To assess the number of individuals visually impaired or blind due to glaucoma and to examine regional differences and temporal changes in this parameter for the period from 1990 to 2012.
As part of ...the Global Burden of Diseases (GBD) Study 2010, we performed a systematic literature review for the period from 1980 to 2012. We primarily identified 14,908 relevant manuscripts, out of which 243 high-quality, population-based studies remained after review by an expert panel that involved application of selection criteria that dwelt on population representativeness and clarity of visual acuity methods used. Sixty-six specified the proportion attributable to glaucoma. The software tool DisMod-MR (Disease Modeling-Metaregression) of the GBD was used to calculate fraction of vision impairment due to glaucoma.
In 2010, 2.1 million (95% Uncertainty Interval (UI):1.9,2.6) people were blind, and 4.2 (95% UI:3.7,5.8) million were visually impaired due to glaucoma. Glaucoma caused worldwide 6.6% (95% UI:5.9,7.9) of all blindness in 2010 and 2.2% (95% UI:2.0,2.8) of all moderate and severe visual impairment (MSVI). These figures were lower in regions with younger populations (<5% in South Asia) than in high-income regions with relatively old populations (>10%). From 1990 to 2010, the number of blind or visually impaired due to glaucoma increased by 0.8 million (95%UI:0.7, 1.1) or 62% and by 2.3 million (95%UI:2.1,3.5) or 83%, respectively. Percentage of global blindness caused by glaucoma increased between 1990 and 2010 from 4.4% (4.0,5.1) to 6.6%. Age-standardized prevalence of glaucoma related blindness and MSVI did not differ markedly between world regions nor between women.
By 2010, one out of 15 blind people was blind due to glaucoma, and one of 45 visually impaired people was visually impaired, highlighting the increasing global burden of glaucoma.
Summary Background Data on causes of vision impairment and blindness are important for development of public health policies, but comprehensive analysis of change in prevalence over time is lacking. ...Methods We did a systematic analysis of published and unpublished data on the causes of blindness (visual acuity in the better eye less than 3/60) and moderate and severe vision impairment (MSVI visual acuity in the better eye less than 6/18 but at least 3/60) from 1980 to 2012. We estimated the proportions of overall vision impairment attributable to cataract, glaucoma, macular degeneration, diabetic retinopathy, trachoma, and uncorrected refractive error in 1990–2010 by age, geographical region, and year. Findings In 2010, 65% (95% uncertainty interval UI 61–68) of 32·4 million blind people and 76% (73–79) of 191 million people with MSVI worldwide had a preventable or treatable cause, compared with 68% (95% UI 65–70) of 31·8 million and 80% (78–83) of 172 million in 1990. Leading causes worldwide in 1990 and 2010 for blindness were cataract (39% and 33%, respectively), uncorrected refractive error (20% and 21%), and macular degeneration (5% and 7%), and for MSVI were uncorrected refractive error (51% and 53%), cataract (26% and 18%), and macular degeneration (2% and 3%). Causes of blindness varied substantially by region. Worldwide and in all regions more women than men were blind or had MSVI due to cataract and macular degeneration. Interpretation The differences and temporal changes we found in causes of blindness and MSVI have implications for planning and resource allocation in eye care. Funding Bill & Melinda Gates Foundation, Fight for Sight, Fred Hollows Foundation, and Brien Holden Vision Institute.
We present the H
I
emission project within the MIGHTEE survey, currently being carried out with the newly commissioned MeerKAT radio telescope. This is one of the first deep, blind, medium-wide ...interferometric surveys for neutral hydrogen (H
I
) ever undertaken, extending our knowledge of H
I
emission to
z
= 0.6. The science goals of this medium-deep, medium-wide survey are extensive, including the evolution of the neutral gas content of galaxies over the past 5 billion years. Simulations predict nearly 3000 galaxies over 0 <
z
< 0.4 will be detected directly in H
I
, with statistical detections extending to
z
= 0.6. The survey allows us to explore H
I
as a function of galaxy environment, with massive groups and galaxy clusters within the survey volume. Additionally, the area is large enough to contain as many as 50 local galaxies with H
I
mass < 10
8
M
⊙
, which allows us to study the low-mass galaxy population. The 20 deg
2
main survey area is centred on fields with exceptional multi-wavelength ancillary data, with photometry ranging from optical through far-infrared wavelengths, supplemented with multiple spectroscopic campaigns. We describe here the survey design and the key science goals. We also show first results from the Early Science observations, including kinematic modelling of individual sources, along with the redshift, H
I
, and stellar mass ranges of the sample to date.
AIM: Enhanced management of areas important for marine biodiversity are now obligations under a range of international treaties. Tracking data provide unparalleled information on the distribution of ...marine taxa, but there are no agreed guidelines that ensure these data are used consistently to identify biodiversity hotspots and inform marine management decisions. Here, we develop methods to standardize the analysis of tracking data to identify sites of conservation importance at global and regional scales. LOCATION: We applied these methods to the largest available compilation of seabird tracking data, covering 60 species, collected from 55 deployment locations ranging from the poles to the tropics. METHODS: Key developments include a test for pseudo‐replication to assess the independence of two groups of tracking data, an objective approach to define species‐specific smoothing parameters (h values) for kernel density estimation based on area‐restricted search behaviour, and an analysis to determine whether sites identified from tracked individuals are also representative for the wider population. RESULTS: This analysis delineated priority sites for marine conservation for 52 of the 60 species assessed. We compiled 252 data groupings and defined 1052 polygons, between them meeting Important Bird and Biodiversity Area criteria over 1500 times. Other results showed 13% of data groups were inadequate for site definition and 10% showed some level of pseudo‐replication. Between 25 and 50 trips were needed within a data group for data to be considered at least partially representative of the respective population. MAIN CONCLUSIONS: Our approach provides a consistent framework for using animal tracking data to delineate areas of global conservation importance, allowing greater integration into marine spatial planning and policy. The approaches we describe are exemplified for pelagic seabirds, but are applicable to a range of taxonomic groups. Covering 4.3% of the oceans, the sites identified would benefit from enhanced protection to better safeguard the threatened species populations they contain.
