Pub Date : 2014-04-28DOI: 10.14293/S2199-1006.1.SOR-MATH.A6G464.V1
P. Davis
There are many paradoxes associated with the concept of infinity. I would like to set forth and comment on one which, though well-known in principle, I have not seen stated in the following form.
{"title":"The Relevance of the Irrelevant Beginning","authors":"P. Davis","doi":"10.14293/S2199-1006.1.SOR-MATH.A6G464.V1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-MATH.A6G464.V1","url":null,"abstract":"There are many paradoxes associated with the concept of infinity. I would like to set forth and comment on one which, though well-known in principle, I have not seen stated in the following form.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84541225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-28DOI: 10.14293/A2199-1006.01.SOR-ASTRO.WXWIL.v1
M. Efroimsky
{"title":"Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system","authors":"M. Efroimsky","doi":"10.14293/A2199-1006.01.SOR-ASTRO.WXWIL.v1","DOIUrl":"https://doi.org/10.14293/A2199-1006.01.SOR-ASTRO.WXWIL.v1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79979487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-28DOI: 10.14293/A2199-1006.01.SOR-MATH.6G464.V1
Sebastian Lutz
{"title":"The Relevance of the Irrelevant Beginning","authors":"Sebastian Lutz","doi":"10.14293/A2199-1006.01.SOR-MATH.6G464.V1","DOIUrl":"https://doi.org/10.14293/A2199-1006.01.SOR-MATH.6G464.V1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"112 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75031561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-28DOI: 10.14293/A2199-1006.01.SOR-LIFE.67837.V1
Claudia Chica
{"title":"FASTA Herder: a web application to trim protein sequence sets","authors":"Claudia Chica","doi":"10.14293/A2199-1006.01.SOR-LIFE.67837.V1","DOIUrl":"https://doi.org/10.14293/A2199-1006.01.SOR-LIFE.67837.V1","url":null,"abstract":"","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82464338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-16DOI: 10.14293/S2199-1006.1.SOR-PHYS.A2CEM4.v1
J. M. Zhang, M. Haque
We point out that in the first order time-dependent perturbation theory, the transition probability may behave nonsmoothly in time and have kinks periodically. Moreover, the detailed temporal evolution can be sensitive to the exact locations of the eigenvalues in the continuum spectrum, in contrast to coarse-graining ideas. Underlying this nonsmooth and level-resolved dynamics is a simple equality about the sinc function $sinc x equiv sin x / x$. These physical effects appear in many systems with approximately equally spaced spectra, and is also robust for larger-amplitude coupling beyond the domain of perturbation theory. We use a one-dimensional periodically driven tight-binding model to illustrate these effects, both within and outside the perturbative regime.
我们指出在一阶时变微扰理论中，跃迁概率在时间上可能表现为非光滑的，并且具有周期性的扭结。此外，与粗粒度思想相比，详细的时间演变可以对连续谱中特征值的精确位置敏感。在这种非光滑和水平分辨动态的基础上是关于sinc函数$sinc x equiv sin x / x$的一个简单等式。这些物理效应出现在许多具有近似等间隔光谱的系统中，并且对于超出摄动理论范围的较大振幅耦合也具有鲁棒性。我们使用一维周期性驱动的紧密结合模型来说明这些影响，无论是在扰动状态内还是在扰动状态外。
{"title":"Nonsmooth and level-resolved dynamics illustrated with a periodically driven tight binding model","authors":"J. M. Zhang, M. Haque","doi":"10.14293/S2199-1006.1.SOR-PHYS.A2CEM4.v1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-PHYS.A2CEM4.v1","url":null,"abstract":"We point out that in the first order time-dependent perturbation theory, the transition probability may behave nonsmoothly in time and have kinks periodically. Moreover, the detailed temporal evolution can be sensitive to the exact locations of the eigenvalues in the continuum spectrum, in contrast to coarse-graining ideas. Underlying this nonsmooth and level-resolved dynamics is a simple equality about the sinc function $sinc x equiv sin x / x$. These physical effects appear in many systems with approximately equally spaced spectra, and is also robust for larger-amplitude coupling beyond the domain of perturbation theory. We use a one-dimensional periodically driven tight-binding model to illustrate these effects, both within and outside the perturbative regime.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86584607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-04-16DOI: 10.14293/S2199-1006.1.SOR-PHYS.A2CEM4.V2
M. Haque, J. M. Zhang
We point out that in the first order time-dependent perturbation theory, the transition probability may behave nonsmoothly in time and have kinks periodically. Moreover, the detailed temporal evolution can be sensitive to the exact locations of the eigenvalues in the continuum spectrum, in contrast to coarse-graining ideas. Underlying this nonsmooth and level-resolved dynamics is a simple equality about the sinc function $sinc x equiv sin x / x$. These physical effects appear in many systems with approximately equally spaced spectra, and is also robust for larger-amplitude coupling beyond the domain of perturbation theory. We use a one-dimensional periodically driven tight-binding model to illustrate these effects, both within and outside the perturbative regime.
