High-precision handling processes are essential for various high-tech industries and are typically realized using specialized high precision robots. Articulated robots are rarely used for such tasks ...due to their low stiffness and accuracy stemming from their kinematic structure. This work presents a methodology for designing handling processes that maximise repeatability with articulated robots. By considering their kinematic structures’ highly pose dependent properties as well as sensitivity to external disturbances in every step of the processes design, significantly improved repeatability can be achieved. The applicability of the new methodology is verified experimentally using the example of handling of large silicon dies.
Purpose
The purpose was to evaluate the repeatability of a new swept-source optical biometer for measuring ocular biometric parameters.
Methods
Thirty subjects with healthy and phakic eyes were ...included in this study, and only one eye per participant was analysed. Each eye was measured five times with the IOLMaster 700 swept-source optical biometer (Carl Zeiss Meditec, Jena, Germany). Axial length (AL), anterior chamber depth (ACD), central corneal thickness (CCT), lens thickness (LT), white-to-white (WTW), and K1 and K2 keratometric readings were evaluated. The repeatability of swept-source biometry was evaluated on the basis of five measurements captured for each patient.
Results
The repeatability limits for the axial measurements AL, ACD, CCT, and LT were 0.03, 0.07, 0.004, and 0.11 mm, respectively. For the WTW distance and both keratometry readings, the repeatability limits were 0.20, 0.06, and 0.05 mm, respectively. The AL resulted in the lowest coefficient of variation, and the LT had the highest one. The spherical equivalent showed statistically significant negative correlations with the AL and ACD.
Conclusion
Swept-source optical biometry showed high repeatability performance for all biometric parameters in healthy eyes, where the correlation between the spherical equivalent and AL showed the strongest value.
Cardiac-related mortality is increasing in farmed salmon. Non-invasive tools for examining and screening for cardiac morphology and function are limited, and most common methodologies are lethal, ...time-consuming, and immobile. Echocardiography has previously been tested as a non-invasive, quick, and portable alternative, though its implementation is minimal. Improvements in echocardiographic techniques during the last decade have enabled more refined assessments of structure and function and hold potential for use in fish farms. Utilising a compact, transportable ultrasound system, we examined the applicability of echocardiography in Atlantic salmon (Salmo salar L.). Several protocols and projections were tested, and intra- and inter-variation for both operators (image acquisition) and observers (image analysis) were assessed. In addition, the accuracy of cardiac structure/function measurements was compared with standard methods. In general, high accuracy and reproducibility of cardiac dimensions and functional parameters were found within the same and between different observers analysing the same dataset (intra- and inter-observer). Measurements between recordings of the same operator (intra-operator) and between different operators (inter-operator) were less accurate and repeatable but comparable to observations in previous human and mammalian studies. Cardiac output was slightly higher when measured with echocardiography compared to transit time flow probe. Yet, a strong correlation exists between the two methods. Furthermore, morphology measured in excised hearts ex vivo was comparable to echocardiography measurements and strongly correlated. Thus, ultrasound presents a highly feasible, non-invasive, and swift alternative to current methods for detailed cardiac assessment of salmon hearts.
•Echocardiography is a non-invasive option for cardiac analysis in Atlantic salmon.•Intra- and inter-variability is comparable to human and mammalian studies.•Echocardiography yields measurements similar to invasive methods.
The objective of this study was to select progenies of Opuntia undulata Griffiths cv. African Elephant Ear (AEE) through morphological, productive, and nutritional traits, and also evaluate the ...repeatability and selection gain. The experiment was carried out between 2018 and 2020, in the semiarid region of Brazil. A completely randomized design was used, with ten replications. The treatments consisted of 12 progenies of Opuntia undulata cv. AEE. Morphological, productive, and nutritional characteristics were evaluated, also the selection gain and repeatability were estimated. There was a variation in the productivity of up to 11.2 t DM ha−1. Progenies number 6 and 7 stood out in terms of selection gain. Progenies 6, 7, 9, and 12 were the most productive. Progeny 6 stood out in terms of dry matter production and minor presence of spines; both traits are of great interest in breeding programs of forage cacti. Based on the repeatability analysis, fewer evaluations were enough to predict with confidence morphological traits and dry matter production in different progenies of Opuntia undulata Griffiths.
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•Fewer evaluations could predict the morphological traits in Opuntia undulata Griffiths.•Forage cacti Opuntia undulata Griffiths displays high repeatability for the morphological and productive traits.•Forage cacti Opuntia undulata Griffiths displays a superior in vitro dry matter digestibility.
