Awareness of cognitive decline trajectories in asymptomatic individuals at risk for AD

Background: Lack of awareness of cognitive decline (ACD) is common in late-stage Alzheimer’s disease (AD). Recent studies showed that ACD can also be reduced in the early stages. Methods: We described different trends of evolution of ACD over 3 years in a cohort of memory-complainers and their association to amyloid burden and brain metabolism. We studied the impact of ACD at baseline on cognitive scores’ evolution and the association between longitudinal changes in ACD and in cognitive score. Results: 76.8% of subjects constantly had an accurate ACD (reference class). 18.95% showed a steadily heightened ACD and were comparable to those with accurate ACD in terms of demographic characteristics and AD biomarkers. 4.25% constantly showed low ACD, had significantly higher amyloid burden than the reference class, and were mostly men. We found no overall effect of baseline ACD on cognitive scores’ evolution and no association between longitudinal changes in ACD and in cognitive scores. Conclusions: ACD begins to decrease during the preclinical phase in a group of individuals, who are of great interest and need to be further characterized. Trial registration: The present study was conducted as part of the INSIGHT-PreAD study. The identification number of INSIGHT-PreAD study (ID-RCB) is 2012-A01731-42

Low Cognitive Awareness, but Not Complaint, is a Good Marker of Preclinical Alzheimer's Disease

Subjective cognitive decline (SCD) may result from many conditions, including Alzheimer's disease (AD)

Retrospective French nationwide survey of childhood aggressive vascular anomalies of bone, 1988-2009

<p>Abstract</p> <p>Objective</p> <p>To document the epidemiological, clinical, histological and radiological characteristics of aggressive vascular abnormalities of bone in children.</p> <p>Study design</p> <p>Correspondents of the French Society of Childhood Malignancies were asked to notify all cases of aggressive vascular abnormalities of bone diagnosed between January 1988 and September 2009.</p> <p>Results</p> <p>21 cases were identified; 62% of the patients were boys. No familial cases were observed, and the disease appeared to be sporadic. Mean age at diagnosis was 8.0 years [0.8-16.9 years]. Median follow-up was 3 years [0.3-17 years]. The main presenting signs were bone fracture (n = 4) and respiratory distress (n = 7), but more indolent onset was observed in 8 cases. Lung involvement, with lymphangiectasies and pleural effusion, was the most frequent form of extraosseous involvement (10/21). Bisphosphonates, alpha interferon and radiotherapy were used as potentially curative treatments. High-dose radiotherapy appeared to be effective on pleural effusion but caused major late sequelae, whereas antiangiogenic drugs like alpha interferon and zoledrenate have had a limited impact on the course of pulmonary complications. The impact of bisphosphonates and alpha interferon on bone lesions was also difficult to assess, owing to insufficient follow-up in most cases, but it was occasionally positive. Six deaths were observed and the overall 10-year mortality rate was about 30%. The prognosis depended mainly on pulmonary and spinal complications.</p> <p>Conclusion</p> <p>Aggressive vascular abnormalities of bone are extremely rare in childhood but are lifethreatening. The impact of anti-angiogenic drugs on pulmonary complications seems to be limited, but they may improve bone lesions.</p

GRAVY: Towards virtual file system for the grid

International audienc

186 Os-187 Os systematics of Gorgona Island komatiites: implications for early growth of the inner core

The presence of coupled enrichments in 186Os/188Os and 187Os/188Os in some mantle-derived materials reflects long-term elevation of Pt/Os and Re/Os relative to the primitive upper mantle. New Os data for the 89 Ma Gorgona Island, Colombia komatiites indicate that these lavas are also variably enriched in 186Os and 187Os, with 186Os/188Os ranging between 0.1198397±22 and 0.1198470±38, and with ?Os correspondingly ranging from +0.15 to +4.4. These data define a linear trend that converges with the previously reported linear trend generated from data for modern Hawaiian picritic lavas and a sample from the ca. 251 Ma Siberian plume, to a common component with a 186Os/188Os of approximately 0.119870 and ?Os of +17.5. The convergence of these data to this Os isotopic composition may imply a single ubiquitous source in the Earth's interior that mixes with a variety of different mantle compositions distinguished by variations in ? Os. The 187Os- and 186Os-enriched component may have been generated via early crystallization of the solid inner core and consequent increases in Pt/Os and Re/Os in the liquid outer core, with time leading to suprachondritic 186Os/188Os and ?Os in the outer core. The presence of Os from the outer core in certain portions of the mantle would require a mechanism that could transfer Os from the outer core to the lower mantle, and thence to the surface. If this is the process that generated the isotopic enrichments in the mantle sources of these plume-derived systems, then the current understanding of solid metal–liquid metal partitioning of Pt, Re and Os requires that crystallization of the inner core began prior to 3.5 Ga. Thus, the Os isotopic data reported here provide a new source of data to better constrain the timing of inner core formation, complementing magnetic field paleo-intensity measurements as data sources that constrain models based on secular cooling of the Earth

Nitrate fluorimetric analysis using an active optical fiber

With the objective to use a fluorimetric determination of nitrate based on fluorescein as the sensit ive fluorescent indicator, an active optical fiber was elaborated and its response was tested using a specific ally adapted fluorimeter. So, the three required chemical steps to fix fluorescein via a covalent bond on the silica fiber tip will be described, as well as the amount of grafted probe and the stability of the optrode in sulfuric acid (the required medium for the analysis). Then, for the determination of nitrate, the active optr odes were connected to the specially designed optical fiber fluorimeter. The integrating optical fiber sensor response is linear for concentrations between 2 10-6 and 10-5 mol NO3- L-1 (i.e. between 0.12 and 0.62 mg NO3- L-1 in the reactive medium). One optrode has to be used for each analysis (or each set of analyses if all the grafted fluorescein is not consumed)

A new continental hydrogen play in Damara Belt (Namibia)

Serpentinization is commonly presented as the main source of natural hydrogen (H2) in the continental domains. However, recent works in Australia and Brazil showed that Archean–Paleoproterozoic banded iron formations could be another natural source of H2 gas. Although the reaction that produces hydrogen is similar (Fe2+ oxidation—H2O reduction process), the iron content may be higher in banded iron formations than in mafic igneous lithologies, potentially generating H2 more efficiently. Here, we present structural evidence that reported H2 emissions from Waterberg Basin, Namibia are associated with underlying Neoproterozoic banded iron formations—the Chuos Formation. Magnetite, a known H2-generating mineral, is ubiquitous and accompanied by other suspected H2-generating minerals (biotite and siderite) in Chuos Formation. Magnetite occurs either as pervasive cm to dm continuous metamorphic laminations in foliation and fractures planes and/or diffusely disseminated in metachert and metacarbonate levels. From this, we infer that metamorphism does not negatively affect the Fe2+ content that is required to generate hydrogen. H2 seepages in Waterberg Basin suggest that an active H2-generating system may exist at depth and that the presence of potential traps and reservoirs is likely based on field observations