我们指出在一阶时变微扰理论中，跃迁概率在时间上可能表现为非光滑的，并且具有周期性的扭结。此外，与粗粒度思想相比，详细的时间演变可以对连续谱中特征值的精确位置敏感。在这种非光滑和水平分辨动态的基础上是关于sinc函数$sinc x equiv sin x / x$的一个简单等式。这些物理效应出现在许多具有近似等间隔光谱的系统中，并且对于超出摄动理论范围的较大振幅耦合也具有鲁棒性。我们使用一维周期性驱动的紧密结合模型来说明这些影响，无论是在扰动状态内还是在扰动状态外。
{"title":"Nonsmooth and level-resolved dynamics illustrated with a periodically driven tight-binding model","authors":"M. Haque, J. M. Zhang","doi":"10.14293/S2199-1006.1.SOR-PHYS.A2CEM4.V2","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-PHYS.A2CEM4.V2","url":null,"abstract":"We point out that in the first order time-dependent perturbation theory, the transition probability may behave nonsmoothly in time and have kinks periodically. Moreover, the detailed temporal evolution can be sensitive to the exact locations of the eigenvalues in the continuum spectrum, in contrast to coarse-graining ideas. Underlying this nonsmooth and level-resolved dynamics is a simple equality about the sinc function $sinc x equiv sin x / x$. These physical effects appear in many systems with approximately equally spaced spectra, and is also \u0000robust for larger-amplitude coupling beyond the domain of perturbation theory. \u0000We use a one-dimensional periodically driven tight-binding model to illustrate these effects, both within and outside the perturbative regime.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88582315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.14293/S2199-1006.1.SORLIFE.AEEERM.v1
Sari Paavilainen, Guido Guidotti
Rat CD39, a membrane-bound ectonucleoside triphosphate diphosphohydrolase that hydrolyzes extracellular nucleoside tri- and diphosphates, is anchored to the membrane by two transmembrane domains at the two ends of the molecule. The transmembrane domains are important for enzymatic activity, as mutants lacking one or both of these domains have a fraction of the enzymatic activity of the wild-type CD39. We investigated the interactions between the transmembrane domains by using a strain of yeast that requires surface expression of CD39 for growth. Random mutagenesis of selected amino acid residues in the N-terminal transmembrane domain revealed that the presence of charged amino acids at these positions prevents expression of functional protein. Rescue of the growth of these mutants by complementary mutations on selected residues of the C-terminal transmembrane domain indicates that there is contact between particular faces of the transmembrane domains.
