Trigeminal Nerve Root Demyelination Not Seen in Six Horses Diagnosed with Trigeminal-Mediated Headshaking

Trigeminal-mediated headshaking is an idiopathic neuropathic facial pain syndrome in horses. There are clinical similarities to trigeminal neuralgia, a neuropathic facial pain syndrome in man, which is usually caused by demyelination of trigeminal sensory fibers within either the nerve root or, less commonly, the brainstem. Our hypothesis was that the neuropathological substrate of headshaking in horses is similar to that of trigeminal neuralgia in man. Trigeminal nerves, nerve roots, ganglia, infraorbital, and caudal nasal nerves from horse abattoir specimens and from horses euthanized due to trigeminal-mediated headshaking were removed, fixed, and processed for histological assessment by a veterinary pathologist and a neuropathologist with particular experience of trigeminal neuralgia histology. No histological differences were detected between samples from horses with headshaking and those from normal horses. These results suggest that trigeminal-mediated headshaking may have a different pathological substrate from trigeminal neuralgia in man

Measuring the Absolute Height and Profile of the Mesospheric Sodium Layer using a Continuous Wave Laser

We have developed and tested a novel method, based on LIDAR, of measuring the height and profile of the mesospheric sodium layer using a continuous wave laser. It is more efficient than classical LIDAR as the laser is on for 50% of the time, and so can in principle be used during laser guide star adaptive optics observations. It also has significant advantages over direct imaging techniques because it does not require a second telescope, is almost independent of the atmospheric conditions, and avoids triangulation problems in determining the height. In the long term, regular monitoring using this method would allow a valuable database of sodium layer profiles, heights, and return flux measurements to be built up which would enable observatory staff astronomers to schedule observations optimally. In this paper we describe the original experiment carried out using the ALFA laser guide star system at Calar Alto Observatory in Spain. We validate the method by comparing the LIDAR results with those obtained from simultaneous imaging from an auxiliary telescope. Models are presented of a similar system to be implemented in the Very Large Telescope Laser Guide Star Facility, which will enable the initial focus setting for the adaptive optics systems to be determined with an accuracy of less than 200 m on a timescale of 1 minute.Comment: Accepted for publication in Astronomy & Astrophysics, 12 pages, 14 figure

Distance to high-voltage power lines and risk of childhood leukemia:An analysis of confounding by and interaction with other potential risk factors

We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters the association between distance to nearest power line and childhood leukemia. We included 1024 cases aged <15, diagnosed with leukemia during 1968-1991, from the Danish Cancer Registry and 2048 controls randomly selected from the Danish childhood population and individually matched by gender and year of birth. We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door) were estimated using validated models. We found a statistically significant interaction between distance to nearest power line and domestic radon regarding risk of childhood leukemia (p = 0.01) when using the median radon level as cut-off point but not when using the 75th percentile (p = 0.90). We found no evidence of an interaction between distance to nearest power line and traffic-related air pollution (p = 0.73). We found almost no change in the estimated association between distance to power line and risk of childhood leukemia when adjusting for socioeconomic status of the municipality, urbanization, maternal age, birth order, domestic radon and traffic-related air pollution. The statistically significant interaction between distance to nearest power line and domestic radon was based on few exposed cases and controls and sensitive to the choice of exposure categorization and might, therefore, be due to chance

