10,967 research outputs found
Retinal Dysplasia Mimicking Retinoblastoma.
Retinal dysplasia represents a congenital disorder characterized by abnormal proliferation of retinal tissue causing leukocoria. We present a case of an infant with bilateral leukocoria, clinically diagnosed as retinoblastoma, followed by enucleation of the left eye. Microscopy however, demonstrated retinal dysplasia consisting of a disorderly proliferation of retinal tissue with formation of rosettes, mimicking retinoblastoma. Microscopic features that aid in differentiating this lesion from retinoblastoma are discussed
On dust–gas gravitational instabilities in protoplanetary discs
In protoplanetary discs the aerodynamical friction between particles and gas induces a variety of instabilities that facilitate planet formation. Of these we examine the so-called ‘secular gravitational instability’ (SGI) in the two-fluid approximation, deriving analytical expressions for its stability criteria and growth rates. Concurrently, we present a physical explanation of the instability that shows how it manifests upon an intermediate range of lengthscales exhibiting geostrophic balance in the gas component. The two-fluid SGI is completely quenched within a critical disc radius, as large as 10 au and 30 au for centimetre- and millimetre-sized particles, respectively, although establishing robust estimates is hampered by uncertainties in the parameters (especially the strength of turbulence) and deficiencies in the razor-thin disc model we employ. It is unlikely, however, that the SGI is relevant for well-coupled dust. We conclude by applying these results to the question of planetesimal formation and the provenance of large-scale dust rings.HNL acknowledges partial funding from Science and Technology Facilities Council (Grant ID: ST/L000636/1), and RR from a Bridgewater summer internship and from Newnham college
A Multistage Stochastic Programming Approach to the Dynamic and Stochastic VRPTW - Extended version
We consider a dynamic vehicle routing problem with time windows and
stochastic customers (DS-VRPTW), such that customers may request for services
as vehicles have already started their tours. To solve this problem, the goal
is to provide a decision rule for choosing, at each time step, the next action
to perform in light of known requests and probabilistic knowledge on requests
likelihood. We introduce a new decision rule, called Global Stochastic
Assessment (GSA) rule for the DS-VRPTW, and we compare it with existing
decision rules, such as MSA. In particular, we show that GSA fully integrates
nonanticipativity constraints so that it leads to better decisions in our
stochastic context. We describe a new heuristic approach for efficiently
approximating our GSA rule. We introduce a new waiting strategy. Experiments on
dynamic and stochastic benchmarks, which include instances of different degrees
of dynamism, show that not only our approach is competitive with
state-of-the-art methods, but also enables to compute meaningful offline
solutions to fully dynamic problems where absolutely no a priori customer
request is provided.Comment: Extended version of the same-name study submitted for publication in
conference CPAIOR201
Developing a spinal cord injury rehabilitation service in Madagascar
Rehabilitation for people with spinal cord injury in many low- and middle-income countries is not avail-able or is in the early stages of development. However, rehabilitation is recognized as crucial in order to optimize functional recovery and outcomes for patients with spinal cord injury. With an increasing incidence of spinal cord injury, the unmet need for rehabilitation is huge. This report describes the early development of a specialist rehabilitation service for spinal cord injury in Madagascar, one of the poorest countries in the world. The sustained input to an expanding rehabilitation team has led to reductions in avoidable complications. The input of the rehabilitation team has been welcomed by the neurosurgery department, which has recognized fewer delays in patients undergoing surgical treatments. Cost, lack of resources and trained staff, and poor understanding of disability continue to provide challenges. However, the development of the rehabilitation service using low technology, but with a high level of knowledge and systematic management, is a source of considerable pride. This development in Madagascar can be regarded as a model for spinal cord injury rehabilitation in other low-resource settings
A cross sectional study of water quality from dental unit water lines in dental practices in the West of Scotland
