Tracking Study Research Articles

Serum Dioxin Levels in a Subset of Participants of the East Palestine, Ohio Train Derailment Health Tracking Study

Serum Dioxin Levels in a Subset of Participants of the East Palestine, Ohio Train Derailment Health Tracking Study

Performance Study of Object Tracking with Multiple Kalman Filters in Autonomous Driving Systems

Object tracking is an important and central aspect of autonomous driving, as it underlies the obstacle detection and avoidance systems of any type of autonomous vehicles. A widely used method for tracking is based on Kalman filters, both for linear and non-linear cases, with different computational burden. Unfortunately, object tracking algorithms are computationally intensive, and they may not easily meet the efficiency and responsiveness requirements of real-time applications such as autonomous driving. This issue motivates ad-hoc investigations to speed up the computation and make Kalman filtering available even within limited computational power. This paper carry out a performance evaluation of a Kalman filter based object tracking system taken from a real tramway use-case, and aims at improving its performance efficiency by leveraging parallelization. In particular, this work analyzes the possibilities of execution parallelization on multi-core processors, proposing a target-specific optimization approach and comparing the obtained results, then summing them in general lessons learned. Our technique achieves up to 80% reduction of single frame processing time in the most crowded cases.

Microstructure and mechanical properties of IN718 on 42CrMo for repair applications by laser directed energy deposition

Laser Directed Energy Deposition (LDED) has gained significant attention as a promising additive manufacturing technology for the repair and restoration of worn parts. The objective of this study is to assess the feasibility and performance of repairing 42CrMo substrates using Inconel 718(IN718) powder. In this study, the LDED process was employed to investigate the influence of varying laser power, scanning speed, and feed rate on a single track study. The optimal process parameters for trapezoidal groove repair were determined by comparing and evaluating factors such as dilution, aspect ratio, track continuity, and molten pool shape. Furthermore, the effects of different repair strategies (X-, Y-, Cross-paths) on the microstructure and mechanical properties were investigated. The results indicate that by using suitable process parameters, successful deposition of IN718 on 42CrMo is achieved. The investigation reveals elemental diffusion between the two materials, quenching phase transition on the substrate surface, and the formation of intermetallic compounds in the fusion zone. The fusion zone(FZ) and heat-affected zone(HAZ) exhibited the highest microhardness compared to the substrate. Significant changes in molten pool shape and arrangement were observed using different repair strategies, while the effect on grain size was not significant. Due to the high directionality of the samples fabricated using the LDED process, the samples of the X-path demonstrated the highest ultimate tensile strength and elongation compared to the other two repair strategies. The ultimate tensile strength after repair is comparable to that of the substrate, while the elongation is reduced.

Tracking Studies on the Effects of Qi Gong Fitness on Stress, Anxiety, and Depression Among Underprivileged Working Youth.

This study aimed to evaluate the effectiveness of Qi Gong fitness in alleviating stress, anxiety, and depression among underprivileged working youth with a follow-up study. Eighty subjects were randomly assigned to normal groups (NG) and treatment groups (TG), with 40 participants in each group. The Perceived Stress Scale (PSS), Generalized Anxiety Disorder 7 (GAD-7), and 24-Item Hamilton Rating Scale for Depression (HAMD-24) were used to evaluate the effect of Qi Gong fitness on alleviating stress, anxiety, and depression symptoms in underprivileged working youth. There was no significant difference in demographic outcome indicators between NG and TG. The main analytic results showed significant differences (P < .05) in the intra- and inter-group comparisons of NG and TG in stress, anxiety, and depression before and after intervention. When compared with prior intervention, NG and TG after intervention showed more favorable scores in PSS, GAD-7, and HAMD-24, among which PSS (NG: 51.61 ± 4.32 vs. 29.80 ± 3.08; TG: 55.21 ± 5.41 vs. 15.85 ± 2.25; P < .01), GAD-7 (NG: 10.83 ± 2.45 vs. 9.85 ± 2.52; TG: 12.23 ± 1.90 vs. 7.84 ± 1.57; P < .01), and HAMD-24 (NG: 10.83 ± 2.45 vs. 9.85 ± 2.52; TG: 25.63 ± 3.94 vs. 11.40 ± 3.82; P < .01); These results indicate that NG and TG have significant effects on alleviating occupational stress, anxiety, and depression in young underprivileged people. The study indicates that Qi Gong fitness had a positive effect on reducing and alleviating stress, anxiety, and depression among young underprivileged professionals. This highlights the potential benefits of incorporating Qi Gong fitness into treatment plans.

