3,458 research outputs found
Too poor to live? A case study of vulnerability and maternal mortality in Burkina Faso.
This paper examines the concept of vulnerability in the context of maternal morbidity and mortality in Burkina Faso, an impoverished country in West Africa. Drawing on a longitudinal cohort study into the consequences of life-threatening or 'near miss' obstetric complications, we provide an in-depth case study of one woman's experience of such morbidity and its aftermath. We follow Kalizeta's trajectory from her near miss and the stillbirth of her child to her death from pregnancy-related hypertension after a subsequent delivery less than two years later, in order to examine the impact of severe and persistent illness and catastrophic health expenditure on her health and on her family's everyday life. Kalizeta's case illustrates how vulnerability in health emerges and is maintained or exacerbated over time. Even where social arrangements are supportive, structural impediments, including unaffordable and inadequate healthcare, can severely limit individual resilience to mitigate the negative social and economic consequences of ill health
Collimated fast electron beam generation in critical density plasma
Significantly collimated fast electron beam with a divergence angle 10° (FWHM) is observed when an ultra-intense laser pulse (Iâ=â1014âW/cm2, 300 fs) irradiates a uniform critical density plasma. The uniform plasma is created through the ionization of an ultra-low density (5âmg/c.c.) plastic foam by X-ray burst from the interaction of intense laser (Iâ=â1014âW/cm2, 600 ps) with a thin Cu foil. 2D Particle-In-Cell (PIC) simulation well reproduces the collimated electron beam with a strong magnetic field in the region of the laser pulse propagation. To understand the physical mechanism of the collimation, we calculate energetic electron motion in the magnetic field obtained from the 2D PIC simulation. As the results, the strong magnetic field (300 MG) collimates electrons with energy over a few MeV. This collimation mechanism may attract attention in many applications such as electron acceleration, electron microscope and fast ignition of laser fusion.Peer reviewe
Magnetic properties of the insulating ferromagnetic phase in strained Pr_0.6Ca_0.4MnO_3 thin films
Bulk magnetization in Pr_{0.6}Ca_{0.4}MnO_3 thin films with tensile (SrTiO_3)
and compressive (LaAlO_3) substrate-induced strain is compared to the
magnetooptical Kerr effect (MOKE) measurements. In the absence of an external
magnetic field, in both films, a stable ferromagnetic insulating majority phase
coexists with an antiferromagnetic insulating phase below ~120K. MOKE
measurements indicate that at 5K a metastable ferromagnetic metallic (FM) phase
is formed at the surface of the stretched film in a magnetic field below 1.1T
already, while in the bulk the FM phase starts to form in the field above ~4T
in both films.Comment: Accepted in AP
Estudo da herança da resistĂȘncia a brusone em duas cultivares de arroz (Oryza sativa).
O objetivo do presente trabalho foi de identificar o nĂșmero de alelos envolvidos na expressĂŁo da resistĂȘncia qualitativa Ă brusone nas folhas nas cultivares Cica-8 e Metica-1.Conpeex 2010
Ultrafast photoinduced phase separation dynamics in Pr(0.6)Ca(0.4)MnO(3) thin films
The time resolved Magnetooptical Kerr effect in the substrate-strain-induced
insulating ferromagnetic phase in (PrCa)MnO thin films on
two different substrates was measured in a magnetic field up to 1.1T. The
photoinduced Kerr rotation and ellipticity show remarkably different
magnetic-field dependence. From the comparison of the magnetic field
dependencies of the photoinduced and static Kerr rotation and ellipticity we
conclude that a transient ferromagnetic metallic phase, embedded within the
insulating ferromagnetic phase, is created upon the photoexcitation at low
temperatures. A comparison of temporal dependence of the photoinduced Kerr
signals with the photoinduced reflectivity indicates the change of the
fractions of the phases takes place on a timescale of ten picoseconds
independent of the substrate.Comment: accepted in EP
The role of electronic correlation in the Si(100) reconstruction: a quantum Monte Carlo study
Recent low-temperature scanning tunneling experiments have challenged the
generally accepted picture of buckled silicon dimers as the ground state
reconstruction of the Si(100) surface. Together with the symmetric dimer model
of the surface suggested by quantum chemistry calculations on small clusters,
these findings question our general understanding of electronic correlations at
surfaces and its proper description within density functional theory. We
present quantum Monte Carlo calculations on large cluster models of the
symmetric and buckled surface, and conclude that buckling remains energetically
more favorable even when the present-day best treatment of electronic
correlation is employed.Comment: 5 pages, Revtex, 10 figure
The effect of interferon beta-1b treatment on MRI measures of cerebral atrophy in secondary progressive multiple sclerosis.
The recently completed European trial of interferon beta-1b (IFN beta -1b) in patients with secondary progressive multiple sclerosis (SP multiple sclerosis) has given an opportunity to assess the impact of treatment on cerebral atrophy using serial MRI. Unenhanced T-1-weighted brain imaging was acquired in a subgroup of 95 patients from five of the European centres; imaging was performed at 6-month intervals from month 0 to month 36. A blinded observer measured cerebral volume on four contiguous 5 mm cerebral hemisphere slices at each time point, using an algorithm with a high level of reproducibility and automation. There was a significant and progressive reduction in cerebral volume in both placebo and treated groups, with a mean reduction of 3.9 and 2.9%, respectively, by month 36 (P = 0.34 between groups). Exploratory subgroup analyses indicated that patients without gadolinium (Gd) enhancement at the baseline had a greater reduction of cerebral volume in the placebo group (mean reduction at month 36: placebo 5.1%, IFN beta -1b 1.8%, P < 0.05) whereas those with Gd-enhancing lesions showed a trend to greater reduction of cerebral volume if the patient was on IFN<beta>-1b (placebo 2.6%, IFN beta -1b, 3.7%; P > 0.05). These results are consistent with ongoing tissue loss in both arms of this study of secondary progressive multiple sclerosis. This finding is concordant with previous observations that disease progression, although delayed, is not halted by IFN beta. The different pattern seen in patients with and without baseline gadolinium enhancement suggests that part of the cerebral volume reduction observed in IFN beta -treated patients may be due to the anti-inflammatory/antioedematous effect of the drug. Longer periods of observation and larger groups of patients may be needed to detect the effects of treatment on cerebral atrophy in this population of patients with advanced disease
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