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Estimating Time From Atomic Clocks.

J Res Natl Bur Stand (1977) 1983 Jan-Feb;88(1):17-24

National Bureau of Standards, Boulder, CO 80303.

A Kalman recursive algorithm for estimating time from an ensemble of atomic clocks has been developed. The algorithm allows for the addition or deletion of clocks at any time, and provides automatic error detection and correction. The observations consist of time differences between clocks and may be taken at unequally spaced time points. Read More

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September 2021

Estimation of Parameters in Models for Cesium Beam Atomic Clocks.

J Res Natl Bur Stand (1977) 1983 Jan-Feb;88(1):3-16

National Bureau of Standards, Boulder, CO 80303.

This paper is intended to serve as an introduction to the use of the Kalman filter in modeling atomic clocks and obtaining maximum likelihood estimates of the model paramaters from data on an ensemble of clocks. Tests for the validity of the model and confidence intervals for the parameter estimates are discussed. Techniques for dealing with unequally spaced and partially or completely missing multivariate data are described. Read More

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September 2021

Multiparameter optimization of nonuniform passive diffusion properties for creating coarse-grained equivalent models of cardiac propagation.

Comput Biol Med 2021 Sep 10;138:104863. Epub 2021 Sep 10.

Pharmacology and Physiology Department, Institute of Biomedical Engineering, Université de Montréal, Montreal, QC, H3T 1J4, Canada; Hôpital Du Sacré-Cœur de Montréal, Research Center, 5400 Boul. Gouin Ouest, Montreal, QC, H4J 1C5, Canada. Electronic address:

The arrhythmogenic role of discrete cardiac propagation may be assessed by comparing discrete (fine-grained) and equivalent continuous (coarse-grained) models. We aim to develop an optimization algorithm for estimating the smooth conductivity field that best reproduces the diffusion properties of a given discrete model. Our algorithm iteratively adjusts local conductivity of the coarse-grained continuous model by simulating passive diffusion from white noise initial conditions during 3-10 ms and computing the root mean square error with respect to the discrete model. Read More

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September 2021

Robust neuronal differentiation of human iPSC-derived neural progenitor cells cultured on densely-spaced spiky silicon nanowire arrays.

Sci Rep 2021 Sep 22;11(1):18819. Epub 2021 Sep 22.

Center for Hybrid Nanostructures, Universität Hamburg, Luruper Chaussee 149, 22761, Hamburg, Germany.

Nanostructured cell culture substrates featuring nanowire (NW) arrays have been applied to a variety of basic cell lines and rodent neurons to investigate cellular behavior or to stimulate cell responses. However, patient-derived human neurons-a prerequisite for studying e.g. Read More

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September 2021

Discrepancies in the German Pharmacopoeia procedure for quality control of Quillaja saponin extracts.

Arch Pharm (Weinheim) 2021 Sep 17:e2100262. Epub 2021 Sep 17.

Institute of Analytical Chemistry, Johannes-Kepler University, Linz, Austria.

This study focused on the evaluation of Quillaja saponin extracts with the additional quality designation DAB-which means the abbreviation of the German Pharmacopoeia (Deutsches Arzneibuch). This label suggests that Quillaja saponin extracts marked in this way are of pharmacopoeial quality and thus stand out from other Quillaja saponin extracts. The DAB ninth edition listed Quillaia saponin as a reagent. Read More

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September 2021

Front-loading of anatomy content has no effect on long-term anatomy knowledge retention among physical therapy students: a prospective cohort study.

BMC Med Educ 2021 Sep 14;21(1):491. Epub 2021 Sep 14.

St. Luke's University Health Network, Bethlehem, PA, USA.

Background: Information learned over a longer period of time has been shown to result in better long-term knowledge retention than information learned over a shorter period of time. In order to address multiple curricular goals, the timing and spacing of anatomy content within the Doctor of Physical Therapy (DPT) program at our institution recently changed from a very spaced to a very compressed format. The purpose of the present study was to assess differences in anatomy knowledge retention that might have been impacted by this change. Read More

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September 2021

Reward learning and working memory: Effects of massed versus spaced training and post-learning delay period.

