Cumulative Distance Research Articles

Ambulation of Patients With In Situ Femoral Intraaortic Balloon Pump While Awaiting Heart Transplantation.

Ambulation of Patients With In Situ Femoral Intraaortic Balloon Pump While Awaiting Heart Transplantation.

Differential ability of three bee species to move genes via pollen.

Since the release of genetically engineered (GE) crops, there has been increased concern about the introduction of GE genes into non-GE fields of a crop and their spread to feral or wild cross-compatible relatives. More recently, attention has been given to the differential impact of distinct pollinators on gene flow, with the goal of developing isolation distances associated with specific managed pollinators. To examine the differential impact of bee species on gene movement, we quantified the relationship between the probability of getting a GE seed in a pod, and the order in which a flower was visited, or the cumulative distance traveled by a bee in a foraging bout. We refer to these relationships as 'seed curves' and compare these seeds curves among three bee species. The experiments used Medicago sativa L. plants carrying three copies of the glyphosate resistance (GR) allele as pollen donors (M. sativa is a tetraploid), such that each pollen grain carried the GR allele, and conventional plants as pollen recipients. Different foraging metrics, including the number of GR seeds produced over a foraging bout, were also quantified and contrasted among bee species. The lowest number of GR seeds set per foraging bout, and the GR seeds set at the shortest distances, were produced following leafcutting bee visits. In contrast, GR seeds were found at the longest distances following bumble bee visits. Values for honey bees were intermediate. The ranking of bee species based on seed curves correlated well with field-based gene flow estimates. Thus, differential seed curves of bee species, which describe patterns of seed production within foraging bouts, translated into distinct abilities of bee species to move genes at a landscape level. Bee behavior at a local scale (foraging bout) helps predict gene flow and the spread of GE genes at the landscape scale.

562 Investigation of Cerebral Vessel Geometric Morphometrics for Prediction of Mechanical Thrombectomy First Pass Outcome

INTRODUCTION: Vessel tortuosity is a major factor in successful first pass outcomes for mechanical thrombectomy (MT), but previous methods to quantify tortuosity are not accurate enough to predict outcome. We investigated a new method for vessel characterization and outcome prediction based on geometric morphometrics (GMM). METHODS: Vessels and clots were manually segmented and reconstructed from pre-treatment CTA and nCCT images (n=5 cases). The vasculature corresponding to the ICA and MCA from the affected hemisphere was isolated, and centerlines were engineered as curved landmarks. MorphoJ, a GMM software, was used to complete generalized Procrustes and principal component (PC) Analysis that included registration of patient geometries, calculation of average morphology and landmark variation, and identification of anatomical landmarks differentiating MT outcomes. Morphometrics were compared against local and overall tortuosity by measuring the separability of and cohesion within outcome classes. RESULTS: GMM produced two PCs, which described local variation in M1 (PC1) and the ICA (PC2). When compared against vessel tortuosity features, GMM PCs increased the distance between outcome classes (first pass effect vs. no first pass effect), improving separability by 23.6%. Further, GMM PCs increased the compactness/cohesion of outcome classes, reducing cumulative distance between failures by 50% and successes by 9.4%. CONCLUSIONS: GMM analysis of pre-treatment vessel characteristic highlights regional variation in M1 as a strong indicator of MT failure, and suggests that GMM has the potential to better predict MT outcome than ICA tortuosity alone. Investigation of more complex vessel morphometry through feature engineering is needed.

Neighbour Node Ratio AODV (NNR-AODV) Routing Protocol for Wormhole Attack Detection in Manets

This paper aimed at the detection of wormhole attack and proposed a new method called as Neighbour Node Ratio Adhoc On demand Distance Vector Routing (NNR-AODV). NNR-AODV is an extended version of the traditional AODV routing protocol. The proposed NNR-AODV calculates the neighbour node count for every node and based on that it will decide whether the wormhole is present or not. Furthermore, NNR-AODV is able to detect both external and internal wormhole attacked nodes. Also, NNR-AODV derived a Neighbor node Threshold value which is based on the cumulative distances between nodes present in the wormhole attack. For experimental validation, we have accomplished an extensive simulation and the performance is measured through Number of bogus links, Detection rate, False positive Rate, Packet delivery ratio and Packet loss ratio. The obtained results have shown superior performance in the detection of wormhole attacks than the existing methods.

