Testing for the myth of cognitive reserve. Are the static and dynamic cognitive reserve indexes a representation of different reserve warehouses?

Background: Cognitive reserve (CR) explains the individual resilience to neurodegeneration. Years of formal education express the static measure of reserve (sCR). A dynamic aspect of CR (dCR) has been recently proposed. Objective: The aim of the study was to compare sCR and dCR indexes, respectively, to detect brain abnormalities in Alzheimer's disease (AD) patients. Methods: 117 individuals [39 AD, 40 amnestic mild cognitive impairment (aMCI), 38 healthy subjects (HS)] underwent neuropsychological evaluation and a 3T-MRI. T1-weighted volumes were used for manual segmentation of the hippocampus and of the parahippocampal cortices. Years of formal education were used as an index of sCR. Partial Least Square analysis was used to decompose the variance of individual MMSE scores, considered as a dCR index. In aMCI and AD patients, the brain abnormalities have been assessed comparing individuals with high and low levels of sCR and dCR in turn. Moreover, we investigated the effect of the different CR indexes in mediating the relationship between changes in brain volumes and memory performances. Results: sCR and dCR indexes classified differently individuals having high or low levels of CR. Smaller hippocampal and parahippocampal volumes in high dCR patients were found. The sCR and dCR indexes mediated significantly the relationship between brain abnormalities and memory in patients. Conclusions: CR mediated the relationship between brain and memory dysfunctions. We hypothesized that sCR and dCR indexes are a representation of different warehouses of reserve not operating in parallel but forming a complex system, in which crystalized cognitive abilities and actual cognitive efficiency interact with brain atrophy impacting on memory

Another look at the BL Lacertae flux and spectral variability

The GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) monitored BL Lacertae in 2008-2009 at radio, near-IR, and optical frequencies. During this period, high-energy observations were performed by XMM-Newton, Swift, and Fermi. We analyse these data with particular attention to the calibration of Swift UV data, and apply a helical jet model to interpret the source broad-band variability. The GASP-WEBT observations show an optical flare in 2008 February-March, and oscillations of several tenths of mag on a few-day time scale afterwards. The radio flux is only mildly variable. The UV data from both XMM-Newton and Swift seem to confirm a UV excess that is likely caused by thermal emission from the accretion disc. The X-ray data from XMM-Newton indicate a strongly concave spectrum, as well as moderate flux variability on an hour time scale. The Swift X-ray data reveal fast (interday) flux changes, not correlated with those observed at lower energies. We compare the spectral energy distribution (SED) corresponding to the 2008 low-brightness state, which was characterised by a synchrotron dominance, to the 1997 outburst state, where the inverse-Compton emission was prevailing. A fit with an inhomogeneous helical jet model suggests that two synchrotron components are at work with their self inverse-Compton emission. Most likely, they represent the radiation from two distinct emitting regions in the jet. We show that the difference between the source SEDs in 2008 and 1997 can be explained in terms of pure geometrical variations. The outburst state occurred when the jet-emitting regions were better aligned with the line of sight, producing an increase of the Doppler beaming factor. Our analysis demonstrates that the jet geometry can play an extremely important role in the BL Lacertae flux and spectral variability.Comment: 12 pages, 10 figures, accepted for publication in A&

Maids, machines and morality in Brazilian homes

This paper engages with debates about the increasing use of paid domestic labour in Europe and the USA contributing with a reflection about the case of Brazil. Relations of gender, class and race are considered in the deployment of maids for housework, the patterns of consumption of household technologies and the moral reasoning of daily living with hierarchical divisions within the home. The paper considers some parallels between the Brazilian context and that of more developed countries and also the specificity of Brazil. Based on participant observation, secondary data and an ethnographic study, rich empirical data are weaved through to discuss material and moral dimensions of domestic labour and care. How does the availability of cheap domestic labour configure relations of inequality? How are social differences in the home lived with and justified? The exploration of the Brazilian case illuminates some of the problems, contradictions and possible consequences of wealthier households benefitting from the displacement of poor women that is currently happening through international migration. The paper argues that in Brazil the deflecting of tensions in gender divisions of labour in households onto a subordinate person has affected relations of equality between women and men and also the patterns of technological innovation to facilitate housework. These are outcomes to be guarded against in Europe and the United States in face of the current trends in 'global woman' relations

