Variability In Position Research Articles

Trophic position variability of European sardine by compound-specific stable isotope analyses

The study of the trophic position (TP) of organisms is crucial to understand the trophodynamics of ecosystems. The European sardine from the western Mediterranean has been highly exploited during the last decades and has shown an important population decline. To determine the TP, we quantified seasonal nitrogen stable isotope (δ15N) values of compound-specific stable isotope analysis of amino acids (CSIA-AA), as well as bulk δ15N (SIA-bulk) values in muscle from three areas of the north-western Mediterranean. Our results highlight that, despite observing latitudinal changes in nitrogen SIA-bulk, the TP of sardine remains similar between sites. These results suggest that changes in nitrogen SIA-bulk are mainly driven by changes in the isotopic ratio of the baseline. Furthermore, the seasonal nitrogen variation in SIA-bulk is linked to differences in the isotopic baseline of the pelagic food web observed in the source AAs. Using CSIA-AA allowed us to decouple the variation in the baseline from the trophic variation producing robust TP estimates. Without using CSIA-AA, the interpretation of nitrogen SIA-bulk was hampered by the lack of a proper regional baseline of the primary producers.

The validation case on invasive crustaceans of the LifeWatch ERIC Internal Joint Initiative: State of the art and next steps forward

LifeWatch ERIC, the e-Science European infrastructure for biodiversity and ecosystem research, launched an Internal Joint Initiative on Non-indigenous Species and Invasive Alien Species (NIS-IAS) as they are considered one of the major drivers of biodiversity and ecosystem change. Here, the case study focused on the trophic biogeography of invasive crustaceans is presented, describing the procedures, resources, and analytical web services implemented to investigate the trophic habits of these taxa by using carbon and nitrogen stable isotope data. The case study offers a number of analytical tools to determine the variability of the trophic position of invasive crustaceans in a spatially-explicit context and to model it as a function of relevant environmental predictors. Literature-based stable isotope data of the Atlantic blue crab Callinectes sapidus and of the Louisiana crayfish Procambarus clarkii have been used to evaluate the functionalities and outcomes of the workflow. The Tesseract Virtual Research Environment integrates all the analytical services offered by LifeWatch ERIC, including the ones developed for this case study, by means of a user-friendly interface. The analytical functions implemented for the crustacean workflow provide a proof of concept for future open e-science platforms focusing on NIS-IAS. The workflow conceptual structure can be adapted to a wide range of species, and can be further improved to support researchers in monitoring and predicting trophic-related impacts of NIS-IAS. In addition, it can support policymakers and stakeholders in the implementation of effective management and control measures to limit the negative effects of bioinvaders in recipient environments.

In Addition to Discussion on the Correlation of the Bajocian–Bathonian Sections in the Izhma River Basin, European North of Russia

In the Izhma River basin, the Upper Bajocian–Lower Bathonian sections crop out at several localities along the Dreshchanka River. The recently published views (Ippolitov A.P., Kiselev D.N. “Geological Features of the Bajocian–Bathonian in the Reference Section of the Izhma River Basin (European North of Russia) and the Succession of Ammonites of the Subfamily Arctocephalitinae Meledina”, Stratigraphy and Geological Correlation, 2021, vol. 29, pp. 742–755) on the correlation of these sections, as well as the comments made in the same article on the results of our research, are critically reviewed. The correlation model based on the stratohypses of the top of the Arcticoceras-bearing sandstone horizon, constructed by the opponents relative to four marks of the water’s edge, turned out to be factually unfounded and methodologically unjustified. Arguments against this model are as follows: the low efficiency of the interpolation method on a small sample size when constructing the riverbed dip profile under conditions of intensive meandering of the Dreshchanka River on the floodplain terrace; ignoring the geomorphological situation as a whole; the irrelevance of the topographic map of the 1999 edition; the underestimation of the variability of the low-water position of the water’s edge in different years due to changes in the amount of precipitation.

An Efficient Lightweight Hybrid Model with Attention Mechanism for Enhancer Sequence Recognition

Enhancers are sequences with short motifs that exhibit high positional variability and free scattering properties. Identification of these noncoding DNA fragments and their strength are extremely important because they play a key role in controlling gene regulation on a cellular basis. The identification of enhancers is more complex than that of other factors in the genome because they are freely scattered, and their location varies widely. In recent years, bioinformatics tools have enabled significant improvement in identifying this biological difficulty. Cell line-specific screening is not possible using these existing computational methods based solely on DNA sequences. DNA segment chromatin accessibility may provide useful information about its potential function in regulation, thereby identifying regulatory elements based on its chromatin accessibility. In chromatin, the entanglement structure allows positions far apart in the sequence to encounter each other, regardless of their proximity to the gene to be acted upon. Thus, identifying enhancers and assessing their strength is difficult and time-consuming. The goal of our work was to overcome these limitations by presenting a convolutional neural network (CNN) with attention-gated recurrent units (AttGRU) based on Deep Learning. It used a CNN and one-hot coding to build models, primarily to identify enhancers and secondarily to classify their strength. To test the performance of the proposed model, parallels were drawn between enhancer-CNNAttGRU and existing state-of-the-art methods to enable comparisons. The proposed model performed the best for predicting stage one and stage two enhancer sequences, as well as their strengths, in a cross-species analysis, achieving best accuracy values of 87.39% and 84.46%, respectively. Overall, the results showed that the proposed model provided comparable results to state-of-the-art models, highlighting its usefulness.

Driving with a Haptic Guidance System in Degraded Visibility Conditions: Behavioral Analysis and Identification of a Two-Point Steering Control Model

The objective of this study is to determine the ability of a two-point steering control model to account for the influence of a haptic guidance system in different visibility conditions. For this purpose, the lateral control of the vehicle was characterized in terms of driving performance as well as through the identification of anticipation and compensation parameters of the driver model. The hypothesis is that if the structure of the model is valid in the considered conditions, the value of the parameters will change in coherence with the observed behavior. The results of an experiment conducted on a driving simulator demonstrate that the identified model can account for the cumulative influence of the haptic guidance system and degraded visibility. The anticipatory gain is sensitive to changes in driving conditions that have a direct influence on the produced trajectory, and the compensatory gain is sensitive to a decrease in the variability of the lateral position. However, a model with only the steering wheel angle as output is not able to determine whether the change in lateral position variability is due to the driver’s lack of anticipation or to the assistance provided by the haptic guidance system.

Cognitive functioning and simulated driving in older adults with and without cognitive impairment

AbstractBackgroundAge‐related changes in cognitive functions affect complex task engagement such as driving. Studies have demonstrated high occurrences of driving errors and crashes among older adults, particularly those with mild cognitive impairment (MCI). We have previously demonstrated that fatigue contributes to detriments in driving ability, especially among MCI, and that attention‐maintenance tasks (AMT) improve older cognitively normal (OCN) but not MCI performance. This study considers which cognitive deficits predict driving performance across AMT conditions.MethodsParticipants included 34 OCN and 21 MCI adults age 60+ years diagnosed through consensus conference, who completed tests of memory (HVLT‐R delayed recall), executive functioning (Trail Making Test B; TMB), working memory (CogState One Back Test, ONB), simple reaction time (CogState Detection Test, DET), and choice reaction time (CogState Identification Test, IDN). Computerized driving scenarios were presented on a 45” flat screen monitor, which included a 50‐minute simulated drive designed to induce fatigue, followed by four 10‐minute sessions alternating between driving with and without AMT. Lane position, velocity, lane and velocity variability, and driving errors (e.g., leaving the road, crossing midline) were compared across 10‐minute driving segments. Cognitive measures and diagnosis were used to predict driving performance.ResultsParticipants with MCI 1) maintained significantly slower average speed, 2) demonstrated higher variability in lane‐keeping, and 3) had greater velocity variability, only in the non‐AMT condition. OCN participants performed significantly better on all cognitive measures, except DET. Linear regressions showed that TMB, alone, predicted average velocity during the AMT driving condition with no significant predictors for the non‐AMT. Velocity variability during the non‐AMT driving condition was predicted by the main effect of Diagnosis, TMBxDiagnosis, and ONBxDiagnosis interactions. TMB and HVLT‐R predicted velocity variability during the AMT condition. Lane variability during both driving conditions was predicted by DETxDiagnosis and IDNxDiagnosis.ConclusionsPerformance on TMB and its interactions are predominantly important predictors for velocity‐related driving conditions. Reaction time decrements among those with MCI predict lane variability. This suggests that executive functions are particularly needed in maintaining velocity, while monitoring is critical for maintaining lane position. Our findings demonstrate that higher cognitive burden likely accentuates driving difficulty, especially in MCI.

