callidora * Myanmar Subject RIV: EG - Zoology Impact factor: 0.900, year: 2011

  12. Schistura puncticeps, a new species of loach from Myanmar (Cypriniformes: Nemacheilidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2013-01-01

    Roč. 24, č. 1 (2013), s. 85-92 ISSN 0936-9902 R&D Projects: GA ČR GA206/08/0637 Institutional research plan: CEZ:AV0Z50450515 Keywords : Teleostei Nemacheilidae * basin Subject RIV: EG - Zoology Impact factor: 2.275, year: 2013

  13. Schistura hypsiura, a new species of loach (Cobitoidea: Nemacheilidae) from South-West Myanmar

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula; Udomritthiruj, K.

    2014-01-01

    Roč. 62, č. 1 (2014), s. 21-27 ISSN 0217-2445 R&D Projects: GA ČR GA206/08/0637; GA MŠk LC06073 Institutional support: RVO:67985904 Keywords : Rakhine State * Burma * caudal peduncle Subject RIV: EG - Zoology Impact factor: 1.024, year: 2014

  14. Schistura shuensis, a new species of loach from Myanmar (Teleostei: Nemacheilidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2014-01-01

    Roč. 24, č. 3 (2014), s. 217-223 ISSN 0936-9902 R&D Projects: GA ČR GA206/08/0637 Institutional support: RVO:67985904 Keywords : Schistura shuensis Subject RIV: EG - Zoology Impact factor: 1.400, year: 2014

  15. Evolutionary history of asexual hybrid loaches (Cobitis: Teleostei) inferred from phylogenetic analysis of mitochondrial DNA variation

    Czech Academy of Sciences Publication Activity Database

    Janko, Karel; Kotlík, Petr; Ráb, Petr

    2003-01-01

    Roč. 16, - (2003), s. 1280-1287 ISSN 1010-061X R&D Projects: GA AV ČR KSK6005114; GA ČR GA206/00/0668; GA ČR GA206/01/0989; GA AV ČR IBS5045111 Institutional research plan: CEZ:AV0Z5045916 Keywords : asexual vertebrates * Cobitis * maternal ancestry Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.010, year: 2003

  16. Molecular Evidence for Multiple Origins of the European Spined Loaches (Teleostei, Cobitidae)

    Czech Academy of Sciences Publication Activity Database

    Percides, A.; Bohlen, Jörg; Šlechtová, Vendula; Doadrio, I.

    2016-01-01

    Roč. 11, č. 1 (2016), e0144628-e0144628 E-ISSN 1932-6203 R&D Projects: GA ČR GA206/08/0637 Institutional support: RVO:67985904 Keywords : mitochondrial DNA sequences * cytochrome b gene * phylogenetic relationship Subject RIV: EG - Zoology Impact factor: 2.806, year: 2016

  17. Leptobotia micra, a new species of loach (Teleostei: Botiidae) from Guilin, southern China

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2017-01-01

    Roč. 4250, č. 1 (2017), s. 90-100 ISSN 1175-5326 R&D Projects: GA ČR GA13-37277S Institutional support: RVO:67985904 Keywords : Cypriniformes * Cobitoidea * taxonomy Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 0.972, year: 2016

  18. Preparation of Chameleon Coatings for Space and Ambient Environments (Preprint)

    National Research Council Canada - National Science Library

    Baker, C. C; Chromik, R. R; Wahl, K. J; Hu, J. J; Voevodin, A. A

    2006-01-01

    ... (dry, humid and high temperature). For four-component YSZ/Au/DLC/MoS2 coatings, the optimal compositions for friction adaptation between dry nitrogen and humid air included relatively high concentrations of the soft phase, Au (>20...

  19. Foot placement cues used by chameleons while walking and climbing

    African Journals Online (AJOL)

    Whenever vision was impaired, the animal utilized touch. Placement of the forelimb was the locator for the hind limb. Regardless of perch diameter, the hind foot was placed fully or partially overlapping the position that the ipsilateral forefoot had just occupied. (Journal of the Ghana Science Association: 2001 3(3): 22-29) ...

  20. Chameleon-reconfigurability in hand-held multimedia computers

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Bos, M.; Havinga, Paul J.M.; Smit, Jaap; Mullender, Sape J.; Gellersen, H.W.

    In this paper a reconfigurable systems-architecture in combination with a QoS driven operating system is introduced that can deal with the inherent dynamics of future mobile systems. We claim that a radical new approach has to be taken in order to fulfill the requirements - in terms of processing

  1. Living as a Chameleon: Girls, Anger, and Mental Health

    Science.gov (United States)

    van Daalen-Smith, Cheryl

    2008-01-01

    One's practice as a school nurse affords numerous privileges. One that stands out in my mind is the privilege of bearing witness to the lives of countless girls as they navigated their own aspirations and the expectations of the culture. The stories they iterated to me in my school nurse office form the basis for this discussion regarding the…

  2. The Postgraduate Chameleon. Changing Roles in Doctoral Education

    Science.gov (United States)

    Harland, Tony; Plangger, Gabi

    2004-01-01

    This article is based on the experiences of 25 PhD students at a New Zealand university who came to do research and soon found themselves taking on substantial teaching loads. Teaching was highly valued and it helped students develop their professional identity as they broadened their subject knowledge and practised a disciplinary research…

  3. Chem I Supplement: Liquid Crystals--The Chameleon Chemicals.

    Science.gov (United States)

    Brown, Glenn H.

    1983-01-01

    Presents information relevant to everyday life so as to stimulate student interest in the properties of the two basic types of liquid crystals: thermotropic and lyotropic. Describes the applications of liquid crystals to electronics, biomedicine, and polymer science and appraises the future of liquid crystal research. (JM)

  4. Comments About a Chameleon Theory: Level I/Level II.

    Science.gov (United States)

    Horn, John; Stankov, Lazar

    1982-01-01

    Jensen's ideas about two levels of intellectual abilities are criticized as being oversimplified. More than two levels of intellectual abilities and relationships between variables reflecting more than racial and socioeconomic status (SES) differences are suggested, arguing that Jensen's statements about race and SES differences are not properly…

  5. "Chameleon" Macromolecules: Synthesis, Structures and Applications of Stimulus Responsive Polymers

    NARCIS (Netherlands)

    Sui, Xiaofeng

    2012-01-01

    This thesis describes the preparation and characterization of addressable responsive polymer structures and their versatile applications. Stimuli responsive polymer chains including temperature responsive poly(N-isopropylacrylamide), PNIPAM, pH responsive poly(methacrylic acid), PMAA and redox

  6. Effect Chameleon. The Art of Negotiating the Diversity

    Directory of Open Access Journals (Sweden)

    Raquel Cantos Vicent

    2009-08-01

    Full Text Available This document intends to give notice of a youth participation experience mainly characterized by its inclusive attention in all the intervention process. Its outstanding intention was, from the beginning, to stir into action a participation space that accepted and contemplated as much diversity as possible. It is overall, a purpose to put in practise the theories defending the management of differences from common interest, the exercise of shared citizenship and not from the creation of specified resources and spaces.

  7. Staff Considerations in Technical Services: The Chameleon Approach.

    Science.gov (United States)

    Foster, Constance L.

    1988-01-01

    Discusses the need to cope effectively with technological transitions in library technical services and to plan for successful staff development. The areas discussed include changing job skills, financial planning, ergonomics, innovative partnerships, training, and an emphasis on human resources development. (21 references) (Author/CLB)

  8. Chameleon of head and neck diseases: Intraoral actinomycosis

    Directory of Open Access Journals (Sweden)

    Srisha Basappa

    2015-01-01

    Full Text Available Actinomycosis is a chronic infectious granulomatous disease caused by saprophytic Actinomyces species. The case discussed in this report is of an adult female patient with a large actinomycotic lesion in the region of the mandibular left second premolar, first and second molars. Provisional diagnosis was made as extragingival pyogenic granuloma. Definitive diagnosis was based on histopathological examination. Since actinomycotic infection has opportunistic characteristics, early diagnosis and proper management of the disease is mandatory to prevent further complications.

  9. The UK Postgraduate Masters Dissertation: An "Elusive Chameleon"?

    Science.gov (United States)

    Pilcher, Nick

    2011-01-01

    Many studies into the process of producing and supervising dissertations exist, yet little research into the "product" of the Masters dissertation, or into how Masters supervision changes over time exist. Drawing on 62 semi-structured interviews with 31 Maths and Computer Science supervisors over a two-year period, this paper explores…

  10. The Chameleonic Nature of Platinum(II) Imidazopyridine Complexes.

    Science.gov (United States)

    Pinter, Piermaria; Pittkowski, Rebecca; Soellner, Johannes; Strassner, Thomas

    2017-10-12

    The synthesis and characterization of cyclometalated C^C* platinum(II) complexes with unique photophysical properties, aggregation induced enhancement of the quantum yields with a simultaneous decrease of phosphorescence lifetimes, is reported. Additionally, a change of emission color is induced by variation of the excitation wavelength. The aggregation behavior of these complexes is controlled by the steric demand of the substituents. The photophysical properties of these complexes are investigated through emission-excitation matrix analysis (EEM). The monomeric complexes are excellent room temperature phosphorescent blue emitters with emission maxima below 470 nm and quantum yields of up to 93 %. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Little chameleons: The development of social mimicry during early childhood

    NARCIS (Netherlands)

    Schaik, J.E. van; Hunnius, S.

    2016-01-01

    Adults use behavioral mimicry to blend in with (or stand out from) their social environment. Adopting another’s mannerisms and behaviors, or "mimicking", communicates liking and similarity between interaction partners and has been shown to serve as an implicit affiliation mechanism. Given this

  12. Chameleons: Electrocardiogram Imitators of ST-Segment Elevation Myocardial Infarction.

    Science.gov (United States)

    Nable, Jose V; Lawner, Benjamin J

    2015-08-01

    The imperative for timely reperfusion therapy for patients presenting with ST-segment elevation myocardial infarction (STEMI) underscores the need for clinicians to have an understanding of how to distinguish patterns of STEMI from its imitators. These imitating diagnoses may confound an evaluation, potentially delaying necessary therapy. Although numerous diagnoses may mimic STEMI, several morphologic clues may allow the physician to determine if the pattern is concerning for either STEMI or a mimicking diagnosis. Furthermore, obtaining a satisfactory history, comparing previous electrocardiograms, and assessing serial tests may provide valuable clues. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Time-delayed chameleon: Analysis, synchronization and FPGA ...

    Indian Academy of Sciences (India)

    Karthikeyan Rajagopal

    of Technology, Lae, Papua New Guinea. 2Biomedical ... MS received 7 June 2017; revised 20 July 2017; accepted 2 August 2017; published online 2 December 2017 ... families of chaotic attractors depending on the choices of parameters.

  14. Time-delayed chameleon: Analysis, synchronization and FPGA

    Indian Academy of Sciences (India)

    ... chaotic system which can belong to different families of chaotic attractors depending ... and Communication Engineering, The PNG University of Technology, Lae, ... version published online: Final version published online: 2 December 2017 ...

  15. Chameleonic Learner: Learning and Self-Assessment in Context

    Science.gov (United States)

    Bourke, Roseanna

    2010-01-01

    Author Dr Roseanna Bourke takes the reader on a fascinating exploration of learning: the theory, practice and young people's take on it. What do you say to a young person who tells you her brain is an eighth full? Or to the one who says he only knows he has learned something when he receives a stamp or a sticker? This book is about how learners…

  16. 'Being a Chameleon': labour processes of male nurses performing bodywork.

    Science.gov (United States)

    Fisher, Murray J

    2009-12-01

    This paper is a report of a study examining the labour processes of male nurses in the conduct of bodywork, and is part of a broader study of social practices that configure masculinity through the lives of male nurses. Bodywork is defined as the direct work on others' bodies, and involves interactions of bodies and the control of emotions. As the body is an arena in which social practice occurs then bodywork is a form of social engagement. Bodywork is inextricably intertwined with gender where bodywork is socially structured and culturally accepted as women's work. Life history method was used in this study. Twenty-one life stories from male registered nurses were gathered in 2003-2004 using semi-structured interviews. Each life story underwent structural analysis, using a four-dimension structural model of gender relations. The ability of male nurses to do bodywork and provide care is dependent on the way they 'do' gender, that is, they have to be perceived to be performing the masculine identity that best represents the individual patient's ideology of what it is to be a man, which is set in a particular location and time. In addition, they have to counter the representations of the male nurse, whether it is homosexual, paedophile or heterosexual deviant. Respondents develop labour processes and workplace strategies to overcome the effects of gender stereotypes that may hinder their nursing work. Nursing procedures, policies and texts should reflect the complexity and multiplicity in the conduct of bodywork in nursing and refrain from representing essentialist ways (reinforcing nursing as feminine) of doing nursing.

  17. Low mitochondrial divergence indicates a rapid postglacial expansion across Europe in the weather loach, Misgurnus fossilis (L.)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula; Doadrio, I.; Ráb, Petr

    2007-01-01

    Roč. 71, Suppl B (2007), s. 186-194 ISSN 0022-1112 R&D Projects: GA ČR GA206/05/2556; GA ČR GA206/00/0668; GA AV ČR IBS5045111; GA AV ČR IAA600450508 Grant - others:GA MŽP SM/6/3/05 Program:SM Institutional research plan: CEZ:AV0Z50450515 Keywords : colonization * fresh water * glaciations Subject RIV: EG - Zoology Impact factor: 1.404, year: 2007

  18. European colonization by the spined loach (Cobitis taenia) from Ponto-Caspian refugia based on mitochondrial DNA variation

    Czech Academy of Sciences Publication Activity Database

    Culling, M.; Janko, Karel; Boron, A.; Vasiljev, V. P.; Cote, I. M.; Hewitt, G. M.

    2006-01-01

    Roč. 15, 1 (2006), s. 173-190 ISSN 0962-1083 R&D Projects: GA ČR GP206/05/P586; GA AV ČR IBS5045111 Grant - others:RFBR 02-04-48354 Institutional research plan: CEZ:AV0Z50450515 Keywords : colonization * glacial refugia * mitochondrial DNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.825, year: 2006

  19. A Ploidy Difference Represents an Impassable Barrier for Hybridisation in Animals. Is There an Exception among Botiid Loaches (Teleostei: Botiidae)?

