The Effect of Shoe Forefoot Stiffness On The Windlass Mechanism In Running

Research evaluating the effects of running footwear on gait has deduced foot motion from upper and sole movement of footwear. The aim of the present study was to evaluate a technique that allows for direct assessment of the medial longitudinal arch (MLA) in running. A secondary purpose was to evaluate the effect of increased bending stiffness of footwear on the MLA during running. Using a unique marker set, a multi-segment foot model was created to analyze dorsiflexion of the first metatarsal, navicular displacement, rearfoot motion, and tibial rotation. Virtual markers were created based on the movement of these foot segments. Two different pairs of running shoes (flexible, stiff) were evaluated. 13 participants ran barefoot, and in both shoe conditions. The mean difference between actual and virtual markers created was 0.69 mm. Independent t-tests determined first metatarsal dorsiflexion was restricted in the stiff condition compared to the flexible (p \u3c 0.05) with an effect size of 0.36. The study provides a useful method of assessing foot motion while wearing footwear, and indicates that stiffer shoes restrict foot motion

Regional differences in the biodiversity of woodland key habitats : with respect to quantity of dead wood and number of species

Den svenska skogen har genomgått en stor förändring de senaste århundradena av en markanvändning som startade tidigare och var mer intensiv i södra Sverige än i norra. De skogar som tidigare var naturliga och variationsrika är nu omvandlade till enskiktade produktionsskogar. En följd är att bestånd med äldre skog som innehåller stora mängder död ved har minskat och fragmenterats i landskapet. Minskningen av död ved har orsakat att vissa av skogens växter och djur har blivit sällsynta. I Sverige är 4 % av den produktiva skogsmarksarealen formellt skyddad. Utöver dessa områden finns nyckelbiotoper, vilka är områden i skogen som hyser höga naturvärden och är viktiga för skogens flora och fauna. Nyckelbiotoper innehåller ofta element såsom stående och liggande död ved och biotoptyperna kan skilja sig mellan norr och söder. I denna studie analyseras mängd död ved och artantal i 19 nyckelbiotoper i norra Sverige och 20 stycken i södra Sverige. Data är insamlad av Skogsstyrelsen under tidsperioden 2009-2015. Resultaten visar att det inte finns någon skillnad i varken antal objekt eller volym död ved mellan norra och södra Sverige. Det återfinns fler signalarter och rödlistade signalarter i norra än i södra Sverige och det finns en positiv korrelation mellan artantal och mängd död ved i båda landsdelarna, vilken är starkast i södra Sverige. Resultaten indikerar att det finns fler faktorer än död ved som har betydelse för artantalet, vilket gör naturvärdesbedömningar väldigt komplexa.The forest landscape in Sweden has changed dramatically during the last centuries because of the land use, which began earlier and was more intense in the southern part of Sweden compared to the north part. Natural old-growth forests have been transformed into even-aged stands for commercial use which has led to a loss in old forest structures such as dead wood and biodiversity. These changes have disfavored many species which has turned them into threatened species. In Sweden, 4 % of the productive forest land area is protected by law. In addition to this protection are woodland key habitats. Woodland key habitats contain important elements for biodiversity such as downed logs and snags and they can vary throughout the landscape. In this study, we have analyzed the amount of dead wood and number of species in 19 woodland key habitats in the north part of Sweden and 20 woodland key habitats in the south part. The results show no differences in number nor in volume of dead wood between the north part and south part of Sweden. We found that there are more signal species and redlisted signal species in the north part of Sweden compared to the south part. Number of species has a positive correlation to dead wood in both regions, although the correlation is stronger in the south part of Sweden. The results indicate that there are more components than just dead wood that play an important role for biodiversity, which makes natural conservation a complex subject

Medial Longitudinal Arch Deformation during Walking and Stair Navigation While Carrying Loads

