bluuebunny/crossref_metadata_2025 huggingface dataset:
Large‐scale, image‐based tree species mapping in a tropical forest using artificial perceptual learning
Authors: Tang Chengliang , Uriarte María , Jin Helen , C. Morton Douglas , Zheng Tian
Published: January 2021

Information about the spatial distribution of species lies at the heart of many important questions in ecology. Logistical limitations and collection biases, however, limit the availability of such data at ecologically relevant scales. Remotely sensed information can alleviate some of these concerns, but presents challenges associated with accurate species identification and limited availability of field data for validation, especially in high diversity ecosystems such as tropical forests.

Recent advances in machine learning offer a promising and cost‐efficient approach for gathering a large amount of species distribution data from aerial photographs. Here, we propose a novel machine learning framework, artificial perceptual learning (APL), to tackle the problem of weakly supervised pixel‐level mapping of tree species in forests. Challenges arise from limited availability of ground labels for tree species, lack of precise segmentation of tree canopies and misalignment between visible canopies in the aerial images and stem locations associated with ground labels. The proposed APL framework addresses these challenges by constructing a workflow using state‐of‐the‐art machine learning algorithms.

We develop and illustrate the proposed framework by implementing a fine‐grain mapping of three species, the palmPrestoea acuminataand the tree speciesCecropia schreberianaandManilkara bidentata, over a 5,000‐ha area of El Yunque National Forest in Puerto Rico. These large‐scale maps are based on unlabelled high‐resolution aerial images of unsegmented tree canopies. Misaligned ground‐based labels, available for <1% of these images, serve as the only weak supervision. APL performance is evaluated using ground‐based labels and high‐quality human segmentation using Amazon Mechanical Turk, and compared to a basic workflow that relies solely on labelled images.

Receiver operating characteristic (ROC) curves and Intersection over Union (IoU) metrics demonstrate that APL substantially outperforms the basic workflow and attains human‐level cognitive economy, with 50‐fold time savings. For the palm andC. schreberiana, the APL framework has high pixelwise accuracy and IoU with reference to human segmentations. ForM.bidentata, APL predictions are congruent with ground‐based labels. Our approach shows great potential for leveraging existing data from global forest plot networks coupled with aerial imagery to map tree species at ecologically meaningful spatial scales.
Against Three “Cultural” Characters Speaks Self‐Improvement: Social Critique and Desires for “Modernity” in Pedagogies of Soft Skills in Contemporary China
Authors: Hizi Gil
Published: January 2021

Despite recent socioeconomic transformations, young adults in China construe local social norms as inhibiting their individualized selfhood. Based on a study of pedagogies of interpersonal “soft” skills, this article describes an apparatus of self‐improvement where self‐ and social critique play a pivotal role. Through comparison with Foucault’s “technologies of the self,” I illustrate that self‐improvement in China is largely oriented toward performative expressions that counteract the “local” rather than the habituation of virtues or skills.
Mechanism and prognostic indicators for explosion‐related eye trauma: eye injury vitrectomy study
Authors: Feng Kang , Yao Yi , Wang Zhi‐Jun , Nie Hong‐Ping , Pang Xiu‐Qin , Chen Hui‐Jin , Jiang Yan‐Rong , Hu Yun‐Tao , Ma Zhi‐Zhong
Published: January 2021

Purpose

To explore the clinical features, surgical interventions and prognosis of injured eyes following explosion and to develop the risk factors for poor prognosis.

Methods

A nested case–control study. To the date of 31 December 2018, 99 explosion‐related eye globes were selected from the Eye Injury Vitrectomy Study database, which is a multicenter prospective cohort study and began in 1990s. All cases selected underwent vitreoretinal surgery or enucleation and were followed up for at least 6 months. Clinically meaningful preoperative variables and outcomes were used to develop logistic regression models.

Results

The unfavourable outcomes were defined as silicone oil‐filled eyes, phthisis bulbi, enucleation and anatomically restored eyes whose final BCVA is worse than initial vision after 6 months of follow‐up. The proportion of unfavourable outcomes was 92.0%, 60.9% and 66.7% in large festive fireworks, detonator and beer bottle groups respective. The anatomic and visual outcome of injured eyes with combined injury of blast wave and projectile were worse than that of ruptured eyes (Fisher's exact = 0.041). The extrusion of iris/lens (OR = 3.20, p = 0.015), PVR‐C (OR = 6.08, p = 0.036) and choroid damage (OR = 5.84, p = 0.025) is independent risk factors of unfavourable prognosis for explosion‐related eye trauma.

Conclusion

The extrusion of iris/lens, PVR‐C and choroid damage is the independent risk factors for unfavourable outcomes in explosion‐related eye trauma. There is a unique injury mechanism in explosion‐related eye trauma.

