Metatheory of actions: beyond consistency

Consistency check has been the only criterion for theory evaluation in logic-based approaches to reasoning about actions. This work goes beyond that and contributes to the metatheory of actions by investigating what other properties a good domain description in reasoning about actions should have. We state some metatheoretical postulates concerning this sore spot. When all postulates are satisfied together we have a modular action theory. Besides being easier to understand and more elaboration tolerant in McCarthy's sense, modular theories have interesting properties. We point out the problems that arise when the postulates about modularity are violated and propose algorithmic checks that can help the designer of an action theory to overcome them

Vitamin D supplementation and breast cancer prevention : a systematic review and meta-analysis of randomized clinical trials

In recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the “Related Article” feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I2 test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74–1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23–1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54–1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L

The relationship between hip abductor muscle strength and iliotibial band tightness in individuals with low back pain

<p>Abstract</p> <p>Background</p> <p>Shortening of the iliotibial band (ITB) has been considered to be associated with low back pain (LBP). It is theorized that ITB tightness in individuals with LBP is a compensatory mechanism following hip abductor muscle weakness. However, no study has clinically examined this theory. The purpose of this study was to investigate the muscle imbalance of hip abductor muscle weakness and ITB tightness in subjects with LBP.</p> <p>Methods</p> <p>A total of 300 subjects with and without LBP between the ages of 20 and 60 participated in this cross-sectional study. Subjects were categorized in three groups: LBP with ITB tightness (n = 100), LBP without ITB tightness (n = 100) and no LBP (n = 100). Hip abductor muscle strength was measured in all subjects.</p> <p>Results</p> <p>Analysis of Covariance (ANCOVA) with the body mass index (BMI) as the covariate revealed significant difference in hip abductor strength between three groups (P < 0.001). Post hoc analysis showed no significant difference in hip abductor muscle strength between the LBP subjects with and without ITB tightness (P = 0.59). However, subjects with no LBP had significantly stronger hip abductor muscle strength compared to subjects with LBP with ITB tightness (P < 0.001) and those with LBP without ITB tightness (P < 0.001).</p> <p>Conclusion</p> <p>The relationship between ITB tightness and hip abductor weakness in patients with LBP is not supported as assumed in theory. More clinical studies are needed to assess the theory of muscle imbalance of hip abductor weakness and ITB tightness in LBP.</p

Dissociation between Mature Phenotype and Impaired Transmigration in Dendritic Cells from Heparanase-Deficient Mice

To reach the lymphatics, migrating dendritic cells (DCs) need to interact with the extracellular matrix (ECM). Heparanase, a mammalian endo-β-D-glucuronidase, specifically degrades heparan sulfate proteoglycans ubiquitously associated with the cell surface and ECM. The role of heparanase in the physiology of bone marrow-derived DCs was studied in mutant heparanase knock-out (Hpse-KO) mice. Immature DCs from Hpse-KO mice exhibited a more mature phenotype; however their transmigration was significantly delayed, but not completely abolished, most probably due to the observed upregulation of MMP-14 and CCR7. Despite their mature phenotype, uptake of beads was comparable and uptake of apoptotic cells was more efficient in DCs from Hpse-KO mice. Heparanase is an important enzyme for DC transmigration. Together with CCR7 and its ligands, and probably MMP-14, heparanase controls DC trafficking

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

An amendment to this paper has been published and can be accessed via the original article

Lysosomal damage and K+ efflux in pMΦ.

<p><b>(A)</b> Flow-cytometer analysis of B6 pMΦ treated for 2h with apoptotic cells and/or 24h with DSS were stained with fluorochrome acridine orange (AO). Loss of fluorescence, which correlates with reduced numbers of lysosomes, was analyzed by flow-cytometer, excluding dead cells base on FSC/SSC parameters. Shown are means ± SEM of 4 independent experiments (*<i>p</i><0.05, **<i>p</i><0.03, one way ANOVA). <b>(B)</b> confocal microscopy of LPS primed pMΦ incubated (or not; left) for 2h with apoptotic cells (middle) or DAPI-stained apoptotic cells (right), stained with 1μg/mL acridine orange for 15 min and then incubated for 2.5 h with 3% DSS. Representative data from four experiments. <b>(C)</b> Apoptotic cell treatment inhibits nigericin-induced IL-1β secretion. B6 pMΦ cells were treated with nigericin at the indicated concentrations in the presence of LPS priming, with or without apoptotic cell treatment (*<i>p</i><0.01, unpaired t-test).</p

Histological appearance and neutrophil infiltration of distal colon sections.

<p>(<b>A</b>) H&E appearance. (<b>A-I</b>) DSS uptake leads to severe epithelial damage (black arrowed) while (<b>A-II</b>) apoptotic cell treatment maintain integrity of treated mice (<b>A-III</b>) histological score of distal colon sections of DSS-treated Balb/c mice Results from 3 independent experiments (*<i>p</i><0.05, t-test). (<b>B</b>) Apoptotic cell treatment inhibits neutrophil accumulation in inflamed colon. Mouse colon tissue sections were stained by immunohistochemistry assay using a rabbit monoclonal antibody against mouse myeloperoxidase (MPO). After immunostaining, slides were counterstained by hematoxylin. Images show the MPO stain followed by HRP-anti rabbit secondary antibody. All images are x200. <b>(B-I)</b> Staining control. Untreated colon stained with HRP-anti rabbit secondary antibody only, without anti-MPO. <b>(B-II)</b> Normal colon control. MPO-stained neutrophils in untreated colon. <b>(B-III)</b> DSS treatment. MPO-stained neutrophils in 3% DSS treated colon (3% DSS+PBS). <b>(B-IV)</b> Apoptotic cell & DSS treatment. MPO-stained neutrophils in 3% DSS-treated colon with apoptotic cell infusion (3% DSS+ApoCell).</p