The Best of Times, the Worst of Times: Understanding Pro-cyclical Mortality

A growing literature documents cyclical movements in mortality and health. We examine this pattern more closely and attempt to identify the mechanisms behind it. Specifically, we distinguish between mechanisms that rely on fluctuations in own employment or time use and those involving factors that are external to the individual. Our investigation suggests that changes in individuals’ own behavior contribute very little to pro-cyclical mortality. Looking across broad age and gender groups, we find that own-group employment rates are not systematically related to own-group mortality. In addition, we find that most of the additional deaths that occur during times of economic growth are among the elderly, particularly elderly women, who have limited labor force attachment. Focusing on mortality among the elderly, we show that cyclicality is especially strong for deaths occurring in nursing homes, and is stronger in states where a higher fraction of the elderly reside in nursing homes. We also demonstrate that staffing in skilled nursing facilities moves counter-cyclically. Taken together, these findings suggest that cyclical fluctuations in the mortality rate may be largely driven by fluctuations in the quality of health care.

Tools for live imaging of active Rho GTPases in Xenopus

Rho family GTPases are signaling molecules that orchestrate cytoskeletal dynamics in a variety of cellular processes. Because they effect localized changes to the cytoskeleton only in their active (GTP‐bound) conformation, the ability to monitor the active state of Rho GTPases in space and time is critical for understanding their function. Here, we summarize popular tools used for live imaging of active Rho GTPases, outlining advantages and drawbacks of these approaches. Additionally, we highlight key features of the Xenopus laevis embryo that make it well‐suited for epithelial cell biology and discuss how application of Rho activity reporters in the Xenopus laevis embryo led to the discovery of a novel phenomenon, junctional Rho flares.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136041/1/dvg22998_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136041/2/dvg22998.pd

Near-infrared imaging of 222 nearby Hdelta-strong galaxies from the SDSS

We present UFTI K-band imaging observations of 222 galaxies that are selected from the Sloan Digital Sky Survey to have unusually strong Hdelta absorption equivalent widths, W(Hd)>4A. Using GIM2D, the images are fit with two-dimensional surface brightness models consisting of a simple disk and bulge component to derive B/T, the fraction of luminosity in the bulge. We find that the galaxies with weak or absent Halpha or [OII] emission (known as k+a galaxies) are predominantly bulge-dominated (with a mode of B/T~0.6), while galaxies with nebular emission (known as e[a] galaxies) are mostly disk-dominated (B/T~0.1). The morphologies and (r-k) colours of most k+a galaxies are inconsistent with the hypothesis that they result from the truncation of star formation in normal, spiral galaxies. However, their (u-g) and (r-k) colours, as well as their Hdelta line strengths, form a sequence that is well matched by a model in which >5 per cent of the stellar mass has been produced in a recent starburst. The lack of scatter in the dust-sensitive (r-k) colours suggests that the unusual spectra of k+a galaxies are not due to the effects of dust. The e(a) galaxies, on the other hand, have a colour distribution that is distinct from the k+a population, and typical of normal or dusty (tauV~2) spiral galaxies. We conclude that many e(a) galaxies are not progenitors of k+a galaxies, but are a separate phenomenon. Both k+a and e(a) galaxies reside in environments (characterized by the local density of galaxies brighter than Mr=-20) that are typical of normal galaxies and that are inconsistent with overdense regions like rich galaxy clusters.Comment: MNRAS, in press. 18 pages in mn2e style, with 10 inline figures and two long tables. Appendix figures provided as separate, low resolution gif images. Full paper with inline figures available at http://quixote.uwaterloo.ca/~mbalogh/papers/EA.ps.g

The Lantern Vol. 33, No. 1, Spring 1967

• The Implement • A Broken Backstop • City • My Friend Is • Meditation on Eight Dead Nurses and a Mad Austin Sniper • Fact and Fancy • Valhalla • A Blandishment • You Say You Were a Name So Sweet • Preview Rerun • To Lynne • Shards • The Initial Error • Daniel • Gold on Gold • If Morning Ever Comes • Third Poem to Tonya • The Kiss • Her Soul Was Slippery • Quietlyhttps://digitalcommons.ursinus.edu/lantern/1090/thumbnail.jp