Background: Understanding the biomechanics of the medial longitudinal arch (MLA) may provide insights into injury risk and prevention, as well as function of the arch-supporting structures. Our understanding of MLA deformation is currently limited to sit-to-stand, walking, and running. Material and Methods: Three-dimensional deformation of the MLA of the right foot was characterized in 17 healthy participants during several simulated activities of daily living. MLA deformation was quantified by both changes in arch length and navicular displacement during the stance phase of three motions: walking, stair ascent, and stair descent. Three levels of load were also evaluated: no load, a front load (13.6 kg), and a backpack load (13.6 kg). Force platforms and an eight-camera motion capture system were used to collect relevant lower extremity kinetic and kinematic data. Results: Motion type had a significant (p \u3c 0.05) effect on navicular displacement and arch length elongation with navicular displacement being greatest during stair descent, while the walking and stair descent conditions showed the greatest increase in arch length. External load did not significantly affect either of these two measures (p \u3e 0.05). Conclusion: Differences in the MLA deformation variables resulting from varied dynamic activities of daily living can be greater than those during walking and should be considered. Clinical Relevance: Detailing the mechanics of the MLA may aid in further understanding injuries associated with the MLA, and the results of the current study indicate that these mechanics change based on activity

Assays for determining heparan sulfate and heparin O-sulfotransferase activity and specificity

O-sulfotransferases (OSTs) are critical enzymes in the cellular biosynthesis of the biologically and pharmacologically important heparan sulfate and heparin. Recently, these enzymes have been cloned and expressed in bacteria for application in the chemoenzymatic synthesis of glycosaminoglycan-based drugs. OST activity assays have largely relied on the use of radioisotopic methods using [35S] 3'-phosphoadenosine-5'-phosphosulfate and scintillation counting. Herein, we examine alternative assays that are more compatible with a biomanufacturing environment. A high throughput microtiter-based approach is reported that relies on a coupled bienzymic colorimetric assay for heparan sulfate and heparin OSTs acting on polysaccharide substrates using arylsulfotransferase-IV and p-nitrophenylsulfate as a sacrificial sulfogroup donor. A second liquid chromatography-mass spectrometric assay, for heparan sulfate and heparin OSTs acting on structurally defined oligosaccharide substrates, is also reported that provides additional information on the number and positions of the transferred sulfo groups within the product. Together, these assays allow quantitative and mechanistic information to be obtained on OSTs that act on heparan sulfate and heparin precursors

Biomarkers of Alzheimer’s disease and cerebrovascular disease in relation to depressive symptomatology in individuals with subjective cognitive decline

Background: Subjective cognitive decline (SCD) has gained recent interest as a potential harbinger of neurodegenerative diseases such as Alzheimer’s disease (AD) and cerebrovascular disease (CVD). In addition, SCD can be related to depressive symptomatology. However, the association between AD and CVD biomarkers, depressive symptomatology, and SCD is still unclear. We investigated the association of AD and CVD biomarkers and depressive symptomatology with SCD in individuals with subjective memory complaints (SCD-memory group) and individuals with subjective concentration complaints (SCD-concentration group).// Methods: We recruited a population-based cohort of 217 individuals (all aged 70 years, 53% female, 119 SCD-memory individuals, 23 SCD-concentration individuals, 89 controls). AD and CVD were assessed through cerebrospinal fluid levels of the Aβ42/40 ratio and phosphorylated tau, and white matter signal abnormalities on magnetic resonance imaging, respectively. Associations between biomarkers, depressive symptomatology, and SCD were tested via logistic regression and correlation analyses.// Results: We found a significant association of depressive symptomatology with SCD-memory and SCD-concentration. Depressive symptomatology was not associated with AD and CVD biomarkers. Both the phosphorylated tau biomarker and depressive symptomatology predicted SCD-memory, and the Aβ42/40 ratio and depressive symptomatology predicted SCD-concentration.// Conclusions: The role of depressive symptomatology in SCD may differ depending on the stage within the spectrum of preclinical AD (as determined by amyloid-beta and tau positivity), and does not seem to reflect AD pathology. Our findings contribute to the emerging field of subclinical depressive symptomatology in SCD, and clarify the association of different types of subjective complaints with distinct syndromic and biomarker profiles