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula; Šlechta, Vlastimil; Šlechtová, Věra; Sember, Alexandr; Ráb, Petr

    2016-01-01

    Roč. 11, č. 7 (2016), e0159311-e0159311 E-ISSN 1932-6203 R&D Projects: GA ČR GA13-37277S Institutional support: RVO:67985904 Keywords : molecular phylogeny * genetic data Subject RIV: EG - Zoology Impact factor: 2.806, year: 2016

  20. Proteocephalid tapeworms (Cestoda: Onchoproteocephalidea) of loaches (Cobitoidea): Evidence for monophyly and high endemism of parasites in the Far East

    Czech Academy of Sciences Publication Activity Database

    Scholz, Tomáš; de Chambrier, A.; Shimazu, T.; Ermolenko, A.; Waeschenbach, A.

    2017-01-01

    Roč. 66, č. 1 (2017), s. 871-883 ISSN 1383-5769 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : taxonomy * morphology * 16S rDNA * 18S rDNA * 28S rDNA * coxl * Proteocephalidae * Nemacheilidae * Cobitidae * Palaearctic Region Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 1.744, year: 2016

  1. Leptobotia bellacauda, a new species of loach from the lower Yangtze basin in China (Teleostei: Cypriniformes: Botiidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2016-01-01

    Roč. 4205, č. 1 (2016), s. 65-72 ISSN 1175-5326 R&D Projects: GA ČR GA13-37277S Institutional support: RVO:67985904 Keywords : morphology * taxonomy * Anhui Subject RIV: EG - Zoology Impact factor: 0.972, year: 2016

  2. Seasonal dynamics of Proteocephalus sagittus in the stone loach Barbatula barbatula from the Haná River, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Jarkovský, J.; Koubková, B.; Scholz, Tomáš; Prokeš, Miroslav; Baruš, Vlastimil

    2004-01-01

    Roč. 78, č. 3 (2004), s. 225-229 ISSN 0022-149X R&D Projects: GA ČR GA524/01/1314; GA AV ČR IAA6093104 Institutional research plan: CEZ:AV0Z6022909; CEZ:AV0Z6093917 Keywords : Cestoda * Proteocephalus sagittus * seasonal dynamics Subject RIV: EH - Ecology, Behaviour Impact factor: 0.676, year: 2004

  3. New species of Choleoeimeria (Apicomplexa: Eimeriidae) from the veiled chameleon, Chamaeleo calyptratus (Sauria: Chamaeleonidae), with taxonomic rvision of eimerian coccidia from chameleons

    Czech Academy of Sciences Publication Activity Database

    Sloboda, M.; Modrý, David

    2006-01-01

    Roč. 53, č. 2 (2006), s. 91-97 ISSN 0015-5683 R&D Projects: GA ČR GP524/03/D104; GA ČR GD524/03/H133 Institutional research plan: CEZ:AV0Z60220518 Keywords : Choleoeimeria * Apicomplexa * Coccidia Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.511, year: 2006

  4. The Paradox of Authentic Selves and Chameleons: Self-monitoring, Perceived Job Autonomy and Contextual Performance

    OpenAIRE

    Giuseppe. Soda; Lorenzo. Bizzi

    2011-01-01

    We investigate how self-monitoring combines with the degree of perceived job autonomy to affect contextual performance. We explore both a mediation model, built on theories on individual differences in the perception of job characteristics, and a moderation model, built on theories of the interaction between personality and perceived job situation. Empirical evidence suggests that self-monitoring and perceived job autonomy significantly predict contextual performance. In addition, an inter...

  5. Chameleon Coatings: Adaptive Surfaces to Reduce Friction and Wear in Extreme Environments

    Science.gov (United States)

    Muratore, C.; Voevodin, A. A.

    2009-08-01

    Adaptive nanocomposite coating materials that automatically and reversibly adjust their surface composition and morphology via multiple mechanisms are a promising development for the reduction of friction and wear over broad ranges of ambient conditions encountered in aerospace applications, such as cycling of temperature and atmospheric composition. Materials selection for these composites is based on extensive study of interactions occurring between solid lubricants and their surroundings, especially with novel in situ surface characterization techniques used to identify adaptive behavior on size scales ranging from 10-10 to 10-4 m. Recent insights on operative solid-lubricant mechanisms and their dependency upon the ambient environment are reviewed as a basis for a discussion of the state of the art in solid-lubricant materials.

  6. The chameleon of neuroinflammation : magnetic resonance imaging characteristics of natalizumab-associated progressive multifocal leukoencephalopathy

    NARCIS (Netherlands)

    Wattjes, Mike P.; Richert, Nancy D.; Killestein, Joep; de Vos, Marlieke; Sanchez, Esther; Snaebjornsson, Petur; Cadavid, Diego; Barkhof, Frederik

    2013-01-01

    Natalizumab is a monoclonal antibody against 4-integrin approved for the treatment of multiple sclerosis (MS) due to a positive effect on clinical and magnetic resonance imaging (MRI) outcome measures. However, one relatively rare but serious side effect of this drug is a higher risk of developing

  7. Folate, cancer risk, and the greek god, Proteus: a tale of two chameleons

    Science.gov (United States)

    Evidence indicates that an abundant intake of foodstuffs rich in folate conveys protection against the development of colorectal cancer, and perhaps some other common cancers as well. The issue is a complex one however, since some observations in animal and human studies demonstrate that an overly ...

  8. Chameleon-like elastomers with molecularly encoded strain-adaptive stiffening and coloration

    Science.gov (United States)

    Vatankhah-Varnosfaderani, Mohammad; Keith, Andrew N.; Cong, Yidan; Liang, Heyi; Rosenthal, Martin; Sztucki, Michael; Clair, Charles; Magonov, Sergei; Ivanov, Dimitri A.; Dobrynin, Andrey V.; Sheiko, Sergei S.

    2018-03-01

    Active camouflage is widely recognized as a soft-tissue feature, and yet the ability to integrate adaptive coloration and tissuelike mechanical properties into synthetic materials remains elusive. We provide a solution to this problem by uniting these functions in moldable elastomers through the self-assembly of linear-bottlebrush-linear triblock copolymers. Microphase separation of the architecturally distinct blocks results in physically cross-linked networks that display vibrant color, extreme softness, and intense strain stiffening on par with that of skin tissue. Each of these functional properties is regulated by the structure of one macromolecule, without the need for chemical cross-linking or additives. These materials remain stable under conditions characteristic of internal bodily environments and under ambient conditions, neither swelling in bodily fluids nor drying when exposed to air.

  9. Chameleon Changes: An Exploration of Racial Identity Themes of Multiracial People

    Science.gov (United States)

    Miville, Marie L.; Constantine, Madonna G.; Baysden, Matthew F.; So-Lloyd, Gloria

    2005-01-01

    The current study explored essential themes of racial identity development among 10 self-identified multiracial adults from a variety of racial backgrounds. Participants were interviewed using a semistructured protocol, and the interviews were recorded, transcribed, and then coded for themes by research team members. Four primary themes were…

  10. I Am a Chameleon in Pearls: How Three Select Female Superintendents Perceive Their Professional Lives

    Science.gov (United States)

    Ryan, Catherine Agnes

    2012-01-01

    The public school superintendent is the least progressive position in education at integrating women and balancing the scales of equitable representation. Statistical data indicates there are far fewer females than males serving as superintendents. Current statistics show women make up: 1) over 70 percent of all public school educators; 2) nearly…

  11. The Chameleon as a Leech: The Costs of Mimicry for the Mimickee

    Directory of Open Access Journals (Sweden)

    Kot Sylwia

    2016-04-01

    Full Text Available Mimicry is known to produce benefits for the mimicker such as liking, increased prosocial tendencies (e.g., higher donations, and trust. Little is known about the benefits or costs to the mimickee. The aim of this study is to explore this issue. Participants were mimicked or not by a confederate. The confederate then dropped pens and checked if the participants picked them up (a proxy for prosocial behavior. Finally, questionnaires were administered that assessed each participant’s liking of the confederate and self-liking, and self-esteem. As expected, mimicked participants picked up more pens and liked the mimicker more. Surprisingly, mimicked participants reported significantly lower self-like when compared to non-mimicked participants, and their self-esteem tended towards being lower. This research fills an important theoretical gap showing that there is a great cost to mimicry.

  12. The Chameleon Career: An Exploratory Study of the Work Biography of Information Technology Workers in Nigeria

    Science.gov (United States)

    Ituma, Afam; Simpson, Ruth

    2006-01-01

    Purpose: This paper seeks to explore claims about the changing nature of careers by focusing on how information technology (IT) workers enact careers in the context of Nigeria. The theoretical framework guiding this research is that societal context (social structure and institutions) has an influence on the career patterns exhibited by…

  13. Chameleon in the Classroom: Developing Roles for Computers. Symposium. Technical Report No. 22.

    Science.gov (United States)

    Sheingold, Karen; And Others

    This symposium includes the following papers: "Software for the Classroom: Issues in the Design of Effective Software Tools" (D. Midian Kurland); "Computers for Composing" (Janet H. Kane); "LOGO Programming and Problem Solving" (Roy D. Pea); "The Computer as Sandcastle" (Jeanne Bamberger); "Learning…

  14. The optoelectronic chameleon - GaN-based light emitters from the UV to green

    Energy Technology Data Exchange (ETDEWEB)

    Kneissl, Michael [Institut fuer Festkoerperphysik, Technische Universitaet Berlin (Germany)

    2008-07-01

    Group III-nitrides have evolved into one of the most versatile and important semiconductor materials for optoelectronic devices. GaN-based blue, green and white light emitting diodes have already entered many parts of everyday life and violet lasers are expected to be following soon. However, considering the extraordinary electronic properties and the wide spectral range that is accessible through nitride materials, it appears that it we have just touched the tip of the iceberg. We discuss some of the new fields of research for InAlGaN materials and devices and review progress in the development of near and deep ultraviolet light emitting diodes, as well as growth and optical properties of InN and indium rich InGaN alloys for emitter in the blue-green spectral range and beyond.

  15. Of Moving Targets and Chameleons: Why the Concept of Difficulty Is So Hard to Pin Down

    Science.gov (United States)

    DeKeyser, Robert

    2016-01-01

    In this short article I try to present a taxonomy of sources of difficulty, in particular complexity. I emphasize how these factors interact with each other and with individual differences and treatments, before illustrating some of these interactions and the methodological issues involved in studying them with examples from the empirical studies…

  16. Chameleons in Marketspace: Industry Transformation in the New Electronic Marketing Environment.

    Science.gov (United States)

    Pattinson, Hugh; Brown, Linden

    1996-01-01

    Discusses the new information infrastructure and its possible influences on marketing. Highlights include an alternative perspective of industrial economic history based on infrastructure development; the Internet and its positioning within the new information infrastructure; future possibilities and impacts on organizational structure; and…

  17. The Politics of Testing/Assessment (Or a Chameleon in the Classroom).

    Science.gov (United States)

    Lewis, Anne E.

    A number of political issues are involved in educational testing and the National Assessment of Educational Progress (NAEP). Many school officials are disturbed by the number of tests administered and the information and instructional time lost; they are reluctant to accede to further voluntary testing programs which might duplicate current…

  18. Chameleon behaviour of α-synuclein: brownian dynamics simulations of protein aggregation

    NARCIS (Netherlands)

    Ilie, Ioana Mariuca

    2015-01-01

    Over the past decades a large number of studies have been carried out in order to determine the physiological function of α-synuclein and its implication in Parkinson's disease. A complementary tool to experiments are computer simulations, which are intensively used for problems for which

  19. Educational Psychology as an Academic Chameleon: An Editorial Assessment After 75 Years.

    Science.gov (United States)

    Ball, Samuel

    1984-01-01

    Content analysis of articles published in this journal was used to analyze research trends since 1910. Emphasis began with practical issues, moved to personal/social issues in the 1940s and 1950s, and concentrated on theoretical issues after 1970. Evaluation, motivation, and linguistics were the three top areas of recent interest. (BS)

  20. A Chameleon with a Complex: Searching for Transformation in International Service-Learning

    Science.gov (United States)

    Kiely, Richard

    2004-01-01

    This article reports findings from a longitudinal case study investigating how students experience perspective transformation from their participation in international service-learning program with an explicit social justice orientation. Findings indicate that each student experienced profound changes in their world-view in at least one of six…

  1. Chameleons in the Classroom: Meeting Students' Needs through Academic and Continuing Education Partnerships.

    Science.gov (United States)

    Dolezal, Pamala; Franks, Megan

    In concurrent enrollment (CE) classes, academic and continuing education students enroll in courses that are held simultaneously, using the same classroom and instructors and having the same requirements and learning expectations. At North Harris College (NHC), in Texas, the introduction of CE was aided by a new strategic plan developed for the…

  2. The moody chameleon: The effect of mood on non-consious mimicry

    NARCIS (Netherlands)

    van Baaren, Rick B.; Fockenberg, Daniel A.; Holland, Rob W.; Janssen, L.; van Knippenberg, Ad

    2006-01-01

    Whereas previous findings suggest that mood alters information processing style judgment and strategic behavior, in the present article, the hypothesis is tested that moods influence our non–conscious behavior. In the first study, we observed a correlation between participants’ mood and their

  3. The Computer in Performance and Instruction: Or, How to Tell the True Color of a Chameleon.

    Science.gov (United States)

    Davis, Richard

    1979-01-01

    Discusses such potential uses for the computer in employee training programs as management support for training and performance, training project control, improved design and development methods, training program implementation and delivery, and program evaluation, revision, and maintenance. (JEG)

  4. The Chameleon on a Tartan Rug: Adaptations of Three Academic Developers' Professional Identities

    Science.gov (United States)

    Kensington-Miller, Barbara; Renc-Roe, Joanna; Morón-García, Susan

    2015-01-01

    This paper builds on discussions of academic developers' identity experienced as a discomfiting, troubled, and often marginal space. Three experienced academic developers, located in research-intensive institutions in three different countries, using auto-ethnographic writing and a shared narrative inquiry, explore moments of congruence and…

  5. "A Bit of a Chameleon Act": A Case Study of One Teacher's Understandings of Diversity

    Science.gov (United States)

    Allard, Andrea C.