Assessing the Effects of Physical Barriers and Hypoxia on Red Drum Movement Patterns to Develop More Effective Management Strategies

Human modification of coastal ecosystems often creates barriers to fish movement. Passive acoustic telemetry was used to quantify movement patterns and habitat use of red drums (Sciaenops ocellatus) within and around a complex of coastal impoundments, and explored how the presence of artificial structures (i.e., bollards and culverts) and a hypoxia-related mortality event impacted fish movement. Results indicated bollards impede the movement of individuals with head widths greater than the mean distance between bollards (~16.0 cm). Red drum home range area and daily distance traveled were related to water dissolved oxygen concentrations; as oxygen levels decreased, fish habitat use area decreased initially. However, continued exposure to hypoxic conditions increased fish cumulative daily distance traveled. When exposed to anoxic waters, fish daily distance traveled and rate of movement were greatly reduced. These findings suggest prolonged exposure to low dissolved oxygen in combination with artificial structures can reduce movement of red drum, increase risk of mortality, and decrease habitat connectivity. Constructing and maintaining (sediment and biofouling removal) larger culvert openings and/or using wider bollard spacing would improve water circulation in impoundments, increase habitat connectivity, and facilitate movement of large sportfish inhabiting Florida’s coastal waters.

Quantitative Analysis of the Influence of the Xiaolangdi Reservoir on Water and Sediment in the Middle and Lower Reaches of the Yellow River

The Xiaolangdi Reservoir is the second largest water conservancy project in China and the last comprehensive water conservancy hub on the mainstream of the Yellow River, playing a vital role in the middle and lower reaches of the Yellow River. To study the effects of the construction of the Xiaolangdi Reservoir (1997-2001) on the runoff and sediment transport in the middle and lower reaches of the Yellow River, runoff and sediment transport data from 1963 to 2021 were based on the hydrological stations of Huayuankou, Gaocun, and Lijin. The unevenness coefficient, cumulative distance level method, Mann-Kendall test method, and wavelet transform method were used to analyze the runoff and sediment transport in the middle and lower reaches of the Yellow River at different time scales. The results of the study reveal that the completion of the Xiaolangdi Reservoir in the interannual range has little impact on the runoff in the middle and lower reaches of the Yellow River and a significant impact on sediment transport. The interannual runoff volumes of Huayuankou station, Gaocun station, and Lijin station were reduced by 20.1%, 20.39%, and 32.87%, respectively. In addition, the sediment transport volumes decreased by 90.03%, 85.34%, and 83.88%, respectively. It has a great influence on the monthly distribution of annual runoff. The annual runoff distribution is more uniform, increasing the runoff in the dry season, reducing the runoff in the wet season, and bringing forward the peak flow. The runoff and Sediment transport have obvious periodicity. After the operation of the Xiaolangdi Reservoir, the main cycle of runoff increases and the second main cycle disappears. The main cycle of Sediment transport did not change obviously, but the closer it was to the estuary, the less obvious the cycle was. The research results can provide a reference for ecological protection and high-quality development in the middle and lower reaches of the Yellow River.

Cost-Effective Maintenance Policy for Sliding Surfaces of Bridge Bearings Using a Gamma Stochastic Process for Forecasting

To determine the optimal alert threshold for sliding surface replacement of bridge bearings, a cost-effective maintenance policy is proposed in this paper using a gamma stochastic process. First, the sliding surface-triggered run-to-failure process of bridge bearings is discussed based on existing field inspection and maintenance records. Then, the wear thickness of sliding materials is estimated step-by-step based on the cumulative travel distance and wear rate. The gamma stochastic process is used to model degradation of sliding surfaces by using the indicator of wear thickness to depict uncertainties during the degrading process. Next, the optimal alert threshold for replacement of sliding surfaces is determined based on the cost-effective maintenance policy by minimizing the long-term expected maintenance cost rate. Finally, bearings of a long-span suspension bridge are employed to demonstrate the potential effectiveness of the proposed methodology. As a result, the wear thickness of sliding materials approximately follows a linear degrading law. Based on the gamma degrading model, the objective function subject to the long-term expected cost rate is formed. After optimization, the optimal alert threshold for replacement of sliding surfaces is 2.016 mm to achieve a minimum long-term expected maintenance cost rate of US$9,427 per day. In addition, the estimated service life subject to the alert threshold obeys a Gaussian distribution with a mean of 1278 days based on the one-year monitored displacement data.

