The Down syndrome (DS) phenotype is usually characterized by relative strengths in non-verbal skills and deficits in verbal processing, but high interindividual variability has been registered in the ...syndrome. The goal of this study was to explore the cognitive profile, considering verbal and non-verbal intelligence, of children and adolescents with DS, also taking into account interindividual variability. We particularly aimed to investigate whether this variability means that we should envisage more than one cognitive profile in this population. The correlation between cognitive profile and medical conditions, parents' education levels and developmental milestones was also explored. Seventy-two children/adolescents with DS, aged 7-16 years, were assessed with the Wechsler Preschool and Primary Scale of Intelligence-III. Age-equivalent scores were adopted, and Verbal and Non-Verbal indices were obtained for each individual. The cognitive profile of the group as a whole was characterized by similar scores in the verbal and non-verbal domain. Cluster analysis revealed three different profiles, however: one group, with the lowest scores, had the typical profile associated with DS (with higher non-verbal than verbal intelligence); one, with intermediate scores, had greater verbal than non-verbal intelligence; and one, with the highest scores, fared equally well in the verbal and non-verbal domain. Three cognitive profiles emerged, suggesting that educational support for children and adolescents with DS may need to be more specific.
Down syndrome (DS) is characterised by several clinical features including intellectual disability (ID) and craniofacial dysmorphisms. In 1976, Jackson and coll. identified a checklist of signs for ...clinical diagnosis of DS; the utility of these checklists in improving the accuracy of clinical diagnosis has been recently reaffirmed, but they have rarely been revised. The purpose of this work is to reassess the characteristic phenotypic signs and their frequencies in 233 DS subjects, following Jackson's checklist. 63.77% of the subjects showed more than 12 signs while none showed less than 5, confirming the effectiveness of Jackson's checklist for the clinical diagnosis of DS. An association between three phenotypic signs emerged, allowing us to distinguish two sub-phenotypes: Brachycephaly, short and broad Hands, short Neck (BHN), which is more frequent, and "non-BHN". The strong association of these signs might be interpreted in the context of the growth defects observed in DS children suggesting decreased cell proliferation. Lastly, cognitive assessments were investigated for 114 subjects. The lack of association between the presence of a physical sign or the number of signs present in a subject and cognitive skills disproves the stereotype that physical characteristics are predictive of degree of ID.
In this work an innovative method to obtain natural and biocompatible small diameter tubular structures is proposed. The biocompatibility and good mechanical properties of electrospun silk fibroin ...tubular matrices (SFts), extensively studied for tissue engineering applications, have been coupled with the excellent cell interaction properties of gelatin. In fact, an innovative non-cytotoxic gelatin gel, crosslinked in mild conditions via a Michael-type addition reaction, has been used to coat SFt matrices and obtain SFt/gel structures (I.D. = 6 mm). SFts/gel exhibited homogeneous gelatin coating on the electrospun fibrous tubular structure. Circumferential tensile tests performed on SFts/gel showed mechanical properties comparable to those of natural blood vessels in terms of UTS, compliance and viscoelastic behavior. Finally, SFt/gel in vitro cytocompatibility was confirmed by the good viability and spread morphology of L929 fibroblasts up to 7 days. These results demonstrated that SFt/gel is a promising off-the-shelf graft for small diameter blood vessel regeneration.
