Feasibility study of tomato fruit characterization by fast XRF analysis for quality assessment and food traceability

Food product nutritional and sensory characteristics are often deeply linked to its territory of origin; therefore, its authentication by means of elemental composition becomes crucial for traceability and fighting food fraud. This study aims to establish a fast and reproducible procedure for origin and quality assessment of Sicilian tomato fruits, including PGI "Pomodoro di Pachino", by using the X-ray fluorescence (XRF) technique. Measurements were performed on different parts of PGI Pachino tomatoes belonging to the same production lot. Principal Component and Cluster Analyses show that the samples cluster accordingly with the production lot, disentangling the different parts of the fruit. This procedure, which uses XRF yield elemental pattern and statistical analysis, establishes a solid basis for characterizing elemental profiles by a fast XRF in-situ campaign, supporting the traceability system. The reliability of XRF results was confirmed by comparing elemental concentrations with ICP-MS measurements, performed for comparison, and tomato literature values.

Multi-scale laboratory routine in the efficacy assessment of conservative products for natural stones

The evaluation of conservative treatments' efficacy on natural building stones are usually based on standard recommendation routines finalized to evaluate compatibility and harmfulness of products in turn of the substrate. However, the visualization and the quantification of products inside pore structure of natural stones is not immediate through standard tests, so that imaging and advanced techniques are recently proposed in material conservation field to improve knowledge on penetration depth, modification of pore-air interface at different scale and monitor dynamic absorption processes. Moreover, natural stones are usually characterized by complex structure, which changes due to conservative treatments have to be inspected at different scale (from micrometer to nanometer). In this prospective, the assessment of laboratory practices able to integrate multiscale methods and give back a complete overview on interaction between new conservative formulates and natural stones is of high interest. In this paper, we propose a methodological routine for efficacy assessment of conservative products, incorporating classical and innovative nondestructive techniques. Validation of the workflow has been verified on a high porous natural stone treated with new hybrid formulates appropriately customized for conservation issues. •The study intends to add new insights on problems related to consolidation of high porous carbonate stone, application methods in consolidating natural stones and methods to evaluate efficacy of new products.•A multi-scale laboratory investigation procedure is proposed by integrating standard and innovative nondestructive methods. Merits and limits of each applied method are discussed during validation.•The possibility to incorporate standard routines and/or substitute destructive testing with non-destructive ones seem to be a valid alternative to evaluate efficiency and monitor behavior of stones treated with consolidating products.

Linear and Fractal Heart Rate Dynamics during Sleep at High Altitude

Objectives: To investigate the effects of hypoxia during sleep on linear and self-similar components of heart rate variability (HRV) in eight healthy subjects at high altitude on Mount Everest.

Methods: ECG was monitored by using an innovative textile-based device, the MagIC system. For each subject three night recordings were performed at sea level (SL), at 3500 m and 5400 m above SL. RR Interval (RRI) was derived on a beat-by-beat basis from the ECG and the VLF, LF and HF spectral components and the LF/HF ratio were estimated. Short-(α1) and long-term (α2) scale exponents as well as the recently proposed spectrum of self-similarity coefficients, α(n) were estimated by detrended fluctuation analysis (DFA).

Results: With respect to SL, all HRV parameters but one (α2) were significantly modified at 3500 m. However, at 5400 m they tended to return to the SL values and this was in contrast with the increase in the hypobaric hypoxia and in the number of central sleep apneas occurring at higher altitude. The only HRV index that displayed changes at 5400 m was the DFA α(n) spectrum, with α(n) values significantly lower than at SL for 20 < n < 50 and higher for 200 < n < 400, being n the box size..

Conclusions: While the biological interpretation of these results is still in progress, our data indicates that the cardiac response to high altitude hypoxia during sleep can hardly be fully explored by traditional HRV estimators only, and requires the additional support of more sophisticated indexes exploring also nonlinear and fractal features of cardiac variability.

Multi-scale laboratory routine in the efficacy assessment of conservative products for natural stones

The evaluation of conservative treatments' efficacy on natural building stones are usually based on standard recommendation routines finalized to evaluate compatibility and harmfulness of products in turn of the substrate. However, the visualization and the quantification of products inside pore structure of natural stones is not immediate through standard tests, so that imaging and advanced techniques are recently proposed in material conservation field to improve knowledge on penetration depth, modification of pore-air interface at different scale and monitor dynamic absorption processes. Moreover, natural stones are usually characterized by complex structure, which changes due to conservative treatments have to be inspected at different scale (from micrometer to nanometer). In this prospective, the assessment of laboratory practices able to integrate multiscale methods and give back a complete overview on interaction between new conservative formulates and natural stones is of high interest. In this paper, we propose a methodological routine for efficacy assessment of conservative products, incorporating classical and innovative nondestructive techniques. Validation of the workflow has been verified on a high porous natural stone treated with new hybrid formulates appropriately customized for conservation issues. •The study intends to add new insights on problems related to consolidation of high porous carbonate stone, application methods in consolidating natural stones and methods to evaluate efficacy of new products.•A multi-scale laboratory investigation procedure is proposed by integrating standard and innovative nondestructive methods. Merits and limits of each applied method are discussed during validation.•The possibility to incorporate standard routines and/or substitute destructive testing with non-destructive ones seem to be a valid alternative to evaluate efficiency and monitor behavior of stones treated with consolidating products.

Gait pattern classification in children with Charcot-Marie-Tooth disease type 1A

Gait pattern classification may assist in clinical decision making and cluster analysis (CA) has been often adopted to this aim. The goal of this study was to identify, through CA, typical walking patterns in a group of 21 young subjects with CMT1A, a hereditary progressive neuropathy, and to study possible correlation with the disease's clinical status. The protocol included kinematic/kinetic analysis of natural walking and more demanding locomotor tasks, i.e. toe- and heel-walking. Hierarchical cluster analysis was carried out on parameters related to primary signs (foot-drop and push-off deficit) and, separately, to compensatory mechanisms at proximal (pelvis, hip and knee) or distal (ankle) level. CA on primary signs during natural walking identified three clusters: (1) pseudo-normal patients (PN), not significantly different from controls; (2) patients showing only foot-drop (FD); (3) patients with foot-drop and push-off deficit (FD&POD). Patients belonging to the PN subgroup showed distal abnormalities during heel-walking. The FD&POD subgroup was associated to a significantly worse clinical score (CMTES, p<0.05). The main compensatory strategies, which occurred independently from primary clusterization, included augmented hip/knee flexion in swing (steppage) and early ankle plantarflexion at mid stance (vaulting). We concluded that, although a number of young CMT1A patients do not show typical primary deviations during natural walking, they do show significant abnormalities in more demanding locomotor tasks that should be therefore considered. It is also hypothesized that progression of this degenerative condition may be associated to the migration of patients to more severe clusters, with possible appearance of compensatory strategies.

Reliability of instrumented movement analysis as outcome measure in Charcot-Marie-Tooth disease: results from a multitask locomotor protocol

Some neurodegenerative diseases at early stage may not drastically affect basic gait ability, whereas more demanding locomotor tasks are more prone to disease-induced abnormalities. In this study, we evaluated the interday test-retest reliability, 4-6 weeks apart, of instrumented movement analysis on a group of 20 subjects with Charcot-Marie-Tooth (CMT) disease considering a set of kinematic and kinetic curves and related parameters obtained during natural walking (NW) and faster walking, heel and toe-walking, step ascending and descending. Results showed that the reliability was good for NW, with the exception of trunk curves, pelvic tilt and EMG profiles (moderate reliability), and trunk ROM in sagittal/transverse plane (poor reliability). Comparing our results with literature, CMT patients did not present a greater variability during NW than healthy subjects or patients with diseases of CNS. Additional locomotor tasks showed a slight reduction of reliability, although the moderate-to-good level shown in NW was almost never reduced to poor. Most of SEM values (absolute measurement errors) were smaller than 5°, a clinically acceptable threshold. In particular THS, an ankle joint related parameter computed across heel and toe-walking tasks, showed an optimal reliability (ICC=0.95, SEM=2.7°) and correlation with CMT clinical scores. Toe and heel-walking and step ascending tasks maximised the number of parameters with a moderate-to-good correlation with patients' clinical status. We concluded that, in addition to natural walking, more challenging locomotor tasks are good candidates to provide reliable and sensitive outcome measures for CMT patients.

The association between impaired turning and normal straight walking in Parkinson's disease

Turning whilst walking was investigated by gait analysis in a group of Parkinson's Disease (PD) patients with mild clinical impairment and no significant abnormalities in stride parameters and kinematics of steady-state, linear walking. Comparison with age-matched controls demonstrated that patients approached turns with a slower step and completed turning with a greater number of steps. Moreover, the normal cranio-caudal sequence, whereby rotation of the head toward the intended direction of travel is followed by rotation of the trunk, was replaced by nearly simultaneous rotation of head and trunk and decreased relative head excursion after the second turning step. The evidence of abnormal inter-segmental coordination during turning in mildly affected, normally walking patients suggests that task-specific pathophysiological mechanisms, not necessary related to basic locomotor deficits, underlie disturbed directional changes in PD. Furthermore, turning-related neural systems may be more vulnerable to functional impairments associated with PD, as compared with linear walking. Hierarchically higher control levels involved in the turning ability may explain the observed unexpected association.

Experimental protocol for the kinematic analysis of the hand: definition and repeatability

A quantitative and objective method based on the optoelectronic kinematic analysis of hand segments and on the calculation of global and partial parameters, which provide measures of the degree of long finger and thumb extension is proposed for the evaluation of the hand's voluntary range of motion and maximal opening of the fingers and thumb. To test the precision and repeatability of the method, the protocol was applied on 14 healthy subjects (28 hands). The proposed parameters are repeatable and show a precision between 5.5 degrees and 10.4 degrees (mean value: 7.3 degrees), comparable to values obtained with other methods. Advantages of the present approach include simultaneous analysis of all fingers, absence of cumbersome connecting cables and no need for individually customized devices. The method, also applied to the paretic hands of two hemiplegic stroke patients before and after electrical stimulation of the wrist and finger extensor muscles, has shown encouraging results for its clinical feasibility and utility in addition to functional tests.

Locomotor disorders in patients at early stages of Parkinson's disease: a quantitative analysis

Several studies have been performed with automatic motion analysis techniques to investigated the locomotor disorders of patients with severe Parkinson's disease (PD). These are mainly related to steady-state walking. Aim of the present study was to investigate the presence and the degree of these disorders in patients at early stages of PD. For this purpose a group of patients with mild PD (H&Y < or =2) and a group of age-matched controls were assessed by means of multifactorial analysis of kinematic and kinetic variables, during the execution of the following motor tasks: steady-state walking, gait initiation and turning around an obstacle. Results showed that PD patients did not differ from controls in steady-state walking, while significant differences emerged in gait initiation and turning strategies. Main differences consisted in a limitation of the amplitude of the imbalance phase and of the first step, and, for the turning task, in a delayed initiation of the turning movement, with an altered head-trunk rotational strategy. It is concluded that patients in early stages of PD do not reveal, during steady state walking, consistent impairments of kinematic and kinetic patterns typical of severe PD patients. Nevertheless, they present significant alterations in transient conditions such as gait initiation and change of walking direction. The above results suggest that a quantitative analysis of locomotor tasks which imply the transition from one condition to another, could provide parameters useful for the characterization of early stage PD patients and, potentially, markers for a precox differential diagnosis respect other neurodegenerative diseases characterized by parkinsonisms.

Procedure for the quantitative evaluation of motor disturbances in cerebellar ataxic patients

Cerebellar ataxia is a complex motor disturbance that involves the planning and execution of movements and reduces movement accuracy and co-ordination. The quantification of ataxic signs is commonly realised through visual examination of motor tasks performed by the patient and assignment of scores to specific items composing the international co-operative ataxia rating scale (ICARS). The present work studied an experimental procedure to characterise specific aspects of motor disturbances in ataxia objectively. Four tests belonging to the ICARS were considered: walking, knee-tibia test, finger-to-nose and finger-to-finger test. Through a kinematic analysis performed during the above tests, specific indices were defined to quantify velocity, linearity, asymmetry, tremor, instability and smoothness of movement or posture. The procedure was applied to five patients with cerebellar ataxia and to ten healthy adult subjects. Results demonstrated that the patients moved significantly more slowly than the healthy subjects (0.67 against 0.97m s(-1) and 0.81 against 1.02 m s(-1), respectively, for straight walk and finger-to-nose tests) and showed poorer linearity and smoothness behaviour. Velocity, linearity, tremor, smoothness and instability indices showed moderate to good correlation with the corresponding ICARS score. Some of these indices can separately evaluate aspects that are combined in single ICARS subscores. It is concluded that the combination of clinical assessments and instrumental evaluations allows a better insight into ataxic patients' motor disturbances and is a useful tool for the definition and follow-up of rehabilitation programmes.

Optimised procedure for the calibration of the force platform location

An innovative optimised method, including an experiment and a mathematical model, for the calibration of the force platform location in the optoelectronic reference frame is proposed. The calibration experiment adopts a bearing-marker testing object contacting the platform and does not directly measure the platform location. The experiment is designed in order to avoid the main drawbacks possibly occurring in commonly adopted methods. The mathematical model of the experiment estimates the expected ground reaction. An optimisation algorithm identifies the optimal platform location as the one that best matches the measured outcome of the calibration experiment with the corresponding model estimate. The innovative calibration procedure has been assessed in terms of inter-tester reliability and compared with commonly used calibration procedures of platform location. These results evidenced how the introduction of such optimised procedure could improve the reliability of the calibrated platform location and, consequently, of the kinetic variables considered in posture and gait analysis.