Mean Density Research Articles

Post-fire Pinus radiata invasion in a threatened biodiversity hotspot forest: A multi-scale remote sensing assessment

Biological invasions are one of the most relevant factors of biodiversity loss, especially after fire disturbances. Wildfires can accelerate invasions of fire-prone species, like Pinus radiata, and dramatically alter ecosystems. However, how to assess the main impacts of this invasion process on the composition, structure, and functionality of ecosystems, including the post-fire revegetation processes, has not been fully resolved. This study aimed to evaluate the impacts of P. radiata invasion on fire-damaged forest ecosystems using combined remote sensing and in situ data, focusing particularly on changes in biodiversity, ecosystem structure, and functionality. The recovery of forest leaf area index (LAI) and the fraction of photosynthetically active radiation (FPAR) were monitored using Sentinel-2 time series products. Then the pre- and post-fire native community composition and the relationships of invasion and biodiversity with biotic and abiotic components were characterized using structural equation modeling (SEM). The postfire P. radiata density was mapped to quantify invasion intensity in three burned native forest fragments using generalized additive modeling (GAM) regressions based on UAS multispectral data. Biophysical metrics indicate that all forest fragments impacted by high, medium-high, and medium-low severity fires achieved a partial recovery of their canopy. The SEM model showed that microtopographic features and vegetation height explain native species diversity under pre-fire conditions due to their close relationship with favorable microclimatic conditions for species establishment. Vegetation height determined the abundance of P. radiata in post-fire conditions, and it negatively impacted diversity by promoting the homogenization of vegetation cover and altering diversity patterns. The general composition and abundance metrics also showed a substantial modification associated with the heavy (significant) invasion of P. radiata species. Predictive mapping of P. radiata density showed high accuracies (R2 =0.73 and explained deviation of 80%). The maps depicted an intense concentration of the invasive tree with a mean density of 76,217 individuals per ha−1 and high invasion spots with more than 176,000 individuals per ha−1. The quantification of invasion and mapping is a fundamental input for prioritizing areas and resources for a large-scale restoration program, and is a priority to avoid the loss of these highly threatened forest ecosystems.

Quest for the golden ratio universality class.

Using mode-coupling theory, the conditions for all allowed dynamical universality classes for the conserved modes in one-dimensional driven systems are presented in closed form as a function of the stationary currents and their derivatives. With an eye on the search for the golden ratio universality class, the existence of some families of microscopic models is ruled out a priori by using an Onsager-type macroscopic current symmetry. In particular, if the currents are symmetric or antisymmetric under the interchange of the conserved densities, then at equal mean densities the golden modes can only appear in the antisymmetric case and if the conserved quantities are correlated, but not in the symmetric case where at equal densities one mode is always diffusive and the second may be either Kardar-Parisi-Zhang (KPZ), modified KPZ, 3/2-Lévy, or also diffusive. We also show that the predictions of mode-coupling theory for a noisy chain of harmonic oscillators are exact.

Pulmonary volumes and signs of chronic airflow limitation in quantitative computed tomography.

Computed tomography (CT) offers pulmonary volumetric quantification but is not commonly used in healthy individuals due to radiation concerns. Chronic airflow limitation (CAL) is one of the diagnostic criteria for chronic obstructive pulmonary disease (COPD), where early diagnosis is important. Our aim was to present reference values for chest CT volumetric and radiodensity measurements and explore their potential in detecting early signs of CAL. From the population-based Swedish CArdioPulmonarybioImage Study (SCAPIS), 294 participants aged 50-64, were categorized into non-CAL (n = 258) and CAL (n = 36) groups based on spirometry. From inspiratory and expiratory CT images we compared lung volumes, mean lung density (MLD), percentage of low attenuation volume (LAV%) and LAV cluster volume between groups, and against reference values from static pulmonary function test (PFT). The CAL group exhibited larger lung volumes, higher LAV%, increased LAV cluster volume and lower MLD compared to the non-CAL group. Lung volumes significantly deviated from PFT values. Expiratory measurements yielded more reliable results for identifying CAL compared to inspiratory. Using a cut-off value of 0.6 for expiratory LAV%, we achieved sensitivity, specificity and positive/negative predictive values of 72%, 85% and 40%/96%, respectively. We present volumetric reference values from inspiratory and expiratory chest CT images for a middle-aged healthy cohort. These results are not directly comparable to those from PFTs. Measures of MLD and LAV can be valuable in the evaluation of suspected CAL. Further validation and refinement are necessary to demonstrate its potential as a decision support tool for early detection of COPD.

Anomalous Resistivity and Electron Heating by Lower Hybrid Drift Waves during Magnetic Reconnection with a Guide Field.

The lower hybrid drift wave (LHDW) has been a candidate for anomalous resistivity and electron heating inside the electron diffusion region of magnetic reconnection. In a laboratory reconnection layer with a finite guide field, quasielectrostatic LHDW (ES-LHDW) propagating along the direction nearly perpendicular to the local magnetic field is excited in the electron diffusion region. ES-LHDW generates large density fluctuations (δn_{e}, about 25% of the mean density) that are correlated with fluctuations in the out-of-plane electric field (δE_{Y}, about twice larger than the mean reconnection electric field). With a small phase difference (∼30°) between two fluctuating quantities, the anomalous resistivity associated with the observed ES-LHDW is twice larger than the classical resistivity and accounts for 20% of the mean reconnection electric field. After we verify the linear relationship between δn_{e} and δE_{Y}, anomalous electron heating by LHDW is estimated by a quasilinear analysis. The estimated electron heating is about 2.6±0.3 MW/m^{3}, which exceeds the classical Ohmic heating of about 2.0±0.2 MW/m^{3}. This LHDW-driven heating is consistent with the observed trend of higher electron temperatures when the wave amplitude is larger. Presented results provide the first direct estimate of anomalous resistivity and electron heating power by LHDW, which demonstrates the importance of wave-particle interactions in magnetic reconnection.

Population and distribution change of Eurasian Woodcocks Scolopax rusticola breeding in the UK: results of the 2023 Breeding Woodcock Survey

ABSTRACT Capsule The UK breeding population estimate comprised 50,750 male Eurasian Woodcocks (95% CI: 42,935–59,251) in Britain and 937 males (95% CI: 274–1714) in Northern Ireland. The British population has continued to decline since 2013. Aim To produce UK, British and regional estimates of breeding population size for Eurasian Woodcocks, and to assess the population change since 2003. Methods The 2023 Breeding Woodcock Survey enlisted volunteer surveyors to count birds across a stratified sample of 1230 squares in England, Scotland, Wales, and Northern Ireland. The established ‘roding count’ methodology consists of up to three dusk visits, each lasting 75 min, during May and/or June. The results were used to calculate presence and mean density across 48 strata based on wooded area and regions, and extrapolated to produce regional and national estimates of population size. Results The population in Britain in 2023 was estimated at 50,750 male Woodcocks (95 CI: 42,935–59,251), representing an 8% decline since 2013, and a 35% decline since 2003. Despite small population increases in Wales and England since 2013, the continuing decline was driven by a 49.5% reduction in the population estimate for North Scotland. In 2023, Northern Ireland’s breeding population of Eurasian Woodcocks was estimated at 937 males (95% CI: 274–1714), which is the first estimate produced using this species-specific method. Conclusion Nationally, populations of Eurasian Woodcocks continue to decline, but the 2013–2023 declines were not as severe as those recorded between 2003 and 2013. The diverging population trends between North Scotland and the rest of Britain raise questions regarding regional variation in habitat suitability/availability and factors influencing overwinter survival. Recommendations are made for future versions of the Breeding Woodcock Survey regarding the composition of the random sample of squares, the treatment of incomplete data, and the sampling of non-woodland habitat.

Attention and executive function impairments in obstructive sleep apnea are associated with decreased sleep spindles.

