142 research outputs found
Mineralogy and Malignant Mesothelioma: The South African Experience
South Africa is a uniquely mineral rich country. Of the six types of asbestiform minerals found in the country, three, namely crocidolite, amosite and chrysotile were mined and milled on a large commercial scale. Asbestos was used locally in South Africa, but the majority of its production was exported worldwide. In the 1970s, South Africa was the world’s third largest producer of asbestos, behind Canada and the USSR. About 97% of the world’s production of crocidolite and virtually all of the amosite came from South Africa. The output from the South African asbestos mining industry peaked at 380,000 tonnes in 1977 and declined thereafter as export markets declined due to restrictive legislation in countries that imported asbestos (Virta, 2006; Kielkowski et al., 2011). Legislation in South Africa banning the use of all types of asbestos came into effect in 2008, well after the last asbestos mine ceased production in 2001 and closed in 2002. Although South Africa benefitted financially from the exploitation of its asbestos mineral reserves, the revenue from asbestos never accounted for more than 3% of the value of its total minerals output (McCulloch, 2003). There is however a high price to pay in terms of a legacy of disease and environmental contamination through mining activities and the transport of asbestos and asbestos containing products
Identification of motifs that function in the splicing of non-canonical introns
The enrichment of specific intronic splicing enhancers upstream of weak PY tracts suggests a novel mechanism for intron recognition that compensates for a weakened canonical pre-mRNA splicing motif
Chemokine (C-C motif) ligand 2 mediates direct and indirect fibrotic responses in human and murine cultured fibrocytes
<p>Abstract</p> <p>Background</p> <p>Fibrocytes are a population of circulating bone-marrow-derived cells that express surface markers for leukocytes and mesenchymal cells, and are capable of differentiating into myofibroblasts. They have been observed at sites of active fibrosis and increased circulating numbers correlate with mortality in idiopathic pulmonary fibrosis (IPF). Inhibition of chemokine (C-C motif) receptor 2 (CCR2) during experimental models of lung fibrosis reduces lung collagen deposition, as well as reducing lung fibrocyte accumulation. The aim of the present study was to determine whether human and mouse fibrocytes express functional CCR2.</p> <p>Results</p> <p>Following optimized and identical human and murine fibrocyte isolation, both cell sources were shown to be positive for CCR2 by flow cytometry and this expression colocalized with collagen I and CD45. Human blood fibrocytes stimulated with the CCR2 ligand chemokine (C-C motif) ligand 2 (CCL2), demonstrated increased proliferation (<it>P </it>< 0.005) and differentiation into myofibroblasts (<it>P </it>< 0.001), as well as a chemotactic response (<it>P </it>< 0.05). Murine fibrocytes also responded to CCR2 stimulation, with CCL12 being more potent than CCL2.</p> <p>Conclusions</p> <p>This study directly compares the functional responses of human and murine fibrocytes to CCR2 ligands, and following comparable isolation techniques. We have shown comparable biological effects, strengthening the translatability of the murine models to human disease with respect to targeting the CCR2 axis to ameliorate disease in IPF patients.</p
Certified to make a difference’: the motivation and perceptions of newly qualified early years teachers in England
The last 20 years have brought numerous workforce reforms to the early years sector, enacted in the name of professionalisation, including the recent introduction of a new postgraduate qualification, the Early Years Teacher Status. This article features data from interviews with 22 participants who had just completed this award and situates their views in the relevant policy context and alongside a discussion of what it means to professionalise the early years sector and create a graduate led workforce. The data support findings from similar studies of Early Years Professionals, namely that the interviewees are passionate about working with young children. They view the sector as in need of change, and themselves as potential leaders and agents of change. The participants endorse the view that up-skilling the workforce is essential to the professionalisation of the sector and improving the quality of early years educatio
LIMPRINT: the UK experience - subjective control of swelling in patients attending specialist lymphedema services
Background and study design: This study was undertaken as part of the UK LIMPRINT international study to determine the number of people with chronic oedema and its impact on health services. Overall 7436 with chronic oedema (CO) were recruited in the main UK study from a range of health settings.
Methods and results: Subjective control of arm and leg chronic oedema (CO) was defined for patients attending three Lymphoedema services in the UK. Of the total available in the UK dataset 5165 (69.4%)/ 7436(100%) of participants were included. Reasons for exclusions included the following: lack of information (1669), having both arm and leg swelling (272), lack of description of control (5) and professional inability to decide whether CO was controlled (325). Arm swelling occurred in 953 (18.5%), with leg CO in 4212 (81.5%). Poor control was found in 1430 (27.7%) and good control in 3735 (72.3%). Control of arm swelling was worse in men and control increased overall in those aged over 45 years. In contrast control of CO worsened in those with leg CO with increasing age and multiple co-morbidities. Obesity and cellulitis, particularly an episode in the last year were associated with poor control. Independent risk factors for arm CO were obesity, neurological disease and cellulitis in the last year and for leg CO: obesity, poor mobility, heart disease, presence of a wound, cellulitis in the last year and duration of swelling.