On the right TRACK: Providing comprehensive genomic profiling (CGP) and molecular tumor board (MTB) for patients (pts) with rare cancers.

3127 Background: Patients (pts) with rare cancers are under-represented in precision medicine trials despite making up ~22% of cancer incidence. We created the TCF-001 TRACK (Target RAre Cancer Knowledge, NCT04504604) study to provide a home-based, patient-centered trial utilizing comprehensive genomic profiling (CGP) at enrollment and progression with review by a molecular tumor board (MTB). Methods: Pts with rare cancers (incidence&lt;6/100,000) were enrolled and consented remotely (WCG IRB 1287011). Liquid (blood via mobile phlebotomy) and tissue biopsy samples were sent for CGP at Foundation Medicine. A fully remote MTB was convened following availability of each test. MTB notes and therapy recommendations were returned to patients and local physicians. Results: TRACK activated on 1 Oct 2020. The MTB included medical/surgical oncologists, genomics experts, molecular pathologists, a basic scientist, a pharmacist, a genetic counselor, regulatory staff, a scribe, an oncology fellow (“mentern”), and a medication acquisition specialist. MTB members were from 8 states. 132 eligible pts with evaluable results were enrolled from 41 states. Tissue and liquid biopsy results were available in 89 pts; tissue only in 5; liquid only in 38. 128 pts had an MTB before the 30 June2023 cut-off date (mean age 54.1 y; female 61.7%). There were &gt;40 rare/ultra-rare cancers, including cholangiocarcinoma (62) and soft tissue tumors (24). No pts had identical molecular alterations. The median number of pathogenic alterations per tissue sample was 3 (range: 0-14) and blood was 2 (range: 0-40). 3 patients had no pathogenic alterations on tissue or liquid CGP. The most commonly altered genes found by tissue biopsy CGP on study (n=68) were TP53(33.8%), CDKN2A (25.0%), KRAS (23.5%), CDKN2B (17.6%), IDH1 (17.6%), and MTAP (14.7%); by liquid biopsy (n=126), they were TP53 (31.7%), KRAS (11.9%), and IDH1 (8.7%), as well as genes often associated with clonal hematopoiesis: DNMT3A (22.2%), ATM (12.7%), and CHEK2 (8.7%). The sensitivity of liquid biopsy for pathogenic alterations found in tissue was 89.3% for pts with ctDNA tumor fraction (TF) ≥1% and 28.1% for TF &lt;1%. 1 pt had microsatellite instability. Median tumor mutational burden (TMB) by tissue was 2.5 mutations/megabase and by blood was 1.3. 3 pts had TMB≥10. Liquid biopsy results were available more quickly than tissue (median processing time, 9.1 vs 13.3 days); time from submission to processing was shorter for blood than tissue (2.4 vs 4.9 weeks). TRACK staff encountered 0.94 queries/sample. MTB recommendations based on CGP were generated for 87.5% of the 128 pts presented. Conclusions: A fully remote, advocacy driven, national precision genomics trial is feasible for managing rare cancers. CGP with expert MTB review can identify potentially targetable alterations and inform therapeutic options. Clinical trial information: NCT04504604 .

The Use of Machine Learning in Eye Tracking Studies in Medical Imaging: A Review.

Machine learning (ML) has revolutionized medical image-based diagnostics. In this review, we cover a rapidly emerging field that can be potentially significantly impacted by ML - eye tracking in medical imaging. The review investigates the clinical, algorithmic, and hardware properties of the existing studies. In particular, it evaluates 1) the type of eye-tracking equipment used and how the equipment aligns with study aims; 2) the software required to record and process eye-tracking data, which often requires user interface development, and controller command and voice recording; 3) the ML methodology utilized depending on the anatomy of interest, gaze data representation, and target clinical application. The review concludes with a summary of recommendations for future studies, and confirms that the inclusion of gaze data broadens the ML applicability in Radiology from computer-aided diagnosis (CAD) to gaze-based image annotation, physicians' error detection, fatigue recognition, and other areas of potentially high research and clinical impact.

Can displaced Anguilla marmorata return to their original habitat? Daily tracking study of their homing behavior.

