Metabolic adaptation and related biomechanics in an ankle-based exoskeleton system during six sessions of steady state walking.

Ankle-based exoskeletons have demonstrated metabolic benefits during steady-state walking; however, variability exists in individual adaptation timelines necessary to achieve those benefits. This study assessed timelines for metabolic and gait-related adaptation while wearing an ankle-based exoskeleton while powered (EXOP) compared to unpowered (EXNP) and no device worn (NOEX). Metabolic (VO) and biomechanics data were collected while 14 participants walked on a treadmill at 1.

The parasitic lifestyle of an archaeal symbiont.

DPANN archaea are a diverse group of microorganisms characterised by small cells and reduced genomes. To date, all cultivated DPANN archaea are ectosymbionts that require direct cell contact with an archaeal host species for growth and survival. However, these interactions and their impact on the host species are poorly understood.

The Archaeal Cell Cycle.

Since first identified as a separate domain of life in the 1970s, it has become clear that archaea differ profoundly from both eukaryotes and bacteria. In this review, we look across the archaeal domain and discuss the diverse mechanisms by which archaea control cell cycle progression, DNA replication, and cell division. While the molecular and cellular processes archaea use to govern these critical cell biological processes often differ markedly from those described in bacteria and eukaryotes, there are also striking similarities that highlight both unique and common principles of cell cycle control across the different domains of life.

The Use of Holographic Memory Resolution® to Improve the Physical and Biopsychosocial Symptoms of Chronic Pain: A Feasibility, Mixed Methods Study.

Objective: Holographic Memory Resolution® (HMR®), a mind-based therapy, has been used for decades as a nonpharmacologic intervention for trauma imprinting to alleviate depression, anxiety, pain, and post-traumatic stress disorder (PTSD). No clinical studies were found examining the use of HMR®. This study examined the feasibility and preliminary efficacy of administering HMR® to individuals experiencing chronic pain and related biopsychosocial symptoms.

Race and geography impact validity of maximum allowable standing height equations for para-athletes.

World Athletics use maximum allowable standing height (MASH) equations for para-athletes with bilateral lower extremity amputations to estimate stature and limit prosthesis length since longer prostheses can provide running performance advantages. The equations were developed using a white Spanish population; however, validation for other races and geographical groups is limited. This study aimed to determine the validity of the MASH equations for Black and white Americans and whether bias errors between calculated and measured stature were similar between these populations.

Roles of ESCRT-III polymers in cell division across the tree of life.

Every cell becomes two through a carefully orchestrated process of division. Prior to division, contractile machinery must first be assembled at the cell midzone to ensure that the cut, when it is made, bisects the two separated copies of the genetic material. Second, this contractile machinery must be dynamically tethered to the limiting plasma membrane so as to bring the membrane with it as it constricts.

Changes in Running Kinematics and Kinetics Following a 10 km Run.

Background: Little is known about changes in kinetics or kinematics following a 10 km training run. This information has implications on risk of running-related injury.

Purpose: The purpose of this study was to examine the effect of a 10 km run on running kinematics and kinetics in a sample of experienced runners.

Polarized SCAR and the Arp2/3 complex regulate apical cortical remodeling in asymmetrically dividing neuroblasts.

Although the formin-nucleated actomyosin cortex has been shown to drive the changes in cell shape that accompany animal cell division in both symmetric and asymmetric cell divisions, the mitotic role of cortical Arp2/3-nucleated actin networks remain unclear. Here using asymmetrically dividing neural stem cells as a model system, we identify a pool of membrane protrusions that form at the apical cortex of neuroblasts as they enter mitosis. Strikingly, these apically localized protrusions are enriched in SCAR, and depend on SCAR and Arp2/3 complexes for their formation.

Oncogenic Ras deregulates cell-substrate interactions during mitotic rounding and respreading to alter cell division orientation.

Oncogenic Ras has been shown to change the way cancer cells divide by increasing the forces generated during mitotic rounding. In this way, Ras enables cancer cells to divide across a wider range of mechanical environments than normal cells. Here, we identify a further role for oncogenic Ras-ERK signaling in division by showing that Ras expression alters the shape, division orientation, and respreading dynamics of cells as they exit mitosis.

