Comparison of Pittsburgh compound B and florbetapir in cross-sectional and longitudinal studies.

IntroductionQuantitative in vivo measurement of brain amyloid burden is important for both research and clinical purposes. However, the existence of multiple imaging tracers presents challenges to the interpretation of such measurements. This study presents a direct comparison of Pittsburgh compound B-based and florbetapir-based amyloid imaging in the same participants from two independent cohorts using a crossover design.MethodsPittsburgh compound B and florbetapir amyloid PET imaging data from three different cohorts were analyzed using previously established pipelines to obtain global amyloid burden measurements. These measurements were converted to the Centiloid scale to allow fair comparison between the two tracers. The mean and inter-individual variability of the two tracers were compared using multivariate linear models both cross-sectionally and longitudinally.ResultsGlobal amyloid burden measured using the two tracers were strongly correlated in both cohorts. However, higher variability was observed when florbetapir was used as the imaging tracer. The variability may be partially caused by white matter signal as partial volume correction reduces the variability and improves the correlations between the two tracers. Amyloid burden measured using both tracers was found to be in association with clinical and psychometric measurements. Longitudinal comparison of the two tracers was also performed in similar but separate cohorts whose baseline amyloid load was considered elevated (i.e., amyloid positive). No significant difference was detected in the average annualized rate of change measurements made with these two tracers.DiscussionAlthough the amyloid burden measurements were quite similar using these two tracers as expected, difference was observable even after conversion into the Centiloid scale. Further investigation is warranted to identify optimal strategies to harmonize amyloid imaging data acquired using different tracers

Ornithological report 2001-2006 for the Camargue

The present ornithological report for the Camargue covers six years (2001-2006). This time-period has been marked by an accelerated global warming (the summer 2003 was particularly extreme). Owing to a constant high observation pressure, 18 new species have been recorded and many rare species have been resighted in that region (Camargue, Crau, Alpilles). Among the species or group of species which are regularly censused, the number of breeding Greater Flamingos Phoenicopterus roseus and that of wintering ducks and coots did not show any significant change. The colonial herons have continued either to increase or to fluctuate at a high level. For example, the Great White Egret Casmerodius albus has definitely settled in the delta and the Squacco Heron Ardeola ralloides has reached a new peak of 505 pairs in 2006. More efficient prospection efforts gave more precise breeding numbers for two species of solitary herons, the Great Bittern Botaurus stellaris and the Little Bittern Ixobrychus minutus. New breeding species such as the Great Cormorant Phalacrocorax carbo, White Stork Ciconia ciconia, Eurasian Spoonbill Platalea leucorodia and Greylag Anser anser increased their numbers as well as the Glossy Ibis Plegadis falcinellus of which 14 pairs has bred in 2006 and the Purple Swamphen Porphyrio porphyrio which was found for the first time breeding in 2006. The breeding species showing the most serious concern are actually the breeding gulls and terns whose figures have dramatically decreased. Without human management, this situation will even become worse in a near future. Further remarkable observations were the first case of wintering Lesser Spotted Eagle Aquila pomarina in 2001/2002, a mixed pair of Black-winged Pratincole Glareola nordmanni x Collared Pratincole G. pratincola in 2001, the settling of the Rook Corvus frugilegus in ArlesCe calendrier ornithologique couvre les six années de 2001 à 2006, une période marquée par un phénomène de réchauffement général accéléré du climat en général et par la canicule de l'été 2003 en particulier. Compte tenu de la pression d'observation élevée, 18 nouvelles espèces ont été signalées et de nombreuses espèces rares ont été revues dans la région (Camargue, Crau, Alpilles). Parmi les espèces ou groupes d'espèces qui font l'objet de recensements réguliers, les effectifs nicheurs de Flamant rose Phoenicopterus roseus de même que ceux des Anatidés et des Foulques hivernants n'appellent pas de commentaires particuliers pour ce laps de temps. Les Ardéidés coloniaux continuent soit de progresser pour certains, soit de fluctuer dans des limites qui restent élevées pour d'autres. Par exemple, la Grande Aigrette Casmerodius albus s'est installée durablement dans le delta, le Crabier chevelu Ardeola ralloides a atteint un nouveau maximum avec 505 couples en 2006. Des effectifs plus précis sont fournis pour deux espèces comme le Butoir étoilé Botaurus stellaris et le Blongios nain Ixohrychus minutus grâce à des prospections plus efficaces. Des espèces nicheuses d'installation récente comme le Grand Cormoran Phalacrocorax carho, la Cigogne blanche Ciconia ciconia, la Spatule blanche Platalea leucorodia et l'Oie cendrée Anser anser continuent de progresser de même que l'Ibis falcinelle Plegadis falcinellus dont 14 couples se sont reproduits en 2006 et la Talève sultane Porphyrio porphyrio dont la reproduction a enfin été confirmée en 2006. Parmi les espèces posant un problème grave, il faut relever les laro-limicoles nicheurs dont les effectifs se sont effondrés. Sans intervention urgente de gestion, leur situation risque d'empirer. Parmi les faits remarquables, signalons le premier cas d'hivernage de l'Aigle pomarin Aquila pomarina en 2001/2002, un couple mixte de Glaréole à ailes noires Glareola nordmanni x Glaréole à collier G. pratincola en 2001, l'installation du Corbeau freux Corvus frugilegus à Arles

