ABSTRACT
Despite great loss in gathering and consumption of traditional foods among Indigenous communities, there is great hope for reclaiming and preserving knowledge. The Restoring Shoshone Ancestral Food Gathering (RSAFG) is a community group leading grassroots efforts on the Wind River reservation to reclaim Shoshone ancestral foods and promote food sovereignty. The story of the RSAFG promotes equitable, decolonized, and community empowered methods of reclaiming Indigenous foods by sharing three of RSAFG's acts of decolonization: 1) enacting treaty rights through gathering traditional plants, 2) demanding equitable partnerships in community-based research, and 3) sharing the story through radical authorship via layered narratives. A pesar de la gran pérdida en la recolección y el consumo de alimentos tradicionales entre las comunidades indígenas, existe una gran esperanza para recuperar y preservar el conocimiento. El Restoring Shoshone Ancestral Food Gathering (RSAFG) es un grupo comunitario que lidera los esfuerzos de base en la reserva wind river para recuperar los alimentos ancestrales shoshone y promover la soberanía alimentaria. La historia de la RSAFG promueve métodos equitativos, descolonizados y empoderados por la comunidad para recuperar los alimentos indígenas al compartir tres de los actos de descolonización de RSAFG: 1) promulgar los derechos de los tratados mediante la recolección de plantas tradicionales, 2) exigir asociaciones equitativas en la investigación basada en la comunidad, y 3) compartir la historia a través de la autoría radical a través de narrativas en capas.
ABSTRACT
We report charge transfer and built-in electric fields across the epitaxial SrNb_{x}Ti_{1-x}O_{3-δ}/Si(001) interface. Electrical transport measurements indicate the formation of a hole gas in the Si and the presence of built-in fields. Hard x-ray photoelectron measurements reveal pronounced asymmetries in core-level spectra that arise from these built-in fields. Theoretical analysis of core-level spectra enables built-in fields and the resulting band bending to be spatially mapped across the heterojunction. The demonstration of tunable charge transfer, built-in fields, and the spatial mapping of the latter, lays the groundwork for the development of electrically coupled, functional heterojunctions.
ABSTRACT
We establish a series of deep convolutional neural networks to automatically analyze position averaged convergent beam electron diffraction patterns. The networks first calibrate the zero-order disk size, center position, and rotation without the need for pretreating the data. With the aligned data, additional networks then measure the sample thickness and tilt. The performance of the network is explored as a function of a variety of variables including thickness, tilt, and dose. A methodology to explore the response of the neural network to various pattern features is also presented. Processing patterns at a rate of â¯â¼â¯0.1â¯s/pattern, the network is shown to be orders of magnitude faster than a brute force method while maintaining accuracy. The approach is thus suitable for automatically processing big, 4D STEM data. We also discuss the generality of the method to other materials/orientations as well as a hybrid approach that combines the features of the neural network with least squares fitting for even more robust analysis. The source code is available at https://github.com/subangstrom/DeepDiffraction.
ABSTRACT
Transmission electron microscopy specimens typically exhibit local distortion at thin foil edges, which can influence the absorption of X-rays for quantitative energy dispersive X-ray spectroscopy (EDS). Here, we report a numerical, three-dimensional approach to model the geometry of general specimens and its influence on quantification when using single and multiple detector configurations. As a function of specimen tilt, we show that the model correctly predicts the asymmetric nature of X-ray counts and ratios. When using a single detector, we show that complex specimen geometries can introduce significant uncertainty in EDS quantification. Further, we show that this uncertainty can be largely negated by collection with multiple detectors placed symmetrically about the sample such as the FEI Super-X configuration. Based on guidance provided by the model, we propose methods to reduce quantification error introduced by the sample shape. The source code is available at https://github.com/subangstrom/superAngle.