Sleep spindles play a key role in sleep-mediated cognitive processes. Cognitive functions are well-known to be affected in obstructive sleep apnea (OSA). Here, we analyzed attention and executive functions in patients with OSA and investigated the relationship between sleep spindles and cognitive abilities. Sixty patients with OSA (18-65years, 19 females and 41 males) and a control group (n = 41) including age-and sex-matched healthy individuals were consecutively and prospectively enrolled. All participants had a full-night polysomnography, and sleep spindles were analyzed using a semi-automated program. For the evaluation of short-term memory, attention and executive functions, Stroop test, forward and backward digit span tests were applied to all participants upon awakening following polysomnography. Scores of forward and backward digit span and Stroop tests were worse in OSA patients in compared to those in controls. Mean density of sleep spindles was decreased in OSA patients than those in controls (p = 0.044). A positive correlation was found between fast sleep spindle frequency and forward digit span (r = 2.222; p = 0.038) and backward digit span test scores (r = 2,157; p = 0.042) in OSA patients. In patients with moderate to severe OSA, sleep spindle density was positively correlated with forward (r = 2.323, p = 0.029) and backward (r = 2.500, p = 0.016) DSTs, and the duration of sleep spindles had positive correlation with backward DST (r = 2.452, p = 0.010). Our findings demonstrated that the disturbances in sleep spindle characteristics in OSA are associated with the cognitive impairments in attention, short-term memory, and executive functions, especially in patients with moderate to severe OSA.

Compton Scattering of Electrons in the Intergalactic Medium

This paper investigates the distribution and implications of cosmic-ray electrons within the intergalactic medium (IGM). Utilizing a synthesis model of the extragalactic background, we evolve the spectrum of Compton-included cosmic rays. The energy density distribution of cosmic-ray electrons peaks at redshift z ≈ 2, and peaks in the ∼MeV range. The fractional contribution of cosmic-ray pressure to the general IGM pressure progressively increases toward lower redshift. At mean density, the ratio of cosmic-ray electron to thermal pressure in the IGM PCRe/Pth is 0.3% at z = 2, rising to 1.0% at z = 1, and 1.8% at z = 0.1 (considering only the cosmic rays produced locally by Compton scattering). We compute the linear Landau damping rate of plasma oscillations in the IGM caused by the ∼MeV cosmic-ray electrons, and find it to be of order ∼10−6 s−1 for wavenumbers 1.2 ≲ ck/ω p ≲ 5 at z = 2 and mean density (where ω p is the plasma frequency). This strongly affects the fate of TeV e + e − pair beams produced by blazars, which are potentially unstable to oblique instabilities involving plasma oscillations with wavenumber ck/ωp≈secθ (θ being the angle between the beam and wavevector). Linear Landau damping is at least thousands of times faster than either pair beam instability growth or collisional effects; it thus turns off the pair beam instability except for modes with very small θ (ck/ω p → 1, where linear Landau damping is kinematically suppressed). This leaves open the question of whether the pair beam instability is turned off entirely, or can still proceed via the small-θ modes.

Splitting the spacetime: a systematic analysis of foliation dependence in cosmic averaging

It is a fundamental unsolved question in general relativity how to unambiguously characterize the effective collective dynamics of an ensemble of fluid elements sourcing the local geometry, in the absence of exact symmetries.In a cosmological context this is sometimes referred to as the averaging problem.At the heart of this problem in relativity is the non-uniqueness of the choice of foliation within which the statistical properties of the local spacetime are quantified,which can lead to ambiguity in the formulated average theory. This has led to debate in the literature on how to best construct and view such a coarse-grained hydrodynamic theory.Here, we address this ambiguity by performing the first quantitative investigation of foliation dependence in cosmological spatial averaging. Starting from the aim of constructing slicing-independent integral functionals (volume, mass, entropy, etc.) as well as average functionals (mean density, average curvature, etc.) defined on spatial volume sections, we investigate infinitesimal foliation variations and derive results on the foliation dependence of functionals and on extremal leaves.Our results show that one may only identify fully foliation-independent integral functionals in special scenarios, requiring the existence of associated conserved currents.We then derive bounds on the foliation dependence of integral functionals for general scalar quantities under finite variations within physically motivated classes of foliations.Our findings provide tools that are useful for quantifying, eliminating or constraining the foliation dependence in cosmological averaging.

