6,917 research outputs found
Exact Treatment of the Pauli Exclusion Operator in Nuclear Matter Calculation
Exact expressions of the Pauli exclusion operator Q in the nuclear matter
calculation are presented in detail. Exact formulae are also given for the
calculations of the single-particle-potential energy and the binding energy per
nucleon with the exact Q operator. Numerical calculations of the G matrix in
the lowest-order Brueckner theory are carried out to check the reliability of
the standard angle-average approximation for the
Q operator by employing the Bonn B and C NN potentials. It is observed that
the exact treatment of the operator Q brings about non-negligible and
attractive contributions to the binding energy.Comment: 16 pages, 3 figure
Building a Community of Mentors in Engineering Education Research Through Peer Review Training
Peer review of scholarship is critical to the advancement of knowledge in a scholarly discipline. Despite this, scholars receive little or no training in effective and constructive peer review. The process of peer review has been routinely criticized in higher education for lack of quality reviews and reviewers, and reviews that are personal and not constructive. As a discipline, engineering education research (EER) benefits from diverse disciplinary backgrounds and perspectives of scholars, and as such relies on peer review of scholarship to generate, interpret, and translate knowledge. Supported by funding through the National Science Foundation, this project is developing, implementing, and assessing a project that conducts training in EER peer review for journal articles and grant proposals. This paper describes the Engineering Education Research Peer Review Training (EER PERT) project, which is designed to develop EER scholars’ peer review skills through mentored reviewing experiences. The overall goals of the EER PERT project are twofold: to establish, assess and evaluate a mentored reviewer program for 1) EER journal manuscripts and 2) EER grant proposals. In the first year of the project, two cohorts have participated in the mentored EER journal manuscript program through partnership with the Journal of Engineering Education (JEE), where triads (two mentees and one mentor) work collaboratively to review three manuscripts. Triads work with coaches informally to provide feedback on their experience and discuss manuscripts they are reviewing. Across the two cohorts, 42 mentees have collaborated with 18 mentors and 3 coaches, with some mentors and coaches participating in both cohorts. Project evaluation activities for the mentored manuscript review program included focus groups and exit surveys with both mentees and mentors in the first cohort. The main findings from the evaluation of the first cohort included the following themes: 1) the program provided valuable training and increased participant’s confidence in conducting EER scholarship, 2) the program fostered a sense of community and inclusion, particularly for those without EER backgrounds and from outside the US, and 3) program logistics could create barriers for participants, including working across time zones and tracking triad progress. Two main changes were implemented for the second cohort, including 1) a program dashboard for teams to track progress and organize update form submissions and 2) an optional monthly discussion meeting to supplement initial program orientation and triad meetings. The monthly discussions are intended to provide additional training in peer review topics and develop community among participants through networking opportunities. Planned discussion topics include updated JEE Author Guidelines and Review Criteria, inclusive language in scholarly publications, anti-racism in peer review, getting involved with the EER community, and roles and processes within the JEE Editorial Board. Program evaluation of the mentored manuscript review program is being leveraged to develop a mentored grant proposal review program wherein participants will work with former NSF program officers to review six grant proposals and participate in a mock review panel. This paper will present an overview of the journal manuscript and proposal mentored reviewer programs and findings from program evaluation
The Influence of Disciplinary Background on Peer Reviewers’ Evaluations of Engineering Education Journal Manuscripts
This is the first of a series of studies that explore the relationship between disciplinary background and the weighting of various elements of a manuscript in peer reviewers’ determination of publication recommendations. Research questions include: (1) To what extent are tacit criteria for determining quality or value of EER manuscripts influenced by reviewers’ varied disciplinary backgrounds and levels of expertise? and (2) To what extent does mentored peer review professional development influence reviewers’ EER manuscript evaluations? Data were collected from 27 mentors and mentees in a peer review professional development program. Participants reviewed the same two manuscripts, using a form to identify strengths, weaknesses, and recommendations. Responses were coded by two researchers (70% IRR). Our findings suggest that disciplinary background influences reviewers’ evaluation of EER manuscripts. We also found evidence that professional development can improve reviewers’ understanding of EER disciplinary conventions. Deeper understanding of the epistemological basis for manuscript reviews may reveal ways to strengthen professional preparation in engineering education as well as other disciplines
A transfer matrix approach to the enumeration of plane meanders
A closed plane meander of order is a closed self-avoiding curve
intersecting an infinite line times. Meanders are considered distinct up
to any smooth deformation leaving the line fixed. We have developed an improved
algorithm, based on transfer matrix methods, for the enumeration of plane
meanders. While the algorithm has exponential complexity, its rate of growth is
much smaller than that of previous algorithms. The algorithm is easily modified
to enumerate various systems of closed meanders, semi-meanders, open meanders
and many other geometries.Comment: 13 pages, 9 eps figures, to appear in J. Phys.
