There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

SciPy is an open source scientific computing library for the Python programming language. SciPy 1.0 was released in late 2017, about 16 years after the original version 0.1 release. SciPy has become a de facto standard for leveraging scientific algorithms in the Python programming language, with more than 600 unique code contributors, thousands of dependent packages, over 100,000 dependent repositories, and millions of downloads per year. This includes usage of SciPy in almost half of all machine learning projects on GitHub, and usage by high profile projects including LIGO gravitational wave analysis and creation of the first-ever image of a black hole (M87). The library includes functionality spanning clustering, Fourier transforms, integration, interpolation, file I/O, linear algebra, image processing, orthogonal distance regression, minimization algorithms, signal processing, sparse matrix handling, computational geometry, and statistics. In this work, we provide an overview of the capabilities and development practices of the SciPy library and highlight some recent technical developments.

/pdf/scipy-1-0-fundamental-algorithms-for-scientific-computing-in-111lr790ol.pdf

SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python

The combination of seven-year data from WMAP and improved astrophysical data rigorously tests the standard cosmological model and places new constraints on its basic parameters and extensions. By combining the WMAP data with the latest distance measurements from the baryon acoustic oscillations (BAO) in the distribution of galaxies and the Hubble constant (H0) measurement, we determine the parameters of the simplest six-parameter ΛCDM model. The power-law index of the primordial power spectrum is ns = 0.968 ± 0.012 (68% CL) for this data combination, a measurement that excludes the Harrison–Zel’dovich–Peebles spectrum by 99.5% CL. The other parameters, including those beyond the minimal set, are also consistent with, and improved from, the five-year results. We find no convincing deviations from the minimal model. The seven-year temperature power spectrum gives a better determination of the third acoustic peak, which results in a better determination of the redshift of the matter-radiation equality epoch. Notable examples of improved parameters are the total mass of neutrinos, � mν < 0.58 eV (95% CL), and the effective number of neutrino species, Neff = 4.34 +0.86 −0.88 (68% CL), which benefit from better determinations of the third peak and H0. The limit on a constant dark energy equation of state parameter from WMAP+BAO+H0, without high-redshift Type Ia supernovae, is w =− 1.10 ± 0.14 (68% CL). We detect the effect of primordial helium on the temperature power spectrum and provide a new test of big bang nucleosynthesis by measuring Yp = 0.326 ± 0.075 (68% CL). We detect, and show on the map for the first time, the tangential and radial polarization patterns around hot and cold spots of temperature fluctuations, an important test of physical processes at z = 1090 and the dominance of adiabatic scalar fluctuations. The seven-year polarization data have significantly improved: we now detect the temperature–E-mode polarization cross power spectrum at 21σ , compared with 13σ from the five-year data. With the seven-year temperature–B-mode cross power spectrum, the limit on a rotation of the polarization plane due to potential parity-violating effects has improved by 38% to Δα =− 1. 1 ± 1. 4(statistical) ± 1. 5(systematic) (68% CL). We report significant detections of the Sunyaev–Zel’dovich (SZ) effect at the locations of known clusters of galaxies. The measured SZ signal agrees well with the expected signal from the X-ray data on a cluster-by-cluster basis. However, it is a factor of 0.5–0.7 times the predictions from “universal profile” of Arnaud et al., analytical models, and hydrodynamical simulations. We find, for the first time in the SZ effect, a significant difference between the cooling-flow and non-cooling-flow clusters (or relaxed and non-relaxed clusters), which can explain some of the discrepancy. This lower amplitude is consistent with the lower-than-theoretically expected SZ power spectrum recently measured by the South Pole Telescope Collaboration.

/pdf/seven-year-wilkinson-microwave-anisotropy-probe-wmap-19dgu0rhy7.pdf

Seven-year wilkinson microwave anisotropy probe (wmap *) observations: cosmological interpretation

https://pure.mpg.de/pubman/item/item_52318_3/component/file_52319/AdSpR_32_1263.pdf

Position determination of gravitational wave sources with LISA

Summary form only given. We study the optical properties of negative dispersive but nevertheless transparent media. Such medium can be generated using atomic phase coherence. Theoretical studies have shown that strongly driven two level systems may exhibit the desired optical properties, that is negative dispersion of a well defined amount at a point of vanishing absorption. When this medium is placed inside an optical resonator the linewidth is increased without sacrificing its build up. We present the experimental setup which is used to realize a negative dispersive non-absorbing medium. To obtain a strongly driven two level system a calcium atomic beam is pumped at the transition 4s/sup 21/S/sub 0//spl rarr/4s4p/sup 1/P/sub 1/. The optical properties of the beam are studied.

Negative dispersion without absorption

http://ieeexplore.ieee.org/iel4/5799/15473/00714903.pdf

Correlation of frequency, amplitude, and beam-geometry noise of monolithic diode-pumped non-planar ringlasers (NPRO)

Summary form only given. The field of atom manipulation using laser light has experienced a rapid growth in the recent years. By the interaction of the atoms with laser light it is possible to design media with desired optical properties such as transparent media showing negative or positive dispersion. Negative dispersive transparent media can be used e.g. to realize an optical cavity with large build up but broadband response (white light cavity) or to demonstrate superluminal light propagation. It has also been demonstrated that positive dispersive media can exhibit steep dispersion leading to small absolute values of the group velocity (slow light, see e.g.) or reducing e.g. the line width of a cavity relative to the line width of the empty resonator.We report on recent experiments on investigation the absorptive and dispersive properties of a coherent prepared media, that shows electromagnetically induced transparency on extremely narrow dark resonances. We have carried out the experimental study of a two-photon excitation via quantum interference in a three level Cs atomic system. The experiments were done on a Cs atomic beam.

Parametric phase shift in electromagnetically induced transparencies

Reliable and efficient algorithms are needed to model complex mechanical systems such as multiple stage pendulum suspensions. A possible approach is the one based on the input–output formalism. This method allows us to model the system in a modular way. The basic objects (which are the individual stages) are modelled via matrices and then simply joined together through matrix multiplication. It is currently not widely used because it is known to be unstable. Some interesting results towards the stabilization of such algorithm are reported.

/pdf/an-algorithm-to-compute-the-transfer-function-of-a-5cgajprd2a.pdf

Karsten Danzmann

Papers

Position determination of gravitational wave sources with LISA

Negative dispersion without absorption

Correlation of frequency, amplitude, and beam-geometry noise of monolithic diode-pumped non-planar ringlasers (NPRO)

Parametric phase shift in electromagnetically induced transparencies

An algorithm to compute the transfer function of a mechanical system