ABSTRACT
Here, we present a sample preparation approach that simplifies the thinning of very brittle wide bandgap semiconducting materials in cross-section geometry for (scanning) transmission electron microscopy. Using AlN thin films grown on sapphire and AlN substrates as case studies, we demonstrate that high-quality samples can be routinely prepared while greatly reducing the preparation time and consumables cost. The approach removes the sample preparation barrier to studying a wide variety of materials by electron microscopy.
ABSTRACT
Here we report the influence of key experimental parameters on atomically resolved energy dispersive X-ray spectroscopy (EDX). In particular, we examine the role of the probe forming convergence semi-angle, sample thickness, lattice spacing, and dwell/collection time. We show that an optimum specimen-dependent probe forming convergence angle exists to maximize the signal-to-noise ratio of the atomically resolved signal in EDX mapping. Furthermore, we highlight that it can be important to select an appropriate dwell time to efficiently process the X-ray signal. These practical considerations provide insight for experimental parameters in atomic resolution energy dispersive X-ray analysis.
ABSTRACT
Quantitative agreement on an absolute scale is demonstrated between experiment and simulation for two-dimensional, atomic-resolution elemental mapping via energy dispersive X-ray spectroscopy. This requires all experimental parameters to be carefully characterized. The agreement is good, but some discrepancies remain. The most likely contributing factors are identified and discussed. Previous predictions that increasing the probe forming aperture helps to suppress the channelling enhancement in the average signal are confirmed experimentally. It is emphasized that simple column-by-column analysis requires a choice of sample thickness that compromises between being thick enough to yield a good signal-to-noise ratio while being thin enough that the overwhelming majority of the EDX signal derives from the column on which the probe is placed, despite strong electron scattering effects.
ABSTRACT
Here we report a numerical approach to model a four quadrant energy dispersive X-ray spectrometer in the transmission electron microscope. The model includes detector geometries, specimen position and absorption, shadowing by the holder, and filtering by the Be carrier. We show that this comprehensive model accurately predicts absolute counts and intensity ratios as a function of specimen tilt and position. We directly compare the model to experimental results acquired with a FEI Super-X EDS four quadrant detector. The contribution from each detector to the sum is investigated. The program and source code can be downloaded from https://github.com/subangstrom/superAngle.
ABSTRACT
Colorectal cancer (CRC) mass screening has been implemented in France since 2008. Participation rates remain too low. The objective of this study was to test if the implementation of a training course focused on communication skills among general practitioners (GP) would increase the delivery of gaiac faecal occult blood test and CRC screening participation among the target population of each participating GP. A cluster randomised controlled trial was conducted with GP's practice as a cluster unit. GPs from practices in the control group were asked to continue their usual care. GPs of the intervention group received a 4-h educational training, built with previous qualitative data on CRC screening focusing on doctor-patient communication with a follow-up of 7 months for both groups. The primary outcome measure was the patients' participation rate in the target population for each GP. Seventeen GPs (16 practices) in intervention group and 28 GPs (19 practices) in control group participated. The patients' participation rate in the intervention group were 36.7% vs. 24.5% in the control group (P = 0.03). Doctor-patient communication should be developed and appear to be one of the possible targets of improvement patients adherence and participation rate in the target population for CRC mass screening.
Subject(s)
Colorectal Neoplasms/diagnosis , Communication , Early Detection of Cancer , Education, Professional/methods , Family Practice , Physician-Patient Relations , Adult , Cluster Analysis , Family Practice/statistics & numerical data , Female , France , Humans , Male , Mass Screening/methods , Mass Screening/statistics & numerical data , Middle Aged , Occult Blood , Outcome Assessment, Health Care , Patient Participation/statistics & numerical data , Patient-Centered Care/standards , Practice Patterns, Physicians'/statistics & numerical dataABSTRACT
Strong magnetoelectric coupling can occur at the interface between ferromagnetic and ferroelectric films. Similar to work on interfacial exchange bias, photoemission electron microscopy was utilized to image both magnetic and ferroelectric domains and the resulting interfacial Ti spin in the same locations of La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 heterostructures. Multiple image analysis techniques, which could be applicable for a variety of fields needing quantitative data on image switching, confirm both improved magnetic switching and an increased population of interfacial spins with increased thickness of the ultrathin La0.7Sr0.3MnO3 layer. The perpendicular orientation of the interfacial spins is also discussed. This work suggests a magnetoelectric dead layer, with reduced interfacial magnetoelectricity when thin magnetic films are present.