Anguilla marmorata collected in the Odana River lower reaches were passive integrated transponder-tagged displaced and released into the upper river reaches (54 up-transported eels), and eels collected in the upper reaches were tagged and released downstream (52 down-transported eels). Their movements were detected once per day for 10 days using a portable radio-frequency identification (RFID) system. The homing rate of the down-transported eels was 38.9%, compared to 3.7% for the up-transported eels, suggesting that eels inhabiting upstream areas have relatively high fidelity to their habitats and downstream eels have less fidelity.

Less frequent face looking in infancy is related to autism likelihood status but not diagnosis: A study of parent-infant interaction

BackgroundPrevious research suggest that autistic children look less at faces than neurotypically developing children, but this finding is based predominantly on screen-based eye tracking studies, with unfamiliar faces used as stimuli. The aim of the current study was to assess 10-month-olds’ gaze to faces in a more naturalistic context - during free play with a parent - in relation to later autism diagnosis. MethodParents were asked to play with their infant ‘as they usually would’ with a set of toys on the floor. During the first 5 min of play, infant gaze to parent’s face was video coded. ResultsInfants at elevated likelihood of autism (N = 18 with later diagnosis; 46 without later diagnosis), regardless of later diagnostic status, produced fewer gaze shifts towards their parents’ faces than infants at low likelihood of autism (N = 18). Infants in all groups spent only ∼3 % of their time looking at parents’ faces, and there was no group difference in terms of the proportion of time spent looking at faces. There was neither a correlation between infant face looking and scores on the Autism Diagnostic Observation Schedule-2, nor between infant face looking and autistic traits in the parent. ConclusionsDuring toy play, all infants – irrespective of later diagnosis – spent very little time looking at parents’ faces. Infants at elevated likelihood of autism made fewer gazes to their parents’ faces than neurotypically developing infants, which could potentially affect opportunities for social learning. The effect was not specifically linked to later autism diagnosis.

Hematological and plasma profiles and ticks and tick-borne pathogens in wild Formosan black bears (Ursus thibetanus formosanus)

BackgroundThe endangered Formosan black bear (Ursus thibetanus formosanus) is the largest native carnivorous mammal in Taiwan. Diseases, poor management, illegal hunting, and habitat destruction are serious threats to the survival of bear populations. However, studies on the impact of diseases on bear populations are limited. Therefore, this study aimed to establish a database of the hematological and plasma profiles of free-ranging Formosan black bears and investigate the occurrence of ectoparasites, blood parasites, and vector-borne pathogens.MethodsFormosan black bears were captured in Yushan National Park (YNP) and Daxueshan Forest Recreation Area (DSY) in Taiwan. Blood samples were collected from each bear for hematological analysis and plasma biochemistry using a hematology analyzer. Parasites and pathogens were detected using a thin blood smear with Wright–Giemsa staining and polymerase chain reaction (PCR) assay. Additionally, macroscopic ectoparasites were collected from bears to detect blood parasites and other pathogens. Moreover, the relationships between the bear variables (sex, age, and occurrence of parasites or pathogens), ectoparasites, and infectious agents were also analyzed.ResultsIn all, 21 wild bears (14 in YNP and 7 in DSY) were captured and released during the satellite tracking studies. Hematological analysis and plasma biochemistry indicated significant differences in white blood cells (WBC), segments, creatine kinase (CK), and lactate dehydrogenase (LDH) levels between foot snare and culvert-captured bears. Additionally, there were significant differences in total plasma protein (TPP), creatinine, Ca2+, Mg2+, and K+ levels between male and female bears. Moreover, pathogen-infected bears had significantly higher erythrocyte sedimentation rate (ESR; 30 min and 1 h) and globulin levels than uninfected bears. In total, 240 ticks were collected from 13 bears, among which eight adult tick species were identified, including Haemaphysalis flava, Haemaphysalis hystricis, Amblyomma testudinarium, Ixodes ovatus, Dermacentor taiwanensis, Haemaphysalis longicornis, Ixodes acutitarsus, Amblyomma javanense, and nymphs belonging to Haemaphysalis spp. PCR revealed that 13 (61.90%) and 8 (38.10%) bears harbored Hepatozoon ursi and Babesia DNA, respectively. Among the ticks examined, 157 (65.41%) and 128 (53.33%) samples were positive for H. ursi and Babesia, respectively.ConclusionsTo the best of our knowledge, this is the first study to establish a database of the hematological and plasma profiles of wild Formosan black bears and investigate ectoparasite infestation and Hepatozoon and Babesia spp. infection. In conclusion, these findings may serve as a reference for monitoring the health and population of locally endangered bears.Graphical

