Higher Peak Velocity Research Articles

Peak Velocity Pressure of Air Traffic Control Towers: A Comparative Study

The aim of the study was to compare the structural resistance of air traffic control towers (ATCTs) in Europe over 100 feet (30.48 meters) in height by determining their peak velocity pressure. A comprehensive examination was conducted on the ATCTs of 64 airports across Europe, with a reference to the EN-1991-1-4 criteria. The findings revealed notable differences in wind speeds and peak velocity pressure values experienced by ATCTs located in diverse geographical regions of Europe. The Athens Airport ATCT recorded the highest peak velocity pressure at 2.52 kN/m², while the lowest value was recorded at Zagreb Airport ATCT at 0.89 kN/m². These differences play a crucial role in determining the structural resistance of ATCTs. ATCTs exposed to high peak velocity pressures should use stronger materials and incorporate aerodynamic designs. Considering the significant influence of geographical location on wind loads, these results provide important insights into the safety of existing and future ATCTs. It is recommended that these findings be extended by investigating ATCTs in different geographical regions and that structural design strategies against wind loads be more thoroughly investigated in future studies.

Relationships between sprint skating performance and insole plantar forces in national-level hockey athletes

BackgroundSprint skating is essential for competitive success in hockey. Previous studies have highlighted various measures of lower-body strength and power as key factors influencing sprint performance. However, while these studies have indicated a significant association between the ability to exert greater force and impulse into the ice surface, and the capacity to achieve faster sprint skating speeds, the direct relationship between these factors remains largely inferred. Research questionWhat are the relationships between insole plantar force variables, sprint skating performance, and their association with physical capacity measures, in national-level male hockey athletes? MethodsAthletes (n=13) performed 25 m sprint skating trials with insole force sensors and completed: ankle dorsiflexion and hip abduction range-of-motion (ROM), countermovement jump (CMJ), seated single-leg jump, and 10–5 repeated-hop test (RHT) assessments. ResultsRelationships were assessed using Kendall’s Tau rank correlations (τ), with significant relationships identified between mean relative weight acceptance impulse [WAI] and 0–5 m (τ=0.47) and total distance (τ=0.46) times. Additionally, significant associations were observed between mean relative WAI and: CMJ relative eccentric deceleration impulse (τ=0.44), CMJ eccentric peak velocity (τ=-0.46) and RHT concentric impulse (τ=-0.56). Finally, significant relationships were identified between mean relative PI for all strides and the 10–20 m split, with peak velocity (PV) (τ=-0.58 to −0.73); and between ankle dorsiflexion ROM and PV (τ=-0.57). SignificanceAthletes with faster initial acceleration and overall sprint performance times demonstrated lower relative WAI during their strides and employed a jump strategy that optimized concentric impulse with a rapid eccentric phase. To attain a high PV the athletes appeared to require a stride that maximized glide and minimized vertical force, with greater ankle dorsiflexion ROM potentially facilitating this.

Comparative analysis of motor skill acquisition in a novel bimanual task: the role of mental representation and sensorimotor feedback.

This study investigates the multifaceted nature of motor learning in a complex bimanual task by examining the interplay between mental representation structures, biomechanics, tactile pressure, and performance. We developed a novel maze game requiring participants to maneuver a rolling sphere through a maze, exemplifying complex sequential coordination of vision and haptic control using both hands. A key component of this study is the introduction of cognitive primitives, fundamental units of cognitive and motor actions that represent specific movement patterns and strategies. Participants were divided into two groups based on initial performance: poor performers (PPG) and good performers (GPG). The experimental setup employed motion capture and innovative tactile sensors to capture a detailed multimodal picture of the interaction process. Our primary aims were to (1) assess the effects of daily practice on task performance, biomechanics, and tactile pressure, (2) examine the relationship between changes in mental representation structures and skill performance, and (3) explore the interplay between biomechanics, tactile pressure, and cognitive representation in motor learning. Performance analysis showed that motor skills improved with practice, with the GPG outperforming the PPG in maze navigation efficiency. Biomechanical analysis revealed that the GPG demonstrated superior movement strategies, as indicated by higher peak velocities and fewer velocity peaks during task execution. Tactile feedback analysis showed that GPG participants applied more precise and focused pressure with their right-hand thumb, suggesting enhanced motor control. Cognitively, both groups refined their mental representation structures over time, but the GPG exhibited a more structured and sophisticated cognitive mapping of the task post-practice. The findings highlight the intertwined nature of biomechanical control, tactile feedback, and cognitive processing in motor skill acquisition. The results support established theories, such as the cognitive action architecture approach, emphasizing the role of mental representation in planning and executing motor actions. The integration of cognitive primitives in our analysis provides a theoretical framework that connects observable behaviors to underlying cognitive strategies, enhancing the understanding of motor learning across various contexts. Our study underscores the necessity of a holistic approach to motor learning research, recognizing the complex interaction between cognitive and motor processes in skill acquisition.

