857 research outputs found
Public attitudes to organ donation in South Africa
Public attitudes to organ donation may be influenced by cultural beliefs as well as racial prejudices and superstitions. In South Africa we are able to examine these issues from both a Firstand a Third-World perspective. In this study the attitudes of 1 299 urban white, 625 rural black and 826 urban black South Africans were examined.Eighty-nine per cent of white, 84% of rural black and 76% of urban black South Africans are prepared to donate their own organs. All groups are less willing to donate the organs of close relatives (76% white, 76% rural black and 67% urban black). Most people felt that this decision should be made by the person before death.Most black people (88%) felt that the race of both donor and recipient were irrelevant. Only 23% of black people were prepared to donate their corneas, compared with the 69% and 70% willing to donate their kidneys and heart respectivel
Trophic relationships between palms and bruchids (Coleoptera : Bruchidae : Pachymerini) in Peruvian Amazonia
Des données quantitatives et qualitatives concernant les plantes hôtes des bruches des palmiers sont fournies pour une région de l'Amazonie où l'on disposait jusqu'à présent de peu d'informations. Ces données permettent d'étendre la distribution géographique et le spectre alimentaire de plusieurs espèces. Le rôle de la structure du fruit dans sa sensibilité à l'infestation par les bruches, le rôle de la maturité du fruit dans la sélection du site de ponte sont discutés. L'importance des conditions mésologiques, en particulier en zone inondable, dans la dynamique des populations de bruches, est relevée. Un parasitoïde spécialiste de #Caryoborus serripes, qui est un prédateur spécifique des noix d'#Astrocaryum, est obtenu pour la première fois; un trichogramme parasite des oeufs de cette même bruche est également identifié. (Résumé d'auteur
Exchange Interaction in Binuclear Complexes with Rare Earth and Copper Ions: A Many-Body Model Study
We have used a many-body model Hamiltonian to study the nature of the
magnetic ground state of hetero-binuclear complexes involving rare-earth and
copper ions. We have taken into account all diagonal repulsions involving the
rare-earth 4f and 5d orbitals and the copper 3d orbital. Besides, we have
included direct exchange interaction, crystal field splitting of the rare-earth
atomic levels and spin-orbit interaction in the 4f orbitals. We have identified
the inter-orbital repulsion, U and crystal field parameter,
as the key parameters involved in controlling the type of exchange
interaction between the rare earth and copper 3d spins. We have explored
the nature of the ground state in the parameter space of U, ,
spin-orbit interaction strength and the filling n. We find
that these systems show low-spin or high-spin ground state depending on the
filling of the levels of the rare-earth ion and ground state spin is
critically dependent on U and . In case of half-filling
(Gd(III)) we find a reentrant low-spin state as U is increased, for
small values of , which explains the recently reported apparent
anomalous anti-ferromagnetic behaviour of Gd(III)-radical complexes. By varying
U we also observe a switch over in the ground state spin for other
fillings . We have introduced a spin-orbit coupling scheme which goes beyond
L-S or j-j coupling scheme and we find that spin-orbit coupling does not
significantly alter the basic picture.Comment: 22 pages, 11 ps figure
How to make effective HPV vaccine recommendations starting at age 9
This article provides best and promising practices for recommending HPV vaccination at age 9 as a way to ensure high uptake. An effective method for recommending HPV vaccination is the Announcement Approach, which consists of 3 evidence-based steps. The first step, Announce, involves noting that the child is 9 years old, saying they are due for a vaccine that prevents 6 HPV cancers, and saying you’ll vaccinate today. This adapted version of the Announce step simplifies the bundled approach used at ages 11–12 that emphasizes the prevention of meningitis and whooping cough in addition to HPV cancers. For hesitant parents, the second step, Connect and Counsel, involves finding common ground with the parent and communicating the value of starting HPV vaccination at the first opportunity. Finally, for parents who decline, the third step is to Try Again at a later visit. Using the Announcement Approach at age 9 stands to increase HPV vaccine uptake, save time, and lead to high family and provider satisfaction
Comparison between the Cramer-Rao and the mini-max approaches in quantum channel estimation
In a unified viewpoint in quantum channel estimation, we compare the
Cramer-Rao and the mini-max approaches, which gives the Bayesian bound in the
group covariant model. For this purpose, we introduce the local asymptotic
mini-max bound, whose maximum is shown to be equal to the asymptotic limit of
the mini-max bound. It is shown that the local asymptotic mini-max bound is
strictly larger than the Cramer-Rao bound in the phase estimation case while
the both bounds coincide when the minimum mean square error decreases with the
order O(1/n). We also derive a sufficient condition for that the minimum mean
square error decreases with the order O(1/n).Comment: In this revision, some unlcear parts are clarifie
The rms-flux relations in different branches in Cyg X-2
In this paper, the rms-flux (root mean square-flux) relation along the
Z-track of the bright Z-Source Cyg X-2 is analyzed using the observational data
of Rossi X-ray Timing Explorer (RXTE). Three types of rms-flux relations, i.e.
