331 research outputs found
Gamma and Beta Bursts Underlie Working Memory
Working memory is thought to result from sustained neuron spiking. However, computational models suggest complex dynamics with discrete oscillatory bursts. We analyzed local field potential (LFP) and spiking from the prefrontal cortex (PFC) of monkeys performing a working memory task. There were brief bursts of narrow-band gamma oscillations (45â100 Hz), varied in time and frequency, accompanying encoding and re-activation of sensory information. They appeared at a minority of recording sites associated with spiking reflecting the to-be-remembered items. Beta oscillations (20â35 Hz) also occurred in brief, variable bursts but reflected a default state interrupted by encoding and decoding. Only activity of neurons reflecting encoding/decoding correlated with changes in gamma burst rate. Thus, gamma bursts could gate access to, and prevent sensory interference with, working memory. This supports the hypothesis that working memory is manifested by discrete oscillatory dynamics and spiking, not sustained activity.National Institute of Mental Health (U.S.) (Grant 5R01MH091174-05)National Institute of Mental Health (U.S.) (Grant 5R37MH087027-07
Nanoscale structure of type I collagen fibrils: Quantitative measurement of Dâspacing
This article details a quantitative method to measure the Dâperiodic spacing of type I collagen fibrils using atomic force microscopy coupled with analysis using a twoâdimensional fast fourier transform approach. Instrument calibration, data sampling and data analysis are discussed and comparisons of the data to the complementary methods of electron microscopy and Xâray scattering are made. Examples of the application of this new approach to the analysis of type I collagen morphology in disease models of estrogen depletion and osteogenesis imperfecta (OI) are provided. We demonstrate that it is the Dâspacing distribution, not the Dâspacing mean, that showed statistically significant differences in estrogen depletion associated with early stage osteoporosis and OI. The ability to quantitatively characterize nanoscale morphological features of type I collagen fibrils will provide important structural information regarding type I collagen in many research areas, including tissue aging and disease, tissue engineering, and gene knockout studies. Furthermore, we also envision potential clinical applications including evaluation of tissue collagen integrity under the impact of diseases or drug treatments. The distribution of Type I collagen fibril Dâspacing provides important morphological information regarding Type I collagen in diseases such as early stages of osteoporosis and osteogenesis Imperfecta . In this article, the authors use Atomic Force Microscopy (AFM) imaging combined with two Dimensional Fast Fourier Transform (2D FFT) analysis to quantitatively assess Type I collagen fibril Dâspacing. This methodology allows imaging and characterization of Type I collagen constituted biological tissues, hydrogels, and other collagen based biomaterials.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94732/1/117_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/94732/2/biot_201200174_sm_suppinfo.pd
Assessment of intelligibility in dysarthria: development of a Maltese word and phrase list
This paper describes the development of the Maltese Intelligibility Lists (MIL) for the assessment of word and phrase intelligibility in dysarthria. Two main tools were employed: the Frenchay Dysarthria Assessment-2 (FDA), and the Maltese Language Resource Server (MLRS). Three main criteria served as the basis for the construction of the word and phrase lists: frequency of occurrence of Maltese phonemes, word frequency and an analysis of syllable types and structures. The most common 500 words in the MLRS corpus (Korpus Malti v. 3) were broadly transcribed and an analysis of different types of syllables and their frequency of occurrence was carried out. Based on this analysis, the relevant proportion of different syllable types required for the word and phrase lists for Maltese was calculated in line with the number of items present in the FDA-2. With regards to phoneme frequency, the words chosen demonstrate a similar short-vowel and consonant distribution as reported in a previous large-scale study. The MIL consists of 116 words and 50 phrases which are representative of Standard Maltese and can be used in the clinic to assess speech intelligibility in Maltese individuals with dysarthria
The disappearance and reappearance of optical emission lines and the drop in a Swift/XRT count rate during the recent rebrightening of TCP J21040470+4631129
We report the results of our continuing optical and X-ray monitoring of the bright WZ Sge-type dwarf
