452 research outputs found
RECONCILIATION AND JUSTICE IN SOUTH AFRICA
In this paper I argue that, understood theologically, reconciliation is both an accomplished, transacted fact and a progressively achieved, relational reality. Applied to South Africa, I argue that reconciliation was transacted in the negotiated end to apartheid and the peaceful transition of power, but that the relational aspect of reconciliation is still largely an aspiration, and that South Africa lives in the tension of the âalready, but not yetâ. Notwithstanding the Truth and Reconciliation Commission, I contend that South Africa has made little progress in relational reconciliation. I focus on two reasons for this: 1) a lack of repentance from perpetrators and beneficiaries of apartheid; and 2) a lack of progress in redressing apartheid injustices, particularly socio-economic justice. I propose that addressing these two deficiencies is key to greater reconciliation and that the Church, claiming to be the resurrection community, has a unique role to model a new, reconciled humanity
Bioresponsive hydrogels
We highlight recent developments in hydrogel materials with biological responsiveness built in. These âsmartâ biomaterials change properties in response to selective biological recognition events. When exposed to a biological target (nutrient, growth factor, receptor, antibody, enzyme, or whole cell), molecular recognition events trigger changes in molecular interactions that translate into macroscopic responses, such as swelling/collapse or solution-to-gel transitions. The hydrogel transitions may be used directly as optical readouts for biosensing, linked to the release of actives for drug delivery, or instigate biochemical signaling events that control or direct cellular behavior. Accordingly, bioresponsive hydrogels have gained significant interest for application in diagnostics, drug delivery, and tissue regeneration/wound healing
Approximate tight-binding sum rule for the superconductivity related change of c-axis kinetic energy in multilayer cuprate superconductors
We present an extension of the c-axis tight-binding sum rule discussed by
Chakravarty, Kee, and Abrahams [Phys. Rev. Lett. 82, 2366 (1999)] that applies
to multilayer high-Tc cuprate superconductors (HTCS) and use it to
estimate--from available infrared data--the change below Tc of the c-axis
kinetic energy, Hc, in YBa2Cu3O(7-delta) (delta=0.45,0.25,0.07), Bi2Sr2CaCu2O8,
and Bi2Sr2Ca2Cu3O10. In all these compounds Hc decreases below Tc and except
for Bi2Sr2CaCu2O8 the change of Hc is of the same order of magnitude as the
condensation energy. This observation supports the hypothesis that in
multilayer HTCS superconductivity is considerably amplified by the interlayer
tunnelling mechanism.Comment: 6 pages, 2 figure
Semileptonic form factors - a model-independent approach
We demonstrate that the B->D(*) l nu form factors can be accurately predicted
given the slope parameter rho^2 of the Isgur-Wise function. Only weak
assumptions, consistent with lattice results, on the wavefunction for the light
degrees of freedom are required to establish this result. We observe that the
QCD and 1/m_Q corrections can be systematically represented by an effective
Isgur-Wise function of shifted slope. This greatly simplifies the analysis of
semileptonic B decay. We also investigate what the available semileptonic data
can tell us about lattice QCD and Heavy Quark Effective Theory. A rigorous
identity relating the form factor slope difference rho_D^2-rho_A1^2 to a
combination of form factor intercepts is found. The identity provides a means
of checking theoretically evaluated intercepts with experiment.Comment: 18 pages, Revtex, 4 postscript figures, uses epsfig.st
A model for spin-polarized transport in perovskite manganite bi-crystal grain boundaries
We have studied the temperature dependence of low-field magnetoresistance and
current-voltage characteristics of a low-angle bi-crystal grain boundary
junction in perovskite manganite La_{2/3}Sr_{1/3}MnO_3 thin film. By gradually
trimming the junction we have been able to reveal the non-linear behavior of
the latter. With the use of the relation M_{GB} \propto M_{bulk}\sqrt{MR^*} we
have extracted the grain boundary magnetization. Further, we demonstrate that
the built-in potential barrier of the grain boundary can be modelled by
V_{bi}\propto M_{bulk}^2 - M_{GB}^2. Thus our model connects the
magnetoresistance with the potential barrier at the grain boundary region. The
results indicate that the band-bending at the grain boundary interface has a
