Tip Movement Research Articles

Mesiodistal tip expression of mandibular anterior teeth in patients with mandibular incisor extraction treated with Invisalign aligners

Extraction of a single mandibular incisor may be prescribed in conjunction with clear aligner orthodontic treatment. The accuracy of therapeutic mesiodistal tooth positioning for the remaining mandibular anterior teeth for such patients has not been comprehensively evaluated. This retrospective study compared the predicted and achieved mesiodistal tooth movements in the mandibular anterior region for patients treated with Invisalign (Align Technology, Santa Clara, Calif), along with the influence of aligner attachments and the frequency of aligner change. A sample of 83 subjects who had undergone Invisalign treatment with a single mandibular incisor extraction was collected from an existing database. The pretreatment tooth positions, the predicted mesiodistal tooth movement, and the achieved outcomes were measured for the remaining mandibular anterior teeth using Geomagic Control X metrology software (3D Systems, Rock Hill, SC). The predicted and achieved mesiodistal tip movements were analyzed and compared. Regression analysis revealed significant differences (P<0.001) between the predicted and achieved mesiodistal tooth positioning for incisors and canines. For every degree of predicted incisor mesiodistal tip, 78.89% of this tip was achieved (R2= 0.4901). For every degree of predicted canine tip, 54.16% was clinically expressed (R2= 0.5965). The accuracy of mesiodistal tip expression was not significantly affected by the prescribed number of aligners, 1-week vs 2-week aligner change protocols, or the presence of attachments (P>0.05). In addition, incisors were less likely to express the correct direction of the mesiodistal tip predicted than canines (P= 0.020). A shortfall between the predicted and clinically achieved expression of mesiodistal tooth movement with Invisalign was found for the anterior teeth after a mandibular incisor extraction. The number of aligners, duration of aligner wear, and specific attachment designs were not found to significantly influence the accuracy of the achieved mesiodistal tip movements.

Native mechano-regulative matrix properties stabilize alternans dynamics and reduce spiral wave stabilization in cardiac tissue.

The stability of wave conduction in the heart is strongly related to the proper interplay between the electrophysiological activation and mechanical contraction of myocytes and extracellular matrix (ECM) properties. In this study, we statistically compare bioengineered cardiac tissues cultured on soft hydrogels ( kPa) and rigid glass substrates by focusing on the critical threshold of alternans, network-physiological tissue properties, and the formation of stable spiral waves that manifest after wave breakups. For the classification of wave dynamics, we use an improved signal oversampling technique and introduce simple probability maps to identify and visualize spatially concordant and discordant alternans as V- and X-shaped probability distributions. We found that cardiac tissues cultured on ECM-mimicking soft hydrogels show a lower variability of the calcium transient durations among cells in the tissue. This lowers the likelihood of forming stable spiral waves because of the larger dynamical range that tissues can be stably entrained with to form alternans and larger spatial spiral tip movement that increases the chance of self-termination on the tissue boundary. Conclusively, we show that a dysfunction in the excitation-contraction coupling dynamics facilitates life-threatening arrhythmic states such as spiral waves and, thus, highlights the importance of the network-physiological interplay between contractile myocytes and the ECM.

Prosody matters: Preserved prominence marking strategies in people with Parkinson's disease independent of motor status.

While many studies focus on segmental variation in Parkinsonian speech, little is known about prosodic modulations reflecting the ability to adapt to communicative demands in people with Parkinson's disease (PwPD). This type of prosodic modulation is important for social interaction, and it involves modifications in speech melody (intonational level) and articulation of consonants and vowels (segmental level). The present study investigates phonetic cues of prosodic modulations with respect to different focus structures in mild dysarthric PwPD as a function of levodopa. Acoustic and kinematic speech parameters of 25 PwPD were assessed in two motor conditions. Speech production data from PwPD were collected before (medication-OFF) and after levodopa intake (medication-ON) by means of 3-D electromagnetic articulography. On the acoustic level, intensity, pitch, and syllable durations were analyzed. On the kinematic level, movement duration and amplitude were investigated. Spatio-temporal modulations of speech parameters were examined and compared across three different prosodic focus structures (out-of-focus, broad focus, contrastive focus) to display varying speech demands. Overall, levodopa had beneficial effects on motor performance, speech loudness, and pitch modulation. Acoustic syllable durations and kinematic movement durations did not change, revealing no systematic effects of motor status on the temporal domain. In contrast, there were spatial modulations of the oral articulators: tongue tip movements were smaller and lower lip movements were larger in amplitude under levodopa, reflecting a more agile and efficient articulatory movement under levodopa. Thus, respiratory-phonatory functions and consonant production improved, while syllable duration and tongue body kinematics did not change. Interestingly, prominence marking strategies were comparable between the medication conditions under investigation, and in fact, appear to be preserved in mild dysarthric PwPD.