The compositional and evolutionary logic of metabolism

Metabolism displays striking and robust regularities in the forms of modularity and hierarchy, whose composition may be compactly described. This renders metabolic architecture comprehensible as a system, and suggests the order in which layers of that system emerged. Metabolism also serves as the foundation in other hierarchies, at least up to cellular integration including bioenergetics and molecular replication, and trophic ecology. The recapitulation of patterns first seen in metabolism, in these higher levels, suggests metabolism as a source of causation or constraint on many forms of organization in the biosphere. We identify as modules widely reused subsets of chemicals, reactions, or functions, each with a conserved internal structure. At the small molecule substrate level, module boundaries are generally associated with the most complex reaction mechanisms and the most conserved enzymes. Cofactors form a structurally and functionally distinctive control layer over the small-molecule substrate. Complex cofactors are often used at module boundaries of the substrate level, while simpler ones participate in widely used reactions. Cofactor functions thus act as "keys" that incorporate classes of organic reactions within biochemistry. The same modules that organize the compositional diversity of metabolism are argued to have governed long-term evolution. Early evolution of core metabolism, especially carbon-fixation, appears to have required few innovations among a small number of conserved modules, to produce adaptations to simple biogeochemical changes of environment. We demonstrate these features of metabolism at several levels of hierarchy, beginning with the small-molecule substrate and network architecture, continuing with cofactors and key conserved reactions, and culminating in the aggregation of multiple diverse physical and biochemical processes in cells.Comment: 56 pages, 28 figure

Fibroblast Growth Factor-based Signaling through Synthetic Heparan Sulfate Blocks Copolymers Studied Using High Cell Density Three-dimensional Cell Printing

Four well-defined heparan sulfate (HS) block copolymers containing S-domains (high sulfo group content) placed adjacent to N-domains (low sulfo group content) were chemoenzymatically synthesized and characterized. The domain lengths in these HS block co-polymers were ∼40 saccharide units. Microtiter 96-well and three-dimensional cell-based microarray assays utilizing murine immortalized bone marrow (BaF3) cells were developed to evaluate the activity of these HS block co-polymers. Each recombinant BaF3 cell line expresses only a single type of fibroblast growth factor receptor (FGFR) but produces neither HS nor fibroblast growth factors (FGFs). In the presence of different FGFs, BaF3 cell proliferation showed clear differences for the four HS block co-polymers examined. These data were used to examine the two proposed signaling models, the symmetric FGF2-HS2-FGFR2 ternary complex model and the asymmetric FGF2-HS1-FGFR2 ternary complex model. In the symmetric FGF2-HS2-FGFR2 model, two acidic HS chains bind in a basic canyon located on the top face of the FGF2-FGFR2 protein complex. In this model the S-domains at the non-reducing ends of the two HS proteoglycan chains are proposed to interact with the FGF2-FGFR2 protein complex. In contrast, in the asymmetric FGF2-HS1-FGFR2 model, a single HS chain interacts with the FGF2-FGFR2 protein complex through a single S-domain that can be located at any position within an HS chain. Our data comparing a series of synthetically prepared HS block copolymers support a preference for the symmetric FGF2-HS2-FGFR2 ternary complex model

Modeling acid-gas generation from boiling chloride brines

<p>Abstract</p> <p>Background</p> <p>This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate.</p> <p>Results</p> <p>Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150°C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies.</p> <p>Conclusion</p> <p>The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent expected conditions in an emplacement drift, but nevertheless illustrate the potential for acid-gas generation at moderate temperatures (<150°C).</p

Stellar Spectroscopy in the Near-infrared with a Laser Frequency Comb

The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness of Earth and our Solar System, and the conditions under which life could exist elsewhere in our Galaxy. Doppler spectroscopy, or the radial velocity (RV) technique, has been used extensively to identify hundreds of exoplanets, but with notable challenges in detecting terrestrial mass planets orbiting within habitable zones. We describe infrared RV spectroscopy at the 10 m Hobby-Eberly telescope that leverages a 30 GHz electro-optic laser frequency comb with nanophotonic supercontinuum to calibrate the Habitable Zone Planet Finder spectrograph. Demonstrated instrument precision <10 cm/s and stellar RVs approaching 1 m/s open the path to discovery and confirmation of habitable zone planets around M-dwarfs, the most ubiquitous type of stars in our Galaxy

Priorities for synthesis research in ecology and environmental science

ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD