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"Butler, A"
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Adaptive changes in pancreatic beta cell fractional area and beta cell turnover in human pregnancy
Aims/hypothesis We sought to establish the extent and basis for adaptive changes in beta cell numbers in human pregnancy. Methods Pancreas was obtained at autopsy from women who had died while pregnant (n = 18), post-partum (n = 6) or were not pregnant at or shortly before death (controls; n = 20). Pancreases were evaluated for fractional pancreatic beta cell area, islet size and islet fraction of beta cells, beta cell replication (Ki67) and apoptosis (TUNEL), and indirect markers of beta cell neogenesis (insulin-positive cells in ducts and scattered beta cells in pancreas). Results The pancreatic fractional beta cell area was increased by ∼1.4-fold in human pregnancy, with no change in mean beta cell size. In pregnancy there were more small islets rather than an increase in islet size or beta cells per islet. No increase in beta cell replication or change in beta cell apoptosis was detected, but duct cells positive for insulin and scattered beta cells were increased with pregnancy. Conclusions/interpretation The adaptive increase in beta cell numbers in human pregnancy is not as great as in most reports in rodents. This increase in humans is achieved by increased numbers of beta cells in apparently new small islets, rather than duplication of beta cells in existing islets, which is characteristic of pregnancy in rodents.
Journal Article
Predicting Everyday Critical Thinking: A Review of Critical Thinking Assessments
Our ability to think critically and our disposition to do so can have major implications for our everyday lives. Research across the globe has shown the impact of critical thinking on decisions about our health, politics, relationships, finances, consumer purchases, education, work, and more. This chapter will review some of that research. Given the importance of critical thinking to our everyday lives, the fair and unbiased assessment of critical thinking is useful for guiding educators in their classrooms, for the sake of self-improvement, and in employment decisions. This chapter will also review the psychometric properties of several critical thinking assessments, with a special emphasis on the everyday behaviors predicted by these assessments. The practical challenges faced by test adopters and future directions in the assessment of critical thinking will be discussed.
Journal Article
Enhanced cell deconvolution of peripheral blood using DNA methylation for high-resolution immune profiling
DNA methylation microarrays can be employed to interrogate cell-type composition in complex tissues. Here, we expand reference-based deconvolution of blood DNA methylation to include 12 leukocyte subtypes (neutrophils, eosinophils, basophils, monocytes, naïve and memory B cells, naïve and memory CD4 + and CD8 + T cells, natural killer, and T regulatory cells). Including derived variables, our method provides 56 immune profile variables. The IDOL (IDentifying Optimal Libraries) algorithm was used to identify libraries for deconvolution of DNA methylation data for current and previous platforms. The accuracy of deconvolution estimates obtained using our enhanced libraries was validated using artificial mixtures and whole-blood DNA methylation with known cellular composition from flow cytometry. We applied our libraries to deconvolve cancer, aging, and autoimmune disease datasets. In conclusion, these libraries enable a detailed representation of immune-cell profiles in blood using only DNA and facilitate a standardized, thorough investigation of immune profiles in human health and disease.
Deconvolution algorithms facilitate studying cell type-specific changes using bulk data from complex tissues. Here, the authors present a deconvolution method that predicts DNA methylation levels in 12 leukocyte subtypes using human microarray data and apply it to various examples.
Journal Article
An optimized library for reference-based deconvolution of whole-blood biospecimens assayed using the Illumina HumanMethylationEPIC BeadArray
Genome-wide methylation arrays are powerful tools for assessing cell composition of complex mixtures. We compare three approaches to select reference libraries for deconvoluting neutrophil, monocyte, B-lymphocyte, natural killer, and CD4+ and CD8+ T-cell fractions based on blood-derived DNA methylation signatures assayed using the Illumina HumanMethylationEPIC array. The IDOL algorithm identifies a library of 450 CpGs, resulting in an average R
2
= 99.2 across cell types when applied to EPIC methylation data collected on artificial mixtures constructed from the above cell types. Of the 450 CpGs, 69% are unique to EPIC. This library has the potential to reduce unintended technical differences across array platforms.
Journal Article
The sound of a tropical forest
Recording of forest soundscapes can help monitor animal biodiversity for conservation Conservation areas around the world aim to help conserve animal biodiversity, but it is often difficult to measure conservation success without detailed on-the-ground surveys. High-resolution satellite imagery can be used to verify whether or not deforestation has occurred in areas dedicated for conservation ( 1 ). Such remote sensing analyses can reveal forest loss and, in some cases, severe forest degradation, such as through fragmentation and intensive selective logging, especially if it includes the construction of roads or camps. However, conservation benefit is determined not only by forest loss but also by the level of degradation in those forests left standing. Bioacoustics—specifically the recording and analysis of entire soundscapes—is an emerging tool with great promise for effectively monitoring animal biodiversity in tropical forests under various conservation schemes ( 2 , 3 ).
Journal Article