Experimental characterization of exhaled flow dynamics of human breathing and vocalization

During the onging pandemic of COVID-19, there are numerous asymptomatic patients who are infectious. The exhaled droplets from their daily respiratory activities like breathing or speaking can be the sources of airborne disease transmission of COVID-19. The understanding of the airflow dynamics of these respiratory activities may be helpful to develop effective measures to prevent and control the spread of the disease. In this study, the exhaled flows from human breathing and vocalization of specific syllables are characterized using particle image velocimetry (PIV) and smoke visualization. The exhaled flow generated by ten phonemes including vowels, fricatives, affricates, plosives and nasals as well as mouth breathing are studied. The dynamic developments of the airflow processes are described by a series of parameters, including peak velocity, peak velocity time, duration time, propagation velocity and distance. Results show that vocalization of affricates and plosives as well as mouth breathing tend to have higher peak velocities and propagation distances. The evolutions of exhaled flows generated from these respiratory processes are found to have different jet structures, which are related to the stroke ratio (L/D). The flow field of a small L/D only has a pair of dominant vortices. Whereas that of a large L/D presents both a pair of dominant vortex ring and a trailing jet. Certain phoneme (e.g., /t/) is found to display a two-stage jet similar to a cough with the starting jet and an interrupted jet. The characterization of human exhaled flow of this study may be helpful to provide basis of CFD simulations and a better understanding of the spread of airborne diseases from human breathing.

Abstract 13873: Deep Learning-Based GWAS of Aortic Valve Function Links 81 Loci to Aortic Stenosis Risk

Background & Aims: The genetic influences on normal aortic valve (AV) function and their impact on aortic stenosis (AS) risk are of significant interest. We sought to identify common genetic determinants of normal variation in AV function, and to understand their relationship with clinical disease. Methods: We used deep learning to measure peak velocity, mean gradient, and aortic valve area from MRI in UK Biobank participants. We conducted genome-wide association studies (GWAS) in a subset of 44,780 participants without cardiovascular disease. We performed multi-trait analysis of GWAS (MTAG) to incorporate data from AV measurements and AS diagnoses in UK Biobank and FinnGen, and applied PRScs to construct polygenic scores (PGS). Results: In the unadjusted analysis, 26 loci were associated with at least one AV measurement. Incorporating the AS GWAS using MTAG, we identified 81 distinct loci (62 with AV traits, 54 with AS, 35 overlapping), including PCSK9 (β=0.032, P=5.8E-09) and LDLR (β=0.018, P=2.3E-10). Additional loci were associated with lipid metabolism (LPA, FADS2, SORT1), atherosclerosis (CDKN2B, ARHGEF26, OTUD7B, PRDM16), inflammation (IL6, KLF2, TRAF1), and cardiac development and aortic root function (SMAD3, GATA4, ELN, TBX20, TEX41). The PGS for the unadjusted mean gradient was predictive of AS in FinnGen (HR 1.36 for the top 5% of participants vs all others, P=1.8E-14). All of Us participants in the top 5% of the MTAG-adjusted peak velocity PGS had an HR of 2.5 for incident AS (P=4.4E-08). Mendelian randomization showed association between Lp(a) and LDL—but not ApoA—on greater peak velocity (P=2.7E-13, P=1.6E-16, and P=0.60, respectively). Conclusion: We identified 81 genetic loci linked to AV function or AS. AV measurement PGS were strong predictors of AS risk. ApoB and Lp(a) showed causal association with higher peak velocity. These findings have implications for the early pathogenesis of AS and suggest modifiable pathways as targets for prevention.