Unique Presentation of Bing-Neel Syndrome With Co-existing Chronic Lymphocytic Leukemia.

Unique Presentation of Bing-Neel Syndrome With Co-existing Chronic Lymphocytic Leukemia.

Presynaptic contact and activity opposingly regulate postsynaptic dendrite outgrowth.

The organization of neural circuits determines nervous system function. Variability can arise during neural circuit development (e.g. neurite morphology, axon/dendrite position). To ensure robust nervous system function, mechanisms must exist to accommodate variation in neurite positioning during circuit formation. Previously, we developed a model system in the Drosophila ventral nerve cord to conditionally induce positional variability of a proprioceptive sensory axon terminal, and used this model to show that when we altered the presynaptic position of the sensory neuron, its major postsynaptic interneuron partner modified its dendritic arbor to match the presynaptic contact, resulting in functional synaptic input (Sales et al., 2019). Here, we investigate the cellular mechanisms by which the interneuron dendrites detect and match variation in presynaptic partner location and input strength. We manipulate the presynaptic sensory neuron by (a) ablation; (b) silencing or activation; or (c) altering its location in the neuropil. From these experiments we conclude that there are two opposing mechanisms used to establish functional connectivity in the face of presynaptic variability: presynaptic contact stimulates dendrite outgrowth locally, whereas presynaptic activity inhibits postsynaptic dendrite outgrowth globally. These mechanisms are only active during an early larval critical period for structural plasticity. Collectively, our data provide new insights into dendrite development, identifying mechanisms that allow dendrites to flexibly respond to developmental variability in presynaptic location and input strength.

PO19: Quantifying the Ir-192 Source Position Accuracy QA Test for HDR Brachytherapy Afterloaders

