19 research outputs found

    Catching a Ball at the Right Time and Place: Individual Factors Matter

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    Intercepting a moving object requires accurate spatio-temporal control. Several studies have investigated how the CNS copes with such a challenging task, focusing on the nature of the information used to extract target motion parameters and on the identification of general control strategies. In the present study we provide evidence that the right time and place of the collision is not univocally specified by the CNS for a given target motion; instead, different but equally successful solutions can be adopted by different subjects when task constraints are loose. We characterized arm kinematics of fourteen subjects and performed a detailed analysis on a subset of six subjects who showed comparable success rates when asked to catch a flying ball in three dimensional space. Balls were projected by an actuated launching apparatus in order to obtain different arrival flight time and height conditions. Inter-individual variability was observed in several kinematic parameters, such as wrist trajectory, wrist velocity profile, timing and spatial distribution of the impact point, upper limb posture, trunk motion, and submovement decomposition. Individual idiosyncratic behaviors were consistent across different ball flight time conditions and across two experimental sessions carried out at one year distance. These results highlight the importance of a systematic characterization of individual factors in the study of interceptive tasks

    Wrist-Worn Wearables Based on Force Myography: On the Significance of User Anthropometry

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    Background Force myography (FMG) is a non-invasive technology used to track functional movements and hand gestures by sensing volumetric changes in the limbs caused by muscle contraction. Force transmission through tissue implies that differences in tissue mechanics and/or architecture might impact FMG signal acquisition and the accuracy of gesture classifier models. The aim of this study is to identify if and how user anthropometry affects the quality of FMG signal acquisition and the performance of machine learning models trained to classify different hand and wrist gestures based on that data. Methods Wrist and forearm anthropometric measures were collected from a total of 21 volunteers aged between 22 and 82 years old. Participants performed a set of tasks while wearing a custom-designed FMG band. Primary outcome measure was the Spearman’s correlation coefficient (R) between the anthropometric measures and FMG signal quality/ML model performance. Results Results demonstrated moderate (0.3 ≤|R| < 0.67) and strong (0.67 ≤ |R|) relationships for ratio of skinfold thickness to forearm circumference, grip strength and ratio of wrist to forearm circumference. These anthropometric features contributed to 23–30% of the variability in FMG signal acquisition and as much as 50% of the variability in classification accuracy for single gestures. Conclusions Increased grip strength, larger forearm girth, and smaller skinfold-to-forearm circumference ratio improve signal quality and gesture classification accuracy

    Sound-evoked vestibular stimulation affects the anticipation of gravity effects during visual self-motion

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    Humans anticipate the effects of gravity during visually simulated self-motion in the vertical direction. Here we report that an artificial vestibular stimulation consisting of short-tone bursts (STB) suppresses this anticipation. Participants pressed a button upon entering a tunnel during virtual-reality roller coaster rides in downward or forward directions. In different trials, we delivered STB, pulsed white noise (WN), or no sound (NO). In the control conditions (WN, NO), participants responded earlier during downward than forward motion irrespective of true kinematics, consistent with the a priori expectation that downward but not forward motion is accelerated by gravity. STB canceled the difference in response timing between the two directions, without affecting overall task performance. Thus, we argue that vestibular signals play a role in the anticipation of visible gravity effects during self-motion

    Fruit juice drinks prevent endogenous antioxidant response to high-fat meal ingestion

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    High-fat meals (HFM) induce metabolic stress, leading to the activation of protective mechanisms, including inflammation and endogenous antioxidant defences. In the present study, we investigated the effects of antioxidant-rich fruit juice drinks on the endogenous antioxidant response induced by HFM. In a double-blind, cross-over design (10 d washout), fourteen overweight volunteers were randomly assigned to one of the following interventions: HFM þ 500 ml placebo beverage (HFM-PB, free from fruit); HFM þ 500 ml antioxidant beverage 1 (HFM-AB1; apple, grape, blueberry and pomegranate juices and grape skin, grape seed and green tea extracts); HFM þ 500 ml antioxidant beverage 2 (HFM-AB2; pineapple, black currant and plum juices). HFM-PB consumption increased the plasma levels of thiols (SH) (4 h, P,0·001) and uric acid (UA) (2 h, P,0·01) and total radical-trapping antioxidant parameter (TRAP) (4 h, P,0·01). Following the consumption of drinks, UA production was significantly reduced with respect to placebo beverage consumption 8 h after HFM-AB2 consumption (P,0·05). SH levels were reduced 0·5 (P,0·05), 1 (P,0·05) and 2 h (P,0·01) after HFM-AB1 consumption and 2, 4 and 8h (P,0·05) after HFM-AB2 consumption. Plasma TRAP (2 h, P,0·001) and urinary ferric reducing antioxidant power (0–8 h, P,0·01) were increased by HFM-AB1 consumption, the drink with the highest in vitro antioxidant capacity, but not by HFM-AB2 consumption. In urine, UA levels were significantly increased from basal levels after the consumption of HFM-PB and HFM-AB2. However, neither of the beverages increased the urinary excretion of UA with respect to the placebo beverage. In conclusion, the increase in UA and SH levels induced by HFM as part of an endogenous antioxidant response to postprandial stress can be prevented by the concomitant ingestion of antioxidant-rich fruit juice drinks