Utility of (11)C-methionine and (11)C-donepezil for imaging of Staphylococcus aureus induced osteomyelitis in a juvenile porcine model:comparison to autologous (111)In-labelled leukocytes, (99m) Tc-DPD, and (18)F-FDG
The aim of this study was to compare (11)C-methionine and (11)C-donepezil positron emission tomography (PET) with (111)In-labeled leukocyte and (99m)Tc-DPD (Tc-99m 3,3-diphosphono-1,2-propanedicarboxylic acid) single-photon emission computed tomography (SPECT), and (18)F-fluorodeoxyglucose ((18)F-FDG) PET to improve detection of osteomyelitis. The tracers’ diagnostic utility where tested in a juvenile porcine hematogenously induced osteomyelitis model comparable to osteomyelitis in children. Five 8-9 weeks old female domestic pigs were scanned seven days after intra-arterial inoculation in the right femoral artery with a porcine strain of Staphylococcus aureus. The sequential scan protocol included Computed Tomography, (11)C-methionine and (11)C-donepezil PET, (99m)Tc-DPD and (111)In-labelled leukocytes scintigraphy, and (18)F-FDG PET. This was followed by necropsy of the pigs and gross pathology, histopathology, and microbial examination. The pigs developed a total of 24 osteomyelitic lesions, 4 lesions characterized as contiguous abscesses and pulmonary abscesses (in two pigs). By comparing the 24 osteomyelitic lesions, (18)F-FDG accumulated in 100%, (111)In-leukocytes in 79%, (11)C-methionine in 79%, (11)C-donepezil in 58%, and (99m)Tc-DPD in none. Overall, (18)F-FDG PET was superior to (111)In-leukocyte SPECT and (11)C-methionine in marking infectious lesions
Upper-Room Ultraviolet Light and Negative Air Ionization to Prevent Tuberculosis Transmission
Background Institutional tuberculosis (TB) transmission is an important public health problem highlighted by the HIV/AIDS pandemic and the emergence of multidrug- and extensively drug-resistant TB. Effective TB infection control measures are urgently needed. We evaluated the efficacy of upper-room ultraviolet (UV) lights and negative air ionization for preventing airborne TB transmission using a guinea pig air-sampling model to measure the TB infectiousness of ward air. Methods and Findings For 535 consecutive days, exhaust air from an HIV-TB ward in Lima, Perú, was passed through three guinea pig air-sampling enclosures each housing approximately 150 guinea pigs, using a 2-d cycle. On UV-off days, ward air passed in parallel through a control animal enclosure and a similar enclosure containing negative ionizers. On UV-on days, UV lights and mixing fans were turned on in the ward, and a third animal enclosure alone received ward air. TB infection in guinea pigs was defined by monthly tuberculin skin tests. All guinea pigs underwent autopsy to test for TB disease, defined by characteristic autopsy changes or by the culture of Mycobacterium tuberculosis from organs. 35% (106/304) of guinea pigs in the control group developed TB infection, and this was reduced to 14% (43/303) by ionizers, and to 9.5% (29/307) by UV lights (both p < 0.0001 compared with the control group). TB disease was confirmed in 8.6% (26/304) of control group animals, and this was reduced to 4.3% (13/303) by ionizers, and to 3.6% (11/307) by UV lights (both p < 0.03 compared with the control group). Time-to-event analysis demonstrated that TB infection was prevented by ionizers (log-rank 27; p < 0.0001) and by UV lights (log-rank 46; p < 0.0001). Time-to-event analysis also demonstrated that TB disease was prevented by ionizers (log-rank 3.7; p = 0.055) and by UV lights (log-rank 5.4; p = 0.02). An alternative analysis using an airborne infection model demonstrated that ionizers prevented 60% of TB infection and 51% of TB disease, and that UV lights prevented 70% of TB infection and 54% of TB disease. In all analysis strategies, UV lights tended to be more protective than ionizers. Conclusions Upper-room UV lights and negative air ionization each prevented most airborne TB transmission detectable by guinea pig air sampling. Provided there is adequate mixing of room air, upper-room UV light is an effective, low-cost intervention for use in TB infection control in high-risk clinical settings
Coronary Atherosclerosis Phenotypes in Focal and Diffuse Disease.
The interplay between coronary hemodynamics and plaque characteristics remains poorly understood.
