Software is continually evolving, to fix bugs and add new features. Industry users, however, often value stability, and thus may not be able to update their code base to the latest versions. This raises the need to selectively backport new features to older software versions. Traditionally, backporting has been done by cluttering the backported code with preprocessor directives, to replace behaviors that are unsupported in an earlier version by appropriate workarounds. This approach however involves writing a lot of error-prone backporting code, and results in implementations that are hard to read and maintain. We consider this issue in the context of the Linux kernel, for which older versions are in wide use. We present a new backporting strategy that relies on the use of a backporting compatability library and on code that is automatically generated using the program transformation tool Coccinelle. This approach reduces the amount of code that must be manually written, and thus can help the Linux kernel backporting effort scale while maintaining the dependability of the backporting process.

This work describes a mechanical approach for manipulating the capillary length and spreading of liquid coatings on flexible substrates with high gravity. Experimental verification in the literature has focused on cases under standard gravity on earth, and to the authors' knowledge, this work is the first to explore its relevance to spreading puddles under high gravity. By using centrifugation with a high-density liquid base underneath a coated substrate, it is possible to apply acceleration normal to a substrate to decrease the capillary length and increase the rate of spreading. Due to the nature of centrifugation, this method works primarily on flexible substrates, which bend with a curvature that conforms to a contour of uniformly distributed centrifugal acceleration. With high gravity of 600 g applied, the capillary length reduces by a factor of 24.5, and the spreading shifts from "transient spreading" between the surface tensiondriven and gravity-driven regimes to the gravity-driven regime. Experimental results show that high gravitational acceleration will enhance the rate of spreading such that a puddle, which would require 12 hours under standard gravity on earth to go from an 8-µl droplet to a 40-µm thick puddle, would require less than 1 minute under 600 g. Overall, this work suggests that previously derived expressions for gravity-driven spreading of puddles under earth's standard gravity extend to predicting the behavior of puddles spreading on smooth, wetting substrates exposed to more than 100 g's of acceleration.

Las plantas con propiedades terapéuticas son utilizadas comúnmente en medicina tradicional, tal es el caso del Yawar Panga, Aristolochia cf. Cauliflora Ule. En la bibliografía no se han publicado estudios relativos a la composición química de las hojas de Yawar Panga, ni de ninguna otra parte de la planta. A partir de los extractos de éter de petróleo y diclorometano de las hojas de Yawar panga, colectadas en el Jardín Botánico del Centro Takiwasi (Tarapoto,región San Martín, Amazonia peruana), se identificaron tres esteroles, γ-sitosterol, estigmasterol y campesterol, los cuales fueron analizados mediante cromatografía de gases e identificados mediante sus espectros de masas (CG-EM). Así mismo, del extracto etanólico se aisló la rotenona (con 93,4% de pureza), que fue identificada mediante CG-EM, resonancia magnética nuclear de 1H y 13C (RMN 1H y RMN 13C) y por espectroscopía infrarroja contransformada de Fourier (FTIR).