Mapping Mode Research Articles

Urban-focused satellite CO2 observations from the Orbiting Carbon Observatory-3: A first look at the Los Angeles megacity

NASA's Orbiting Carbon Observatory-3 (OCO-3) was designed to support the quantification and monitoring of anthropogenic CO2 emissions. Its Snapshot Area Map (SAM) and target mode measurements provide an innovative dataset for carbon studies on sub-city scales. Unlike any other current space-based instrument, OCO-3 has the ability to scan large contiguous areas of emission hot spots like cities, power plants, and volcanoes. These measurements result in dense, fine-scale spatial maps of column averaged dry-air mole fractions of carbon dioxide (XCO2). For the first time, we present and analyze XCO2 distributions over the Los Angeles megacity (LA) derived from OCO-3 SAM and target mode observations. Urban XCO2 enhancements range from 0 − 6 ppm (median enhancements ≃ 2 ppm) relative to a clean background and show excellent agreement with nearby ground-based TCCON measurements of XCO2. OCO-3's dense observations reveal intra-urban variations of XCO2 over the city that have never been observed from space before. The spatial variations are mainly driven by the complex fossil fuel emission patterns and meteorological conditions in the LA Basin and are in good agreement with those from co-located TROPOMI measurements of co-emitted NO2. Differences between measured and simulated XCO2 enhancements from two models (WRF-Chem and X-STILT) are typically below 1 ppm with larger differences for some sub regions. Both models capture the observed intra-urban XCO2 gradients. Further, OCO-3's multi-swath measurements capture about three times as much of the city emissions compared to single-swath overpasses. OCO-3's frequent target and SAM mode observations will pave the way to constrain urban emissions at finer, sub-city scales.

Effect of Rehydration Ratio and Inlet Pressure on Shock Wave Focus in Hemispherical Concave Cavity

Shock wave focus is a phenomenon where energy is rapidly converged in a small area of the medium through the interaction of shock waves, resulting in extremely high temperature and pressure near the aerodynamic focus. Experimental and numerical studies are in progress using the high energy area generated by shock wave focus to induce detonation to study shock wave focus phenomenon, the experiments of shock wave focus in the hemispherical concave cavity was carried out. The emphasis is placed on the effect of ring vent width and inlet pressure. By comparing the peak pressure at the bottom of the concave cavity under different ring vent widths, it was found that the reflection of the incident shock wave formed in the channel decreased with the width of the ring vent as well as the intensity of the shock wave increased. The greater the intensity, the more likely it is to produce the focusing of the shock wave. When the subsonic speed airflow flowed into the cavity through the ring vent, it was found that under the influence of the reflection of the concave cavity and complex motion of shock wave, a local high temperature and high pressure area was formed. By comparing the pressure spectrum at the bottom of the concave cavity under different flow pressures, it was found that with the increase of the flow pressure, there were two whistling modes on the spectrum map, C1 and D1 modes, respectively. It was also found that the pressure pulsation in the concave cavity was more disordered and the magnitude was smaller when the inlet pressure decreased, which means the shock waves were not well focused. It can be concluded that in ignition experiments, inlet pressure is significant to shock wave focusing phenomenon and there is a prompt rehydration ratio which lead to better shock wave focusing.

Cross-task congruency sequence effect without the contribution of multiple expectancy

The confound-minimized cross-task design has been widely used to examine the characteristics of top-down cognitive control underlying the congruency sequence effect (CSE) without feature integration and contingency learning confounds. The present study reanalyzed our previous data obtained with the confound-minimized cross-task design, this time including the preceding congruency repetition type, to examine whether the cross-task CSE is confounded by feature integration from two-back (n-2) trials or multiple expectancies regarding the congruency and the congruency repetition type of the upcoming trial. As a result, the cross-task CSE interacted with the arbitrariness of S-R mapping or response mode regardless of the preceding congruency repetition type, indicating the contribution of top-down control triggered by conflict. Feature integration from n-2 trials, but not multiple expectancies, was found to have a lingering effect on the sequential modulation of the congruency effect between previous and current trials. However, because the influence of feature integration operated in opposite directions depending on the preceding congruency repetition type, the contribution of feature integration to the cross-task CSE can be minimized when the combined datasets of trials following a congruency repetition trial and those following a congruency alternation trial are analyzed. These findings are consistent with recent perspectives on cognitive control, which posit that top-down cognitive control and bottom-up feature integration operate independently to optimize task performance.

