A Genetic Association Study of Serum Acute-Phase C-Reactive Protein Levels in Rheumatoid Arthritis: Implications for Clinical Interpretation

A genetic association study by Timothy Vyse and colleagues suggests that there is a significant association between CRP variants and acute-phase serum CRP concentrations in patients with rheumatoid arthritis, including those with chronic inflammation

Ageing vision and falls: a review

Background: Falls are the leading cause of accidental injury and death among older adults. One of three adults over the age of 65 years falls annually. As the size of elderly population increases, falls become a major concern for public health and there is a pressing need to understand the causes of falls thoroughly. Main body of the abstract: While it is well documented that visual functions such as visual acuity, contrast sensitivity, and stereo acuity are correlated with fall risks, little attention has been paid to the relationship between falls and the ability of the visual system to perceive motion in the environment. The omission of visual motion perception in the literature is a critical gap because it is an essential function in maintaining balance. In the present article, we first review existing studies regarding visual risk factors for falls and the effect of ageing vision on falls. We then present a group of phenomena such as vection and sensory reweighting that provide information on how visual motion signals are used to maintain balance. Conclusion: We suggest that the current list of visual risk factors for falls should be elaborated by taking into account the relationship between visual motion perception and balance control

Understanding the retinal basis of vision across species

The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision

Frequency of anxiety after stroke: a systematic review and meta-analysis of observational studies.

BACKGROUND AND PURPOSE: Negative psychological outcomes occur frequently after stroke; however, there is uncertainty regarding the occurrence of anxiety disorders and anxiety symptoms after stroke. A systematic review of observational studies was conducted that assessed the frequency of anxiety in stroke patients using a diagnostic or screening tool. SUMMARY OF REVIEW: Databases were searched up to March 2011. A random effects model was used to summarize the pooled estimate. Statistical heterogeneity was assessed using the I(2) statistic. Forty-four published studies comprising 5760 stroke patients were included. The overall pooled estimate of anxiety disorders assessed by clinical interview was 18% (95%confidence interval 8-29%, I(2)  = 97%) and was 25% (95% confidence interval 21-28%, I(2)  = 90%) for anxiety assessed by rating scale. The Hospital Anxiety and Depression Scale-Anxiety subscale 'probable' and 'possible' cutoff scores were the most widely used assessment criteria. The combined rate of anxiety by time after stroke was: 20% (95% confidence interval 13-27%, I(2)  = 96%) within one-month of stroke; 23% (95% confidence interval 19-27%, I(2)  = 84%) one to five-months after stroke; and 24% (95% confidence interval 19-29%, I(2)  = 89%) six-months or more after stroke. CONCLUSION: Anxiety after stroke occurs frequently although methodological limitations in the primary studies may limit generalizability. Given the association between prevalence rates and the Hospital Anxiety and Depression Scale-Anxiety cutoff used in studies, reported rates could in fact underrepresent the extent of the problem. Additionally, risk factors for anxiety, its impact on patient outcomes, and effects in tangent with depression remain unclear

Clay mineral formation in Permian rocks of a geothermal borehole at Northern Upper Rhine Graben, Germany

<jats:title>Abstract</jats:title><jats:p>Hydrothermally altered rhyolite rocks in the Permian Donnersberg Formation of a geothermal borehole in the Northern Upper Rhine Graben (Germany) were investigated to find out answers for the low hydraulic conductivity of the rocks. The composition of clay minerals and the temperature of smectite–illite transformation were carried out using X-ray diffraction, X-ray fluorescence, transmission electron microscopy, Fourier transform infrared spectroscopy, and polarized-light microscopy analyses. Clay mineral (CM) composition includes illite/muscovite (1<jats:italic>M</jats:italic>and 2<jats:italic>M</jats:italic><jats:sub>1</jats:sub>polytypes), illite–smectite interstratifications (IS-ml), smectite, and chlorite; and non-clay minerals such as quartz, feldspars, epidote, calcite, dolomite, and hematite were detected. The 2<jats:italic>M</jats:italic><jats:sub>1</jats:sub>-polytype mica might be the only primary sheet silicates from the parent rocks, while the others occur as authigenic neo-formed CMs under heat flow and geothermal gradient. The development of CMs indicates different mechanisms of illitization and smectitization. Based on the texture, morphology, structure/polytype, and chemistry of rocks and minerals, in particular CMs, the study grouped the CM formation into three transformation processes: smectitization during magma cooling and possible contact metamorphisms with decreasing and low temperature, smectite illitization controlled by burial diagenesis and hydrothermal alteration, and illite smectitization followed exhumation and Cenozoic subsidence with decreasing temperature. The rhyolites were altered to all of the orders IS-R0, IS-R1, and IS-R3 by the dissolution-precipitation and layer-to-layer mechanisms. The first one supported small xenomorphic plates and flakes of 1<jats:italic>M</jats:italic><jats:sub><jats:italic>d</jats:italic></jats:sub>, elongated particles of 1<jats:italic>M</jats:italic>, and pseudo-hexagonal forms of 2<jats:italic>M</jats:italic><jats:sub>1</jats:sub>. The second one could lead to the platy particles of 1<jats:italic>M</jats:italic><jats:sub><jats:italic>d</jats:italic></jats:sub>and 2<jats:italic>M</jats:italic><jats:sub>1</jats:sub>polytypes. The dominant temperature range for the transformation in the area has been 140–170 °C– ~ 230 °C.</jats:p&gt