Extremal maps of the universal hyperbolic solenoid

We show that the set of points in the Teichmuller space of the universal hyperbolic solenoid which do not have a Teichmuller extremal representative is generic (that is, its complement is the set of the first kind in the sense of Baire). This is in sharp contrast with the Teichmuller space of a Riemann surface where at least an open, dense subset has Teichmuller extremal representatives. In addition, we provide a sufficient criteria for the existence of Teichmuller extremal representatives in the given homotopy class. These results indicate that there is an interesting theory of extremal (and uniquely extremal) quasiconformal mappings on hyperbolic solenoids.Comment: LaTeX, 15 page

Discovery of Infection Associated Metabolic Markers in Human African Trypanosomiasis

Peer reviewedPublisher PD

Lipid membrane-mediated attraction between curvature inducing objects

The interplay of membrane proteins is vital for many biological processes, such as cellular transport, cell division, and signal transduction between nerve cells. Theoretical considerations have led to the idea that the membrane itself mediates protein self-organization in these processes through minimization of membrane curvature energy. Here, we present a combined experimental and numerical study in which we quantify these interactions directly for the first time. In our experimental model system we control the deformation of a lipid membrane by adhering colloidal particles. Using confocal microscopy, we establish that these membrane deformations cause an attractive interaction force leading to reversible binding. The attraction extends over 2.5 times the particle diameter and has a strength of three times the thermal energy (−3.3 kBT). Coarse-grained Monte-Carlo simulations of the system are in excellent agreement with the experimental results and prove that the measured interaction is independent of length scale. Our combined experimental and numerical results reveal membrane curvature as a common physical origin for interactions between any membrane-deforming objects, from nanometre-sized proteins to micrometre-sized particles

Consumer perception on purchase decision factors and health indicators related to the quality and safety of meat sold in dibiteries in Dakar, Senegal

Accelerated socio-economic and demographic changes have led to the transformation of eating habits in sub-Saharan African cities including Dakar, Senegal. The result is the proliferation of informal fast-food establishments, such as the 'dibiteries' serving braised sheep meat. However, owing to poor hygiene practices, consumption of dibiterie meat poses a public health concern. It was unclear how the dibiterie meat quality and safety were perceived among customers who define their own purchasing social norms. A total of 165 meat consumers were randomly selected and interviewed, from 165 dibiteries sampled by convenience in the Dakar region using a structured questionnaire. Results showed that purchase decisions were guided by trust in the salesperson's expertise, the taste of the product, perceived risk of meat contamination, tenderness, price, the nutritional value, the smell and the colour and freshness of the meat. The perceived quality and safety of dibiterie meat was expressed by the 'organoleptic quality', 'environment and service' and 'price and trust of the product's safety' factors. The majority of consumers (61%) were 'less concerned' about the safety of dibiterie meat, and the acceptable price range of the product was between $5.08 and$7.62. As this food product is gaining popularity in Dakar and the majority of our participating consumers do not show high levels of concern, we suggest stricter standards

Efecto del injerto en las propiedades antioxidantes del tomate (Solanum lycopersicum L.)

