1,302 research outputs found
H-alpha and Free-Free Emission from the WIM
Recent observations have found the ratio of H-alpha to free-free radio
continuum to be surprisingly high in the diffuse ionized ISM (the so-called
WIM), corresponding to an electron temperature of only ~3000K. Such low
temperatures were unexpected in gas that was presumed to be photoionized. We
consider a 3-component model for the observed diffuse emission, consisting of a
mix of (1) photoionized gas, (2) gas that is recombining and cooling, and (3)
cool H I gas. This model can successfully reproduce the observed intensities of
free-free continuum, H-alpha, and collisionally-excited lines such as NII 6583.
To reproduce the low observed value of free-free to H-alpha, the PAH abundance
in the photoionized regions must be lowered by a factor ~3, and ~20% of the
diffuse H-alpha must be reflected from dust grains, as suggested by Wood &
Reynolds (1999).Comment: 25 pages, 7 figures, 4 tables, single column, details of the
calculation and atomic physics added, accepted by Ap
Cooling process for inelastic Boltzmann equations for hard spheres, Part II: Self-similar solutions and tail behavior
We consider the spatially homogeneous Boltzmann equation for inelastic hard
spheres, in the framework of so-called constant normal restitution
coefficients. We prove the existence of self-similar solutions, and we give
pointwise estimates on their tail. We also give general estimates on the tail
and the regularity of generic solutions. In particular we prove Haff 's law on
the rate of decay of temperature, as well as the algebraic decay of
singularities. The proofs are based on the regularity study of a rescaled
problem, with the help of the regularity properties of the gain part of the
Boltzmann collision integral, well-known in the elastic case, and which are
extended here in the context of granular gases.Comment: 41 page
Biowaiver Monographs for Immediate‐Release Solid Oral Dosage Forms: Codeine Phosphate
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106898/1/jps23977.pd
Still a long way to go to achieve multidisciplinarity for the benefit of patients: commentary on the ESMO position paper (Annals Oncology Jan;25(1): 9-15, 2014)
Guidance on the use of bisphosphonates in solid tumours: recommendations of an international expert panel
Bisphosphonates (BP) prevent, reduce, and delay cancer-related skeletal complications in patients, and have substantially decreased the prevalence of such events since their introduction. Today, a broad range of BP with differences in potency, efficacy, dosing, and administration as well as approved indications is available. In addition, results of clinical trials investigating the efficacy of BP in cancer treatment-induced bone loss (CTIBL) have been recently published. The purpose of this paper is to review the current evidence on the use of BP in solid tumours and provide clinical recommendations. An interdisciplinary expert panel of clinical oncologists and of specialists in metabolic bone diseases assessed the widespread evidence and information on the efficacy of BP in the metastatic and nonmetastatic setting, as well as ongoing research on the adjuvant use of BP. Based on available evidence, the panel recommends amino-bisphosphonates for patients with metastatic bone disease from breast cancer and zoledronic acid for patients with other solid tumours as primary disease. Dosing of BP should follow approved indications with adjustments if necessary. While i.v. administration is most often preferable, oral administration (clodronate, IBA) may be considered for breast cancer patients who cannot or do not need to attend regular hospital care. Early-stage cancer patients at risk of developing CTIBL should be considered for preventative BP treatment. The strongest evidence in this setting is now available for ZOL. Overall, BP are well-tolerated, and most common adverse events are influenza-like syndrome, arthralgia, and when used orally, gastrointestinal symptoms. The dose of BP may need to be adapted to renal function and initial creatinine clearance calculation is mandatory according to the panel for use of any BP. Subsequent monitoring is recommended for ZOL and PAM, as described by the regulatory authority guidelines. Patients scheduled to receive BP (mainly every 3-4 weeks i.v.) should have a dental examination and be advised on appropriate measures for reducing the risk of jaw osteonecrosis. BP are well established as supportive therapy to reduce the frequency and severity of skeletal complications in patients with bone metastases from different cancer
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Global prevalence of childhood cataract: a systematic review
Childhood cataract is an avoidable cause of visual disability worldwide and is a priority for VISION 2020: The Right to Sight. There is a paucity of information about the burden of cataract in children and the aim of this review is to assess the global prevalence of childhood cataract. The methodology for the review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a literature search for studies reporting estimates of prevalence or incidence of cataract among children (aged<18 years) at any global location using the Cochrane Library, Medline and Embase up to January 2015. No restrictions were imposed based on language or year of publication. Study quality was assessed using a critical appraisal tool designed for systematic reviews of prevalence. Twenty prevalence and four incidence studies of childhood cataract from five different geographical regions were included. The overall prevalence of childhood cataract and congenital cataract was in the range from 0.32 to 22.9/10000 children (median=1.03) and 0.63 to 9.74/10000 (median=1.71), respectively. The incidence ranged from 1.8 to 3.6/10000 per year. The prevalence of childhood cataract in low-income economies was found to be 0.42 to 2.05 compared with 0.63 to 13.6/10000 in high-income economies. There was no difference in the prevalence based on laterality or gender. This review highlights substantial gaps in the epidemiological knowledge of childhood cataract worldwide, particularly from low and lower middle-income economies. More studies are needed using standard definitions and case ascertainment methods with large enough sample sizes
Survival Rate, Fracture Strength and Failure Mode of Ceramic Implant Abutments After Chewing Simulation