    2006-01-01

    While for political, economic and social justice reasons, there is now an emphasis on ensuring that all children achieve educationally, including those whose ethnicity, "race" or socio-economic status are different from the dominant culture, multiple and often contradictory discourses operate concerning how teachers should work with…

  6. Cap the Chameleon: A Review of Captain America, Masculinity, and Violence

    OpenAIRE

    Clarke Gray, Brenna

    2017-01-01

    'Captain America, Masculinity, and Violence: The Evolution of a National Icon', by J. Richard Stevens, Syracuse University Press, 376 pages, 6 . 9, 2015, ISBN 978-0-8156-3395-2; ebook 978-0-8156-5320-2 This article favourably reviews' Captain America, Masculinity, and Violence: The Evolution of a National Icon' (Stevens 2015) and offers some suggestions for further research. The review explores the ways in which the book offers insights into one of the most popular characters in comics and a...

  7. Speeding up N -body simulations of modified gravity: chameleon screening models

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Sownak; Li, Baojiu; He, Jian-hua; Llinares, Claudio [Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Barreira, Alexandre [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany); Hellwing, Wojciech A.; Koyama, Kazuya [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom); Zhao, Gong-Bo, E-mail: sownak.bose@durham.ac.uk, E-mail: baojiu.li@durham.ac.uk, E-mail: barreira@mpa-garching.mpg.de, E-mail: jianhua.he@durham.ac.uk, E-mail: wojciech.hellwing@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: claudio.llinares@durham.ac.uk, E-mail: gbzhao@nao.cas.cn [National Astronomy Observatories, Chinese Academy of Science, Beijing, 100012 (China)

    2017-02-01

    We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied f ( R ) gravity models. High resolution simulations for such models are currently very slow due to the highly nonlinear partial differential equation that needs to be solved exactly to predict the modified gravitational force. This nonlinearity is partly inherent, but is also exacerbated by the specific numerical algorithm used, which employs a variable redefinition to prevent numerical instabilities. The standard Newton-Gauss-Seidel iterative method used to tackle this problem has a poor convergence rate. Our new method not only avoids this, but also allows the discretised equation to be written in a form that is analytically solvable. We show that this new method greatly improves the performance and efficiency of f ( R ) simulations. For example, a test simulation with 512{sup 3} particles in a box of size 512 Mpc/ h is now 5 times faster than before, while a Millennium-resolution simulation for f ( R ) gravity is estimated to be more than 20 times faster than with the old method. Our new implementation will be particularly useful for running very high resolution, large-sized simulations which, to date, are only possible for the standard model, and also makes it feasible to run large numbers of lower resolution simulations for covariance analyses. We hope that the method will bring us to a new era for precision cosmological tests of gravity.

  8. The Chameleon Effect: Characterization Challenges Due to the Variability of Nanoparticles and Their Surfaces

    Directory of Open Access Journals (Sweden)

    Donald R. Baer

    2018-05-01

    Full Text Available Nanoparticles in a variety of forms are increasing important in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce, appropriately characterize, and consistently deliver well-defined particles, frequently leading to inconsistencies, and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

  9. Speeding up N-body simulations of modified gravity: chameleon screening models

    Science.gov (United States)

    Bose, Sownak; Li, Baojiu; Barreira, Alexandre; He, Jian-hua; Hellwing, Wojciech A.; Koyama, Kazuya; Llinares, Claudio; Zhao, Gong-Bo

    2017-02-01

    We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied f(R) gravity models. High resolution simulations for such models are currently very slow due to the highly nonlinear partial differential equation that needs to be solved exactly to predict the modified gravitational force. This nonlinearity is partly inherent, but is also exacerbated by the specific numerical algorithm used, which employs a variable redefinition to prevent numerical instabilities. The standard Newton-Gauss-Seidel iterative method used to tackle this problem has a poor convergence rate. Our new method not only avoids this, but also allows the discretised equation to be written in a form that is analytically solvable. We show that this new method greatly improves the performance and efficiency of f(R) simulations. For example, a test simulation with 5123 particles in a box of size 512 Mpc/h is now 5 times faster than before, while a Millennium-resolution simulation for f(R) gravity is estimated to be more than 20 times faster than with the old method. Our new implementation will be particularly useful for running very high resolution, large-sized simulations which, to date, are only possible for the standard model, and also makes it feasible to run large numbers of lower resolution simulations for covariance analyses. We hope that the method will bring us to a new era for precision cosmological tests of gravity.

  10. Speeding up N -body simulations of modified gravity: chameleon screening models

    International Nuclear Information System (INIS)

    Bose, Sownak; Li, Baojiu; He, Jian-hua; Llinares, Claudio; Barreira, Alexandre; Hellwing, Wojciech A.; Koyama, Kazuya; Zhao, Gong-Bo

    2017-01-01

    We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied f ( R ) gravity models. High resolution simulations for such models are currently very slow due to the highly nonlinear partial differential equation that needs to be solved exactly to predict the modified gravitational force. This nonlinearity is partly inherent, but is also exacerbated by the specific numerical algorithm used, which employs a variable redefinition to prevent numerical instabilities. The standard Newton-Gauss-Seidel iterative method used to tackle this problem has a poor convergence rate. Our new method not only avoids this, but also allows the discretised equation to be written in a form that is analytically solvable. We show that this new method greatly improves the performance and efficiency of f ( R ) simulations. For example, a test simulation with 512 3 particles in a box of size 512 Mpc/ h is now 5 times faster than before, while a Millennium-resolution simulation for f ( R ) gravity is estimated to be more than 20 times faster than with the old method. Our new implementation will be particularly useful for running very high resolution, large-sized simulations which, to date, are only possible for the standard model, and also makes it feasible to run large numbers of lower resolution simulations for covariance analyses. We hope that the method will bring us to a new era for precision cosmological tests of gravity.

  11. The Chameleon Effect: characterization challenges due to the variability of nanoparticles and their surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Donald R.

    2018-05-07

    Nanoparticles in a variety of forms are of increasing importance in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce and consistently deliver well defined particles and their appropriate characterization, frequently leading to inconsistencies and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

  12. Female heterogamety in Madagascar chameleons (Squamata: Chamaeleonidae: Furcifer): differentiation of sex and neo-sex chromosomes

    Czech Academy of Sciences Publication Activity Database

    Rovatsos, M.; Johnson Pokorná, Martina; Altmanová, M.; Kratochvíl, L.

    2015-01-01

    Roč. 5, č. 13196 (2015) ISSN 2045-2322 R&D Projects: GA ČR GAP506/10/0718 Institutional support: RVO:67985904 Keywords : determining mechanisms * telomeric repeats Subject RIV: EG - Zoology Impact factor: 5.228, year: 2015

  13. IRAS IDENTIFICATION OF PRE-MAIN-SEQUENCE STARS IN THE CHAMELEON-II ASSOCIATION

    NARCIS (Netherlands)

    PRUSTI, T; WHITTET, DCB; ASSENDORP, R; WESSELIUS, PR

    We report the results of a search for new pre-main sequence candidates in the Chamaeleon II dark cloud based on three IRAS catalogues (the Point Source Catalog, the Serendipitous Survey Catalog and the Faint Source Survey). A total of 30 sources were selected. Twelve of these display IRAS colours

  14. Stories in Motion: Inviting Immersive Possibilities through the Chimera of Transmedia and Chameleon of Mediatecture

    Science.gov (United States)

    Paciencia Bamrungpong, Silvina G.

    2012-01-01

    Narratives are part of human culture; they provide a fundamental epistemological structure that assists us in making sense of the world. Narratives are the connection between discourse and story that have extended through various media. With the advancements made in technology, stories can be archived easily, accessed quickly, transferred among…

  15. Populists as Chameleons? An Adaptive Learning Approach to the Rise of Populist Politicians

    Directory of Open Access Journals (Sweden)

    Jasper Muis

    2015-04-01

    Full Text Available This paper envisions populism as a vote- and attention-maximizing strategy. It applies an adaptive learning approach to understand successes of populist party leaders. I assume that populists are ideologically flexible and continually search for a more beneficial policy position, in terms of both electoral support and media attention, by retaining political claims that yield positive feedback and discard those that encounter negative feedback. This idea is empirically tested by analyzing the Dutch populist leader Pim Fortuyn and the development of his stance about immigration and integration issues. In contrast to the conventional wisdom, the results do not show any empirical support for the claim that Fortuyn was ideologically driven by the opinion polls or by media publicity during the 2002 Dutch parliamentary election campaign. The findings thus suggest that populist parties are perhaps less distinctive in their strategies from mainstream parties than often claimed.

  16. The Chameleonic Behavior of Ionic Liquids and its Impact on the Solubility Parameters Estimation

    DEFF Research Database (Denmark)

    Batista, Marta; Neves, Catarina S; Carvalho, Pedro Jorge

    2011-01-01

    The possibility to develop a solubility parameter scale, with the purpose of predicting the performance and help the selection of ILs, is here evaluated. For the estimation of solubility parameters infinite dilution activity coefficient data is used. The results allowed the identification of a cu...

  17. Developmental plasticity in reptiles: Insights into thermal and maternal effects on chameleon phenotypes.

    Science.gov (United States)

    Andrews, Robin M

    2018-04-23

    Embryonic environments affect a range of phenotypic traits including sex and reproductive success. I determined (1) how the interaction between incubation temperature and egg size affects sex allocation of Chamaeleo calyptratus and (2) how incubation temperature and maternal parent (clutch) affect water uptake by eggs and body size, growth, and climbing speed of hatchlings and juveniles. Eggs from five clutches were exposed to five temperature treatments with clutches replicated within and among treatments. Temperature affected sex, but only when egg size was included as a factor in analyses. At intermediate (28°C) temperatures, daughters were more likely to be produced from large eggs and sons more likely to be produced from small eggs, while at 25 and 30°C, the pattern of sex allocation was reversed. Temperature and clutch affected water uptake and body size. Nonetheless, the direction of temperature and clutch effects on water uptake by eggs and on the size of hatchlings were not the same and the direction of temperature effects on body sizes of hatchlings and juveniles differed as well. Clutch affected hatchling size but not juvenile size and growth rate. Clutch, but not incubation temperature, affected climbing speed, but the fastest hatchlings were not from the same clutches as the fastest juveniles. The independent effects of incubation temperature and clutch indicate that hatchling phenotypes are influenced largely by conditions experienced during incubation, while juvenile phenotypes are influenced largely by conditions experienced in the rearing environment. © 2018 Wiley Periodicals, Inc.

  18. Cap the Chameleon: A Review of 'Captain America, Masculinity, and Violence'

    Directory of Open Access Journals (Sweden)

    Brenna Clarke Gray

    2017-11-01

    Full Text Available 'Captain America, Masculinity, and Violence: The Evolution of a National Icon', by J. Richard Stevens, Syracuse University Press, 376 pages, 6 . 9, 2015, ISBN 978-0-8156-3395-2; ebook 978-0-8156-5320-2 This article favourably reviews' Captain America, Masculinity, and Violence: The Evolution of a National Icon' (Stevens 2015 and offers some suggestions for further research. The review explores the ways in which the book offers insights into one of the most popular characters in comics and also gestures towards the work scholars of mainstream American superhero comics must tackle in the future.

  19. Solid-phase synthesis of isoxazoles using vinyl ethers as chameleon catches.

    Science.gov (United States)

    Barrett, A G; Procopiou, P A; Voigtmann, U

    2001-10-04

    [reaction: see text] Regioselective 1,3-dipolar cycloadditions of supported vinyl ethers R(1)C(=CH(2))O-CH(2)-polymer, prepared by the Tebbe olefination of R(1)CO(2)-CH(2)-polymer, with ethyl cyanoformate N-oxide gave supported isoxazoline derivatives. Release from the support under mild acidic conditions gave the isoxazoles ethyl 5-R(1)-isoxazole-3-carboxylates. Alternatively, further on-resin functionalization of the R(1) substituent using Suzuki coupling reactions and release from the support under acidic conditions gave more structurally diverse isoxazoles.

  20. Like a Chameleon: A Beginning Teacher's Journey to Implement Active Learning

    Science.gov (United States)

    Edwards, Susan

    2017-01-01

    The purpose of this study was to follow the learning trajectory of a beginning teacher attempting to implement active learning instructional methods in a middle grades classroom. The study utilized a qualitative case study methodological approach with the researcher in the role of participant observer. Three research questions were explored: the…

  1. Karyotype differentiation in 19 species of river loach fishes (Nemacheilidae, Teleostei): extensive variability associated with rDNA and heterochromatin distribution and its phylogenetic and ecological interpretation

    Czech Academy of Sciences Publication Activity Database

    Sember, Alexandr; Bohlen, Jörg; Šlechtová, Vendula; Altmanová, M.; Symonová, Radka; Ráb, Petr

    2015-01-01

    Roč. 15, č. 251 (2015) ISSN 1471-2148 R&D Projects: GA ČR GA206/08/0637 Institutional support: RVO:67985904 Keywords : fish cytotaxonomy * karyotype variability vs. 2n uniformity * FISH Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.406, year: 2015

  2. Molecular evidence of cryptic diversity in Paracaryophyllaeus (Cestoda: Caryophyllidea), parasites of loaches (Cobitidae) in Eurasia, including description of P. vladkae n. sp

    Czech Academy of Sciences Publication Activity Database

    Scholz, Tomáš; Oros, M.; Bazsalovicsová, E.; Brabec, Jan; Waeschenbach, A.; Xi, B. W.; Aydoğdu, A.; Besprozvannykh, V. V.; Shimazu, T.; Kraľová-Hromadová, I.; Littlewood, D. T. J.

    2014-01-01

    Roč. 63, č. 6 (2014), s. 841-850 ISSN 1383-5769 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Taxonomy * Molecular phylogeny * Caryophyllidea * Species complex * Freshwater fishes * Eurasia Subject RIV: EG - Zoology Impact factor: 1.859, year: 2014

  3. Dentirumai philippinensis n. gen., n. sp (Nematoda: Philometridae), a new tissue-infecting philometrid nematode from the loach goby Rhyacichthys aspro (Valenciennes) (Rhyacichthyidae) in the Philippines

    Czech Academy of Sciences Publication Activity Database

    Quiazon, K.M.A.; Moravec, František

    2013-01-01

    Roč. 87, č. 1 (2013), s. 59-65 ISSN 0022-149X R&D Projects: GA MŠk LC522 Institutional support: RVO:60077344 Keywords : Philometridae * Phillipine Archipelago * Parasitic nematode Subject RIV: EA - Cell Biology Impact factor: 1.303, year: 2013

  4. Extensive polymorphism and chromosomal characteristics of ribosomal DNA in a loach fish, Cobitis vardarensis (Ostariophysi, Cobitidae) detected by different banding techniques and fluorescence in situ hybridization (FISH)

    Czech Academy of Sciences Publication Activity Database

    Rábová, Marie; Ráb, Petr; Ozouf-Costaz, C.