Summary Statement

Through the nested case‐control study, the extrusion of iris/lens, PVR‐C, and choroid damage are the independent risk factors for unfavorable outcomes in explosion‐related eye trauma. The mechanism of open globe mixture and close globe mixture in explosion‐related eye trauma need more cases and participating units to explore together in the future.
The panel of syntaxin 1 and insulinoma‐associated protein 1 outperforms classic neuroendocrine markers in pulmonary neuroendocrine neoplasms
Authors: Zombori Tamás , Turkevi‐Nagy Sándor , Sejben Anita , Juhász‐Nagy Gréta , Cserni Gábor , Furák József , Tiszlavicz László , Krenács László , Kővári Bence
Published: January 2021

Syntaxin‐1 (STX1) is a recently described highly sensitive and specific neuroendocrine marker. We evaluated the applicability of STX1 as an immunohistochemical marker in pulmonary neuroendocrine neoplasms (NENs). We compared STX1 with established neuroendocrine markers, including insulinoma‐associated protein 1 (INSM1). Typical carcinoids (n = 33), atypical carcinoids (n = 7), small cell lung carcinomas ([SCLCs] n = 30), and large cell neuroendocrine lung carcinomas (n = 17) were immunostained using tissue microarray for STX1, chromogranin A, synaptophysin, CD56, and INSM1. Eighty‐four of eighty‐seven (96.5%) NENs showed STX1 positivity. Carcinoids and LCNECs typically presented a combined strong membranous and weak cytoplasmic staining pattern; cytoplasmic expression was predominately observed in SCLCs. The sensitivity of STX1 was 90% in SCLCs and 100% in typical carcinoids, atypical carcinoids, and large cell neuroendocrine lung carcinomas. The overall sensitivity of STX1 in pulmonary NENs was 96.6%, and the sensitivity of the other markers was as follows: chromogranin A (85.2%), synaptophysin (85.2%), CD56 (92.9%), and INSM1 (97.7%). STX1 was found to be an excellent neuroendocrine marker of pulmonary NENs, with sensitivity and specificity surpassing that of classic markers. We propose a panel of STX1 and INSM1 for the routine immunohistochemical workup of pulmonary NENs.
The effect of leucaena hay as a source of effective fibre and nutrients in diets with forage palm for finishing sheep in semi‐arid regions
Authors: Moreira Antonia L. , Alves Arnaud A. , Araújo Daniel L. C. , Moreira Filho Miguel A. , Costa Jandson V. , Azevêdo Danielle M. M. R. , Parente Henrique N. , Alves Fabiana C.
Published: January 2021

The present study was conducted to evaluate the intake, digestibility and nitrogen balance of diets for finishing sheep, containing leucaena hay as a source of effective fibre and forage palm. Twenty‐one male sheep were used in a randomized block design with three treatments, represented by total diets, where the forage was leucaena hay and forage palm in natura in proportions 350:650, 450:550 and 550:450 g/kg respectively. For the pH and NH3‐N in the ruminal fluid, and urea in the blood serum, plots split in time were adopted. Dry matter and nutrient digestibility, and the nitrogen balance were not influenced (p > .05) by the diets. The neutral detergent fibre digestibility decreased (p < .05) as the proportions of leucaena hay in the diets increased. The pH and NH3‐N were suitable for ruminal fermentation, and blood urea was maintained under normal physiological conditions for sheep. Combining 350 to 550 g/kg of leucaena hay with 450 to 650 g/kg of forage palm in total diets with a forage:concentrate ratio of 60:40 in late‐maturing sheep meets the nutritional requirements for daily gain 200 g, characterizing leucaena hay as important source of effective fibre and nutrients in diets.
A Developmental Eye Tracking Investigation of Cued Task Switching Performance
Authors: Zheng Annie , Church Jessica A.
Published: January 2021

Children perform worse than adults on tests of cognitive flexibility, which is a component of executive function. To assess what aspects of a cognitive flexibility task (cued switching) children have difficulty with, investigators tested where eye gaze diverged over age. Eye‐tracking was used as a proxy for attention during the preparatory period of each trial in 48 children ages 8–16 years and 51 adults ages 18–27 years. Children fixated more often and longer on the cued rule, and made more saccades between rule and response options. Behavioral performance correlated with gaze location and saccades. Mid‐adolescents were similar to adults, supporting the slow maturation of cognitive flexibility. Lower preparatory control and associated lower cognitive flexibility task performance in development may particularly relate to rule processing.
Single versus two‐implant mandibular overdentures using early‐loaded titanium‐zirconium implants with hydrophilic surface and ball attachments: 1‐year randomized clinical trial
Authors: de Resende Gabriela Pereira , Jordão Lídia Moraes Ribeiro , de Souza João Antônio Chaves , Schimmel Martin , Leles Cláudio Rodrigues
Published: January 2021

Objective

This randomized clinical trial aimed to compare the outcomes of the mandibular overdenture retained by one (1‐IOD) or two (2‐IOD) implants.

Materials and methods

Participants received new complete dentures, were assessed at baseline and randomly assigned to groups. Early loaded single midline implant (1‐IOD) or two implants in the canine regions bilaterally (2‐IOD). Ball attachments were used for overdenture retention. Post‐treatment outcomes (6‐ and 12‐month follow‐ups) included patient satisfaction, oral health‐related quality of life measures, and chewing function. Data analysis included within‐ and between‐group comparisons, and Generalized Estimating Equations. Both superiority and non‐inferiority hypotheses were tested.

Results

Forty‐seven participants were included (1‐IOD = 23; 2‐IOD = 24). Significant improvements in OHIP‐Edent were observed after insertion of new dentures and at the 1‐year follow‐up compared with baseline. No differences were found between the 1‐ and 2‐IOD groups for the OHIP‐Edent and QoLFAST scores. Patient satisfaction with the mandibular denture improved significantly from baseline to the 6‐month follow‐up and remained unaltered until 1 year, with no differences between groups. The magnitudes of treatment effect sizes were moderate to large for patient‐reported outcomes. Progressive improvement in chewing function occurred in both groups. Non‐inferiority testing based on a 15% non‐inferiority margin showed inconclusive results for patient‐reported outcomes, whilst chewing function in the 1‐IOD group was concluded to be not inferior to the 2‐IOD group.