Torsional Harmonic Kelvin Probe Force Microscopy for High-Sensitivity Mapping of Surface Potential

This article presents a torsional harmonic Kelvin probe force microscopy (TH-KPFM) working in amplitude modulation (AM) mode for high-sensitivity mapping of surface potential (SP). Compared with frequency modulation KPFM with higher spatial resolution, AM-KPFM has higher potential sensitivity and scanning speed. However, the traditional AM-KPFM is usually limited in the crosstalk from topography measurement and cantilever homogenization effect which causes the measured SP to be seriously affected by the substrate. TH-KPFM can effectively suppress the artifacts induced by the cantilever homogenization effect, and the coupling crosstalk caused by the topography measurement. The torsional harmonic cantilever suitable for TH-KPFM is fabricated and calibrated using the nanorobotic system first. Then, this technique is applied to determine the SP of the tobacco mosaic virus (TMV), and detect surface contaminants of a silicon wafer. Experimental results show that TH-KPFM has a 3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 4 mV energy resolution and sub-20 nm spatial resolution. Compared with the proposed TH-KPFM, the energy level of TMV obtained by the traditional AM-KPFM is pulled down by 80 meV. TH-KPFM is a powerful and useful technique to study the SP on the nanoscale, and greatly simplifies the difficulty of high-sensitivity measurement of the actual SP of many important nanoscale systems.

Algorithm of ultrasonographic examination of patency of venous stents

Analysed in the article are the results of ultrasonographic examination of patency of venous stents implanted in 86 patients with obstructive lesions of the iliofemoral segment of deep veins. The authors proposed an algorithm of triplex scanning, making it possible to optimize ultrasonographic examination, as well as increasing the accuracy of assessing the state of the stent and patency of the stented segments of veins. The first stage was to examine the state of the stented venous segment in the mode of grey-scale scanning (B-mode), for which purpose the study was performed in the longitudinal and transverse projections. This made it possible to determine the qualitative state of the stent as either presence or absence of its migration and deformation, completeness of expansion, extravasal compression. The second stage was to locate the venous stent in the mode of colour Doppler mapping (CD-mode), thus making it possible to assess stent patency. The third stage was examination in the spectral Doppler mode with the use of the distal compression test. Ultrasonographically detected phasic, respiration-synchronized blood flow with an increase of its linear velocity proximal to the stent in distal compression (positive compression test) is suggestive of no obstructive alterations in the stent's lumen. Determination of the blood flow velocity makes it possible to evaluate the stent patency or stenotic alterations. Monophasic low-velocity blood flow in the ipsilateral common femoral artery may also be indirectly indicative of impaired stent patency (pronounced stenosis, thrombosis, occlusion). The proposed algorithm of ultrasonographic triplex study of patency of venous stents may be used in out-patient conditions repeatedly and safely for the patient.

Possibilities of duplex scanning in assessment of endoleaks after abdominal aorta endoprosthetic repair

Endovascular abdominal aortic aneurysm repair is an operation of choice in rendering hi-tech care for patients with aneurysms of the infrarenal aortic portion. The most frequently performed reoperations account for cases related to removing endoleaks. The article deals with assessing the presence of various types of endoleaks depending on the time elapsed after abdominal aortic aneurysm repair by means of duplex scanning and multislice computed tomography. Duplex scanning proved highly informative in detecting various types of endoleaks, being comparable with the findings of multislice computed tomography (p=0.917). The presence or absence of aneurysmal cavity coloration in the mode of Doppler colour mapping makes it possible to dynamically follow up the process of thrombogenesis. For timely diagnosis of complications after endoprosthetic repair of abdominal aortic aneurysms, the use of ultrasound duplex scanning is considered to be an informative and safe technique, possessing potential possibility of detecting endoleaks and, in our opinion, may be included into the protocol of follow-up of patients in the early postoperative period.