Large-scale movement patterns in a social vulture are influenced by seasonality, sex, and breeding region.

Quantifying space use and segregation, as well as the extrinsic and intrinsic factors affecting them, is crucial to increase our knowledge of species-specific movement ecology and to design effective management and conservation measures. This is particularly relevant in the case of species that are highly mobile and dependent on sparse and unpredictable trophic resources, such as vultures. Here, we used the GPS-tagged data of 127 adult Griffon Vultures Gyps fulvus captured at five different breeding regions in Spain to describe the movement patterns (home-range size and fidelity, and monthly cumulative distance). We also examined how individual sex, season, and breeding region determined the cumulative distance traveled and the size and overlap between consecutive monthly home-ranges. Overall, Griffon Vultures exhibited very large annual home-range sizes of 5027 ± 2123 km2, mean monthly cumulative distances of 1776 ± 1497 km, and showed a monthly home-range fidelity of 67.8± 25.5%. However, individuals from northern breeding regions showed smaller home-ranges and traveled shorter monthly distances than those from southern ones. In all cases, home-ranges were larger in spring and summer than in winter and autumn, which could be related to difference in flying conditions and food requirements associated with reproduction. Moreover, females showed larger home-ranges and less monthly fidelity than males, indicating that the latter tended to use the similar areas throughout the year. Overall, our results indicate that both extrinsic and intrinsic factors modulate the home-range of the Griffon Vulture and that spatial segregation depends on sex and season at the individual level, without relevant differences between breeding regions in individual site fidelity. These results have important implications for conservation, such as identifying key threat factors necessary to improve management actions and policy decisions.

Does weather drive habitat use and movement of a nonmigratory bird?

AbstractClimate change is predicted to increase the intensity and frequency of weather extremes (e.g., extreme heat and drought), which will likely affect wildlife species in significant ways. Maintaining landscape heterogeneity has been suggested as a potential conservation strategy to buffer animals from weather extremes. Because animal movement influences survival and population connectivity, understanding animal space use and movement in response to shifts in weather is useful for the conservation of wildlife. Nonmigratory species are predicted to be more negatively affected by climate change because they have a limited ability to disperse to find resources. We studied the Northern Bobwhite (Colinus virginianus; hereafter, bobwhite) to understand how weather alters habitat use and movement of a nonmigratory animal across a landscape. We collected telemetry locations on bobwhite across western Oklahoma during 2019–2020 and paired these data with meteorological and vegetation data. We analyzed the data at two temporal scales—hourly locations and 12‐h paths. At the hourly scale, we analyzed tree cover use, shrub cover use, and normalized difference vegetation index (NDVI) use using generalized or linear‐mixed models. At the 12‐h scale, we calculated three different movement metrics: cumulative distance, net displacement, sinuosity and analyzed each movement metric separately using generalized linear‐mixed models. We found that bobwhite used denser tree cover and higher NDVI values as air temperature increased in conjunction with solar radiation. Bobwhite used denser shrub cover as air temperature increased and average wind speed was high as well as when air temperature and average wind speed were low. The interaction between variability in vegetation and climate influenced bobwhite movement. Bobwhite in areas with higher NDVI variance moved farther when mean air temperatures were >0°C than bobwhite in areas with low NDVI variance. When mean air temperatures were ≤0°C, NDVI variance had little effect on the cumulative distance moved of bobwhite. Our findings show that some animals use different vegetation types during different weather conditions and that variability in vegetation on the landscape and weather together alters animal movement. Managing for landscape heterogeneity is a solution that may buffer animals from increased climate variability in the future.

Long-term satellite tracking reveals patterns of long-distance dispersal in juvenile and adult Arctic foxes (Vulpes lagopus).

