249 research outputs found

    Enumerating the Digitally Convex Sets of Powers of Cycles and Cartesian Products of Paths and Complete Graphs

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    Given a finite set VV, a convexity C\mathscr{C}, is a collection of subsets of VV that contains both the empty set and the set VV and is closed under intersections. The elements of C\mathscr{C} are called convex sets. The digital convexity, originally proposed as a tool for processing digital images, is defined as follows: a subset S⊆V(G)S\subseteq V(G) is digitally convex if, for every v∈V(G)v\in V(G), we have N[v]⊆N[S]N[v]\subseteq N[S] implies v∈Sv\in S. The number of cyclic binary strings with blocks of length at least kk is expressed as a linear recurrence relation for k≄2k\geq 2. A bijection is established between these cyclic binary strings and the digitally convex sets of the (k−1)th(k-1)^{th} power of a cycle. A closed formula for the number of digitally convex sets of the Cartesian product of two complete graphs is derived. A bijection is established between the digitally convex sets of the Cartesian product of two paths, Pn□PmP_n \square P_m, and certain types of n×mn \times m binary arrays.Comment: 16 pages, 3 figures, 1 tabl

    Seerratus Anterior Plane Block (SAPB) Improves Paine Control in Rib Fractures

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    Background: ‱Trauma is a major cause of morbidity and mortality worldwide. Rib fractures are identified in at least 10% of all injured patients. ‱Rib fractures can lead to significant respiratory complications, with pneumonia and respiratory failure occurring in up to 31% of patients with rib fractures. Early initiation of aggressive pain control and pulmonary hygiene with incentive spirometry are standard of care to prevent complications from developing. ‱In the Emergency Department, patients with rib fractures typically receive systemic analgesia that is largely narcotic-based. This pain control strategy puts patients at risk for the side effects of narcotics such as constipation, delirium, and opioid addiction. ‱Regional ultrasound-guided anesthesia is well within the purview of emergency physicians and offers a safe and effective alternative to systemic pain medications. A regional block known as the Serratus Anterior Plane Block (SAPB) was described in the anesthesia literature in 2013 as a strategy for improving pain related to rib fractures. ‱The literature evaluating the effectiveness of the SAPB is limited to case reports with a small number of patients (n = 1-6). No published studies have assessed incentive spirometry performance in patients who have received the SAPB, described the systemic analgesia required by patients who have received the SAPB, or formally evaluated the safety of the SAPB

    Air quality simulations for London using a coupled regional-to-local modelling system

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    A coupled regional-to-local modelling system comprising a regional chemistry–climate model with 5km horizontal resolution (EMEP4UK) and an urban dispersion and chemistry model with explicit road source emissions (ADMS-Urban) has been used to simulate air quality in 2012 across London. The study makes use of emission factors for NOx and NO2 and non-exhaust emission rates of PM10 and PM2.5 which have been adjusted compared to standard factors to reflect real-world emissions, with increases in total emissions of around 30% for these species. The performance of the coupled model and each of the two component models is assessed against measurements from background and near-road sites in London using a range of metrics concerning annual averages, high hourly average concentrations and diurnal cycles. The regional model shows good performance compared to measurements for background sites for these metrics, but under-predicts concentrations of all pollutants except O3 at near-road sites due to the low resolution of input emissions and calculations. The coupled model shows good performance at both background and near-road sites, which is broadly comparable with that of the urban model that uses measured concentrations as regional background, except for PM2.5 where the under-prediction of the regional model causes the coupled model to also under-predict concentrations. Using the coupled model, it is estimated that 13% of the area of London exceeded the EU limit value of 40”gm−3 for annual average NO2 in 2012, whilst areas of exceedances of the annual average limit values of 40 and 25”gm−3 for PM10 and PM2.5 respectively were negligible

    Automatic pharynx and larynx cancer segmentation framework (PLCSF) on contrast enhanced MR images

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    A novel and effective pharynx and larynx cancer segmentation framework (PLCSF) is presented for automatic base of tongue and larynx cancer segmentation from gadolinium-enhanced T1-weighted magnetic resonance images (MRI). The aim of the proposed PLCSF is to assist clinicians in radiotherapy treatment planning. The initial processing of MRI data in PLCSF includes cropping of region of interest; reduction of artefacts and detection of the throat region for the location prior. Further, modified fuzzy c-means clustering is developed to robustly separate candidate cancer pixels from other tissue types. In addition, region-based level set method is evolved to ensure spatial smoothness for the final segmentation boundary after noise removal using non-linear and morphological filtering. Validation study of PLCSF on 102 axial MRI slices demonstrate mean dice similarity coefficient of 0.79 and mean modified Hausdorff distance of 2.2 mm when compared with manual segmentations. Comparison of PLCSF with other algorithms validates the robustness of the PLCSF. Inter- and intra-variability calculations from manual segmentations suggest that PLCSF can help to reduce the human subjectivity

    The activity of cAMP-Phosphodiesterase 4D7 (PDE4D7) is regulated by protein kinase A-dependent phosphorylation within its unique N-terminus

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    The cyclic AMP phosphodiesterases type 4 (PDE4s) are expressed in a cell specific manner, with intracellular targeting directed by unique N-terminal anchor domains. All long form PDE4s are phosphorylated and activated by PKA phosphorylation within their upstream conserved region 1 (UCR1). Here, we identify and characterise a novel PKA site (serine 42) within the N-terminal region of PDE4D7, an isoform whose activity is known to be important in prostate cancer progression and ischemic stroke. In contrast to the UCR1 site, PKA phosphorylation of the PDE4D7 N-terminus appears to occur constitutively and inhibits PDE4 activity to allow cAMP signalling under basal conditions

    COVID Aftermath: The Impact of the Pandemic on Florida\u27s Public School Students