Polychromatic guide star: feasibility study

International audienceAdaptive optics at astronomical telescopes aims at correcting in real time the phase corrugations of incoming wavefronts caused by the turbulent atmosphere, as early proposed by Babcock. Measuring the phase errors requires a bright source located within the isoplanatic patch of the program source. The probability that such a reference source exists is a function of the wavelength, of the required image quality (Strehl ratio), of the turbulence optical properties, and of the direction of the observation. It turns out that the sky coverage is disastrously low in particular in the visible wavelength range where, unfortunately, the gain in spatial resolution brought by adaptive optics is the largest. Foy and Labeyrie have proposed to overcome this difficulty by creating an artificial point source in the sky in the direction of the observation relying on the backscattered light due to a laser beam. This laser guide star (hereinafter referred to as LGS) can be bright enough to allow us to accurately measure the wavefront phase errors, except for two modes which are the piston (not relevant in this case) and the tilt. Pilkington has emphasized that the round trip time of the laser beam to the mesosphere, where the LGS is most often formed, is significantly shorter than the typical tilt coherence time; then the inverse-return-of-light principle causes deflections of the outgoing and the ingoing beams to cancel. The apparent direction of the LGS is independent of the tilt. Therefore the tilt cannot be measured only from the LGS. Until now, the way to overcome this difficulty has been to use a natural guide star to sense the tilt. Although the tilt is sensed through the entire telescope pupil, one cannot use a faint source because $APEX 90% of the variance of the phase error is in the tilt. Therefore, correcting the tilt requires a higher accuracy of the measurements than for higher orders of the wavefront. Hence current adaptive optics devices coupled with a LGS face low sky coverage. Several methods have been proposed to get a partial sky coverage for the tilt. The only one providing us with a full sky coverage is the polychromatic LGS (hereafter referred to as PLGS). We present here a progress report of the R&D; program Etoile Laser Polychromatique et Optique Adaptative (ELP-OA) carried out in France to develop the PLGS concept. After a short recall of the principles of the PLGS, we will review the goal of ELP-OA and the steps to get over to bring it into play. We finally shortly described the effort in Europe to develop the LGS

Disaggregated Analysis: The Key to Understanding Wellbeing in Kenya in the Context of Food Price Volatility

This article provides a national?level picture of food security and wellbeing in Kenya, focusing on the situation before the 2008 food price crisis, and the period after 2008. The extent and impact of food price changes differ spatially, and households have different ways of trying to respond. The major food price shocks in 2008 and 2011 impacted negatively on wellbeing, but even after 2011 prices continued to rise in most areas. Seasonal price movements also have adverse effects for resource?poor households. Food price rises have a particularly negative impact on the poorest households. Urban slum dwellers are vulnerable given their dependence on market purchases to meet food needs, but most rural households also have high dependence on market purchases. Current social protection programmes are piecemeal and unreliable. The article concludes with proposals on more effective social protection approaches and agricultural programmes which can address problems linked to food price rises

Polychromatic guide star: feasibility study

International audienceAdaptive optics at astronomical telescopes aims at correcting in real time the phase corrugations of incoming wavefronts caused by the turbulent atmosphere, as early proposed by Babcock. Measuring the phase errors requires a bright source located within the isoplanatic patch of the program source. The probability that such a reference source exists is a function of the wavelength, of the required image quality (Strehl ratio), of the turbulence optical properties, and of the direction of the observation. It turns out that the sky coverage is disastrously low in particular in the visible wavelength range where, unfortunately, the gain in spatial resolution brought by adaptive optics is the largest. Foy and Labeyrie have proposed to overcome this difficulty by creating an artificial point source in the sky in the direction of the observation relying on the backscattered light due to a laser beam. This laser guide star (hereinafter referred to as LGS) can be bright enough to allow us to accurately measure the wavefront phase errors, except for two modes which are the piston (not relevant in this case) and the tilt. Pilkington has emphasized that the round trip time of the laser beam to the mesosphere, where the LGS is most often formed, is significantly shorter than the typical tilt coherence time; then the inverse-return-of-light principle causes deflections of the outgoing and the ingoing beams to cancel. The apparent direction of the LGS is independent of the tilt. Therefore the tilt cannot be measured only from the LGS. Until now, the way to overcome this difficulty has been to use a natural guide star to sense the tilt. Although the tilt is sensed through the entire telescope pupil, one cannot use a faint source because $APEX 90% of the variance of the phase error is in the tilt. Therefore, correcting the tilt requires a higher accuracy of the measurements than for higher orders of the wavefront. Hence current adaptive optics devices coupled with a LGS face low sky coverage. Several methods have been proposed to get a partial sky coverage for the tilt. The only one providing us with a full sky coverage is the polychromatic LGS (hereafter referred to as PLGS). We present here a progress report of the R&D; program Etoile Laser Polychromatique et Optique Adaptative (ELP-OA) carried out in France to develop the PLGS concept. After a short recall of the principles of the PLGS, we will review the goal of ELP-OA and the steps to get over to bring it into play. We finally shortly described the effort in Europe to develop the LGS