    2001-01-01

    Roč. 111, - (2001), s. 413-422 ISSN 0016-6707 R&D Projects: GA ČR GA206/00/0668; GA AV ČR IAA6045704; GA AV ČR KSK6005114 Keywords : chromosome banding * cytotaxonomy * fish Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.916, year: 2001

  5. The gynogenetic reproduction of diploid and triploid hybrid spined loaches (Cobitis: Teleostei), and their ability to establish successful clonal lineages - on the evolution of polyploidy in asexual vertebrates

    Czech Academy of Sciences Publication Activity Database

    Janko, Karel; Bohlen, Jörg; Lamatsch, D.; Flajšhans, Martin; Epplen, J. T.; Ráb, Petr; Kotlík, Petr; Šlechtová, Věra

    2007-01-01

    Roč. 131, - (2007), s. 185-194 ISSN 0016-6707 R&D Projects: GA ČR GP206/05/P586 Grant - others:EU Marie Curie Research amd Training Network(EU) MCRTN-CT-2004-512492; German Research Foundation(DE) SFB 567 Institutional research plan: CEZ:AV0Z50450515 Keywords : asexual reproduction * evolution of polyploidy * hybridisation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.396, year: 2007

  6. Changes of ammonia, urea contents and transaminase activity in the body during aerial exposure and ammonia loading in Chinese loach Paramisgurnus dabryanus.

    Science.gov (United States)

    Zhang, Yun-Long; Zhang, Hai-Long; Wang, Ling-Yu; Gu, Bei-Yi; Fan, Qi-Xue

    2017-04-01

    The Paramisgurnus dabryanus was exposed to 30 mmol L -1 NH 4 Cl solution and air to assessing the change of body ammonia and urea contents and the activities of alanine aminotransferase (ALT) and aspartate transaminase (AST). After 48 h of ammonia exposure, ammonia concentration in the plasma, brain, liver and muscle were 3.3-fold, 5.6-fold, 3.5-fold and 4.2-fold, respectively, those of the control values. Plasma, brain, liver and muscle ammonia concentrations increased to 2.2-fold, 3.3-fold, 2.5-fold and 2.9-fold, respectively, those of control values in response to 48 h of aerial exposure. Within the given treatment (ammonia or aerial exposure), there was no change in plasma, brain and liver urea concentrations between exposure durations. The plasma ALT activity was significantly affected by exposure time during aerial exposure, while the liver ALT activity was not affected by ammonia or aerial exposure. Exposure to NH 4 Cl or air had no effect on either plasma or liver AST activity. Our results suggested that P. dabryanus could accumulate quite high level of internal ammonia because of the high ammonia tolerance in its cells and tissues, and NH 3 volatilization would be a possible ammonia detoxification strategy in P. dabryanus. Urea synthesis was not an effective mechanism to deal with environmental or internal ammonia problem. The significant increase of ALT activity in plasma during aerial exposure, indicating that alanine synthesis through certain amino acid catabolism may be subsistent in P. dabryanus.

  7. Vicariance, colonization, and fast local speciation in Asia Minor and the Balkans as revealed from the phylogeny of spined loaches (Osteichthyes; Cobitidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Percides, A.; Doadrio, I.; Economidis, P. S.

    2006-01-01

    Roč. 39, 2 (2006), s. 552-561 ISSN 1055-7903 R&D Projects: GA ČR GA206/05/2556; GA ČR GA206/00/0668; GA AV ČR IBS5045111; GA AV ČR IAA600450508 Institutional research plan: CEZ:AV0Z50450515 Keywords : zoogeography * freshwater fishes * cobitis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.528, year: 2006

  8. Fulltext PDF

    Indian Academy of Sciences (India)

    [Xiong F., Liu H.-Y., Duan X.-B. and Chen D.-Q. 2014 Identification and ... threatened freshwater fish, Botia superciliaris. J. Genet. 93, e5-e7. Online only: ..... in fo rm atio n content. Journal of Genetics Vol. 93, Online Resources e6 ...

  9. Chameleonic reactivity of vicinal diazonium salt of acetylenyl-9,10-anthraquinones: synthetic application toward two heterocyclic targets.

    Science.gov (United States)

    Stepanov, A A; Gornostaev, L M; Vasilevsky, S F; Arnold, E V; Mamatyuk, V I; Fadeev, D S; Gold, B; Alabugin, I V

    2011-11-04

    The nature of products in the diazotization of 1-amino-2-acetylenyl-9,10-anthraquinones strongly depends on the nature of substituents at both the alkyne and at the anthraquinone core. Donor substitution (NHAr, OH) at the fourth position stabilizes the diazonium salt at C1, decelerating electrophilic cyclization at the arylethynyl substituent at C2. This effect allows the replacement of the diazonium with azide group and subsequent closure into isoxazole ring with preservation of the alkyne. In contrast, electrophilic 5-exo-dig cyclizations to condensed pyrazoles is observed for the combination of donor substituents at the aryl alkyne moiety and an OAc substituent at C4. The latter process provides a new synthetic route to 3-ethynyl-[1,9-cd]isoxazol-6-ones that are difficult to access otherwise. DFT calculations suggest that donor substituents have only a minor effect on alkyne and diazonium polarization in the reactant but provide specific transition state stabilization by stabilizing the incipient vinyl cation. This analysis provides the first computational data on electrophilic 5-exo-dig cyclization in its parent form and the nucleophile-promoted version. This cyclization is a relatively fast but endothermic process that is rendered thermodynamically feasible by the enol-keto tautomerization with concomitant aromatization in the five-membered heteroaromatic ring. Computations suggest that the importance of nucleophilic assistance in the transition state for a relatively weak nucleophile such as water is minor because the energy gain due to the Lewis base coordination to the carbocationic center is more than compensated for by the unfavorable entropic term for the bimolecular proces.

  10. Conglomeration or Chameleon? Teachers' Representations of Language in the Assessment of Learners with English as an Additional Language.

    Science.gov (United States)

    Gardner, Sheena; Rea-Dickins, Pauline

    2001-01-01

    Investigates teacher representations of language in relation to assessment contexts. Analyzes not only what is represented in teachers' use of metalanguage, but also how it is presented--in terms of expression, voice, and source. The analysis is based on interviews with teachers, transcripts of lessons, and classroom-based assessments, formal…

  11. Issues Surrounding the Self: Using the Films "Defending Your Life" and "Chameleon Street" in the Interpersonal Class.

    Science.gov (United States)

    Hayward, Pamela A.

    The use of film to supplement course material can be an excellent way to stimulate critical thinking. Film can be a particularly useful tool in the interpersonal communication course since students are able to observe both the verbal and nonverbal behaviors of the characters. However, discussion prior to and following the film is important, so…

  12. The Chameleon Effect: characterization challenges due to the variability of nanoparticles and their surfaces of nanoparticles and their surfaces

    Science.gov (United States)

    Baer, Donald R.

    2018-05-01

    Nanoparticles in a variety of forms are increasing important in fundamental research, technological and medical applications, and environmental or toxicology studies. Physical and chemical drivers that lead to multiple types of particle instabilities complicate both the ability to produce, appropriately characterize, and consistently deliver well-defined particles, frequently leading to inconsistencies and conflicts in the published literature. This perspective suggests that provenance information, beyond that often recorded or reported, and application of a set of core characterization methods, including a surface sensitive technique, consistently applied at critical times can serve as tools in the effort minimize reproducibility issues.

  13. Chameleon or Chimera? The Role of the Higher Level Teaching Assistant (HLTA) in a Remodelled Workforce in English Schools

    Science.gov (United States)

    Graves, Susan

    2013-01-01

    This article draws on research conducted with HLTAs in the North-West of England over two years and is located in the context of workforce remodelling. The respondents have presented a picture of a role which is developing outside the hegemonic discourse of rationality, testing, accountability and performativity within which the teacher role is…

  14. The Power of Chameleonic Ideas in the Policy Decision-Making Process: The Case of the "Students' Revolution" in Chile

    Science.gov (United States)

    Cabieses, Baltica; Espinoza, Manuel

    2012-01-01

    Chile is facing a major intellectual revolution: organised college students are arguing for the most significant educational reform since the period of dictatorship (1973-1990). Thousands of high-school and university students have refused to go to lessons since early June 2011, calling for better and more affordable education and an end to a…

  15. Invited review: Frontotemporal dementia caused by microtubule-associated protein tau gene (MAPT) mutations: a chameleon for neuropathology and neuroimaging.

    Science.gov (United States)

    Ghetti, B; Oblak, A L; Boeve, B F; Johnson, K A; Dickerson, B C; Goedert, M

    2015-02-01

    Hereditary frontotemporal dementia associated with mutations in the microtubule-associated protein tau gene (MAPT) is a protean disorder. Three neuropathologic subtypes can be recognized, based on the presence of inclusions made of tau isoforms with three and four repeats, predominantly three repeats and mostly four repeats. This is relevant for establishing a correlation between structural magnetic resonance imaging and positron emission tomography using tracers specific for aggregated tau. Longitudinal studies will be essential to determine the evolution of anatomical alterations from the asymptomatic stage to the various phases of disease following the onset of symptoms. © 2014 The Authors. Neuropathology and Applied Neurobiology published by John Wiley & Sons Ltd on behalf of British Neuropathological Society.

  16. The Chameleon Concept: Modeling Quaternary Geomorphic Surfaces Using Laboratory, Field, and Imaging Spectrometry in the Lower Colorado Sonoran Desert

    Science.gov (United States)

    2005-11-01

    Oblique aerial photographs of dry deciduous tropical forest at the STRI Tropical Research Crane at the Parque Natural Metropolitano, Republic of Panama...Research Crane at the Parque Natural Metropolitano, Republic of Panama. ......................... 134 58. Original (a) and synthetic (b and c) tropical... Parque Natural Metropolitano, Republic of Panama. 133 b. Double canopy tropical forest diversity as seen from the can- opy crane gondola

  17. Chameleon Effects in Homework Research: The Homework-Achievement Association Depends on the Measures Used and the Level of Analysis Chosen

    Science.gov (United States)

    Trautwein, Ulrich; Schnyder, Inge; Niggli, Alois; Neumann, Marko; Ludtke, Oliver

    2009-01-01

    Using a data set specifically tailored to homework research, with a sample of 1275 students from 70 classes in Switzerland, the association between homework and achievement in French as a second language was tested at three levels (class level, between-student level, and within-student level). The strength and direction of the homework-achievement…

  18. BIRD-LIKE HEAD ON A CHAMELEON BODY: NEW SPECIMENS OF THE ENIGMATIC DIAPSID REPTILE MEGALANCOSAURUS FROM THE LATE TRIASSIC OF NORTHERN ITALY

    Directory of Open Access Journals (Sweden)

    SILVIO RENESTO

    2000-07-01

    Full Text Available Two new Megalancosaurus specimens collected from the Norian (Late Triassic Calcare di Zorzino (Zorzino Limestone Formation (Bergamo, Lombardy, Northern Italy, and from the coeval Dolomia di Forni (Forni Dolostone Formation (Udine, Friuli, North-eastern Italy improve our knowledge of skeletal anatomy and mode of life of this genus. Morphology of observable skull elements and cervical vertebrae in one of the new specimens shows some resemblance to the possible Triassic bird Protoavis, while the postcranial skeleton of Megalancosaurus is completely non-avian. This may suggest that either Megalancosaurus and Protoavis developed a similar neck structure as a response to the same functional requirement, or that part of the disarticulated material ascribed to Protoavis may indeed belong to a Megalancosaurus-like reptile. Megalancosaurus shows a very high adaptation to arboreal life and a peculiar feeding strategy. Recent suggestions that Megalancosaurus may have been a glider and a possible model for bird ancestry are discussed. Some skeletal features of Megalancosaurus may indeed be interpreted as gliding adaptation, but evidence is weak, and if this reptile was a glider, however, its gliding bauplan should have been completely different from the one usually accepted for bird ancestors, showing instead more morphological similarities with gliding squirrels, phalangeriids and putative ancestors of bats and pterosaurs (according to a non cursorial model for these latter. 

  19. "Pedagogias Del Camaleon"/Pedagogies of the Chameleon: Identity and Strategies of Survival for Transnational Indigenous Latino Immigrants in the US South

    Science.gov (United States)

    Machado-Casas, Margarita

    2012-01-01

    Based on a 3-year qualitative research study that took place in a new immigrant-receiving community in North Carolina, the manuscript examines the implications of transnational cultural and sociolinguistic patterns of multilingual indigenous Latino immigrants (ILIs), and its effects on their survival in the US. Utilizing narrative analysis, it…

  20. Dinosaurs, Chameleons, Humans, and Evo-Devo Path: Linking Étienne Geoffroy's Teratology, Waddington's Homeorhesis, Alberch's Logic of "Monsters," and Goldschmidt Hopeful "Monsters".

    Science.gov (United States)

    Diogo, Rui; Guinard, Geoffrey; Diaz, Raul E

    2017-05-01

    Since the rise of evo-devo (evolutionary developmental biology) in the 1980s, few authors have attempted to combine the increasing knowledge obtained from the study of model organisms and human medicine with data from comparative anatomy and evolutionary biology in order to investigate the links between development, pathology, and macroevolution. Fortunately, this situation is slowly changing, with a renewed interest in evolutionary developmental pathology (evo-devo-path) in the past decades, as evidenced by the idea to publish this special, and very timely, issue on "Developmental Evolution in Biomedical Research." As all of us have recently been involved, independently, in works related in some way or another with evolution and developmental anomalies, we decided to join our different perspectives and backgrounds in the present contribution for this special issue. Specifically, we provide a brief historical account on the study of the links between evolution, development, and pathologies, followed by a review of the recent work done by each of us, and then by a general discussion on the broader developmental and macroevolutionary implications of our studies and works recently done by other authors. Our primary aims are to highlight the strength of studying developmental anomalies within an evolutionary framework to understand morphological diversity and disease by connecting the recent work done by us and others with the research done and broader ideas proposed by authors such as Étienne Geoffroy Saint-Hilaire, Waddington, Goldschmidt, Gould, and Per Alberch, among many others to pave the way for further and much needed work regarding abnormal development and macroevolution. © 2016 Wiley Periodicals, Inc.