Patterning of the cell cortex by Rho GTPase Dynamics

The Rho GTPases — RHOA, RAC1 and CDC42 — are small GTP binding proteins that regulate basic biological processes such as cell locomotion, cell division and morphogenesis by promoting cytoskeleton-based changes in the cell cortex. This regulation results from active (GTP-bound) Rho GTPases stimulating target proteins that, in turn, promote actin assembly and myosin 2-based contraction to organize the cortex. This basic regulatory scheme, well supported by in vitro studies, led to the natural assumption that Rho GTPases function in vivo in an essentially linear matter, with a given process being initiated by GTPase activation and terminated by GTPase inactivation. However, a growing body of evidence based on live cell imaging, modelling and experimental manipulation indicates that Rho GTPase activation and inactivation are often tightly coupled in space and time via signalling circuits and networks based on positive and negative feedback. In this Review, we present and discuss this evidence, and we address one of the fundamental consequences of coupled activation and inactivation: the ability of the Rho GTPases to self-organize, that is, direct their own transition from states of low order to states of high order. We discuss how Rho GTPase self-organization results in the formation of diverse spatiotemporal cortical patterns such as static clusters, oscillatory pulses, travelling wave trains and ring-like waves. Finally, we discuss the advantages of Rho GTPase self-organization and pattern formation for cell function

Pilot Study of an Individualised Early Postpartum Intervention to Increase Physical Activity in Women with Previous Gestational Diabetes

Optimal strategies to prevent progression towards overt diabetes in women with recent gestational diabetes remain ill defined. We report a pilot study of a convenient, home based exercise program with telephone support, suited to the early post-partum period. Twenty eight women with recent gestational diabetes were enrolled at six weeks post-partum into a 12 week randomised controlled trial of Usual Care (n = 13) versus Supported Care (individualised exercise program with regular telephone support; n = 15). Baseline characteristics (Mean ± SD) were: Age  33 ± 4  years; Weight 80 ± 20 kg and Body Mass Index (BMI) 30.0 ± 9.7 kg/m2. The primary outcome, planned physical activity {Median (Range)}, increased by 60 (0–540) mins/week in the SC group versus 0 (0–580) mins/week in the UC group (P = 0.234). Walking was the predominant physical activity. Body weight, BMI, waist circumference, % body fat, fasting glucose and insulin did not change significantly over time in either group. This intervention designed to increase physical activity in post-partum women with previous gestational diabetes proved feasible. However, no measurable improvement in metabolic or biometric parameters was observed over a three month period

The Abl-related gene (Arg) requires its F-actin–microtubule cross-linking activity to regulate lamellipodial dynamics during fibroblast adhesion

Microtubules (MTs) help establish and maintain cell polarity by promoting actin-dependent membrane protrusion at the leading edge of the cell, but the molecular mechanisms that mediate cross-talk between actin and MTs during this process are unclear. We demonstrate that the Abl-related gene (Arg) nonreceptor tyrosine kinase is required for dynamic lamellipodial protrusions after adhesion to fibronectin. arg−/− fibroblasts exhibit reduced lamellipodial dynamics as compared with wild-type fibroblasts, and this defect can be rescued by reexpression of an Arg-yellow fluorescent protein fusion. We show that Arg can bind MTs with high affinity and cross-link filamentous actin (F-actin) bundles and MTs in vitro. MTs concentrate and insert into Arg-induced F-actin–rich cell protrusions. Arg requires both its F-actin–binding domains and its MT-binding domain to rescue the defects in lamellipodial dynamics of arg−/− fibroblasts. These findings demonstrate that Arg can mediate physical contact between F-actin and MTs at the cell periphery and that this cross-linking activity is required for Arg to regulate lamellipodial dynamics in fibroblasts

The Lantern Vol. 33, No. 2, May 1967

• The Plea • Arrival • Nouvelle • Poem on Theme by Leroi Jones • Night Thoughts • Finals • Caught in the Act • Tomorrow • The Rail • The Price • Lost • It\u27s a Svaden Spring • No Thanks to City Hall • Grinding Them to Dust • Four • Five • Nine • Ten • Twelve • Thirty-Six • Psyched Up and Out • Gutted Gloryhttps://digitalcommons.ursinus.edu/lantern/1091/thumbnail.jp