Inner ear ossification and mineralization kinetics in human embryonic development - microtomographic and histomorphological study.

Little is known about middle and inner ear development during the second and third parts of human fetal life. Using ultra-high resolution Microcomputed Tomography coupled with bone histology, we performed the first quantitative middle and inner ear ossification/mineralization evaluation of fetuses between 17 and 39 weeks of gestational age. We show distinct ossification paces between ossicles, with a belated development of the stapes. A complete cochlear bony covering is observed within the time-frame of the onset of hearing, whereas distinct time courses of ossification for semicircular canal envelopes are observed in relation to the start of vestibular functions. The study evidences a spatio-temporal relationship between middle and inner ear structure development and the onset of hearing and balance, critical senses for the fetal adaptation to birth

Reverse engineering Flash EEPROM memories using Scanning Electron Microscopy

In this article, a methodology to extract Flash EEPROM memory contents is presented. Samples are first backside prepared to expose the tunnel oxide of floating gate transistors. Then, a Scanning Electron Microscope (SEM) in the so called Passive Voltage Contrast (PVC) mode allows distinguishing ‘0’ and ‘1’ bit values stored in individual memory cell. Using SEM operator-free acquisition and standard image processing technique we demonstrate the possible automating of such technique over a full memory. The presented fast, efficient and low cost technique is successfully implemented on 0.35$\mu \textit{m}$ technology node microcontrollers and on a 0.21$\mu \textit{m}$ smart card type integrated circuit. The technique is at least two orders of magnitude faster than state-of-the-art Scanning Probe Microscopy (SPM) methods. Without adequate protection an adversary could obtain the full memory array content within minutes. The technique is a first step for reverse engineering secure embedded systems

Finite deformations govern the anisotropic shear-induced area reduction of soft elastic contacts

Solid contacts involving soft materials are important in mechanical engineering or biomechanics. Experimentally, such contacts have been shown to shrink significantly under shear, an effect which is usually explained using adhesion models. Here we show that quantitative agreement with recent high-load experiments can be obtained, with no adjustable parameter, using a non-adhesive model, provided that finite deformations are taken into account. Analysis of the model uncovers the basic mechanisms underlying shear-induced area reduction, local contact lifting being the dominant one. We confirm experimentally the relevance of all those mechanisms, by tracking the shear-induced evolution of tracers inserted close to the surface of a smooth elastomer sphere in contact with a smooth glass plate. Our results suggest that finite deformations are an alternative to adhesion, when interpreting a variety of sheared contact experiments involving soft materials.Comment: Version accepted at J. Mech. Phys. Solids. It includes Supplementary Informatio

Direct charge measurement in Floating Gate transistors of Flash EEPROM using Scanning Electron Microscopy

We present a characterization methodology for fast direct measurement of the charge accumulated on Floating Gate (FG) transistors of Flash EEPROM cells. Using a Scanning Electron Microscope (SEM) in Passive Voltage Contrast (PVC) mode we were able to distinguish between '0' and '1' bit values stored in each memory cell. Moreover, it was possible to characterize the remaining charge on the FG; thus making this technique valuable for Failure Analysis applications for data retent ion measurements in Flash EEPROM. The technique is at least two orders of magnitude faster than state-of-the-art Scanning Probe Microscopy (SPM) methods. Only a relatively simple backside sample preparation is necessary for accessing the FG of memory transistors. The technique presented was successfully implemented on a 0.35 μm technology node microcontroller and a 0.21 μm smart card integrated circuit. We also show the ease of such technique to cover all cells of a memory (using intrinsic features of SEM) and to automate memory cells characterization using standard image processing technique

16α-[18F]-fluoro-17ß-oestradiol ([18F]FES): A biomarker for imaging oestrogen receptor expression with positron emission tomography (PET)

Oestrogens play a major role in the development of gynaecological oestrogen-dependent diseases that overexpress oestrogen receptors (ER+). The ER status is assessed using immunohistochemistry  analysis of tissues samples. It is believed that a non-invasive method such as positron emission tomography (PET) that would accurately evaluate and quantify in vivo the presence of ER could play an important role in managing such diseases. PET using fluorinated oestrogen analogues may be helpful in selecting patients who will benefit from endocrine therapy or could be used to identify high-grade cancer with poorer prognosis. Among more than 20 fluorinated oestrogens analogues that have been proposed as PET tracer candidates, 16a-[18F]fluoro-17b-oestradiol ([18F]FES) has been the most actively investigated in preclinical and clinical studies

Broad white matter impairment in multiple system atrophy.

Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by the widespread aberrant accumulation of α-synuclein (α-syn). MSA differs from other synucleinopathies such as Parkinson's disease (PD) in that α-syn accumulates primarily in oligodendrocytes, the only source of white matter myelination in the brain. Previous MSA imaging studies have uncovered focal differences in white matter. Here, we sought to build on this work by taking a global perspective on whole brain white matter. In order to do this, in vivo structural imaging and diffusion magnetic resonance imaging were acquired on 26 MSA patients, 26 healthy controls, and 23 PD patients. A refined whole brain approach encompassing the major fiber tracts and the superficial white matter located at the boundary of the cortical mantle was applied. The primary observation was that MSA but not PD patients had whole brain deep and superficial white matter diffusivity abnormalities (p < .001). In addition, in MSA patients, these abnormalities were associated with motor (Unified MSA Rating Scale, Part II) and cognitive functions (Mini-Mental State Examination). The pervasive whole brain abnormalities we observe suggest that there is widespread white matter damage in MSA patients which mirrors the widespread aggregation of α-syn in oligodendrocytes. Importantly, whole brain white matter abnormalities were associated with clinical symptoms, suggesting that white matter impairment may be more central to MSA than previously thought

Capgras Syndrome: A Novel Probe for Understanding the Neural Representation of the Identity and Familiarity of Persons

Patients with Capgras syndrome regard people whom they know well such as their parents or siblings as imposters. Here we describe a case (DS) of this syndrome who presents several novel features. DS was unusual in that his delusion was modality-specific: he claimed that his parents were imposters when he was looking at them but not when speaking to them on the telephone. Unlike normals, DS's skin conductance responses to photographs of familiar people, including his parents, were not larger in magnitude than his responses to photographs of unfamiliar people. We suggest that in this patient connections from face-processing areas in the temporal lobe to the limbic system have been damaged, a loss which may explain why he calls his parents imposters. In addition, DS was very poor at judging gaze direction. Finally, when presented with a sequence of photographs of the same model's face looking in different directions, DS asserted that they were "different women who looked just like each other'. In the absence of limbic activation, DS creates separate memory "files' of the same person, apparently because he is unable to extract and link the common denominator of successive episodic memories. Thus, far from being a medical curiosity. Capgras syndrome may help us to explore the formation of new memories caught in flagrante delicto