Salivary Calprotectin Levels and Bone Mineral Density in Post-Menopausal Women With and Without Chronic Periodontitis - An Evaluative Study.

Menopause is a normal developmental stage in a woman's life marking the permanent cessation of menstruation. Periodontitis and osteoporosis are noteworthy health concerns in post-menopausal women. Calprotectin is an inflammatory biomarker for precise diagnosis of periodontal disease. This study was performed to evaluate the variations in salivary calprotectin levels and bone mineral density in post-menopausal women with and without chronic periodontitis. The study included 24 post-menopausal women aged 45-57 years and was divided into group 1 (12 post-menopausal women without chronic periodontitis) and group 2 (12 post-menopausal women with chronic periodontitis). Unstimulated salivary samples, panoramic radiographs and clinical examination were performed. The collected samples were combined with CALPRO antibody with horseradish peroxide (HRP) that results in the formation of antigen-antibody complex. Tetramethylbenzidine (TMB) solution was added that turned blue. Colour change was measured at 450nm. A human ELISA kit was used. Data collected were sent for statistical analysis. There was a statistically significant difference in salivary calprotectin levels between groups 1 and 2 ( P = 0.016) and no statistical difference in mean bone mineral density levels between the two groups ( P = 0.235). A positive correlation was seen between salivary calprotectin levels and bone mineral density in group 2 ( P = 0.013).

Evaluation and comparison of optical coherence tomography angiography (OCTA) parameters in normal and moderate myopic individuals

ObjectiveThe objective of this study was to evaluate and compare Optical Coherence Tomography Angiography (OCTA) parameters in patients with moderate myopia and healthy individuals retrospectively. MethodsA total of 80 male individuals aged 18–20 years were included in the study with 40 moderate myopic and 40 healthy persons. All participants underwent detailed ocular examination including refraction, intraocular pressure (IOP), visual acuity, biomicroscopy, OCTA measurement and optic biometry measurement. Retinal, retinal nerve fiber layer and choroidal layer thicknesses were evaluated in µm with the help of the software available in the OCTA device. ResultsThe mean axial length (24.32 ± 0.53 mm) was statistically significantly higher in the moderate myopic group (24.32 mm) compared to the healthy group (23.33 ± 0.61 mm) (p < 0.001). Spherical equivalent (SE) was found as -3.79 ± 0.91 D in the moderate myopic group and -0.22 ± 0.32 D in the healthy group (p < 0.05). The mean superficial foveal mean density (FovSupMVD) and the mean deep foveal mean density (FovDepMVD) were statistically significantly lower in the moderate myopic group than in the healthy group (both, p < 0.001). The mean retinal temporal thickness (RTt) was statistically significantly lower in the moderate myopic group (p = 0.017). There was a mild negative correlation between axial length and FovSupMVD, FovDepMVD in myopes. In axial length ROC analysis, the cutoff value for moderate myopes was found to be 24.15 mm. Mean superficial foveal mean density (FovSupMVD) and mean deep foveal mean density (FovDepMVD), mean retinal temporal thickness (RTt) were significantly lower in the group above 24.15 mm axial length compared to the group below 24.15 mm axial length (all three, p < 0.001). Foveal avascular zone was significantly higher in the group above 24.15 mm axial length (p = 0.016) ConclusionThe results of our study indicate that the mean axial length and spherical equivalent were significantly higher, while retinal temporal thickness, the mean superficial foveal mean density and the mean deep foveal mean density were significantly lower in patients with myopia up to -6.0 D compared to the healthy individuals.

Thrombus discrimination with electron density: potential implications for non-contrast computed tomography imaging.