Abstract 15834: The Utility of Intra-Operative Coronary Doppler Profiles in Predicting Early and Late Major Adverse Cardiovascular Events After Arterial Switch Operation

Introduction: Coronary artery transfer is the most important technical point in the arterial switch operation (ASO). Intra-operative echocardiography identifies aberrancies in coronary artery Doppler profiles guiding immediate surgical management. Objective: We sought to determine whether abnormal intra-operative coronary artery Doppler profiles are associated with major adverse cardiovascular events (MACE; death, transplantation, heart failure, arrhythmia, need for coronary re-intervention) following ASO at 30-days, 5 & 10 years. Methods: Single centre retrospective review of patients undergoing ASO between 2009 - 2022. Transesophageal or epicardial intra-operative coronary artery Doppler profiles were analysed. Patient variables were abstracted from records. Freedom from MACE was estimated using Kaplan-Meier methods. Results: 347 patients were included. Coronary anatomy was usual (1LCx2R) in 237 (68%), single sinus ostia in 24 (7%), intramural in 14 (4 %). Overall 30-day MACE was 11.2% [8.3%, 15.1%], increasing to 25% [12.1, 47.4%] with single sinus ostia & 35.7% [16.7%, 65.7%] with intramural. Overall 5 & 10-year MACE was 16.5% [12.9, 20.9%], 33.8% [18.5%, 56.4%] with single sinus ostia & 50.0% [27.8%, 77.1%] with intramural. A higher probability of MACE was seen with coronary Doppler reverse flow, absence of normal pattern (Table 1) and a higher peak velocity (Figure 1). Overall 30-day mortality was 1.2% [95%CI 0.4%, 3.0%] and at 5 & 10 years was 6.5% [4.3%, 9.8%]. Conclusions: Intra-operative abnormal coronary artery Doppler profiles during ASO may identify those at highest risk of early and late adverse events, guiding follow-up surveillance strategies.

The Effect of Stimulus Contrast and Spatial Position on Saccadic Eye Movement Parameters.

(1) Background: Saccadic eye movements are rapid eye movements aimed to position the object image on the central retina, ensuring high-resolution data sampling across the visual field. Although saccadic eye movements are studied extensively, different experimental settings applied across different studies have left an open question of whether and how stimulus parameters can affect the saccadic performance. The current study aims to explore the effect of stimulus contrast and spatial position on saccadic eye movement latency, peak velocity and accuracy measurements. (2) Methods: Saccadic eye movement targets of different contrast levels were presented at four different spatial positions. The eye movements were recorded with a Tobii Pro Fusion video-oculograph (250 Hz). (3) Results: The results demonstrate a significant effect of stimulus spatial position on the latency and peak velocity measurements at a medium grey background, 30 cd/m2 (negative and positive stimulus polarity), light grey background, 90 cd/m2 (negative polarity), and black background, 3 cd/m2 (positive polarity). A significant effect of the stimulus spatial position was observed on the accuracy measurements when the saccadic eye movement stimuli were presented on a medium grey background (negative polarity) and on a black background. No significant effect of stimulus contrast was observed on the peak velocity measurements under all conditions. A significant stimulus contrast effect on latency and accuracy was observed only on a light grey background. (4) Conclusions: The best saccadic eye movement performance (lowest latency, highest peak velocity and accuracy measurements) can be observed when the saccades are oriented to the right and left from the central fixation point. Furthermore, when presenting the stimulus on a light grey background, a very low contrast stimuli should be considered carefully.

Short-term Outcomes of Urgent Transcatheter Aortic Valve Replacement in Symptomatic Aortic Stenosis That Requires Emergency Hospital Admission.

