Radiative transfer modelling of parsec-scale dusty warped discs

Warped discs have been found on (sub-)parsec scale in some nearby Seyfert nuclei, identified by their maser emission. Using dust radiative transfer simulations we explore their observational signatures in the infrared in order to find out whether they can partly replace the molecular torus. Strong variations of the brightness distributions are found, depending on the orientation of the warp with respect to the line of sight. Whereas images at short wavelengths typically show a disc-like and a point source component, the warp itself only becomes visible at far-infrared wavelengths. A similar variety is visible in the shapes of the spectral energy distributions. Especially for close to edge-on views, the models show silicate feature strengths ranging from deep absorption to strong emission for variations of the lines of sight towards the warp. To test the applicability of our model, we use the case of the Circinus galaxy, where infrared interferometry has revealed a highly elongated emission component matching a warped maser disc in orientation and size. Our model is for the first time able to present a physical explanation for the observed dust morphology as coming from the AGN heated dust. As opposed to available torus models, a warped disc morphology produces a variety of silicate feature shapes for grazing lines of sight, close to an edge-on view. This could be an attractive alternative to a claimed change of the dust composition for the case of the nearby Seyfert 2 galaxy NGC 1068, which harbours a warped maser disc as well.Comment: accepted by MNRA

The Relationship between Socio Economic Status, Personality Traits and Spouse Abuse of Married Secondary School Teachers in Delta State

This study investigated the relationship between socio economic status, personality traits and spouse abuse of married secondary school teachers in Delta State. The population of the study consist of married teachers in public secondary schools in Delta Central Senatorial District of Delta State. The sample comprised of 300 married men and 300 married women, giving a total of 600 married persons. The study used simple random sampling technique to select the schools and stratified proportional sampling to draw the sample. Six research hypotheses were used for the study. The design for the study was correlational research design. The instrument for the study was a questionnaire titled Spousal Abuse Scale (SAS). The instrument was validated and had a reliability level of 0.85. Data was analysed using regression statistics. Findings revealed that traits of openness, conscientiousness, agreeableness and neuroticism has significant relationship with spouse abuse among couples. Socio-economic status and extraversion had no significant relationship with spouse abuse among couples. It was however recommended that Counselor Educators should equip those in training with relevant skills so that they can assist both abusers and victims to acquire positive behaviour and relate with each other positively. Practicing counselors can assist the victims to identify the weak behavioural pattern and strengthen same so that they can overcome the abusive behaviour of the partners. Also the Counseling Association of Nigeria (CASSON) in each State should organized seminars, conference and workshops on regular basis to keep married men and women abreast on the consequences of spouse abuse

X-ray dark-field tomography reveals tooth cracks

Abstract Cracked tooth syndrome (CTS) is a common clinical finding for teeth, it affects about 5% of all adults each year. The finding of CTS is favored by several risk factors such as restorations, bruxism, occlusion habits, and age. Treatment options range, depending on the severity, from no treatment at all to tooth extraction. Early diagnosis of CTS is crucial for optimal treatment and symptom reduction. There is no standard procedure for an evidence-based diagnosis up to date. The diagnosis is a challenge by the fact that the symptoms, including pain and sensitivity to temperature stimuli, cannot be clearly linked to the disease. Commonly used visual inspection does not provide in-depth information and is limited by the resolution of human eyes. This can be overcome by magnifying optics or contrast enhancers, but the diagnosis will still strongly rely on the practicians experience. Other methods are symptom reproduction with percussions, thermal pulp tests or bite tests. Dental X-ray radiography, as well as computed tomography, rarely detect cracks as they are limited in resolution. Here, we investigate X-ray dark-field tomography (XDT) for the detection of tooth microcracks. XDT simultaneously detects X-ray small-angle scattering (SAXS) in addition to the attenuation, whereas it is most sensitive to the micrometer regime. Since SAXS originates from gradients in electron density, the signal is sensitive to the sample morphology. Microcracks create manifold interfaces which lead to a strong signal. Therefore, it is possible to detect structural changes originating from subpixel-sized structures without directly resolving them. Together with complementary attenuation information, which visualizes comparatively large cracks, cracks are detected on all length-scales for a whole tooth in a non-destructive way. Hence, this proof-of principle study on three ex-vivo teeth shows the potential of X-ray scattering for evidence-based detection of cracked teeth