Long-distance dispersal plays a key role in species distribution and persistence. However, its movement metrics and ecological implications may differ whether it is undertaken by juveniles (natal dispersal) or adults (breeding dispersal). We investigated the influence of life stage on long-distance dispersal in the Arctic fox, an important tundra predator. We fitted 170 individuals with satellite collars during a 13-year study on Bylot Island (Nunavut, Canada), and analysed the tracks of 10 juveniles and 27 adults engaging in long-distance dispersal across the Canadian High Arctic. This behaviour was much more common than expected, especially in juveniles (62.5%, adults: 19.4%). Emigration of juveniles occurred mainly at the end of summer while departure of adults was not synchronized. Juveniles travelled for longer periods and over longer cumulative distances than adults, but spent similar proportions of their time travelling on sea ice versus land. Successful immigration occurred mostly in late spring and was similar for juveniles and adults (30% versus 37%). Our results reveal how life stage influences key aspects of long-distance dispersal in a highly mobile canid. This new knowledge is critical to understand the circumpolar genetic structure of the species, and how Arctic foxes can spread zoonoses across vast geographical areas.

Reproduction strategy of nocturnal marine molluscs: running for love.

The cost of reproduction is the core driver of life history evolution in animals. This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones, Haliotis discus hannai, kept in various male and female groups, were significantly higher than those of sexually mature individuals, except when kept in mixed cultures of mature males and females. After mixed-culture, sexually mature males moved significantly further and for a longer duration than mature female abalones, and even more so than mature male abalones of any other group. Examination of the LC-MS metabolomics of mature males cultured with sexually mature females (AM) and those cultured with sexually immature females (JM) showed that cyclic adenosine monophosphate (cAMP) acted as a differential metabolic biomarker. After 24-h uninterrupted sampling, the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM. After further injection of 5-HT2 and 5-HT6 receptor antagonists, the concentrations of cAMP and PKA rose again, but the cumulative movement duration and distance of male abalones decreased significantly, showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways. The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females, providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.

A survey of feature detection methods for localisation of plain sections of axial brain magnetic resonance imaging

Matching MRI brain images between patients or mapping patients’ MRI slices to the simulated atlas of a brain is key to the automatic registration of MRI of a brain. The ability to match MRI images would also enable such applications as indexing and searching MRI images among multiple patients or selecting images from the region of interest. In this work, we have introduced robustness, accuracy and cumulative distance metrics and methodology that allows us to compare different techniques and approaches in matching brain MRI of different patients or matching MRI brain slice to a position in the brain atlas. To that end, we have used feature detection methods AGAST, AKAZE, BRISK, GFTT, HardNet, and ORB, which are established methods in image processing, and compared them on their resistance to image degradation and their ability to match the same brain MRI slice of different patients. We have demonstrated that some of these techniques can correctly match most of the brain MRI slices of different patients. When matching is performed with the atlas of the human brain, their performance is significantly lower. The best performing feature detection method was a combination of SIFT detector and HardNet descriptor that achieved 93% accuracy in matching images with other patients and only 52% accurately matched images when compared to atlas.

Bacterial Community and Diversity of River Ecosystems on the Qinghai-Tibet Plateau Based on 16S rRNA Gene Sequencing

