6,360 research outputs found
A Unique Case of Autoimmune Retinopathy Associated with Anti-Alpha-Enolase Antibodies
Background. We report a case of autoimmune retinopathy associated with anti-alpha-enolase antibodies with unique manifestations. Methods. A case report. Results. A 30-year-old male experienced recurrent, primarily peripheral visual field disturbances and minimal photopsia, with interval symptom resolution. Fundus changes subsequently developed in areas corresponding to the previous visual field symptoms. Electroretinogram showed bilaterally symmetric abnormalities of light-adapted responses and suggested loss of photoreceptor function. Only anti-alpha-enolase antibodies were detected on Western blot. Our patient noted cutaneous symptoms at the time of both episodes of visual symptoms, but not in the interim. Biomicroscopy revealed subtle small reddish spots in areas of the peripheral retina corresponding to the areas of the patient's visual field where he noted symptoms. To our knowledge these reddish spots have not been reported in autoimmune retinopathy and may clinically support in vitro and in vivo evidence that anti-alpha-enolase antibodies may target photoreceptors. Conclusions. Our patient demonstrates some unique features adding to the known characteristics of autoimmune retinopathy associated with anti-alpha-enolase antibodies. As more cases are reported, further understanding of the features and pathophysiology of this rare condition will hopefully be elucidated
Agriculture, meteorology and water quality in Ireland: a regional evaluation of pressures and pathways of nutrient loss to water
peer-reviewedThe main environmental impact of Irish agriculture on surface and ground water quality is the potential transfer of nutrients to water. Soil water dynamics mediate the transport of nutrients to water, and these dynamics in turn depend on agro-meteorological conditions, which show large variations between regions, seasons and years. In this paper we quantify and map the spatio-temporal variability of agro-meteorological factors that control nutrient pressures and pathways of nutrient loss. Subsequently, we evaluate their impact on the water quality of Irish rivers. For nitrogen, pressure and pathways factors coincide in eastern and southern areas, which is reflected in higher nitrate levels of the rivers in these regions. For phosphorus, pathway factors are most pronounced in north-western parts of the country. In south-eastern parts, high pressure factors result in reduced biological water quality. These regional differences require that farm practices be customised to reflect the local risk of nutrient loss to water. Where pathways for phosphorus loss are present almost year-round—as is the case in most of the north-western part of the country—build-up of pressures should be prevented, or ameliorated where already high. In south-eastern areas, spatio-temporal coincidence of nutrient pressures and pathways should be prevented, which poses challenges to grassland management
Mixed-model Sequencing with Reinsertion of Failed Vehicles: A Case Study for Automobile Industry
In the automotive industry, some vehicles, failed vehicles, cannot be
produced according to the planned schedule due to some reasons such as material
shortage, paint failure, etc. These vehicles are pulled out of the sequence,
potentially resulting in an increased work overload. On the other hand, the
reinsertion of failed vehicles is executed dynamically as suitable positions
occur. In case such positions do not occur enough, either the vehicles waiting
for reinsertion accumulate or reinsertions are made to worse positions by
sacrificing production efficiency.
This study proposes a bi-objective two-stage stochastic program and
formulation improvements for a mixed-model sequencing problem with stochastic
product failures and integrated reinsertion process. Moreover, an evolutionary
optimization algorithm, a two-stage local search algorithm, and a hybrid
approach are developed. Numerical experiments over a case study show that while
the hybrid algorithm better explores the Pareto front representation, the local
search algorithm provides more reliable solutions regarding work overload
objective. Finally, the results of the dynamic reinsertion simulations show
that we can decrease the work overload by ~20\% while significantly decreasing
the waiting time of the failed vehicles by considering vehicle failures and
integrating the reinsertion process into the mixed-model sequencing problem.Comment: 26 pages, 6 figures, 5 table
Measurement of Lande g factor of 5D5/2 state of BaII with a single trapped ion
We present the first terrestrial measurement of the Lande g factor of the
5D5/2 state of singly ionized barium. Measurements were performed on single
Doppler-cooled 138Ba+ ions in a linear Paul trap. A frequency-stabilized fiber
laser with nominal wavelength 1.762 um was scanned across the 6S1/25D5/2
transition to spectroscopically resolve transitions between Zeeman sublevels of
the ground and excited states. From the relative positions of the four narrow
transitions observed at several different values for the applied magnetic
field, we find a value of 1.2020+/-0.0005 for g of 5D5/2.Comment: 3 figure
Mixed-model Sequencing with Stochastic Failures: A Case Study for Automobile Industry
In the automotive industry, the sequence of vehicles to be produced is
determined ahead of the production day. However, there are some vehicles,
failed vehicles, that cannot be produced due to some reasons such as material
shortage or paint failure. These vehicles are pulled out of the sequence, and
the vehicles in the succeeding positions are moved forward, potentially
resulting in challenges for logistics or other scheduling concerns.
This paper proposes a two-stage stochastic program for the mixed-model
sequencing (MMS) problem with stochastic product failures, and provides
improvements to the second-stage problem. To tackle the exponential number of
scenarios, we employ the sample average approximation approach and two solution
methodologies. On one hand, we develop an L-shaped decomposition-based
algorithm, where the computational experiments show its superiority over
solving the deterministic equivalent formulation with an off-the-shelf solver.
Moreover, we provide a tabu search algorithm in addition to a greedy heuristic
to tackle case study instances inspired by our car manufacturer partner.
Numerical experiments show that the proposed solution methodologies generate
high quality solutions by utilizing a sample of scenarios. Particularly, a
robust sequence that is generated by considering car failures can decrease the
expected work overload by more than 20\% for both small- and large-sized
instances.Comment: 30 pages, 9 figure
- …