Pointing in cervical dystonia patients

IntroductionThe normal hemispheric balance can be altered by the asymmetric sensorimotor signal elicited by Cervical Dystonia (CD), leading to motor and cognitive deficits.MethodsDirectional errors, peak velocities, movement and reaction times of pointing towards out-of-reach targets in the horizontal plane were analysed in 18 CD patients and in 11 aged-matched healthy controls.ResultsCD patients displayed a larger scatter of individual trials around the average pointing direction (variable error) than normal subjects, whatever the arm used, and the target pointed. When pointing in the left hemispace, all subjects showed a left deviation (constant error) with respect to the target position, which was significantly larger in CD patients than controls, whatever the direction of the abnormal neck torsion could be. Reaction times were larger and peak velocities lower in CD patients than controls.DiscussionDeficits in the pointing precision of CD patients may arise from a disruption of motor commands related to the sensorimotor imbalance, from a subtle increase in shoulder rigidity or from a reduced agonists activation. Their larger left bias in pointing to left targets could be due to an increased right parietal dominance, independently upon the direction of head roll/jaw rotation which expands the left space representation and/or increases left spatial attention. These deficits may potentially extend to tracking and gazing objects in the left hemispace, leading to reduced skills in spatial-dependent motor and cognitive performance

Implantable hearing devices in clinical practice. Systematic review and consensus statements

Objective. Implantable hearing devices represent a modern and innovative solution for hearing restoration. Over the years, these high-tech devices have increasingly evolved but their use in clinical practice is not universally agreed in the scientific literature. Congresses, meetings, conferences, and consensus statements to achieve international agreement have been made. This work follows this line and aims to answer unsolved questions regarding examinations, selection criteria and surgery for implantable hearing devices. Materials and methods. A Consensus Working Group was established by the Italian Society of Otorhinolaryngology. A method group performed a systematic review for each single question to identify the current best evidence on the topic and to guide a multidisciplinary panel in developing the statements. Results. Twenty-nine consensus statements were approved by the Italian Society of Otorhinolaryngology. These were associated with 4 key area subtopics regarding pre -operative tests, otological, audiological and surgical indications. Conclusions. This consensus can be considered a further step forward to establish realistic guidelines on the debated topic of implantable hearing devices

The path from trigeminal asymmetry to cognitive impairment: a behavioral and molecular study

Trigeminal input exerts acute and chronic effects on the brain, modulating cognitive functions. Here, new data from humans and animals suggest that these effects are caused by trigeminal influences on the Locus Coeruleus (LC). In humans subjects clenching with masseter asymmetric activity, occlusal correction improved cognition, alongside with reductions in pupil size and anisocoria, proxies of LC activity and asymmetry, respectively. Notably, reductions in pupil size at rest on the hypertonic side predicted cognitive improvements. In adult rats, a distal unilateral section of the trigeminal mandibular branch reduced, on the contralateral side, the expression of c-Fos (brainstem) and BDNF (brainstem, hippocampus, frontal cortex). This counterintuitive finding can be explained by the following model: teeth contact perception loss on the lesioned side results in an increased occlusal effort, which enhances afferent inputs from muscle spindles and posterior periodontal receptors, spared by the distal lesion. Such effort leads to a reduced engagement of the intact side, with a corresponding reduction in the afferent inputs to the LC and in c-Fos and BDNF gene expression. In conclusion, acute effects of malocclusion on performance seem mediated by the LC, which could also contribute to the chronic trophic dysfunction induced by loss of trigeminal input

A Compact Probe for Beta+Emitting Radiotracer Detection in Suregery, Biopsy, and Medical Diagnostics based on Silicon Photomultipliers

We present a new probe for radiotracer detection in vivo. The device is based on silicon photomultipliers coupled with a scintillator and wirelessly compensated for supply voltage and temperature variations. The probe is positron sensitive

Towards quantum 3d imaging devices

We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed