Ca2+ signaling driving pacemaker activity in submucosal interstitial cells of Cajal in the murine colon.

Interstitial cells of Cajal (ICC) generate pacemaker activity responsible for phasic contractions in colonic segmentation and peristalsis. ICC along the submucosal border (ICC-SM) contribute to mixing and more complex patterns of colonic motility. We show the complex patterns of Ca2+ signaling in ICC-SM and the relationship between ICC-SM Ca2+ transients and activation of smooth muscle cells (SMCs) using optogenetic tools. ICC-SM displayed rhythmic firing of Ca2+transients ~ 15 cpm and paced adjacent SMCs. The majority of spontaneous activity occurred in regular Ca2+ transients clusters (CTCs) that propagated through the network. CTCs were organized and dependent upon Ca2+ entry through voltage-dependent Ca2+ conductances, L- and T-type Ca2+ channels. Removal of Ca2+ from the external solution abolished CTCs. Ca2+ release mechanisms reduced the duration and amplitude of Ca2+ transients but did not block CTCs. These data reveal how colonic pacemaker ICC-SM exhibit complex Ca2+-firing patterns and drive smooth muscle activity and overall colonic contractions.

A high throughput machine-learning driven analysis of Ca2+ spatio-temporal maps.

High-resolution Ca2+ imaging to study cellular Ca2+ behaviors has led to the creation of large datasets with a profound need for standardized and accurate analysis. To analyze these datasets, spatio-temporal maps (STMaps) that allow for 2D visualization of Ca2+ signals as a function of time and space are often used. Methods of STMap analysis rely on a highly arduous process of user defined segmentation and event-based data retrieval. These methods are often time consuming, lack accuracy, and are extremely variable between users. We designed a novel automated machine-learning based plugin for the analysis of Ca2+ STMaps (STMapAuto). The plugin includes optimized tools for Ca2+ signal preprocessing, automated segmentation, and automated extraction of key Ca2+ event information such as duration, spatial spread, frequency, propagation angle, and intensity in a variety of cell types including the Interstitial cells of Cajal (ICC). The plugin is fully implemented in Fiji and able to accurately detect and expeditiously quantify Ca2+ transient parameters from ICC. The plugin's speed of analysis of large-datasets was 197-fold faster than the commonly used single pixel-line method of analysis. The automated machine-learning based plugin described dramatically reduces opportunities for user error and provides a consistent method to allow high-throughput analysis of STMap datasets.

Minimum wages and public health: A literature review.

We evaluate evidence for the effectiveness of raising minimum wages on various measures of public health within the US, Canada, the UK, and Europe. We search four scientific websites from the inception of the research through May 20, 2018. We find great variety (20+) in measured outcomes among the 33 studies that pass our initial screening. We establish quality standards in a second screening resulting in 15 studies in which we create outcome-based groups. Outcomes include four broad measures (general overall health, behavior, mental health, and birth weight) and eight narrow measures (self-reported health, "bad" health days, unmet medical need, smoking, problem-drinking, obesity, eating vegetables, and exercise). We establish criteria for "stronger" findings for outcomes and methods. Stronger findings include: $1 increases in minimum wages are associated with 1.4 percentage point (4% evaluated at mean) decreases in smoking prevalence; failure to reject null hypotheses that minimum wages have no effects for most outcomes; and no consistent evidence that minimum wages harm health. One "suggestive" finding is that the best-designed studies have well-defined treatment (or likely affected) and control (unaffected) groups and contain longitudinal data. The major methodological weaknesses afflicting many studies are the lack of focus on persons likely affected by minimum wages and omission of "falsification tests" on persons likely unaffected. An additional weakness is lack of attention to how findings might differ across populations such as teenagers, adults, men, women, continuously employed and unemployed persons. Research into health effects of minimum wages is in its infancy and growing rapidly. We present a list of "better practices" for future research.