The aim of this study was to compare titanium-reinforced ZrO2 and pure Al2O3 abutments regarding their outcome after chewing simulation and static loading. Forty-eight standard diameter implants with an external hexagon were divided into three groups of 16 implants each and restored with three different types of abutments (group A: ZrO2 abutments with titanium inserts; group B: densely sintered high-purity Al2O3 abutments; group C: titanium abutments). All abutments were fixated on the implants with gold-alloy screws at 32 Ncm torque, and metal crowns were adhesively cemented onto the abutments. The specimens were exposed to 1.2 million cycles in a chewing simulator. Surviving specimens were subsequently loaded until fracture in a static testing device. Fracture loads (N) and fracture modes were recorded. A Wilcoxon Rank test to compare fracture loads among the 3 groups and a Fisher exact test to detect group differences in fracture modes were used for statistical evaluation (
Institutional assessment as an instrument of rationalization back to the school as a formal organisation
O papel central da avaliação, da avaliação institucional e dos
processos de garantia da qualidade de escolas e universidades
nas políticas educacionais é objeto de discussão, também
considerando a reforma do Estado. As teorias da nova gestão
pública e as perspectivas gestionárias são consideradas como
algumas das principais fontes de inspiração e de legitimação no
contexto dominante de uma educação contábil. Dados empíricos
preliminares resultantes do processo de avaliação externa de
escolas básicas e secundárias portuguesas são apresentados
e interpretados de acordo com os principais conceitos e
representações organizacionais de escola presentes nos relatórios
externos. Examinando algumas das imagens e dos significados de
escola, cultura de escola, autonomia, objetivos, liderança e eficácia
presentes nos relatórios de avaliação, o autor releva a importância
das imagens formais, racionais e burocráticas de escolas. Várias
questões de investigação são apresentadas tendo por base aquilo
a que o autor chama o processo da hiperburocratização das
organizações educativas. Algumas dimensões do conceito de
burocracia de Max Weber são revisitadas, em articulação com
perspectivas neocientíficas de garantia da qualidade e com as
tecnologias da informação e comunicação. O autor sugere que
maior relevância deve ser atribuída aos modelos formais e racionais
de interpretação das organizações educativas, pois os processos de
avaliação e de garantia da qualidade estão a contribuir para a
formalização de escolas e universidades e para a intensificação do
seu processo de racionalização, isto é, para a emergência de uma
imagem analítica das escolas como hiperburocracias.The central role of evaluation, institutional assessment and quality
assurance processes of schools and universities in education policy
is object of discussion also considering the reform of the state. New
Public Management theories and managerialist perspectives are
considered some of the main sources of inspiration and legitimation
in the dominant context of an audit education. Preliminary
empirical data from external assessment of Portuguese primary and
secondary schools are introduced and interpreted according to the
main concepts and organizational representations of school found
in external reports. Examining some of the central organizational
images and meanings of school, school culture, autonomy, goals,
leadership and effectiveness included in the external reviews, the
author stresses the importance of formal, rational and bureaucratic
images of schools. Several new research questions are presented
for further inquiry based on the hypothesis of what it is called by
the author the process of hyperbureaucratization of educational
organizations. Some of the main dimensions of the concept of
bureaucracy as presented by Max Weber are revisited in close
relation with neo-scientific approaches of quality assurance and
taking in consideration the use of information and communication
technologies. Accordingly the author suggests that much more
importance must be given to formal and rational models of
interpreting educational organizations because assessment and
quality assurance procedures are contributing to the formalization
of schools and universities and to the intensification of their process
of rationalization, i. e., to the emergence of an analytic image of
schools as hyperbureaucracies.(undefined
The effect of cataract on early stage glaucoma detection using spatial and temporal contrast sensitivity tests
Background:
To investigate the effect of cataract on the ability of spatial and temporal contrast sensitivity tests used to detect early glaucoma.
Methods:
Twenty-seven glaucoma subjects with early cataract (mean age 60 ±10.2 years) which constituted the test group were recruited together with twenty-seven controls (cataract only) matched for age and cataract type from a primary eye care setting. Contrast sensitivity to flickering gratings at 20 Hz and stationary gratings with and without glare, were measured for 0.5, 1.5 and 3 cycles per degree (cpd) in central vision. Perimetry and structural measurements with the Heidelberg Retinal Tomograph (HRT) were also performed.
Results:
After considering the effect of cataract, contrast sensitivity to stationary gratings was reduced in the test group compared with controls with a statistically significant mean difference of 0.2 log units independent of spatial frequency. The flicker test showed a significant difference between test and control group at 1.5 and 3 cpd (p = 0.019 and p = 0.011 respectively). The percentage of glaucoma patients who could not see the temporal modulation was much higher compared with their cataract only counterparts. A significant correlation was found between the reduction of contrast sensitivity caused by glare and the Glaucoma Probability Score (GPS) as measured with the HRT (p<0.005).
Conclusions:
These findings indicate that both spatial and temporal contrast sensitivity tests are suitable for distinguishing between vision loss as a consequence of glaucoma and vision loss caused by cataract only. The correlation between glare factor and GPS suggests that there may be an increase in intraocular stray light in glaucoma
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