Drug for contrast-enhanced ultrasound examination: new dimension in early diagnosis of angionephrosclerosis in patients with type 2 diabetes on non-alcoholic fatty liver disease background

Objective. To evaluate the diagnostic efficiency of the contrast-enhanced third-generation agent in the detection of angionephrosclerosis in patients with type 2 diabetes and non-alcoholic fatty liver disease background.Materials and methods. 26 patients (9 men and 17 women; mean age 61.5 ± 4.3 years) with a confirmed diagnosis of type 2 diabetes mellitus and NAFLD were examined. All patients underwent complex diagnostics, including: quantitative ultrasound steatometry of the liver in the framework of combined elastography with visual and quantitative assessment of the attenuation coefficient of the ultrasonic wave; ultrasound examination of the kidneys in B-mode with vascular diagnostics in the Doppler mapping mode. Also, all patients underwent contrast-enhanced ultrasound examination of the kidneys with the contrast agent for the diagnosis of angionephrosclerosis.Results. The method of CEUS of the kidneys with patients with type 2 diabetes and NAFLD has sensitivity of 92.7 %, and accuracy of 90.4 %. Color Doppler mode has sensitivity of 66.5–81.4 %, and accuracy of 58.4–73.6 %.Conclusion. The ultrasound contrast agent may be used in the early diagnosis of angionephrosclerosis in patients with type 2 diabetes and NAFLD as a non-alternative imaging method with no radiation exposure and no nephrotoxicity.

“By Degrees”

Paul Giles, “‘By Degrees’: Jane Austen’s Chronometric Style of World Literature” (pp. 265–293) This essay considers how Jane Austen’s work relates to “World Literature” by internalizing a chronometric style. Examining the emergence of the chronometer in the eighteenth century, it suggests how Austen drew on nautical frames of reference to combine disparate trajectories of local realism, geographical distance, and historical time. The essay thus argues that Austen’s fiction is interwoven with a reflexive mode of cartographic mapping, one that draws aesthetically on nautical instruments to remap time and space. This style involves charting various fluctuations of perspective that reorder history, memory, and genealogy, while also recalibrating Britain’s position in relation to the wider world. Moving on from an initial analysis of Austen’s juvenilia and early novels, the essay proceeds in its second part to discuss Mansfield Park (1814) in relation to Pacific exploration and trade. In its third part, it considers Emma (1815) in the context of comic distortions and the misreadings that arise from temporal and spatial compressions in the narrative, a form heightened by the novel’s reflexive wordplay. Hence the essay argues that Austen’s particular style of World Literature integrates chronometric cartography with domestic circumstances, an elusive idiom that also manifests itself in relation to the gender dynamics of Persuasion (1817) and the unfinished “Sanditon,” as discussed in the essay’s concluding pages. This is correlated finally with the way Austen’s novels are calibrated, either directly or indirectly, in relation to a global orbit.

The critical turn of resilience: Mapping thematic communities and modes of critical scholarship

This paper explores the structures of the critical literature on resilience by mapping the ways in which critical trajectories developed and travelled across thematic communities. We use bibliometric analysis to examine 49 years of scholarship on resilience from international relations, geography, political ecology, and other social science disciplines that foremost focused on questions of power, inequality, and social justice. As a result, this paper delves into the composition of different types of critique mobilised in resilience scholarship and identifies the interdependencies between modes of critical thought and their degree of interdisciplinary connectivity.

