4,706 research outputs found
On the separable quotient problem for Banach spaces
While the classic separable quotient problem remains open, we survey general
results related to this problem and examine the existence of a particular
infinitedimensional separable quotient in some Banach spaces of vector-valued
functions, linear operators and vector measures. Most of the results presented
are consequence of known facts, some of them relative to the presence of
complemented copies of the classic sequence spaces c_0 and l_p, for 1 <= p <=
\infty. Also recent results of Argyros - Dodos - Kanellopoulos, and Sliwa are
provided. This makes our presentation supplementary to a previous survey (1997)
due to Mujica
Extreme CO Isotopic Abundances in the ULIRG IRAS 13120-5453: An Extremely Young Starburst or Top-Heavy Initial Mass Function
We present ALMA CO (J=1-0, 3-2 and 6-5), CO (J=1-0) and
CO (J=1-0) observations of the local Ultra Luminous Infrared Galaxy,
IRAS 13120-5453 (dubbed "The Yo-yo"). The morphologies of the three isotopic
species differ, where CO shows a hole in emission towards the center. We
measure integrated brightness temperature line ratios of CO/CO
60 (exceeding 200) and CO/CO 1 in the central
region. Assuming optical thin emission, CO is more abundant than
CO in several regions. The abundances within the central 500 pc are
consistent with enrichment of the ISM via a young starburst (7Myr), a
top-heavy initial mass function or a combination of both.Comment: 7 pages, 3 figures, accepted for publication in ApJ
Cubic anisotropy in high homogeneity thin (Ga,Mn)As layers
Historically, comprehensive studies of dilute ferromagnetic semiconductors,
e.g., -type (Cd,Mn)Te and (Ga,Mn)As, paved the way for a quantitative
theoretical description of effects associated with spin-orbit interactions in
solids, such as crystalline magnetic anisotropy. In particular, the theory was
successful in explaining {\em uniaxial} magnetic anisotropies associated with
biaxial strain and non-random formation of magnetic dimers in epitaxial
(Ga,Mn)As layers. However, the situation appears much less settled in the case
of the {\em cubic} term: the theory predicts switchings of the easy axis
between in-plane and directions as a
function of the hole concentration, whereas only the
orientation has been found experimentally. Here, we report on the observation
of such switchings by magnetization and ferromagnetic resonance studies on a
series of high-crystalline quality (Ga,Mn)As films. We describe our findings by
the mean-field - Zener model augmented with three new ingredients. The
first one is a scattering broadening of the hole density of states, which
reduces significantly the amplitude of the alternating carrier-induced
contribution. This opens the way for the two other ingredients, namely the
so-far disregarded single-ion magnetic anisotropy and disorder-driven
non-uniformities of the carrier density, both favoring the
direction of the apparent easy axis. However, according to our results, when
the disorder gets reduced a switching to the orientation
is possible in a certain temperature and hole concentration range.Comment: 12 pages, 9 figure
Pregnancy and cardiac disease
PKMedical disorders in pregnancy are one of the top five causes of maternal mortality in South Africa (SA), cardiac disease (CD) being the main contributor to this group. In developed countries, surgically corrected congenital heart disease (CHD) comprises the greater
proportion of maternal deaths from CD. In SA and other developing countries, acquired heart disease such as rheumatic heart disease and cardiomyopathies are the major causes, although CHD remains significantly represented. Both congenital and acquired cardiac lesions may present for the first time during pregnancy. CD may also occur for the first time during or after pregnancy, e.g. peripartum cardiomyopathy. The risk to both the mother and the fetus increases exponentially with the complexity of the underlying disease. Generally, the ability to tolerate a pregnancy is related to: (i) the haemodynamic significance of any lesion; (ii) the functional class – New York Heart Association classes III and IV have poorer outcomes; (iii) the presence of cyanosis; and (iv) the presence of pulmonary hypertension. While the ideal time to assess these factors is before conception, women frequently present when already pregnant. This review discusses risk assessment and management of CD in pregnant women and the role of a combined cardiology and
obstetric clinic
Throwing shoes...
What is the structure of the social? If we accept organismic metaphors, the social is analogous to the body, usually the human body. The foot/shoe is the most basic foundation, the ground upon which the rest of the socialbody rests. By standing on two feet, the hands are freed to become tool making and using appendages, and the mouth is thereby freed from carrying to bear words instead. In structural terms, the foot/shoe functions as base to the face?s superstructure. But when a shoe is thrown at the face of power, a double inversion comes into play. On the one hand, the base rises up to strike directly at the superstructure and to challenge materially the basis of its legitimacy. On the other hand, the most basic sign of development and civilization ? the shoe ? is removed from the bare foot. As well as turning the foot?s prosthesis into a projectile weapon, this move symbolically reaffirms the body against a becoming-face or a becoming-technology. This moment of unshod insubordination asserts a basic, naked, human dignity in the face of dehumanization. These themes of insubordination and rehumanization, structure and ideology, run through the various contributions to this issue of ephemer
- …