Flexible Nasal Tip Produced by Slender Septal Extension Graft.

Septal extension grafts (SEGs) can increase projection. However, it requires a large amount of graft and can result in a frozen tip. Thus, this study introduces a modified SEG, called a partial SEG. Partial SEGs minimize the amount of graft material requirement, avoid the occurrence of frozen tips, and increase nasal tip projection. This method is comparable to the fixed-mobile SEG (Rohrich et al. in Plast Reconstr Surg 149: 1350-1356, 2022) and anterior nasal septal angle (ANSA) banner (Neves and Tagle in Ann Plast Reconstr Surg 4(3): 1059, 2020); however, unlike those techniques, the tip is not sutured to the graft and the alar complex is not fixed, allowing free movement of the nasal tip within its anatomical limits. To further prevent long-term displacement or minimize loss of nasal tip projection, a method of fixing the graft with Prolene and a third end-to-end SEG method for preventing sliding between grafts were used, which was also effective. Among the patients who underwent surgery between September 2019 and September 2023, 238 were followed up for over 6 months. Most patients were satisfied with the natural and flexible nature of the nasal tip. In conclusion, the alar wrap around a slender SEG technique can be an option for who want a flexible nasal tip that is projected adequately rather than excessively.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Dynamic Analysis of Crane Vessel and Floating Wind Turbine during Temporary Berthing for Offshore On-Site Maintenance Operations

With the increased scale and deployment of floating wind turbines in deep sea environments, jack-up installation vessels are unable to conduct maintenance operations due to limitations in water depth. This has led to the recognition of the advantages of floating cranes in offshore maintenance activities. However, the dynamic coupling between the crane and the floating wind turbine under wave and wind action can result in complex responses, which also relate to complex mooring configurations. The ability to maintain stability during maintenance operations has become a primary concern. In order to address this issue, a method of connecting a floating crane with a floating wind turbine is proposed, simulating the berthing of a floating offshore wind turbine (FOWT) to a crane. Thus, a systematic comparison was conducted with frequency- and time-domain simulation using ANSYS-AQWA software. The simulation results demonstrated the feasibility and dynamic efficiency of this novel berthing approach. Connecting the crane vessel to a floating wind turbine significantly reduced the crane tip movement. Simulations showed that the crane tip movement in the X-, Y-, and Z-directions was reduced by over 30%, which implies that it may be feasible to conduct offshore on-site maintenance operations for the FOWT by using floating crane vessels if the two bodies were properly constrained.

Rate dependent C* fracture parameter using the optimized wedge-split test geometry and vision-based automated crack tip detection

Typical monotonic load-line displacement (LLD) control and crack mouth opening displacement (CMOD) control cracking tests are limited to singular loading rates and testing temperatures. These experimental protocols are not designed to derive a fundamental fracture parameter capable of relating to the viscoelastic property and cracking behavior of asphalt concrete (AC). On the other hand, a multi-rate LLD-control monotonic fracture experiment is capable of capturing the viscoelastic cracking behavior of AC by providing the rate-dependent fundamental C* fracture parameter as an output. Crack length and crack speed parameters are combined with reaction loads to calculate the rate-dependent C* parameter. The current C* experiment protocol implements manual processing of video images and exhibits high variability. The study aims to optimize the wedge-split geometry and improve the C* fracture parameter calculation protocol by applying an automated vision-based crack detection system and recording the crack growth path, considering the horizontal and vertical movement of the crack tip with higher accuracy. The three notch lengths (5, 15, and 30 mm) were evaluated. Plant and laboratory-produced mixes with varying stiffness and fracture characteristics were included in the testing program. An optimized notch length for the test geometry was determined based on the on-specimen strain field observed using the digital image correlation (DIC) technique and crack path analysis. The optimum notch length was found to be 15 mm due to consistent strain localization at the crack tip and less crack deviation in the horizontal direction. The main contribution of this paper is the proposed vision-based crack path detection method, which enables measuring the crack path's true crack length and maximum horizontal deviation. The developed protocol and optimization of the testing geometry led to a significant improvement of the existing C* testing protocol, resulting in higher data quality and consistent results. The proposed protocol was validated using three comparable and distinctively different lab-produced mixtures. The results show that the C* experiment effectively differentiated between the mixes based on crack speed and the C* parameter.