  1. Lymphogranuloma venereum: "a clinical and histopathological chameleon?" Linfogranuloma venéreo: "um camaleão clínico e histopatológico?"

    Directory of Open Access Journals (Sweden)

    Georgi Tchernev

    2010-08-01

    Full Text Available Lymphogranuloma venereum is an infection caused by a variety of the bacterium Chlamydia trachomatis. Both genital and extragenital manifestations of the disease can cause serious differential diagnostic difficulties, indirectly leading to progression and dissemination of the infection. This work describes cases of patients with lymphogranuloma venereum showing atypical clinical and/or histopathological findings. It also focuses on alternative therapeutic approaches, such as surgical excision at stage 1, that may lead to a positive outcome. It is not completely clear whether histopathological findings of lymphogranuloma venereum can reveal progression or changes in the course of the disease over time, as is the case in other diseases. We conclude that both clinical and histopathological observations in a larger number of patients are needed in order to further evaluate the findings presented in this article.Linfogranuloma venéreo é uma infecção causada por um tipo específico da bactéria Chlamydia trachomatis. Manifestações genitais e extragenitais da doença podem causar uma série de dificuldades no diagnóstico diferencial, indiretamente levando a progressão ou disseminação da infecção. Este trabalho apresenta casos de pacientes com linfogranuloma venéreo cujos achados clínicos e/ou histopatológicos são atípicos, além de abordar métodos de terapia alternativos, tais como excisão cirúrgica na fase 1, os quais podem trazer um resultado positivo. Ainda não se sabe se achados histopatológicos do linfogranuloma venéreo podem revelar progressão ou mudanças no curso da doença ao longo do tempo, como ocorre com outras enfermidades. Concluímos que observações clínicas e histopatológicas devem envolver um número maior de pacientes a fim de avaliar os resultados clínicos deste trabalho.

  2. DNA BARCODING IKAN HIAS INTRODUKSI

    Directory of Open Access Journals (Sweden)

    Melta Rini Fahmi

    2017-05-01

    Full Text Available Identifikasi spesies menjadi tantangan dalam pengelolaan ikan hias introduksi baik untuk tujuan budidaya maupun konservasi. Penelitian ini bertujuan untuk melakukan identifikasi molekuler ikan hias introduksi yang beredar di pembudidaya dan pasar ikan hias Indonesia dengan menggunakan barcode DNA gen COI. Sampel ikan diperoleh dari pembudidaya dan importir ikan hias di kawasan Bandung dan Jakarta. Total DNA diekstraksi dari jaringan sirip ekor dengan menggunakan metode kolom. Amplifikasi gen target dilakukan dengan menggunakan primer FishF1, FishF2, FishR1, dan FishR2. Hasil pembacaan untai DNA disejajarkan dengan sekuen yang terdapat pada genbank melalui program BLAST. Identifikasi dilakukan melalui kekerabatan pohon filogenetik dan presentasi indeks kesamaan dengan sekuen genbank. Hasil identifikasi menunjukkan sampel yang diuji terbagi menjadi lima grup, yaitu: Synodontis terdiri atas lima spesies, Corydoras: empat spesies, Phseudoplatystoma: tiga spesies, Botia: tiga spesies, dan Leporinus: tiga spesies dengan nilai boostrap 99-100. Indeks kesamaan sekuen menunjukkan sebanyak 11 spesies memiliki indeks kesamaan 99%-100% dengan data genbank yaitu Synodontis decorus, Synodontis eupterus, Synodontis greshoffi, Botia kubotai, Botia lohachata, Rasbora erythromicron, Corydoras aeneus, Gyrinocheilus aymonieri, Eigenmannia virescens, Leporinus affinis, Phractocephalus hemioliopterus. Dua spesies teridentifikasi sebagai hasil hibridisasi (kawin silang yaitu Leopard catfish (100% identik dengan Pseudoplatystoma faciatum dan Synodontis leopard (100% identik dengan Synodontis notatus. Hasil analisis nukleotida penciri diperoleh tujuh nukleotida untuk Synodontis decora, 10 nukleotida untuk Synodontis tanganyicae, 13 nukleotida untuk Synodontis euterus, empat nukleotida untuk Synodontis notatus, dan 14 untuk Synodontis grashoffi. Kejelasan identifikasi spesies ikan menjadi kunci utama dalam budidaya, perdagangan, manajemen, konservasi, dan pengembangan

  3. Integrated water quality, emergy and economic evaluation of three bioremediation treatment systems for eutrophic water

    Science.gov (United States)

    This study was targeted at finding one or more environmentally efficient, economically feasible and ecologically sustainable bioremediation treatment modes for eutrophic water. Three biological species, i.e. water spinach (Ipomoea aquatica), loach (Misgurus anguillicaudatus) and ...

  4. Descriptive osteology of Paracobitis iranica Nalbant and Bianco, 1998 (Cypriniformes, Nemacheilidae) from Namak Lake basin of Iran

    OpenAIRE

    EAGDERI, Soheil; NIKMEHR, Nasrin

    2016-01-01

    This study was carried out to describe the osteological structure of Iranian crested loach, Paracobitis iranica, Nalbant and Bianco, 1998 an Iranian endemic loach species. For this purpose, ten specimens of P. Iranica were collected from the Qom River. After clearing and staining, its osteological characteristics were examined and a detailed description of its skeletal structure was provided. The results revealed that P .iranica can be distinguished from other members of the family Nemacheili...

  5. Black Hats and White Hats: The Effect of Organizational Culture and Institutional Identity on the Twenty-third Air Force

    Science.gov (United States)

    2006-12-01

    the two communities, their institutional histories have played a significant role in their organizational development. According to Col Ken Pribyla...Low IIIs, UH-60 Blackhawks (the Army’s first operational company of UH-60s), CH-47C Chi- nooks from the 101st Airborne Division, and OH-6 Loach ...Blackhawks (the Army’s first operational company of UH-60s), CH-47C Chinooks from the 101st Airborne Division, and OH-6 Loach helicopters that could

  6. Flightfax - Army Aviation Risk-Management Information. Volume 25, Number 11, August 1997. Snow

    Science.gov (United States)

    1997-08-01

    but why haven’t Loach that would ensure our surviving a multiple- you been acknowledging the radio calls?" A quick wire strike. check confirmed that...helicopter upright with only the collective and Loach on post with skid shoes, the skid cleats would pedals. have snagged the middle wire and flipped...is more cost effective to overhaul until because masking violated FAA Mr. Ken Muzzo, DSN 490-2257 (314-260- the retirement life is reached. The

  7. Falconry

    Science.gov (United States)

    2015-12-01

    8217 --Independent--Back cover." - 150 - Filmed as Kes by Ken Loach in 1969, Barry Hines’ novel is a modern classic, and is a set GCSE text. Lawrence...signed by Richard Leach; and biographies of Richard Leach and Alfred V. Fedak. A compact disc accompanies the volume 52. Loach , Ken . KesNew...Passion of Falconry. London: Thames & Hudson, 2008. Call Number: SK 321 .A47 2008 23. Andersen, David Eric . "Military Training and the Ecology of Raptor

  8. The GammeV suite of experimental searches for axion-like particles

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Upadhye, Amol

    2009-01-01

    We report on the design and results of the GammeV search for axion-like particles and for chameleon particles. We also discuss plans for an improved experiment to search for chameleon particles, one which is sensitive to both cosmological and power-law chameleon models. Plans for an improved axion-like particle search using coupled resonant cavities are also presented. This experiment will be more sensitive to axion-like particles than stellar astrophysical models or current helioscope experiments

  9. Why Density Dependent Propulsion?

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    In 2004 Khoury and Weltman produced a density dependent cosmology theory they call the Chameleon, as at its nature, it is hidden within known physics. The Chameleon theory has implications to dark matter/energy with universe acceleration properties, which implies a new force mechanism with ties to the far and local density environment. In this paper, the Chameleon Density Model is discussed in terms of propulsion toward new propellant-less engineering methods.

  10. Controlled Redox and Electrical Properties in Polyheterocycles

    National Research Council Canada - National Science Library

    Reynolds, John

    2001-01-01

    Electrochromic and conducting polymers may prove especially important for a number of Air Force applications including chameleon coatings, informational displays, IR and microwave attenuation, dialed...

  11. Controlled Redox and Electrical Properties in Polyheterocycles

    National Research Council Canada - National Science Library

    Reynolds, John

    2000-01-01

    Electrochromic polymers may prove especially important for a number of Air Force applications including chameleon coatings, informational displays, IR and microwave attenuation, and dialed tint windows...

  12. Probing dark energy with atom interferometry

    International Nuclear Information System (INIS)

    Burrage, Clare; Copeland, Edmund J.; Hinds, E.A.

    2015-01-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry

  13. Probing dark energy with atom interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare; Copeland, Edmund J. [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Hinds, E.A., E-mail: Clare.Burrage@nottingham.ac.uk, E-mail: Edmund.Copeland@nottingham.ac.uk, E-mail: Ed.Hinds@imperial.ac.uk [Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom)

    2015-03-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  14. Predation and control efficacies of Misgurnus mizolepis (Cypriniformes: Cobitidae) toward Culex pipiens molestus (Diptera: Culicidae) and fish toxicity of temephos in laboratory and septic tank conditions.

    Science.gov (United States)

    Chae, Seong Chun; Kwon, Young Hyun; Min, Kyung Il; Kim, Hyung Soo; Kim, Nam-Jin; Kim, Jun-Ran; Son, Bong Gi; Ahn, Young-Joon

    2014-07-01

    Culex pipiens molestus Forskal (Diptera: Culicidae) is the dominant mosquito species in septic tanks in South Korea. An assessment was made of the biological control potential of mud loaches, Misgurnus mizolepis Günther (Cypriniformes: Cobitidae), toward Cx. p. molestus larvae in laboratory and septic tanks. Results were compared with those of temephos 20% emulsifiable concentrate. In laboratory tests, all mud loaches survived on sedimentation chamber- and effluent chamber-collected water of aerobic septic tanks (ASTs), whereas all mud loaches died within 3-12 h after introduction into sedimentation chamber- and effluent chamber-collected water of anaerobic septic tanks, Gill hyperplasia and hemorrhages at the bases of pectoral fins were detected in all dead mud loaches. These appeared to have been caused by bacterial disease, rather than the physical and chemical characteristics of the septic tank water. A mud loach consumed an average range of 1,072-1,058 larvae of Cx. p. molestus in the AST water at 24 h. At the manufacturer's recommended rate (10 ml/ton) in the AST water, the temephos formulation did not cause fish mortality. In the AST experiment, predation of mosquito larvae by mud loaches at a release rate of one fish per 900 mosquito larvae resulted in complete mosquito control from the third day after treatment throughout the 18-wk survey period, compared with temephos 20% emulsifiable concentrate-treated AST water (reduction rate, 40% at 28 days after treatment). Reasonable mosquito control in aerobic septic tanks can be achieved by mosquito breeding season stocking of a rate of one mud loach per 900 mosquito larvae.

  15. Microsatellite loci isolated from Chamaeleo chamaeleon

    Indian Academy of Sciences (India)

    existing chameleons in Iberian peninsula were founded by chameleons from North Africa, through two separate colonizations, one from Mediterranean North African populations which originated the Mediterranean Malaga population; and the other from the Atlantic coast of Morocco which originated the Atlantic populations ...

  16. Using 3D Computer Graphics Multimedia to Motivate Preservice Teachers' Learning of Geometry and Pedagogy

    Science.gov (United States)

    Goodson-Espy, Tracy; Lynch-Davis, Kathleen; Schram, Pamela; Quickenton, Art

    2010-01-01

    This paper describes the genesis and purpose of our geometry methods course, focusing on a geometry-teaching technology we created using NVIDIA[R] Chameleon demonstration. This article presents examples from a sequence of lessons centered about a 3D computer graphics demonstration of the chameleon and its geometry. In addition, we present data…

  17. Photon Rao

    Indian Academy of Sciences (India)

    Volume 2 Issue 5 May 1997 pp 69-72 Feature Article. Molecule of the Month Molecular–Chameleon: Solvatochromism at its Iridescent Best! Photon Rao · More Details Fulltext PDF. Volume 16 Issue 12 December 2011 pp 1303-1306. Molecule of the Month - Molecular-Chameleon: Solvatochromism at its Iridescent Best!

  18. Effects of Misgurnus anguillicaudatus and Cipangopaludina cathayensis on Pollutant Removal and Microbial Community in Constructed Wetlands

    Directory of Open Access Journals (Sweden)

    Pengfei Li

    2015-05-01

    Full Text Available Aquatic animals play an important role in the energy flow and matter cycling in the wetland ecosystem. However, little is known about their effects on pollutant removal performance and microbial community in constructed wetlands. This work presents an initial attempt to investigate the effects of Misgurnus anguillicaudatus (loach and Cipangopaludina cathayensis (snail on nutrient removal performance and microbial community of constructed wetlands (CWs. Compared with a control group, CW microcosms with aquatic animals exhibited better pollutant removal performance. The removal efficiencies of total phosphorus (TP in the loach group were 13.1% higher than in the control group, and snails increased the ammonium removal most effectively. Moreover, the concentration of total organic carbon (TOC and TP in sediment significantly reduced with the addition of loaches and snails (p < 0.05, whereas the concentration of total nitrogen (TN showed an obvious increase with the addition of loaches. High-throughput sequencing showed a microbial community structure change. Loaches and snails in wetlands changed the microbial diversity, especially in the Proteobacteria and denitrifying community. Results suggested that benthic aquatic animals might play an important role in CW ecosystems.

  19. Molecular characterization of elongase of very long-chain fatty acids 6 (elovl6) genes in Misgurnus anguillicaudatus and their potential roles in adaptation to cold temperature.