The potential clinical usefulness of electron density (ED) imaging, that can be directly estimated using dual-layer spectral computed tomography (CT), has been poorly investigated. We explored whether ED imaging might improve thrombus identification compared to conventional imaging in vitro. We evaluated mechanical thrombectomy material obtained from patients with acute ischemic stroke (AIS) treated in a tertiary level stroke center and immediately fixed in 10% neutral buffered formalin and stored in polystyrene test tubes. The test tubes were immersed in a bucket of water for evaluation by spectral CT, along with scattered control tubes. All images were obtained using a dual-layer detector CT scanner. Each tube was assessed using multiparametric side-by-side view of conventional CT (120 kVp), low monoenergetic imaging (40 keV), and ED images. Fifty-eight polystyrene tubes were analyzed, comprising 52 tubes with thrombectomy material of at least 1 mm2 size obtained from 52 AIS patients, and six control tubes filled with formalin. ED imaging identified accurately the presence of material in all tubes, whereas 2 (3%) of the tubes containing thrombus were not identified by conventional CT, leading to a very good agreement between observers for the presence of material using conventional CT and ED imaging (kappa =0.84, P<0.001). Using ED imaging, thrombus material showed a mean density of 108.8±2.9 percent ED relative to water (%EDW), water had a mean density of 100.0±0.3 %EDW, and formalin a mean density of 103.5±1.2 %EDW. Compared to conventional imaging and 40 keV monoenergetic, ED imaging had a significantly higher signal-to-noise ratio (conventional 10.4±7.0, vs. 40 keV 11.5±8.4, vs. ED 490.0±304.5, P<0.001) and contrast-to-noise ratio (CNR) (conventional 4.3±4.3, vs. 40 keV 5.7±11.2, vs. ED 37.8±29.1, P<0.001). In this in-vitro study, we demonstrated improved visualization of thrombus with ED imaging compared to conventional imaging and low monoenergetic imaging, with a significant increase in CNR.

The Effect of Location, Time, and Environmental Conditions on Fish Use of Southern Temperate Saltmarshes

Fish use of saltmarsh varies spatially, temporally, and with environmental conditions. The specific impact of these effects on fish assemblages in southern temperate Tasmania, Australia—the only mangrove-free Australian state—is as yet largely unknown. Seasonal variation in fish abundance, richness, diversity, and size was investigated in succulent saltmarshes in three estuaries (Marion Bay, Barilla Bay, and Ralphs Bay) in south-eastern Tasmania. All parameters varied between sampling locations. Greater numbers of fish were recorded at two sites (Marion Bay, mean density and standard error of 396.9 ± 71.3 individuals per 100 m2; Barilla Bay, mean density and standard error of 94.1 ± 30.1 individuals per 100 m2) than have been previously reported in Australian saltmarshes. Fish abundance was greatest in July–August (mean density and standard error of 200.2 ± 49.7 individuals per 100 m2) reflecting the breeding patterns of the numerically dominant Atherinosoma microstoma. Both abundance and species richness responded positively to water temperature in ordinal logistic regression models, and species richness and diversity increased with water depth in the models. It is likely that the strong differences between sampling locations are partly related to differences in water depth and water temperature between the estuaries. They may be also related to the habitat context of each estuary, especially the presence or absence of seagrass. The greater numbers of fish found in the present study relative to abundances reported in mainland Australia may relate to the absence of mangroves and the consequent differences in seascape habitat context, including greater water depths in marshes. Importantly, these results demonstrate that temperate southern hemisphere saltmarshes are year-round habitat for fish, thus emphasising their importance as a fish habitat.

Assessment of stocking, productivity, and aboveground biomass of tree species used as fuelwood in Rwanda's agricultural landscapes

Tree-based systems (TBS) in the agricultural landscape of Rwanda do supply considerable amounts of fuelwood to the local communities. However, there needs to be more information on the available stocking, aboveground biomass (AGB), and productivity of the trees used for fuelwood. The study aims to assess the common tree species used for fuelwood and quantify the biomass stock across various TBS in the agricultural landscape. The study used a systematic sampling design, establishing 130 band transects, each measuring 2 km x 5 m. The transects were systematically distributed across the Bugesera and Musanze Districts, representing low and high-altitude regions. In Bugesera District, the common tree species for fuelwood use were Grevillea robusta, Eucalyptus spp., Senna spectabilis, and Markhamia lutea. The results indicated that the mean stem density and AGB of Eucalyptus spp. and S.spectabilis were substantially higher than other species. Across all TBS categories, trees covered an average stem density of 50 stems/ha and an AGB of 2.07t/ha. The stem density and AGB were substantially higher in boundary plantings and mixed cropping than in other TBS. Most trees in all TBS categories had a DBH ranging from 1 to 5 cm, except for the woodlot, where trees had a DBH ranging between 5.1–10 cm. In Musanze District, the common tree species for fuelwood use were G.robusta, Eucalyptus spp., Alnus acuminata, and M.lutea. The mean stem density, standing AGB, and productivity of Eucalyptus spp. were substantially higher than those of the other species. Across all TBS, trees covered an average stem density of 109 stems/ha and AGB of 5.38t/ha. The number of stems and AGB were substantially higher in boundary plantings and woodlots than in mixed cropping, live fences, and home gardens. Furthermore, the results on fuelwood supply indicated that S.spectabilis in Bugesera and Eucalyptus spp. in Musanze have a higher potential to produce higher biomass in short rotation.