Mem Cognit 2021 Sep 14. Epub 2021 Sep 14.

Department of Psychology, Stanford University, 450 Jane Stanford Way, Stanford, CA, 94305, USA.

Neuroscience research has illuminated the mechanisms supporting learning from reward feedback, demonstrating a critical role for the striatum and midbrain dopamine system. However, in humans, short-term working memory that is dependent on frontal and parietal cortices can also play an important role, particularly in commonly used paradigms in which learning is relatively condensed in time. Given the growing use of reward-based learning tasks in translational studies in computational psychiatry, it is important to understand the extent of the influence of working memory and also how core gradual learning mechanisms can be better isolated. Read More

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September 2021

Engagement and learning in an electronic spaced repetition curriculum companion for a paediatrics academic half-day curriculum.

Perspect Med Educ 2021 Sep 13. Epub 2021 Sep 13.

Department of Paediatrics, McMaster University Medical Centre, Hamilton ON, Canada.

Postgraduate residencies utilize academic half-days to supplement clinical learning. Spaced repetition reinforces taught content to improve retention. We leveraged spaced repetition in a curriculum companion for a paediatric residency program's half-day. Read More

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September 2021

Rational design for high-yield monolayer WSfilms in confined space under fast thermal processing.

Nanotechnology 2021 Sep 21;32(50). Epub 2021 Sep 21.

Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, People's Republic of China.

Tungsten Disulfide (WS) films, as one of the most attractive members in the family of transition metal dichalcogenides, were synthesized typically on SiO/Si substrate by confine-spaced chemical vapor deposition method. The whole process could be controlled efficiently by precursor concentration and fast thermal process. To be priority, the effect of fast heating-up to cooling-down process and source ratio-dependent rule for WSstructure have been systematically studied, leading to high-yield and fine structure of monolayer WSfilms with standard triangular morphology and average edge length of 92. Read More

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September 2021

X-ray multi-probe data acquisition: A novel technique for laser pump x-ray transient absorption spectroscopy.

Rev Sci Instrum 2021 Aug;92(8):085109

X-ray Sciences Division, Argonne National Laboratory, Lemont, Illinois 60439, USA.

We report the development and implementation of a novel data acquisition (DAQ) technique for synchrotron-based laser pump X-ray Transient Absorption (XTA) spectroscopy, called X-ray Multi-Probe DAQ (XMP DAQ). This technique utilizes high performance analog to digital converters and home-built software to efficiently measure and process the XTA signal from all x-ray pulses between laser excitations. XMP DAQ generates a set of time resolved x-ray absorption spectra at thousands of different pump-probe time delays simultaneously. Read More

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Radius selection using kernel density estimation for the computation of nonlinear measures.

Chaos 2021 Aug;31(8):083131

LIRMM, CNRS UMR 5506, University of Montpellier, F-34095 Montpellier, France.

When nonlinear measures are estimated from sampled temporal signals with finite-length, a radius parameter must be carefully selected to avoid a poor estimation. These measures are generally derived from the correlation integral, which quantifies the probability of finding neighbors, i.e. Read More

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A Chinese Boy with Mowat-Wilson Syndrome Caused by a 10 bp Deletion in the Gene.

Pharmgenomics Pers Med 2021 23;14:1041-1045. Epub 2021 Aug 23.

Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan Maternal and Child Care Hospital, Jinan, 250001, Shandong Province, People's Republic of China.

Purpose: Mowat-Wilson syndrome (MWS) is a rare complex malformation syndrome which is characterized by typical facial dysmorphism, moderate to severe intellectual disability, global developmental delay, and multiple congenital anomalies. Here, we summarize the clinical characteristics and gene mutation analysis of a Chinese boy with MWS.

Patients And Methods: The clinical features of the patient were monitored. Read More

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Developmental single-cell transcriptomics in the Lytechinus variegatus sea urchin embryo.

Development 2021 Aug 31. Epub 2021 Aug 31.

Department of Biology, Duke University, Durham, NC 27708, USA.