magnetic origin.Comment: 9 pages, 5 figure
Proximity induced metal/insulator transition in superlattices
The far-infrared dielectric response of superlattices (SL) composed of
superconducting YBaCuO (YBCO) and ferromagnetic La%
CaMnO (LCMO) has been investigated by ellipsometry. A drastic
decrease of the free carrier response is observed which involves an unusually
large length scale of d20 nm in YBCO and d10
nm in LCMO. A corresponding suppression of metallicity is not observed in SLs
where LCMO is replaced by the paramagnetic metal LaNiO. Our data suggest
that either a long range charge transfer from the YBCO to the LCMO layers or
alternatively a strong coupling of the charge carriers to the different and
competitive kind of magnetic correlations in the LCMO and YBCO layers are at
the heart of the observed metal/insulator transition. The low free carrier
response observed in the far-infrared dielectric response of the magnetic
superconductor RuSrGdCuO is possibly related to this effect
Measurements of long-range near-side angular correlations in TeV proton-lead collisions in the forward region
Two-particle angular correlations are studied in proton-lead collisions at a
nucleon-nucleon centre-of-mass energy of TeV, collected
with the LHCb detector at the LHC. The analysis is based on data recorded in
two beam configurations, in which either the direction of the proton or that of
the lead ion is analysed. The correlations are measured in the laboratory
system as a function of relative pseudorapidity, , and relative
azimuthal angle, , for events in different classes of event
activity and for different bins of particle transverse momentum. In
high-activity events a long-range correlation on the near side, , is observed in the pseudorapidity range . This
measurement of long-range correlations on the near side in proton-lead
collisions extends previous observations into the forward region up to
. The correlation increases with growing event activity and is found
to be more pronounced in the direction of the lead beam. However, the
correlation in the direction of the lead and proton beams are found to be
compatible when comparing events with similar absolute activity in the
direction analysed.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm
Study of the production of and hadrons in collisions and first measurement of the branching fraction
The product of the () differential production
cross-section and the branching fraction of the decay () is
measured as a function of the beauty hadron transverse momentum, ,
and rapidity, . The kinematic region of the measurements is and . The measurements use a data sample
corresponding to an integrated luminosity of collected by the
LHCb detector in collisions at centre-of-mass energies in 2011 and in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, , the
branching fraction of the decay is
measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi
pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4},
\end{equation*} where the first uncertainty is statistical, the second is
systematic, the third is due to the uncertainty on the branching fraction of
the decay , and the
fourth is due to the knowledge of . The sum of the
asymmetries in the production and decay between and
is also measured as a function of and .
The previously published branching fraction of , relative to that of , is updated.
The branching fractions of are determined.Comment: 29 pages, 19figures. All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
Soldiering On? The PrisonâMilitary Complex and ExâMilitary Personnel as Prison Officers: Transition, Rehabilitation and Prison Reform
Arguing that criminology has thus far inadequately theorised militarism as it relates to the prison system, this agenda-setting article introduces the âprison-military complexâ as a means to initiate examination of militarism in relation to institutions and practices of incarceration. In so doing, it identifies a key knowledge gap vis-Ă -vis the role of ex-military personnel employed as prison staff; and poses key questions about the ways in which military staff and military methods are being directly targeted as a means to reform a prison service reeling from unprecedented levels of violence, self-harm, riots, and escapes. Encouraging criminologists to think beyond stereotypical ideas about the military, the article revolves around a multiscalar articulation of the prison-military complex, discussed here as it relates to reform of the prison system as a whole; the rehabilitation of offenders; and individualsâ ex-military transitions to civilian life
- âŠ