The use of grafted plants in vegetable crop production is now being expanded greatly. However, few data are available on the nutritional composition of grafted vegetables with emphasis on antioxidant properties. Therefore, the major objective of this study was to evaluate antioxidant components of tomatoes influenced by grafting technique. The tomato plants were grown in a greenhouse located at Kriz˘evci, Croatia. The cultivars ‘Efialto’, ‘Heman’, and ‘Maxifort’ were used as rootstocks, while ‘Tamaris’ was used as scion. Grafting resulted in increase of number of marketable fruits per plant by 30%. Content of total vitamin C and total phenolics significantly decreased after grafting. The concentration of total extractable phenolics in tomatoes ranged from 287.1 to 977.4 mg gallic acid equivalents (GAE) kg–1 fresh weight, whereas lycopene content ranged from 11.44 to 60.99 mg kg–1 fresh weight. Antioxidant activities determined by 1,1-diphenyl-2 picrylhydrazyl (DPPH) method of grafts were significantly different compared to their respective rootstocks. The overall results showed that tomato grafting on suitable rootstocks has positive effects on the cultivation performance, but decreases nutritional quality of tomatoes. En la producción de cultivos hortícolas se está expandiendo actualmente de forma considerable el uso de plantas injertadas. Sin embargo, hay pocos datos disponibles sobre la composición nutricional de las hortícolas injertadas, especialmente sobre sus propiedades antioxidantes. El principal objetivo de este estudio fue evaluar los componentes antioxidantes de tomates influenciados por la técnica de injerto. Se cultivaron plantas de tomate en un invernadero de Kriz˘evcii, Croacia. Se utilizaron como portainjertos los cultivares ‘Efialto’, ‘Heman’, y ‘Maxifort’, mientras que ‘Tamaris’ fue utilizado como injerto. El resultado del injerto fue un aumento del 30% en el número de frutos comerciales por planta, mientras que el contenido de vitamina C y de fenoles totales disminuyó significativamente. La concentración del total de fenoles extraíbles en los tomates varió entre 287,1 y 977,4 mg de equivalentes de ácido gálico (GAE) por kilo sobre la base de peso fresco, mientras que el contenido de licopeno varió desde 11,44 hasta 60,99 mg kg–1 de peso fresco. Las actividades antioxidantes determinadas por el método DPPH (2,2-difenil-1-picrilhidrazilo) de los injertos fueron significativamente diferentes respecto de sus respectivos patrones. Los resultados globales muestran que el injerto de tomate sobre patrones adecuados tiene efectos positivos sobre el rendimiento de cultivo, pero la calidad nutricional de los frutos disminuye

Active flow control systems architectures for civil transport aircraft

Copyright @ 2010 American Institute of Aeronautics and AstronauticsThis paper considers the effect of choice of actuator technology and associated power systems architecture on the mass cost and power consumption of implementing active flow control systems on civil transport aircraft. The research method is based on the use of a mass model that includes a mass due to systems hardware and a mass due to the system energy usage. An Airbus A320 aircraft wing is used as a case-study application. The mass model parameters are based on first-principle physical analysis of electric and pneumatic power systems combined with empirical data on system hardware from existing equipment suppliers. Flow control methods include direct fluidic, electromechanical-fluidic, and electrofluidic actuator technologies. The mass cost of electrical power distribution is shown to be considerably less than that for pneumatic systems; however, this advantage is reduced by the requirement for relatively heavy electrical power management and conversion systems. A tradeoff exists between system power efficiency and the system hardware mass required to achieve this efficiency. For short-duration operation the flow control solution is driven toward lighter but less power-efficient systems, whereas for long-duration operation there is benefit in considering heavier but more efficient systems. It is estimated that a practical electromechanical-fluidic system for flow separation control may have a mass up to 40% of the slat mass for a leading-edge application and 5% of flap mass for a trailing-edge application.This work is funded by the Sixth European Union Framework Programme as part of the AVERT project (Contract No. AST5-CT-2006-030914

SNX19 restricts endolysosome motility through contacts with the endoplasmic reticulum.

The ability of endolysosomal organelles to move within the cytoplasm is essential for the performance of their functions. Long-range movement involves coupling of the endolysosomes to motor proteins that carry them along microtubule tracks. This movement is influenced by interactions with other organelles, but the mechanisms involved are incompletely understood. Herein we show that the sorting nexin SNX19 tethers endolysosomes to the endoplasmic reticulum (ER), decreasing their motility and contributing to their concentration in the perinuclear area of the cell. Tethering depends on two N-terminal transmembrane domains that anchor SNX19 to the ER, and a PX domain that binds to phosphatidylinositol 3-phosphate on the endolysosomal membrane. Two other domains named PXA and PXC negatively regulate the interaction of SNX19 with endolysosomes. These studies thus identify a mechanism for controlling the motility and positioning of endolysosomes that involves tethering to the ER by a sorting nexin

Deconstructing design thinking as a tool for the implementation of a population health initiative