Conclusion: Control of CO within specialised centres is complex due to sociodemographic and clinical comorbidities
Occurrence of an Intersexual Blacktip Shark in the Northern Gulf of Mexico, with Notes on the Standardization of Classifications for This Condition in Elasmobranchs
An intersexual Blacktip Shark Carcharhinus limbatus with a testis, immature female reproductive tracts (embedded), and claspers was caught in the Gulf of Mexico. Histology of the single gonad revealed that all stages of spermatogenesis were occurring; however, the absence of ovaries and a male duct system suggests that neither sex would have been functional in this individual. Intersexuality has been reported in 17 families and 36 species of elasmobranchs. The degree to which the different sexes are present in a given individual is often difficult to categorize by normal hermaphroditic standards, as this is typically an anomalous presentation in elasmobranchs. Therefore, this report provides three categories for classification (basic, incomplete, and complete intersexuality) to standardize terminology and allow for more precise comparisons to be made among elasmobranch examples. Basic intersexuals have gonadal tissue of only one sex and a combination of other male and female characters with neither or only one sex being complete. Incomplete intersexuals have gonadal tissue of both sexes and a combination of other male and female characters; however, neither or only one sex is complete. Complete intersexuals have claspers as well as gonadal tissue and tracts for both sexes. The majority of the reported intersexual elasmobranchs, including the shark described here, are basic intersexuals
The SOLAS air-sea gas exchange experiment (SAGE) 2004
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 58 (2011): 753-763, doi:10.1016/j.dsr2.2010.10.015.The SOLAS air-sea gas exchange experiment (SAGE) was a multiple-objective study investigating
gas-transfer processes and the influence of iron fertilisation on biologically driven gas exchange in
high-nitrate low-silicic acid low-chlorophyll (HNLSiLC) Sub-Antarctic waters characteristic of the
expansive Subpolar Zone of the southern oceans. This paper provides a general introduction and
summary of the main experimental findings. The release site was selected from a pre-voyage desktop
study of environmental parameters to be in the south-west Bounty Trough (46.5°S 172.5°E) to the
south-east of New Zealand and the experiment conducted between mid-March and mid-April 2004. In
common with other mesoscale iron addition experiments (FeAX’s), SAGE was designed as a
Lagrangian study quantifying key biological and physical drivers influencing the air-sea gas exchange
processes of CO2, DMS and other biogenic gases associated with an iron-induced phytoplankton
bloom. A dual tracer SF6/3He release enabled quantification of both the lateral evolution of a labelled
volume (patch) of ocean and the air-sea tracer exchange at the 10’s of km’s scale, in conjunction with
the iron fertilisation. Estimates from the dual-tracer experiment found a quadratic dependency of the
gas exchange coefficient on windspeed that is widely applicable and describes air-sea gas exchange in strong wind regimes. Within the patch, local and micrometeorological gas exchange process studies (100 m scale) and physical variables such as near-surface turbulence, temperature microstructure at the interface, wave properties, and wind speed were quantified to further assist the development of gas exchange models for high-wind environments.
There was a significant increase in the photosynthetic competence (Fv/Fm) of resident phytoplankton
within the first day following iron addition, but in contrast to other FeAX’s, rates of net primary
production and column-integrated chlorophyll a concentrations had only doubled relative to the
unfertilised surrounding waters by the end of the experiment. After 15 days and four iron additions
totalling 1.1 tonne Fe2+, this was a very modest response compared to the other mesoscale iron
enrichment experiments. An investigation of the factors limiting bloom development considered co-
limitation by light and other nutrients, the phytoplankton seed-stock and grazing regulation. Whilst
incident light levels and the initial Si:N ratio were the lowest recorded in all FeAX’s to date, there was
only a small seed-stock of diatoms (less than 1% of biomass) and the main response to iron addition
was by the picophytoplankton. A high rate of dilution of the fertilised patch relative to phytoplankton
growth rate, the greater than expected depth of the surface mixed layer and microzooplankton grazing
were all considered as factors that prevented significant biomass accumulation. In line with the limited
response, the enhanced biological draw-down of pCO2 was small and masked by a general increase in pCO2 due to mixing with higher pCO2 waters. The DMS precursor DMSP was kept in check through grazing activity and in contrast to most FeAX’s dissolved dimethylsulfide (DMS) concentration declined through the experiment. SAGE is an important low-end member in the range of responses to iron addition in FeAX’s. In the context of iron fertilisation as a geoengineering tool for atmospheric CO2 removal, SAGE has clearly demonstrated that a significant proportion of the low iron ocean may not produce a phytoplankton bloom in response to iron addition.SAGE was jointly funded through
the New Zealand Foundation for Research, Science and Technology (FRST) programs
(C01X0204) "Drivers and Mitigation of Global Change" and (C01X0223) "Ocean
Ecosystems: Their Contribution to NZ Marine Productivity." Funding was also provided for
specific collaborations by the US National Science Foundation from grants OCE-0326814
(Ward), OCE-0327779 (Ho), and OCE 0327188 OCE-0326814 (Minnett) and the UK Natural
Environment Research Council NER/B/S/2003/00282 (Archer). The New Zealand
International Science and Technology (ISAT) linkages fund provided additional funding
(Archer and Ziolkowski), and the many collaborator institutions also provided valuable
support
Memantine in patients with frontotemporal lobar degeneration: a multicentre, randomised, double-blind, placebo-controlled trial
Memantine has been used off-label to treat frontotemporal lobar degeneration (FTD). A previous 26 week open label study suggested a transient, modest benefit on neuropsychiatric symptoms as measured by the Neuropsychiatric Inventory (NPI)
Number of People Blind or Visually Impaired by Glaucoma Worldwide and in World Regions 1990 – 2010: A Meta-Analysis
Objective:
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.
Methods:
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.
Results:
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 (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.
Significance:
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
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