Pushing for answers: is myosin V directly involved in moving mitochondria?

In budding yeast, the actin-based class V myosin motors, Myo2 and Myo4, transport virtually all organelles from mother to bud during cell division. Until recently, it appeared that mitochondria may be an exception, with studies showing that the Arp2/3 complex is required for their movement. However, several recent studies have proposed that Myo2 has a direct involvement in mitochondria inheritance. In this issue, Altmann et al. (Altmann, K., M. Frank, D. Neumann, S. Jakobs, and B. Westermann. 2008. J. Cell Biol. 181:119–130) provide the strongest support yet that Myo2 and its associated light chain Mlc1 function directly and significantly in both mitochondria–actin interactions and in the movement of mitochondria from mother to bud. The conflicting functions of Arp 2/3 and Myo2 may be reconciled by the existence of multiple pathways involved in mitochondrial transport

Changing Definitions of Women's Health: Implications for Health Care and Policy

Objectives: To present an overview of how and why normative conceptions of women's health are changing and to discuss some implications of definitional shifts in the context of the changing U.S. health care system. Method: The paper describes the historical development of views of women's health and health care, contrasts the biomedical and biopsychosocial perspectives on women's health, and presents some evidence of challenges and opportunities for change in health care and policy. Results: While women's health has generally been equated with reproductive functions, expanded definitions focus on health through the life span and in the context of women's multiple roles and diverse social circumstances. This expanded view highlights the limitations of health services and policy based on narrower conceptions and program mandates and the need for strategies for integrated, continuous care. There is evidence of change in women's health care, including in Title V programs. Conclusions: New understandings of women's health are particularly relevant to maternal and child health programs, which are positioned to provide model approaches for improving women's health care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45318/1/10995_2004_Article_422986.pd

The Vac14p–Fig4p complex acts independently of Vac7p and couples PI3,5P2 synthesis and turnover

Phosphoinositide-signaling lipids function in diverse cellular pathways. Dynamic changes in the levels of these signaling lipids regulate multiple processes. In particular, when Saccharomyces cerevisiae cells are exposed to hyperosmotic shock, PI3,5P2 (phosphatidylinositol [PI] 3,5-bisphosphate) levels transiently increase 20-fold. This causes the vacuole to undergo multiple acute changes. Control of PI3,5P2 levels occurs through regulation of both its synthesis and turnover. Synthesis is catalyzed by the PI3P 5-kinase Fab1p, and turnover is catalyzed by the PI3,5P2 5-phosphatase Fig4p. In this study, we show that two putative Fab1p activators, Vac7p and Vac14p, independently regulate Fab1p activity. Although Vac7p only regulates Fab1p, surprisingly, we find that Vac14 regulates both Fab1p and Fig4p. Moreover, Fig4p itself functions in both PI3,5P2 synthesis and turnover. In both the absence and presence of Vac7p, the Vac14p–Fig4p complex controls the hyperosmotic shock–induced increase in PI3,5P2 levels. These findings suggest that the dynamic changes in PI3,5P2 are controlled through a tight coupling of synthesis and turnover

Excitonic Effects and Optical Spectra of Single-Walled Carbon Nanotubes

Many-electron effects often dramatically modify the properties of reduced dimensional systems. We report calculations, based on an many-electron Green's function approach, of electron-hole interaction effects on the optical spectra of small-diameter single-walled carbon nanotubes. Excitonic effects qualitatively alter the optical spectra of both semiconducting and metallic tubes. Excitons are bound by ~ 1 eV in the semiconducting (8,0) tube and by ~ 100 meV in the metallic (3,3) tube. These large many-electron effects explain the discrepancies between previous theories and experiments.Comment: 6 pages, 3 figures, 2 table

Artificial Perches as a Technique for Enhancing Tropical Forest Restoration: A Case Study From the Dominican Republic

Recovering secondary forests on degraded agricultural lands represents a promising opportunity to offset global carbon emissions as well as increasing local biodiversity and ecosystem services. In the insular tropical forests of the Caribbean, frugivorous birds are the primary seed dispersers for most native woody plants and have a large influence on regeneration dynamics during forest succession. In 2017, we initiated an experimental forest restoration program incorporating artificial perches on private farms within the Rio Yaque del Norte watershed in La Vega province, Dominican Republic. Five restoration plots (0.15–0.25 ha) were constructed in pastures near deforested streams. In each plot, 6-12 artificial perches, each 5 m in height, were constructed from bamboo poles fitted with crossbars. We remotely monitored perch use by birds using video cameras and evaluated the effects of perches on the establishment of woody plants in seedling quadrats both below perches and in open spaces. During the summer of 2019, we conducted a behavioral experiment using audio broadcasts of bird sound to test the effect of different avian taxa and feeding guilds on attracting seed dispersers. Eleven avian species were recorded visiting perches, with the most common being Northern Mockingbird and Gray Kingbird. Broadcasting bird sounds led to a significantly greater number of avian visits to the plot. We documented 1,171 seeds from 31 distinguishable species collected from seed traps below perches during the study. Most seedling regeneration in our plots was from exotic non-bird-dispersed taxa which grew equally in perches and control quadrats. Native plant seedlings were infrequent (i.e. beneath 4 of 36 perches) but grew exclusively beneath perches. We conclude that artificial perches are an effective method for augmenting the natural seed bank but are likely to be most effective when used in tandem with planting trees that readily grow to produce shade and litter.https://digitalcommons.odu.edu/gradposters2020_sciences/1004/thumbnail.jp

PLANR.: Planar Learning Autonomous Navigation Robot

PLANR is a self-contained robot capable of mapping a space and generating 2D floor plans of a building while identifying objects of interest. It runs Robot Operating System (ROS) and houses four main hardware components. An Arduino Mega board handles the navigation, while an NVIDIA Jetson TX2, holds most of the processing power and runs ROS. An Orbbec Astra Pro stereoscopic camera is used for recognition of doors, windows and outlets and the RPLiDAR A3 laser scanner is able to give depth for wall detection and dimension measurements. The robot is intended to operate autonomously and without constant human monitoring or intervention. The user is responsible for booting up the robot and extracting the map via SSH before shutting down