2,608 research outputs found
Suprachoroidal hemorrhage during femtosecond laser assisted cataract surgery.
Purpose:To describe a case of suprachoroidal hemorrhage that occurred during femtosecond laser assisted cataract surgery (FLACS). Observations:A 67-year-old woman with high myopia underwent FLACS. Following two unsuccessful attempts at docking due to interface air bubbles, the third attempt was successful. Laser treatment and cataract surgery proceeded uneventfully until intraocular lens (IOL) implantation. While positioning the IOL within the capsular bag, the anterior chamber began to shallow, intraocular pressure became high by palpation, and the optic of the IOL prolapsed partially out of the bag. A segmental suprachoroidal hemorrhage was identified in the superior peripheral retina by intraoperative indirect ophthalmoscopy. Following an hour of waiting in the recovery room, the anterior chamber deepened and the intraocular pressure was low enough to position the IOL centrally within the bag. Her subsequent postoperative course was uneventful. Conclusions and Importance:To our knowledge, this is the first report of suprachoroidal hemorrhage during FLACS. We speculate that repeated sudden drops in intraocular pressure associated with multiple undockings triggered the suprachoroidal hemorrhage in this case
Origin of gamma-ray emission in the shell of Cassiopeia A
Non-thermal X-ray emission from the shell of Cassiopeia A (Cas A) has been an
interesting subject of study, as it provides information about relativistic
electrons and their acceleration mechanisms in the shocks. Chandra X-ray
observatory revealed the detailed spectral and spatial structure of this SNR in
X-rays. The spectral analysis of Chandra X-ray data of Cas A shows unequal flux
levels for different regions of the shell, which can be attributed to different
magnetic fields in those regions. Additionally, the GeV gamma-ray emission
observed by Large Area Telescope on board Fermi Gamma Ray Space Telescope
showed that the hadronic processes are dominating in Cas A, a clear signature
of acceleration of protons. In this paper we aim to explain the GeV-TeV
gamma-ray data in the context of both leptonic and hadronic scenario. We
modeled the multi-wavelength spectrum of Cas A. We use synchrotron emission
process to explain the observed non-thermal X-ray fluxes from different regions
of the shell. These result in estimation of the model parameters, which are
then used to explain TeV gamma-ray emission spectrum. We also use hadronic
scenario to explain both GeV and TeV fluxes simultaneously. We show that a
leptonic model alone cannot explain the GeV-TeV data. Therefore, we need to
invoke a hadronic model to explain the observed GeV-TeV fluxes. We found that
although pure hadronic model is able to explain the GeV-TeV data, a
lepto-hadronic model provides the best fit to the data.Comment: Accepted in A&
The effect of dietary inclusion of meat and bone meal on the performance of laying hens at old age
The effect of the inclusion of meat and bone meal (MBM) in the diet of old laying hens on their egg production and the quality of their eggs was investigated. Meat and bone meal containing a high concentration of ash and a low concentration of crude protein was included at levels of 2.0, 4.0 and 6.0% in the diets and fed for 20 weeks. Forced moulted 84-week old laying hens (Brown-Nick) were divided randomly into four treatment groups of 120 hens each. The inclusion of 2.0% MBM to the layer diet increased hen-day egg production significantly, whereas inclusion in excess of 2.0% MBM had no additional beneficial effect on egg production. However, the inclusion of dietary MBM at all three levels depressed egg weight. There were no significant effects of dietary treatments on egg weight, feed intake and feed conversion ratio of the hens. The specific gravity of the eggs from hens fed the control diet was significantly lower than from those receiving the diets containing 2.0 and 4.0% MBM. The Haugh Unit value of eggs in the 6.0% MBM treatment was significantly higher than the other treatments. There were no significant effects of MBM inclusion on yolk colour score, yolk height, eggshell thickness, eggshell weight and eggshell strength. However, MBM inclusion in a diet had a significant beneficial effect on eggshell quality. The eggshell ratios of the 2.0, 4.0 and 6.0% MBM treatments were significantly higher than in the control diet, while the cracked/broken egg ratio was significantly lower. In conclusion, inclusion of MBM containing a high ash and low crude protein content to conventional maize-soya bean diet improved egg production performance of laying hens. The dicalcium phosphate level in the diet could also be reduced without any adverse effects on egg production and egg quality.