Measuring the micromechanical properties of oesophageal mucosa with atomic force microscopy

The micromechanical properties of soft tissue can be used as markers for the physiological state and function of the tissue. Deep understanding of the micromechanics of soft tissue, such as the oesophagus, is of great significance to the design of artificial oesophagi, endoscope materials and coatings for medical devices. Here, the micromechanical properties of oesophageal mucosa were studied under different loading rates, deflections, and dwell time by using atomic force microscopy. The micromechanical properties of soft tissue included elastic modulus, plasticity and adhesion force. Results showed that the micromechanical properties changed with increasing loading rate, deflection and dwell time. The micromechanical properties of oesophageal mucosa were related to time-dependent behaviours, such as contact stress, energy transformation, and strain gradient plasticity. Furthermore, the heterogeneity of oesophageal mucosa affected the micromechanical properties. The force mapping mode was a reliable and effective means to study the micromechanical properties of soft tissue. The results can provide a basis and technical support for the diagnosis of oesophageal diseases from a microscale as well as a material design perspective.

Comparison of Unipolar and Bipolar Voltage Mapping for Localization of Left Atrial Arrhythmogenic Substrate in Patients With Atrial Fibrillation.

Background: Presence of left atrial low voltage substrate in bipolar voltage mapping is associated with increased arrhythmia recurrences following pulmonary vein isolation for atrial fibrillation (AF). Besides local myocardial fibrosis, bipolar voltage amplitudes may be influenced by inter-electrode spacing and bipole-to-wavefront-angle. It is unclear to what extent these impact low voltage areas (LVA) in the clinical setting. Alternatively, unipolar electrogram voltage is not affected by these factors but requires advanced filtering.Objectives: To assess the relationship between bipolar and unipolar voltage mapping in sinus rhythm (SR) and AF and identify if the electrogram recording mode affects the quantification and localization of LVA.Methods: Patients (n = 28, 66±7 years, 46% male, 82% persistent AF, 32% redo-procedures) underwent high-density (>1,200 sites, 20 ± 10 sites/cm2, using a 20-pole 2-6-2 mm-spaced Lasso) voltage mapping in SR and AF. Bipolar LVA were defined using four different thresholds described in literature: <0.5 and <1 mV in SR, <0.35 and <0.5 mV in AF. The optimal unipolar voltage threshold resulting in the highest agreement in both unipolar and bipolar mapping modes was determined. The impact of the inter-electrode distance (2 vs. 6 mm) on the correlation was assessed. Regional analysis was performed using an 11-segment left atrial model.Results: Patients had relevant bipolar LVA (23 ± 23 cm2 at <0.5 mV in SR and 42 ± 26 cm2 at <0.5 mV in AF). 90 ± 5% (in SR) and 85 ± 5% (AF) of mapped sites were concordantly classified as high or low voltage in both mapping modes. Discordant mapping sites located to the border zone of LVA. Bipolar voltage mapping using 2 vs. 6 mm inter-electrode distances increased the portion of matched mapping points by 4%. The unipolar thresholds (y) which resulted in a high spatial concordance can be calculated from the bipolar threshold (x) using following linear equations: y = 1.06x + 0.26mV (r = 0.994) for SR and y = 1.22x + 0.12mV (r = 0.998) for AF.Conclusion: Bipolar and unipolar voltage maps are highly correlated, in SR and AF. While bipole orientation and inter-electrode spacing are theoretical confounders, their impact is unlikely to be of clinical importance for localization of LVA, when mapping is performed at high density with a 20-polar Lasso catheter.

China’s high-resolution optical remote sensing satellites and their mapping applications

ABSTRACT Since the beginning of the twenty-first century, several countries have made great efforts to develop space remote sensing for building a high-resolution earth observation system. Under the great attention of the government and the guidance of the major scientific and technological project of the high-resolution earth observation system, China has made continuous breakthroughs and progress in high-resolution remote sensing imaging technology. The development of domestic high-resolution remote sensing satellites shows a vigorous trend, and consequently, a relatively stable and perfect high-resolution earth observation system has been formed. The development of high-resolution remote sensing satellites has greatly promoted and enriched modern mapping technologies and methods. In this paper, the development status, along with mapping modes and applications of China’s high-resolution remote sensing satellites are reviewed, and the development trend in high-resolution earth observation system for global and ground control-free mapping is discussed, providing a reference for the subsequent development of high-resolution remote sensing satellites in China.