Objective This study retrospectively compared the outcomes of emergently admitted patients with aortic stenosis (AS) with or without urgent transcatheter aortic valve replacement (TAVR). Methods Patients hospitalized between February 2015 and December 2019 for symptomatic AS were retrospectively analyzed by comparing the received conservative management [continued medical therapy with or without elective surgical transcatheter replacement (SAVR) or TAVR scheduled after the index hospitalization] and urgent TAVR (TAVR during the index hospitalization). Results The cohort comprised 114 patients with symptomatic AS who required emergency admission. Urgent TAVR was performed for 37 patients, while conservative management was provided for 77 patients, including 1 who received urgent SAVR. Urgent TAVR was more likely to be performed in patients with a history of hospitalization for heart failure, high New York Heart Association class scores, a lower clinical frailty scale at admission, and a high aortic valve peak velocity (p=0.01, p<0.001, p<0.01 and p=0.02, respectively). Kaplan-Meier analyses with log-rank test revealed favorable outcomes of urgent TAVR in all-cause mortality and cardiovascular events within 60 days of admission (p<0.01, p<0.01, respectively). Conclusion Urgent TAVR had better short-term outcomes in patients with symptomatic AS who required emergency hospital admission than conservative management. When considering urgent TAVR, patients with typical heart failure symptoms due to AS with a history of heart failure hospitalization and relatively little frailty can be selected.

Faces in scenes attract rapid saccades.

During natural vision, the human visual system has to process upcoming eye movements in parallel to currently fixated stimuli. Saccades targeting isolated faces are known to have lower latency and higher velocity, but it is unclear how this generalizes to the natural cycle of saccades and fixations during free-viewing of complex scenes. To which degree can the visual system process high-level features of extrafoveal stimuli when they are embedded in visual clutter and compete with concurrent foveal input? Here, we investigated how free-viewing dynamics vary as a function of an upcoming fixation target while controlling for various low-level factors. We found strong evidence that face- versus inanimate object-directed saccades are preceded by shorter fixations and have higher peak velocity. Interestingly, the boundary conditions for these two effects are dissociated. The effect on fixation duration was limited to face saccades, which were small and followed the trajectory of the preceding one, early in a trial. This is reminiscent of a recently proposed model of perisaccadic retinotopic shifts of attention. The effect on saccadic velocity, however, extended to very large saccades and increased with trial duration. These findings suggest that multiple, independent mechanisms interact to process high-level features of extrafoveal targets and modulate the dynamics of natural vision.

Reasons for and time to seeking healthcare in cardiac clinics by women with a history of successfully treated breast cancer

Background: Various methods of breast cancer treatment are potentially cardiotoxic: anthracycline chemotherapy, HER2-targeted therapy, and radiation therapy to the left side of the chest. In clinical practice, cardiologists deal with a wide range of complications caused by the mentioned methods.Objective: To analyze the reasons for and timing of seeking healthcare in cardiac clinics by women with a history of successfully treated breast cancer.Methods: Our single-center retrospective observational study included 125 women (mean age at the time of seeking healthcare was 68.1 ± 8.6 years).Results: Patients with a history of radiation therapy had higher peak velocity (P = .015) and peak gradient (P = .017) across the aortic valve. As part of their examination and treatment 71 patients underwent coronary angiography. Of them, 21 patients (29.6%) had coronary artery stenting, and 23 patients (32.4%) underwent coronary artery bypass grafting. Forty-two patients (33.6%) underwent heart valve replacement: aortic valve replacement in 92.9% of the cases (n = 39) and mitral valve replacement in 7.1% of the cases (n = 3). We found a strong negative correlation between the age at the time of radiation therapy and the time to onset of valvular heart disease (r = −0.748; P = .000004) and an average negative correlation between the age and the time to surgical treatment (r = −0.695; P = .00003).Conclusion: We studied the main reasons for seeking healthcare in cardiac clinics by women with a history of breast cancer, analyzed cardiac operations in terms of antitumor therapy types, and found a strong correlation between the age at the time of antitumor therapy and the time to onset of valvular heart disease, as well as the time to cardiac surgery. Received 20 November 2022. Revised 21 May 2023. Accepted 31 May 2023. Funding: The study was supported by Ministry of Science and Higher Education of Russian Federation (No. 075-15-2022-301). Conflict of interest: The authors declare no conflict of interest. Contribution of the authors: The authors contributed equally to this article.