The spatial extent of Walleye and Lake Sturgeon spawning migrations below a dam in the lower Black Sturgeon River, Lake Superior

AbstractIn the Laurentian Great Lakes, the issue of barrier removal is complicated by the presence of non‐native species below barriers. A fish tracking study was conducted to guide efforts for barrier remediation decisions for the restoration of fish populations with a focus on Walleye (Scander vitreus) and Lake Sturgeon (Acipenser fulvescens) in the Black Sturgeon River, a river system fragmented by a dam which blocks access of fishes to the majority of a large, otherwise barrier‐free watershed. Data from 3 years of spawning migrations (2018–2020) indicated that the Walleye population in Black Bay likely consists of both river (65%) and lake spawners (27%), with the remaining individuals spawning in the bay or river in different years. Walleye and Lake Sturgeon showed consistent differences in the extent to which individuals migrated upstream in the river during the spawning season, despite expectations that both species would spawn at the base of the dam when prevented from further migration. The dam was presumably a barrier to migration for Lake Sturgeon, as nearly all Lake Sturgeon that entered the river migrated to the base of the dam. In contrast, few Walleye entering the river during the spawning season migrated to the dam annually. These findings suggest that Walleye and Lake Sturgeon may not benefit equally, at least in the short term, from barrier remediation or dam removal.

A meta-analysis of parrot tracking studies reveals the difficulties of transmitter attachment to Little Corella (Cacatua sanguinea)

ABSTRACT Little Corellas (Cacatua sanguinea) are notorious for damaging crops and ornamental trees, and are an overabundant nuisance native in some urban areas. Habitat and landscape use studies ideally require the attachment of tracking devices. Here, we describe an attempt to attach GPS transmitters to Little Corellas using the backpack and keel-strap harness method. All five tracking devices initially attached to Little Corellas were removed by the birds within 48-hours. Additionally, a conspecific was observed chewing on the Teflon ribbon of a GPS harness shortly after the release of a Little Corella; a novel record that suggests cooperative abilities for the species. To complement our study, we conducted a literature review of parrot (psittacine) tracking studies. We investigated attachment styles and potential reasons for past device removals. Of the 46-relevant studies, neck collars were the most common attachment method (38.8%), followed by backpack harnesses (24.5%). Transmitter removal was documented in 28.3% of studies, with removals being most common for medium-sized (500–1000 g) species, and for combination (simultaneous back- and tail-mounts; n = 4) and backpack harness attachments (n = 6). Although there are relatively few parrot telemetry studies to date, they are increasing, and future studies will require considerable innovation and collaboration to overcome attachment style hurdles for difficult species, like the Little Corella.

Endothelial Dysfunction Linked to Ventricular Dysfunction in Children With Sickle Cell Disease, a 3D Speckle Tracking Study.

Sickle Cell Disease (SCD) is not a hematologic disease that occurs in isolation; it results in multi-organ complications. There is growing evidence of vascular stiffness as its underlying cause. This study aimed to investigate the relationship between endothelial stiffness and LV dysfunction in SCD patients and to explore its pathophysiology, particularly regarding the depletion of vasodilators such as Nitric Oxide (NO). 32 patients with established criteria for SCD and 40 healthy control subjects were selected for this case-control study. Comprehensive clinical assessment and assessment of endothelial function using Brachial Flow-mediated dilation (FMD) were performed, along with serum NO measurement, which was followed by diagnosis and echocardiographic assessment using 3D speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI). Collected SCD cases showed echocardiographic features of Systo-diastolic dysfunction with reduced FMD compared to controls, denoting endothelial dysfunction in those patients. LDH showed a marked elevation, while serum NO showed a significant reduction in cases compared with controls. We also noted a positive correlation between FMD on the one hand and measures of ventricular dysfunction and level of serum NO on the other hand, the latter proving that reduction of NO is responsible for reduced endothelial function. We present the first report to date to outline the role of vascular stiffness as measured by brachial FMD in the induction of left ventricular dysfunction in SCD. We recommend that more research be conducted regarding possible strategies to replenish serum NO stores to delay microvascular injury and, in turn, ventricular dysfunction in SCD.

