Explore the vast range of titles available.

A collective, macroscopic signature to detect radiation friction in laser-plasma experiments is proposed. In the interaction of superintense circularly polarized laser pulses with high density targets, the effective dissipation due to radiative losses allows the absorption of electromagnetic angular momentum, which in turn leads to the generation of a quasistatic axial magnetic field. This peculiar 'inverse Faraday effect' is investigated by analytical modeling and three-dimensional simulations, showing that multi-gigagauss magnetic fields may be generated at laser intensities > 10 23 W cm − 2 .

Surface plasmon (SP) excitation in intense laser interaction with solid target can be exploited for enhancing secondary emissions, in particular efficient acceleration of high charge electron bunches. Previous studies have mostly used grating coupling to allow SP excitation, which requires stringent laser contrast conditions to preserve the structural integrity of the target. Here we show via simulations that efficient SP electron acceleration for currently available short pulse lasers can occur in a flat foil irradiated at parallel or grazing incidence ( ∼ 5 ° with the target surface) without a surface modulation. In turn, the accelerated electrons can be effective for generating proton beams with narrow spectra peaked at > 100 MeV energies for currently available laser drivers.

In the interaction of laser pulses of extreme intensity (>1023 Wcm−2) with high-density, thick plasma targets, simulations show significant radiation friction losses, in contrast to thin targets for which such losses are negligible. We present an analytical calculation, based on classical radiation friction modeling, of the conversion efficiency of the laser energy into incoherent radiation in the case when a circularly polarized pulse interacts with a thick plasma slab of overcritical initial density. By accounting for three effects including the influence of radiation losses on the single electron trajectory, the global 'hole boring' motion of the laser-plasma interaction region under the action of radiation pressure, and the inhomogeneity of the laser field in both longitudinal and transverse direction, we find a good agreement with the results of three-dimensional particle-in-cell simulations. Overall, the collective effects greatly reduce radiation losses with respect to electrons driven by the same laser pulse in vacuum, which also shift the reliability of classical calculations up to higher intensities.

The characteristics of laser driven proton beams can be efficiently controlled and optimised by employing a recently developed helical coil technique, which exploits the transient self-charging of solid targets irradiated by intense laser pulses. Here we demonstrate a well collimated (<1° divergence) and narrow bandwidth (~10% energy spread) proton beamlet of ~10 7 particles at 10 ± 0.5 MeV obtained by irradiating helical coil targets with a few joules, sub-ps laser pulses at an intensity of ~2 × 10 19  W cm −2 . The experimental data are in good agreement with particle tracing simulations suggesting post-acceleration of protons inside the coil at a rate ~0.7 MeV/mm, which is comparable to the results obtained from a similar coil target irradiated by a fs class laser at an order of magnitude higher intensity, as reported in S. Kar et al ., Nat. Commun, 7, 10792 (2016). The dynamics of hot electron escape from the laser irradiated target was studied numerically for these two irradiation regimes, which shows that the target self-charging can be optimised at a pulse duration of few hundreds of fs. This information is highly beneficial for maximising the post-acceleration gradient in future experiments.

Light sail acceleration by ultrashort, superintense laser pulses is presently investigated as an approach to compact accelerators of matter. The usual light sail equation assumes a cycle-averaged light pressure, which becomes questionable for ultrashort pulse drivers or in the highly relativistic regime. Here, we remove such assumption and compute solutions of the light sail equations which show oscillations of the sail acceleration. The dependence of the final sail velocity on the temporal profile of extremely short pulses is discussed.

The treatment of severely atrophied posterior mandibles with standard-diameter root-form implants may present a challenge. Bone reconstructive surgery represents the treatment of choice; however, it may not be accepted by some patients for economic reasons or due to higher morbidity. Computer-aided design/computer-aided manufacturing (CAD/CAM) technologies have recently opened new frontiers in biomedical applications. Selective laser sintering (SLS) is a CAD/CAM technique that allows the fabrication of complex three-dimensional (3D) structures created by computer-generated image-based design techniques. The aim of this study is to present a protocol for the manufacture and clinical use of custom-made SLS titanium blade implants as a non-conventional therapeutic treatment for the prosthetic rehabilitation of extremely atrophied posterior mandibles. Computed tomography datasets of five patients were transferred to a specific reconstruction software, where a 3D projection of the atrophied mandible was obtained, and custom-made endosseous blade implants were designed. The custom-made implants were fabricated with SLS technique, placed in the extremely atrophied posterior (<4 mm width) mandible, and immediately restored with fixed partial restorations. After 2 years of loading, all implants were in function, showing a good esthetic integration. Blade implants can be fabricated on an individual basis as a custom-designed device. This non-conventional approach may represent an option for restoring the atrophied posterior mandible of elderly patients.