Conclusions

Results support the use of both 1‐ and 2‐IOD. The 1‐IOD was also an acceptable alternative to the 2‐IOD as a secondary option for the treatment of the edentulous mandible.
A 52‐week randomized controlled trial of ipragliflozin or sitagliptin in type 2 diabetes combined with metformin: The N‐ISM study
Authors: Kitazawa Masaru , Katagiri Takashi , Suzuki Hiromi , Matsunaga Satoshi , H Yamada Mayuko , Ikarashi Tomoo , Yamamoto Masahiko , Furukawa Kazuo , Iwanaga Midori , Hatta Mariko , Fujihara Kazuya , Yamada Takaho , Tanaka Shiro , Sone Hirohito
Published: January 2021

Aim

To compare the long‐term efficacy of sodium‐glucose co‐transporter‐2 inhibitors and dipeptidyl peptidase‐4 inhibitors as second‐line drugs after metformin for patients not at high risk of atherosclerotic cardiovascular disease (ASCVD).

Materials and methods

In a 52‐week randomized open‐label trial, we compared ipragliflozin and sitagliptin in Japanese patients diagnosed with type 2 diabetes, without prior ASCVD and treated with metformin. The primary endpoint was a glycated haemoglobin (HbA1c) reduction of ≥0.5% (5.5 mmol/mol) without weight gain at 52 weeks.

Results

Of a total of 111 patients (mean age 59.2 years, mean body mass index [BMI] 26.6 kg/m2, 61.3% men), 54 patients received ipragliflozin and 57 received sitagliptin. After 52 weeks, achievement of the primary endpoint was not significantly different (37.0% and 40.3%; P = 0.72). HbA1c reduction rate at 24 weeks was greater for sitagliptin (56.1%) than for ipragliflozin (31.5%; P = 0.01). From 24 to 52 weeks, the HbA1c reduction with sitagliptin was attenuated, with no significant difference in HbA1c reduction after 52 weeks between sitagliptin (54.4%) and ipragliflozin (38.9%; P = 0.10). Improvements in BMI, C‐peptide and high‐density lipoprotein cholesterol were greater with ipragliflozin than with sitagliptin. Adverse events occurred in 17 patients with ipragliflozin and in 10 patients with sitagliptin (P = 0.11).

Conclusion

The HbA1c‐lowering effect at 24 weeks was greater with sitagliptin than with ipragliflozin, but with no difference in efficacy related to HbA1c and body weight at 52 weeks. However, some ASCVD risk factors improved with ipragliflozin.
Young healthy adults with a family history of hypertension have increased microvascular reactivity but decreased macrovascular function
Authors: Matthews Evan L. , Guers John J. , Hosick Peter A.
Published: January 2021

Objective

To determine whether, like hypertensives, normotensive adults with a family history of hypertension (+FHH) display lower microvascular reactivity and conduit artery function than normotensive adults without a family history of hypertension (−FHH).

Methods

A forearm vascular occlusion test was performed on healthy normotensive adults while resting in the supine position. A near‐infrared spectroscopy sensor placed on the forearm measured skeletal muscle oxygen saturation kinetics to determine microvascular reactivity. Simultaneously, an ultrasound probe placed on the brachial artery above the occlusion cuff was used to assess flow‐mediated dilation; a test of macrovascular function.

Results

Twenty‐two participants were included in this investigation (−FHH n = 13, +FHH n = 9). Following cuff release, the resaturation slope (1st 10 s median ± SD, −FHH 2.76 ± 2.10, +FHH 5.59 ± 2.47%/s; p = .036) was greater in +FHH when accounting for the magnitude and rate of the decrease in skeletal muscle oxygen saturation during occlusion. Conversely, flow‐mediated dilation (median ± SD, −FHH 5.96 ± 5.22, +FHH 4.10 ± 3.17%∆; p = .031) was lower in +FHH when accounting for baseline artery diameter and shear rate.

Conclusions

Young +FHH adults have altered microvascular and macrovascular reactivity compared with young −FHH adults.
The Oval‐like Cross‐section of Femoral Neck Isthmus in Three‐dimensional Morphological Analysis
Authors: Zhang Ru‐yi , Zhao Yan‐peng , Su Xiu‐yun , Li Jian‐tao , Zhao Jing‐xin , Zhang Li‐cheng , Tang Pei‐fu
Published: January 2021

Objectives

To investigate the cross‐section shape of the femoral neck isthmus (FNI) in three‐dimensional reconstruction model of the femoral neck.

Methods

From December 2009 to December 2012, computed tomography (CT) data of bilateral hip joint from 200 consecutive patients (137 males and 63 females, 69.41 ± 9.21 years old, ranged from 50–85 years old) who underwent surgical treatments for proximal femoral fracture were retrospectively reviewed. The 3D model of the proximal femur was reconstructed, and the “inertia axis” method, which was applied to measure the long and short axes of the cross‐section of the FNI, was established. The cross‐sectional area and perimeter were calculated by a formula using the length of the long and short axes and then compared with the actual measured values by the software. Correlation between the descriptive parameters of the FNI cross‐section (area, perimeter, and eccentricity) and patients' demographics (age, height, and weight) was analyzed. Stepwise linear regression analysis was used to determine the main relevant factors.