Using scRNA-seq coupled with computational approaches, we studied transcriptional changes in cell states of sea urchin embryos during development to the larval stage. Eighteen closely spaced time points were taken during the first 24 hours of development of Lytechinus variegatus (Lv). Developmental trajectories were constructed using Waddington-OT, a computational approach to "stitch" together developmental timepoints. Read More

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Novel Spaced Repetition Flashcard System for the In-training Examination for Obstetrics and Gynecology.

Med Sci Educ 2021 Aug 19;31(4):1393-1399. Epub 2021 May 19.

Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC USA.

Introduction: Electronic flashcards allow repeated information exposure over time along with active recall. It is increasingly used for self-study by medical students but remains poorly implemented for graduate medical education. The primary goal of this study was to determine whether a flashcard system enhances preparation for the in-training examination in obstetrics and gynecology (ob-gyn) conducted by the Council on Resident Education in Obstetrics and Gynecology (CREOG). Read More

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Spaced Repetition Flashcards for Teaching Medical Students Psychiatry.

Med Sci Educ 2021 Jun 6;31(3):1125-1131. Epub 2021 Apr 6.

Department of Psychiatry, Duke University School of Medicine, Durham, NC USA.

Objective: Retrieval practice, often using electronic flashcards, is increasingly utilized among medical students for self-study. In this study, the authors evaluated usage and satisfaction with electronic flashcards based on a medical school psychiatry curriculum.

Methods: First-year medical students at one institution consented to participate and received access to a set of pre-made flashcards. Read More

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Endothelial Semaphorin 3fb regulates Vegf pathway-mediated angiogenic sprouting.

PLoS Genet 2021 Aug 23;17(8):e1009769. Epub 2021 Aug 23.

Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada.

Vessel growth integrates diverse extrinsic signals with intrinsic signaling cascades to coordinate cell migration and sprouting morphogenesis. The pro-angiogenic effects of Vascular Endothelial Growth Factor (VEGF) are carefully controlled during sprouting to generate an efficiently patterned vascular network. We identify crosstalk between VEGF signaling and that of the secreted ligand Semaphorin 3fb (Sema3fb), one of two zebrafish paralogs of mammalian Sema3F. Read More

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Beat perception in polyrhythms: Time is structured in binary units.

PLoS One 2021 20;16(8):e0252174. Epub 2021 Aug 20.

Center for Music in the Brain, Department of Clinical Medicine, Aarhus University & The Royal Academy of Music Aarhus/Aalborg, Aarhus C, Denmark.

In everyday life, we group and subdivide time to understand the sensory environment surrounding us. Organizing time in units, such as diurnal rhythms, phrases, and beat patterns, is fundamental to behavior, speech, and music. When listening to music, our perceptual system extracts and nests rhythmic regularities to create a hierarchical metrical structure that enables us to predict the timing of the next events. Read More

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DLFF-ACP: prediction of ACPs based on deep learning and multi-view features fusion.

PeerJ 2021 3;9:e11906. Epub 2021 Aug 3.

Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education, School of Computer Science and Technology, Anhui University, Hefei, Anhui, China.

An emerging type of therapeutic agent, anticancer peptides (ACPs), has attracted attention because of its lower risk of toxic side effects. However process of identifying ACPs using experimental methods is both time-consuming and laborious. In this study, we developed a new and efficient algorithm that predicts ACPs by fusing multi-view features based on dual-channel deep neural network ensemble model. Read More

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Longitudinal K-means approaches to clustering and analyzing EHR opioid use trajectories for clinical subtypes.

J Biomed Inform 2021 Aug 16;122:103889. Epub 2021 Aug 16.

University at Buffalo, The State University of New York, United States; Department of Veterans Affairs, WNY VA, United States; Faculty of Engineering, University of Southern Denmark, Denmark.

Identification of patient subtypes from retrospective Electronic Health Record (EHR) data is fraught with inherent modeling issues, such as missing data and variable length time intervals, and the results obtained are highly dependent on data pre-processing strategies. As we move towards personalized medicine, assessing accurate patient subtypes will be a key factor in creating patient specific treatment plans. Partitioning longitudinal trajectories from irregularly spaced and variable length time intervals is a well-established, but open problem. Read More

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Adaptive Capacities and Complexity of Heart Rate Variability in Patients With Chronic Obstructive Pulmonary Disease Throughout Pulmonary Rehabilitation.