Quantitative evaluation of different high-density 3D mapping modes for atrial and ventricular substrate assessment of cardiac arrhythmias with the HD grid catheter

BackgroundAtrial and ventricular arrhythmias significantly contribute to morbidity and mortality of patients with cardiac disease. Ablation of these arrhythmias has shown to improve clinical outcomes, yet targeted ablation strategies rely on proper mapping capabilities. In the present study, we compare different modes of high-resolution mapping in clinically relevant arrhythmias using HD grid. Methods and resultsUsing the Advisor™ HD Grid Mapping Catheter in either the standard, the wave (bipolar along spline and bipolar orthogonal) or the wave diagonal setting, low-voltage areas were determined. Low-voltage was defined as local electrograms with an amplitude <0.5 mV (bipolar; atria/ventricle) or <4 mV (unipolar; ventricle). Ultra high-density mapping in 47 patients with ventricular tachycardia, ventricular premature beats, atrial fibrillation and atrial tachycardia provided reliable information for the understanding of the arrhythmia mechanism resulting in safe ablation procedures. Regions of low voltage were significantly decreased by 14 ± 2% and 31 ± 3% with wave and wave diagonal settings as compared to standard settings, respectively. ConclusionSubstrate mapping and risk stratification relies on proper low voltage discrimination. Even though the Advisor™ HD Grid Mapping Catheter was safely used in all cases, the extent of low voltage areas was mapping-mode dependent.

Patient Retention and Continuity of Care of an Underserved Oncology Population within a Public Safety-Net Health System

Cancer patients in underserved populations are at high risk for patient attrition and treatment delay. Infrequent appointment recording often results in patients who are lost to follow-up. We hypothesized that the utilization of Lean Six Sigma methodologies would increase patient scheduling for radiation oncology appointments thereby increasing patient retention within a large urban safety-net health system. The entire clinic staff collaborated to improve electronic health record (EHR) appointment scheduling using the Lean Six Sigma DMAIC approach (Define, Measure, Analyze, Improve and Control). Appointment data was collected for three months prior to and during the pilot study period from the EHR and the radiation oncology record and verify system. We determined the root causes for delinquent scheduling, including lack of staff availability to schedule patients into two electronic systems and to call no-show patients to reschedule. Interventions included implementation of an electronic order for follow-up scheduling and blocked time for personnel to contact no-show patients and verify scheduling. After the formation of a novel process map, control plan, and Failure Modes Effects Analysis (FMEA), the pilot study commenced for a planned six-month period. We report on the first two months of our pilot study. Follow-up appointment scheduling into the EHR improved from baseline 2% to 98% (p<0.01). No-show appointment rescheduling into the EHR improved from baseline 0% to 64%(p<0.01). A novel electronic scheduling intervention was added after the first month when no-show rescheduling into the EMR was at 43% with subsequent no-show rescheduling after the second month at 87% (p = 0.01). The patient no-show rate declined from 19% for the pre-intervention period to 17% for the first pilot month and to 15% for the second pilot month (p = 0.3). Utilization of the Lean Six Sigma methodology resulted in a significant increase in appointment scheduling within the radiation oncology department. While not yet significant, the no-show rate appears to be trending downward as a result of this scheduling improvement, and we expect the no-show rate to continue to decline as the study matures. These findings suggest that optimized appointment scheduling may improve patient retention and continuity of care in an at-risk population. Future directions include evaluating cancer outcomes and healthcare cost savings as a result of higher patient retention.

