2,104 research outputs found

    Collagen type IV at the fetal-maternal interface.

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    INTRODUCTION: Extracellular matrix proteins play a crucial role in influencing the invasion of trophoblast cells. However the role of collagens and collagen type IV (col-IV) in particular at the implantation site is not clear. METHODS: Immunohistochemistry was used to determine the distribution of collagen types I, III, IV and VI in endometrium and decidua during the menstrual cycle and the first trimester of pregnancy. Expression of col-IV alpha chains during the reproductive cycle was determined by qPCR and protein localisation by immunohistochemistry. The structure of col-IV in placenta was examined using transmission electron microscopy. Finally, the expression of col-IV alpha chain NC1 domains and collagen receptors was localised by immunohistochemistry. RESULTS: Col-IV alpha chains were selectively up-regulated during the menstrual cycle and decidualisation. Primary extravillous trophoblast cells express collagen receptors and secrete col-IV in vitro and in vivo, resulting in the increased levels found in decidua basalis compared to decidua parietalis. A novel expression pattern of col-IV in the mesenchyme of placental villi, as a three-dimensional network, was found. NC1 domains of col-IV alpha chains are known to regulate tumour cell migration and the selective expression of these domains in decidua basalis compared to decidua parietalis was determined. DISCUSSION: Col-IV is expressed as novel forms in the placenta. These findings suggest that col-IV not only represents a structural protein providing tissue integrity but also influences the invasive behaviour of trophoblast cells at the implantation site.This work was supported by funding from the Wellcome Trust [090108/Z/09/Z], [085992/Z/08/Z] and the British Heart Foundation [PG/09/077/27964]. C.M. Oefner was in receipt of a German National Academic Foundation PhD studentship. The authors also thank the Centre for Trophoblast Research for generous support.This is the final published version of the article. It first appeared at http://www.sciencedirect.com/science/article/pii/S0143400414008248#

    P4‐154: The Protein Quality Control Protein, Ubiquilin‐2, Regulates Tau Accumulation

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152960/1/alzjjalz2019063816.pd

    Measuring motion with kinematically redundant accelerometer arrays: theory, simulation and implementation

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    This work presents two schemes of measuring the linear and angular kinematics of a rigid body using a kinematically redundant array of triple-axis accelerometers with potential applications in biomechanics. A novel angular velocity estimation algorithm is proposed and evaluated that can compensate for angular velocity errors using measurements of the direction of gravity. Analysis and discussion of optimal sensor array characteristics are provided. A damped 2 axis pendulum was used to excite all 6 DoF of the a suspended accelerometer array through determined complex motion and is the basis of both simulation and experimental studies. The relationship between accuracy and sensor redundancy is investigated for arrays of up to 100 triple axis (300 accelerometer axes) accelerometers in simulation and 10 equivalent sensors (30 accelerometer axes) in the laboratory test rig. The paper also reports on the sensor calibration techniques and hardware implementation

    Compositional Constraints for Lucy Mission Trojan Asteroids via Near-Infrared Spectroscopy

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    We report near-infrared (0.7-2.5 micron) reflectance spectra for each of the six target asteroids of the forthcoming NASA Discovery-class mission Lucy. Five Jupiter Trojans (the binary (617) Patroclus system, (3548) Eurybates, (21900) Orus, (11351) Leucus, and (15094) Polymele) are well-characterized, with measurable spectral differences. We also report a survey-quality spectrum for main belt asteroid (52246) Donaldjohanson. We measured a continuum of spectral slopes including "red" (Orus, Leucus), "less red" (Eurybates, Patroclus-Menoetius) and intermediate (Polymele), indicating a range of compositional end-members or geological histories. We perform radiative transfer modeling of several possible surface compositions. We find that the mild-sloped spectra and low albedo of Patroclus and Eurybates imply similar compositions. Eurybates (~7 wt.% water ice) and Patroclus (~4 wt.% water ice) are consistent with a hydrated surface. Models for Orus and Leucus are consistent with each other and require a significantly more reddening agent (e.g. iron-rich silicates or tholin-like organics). Polymele has a linear spectrum like Patroclus, but a higher albedo more closely aligned with Orus/Leucus, defying simple grouping. Solar system formation models generally predict that the Jovian Trojans accreted in the outer solar system. Our observations and analysis are generally consistent with this expectation, although not uniquely so.Comment: Accepted by AJ. 10 Figures, 5 Table

    Should we welcome robot teachers?

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    Abstract Current uses of robots in classrooms are reviewed and used to characterise four scenarios: (s1) Robot as Classroom Teacher; (s2) Robot as Companion and Peer; (s3) Robot as Care-eliciting Companion; and (s4) Telepresence Robot Teacher. The main ethical concerns associated with robot teachers are identified as: privacy; attachment, deception, and loss of human contact; and control and accountability. These are discussed in terms of the four identified scenarios. It is argued that classroom robots are likely to impact children’s’ privacy, especially when they masquerade as their friends and companions, when sensors are used to measure children’s responses, and when records are kept. Social robots designed to appear as if they understand and care for humans necessarily involve some deception (itself a complex notion), and could increase the risk of reduced human contact. Children could form attachments to robot companions (s2 and s3), or robot teachers (s1) and this could have a deleterious effect on their social development. There are also concerns about the ability, and use of robots to control or make decisions about children’s behaviour in the classroom. It is concluded that there are good reasons not to welcome fully fledged robot teachers (s1), and that robot companions (s2 and 3) should be given a cautious welcome at best. The limited circumstances in which robots could be used in the classroom to improve the human condition by offering otherwise unavailable educational experiences are discussed