#5555 TAKAYASU ARTERITIS IN THE TIME OF SARS-COV-2

Abstract Background and Aims SARS CoV 2 infection is characterized by pulmonary, cardiovascular, neurological and other complications. New onset hypertension after SARS Cov 2 infection was observed in various studies with an unclear mechanism. Vessel inflammation is a common finding in these patients. Case A young woman (24 years old) referred to our Unit for high blood pressure levels appeared few days after SARS COVID 2 infection. She had a positive familiar history of hypertension. A 24 hours blood pressure monitoring confirmed hypertension and the patient was treated with a beta-blocker and referred to the nephrologist. Physical examination was negative and peripheral pulses were palpable. Blood pressure was 150/90 mmHg without significative discrepancy (&amp;lt;10 mmHg) between right and left arm and between upper and lower limbs. Carotid-femoral and carotid-radial pulse wave velocity was in the upper limit of the normal range (9.8 and 8.0 m/sec respectively), renal function was preserved (serum creatinine 0.6 mg/dl, eGFR 154 ml/min) and proteinuria was 450 mg/die. C-reactive protein was 13 mg/L. Complement components C3 and C4 as well as IgG and anti-neutrophil cytoplasmic antibody (ANCA) levels were in the normal range. IgA and IgM were slightly elevated and anti-nuclear antibody (ANA) levels were 1:160. TSH was in the normal range. Patient was switched to calcium channel blockers and a screening to exclude secondary hypertension was performed. Hormonal profile showed hypersecretion of cortex and medullary adrenal gland (high renin and aldosterone, plasma and urinary cortisol, and epinephrine levels). Patient was treated with ACE inhibitor and showed an optimal blood pressure profile. Abdominal-Chest CT angiography detected no increase in adrenal gland dimension. Conversely, a left renal artery stenosis and a mild enlargement of the para-aortic tissue, suggestive of a retroperitoneal fibrosis, was described (Figure 1). A Doppler ultrasound examination confirmed a high systolic peak velocity in left renal artery and a low resistive index in the left kidney. According to the diagnosis of renal fibrosis, patient was treated with oral prednisone at a dosage of 1 mg/Kg/BW. Three months later, Doppler ultrasound and CT were materially unchanged. After a case revision and a negative evidence of inflammation at PET-FDG examination, the Takayasu Arteritis diagnosis was formulated and the patient underwent left renal artery angioplasty. Oral prednisone was tapered and methotrexate was started. One month later blood pressure and Doppler ultrasound velocimetric parameters were normalized. Conclusion This case report suggests that Takayasu arteritis may occur after SARS COVID 2 infection.

Finger Kinematics during Human Hand Grip and Release.

A bionic robotic hand can perform many movements similar to a human hand. However, there is still a significant gap in manipulation between robot and human hands. It is necessary to understand the finger kinematics and motion patterns of human hands to improve the performance of robotic hands. This study aimed to comprehensively investigate normal hand motion patterns by evaluating the kinematics of hand grip and release in healthy individuals. The data corresponding to rapid grip and release were collected from the dominant hands of 22 healthy people by sensory glove. The kinematics of 14 finger joints were analyzed, including the dynamic range of motion (ROM), peak velocity, joint sequence and finger sequence. The results show that the proximal interphalangeal (PIP) joint had a larger dynamic ROM than metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints. Additionally, the PIP joint had the highest peak velocity, both in flexion and extension. For joint sequence, the PIP joint moved prior to the DIP or MCP joints during flexion, while extension started in DIP or MCP joints, followed by the PIP joint. Regarding the finger sequence, the thumb started to move before the four fingers, and stopped moving after the fingers during both grip and release. This study explored the normal motion patterns in hand grip and release, which provided a kinematic reference for the design of robotic hands and thus contributes to its development.