positive, negative, and 'arch'-like correlations are found in different
branches. The rms is positively correlated with flux in normal branch (NB), but
anti-correlated in the vertical horizontal branch (VHB). The rms-flux relation
shows an 'arch'-like shape in the horizontal branch (HB). We also try to
explain this phenomenon using existing models.Comment: Accepted for publication in Astrophysics & Space Scienc
4f-spin dynamics in La(2-x-y)Sr(x)Nd(y)CuO(4)
We have performed inelastic magnetic neutron scattering experiments on
La(2-x-y)Sr(x)Nd(y)CuO(4) in order to study the Nd 4f-spin dynamics at low
energies. In all samples we find at high temperatures a quasielastic line
(Lorentzian) with a line width which decreases on lowering the temperature. The
temperature dependence of the quasielastic line width Gamma/2(T) can be
explained with an Orbach-process, i.e. a relaxation via the coupling between
crystal field excitations and phonons. At low temperatures the Nd-4f magnetic
response S(Q,omega) correlates with the electronic properties of the
CuO(2)-layers. In the insulator La(2-y)Nd(y)CuO(4) the quasielastic line
vanishes below 80 K and an inelastic excitation occurs. This directly indicates
the splitting of the Nd3+ ground state Kramers doublet due to the static
antiferromagnetic order of the Cu moments. In La(1.7-x)Sr(x)Nd(0.3)CuO(4) with
x = 0.12, 0.15 and La(1.4-x)Sr(x)Nd(0.6)CuO(4) with x = 0.1, 0.12, 0.15, 0.18
superconductivity is strongly suppressed. In these compounds we observe a
temperature independent broad quasielastic line of Gaussian shape below T about
30 K. This suggests a distribution of various internal fields on different Nd
sites and is interpreted in the frame of the stripe model. In
La(1.8-y)Sr(0.2)Nd(y)CuO(4) (y = 0.3, 0.6) such a quasielastic broadening is
not observed even at lowest temperature.Comment: 8 pages, 10 figures included, to appear in Phys. Rev.
Using job strain and organizational justice models to predict multiple forms of employee performance behaviours among Australian policing personnel
The overall purpose of this investigation was to examine the relationship between stress-related working conditions and three forms of employee performance behaviours: in-role behaviours, citizenship behaviours directed at other individuals and citizenship behaviours directed at the organization. The potentially stressful working conditions were based on the job strain model (incorporating job demands, job control and social support) as well as organizational justice theory. A sample of Australian-based police officers (n = 640) took part in this study and the data were collected via a mail-out survey. Multiple regression analyses were undertaken to assess both the strength and the nature of the relationships between the working conditions and employee performance and these analyses included tests for additive, interactional and curvilinear effects. The overall results indicated that a significant proportion of the explained variance in all three outcome measures was attributed to the additive effects of demand, control and support. The level of variance associated with the organizational justice dimensions was relatively small, although there were signs that specific dimensions of justice may provide unique insights into the relationship between job stressors and employee performance. The implications of these and other notable findings are discussed.<br /
A narrative analysis of career transition themes and outcomes using chaos theory as a guiding metaphor
In a rapidly changing world of work little research exists on mid-career transitions. We investigated these using the open-systems approach of chaos theory as a guiding metaphor and conducted interviews with seven mid-career individuals chosen for their experience of a significant mid-career transition. Four common themes were identified through narrative analysis, where ‘false starts’ to a career were a common experience prior to finding a career ‘fit’. Career transitions, precipitated by a trigger state and/or event such as a period of disillusionment, were an important part of this ‘finding a fit’ process. Overall, career success outcomes were shaped by a combination of chaos elements: chance, unplanned events, and non-linearity of resultant outcomes. We discuss implications for future research and for practice
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