Comparison of 2-D and 3-D Analysis of Running Kinematics and Actual Versus Predicted Running Kinetics.

Background: Providing clinicians with an accurate method to predict kinetic measurements using 2D kinematic motion analysis is crucial to the management of distance runners. Evidence is needed to compare the accuracy of 2D and 3D kinematic measurements as well as measured and estimated kinetic variables.

Purposes: The objectives of this study were to (1) compare 2D video analysis of running kinematics with gold standard 3D motion capture and, (2) to evaluate published equations which estimate running kinetics using 2D kinematic and spatiotemporal values and modify these equations based on study findings.

Mechanochemical Rules for Shape-Shifting Filaments that Remodel Membranes.

The sequential exchange of filament composition to increase filament curvature was proposed as a mechanism for how some biological polymers deform and cut membranes. The relationship between the filament composition and its mechanical effect is lacking. We develop a kinetic model for the assembly of composite filaments that includes protein-membrane adhesion, filament mechanics and membrane mechanics.

The cell biology of archaea.

The past decade has revealed the diversity and ubiquity of archaea in nature, with a growing number of studies highlighting their importance in ecology, biotechnology and even human health. Myriad lineages have been discovered, which expanded the phylogenetic breadth of archaea and revealed their central role in the evolutionary origins of eukaryotes. These discoveries, coupled with advances that enable the culturing and live imaging of archaeal cells under extreme environments, have underpinned a better understanding of their biology.

The role of RAS oncogenes in controlling epithelial mechanics.

Mutations in RAS are key oncogenic drivers and therapeutic targets. Oncogenic Ras proteins activate a network of downstream signalling pathways, including extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K), promoting cell proliferation and survival. However, there is increasing evidence that RAS oncogenes also alter the mechanical properties of both individual malignant cells and transformed tissues.

Ahead of her time: The multidimensional impact of Marie Ussing Nylen.

Marie Ussing Nylen was a trail blazing scientist and administrative leader at the US National Institutes of Health. She accomplished this when it was extremely difficult for a woman to do so. She was also a whole person - a wife, mother, and talented athlete, that is, a well-rounded person by any definition.

Users Maintain Task Accuracy and Gait Characteristics During Missed Exoskeleton Actuations Through Adaptations In Joint Kinematics.

In operational settings, lower-limb active exoskeletons may experience errors, where an actuation that should be present is missed. These missed actuations may impact users' trust in the system and the adapted human-exoskeleton coordination strategies. In this study, we introduced pseudorandom catch trials, in which an assistive exoskeleton torque was not applied, to understand the immediate responses to missed actuations and how users' internal models to an exoskeleton adapt upon repeated exposure to missed actuations.

Local synthesis of the phosphatidylinositol-3,4-bisphosphate lipid drives focal adhesion turnover.

Focal adhesions are multifunctional organelles that couple cell-matrix adhesion to cytoskeletal force transmission and signaling and to steer cell migration and collective cell behavior. Whereas proteomic changes at focal adhesions are well understood, little is known about signaling lipids in focal adhesion dynamics. Through the characterization of cells from mice with a kinase-inactivating point mutation in the class II PI3K-C2β, we find that generation of the phosphatidylinositol-3,4-bisphosphate (PtdIns(3,4)P) membrane lipid promotes focal adhesion disassembly in response to changing environmental conditions.

Spindle reorientation in response to mechanical stress is an emergent property of the spindle positioning mechanisms.

Proper orientation of the mitotic spindle plays a crucial role in embryos, during tissue development, and in adults, where it functions to dissipate mechanical stress to maintain tissue integrity and homeostasis. While mitotic spindles have been shown to reorient in response to external mechanical stresses, the subcellular cues that mediate spindle reorientation remain unclear. Here, we used a combination of optogenetics and computational modeling to investigate how mitotic spindles respond to inhomogeneous tension within the actomyosin cortex.