The onset and cessation of seasonal rainfall over Africa

Variation in the seasonal cycle of African rainfall is of key importance for agriculture. Here, an objective method of determining the timing of onset and cessation is, for the first time, extended to the whole of Africa. The method is applied to five observational datasets and the ERA-Interim reanalysis. Compatibility with known physical drivers of African rainfall, consistency with indigenous methods, and generally strong agreement between satellite-based rainfall datasets confirm the method is capturing the correct seasonal progression of African rainfall. The biannual rainfall regime is correctly identified over the coastal region of Ghana and the Ivory Coast. However, the ERA-Interim reanalysis exhibits timing biases over areas with two rainy seasons, and both ERA-Interim and the ARCv2 observational dataset exhibit some inconsistent deviations over West Africa. The method can be used to analyze both seasonal - interannual variability and long-term change. Over East Africa, we find that failure of the rains and subsequent humanitarian disaster is associated with shorter as well as weaker rainy seasons, e.g. on average the long rains were 11 days shorter in 2011. Cessation of the short rains over this region is 7 days later in El Niño and 5 days earlier in La Niña years with only a small change in onset date. The methodology described in this paper is applicable to multiple datasets and to large regions, including those that experience multiple rainy seasons. As such, it provides a means for investigating variability and change in the seasonal cycle over the whole of Africa

A systematic approach to assess climate information products applied to agriculture and food security in Guatemala and Colombia

[EN] Increased interannual climate variability affects agricultural livelihoods throughout the world. In many regions, climate services support decision-makers in their adaptation efforts. The range of these services and the number of associated information products have increased dramatically in recent years. However, the relationships between these products and their use and usability for targeted decision-making have rarely been systematically evaluated. Here, we report on the development of a systematic and user-centered approach to assess climate information products and networks of products; and apply it to products covering the nexus of climate, agri- culture, and food security in Guatemala and Colombia. Across both countries, we assessed 28 products used for agricultural decision making, outreach, planning research, and design of emergency responses. While climate- only information products play a central role in each network, information products intended to support agri- culture and food security need to integrate information from different themes or disciplines and sources at different scales. We find that major improvements in the credibility, legitimacy, scale, cognition, procedures, recommendations, and content of most existing products are required. Brevity and clarity of language are highlighted as desirable in both countries, as well as use of trusted and publicly-available data, and non-paper- based delivery formats. The approach and methodology are valuable for facilitating the prioritization of actions for improvement and/or the development of new products, thereby helping climate services for agriculture and food security to realize their true potential.We acknowledge support from the Climate Change, Agriculture and Food Security (CCAFS), under the project P42 Agroclimas 1 - Tailored agroclimatic and food security information for decision making in Latin America and P1604 Agroclimas 2 - Digitally integrated approaches for managing climate risks and increasing food security (http://bit.ly/2i3V0Nh).CCAFS is carried out with support from CGIAR Trust Fund Donors and through bilateral funding agreements. For details please visit https://ccafs.cgiar.org/donors.The views expressed in this paper cannot be taken to reflect the official opinions of these organizations. We also acknowledge support from the Colombian Ministry of Agriculture (MADR), who enable the co-production of climate services in Colombia through the AClimateColombia program (http://www.aclimatecolombia.org).JR-V and DG were partly supported by the project Climate Services for Resilient Development (CSRD)-United States Agency for International Development (USAID) Award#: AID-BFS-G-11-00002-10 towards the CGIAR Fund (MTO 069018). CSRD (http://www.cs4rd.org/) brings together public and private organizations and agencies committed to realizing the potential to enhance climate resilience and climate-smart policies and practices throughout the world, particularly in developing countries.Bouroncle-Seoane, C.; Müller, A.; Giraldo, D.; Rios, D.; Imbach, P.; Girón, E.; Portillo, F.... (2019). A systematic approach to assess climate information products applied to agriculture and food security in Guatemala and Colombia. Climate Services. 16:1-17. https://doi.org/10.1016/j.cliser.2019.100137S1171