Inter-fractional Respiratory Motion Modelling from Abdominal Ultrasound: A Feasibility Study

Motion management strategies are crucial for radiotherapy of mobile tumours in order to ensure proper target coverage, save organs at risk and prevent interplay effects. We present a feasibility study for an inter-fractional, patient-specific motion model targeted at active beam scanning proton therapy. The model is designed to predict dense lung motion information from 2D abdominal ultrasound images. In a pretreatment phase, simultaneous ultrasound and magnetic resonance imaging are used to build a regression model. During dose delivery, abdominal ultrasound imaging serves as a surrogate for lung motion prediction. We investigated the performance of the motion model on five volunteer datasets. In two cases, the ultrasound probe was replaced after the volunteer has stood up between two imaging sessions. The overall mean prediction error is 2.9 mm and 3.4 mm after repositioning and therefore within a clinically acceptable range. These results suggest that the ultrasound-based regression model is a promising approach for inter-fractional motion management in radiotherapy

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing

Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time $t$. Changes in the tensile stress, mode of failure and interfacial fracture energy $G_I$ are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small $t$ welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy $G_I$ is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average bulk fracture energy $G_b$. As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, $G_I$ is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and $G_I \ll G_b$

Conversion of hydroperoxides to carbonyls in field and laboratory instrumentation: Observational bias in diagnosing pristine versus anthropogenically controlled atmospheric chemistry

Atmospheric volatile organic compound (VOC) oxidation mechanisms under pristine (rural/remote) and urban (anthropogenically-influenced) conditions follow distinct pathways due to large differences in nitrogen oxide (NO_x) concentrations. These two pathways lead to products that have different chemical and physical properties and reactivity. Under pristine conditions, isoprene hydroxy hydroperoxides (ISOPOOHs) are the dominant first-generation isoprene oxidation products. Utilizing authentic ISOPOOH standards, we demonstrate that two of the most commonly used methods of measuring VOC oxidation products (i.e., gas chromatography and proton transfer reaction mass spectrometry) observe these hydroperoxides as their equivalent high-NO isoprene oxidation products – methyl vinyl ketone (MVK) and methacrolein (MACR). This interference has led to an observational bias affecting our understanding of global atmospheric processes. Considering these artifacts will help close the gap on discrepancies regarding the identity and fate of reactive organic carbon, revise our understanding of surface-atmosphere exchange of reactive carbon and SOA formation, and improve our understanding of atmospheric oxidative capacity

United States Military Fatalities During Operation Inherent Resolve and Operation Freedom\u27s Sentinel.

BACKGROUND: Military operations provide a unified action and strategic approach to achieve national goals and objectives. Mortality reviews from military operations can guide injury prevention and casualty care efforts. METHODS: A retrospective study was conducted on all U.S. military fatalities from Operation Inherent Resolve (OIR) in Iraq (2014-2021) and Operation Freedom\u27s Sentinel (OFS) in Afghanistan (2015-2021). Data were obtained from autopsy reports and other existing records. Fatalities were evaluated for population characteristics; manner, cause, and location of death; and underlying atherosclerosis. Non-suicide trauma fatalities were also evaluated for injury severity, mechanism of death, injury survivability, death preventability, and opportunities for improvement. RESULTS: Of 213 U.S. military fatalities (median age, 29 years; male, 93.0%; prehospital, 89.2%), 49.8% were from OIR, and 50.2% were from OFS. More OIR fatalities were Reserve and National Guard forces (OIR 22.6%; OFS 5.6%), conventional forces (OIR 82.1%; OFS 65.4%), and support personnel (OIR 61.3%; OFS 33.6%). More OIR fatalities also resulted from disease and non-battle injury (OIR 83.0%; OFS 28.0%). The leading cause of death was injury (OIR 81.1%; OFS 98.1%). Manner of death differed as more homicides (OIR 18.9%; OFS 72.9%) were seen in OFS, and more deaths from natural causes (OIR 18.9%; OFS 1.9%) and suicides (OIR 29.2%; OFS 6.5%) were seen in OIR. The prevalence of underlying atherosclerosis was 14.2% in OIR and 18.7% in OFS. Of 146 non-suicide trauma fatalities, most multiple/blunt force injury deaths (62.2%) occurred in OIR, and most blast injury deaths (77.8%) and gunshot wound deaths (76.6%) occurred in OFS. The leading mechanism of death was catastrophic tissue destruction (80.8%). Most fatalities had non-survivable injuries (80.8%) and non-preventable deaths (97.3%). CONCLUSIONS: Comprehensive mortality reviews should routinely be conducted for all military operation deaths. Understanding death from both injury and disease can guide preemptive and responsive efforts to reduce death among military forces