Influence of Layer Thickness and Shade on the Transmission of Light through Contemporary Resin Composites.

Material-dependent parameters have an important impact on the efficiency of light polymerization. The present in vitro study aimed to investigate the influence of the increment thickness and shade of nano- and nanohybrid resin composites on the transmission of curing light. Three contemporary resin composites were evaluated: Tetric EvoCeram® (TEC); Venus Diamond® (VD); and Filtek Supreme XTE® (FS XTE). Light transmission (LT) was recorded in accordance with the sample thickness (0.5 to 2.7 mm) and the shade. Polymerized samples were irradiated for 10 s each using the high-power LED curing light Celalux 2 (1900 mW/cm2). LT was simultaneously recorded using the MARC Patient Simulator (MARC-PS). LT was strongly influenced by the composite layer thickness. For 0.5 mm-thick samples, a mean power density of 735 mW/cm2 was recorded at the bottom side. For the 2.7 mm samples, a mean power density of 107 mW/cm2 was measured. Only LT was markedly reduced in the case of darker shades. From A1 to A4, LT decreased by 39.3% for FS XTE and 50.8% for TEC. Dentin shades of FS XTE and TEC (A2, A4) showed the lowest LT. The thickness and shade of resin composite increments strongly influences the transmission of curing light. More precise information about these parameters should be included in the manufacture manual.

Distribution and composition of floating marine debris in Shiretoko peninsula, Japan, using opportunistic sighting survey

Floating marine debris (FMD) poses several threats to marine species, such as entanglement, ingestion, and the transport of pollutants. The Shiretoko Peninsula, located in northern Japan, is a registered World Natural Heritage Site and a biodiversity hotspot. However, FMD has not yet been thoroughly investigated in this region. In 2022, sighting surveys were conducted in Abashiri (west side of the peninsula) and Rausu (east side) to assess the abundance, composition, and distribution of FMD. The mean densities were notably higher in Abashiri, and there was more fishing-related debris in Rausu. Regarding local human activities, the population and number of tourists are higher in Abashiri, and fishing activities are higher in Rausu. While marine pollution is a global issue, our study suggests that addressing it should commence with community-based management at the local level.

Abstract 6825: Epigenetic dysregulation in well-differentiated pancreatic neuroendocrine tumor (PNET): An immunohistochemistry (IHC) analysis