Results

The ICC results showed excellent data reproducibility ranged from 0.989 to 0.996. There was no significant difference in the cross‐sectional area of the FNI between the actual measured values and the predicted values using the formula (732.83 ± 126.74 mm2 vs 731.62 ± 128.15 mm2, P = 0.322). The perimeter using the two methods showed narrow while significant difference (97.86 ± 8.60 mm vs 92.84 ± 8.65 mm, P < 0.001), the actual measured values were about 5 mm greater than the predicted values. The parameters (area, perimeter, and eccentricity) were significantly larger in male than female (P < 0.001). A positive correlation between the cross‐sectional area, perimeter, height, and weight was observed. The stepwise linear regression analysis showed that the regression equation of the FNI area was as follows: Y = −1083.75 + 1033.86 × HEIGHT + 1.92 × WEIGHT, R2 = 0.489.

Conclusion

The cross‐section shape of the FNI appears to be oval‐like in the 3D model, which is separated according to the inertia axis, and the findings proposed an anatomical basis for the further study of the spatial configuration of cannulated screws in the treatment of femoral neck fractures.
Reevaluation of concurrent acetylcholinesterase and hematoxylin and eosin staining for Hirschsprung’s disease
Authors: Yoshimaru Koichiro , Matsuura Toshiharu , Yanagi Yusuke , Obata Satoshi , Takahashi Yoshiaki , Kajihara Keisuke , Ohmori Atsuko , Irie Keiko , Hino Yuko , Shibui Yuichi , Tamaki Akihiko , Kohashi Kenichi , Oda Yoshinao , Taguchi Tomoaki
Published: January 2021

Background

Acetylcholinesterase (AChE) histochemistry has been widely performed for the histopathological diagnosis of Hirschsprung’s disease (HD). However, we occasionally come across diagnostic difficulties. We conducted concurrent AChE histochemistry and hematoxylin and eosin (HE) staining to validate the ancillary value of this technique.

Methods

Of 177 patients diagnosed using AChE histochemistry from January 2014 to December 2016, 90 patients underwent formalin‐fixed paraffin‐embedded HE staining. The histopathological findings and diagnostic abilities were investigated and compared retrospectively.

Results

The sensitivity, specificity, accuracy, and kappa index of AChE histochemistry and HE staining were 94.1%, 100%, 98.9%, and 0.964 and 76.5%, 84.9%, 83.3%, and 0.530, respectively. The specificity, accuracy and kappa index of AChE histochemistry were significantly higher than those of HE staining (P < 0.001, <0.001, and <0.05). Hematoxylin and eosin staining supported the suspected diagnosis of total colon aganglionosis at the initial biopsy; furthermore, HE staining helped confirm the distinct shape of ganglion cells and hypertrophic nerve bundles.

Conclusion

We re‐confirmed that AChE histochemistry is an excellent method for diagnosing HD. Although the diagnostic ability of HE staining is limited, it has acceptable utility as an ancillary method. Thus, AChE staining is a useful test and it should be performed together with HE staining.
Grounding, metaphysical laws, and structure
Authors: Grajner Martin
Published: January 2021

According to the deductive‐nomological account of ground, a fact A grounds another fact B in case the laws of metaphysics determine the existence of B on the basis of the existence of A. Accounts of grounding of this particular variety have already been developed in the literature. My aim in this paper is to sketch a new version of this account. My preferred account offers two main improvements over existing accounts. First, the present account is able to deal with necessitarian as well as non‐necessitarian cases of grounding by acknowledging the existence of two types of metaphysical laws. I will argue that we should assume that metaphysical laws come in the necessitarian as well as in the non‐necessitarian variety—closely paralleling the distinction between strict and non‐strict laws in the philosophy of science. The second main improvement of the present account is that this account is able to provide an explanation of why the laws of metaphysics have a direction built into them. I will argue that we should characterize metaphysical laws with the help of Theodore Sider’s (2011) notion of structure, which is a descendent of David Lewis’s (1983) notion of naturalness. According to the account of metaphysical laws developed in this paper, metaphysical laws express in their antecedents either perfectly structural truths or more structural truths than in their consequents. Since on Sider’s account structural features of reality are fundamental features of reality, the account is able to explain as to why the laws of metaphysics take us from the fundamental to the derivative.
The influence of clinical severity and topical antimicrobial treatment on bacteriological culture and the microbiota of equine pastern dermatitis
Authors: Sangiorgio Daphne B. , Hilty Markus , Kaiser‐Thom Sarah , Epper Pascale G. , Ramseyer Alessandra A. , Overesch Gudrun , Gerber Vinzenz M.
Published: January 2021

Background

Equine pastern dermatitis (EPD) is a common dermatological problem in horses, yet its aetiology and pathogenesis are poorly understood.

Objectives

This study aimed to investigate the effects of lesion severity and topical antimicrobial treatment on bacterial flora of EPD‐affected skin.

Animals

Sixteen horses with EPD were investigated.

Methods and materials

An observational study was conducted by assigning a clinical severity score ranging from 0 (macroscopically nonlesional) to 21 (severe), and sampling the most and least severely affected limbs of 16 horses (32 limbs) for bacteriological culture and 16S rRNA sequencing. Topical antimicrobial treatment in the month before sampling was recorded. The limbs were allocated to a nonlesional or mildly affected group (Group A, score 0–3) and a moderate to severely affected group (Group B, score 4–21).