Key Words: Meat and bone meal, Egg production, Egg quality, Laying hens
SA Jnl Animal Sci Vol.34(1) 2004: 31-3
Projections Onto Convex Sets (POCS) Based Optimization by Lifting
Two new optimization techniques based on projections onto convex space (POCS)
framework for solving convex and some non-convex optimization problems are
presented. The dimension of the minimization problem is lifted by one and sets
corresponding to the cost function are defined. If the cost function is a
convex function in R^N the corresponding set is a convex set in R^(N+1). The
iterative optimization approach starts with an arbitrary initial estimate in
R^(N+1) and an orthogonal projection is performed onto one of the sets in a
sequential manner at each step of the optimization problem. The method provides
globally optimal solutions in total-variation, filtered variation, l1, and
entropic cost functions. It is also experimentally observed that cost functions
based on lp, p<1 can be handled by using the supporting hyperplane concept
Children’s interactions with water in city centres: a case study from Sheffield, UK
Children’s experiences of outdoor environments have been studied now for more than 40 years yet no research has specifically focussed on children’s experiences of water play in constructed spaces of city centres. This article discusses the development of an observational mapping tool, called TOWEC, to record the interaction of children with water. It then reports findings and analysis from observations over a year-long period of 3,399 children interacting with water in the award winning public open space of the Peace Gardens in the centre of the City of Sheffield, UK. The findings reveal that children undertake both active and passive activities associated with the constructed water features and that these activities are influenced by gender, age and temperature, but not ethnicity. The water features were not designed for children to play in but the children realise the potential affordance that the water features provide
Shortcuts through Colocation Facilities
Network overlays, running on top of the existing Internet substrate, are of
perennial value to Internet end-users in the context of, e.g., real-time
applications. Such overlays can employ traffic relays to yield path latencies
lower than the direct paths, a phenomenon known as Triangle Inequality
Violation (TIV). Past studies identify the opportunities of reducing latency
using TIVs. However, they do not investigate the gains of strategically
selecting relays in Colocation Facilities (Colos). In this work, we answer the
following questions: (i) how Colo-hosted relays compare with other relays as
well as with the direct Internet, in terms of latency (RTT) reductions; (ii)
what are the best locations for placing the relays to yield these reductions.
To this end, we conduct a large-scale one-month measurement of inter-domain
paths between RIPE Atlas (RA) nodes as endpoints, located at eyeball networks.
We employ as relays Planetlab nodes, other RA nodes, and machines in Colos. We
examine the RTTs of the overlay paths obtained via the selected relays, as well
as the direct paths. We find that Colo-based relays perform the best and can
achieve latency reductions against direct paths, ranging from a few to 100s of
milliseconds, in 76% of the total cases; 75% (58% of total cases) of these
reductions require only 10 relays in 6 large Colos.Comment: In Proceedings of the ACM Internet Measurement Conference (IMC '17),
London, GB, 201
Effect of phytase supplementation of diets with different levels of phosphorus on performance and egg quality of laying hens in hot climatic conditions
Four hundred and eighty 54-week old Nick-Brown hens were assigned to four dietary treatments. Each treatment consisted of four replications of 10 cages (three hens per cage). The experimental diets were: 4.5 g available phosphorus (aP)/kg without phytase (control); 4.5 g aP/kg with phytase; 3.0 g aP/kg without phytase; 3.0 g aP/kg with phytase. Commercial microbial phytase, Natuphos(R), was added at 300 phytase unit (FTU) /kg diet. Diets were isonitrogenous (16.5% crude protein) and isoenergetic (11.5 MJ, ME/kg). Criteria evaluated included egg production, feed consumption, feed conversion, proportion of cracked/broken eggs, egg weight, eggshell weight, eggshell strength, eggshell thickness and body weight. Phytase supplementation to the control diet (4.5 g aP/kg) and the low 3.0 g aP/kg diet significantly increased hen-day egg production from 75.49 to 77.96% and from 64.59 to 76.54%, respectively. Average daily feed consumption was significantly different between treatments: Phytase supplementation to the control and the 3.0 g aP/kg diets increased daily feed consumption significantly from 101.31 to 103.43 g/day and from 95.24 to 101.69 g/day, respectively. There were no significant differences between the treatments in eggshell weight, eggshell thickness, eggshell strength and cracked/broken eggs. Phytase supplementation to the control (4.5 g aP/kg) and the 3.0 g aP/kg diets increased egg weight significantly from 62.66 to 64.32 g. and from 62.49 to 63.98 g, respectively. The beneficial effects of phytase supplementation to laying hen diets were clearly evident under the high ambient temperatures pertaining to this study. Hens consuming the 3.0 g aP/kg diet with phytase performed as well as hens fed the diet containing 4.5 g aP/kg without phytase.
Key Words: Phytase, Laying hen, Available phosphorus, Performance, Ambient temperature
SA Jnl Animal Sci Vol.34(1) 2004: 13-1
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