ABSTRACT
BACKGROUND: The 2010-2014 HIV/AIDS French program recommends using HIV rapid diagnostic tests in family practice. Our aim was to assess the acceptability and feasibility of the RDT in family practice in France. METHODS: The first part of this study was to determine the opinions of family practitioners (FPs) concerning the news guidelines for screening and the possible use of rapid HIV tests in their practice. The second part was a feasibility study of the actual use of rapid HIV tests given to FPs during six months. The third part was a qualitative analysis of experience feedback to determine the impediments to using rapid HIV tests. RESULTS: Seventy-seven percent of the 352 FPs interviewed were favorable to rapid HIV tests use. The three main impediments were: misinterpretation of test result, complexity of quality control, and lack of training: 23 of the 112 FPs having volunteered to evaluate the rapid HIV tests followed the required training session. Sixty-nine tests were handed out, and three rapid HIV tests were used; the qualitative study involved 12 FPs. The participants all agreed on the difficult use of rapid HIV tests in daily practice. The main reasons were: too few opportunities or requests for use, complex handling, difficulties in proposing the test, fear of having to announce seropositivity, significantly longer consultation. CONCLUSION: Although FPs are generally favorable to rapid HIV tests use in daily practice, the feasibility and contribution of rapid HIV tests are limited in family practice.
Subject(s)
AIDS Serodiagnosis/methods , Family Practice/methods , HIV Infections/diagnosis , Physicians, Family/psychology , AIDS Serodiagnosis/statistics & numerical data , Adult , Attitude of Health Personnel , Feasibility Studies , Female , France/epidemiology , HIV Antibodies/blood , HIV Infections/epidemiology , HIV-1/immunology , HIV-2/immunology , Humans , Male , Middle Aged , Patient Acceptance of Health Care , Physician-Patient Relations , Practice Patterns, Physicians' , Prospective Studies , Quality Assurance, Health Care , Sampling Studies , Sensitivity and Specificity , Surveys and Questionnaires , Time FactorsABSTRACT
BACKGROUND: Since 2004, we have chosen a nipple reconstruction with a "double flag" local flap. We have retrospectively assessed its results in the long term and identified the factors likely to influence them. METHODS: Seventy reconstructions have been analyzed through a subjective study and objective one through measures of size and the projection of the nipple. RESULTS: They were examined in an average of 15months. The result was found satisfying for 74% of the patients and 66% of the clinician. The diameter of new nipple was 12.6mm (less 1mm than controlateral). The average height was 4.9mm and an average projection ratio was 0.8 (between reconstructed and controlateral). The limit of satisfaction of the patients and of the surgeon corresponded to a 0.7 projection ratio. We observed 4% of complete necroses. CONCLUSIONS: These results, compared to those of the literature, are very encouraging. The tegument quality of the reconstructed breast has a great influence on that of the nipple.