Effects of hydrogen and specimen thickness on fracture toughness of ferritic steel welded joint

In this study, fracture behaviors of base metal and weld metal of ferritic steel welded joint in the thick wall pipeline for hydrogen transportation were investigated and the effects of hydrogen and specimen thickness (B) on fracture toughness were comprehensively considered in detail. A series of single edge notched tensile (SENT) tests for base metal and weld metal with B/W (width) ratio of 0.5, 1 and 2 were conducted with and without pre-electrochemical hydrogen charging, and crack tip opening displacement (CTOD) of δm value was obtained by the double clip gauges method. It was found that fracture toughness (δm) of base metal and weld metal decreased with increasing specimen thickness or hydrogenating, and δm of hydrogenating specimen with B/W ratio of 2 was smallest. It was believed that large specimen thickness decreased fracture toughness by constraining plastic deformation at crack tip and restricting dislocations movement, while hydrogen promoted embrittlement by reducing cohesive energy of fracture. In the hydrogenating specimen with larger thickness, there was lower dislocation density near crack tip, leading to a decrease in trapped hydrogen and intensifying the cohesive energy reduction effect, which resulted in reduced δm and the worse fracture toughness, and it means that hydrogen and specimen thickness synergistically affected fracture toughness. In addition, effect of thickness and hydrogen on decreasing fracture toughness was more pronounced for weld metal than base metal, which could be attributed to poorer plastic deformation ability of weld metal and lower dislocation density at crack tip. It is concluded that the hydrogen and thickness effects should be taken into account for the structural integrity evaluation of welded joint in hydrogen transportation pipeline.

Securement to Prevent Noncuffed Central Venous Catheter Dislodgement in Pediatrics

Catheter dislodgement is a common complication for children with tunneled or peripherally inserted noncuffed central venous catheters (CVCs). A subcutaneous anchor securement system (SASS) may reduce this risk compared with traditional adhesive securement. To compare dislodgement of noncuffed CVCs secured with SASS with dislodgement of noncuffed CVCs secured with sutureless securement devices (SSDs). The SECURED (Securing Central Venous Catheters to Prevent Dislodegment) trial was a pragmatic, multicenter, superiority randomized clinical trial with an internal pilot and was conducted from August 5, 2020, to August 30, 2022, at 2 Australian quaternary pediatric hospitals. Data analysis was performed in January 2023. Patients aged 0 to 18 years requiring a noncuffed CVC (≥3F catheter) were eligible for inclusion. Follow-up duration was 8 weeks or until device removal. Patients were randomly assigned 1:1 to receive an SASS or SSD, stratified by hospital and catheter type. Only 1 catheter was studied per patient. The primary outcome was dislodgement (partial or total), defined as movement of the catheter tip by greater than 1 cm (change in external catheter length) at any point during catheter dwell. Dislodgement, reported as a risk ratio (RR), was estimated using a generalized linear model with binomial family and log link. Secondary outcomes were reported as incidence rate ratios and were analyzed using Poission regression. Outcomes reported as mean differences (MDs) were analyzed using linear regression. Of 310 randomized patients, 175 patients (56.5%) were male and median (IQR) patient age was 48 (16-120) months. A total of 307 patients had a catheter device inserted, of which 153 (49.8%) were SASS and 154 (50.2%) were SSD, and were included in the intention-to-treat (ITT) analysis. Device dislodgement was lower with SASS (8 dislodgements in 153 patients [5.2%]) compared with SSD (35 dislodgements in 154 patients [22.7%]) (RR, 0.23; 95% CI, 0.11-0.48; P < .001). The per-protocol analysis was consistent with the ITT analysis. Partial dislodgement accounted for most dislodgement events, including 6 partial dislodgements in the SASS group (3.9%) and 30 partial dislodgements in the SSD group (19.5%) (RR, 0.18; 95% CI, 0.08-0.42). This contributed to fewer complications during dwell in the SASS group (37 reported complications [24.2%]) vs the SSD group (60 reported complications [39.0%]) (RR, 0.62; 95% CI, 0.44-0.87). Staff reported greater difficulty removing devices anchored with SASS vs SSD (mean [SD], 29.1 [31.3] vs 5.3 [17.0], respectively; MD, 23.8; 95% CI, 16.7-31.0). However, use of SASS resulted in reduced per-participant health care costs of A$36.60 (95% credible interval, 4.25-68.95; US $24.36; 95% credible interval, 2.83-45.89). In the SECURED trial, noncuffed CVCs secured with SASS had fewer dislodgements compared with SSDs, with a lower cost per patient and an acceptable safety profile. Future efforts should be directed at SASS implementation at the health service level. anzctr.org.au Identifier: ACTRN12620000783921.