Abstract Epigenetic dysregulation through DNA Methyltransferase 1 (DNMT1) is integral to pancreatic neuroendocrine tumorigenesis. We aim to investigate the interplay between epigenetic modifiers and pathogenetic markers in the PNET microenvironment. 12 paraffin-embedded PNET specimens and 12 benign adjacent tissue specimens, used as controls, were obtained from Cooper University Hospital Pathology Department (IRB 23-130). IHC was performed using epigenetic markers, including DNMT1, DNMT3A, DNMT3B, and 5-Hydroxymethylcytosine (5-HMC), and pathogenic markers, including Multiple Endocrine Neoplasia 1 (MEN1), Protein-Tyrosine Phosphatase (PTEN), and Ras Association Domain Family 1 (RASSF1). Image J software was utilized for IHC scoring under the guidance of a board-certified pathologist. DNMT1 was upregulated in PNET tumor specimens with a mean density score of 72.02 +/- 31 versus 16.02 +/- 17 in adjacent benign tissue (p&amp;lt;.001). Grade 2 tumors displayed increased DNMT1 expression compared to Grade 1 tumors with a mean score of 37 +/-21 versus 71 +/- 23 (p&amp;lt;.05). Decreased expression of 5-HMC was noted in tumor specimens in comparison to benign tissue with a mean score of 3.92 +/- 5.05 versus 19.37 +/- 5.05 (p&amp;lt;.05). Loss of 5-HMC was observed in higher tumor grades with a mean score of .79 +/- 2 versus 8.2+/-2 (p&amp;lt;.01). DNMT3B was upregulated in PNET tumor specimens with a mean score of 13.16 +/- 3.94 versus 7.02+/- 2.553 (p&amp;lt;.01) in adjacent benign tissue and was positively correlated to DNMT1 expression. DNMT3A was not found to have a difference in expression between tumor and benign tissue. MEN1 was downregulated in PNET, with 45% of tumor specimens displaying loss of MEN1 expression. Mean MEN1 density in tumor tissue was 4.47 +/- 5.95 versus 11.41 +/- 3.53 in adjacent benign (p&amp;lt;.01). Increased expression of DNMT1 found to negatively correlate with MEN1 expression (R2=.23). Loss of RASSF1 expression was present in 70% of tumor specimens with a mean score of 1.32 +/- 1.99 versus 9.50+/- 6.89 (p&amp;lt;.001) in adjacent benign tissue. RASSF1 expression correlated negatively with DNMT1 (R2=.21). PTEN expression showed intratumoral homogeneity to benign tissue, and its expression was not correlated with any epigenetic markers. Our work provides a framework of epigenetic regulators involved in the pathobiology of PNET, and can refine prognostic evaluation while providing therapeutic benefits for patients with PNET. Citation Format: Zena Saleh, Yazid Ghanem, Hansa Joshi, Mathew C. Moccia, Helen Toma, Yahui Li, Upsana Joneja, Tao Gao, Young Hong. Epigenetic dysregulation in well-differentiated pancreatic neuroendocrine tumor (PNET): An immunohistochemistry (IHC) analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6825.

Discoveries and timing of pulsars in M62

ABSTRACT Using MeerKAT, we have discovered three new millisecond pulsars (MSPs) in the bulge globular cluster M62: M62H, M62I, and M62J. All three are in binary systems, which means all ten known pulsars in the cluster are in binaries. M62H has a planetary-mass companion with a median mass Mc, med ∼ 3 MJ and a mean density of ρ ∼ 11 g cm−3. M62I has an orbital period of 0.51 d and a Mc, med ∼ 0.15 M⊙. Neither of these low-mass systems exhibit eclipses. M62J has only been detected in the two Ultra High Frequency band (816 MHz) observations with a flux density S816 = 0.08 mJy. The non-detection in the L-band (1284 MHz) indicates it has a relatively steep spectrum (β &amp;lt; −3.1). We also present 23-yr-long timing solutions obtained using data from the Parkes ‘Murriyang’, Effelsberg, and MeerKAT telescopes for the six previously known pulsars. For all these pulsars, we measured the second spin-period derivatives and the rate of change of orbital period caused by the gravitational field of the cluster, and their proper motions. From these measurements, we conclude that the pulsars’ maximum accelerations are consistent with the maximum cluster acceleration assuming a core-collapsed mass distribution. Studies of the eclipses of the redback M62B and the black widow M62E at four and two different frequency bands, respectively, reveal a frequency dependence with longer and asymmetric eclipses at lower frequencies. The presence of only binary MSPs in this cluster challenges models which suggest that the MSP population of core-collapsed clusters should be dominated by isolated MSPs.