Tissue functions mediated by β3-adrenoceptors—findings and challenges

As β3-adrenoceptor agonists metamorphose from experimental tools into therapeutic drugs, it is vital to obtain a comprehensive picture of the cell and tissue functions mediated by this receptor subtype in humans. Human tissues with proven functions and/or a high expression of β3-adrenoceptors include the urinary bladder, the gall bladder, and other parts of the gastrointestinal tract. While several other β3-adrenoceptor functions have been proposed based on results obtained in animals, their relevance to humans remains uncertain. For instance, β3-adrenoceptors perform an important role in thermogenesis and lipolysis in rodent brown and white adipose tissue, respectively, but their role in humans appears less significant. Moreover, the use of tools such as the agonist BRL 37344 and the antagonist SR59230A to demonstrate functional involvement of β3-adrenoceptors may lead in many cases to misleading conclusions as they can also interact with other β-adrenoceptor subtypes or even non-adrenoceptor targets. In conclusion, we propose that many responses attributed to β3-adrenoceptor stimulation may need re-evaluation in the light of the development of more selective tools. Moreover, findings in experimental animals need to be extended to humans in order to better understand the potential additional indications and side effects of the β3-adrenoceptor agonists that are beginning to enter clinical medicine

International Geomagnetic Reference Field: the 12th generation

The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch 2010.0, a main field model for epoch 2015.0, and a linear annual predictive secular variation model for 2015.0-2020.0. Here, we present the equations defining the IGRF model, provide the spherical harmonic coefficients, and provide maps of the magnetic declination, inclination, and total intensity for epoch 2015.0 and their predicted rates of change for 2015.0-2020.0. We also update the magnetic pole positions and discuss briefly the latest changes and possible future trends of the Earth’s magnetic fiel

Guelb el Ahmar (Bathonian, Anoual Syncline, eastern Morocco): First continental flora and fauna including mammals from the Middle Jurassic of Africa

