Do Truth Commissions Really Improve Democracy?

This article presents and tests an original theory that truth commissions (TCs) inspire democratic behaviors, but have little discernible impact on democratic institutions. Using quantitative analyses of countries undergoing transitions between 1970 and 2015, and accounting for endogeneity of TCs, we find that these temporary bodies are associated with greater democratic participation and state agent observance of physical integrity rights. However, they have no measurable effect on institutions like fair elections, rules regulating political association, liberal checks on the executive, or judicial independence. This contradicts a key argument in the transitional justice literature that TCs catalyze institutional reform through investigation and extensive recommendations. This article’s findings might encourage those who intend to use these bodies as a tool to promote citizen activism or police restraint. However, the findings might discourage those who hope TCs could jump-start judicial reforms or create a firewall against executive overreach.

Long-Term Incidence of Stroke and Dementia in ASCOT

Background and Purpose: Management of stroke risk factors might reduce later dementia. In ASCOT (Anglo-Scandinavian Outcome Trial), we determined whether dementia or stroke were associated with different blood pressure (BP)–lowering regimens; atorvastatin or placebo; and mean BP, BP variability, and mean cholesterol levels. Methods: Participants with hypertension and ≥3 cardiovascular disease risk factors were randomly allocated to amlodipine- or atenolol-based BP-lowering regimen targeting BP <140/90 mm Hg for 5.5 years. Participants with total cholesterol ≤6.5 mmol/L were also randomly allocated to atorvastatin 10 mg or placebo for 3.3 years. Mean and LDL (low-density lipoprotein) cholesterol, BP, and SD of BP were calculated from 6 months to end of trial. UK participants were linked to electronic health records to ascertain deaths and hospitalization in general and mental health hospitals. Dementia and stroke were ascertained by validated code lists and within-trial ascertainment. Results: Of 8580 UK participants, 7300 were followed up to 21 years from randomization. Atorvastatin for 3.3 years had no measurable effect on stroke (264 versus 272; adjusted hazard ratio [HR], 0.92 [95% CI, 0.78–1.09]; P =0.341) or dementia (238 versus 227; adjusted HR, 0.98 [95% CI, 0.82–1.18]; P =0.837) compared with placebo. Mean total cholesterol was not associated with later stroke or dementia. An amlodipine-based compared with an atenolol-based regimen for 5.5 years reduced stroke (443 versus 522; adjusted HR, 0.82 [95% CI, 0.72–0.93]; P =0.003) but not dementia (450 versus 465; adjusted HR, 0.94 [95% CI, 0.82–1.07]; P =0.334) over follow-up. BP variability (SD mean BP) was associated with a higher risk of dementia (per 5 mm Hg HR, 1.14 [95% CI, 1.06–1.24]; P <0.001) and stroke (HR, 1.21 [95% CI, 1.12–1.32]; P <0.001) adjusted for mean BP. Conclusions: An amlodipine-based BP regimen reduced the long-term incidence of stroke compared with an atenolol-based regimen but had no measurable effect on dementia. Atorvastatin had no effect on either stroke or dementia. Higher BP variability was associated with a higher incidence of later dementia and stroke.

Increased letter spacing and greater letter width improve reading acuity in low vision readers

Low vision readers depend on magnification, but magnification reduces the amount of text that can be overviewed and hampers text navigation. In this study, we evaluate the effects that font variations letter spacing, letter width, and letter boldness have on low vision reading. We tested 20 low-vision patients with age-related macular degeneration (AMD) and used the Radner Reading Chart, which measures reading acuity (logRAD), maximum reading speed, and critical print size. The results demonstrated a small, but measurable effect of letter spacing and letter width on reading acuity near critical font sizes.

Gene body methylation is under selection in Arabidopsis thaliana

In plants, mammals and insects, some genes are methylated in the CG dinucleotide context, a phenomenon called gene body methylation (gbM). It has been controversial whether this phenomenon has any functional role. Here we took advantage of the availability of 876 leaf methylomes in Arabidopsis thaliana to characterize the population frequency of methylation at the gene level and to estimate the site-frequency spectrum of allelic states. Using a population genetics model specifically designed for epigenetic data, we found that genes with ancestral gbM are under significant selection to remain methylated. Conversely, ancestrally unmethylated genes were under selection to remain unmethylated. Repeating the analyses at the level of individual cytosines confirmed these results. Estimated selection coefficients were small, on the order of 4Nes = 1.4, which is similar to the magnitude of selection acting on codon usage. We also estimated that A. thaliana is losing gbM three-fold more rapidly than gaining it, which could be due to a recent reduction in the efficacy of selection after a switch to selfing. Finally, we investigated the potential function of gbM through its link with gene expression. Across genes with polymorphic methylation states, the expression of gene body methylated alleles was consistently and significantly higher than unmethylated alleles. Although it is difficult to disentangle genetic from epigenetic effects, our work suggests that gbM has a small but measurable effect on fitness, perhaps due to its association to a phenotype like gene expression.