Subject(s)
Mammaplasty , Nipples/surgery , Surgical Flaps , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Mammaplasty/methods , Middle Aged , Patient Satisfaction , Retrospective Studies , Risk Factors , Smoking/adverse effects , Treatment OutcomeABSTRACT
A growing body of evidence attributes properties of chemo- and/or radiation-resistance to cancer stem cells (CSCs). Moreover, non-targeted delayed effects such as genomic instability, transmitted through many generations, can be observed in the progeny of surviving irradiated cells. As a consequence, we propose that radiation-resistance properties associated to CSCs could confer a key role to this subpopulation in the transmission of genomic instability. To test this hypothesis, we searched the CSC markers associated to radiation-resistance in breast cancer cell lines and studied the role of the resistant cells in the transmission of genomic instability. First, we show that irradiation induces a 2-4 weeks period of intense cell death leading to the emergence of chromosomal unstable cells during more than 35 population doublings. Then, among seven breast CSC markers, we identify CD24(-/low) labelling as a marker of radiation-resistance. We demonstrate that CD24(+) progeny of irradiated cells exclusively descends from CD24(-/low) cells. Finally, we show that delayed chromosomal instability is only expressed by CD24(+) cells, but is transmitted by stable surviving CD24(-/low) cells. So, for the first time a CSC marker, CD24, is associated with the transmission of genomic instability. This work may assign a new deleterious role to breast CSCs in aggressive recurrence after radiotherapy, as the transmitted genomic instability potentially leads tumour cells to acquire more aggressive characteristics.
Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/radiotherapy , CD24 Antigen/analysis , Genomic Instability/radiation effects , Biomarkers, Tumor/genetics , Biomarkers, Tumor/radiation effects , Breast Neoplasms/metabolism , Cell Line, Tumor , Chromosome Breakage/radiation effects , Female , Humans , Hyaluronan Receptors/metabolism , Neoplastic Stem Cells/radiation effects , Polyploidy , Radiation Tolerance/geneticsABSTRACT
A non-uniform response across scanning transmission electron microscope annular detectors has been found experimentally, but is seldom incorporated into simulations. Through case study simulations, we establish the nature and scale of the discrepancies which may arise from failing to account for detector non-uniformity. If standard detectors are used at long camera lengths such that the detector is within or near to the bright field region, we find errors in contrast of the order of 10%, sufficiently small for qualitative work but non-trivial as experiments become more quantitative. In cases where the detector has been characterized in advance, we discuss the detector response normalization and how it may be incorporated in simulations.
Subject(s)
Microscopy, Electron, Scanning Transmission/instrumentation , Microscopy, Electron, Scanning Transmission/methodsABSTRACT
Lysosomal regulation is a poorly understood mechanism that is central to degradation and recycling processes. Here we report that LAMTOR1 (late endosomal/lysosomal adaptor, MAPK and mTOR activator 1) downregulation affects lysosomal activation, through mechanisms that are not solely due to mTORC1 inhibition. LAMTOR1 depletion strongly increases lysosomal structures that display a scattered intracellular positioning. Despite their altered positioning, those dispersed structures remain overall functional: (i) the trafficking and maturation of the lysosomal enzyme cathepsin B is not altered; (ii) the autophagic flux, ending up in the degradation of autophagic substrate inside lysosomes, is stimulated. Consequently, LAMTOR1-depleted cells face an aberrant lysosomal catabolism that produces excessive reactive oxygen species (ROS). ROS accumulation in turn triggers p53-dependent cell cycle arrest and apoptosis. Both mTORC1 activity and the stimulated autophagy are not necessary to this lysosomal cell death pathway. Thus, LAMTOR1 expression affects the tuning of lysosomal activation that can lead to p53-dependent apoptosis through excessive catabolism.
Subject(s)
Apoptosis , Carrier Proteins/metabolism , Lysosomes/metabolism , Tumor Suppressor Protein p53/metabolism , Autophagy , Carrier Proteins/genetics , Cathepsin B/metabolism , Cell Cycle Checkpoints , Cell Line, Tumor , Humans , Intracellular Signaling Peptides and Proteins , Lysosomes/enzymology , RNA Interference , RNA, Small Interfering/metabolism , Reactive Oxygen Species/metabolism , TOR Serine-Threonine Kinases/metabolismABSTRACT
In conventional transmission electron microscopy, thermal scattering significantly affects the image contrast. It has been suggested that not accounting for this correctly is the main cause of the Stobbs factor, the ubiquitous, large contrast mismatch found between theory and experiment. In the case where a hard aperture is applied, we show that previous conclusions drawn from work using bright field scanning transmission electron microscopy and invoking the principle of reciprocity are reliable in the presence of thermal scattering. In the aperture-free case it has been suggested that even the most sophisticated mathematical models for thermal diffuse scattering lack in their numerical implementation, specifically that there may be issues in sampling, including that of the contrast transfer function of the objective lens. We show that these concerns can be satisfactorily overcome with modest computing resources; thermal scattering can be modelled accurately enough for the purpose of making quantitative comparison between simulation and experiment. Spatial incoherence of the source is also investigated. Neglect or inadequate handling of thermal scattering in simulation can have an appreciable effect on the predicted contrast and can be a significant contribution to the Stobbs factor problem.