Front Physiol 2021 28;12:669722. Epub 2021 Jul 28.

EuroMov Digital Health in Motion, University of Montpellier, IMT Mines Ales, Montpellier, France.

Introduction: The complexity of bio-signals, like R-R intervals, is considered a reflection of the organism's capacity to adapt. However, this association still remains to be consolidated. We investigated whether the complexity of R-R intervals at rest and during perturbation [6-minute walking test (6MWT)], yielded information regarding adaptive capacities in Chronic Obstructive Pulmonary Disease (COPD) patients during pulmonary rehabilitation (PR). Read More

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Directional biosonar beams allow echolocating harbour porpoises to actively discriminate and intercept closely spaced targets.

J Exp Biol 2021 08 13;224(16). Epub 2021 Aug 13.

Zoophysiology, Department of Biology, Aarhus University, Aarhus 8000, Denmark.

Echolocating toothed whales face the problem that high sound speeds in water mean that echoes from closely spaced targets will arrive at time delays within their reported auditory integration time of some 264 µs. Here, we test the hypothesis that echolocating harbour porpoises cannot resolve and discriminate targets within a clutter interference zone given by their integration time. To do this, we trained two harbour porpoises (Phocoena phocoena) to actively approach and choose between two spherical targets at four varying inter-target distances (13. Read More

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Impact of region-of-interest size and location on quantitative contrast-enhanced ultrasound of canine splenic perfusion.

BMC Vet Res 2021 Aug 11;17(1):271. Epub 2021 Aug 11.

Department of Veterinary Sciences, University of Messina, Polo Universitario Annunziata, 98168, Messina, Italy.

Background: During contrast enhanced ultrasound (CEUS), the features of the regions of interest (ROI) can affect the value of the perfusion-related parameters obtained from a time intensity curve (TIC). In veterinary medicine, conflicting have been reported on the influence of ROI size and location on renal CEUS. There are some disagreeing evidences regarding the optimal method for selecting ROI in quantitative analysis of renal perfusion using CEUS. Read More

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Coupling between Emissive Defects on Carbon Nanotubes: Modeling Insights.

J Phys Chem Lett 2021 Aug 11;12(32):7846-7853. Epub 2021 Aug 11.

Center for Integrated Nanotechnologies, Center for Nonlinear Studies, and Theoretical Division Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.

Covalent functionalization of single-walled carbon nanotubes (SWCNTs) with organic molecules results in red-shifted emissive states associated with sp-defects in the tube lattice, which facilitate their improved optical functionality, including single-photon emission. The energy of the defect-based electronic excitations (excitons) depends on the molecular adducts, the configuration of the defect, and concentration of defects. Here we model the interactions between two sp-defects placed at various distances in the (6,5) SWCNT using time-dependent density functional theory. Read More

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The Multi-hub Academic Conference: Global, Inclusive, Culturally Diverse, Creative, Sustainable.

Front Res Metr Anal 2021 23;6:699782. Epub 2021 Jul 23.

Department of Music, University of Sheffield, Sheffield, United Kingdom.

New conference formats are emerging in response to COVID-19 and climate change. are sustainable and inclusive regardless of participant mobility (financial means, caring commitments, disability), but lack face-to-face contact. (physical meetings with additional virtual presentations) tend to discriminate against non-fliers and encourage unsustainable flying. Read More

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"… I would have left that man long time ago but, …" exploring circumstances of and motivators for repeat adolescent birth in Eastern Uganda.

Arch Public Health 2021 Aug 6;79(1):142. Epub 2021 Aug 6.

Department of Community Health and Behavioral Sciences, Makerere University School of Public Health, Kampala, Uganda.

Background: First birth before 18 years has declined in Uganda unlike repeat adolescent birth (=second or more births before age 20 years). We explored the circumstances of and motivators for repeat adolescent birth in Eastern Uganda.