Graphical Abstract
The extracellular matrix (ECM), the physiological scaffold for cells in vivo, provides structural support to cells and guaranties tissue integrity. At the same time, however, it represents an ...extremely complex and finely tuned signaling environment that contributes in regulating tissue homeostasis and repair. ECM can bind, release and activate signaling molecules and also modulate cell reaction to soluble factors. Cell-ECM interactions, as a result, are recognized to be critical for physiological wound healing, and consequently in guiding regeneration. Due to its complexity, mimicking ECM chemistry and architecture appears a straightforward strategy to exploit the benefits of a biologically recognizable and cell-instructive environment. As ECM consists primarily of sub-micrometric fibers, electrospinning, a simple and versatile technique, has attracted the majority efforts aimed at reprocessing of biologically occurring molecules. However, the ability to trigger specific cellular behavior is likely to depend on both the chemical and conformational properties of biological molecules. As a consequence, when ECM macromolecules are electrospun, investigating the effect of processing on their structure, and the extent to which their potential in directing cellular behavior is preserved, appears crucial. In this perspective, this review explores the electrospinning of ECM molecules specifically focusing on the effect of processing on polymer structure and on in vitro or in vivo experiments designed to confirm the maintenance of their instructive role.
Down Syndrome (DS) is the most common genetic alteration responsible for intellectual disability, which refers to deficits in both intellectual and adaptive functioning. According to this, ...individuals with Down Syndrome (DS) reach developmental milestones (e.g., sitting, walking, and babbling) in the same order as their typically developing peers, but later in life. Since developmental milestones are the first blocks on which development builds, the aims of the current study are to: (i) expand the knowledge of developmental milestone acquisition; and (ii) explore the relationship between developmental milestone acquisition and later development. For this purpose 105 children/adolescents with DS were involved in this study, divided in two groups, Preschoolers (
= 39) and School-age participants (
= 66). Information on the age of acquisition of
and
was collected, together with cognitive, motor, and adaptive functioning.
predicted later motor development, but, with age, it became less important in predicting motor development in everyday life.
predicted later language development in older children. Finally,
emerged as the strongest predictor of motor, cognitive, language, and adaptive skills, with its role being more evident with increasing age. Our data suggest that the age of reaching the milestones considered in the study has an influence on successive development, a role that can be due to common neural substrates, the environment, and the developmental cascade effect.
Persons with Down syndrome (DS) reveal adaptive functioning (AF) difficulties. Studies on AF in DS have focused mainly on describing the profile (i.e., strengths in socialization, and weaknesses in ...communication), while less is known about age-related differences. This study aimed to elucidate how AF changes with age in children and adolescents with DS, taking a cross-sectional developmental trajectory approach. Moreover, the contribution of both chronological age (CA) and mental age (MA) on AF development was explored.
This study involved 115 children and adolescents (between 3 and 16 years old) with DS. Parents were interviewed about their children's AF on communication, daily living and socialization skills. Children and adolescents with DS were assessed on their developmental level.
While participants' standard scores on AF decreased linearly over time, their age-equivalent scores increased with linear or segmented patterns, depending on the skill considered. CA and MA were related to daily living skills and socialization to much the same degree, while MA correlated more strongly than CA with communication.
This study contributes to the understanding of how AF develops in children and adolescents with DS, showing that CA and MA both contribute to shaping the skills involved.
Elevated energy cost is a hallmark feature of gait in older adults. As such, older adults display a general avoidance of walking which contributes to declining health status and risk of morbidity. ...Exoskeletons offer a great potential for lowering the energy cost of walking, however their complexity and cost often limit their use. To overcome some of these issues, in the present work we propose a passive wearable assistive device, namely Exoband, that applies a torque to the hip flexors thus reducing the net metabolic power of wearers.
Nine participants (age: 62.1 ± 5.6 yr; height: 1.71 ± 0.05 m; weight: 76.3 ± 11.9 kg) walked on a treadmill at a speed of 1.1 m/s with and without the Exoband. Metabolic power was measured by indirect calorimetry and spatio-temporal parameters measured using an optical measurement system. Heart rate and ratings of perceived exertion were recorded during data collection to monitor relative intensity of the walking trials.
The Exoband was able to provide a consistent torque (~ 0.03-0.05 Nm/kg of peak torque) to the wearers. When walking with the Exoband, participants displayed a lower net metabolic power with respect to free walking (- 3.3 ± 3.0%; p = 0.02). There were no differences in spatio-temporal parameters or relative intensities when walking with or without the Exoband.