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    The goal of this White Paper is to provide an overview of the current and future impacts the COVID-19 pandemic (“COVID”) has left on Florida’s public school education system. Additionally, this White Paper review shows how public education institutions are still working to address the loss of instructional time and long-term consequences due to pandemic-related school disruptions

    Epidemiology of Traumatic Posterior Hip Instability in the National Football League

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    BACKGROUND There is a paucity of literature regarding injury incidence, mechanism, and return to play in National Football League (NFL) players who have sustained traumatic posterior hip instability. PURPOSE To describe the incidence of traumatic posterior hip instability and the rate of return to play in NFL players across 18 seasons. STUDY DESIGN Descriptive epidemiology study. METHODS We retrospectively assessed all traumatic posterior hip dislocations/subluxations that occurred during football-related activities in the NFL seasons from 2000 through 2017. Player demographics and injury data (injury mechanism, season of injury, treatment, days missed, and return to play time) were collected from all 32 NFL teams prospectively through a leaguewide electronic health record system. Descriptive statistics are presented. RESULTS Across the 18 NFL seasons, 16 posterior hip instability injuries in 14 players were reported, with a maximum incidence of 4 (25%) in 2013. Posterior hip instability was predominantly sustained by offensive players (64.3%), with tight ends being the most affected (31.3%). Half of the injuries occurred during the regular season, 43.8% in the preseason, and 6.2% in the offseason. Of all injuries, 37.5% were noncontact, while 56.3% involved contact (direct or indirect), and 6.2% were of unknown mechanism. Among noncontact injuries, 66.7% occurred during cutting and change of direction while sprinting. The time of return to full participation was documented for 11 of the 16 reported injuries (68.8%); among them, the mean time loss was 136.7 ± 83.8 days-143.3 ± 99.6 days if the player underwent surgery (n = 4) and 116.7 ± 76.2 days missed by players without surgery (n = 6)-the treatment modality was unknown in 1 player. CONCLUSION Although the incidence of traumatic posterior hip instability during the study period was low, all injured athletes missed time from football activities and competitions. Injuries that required surgery led to more missed time than those that did not. Ongoing research to understand risk factors and mechanisms of this injury, in conjunction with improvements to prevention and rehabilitation protocols, is necessary to ensure the safety of professional American football players

    Compact [C II] emitters around a C IV absorption complex at redshift 5.7

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    The physical conditions of the circumgalactic medium are probed by intervening absorption-line systems in the spectrum of background quasi-stellar objects out to the epoch of cosmic reionization. A correlation between the ionization state of the absorbing gas and the nature of the nearby galaxies has been suggested by the sources detected either in Lyalpha or [C ii] 158 m near to respectively highly-ionized and neutral absorbers. This is also likely linked to the global changes in the incidence of absorption systems of different types and the process of cosmic reionization. Here we report the detection of two [C ii]-emitting galaxies at redshift z∌5.7z \sim 5.7 that are associated with a complex high-ionization C iv absorption system. These objects are part of an overdensity of galaxies and have compact sizes (< 2.4 kpc) and narrow line widths (FWHM ∌\sim 62--64 km s-1). Hydrodynamic simulations predict that similar narrow [C ii] emission may arise from the heating of small (â‰Č\lesssim 3 kpc) clumps of cold neutral medium or a compact photodissociation region. The lack of counterparts in the rest-frame ultraviolet indicates severe obscuration of the sources that are exciting the [C ii] emission. These results may suggest a connection between the properties of the [C ii] emission, the rare overdensity of galaxies and the unusual high ionization state of the gas in this region.Comment: Published in Nature on 10 May 2023; authors' version; link to the paper: https://www.nature.com/articles/s41586-023-05901-

    EIGER I. a large sample of [OIII]-emitting galaxies at 5.3<z<6.95.3 < z < 6.9 and direct evidence for local reionization by galaxies

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    We present a first sample of 117 [OIII]λλ\lambda\lambda4960,5008-selected star-forming galaxies at 5.33<z<6.935.33 < z < 6.93 detected in JWST/NIRCam 3.5ÎŒ\mum slitless spectroscopy of a 6.5×3.46.5 \times 3.4 arcmin2^2 field centered on the hyperluminous quasar SDSS J0100+2802, obtained as part of the EIGER (Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization) survey. Three prominent galaxy overdensities are observed, one of them at the redshift of the quasar. Galaxies are found within 200 pkpc and 105 km s−1^{-1} of four known metal absorption-line systems in this redshift range. We focus on the role of the galaxies in ionizing the surrounding intergalactic medium (IGM) during the later stages of cosmic reionization and construct the mean Lyα\alpha and LyÎČ\beta transmission as a function of distance from the galaxies. At the lowest redshifts in our study, 5.3<z<5.75.3 < z < 5.7, the IGM transmission rises monotonically with distance from the galaxies. This is as expected when galaxies reside at peaks in the overdensity field of an IGM that is ionized by more or less uniform ionizing background, and has been seen at lower redshifts. In contrast, at 5.7<z<6.145.7 < z < 6.14, the transmission of both Lyα\alpha and LyÎČ\beta first increases with distance, but then peaks at a distance of 5 cMpc before declining. This peak in transmission is qualitatively similar to that seen (albeit at smaller distances and higher redshifts) in the THESAN simulations. Finally, in the region 6.15<z<6.266.15 < z < 6.26 where the additional ionizing radiation from the quasar dominates, the monotonic increase in transmission with distance is re-established. This result is interpreted to represent evidence that the transmission of the IGM at z∌5.9z \sim 5.9 towards J0100+2802 results from the ``local'' ionizing radiation of galaxies that dominates over the much reduced cosmic background.Comment: 24 pages, 14 figures, submitted to ApJ, comments welcom
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