In recent years, the ecosystems on the Qinghai-Tibet Plateau (QTP) have been facing a high risk of degradation due to the impacts of climate change and human activities. As one of the important components in river ecosystems, microbial communities can reflect the overall changes in the watershed and are regarded as indicators of the health of river ecosystems. In order to investigate the diversity and composition characteristics of bacterial communities in river ecosystems on the QTP, 65 samples were collected from the Yellow River, Yangtze River, Lancang River, Nujiang River, Yarlung Tsangpo River, and Qaidam Basin on the QTP in July 2021 and were analyzed using 16S rRNA high-throughput sequencing. The results showed that the detected bacterial communities covered 65 phyla and 1311 genera in total. Bacterial communities had high α-diversity indexes across the rivers, indicating that the bacterial richness and diversity in rivers on the QTP were at a high level. Among them, Chao and observed OTUs had significantly negative relationships with SRP/TP. The dominant phyla were Proteobacteria, Bacteroidota, Actinobacteriota, and Cyanobacteria. The dominant classes were γ-proteobacteria, Bacteroidia, and α-proteobacteria. The dominant genera were Flavobacterium and Limnohabitans. The results of principal coordinate analysis and permutational MANOVA suggested significant differences in bacterial community structure among the rivers on the QTP. Canonical correspondence analysis showed that the significant environmental variables associated with the variation in the bacterial communities were physicochemical properties of the river water, including conductivity, pH, dissolved silicon, and dissolved organic carbon, as well as watershed characteristics, including the average normalized differential vegetation index, average slope, cumulative water channel distance, catchment size, proportion of shrub area, and average elevation. Among them, conductivity had the strongest influence on bacteria distribution on the QTP. These results provide a database and information for understanding the composition characteristics of microbial communities on the QTP and identifying environmental factors influencing the diversity of bacteria communities.

Platelet-rich plasma's (PRP) impacts on accelerated canine movement.

To investigate the impact of platelet-rich plasma (PRP) on canine movement acceleration. Randomized clinical trial split-mouth study with a double-blind design and controlled group on 31 orthodontic patients, which had been indicated bilateral maxillary first premolar extraction. Each patient recorded clinical features, analyzed lateral cephalometric film, and evaluated the acceleration on dental models at every specific interval. The cumulative distance to the distal canines was larger for the PRP injection group than for the control group at three time points (4 weeks, 8 weeks, and 12 weeks), all of which were statistically significant. The PRP injection group's canine distal width increased from the first 4 weeks (ΔT1) to the highest in the middle 4 weeks (ΔT2 = 1.78 ± 0.11 mm/month), and then it gradually decreased in the last 4 weeks (ΔT3). The speed of the PRP-injected canine was faster than the control group by 1.51 times. PRP can accelerate the speed of canine movement in orthodontics and can be applied for severe cases, for example, impacted tooth retraction, molar protraction or retraction, and other cases.

Structural characteristics of orexin receptor type 2 in Pacific abalone and its diurnal expression pattern after fasting and re-feeding

Pacific abalone (Haliotis discus hannai) is a typical nocturnal organism. To examine the circadian expression pattern of orexin receptor type 2 (OX2R) and its potential effect on the feeding behavior of abalone, the coding region sequence of OX2R that is 1215 bp in length and encodes 404 amino acids was first cloned using the rapid amplification of cDNA ends technique. A recombinant expression vector was constructed for H. discus hannai based on the OX2R protein, obtaining a recombinant protein with a molecular weight of 46 kDa. Polyclonal antibody was prepared with the purified recombinant protein used as the antigen, and the antibody titer of ≥512 K was detected by enzyme-linked immunosorbent assay. The expression levels of OX2R determined using western blotting were highest in the intestinal tract (P < 0.05), but they were not significantly different from the levels in the pedal. Immunofluorescence experiments affirmed that OX2R was widely expressed in the columnar cells of the intestinal mucosal epithelium. To further account for the relationship between the onset of feeding behavior and the expression level of OX2R in abalone, the circadian expression characteristics of OX2R were analyzed by dissecting the intestinal tissues after three days of normal feeding and fasting and following the refeeding treatment. The expression levels of OX2R in the refeeding group were significantly higher than those in the normal feeding and fasting groups at any time point (P < 0.05). The cosine curve analysis revealed that the expression levels of OX2R lost rhythmicity after fasting. Based on the quantification of behavioral data for abalone after fasting and refeeding, the cumulative movement distance and movement duration in each group followed a significant cosine rhythm (P < 0.05), which is consistent with abalone's nocturnal ecological habits. However, the cumulative movement distance and movement duration in the fasting group were significantly lower than those in the normal feeding and refeeding groups (P < 0.05). The peak phases of the cumulative movement distance and movement duration in the refeeding group (ZT08:22 and ZT08:44) shifted backward compared to the normal feeding group (ZT07:33 and ZT07:39). The above results first identified the structural characteristics and circadian expression patterns of OX2R in the marine mollusk abalone, which may reveal the molecular mechanism behind the generation of a feeding rhythm in marine nocturnal organisms and serve as a tool helping to maintain the diversity of marine benthic resources.

