The multi-arm robotic systems consisting of redundant robots are able to conduct more complex and coordinated tasks, such as manipulating large or heavy objects. The challenges of the motion planning and control for such systems mainly arise from the closed-chain constraint and redundancy resolution problem. The closed-chain constraint reduces the configuration space to lower-dimensional subsets, making it difficult for sampling feasible configurations and planning path connecting them. A global motion planner is proposed in this paper for the closed-chain systems, and motions in different disconnected manifolds are efficiently bridged by two type regrasping moves. The regrasping moves are automatically chosen by the planner based on cost-saving principle, which greatly improve the success rate and efficiency. Furthermore, to obtain the optional inverse kinematic solutions satisfying joint physical limits (e.g., joint position, velocity, acceleration limits) in the planning, the redundancy resolution problem for dual redundant robots is converted into a unified quadratic programming problem based on the combination of two diff erent-level optimizing criteria, i.e. the minimization velocity norm (MVN) and infinity norm torque-minimization (INTM). The Dual-MVN-INTM scheme guarantees smooth velocity, acceleration profiles, and zero final velocity at the end of motion. Finally, the planning results of three complex closed-chain manipulation task using two Franka Emika Panda robots and two Kinova Jaco2 robots in both simulation and experiment demonstrate the effectiveness and efficiency of the proposed method.

The effect of coffee consumption on functional disability has been scarcely investigated. Thus, this study aimed to examine the association between coffee consumption and functional disability in older American adults. Participants (≥60 years old, n 7704) were from the National Health and Nutrition Examination Survey 2007–2016. Coffee consumption was assessed through two 24-h dietary recall interviews. Five domains of functional disability including lower extremity mobility (LEM), general physical activity (GPA), leisure and social activities (LSA), activities of daily living (ADL) and instrumental activities of daily living (IADL) were self-reported. Age- and multivariate-adjusted logistic regression models and restricted cubic spline analyses were used. Total coffee consumption was inversely associated with LEM, GPA, LSA and IADL disability. Compared with non-drinkers of total coffee, those who consumed ≥2 cups/d reported lower odds of LEM (OR 0·67, 95 % CI 0·50, 0·91), GPA (OR 0·65, 95 % CI 0·47, 0·88), LSA (OR 0·61, 95 % CI 0·45, 0·83) and IADL (OR 0·59, 95 % CI 0·44, 0·78) disability. The dose–response analyses confirmed these relationships. Intake of ≥2 cups/d caffeinated coffee was also inversely linked to GPA (OR 0·67, 95 % CI 0·48, 0·92), LSA (OR 0·66, 95 % CI 0·46, 0·93) and IADL (OR 0·57, 95 % CI 0·43, 0·75) disability, whereas the inverse association of 2+ cups/d decaffeinated coffee was only on LEM (OR 0·43, 95 % CI 0·23, 0·81) and LSA (OR 0·39, 95 % CI 0·16, 0·94) disability. The present study suggested that coffee consumption was inversely associated with functional disability in older American adults. Those associations of diverse coffee types differed across domains of functional disability.

The genetic and environmental impacts on correlations between hearing and cognitive functions have not been well studied. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCA). Hearing function was assessed by audiometric pure-tone hearing thresholds at different frequencies, including 0.5 kHz, 1 kHz, 2 kHz, 4 kHz, 8 kHz, and 12.5 kHz, with the lower hearing thresholds indicating better hearing function. Cognitive and hearing functions were measured on 379 complete twin pairs (240 monozygotic and 139 dizygotic pairs) with a median age of 50 years (range: 40–80 years). Bivariate twin models were fitted to quantify the genetic and environmental components of the correlations between hearing and cognitive functions. The analysis showed significantly high genetic correlation between 2 kHz of hearing and cognition (rG = −1.00, 95% CI [−1.00, −0.46]) and moderate genetic correlation between 4 kHz of hearing and cognition (rG = −0.62, 95% CI [−1.00, −0.14]). We found no significant genetic correlations between low as well as high frequencies of hearing and cognition. Low to moderate common and unique environmental correlations were shown between low frequencies of hearing and cognition (−0.13 to −0.39) and the common environmental correlation between 8 kHz, one of the high frequencies of hearing, and cognition (−0.22). The middle frequencies of hearing and cognitive functions may have a shared genetic basis. Low frequencies of hearing and cognition may share similar common and unique environmental factors. At 8 kHz, the high frequency of hearing and cognition may share similar common environment. This twin study detected a significant genetic and environmental basis in the phenotype correlation between cognition and hearing, which differed across frequencies.

