Corticospinal Integration in Healthy Humans

Synchronized arrival of neuronal signals from the periphery and motor cortex has been associated with neuronal plasticity and motor learning. The main objective of this study was to examine neuronal interactions following excitation of descending motor axons from the primary motor cortex (M1) and spinal neuronal circuits via transcranial magnetic stimulation (TMS) and transcutaneous electric stimulation of the spine (tsESS) in 15 healthy humans while seated semiprone. TMS was delivered below or above the resting motor evoked potential (MEP) threshold, for the tibialis anterior (TA) muscle, while tsESS was delivered at the lowest stimulation intensity that evoked responses in most or all leg muscles. TMS was delivered either alone or with tsESS at different interstimulus intervals ranging from negative 50 ms to positive 50 ms. tsESS induced a biphasic excitability pattern of MEPs recorded from the distal ankle muscles of the right leg with negative interstimulus intervals showing depression of MEPs followed by a non significant effect at the interstimulus interval of 0 ms, and potentiation of MEPs at positive interstimulus intervals. These findings suggest that 1) cortical descending motor volleys can either be potentiated or depressed based on the time that cortical and spinal signals meet at the spinal cord level, and 2) MEPs and tsESS-induced compound action muscle potentials likely share common neuronal pathways. These findings constitute the first evidence that synchronized neuronal signals from the primary motor cortex and spine can potentiate corticospinal motor output

Mosaic: A Satellite Constellation to Enable Groundbreaking Mars Climate System Science and Prepare for Human Exploration

The Martian climate system has been revealed to rival the complexity of Earth\u27s. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars\u27 diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced in local time) enable vertical profiling of wind, aerosols, water, and temperature, as well as mapping of surface and subsurface ice. Second, elliptical orbits sampling all of Mars\u27 plasma regions enable multipoint measurements necessary to understand mass/energy transport and ion-driven escape, also enabling, with the polar orbiters, dense radio occultation coverage. Last, longitudinally spaced areostationary orbits enable synoptic views of the lower atmosphere necessary to understand global and mesoscale dynamics, global views of the hydrogen and oxygen exospheres, and upstream measurements of space weather conditions. MOSAIC will characterize climate system variability diurnally and seasonally, on meso-, regional, and global scales, targeting the shallow subsurface all the way out to the solar wind, making many first-of-their-kind measurements. Importantly, these measurements will also prepare for human exploration and habitation of Mars by providing water resource prospecting, operational forecasting of dust and radiation hazards, and ionospheric communication/positioning disruptions

Traditional midwifery or ‘wise women’ models of leadership: Learning from Indigenous cultures

This article originated in a leadership program for Indigenous1 Australian researchers, where a participant who had worked with traditional midwives in South Sudan reflected on her experiences. While there is increasing interest in how leadership studies can learn from Indigenous leadership experiences, much of this work has focused on men’s experiences or has not paid particular attention to women’s leadership. In this article, we suggest that women’s experience as traditional midwives or ‘wise women’ has been a crucial domain of leadership over millennia. We begin by describing the features of traditional women’s leadership through midwifery before reviewing Indigenous and non-Indigenous leadership theories. Drawing on published and unpublished sources, four principles of midwifery leadership are identified: being a leader who empowers and frees others with ‘no one person wiser than the other’; embodying wisdom and ethical practice which nurtures social, cultural and spiritual needs of women and mentors the next generation by ‘walking together’; being competent and skilled as well as emotionally attuned (‘feeling the job’) to engender trust and calm which is crucial to birth, ‘depending on each other but looking to her to be in charge’ and paying attention and being responsive to emergent change and unfolding present reality rather than being prescriptive, ‘using her knowledge to adjust the situation’. While these emphases are recognisable as part of several ancient wisdom traditions, we suggest that they connect to, and have relevance for, emerging leadership thinking and practice beyond the midwifery or medical context, for men as well as women and for non-Indigenous and Indigenous leadership alike

Mosaic: A Satellite Constellation to Enable Groundbreaking Mars Climate System Science and Prepare for Human Exploration

The Martian climate system has been revealed to rival the complexity of Earth\u27s. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars\u27 diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced in local time) enable vertical profiling of wind, aerosols, water, and temperature, as well as mapping of surface and subsurface ice. Second, elliptical orbits sampling all of Mars\u27 plasma regions enable multipoint measurements necessary to understand mass/energy transport and ion-driven escape, also enabling, with the polar orbiters, dense radio occultation coverage. Last, longitudinally spaced areostationary orbits enable synoptic views of the lower atmosphere necessary to understand global and mesoscale dynamics, global views of the hydrogen and oxygen exospheres, and upstream measurements of space weather conditions. MOSAIC will characterize climate system variability diurnally and seasonally, on meso-, regional, and global scales, targeting the shallow subsurface all the way out to the solar wind, making many first-of-their-kind measurements. Importantly, these measurements will also prepare for human exploration and habitation of Mars by providing water resource prospecting, operational forecasting of dust and radiation hazards, and ionospheric communication/positioning disruptions

MOSAIC: A Satellite Constellation to Enable Groundbreaking Mars Climate System Science and Prepare for Human Exploration

International audienceThe Martian climate system has been revealed to rival the complexity of Earth's. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars' diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced in local time) enable vertical profiling of wind, aerosols, water, and temperature, as well as mapping of surface and subsurface ice. Second, elliptical orbits sampling all of Mars' plasma regions enable multipoint measurements necessary to understand mass/energy transport and ion-driven escape, also enabling, with the polar orbiters, dense radio occultation coverage. Last, longitudinally spaced areostationary orbits enable synoptic views of the lower atmosphere necessary to understand global and mesoscale dynamics, global views of the hydrogen and oxygen exospheres, and upstream measurements of space weather conditions. MOSAIC will characterize climate system variability diurnally and seasonally, on meso-, regional, and global scales, targeting the shallow subsurface all the way out to the solar wind, making many first-of-their-kind measurements. Importantly, these measurements will also prepare for human exploration and habitation of Mars by providing water resource prospecting, operational forecasting of dust and radiation hazards, and ionospheric communication/positioning disruptions