Bearing fault feature selection method based on dynamic time warped related searches

Traditional feature selection algorithms rarely consider the dynamic misalignment between different time series, and have poor fault tolerance and robustness. In this paper, a fault feature selection method for rolling bearings based on Dynamic Time Warped Related Searches (DTWRS) is proposed. Firstly, the bearing fault feature set is constructed, and the dynamic time warping algorithm is used to calculate the shortest cumulative distance between feature of different faults, and this distance is used as the correlation evaluation standard. Then, two new search rules, dynamic time warping difference and dynamic time warping entropy, are proposed based on the minimum redundancy between bearing fault features and the maximum correlation between fault features and feature categories, use these two search rules to judge the ability of the feature to express the fault, define the quality of the fault feature and sort from good to bad according to the level of ability. Finally, in this order, the number of features is gradually increased and input to the fault classifier, and the sensitive fault feature set is obtained based on the principle of the highest recognition rate and the least number of features. The experimental results show that the fault feature selection method of rolling bearing based on DTWRS can increase the accuracy of fault diagnosis while minimizing the number of features, and improve the efficiency and effect of fault diagnosis.

Posterior Corneal Astigmatism Does Not Influence Manifest-Treated Topography-guided LASIK Outcomes

To investigate whether the magnitude of posterior corneal astigmatism (PCA) impacts refractive and visual outcomes of primary topography-guided laser in situ keratomileusis (LASIK) and to provide guidance on treating eyes with high PCA. Comparative retrospective analysis of 4,541 consecutive eyes treated with Contoura (Alcon Laboratories, Inc) on the manifest refractive astigmatism. Standard outcomes of the 1,514 eyes with the lowest PCA (first tercile; low PCA group) were compared to the 1,514 eyes with the highest PCA (last tercile; high PCA group). Pearson correlation coefficient was used to assess relationships between variables. Preoperatively, 20.9% of eyes presented with PCA of 0.50 diopters (D) or greater. The mean PCA was 0.18 ± 0.07 D in eyes with low PCA, and 0.50 ± 0.11 D in eyes with high PCA. An equivalent number of eyes achieved a cumulative postoperative unilateral uncorrected distance visual acuity of 20/20 in both the low PCA and high PCA groups (95.3% vs 94.7%; P = .4489). The efficacy index of both low and high PCA eyes was identical (0.99 ± 0.06 vs 0.99 ± 0.08; P = .3192), as was the safety index (1.00 ± 0.02 vs 1.00 ± 0.03; P = .0110). The magnitude of preoperative PCA was weakly correlated with postoperative refractive astigmatism (R = 0.1323), but not with postoperative defocus equivalent (R = -0.0414) or spherical equivalent (R = -0.0128). PCA does not negatively impact the outcomes of topography-guided LASIK targeting the manifest refraction, having identical accuracy, efficacy, and safety in eyes with both low and high PCA. There is no scientific basis to measure and consider PCA in topography-guided LASIK planning software or nomograms if the excimer laser treatment input targets the manifest refraction. [J Refract Surg. 2022;38(12):780-790.].

Uncertainty in Automated Well-Log Correlation Using Stochastic Dynamic Time Warping

Well-log correlation is used extensively to generate subsurface cross sections from sparse well data. This is commonly done by a subject matter expert such as stratigraphers and exploration geophysicists. Several methodologies exist for automating the procedure with varying success. Dynamic time warping (DTW) is a signal-processing technique where one signal is locally stretched and squeezed to maximize the similarity between a reference second signal. This is done by calculating a similarity cost matrix that is traversed to minimize the cumulative distance. The technique produces reasonable results when applied to the well correlation problem. The produced correlation, however, is deterministic, and thus, it does not allow for studying the associated uncertainty. This study presents an extension of traditional dynamic time warping to allow the generation of multiple realizations of correlations. To accomplish this, the cost matrix is traversed deterministically or probabilistically based on a local correlation metric, e.g., the local correlation coefficient. The resultant realizations show stability in the correlation markers where the signals are similar and instability where they are not. The methodology is applied to two adjacent wells. Multiple well-log types (gamma ray, sonic, and resistivity) are used to construct the similarity cost matrix between the two wells. The cost matrix is traversed multiple times to produce multiple realizations. The produced realizations are geologically acceptable. By generating a large number of realizations, the uncertainty in the solutions is quantified. While the application presented here relates to well-log correlation, the presented stochastic dynamic time warping methodology can be applied to other types of signals and data, such as seismic, chemostratigraphy data, and real-time drilling measurements.