<h3>Purpose</h3> The source positioning test is a recommended part of HDR Brachytherapy QA with an accuracy of ±1 mm per AAPM TG-40, and ±2 mm per AAPM TG-56 and ESTRO Report No. 8. Our institutional QA tolerance is ±1 mm. Typically, the test is performed using radiochromic film and a Perma-Doc jig. At a minimum, visual inspection to verify the accuracy of radioactive source position with respect to their expected dwell position should be performed as part of daily QA prior to patient treatment and at every source exchange. However, an automated digital analysis of the accuracy of the source position QA film is not routinely done. The purpose of this study is to develop a method to quantitatively measure the offset of the Ir-192 source position and to analyze factors that may impact the offset based on different afterloaders, different radioactive sources, different dwell positions, and over time. <h3>Materials and Methods</h3> In this study, one-year data for the source position accuracy tests from two GammaMedplus™ iX (GMPiX) HDR afterloaders (B and C) were analyzed. A method was developed to scan the radiochromic QA films, straighten the films, and quantitatively calculate the source position offsets to the of expected nine dwell positions per film using MATLAB R2021b. We analyzed the offset of the radioactive source position as a function of time, different radioactive source, and different afterloaders. A reproducibility test of the method was done by performing the procedure end-to-end seven times for six arbitrarily chosen QA films. <h3>Results</h3> The Ir-192 source is exchanged quarterly to account for radioactive decay, thus four Ir-192 sources and five Ir-192 sources for the B and C afterloaders were analyzed for a total of 171 QA films. Each QA film has nine expected dwell positions that are analyzed for a total of 1539 dwell positions. One hundred percent of the offsets of 1539 radioactive source positions in all the films are less than ± 1 mm and 99% of offsets were less than ± 0.5 mm. Differences of the source position offset between the B and C afterloader were observed: 60% of all source position offsets to the expected dwell positions for both afterloaders were found to be more proximal (away from afterloader, shifted towards patient). The average offset for the B and C afterloader for all source positions were -0.05 mm and -0.01 mm, respectively. Analysis of each dwell position offset showed variability in offset: when comparing between the B and C afterloader: (1) 0.04 vs 0.01 mm, (2) -0.02 vs 0.01 mm, (3) -0.04 vs -0.01 mm, (4) -0.07 vs -0.01 mm, (5) -0.05 vs -0.02 mm, (6) -0.05 vs -0.05 mm, (7) -0.08 vs -0.03 mm, (8) -0.10 vs -0.04 mm, (9) -0.07 -0.01 mm, respectively. The source position offsets for the seventh, eighth, ninth positions were worse than average for both afterloaders. No correlation between source offset over time was found. Result of reproducibility test shows that the offsets of the location of radioactive sources in the daily QA the reported method is feasible, with a standard deviation less than 0.2 mm. <h3>Conclusions</h3> This study has the potential to be used in daily QA for quantitative analysis of the source position accuracy test. We demonstrated the variability of the source position to the expected dwell position with respect to different afterloaders, different sources, and different dwell positions. Despite the upcoming new, currently unpublished, guidelines by the AAPM that increase the tolerance for the source positioning accuracy test to be equal to or less than ± 2 mm, our results show that our QA methodology can detect differences within ± 1 mm.

Density Overrides that Best Predict Bowel Changes during Pencil Beam Scanning Proton Radiotherapy for Prostate Cancer

<h3>Purpose/Objective(s)</h3> Changes in patient anatomy during pencil beam scanning proton radiotherapy (PBSPT) can result in substantial differences in dose distribution. In patients with prostate cancer receiving elective nodal irradiation (ENI), interfraction variability in bowel position or bowel filling can highlight this uncertainty. Such changes are often managed by assessing the plan on CT dataset copies with the bowel contour overridden to other densities. The ideal Hounsfield Unit (HU) overrides remain unclear, but extremes (HU=0 water and HU=-1000 air) are often utilized. The aim of the present study is to determine the bowel density overrides that are most predictive of bowel changes during a course of PBSPT. <h3>Materials/Methods</h3> Consecutive patients, from a single institution, receiving PBSPT with ENI for intact prostate cancer were retrospectively reviewed for the period between 10/2020-12/2021. Proton radiotherapy consisted of 50.4 Gy in 28 fractions to the pelvic lymph node stations with a simultaneous integrated boost to 70 Gy in 28 fractions to the prostate. Individually contoured loops of small bowel, large bowel, and rectum were overridden to HU of 0 to -1000 in 100 HU intervals. A bowel evaluation structure, consisting of a bowel bag cropped 3 cm away from the high-risk volume, was created; its dose volume histogram was reviewed; and values for the maximum point dose (Dmax), V105%, V45Gy, V20Gy were recorded for each plan. The dosimetry of bowel override plans were compared to the patient's Quality Assurance CT (QACT) scans. The bowel override plan which most closely matched the dosimetry of each QACT for each dosimetric parameter was determined, and the prevalence of closest prediction for each override value was tabulated. <h3>Results</h3> A total of 32 QACTs from 12 patients were included. For Dmax, HU=0, HU=-100, and HU=-700 predicted most accurately with 10 (31.3%), 5 (15.6%), and 4 (12.5%) closest predictions, respectively. For V105%, HU=-700 and HU=-1000 performed best with 6 (18.8%) and 7 (21.9%), respectively. For V45, HU=0 and HU=-500 predicted best with 13 (40.6%) and 5 (15.6%), respectively. For V20, HU=0, HU=-200, and HU=-600 predicted best with 18 (56.3%), 4 (12.5%), and 3 (9.4%), respectively. Overall, HU=0, -100, -600, -700, and -1000 predicted best with 42 (32.8%), 11 (8.6%), 10 (7.8%), 12 (9.4%), and 12 (9.4%) out of the 128 total dose metrics, respectively. This created a relative bimodal distribution with peaks in the 0 to -100 and -600 to -700 ranges. The nominal plan predicted best in 13 scenarios. <h3>Conclusion</h3> Bowel density override plans remain an important tool for assessment of PBSPT robustness to bowel filling changes throughout the course of therapy as the nominal CT relatively poorly predicts QACT dosimetry. The relatively bimodal distribution of accurate predictions in this study would suggest that the most predictive overrides would be HU∼0 and HU∼-650. Future investigation into multidataset robust optimization with these overrides to improve plan robustness is planned.

Effects of short-term hypercaloric nutrition on orthostatic tolerance in healthy individuals: a randomized controlled crossover study

Reduced-caloric intake lowers blood pressure through sympathetic inhibition, and worsens orthostatic tolerance within days. Conversely, hypercaloric nutrition augments sympathetic activity and blood pressure. Because dietary interventions could be applied in patients with syncope, we tested the hypothesis that short-term hypercaloric dieting improves orthostatic tolerance. In a randomized crossover trial, 20 healthy individuals (7 women, 26.7 ± 8 years, 22.6 ± 2 kg/m2) followed a 4-day hypercaloric (25% increase of energy intake by fat) or normocaloric nutritional plan, with a washout period of at least 23 days between interventions. We then performed head-up tilt table testing with incremental lower body negative pressure while recording beat-by-beat blood pressure and heart rate. The primary endpoint was orthostatic tolerance defined as time to presyncope. Time to presyncope during combined head-up tilt and lower body negative pressure did not differ between hypercaloric and normocaloric dieting (median 23.19 versus 23.04 min, ratio of median 1.01, 95% CI of ratio 0.5–1.9). Heart rate, blood pressure, heart rate variability, and blood pressure variability in the supine position and during orthostatic testing did not differ between interventions. We conclude that 4 days of moderate hypercaloric nutrition does not significantly improve orthostatic tolerance in healthy individuals. Nevertheless, given the important interaction between energy balance and cardiovascular autonomic control in the brain, caloric intake deserves more attention as a potential contributor and treatment target for orthostatic intolerance.

Вариативность гласных и ее зависимость от типа ударения и фразовой позиции

The position of vowels in acoustic space is described using the values of the F1 and F2 formants. The approach is determined by the need to perceptually distinguish neighboring vowels. The area occupied by a specific vowel is described as a combination of microfields with each microfield formed by a set of allophone positions of the vowel in question. The results obtained demonstrate that the variability of the allophone position in the acoustic field can be determined by a number of factors, such as the degree of prominence and vowel position in the phrase. With this aim vowel positioning in the acoustic space in words with neutral and emphatic stress was studied. The speech material for analysis comprised the word 'Stas' embedded in the carrier phrase 'Stas ne byl tihoney' ('Stas was not quiet') with the target word occupying initial, medial and final positions in the phrase; in each position the word was pronounced with neutral and emphatic stress. F1 and F2 values of the sound [a] in the word 'Stas' were extracted with the FFT method using the Praat software. The Student paired t-test was employed to note the significance of difference between the first and second formant frequencies of neutrally and emphatically stressed vowels. The analysis revealed that the vowels uttered with emphatic stress are characterized by an expansion of their acoustic vowel space by moving off the vowel space center. The displacement occurs either through an increase of F1, a decrease of F2, or both. A general trend was observed in the impact of phrasal position on vowel formant frequencies. Though the vowels under neutral stress seemed to display greater response to the phrasal position factor compared to the emphatically stressed ones, noticeable regularities could not be established due to a high intradialectal variability of speakers.

Clinical implementation of the first Cherenkov imaging system in a community-based hospital.

PurposeTo document experiences with one year of clinical implementation of the first Cherenkov imaging system and share the methods that we developed to utilize Cherenkov imaging to improve treatment delivery accuracy in real-time.MethodsA Cherenkov imaging system was installed commissioned and calibrated for clinical use. The optimal room lighting conditions and imaging setup protocols were developed to optimize both image quality and patient experience. The Cherenkov images were analyzed for treatment setup and beam delivery verification.ResultsWe have successfully implemented a clinical Cherenkov imaging system in a community-based hospital. Several radiation therapy patient setup anomalies were found in 1) exit dose to the contralateral breast, 2) dose to the chin due to head rotation for a supraclavicular field, 3) intrafractional patient motion during beam delivery, and 4) large variability (0.5 cm to 5 cm) in arm position between fractions. The system was used to deliver deep inspiration breath hold (DIBH) treatment delivery of an electron treatment beam. Clinical process and procedures were improved to mitigate the identified issues to ensure treatment delivery safety and to improve treatment accuracy.ConclusionThe Cherenkov imaging system has proven to be a valuable clinical tool for the improvement of treatment delivery safety and accuracy at our hospital. With only minimal training the therapists were able to adjust or correct treatment positions during treatment delivery as needed. With future Cherenkov software developments Cherenkov imaging systems could provide daily surface guided radiotherapy (SGRT) and real time treatment delivery quality control for all 3D and clinical setup patients without adding additional radiation image dose as in standard kV, MV and CBCT image verifications. Cherenkov imaging can greatly improve clinical efficiency and accuracy, making real time dose delivery consistency verification and SGRT a reality.

Anatomical Variation in Diaphragm Thickness Assessed with Ultrasound in Healthy Volunteers.

Ultrasonography of the diaphragm in the zone of apposition has become increasingly popular to evaluate muscle thickness and thickening fraction. However, measurements in this anatomical location are frequently hindered by factors that constrain physical accessibility or that alter diaphragm position. Therefore, other anatomical positions at the chest wall for transducer placement are used, but the variability in diaphragm thickness across the dome has not been systematically studied. The aim of this study was to evaluate anatomical variation of diaphragm thickness in 46 healthy volunteers on three ventrodorsal lines and two craniocaudal positions on these three lines. The intraclass correlation coefficient (ICC) for diaphragm thickness in the craniocaudal direction on the mid-axillary line was significantly higher than those on the posterior axillary and midclavicular lines, suggesting it had the lowest variability (ICCmidaxillary=.89, 95% confidence interval [CI]: 0.83-0.93, ICCposterior axillary=0.74, 95% CI: 0.62-0.85, ICCmidclavicular=0.62, 95% CI: 0.43-0.47, p < 0.05). Average diaphragm thickness was comparable on the posterior axillary and midaxillary lines and substantially larger on the midclavicular line (1.24 mm [1.06-1.47], 1.27 mm [1.10-1.42] and 2.32 [1.97-2.70], p < 0.01). We conclude that the normal diaphragm has a large variability in thickness, especially in the ventrodorsal direction. Variability in craniocaudal position is the lowest at the midaxillary line, which therefore appears to be the preferred site for diaphragm thickness measurement.

