Transmission of optical communication signals through ring core fiber using perfect vortex beams

Orbital angular momentum can be used to implement high capacity data transmission systems that can be applied for classical and quantum communications. Here we experimentally study the generation and transmission properties of the so-called perfect vortex beams and the Laguerre-Gaussian beams in ring-core optical fibers. Our results show that when using a single preparation stage, the perfect vortex beams present less ring-radius variation that allows coupling of higher optical power into a ring core fiber. These results lead to lower power requirements to establish fiber-based communications links using orbital angular momentum and set the stage for future implementations of high-dimensional quantum communication over space division multiplexing fibers.Comment: 13 pages, 6 figure

Population Genetics of Plasmodium vivax in the Peruvian Amazon.

BACKGROUND: Characterizing the parasite dynamics and population structure provides useful information to understand the dynamic of transmission and to better target control interventions. Despite considerable efforts for its control, vivax malaria remains a major health problem in Peru. In this study, we have explored the population genetics of Plasmodium vivax isolates from Iquitos, the main city in the Peruvian Amazon, and 25 neighbouring peri-urban as well as rural villages along the Iquitos-Nauta Road. METHODOLOGY/ RESULTS: From April to December 2008, 292 P. vivax isolates were collected and successfully genotyped using 14 neutral microsatellites. Analysis of the molecular data revealed a similar proportion of monoclonal and polyclonal infections in urban areas, while in rural areas monoclonal infections were predominant (p = 0.002). Multiplicity of infection was higher in urban (MOI = 1.5-2) compared to rural areas (MOI = 1) (p = 0.003). The level of genetic diversity was similar in all areas (He = 0.66-0.76, p = 0.32) though genetic differentiation between areas was substantial (PHIPT = 0.17, p<0.0001). Principal coordinate analysis showed a marked differentiation between parasites from urban and rural areas. Linkage disequilibrium was detected in all the areas ([Formula: see text] = 0.08-0.49, for all p<0.0001). Gene flow among the areas was stablished through Bayesian analysis of migration models. Recent bottleneck events were detected in 4 areas and a recent parasite expansion in one of the isolated areas. In total, 87 unique haplotypes grouped in 2 or 3 genetic clusters described a sub-structured parasite population. CONCLUSION/SIGNIFICANCE: Our study shows a sub-structured parasite population with clonal propagation, with most of its components recently affected by bottleneck events. Iquitos city is the main source of parasite spreading for all the peripheral study areas. The routes of transmission and gene flow and the reduction of the parasite population described are important from the public health perspective as well for the formulation of future control policies

Use of metabotropic glutamate 5-receptor antagonists for treatment of levodopa-induced dyskinesias

Background: Modulation of metabotropic glutamate receptors may be a novel therapeutic approach to manage l-Dopa-induced dyskinesias in patients with Parkinson's disease. This article reviews the rationale for use of metabotropic glutamate 5-receptor antagonists in experimental and clinical l-Dopa-induced dyskinesias. Methods: Systematic literature searches were performed (between May 2012-March 2014) for relevant English language articles using PubMed. Additional articles of interest were identified from reference lists of included publications. Relevant clinical abstracts from Movement Disorder Society meetings were included. Results: 16 preclinical studies of metabotropic glutamate 5-receptor antagonists in animal models of l-Dopa-induced dyskinesias and 7 clinical studies in patients with Parkinson's disease and l-Dopa-induced dyskinesias were included. Anti-dyskinetic effects of metabotropic glutamate 5-receptor blockade (MPEP, MTEP, fenobam, or MRZ-8676) were reported in dyskinetic 6-hydroxydopamine-lesioned rats. Studies in MPTP-lesioned non-human primates reported anti-dyskinetic effects of MPEP, MTEP, fenobam and mavoglurant (AFQ056). Three randomized, double-blind clinical trials reported anti-dyskinetic efficacy of mavoglurant, without effects on anti-parkinsonian therapy, with dizziness the most common adverse event. However, two further studies failed to demonstrate significant anti-dyskinetic efficacy. A randomized, double-blind, placebo-controlled safety study of dipraglurant (ADX48621) demonstrated tolerability and positive exploratory secondary outcomes of reduced dyskinesia. Conclusions: Animal model studies provide evidence for anti-dyskinetic efficacy of metabotropic glutamate 5-receptor antagonists. Initial proof-of-concept clinical trials of mavoglurant and dipraglurant showed positive results; anti-dyskinetic efficacy was not supported by two recent mavoglurant trials. Further evaluations of optimal dosage and long-term efficacy and safety of metabotropic glutamate 5-receptor antagonists for management of l-Dopa-induced dyskinesias in Parkinson's disease are required. © 2014 Elsevier Ltd

Behavioral and Cellular Modulation of l-DOPA-Induced Dyskinesia by β-Adrenoceptor Blockade in the 6-Hydroxydopamine-Lesioned Rat

Chronic dopamine replacement therapy in Parkinson's disease (PD) leads to deleterious motor sequelae known as l-DOPA-induced dyskinesia (LID). No known therapeutic can eliminate LID, but preliminary evidence suggests that dl-1-isopropylamino-3-(1-naphthyloxy)-2-propanol [(±)propranolol], a nonselective β-adrenergic receptor (βAR) antagonist, may reduce LID. The present study used the rat unilateral 6-hydroxydopamine model of PD to characterize and localize the efficacy of (±)propranolol as an adjunct to therapy with l-DOPA. We first determined whether (±)propranolol was capable of reducing the development and expression of LID without impairing motor performance ON and OFF l-DOPA. Coincident to this investigation, we used reverse-transcription polymerase chain reaction techniques to analyze the effects of chronic (±)propranolol on markers of striatal activity known to be involved in LID. To determine whether (±)propranolol reduces LID through βAR blockade, we subsequently examined each enantiomer separately because only the (−)enantiomer has significant βAR affinity. We next investigated the effects of a localized striatal βAR blockade on LID by cannulating the region and microinfusing (±)propranolol before systemic l-DOPA injections. Results showed that a dose range of (±)propranolol reduced LID without deleteriously affecting motor activity. Pharmacologically, only (−)propranolol had anti-LID properties indicating βAR-specific effects. Aberrant striatal signaling associated with LID was normalized with (±)propranolol cotreatment, and intrastriatal (±)propranolol was acutely able to reduce LID. This research confirms previous work suggesting that (±)propranolol reduces LID through βAR antagonism and presents novel evidence indicating a potential striatal locus of pharmacological action

<i>PHI</i>_PT values obtained from pairwise comparison between study areas (A1–A5) and between villages within each area.

<p><i>PHI</i>_PT values obtained from pairwise comparison between study areas (A1–A5) and between villages within each area.</p

PCoA of the parasite population at village and individual haplotype level.

<p>(A) Principal coordinate analysis of the study areas resulted from intercomparison of individual villages. Percentages in the parenthesis indicate the proportion of total variation explained by each principal coordinate. The term “others…” was used to group villages within specific areas that had less than 2 isolates with known haplotype. (B) PCoA among the individual haplotypes within the areas. Areas are defined in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004376#pntd.0004376.g001" target="_blank">Fig 1A</a> and village abbreviations are detailed in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004376#pntd.0004376.s001" target="_blank">S1 Table</a>.</p