Improving patient retention by optimizing appointment scheduling in an underserved oncology population within a public safety-net health system.

193 Background: Cancer patients in underserved populations are at high risk for patient attrition and treatment delay. We theorized that decreased appointment scheduling was contributing to a high no-show rate within an urban safety-net hospital. Clinic appointments were being scheduled in the department-specific record and verify system rather than the hospital-wide electronic health record (EHR). We sought to adopt EHR scheduling with the long-term goal of decreasing the no-show rate. Our aim was to utilize the Lean Six Sigma (LSS) methodologies to increase EHR scheduling of follow-up and rescheduling of no-show appointments to 50%. Methods: While involving the entire clinic staff, we utilized the Lean Six Sigma DMAIC model: define, measure, analyze, improve and control, to improve EHR appointment scheduling. Appointment data was collected for the 3 months prior to and during the intervention time period. We determined the root causes for delinquent scheduling, including lack of staff availability to schedule patients into two electronic systems and to call no-show patients. Interventions included implementation of an electronic order for follow-up scheduling and blocked time for personnel to contact no-show patients and verify scheduling. After the formation of a novel process map, control plan, and Failure Modes Effects Analysis (FMEA), the pilot study ran for 2 months. Results: Follow-up appointment scheduling into the EHR improved from 2% to 98% (p &lt; 0.01). After the first intervention month, the no-show rescheduling rate improved from 0% to 43% (p &lt; 0.01): below goal. The team revised the process map by substituting a no-show EHR order in place of the calendar intervention. This constituted the beginning of month 2 and no-show appointment rescheduling subsequently improved from 43% to 87% (p &lt; 0.01). The patient no-show rate was 19% during the pre-intervention period, 17% for the first intervention cycle and 15% for the second intervention cycle (p = 0.3). Conclusions: Utilization of LSS allowed for successful adoption of EHR appointment scheduling within our department. While not yet significant, the no-show rate appears to be trending downward as a result of improved scheduling, and we expect the no-show rate to continue to decline as the study matures. These findings suggest that optimized appointment scheduling may decrease patient retention in an at-risk population. Future directions include evaluating cancer outcomes and decreased healthcare costs as a result of higher patient retention.

Mapping global patterns of land use decision-making

Humans have changed most of the terrestrial surface by changing land-use and land-cover. The spatial distribution and extent of land-cover changes have been studied and mapped widely, using remote sensing and geospatial technologies. Although there are numerous studies on the human decisions underlying such changes, they are limited to local case-studies. How such local-scale patterns of decision-making can be used to explain land-use change globally is unknown. Using a collection of local studies from a literature review, we studied the contextual conditions of different modes of land-use change decision-making and present global maps of the potential distribution of decision-making in land-use change. We find that decision-making in land-use can be explained, to a large extent, by the socio-economic, climatic and soil conditions of a location, captured by global data proxies of these conditions. Survival and livelihood objectives are positively associated to the spatial variation in childhood malnutrition and distance to roads, and negatively to total economic output of an area. Economic objectives on the other hand, are positively associated to total economic output, but also to the annual precipitation at the location. Similar trends are observed when looking at more detailed decision-making types: survivalist, subsistence-oriented and market-oriented smallholder decision-making types are more likely found in areas with higher poverty levels and overall lower levels of socio-economic development. The spatial distribution can be used to understand the occurrence of land-use intensification trajectories and to account for variation in decision-making in global land-use models. Finally, we provide a representation of the spread of case-studies and which contexts are poorly represented by case-studies.