Genetic and environmental influences on predictors of decline in daily functioning, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), handgrip, and five-times-sit-to-stand test (FTSST), have not been addressed in the aging Chinese population. We performed classical twin modeling on FEV1, FVC, handgrip, and FTSST in 379 twin pairs (240 MZ and 139 DZ) with median age of 50 years (40–80 years). Data were analyzed by fitting univariate and bivariate twin models to estimate the genetic and environmental influences on these measures of physical function. Heritability was moderate for FEV1, handgrip, and FTSST (55–60%) but insignificant for FVC. Only FVC showed moderate control, with shared environmental factors accounting for about 50% of the total variance. In contrast, all measures of pulmonary function and muscle strength showed modest influences from the unique environment (40–50%). Bivariate analysis showed highly positive genetic correlations between FEV1 and FVC (rG = 1.00), and moderately negative genetic correlations between FTSST and FEV1 (rG = −0.33) and FVC (rG = −0.42). FEV1 and FVC, as well as FEV1 and handgrip, displayed high common environmental correlations (rC = 1.00), and there were moderate correlations between FVC and handgrip (rC = 0.44). FEV1 and FVC showed high unique environmental correlations (rE = 0.76) and low correlations between handgrip and FEV1 (rE = 0.17), FVC (rE = 0.14), and FTSST (rE = −0.13) with positive or negative direction. We conclude that genetic factors contribute significantly to the individual differences in common indicators of daily functioning (FEV1, handgrip, and FTSST). FEV1 and FVC were genetically and environmentally correlated. Pulmonary function and FTSST may share similar sets of genes but in the negative direction. Pulmonary function and muscle strength may have a shared environmental background.

Although the correlation between cognition and physical function has been well studied in the general population, the genetic and environmental nature of the correlation has been rarely investigated. We conducted a classical twin analysis on cognitive and physical function, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), handgrip strength, five-times-sit-to-stand test (FTSST), near visual acuity, and number of teeth lost in 379 complete twin pairs. Bivariate twin models were fitted to estimate the genetic and environmental correlation between physical and cognitive function. Bivariate analysis showed mildly positively genetic correlations between cognition and FEV1, rG = 0.23 [95% CI: 0.03, 0.62], as well as FVC, rG = 0.35 [95% CI: 0.06, 1.00]. We found that FTSST and cognition presented very high common environmental correlation, rC = -1.00 [95% CI: -1.00, -0.57], and low but significant unique environmental correlation, rE = -0.11 [95% CI: -0.22, -0.01], all in the negative direction. Meanwhile, near visual acuity and cognition also showed unique environmental correlation, rE = 0.16 [95% CI: 0.03, 0.27]. We found no significantly genetic correlation for cognition with handgrip strength, FTSST, near visual acuity, and number of teeth lost. Cognitive function was genetically related to pulmonary function. The FTSST and cognition shared almost the same common environmental factors but only part of the unique environmental factors, both with negative correlation. In contrast, near visual acuity and cognition may positively share part of the unique environmental factors.

Systolic and diastolic blood pressure, pulse pressure (PP), and body mass index (BMI) are heritable traits in human metabolic health but their common genetic and environmental backgrounds are not well investigated. The aim of this article was to explore the phenotypic and genetic associations among PP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. The studied sample contained 615 twin pairs (17–84 years) collected in the Qingdao municipality. Univariate and multivariate structural equation models were fitted for assessing the genetic and environmental contributions. The AE model combining additive genetic (A) and unique environmental (E) factors produced the best fit for each four phenotypes. Heritability estimated in univariate analysis ranged from 0.42 to 0.74 with the highest for BMI (95% CI 0.70–0.78), and the lowest for PP (95% CI 0.34–0.49). The multivariate model estimated (1) high genetic correlations for DBP with SBP (0.87), PP with SBP (0.75); (2) low–moderate genetic correlations between PP and DBP (0.32), each BP component and BMI (0.24–0.37); (3) moderate unique environmental correlation for PP with SBP (0.68) and SBP with DBP (0.63); (4) there was no significant unique environmental correlation between PP and BMI. Overall, our multivariate analyses revealed common genetic and environmental backgrounds for PP, BP, and BMI in Chinese twins.