Bronchospasm and its Biophysical Basis in Airway Smooth Muscle

Airways hyperresponsiveness is a cardinal feature of asthma but remains unexplained. In asthma, the airway smooth muscle cell is the key end-effector of bronchospasm and acute airway narrowing, but in just the past five years our understanding of the relationship of responsiveness to muscle biophysics has dramatically changed. It has become well established, for example, that muscle length is equilibrated dynamically rather than statically, and that non-classical features of muscle biophysics come to the forefront, including unanticipated interactions between the muscle and its time-varying load, as well as the ability of the muscle cell to adapt rapidly to changes in its dynamic microenvironment. These newly discovered phenomena have been described empirically, but a mechanistic basis to explain them is only beginning to emerge

Staten, kriget och moralen

Denna studie kommer undersöka vilken moralisk roll det spelar om en aktör är en stat eller inte i militära konflikter. Detta görs efter en kort introduktion av den mediala benämningen av IS orsakade, där det tydligt klargjordes att huruvida en aktör kallas för en stat eller inte antogs ha stor betydelse. För att avgöra vilken moralisk betydelse det har att behandlas som en stat så konsulteras Just War Theory (JWT) som bidrar med ett ramverk för hur frågan kan angripas. Genom studiens diskussionsavsnitt så appliceras JWT:s kriterier för vad som är legitima krig löpande på frågeställningen, normativa argument från företrädare för JWT granskas kritiskt och diskuteras tillsammans med tidigare forskning. Studiens resultat visar att det spelade en relativt liten moralisk roll att behandlas som en stat, betydelsen var dock positiv i den mening att stater på olika sätt anses mer moraliskt befriade än icke-stater, det kunde samtidigt göras ett argument för att det kan finns en moralisk skyldighet att behandla sina fiender i militära konflikter som stater. Studiens diskussion reser dessutom en serie uppföljande frågor vilka lämnas som förslag till framtida forskning. Studien uppmanar till undersökningar av 1. hur diplomatiska relationer kan öppnas till organisationer som exempelvis IS, 2. huruvida stater äger bättre möjligheter att formulera och få stöd för sina orsaker och intentioner i krig än icke-stater

Method and system for measurement of mechanical properties of molecules and cells

Mechanical stresses and deformations are applied directly to cell surface receptors or molecules and measured using a system including a magnetic twisting device in combination with ferromagnetic microbeads coated with ligands for integrins or any other surface receptors. The system can be used diagnostically to characterize cells and molecules and to determine the effect of transformation and compounds, including drugs, on the cells and molecules. The system can also be used to induce cells to grow or alter production of molecules by the cells

Injury risk factors, screening tests and preventative strategies: A systematic review of the evidence that underpins the perceptions and practices of 44 football (soccer) teams from various premier leagues

Purpose: To systematically review the scientific level of evidence for the ‘Top 3’ risk factors, screening tests and preventative exercises identified by a previously published survey of 44 premier league football (soccer) teams. Also, to provide an overall scientific level of evidence and graded recommendation based on the current research literature. Methods: A systematic literature search (Pubmed [MEDLINE], SportDiscus, PEDRO and Cochrane databases). The quality of the articles was assessed and a level of evidence (1++ to 4) was assigned. Level 1++ corresponded to the highest level of evidence available and 4, the lowest. A graded recommendation (A: strong, B: moderate, C: weak, D: insufficient evidence to assign a specific recommendation) for use in the practical setting was given. Results: Fourteen studies were analysed. The overall level of evidence for the risk factors previous injury, fatigue and muscle imbalance were 2++, 4 and ‘inconclusive’, respectively. The graded recommendation for functional movement screen, psychological questionnaire and isokinetic muscle testing were all ‘D’. Hamstring eccentric had a weak graded ‘C’ recommendation, and eccentric exercise for other body parts was ‘D’. Balance/proprioception exercise to reduce ankle and knee sprain injury was assigned a graded recommendation ‘D’. Conclusions: The majority of perceptions and practices of premier league teams have a low level of evidence and low graded recommendation. This does not imply that these perceptions and practices are not important or not valid, as it may simply be that they are yet to be sufficiently validated or refuted by research

Monolayer Stress Microscopy: Limitations, Artifacts, and Accuracy of Recovered Intercellular Stresses

In wound healing, tissue growth, and certain cancers, the epithelial or the endothelial monolayer sheet expands. Within the expanding monolayer sheet, migration of the individual cell is strongly guided by physical forces imposed by adjacent cells. This process is called plithotaxis and was discovered using Monolayer Stress Microscopy (MSM). MSM rests upon certain simplifying assumptions, however, concerning boundary conditions, cell material properties and system dimensionality. To assess the validity of these assumptions and to quantify associated errors, here we report new analytical, numerical, and experimental investigations. For several commonly used experimental monolayer systems, the simplifying assumptions used previously lead to errors that are shown to be quite small. Out-of-plane components of displacement and traction fields can be safely neglected, and characteristic features of intercellular stresses that underlie plithotaxis remain largely unaffected. Taken together, these findings validate Monolayer Stress Microscopy within broad but well-defined limits of applicability