{"title":"Interactions between the transmembrane domains of CD39: identification of interacting residues by yeast selection.","authors":"Sari Paavilainen, Guido Guidotti","doi":"10.14293/S2199-1006.1.SORLIFE.AEEERM.v1","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SORLIFE.AEEERM.v1","url":null,"abstract":"<p><p>Rat CD39, a membrane-bound ectonucleoside triphosphate diphosphohydrolase that hydrolyzes extracellular nucleoside tri- and diphosphates, is anchored to the membrane by two transmembrane domains at the two ends of the molecule. The transmembrane domains are important for enzymatic activity, as mutants lacking one or both of these domains have a fraction of the enzymatic activity of the wild-type CD39. We investigated the interactions between the transmembrane domains by using a strain of yeast that requires surface expression of CD39 for growth. Random mutagenesis of selected amino acid residues in the N-terminal transmembrane domain revealed that the presence of charged amino acids at these positions prevents expression of functional protein. Rescue of the growth of these mutants by complementary mutations on selected residues of the C-terminal transmembrane domain indicates that there is contact between particular faces of the transmembrane domains.</p>","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"2014 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4526264/pdf/nihms708019.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33975977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-26DOI: 10.14293/S2199-1006.1.SOR-ASTRO.AWXWIL.v2
L. Iorio
We analytically compute the long-term orbital variations of a test particle orbiting a central body acted upon by an incident monochromatic plane gravitational wave. We assume that the characteristic size of the perturbed two-body system is much smaller than the wavelength of the wave. Moreover, we also suppose that the wave’s frequency ng is much smaller than the particle’s orbital one nb. We make neither a priori assumptions about the direction of the wavevector b nor on the orbital configuration of the particle. While the semi-major axis a is left unaffected, the eccentricity e, the inclination I, the longitude of the ascending node Ω, the longitude of pericenter ϖ and the mean anomaly M undergo non-vanishing long-term changes of the form dW=dt ¼ FðKij;e;I;X;xÞ;W ¼ e;I;X;-; M, where Kij; i;j ¼ 1;2;3 are the coefficients of the tidal matrix K. Thus, in addition to the variations of its orientation in space, the shape of the orbit would be altered as well. Strictly speaking, such effects are not secular trends because of the slow modulation introduced by K and by the orbital elements themselves: they exhibit peculiar long-term temporal patterns which would be potentially of help for their detection in multidecadal analyses of extended data records of planetary observations of various kinds. In particular, they could be useful in performing independent tests of the inflation-driven ultra-low gravitational waves whose imprint may have been indirectly detected in the Cosmic Microwave Background by the Earthbased experiment BICEP2. Our calculation holds, in general, for any gravitationally bound two-body system whose orbital frequency nb is much larger than the frequency ng of the external wave, like, e.g., extrasolar planets and the stars orbiting the Galactic black hole. It is also valid for a generic perturbation of tidal type with constant coefficients over timescales of the order of the orbital period of the perturbed particle.
{"title":"Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system","authors":"L. Iorio","doi":"10.14293/S2199-1006.1.SOR-ASTRO.AWXWIL.v2","DOIUrl":"https://doi.org/10.14293/S2199-1006.1.SOR-ASTRO.AWXWIL.v2","url":null,"abstract":"We analytically compute the long-term orbital variations of a test particle orbiting a central body acted upon by an incident monochromatic plane gravitational wave. We assume that the characteristic size of the perturbed two-body system is much smaller than the wavelength of the wave. Moreover, we also suppose that the wave’s frequency ng is much smaller than the particle’s orbital one nb. We make neither a priori assumptions about the direction of the wavevector b nor on the orbital configuration of the particle. While the semi-major axis a is left unaffected, the eccentricity e, the inclination I, the longitude of the ascending node Ω, the longitude of pericenter ϖ and the mean anomaly M undergo non-vanishing long-term changes of the form dW=dt ¼ FðKij;e;I;X;xÞ;W ¼ e;I;X;-; M, where Kij; i;j ¼ 1;2;3 are the coefficients of the tidal matrix K. Thus, in addition to the variations of its orientation in space, the shape of the orbit would be altered as well. Strictly speaking, such effects are not secular trends because of the slow modulation introduced by K and by the orbital elements themselves: they exhibit peculiar long-term temporal patterns which would be potentially of help for their detection in multidecadal analyses of extended data records of planetary observations of various kinds. In particular, they could be useful in performing independent tests of the inflation-driven ultra-low gravitational waves whose imprint may have been indirectly detected in the Cosmic Microwave Background by the Earthbased experiment BICEP2. Our calculation holds, in general, for any gravitationally bound two-body system whose orbital frequency nb is much larger than the frequency ng of the external wave, like, e.g., extrasolar planets and the stars orbiting the Galactic black hole. It is also valid for a generic perturbation of tidal type with constant coefficients over timescales of the order of the orbital period of the perturbed particle.","PeriodicalId":91169,"journal":{"name":"ScienceOpen research","volume":"13 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80678734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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