The invasion of the Asiatic clam Corbicula fluminea in South America has already reached Patagonia. Despite the well-known direct and indirect impacts that this species exerts on fresh-water ecosystems, particularly on benthic communities, few studies have been undertaken on its effect on the composition and structure of aquatic macroinvertebrate assemblages. This study evaluated the effects of the invasion of the Asiatic clam C. fluminea on the aquatic macroinvertebrate assemblages of the Limay River, one of the most important rivers of the arid plateau of Argentinian Patagonia. As this river is currently in the process of being invaded, it was possible to compare invaded and non-invaded sites. Invaded sites displayed a certain homogenization of their constituent species and functional composition. Non-metric multidimensional scaling, similarity analysis and similarity percentages showed negative or positive influence of the presence of this species on the abundance of some taxa, due to competition for resources in this low-productivity Patagonian ecosystem. The deposition of the faeces and pseudo-faeces of C. fluminea enriches the organic content of the sediments. However, its pedal feeding can function as a competitive strategy: by consuming its own deposited organic matter when food is scarce, the amount available to other macroinvertebrates is reduced. This paper is the first contribution on the impact of this invasion on northern Patagonia’s aquatic macroinvertebrate assemblages.

Given the multiple stressors affecting freshwater ecosystems and the limited resources devoted to their management, effective conservation of freshwater biodiversity requires regional prioritization. Patagonian wetlands are essential for regional biodiversity and the economy, but they are still far from reaching global conservation targets and many of them could disappear due to climate change. Our study aimed at prioritizing wetlands based on aquatic and terrestrial biodiversity, their conservation status and vulnerability to climate change. First, we identified 43 priority wetlands containing all aquatic biodiversity collected in 82 Patagonian wetlands located over a 1500 km north–south gradient, by using the software Marxan. Then, we ranked within priority wetlands according to their conservation status (low priority if they were already protected; medium priority if not), importance for terrestrial biodiversity conservation (high priority) and vulnerability to climate change. Highly ranked priority wetlands in National Parks (low priority), contained diverse wetlands (57% aquatic taxon richness), including a large proportion of rare species (33%). High priority wetlands are oases of water in an arid and semiarid steppe, containing not only a large proportion of the aquatic biodiversity, but also acting as a refuge for terrestrial flora and fauna. Different management actions are proposed according to wetland priority level (e.g. fencing, creation of artificial ponds), and since 20% of medium priority and 36% of high priority wetlands are expected to disappear by 2050, their inclusion in conservation or restoration plans needs to be carefully evaluated.

In this study, we tested the significance of environmental influences on non-marine ostracod communities at high taxonomic levels across Patagonia, Argentina. We used a dataset compiled from 243 Patagonian freshwater bodies, representing an area of ~ 900,000 km2 and covering the main local and climatic gradients. We applied generalized linear models to test the effects of hydroperiod, local and climatic variables on the occurrence and abundance of Ostracoda, and the occurrence of the most frequent families (i.e., Cyprididae, Ilyocyprididae and Limnocytheridae). We found ostracods in 77% of the total sampled sites, driven mainly by dissolved oxygen levels and water temperature (local variables) as well as precipitation and air temperature (climatic variables). Specifically, warmer winters and dryer climates favored ostracod occurrences, which covered wide ecological ranges, such as peat bogs or high-altitude wetlands. For the Ilyocyprididae and Limnocytheridae families, precipitation and pH were important predictors of their occurrence. Furthermore, wind speed, nutrient levels and water depth had positive effects on ostracod abundance. This updated Patagonian freshwater dataset contributes towards filling those knowledge gaps related to the habitat suitability of ostracods communities in this vast region. Our findings could help us understand the past and future responses of ostracods to environmental changes.

Purpose of ReviewThis review summarizes the current state of evidence for palliative care (PC) in movement disorders, describes the application of PC to clinical practice, and suggests future research directions.Recent FindingsPC needs are common in persons living with movement disorders and their families from the time of diagnosis through end-of-life and contribute to quality of life. Early advance care planning is preferred by patients, impacts outcomes and is promoted by PC frameworks. Systematic assessment of non-motor symptoms, psychosocial needs and spiritual/existential distress may address gaps in current models of care. Several complementary and emerging models of PC may be utilized to meet the needs of this population.SummaryA PC approach may identify and improve important patient and caregiver-centered outcomes. As a relatively new application of PC, there is a need for research to adapt, develop and implement approaches to meet the unique needs of this population.