A comparison of HREM and weak beam transmission electron microscopy for the quantitative measurement of the thickness of ferroelectric domain walls

In this paper we present two methods for the quantitative measurement of the thickness of ferroelectric domain walls, one using high-resolution electron microscopy (HREM) and the other weak beam transmission electron microscopy (WBTEM). These techniques can be used to determine the thickness of domain walls at room temperature as well as close to the ferroelectric to paraelectric phase transition. The first method allows a direct visualization of the lattice distortion across the domain wall, by measuring the continuous deviation of a set of planes with respect to the undistorted lattice. The second method consists in a quantitative analysis of the thickness fringes that appear on weak beam images of inclined domain walls. By fitting simulated fringe profiles to experimental ones, we can extract the thickness of the domain walls in a quantitative way. These two complementary techniques lead to a complete characterization of the thickness of ferroelectric domain walls over a wide range of specimen thicknesses at different magnifications. As an example we apply these methods to ferroelectric domain walls in PbTiO3 The domain wall thickness at room temperature is found to be 1.5 ± 0.3 nm using HREM (in very thin samples≈10 nm) and 2.1 ± 0.7 nm using WBTEM (in samples thicker than 30 nm

Neurodegeneration behind bars: from molecules to jurisprudence

The prison population is aging and developing neurodegenerative disorders at a faster pace than the general population. Hidden among this group of recidivist, career criminals, there is a subpopulation of first offenders with frontotemporal dementia behavioral variant (bvFTD). The pathological hallmark of this condition is frontotemporal lobar degeneration (FTLD), which early on spares cognition, yet predisposes to criminal violations. From the neurobiological perspective, bvFTD originates in a large-scale brain network in charge of motivation and concern, the salience network (SN). From the judiciary perspective, bvFTD is challenging because patients often retain the “appreciation” of right and wrong, yet may be organically incapable to act accordingly. Equally challenging are the dispositions in regards to bvFTD patients: return to the community, risking further violations, vs. incarceration with dismal punitive or rehabilitative benefit. In this article, we advocate for screening of all first offenders who are 55 years of age or older via neuropsychological testing and/or positron emission tomography (PET) and should bvFTD be diagnosed, their placement in, yet to be developed, palliative programs in state or private facilities

Neurodegeneration behind bars: from molecules to jurisprudence.

The prison population is aging and developing neurodegenerative disorders at a faster pace than the general population. Hidden among this group of recidivist, career criminals, there is a subpopulation of first offenders with frontotemporal dementia behavioral variant (bvFTD). The pathological hallmark of this condition is frontotemporal lobar degeneration (FTLD), which early on spares cognition, yet predisposes to criminal violations. From the neurobiological perspective, bvFTD originates in a large-scale brain network in charge of motivation and concern, the salience network (SN). From the judiciary perspective, bvFTD is challenging because patients often retain the “appreciation” of right and wrong, yet may be organically incapable to act accordingly. Equally challenging are the dispositions in regards to bvFTD patients: return to the community, risking further violations, vs. incarceration with dismal punitive or rehabilitative benefit. In this article, we advocate for screening of all first offenders who are 55 years of age or older via neuropsychological testing and/or positron emission tomography (PET) and should bvFTD be diagnosed, their placement in, yet to be developed, palliative programs in state or private facilities.The prison population is aging and developing neurodegenerative disorders at a faster pace than the general population. Hidden among this group of recidivist, career criminals, there is a subpopulation of first offenders with frontotemporal dementia behavioral variant (bvFTD). The pathological hallmark of this condition is frontotemporal lobar degeneration (FTLD), which early on spares cognition, yet predisposes to criminal violations. From the neurobiological perspective, bvFTD originates in a large-scale brain network in charge of motivation and concern, the salience network (SN). From the judiciary perspective, bvFTD is challenging because patients often retain the “appreciation” of right and wrong, yet may be organically incapable to act accordingly. Equally challenging are the dispositions in regards to bvFTD patients: return to the community, risking further violations, vs. incarceration with dismal punitive or rehabilitative benefit. In this article, we advocate for screening o