128 research outputs found
Women in modern economic society: demographic and geographic images and realities
With the approach of the Fourth World Conference on Women
in Beijing, it is appropriate for scholars to reflect on the status of
women in modern society, on the changes that ha ve occurred in
that status, and on the plans for future changes
Sterically restricted tin phosphines, stabilized by weak intramolecular donor-acceptor interactions
Funding: Engineering and Physical Sciences Research Council (EPSRC)Four related sterically restricted pen-substituted acenaphthenes have been prepared containing mixed tin phosphorus moieties in the proximal 5,6-positions (Acenap[SnR3][(PPr2)-Pr-i]; Acenap = acenaphthene-5,6-diyl; R-3 = Ph-3 (1), Ph2Cl (2), Me2Cl (3), Bu2Cl (4)). The degree of intramolecular P-Sn bonding within the series was investigated by X-ray crystallography, solution and solid-state NMR spectroscopy, and density functional theory (DFT/B3LYP/SBKJC/PCM) calculations. All members of the series adopt a conformation such that the phosphorus lone pair is located directly opposite the tin center, promoting an intramolecular donor acceptor P -> Sn type interaction. The extent of covalent bonding between Sn and P is found to be much greater in triorganotin chlorides 2-4 in comparison with the triphenyl derivative 1. Coordination of a highly electronegative chlorine atom naturally increases the Lewis acidity of the tin center, enhancing the Ip(P)-sigma*(Sn-Y) donor acceptor 3c-4e type interaction, as indicated by conspicuously short Sn-P peri distances and significant (1)J(P-31,Sn-119) spin spin coupling constants (SSCCs) in the range 740-754 Hz. Evidence supporting the presence of this interaction was also found in solid-state NMR spectra of some of the compounds which exhibit an indirect spin spin coupling on the same order of magnitude as observed in solution. DFT calculations confirm the increased covalent bonding between P and Sn in 2-4, with notable WBIs of ca. 0.35 obtained, in comparison to 0.1 in 1.PostprintPeer reviewe
Anatomical relations of the superficial sensory branches of the radial nerve: a cadaveric study with clinical implications
Speckle-pattern visibility of light transmitted through a multimode optical fiber
We show that the reduction in visibility of the speckle pattern obtained from laser light that has been passed through a step-index light guide can be found from a knowledge of the model dispersion of the guide, and the bandwidth of the laser beam
The Bio-Politics of Population Control and Sex Selective Abortion in China and India
China and India, two countries with skewed sex ratios in favor of males, have introduced a wide range of policies over the past few decades to prevent couples from deselecting daughters, including criminalizing sex-selective abortion through legal jurisdiction. This article aims to analyze how such policies are situated within the bio-politics of population control and how some of the outcomes reflect each governmentâs inadequacy in addressing the social dynamics around abortion decision making and the social, physical, and psychological effects on womenâs wellbeing in the face of criminalization of sex-selective abortion. The analysis finds that overall, the criminalization of sex selection has not been successful in these two countries. Further, the broader economic, social, and cultural dynamics which produce bias against females must be a part of the strategy to combat sex selection, rather than a narrow criminalization of abortion which endangers womenâs access to safe reproductive health services and their social, physical, and psychological wellbeing
A deep wide survey of faint low surface brightness galaxies in the direction of the Coma cluster of galaxies
We report on a search for faint (R total magnitude fainter than 21) and low
surface brightness galaxies (R central surface brightness fainter than ~24)
(fLSBs) in a 0.72x0.82 deg2 area centered on the Coma cluster. We analyzed deep
B and R band CCD imaging obtained using the CFH12K camera at CFHT and found 735
fLSBs. The total B magnitudes, at the Coma cluster redshift, range from -13 to
-9 with B central surface brightness as faint as 27 mag/arcsec2. Using empty
field comparisons, we show that most of these fLSBs are probably inside the
Coma cluster. We present the results of comparing the projected fLSB
distributions with the distributions of normal galaxies and with known X-ray
over densities. We also investigate their projected distribution relative to
their location in the color magnitude relation. Colors of fLSBs vary between
B-R~0.8 and ~1.4 for 2/3 of the sample and this part is consistent with the
known CMR red-sequence for bright (R<18) ellipticals in Coma. These fLSBs are
likely to have followed the same evolution as giant ellipticals, which is
consistent with a simple feedback/collapse formation and a passive evolution.
These fLSBs are mainly clustered around NGC4889. We found two other distinct
fLSB populations. These populations have respectively redder and bluer colors
compared to the giant elliptical red-sequence and possibly formed from stripped
faint ellipticals and material stripped from spiral in-falling galaxies.Comment: To be published in A&A, 3 jpeg figures, data and full resolution
article can be retrieved from http://cencosw.oamp.fr/. Updated CFHT
ackowledgement
Shapes and Alignments of Galaxy Cluster Halos
We present distribution functions and spatial correlations of the shapes of
dark matter halos derived from Hubble Volume simulations of a LambdaCDM
universe. We measure both position and velocity shapes within spheres
encompassing mean density 200 times the critical value, and calibrate small-N
systematic errors using Poisson realizations of isothermal spheres and higher
resolution simulations. For halos more massive than 3x10^{14} Msun/h, the shape
distribution function peaks at (minor/major, intermediate/major) axial ratios
of (0.64,0.76) in position, and is rounder in velocity, peaking at (0.72,0.82).
Halo shapes are rounder at lower mass and/or redshift; the mean minor axis
ratio in position follows (M,z) = c_{15,0} [1-\alpha\ln(M/10^{15}Msun/h)]
(1+z)^{-\epsilon}, with c_{15,0}=0.631 \pm 0.001, \alpha=0.023 \pm 0.002 and
\epsilon=0.086 \pm 0.004. Position and velocity principal axes are well aligned
in direction, with median alignment angle , and the axial ratios in
these spaces are correlated in magnitude. We investigate mark correlations of
halo pair orientations using two measures: a simple scalar product shows alignment extending to 30 \hinv \mpc while a filamentary statistic
exhibits non-random alignment extending to scales \sims 200 \hinv \mpc, ten
times the sample two-point correlation length and well into the regime of
negative two-point correlation. Cluster shapes are unaffected by the
large-scale environment; the shape distribution of supercluster members is
consistent with that of the general population.Comment: 12 pages, 8 figures, submitted to Ap
How Malthusian Ideology crept into the Newsroom: British tabloids and the coverage of the âunderclassâ
This article argues that Malthusianism as a series of discursive regimes, developed in the Victorian-era, serves in times of austerity to reproduce an elite understanding of social exclusion in which those in a state of poverty are to blame for their own situation. It highlights that Malthusianism is present in the public discourse, becoming an underlining feature in news coverage of the so-called âunderclassâ. Our findings broadly contradict the normative claim that journalism âspeaks truth to powerâ, and suggest instead that overall as a political practice, journalism tends to reproduce and reinforce hegemonic discourses of power. The piece is based on critical discourse analysis (CDA), which has been applied to a significant sample of news articles published by tabloid newspapers in Britain which focussed on the concept of the âunderclassâ. By looking at the evidence, the authors argue that the âunderclassâ is a concept used by some journalists to cast people living in poverty as âundeservingâ of public and state support. In so doing, these journalists help create a narrative which supports cuts in welfare provisions and additional punitive measures against some of the most vulnerable members of society
Hidden knowing of working-class transnational Mexican families in schools: bridge-building, Nepantlera knowers
On the spin distributions of CDM haloes
We used merger trees realizations, predicted by the extended Press-Schechter
theory, in order to study the growth of angular momentum of dark matter haloes.
Our results showed that: 1) The spin parameter resulting from the
above method, is an increasing function of the present day mass of the halo.
The mean value of varies from 0.0343 to 0.0484 for haloes with
present day masses in the range of to
. 2)The distribution of is close to
a log-normal, but, as it is already found in the results of N-body simulations,
the match is not satisfactory at the tails of the distribution. A new
analytical formula that approximates the results much more satisfactorily is
presented. 3) The distribution of the values of depends only weakly
on the redshift. 4) The spin parameter of an halo depends on the number of
recent major mergers. Specifically the spin parameter is an increasing function
of this number.Comment: 10 pages, 8 figure
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