Nanomechanical Effects

This chapter discusses the effect of force and deformation of the tip apex and the sample surface in the operation and imaging mechanism of STM and AFM. Because the contact area is of atomic dimension, a very small force and deformation would generate a large measurable effect. Three effects are discussed. First is the stability of the STM junction, which depends on the rigidity of the material. For soft materials, hysterisis is more likely. For rigid materials, the approaching and retraction cycles are continuous and reproducible. Second is the effect of force and deformation to the STM imaging mechanism. For soft material such as graphite, force and deformation can amplify the observed corrugation. For hard materials as most metals, force and deformation can decrease the observed corrugation. Finally, the effect of force and deformation on tunneling barrier height measurements is discussed.

Optimal Targeting Display for Navigated Pelvic Screw Insertions

Surgical navigation can be used for complex orthopaedic procedures, such as iliosacral screw fix- ations, to achieve accurate and efficient results [11]. Although there have been studies studying the impact of navigation systems on surgical outcomes [6, 3], we are not aware of any studies that have quantified the effect of how information regarding the surgical navigation scene is displayed to surgeons on conventional monitors. However, the display of information can have a measurable effect on both accuracy and time required to perform the navigated surgery, as the surgical scene can be presented in many different formats [9]. Optimizing surgical accuracy potentially helps improves patient safety by reducing screw malplacement [11], while optimiz- ing time efficiency reduces opportunity cost [1]. Therefore, we designed a study to determine the optimal visualizations for performing navigated pelvic screw insertions. The findings of this study can be used to more systematically design visualization components of a navigation system.

An apoptosis-dependent checkpoint for autoimmunity in memory B and plasma cells

B lymphocytes acquire self-reactivity as an unavoidable byproduct of antibody gene diversification in the bone marrow and in germinal centers (GCs). Autoreactive B cells emerging from the bone marrow are silenced in a series of well-defined checkpoints, but less is known about how self-reactivity that develops by somatic mutation in GCs is controlled. Here, we report the existence of an apoptosis-dependent tolerance checkpoint in post-GC B cells. Whereas defective GC B cell apoptosis has no measurable effect on autoantibody development, disruption of post-GC apoptosis results in accumulation of autoreactive memory B cells and plasma cells, antinuclear antibody production, and autoimmunity. The data presented shed light on mechanisms that regulate immune tolerance and the development of autoantibodies.

Investigation Gene body methylation is under selection in Arabidopsis thaliana

In plants, mammals and insects, some genes are methylated in the CG dinucleotide context, a phenomenon called gene body methylation. It has been controversial whether this phenomenon has any functional role. Here, we took advantage of the availability of 876 leaf methylomes in Arabidopsis thaliana to characterize the population frequency of methylation at the gene level and estimated the site-frequency spectrum of allelic states (epialleles). Using a population genetics model specifically designed for epigenetic data, we found that genes with ancestral gene body methylation are under significant selection to remain methylated. Conversely, all genes taken together were inferred to be under selection to be unmethylated. The estimated selection coefficients were small, similar to the magnitude of selection acting on codon usage. We also estimated that A. thaliana is losing gene body methylation three-fold more rapidly than gaining it, which could be due to a recent reduction in the efficacy of selection after a switch to selfing. Finally, we investigated the potential function of gene body methylation through its link with gene expression level. Across genes with polymorphic methylation states, the expression of gene body methylated alleles was consistently and significantly higher than unmethylated alleles. Although it is difficult to disentangle genetic from epigenetic effects, our work suggests that gbM has a small but measurable effect on fitness, perhaps due to its association to a phenotype like gene expression.

Surface area-to-volume ratio, not cellular rigidity, determines red blood cell traversal through small capillaries

SummaryThe remarkable deformability of red blood cells (RBCs) depends on the viscoelasticity of the plasma membrane and cell contents and the surface area to volume (SA:V) ratio; however, it remains unclear which of these factors is the key determinant for passage through small capillaries. We used a microfluidic device to examine the traversal of normal, stiffened, swollen, parasitised and immature RBCs. We show that dramatic stiffening of RBCs had no measurable effect on their ability to traverse small channels. By contrast, a moderate decrease in the SA:V ratio had a marked effect on the equivalent cylinder diameter that is traversable by RBCs of similar stiffness. We developed a finite element model that provides a coherent rationale for the experimental observations, based on the nonlinear mechanical behaviour of the RBC membrane skeleton. We conclude that the SA:V ratio should be given more prominence in studies of RBC pathologies.

Studies on Beneficiation of Manganese Ore through High Intensity Magnetic Separator

Upgradation techniques like wet sieving and magnetic separation were used to evaluate the beneficiation potential of manganese ore. During wet sieving, manganese content in raw ore was upgraded from 27% to a maximum value of 38% in the concentrate with a recovery of 30%. Size classification was found to have no measurable effect on manganese grade in magnetic separation. In the unsieved ground ore, manganese content of 45% was achieved with a recovery of 23% and Mn/Fe ratio of 19% at a magnetic intensity of 8500 Gauss. At the same operating conditions, SiO2 was reduced from 56% in the raw ore to 30% in the magnetic fraction. So, wet sieving technique leads to a comparatively lower manganese grade but better recovery. Conversely, a magnetic separation technique produced higher manganese grade but relatively lower recovery. Blending of the upgraded manganese ore with high grade iron ore can be done to achieve the required Mn/Fe ratio.