Impact of the large-scale deployment of artemether/lumefantrine on the malaria disease burden in Africa: case studies of South Africa, Zambia and Ethiopia

Malaria is one of the most significant causes of morbidity and mortality worldwide. Every year, nearly one million deaths result from malaria infection. Malaria can be controlled in endemic countries by using artemisinin-based combination therapy (ACT) in combination with indoor residual spraying (IRS) and insecticide-treated nets (ITNs). At least 40 malaria-endemic countries in sub-Saharan Africa now recommend the use of ACT as first-line treatment for uncomplicated falciparum malaria as a cornerstone of their malaria case management. The scaling up of malaria control strategies in Zambia has dramatically reduced the burden of malaria. Zambia was the first African country to adopt artemether/lumefantrine (AL; Coartem(R)) as first-line therapy in national malaria treatment guidelines in 2002. Further, the vector control with IRS and ITNs was also scaled up. By 2008, the rates of in-patient malaria cases and deaths decreased by 61% and 66%, respectively, compared with the 2001-2002 reference period.Treatment with AL as first-line therapy against a malaria epidemic in the KwaZulu-Natal province of South Africa, in combination with strengthening of vector control, caused the number of malaria-related outpatient cases and hospital admissions to each fall by 99% from 2001 to 2003, and malaria-related deaths decreased by 97% over the same period. A prospective study also showed that gametocyte development was prevented in all patients receiving AL. This reduction in malaria morbidity has been sustained over the past seven years.AL was introduced as first-line anti-malarial treatment in 2004 in the Tigray region of Ethiopia. During a major malaria epidemic from May-October 2005, the district in which local community health workers were operating had half the rate of malaria-related deaths compared with the district in which AL was only available in state health facilities. Over the two-year study period, the community-based deployment of AL significantly lowered the risk of malaria-specific mortality by 37%. Additionally, the malaria parasite reservoir was three-fold lower in the intervention district than in the control district during the 2005 high-transmission season.Artemisinin-based combination therapy has made a substantial contribution to reducing the burden of malaria in sub-Saharan Africa

Molecular Monolayer Strong Coupling in Dielectric Soft Microcavities (article)

This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe dataset associated with this article is available in ORE: https://doi.org/10.24378/exe.2823We report strong coupling of a monolayer of J-aggregated dye molecules to the whispering gallery modes of a dielectric microsphere at room temperature. We systematically studied the evolution of strong coupling as the number of layers of dye molecules was increased and found the Rabi splitting to rise from 56 meV for a single layer to 94 meV for four layers of dye molecules. We compare our experimental results with two-dimensional (2D) numerical simulations and a simple coupled oscillator model, finding good agreement. We anticipate that these results will act as a stepping stone for integrating molecule-cavity strong coupling in a microfluidic environment since microspheres can be easily trapped and manipulated in such an environment and provide open access cavities.European Research Council (ERC

Polariton assisted photoemission from a layered molecular material: Role of vibrational states and molecular absorption (article)

This is the final version. Available on open access from the Royal Society of Chemistry via the DOI in this recordThe dataset associated with this article is available in ORE at: https://doi.org/10.24378/exe.3483The way molecules absorb, transfer, and emit light can be modified by coupling them to optical cavities. The extent of the modification is often defined by the cavity–molecule coupling strength, which depends on the number of coupled molecules. We experimentally and numerically study the evolution of photoemission from a thin layered J-aggregated molecular material strongly coupled to a Fabry–Perot microcavity as a function of the number of coupled layers. We unveil an important difference between the strong coupling signatures obtained from reflection spectroscopy and from polariton assisted photoluminescence. We also study the effect of the vibrational modes supported by the molecular material on the polariton assisted emission both for a focused laser beam and for normally incident excitation, for two different excitation wavelengths: a laser in resonance with the lower polariton branch, and a laser not in resonance. We found that Raman scattered photons appear to play an important role in populating the lower polariton branch, especially when the system was excited with a laser in resonance with the lower polariton branch. We also found that the polariton assisted photoemission depends on the extent of modification of the molecular absorption induced by the molecule–cavity coupling.Leverhulme TrustEuropean Research Council (ERC

Field-dependent Behavior of AC Susceptibility in [Y<inf>0.8</inf>Ca<inf>0.2</inf>](Ba<inf>0.5</inf>Sr<inf>0.5</inf>)<inf>2</inf>Cu<inf>3</inf>O<inf>7−δ</inf>

The AC susceptibility of [Y0.8Ca0.2](Ba0.5Sr0.5)2 Cu3O7−δ was investigated as a function of frequency and amplitude of AC magnetic field. The susceptibilities of the sample display the field amplitude dependence. The peak temperature (Tp) of its imaginary part shows not frequency dependence but field amplitude dependence. The frequency effect on AC susceptibility was negligible. As the field amplitude increases, Tp shifts to lower temperature. This effect can be interpreted in terms of bulk pinning hysteresis loss due to the vortices motion in/out grain boundary.The work in Peru has been supported by the Superior Council of Research of the National University of San Marcos (Grant No. 151301031). This work was also supported by the National Research Foundation of President Post-doctoral fellowship Program (NRF-2013R1A6A3A060443). “L. De Los Santos thanks the Ministry of the Production “Programa Nacional de Innovacion´ para la Competitividad y Productividad” for financial support (Project ECIP-1-P-069-14)”.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s10948-015-3238-