Teaching Eye Tracking: Challenges and Perspectives

Eye tracking studies are more complicated to design, conduct, and to evaluate than traditional studies solely based on performance measures like error rates and response times. This is typically due to the more complex hardware setup, the calibration procedures, and the spatio-temporal nature of the recorded data that must be analyzed, visualized, or statistically evaluated. As a benefit, eye movement data contains patterns of visual attention over space and time that are not observable in standard error rates, completion times, and qualitative feedback. Students in the field of visualization, human-computer interaction, and user experience represent an interest group that would benefit from the application of eye tracking during their studies and in their future careers. Consequently, instructing them how to design, setup, conduct, and evaluate an eye tracking study is of special interest to current researchers involved in teaching. We describe education in eye tracking in five courses with 79 students from bachelor, master, and PhD levels. We outline our concept and discuss the challenges to raise people with no experience in eye tracking to a level of knowledge that allows them to apply this emerging technology to different scenarios including visual stimuli and related research questions. We discuss our teaching strategy in two course setups (summer school and traditional university lecture), the results of the students' eye tracking studies, and which challenges they and the teachers faced during the course.

Beyond screentime: a 7-day mobile tracking study among college students to disentangle smartphone screentime and content effects on sleep

ABSTRACT Health professionals and scholars alike consider evening smartphone use an important public health challenge. Existing research on the effects of smartphone usage on sleep has three limitations, namely reliance on self-report measures of smartphone use and/or sleep, limited attention to within-person effects, and a focus on general screentime rather than specific app usage. The current study addressed these limitations by conducting a seven-day study assessing smartphone use and sleep with a combination of subjective and objective measures among 75 students. The findings do not support the assumption that evening smartphone interferes with sleep. We did observe between-person relationships between specific indicators of smartphone usage and sleep, e.g. sleep quality was positively related to the use of meditation apps, and negatively related to the use of work-related apps. These findings indicate research should focus on what individuals do on their phones instead of how much time they spend.

Lexical-semantic processing in preschoolers with Developmental Language Disorder: an eye tracking study.

This study examined lexical-semantic processing in children with Developmental Language Disorder (DLD) during visually situated comprehension of real-time spoken words. Existing evidence suggests that children with DLD may experience challenges in lexical access and retrieval, as well as greater lexical competition compared to their peers with Typical Development (TD). However, the specific nature of these difficulties remains unclear. Using eye-tracking methodology, the study investigated the real-time comprehension of semantic relationships in children with DLD and their age-matched peers. The results revealed that, for relatively frequent nouns, both groups demonstrated similar comprehension of semantic relationships. Both groups favored the semantic competitor when it appeared with an unrelated visual referent. In turn, when the semantic competitor appeared with the visual referent of the spoken word, both groups disregarded the competitor. This finding shows that, although children with DLD usually present a relatively impoverished vocabulary, frequent nouns may not pose greater difficulties for them. While the temporal course of preference for the competitor or the referent was similar between the two groups, numerical, though non-significant, differences in the extension of the clusters were observed. In summary, this research demonstrates that monolingual preschoolers with DLD exhibit similar lexical access to frequent words compared to their peers with TD. Future studies should investigate the performance of children with DLD on less frequent words to provide a comprehensive understanding of their lexical-semantic abilities.

Cardiac Mechanics Evaluation in Preschool-Aged Children with Preterm Birth History: A Speckle Tracking and 4D Echocardiography Study.

Background: The premature-born adult population is set to grow significantly, and prematurity has emerged as an important cardiovascular risk factor. We aimed to comprehensively assess cardiac mechanics and function in a cohort of ex-preterm preschoolers. Methods: Ex-preterm children (<30 weeks of gestation), aged 2 to 5 years, underwent transthoracic 2D, speckle-tracking, and 4D echocardiography. The findings were compared with 19 full-term children. Results: Our cohort of 38 children with prematurity history showed a normal morpho-functional echocardiographic assessment. However, compared to controls, the indexed 3D end-diastolic volumes of ventricular chambers were reduced (left ventricle 58.7 ± 11.2 vs. 67.2 ± 8.5 mL/m2; right ventricle 50.3 ± 10.4 vs. 57.7 ± 11 mL/m2; p = 0.02). Left ventricle global and longitudinal systolic function were worse in terms of fraction shortening (32.9% ± 6.8 vs. 36.5% ± 5.4; p = 0.05), ejection fraction (59.2% ± 4.3 vs. 62.3% ± 3.7; p = 0.003), and global longitudinal strain (-23.6% ± 2.4 vs. -25.5% ± 1.7; p = 0.003). Finally, we found a reduced left atrial strain (47.4% ± 9.7 vs. 54.9% ± 6.8; p = 0.004). Conclusions: Preschool-aged ex-preterm children exhibited smaller ventricles and subclinical impairment of left ventricle systolic and diastolic function compared to term children. Long-term follow-up is warranted to track the evolution of these findings.