The aim of this study was to compare atherosclerotic plaque phenotypes between focal and diffuse coronary artery disease (CAD) defined by coronary hemodynamics.
This multicenter, prospective, single-arm study was conducted in 5 countries. Patients with functionally significant lesions based on an invasive fractional flow reserve ≤0.80 were included. Plaque analysis was performed by using coronary computed tomography angiography and optical coherence tomography. CAD patterns were assessed using motorized fractional flow reserve pullbacks and quantified by pullback pressure gradient (PPG). Focal and diffuse CAD was defined according to the median PPG value.
A total of 117 patients (120 vessels) were included. The median PPG was 0.66 (IQR: 0.54-0.75). According to coronary computed tomography angiography analysis, plaque burden was higher in patients with focal CAD (87% ± 8% focal vs 82% ± 10% diffuse; P = 0.003). Calcifications were significantly more prevalent in patients with diffuse CAD (Agatston score per vessel: 51 [IQR: 11-204] focal vs 158 [IQR: 52-341] diffuse; P = 0.024). According to optical coherence tomography analysis, patients with focal CAD had a significantly higher prevalence of circumferential lipid-rich plaque (37% focal vs 4% diffuse; P = 0.001) and thin-cap fibroatheroma (TCFA) (47% focal vs 10% diffuse; P = 0.002). Focal disease defined by PPG predicted the presence of TCFA with an area under the curve of 0.73 (95% CI: 0.58-0.87).
Atherosclerotic plaque phenotypes associate with intracoronary hemodynamics. Focal CAD had a higher plaque burden and was predominantly lipid-rich with a high prevalence of TCFA, whereas calcifications were more prevalent in diffuse CAD. (Precise Percutaneous Coronary Intervention Plan [P3]; NCT03782688)
Phosphoproteome profiling reveals critical role of JAK-STAT signaling in maintaining chemoresistance in breast cancer
The yeast P5 type ATPase, Spf1, regulates manganese transport into the endoplasmic reticulum
The endoplasmic reticulum (ER) is a large, multifunctional and essential organelle. Despite intense research, the function of more than a third of ER proteins remains unknown even in the well-studied model organism Saccharomyces cerevisiae. One such protein is Spf1, which is a highly conserved, ER localized, putative P-type ATPase. Deletion of SPF1 causes a wide variety of phenotypes including severe ER stress suggesting that this protein is essential for the normal function of the ER. The closest homologue of Spf1 is the vacuolar P-type ATPase Ypk9 that influences Mn2+ homeostasis. However in vitro reconstitution assays with Spf1 have not yielded insight into its transport specificity. Here we took an in vivo approach to detect the direct and indirect effects of deleting SPF1. We found a specific reduction in the luminal concentration of Mn2+ in ∆spf1 cells and an increase following it’s overexpression. In agreement with the observed loss of luminal Mn2+ we could observe concurrent reduction in many Mn2+-related process in the ER lumen. Conversely, cytosolic Mn2+-dependent processes were increased. Together, these data support a role for Spf1p in Mn2+ transport in the cell. We also demonstrate that the human sequence homologue, ATP13A1, is a functionally conserved orthologue. Since ATP13A1 is highly expressed in developing neuronal tissues and in the brain, this should help in the study of Mn2+-dependent neurological disorders
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Evidence both L-type and non-L-type voltage-dependent calcium channels contribute to cerebral artery vasospasm following loss of NO in the rat
We recently found block of NO synthase in rat middle cerebral artery caused spasm, associated with depolarizing oscillations in membrane potential (Em) similar in form but faster in frequency (circa 1 Hz) to vasomotion. T-type voltage-gated Ca2+ channels contribute to cerebral myogenic tone and vasomotion, so we investigated the significance of T-type and other ion channels for membrane potential oscillations underlying arterial spasm. Smooth muscle cell membrane potential (Em) and tension were measured simultaneously in rat middle cerebral artery. NO synthase blockade caused temporally coupled depolarizing oscillations in cerebrovascular Em with associated vasoconstriction. Both events were accentuated by block of smooth muscle BKCa. Block of T-type channels or inhibition of Na+/K+-ATPase abolished the oscillations in Em and reduced vasoconstriction. Oscillations in Em were either attenuated or accentuated by reducing [Ca2+]o or block of KV, respectively. TRAM-34 attenuated oscillations in both Em and tone, apparently independent of effects against KCa3.1. Thus, rapid depolarizing oscillations in Em and tone observed after endothelial function has been disrupted reflect input from T-type calcium channels in addition to L-type channels, while other depolarizing currents appear to be unimportant. These data suggest that combined block of T and L-type channels may represent an effective approach to reverse cerebral vasospasm
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