1. Repeatability represents a key parameter in ecological and evolutionary research. Repeatability is underpinned by developmental plasticity and genetic variation but may become biased upwards by ...repeatable differences in environments to which individuals respond plastically. The extent of upward bias caused by the latter mechanism (causing "pseudo-repeatability") is important yet rarely investigated in ecological research. 2. We repeatedly assayed a key behaviour (flight initiation distance) affecting longevity in a wild cricket population (Gryllus campestris). We used naturally moving, translocated and forced-stationary individuals to study bias in repeatability caused by spatial variability in environmental conditions. 3. Our experiments acknowledged that translocations might themselves bias repeatability estimates if animals respond to handling procedures (a necessary component of translocations). Individuals were, therefore, either (i) repeatedly translocated and assayed or (ii) assayed at multiple burrows as part of natural movements. This enabled estimation of behavioural variance attributable to individual, burrow and residual components within each treatment; comparison across treatments addressed whether translocations caused bias. We also calculated repeatability for individuals that were forced to be stationary to investigate whether this led to upward bias of repeatability. 4. For adult crickets, individual explained 17.8% versus 17.2%, and burrow 8.7% versus 10.3%, of the behavioural variance in translocated versus natural-movement treatments. Repeatability for forced-stationary adults was 31.1%, thereby demonstrating experimentally that certain study designs bias repeatability upwards. For translocated juveniles, individual explained 10.0% and burrow 6.0% of the variance, while in the natural-movement treatment, those components could not be separated as juveniles do not switch burrows. Translocations did not lead to detectable biases in behavioural mean or variance. 5. Repeatability was not biased for adults subjected to the natural-movement treatment because individuals were assayed under many different environments, facilitating the separation of individual from burrow effects. Upward bias would have occurred with less optimal sampling schemes: if individuals had been assayed repeatedly at the same burrow. We, therefore, recommend that translocation experiments are more commonly applied, particularly in stationary species, to ensure the unbiased estimation of repeatability.
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•We are using AZOD and HDBE as novel modifiers on PLE for the first time.•Modifiers complex with Cd and Pb ions due to electron-donor atoms.•Electrode surfaces were analyzed by EDS, ...EIS, and CV techniques.•SEM was used to investigate the surface morphology of modified electrodes.•The two sensors can be used to analyze Pb (II) and Cd (II) by CV and SWV.
This research introduces a cost-effective and straightforward approach to fabricating two novel electrochemical sensors. The initial novel sensor, termed AZOD/PLE, involves coating the surface of a pencil lead electrode (PLE) with the azo dye molecule (AZOD). The second novel sensor, named HDBE/PLE, is created by coating the pencil lead electrode (PLE) with a newly synthesized novel Schiff base molecule (HDBE), characterized through techniques such as IR, 1H NMR, and 13C NMR. The reason for the choice of the modifier materials in this research is their complexing ability with metal ions since they contain electron donor atoms such as O and N, which can form coordination bonds with the toxic heavy metal’s ions, cadmium and lead. This is the first time using the azo dye molecule (AZOD) and the novel Schiff base molecule (HDBE) as modifiers on PLE. The characterization of the electrode surfaces was made by energy-dispersive X-ray spectroscopy (EDS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The surface morphology of the electrode was investigated by scanning electron microscopy (SEM). CV results indicate that the modified electrodes possess larger electroactive surface areas compared to the bare PLE. Square wave voltammetry (SWV) results demonstrate that both sensors exhibit high sensitivity in detecting low concentrations of Cd (II) and Pb (II) in tris-HCl buffer (0.1 M) for both single-metal and multi-metal solutions. These sensors can be easily produced in a single step and exhibit excellent selectivity, stability, reproducibility, and repeatability, making them well-suited for detecting Pb (II) and Cd (II) in aqueous environments.
Growing evidence suggests that individual variation in learning is ubiquitous, but why this is the case and what the consequences are is still a subject of much debate and research. One key set of ...explanations for variation in learning behaviour is that it relates to variation in animal personality traits. If personality traits affect how an individual interacts with its environment or processes information, this could directly affect performance in learning tasks. While this idea is generally well supported, there are inconsistent results on the relationships between specific personality traits and performance on different learning tasks, highlighting the need to measure multiple personality traits and to quantify different aspects of learning in the same individuals. We examined the relationship between three putative personality traits – aggression, latency to emerge from a shelter and time to contact a novel object – and learning speed in both initial and reversal olfactory learning in the house cricket, Acheta domesticus. Crickets were assayed for each personality trait, then tested for their speed to associate an odour with a water reward. Both aggression and latency to emerge were significantly repeatable, but only latency to emerge was related to learning speed, with individuals that took longer to emerge from the shelter requiring fewer trials to reach the learning criterion for both the initial and reversal learning experiments. We also identified sex differences in learning speed in the different experiments. Thus, our results provide some support for a relationship between personality and learning in an invertebrate.
•Individuals vary in learning ability, and personality may explain why this is.•Aggression and latency to emerge were repeatable personality traits in crickets.•Crickets successfully learned and reversal learned an olfactory association.•Learning speed was associated with latency to emerge.•Personality affects individual variation in learning speed in crickets.