Impact of Type 2 Diabetes Mellitus on Left Atrioventricular Coupling and Left Atrial Deformation in Patients with Essential Hypertension: An MRI Feature Tracking Study.

Hypertension (HTN) and type 2 diabetes mellitus (T2DM) are both associated with left ventricular (LV) and left atrial (LA) structural and functional abnormalities; however, the relationship between the left atrium and ventricle in this population is unclear. To identify differences between hypertensive patients with and without T2DM as the basis for further investigation the atrioventricular coupling relationship. Cross-sectional, retrospective study. 89 hypertensive patients without T2DM [HTN (T2DM-)] (age: 58.4 +/- 11.9 years, 48 male), 62 hypertensive patients with T2DM [HTN (T2DM+)] (age: 58.5 +/- 9.1 years, 32 male) and 70 matched controls (age: 55.0 +/- 9.6 years, 37 male). 2D balanced steady-state free precession cine sequence at 3.0 T. LA reservoir, conduit, and booster strain (εs, εe, and εa) and strain rate (SRs, SRe, and SRa), LV radial, circumferential and longitudinal peak strain (PS) and peak systolic strain rate and peak diastolic strain rate (PSSR and PDSR) were derived from LA and LV cine images and compared between groups. Chi-square or Fisher's exact test, one-way analysis of variance, analysis of covariance, Pearson's correlation, multivariable linear regression analysis, and intraclass correlation coefficient. A P value <0.05 was considered significant. Compared with controls, εs, εe, SRe and PS-longitudinal, PDSR-radial, and PDSR-longitudinal were significantly lower in HTN (T2DM-) group, and they were even lower in HTN (T2DM+) group than in both controls and HTN (T2DM-) group. SRs, εa, SRa, as well as PS-radial, PS-circumferential, PSSR-radial, and PSSR-circumferential were significantly lower in HTN (T2DM+) compared with controls. Multivariable regression analyses demonstrated that: T2DM and PS-circumferential and PS-longitudinal (β = -4.026, -0.486, and -0.670, respectively) were significantly associated with εs; T2DM and PDSR-radial and PDSR-circumferential were significantly associated with εe (β = -3.406, -3.352, and -6.290, respectively); T2DM and PDSR-radial were significantly associated with SRe (β = 0.371 and 0.270, respectively); T2DM and PDSR-longitudinal were significantly associated with εa (β = -1.831 and 5.215, respectively); and PDSR-longitudinal was significantly associated with SRa (β = 1.07). In hypertensive patients, there was severer LA dysfunction in those with coexisting T2DM, which may be associated with more severe LV dysfunction and suggests adverse atrioventricular coupling. 3. Stage 3.

The role of neuroendothelial cells in aging-related vascular cognitive impairment