Analysis of the Evolution Pattern and Driving Mechanism of Lakes in the Northern Ningxia Yellow Diversion Irrigation Area

In the northern part of the Ningxia Autonomous Region, there are rich lake resources, which are known as the “South of the Seas”. In recent years, the natural evolution of the water system and human activities have caused significant changes in the lake area. In order to fully understand the evolution of lakes in the northern Ningxia Yellow Irrigation Area, Landsat, Sentinel-2 images and ArcGIS were used to extract relevant information, and the cumulative distance level curve and Mann–Kendall trend analysis were used to analyze the trends of each driving factor in depth. The results showed that (1) the lake surface area in the northern Yellow Diversion Irrigation Area showed a significant increasing trend from 1986 to 2019. (2) The annual average temperature in the Ningxia Yellow River Irrigation Area has shown an increasing trend over the past 39 years, and no year has obvious cyclical changes, but in 1998, there was a sudden change in temperature and the temperature began to rise sharply; the annual average precipitation showed an increasing trend with a large variation, and the annual average precipitation from 1980 to 2018 showed a fluctuating increasing trend. (3) There is no significant linear pattern of runoff from upstream during 1986–2015, and it is characterized by fluctuating changes; the precipitation in the Yellow Irrigation Area is much lower than the average level in Ningxia, and it is classified as a typical arid area; the water consumption is all decreasing, but its linear trend is not significant; the most significant impact of the change in the substratum on the water surface is the construction of fields around the lake after 1990, followed by the Lake engineering treatment. (4) The water surface area of the mainstream is significantly and positively correlated with the incoming water from upstream, is significantly and negatively correlated with the area of grassland, and is significantly and positively correlated with the areas of arable land and construction land. The effect of land cover on the water surface area of the mainstream is lower than that on the water surface area other than the mainstream.

Abstract 15733: Investigation of Cerebral Vessel Geometric Morphometrics for Prediction of Mechanical Thrombectomy First Pass Outcome

Introduction: Vessel tortuosity is a major factor in successful first pass outcomes for mechanical thrombectomy (MT), but prior methods to quantify tortuosity are not accurate enough to predict outcome. We investigated a new method for vessel characterization and outcome prediction based on geometric morphometrics (GMM). Hypothesis: Our hypothesis was that morphometric analysis of engineered centerline landmarks would identify vessel characteristics that can better predict first pass MT outcome. Methods: Vessels and clots were manually segmented and reconstructed from pre-treatment CTA and nCCT images ( n =5 cases) (Fig. 1A). The vasculature corresponding to the ICA and MCA from the affected hemisphere was isolated, and centerlines were engineered as curved landmarks. MorphoJ, a GMM software, was used to complete generalized Procrustes and principal component (PC) Analysis that included registration of patient geometries, calculation of average morphology and landmark variation, and identification of anatomical landmarks differentiating MT outcomes (Fig. 1B). Morphometrics were compared against local and overall tortuosity by measuring the separability of and cohesion within outcome classes. Results: GMM produced two PCs, which described local variation in M1 (PC1) and the ICA (PC2) (Fig. 1B). When compared against vessel tortuosity features, GMM PCs increased the distance between outcome classes (first pass effect vs. no first pass effect), improving separability by 23.6%. Further, GMM PCs increased the compactness/cohesion of outcome classes, reducing cumulative distance between failures by 50% and successes by 9.4% (Fig. 1C). Conclusions: GMM analysis of pre-treatment vessel characteristic highlights regional variation in M1 as a strong indicator of MT failure and suggests that GMM has the potential to better predict MT outcome than ICA tortuosity alone. Investigation of more complex vessel morphometry through feature engineering is needed.