Identification of dynamic coefficient matrix for drilling process simulations from measured tool geometry, axial force and torque

This paper aims to quantitatively analyze the relationship between forces acting on the tool tip and tool movement during drilling operations. The study encompasses axial and lateral vibrations superimposed on the nominal tool movement, arising from rigid body motion (rotational and axial velocities). Specifically, only forces attributed to the cutting process are considered, excluding considerations of indentation forces around the chisel edge. The research adopts a generalized approach, spanning from tool measurements to establishing the force model. The investigation involves measuring cutting forces and correlating them with the varying rake and inclination angles of the drill’s cutting edges. An analytical model is proposed to describe the distribution of all local force components along drill edges, considering the evolution of forces and geometry. The dynamic coefficient matrix is evaluated by using the identified cutting coefficient and tool geometry. Validation of the proposed methodology is demonstrated through drilling experiments on Ti6Al4V alloy, utilizing three solid carbide drills with distinct geometries. The proposed procedure allows complete identification of the dynamic characteristics from the measurements taken at the entrance stage of hole drilling operation. Moreover, the influence of tool geometry on cutting coefficients and dynamic coefficient matrices are discussed.

Laparoscopic distal gastrectomy skill evaluation from video: a new artificial intelligence-based instrument identification system

The advent of Artificial Intelligence (AI)-based object detection technology has made identification of position coordinates of surgical instruments from videos possible. This study aimed to find kinematic differences by surgical skill level. An AI algorithm was developed to identify X and Y coordinates of surgical instrument tips accurately from video. Kinematic analysis including fluctuation analysis was performed on 18 laparoscopic distal gastrectomy videos from three expert and three novice surgeons (3 videos/surgeon, 11.6 h, 1,254,010 frames). Analysis showed the expert surgeon cohort moved more efficiently and regularly, with significantly less operation time and total travel distance. Instrument tip movement did not differ in velocity, acceleration, or jerk between skill levels. The evaluation index of fluctuation β was significantly higher in experts. ROC curve cutoff value at 1.4 determined sensitivity and specificity of 77.8% for experts and novices. Despite the small sample, this study suggests AI-based object detection with fluctuation analysis is promising because skill evaluation can be calculated in real time with potential for peri-operational evaluation.

Tip-induced nanoscale domain engineering in x-cut lithium niobate on insulator

Nanodomain engineering in lithium niobate on insulator (LNOI) is critical to realize advanced photonic circuits. Here, we investigate the tip-induced nanodomain formation in x-cut LNOI. The effective electric field exhibits a mirror symmetry, which can be divided into preceding and sequential halves according to the tip movement. Under our configuration, the preceding electric field plays a decisive role rather than the sequential one as in previous reports. The mechanism is attributed to the screening field formed by the preceding field counteracting the effect of the subsequent one. In experiment, we successfully fabricate nanodomain dots, lines, and periodic arrays. Our work offers a useful approach for nanoscale domain engineering in x-cut LNOI, which has potential applications in integrated optoelectronic devices.