    Science.gov (United States)

    Chen, Jingwen; Cui, Yun; Yan, Jie; Jiang, Jimin; Cao, Xiaojuan; Gao, Jian

    2018-08-05

    Elongase of very long-chain fatty acids 6 (ELOVL6) is a rate-limiting enzyme catalyzing elongation of saturated and monounsaturated long-chain fatty acid. Although functional characteristics of Elovl6 have been demonstrated in mammal, the role of elovl6 in fish remains unclear. In this study, we firstly cloned three isoforms of elovl6 (elovl6a, elovl6b and elovl6-like) from loach (Misgurnus anguillicaudatus). Molecular characterizations of the three elovl6 isoforms in loach and their expressions of early life stages and different tissues were then determined. We also functionally characterized the three elovl6 isoforms using heterologous expression in baker's yeast. Results obtained here showed the three elovl6 proteins in loach can elongate C16:0 and C16:1 to C18:0 and C18:1, respectively. At last, to confirm the role of three loach elovl6 isoforms for elongation of fatty acids in adaption to cold stress, differences in skin histological structures, body fatty acid compositions, expressions of four hepatic lipogenesis or lipolysis related genes, and expressions of the three elovl6 isoforms and their related gene uncoupling protein 1 (ucp1) in different tissues were investigated in the loach reared in two different water temperatures (28 °C and 4 °C) for ten days. Cold stress increased ratios of C18/C16 and C20:5n-3/C18:3n-3 in loach body, and induced expressions of hepatic acyl-CoA delta-9 desaturase 1 (scd1), sterol-regulator element-binding protein 1 (srebp1), carnitine palmitoyltransferase 1 (cpt1) and fatty acid synthase (fas). Meanwhile, significant differences were found in expressions of the three elovl6 isoforms in different tissues between 28 °C and 4 °C groups. Overall, this study suggests that the three elovl6 isoforms in loach have ability to elongate C16 to C18, and elovl6 proteins in loach may play a role in adaptation to cold stress. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Sex ratio and body size in Cobitis elongatoides and Sabanejewia balcanica (Cypriniformes; Cobitidae) from a thermal spring

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Freyhof, J.; Nolte, A.

    2008-01-01

    Roč. 57, 1-2 (2008), s. 191-197 ISSN 0139-7893. [International Conference Loaches of the genus Cobitis and related genera. Šibenik, 24.09.2006-29.09.2006] R&D Projects: GA ČR GA206/05/2556; GA AV ČR IAA600450508 Institutional research plan: CEZ:AV0Z50450515 Keywords : environmental sex determination * Fisher's principle * cobitine loach Subject RIV: EG - Zoology Impact factor: 0.522, year: 2008

  1. Solar Flare Studies

    Science.gov (United States)

    1982-03-20

    Feldman, U., and Dere, K. P.:ý 1978, Astophys. /. 224, 1017. Underwood, J. H., Milligan, !. C., dc Loach , A. C. and Hoover, R. B.:, 1977, Applied... Loach , A. C., Hoose~r, R. B., and MlcGuire, J. P.: 19 75,Solar Phys. 45, 377. N , Sheridan, K. V.. Jackson, B. V., hict-can, EX. I , and Sulk, G. A...Sacramento Peak Observatory, Ken Nicolas at NRL and Dean Jacobs at UCSD. This research was sponsored by the Air Force Office of Scientific Research, Air Force

  2. Reliability Parts Derating Guidelines

    Science.gov (United States)

    1982-06-01

    226-30, October 1974. 66 I, 26. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser Engineering and...Vol. R-23, No. 4, 226-30, October 1974. 28. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser...opnatien ot 󈨊 deg C, mounted on a 4-inach square 0.250~ inch thick al~loy alum~nusi panel.. This mounting technique should be L~ ken into cunoidur~tiou

  3. Genetic diversity and taxonomy of Sabanejewia balcanica (Osteichthyes: Cobitidae) in the waters of the Czech Republic and Slovakia

    Czech Academy of Sciences Publication Activity Database

    Bartoňová, Eva; Papoušek, Ivo; Lusková, Věra; Koščo, J.; Lusk, Stanislav; Halačka, Karel; Švátora, M.; Vetešník, Lukáš

    2008-01-01

    Roč. 57, 1-2 (2008), s. 60-70 ISSN 0139-7893. [Loaches of the genus Cobitis and related genera /3./. Šibenik, 24.09.2006-29.09.2006] R&D Projects: GA MŽP SM/6/3/05 Grant - others:VEGA(SK) 1/2360/05 Institutional research plan: CEZ:AV0Z60930519 Keywords : Balcan spined loach * conservation * cytochrome b * mitochondrial marker Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.522, year: 2008 http://www.ivb.cz/folia/57/1-2/060-070_MS1279.pdf

  4. Notes on the post-Newtonian limit of the massive Brans-Dicke theory

    International Nuclear Information System (INIS)

    Roshan, Mahmood; Shojai, Fatimah

    2011-01-01

    We consider the post-Newtonian limit of the massive Brans-Dicke theory and make some notes about the post-Newtonian limit of the case ω = 0. This case is dynamically equivalent to the metric f(R) theory. It is known that this theory can be compatible with the solar system tests if the Chameleon mechanism occurs. Also, it is known that this mechanism is because of the nonlinearity in the field equations produced by the largeness of the local curvature relative to the background curvature. Thus, the linearization of the field equations breaks down. On the other hand, we know that the Chameleon mechanism exists when a coupling between the matter and the scalar field exists. In the Jordan frame of the Brans-Dicke theory, we have no such coupling. But in the Einstein frame, this theory behaves like a Chameleon scalar field. By confining ourselves to the case ω = 0, we show that 'Chameleon-like' behaviour can exist also in the Jordan frame, but it has an important difference compared with the Chameleon mechanism. Also we show that the conditions which lead to the existence of a 'Chameleon-like' mechanism are consistent with the conditions in the post-Newtonian limit which correspond to a heavy scalar field at the cosmological scale and a small effective cosmological constant. Thus, one can linearize field equations to the post-Newtonian order, and this linearization has no contradiction with the existence of 'Chameleon-like' behaviour.

  5. [Biobanks and blood transfusion in France: a tool for public health].

    Science.gov (United States)

    Lefrère, J-J; Coudurier, N

    2009-05-01

    Donor and recipient sample biobanks are a precious tool in hemovigilance studies as well as in epidemiological and biological research, in particular with regards to safety against blood-borne agents. This paper describes the main transfusion biobanks existing in France and gives their advantages and limits. The National blood donation biobank, organized for medicolegal reasons, preserves samples of each blood donation for a 5-year period. The biobank of the Blood and Organ Transmissible Infectious Agents (BOTIA) project stocks paired donor-recipient samples with a research objective. Preserved over a long period of time, such transfusion biobanks will be useful in terms of public health, as a reflection of the biological state of a population at a given moment.

  6. Sekavčík balkánský (Sabanejewia balcanica) v České republice – minulost, současnost a budoucnost

    Czech Academy of Sciences Publication Activity Database

    Lusk, S.; Halačka, Karel; Májsky, J.; Vetešník, Lukáš; Mendel, Jan

    2017-01-01

    Roč. 8, č. 8 (2017), s. 90-102 ISSN 1212-1312 R&D Projects: GA ČR GA13-12580S Institutional support: RVO:68081766 Keywords : Balcan Golden Loach * Czech Republic Subject RIV: EG - Zoology OBOR OECD: Zoology

  7. Trip Reports. Hazardous Waste Minimization and Control at Army Depots

    Science.gov (United States)

    1989-08-01

    Chief, Building 114; Major Robert Ronne; and Ken Rollins, Section Chief, Building 409. The purpose of this trip report Is to document the Information...hazardous. 6. Wf-TIM WOR Feosbility of a suitable p-etresaent f waste cuttins oil and sulleln coolant loach as 4iltratlan to remove metals. removal

  8. United States-Vietnam Relations 1945-1967. Book 8 of 12

    Science.gov (United States)

    1971-09-20

    territories t- ken from the enemy in this war, as Might be agreed upon at a later date, end also such other territories as mi~r.it voluntarily...lag controls* In consequence tho process of Giving definition 211 . the ontot’prise * A dispassionate cvpprsisSl loach ) tho United States

  9. A 2011 Risk/Benefit Analysis of the Anthrax Vaccine Immunization Program

    Science.gov (United States)

    2011-06-10

    filled with botulinum toxin, 10 with anthrax, and 2 with aflatoxin.‖18 In 1992, Ken Alibek, a senior Russian bioweapons program manager defected...William K. Honner, Rosha A. Loach , Cynthia A. Moore, and J. David Erickson. ―Birth Defects Among Infants Born to Women Who Received Anthrax Vaccine In

  10. Cannes'i klassikud - tuntud headuses / Jaak Lõhmus

    Index Scriptorium Estoniae

    Lõhmus, Jaak

    2006-01-01

    Cannes'i filmifestival. Nähtud filmidest : soomlase Aki Kaurismäki "Agulituled" ("Laitakaupungin valot"), hispaanlase Pedro Almodovari "Volver" ("Naasta"), inglase Ken Loach'i "Kesva heljutab tuul" ("The Wind that Shakes the Barely"), ameeriklase Richard Linklateri "Rämpstoidu rahvas" ("Fast Food Nation")

  11. Journal of Special Operations Medicine Volume 1, Edition 1

    Science.gov (United States)

    2001-01-01

    the enemy, and generally regard them with unspo- ken respect. The feelings they must have for those who are realistically threatening their lives...Cobras from the 1st Cav Division area of operation just down to the south of us, Loaches , even a Chi- nook. And fixed wing! We had everything but a B-52

  12. Tshempionat mira po kino / Ilona Vinogradova

    Index Scriptorium Estoniae

    Vinogradova, Ilona

    2006-01-01

    Cannes'i filmifestival. Nähtud filmidest : hiinlase Lou Ye "Suvepalee", soomlase Aki Kaurismäki "Äärelinna tuled" ("Laitakaupungin valot"), hispaanlase Pedro Almodovari "Volver" ("Tagasitulek"), inglase Ken Loach'i "Tuul sasib odrapõldu" ("The Wind that Shakes the Barely"). Ka vene filmi kohaloleku probleemidest Cannes'is

  13. Eyes Behind the Lines: US Army Long-Range Reconnaissance and Surveillance Units

    Science.gov (United States)

    2005-01-01

    while still at Fort Campbell, Ken - tucky, converted its divisional Recondo School into a provisional LRRP unit in the summer of 967, before the...helicopter rather than a Hughes OH-6A light observa- tion helicopter (LOH, but commonly called “ loach ”), which had a crew of two (pilot and observer

  14. Implications of Advanced Technologies for Air and Spacecraft Escape

    Science.gov (United States)

    1990-02-01

    yaw, and at high speeds, aallort yaw angle will create high lateral g- loach , and a consequently high DR. on the crew member. Therefore, the first...Figure 5. The risk levels shown on dini plot are approxtisations of the Levels derived fronm Brinkley.* An ejection from an aircraft at 800 kens is

  15. Legislative Environmental Impact Statement: Small Intercontinental Ballistic Missile Program.

    Science.gov (United States)

    1986-11-01

    beautiful shiner, and Apache trout) and four federal-candidate species (desert pupfish, Sonora chub, loach minnow, and flat-tailed horned lizard) occur...Archaeology. A Class I Inventory of Prehistoric Resources. Ethnoscience, Billings, Montana. 9-13 INV Den Beste, Ken and Lois Den Beste 1976 Backgrounded

  16. CSRI Summer Proceedings 2010

    Science.gov (United States)

    2010-12-17

    interpreting the data. In particular, we thank Sophia Corwell, Matthew Bohnsack, Ken Lord, and Marcus Epperson. We thank David Day for his helpful...Commun. ACM, 33 (1990), pp. 30–53. [8] A. Guillon and D. Loach , YetiSim: a C++ simulation library with execution graphs instead of coroutines, in

  17. Küünikute frustratsioon, europeldikute kassikuld ja alkohooliku elukibedus / Tarmo Teder

    Index Scriptorium Estoniae

    Teder, Tarmo, 1958-

    1999-01-01

    II Pimedate Ööde Filmifestivali filme : "Ülestegemata voodid" ("Unmade Beds") : režissöör Nicholas Barker, "Ettevaatust, uksed sulguvad!" ("Sliding Doors") : režissöör Peter Howitt ja "Minu nimi on Joe" ("My Name Is Joe") : režissöör Ken Loach

  18. Workshop on III-V Integrated Optoelectronics Held in Hilton Head, South Carolina on 28-30 March 1989

    Science.gov (United States)

    1990-01-01

    Barney De Loach AT&T Bell Laboratories MH 2D-351 600 Mountain Avenue Murray Hill, NJ 07974 Tel: 201-582-3382 Fax: 201-582-2451 Dr. M.A. Di Giuseppe AT...Park, NC 27709-2211 Tel: 919-549-0641 Fax: 919-549-9399 Professor T. Ken Gustafson Department of Electrical Engineering and Computer Sciences

  19. Pimedad ööd kutsuvad häid filme vaatama / Kaido Soom

    Index Scriptorium Estoniae

    Soom, Kaido

    2008-01-01

    12. Pimedate Ööde filmifestivali filmidest, mis jätsid sügavama mulje artikli autorile - Taani mängufilm "Mine rahus, Jamil" (rezh. Omar Shargawi), Suurbritannia -Itaalia - Saksamaa - Hispaania - Poola koostööfilm "See on vaba maailm" (rezh. Ken Loach) ja Šveitsi dokumentaalfilm "Tagane, saatan" (rezh. Peter Entell)

  20. Cannes : seks ja revolutsioon / Annika Koppel

    Index Scriptorium Estoniae

    Koppel, Annika

    2006-01-01

    Cannes'i filmifestival. Nähtud filmidest : Ron Howardi "Da Vinci kood"("The Code Da Vinci"), hiinlase Lou Ye "Suvepalee", inglase Ken Loach'i "Tuul, mis sasib odrapõldu" ("The Wind that Shakes the Barely"), ungarlase Györgi Palfi "Taksidermia"

  1. Examining the Role of Manipulatives and Metacognition on Engagement, Learning, and Transfer

    Science.gov (United States)

    Belenky, Daniel M.; Nokes, Timothy J.

    2009-01-01

    How does the type of learning material impact what is learned? The current research investigates the nature of students' learning of math concepts when using manipulatives (Uttal, Scudder, & DeLoache, 1997). We examined how the type of manipulative (concrete, abstract, none) and problem-solving prompt (metacognitive or problem-focused) affect…

  2. Two new species of Schistura from Myanmar (Teleostei: Nemacheilidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula

    2013-01-01

    Roč. 24, č. 1 (2013), s. 21-30 ISSN 0936-9902 R&D Projects: GA ČR GA206/08/0637 Institutional research plan: CEZ:AV0Z50450515 Keywords : loach * basin * drainage Subject RIV: EG - Zoology Impact factor: 2.275, year: 2013

  3. Research Article Special Issue

    African Journals Online (AJOL)

    pc

    2017-08-08

    Aug 8, 2017 ... applications concerning computer aided accountancy and business correspondence. Key Words: (CASE tools, programming technique, accounting applications). INTRODUCTION. One of the main features of ... investigations of object-oriented modeling languages (Eliëns,2000, DeLoach,2000) and many.