Characterization of a real-time tracer for isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) from aerosol mass spectrometer measurements

Substantial amounts of secondary organic aerosol (SOA) can be formed from isoprene epoxydiols (IEPOX), which are oxidation products of isoprene mainly under low-NO conditions. Total IEPOX-SOA, which may include SOA formed from other parallel isoprene oxidation pathways, was quantified by applying positive matrix factorization (PMF) to aerosol mass spectrometer (AMS) measurements. The IEPOX-SOA fractions of organic aerosol (OA) in multiple field studies across several continents are summarized here and show consistent patterns with the concentration of gas-phase IEPOX simulated by the GEOS-Chem chemical transport model. During the Southern Oxidant and Aerosol Study (SOAS), 78 % of PMF-resolved IEPOX-SOA is accounted by the measured IEPOX-SOA molecular tracers (2-methyltetrols, C5-Triols, and IEPOX-derived organosulfate and its dimers), making it the highest level of molecular identification of an ambient SOA component to our knowledge. An enhanced signal at C5H6O+ (m/z 82) is found in PMF-resolved IEPOX-SOA spectra. To investigate the suitability of this ion as a tracer for IEPOX-SOA, we examine fC5H6O(fC5H6O= C5H6O+/OA) across multiple field, chamber, and source data sets. A background of ~ 1.7 ± 0.1 &permil; (&permil; = parts per thousand) is observed in studies strongly influenced by urban, biomass-burning, and other anthropogenic primary organic aerosol (POA). Higher background values of 3.1 ± 0.6 &permil; are found in studies strongly influenced by monoterpene emissions. The average laboratory monoterpene SOA value (5.5 ± 2.0 &permil;) is 4 times lower than the average for IEPOX-SOA (22 ± 7 &permil;), which leaves some room to separate both contributions to OA. Locations strongly influenced by isoprene emissions under low-NO levels had higher fC5H6O (~ 6.5 ± 2.2 &permil; on average) than other sites, consistent with the expected IEPOX-SOA formation in those studies. fC5H6O in IEPOX-SOA is always elevated (12–40 &permil;) but varies substantially between locations, which is shown to reflect large variations in its detailed molecular composition. The low fC5H6O (< 3 &permil;) reported in non-IEPOX-derived isoprene-SOA from chamber studies indicates that this tracer ion is specifically enhanced from IEPOX-SOA, and is not a tracer for all SOA from isoprene. We introduce a graphical diagnostic to study the presence and aging of IEPOX-SOA as a triangle plot of fCO2 vs. fC5H6O. Finally, we develop a simplified method to estimate ambient IEPOX-SOA mass concentrations, which is shown to perform well compared to the full PMF method. The uncertainty of the tracer method is up to a factor of ~ 2, if the fC5H6O of the local IEPOX-SOA is not available. When only unit mass-resolution data are available, as with the aerosol chemical speciation monitor (ACSM), all methods may perform less well because of increased interferences from other ions at m/z 82. This study clarifies the strengths and limitations of the different AMS methods for detection of IEPOX-SOA and will enable improved characterization of this OA component

UK Housing Market: Time Series Processes with Independent and Identically Distributed Residuals

The paper examines whether a univariate data generating process can be identified which explains the data by having residuals that are independent and identically distributed, as verified by the BDS test. The stationary first differenced natural log quarterly house price index is regressed, initially with a constant variance and then with a conditional variance. The only regression function that produces independent and identically distributed standardised residuals is a mean process based on a pure random walk format with Exponential GARCH in mean for the conditional variance. There is an indication of an asymmetric volatility feedback effect but higher frequency data is required to confirm this. There could be scope for forecasting the index but this is tempered by the reduction in the power of the BDS test if there is a non-linear conditional variance process