Hybrid Orthodontics for Aesthetic Deep Bite Correction—Case Series and General Clinical Considerations

Background: A range of psychosocial and aesthetic factors motivate patients to undergo orthodontic treatment. The appliance choice depends not only on the type of malocclusion, but also on the aesthetic and functional demands of the patients themselves. Nowadays, digital planning enables the manufacture of individualised and customised orthodontic appliances. However, the predictability of movements with aligner treatment has long been under discussion. This article illustrates, through a series of case reports, how a hybrid approach combining individualised aesthetic orthodontic appliances can improve the predictability of tooth movements, thereby providing additional tools for clinicians charged with choosing the best indicated and biomechanically advantageous technique. To this end, three patients with different malocclusions were treated via a hybrid approach involving clear aligners in the upper arch followed by lingual fixed appliances in the upper and lower arches. All patients were treated using ALIAS lingual PSL 0.018 × 0.018-inch slot brackets and in-house 3D-printed aligners. Findings: The hybrid approach combining aligners and fixed lingual appliances led to the successful resolution of all three complex cases in the series without prolonging treatment time. The superimpositions demonstrate the predictability of even traditionally difficult movements. In particular, the Alias PSL lingual system, used from the beginning, enabled good control of both the torque and inclination of the lower incisors. Conclusions: Combining clear aligners and fixed lingual appliances provides a highly efficient means of treating malocclusions aesthetically. In our cases, the aligners offset the lack of bite-plate effect from the lingual brackets and appliances, providing advantageous biomechanics for rotation correction and control of tip, torque and root movements. Understanding how to exploit the strengths of each appliance enables the clinician to treat adult patients efficaciously, efficiently and aesthetically.

Qualitative age-related changes in fine motor skill performance among 3- to 6-year-old typically developing children

This study described intra-task fine motor skill components of the Manual Dexterity tasks (Posting Coins; PC, Threading Beads; TB, Drawing Trail; DT) of the Movement Assessment Battery for Children-2 Test for typically developing children and investigated age- and sex-related differences. Three- to six-year-old Dutch children (n = 182, Mage 4.5 ± 1.1 years, 51.1% boys) were observed with regard to intra-task fine motor skill components, and changes in intra-task components of the Manual Dexterity tasks were analyzed across age using of the Kruskal–Wallis test with post-hoc Mann–Whitney U tests, and differences between sexes using the Mann–Whitney U test. The following intra-task components were observed: grip type, manipulation, non-dominant or non-writing hand, grip position, posture, head, coin placement, placement of the bead on the lace tip and joint movement. Results showed that the younger children (3-year-olds) more frequently used a grasp with the full hand (PC, TB), more often put the coin on the container and sliding it in (PC), more often supported the side or top of the container (PC), used more bi-manual manipulation (transferring from hand-to-hand or hand, body or surface assist) (TB, DT), more frequently used primitive, too high grips, predominantly used their proximal joints, and did not support the paper (DT). This in comparison with more frequent use of three-point pinch, direct coin placement, grabbing the front or back of the container, in-hand-manipulation, mature grips and correct height, distal joint use and supporting the paper from the side or below by most 5- and 6-year-olds. Furthermore, most sex-related differences were found in the younger age-groups (3- and 4-year-olds) in the DT tasks with girls outperforming boys. Results from this study add to the knowledge on qualitative fine motor skill performance in a convenience sample of 3- to 6-year-old typically developing children. A limitation of the current study was the relatively small sample size of 6-year-old children. The strength of the current study is its novelty in providing qualitative descriptions of intra-task fine motor skill components in typically developing 3- to 6-year-old children.

Anisotropic spin transport and photoresponse characteristics detected by tip movement in magnetic single-molecule junction

Orientation-dependent transport properties induced by anisotropic molecules are enticing in single-molecule junctions. Here, using the first-principles method, we theoretically investigate spin transport properties and photoresponse characteristics in trimesic acid magnetic single-molecule junctions with different molecular adsorption orientations and electrode contact sites. The transport calculations indicate that a single-molecule switch and a significant enhancement of spin transport and photoresponse can be achieved when the molecular adsorption orientation changes from planar geometry to upright geometry. The maximum spin polarization of current and photocurrent in upright molecular junctions exceeds 90%. Moreover, as the Ni tip electrode moves, the tunneling magnetoresistance of upright molecular junctions can be increased to 70%. The analysis of the spin-dependent PDOS elucidates that the spinterfaces between organic molecule and ferromagnetic electrodes are modulated by molecular adsorption orientation, where the molecule in upright molecular junctions yields higher spin polarization. Our theoretical work paves the way for designing spintronic devices and optoelectronic devices with anisotropic functionality base on anisotropic molecules.

Accuracy of Invisalign® aligners in adult patients: a retrospective study of angular tooth movements.