To develop 3D T1ρ and T2 imaging based on the same sequence structure on MR systems from multiple vendors, and to evaluate intra-site repeatability and inter-site inter-vendor reproducibility of T1ρ ...and T2 measurements of knee cartilage.
3D magnetization-prepared angle-modulated partitioned k-space spoiled gradient echo snapshots (3D MAPSS) were implemented on MR systems from Siemens, GE and Philips. Phantom and human subject data were collected at four sites using 3T MR systems from the three vendors with harmonized protocols. Phantom data were collected by means of different positioning of the coil. Volunteers were scanned and rescanned after repositioning. Two traveling volunteers were scanned at all sites. Data were transferred to one site for centralized processing.
Intra-site average coefficient of variations (CVs) ranged from 1.09% to 3.05% for T1ρ and 1.78–3.30% for T2 in phantoms, and 1.60–3.93% for T1ρ and 1.44–4.08% for T2 in volunteers. Inter-site average CVs were 5.23% and 6.45% for MAPSS T1ρ and T2, respectively in phantoms, and 8.14% and 10.06% for MAPSS T1ρ and T2, respectively, In volunteers.
This study showed promising results of multi-site, multi-vendor reproducibility of T1ρ and T2 values in knee cartilage. These quantitative measures may be applied in large-scale multi-site, multi-vendor trials with controlled sequence structure and scan parameters and centralized data processing.
To measure and report the distribution of distance and near contrast sensitivity (CS) and low contrast visual acuity (LCVA) at 5% and 2.5% contrast in children aged 5-15 years with normal visual ...acuity (VA).PURPOSETo measure and report the distribution of distance and near contrast sensitivity (CS) and low contrast visual acuity (LCVA) at 5% and 2.5% contrast in children aged 5-15 years with normal visual acuity (VA).Prospective, Cross-sectional study.DESIGNProspective, Cross-sectional study.Schools in Southern India.SETTINGSchools in Southern India.One thousand fifty-two children aged 5 to 15 years (mean age 10.61±2.85 years) with a presenting visual acuity of 0.00 logMAR or better in both eyes and a stereo acuity of 40 seconds of arc or better were recruited from nine schools. Repeatability of contrast sensitivity and low contrast visual acuities were tested in 246 children. Pelli-Robson charts were used to measure the distance and near contrast sensitivity at 1 m and 40 cm, respectively. The low contrast visual acuity was recorded at 5% and 2.5% contrast using LEA Symbols at 3 m.STUDY POPULATIONOne thousand fifty-two children aged 5 to 15 years (mean age 10.61±2.85 years) with a presenting visual acuity of 0.00 logMAR or better in both eyes and a stereo acuity of 40 seconds of arc or better were recruited from nine schools. Repeatability of contrast sensitivity and low contrast visual acuities were tested in 246 children. Pelli-Robson charts were used to measure the distance and near contrast sensitivity at 1 m and 40 cm, respectively. The low contrast visual acuity was recorded at 5% and 2.5% contrast using LEA Symbols at 3 m.Overall, the mean ± SD, (95% CI) monocular distance and near CS were 1.75±0.11 (1.76-1.75) logCS and 1.72±0.10 (1.73-1.71) logCS, respectively. The mean LCVA at 5% and 2.5% contrasts were 0.20±0.10 (0.21-0.20) logMAR and 0.39±0.11 (0.40-0.39) logMAR, respectively. Distance and near CS gradually improved till the ages of 11 and 13, respectively, and then plateaued. Similarly, LCVA at 5% and 2.5% contrasts gradually improved till age ten before plateauing. The Coefficient of Repeatability (CoR) for CS was ±0.02 logCS for distance, ±0.05 logCS for near, and ±0.01 logMAR for both LCVA contrasts.RESULTSOverall, the mean ± SD, (95% CI) monocular distance and near CS were 1.75±0.11 (1.76-1.75) logCS and 1.72±0.10 (1.73-1.71) logCS, respectively. The mean LCVA at 5% and 2.5% contrasts were 0.20±0.10 (0.21-0.20) logMAR and 0.39±0.11 (0.40-0.39) logMAR, respectively. Distance and near CS gradually improved till the ages of 11 and 13, respectively, and then plateaued. Similarly, LCVA at 5% and 2.5% contrasts gradually improved till age ten before plateauing. The Coefficient of Repeatability (CoR) for CS was ±0.02 logCS for distance, ±0.05 logCS for near, and ±0.01 logMAR for both LCVA contrasts.The study provides age-specific normative values for distance and near CS, and LCVA in a cohort of children aged 5-15 years. These results are important to understand the impact of ocular conditions on CS in children and have utility in clinical evaluations.CONCLUSIONSThe study provides age-specific normative values for distance and near CS, and LCVA in a cohort of children aged 5-15 years. These results are important to understand the impact of ocular conditions on CS in children and have utility in clinical evaluations.
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