Methods: Between January and March 2020, we conducted a qualitative study involving 70 individual in-depth interviews with purposively selected respondents - 20-25-year-old women with and without repeat adolescent birth, their partners, and parents, in the communities of Teso sub-region. Read More

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The Neural Underpinnings of Processing Newly Taught Semantic Information: The Role of Retrieval Practice.

J Speech Lang Hear Res 2021 08 3;64(8):3195-3211. Epub 2021 Aug 3.

Department of Speech, Language, & Hearing Sciences, Purdue University, West Lafayette, IN.

Purpose Recent behavioral studies have demonstrated the effectiveness of implementing retrieval practice into learning tasks for children. Such approaches have revealed that repeated spaced retrieval (RSR) is particularly effective in promoting children's learning of word form and meaning information. This study further examines how retrieval practice enhances learning of word meaning information at the behavioral and neural levels. Read More

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Using Individual Residents' Learning Trajectories to Better Understand the Impact of Gaps in Practice.

Acad Med 2021 Aug 3. Epub 2021 Aug 3.

S. Scott is assistant professor and surgical skills coordinator, Department of Obstetrics and Gynecology, Clinical Gynecologic Oncologist, Dalhousie University, Halifax, Nova Scotia, Canada. N. Van Eyk is associate professor and clinical obstetrician and gynecologist, Department of Obstetrics and Gynecology, Dalhousie University, Halifax, Nova Scotia, Canada. K. Eva is associate director, Centre for Health Education Scholarship, and professor and director of educational research and scholarship, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.

Purpose: To optimize learning, health professional training programs need to achieve the right balance between depth of practice (gaining more experience with particular skills) and breadth of practice (spreading experience across an array of activities). Better understanding how training for a particular skill set is impacted by periods of focus on a different skill set would allow improved curriculum and assessment design, thereby enhancing the efficiency of training and effectiveness of care. To this end, learning curves were used to compare performance in surgery after prolonged periods of practice to performance after gaps in surgical training. Read More

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Anxiety, stress, and binge eating tendencies in adolescence: a prospective approach.

J Eat Disord 2021 Aug 3;9(1):94. Epub 2021 Aug 3.

Department of Experimental Psychology, University of Oxford, Anna Watts Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, UK.

Background: Recent years have witnessed an increasing prevalence of binge eating tendencies in adolescence-warranting a clearer understanding of their underlying predisposing and precipitating factors. The current study investigated whether the interaction between high levels of anxiety and stress predicted increased levels of binge eating tendencies in a prospective cohort of adolescents (N = 324).

Methods: Measurements were taken over three waves (M ages: 13. Read More

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Adaptive vs. Fixed Spacing of Learning Items: Evidence from Studies of Learning and Transfer in Chemistry Education.

Cogsci 2020 Jul-Aug;2020:1598-1604

Department of Psychology, University of California, Los Angeles, Los Angeles, CA 90095 USA.

Spacing presentations of learning items across time improves memory relative to massed schedules of practice - the well-known spacing effect. Spaced practice can be further enhanced by adaptively scheduling the presentation of learning items to deliver customized spacing intervals for individual items and learners. ARTS - Adaptive Response-time-based Sequencing (Mettler, Massey, & Kellman 2016) determines spacing dynamically in relation to each learner's ongoing speed and accuracy in interactive learning trials. Read More

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Recording Strategies for High Channel Count, Densely Spaced Microelectrode Arrays.

Front Neurosci 2021 13;15:681085. Epub 2021 Jul 13.

Institute of Microelectronics of Seville (IMSE-Centro Nacional de Microelectrónica), Spanish National Research Council, Seville, Spain.

Neuroscience research into how complex brain functions are implemented at an extra-cellular level requires neural recording interfaces, including microelectrodes and read-out circuitry, with increased observability and spatial resolution. The trend in neural recording interfaces toward employing high-channel-count probes or 2D microelectrodes arrays with densely spaced recording sites for recording large neuronal populations makes it harder to save on resources. The low-noise, low-power requirement specifications of the analog front-end usually requires large silicon occupation, making the problem even more challenging. Read More

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