1,107 research outputs found
Canine presumed glial brain tumours treated with radiotherapy: Is there an inferior outcome in tumours contacting the subventricular zone?
Post-treatment outcome in canine glial tumours is described with a broad range of survival times between 2 and 28 months. After surgery or radiation therapy, the tumours may progress locally or spread within the central nervous system. It is unknown if tumour- or patient-specific factors influence prognosis. In humans, glioblastoma involving the subventricular zone has been found to recur distantly, with shortened time to progression and overall survival. We included 32 dogs irradiated for a presumptive primary glial brain tumour in this retrospective cohort study. Tumours were grouped relative to subventricular zone contact and overt ventricular invasion assessing pre-treatment magnetic resonance images. Median time to progression (TTP) for all cases was 534 days (95%CI, 310–758), with a significantly shorter TTP in dogs with lesions at the subventricular zone (median TTP, 260 vs. 687 days; p =.049). Tumours at the subventricular zone progressed more often (p =.001), and more likely as CNS-metastasis (52.9% vs. 13.3%, p =.028). Median overall survival (OS) was 489 days (95%CI, 147–831) and median tumour-specific survival 609 days (95%CI, 382–835). Involvement of the subventricular zone was significantly associated with a shorter tumour-specific survival (median, 306 vs. 719 days; p =.044). Glial tumours contacting the subventricular zone in dogs have a shorter tumour-specific survival and a higher rate of progression and CNS-metastasis. Despite local tumour control, metastasis must be considered and should prompt further treatment approaches
Policy vs practice: The use, implementation and enforcement of human rights clauses in the European Union’s international trade agreements
In the mid-1990s, the EU adopted a general policy of including human rights clauses in all of its
international trade agreements. Through these human rights clauses, in addition to other tools such
as Human Rights Dialogue and sanctions, the EU seeks to promote the protection of human rights in its
external relations. There are, however, some issues arising regarding the content, use, implementation
and activation of these clauses. Not only do human rights clauses in different agreements vary in wording
and scope, but also the actual implementation and enforcement by the EU differ from case to case, raising
questions as to the selective character and the consistency of the EU’s action and, consequently, as to
the EU’s credibility as a normative international actor. The main deficiencies in this regard are the
selective and at times inconsistent inclusion and activation of human rights clauses, as shown by an
examination of the EU’s agreements and their implementation and enforcement in practice. This article
examines human rights clauses in the EU’s international trade agreements and the implementation and
enforcement thereof, in order to shed light on the promises and pitfalls of the EU’s human rights efforts
Counteracting Green Alder Shrub Expansion by Low-Input Grazing
In the past decades, the decline of traditional agriculture has caused an abandonment of marginal pastures in many mountain areas of Europe. In the Swiss Alps, green alder (Alnus viridis) is the most abundant successional shrub. A survey of 24 pasture-shrub gradients showed that the encroachment by green alder, in contrast to other shrubs, is associated with a substantial decline in plant species richness. The understorey of alder is primarily populated by very few, broad-leaved herbaceous species benefitting from the atmospheric nitrogen fixed by actinomycetes in symbiosis with green alder. However, the understory vegetation also provides an underestimated forage, rich in protein and comparable in productivity and digestibility to nearby open pastures. A two-year grazing experiment with cattle (Dexter), sheep (local Engadine sheep) and mixed-breed goats in the Eastern Swiss Alps demonstrated that robust breeds were able to exploit these resources as they readily penetrated the thickets. The Engadine sheep and the goats consumed green alder bark and thus actively counteracted shrub encroachment. Dexter cattle did not forage on alder bark but on leaves and opened the thickets by their movement through them. Since goats preferred other woody species to green alder and depleted them before the alder, they may impair the regeneration of late-successional forest. Dexter heifers and Engadine lambs performed equally well on pastures with high shrub cover and on open pastures in terms of average daily weight gain, carcass and meat quality. This was facilitated by the comparatively low productivity of these breeds. In this way, low-input grazing systems utilizing adapted breeds, especially sheep, can add to conservation goals and sustain a viable meat production in marginal areas
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Development of electrically conductive microstructures based on polymer/CNT nanocomposites via two-photon polymerization