Numerical investigation of synthetic jets generated by various signals in quiescent ambient

Synthetic jets generated by four typical and two novel exciting signals are simulated in the present study. Vortex structures and velocity characteristics are analyzed in detail to evaluate the effectiveness of the exciting signal. The synthetic jets excited with the four typical signals, i.e., the triangle signal, sinusoidal signal, trapezoid signal, and square signal, are simulated in the first place. It is found that stronger synthetic jets and higher entrainment can be realized by signals with higher peak velocity. Among the typical signals, the most satisfactory performance is observed in the case of the triangle signal. Two novel signals, i.e., the bi-frequency signal and the signal with varying duty cycle k, are subsequently simulated. The numerical result shows that, even with the same peak velocity, the two novel signals have better performance than the triangle signal. The optimal result is achieved in the case of the varying k signal. The signal momentum msignal is used to fundamentally explain the mechanism behind the different performances of the synthetic jets generated with different signals with the same characteristic velocity. The parameter, i.e., characteristic momentum Msignal, is subsequently utilized to represent the performances of the different signals. The synthetic jets generated with the signals of higher characteristic momentum are found to manifest better performance under the condition of the same frequency and characteristic velocity.

Prognostic value of the dynamic hepatorenal function on intermediate-term mortality in TAVI patients with survival to discharge.

Renal and liver dysfunctions are risk factors for mortality in patients with severe aortic stenosis (AS). Transcatheter aortic valve implantation (TAVI) has the potential to break the vicious cycle between AS and hepatorenal dysfunction by relieving aortic valve obstruction. A part of patients can derive hepatorenal function improvement from TAVI, and this noncardiac benefit improves theintermediate-term outcomes. We developed this retrospective cohort study in 439 consecutive patients undergoing TAVI and described the dynamic hepatorenal function assessed by model for end-stage liver diseasemodel for end-stage liver disease (MELD)-XI score in subgroups. The endpoint was 2-year all-cause mortality. Receiver-operating characteristic analysis showed that the baseline MELD-XI score of 10.71 was the cutoff point. A high MELD-XI score (>10.71) at baseline was an independent predictor of the 2-year mortality hazard ratio(HR: 2.65 [1.29-5.47], p = .008). After TAVI, patients with irreversible high MELD-XI scores had a higher risk of 2-year mortality than patients who improved from high to low MELD-XI scores (HR: 2.50 [1.06-5.91], p = .03). Factors associated with reversible MELD-XI scores improvement were low baseline MELD-XI scores (≤12.00, odds ratio [OR]: 2.02 [1.04-3.94], p = .04), high aortic valve peak velocity (≥5 m/s, OR: 2.17 [1.11-4.24], p = .02), and low body mass index(≤25 kg/m2 , OR: 2.73 [1.25-5.98], p = .01). High MELD-XI score at baseline is an independent predictor for 2-year mortality. Patients with hepatorenal function improvement after TAVI have better outcomes. For patients with irreversible hepatorenal dysfunction after TAVI, further optimization of the subsequent treatment after TAVI is needed to improve the outcomes.

Phenotyping patients with aortic stenosis using cluster analysis to determine mortality and suitability for transcatheter aortic valve replacement

Abstract Background Current classification of aortic stenosis (AS) is based on guideline-recommended echocardiographic criteria. Heterogeneity of patients with AS is increasingly recognised. Clinical and demographic factors in addition to echocardiographic parameters can determine those who may derive the greatest benefit from transcatheter aortic valvular replacement (TAVR) and influence patient outcomes. Purpose Our study aims to define distinct AS echocardiographic and clinical phenotypes and to accurately identify patients most likely to die or benefit from TAVR. Methods Patients diagnosed with at least mild AS between 2009 and 2021 (pre-TAVR) from a multicentre echocardiographic database at a quaternary referral centre included. Unsupervised clustering analysis was performed using K-means, partitioning around medoids, density-based spatial clustering, hierarchical clustering algorithms on 56 demographic, echocardiographic and clinical variables. Associations between AS clusters and clinical outcomes (all-cause mortality, cardiovascular death, AS-related death), and effect of TAVR on clinical outcomes were assessed using Cox proportional hazards models. Results Four AS clusters were identified amongst 2,456 patients with median follow up of 4.7 years (median age: 77 years, male: 66%). Cluster 1 (n=542) had the lowest aortic valvular area (AVA, mean 0.89 cm2), highest peak velocity (Vmax) (4.3 m/s), mean gradient (45 mmHg), and the most bicuspid valves (12.7%). Cluster 2 (n=827) had 50% women, mostly in sinus rhythm and less severe echo findings. Cluster 3 (n=592) had predominantly males (85%) with a mean AVA of 1.65 cm2 and the most cardiovascular risk factors (hypertension, diabetes, hyperlipidaemia, stable angina, acute coronary syndrome, and atherosclerosis). Cluster 4 (n=495) had the highest left atrial size (mean 32 cm2), the most atrial fibrillation (82%), heart failure (80%), rheumatic heart disease (26%) and chronic kidney disease (55.8%), but only moderate AS (AVA 1.3 cm2, Vmax 3 m/s). All-cause mortality was highest in Cluster 4 (Hazard ratio (HR) 1.57, 95% CI: 1.33–1.85) and AS-related death was highest in Cluster 1 (HR 3.96, 95% CI: 2.61–5.99, Figure 1A). TAVR reduced AS-related death in only Cluster 1 (HR 0.22, 95% CI: 0.05–0.88, p=0.033, Figure 1B). Conclusions We demonstrated that phenotypic classification via a combination of demographics, echocardiography and comorbidities can significantly improve management of AS. This personalised approach can be implemented to identify patients most likely to die and most likely to benefit from TAVR. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): National Heart Foundation of Australia (ID: 102578)National Health and Medical Research Council of Australia (ID: 1191044)

