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Hadron therapy offers the possibility of delivering a large amount of radiation dose to tumors with minimal absorption by the surrounding healthy tissue. In order to fully exploit the advantages of this technique, the use of real-time beam monitoring devices becomes mandatory. Compton imaging devices can be employed to map the distribution of prompt gamma emission during the treatment and thus assess its correct delivery. The Compton telescope prototype developed at IFIC-Valencia for this purpose is made of three layers of LaBr3 crystals coupled to silicon photomultipliers. The system has been tested in a 4.44 MeV gamma field at the 3 MV Tandetron accelerator at HZDR, Dresden. Images of the target with the system in three different positions separated by 10 mm were successfully reconstructed. This indicates the ability of MACACO for imaging the prompt gamma rays emitted at such energies.

Este trabajo diseña un novedoso procedimiento de medición que relaciona el tamaño de la mano y el tamaño del balón. Se detalla este procedimiento ideado para la determinación del “Índice de Cobertura de la Mano Porras, Oliver, Sosa” (I.C.M.P.O.S.) sobre el balón. A partir de tres medidas obtenidas de la mano dominante de los deportistas con la mano en máxima apertura tomadas sobre un plano, calcularemos sus coordenadas en el espacio, y las aplicaremos sobre la esfera del balón. Posteriormente, a través de una fórmula, y teniendo en cuenta el valor central de la medida de la circunferencia del balón del deporte y de la categoría deportiva correspondiente, podremos conocer el Índice de Cobertura de la mano del deportista sobre el balón, o cantidad del balón que un deportista es capaz de abarcar con su mano completamente abierta respecto a la media esfera del balón de su categoría deportiva, This paper designs a novel measurement procedure that relates the size of the hand and the size of the ball. This procedure was devised in order to determine the "Hand Coverage Index of Porras, Oliver, Sosa" (H.C.I.P.O.S.) on the ball. Using three measurements obtained from the dominant hand of athletes with the hand on its maximum aperture taken on a flat plane, we calculated their coordinates in space, and their applications on the sphere of the ball. Subsequently, through a formula, and taking into account the central value of the measurement of the circumference of the ball and the corresponding sport category, we will be able to know the Hand Coverage Index of the athlete over the ball, or the surface of the ball that an athlete is able to cover with his fully open hand with respect to the the sphere of the ball of his sport category

Optical second harmonic generation (SHG) from nanostructured graphene has been studied in the framework of classical electromagnetism using a surface integral equation method. Single disks and dimers are considered, demonstrating that the nonlinear conversion is enhanced when a localized surface plasmon resonance is excited at either the fundamental or second harmonic frequency. The proposed approach, beyond the electric dipole approximation used in the quantum description, reveals that SHG from graphene nanostructures with centrosymmetric shapes is possible when retardation e ects and the excitation of high plasmonic modes at the second harmonic frequency are taken into account. Several SHG e ects similar to those arising in metallic nanostructures, such as the silencing of the nonlinear emission and the design of double resonant nanostructures, are also reported. Finally, it is shown that the SHG from graphene disk dimers is very sensitive to a relative vertical displacement of the disks, opening new possibilities for the design of nonlinear plasmonic nanorulers.

Small mammal assemblages in the aridlands of the Southern Hemisphere often have wildly fluctuating dynamics. Previous studies have attributed these fluctuations to climate-driven pulses in food resources resulting in the switching of trophic control from bottom-up (food-limited) to top-down (predation-limited) population regulation, and vice versa. In this study we use a meta-analytic approach to evaluate the evidence for the phenomenon of switching trophic control. If shifting trophic control is a unifying phenomenon that shapes small mammal assemblages in arid Australia, we would expect the abundance and species richness of small mammals to increase with increasing primary productivity and the abundance of small mammals to decrease with increasing predator abundances, which lag behind those of small mammals. We tested these predictions using data compiled from 6 unpublished and 2 published data sets containing time series (3–11 years) of small mammal and predator community dynamics. Our analyses provide moderate support for the notion that switching trophic control is a unifying phenomenon shaping small mammal assemblages. Also, our results provide evidence that top-down and bottom-up control are not mutually exclusive phenomena driving desert small mammal assemblages but rather alternative ecosystem states that exist along a rainfall-driven continuum of ecosystem energy flux through time.