OBJECTIVE: To determine the microbiological quality of water from dental units in a general practice setting and current practice for disinfection of units. DESIGN: A cross-sectional study of the water quality from 40 dental units in 39 general practices and a questionnaire of the disinfection protocols used in those practices. SETTING: NHS practices in primarydental care. SUBJECTS: Thirty-nine general practices from the West of Scotland. METHODS: Water samples were collected on two separate occasions from dental units and analysed for microbiological quality by the total viable count (TVC) method. Water specimens were collected from the triple syringe, high speed outlet, cup filler and surgery tap. Each participating practitioner was asked to complete a questionnaire. Results Microbial contamination was highest from the high speed outlet followed by the triple syringe and cup filler. On average, the TVC counts from the high speed water lines at 37 degrees C and for the high speed lines, triple syringe and cup filler at 22 degrees C were significantly higher than that from the control tap water specimens. The study included units from 11 different manufacturers with ages ranging from under one year to over eight years. The age of the dental unit analysed did not appear to influence the level of microbial contamination. Five of the practices surveyed used disinfectants to clean the dental units but these had no significant effect on the microbiological quality of the water. The majority of dental units (25 out of 40) were never flushed with water between patients. A number of different non-sterile irrigants were used for surgical procedures. CONCLUSION: The microbiological quality of water from dental units in general dental practice is poor compared with that from drinking water sources. Suitable sterile irrigants should be used for surgical procedures in dental practice. Further work is required for pragmatic decontamination regimens of dental unit water lines in a general dental practice setting
Efficacy and safety comparison of topical loteprednol and topical non-steroidal anti-inflammatory drugs in seasonal allergic conjunctivitis: a prospective open label comparative study
Background: Seasonal allergic conjunctivitis (SAC) one of the most common ocular immunological disorder affecting wide population. Various classes of drugs are been used to control allergic inflammation. Traditionally topical glucocorticoids have been used for SAC. However, repeated and continuous use of steroids is associated with various complications like increase in intraocular pressure, posterior sub capsular cataract, increased susceptibility for infections and delayed wound healing. Hence the current emphasis is to prefer topical NSAIDs as they are free from various steroid related complications. As there is paucity of information regarding the comparative efficacy of topical steroids and NSAIDs, the present study was taken up. The main objective was to study the comparative efficacy and safety of three topical NSAIDs: flurbiprofen, diclofenac, ketorolac and the topical steroid loteprednol, in SAC.Methods: A prospective, comparative study enrolled 40 patients for SAC. All study drugs were instilled 4 times daily for 4 weeks. Patients were assessed for objective and subjective parameters of inflammation at baseline and weekly intervals for 4 weeks using four point scales, and also observed for any side effects. The anti-inflammatory action was assessed by the change in mean scores from basal and at various intervals.Results: Loteprednol was more effective than the three NSAIDs, only ketorolac comparable to loteprednol in relieving ocular itching. Study drugs showed good safety and tolerability, with only minimal local side effects.Conclusions: SAC the topical steroid loteprednol was found superior to NSAIDs
Small Carnivores of Biligiri Rangaswamy Temple Tiger Reserve, Karnataka, India
During the present study in Biligiri Rangaswamy Temple Tiger Reserve (BRT), nine species of small carnivores viz., Jungle Cat Felis chaus, Rusty-spotted Cat Prionalilurus rubiginosus, Leopard Cat Prionailurus bengalensis, Small Indian Civet Viverricula indica, Asian Palm Civet Paradoxurus hermaphroditus, Striped-necked Mongoose Herpestes vitticollis, Ruddy Mongoose Herpestes smithii, Common Mongoose Herpestes edwardsii and Smooth-coated Otter Lutrogale perspicillata, were recorded using camera-trapping technique, transect walks, and night surveys. Vegetation type strongly influences the presence and abundance of each species. The most sightings of small carnivores occurred in dry deciduous forests. Among all the species, the Asian Palm Civet was the most abundant and was followed by the small Indian Civet. Compared to many other forests or regions in India, the sight records of the Rusty-spotted Cat were relatively higher in BRT. Although we were unable to use statistical methods to search for higher levels of interdependencies between forest types and small carnivore abundance, our study sheds light on patterns of small carnivore distribution in this unique habitat which bridges the Western Ghats and the Eastern Ghats
Josephson effects in MgB2 meta masked ion damage junctions
Ion beam damage combined with nanoscale focused ion beam direct milling was
used to create manufacturable SNS type Josephson junctions in 100 nm thick
MgB with T of 38 K. The junctions show non-hysteretic current -
voltage characteristics between 36 and 4.2 K. Experimental evidence for the dc
and ac Josephson effects in MgB metal masked ion damage junctions are
presented. This technique is particularly useful for prototyping devices due to
its simplicity and flexibility of fabrication and has a great potential for
high-density integration.Comment: 12 pages, 4 figures, RevTeX4, submitted to AP
- …