Cowbane, Oxypolis occidentalis, A New Native Vascular Plant Species for the Queen Charlotte Islands, British Columbia

We report the recent discovery of Oxypolis occidentalis, a species that is new to both British Columbia and Canada, disjunct on the Queen Charlotte Islands

Contrasting Properties of Motor Output from the Supplementary Motor Area and Primary Motor Cortex in Rhesus Macaques

The goal of this study was to assess the motor output capabilities of the forelimb representation of the supplementary motor area (SMA) in terms of the sign, latency and strength of effects on electromyographic (EMG) activity. Stimulus triggered averages of EMG activity from 24 muscles of the forelimb were computed in SMA during a reach-to-grasp task. Poststimulus facilitation (PStF) from SMA had two distinct peaks (15.2 and 55.2 ms) and one poststimulus suppression (PStS) peak (32.4 ms). The short onset latency PStF and PStS of SMA were 5.5 and 16.8 ms longer than those of the primary motor cortex (M1). The average magnitudes (peak increase or decrease above baseline) of the short and long latency PStF and PStS from SMA at 60 μA were 13.8, 11.3 and −11.9% respectively. In comparison, M1 PStF and PStS magnitudes at 15 μA were 50.2 and −23.8%. Extrapolating M1 PStF magnitude to 60 μA yields a mean effect that is nearly 15 times greater than the mean PStF from SMA. Moreover, unlike M1, the facilitation of distal muscles from SMA was not significantly greater than the facilitation of proximal muscles. We conclude that the output from SMA to motoneurons is markedly weaker compared with M1 raising doubts about the role of SMA corticospinal neurons in the direct control of muscle activit

Myosin-X: a MyTH-FERM myosin at the tips of filopodia

Myosin-X (Myo10) is an unconventional myosin with MyTH4-FERM domains that is best known for its striking localization to the tips of filopodia and its ability to induce filopodia. Although the head domain of Myo10 enables it to function as an actin-based motor, its tail contains binding sites for several molecules with central roles in cell biology, including phosphatidylinositol (3,4,5)-trisphosphate, microtubules and integrins. Myo10 also undergoes fascinating long-range movements within filopodia, which appear to represent a newly recognized system of transport. Myo10 is also unusual in that it is a myosin with important roles in the spindle, a microtubule-based structure. Exciting new studies have begun to reveal the structure and single-molecule properties of this intriguing myosin, as well as its mechanisms of regulation and induction of filopodia. At the cellular and organismal level, growing evidence demonstrates that Myo10 has crucial functions in numerous processes ranging from invadopodia formation to cell migration

Alternative Markers of Performance in Simulation: Where We Are and Where We Need To Go

This article on alternative markers of performance in simulation is the product of a session held during the 2017 Academic Emergency Medicine Consensus Conference â Catalyzing System Change Through Health Care Simulation: Systems, Competency, and Outcomes.â There is a dearth of research on the use of performance markers other than checklists, holistic ratings, and behaviorally anchored rating scales in the simulation environment. Through literature review, group discussion, and consultation with experts prior to the conference, the working group defined five topics for discussion: 1) establishing a working definition for alternative markers of performance, 2) defining goals for using alternative performance markers, 3) implications for measurement when using alternative markers, identifying practical concerns related to the use of alternative performance markers, and 5) identifying potential for alternative markers of performance to validate simulation scenarios. Five research propositions also emerged and are summarized.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142535/1/acem13321_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142535/2/acem13321.pd

Grow Well/Crecer Bien: A Protocol for Research on Infant Feeding Practices in Low-Income Families

Background The prevalence of obesity among children remains high. Given obesity’s significant lifelong consequences, there is great interest in preventing obesity early in life. There is a need to better understand the relation of common infant feeding styles and practices to obesity in infants using longitudinal study designs. There is also an urgent need to understand the role of caregivers other than mothers in feeding. A better understanding of variation in feeding styles and practices can inform the identification of risk groups and the tailoring of interventions to them. Methods In partnership with Early Head Start programs across four counties in southern California, mothers and infants will be enrolled in a two-year longitudinal study collecting survey and anthropometric data. A subsample of mothers and their selected other caregivers will participate in qualitative research involving feeding diaries and dyadic interviews. The results will be used to develop and test an enhanced nutrition education program. Discussion We outline a study methodology to examine feeding styles and practices and their association with early childhood obesity risk and enhance an existing intervention to promote healthy infant feeding and growth among children in low-income families

Headless Myo10 Is a Negative Regulator of Full-length Myo10 and Inhibits Axon Outgrowth in Cortical Neurons

Myo10 is an unconventional myosin that localizes to and induces filopodia, structures that are critical for growing axons. In addition to the ∼240-kDa full-length Myo10, brain expresses a ∼165 kDa isoform that lacks a functional motor domain and is known as headless Myo10. We and others have hypothesized that headless Myo10 acts as an endogenous dominant negative of full-length Myo10, but this hypothesis has not been tested, and the function of headless Myo10 remains unknown. We find that cortical neurons express both headless and full-length Myo10 and report the first isoform-specific localization of Myo10 in brain, which shows enrichment of headless Myo10 in regions of proliferating and migrating cells, including the embryonic ventricular zone and the postnatal rostral migratory stream. We also find that headless and full-length Myo10 are expressed in embryonic and neuronal stem cells. To directly test the function of headless and full-length Myo10, we used RNAi specific to each isoform in mouse cortical neuron cultures. Knockdown of full-length Myo10 reduces axon outgrowth, whereas knockdown of headless Myo10 increases axon outgrowth. To test whether headless Myo10 antagonizes full-length Myo10, we coexpressed both isoforms in COS-7 cells, which revealed that headless Myo10 suppresses the filopodia-inducing activity of full-length Myo10. Together, these results demonstrate that headless Myo10 can function as a negative regulator of full-length Myo10 and that the two isoforms of Myo10 have opposing roles in axon outgrowth

Visualization of individual carbon nanotubes with fluorescence microscopy using conventional fluorophores

We demonstrate that individual carbon nanotubes (CNTs) can be visualized with fluorescence microscopy through noncovalent labeling with conventional fluorophores. Reversal of contrast in fluorescence imaging of the CNTs was observed when performing labeling procedure in a nonpolar solvent. Our results are consistent with a CNT-fluorophore affinity mediated by hydrophobic interaction. The reverse-contrast images also provide clear indication of nanotube location. © 2003 American Institute of Physics