  4. Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides x Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia

    Czech Academy of Sciences Publication Activity Database

    Fedorčák, J.; Koščo, J.; Halačka, Karel; Manko, P.

    2017-01-01

    Roč. 47, č. 2 (2017), s. 125-132 ISSN 0137-1592 R&D Projects: GA ČR GA13-12580S Institutional support: RVO:68081766 Keywords : annulus * back-calculated length * loach * clone * polyploidy Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 0.670, year: 2016

  5. Microhabitat preferences of triploid Cobitis fish and diploid progenitors in two streams in Slovakia (Danube River Basin)

    Czech Academy of Sciences Publication Activity Database

    Fedorčák, J.; Pekárik, L.; Halačka, Karel; Šmiga, Ľ.; Manko, P.; Hajdú, J.; Vetešník, Lukáš; Koščo, J.

    2018-01-01

    Roč. 69, March (2018), s. 59-66 ISSN 0075-9511 R&D Projects: GA ČR GA13-12580S Institutional support: RVO:68081766 Keywords : Spined loach * Polyploidy * Niche * Clone * Coexistence * Sex Subject RIV: EH - Ecology, Behaviour Impact factor: 1.427, year: 2016

  6. 75 FR 66481 - Endangered and Threatened Wildlife and Plants; Endangered Status and Designation of Critical...

    Science.gov (United States)

    2010-10-28

    ... ends of mid-channel sand or gravel bars; and eddies at downstream riffle edges (Rinne 1991, p. 11..., large reservoirs, or dewatered channels, thus eliminating suitable spikedace and loach minnow habitat in... for the persistence of these species. The San Francisco River has undergone sedimentation, riparian...

  7. Investigating Individual Differences in Toddler Search with Mixture Models

    Science.gov (United States)

    Berthier, Neil E.; Boucher, Kelsea; Weisner, Nina

    2015-01-01

    Children's performance on cognitive tasks is often described in categorical terms in that a child is described as either passing or failing a test, or knowing or not knowing some concept. We used binomial mixture models to determine whether individual children could be classified as passing or failing two search tasks, the DeLoache model room…

  8. Igbo Fowl's Wellerism and the Concensus of other Animals: the ...

    African Journals Online (AJOL)

    Religion Dept

    Chameleon says that he can never abandon the rich man's style of movement his ... breaking and eating kolanuts, immolating Fowl and using his chicken in preparing a ... stated that his kinsmen could not touch his body let alone burying him:.

  9. An Adaptive QoS Routing Solution for MANET Based Multimedia Communications in Emergency Cases

    Science.gov (United States)

    Ramrekha, Tipu Arvind; Politis, Christos

    The Mobile Ad hoc Networks (MANET) is a wireless network deprived of any fixed central authoritative routing entity. It relies entirely on collaborating nodes forwarding packets from source to destination. This paper describes the design, implementation and performance evaluation of CHAMELEON, an adaptive Quality of Service (QoS) routing solution, with improved delay and jitter performances, enabling multimedia communication for MANETs in extreme emergency situations such as forest fire and terrorist attacks as defined in the PEACE project. CHAMELEON is designed to adapt its routing behaviour according to the size of a MANET. The reactive Ad Hoc on-Demand Distance Vector Routing (AODV) and proactive Optimized Link State Routing (OLSR) protocols are deemed appropriate for CHAMELEON through their performance evaluation in terms of delay and jitter for different MANET sizes in a building fire emergency scenario. CHAMELEON is then implemented in NS-2 and evaluated similarly. The paper concludes with a summary of findings so far and intended future work.

  10. Massive graviton dark matter with environment dependent mass: A natural explanation of the dark matter-baryon ratio

    Science.gov (United States)

    Aoki, Katsuki; Mukohyama, Shinji

    2017-11-01

    We propose a scenario that can naturally explain the observed dark matter-baryon ratio in the context of bimetric theory with a chameleon field. We introduce two additional gravitational degrees of freedom, the massive graviton and the chameleon field, corresponding to dark matter and dark energy, respectively. The chameleon field is assumed to be nonminimally coupled to dark matter, i.e., the massive graviton, through the graviton mass terms. We find that the dark matter-baryon ratio is dynamically adjusted to the observed value due to the energy transfer by the chameleon field. As a result, the model can explain the observed dark matter-baryon ratio independently from the initial abundance of them.

  11. Solar System constraints on a cosmologically viable f(R) theory

    Energy Technology Data Exchange (ETDEWEB)

    Bisabr, Yousef, E-mail: y-bisabr@srttu.ed [Department of Physics, Shahid Rajaee Teacher Training University, Lavizan, Tehran 16788 (Iran, Islamic Republic of)

    2010-01-18

    Recently, a model f(R) theory is proposed (Miranda et al. (2009)) which is cosmologically viable and distinguishable from LAMBDACDM. We use chameleon mechanism to investigate viability of the model in terms of Solar System experiments.

  12. Role of reactive species in the photocatalytic degradation of ...

    Indian Academy of Sciences (India)

    2017-12-06

    Dec 6, 2017 ... Nitrogen doping; photocatalysis; visible light active; reactive species; ... Of a variety of semiconductors, tungsten oxide (WO3) ... sodium chloride (NaCl, Chameleon reagent), sodium nitrate ..... Ammonium. No ion .... produced.

  13. Solar System constraints on a cosmologically viable f(R) theory

    International Nuclear Information System (INIS)

    Bisabr, Yousef

    2010-01-01

    Recently, a model f(R) theory is proposed (Miranda et al. (2009)) which is cosmologically viable and distinguishable from ΛCDM. We use chameleon mechanism to investigate viability of the model in terms of Solar System experiments.

  14. 121 Book review

    African Journals Online (AJOL)

    than indulgence of one's own aesthetic eccentricity or even plain critical myopia. ... sport with this in Of Chameleons and Gods and the tradition goes back at ... therefore untouched by the experience of the Writers' Workshop. (though, says ...

  15. Download this PDF file

    African Journals Online (AJOL)

    thirty years", features no less than four Malawians - Chimombo,. Chipasula ... task to a team of assistants - Zangaphee Chizeze, Garton Sandifolo, and my fondly .... sport with this in Of Chameleons and Gods and the tradition goes back at least ...

  16. Notes on the post-Newtonian limit of the massive Brans-Dicke theory

    Energy Technology Data Exchange (ETDEWEB)

    Roshan, Mahmood; Shojai, Fatimah, E-mail: fshojai@ut.ac.ir [Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of)

    2011-07-21

    We consider the post-Newtonian limit of the massive Brans-Dicke theory and make some notes about the post-Newtonian limit of the case {omega} = 0. This case is dynamically equivalent to the metric f(R) theory. It is known that this theory can be compatible with the solar system tests if the Chameleon mechanism occurs. Also, it is known that this mechanism is because of the nonlinearity in the field equations produced by the largeness of the local curvature relative to the background curvature. Thus, the linearization of the field equations breaks down. On the other hand, we know that the Chameleon mechanism exists when a coupling between the matter and the scalar field exists. In the Jordan frame of the Brans-Dicke theory, we have no such coupling. But in the Einstein frame, this theory behaves like a Chameleon scalar field. By confining ourselves to the case {omega} = 0, we show that 'Chameleon-like' behaviour can exist also in the Jordan frame, but it has an important difference compared with the Chameleon mechanism. Also we show that the conditions which lead to the existence of a 'Chameleon-like' mechanism are consistent with the conditions in the post-Newtonian limit which correspond to a heavy scalar field at the cosmological scale and a small effective cosmological constant. Thus, one can linearize field equations to the post-Newtonian order, and this linearization has no contradiction with the existence of 'Chameleon-like' behaviour.

  17. General Conversion for Obtaining Strongly Existentially Unforgeable Signatures

    Science.gov (United States)

    Teranishi, Isamu; Oyama, Takuro; Ogata, Wakaha

    We say that a signature scheme is strongly existentially unforgeable (SEU) if no adversary, given message/signature pairs adaptively, can generate a signature on a new message or a new signature on a previously signed message. We propose a general and efficient conversion in the standard model that transforms a secure signature scheme to SEU signature scheme. In order to construct that conversion, we use a chameleon commitment scheme. Here a chameleon commitment scheme is a variant of commitment scheme such that one can change the committed value after publishing the commitment if one knows the secret key. We define the chosen message security notion for the chameleon commitment scheme, and show that the signature scheme transformed by our proposed conversion satisfies the SEU property if the chameleon commitment scheme is chosen message secure. By modifying the proposed conversion, we also give a general and efficient conversion in the random oracle model, that transforms a secure signature scheme into a SEU signature scheme. This second conversion also uses a chameleon commitment scheme but only requires the key only attack security for it.

  18. Azolla as a component of the space diet during habitation on Mars

    Science.gov (United States)

    Katayama, Naomi; Yamashita, Masamichi; Kishida, Yoshiro; Liu, Chung-Chu; Watanabe, Iwao; Wada, Hidenori; Space Agriculture Task Force

    We evaluate a candidate diet and specify its space agricultural requirements for habitation on Mars. Rice, soybean, sweet potato and a green-yellow vegetable have been selected as the basic vegetarian menu. The addition of silkworm pupa, loach, and Azolla to that basic menu was found to meet human nutritional requirements. Co-culture of rice, Azolla, and loach is proposed for developing bio-regenerative life support capability with high efficiency of the usage of habitation and agriculture area. Agriculture designed under the severe constraints of limited materials resources in space would make a positive contribution toward solving the food shortages and environmental problems facing humans on Earth, and may provide an effective sustainable solution for our civilization.

  19. Cine-Club

    CERN Multimedia

    Cine-Club

    2013-01-01

    Thursday 12 September 2013 at 20:00 CERN Council Chamber Raining Stones Directed by Ken Loach (UK, 1993) Original version English; French subtitles; 90 minutes This Ken Loach film tells the story of a man devoted to his family and his religion. Proud, though poor, Bob wants his little girl to have a beautiful and costly brand-new dress for her First Communion. His stubbornness and determination get him into trouble as he turns to more and more questionable measures, in his desperation to raise the needed money. This tragic flaw leads him to risk all that he loves and values, his beloved family, indeed even his immortal soul and salvation, in blind pursuit of that goal. http://cineclub.web.cern.ch/Cineclub/

  20. “Mücadele ve Direnişin” cesur ajanı Ken Loach’un sinemasında insanın “Özgürleşme” sorunu: Psikanalitik yöntemle “Ülke ve Özgürlük” filmi analizi

    OpenAIRE

    Kaplan, Neşe; Kaplan, Ali Barış

    2011-01-01

    Bu çalışmada amacımız, Ken Loach Sinemasının genel özelliklerini ortaya koymak ve spesifik olarak “Ülke ve özgürlük” filmini psikanalitik yöntemle analiz etmektir. Filmlerinde, “Sınıf mücadelesi” ve “bireysel özgürlük” sorununu tartışan Ken Loach, “Ülke ve özgürlük” filmi ile esasen globalleşme süreci içindeki Modern toplumu eleştirmektedir. Yakın geçmişin hikayesini anlatan film, nostaljik değildir; bugüne de mesajı olan dinamik bir anlatı sunar....

  1. Genetic diversity of Misgurnus fossilis populations from the Czech Republic and Slovakia

    Czech Academy of Sciences Publication Activity Database

    Mendel, Jan; Lusk, Stanislav; Koščo, J.; Vetešník, Lukáš; Halačka, Karel; Papoušek, Ivo

    2008-01-01

    Roč. 57, 1-2 (2008), s. 90-99 ISSN 0139-7893. [Loaches of the genus Cobitis and related genera /3./. Šibenik, 24.09.2006-29.09.2006] R&D Projects: GA MŽP SM/6/3/05 Grant - others:IHPP-ARI(XE) HPRI-CT-2001-00180 Institutional research plan: CEZ:AV0Z60930519 Source of funding: R - rámcový projekt EK Keywords : weather loach * control region * microsatellites Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.522, year: 2008 http://www.ivb.cz/folia/57/1-2/090-099_MS1290.pdf

  2. Enobarbus is a synonym of Lepidocephalichthys (Osteichthyes, Cobitidae)

    Czech Academy of Sciences Publication Activity Database

    Harant, R.; Bohlen, Jörg

    2010-01-01

    Roč. 77, č. 10 (2010), s. 2443-2453 ISSN 0022-1112 R&D Projects: GA ČR GA206/05/2556; GA ČR GA206/08/0637; GA AV ČR IAA600450508; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : Chennai * loach * Madras Subject RIV: EG - Zoology Impact factor: 1.330, year: 2010

  3. Role of parasite load and differential habitat preferences in maintaining the coexistence of sexual and asexual competitors in fish of the Cobitis taenia hybrid complex

    Czech Academy of Sciences Publication Activity Database

    Kotusz, J.; Popiolek, M.; Drozd, P.; de Gelas, K.; Šlechtová, V.; Janko, Karel

    2014-01-01

    Roč. 113, č. 1 (2014), s. 220-235 ISSN 0024-4066 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : diploid-polyploid complexes * European distribution * habitat partitioning * niche shift * parasite-mediated coexistence * Red Queen hypothesis * spined loach * unisexuality Subject RIV: EG - Zoology Impact factor: 2.264, year: 2014

  4. The Environmental Assessment and Management (TEAM) Guide: New Mexico Supplement

    Science.gov (United States)

    2010-03-01

    dace, Phoxinus erythrogaster (j) Colorado pikeminnow, Ptychocheilus lucius (k) loach minnow, Tiaroga cobitis 5-13 Natural Resources Management...writing by the Department, off-site at a readily available location. ST.4.38.NM. Corrective actions must be ta ken u pon a release involving a...cause a public nuisance or threat to human health, safety and welfare, or the environment. Verify th at when c ontaminated s oil is ta ken o ff s ite

  5. Bid Responsiveness and the Acceptable Nonconforming Bid.

    Science.gov (United States)

    1979-09-30

    the. fuidaIenta prin ciples of responsiveness. The Conhl trot ler, hnwever, has ta ken this sairn "reasonable- tit’, ’ t. ,t ’’ , T (I I e l iLd i I...cvo rcome otherwise material deviation i f; the bid, thereby renderin gj it a(,ceptable. Tne Comptroller General’s o) p loach to the , i..sue ft

  6. Mehhiko filmikunst toob Cannes'i värskeid tuuli / Annika Koppel

    Index Scriptorium Estoniae

    Koppel, Annika

    2006-01-01

    Cannes'i filmifestival. Nähtud filmidest : soomlase Aki Kaurismäki "Äärelinna tuled" ("Laitakaupungin valot"), hispaanlase Pedro Almodovari "Volver" ("Tagasitulek"), inglase Ken Loach'i "Tuul sasib odrapõldu" ("The Wind that Shakes the Barely"), türklase Nuri Bilge Ceylani "Kliima", itaallase Nanni Moretti "Kaiman" ("The Caiman"), mehhiklase Alejandro Gonzalez Inarritu USA mängufilm Brad Pitt'iga peaosas "Paabel" ("Babel")

  7. Importance of small fishes and invasive crayfish in otter Lutra lutra diet in an English chalk stream

    OpenAIRE

    Britton, J.R.; Berry, M.; Sewell, S.; Lees, C.; Reading, P.