We report the discovery in Mesozoic continental “red beds” of Anoual Syncline, Morocco, of the new Guelb el Ahmar (GEA) fossiliferous sites in the Bathonian Anoual Formation. They produced one of the richest continental biotic assemblages from the Jurassic of Gondwana, including plants, invertebrates and vertebrates. Both the sedimentological facies and the biotic assemblage indicate a lacustrine depositional environment. The flora is represented by tree trunks (three families), pollen (13 species, five major clades) and charophytes. It suggests local forests and humid (non-arid) conditions. The vertebrate fauna is dominated by microvertebrates recovered by screening–washing. It is rich and diverse, with at least 29 species of all major groups (osteichthyans, lissamphibians, chelonians, diapsids, mammals), except chondrichthyans. It includes the first mammals discovered in the Middle Jurassic of Arabo-Africa. The GEA sites yielded some of the earliest known representatives of osteoglossiform fishes, albanerpetontid and caudate amphibians, squamates (scincomorphans, anguimorphan), cladotherian mammals, and likely choristoderes. The choristoderes, if confirmed, are the first found in Gondwana, the albanerpetontid and caudatan amphibians are among the very few known in Gondwana, and the anguimorph lizard is the first known from the Mesozoic of Gondwana. Mammals (Amphitheriida, cf. Dryolestida) remain poorly known, but are the earliest cladotherians known in Gondwana. The GEA biotic assemblage is characterized by the presence of Pangean and Laurasian (especially European) taxa, and quasi absence of Gondwanan taxa. The paleobiogeographical analysis suggests either a major fossil bias in Gondwana during the Middle Jurassic, and an overall vicariant Pangean context for the GEA assemblage, or alternatively, noticeable Laurasian (European) affinities and North-South dispersals. The close resemblance between the Bathonian faunas of GEA and Britain is remarkable, even in a Pangean context. The similarity between the local Anoual Syncline Guelb el Ahmar and Ksar Metlili faunas raises questions on the ?Berriasian age of the latter

Experimental signatures of emergent quantum electrodynamics in Pr2_2Hf2_2O7_7

In a quantum spin liquid, the magnetic moments of the constituent electron spins evade classical long-range order to form an exotic state that is quantum entangled and coherent over macroscopic length scales [1-2]. Such phases offer promising perspectives for device applications in quantum information technologies, and their study can reveal fundamentally novel physics in quantum matter. Quantum spin ice is an appealing proposal of one such state, in which the fundamental ground state properties and excitations are described by an emergent U(1) lattice gauge theory [3-7]. This quantum-coherent regime has quasiparticles that are predicted to behave like magnetic and electric monopoles, along with a gauge boson playing the role of an artificial photon. However, this emergent lattice quantum electrodynamics has proved elusive in experiments. Here we report neutron scattering measurements of the rare-earth pyrochlore magnet Pr$_2$Hf$_2$O$_7$ that provide evidence for a quantum spin ice ground state. We find a quasi-elastic structure factor with pinch points - a signature of a classical spin ice - that are partially suppressed, as expected in the quantum-coherent regime of the lattice field theory at finite temperature. Our result allows an estimate for the speed of light associated with magnetic photon excitations. We also reveal a continuum of inelastic spin excitations, which resemble predictions for the fractionalized, topological excitations of a quantum spin ice. Taken together, these two signatures suggest that the low-energy physics of Pr$_2$Hf$_2$O$_7$ can be described by emergent quantum electrodynamics. If confirmed, the observation of a quantum spin ice ground state would constitute a concrete example of a three-dimensional quantum spin liquid - a topical state of matter which has so far mostly been explored in lower dimensionalities.Comment: 15 pages, 3 figure

Emerging and re-emerging viruses of the honey bee (Apis mellifera L.)

Until the late 1980s, specific viral infections of the honey bee were generally considered harmless in all countries. Then, with the worldwide introduction of the ectoparasite mite Varroa destructor, beekeepers encountered increasing difficulties in maintaining their colonies. Epidemiological surveys and laboratory experiments have demonstrated that the newly acquired virulence of several viruses belonging to the family Dicistroviridae (acute bee paralysis virus, Kashmir bee virus and Israeli acute paralysis virus) in Europe and the USA had been observed in relation with V. destructor acting as a disseminator of these viruses between and within bee colonies and as an activator of virus multiplication in the infected individuals: bee larvae and adults. Equal emphasis is given to deformed wing virus (DWV) belonging to the Iflaviridae. Overt outbreaks of DWV infections have been shown to be linked to the ability of V. destructor to act not only as a mechanical vector of DWV but also as a biological vector. Its replication in mites prior to its vectoring into pupae seemed to be necessary and sufficient for the induction of a overt infection in pupae developing in non-viable bees with deformed wings. DWV in V. destructor infested colonies is now considered as one of the key players of the final collapse. Various approaches for combating bee viral diseases are described: they include selection of tolerant bees, RNA interference and prevention of new pathogen introduction. None of these approaches are expected to lead to enhanced bee-health in the short term