Paleosecular variation record from Pleistocene-Holocene lava flows in southern Colombia

Improvements in the spatial and temporal coverage of paleomagnetic data are essential to better evaluate paleofield behaviour over the past 10 Myr, especially due to data scarcity at low latitudes in the South American region. Here, we provide new Pleistocene-Holocene (0–2 Ma age interval) paleodirectional data from three volcanic systems (Doña Juana Volcanic Complex, Galeras Volcanic Complex and Morasurco Volcano) in southwestern Colombia between latitudes 1.2 and 1.4°N. A total of 38 paleodirectional sites were studied using progressive alternating field and thermal demagnetization treatments. After excluding transitional data, we obtain thirty site-mean directions for analysis of paleosecular variation (PSV) and the time-averaged field (TAF) in the study area. The mean direction (Dec = 351.2°, Inc = −3.4°, α95 = 6.2°, k = 20.0) and the paleomagnetic pole (Plat = 80.7°N, Plon = 173.1°E, A95 = 5.2°, K = 29.1) of these sites are not statistically compatible with the expected geocentric axial dipole (GAD) field direction and geographic north pole, respectively. Virtual geomagnetic pole dispersion (SB) for our filtered dataset (SB(2Ma) = 15.212.017.6°) and the Brunhes chron (SB(Bru) = 16.011.619.1°) are consistent at the 95% confidence level with South American studies at equatorial latitudes and recent PSV models for the 0–10 Ma and Brunhes intervals. Likewise, the corresponding inclination anomaly (ΔI) for two age groups ΔI2Ma = − 5.9−12.10.3° and ΔIBru = − 5.3−13.73.1° suggests large deviations relative to the GAD model, in accordance with predictions from zonal TAF models. The high VGP dispersion could be linked to strong longitudinal variability of the magnetic equator position over South America. This feature reflects the presence of significant non-dipole field components in this region that have been detected in geomagnetic field models for the most recent centuries and millennia, probably associated with the presence of the South Atlantic Magnetic Anomaly in the South American region.

Inferring time-dependent calving dynamics at Helheim Glacier

AbstractWe perform Bayesian inference of the parameters of a time-dependent model of ice flow and calving at Helheim Glacier, East Greenland. We find that, while a time-independent calving parameterization can recover the mean observed terminus position, such a model is unable to recover sub-annual variability, even when forced with seasonally varying climate. To address this, we develop a simple stochastic model relating surface runoff rates and calving threshold. Again inferring model parameters from observations, we find that this parameterization is able to reproduce observations with respect to both mean position and characteristic temporal variability. This result demonstrates the importance of considering potential sub-annual controls on calving rates in numerical models, which may include variable undercutting rates or surface runoff-dependent surface crevasse propagation.

Profiles of movement speed and positional variability based on extended LQG for various noises

Stochastic optimal control has been studied to explain the characteristics of human upper-arm reaching movements. The optimal movement based on an extended linear quadratic Gaussian (LQG) demonstrated that control-dependent noise is the essential factor of the speed-accuracy trade-off in the point-to-point reaching movement. Furthermore, the extended LQG reproduced the profiles of movement speed and positional variability. However, the expected value and variance were computed based on the Monte Carlo method in these studies, which is not considered efficient. In this study, I obtained update equations to efficiently compute the expected value and variance based on the extended LQG. Using the update equations, I computed the profiles of simulated movement speed and positional variability for various amplitudes of noises in a point-to-point reaching movement. The profiles of movement speed were basically bell-shaped for the noises. The speed peak was changed by the control-dependent noise and state-dependent observation noise. The positional variability changed for various noises, and the period during which the variability changed differed with the noise type. Efficient computation in stochastic optimal control based on the extended LQG would contribute to the elucidation of motor control under various noises.

Activity Recognition in Parkinson's Patients from Motion Data Using a CNN Model Trained by Healthy Subjects.