Role of Symmetry Breaking in Observing Strong Molecule-Cavity Coupling Using Dielectric Microspheres

This is the final version. Available from the American Chemical Society via the DOI in this record. The emergence of dielectric open optical cavities has opened a new research avenue in nanophotonics. In particular, dielectric microspheres support a rich set of cavity modes with varying spectral characteristics, making them an ideal platform to study molecule-cavity interactions. The symmetry of the structure plays a critical role in the outcoupling of these modes and, hence, the perceived molecule-cavity coupling strength. Here, we experimentally and theoretically study molecule-cavity coupling mediated by the Mie scattering modes of a dielectric microsphere placed on a glass substrate and excited with far-field illumination, from which we collect scattering signatures both in the air and glass sides. Glass-side collection reveals clear signatures of strong molecule-cavity coupling (coupling strength 2g = 74 meV), in contrast to the air-side scattering signal. Rigorous electromagnetic modeling allows us to understand molecule-cavity coupling and unravel the role played by the spatial mode profile in the observed coupling strength.European Research Council (ERC)European Research Council (ERC)Spanish MICINNSpanish MICINNCatalan CERCA ProgramFundaciós Cellex and Mir-Pui

Higher Equations of Motion in Boundary Liouville Field Theory

In addition to the ordinary bulk higher equations of motion in the boundary version of the Liouville conformal field theory, an infinite set of relations containing the boundary operators is found. These equations are in one-to-one correspondence with the singular representations of the Virasoro algebra. We comment on the possible applications in the context of minimal boundary Liouville gravity.Comment: 18 page

Exactly Marginal Deformations and Global Symmetries

We study the problem of finding exactly marginal deformations of N=1 superconformal field theories in four dimensions. We find that the only way a marginal chiral operator can become not exactly marginal is for it to combine with a conserved current multiplet. Additionally, we find that the space of exactly marginal deformations, also called the "conformal manifold," is the quotient of the space of marginal couplings by the complexified continuous global symmetry group. This fact explains why exactly marginal deformations are ubiquitous in N=1 theories. Our method turns the problem of enumerating exactly marginal operators into a problem in group theory, and substantially extends and simplifies the previous analysis by Leigh and Strassler. We also briefly discuss how to apply our analysis to N=2 theories in three dimensions.Comment: 23 pages, 2 figure

Theory of current-driven motion of Skyrmions and spirals in helical magnets

We study theoretically the dynamics of the spin textures, i.e., Skyrmion crystal (SkX) and spiral structure (SS), in two-dimensional helical magnets under external current. By numerically solving the Landau-Lifshitz-Gilbert equation, it is found that (i) the critical current density of the motion is much lower for SkX compared with SS in agreement with the recent experiment, (ii) there is no intrinsic pinning effect for SkX and the deformation of the internal structure of Skyrmion reduces the pinning effect dramatically, (iii) the Bragg intensity of SkX shows strong time-dependence as can be observed by neutron scattering experiment.Comment: 4 pages, 3 figure

Carbothermal reduction of mill scales formed on steel billets during continuous casting

AbstractA billet is a bar made from crude steel which surface contains scales which are rich in iron oxides. This study presents the carbothermal reduction of the scales formed in steel billets. The process included the reaction of the iron oxides contents with carbon (in ratio 5:1) and annealing in a tubular furnace under argon atmosphere. The occurred reactions are discussed using thermodynamic calculations and thermal analysis which indicate a three-stage reduction process Fe3O4 ➔ FeO ➔ Fe3C ➔α-Fe with intermediate reactions at the interval temperature 960 and 1300 °C. The X-ray diffraction confirms the reduction to α-Fe with minor presence of unreacted C, magnetite and wustite. Mössbauer spectroscopy analysis was performed at room temperature where a typical sextet corresponding to the dominant α-Fe is shown as well as wustite, magnetite and cementite to a lesser extent. The magnetization measurements confirm the ferromagnetic state corresponding to the α-Fe.</jats:p

Differential Effect of Contrast Polarity Reversals in Closed Squares and Open L-Junctions

Scene segmentation depends on interaction between geometrical and photometric factors. It has been shown that reversals in contrast polarity at points of highest orientation discontinuity along closed contours significantly impair shape discrimination performance, while changes in contrast polarity at straight(er) contour segments do not have such deleterious effects (Spehar, 2002). Here we employ (semi) high resolution fMRI (1.5 mm × 1.5 mm × 1.5 mm) to investigate the neuronal substrate underlying these perception effects. Stimuli consisted of simple elements (a) squares with contrast reversals along straight segments; (b) squares with contrast reversals in the corner (highest orientation discontinuity); (c) L-Junctions with contrast reversals along the straight ends; (d) L-Junctions with contrast reversals in the corner. Element with contrast polarity reversals are easy to distinguish though appear geometrically equivalent. For squares with contrast polarity reversals only along straight lines we find significantly lower BOLD modulation compared to any of the control conditions, which show similar responses to each other. In the light of previous psychophysical work (Elder and Zucker, 1993; Spehar, 2002) we speculate that this effect is due to closure perception. We observe this across a wide range of areas on occipital cortex