The interfascicular matrix enables fascicle sliding and recovery in tendon, and behaves more elastically in energy storing tendons

While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of the SDFT and CDET fascicles (the largest tendon subunits). Instead, there is a greater capacity for interfascicular sliding in the SDFT which facilitates the greater extensions in this particular tendon (Thorpe et al., 2012). In the current study, we exposed fascicles and interfascicular matrix (IFM) from the SDFT and CDET to cyclic loading followed by a test to failure. The results show that IFM mechanical behaviour is not a result of irreversible deformation, but the IFM is able to withstand cyclic loading, and is more elastic in the SDFT than in the CDET. We also assessed the effect of ageing on IFM properties, demonstrating that the IFM is less able to resist repetitive loading as it ages, becoming stiffer with increasing age in the SDFT. These results provide further indications that the IFM is important for efficient function in energy storing tendons, and age-related alterations to the IFM may compromise function and predispose older tendons to injury

Seeded gas thrusters and related system components

A program involved with the construction and test of a number of laser heated thrusters is described. These thrusters, with a cavity approximately 23 cm long and 3.5 cm in i.d., are to be tested by NASA at a later date with a laser beam focused through the throat to heat hydrogen propellant containing an opacifier. The heated propellant exhausts through a supersonic nozzle with a 0.6 cm throat at 3000 C. Thrust stands and control systems were furnished with the thrusters. The report describes radio frequency plasma heated hot and cold flow simulation tests by the contractor

It's all action, it's all learning: Action learning in SMEs

Purpose - The purpose of this paper is to argue that action learning (AL) may provide a means of successfully developing small to medium-sized enterprises (SMEs). Design/methodology/approach - The literature around SME learning suggests a number of processes are important for SME learning which similarity, it is argued, are encompassed in AL. AL may therefore offer a means of developing SME. This argument is then supported through the results of a longitudinal qualitative evaluation study conducted in the north-west of England, which involved the use of AL in 100 SMEs. Findings - The paper finds that the discursive and critical reflection aspects of the set environment appeared to be of great utility and importance to the SMEs. Sets also had an optimum level of which helped them find "common ground". Once common ground was established set members often continued to network and form alliances outside of the set environment. SME owner-managers could discuss both personal and business. Finally, AL offered the opportunity to take time out of the business and "disengage" with the operational allowing them to become more strategic. Practical implications - In this paper both the literature review and the results of the evaluation suggest AL may offer a means of engaging SMEs in training, which is relevant and useful to them. AL offers a way for policy makers and support agencies to get involved with SME management development while retaining context and naturalistic conditions. Originality/value - This paper attempts to move beyond other articles which assess SME response to government initiatives, through examining the literature around SME learning and constructing a rationale which proposes that AL encompasses many of the learning processes suggested in the literature as effective for SME development. © Emerald Group Publishing Limited

Path Similarity Analysis: a Method for Quantifying Macromolecular Pathways

Diverse classes of proteins function through large-scale conformational changes; sophisticated enhanced sampling methods have been proposed to generate these macromolecular transition paths. As such paths are curves in a high-dimensional space, they have been difficult to compare quantitatively, a prerequisite to, for instance, assess the quality of different sampling algorithms. The Path Similarity Analysis (PSA) approach alleviates these difficulties by utilizing the full information in 3N-dimensional trajectories in configuration space. PSA employs the Hausdorff or Fr\'echet path metrics---adopted from computational geometry---enabling us to quantify path (dis)similarity, while the new concept of a Hausdorff-pair map permits the extraction of atomic-scale determinants responsible for path differences. Combined with clustering techniques, PSA facilitates the comparison of many paths, including collections of transition ensembles. We use the closed-to-open transition of the enzyme adenylate kinase (AdK)---a commonly used testbed for the assessment enhanced sampling algorithms---to examine multiple microsecond equilibrium molecular dynamics (MD) transitions of AdK in its substrate-free form alongside transition ensembles from the MD-based dynamic importance sampling (DIMS-MD) and targeted MD (TMD) methods, and a geometrical targeting algorithm (FRODA). A Hausdorff pairs analysis of these ensembles revealed, for instance, that differences in DIMS-MD and FRODA paths were mediated by a set of conserved salt bridges whose charge-charge interactions are fully modeled in DIMS-MD but not in FRODA. We also demonstrate how existing trajectory analysis methods relying on pre-defined collective variables, such as native contacts or geometric quantities, can be used synergistically with PSA, as well as the application of PSA to more complex systems such as membrane transporter proteins.Comment: 9 figures, 3 tables in the main manuscript; supplementary information includes 7 texts (S1 Text - S7 Text) and 11 figures (S1 Fig - S11 Fig) (also available from journal site

The Tuktu and Nogak Project: Inuit Knowledge about Caribou and Calving Areas in the Bathurst Inlet Region

... Traditional ecological knowledge is central to Inuit culture in general, and to the sustainable management of lands, resources, and wildlife in particular. Since lifestyles in the Bathurst Inlet region are changing at the same time that elders are passing on and taking their wisdom with them, efforts to document this knowledge are critical. Mineral exploration and the potential for mine development, along with other land use issues, further compound this imperative. For these reasons, a two-year study entitled The Tuktu (caribou) and Nogak (calves) Project ("the project") was initiated in February 1997, with the primary goal of documenting and communicating Inuit knowledge about caribou and calving areas in the Bathurst Inlet region. ..

The Hiukitak School of Tuktu: Collecting Inuit Ecological Knowledge of Caribou and Calving Areas Through an Elder-Youth Camp

... this paper is the first formal report of the elder-youth camp recently held at the Hiukitak River near Bathurst Inlet in the Kitikmeot region. I begin by providing a background on the methods used in developing the project, focusing on how the research and research team developed, and why the camp became a key component of the methods. Next, I show how a camp can be a reliable, effective and fun way to record and communicate Inuit ecological knowledge (IEK). Throughout this section, I explore gender-related differences in expertise about caribou. ..

Fascicles and the interfascicular matrix show decreased fatigue life with ageing in energy storing tendons

Tendon is composed of rope-like fascicles bound together by interfascicular matrix (IFM). The IFM is critical for the function of energy storing tendons, facilitating sliding between fascicles to allow these tendons to cyclically stretch and recoil. This capacity is required to a lesser degree in positional tendons. We have previously demonstrated that both fascicles and IFM in energy storing tendons have superior fatigue resistance compared with positional tendons, but the effect of ageing on the fatigue properties of these different tendon subunits has not been determined. Energy storing tendons become more injury-prone with ageing, indicating reduced fatigue resistance, hence we tested the hypothesis that the decline in fatigue life with ageing in energy storing tendons would be more pronounced in the IFM than in fascicles. We further hypothesised that tendon subunit fatigue resistance would not alter with ageing in positional tendons. Fascicles and IFM from young and old energy storing and positional tendons were subjected to cyclic fatigue testing until failure, and mechanical properties were calculated. The results show that both IFM and fascicles from the SDFT exhibit a similar magnitude of reduced fatigue life with ageing. By contrast, the fatigue life of positional tendon subunits was unaffected by ageing. The age-related decline in fatigue life of tendon subunits in energy storing tendons is likely to contribute to the increased risk of injury in aged tendons. Full understanding of the mechanisms resulting in this reduced fatigue life will aid in the development of treatments and interventions to prevent age-related tendinopathy