89 research outputs found
Law and Peace: A Legal Framework for United Nations Peacekeeping
The hypothesis of this work is that international human rights law and not international humanitarian law is the legal framework that applies to United Nations (UN) peacekeeping operations in collapsed States where the peacekeepers do not become a party to an armed conflict. In order to test this hypothesis the work begins by examining what is meant by peacekeeping and charts the evolution of peacekeeping from its origins as a passive ad hoc activity to the modern highly complex operations capable of providing the foundations for the recreation of civil society. Chapter two of the work builds on the first chapter by analysing the UNâs theoretical approach to peacekeeping through its major reports. This chapter provides insight into the development of peacekeeping as a theoretical construct and then into a central tool in the UNâs attempt to implement the Charter. Chapters three and four analyse peacekeeping as practiced by the UN in operations conducted under Chapters VI and VII of the UN Charter. This analysis leads to the conclusion that as a matter of practice the UN and the State parties that have provided the troops to perform peacekeeping under UN control have acted in accordance with international human rights law and that as a result there is evidence of State practice to support an argument that as a matter of customary international law international human rights law applies as the framework for peacekeeping in collapsed States. With a clear grounding in the practice and theory of peacekeeping the work then examines the competing claims of international humanitarian law and international human rights law as the legal framework for peacekeeping operations. Suggestions are made with regard to the triggers for international humanitarian law to apply and the conclusion is drawn that the vast majority of UN operations between 1949 and 2003 were conducted beneath the threshold for the application of international humanitarian law. The final chapter of the work analyses the practical application of a human rights framework to peacekeeping and concludes that it provides a flexible and adaptive tool for the restoration of peace and the reconstruction of civil society. As a result of the analysis of UN peacekeeping theory, practice and the competing claims of international humanitarian law and international human rights law, the work concludes that international human rights law provides the framework for UN peacekeeping in collapsed States and that international humanitarian law will only apply where peacekeepers cross the threshold into armed conflict
Split-merge cycle, fragmented collapse, and vortex disintegration in rotating Bose-Einstein condensates with attractive interactions
The dynamical instabilities and ensuing dynamics of singly- and
doubly-quantized vortex states of Bose-Einstein condensates with attractive
interactions are investigated using full 3D numerical simulations of the
Gross-Pitaevskii equation. With increasing the strength of attractive
interactions, a series of dynamical instabilities such as quadrupole, dipole,
octupole, and monopole instabilities emerge. The most prominent instability
depends on the strength of interactions, the geometry of the trapping
potential, and deviations from the axisymmetry due to external perturbations.
Singly-quantized vortices split into two clusters and subsequently undergo
split-merge cycles in a pancake-shaped trap, whereas the split fragments
immediately collapse in a spherical trap. Doubly-quantized vortices are always
unstable to disintegration of the vortex core. If we suddenly change the
strength of interaction to within a certain range, the vortex splits into three
clusters, and one of the clusters collapses after a few split-merge cycles. The
vortex split can be observed using a current experimental setup of the MIT
group.Comment: 11 pages, 10 figure
Dynamics of Dark-Bright Solitons in Cigar-Shaped Bose-Einstein Condensates
We explore the stability and dynamics of dark-bright solitons in
two-component elongated Bose-Einstein condensates by developing effective 1D
vector equations as well as solving the corresponding 3D Gross-Pitaevskii
equations. A strong dependence of the oscillation frequency and of the
stability of the dark-bright (DB) soliton on the atom number of its components
is found. Spontaneous symmetry breaking leads to oscillatory dynamics in the
transverse degrees of freedom for a large occupation of the component
supporting the dark soliton. Moreover, the interactions of two DB solitons are
investigated with special emphasis on the importance of their relative phases.
Experimental results showcasing dark-bright soliton dynamics and collisions in
a BEC consisting of two hyperfine states of Rb confined in an elongated
optical dipole trap are presented.Comment: 4 pages, 5 figure
Moving forward in HIV-associated cancer
Cancer has been linked to HIV since the earliest days of the
epidemic. The unusually frequent occurrence of Kaposi sarcoma (KS)
among men who have sex with men (MSM) in 1981 was a sentinel
observation leading to the inclusion of KS in the first AIDS case
definition.1,2 More than three decades later, major research investments
have led to striking advances in understanding HIV pathogenesis,
with antiretroviral therapy (ART) reducing AIDS complications
and allowing HIV-infected individuals to experience life expectancy
approaching that of persons without HIV
Reply to P. de Paoli et al
Weare grateful for the correspondence provided by De Paoli and
Carbone1 regarding our recently published Comments and Controversies
piece focused on HIV-associated cancers. Their letter provides
an important extension of some of the main points articulated in our
article. Indeed, we wish to acknowledge our correspondents’ own
excellent review also highlighting the complexity and heterogeneity of
cancers occurring in the HIV-infected populatio
From QCD lattice calculations to the equation of state of quark matter
We describe two-flavor QCD lattice data for the pressure at finite
temperature and zero chemical potential within a quasiparticle model. Relying
only on thermodynamic selfconsistency, the model is extended to nonzero
chemical potential. The results agree with lattice calculations in the region
of small chemical potential.Comment: 5 eps figure
Adaptable antigen matrix platforms for peptide vaccination strategies and T cell-mediated anti-tumor immunity
Injection of antigenic peptides has been widely used as a vaccine strategy to boost T cell immunity. However, the poor immunogenicity of single peptides can potentially be strengthened through modification of the tertiary structure and the selection of the accompanying adjuvant. Here, we generated antigenic peptides into non-linear trimers by solid phase peptide synthesis, thereby enhancing antigen presentation by dendritic cells to CD8+ T cells in vitro and in vivo. CD8+ T cells from mice vaccinated with trimers showed an KLRG1+ effector phenotype and were able to recognize and kill antigen-expressing tumor cells ex vivo. Importantly, trimers outperformed synthetic long peptide in terms of T cell response even when equal number of epitopes were used for immunization. To improve the synthesis of trimers containing difficult peptide sequences, we developed a novel small molecule that functions as conjugation platform for synthetic long peptides. This platform, termed Antigen MAtriX (AMAX) improved yield, purity and solubility of trimers over conventional solid phase synthesis strategies. AMAX outperformed synthetic long peptides in terms of both CD8+ and CD4+ T cell responses and allowed functionalization with DC-SIGN-binding carbohydrates for in vivo dendritic cell targeting strategies, boosting T cell responses even further. Moreover, we show that ag
Nanofabrication by magnetic focusing of supersonic beams
We present a new method for nanoscale atom lithography. We propose the use of
a supersonic atomic beam, which provides an extremely high-brightness and cold
source of fast atoms. The atoms are to be focused onto a substrate using a thin
magnetic film, into which apertures with widths on the order of 100 nm have
been etched. Focused spot sizes near or below 10 nm, with focal lengths on the
order of 10 microns, are predicted. This scheme is applicable both to precision
patterning of surfaces with metastable atomic beams and to direct deposition of
material.Comment: 4 pages, 3 figure
Deconfining Phase Transition as a Matrix Model of Renormalized Polyakov Loops
We discuss how to extract renormalized from bare Polyakov loops in SU(N)
lattice gauge theories at nonzero temperature in four spacetime dimensions.
Single loops in an irreducible representation are multiplicatively renormalized
without mixing, through a renormalization constant which depends upon both
representation and temperature. The values of renormalized loops in the four
lowest representations of SU(3) were measured numerically on small, coarse
lattices. We find that in magnitude, condensates for the sextet and octet loops
are approximately the square of the triplet loop. This agrees with a large
expansion, where factorization implies that the expectation values of loops in
adjoint and higher representations are just powers of fundamental and
anti-fundamental loops. For three colors, numerically the corrections to the
large relations are greatest for the sextet loop, ; these
represent corrections of for N=3. The values of the renormalized
triplet loop can be described by an SU(3) matrix model, with an effective
action dominated by the triplet loop. In several ways, the deconfining phase
transition for N=3 appears to be like that in the matrix model of
Gross and Witten.Comment: 24 pages, 7 figures; v2, 27 pages, 12 figures, extended discussion
for clarity, results unchange
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