This study demonstrated that it is possible to reduce metabolic power during walking in older adults with the assistance of a passive device that applies a torque to the hip joint. Wearable, lightweight and low-cost devices such as the Exoband have the potential to make walking less metabolically demanding for older individuals.
The invasion of the Asian chestnut gall wasp Dryocosmus kuriphilus (ACGW) in Europe has caused serious biological and economic impacts on chestnut stands that have been partially solved with the ...introduction of the biological control agent Torymus sinensis. However, information concerning tree‐ring growth during the ACGW epidemic has been lacking so far.
Using dendrochronology techniques, we analysed the impact of the ACGW on tree‐ring growth and the capacity of the chestnut tree to recover when biocontrol was achieved in seven sites covering the area of first detection and subsequent spread of the ACGW in Europe. In each site, a non‐target control species (i.e. trees not attacked by the ACGW) has been included as a reference in the analysis.
Results show a reduction in the tree‐ring increment by 60% on average during the ACGW epidemic. Such effects were higher in the magnitude and longer in the duration when compared to other stresses such as insect defoliation or extreme summer droughts.
Synthesis and applications. Marked reductions in radial growth were evident in the years of ACGW attack regardless of the age of the chestnut coppices. Since most of the trees only recovered to an almost normal growth rate after 3–4 years of biocontrol by T. sinensis, an immediate release of the antagonist at the first ACGW appearance is highly recommended. The consequences and perspectives of ACGW's attacks on the quality of the timber produced are also discussed.
Marked reductions in radial growth were evident in the years of ACGW attack regardless of the age of the chestnut coppices. Since most of the trees only recovered to an almost normal growth rate after 3–4 years of biocontrol by T. sinensis, an immediate release of the antagonist at the first ACGW appearance is highly recommended. The consequences and perspectives of ACGW's attacks on the quality of the timber produced are also discussed.
•Natural seed regeneration of chestnut is a key issue in recovering overaging chestnut coppices.•The establishment of seed regeneration was more than sufficient to guarantee a safe turnover of dead ...stools.•Chestnut trees released (standards) after coppicing do not play a relevant role as tree-seeders.•The presence of standards inhibited the growth of seedlings up to 10 m away.•An excessive presence of standards has promoted the settling of regeneration of shade-tolerant species.
The management of Italian chestnut coppices has gradually been suspended after World War II, causing a widespread overaging of the concerned stands. In recent years, the renewed interest in coppice wood products increased the need of a solid knowledge on the most suitable restoration practices of overaged coppices.
In this context, a key issue is assuring a qualitative and abundant seed regeneration of the chestnut tree (Castanea sativa Miller) in order to substitute overaged stools. Open questions still exist however on the role of the standards (trees released after coppicing) and, in particular, on their interaction with the post-coppicing establishment of seed regeneration.
In order to clarify these aspects, we applied different coppicing systems in overaged chestnut coppices so as to create a gradient of residual coverage ranging from full coverage left (no intervention) to simple coppicing (all trees cut, no standards released). The impact of different treatments on chestnut regeneration has been then assessed through field surveys in the second and fifth year post-coppicing, respectively.
Chestnut seed regeneration promptly and abundantly established to guarantee the replacement of dead stools also in the simple coppicing. The post-coppicing pulse of chestnut seed regeneration mostly originated from the existing annual seed bank and it was concentrated in the first two years after the intervention, whereas seed inputs by standards or by adult trees at the forest edge played a secondary or negligible role from the third post-coppicing year onwards. Thus, the presence of standards did not benefit regeneration. Rather, it displayed a marked depressive effect on the growth rate of young chestnut seedlings and, under significant shading conditions, enhanced the establishment of shade-tolerant tree species.
From a silvicultural point of view, simple coppicing of overaged chestnut coppices represents a valuable management option combining a rapid establishment of natural seed regeneration of chestnut with the resprout and development of the most vigorous stools.
PDF