Feasibility and repeatability of ultrasound-guided surface electroenterography to measure colonic slow wave motility in healthy adults

Surface electroenterography is a potential non-invasive alternative to current diagnostics of colonic motility disorders. However, electrode positioning in electroenterography is often based on general anatomy and may lack generalizability. Furthermore, the repeatability of electroenterography measurements is unknown. This study aimed to evaluate ultrasound-guided electrode positioning for electroenterography measurements and to determine the repeatability of those measurements. In ten healthy adults, two electroenterography procedures were performed, consisting of fasting, ultrasound-guided electrode localization and two 20-minute electroenterography recordings separated by a meal. The dominant frequency, the mean power density (magnitude of colonic motility) and the power percent difference (relative pre- to postprandial increase in magnitude) were determined. Repeatability was determined by Lin’s concordance correlation coefficient. The results demonstrated that the dominant frequency did not differ between pre- and postprandial recordings and was 3 cpm, characteristic of colonic motility. The mean power density increased between the pre- and postprandial measurements, with an average difference of over 200%. The repeatability of both the dominant frequency and power density was poor to moderate, whereas the correlation coefficient of the power percent difference was poor. Concluding, ultrasound-guided surface electroenterography seems able to measure the gastrocolic reflex, but the dissatisfactory repeatability necessitates optimization of the measurement protocol.

Long‐Term Variability of Mars' Exosphere Density Based on Precise Orbital Analysis of Mars Reconnaissance Orbiter and Mars Odyssey

AbstractThe variability of Mars exosphere over monthly to solar‐cycle scales at 251 and 412 km altitude is quantified by analysis of 41‐Ls mean densities derived from precise orbit determination of the Mars Reconnaissance Orbiter (MRO) and Mars Odyssey (MO) satellites, respectively. The data encompass 2006–2020 (MRO) and 2002–2020 (MO). At both altitudes, most of the variance is captured by cos(Ls–ϕ), where ϕ ≈ 258°. This term represents the effects of solar heating changes due to the eccentricity of Mars orbit around the Sun, and climatological changes in heating due to lower‐atmosphere dust loading, which does not play a significant role. The remaining variability is connected with the “irregular” variability of solar flux over monthly time scales. For MO, the presence of Helium disrupts a clean correlation with these sources.

Photon-counting CT of degenerative changes and rupture of silicone breast implants: a pilot study

BackgroundAccurate assessment of breast implants is important for appropriate clinical management. We evaluated silicone properties and diagnostic accuracy for characterizing silicone implants and detecting degenerative changes including rupture in photon-counting computed tomography (PCCT).MethodsOver 16 months, we prospectively included patients with silicone implants and available breast magnetic resonance imaging (MRI) who received thoracic PCCT performed in prone position. Consensus reading of all available imaging studies including MRI served as reference standard. Two readers evaluated all implants in PCCT reconstructions for degenerative changes. In a subgroup of implants, mean density of silicone, adjacent muscle, and fat were measured on PCCT reconstructions. Contrast-to-noise ratios (CNRs) were calculated for implant-to-muscle and implant-to-fat.ResultsAmong 21 subjects, aged 60 ± 13.1 years (mean ± standard deviation) with 29 implants PCCT showed the following: high accuracy for linguine sign, intraimplant fluid (all > 0.99), peri-implant silicone (0.95), keyhole sign (0.90), and folds of the membrane (0.81); high specificity for linguine sign, intraimplant fluid, keyhole sign, folds of the membrane (all > 0.99), and peri-implant silicone (0.98); and high sensitivity for linguine sign and intraimplant fluid (all > 0.99). In a subgroup of 12 implants, the highest CNR for implant-to-muscle was observed on virtual unenhanced reconstructions (20.9) and iodine maps (22.9), for implant-to-fat on iodine maps (27.7) and monoenergetic reconstructions (31.8).ConclusionsOur findings demonstrate that silicone breast implants exhibit distinct contrast properties at PCCT, which may provide incremental information for detection of degenerative changes and rupture of implants.Relevance statementThoracic photon-counting computed tomography is a promising modality for the diagnostic assessment of silicone breast implants.Key points• Thoracic photon-counting computed tomography demonstrates unique contrast properties of silicone breast implants.• Iodine map reconstructions reveal strong contrast-to-noise ratios for implant-to-muscle and implant-to-fat.• Thoracic photon-counting computed tomography shows high diagnostic accuracy in detecting implant degeneration and rupture.Trial registrationGerman Clinical Trials Register number DRKS00028997, date of registration 2022–08-08, retrospectively registered.Graphical