Temperature stabilization of WC-Co cutting inserts with feedback to IR pyrometer upon growth of multilayer diamond coatings by microwave plasma chemical vapor deposition

We produced microcrystalline diamond coatings with nanocrystalline top diamond layer on WC-Co cutting inserts in a microwave plasma (2.45 GHz) chemical vapor deposition reactor. The coatings have a high uniformity of the substrate surface owing to elimination of the plasma edge effect by application of a moveable quartz ring above the substrate holder. Computer modeling showed how the positioning of the ring changes the electromagnetic field around the substrates. A new approach was used to stabilize the temperature of the cutting inserts during the coating process, which is based on in situ control of the quartz ring position by proportional-integral-differential (PID) regulation. The coatings have been characterized with microRaman spectroscopy in a mapping mode in cross section of the samples. Depth profiles of diamond Raman peak position and width are demonstrated and the stress in the films is estimated, the minimum stress being determined for the cutting insert apex.

Frame-Wise Detection of Double HEVC Compression by Learning Deep Spatio-Temporal Representations in Compression Domain

Detection of double compression is regarded as one primary step in analyzing the integrity of digital videos, which is of prominent importance in video forensics. However, current methods are vulnerable with the severe lossy quantization in the recompression process such that it is challenging to obtain reliable frame-wise detection results, especially for the high efficiency video coding (HEVC) standard. In view of these issues, in this paper, a hybrid neural network is proposed to reveal abnormal frames in HEVC videos with double compression by learning robust spatio-temporal representations from coding information in the compression domain. Based on the statistical analysis of Coding Units (CUs), it is interesting to find that HEVC video streams contain “rich” coding information that could be leveraged to identify abnormal traces caused by double compression. Two types of coding information maps, including CU Size Map (CSM) and CU Prediction mode Map (CPM), are exploited. In contrast with the conventional paradigm relying on pixel-level representations of decoded frames, CSMs and CPMs of a short-time video clip are treated as the input, aiming to achieve high robustness against recompression of low quality. In our hybrid neural network, an attention-based two-stream residual network is proposed to learn hierarchical representations from CSM and CPM, which are then jointly optimized by the attention-based fusion module. Finally, the temporal variation is modeled by Long Short-Term Memory (LSTM) to obtain frame-wise detection results. We have conducted extensive experiments considering various video content and coding parameters, such as bitrates and sizes of Group of Picture. Experimental results show that our approach can obtain state-of-the-art performance compared with conventional methods, especially when videos are recompressed in the low bitrate coding scenarios.

Mathematical Modeling of Myocardial Perfusion Diagnosed by the Method of Single-Photon Emission Computed Tomography

The results of an investigation intended to develop a mathematical model representation of the left ventricular myocardium in the polar bull’s eye map mode are presented. Comparison of images obtained using the numerical simulation and the cases in clinical practice allows evaluating possible errors and discrepancies of reconstruction in the single-photon emission computed tomography.

Defining Surface Types of Mars Using Global CRISM Summary Product Maps

AbstractFor many regions on Mars, the surface composition and its geological history have been debated in the literature. Because of the limited surface coverage of in situ measurements, either new data or new processing methodologies are required to get a better understanding of the Martian geology. This paper presents the results of a multivariate, unsupervised, analysis on underutilized CRISM (Compact Reconnaissance Imaging Spectrometer) multispectral mapping mode data set for surface type analysis. The devised summary products of Pelkey et al. (2007) and Viviano‐Beck et al. (2014) are averaged for the CRISM ~5° × 5° mosaic grids and used to analyze the variability in this data set. The averaged summary product values are studied using correlation coefficients calculated between summary products, as well as the correlation with dust coverage and elevation. The degree of correlation is used to interpret the summary products for the global distribution of mafic and secondary minerals and the effect of external factors such as ice, atmosphere, and dust coverage. With unsupervised clustering, all grid pixels are classified based on the spectral variability. These clusters are plotted as global maps and interpreted for geological variations in the CRISM data. Some clusters spatially correspond with previously recognized compositional distinct regions Northern Lowlands, Southern Highlands, Meridiani Planum, Syrtis Major, and Nili Fossae. Several other clusters are described here for the first time such as Solis Planum, Ophir Planum, and Hellas Basin. These regions cover known geological units, but the interpretation of the spectral variability is uncertain whether it relates to geological or external factors.