A contingency approach of open innovation intermediaries - the management principles of the "intermediary of the unknown"

International audienceResearch has improved our understanding of the managerial challenges inherent in exploratory intermediation. For instance knowledge brokers help to solve well-defined problems based on existing competences. But what if the relevant actor networks are not known, if there is no clear common interest, or if there are only ill-defined, wicked problems and no legitimate common place where they can be discussed? The aim of this paper is to explore these management principles for intermediation of the unknown. Can intermediaries be active when the degree of unknown is high? And if so, what can they do and how can they manage and drive collective innovation? We first build on a review of the literature to highlight common core functions of the different types of intermediaries. Then, we introduce the "degree of unknown" as a new dimension for analyzing the role of intermediaries, and we discuss whether the core functions of the intermediary could be fulfilled when the degree of unknown is very high. Our analysis is based on four different empirical case studies in Sweden, France, and Germany where these functions have been tackled in particular because of the low level of pre-existing knowledge. We describe the managerial challenges these intermediaries face in the unknown and we demonstrate examples of how they have been handled. We conclude by discussing the theoretical and empirical perspectives raised by this work. The paper contributes to the theory of innovation intermediaries by exploring the properties of a form of intermediary for which the degree of unknown is a key contingency variable, and describes management principles for such intermediaries. In this way we characterize a new role -the "intermediary of the unknown" - that may be well spread in practice but scarcely analysed in the literature

Cellular Contraction and Polarization Drive Collective Cellular Motion

Coordinated motions of close-packed multicellular systems typically generate cooperative packs, swirls, and clusters. These cooperative motions are driven by active cellular forces, but the physical nature of these forces and how they generate collective cellular motion remain poorly understood. Here, we study forces and motions in a confined epithelial monolayer and make two experimental observations: 1) the direction of local cellular motion deviates systematically from the direction of the local traction exerted by each cell upon its substrate; and 2) oscillating waves of cellular motion arise spontaneously. Based on these observations, we propose a theory that connects forces and motions using two internal state variables, one of which generates an effective cellular polarization, and the other, through contractile forces, an effective cellular inertia. In agreement with theoretical predictions, drugs that inhibit contractility reduce both the cellular effective elastic modulus and the frequency of oscillations. Together, theory and experiment provide evidence suggesting that collective cellular motion is driven by at least two internal variables that serve to sustain waves and to polarize local cellular traction in a direction that deviates systematically from local cellular velocity

PIV-Based Examination of Deep Stall on an Oscillating Air foil

A number of studies suggest that the deep stall flow fields produced by a pure-pitch and a pure-plunge oscillating airfoil are equivalent, when effective angles of attack are matched. This assumption is examined using particle image velocimetry (PIV). Sinusoidal oscillations of a pure-plunge and pure-pitch airfoil with matched reduced frequency k = 3.93 and with kinematically equivalent amplitudes of effective angle of attack are comparatively examined using results of PIV in a free surface water tunnel at AFRL/RB, Wright Patterson AFB. Experiments were conducted at Re = 10,000 and Re = 40,000, based on free stream velocity and airfoil chord, in order to observe the legitimacy of assuming Reynolds number insensitivity on the respective flow fields. Comparisons are made to computational flow field results collected in a separate, but coordinated, CFD effort. Results for both the pure-plunge case and the pure-pitch case confirm the Reynolds number insensitivity for the high frequency motions researched here. The resulting flow fields for pure-plunge case and the pure-pitch case were vastly different. Experimental results for the pure-plunge case closely resembled those achieved by computation. However, the pure-pitch case experimental and computation results were dissimilar even after considering possible wall effects of the water tunnel. The flow field disagreement between the two motions is not surprising considering trailing edge kinematic dissimilarities

Acute tear of the fascia cruris at the attachment to the Achilles tendon: a new diagnosis

BACKGROUND: The fascia cruris encloses the posterior structures of the calf and connects to the paratenon and the Achilles tendon. We describe the clinical presentation, ultrasound imaging characteristics and the time to the recovery of tears of the fascia cruris at the attachment to the Achilles tendon. METHODS: Retrospective review of 11 tears of the fascia cruris in the different legs as separate events in 9 patients (6 male and 3 female, mean age 35.52 years, range 11–48) identified using diagnostic ultrasound, after presenting with Achillodynia. RESULTS: 11 participants presented at a mean of 4.5 weeks (range 0.5–12) after onset of symptoms. The left Achilles was more commonly injured than the right (7 : 4) and the lateral side more than the medial (6 : 4) with one case with medial and lateral presentation. Clinically, there was swelling and tenderness over the medial or lateral border in the mid to upper portion of the Achilles. 7 of the 11 (63.6%) had functional overpronation. Ultrasound appearances of a tear were identified as hypoechoic area extending from the medial or lateral border of the Achilles extending along the anatomical plane of the fascia cruris. Average return to activity was 5.2 weeks (range 1–22). Participants presenting later had longer recovery but all participants returned to full activity (r=0.4). CONCLUSIONS: This is the first description of the clinical details and sonographic findings of a tear to the fascia cruris at its attachment to the Achilles tendon. This needs to be considered as a cause of Achillodynia in athletes as recognition will affect the management