    Observational Study Design in Veterinary Pathology, Part 1: Study Design

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    Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature. Investigators should recognize the importance of creativity, insight, and innovation in devising studies that solve problems and fill important gaps in knowledge. Studies should focus on specific and testable hypotheses, questions, or objectives. The methodology is developed to support these goals. We consider the merits and limitations of different types of analytic and descriptive studies, as well as of prospective vs retrospective enrollment. Investigators should define clear inclusion and exclusion criteria and select adequate numbers of study subjects, including careful selection of the most appropriate controls. Studies of causality must consider the temporal relationships between variables and the advantages of measuring incident cases rather than prevalent cases. Investigators must consider unique aspects of studies based on archived laboratory case material and take particular care to consider and mitigate the potential for selection bias and information bias. We close by discussing approaches to adding value and impact to observational studies. Part 2 of the series focuses on methodology and validation of methods

    Impact of COVID-19 pandemic on STEMI care: An expanded analysis from the United States.

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    OBJECTIVE: To evaluate the impact of COVID-19 pandemic migitation measures on of ST-elevation myocardial infarction (STEMI) care. BACKGROUND: We previously reported a 38% decline in cardiac catheterization activations during the early phase of the COVID-19 pandemic mitigation measures. This study extends our early observations using a larger sample of STEMI programs representative of different US regions with the inclusion of more contemporary data. METHODS: Data from 18 hospitals or healthcare systems in the US from January 2019 to April 2020 were collecting including number activations for STEMI, the number of activations leading to angiography and primary percutaneous coronary intervention (PPCI), and average door to balloon (D2B) times. Two periods, January 2019-February 2020 and March-April 2020, were defined to represent periods before (BC) and after (AC) initiation of pandemic mitigation measures, respectively. A generalized estimating equations approach was used to estimate the change in response variables at AC from BC. RESULTS: Compared to BC, the AC period was characterized by a marked reduction in the number of activations for STEMI (29%, 95% CI:18-38, p \u3c .001), number of activations leading to angiography (34%, 95% CI: 12-50, p = .005) and number of activations leading to PPCI (20%, 95% CI: 11-27, p \u3c .001). A decline in STEMI activations drove the reductions in angiography and PPCI volumes. Relative to BC, the D2B times in the AC period increased on average by 20%, 95%CI (-0.2 to 44, p = .05). CONCLUSIONS: The COVID-19 Pandemic has adversely affected many aspects of STEMI care, including timely access to the cardiac catheterization laboratory for PPCI

    The effect of the COVID-19 pandemic in intestinal rehabilitation and transplant patients, initial results of an international survey

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    Introduction: On January 30, 2020 the World Health Organization (WHO) declared the 2019-CoV outbreak in China as a global public health emergency and subsequently, a pandemic on March 11th. It was considered that intestinal failure and intestinal transplant patients might have a higher risk of severe complications from the COVID-19 disease, multidisciplinary intestinal failure teams had to adapt their clinical approaches in order to keep this vulnerable group of patients as safe as possible during the pandemic; but data was lacking. Therefore, in order to improve our knowledge, we designed a voluntary, international survey aiming to address the impact of the COVID-19 disease in intestinal failure and transplant patients worldwide. Patient and Methods: A retrospective, observational, multicenter survey was sent to all centers registered at the Intestinal Rehabilitation and Transplant Association (IRTA). The survey contained three modules: the 1st one consisted of 14 questions about the hospital\u27s activity during the COVID-19 pandemic. The 2nd one, contained 43 questions, was about intestinal failure patient management and outcome and the 3rd one (52 questions) focused on intestinal transplant patients. We used the Google Form platform. We aim to present the preliminary results of the first module. Statistical analysis was performed with the IBM SPSS Statistic version 25.0Ÿ program. Results: 13/42 (41%) centers responded; including centers from France, Netherlands, Italy, United States, UK, Sweden, Germany and Argentina. Only 2 centers reported moratorium on intestinal (IT) or multivisceral transplant (MVT), with a mean of 3 months (±4) [Table 1]. Since the pandemic started, 2 institutions reported 4 patients with intestinal rehabilitation or on TPN diagnosed with COVID-19 while 7 centers hospitals claimed to have had 9 patients post-IT/MTV affected by the disease. While 7 centers had their routine follow up and \u27protocol biopsies\u27 in the post-IT/MTV affected, none reported higher rates of rejection or complications. At the same time, 8 centers (77%) were affected by a mean of 15% decrease in referrals for new evaluations of intestinal failure or transplantation (compared to 2019) [Figure 1]. All centers adapted to utilizing telemedicine to follow up on IT/MVT patients. Conclusions: Many aspects of healthcare have been impacted by the COVID-19 pandemic. The survey showed that the number of affected patients has been lower than expected, the reduced number of centers required transient moratorium of their activity, but a secondary observation was that despite the availability of telemedicine, and probably related to the lockdown, there has been a significant reduction in the referrals for evaluation of intestinal failure and transplant patients, that may have the deleterious effect of the delay of treatment in health care system
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