    Antioxidant and inflammatory response following high-fat meal consumption in overweight subjects

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    Purpose: Postprandial metabolic stress as a consequence of ingestion of high-energy meals is recognized as an important risk factor for cardiovascular disease. The objective of this study was to evaluate the inflammatory and antioxidant response of the body to the acute ingestion of a high-fat meal (HFM). Methods: Fifteen healthy overweight subjects were recruited for the study. After HFM consumption, plasma glucose, insulin, uric acid (UA), triglycerides (TG), total cholesterol (TC), thiols (SH), inflammatory cytokines (IL-6 and TNF-α) and dietary antioxidants were measured at 0, 0, 5, 1, 2, 4, 6 and 8 h points from ingestion. Results: The ingestion of HFM induced significant increases in both TG and TC, with peaks at 4 h (p < 0.001) and 8 h (p < 0.01), respectively. IL-6 and TNF-α significantly increased postprandially, reaching maximum concentrations 8 h after meal consumption (p < 0.001). Whereas plasma concentrations of vitamins and carotenoids were not changed by HFM, SH and UA increased, peaking 2–4 h postingestion (p < 0.001 and 0.01, respectively). Increments of SH and UA were positively correlated with AUC for TG (Pearson coefficient 0.888, p < 0.001 and 0.923, p < 0.001, respectively)

    Hyperprogressive disease in advanced cancer patients treated with nivolumab: a case series study

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    The aim of this retrospective study was to detail the main clinicopathological characteristics of advanced cancer patients exhibiting hyperprogressive disease (HPD) during immune checkpoint inhibitor (ICI) nivolumab as second- or third-line treatment. A cohort of patients starting second or third-line nivolumab for advanced cancer from 2016 to 2018 was identified from our institution IRB approved and prospectively collected registry. HPD was defined as at least two-fold increase in the tumor growth rate (TGR) during immunotherapy compared to TGR during the preimmunotherapy period. Overall, 47 patients were eligible for this analysis. HPD was observed in three patients (6%) with metastatic lung adenocarcinoma, metastatic urothelial transitional carcinoma, and metastatic hepatocellular carcinoma, respectively. These three patients showed a rapid clinical deterioration and survived less than 3.5 months from immunotherapy onset. Their chief preimmunotherapy characteristics were: age &lt; 75 years, ≥2 metastatic sites, programmed death-ligand 1 &lt; 50%, neutrophil-to-lymphocyte ratio &gt; 3, and elevated lactate dehydrogenase. The results of the current study seem to reinforce the hypothesis that in some cases immunotherapy promotes a dramatic increase of TGR and may suggest possible clinical predictors of HPD during nivolumab

    Consumption of mixed fruit-juice drink and vitamin C reduces postprandial stress induced by a high fat meal in healthy overweight subjects.

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    Abstract: Postprandial stress induced by acute consumption of meals with a high fat content results in an increase of markers of cardiometabolic risk. Repeated acute dietary stress may induce a persistent low-grade inflammation, playing a role in the pathogenesis of functional gut diseases. This may cause an impairment of the complex immune response of the gastrointestinal mucosa, which results in a breakdown of oral tolerance. We investigated the effect of ingestion of a fruit-juice drink (FJD) composed by multiple fruit juice and extracts, green tea extracts and vitamin C on postprandial stress induced by a High Fat Meal (HFM) in healthy overweight subjects. Following a double blind, placebo controlled, cross-over design, 15 healthy overweight subjects were randomized to a HFM providing 1334 Kcal (55% fat, 30% carbohydrates and 15% proteins) in combination with 500 mL of a placebo drink (HFM-P) or a fruit-juice drink (HFM-FJD). Ingestion of HFM-P led to an increase in circulating levels of cholesterol, triglycerides, glucose, insulin, TNF

    The British Library guide to bookbinding History and techniques

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