Polarization is one of the basic properties of electromagnetic waves conveying valuable information in signal transmission and sensitive measurements. Conventional methods for advanced polarization ...control impose demanding requirements on material properties and attain only limited performance. We demonstrated ultrathin, broadband, and highly efficient metamaterial-based terahertz polarization converters that are capable of rotating a linear polarization state into its orthogonal one. On the basis of these results, we created metamaterial structures capable of realizing near-perfect anomalous refraction. Our work opens new opportunities for creating high-performance photonic devices and enables emergent metamaterial functionalities for applications in the technologically difficult terahertz-frequency regime.
To estimate global and regional trends from 1990 to 2010 of the prevalence and number of persons visually impaired specifically by diabetic retinopathy (DR), as a complication of the precipitous ...trends in global diabetes, is fundamental for health planning purposes.
The meta-analysis of published population studies from 1990 to 2012 for the Global Burden of Disease Study 2010 (GBD) yielded estimated global regional trends in DR among other causes of moderate and severe vision impairment (MSVI; presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60).
Globally in 2010, out of overall 32.4 million blind and 191 million visually impaired people, 0.8 million were blind and 3.7 million were visually impaired because of DR, with an alarming increase of 27% and 64%, respectively, spanning the two decades from 1990 to 2010. DR accounted for 2.6% of all blindness in 2010 and 1.9% of all MSVI worldwide, increasing from 2.1% and 1.3%, respectively, in 1990. These figures were lower in regions with younger populations (<2% in East and Southeast Asia and Oceania) than in high-income regions (North America, Western Europe, and Australasia) with relatively aging populations (>4%).
The number of persons with visual impairment due to DR worldwide is rising and represents an increasing proportion of all blindness/MSVI causes. Age-standardized prevalence of DR-related blindness/MSVI was higher in sub-Saharan Africa and South Asia. One out of 39 blind people had blindness due to DR, and 1 out of 52 visually impaired people had visual impairment due to DR.
We present a study of the distribution of radio jet position angles of radio galaxies over an area of 1 square degree in the ELAIS N1 field. ELAIS N1 was observed with the Giant Metrewave Radio ...Telescope at 612 MHz to an rms noise level of 10 μJy and angular resolution of 6 arcsec × 5 arcsec. The image contains 65 resolved radio galaxy jets. The spatial distribution reveals a prominent alignment of jet position angles along a ‘filament’ of about 1°. We examine the possibility that the apparent alignment arises from an underlying random distribution and find that the probability of chance alignment is less than 0.1 per cent. An angular covariance analysis of the data indicates the presence of spatially coherence in position angles on scales >0
$_{.}^{\circ}$
5. This angular scales translates to a comoving scale of >20 Mpc at a redshift of 1. The implied alignment of the spin axes of massive black holes that give rise to the radio jets suggest the presence of large-scale spatial coherence in angular momentum. Our results reinforce prior evidence for large-scale spatial alignments of quasar optical polarization position angles.
Cerebellar ataxias are the result of diverse disease processes that can be genetic or acquired. Establishing a diagnosis requires a methodical approach with expert clinical evaluation and ...investigations. We describe the causes of ataxia in 1500 patients with cerebellar ataxia.
All patients were referred to the Sheffield Ataxia Centre, UK, and underwent extensive investigations, including, where appropriate genetic testing using next-generation sequencing (NGS). Patients were followed up on a 6-monthly basis for reassessment and further investigations if indicated.
A total of 1500 patients were assessed over 20 years. Twenty per cent had a family history, the remaining having sporadic ataxia. The commonest cause of sporadic ataxia was gluten ataxia (25%). A genetic cause was identified in 156 (13%) of sporadic cases with other causes being alcohol excess (12%) and cerebellar variant of multiple system atrophy (11%). Using NGS, positive results were obtained in 32% of 146 patients tested. The commonest ataxia identified was EA2. A genetic diagnosis was achieved in 57% of all familial ataxias. The commonest genetic ataxias were Friedreich's ataxia (22%), SCA6 (14%), EA2 (13%), SPG7 (10%) and mitochondrial disease (10%). The diagnostic yield following attendance at the Sheffield Ataxia Centre was 63%.
Immune-mediated ataxias are common. Advances in genetic testing have significantly improved the diagnostic yield of patients suspected of having a genetic ataxia. Making a diagnosis of the cause of ataxia is essential due to potential therapeutic interventions for immune and some genetic ataxias.
The amount of research activity concerning α-methylene-γ-butyrolactones and α-alkylidene-γ-butyrolactones has increased dramatically in recent years. This Review summarizes the structural types, ...biological activities, and biosynthesis of these compounds, concentrating on publications from the past 10 years. Traditional approaches to α-methylene-γ-butyrolactones and α-alkylidene-γ-butyrolactones are then reviewed together with novel approaches, including those from our own research group, reported more recently.
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