    2017-01-01

    The diet composition of the European otter Lutra lutra was assessed using spraint analysis in the Hampshire Avon, a lowland chalk stream in Southern England, over an 18-month period. Small cyprinid fishes were the main prey item taken in all seasons, with bullhead Cottus gobio and stone loach Barbatula barbatula also important; there were relatively few larger fishes of interest to fisheries found. There were significant seasonal differences in diet composition by season, with signal crayfish...

  8. Examining the Role of Manipulatives and Metacognition on Engagement, Learning, and Transfer

    OpenAIRE

    Belenky, Daniel M.; Nokes, Timothy J.

    2009-01-01

    How does the type of learning material impact what is learned? The current research investigates the nature of students’ learning of math concepts when using manipulatives (Uttal, Scudder, & DeLoache, 1997). We examined how the type of manipulative (concrete, abstract, none) and problem-solving prompt (metacognitive or problem-focused) affect student learning, engagement, and knowledge transfer. Students who were given concrete manipulatives with metacognitive prompts showed better transfer o...

  9. Threatened fishes of the world: Paracobitis vignai Nalbant and Bianco, 1998 (Nemacheilidae

    Directory of Open Access Journals (Sweden)

    Hamed Mousavi-Sabet

    2016-04-01

    Full Text Available Paracobitis vignai is a Nemacheilid loach endemic to the Sistan basin. It occurs in Helmand River and its related reservoirs in Sistan-va-Baluchistan Province in southeastern Iran and probably in Afghanistan. This species is currently endangered due to habitat loss or degradation, damming and droughts. Therefore, this paper reviews the available data on taxonomy and distribution of P. vignai, provides its morphometric features, and recommends actions for its conservation.

  10. Bioturbation/bioirrigation effect on thallium released from reservoir sediment by different organism types.

    Science.gov (United States)

    He, Yi; Men, Bin; Yang, Xiaofang; Wang, Dongsheng

    2015-11-01

    Bioturbation can remobilize heavy metal in the sediments and may pose a risk for aquatic biota. The effects of bioturbation/bioirrigation by three different riverine organism types (Tubificid, Chironomid larvae, and Loach) on thallium release from contaminated sediment (10.0 ± 1.1 mg Tl/kg sediment, dry wt.) were evaluated in this study. The bioturbation by the epibenthos clearly caused an increased turbidity in the overlying water, and the effect was in the order of Loach > Chironomid larvae > Tubificid. A significant release of Tl into the water column via the resuspended sediment particles was observed, especially for Loach. During the first few days, the leaching of dissolved Tl from sediment into water was fast, and the dissolved Tl under bioturbation/bioirrigation was much higher than the control group. However, after 14 days, the bioturbation/bioirrigation process seemed to suppress the release of Tl from the sediment particles to water, especially for sediment with Loach. This may partly be due to the sorption or coprecipitation of Tl simultaneous with the formation of iron and manganese hydrous oxides with increased pH values as a consequence of phytoplankton growth. Linear regression analysis confirmed that both the total and particulate Tl concentrations had good correlations with particulate Fe and Mn concentrations as well as turbidity in the overlying water. Additionally, planktonic bacteria may oxidize the Tl(I) to Tl(III), resulting in a reduced solubility of Tl by which Tl(OH)3 becomes the predominant form of Tl. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. The Behavioral Physiology of Labroid Fishes.

    Science.gov (United States)

    1992-09-01

    Cassoti, John Salsig, Noellette (Sam) Conway, Hagan Schempf, Ken Gartner, Steve Bollens, Tom DiChristina and Eric Zettler are hereby thanked. I would...his wife Amy. Jake and Anna Maria Peirson deserve a special grazie for trying to keep me in line (with mixed success). I also thank Eric Fajer. Debbie...the reproductive period the females become active at night. In the cave-dwelling loach Oreonectus evezardi, a circadian rhythm as well as a

  12. Glühwein ja kivisüsi - uus kuum paar / Margit Tõnson

    Index Scriptorium Estoniae

    Tõnson, Margit, 1978-

    2009-01-01

    Euroopa Filmiakadeemia auhinnad anti seekord üle Saksamaal Bochumis toimunud tseremoonial. Euroopa Filmiakadeemia auhindadest: parima filmiauhinna sai Michael Haneke "Valge pael", mille eest sai ka parima režissööri ja stsenaristi auhinna. Elutööpreemia sai režissöör Ken Loach. Ka teistest võitjatest, Ruhrimaast, režissööridest, kes valnud oma filmide võttepaigaks Ruhri ning tseremooniast

  13. Phylogeny of the Southeast Asian freshwater fish genus Pangio (Cypriniformes, Cobitidae)

    Czech Academy of Sciences Publication Activity Database

    Bohlen, Jörg; Šlechtová, Vendula; Tan, H. H.; Britz, R.

    2011-01-01

    Roč. 61, č. 3 (2011), s. 854-865 ISSN 1055-7903 R&D Projects: GA ČR GA206/05/2556; GA ČR GA206/08/0637; GA AV ČR IAA600450508; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : pangio * eel loaches * phylogeny Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.609, year: 2011

  14. Hybrid asexuality as a primary postzygotic barrier between nascent species: on the interconnection between asexuality, hybridization and speciation

    Czech Academy of Sciences Publication Activity Database

    Janko, K.; Pačes, J.; Wilkinson-Herbots, H.; Costa, R. J.; Roslein, Jan; Drozd, P.; Iakovenko, N.; Rídl, J.; Hroudová, M.; Kočí, J.; Reifová, R.; Šlechtová, V.; Choleva, L.

    2018-01-01

    Roč. 27, č. 1 (2018), s. 248-263 ISSN 0962-1083 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : pairwise nucleotide differences * mitochondrial-dna variation * multilocus genotype data * reproductive isolation * maximum-likelihood * loaches cobitis * migration model * gene flow * phylogenetic constraints * coalescence time * balance hypothesis * coalescence * evolution of asexuality * hybridization * phylogeography * speciation Subject RIV: EG - Zoology Impact factor: 6.086, year: 2016

  15. THREATENED FISHES OF THE WORLD: Paracobitis rhadinaeus (Regan, 1906 (NEMACHEILIDAE

    Directory of Open Access Journals (Sweden)

    Hamed Mousavi-Sabet

    2013-01-01

    Full Text Available Paracobitis rhadinaeus is an endemic Nemacheiline loach in the Sistan basin, southeast Iran. The population is declining probably due to habitat loss or degradation, damming, drought and poaching. Urgent habitat protection with bans on further regulation of the Hamoun wetland and related reservoirs is suggested. Captive breeding of the fish should be initiated. Fishing activities should be forbidden or limited. A detailed study of current population status, biology and ecology of P. rhadinaeus is required.

  16. Indigenous fish species in the modern ichthyofauna of the Balkhash basin

    Directory of Open Access Journals (Sweden)

    Nadir Shamilevich Mamilov

    2015-11-01

    Full Text Available Indigenous fish fauna of the Balkhash basin was mostly formed in the postglacial period and consists of 10 species from Cyprinidae family, 5 from Balitoridae, and 1 from Percidae. More than 20 alien fish species were introduced here during XXth century that led to eradication of indigenous fishes from the Balkhash Lake and the Ili River. Our investigations of the fish fauna during last 25 years revealed permanent shortage of living area of indigenous fishes. Nowadays fish communities from only indigenous fish species exist in some remote and isolated water bodies. Areas of all indigenous fish species are become disconnected. Reduction of habitats goes relatively slow for naked osman Gymnodiptychus dybowskii (Kessler, 1874, spotted thicklip loach Triplophysa strauchii (Kessler, 1874, and gray loach Triplophysa dorsalis (Kessler, 1872. Drastic reductions of areas were revealed for Ili marinka Schizothorax pseudoaksaiensis Herzenstein 1889, Balkhash marinka Schizothorax argentatus Kessler 1874, Severtsov’s loach Triplophysa sewerzowii (G.Nikolskii, 1938, Seven River’s minnow Phoxinus brachyurus Berg 1912, Balkhsh minnow Rhynchocypris poljakowii Kessler 1879, and Balkhash perch Perca schrenkii Kessler 1874. Marinkas, osmans and perch often become victims of overfishing and poaching of local people. In that region water resources usually are used by wasteful way and loaded with pollutants. Many indigenous fish species are able to bear relatively high level of environment pollution. Hence, the main threats for indigenous fishes are introductions of trout and sander, habitats lose and unstable hydrological regimen.

  17. A gente parece um camaleão: (reconstruções identitárias em um grupo de estudantes cabo-verdianos no Rio de Janeiro We look like chameleons: identity (reconstructions in a group of Cape Verdean students in RJ

    Directory of Open Access Journals (Sweden)

    Olivia Nogueira Hirsch

    2009-04-01

    Full Text Available O artigo baseia-se em pesquisa realizada com estudantes provenientes do arquipélago de Cabo Verde, localizado na costa Ocidental da África, que se instalaram no Rio de Janeiro com o objetivo de obter uma formação de nível superior. A investigação, que resultou em uma dissertação de mestrado, busca compreender os processos de (reconstrução identitária vividos por esses jovens, muitos dos quais identificados como negros e africanos pelos brasileiros. Com vistas a contextualizar o impacto desse olhar externo sobre esses estudantes, o artigo apresenta a forma como, ao longo da história, a elite intelectual do arquipélago construiu um discurso que atribui à mestiçagem a especificidade da identidade nacional. Ainda que influenciado pelas idéias de Gilberto Freyre, tal discurso, no entanto, visava a um distanciamento da herança negra estigmatizada, diferentemente da proposta de Freyre de valorização dos não-brancos. Levando em conta esse histórico, a investigação aponta como o contato com a sociedade brasileira atual, possibilitado pela experiência de estudo, favoreceu a construção de um olhar mais crítico em relação a esse discurso, ao mesmo tempo que houve uma ênfase na valorização de uma identidade afro-referenciada. Tal processo, entre outros motivos, aparentemente encontra relação com a implementação de políticas de identidade no Rio de Janeiro, estado que abriga a primeira universidade do país a adotar reserva de vagas para negros.The paper is based on a research developed with students from the archipelago of Cape Verde, situated in the west coast of Africa. These students moved to Rio de Janeiro in order to get a college degree. The investigation, which resulted in a master's dissertation, focuses on the identity (reconstruction processes experienced by those youngsters, most of whom identified by Brazilians as Blacks and Africans. In an attempt to contextualize the impact of this external categorization over these students, the paper shows how, historically, the Cape Verdean intellectual elite has constructed a speech that considers miscegenation as a national identity specificity. Even though being influenced by Gilberto Freyre's ideas, this speech was intended to dissociate the Cape Verdeans from a stigmatized Black heritage, in opposition to Freyre's intention to valorize non-whites. Considering this background, the research suggests that the contact with the current Brazilian society, made possible by the study experience, helped them to develop a more critical view regarding this speech, which occurred simultaneously to the valorization of an African identity. For this and other reasons, this process is apparently relatedto the implementation of identity policies in Rio de Janeiro, the first Brazilian state with a university establishing quotas for Black students.

  18. Os “camaleões” e a história da ditadura militar: a memória sobre a militância arenista de Dercy = The "chameleons" and the history of military dictatorship: the memory of the militancy arena party of Dercy Furtado

    Directory of Open Access Journals (Sweden)

    Chaves, Eduardo dos Santos

    2016-01-01

    Full Text Available O artigo pretende discutir a memória construída pós-ditadura militar por políticos gaúchos da extinta Aliança Renovadora Nacional (ARENA. O texto pretende discorrer sobre a trajetória política de Dercy Furtado, ex-vereadora e deputada estadual pela ARENA gaúcha entre 1972 e 1979, a partir de um conjunto de memórias elaboradas por ela após o final da ditadura brasileira. A proposta é verificar como e por que Furtado reconstruiu distante de quaisquer cumplicidades com o "regime dos militares", descrevendo sua carreira parlamentar voltada para a defesa de ideais democráticos e de esquerda. Dessa forma, busco entender a historicidade dessas narrativas, suas permanências, mudanças, omissões, seleções e esquecimentos

  19. Some loopholes to save quantum nonlocality

    Science.gov (United States)

    Accardi, Luigi

    2005-02-01

    The EPR-chameleon experiment has closed a long standing debate between the supporters of quantum nonlocality and the thesis of quantum probability according to which the essence of the quantum pecularity is non Kolmogorovianity rather than non locality. The theory of adaptive systems (symbolized by the chameleon effect) provides a natural intuition for the emergence of non-Kolmogorovian statistics from classical deterministic dynamical systems. These developments are quickly reviewed and in conclusion some comments are introduced on recent attempts to "reconstruct history" on the lines described by Orwell in "1984".

  20. GammeV: Search for WISPs at Fermilab

    International Nuclear Information System (INIS)

    Wester, William

    2010-01-01

    The GammeV experiment has searched for Weakly Interacting Slim Particles (WISPs) and has previously published exclusion plots for axion-like particles and a first exclusion of chameleons that couple to photons. Recently, a new experiment, GammeV-CHASE, has obtained improved preliminary results in the search for chameleons. Members of the collaboration are also involved in R and D in long baseline optical cavities that might be required for a photon resonnant regeneration experiment or a search for holographic noise.