This retrospective study aimed to assess the predictability of Invisalign® aligners regarding rotational, mesio-distal and buccal-lingual tip movements. Two materials were included in the analysis - EX30, used until 2013; and SmartTrack, in current use. The study comprised 56 adult patients treated with Invisalign Comprehensive. Data sample were assessed on three sets of digital models; model 1 - initial, model 2 - predicted, and model 3 - achieved. Sixty reference points were marked in each dental arch, and two reference planes assisted the superimposition. The degree of rotation, mesio-distal and buccal-lingual tip was obtained via trigonometric calculations, through a previously published validated method. The accuracy of outcomes was compared according to the types of tooth movement and teeth groups,and the influence of predetermined variables on movement accuracy was also investigated. Rotation and mesio-distal tip did not present any significant difference when comparing EX30 and SmartTrack groups. Only buccal-lingual tip presented a significant difference, incisor and canine groups treated with EX30 aligners presented an increase in accuracy (p= 0.007 and p = 0.007, respectively). For each additional degree planned for rotation movements, there was an increase of 0.35° in the discrepancy, and an increase of 0.40° and 0.41° for mesio-distal and buccal-lingual tip, respectively. EX30 and SmartTrack discrepancies were compared by multilevel linear regression. EX30 aligners reached higher accuracy for buccal-lingual tip in anterior teeth. However, for rotation and mesio-distal tip, SmartTrack and EX30 are similarly accurate. The total amount of planned movement has a significant impact on accuracy rates, with a decrease in accuracy for every additional degree.

Influence of maxillary molar distalization with clear aligners on three-dimensional direction: molar distal movement, intrusion, distal tip and crown buccal torque

BackgroundThe aim of this study was to evaluate the distal movement, vertical movement, distal tipping and crown buccal torque of maxillary molars after the completion of distalization by comparing the predicted movement with the achieved movement using palatal rugae registration.MethodsThe study included 22 clear aligner patients (7 males and 15 females), and 79 molars were measured. Two digital models were generated before treatment and after molar distalization and were superimposed after selecting the palatal rugae area for registration in GOM inspect suite software 2022 (GOM; Braunschweig, Germany). The predicted and achieved movements of molar distalization, intrusion, distal tip and crown buccal torque were measured and compared.ResultThe achieved distalization (1.25 ± 0.79 mm vs. 2.17 ± 1.03 mm, P < 0.001; 1.41 ± 1.00 mm vs. 2.66 ± 1.15 mm, P < 0.001), intrusion (0.47 ± 0.41 mm vs. 0.18 ± 0.54 mm, P < 0.01; 0.58 ± 0.65 mm vs. 0.10 ± 1.12 mm, P < 0.01), distal tip (5.30 ± 4.56° vs. 1.53 ± 2.55°, P < 0.001; 4.87 ± 4.50° vs. − 1.95 ± 4.32°, P < 0.001) and crown buccal torque (1.95 ± 4.18° vs. − 1.15 ± 4.75°, P < 0.001; 0.43 ± 4.39° vs. − 4.27 ± 6.42°, P < 0.001) were significantly different from the predicted values in the two groups (first molar, second molar). Significant regression relationships were found between the achieved distal movement and deviational intrusion (R2 = 0.203, P < 0.0001), distal tip (R2 = 0.133, P < 0.001) and crown buccal torque (R2 = 0.067, P < 0.05). There was a significant correlation between the deviational movements of intrusion and the distal tip (R = 0.555, P < 0.0001).ConclusionApproximately 2 mm maxillary molar distalization was achieved in this study. Deviational movement of intrusion, distal tip and crown buccal torque beyond the clear aligner virtual design appeared to a certain degree after distalization. Thus, more attention should be given to molar intrusion and distal tip and crown buccal torque as the designed distalization increases.

DEM modelling of root circumnutation-inspired penetration in shallow granular materials

Plant root growth is often accompanied by circumnutative motion consisting of downward helical movement of the root tip. Previous studies indicate that circumnutations allow roots to avoid obstacles that would impede root growth, while other studies show that circumnutations can reduce the penetration resistance mobilised during root growth. Discrete-element modelling (DEM) simulations were performed on probes that employ circumnutation-inspired motion (CIM) to penetrate granular assemblies at shallow depths to evaluate the reduction in penetration resistance. These simulations investigate the effect of the ratio of tangential to vertical velocity of the circumnutative motion (i.e. relative velocity) and of the probe geometry (i.e. tip tilt angle and length). The results indicate that CIM penetration reduces the penetration force and work relative to non-rotational penetration (NRP) by changing the soil fabric and diffusing the force chains around the probe tip. However, the circumnutative motion leads to an increase in torque and associated rotational work. An optimal relative velocity and probe geometry exist for the simulated CIM probes, resulting in a smaller total work than that required for NRP. CIM penetration also mobilises smaller penetration forces and work than rotational penetration (i.e. with a straight tip), particularly at smaller relative velocities. The reduction in penetration forces induced by CIM could facilitate site investigation and monitoring activities.