Vascular cognitive impairment (VCI) is a growing health problem in many developed countries due to aging of its population. Aging-induced impairment of neurovascular coupling (NVC) responses and brain microvascular rarefaction have been implicated as major driving mechanisms in age-related cognitive decline. One of the cellular hallmarks of NVC involve the release of vasodilator nitric oxide (NO) by endothelial cells in response to mediators released from activated neurons. Recent studies from our group identified and characterized a novel, minority subtype of scattered ECs with endothelial and neuronal characteristics, hence the name neuroendothelial cell (NECs). NECs present a well-defined arteriovenous zonal localization exclusively in small resistance arterioles with the highest density in the brain followed by the kidney. Intravital multiphoton microscopy (MPM) of intact brain arterioles in vivo suggest that NECs play an important role in regulating blood flow to the brain and able to detect changes in systemic blood pressure, hypoxia and perhaps other metabolic changes in the local microenvironment. Our central hypothesis is that NECs are novel key players in blood flow autoregulation, vascular control of organ functions in both short-term (hemodynamics) and long-term (angiogenesis, tissue regeneration). We further hypothesize that the decrease in NEC density and function in aged subjects is a major player in the development of age-related cerebral microvascular pathologies and that augmenting NEC number and function in aged animals will provide therapeutic benefit. This study used a NEC specific comprehensive research toolbox including NEC-GFP transgenic mouse models and high-resolution single-cell based transcriptome analysis to establish the NEC specific molecular atlas in young adult (3 month of age) and aged (2 years of age) animals. Furthermore, transgenic animal models combined with serial intravital imaging of the same tissue volume over consecutive days was used to study changes in vascular endothelial cell composition in response to NEC stimuli in young adult and aged mice. Cell fate tracking studies of the Nos1-lineage combined with Nos1 immunostaining revealed that NECs represent a permanent cell type with terminal neuronal differentiation. Importantly, NEC density is reduced with aging in all organs including the brain. High resolution single-cell based transcriptome analysis of 100K endothelial cells isolated from mouse brain demonstrated that, in contrast to other ECs, NECs highly express several traditional (e.g., Nos1, Angpt1, Egfl8) and novel (e.g., Cytl1, MGP, Gkn3) tissue trophic factors that are known to play important roles in acute hemodynamic responses including NO mediated functional hyperemia, and in chronic settings in angiogenesis, aging, vascular (dys)function, and chronic vascular diseases. Furthermore, the expression of many of these factors were significantly reduced in NECs isolated from aged animals. In conclusion, the newly discovered NEC-specific molecular and signaling mechanisms may play a role in the age-related decrease in NVC capacity and microvascular rarefaction and may be targeted for therapeutic benefits in age related VCI. American Society of Nephrology Carl W. Gottschalk Research Scholar Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Visual Field Restriction in the Recognition of Basic Facial Expressions: A Combined Eye Tracking and Gaze Contingency Study.

Uncertainties and discrepant results in identifying crucial areas for emotional facial expression recognition may stem from the eye tracking data analysis methods used. Many studies employ parameters of analysis that predominantly prioritize the examination of the foveal vision angle, ignoring the potential influences of simultaneous parafoveal and peripheral information. To explore the possible underlying causes of these discrepancies, we investigated the role of the visual field aperture in emotional facial expression recognition with 163 volunteers randomly assigned to three groups: no visual restriction (NVR), parafoveal and foveal vision (PFFV), and foveal vision (FV). Employing eye tracking and gaze contingency, we collected visual inspection and judgment data over 30 frontal face images, equally distributed among five emotions. Raw eye tracking data underwent Eye Movements Metrics and Visualizations (EyeMMV) processing. Accordingly, the visual inspection time, number of fixations, and fixation duration increased with the visual field restriction. Nevertheless, the accuracy showed significant differences among the NVR/FV and PFFV/FV groups, despite there being no difference in NVR/PFFV. The findings underscore the impact of specific visual field areas on facial expression recognition, highlighting the importance of parafoveal vision. The results suggest that eye tracking data analysis methods should incorporate projection angles extending to at least the parafoveal level.

Towards a typology of virtual tourists: Efficacy of visual patterns and attentional cues

Virtual tourism is rapidly emerging in prominence in contemporary tourism research. Previous studies tend to consider the virtual tourism population as a homogeneous entity, resulting in unintended consequences. Despite the ocular-centric nature within virtual environments, existing eye tracking studies have rarely classified virtual tourists into benefit-based segments, discounting the critical role of pre-existing visual patterns and associated attentional cues. Subsequently, this research constructs a theoretically rigorous and evidence-informed typology of virtual tourists, based on attention patterns discerned from eye tracking trajectory and associated visual cues, triangulated with interview data. Building on the theory of bottom-up and top-down attentional processing, four discrete virtual tourist typologies emerged in terms of visual completeness and visual cognition: visual passives, curious scanners, focused observers, and comprehensive engagers. The visual and cognitive characteristics among the groups were collated, revealing significant differences articulated between each of the virtual tourist typologies. This research not only advances knowledge through a renewed emphasis on typology-driven theorising within the virtual tourism population, but also offers practical insights into implementing an innovative and effective segmentation approach. Future research should consider comparing the theoretical and empirical specifications of the virtual tourist typology.