Based on a review here, the most recent Tasmanian devil remains on the mainland date from between 3000 and 4000 years BP in three isolated populations. A widely promulgated recent date within the last 500 years is rejected. Previous studies have found the arrival of the dingo (>3500 BP) to be the only suitable coincident extinction cause, although Aboriginal cultural changes have also been recently implicated. I propose that increased climate variability associated with the onset of the El Nino Southern Oscillation after 6000 BP and a subsequent intensification ca 3000 BP was also a causative factor. Other causes are not rejected, but rather all are placed within a multicausal model. Tasmanian devils are particularly susceptible to climate variability because they are the only specialised scavenger in Australia. Specialised scavengers are mostly limited by variability in the availability of carrion, and this would have increased significantly with ENSO. The fossil record (and persistence in Tasmania) indi...

Scavenging is one of the primary taphonomic processes shaping the final composition of fossil faunal assemblages. The taphonomic effect of scavengers is variable and must be understood in the context of the causes of that variation. In this study, we investigated relationships between the El Nino Southern Oscillation (ENSO), variable rainfall and scavenging on 20–40 kg mammal carcasses in semi-arid New South Wales over four years. Following periods of above-average rainfall (coincident with the La Nina phase of the ENSO), there was an increased availability of non-carrion food and scavenging activity was moderate. Following below-average rainfall (coincident with the El Nino phase of the ENSO), foraging options diminished, leading to a greater importance of carrion in the diet of scavengers and a resultant increase in carcass disturbance, transport and destruction by scavengers. Feral pigs (Sus scrofa) and red foxes (Vulpes vulpes) were the most taphonomically significant scavengers in the study. Australian ravens (Corvus coronoides) and wedge-tailed eagles (Aquila audax) were active scavengers throughout the period of the study, but had little impact on bone survival. Lace monitors (Varanus varius) also fed mostly on soft tissue and were only present seasonally. We found that climate variability in the form of short-term oscillation can result in significant variation in the impact of scavengers on carcasses and may be an important consideration when evaluating site formation scenarios and biases in fossil faunal assemblages. Copyright © 2006 John Wiley & Sons, Ltd.

To clarify the role of neuronal complex I activity in idiopathic Parkinson's disease (IPD), expression of mitochondrial mRNA encoding the ND1 subunit of mitochondrial complex I was examined by semiquantitative in situ hybridization histochemistry in melanized neurons of human substantia nigra in IPD cases and control subjects. Expression of mRNA encoding the glycolytic enzyme, aldolase C, was also examined in substantia nigra and other neurons of the midbrain and brain stem. ND1 mRNA expression was strong in melanized substantia nigra neurons but undetectable in nigral glia. Levels of expression in nigral neurons were higher than in neurons of the red nucleus or cranial nerve nuclei, but similar values were obtained in pontine neurons. ND1 mRNA expression was reduced by about 25% in melanized neurons in IPD. There was no relationship between ND1 expression per cell and disease duration or L-DOPA dosage in the IPD group. No change in ND1 expression was observed in pontine neurons in IPD, and ND1 expression in the locus ceruleus was also unchanged. Melanized nigral neurons expressed lower levels of aldolase C mRNA than other midbrain or brain stem populations in both control and IPD material. These findings suggest that dopamine neurons are more strongly dependent on mitochondrial energy metabolism and oxidative phosphorylation than other brain stem populations. Because mitochondrial complex I activity is significantly reduced in IPD, intrinsically low expression of glycolytic enzymes, together with disease-related reduction in complex I activity, may be a contributory factor predisposing nigral neurons to injury.