Femtosecond laser-induced two-photon polymerization (2PP) of carbon nanofiller doped polymers was utilized to produce electrically conductive microstructures, which are expected to be applicable as microelectronic components or micro-electromechanical systems in sensors. The nanocomposites were processed by compounding an inorganic-organic hybrid material with two different types (short and long) of single walled carbon nanotubes (SWCNTs). Different SWCNT contents were dispersed in the polymer by sonication to adjust the electrical conductivity of the nanocomposites. Low surface resistivity values of ~ 4.6 × 105 Ω/sq. could be measured for coated reference films with a thickness of 30 μm having an exceptionally low SWCNT content of 0.01 wt% of the long type of SWCNTs. In contrast, a higher minimum resistivity of 1.5 × 106 Ω/sq. was exhibited for composites with a higher content, 2 wt%, of short SWCNTs. The structural quality of the microstructures processed by 2PP was mainly influenced by the dispersion quality of the SWCNTs. To characterize the electrical conductivity, conductive atomic force microscopy was applied for the first time. In microstructures with 0.05 wt% of the long type of SWCNTs, a contact current could be detected over a wide range of the measured area visualizing the electrical conductive CNT network, which has not been reported before
FPGA basierte, konfigurierbare OFDM Sender-Plattform für die Positionsbestimmung mittels TDoA
Für die Evaluierung von Algorithmen zur Positionsbestimmung nach dem Time Difference of Arrival – Verfahren wird eine frei konfigurierbare OFDM Sender-Plattform benötigt. Da die Berechnung in Echtzeit erfolgen soll, ist eine Implementierung in rekonfigurierbarer Hardware (FPGA) erforderlich. Das Manuskript
gibt sowohl einen Überblick über die Hintergründe und die Architektur des Sendesystems, als auch einen tieferen Einblick in verschiedene Lösungsdetails
Defensive responses of cuttlefish to different teleost predators
Author Posting. © Marine Biological Laboratory, 2013. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 225 (2013): 161-174.We evaluated cuttlefish (Sepia officinalis) responses to three teleost predators: bluefish (Pomatomus saltatrix), summer flounder (Paralichthys dentatus), and black seabass (Centropristis striata). We hypothesized that the distinct body shapes, swimming behaviors, and predation tactics exhibited by the three fishes would elicit markedly different antipredator responses by cuttlefish. Over the course of 25 predator-prey behavioral trials, 3 primary and 15 secondary defense behaviors of cuttlefish were shown to predators. In contrast, secondary defenses were not shown during control trials in which predators were absent. With seabass—a benthic, sit-and-pursue predator—cuttlefish used flight and spent more time swimming in the water column than with other predators. With bluefish—an active, pelagic searching predator—cuttlefish remained closely associated with the substrate and relied more on cryptic behaviors. Startle (deimatic) displays were the most frequent secondary defense shown to seabass and bluefish, particularly the Dark eye ring and Deimatic spot displays. We were unable to evaluate secondary defenses by cuttlefish to flounder—a lie-and-wait predator—because flounder did not pursue cuttlefish or make attacks. Nonetheless, cuttlefish used primary defense during flounder trials, alternating between cryptic still and moving behaviors. Overall, our results suggest that cuttlefish may vary their behavior in the presence of different teleost predators: cryptic behaviors may be more important in the presence of active searching predators (e.g., bluefish), while conspicuous movements such as swimming in the water column and startle displays may be more prevalent with relatively sedentary, bottom-associated predators (e.g., seabass).This project was funded by a United States Department of
Defense, Defense Advanced Research Projects Agency, Defense
Sciences Office (DARPA DSO) Grant (HR0011-09-
1-0017)
Diseño, construcción y experimentación de un horno solar como experiencia educativa en el nivel medio de enseñanza
En el presente trabajo se presenta la fundamentación y los objetivos de un Proyecto Educativo Institucional para el diseño, construcción y experimentación de un homo solar. El proyecto está enmarcado en la necesidad de encauzar la capacidad técnica y humana para el fortalecimiento de las actividades innovativas en al ámbito educativo, la construcción social del saber y la cooperación en el desarrollo científico-tecnológico. El homo está formado por un reflector en forma de casquete esférico protegido con una cáscara exterior de chapa metálica Una aislación de lana de vidrio y poliestireno expandido se ubica entre la cara interna y extema del casquete. Un vidrio y un policarbonato alveolar integran la tapa del homo. Fue factible la cocción de alimentos con el aprovechamiento de la energía solar.Tema: Educación en Energías Renovables.Asociación Argentina de Energía Sola
Потенциометрическое исследование расплавов NaCl–2CsCl, содержащих ионы вольфрама (IV)
En el presente trabajo se presenta la fundamentación y los objetivos de un Proyecto Educativo Institucional para el diseño, construcción y experimentación de un homo solar. El proyecto está enmarcado en la necesidad de encauzar la capacidad técnica y humana para el fortalecimiento de las actividades innovativas en al ámbito educativo, la construcción social del saber y la cooperación en el desarrollo científico-tecnológico. El homo está formado por un reflector en forma de casquete esférico protegido con una cáscara exterior de chapa metálica Una aislación de lana de vidrio y poliestireno expandido se ubica entre la cara interna y extema del casquete. Un vidrio y un policarbonato alveolar integran la tapa del homo. Fue factible la cocción de alimentos con el aprovechamiento de la energía solar.Tema: Educación en Energías Renovables.Asociación Argentina de Energía Sola
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