Results

The most commonly cultured bacterial species was Staphylococcus aureus (one of 15 Group A versus nine of 17 Group B). Within Group B, S. aureus was found in three of six limbs treated with topical antimicrobials and in six of 11 untreated limbs. β‐haemolytic streptococci (three of 32) and Trueperella pyogenes (two of 32) also were cultured exclusively in the untreated limbs of Group B. Staphylococci and streptococci were found more often by 16S rRNA sequencing than in culture. Limbs with higher lesion severity and topical antimicrobial treatment appeared to have a lower alpha diversity and different beta diversity compared to milder and untreated lesions.

Conclusions and clinical importance

Observed differences in microbiota of equine skin are likely to be linked to the presence and severity of EPD and topical antimicrobial treatment. Further research is needed to establish causal bacteria.
Clinical and diagnostic findings, treatment, and short‐ and long‐term survival in horses with peritonitis: 72 cases (2007‐2017)
Authors: Arndt Stefanie , Kilcoyne Isabelle , Vaughan Betsy , Dechant Julie E.
Published: January 2021

Objective

To identify etiology, clinical findings, diagnostic results, treatment, and short‐ and long‐term survival and to report factors associated with nonsurvival and survival in horses with peritonitis.

Study design

Retrospective study.

Animals

Horses (n = 72).

Methods

Medical records at William R. Pritchard Veterinary Medical Teaching Hospital from 2007‐2017 were reviewed for horses diagnosed with peritonitis. The essential inclusion criterion was a peritoneal nucleated cell count of ≥25 000 cells/μL. Gastrointestinal rupture and cases in which peritonitis occurred after abdominal surgery or castration were excluded. Information retrieved from medical records included signalment, history, clinicopathological and peritoneal fluid variables, diagnostic imaging findings, inciting cause, treatment, and short‐ and long‐term survival. Data were analyzed by using Fisher's exact test, Wilcoxon rank sum test, and χ2test (P < .05).

Results

Colic was the most common presenting complaint (34/72 [48%]). A definitive diagnosis could be made in 44 (44/72 [61%]) cases. The most common cause of peritonitis was infectious agents (31/72), followed by trauma (8/72), gastrointestinal thickening (3/72), and eosinophilic peritonitis (2/72). Idiopathic peritonitis was identified in 28 (28/72 [39%]) cases. Sixty (83%) horses survived to hospital discharge. Long‐term follow‐up was available for 49 horses, with 43 (88%) horses alive 1 year after discharge. Significant differences between nonsurvivors and survivors were history of colic, positive peritoneal fluid culture, and several hematological/peritoneal fluid variables.

Conclusion

Peritoneal fluid analysis was essential for a definitive diagnosis of peritonitis, and certain variables were useful for predicting outcome.

Clinical significance

Results of this study provide evidence of the value of peritoneal fluid analysis for identification of peritonitis, prediction of outcome, and successful treatment.
Classification of irreversible and reversible Pimsner operator algebras
Authors: Dor-On Adam , Eilers Søren , Geffen Shirly
Published: January 2021

Since their inception in the 1930s by von Neumann, operator algebras have been used to shed light on many mathematical theories. Classification results for self-adjoint and non-self-adjoint operator algebras manifest this approach, but a clear connection between the two has been sought since their emergence in the late 1960s. We connect these seemingly separate types of results by uncovering a hierarchy of classification for non-self-adjoint operator algebras and$C^{*}$-algebras with additional$C^{*}$-algebraic structure. Our approach naturally applies to algebras arising from$C^{*}$-correspondences to resolve self-adjoint and non-self-adjoint isomorphism problems in the literature. We apply our strategy to completely elucidate this newly found hierarchy for operator algebras arising from directed graphs.
The Effect of Physical Activity on Residual Limb Volume, Comfort, and Gait Symmetry of Transfemoral Amputees
Authors: Salazar-Salgado Sara , Valencia Fanny , Uribe Alejandro , Rendón-Vélez Elizabeth
Published: January 2021

For lower limb amputees, the socket fit is affected by the physical activity performed during the day. The majority of the studies in this field include only transtibial amputees and do not examine the effects of this variable. This paper aims to determine the effect of physical activity on the volume of the residual limb (RL), the comfort, and the symmetry of gait in traumatic transfemoral amputees. RL volume and gait data of five individuals were obtained at the first time of the day and after three sessions of treadmill walking. The ratio symmetry index of selected points of gait parameters was calculated. A short comfort test was used after each session. Data were analyzed throughout the tests within each subject, and statistical analysis was performed. After the physical activity, a tendency toward volume decrease was found on almost all subjects, although it was not significant. Transfemoral amputees may have smaller volume variations than transtibial after treadmill walking tasks. Significant difference was found on the symmetry index of “swing phase (SWP).” The values of gait symmetry were consistent with previous findings regarding transfemoral amputees. The lowest symmetry was noticed on the ankle kinematics. The comfort did not significantly change with the selected amount of physical activity. In subsequent research, it is recommended to increase the intensity or time of physical activity and/or increase the number of participants. These results can help the understanding of how the socket/RL interface behaves, which can improve the design and prescription of prosthetic components.
Quadratic Constrained Periodic Optimization for Bandlimited Linear Systems Via the Fourier-Based Method
Authors: Moretti Giacomo , Zaccarian Luca , Blanchini Franco
Published: January 2021