Physical activity recognition in patients with Parkinson's Disease (PwPD) is challenging due to the lack of large-enough and good quality motion data for PwPD. A common approach to this obstacle involves the use of models trained on better quality data from healthy patients. Models can struggle to generalize across these domains due to motor complications affecting the movement patterns in PwPD and differences in sensor axes orientations between data. In this paper, we investigated the generalizability of a deep convolutional neural network (CNN) model trained on a young, healthy population to PD, and the role of data augmentation on alleviating sensor position variability. We used two publicly available healthy datasets - PAMAP2 and MHEALTH. Both datasets had sensor placements on the chest, wrist, and ankle with 9 and 10 subjects, respectively. A private PD dataset was utilized as well. The proposed CNN model was trained on PAMAP2 in k-fold cross-validation based on the number of subjects, with and without data augmentation, and tested directly on MHEALTH and PD data. Without data augmentation, the trained model resulted in 48.16% accuracy on MHEALTH and 0% on the PD data when directly applied with no model adaptation techniques. With data augmentation, the accuracies improved to 87.43% and 44.78%, respectively, indicating that the method compensated for the potential sensor placement variations between data. Clinical Relevance- Wearable sensors and machine learning can provide important information about the activity level of PwPD. This information can be used by the treating physician to make appropriate clinical interventions such as rehabilitation to improve quality of life.

DMA Analysis of Plasma Modified PVC Films and the Nature of Initiated Surface Changes.

The application of DCSBD (Diffuse Coplanar Surface Barrier Discharge) plasma is referred to as the surface modification/activation of materials. The exposure of material surfaces to DCSBD plasma is initiated by changes in their chemical composition, surface wettability and roughness. The given study presents the mentioned plasma application in the context of the modification of the material viscoelastic properties, namely the PVC polymer film. The measurement of viscoelastic properties changes of PVC was primarily examined by a sensitive thermal method of dynamic-mechanical analysis. This analysis allows identifying changes in the glass transition temperature of PVC, before and after DCSBD plasma application, Tangens Delta, supported by glass transition temperatures of Elastic and Loss modulus. The results of the present study prove that DCSBD plasma applied on both sides to PVC surfaces causes changes in its viscoelastic properties. In addition, these changes are presented depending on the variability of the material position, with respect to the winding of the electrodes in the ceramic dielectric generating the DCSBD plasma during modification. The variability of the PVC position holds an important role, as it determines the proportion of filamentous and diffuse components of the plasma that will interact with the material surface during modification. The application of DCSBD plasma must, therefore, be considered a complex modification of the material, and as a result, non-surface changes must also be considered.

Orbital parameters and activity of ZZ Tau – a low-mass young binary with circumbinary disc

ABSTRACT We present the results of our new observations of the young binary ZZ Tau with a circumbinary disc. The system was found to consist of two coeval (age &amp;lt; 2 Myr) classical T Tauri stars with the total mass 0.86 ± 0.09 M⊙, orbital period 46.8 ± 0.8 yr, semimajor axis 88.2 ± 2.1 mas, eccentricity 0.58 ± 0.02, and the orbital inclination 123${_{.}^{\circ}}$8 ± 1${_{.}^{\circ}}$0. The accretion rate of ZZ Tau A and ZZ Tau B is approximately 7 × 10−10 and 2 × 10−10 M⊙ yr−1, respectively. No correlation was found between the long-term photometric variability of ZZ Tau and orbital position of its components. The periodic light variations with P = 4.171 ± 0.002 d were observed in the BVRI bands presumably connected with an accretion (hot) spot on the surface of the primary (ZZ Tau A). At the same time, no periodicity was observed in the U band nor in the emission line profile variations probably, due to the significant contribution of ZZ Tau B’s emission, which dominates shortward of λ ≈ 0.4 $\mu$m. We argue that the extinction in the direction to the primary is noticeably larger than that to the secondary. It appeared that the rotation axis of the primary is inclined to the line of sight by ≈31° ± 4°. We also concluded that ZZ Tau is the source of a CO molecular outflow; however, ZZ Tau IRS rather than ZZ Tau is the source of the Herbig–Haro object HH393.