BACKGROUND: The translation of evidence-based practices and rapid uptake of innovations into global health practice is challenging. Design thinking is a consultative process involving multiple stakeholders and has been identified as a promising solution to create and apply implementation strategies in complex environments like health systems. METHODS: We conducted a process evaluation of a real-world example, namely an initiative to innovate hypertension screening, diagnosis and care in Sao Paulo, Brazil. The parameters of the evaluation were informed by a specification rubric and categorization system, recommended for the investigation of implementation strategies, and the double-diamond conceptual framework to describe and examine the strategic architecture and nature of the design thinking approach, with particular emphasis on identifying potential areas of "value-add" particular to the approach. The retrospective evaluation was performed by an independent partner who had not been involved in the setting up and implementation of the design thinking process. RESULTS: The evaluation unveiled a dense catalogue of strategically driven, mostly theoretically based, activities involving all identified health system stakeholders including patients. Narrative reconstruction illuminated the systematic and coherent nature of this approach, with different resulting actions progressively accounting for all relevant layers of the health system to engineer a broad selection of specific implementation solutions. The relevance of the identified features and the mechanics used to promote more successful implementation practices was manifested in several distinct ways: design thinking offered a clear direction on which innovations really mattered and when, as well as several new dimensions for consideration in the development of an innovation mindset amongst stakeholders. It thereby promoted relationship quality in terms of familiarity and trust, and commitment to evidence-based enquiry and action. Design thinking was also able to navigate the territory between the need for intervention "fidelity" versus "adaptation" and provide the operational know-how to face familiar implementation hurdles. Lastly, it brought a new kind of skill set to the public health stakeholders that incorporated diplomacy, multidisciplinary approaches and management sciences-skills that are considered necessary but not yet widely taught as part of public health training. CONCLUSIONS: Design thinking is a sound and viable tool to use as part of an implementation strategy for engaging with health system stakeholders and successfully translating evidence-based practices and new innovations into routine practice, thereby addressing an important knowledge-practice gap and, more broadly, contributing to the strategic repertoire available to implementation science

Aerodynamics of the Large-Volume, Flow-Through Detector System. Final report

The Large-Volume Flow-Through Detector System (LVFTDS) was designed to monitor alpha radiation from Pu, U, and Am in mixed-waste incinerator offgases; however, it can be adapted to other important monitoring uses that span a number of potential markets, including site remediation, indoor air quality, radon testing, and mine shaft monitoring. Goal of this effort was to provide mechanical design information for installation of LVFTDS in an incinerator, with emphasis on ability to withstand the high temperatures and high flow rates expected. The work was successfully carried out in three stages: calculation of pressure drop through the system, materials testing to determine surrogate materials for wind-tunnel testing, and wind-tunnel testing of an actual configuration

Stress transfer and connectivity between the Bhutan Himalaya and the Shillong Plateau

International audienceWithin the northern Indian Plate, the Shillong Plateau is a peculiar geodynamic terrane, hosting significant seismic activity outboard the Himalayan belt. This activity is often used as an argument to explain apparent reduced seismicity in the Bhutan Himalayas. Although current geophysical and geodetic data indicate that the Bhutan Himalayas accommodate more deformation than the Shillong Plateau, we aim to quantify the extent to which the two geodynamic regimes are connected and potentially interact through stress transfers. We compiled a map of major faults and earthquakes in the two regions and computed co-seismic stress transfer amplitudes. Our results indicate that the Bhutan Himalayas and the Shillong Plateau are less connected than previously suggested. Major earthquakes in either of the two regions mainly affect transverse faults connecting them, causing up to ~40 bar Coulomb stress change; however, this effect is clearly less on thrust faults of the either region (up to 1 bar only). The MW 8.25 1897 Assam earthquake that affected the Shillong Plateau did not cause a stress shadow on the Main Himalayan Thrust in Bhutan as previously suggested. Similarly, the Mw 8 ± 0.5 1714 Bhutan earthquake had negligible impact on stress accumulation on thrust faults bounding the Shillong Plateau. Furthermore, the main process shaping the regional stress patterns continues to be interseismic loading with complex boundary conditions in a diffuse deformation field involving the Bengal Basin and Indo-Burman Ranges. While both the Bhutan Himalayas and the Shillong Plateau exhibit a compressional regime, their stress evolutions are more weakly connected than hypothesized. Although our modelling suggests lateral increase in stress interactions, from west (less) to east (more), in the Bhutan Himalayas, a clearer picture will only emerge with better constrained fault geometries, slip rates, crustal structure, and seismicity catalogues in the entire region of distributed deformation