ABSTRACT
We recently treated one patient presenting with a disseminated non-operable Merkel cell carcinoma (MCC) by lanreotide (somatostatin analog), with a complete remission of the disease and a follow up of 17 months. We present in this paper a case report with a review of the utilization of somatostatin analogues in the treatment of MCC.
Subject(s)
Carcinoma, Merkel Cell/drug therapy , Remission Induction , Skin Neoplasms/drug therapy , Somatostatin/analogs & derivatives , Aged , Aged, 80 and over , Carcinoma, Merkel Cell/surgery , Female , Humans , Immunohistochemistry , Skin Neoplasms/surgery , Somatostatin/therapeutic useABSTRACT
INTRODUCTION: Severe mandibular incisor crowding with bone insufficiency is usually treated by dental extractions and orthodontic management. Symphyseal distraction was proposed to avoid tooth extraction. This technique is still considered as invasive, complex and unsafe. We evaluated symphyseal distraction to clarify its indications, and to suggest a simplified surgical protocol. PATIENTS AND METHODS: Six patients were treated by symphyseal distraction: three with a bone-anchored device and three with a dental anchored one. Pre and postoperative inter-canine measurements and occlusal stability were analyzed. RESULTS: Postoperative inter-canine measurements increased from 3.4 to 6.8mm (mean 5.2mm). All patients were in Angle class I occlusion without complications. Dental anchored device simplified the surgical procedure. DISCUSSION: Symphyseal distraction with dental anchored device is a simple, efficient and reliable to treat severe transverse mandibular deficiency. The orthodontist can manage the procedure by himself and controls the whole expansion process according to specific requirements.
Subject(s)
Mandible/surgery , Osteogenesis, Distraction/methods , Adolescent , Alveolar Process/pathology , Cephalometry , Child , Cuspid/pathology , Dental Arch/pathology , Equipment Design , External Fixators , Follow-Up Studies , Humans , Lip/pathology , Male , Malocclusion, Angle Class II/surgery , Malocclusion, Angle Class II/therapy , Mandible/abnormalities , Mandible/pathology , Molar/pathology , Orthodontic Anchorage Procedures/instrumentation , Orthodontic Appliance Design , Osteotomy/methods , Postoperative Complications , Retrospective Studies , Sleep Apnea Syndromes/therapy , Tooth Movement Techniques/instrumentation , Tooth Movement Techniques/methodsABSTRACT
Central-facial mutilations, located within the nose lips and chin triangle, require great quality repairs regarding morphology and function. Plastic surgery history affords the ideas evolution in this field crossing over nose and lips reconstructions, which were the subject of successive reports within our society, in 1994 (nose reconstruction) and 2002 (lips reconstruction). Now a day, following this progress, the plastic surgeon has a large choice of reliable techniques. His choice is dictated by a precise evaluation of the limits of the substance loss to repair, according to a (mapping) classification of the nose-lip and chin triangle. This classification defines three units (nose-labial, bilabial and chin-labial) as reflexion bases to the therapeutic indications. This anatomical and surgical approach was built starting from a retrospective study of 195 central-facial mutilations caused by ballistic damage and dog bites. The results evaluation makes possible to carry out a reflexion on the potential indications regarding allograft as a therapeutic alternative to the traditional reconstructions of this territory.