Motivated by engineering applications, we address bounded steady-state optimal control of linear dynamical systems undergoing steady-state bandlimited periodic oscillations. The optimization can be cast as a minimization problem by expressing the state and the input as finite Fourier series expansions, and using the expansions coefficients as parameters to be optimized. With this parametrization, we address linear quadratic problems involving periodic bandlimited dynamics by using quadratic minimization with parametric time-dependent constraints. We hence investigate the implications of a discretization of linear continuous time constraints and propose an algorithm that provides a feasible suboptimal solution whose cost is arbitrarily close to the optimal cost for the original constrained steady-state problem. Finally, we discuss practical case studies that can be effectively tackled with the proposed framework, including optimal control of DC/AC power converters, and optimal energy harvesting from pulsating mechanical energy sources.
Design and Performance Analysis of a Cascaded Model Predictive Controller and Command Governor for Fuel-Efficient Control of Heavy-Duty Trucks
Authors: Groelke Ben , Borek John , Earnhardt Christian , Vermillion Chris
Published: January 2021

This paper presents the design and analysis of a predictive ecological control strategy for a heavy-duty truck that achieves substantial fuel savings while maintaining safe following distances in the presence of traffic. The hallmark of the proposed algorithm is the fusion of a long-horizon economic model predictive controller (MPC) for ecological driving with a command governor (CG) for safe vehicle following. The performance of the proposed control strategy was evaluated in simulation using a proprietary medium-fidelity Simulink model of a heavy-duty truck. Results show that the strategy yields substantial fuel economy improvements over a baseline, the extent of which are heavily dependent on the horizon length of the CG. The best fuel and vehicle-following performance are achieved when the CG horizon has a length of 20–40 s, reducing fuel consumption by 4–6% when compared to a Gipps car-following model.
Application-Specific Learning Curve With a Modern Computer-Assisted Orthopedic Surgery System for Joint Arthroplasty
Authors: Dai Yifei , Kusuma Sharat , Greene Alexander T. , Fan Wen , Jung Amaury , Hamad Cyril , Bras Guillaume , Angibaud Laurent
Published: January 2021

A commonly acknowledged barrier for the adoption of new computer-assisted orthopedic surgery (CAOS) technologies relates to a perceived long and steep learning curve. However, this perception has not been objectively tested with the consideration of surgeon-specific learning approaches. This study employed the cumulative sum control chart (CUSUM) to investigate individual surgeon's learning of CAOS technology by monitoring the stability of the surgical process regarding surgical time. Two applications for total knee arthroplasty (TKA) and two applications for total shoulder arthroplasty (TSA) provided by a modern CAOS system were assessed with a total of 21 surgeons with different levels of previous CAOS experience. The surgeon-specific learning durations identified by CUSUM method revealed that CAOS applications with “full guidance” (i.e., those that offer comprehensive guidance, full customization, and utilize CAOS-specific instrumentation) required on average less than ten cases to learn, while the streamlined application designed as a CAOS augmentation of existing mechanical instrumentation demonstrated a minimal learning curve (less than three cases). During the learning phase, the increase in surgical time was found to be moderate (approximately 15 min or less) for the “full guidance” applications, while the streamlined CAOS application only saw a clinically negligible time increase (under 5 min). The CUSUM method provided an objective and consistent measurement on learning, and demonstrated, contrary to common perception, a minimal to modest learning curve required by the modern CAOS system studied.
Real-Time Planning and Nonlinear Control for Quadrupedal Locomotion With Articulated Tails
Authors: Fawcett Randall T. , Pandala Abhishek , Kim Jeeseop , Akbari Hamed Kaveh
Published: January 2021

The primary goal of this paper is to develop a formal foundation to design nonlinear feedback control algorithms that intrinsically couple legged robots with bio-inspired tails for robust locomotion in the presence of external disturbances. We present a hierarchical control scheme in which a high-level and real-time path planner, based on an event-based model predictive control (MPC), computes the optimal motion of the center of mass (COM) and tail trajectories. The MPC framework is developed for an innovative reduced-order linear inverted pendulum (LIP) model that is augmented with the tail dynamics. At the lower level of the control scheme, a nonlinear controller is implemented through the use of quadratic programming (QP) and virtual constraints to force the full-order dynamical model to track the prescribed optimal trajectories of the COM and tail while maintaining feasible ground reaction forces at the leg ends. The potential of the analytical results is numerically verified on a full-order simulation model of a quadrupedal robot augmented with a tail with a total of 20 degrees-of-freedom. The numerical studies demonstrate that the proposed control scheme coupled with the tail dynamics can significantly reduce the effect of external disturbances during quadrupedal locomotion.
Effect of Sintering on Structural Modification and Phase Transition of Al-Substituted LLZO Electrolytes for Solid State Battery Applications
Authors: Ganesh Kumar K. , Balaji Bhargav P. , Balaji C. , Nafis Ahmed , Aravinth K. , Ramasamy P.
Published: January 2021