Offline Handwritten Chinese Character Using Convolutional Neural Network: State-of-the-Art Methods

Given the presence of handwritten documents in human transactions, including email sorting, bank checks, and automating procedures, handwritten characters recognition (HCR) of documents has been invaluable to society. Handwritten Chinese characters (HCC) can be divided into offline and online categories. Online HCC recognition (HCCR) involves the trajectory movement of the pen tip for expressing linguistic content. In contrast, offline HCCR involves analyzing and categorizing the sample binary or grayscale images of characters. As recognition technology develops, academics’ interest in Chinese character recognition has continuously increased, as it significantly affects social and economic development. Recent development in this area is promising. However, the recognition accuracy of offline HCCR is still a sophisticated challenge owing to their complexity and variety of writing styles. With the advancement of deep learning, convolutional neural network (CNN)-based algorithms have demonstrated distinct benefits in offline HCCR and have achieved outstanding results. In this review, we aim to show the different HCCR methods for tackling the complexity and variability of offline HCC writing styles. This paper also reviews different activation functions used in offline HCCR and provides valuable assistance to new researchers in offline Chinese handwriting recognition by providing a succinct study of various methods for recognizing offline HCC.

Skill rather than beak kinematics affects seed handling performance in a granivorous songbird

Abstract In granivorous songbirds, feeding is a complex process as seeds need to be dehusked before they can be consumed, making the feeding act a biomechanically challenging endeavour. However, most previous research has focused on how beak morphology affects feeding performance, while the influences of beak kinematics remain largely unknown. In this study, we hence investigated at the individual level how feeding performance (i.e. seed processing time and success rate) relates to both beak kinematics (i.e. beak tip speed, acceleration, frequency) and skill (i.e. seed handling tactics and cracking techniques) in the Canary Serinus canaria. To do so, high‐speed videos during feeding were recorded and subjected to automated tracking of beak tip movements. Better skills, that is accurate positioning of the seed for being split in half, reduced total seed handling time compared to more random positioning and crushing the husk into multiple, scattering fragments. Surprisingly, individual variation in beak speed, acceleration or frequency generally did not relate to differences in performance. Thus, our data suggest that seed positioning precision, and hence the control of coordinated beak and tongue movement, is critical to minimize feeding durations in songbirds. Further studies are needed to explore whether this develops via a positive feedback between behaviour, learning and increased efficiency or if it relates to intrinsic differences. Read the free Plain Language Summary for this article on the Journal blog.

Compensatory articulatory mechanisms preserve intelligibility in prodromal Parkinson's disease

IntroductionDysarthria is highly prevalent in patients with Parkinson's disease (PD) and speech changes have already been detected in patients with prodromal PD on the acoustic level. However, the present study directly tracks underlying articulatory movements with electromagnetic articulography to investigate early speech alterations on the kinematic level in isolated REM sleep behavior disorder (iRBD) and compares them to PD and control speakers. MethodsKinematic data of 23 control speakers, 22 speakers with iRBD, and 23 speakers with PD were collected. Amplitude, duration, and average speed of lower lip, tongue tip, and tongue body movements were analyzed. Naive listeners rated the intelligibility of all speakers. ResultsPatients with iRBD produced tongue tip and tongue body movements that were larger in amplitude and longer in duration compared to control speakers, while remaining intelligible. Compared to patients with iRBD, patients with PD had smaller, longer and slower tongue tip and lower lip movements, accompanied by lower intelligibility. Thus, the data indicate that the lingual system is already affected in prodromal PD. Furthermore, lower lip and especially tongue tip movements slow down and speech intelligibility decreases if motor impairment is more pronounced. ConclusionPatients with iRBD adjust articulatory patterns to counteract incipient motor detriment on speech to maintain their intelligibility level.