nova TCP J21040470+4631129 (hereafter TCP2104) discovered on July 12, 2019 (for previous reports,
see ATel #12947, #13009). Our optical photometric observations are mostly performed using 30-cm class
telescopes, while spectroscopic data are obtained with the 2.1-m telescope at the OAN-SPM, the 2.5-m
Isaac Newton Telescope on La Palma, and other smaller telescopes.peer-reviewe
Clomifene citrate or low-dose FSH for the first-line treatment of infertile women with anovulation associated with polycystic ovary syndrome : a prospective randomized multinational study
BACKGROUND: Clomifene citrate (CC) is accepted as the first-line method for ovulation induction (OI) in patients with polycystic ovary syndrome (PCOS) associated with infertility owing to anovulation. Low-dose FSH has been reserved for women failing to conceive with CC. In this RCT, we tested the hypothesis that pregnancy rate (PR) and live birth rates (LBR) are higher after OI with low-dose FSH than with CC as first-line treatment. METHODS: Infertile women (<40 years old) with PCOS-related anovulation, without prior OI treatment, attending 10 centres in Europe/South America were randomized to OI with either CC (50-150 mg/day for 5 days) or FSH (starting dose 50 IU) for up to three treatment cycles. The primary outcome was clinical PR. RESULTS: Patients (n = 302) were randomized to OI with FSH (n = 132 women; 288 cycles) or CC (n = 123; 310 cycles). Per protocol analysis revealed that reproductive outcome was superior after OI with FSH than with CC with respect to PR per first cycle [30 versus 14.6%, respectively, 95 confidence interval (CI) 5.3-25.8, P = 0.003], PR per woman, (58 versus 44% of women, 95% CI 1.5-25.8, P = 0.03), LBR per woman (52 versus 39%, 95% CI 0.4-24.6, P = 0.04), cumulative PR (52.1 versus 41.2%, P = 0.021) and cumulative LBR (47.4 versus 36.9%, P = 0.031), within three cycles of OI. CONCLUSIONS: Pregnancies and live births are achieved more effectively and faster after OI with low-dose FSH than with CC. This result has to be balanced by convenience and cost in favour of CC. FSH may be an appropriate first-line treatment for some women with PCOS and anovulatory infertility, particularly older patients.peer-reviewe
Performance-optimized hierarchical models predict neural responses in higher visual cortex
Changes in connective tissue in patients with pelvic organ prolapse-a review of the current literature
GYNOCARE Update: Modern Strategies to Improve Diagnosis and Treatment of Rare Gynecologic TumorsâCurrent Challenges and Future Directions
More than 50% of all gynecologic tumors can be classified as rare (defined as an incidence of â€6 per 100,000 women) and usually have a poor prognosis owing to delayed diagnosis and treatment. In contrast to almost all other common solid tumors, the treatment of rare gynecologic tumors (RGT) is often based on expert opinion, retrospective studies, or extrapolation from other tumor sites with similar histology, leading to difficulty in developing guidelines for clinical practice. Currently, gynecologic cancer research, due to distinct scientific and technological challenges, is lagging behind. Moreover, the overall efforts for addressing these challenges are fragmented across different European countries and indeed, worldwide. The GYNOCARE, COST Action CA18117 (European Network for Gynecological Rare Cancer Research) programme aims to address these challenges through the creation of a unique network between key stakeholders covering distinct domains from concept to cure: basic research on RGT, biobanking, bridging with industry, and setting up the legal and regulatory requirements for international innovative clinical trials. On this basis, members of this COST Action, (Working Group 1, âBasic and Translational Research on Rare Gynecological Cancerâ) have decided to focus their future efforts on the development of new approaches to improve the diagnosis and treatment of RGT. Here, we provide a brief overview of the current state-of-the-art and describe the goals of this COST Action and its future challenges with the aim to stimulate discussion and promote synergy across scientists engaged in the fight against this rare cancer worldwide
The First Post-Kepler Brightness Dips of KIC 8462852
We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%-2.5% dips, named Elsie, Celeste, Skara Brae, and Angkor, which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar spectrum or polarization during the dips and (ii) the multiband photometry of the dips shows differential reddening favoring non-gray extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale âȘ1 ÎŒm, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term secular dimming, which may be caused by independent processes, or probe different regimes of a single process
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