Owing to high lithium ion conductivity and good stability with lithium metal, Li7La3Zr2O12 (LLZO—a solid electrolyte) has emerged as a viable candidate for solid-state battery applications. In the current study, Al-substituted LLZO (Al-LLZO) powder is synthesized using a typical solid-state reaction. The pellets are made with the synthesized powder and are subjected to annealing for different durations and its effect on the structural properties of the Al-LLZO is investigated in detail. Reitveld refinement of the powder X-ray diffraction pattern reveals that the sintered Al-LLZO belong to the cubic system with the Ia-3d space group at room temperature. Morphology and microstructural properties of sintered powder are analyzed using field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM)/selected area electron diffraction (SAED), respectively. The FESEM image of LLZO pellets shows well-structured cubic grains spread evenly over on the surface after sintering. The chemical compositions of the sample are identified using energy dispersive X-ray analysis (EDAX). The surface chemistry of the prepared samples is examined by X-ray photoelectron spectroscopy (XPS), which states that the observed photoelectron signals from O 1s at about 531 eV and Li1s at 54.52 eV correspond to the Li-O bond in Al-LLZO. Raman spectra have been analyzed and the observed Raman peaks appearing at 299 cm−1, 393 cm−1, 492 cm−1, and 514 cm−1 were assigned to Eg, F2g, A1g, and F2g, respectively. Phase transformation from C-LLZO to the pyrochore LZO phase is noticed when the sample is sintered for 12 h at 1100 °C. The impedance analysis is carried out to measure the conductivity of the Al-LLZO pellet and is found to be 0.3 × 10−5 S cm−1, which is suitable for solid electrolyte applications in lithium ion batteries.
Investigation of the Shock Wave Formation and Intensity in Wave Rotor
Authors: Liu Peiqi , Li Xiang , Liu Xinyu , Yang Jun , Feng Mingyu , Hu Dapeng
Published: January 2021

Actual formation and intensity of shock wave generated during gradual opening and closure between each port and passages of wave rotor are studied by means of experiment and computational fluid dynamics simulation. The results show that the intensity of shock wave increases with the distance from high-pressure inlet, and the reason for the variation tendency is the superposition of compression waves. By changing the rotational speed and the expansion ratio, the shock wave intensity can be adjusted, but the position where the intensity reaches maximum stays constant basically and keeps the distance near 300 mm from high-pressure inlet. Comparing with the one-dimensional simplification result, the actual intensity of shock wave is lower. The difference between the fact and simplification increases with the rotational speed and expansion ratio. The internal mechanism has been analyzed from the aspect of intake mass. Then, the maximum shock wave intensity is found approximately linear to the intake mass of each rotor passage in each cycle.
A Perspective on Tribology and Design
Authors: Suh Nam Pyo
Published: January 2021

The quality of design determines the performance of all tribological systems. Tribological failures of the system may be avoided through rational and creative design. In that sense, there is a symbiotic relationship between tribology and design. Many tribology problems encountered are often the result of poor system design. By properly designing the tribological system, potential failures caused by friction and wear can be avoided or minimized. Continuous testing of poorly designed tribological systems, which occur in some cases, can be costly without noticeable improvements in the system performance. Since well-designed products yield immense benefits, the creation of tribological systems based on rational design should be pursued. The biggest source of tribological problems is the coupling of the functional requirements (FRs) that are introduced during the early stage of design. We should attempt to eliminate coupled tribological systems to improve the performance of tribological systems. Some examples are given to illustrate the importance of rational designs in implementing tribological systems, including the design of additive manufacturing systems.
Comparative Analysis of Intelligence Optimization Algorithms in the Thermo-Economic Performance of an Energy Recovery System Based on Organic Rankine Cycle
Authors: Duarte-Forero Jorge , Obregón-Quiñones Luis , Valencia-Ochoa Guillermo
Published: January 2021

This paper compares the performance of a group of intelligent algorithms such as the genetic algorithm (GA), particle swarm optimization (PSO), and repulsive particle swarm optimization (RPSO) based on the optimization of thermo-economic indicators such as the payback period (PBP), the levelized energy cost (LEC), the specific investment cost (SIC), and also in the optimization of the thermodynamic process (net power output) of an energy recovery system in a 2 MW natural gas internal combustion engine based on an organic Rankine cycle. Four parameters were considered to analyze and compare the performance of these algorithms: integral of squared error (ISE), integral of absolute error (IAE), integral of time-weighted absolute error (ITAE), and the integral of time-weighted squared error (ITSE). Analyses of variances (ANOVA) were proposed for each of the parameters studied. The PSO and RPSO algorithms presented the best performance in terms of the mean and the standard deviation of the ISE, IAE, ITAE, and ITSE parameters. Significant differences were not found between the three algorithms in terms of the parameters considered. However, significant differences did exist when comparing groups (pairs) of algorithms considering a significance level of 5%. The ANOVA analysis showed that ITAE was the most affected parameter by population size, while the IAE and ITSE parameters were the less affected. In the optimization, the PSO algorithm obtained the best performance in terms of convergence with values of 0.1110 USD/kWh (LCOE), 4.6971 years (PBP), 1114 USD/kWh (SIC), and 173.64 kW (Wnet). PSO-based algorithms obtained better performance in computational terms compared with the genetic algorithms.
Predicting Viscosities of Heavy Oils and Solvent–Heavy Oil Mixtures Using Artificial Neural Networks
Authors: Chen Zehua , Yang Daoyong
Published: January 2021