Speed-accuracy tradeoffs influence the main sequence of saccadic eye movements

Several studies have proposed that an optimal speed-accuracy tradeoff underlies the stereotyped relationship between amplitude, duration and peak velocity of saccades (main sequence). To test this theory, we asked 8 participants to make saccades to Gaussian-blurred spots and manipulated the task’s accuracy constraints by varying target size (1, 3, and 5°). The largest targets indeed yielded more endpoint scatter (and lower gains) than the smallest targets, although this effect subsided with target eccentricity. The main sequence depended on several interacting factors: saccade latency, saccade gain and target size. Early saccades, which were faster than amplitude-matched late saccades, followed the target-size dependency one would expect from a speed-accuracy tradeoff process. They had higher peak velocities and shorter durations for larger targets than for smaller targets. For late saccades, however, the opposite was found. Deviations from the main sequence also covaried with saccade gain, in line with the idea that motor noise underlies part of the endpoint variability. Thus, our data provide partial evidence that the saccadic system weighs the detrimental effects of motor noise on saccade accuracy against movement duration and speed, but other factors also modulate the kinematics. We discuss the possible involvement of parallel saccade pathways to account for our findings.

GaN Schottky diode on sapphire substrate for THz frequency multiplier applications

Gallium Nitride, because of its high breakdown field, and peak and saturated electron drift velocity, high chemical stability and high thermal conductivity, is a very promising material as candidate for Schottky varactor diodes for next-generation high-power frequency multipliers. Similarly to the huge interest in the field of HEMT for high frequency and power application, GaN Schottky diodes is of a high interest for the next technological step for frequency multipliers for THz generations, replacing GaAs Schottky diodes. Due to a lack of research focused on GaN Schottky diodes for frequency multiplication, the design and fabrication of GaN frequency multipliers remains a technological challenge. In this paper, we present GaN Schottky diodes fabricated on a heteroepitaxial GaN on sapphire. The barrier height obtained is around 0.53 ​eV, and it increases up to 0.73 ​eV after Schottky contact annealing; and the ideality factor is equal to 1.1 before annealing and 1.2 after annealing. The resulting series resistance is very low, 7Ω and 1Ω, before and after annealing, respectively.

Relationship between incompetent perforator veins and pigmentation below the knee in patients with chronic venous disease