This study investigates the potential of artificial neural networks (ANNs) to accurately predict viscosities of heavy oils (HOs) as well as mixtures of solvents and heavy oils (S–HOs). The study uses experimental data collected from the public domain for HO viscosities (involving 20 HOs and 568 data points) and S–HO mixture viscosities (involving 12 solvents and 4057 data points) for a wide range of temperatures, pressures, and mass fractions. The natural logarithm of viscosity (instead of viscosity itself) is used as predictor and response variables for the ANNs to significantly improve model performance. Gaps in HO viscosity data (with respect to pressure or temperature) are filled using either the existing correlations or ANN models that innovatively use viscosity ratios from the available data. HO viscosities and mixture viscosities (weight-based, molar-based, and volume-based) from the trained ANN models are found to be more accurate than those from commonly used empirical correlations and mixing rules. The trained ANN model also fares well for another dataset of condensate-diluted HOs.
Stability of Diesel/Water Emulsions: Experimental and Modeling Investigations
Authors: Husain Arafat , Adewunmi Ahmad A. , Mahmoud Mohamed , Kamal Muhammad Shahzad , Al-Harthi Mamdouh A.
Published: January 2021

Diesel/water emulsions have several applications in the upstream and downstream petroleum industry. Diesel/water emulsions have been proposed as an alternative fuel due to their potential to emit a lesser amount of nitrogen oxides and particulate matter in the current models of compressed ignition engines. In the upstream petroleum research, diesel/water emulsions are used for the targeted delivery of several chemicals in deep reservoirs. The diesel/water emulsions are not very well understood despite their numerous applications. In this work, diesel/water emulsions were prepared using octylphenol ethoxylate as an emulsifier at different mixing times and speeds, varying surfactant concentrations, and using different water/diesel ratios. The emulsion stability was evaluated using a bottle test method, droplet size distribution (microscope), and rheological measurements. The bottle tests were mainly used to determine the emulsion stability, while the optical microscopic analysis was carried out to validate and understand the relation between the droplet size distribution and its impact on emulsion stability. It was found that emulsion stability not only depends on the concentration of surfactant, water, and diesel but also on mixing speed and time. The emulsion stability was enhanced by increasing the concentration of water, and the most stable emulsions were achieved when the water ratio was higher than 80 v/v%. The emulsion stability significantly increased when the mixing speed was increased up to 1200 rpm compounded with a mixing time of 20 min. An optimum surfactant concentration was noted to get the most stable emulsions ranging from 2.5 v/v% to 5 v/v%. The K-Star model was adopted in this study to predict the experimentally determined viscosity values. Modeling results showed that the predicted and measured viscosities were very close with minimal marginal errors. The excellent predicted viscosity values are demonstrated by the considerable root mean square error: 0.0873 and 2.5164 and mean absolute error: 0.0595 and 1.8675 for the training and testing dataset, respectively. The current study indicated that water to diesel ratio and mixing method could significantly affect the emulsion characteristics.
Novel in situ sensing surface forces apparatus for measuring gold versus gold, hydrophobic, and biophysical interactions
Authors: Wieser Valentina , Bilotto Pierluigi , Ramach Ulrich , Yuan Hui , Schwenzfeier Kai , Cheng Hsiu-Wei , Valtiner Markus
Published: January 2021

The surface forces apparatus (SFA) was developed in the late 1960s as a powerful tool for investigating molecular interactions across apposing surfaces including the first measurement of van der Waals forces and interactions in biologic and liquid media. However, the SFA has two major disadvantages. First, it traditionally uses white light interference between back-silvered muscovite mica surfaces to measure distances and to infer forces from distance shifts during interaction of two surfaces. Hence, distance shifts and force measurement are not decoupled. Second, productive SFA interferometers are so far limited to measuring across mica versus mica or mica versus metal. Direct gold-gold configurations were suggested in the late 1990s but not experimentally achieved as proof-of-principle until recently using a templating technique. In this work, we show how we solve these two disadvantages. First, we present a new SFA design that decouples force and distance measurements with similar resolution. The presented SFA design is inexpensive and can be home-built with mostly commercially available parts. Second, we present an alternative physical vapor deposition approach to construct a stable gold-gold interferometer and demonstrate its performance showing hydrophobic interactions, bubble formation, hemifusion of bilayers, and friction experiments. The presented system is easy to use. The obtained results show excellent reproducibility, indicating that the designed SFA and the three-mirror gold-gold interferometer functions as well as or even better than the traditional interferometer configurations used in SFA. This opens SFA to a wide range of options for various possible applications. Specifically, the gold-gold configuration allows a broad range of surface modifications for studying biophysical interactions as demonstrated in this work.
Temporal cues to onset voicing contrasts in Australian English-speaking children
Authors: Millasseau Julien , Bruggeman Laurence , Yuen Ivan , Demuth Katherine
Published: January 2021

Voicing contrasts are lexically important for differentiating words in many languages (e.g., “bear” vs “pear”). Temporal differences in the voice onset time (VOT) and closure duration (CD) contribute to the voicing contrast in word-onset position. However, little is known about the acoustic realization of these voicing contrasts in Australian English-speaking children. This is essential for understanding the challenges faced by those with language delay. Therefore, the present study examined the VOT and CD values for word-initial stops as produced by 20 Australian English-speaking 4–5-year-olds. As anticipated, these children produced a systematic distinction between voiced and voiceless stops at all places of articulation (PoAs). However, although the children's VOT values for voiced stops were similar to those of adults, their VOTs for voiceless stops were longer. Like adults, the children also had different CD values for voiced and voiceless categories; however, these were systematically longer than those of adults. Even after adjusting for temporal differences by computing proportional ratios for the VOT and CD, children's voicing contrasts were not yet adultlike. These results suggest that children of this age are still developing appropriate timing and articulatory adjustments for voicing contrasts in the word-initial position.