ObjectiveThe aim of the present study was to evaluate the correlation between incompetent perforator veins (PVs) and venous pigmentation. MethodsA total of 203 limbs of patients with chronic venous disease were studied. The limbs were classified into two groups: C2 group (varicose veins) and C4a group (skin changes with pigmentation). The PVs of the lower legs were examined using Doppler ultrasound. The diameter, reflux duration, and peak velocities were measured and analyzed. The pigmentation area in the lower leg was also studied. ResultsPigmentation in the lower legs was significantly associated with venous insufficiency of the PVs. The prevalence of PVs insufficiency was higher for the C4a patients compared with the C2 patients (96 of 164 [58.3%] vs 4 of 39 [10.3%]; P < .001). The presence of incompetent PVs was associated with an increased risk of pigmentation (OR, 8.977; 95% CI, 2.824-28.537; P < .001). The higher the patients’ pigmentation severity (higher VCSS), the greater the prevalence of perforator venous insufficiency (P < .001). The PVs in the areas of pigmentation were larger in diameter, required longer to reach peak velocity, and had higher peak velocities than the PVs in nonpigmented limbs (P < .01 for all). We found a linear relationship between the pigmentation area and the diameter of the PV, reflux time, and peak velocity (r = 0.272, r = 0.172, and r = 0.664, respectively; P < .05). ConclusionsIncompetent PVs are a significant risk factor for venous pigmentation and, therefore, are potentially suitable for surgical correction.

Characterization of stroke-related upper limb motor impairments across various upper limb activities by use of kinematic core set measures

BackgroundUpper limb kinematic assessments provide quantifiable information on qualitative movement behavior and limitations after stroke. A comprehensive characterization of spatiotemporal kinematics of stroke subjects during upper limb daily living activities is lacking. Herein, kinematic expressions were investigated with respect to different movement types and impairment levels for the entire task as well as for motion subphases.MethodChronic stroke subjects with upper limb movement impairments and healthy subjects performed a set of daily living activities including gesture and grasp movements. Kinematic measures of trunk displacement, shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension, forearm pronation/supination, wrist flexion/extension, movement time, hand peak velocity, number of velocity peaks (NVP), and spectral arc length (SPARC) were extracted for the whole movement as well as the subphases of reaching distally and proximally. The effects of the factors gesture versus grasp movements, and the impairment level on the kinematics of the whole task were tested. Similarities considering the metrics expressions and relations were investigated for the subphases of reaching proximally and distally between tasks and subgroups.ResultsData of 26 stroke and 5 healthy subjects were included. Gesture and grasp movements were differently expressed across subjects. Gestures were performed with larger shoulder motions besides higher peak velocity. Grasp movements were expressed by larger trunk, forearm, and wrist motions. Trunk displacement, movement time, and NVP increased and shoulder flexion/extension decreased significantly with increased impairment level. Across tasks, phases of reaching distally were comparable in terms of trunk displacement, shoulder motions and peak velocity, while reaching proximally showed comparable expressions in trunk motions. Consistent metric relations during reaching distally were found between shoulder flexion/extension, elbow flexion/extension, peak velocity, and between movement time, NVP, and SPARC. Reaching proximally revealed reproducible correlations between forearm pronation/supination and wrist flexion/extension, movement time and NVP.ConclusionSpatiotemporal differences between gestures versus grasp movements and between different impairment levels were confirmed. The consistencies of metric expressions during movement subphases across tasks can be useful for linking kinematic assessment standards and daily living measures in future research and performing task and study comparisons.Trial registration: ClinicalTrials.gov Identifier NCT03135093. Registered 26 April 2017, https://clinicaltrials.gov/ct2/show/NCT03135093.

Comparison of Manipulative Indicators of Students and Therapists Using a Robotic Arm: A Feasibility Study

In this study, the motion therapy elements necessary for student education were clarified through comparison of the therapeutic motion techniques of therapists and students using an educational arm robot (Samothrace: SAMO). Eight therapists and 25 fourth-year students participated. The therapeutic motion therapy task was a reciprocating exercise in which the elbow joint of SAMO was flexed from an extended position and then re-extended. This was performed for three types of muscle tone intensities (mild, moderate, and severe), and the peak velocity, angle ratio, velocity time, and movement time were recorded using SAMO. These data were then compared using analysis of covariance. It was found that the SAMO elbow joint kinematic data generated by therapists differed significantly from those of students for different muscle tones. Multiple comparisons showed that the therapeutic motion techniques of students were associated with a higher peak velocity, smaller peak angle ratio, and shorter peak velocity time and movement time than those of the therapists. Thus, when students learn therapeutic motion techniques, they should be taught to (1) deal with multiple muscle tone intensities and (2) reduce the joint movement speed applied to the patient to extend the exercise time and ensure maximum joint movement range.