28 research outputs found
Grasp With Hand and Mouth: A Kinematic Study on Healthy Subjects
No full textGrasp with hand and mouth: a kinematic study
on healthy subjects. J Neurophysiol 86: 1685–1699, 2001. Neurons
involved in grasp preparation with hand and mouth were previously recorded in the premotor cortex of monkey. The aim of the present kinematic study was to determine whether a unique planning underlies the act of grasping with hand and mouth in humans as well. In a set of four experiments, healthy subjects reached and grasped with the hand an object of different size while opening the mouth (experiments 1 and 3), or extending the other forearm (experiment 4), or the fingers of the other hand (experiment 5). In a subsequent set of three experiments,
subjects grasped an object of different size with the mouth,
while opening the fingers of the right hand (experiments 6–8). The
initial kinematics of mouth and finger opening, but not of forearm
extension, was affected by the size of the grasped object congruently
with the size effect on initial grasp kinematics. This effect was due
neither to visual presentation of the object, without the successive
grasp motor act (experiment 2) nor to synchronism between finger and
mouth opening (experiments 3, 7, and 8). In experiment 9 subjects
grasped with the right hand an object of different size while pronouncing
a syllable printed on the target. Mouth opening and sound production
were affected by the grasped object size. The results of the
present study are discussed according to the notion that in an action
each motor act is prepared before the beginning of the motor sequence.
Double grasp preparation can be used for successive motor
acts on the same object as, for example, grasping food with the hand
and ingesting it after bringing it to the mouth. We speculate that the circuits involved in double grasp preparation might have been the neural substrate where hand motor patterns used as primitive communication signs were transferred to mouth articulation system. This is in accordance with the hypothesis that Broca’s area derives phylogenetically from the monkey premotor area where hand movements are controlled
Influence of environmental factors and plant protection products on the growth and survival of Trichoderma harzianum strain INAT11
No full textFusarium head blight of wheat (Fusarium graminearum, henceforth Fg) and Pink Ear Rot of maize (Fusarium verticillioides, henceforth Fv) are diseases caused by fungi of the genus Fusarium causing severe yield losses and mycotoxins contamination. In preliminary studies conducted by University of Padova (Italy), Trichoderma harzianum strain INAT11 (deposit number DSM25764) showed promising activity against Fg and Fv. Within the European research project BIOCOMES, it was therefore decided to investigate whether strain INAT11, applied as a seed treatment (i.e. below-ground), could actually control Fg and Fv in aerial plant parts (i.e. above-ground).
To evaluate whether seed treatments with strain INAT11 could constitute a feasible plant protection tool, the effects of environmental factors and conventional plant protection products, commonly applied in wheat and maize, on the growth of the antagonist were investigated
Visual illusions and the control of children arm movements
No full textThe aim of the present study was to determine whether children like adults (Gentilucci M, Chieffi S, Daprati E, Saetti MC, Toni
I. Visual illusion and action. Neuropsychologia 1996;34:369–76; Gentilucci M, Daprati E, Gangitano M, Toni I. Eye position
tunes the contribution of allocentric and egocentric information to target localisation in human goal directed arm movements.
Neurosci Lett 1997;222:123–6) are influenced by visual illusions when they transform visual information in motor command.
Children and adults pointed to a shaft extremity of the Mu ̈ ller-Lyer configurations, as well as to an extremity of a control
configuration. Movements were executed in two experimental conditions. In the vision condition subjects saw both the stimulus
and their hand before and during movement. In the no vision (memory) condition subjects saw the stimulus and their hand before, but not during movement. Movement started 5 s after vision was precluded. The Mu ̈ ller-Lyer illusion affected pointing kinematics of both children and adults. As found previously (Gentilucci M, Chieffi S, Daprati E, Saetti MC, Toni I. Visual illusion and action. Neuropsychologia 1996;34:369–76; Gentilucci M, Daprati E, Gangitano M, Toni I. Eye position tunes the contribution
of allocentric and egocentric information to target localisation in human goal directed arm movements. Neurosci Lett
1997;222:123–6), subjects undershot and overshot the shaft extremity of the closed and of the open configuration, respectively.
The illusion effect was greater in the no vision than in the vision condition. These results show that in children like in adults the
system underlying visual perception in an object-centered frame of reference and that involved in motor control functionally
interact with each other. Although the processes of target localisation were the same, the transformation of target position
information in a sequence of motor patterns was different in children from that in adults. Even if both children and adults
lengthened duration of the deceleration phase in the vision condition, only adults shortened duration of the acceleration phase in order to maintain constant movement time (Viviani P, Schneider R. A developmental study of the relationship between geometry
and kinematics in drawing movements. J Exp Psychol 1991;17:198–218). This result suggests that children are yet unable to co-ordinate temporally acceleration with deceleration phase
Absence of change in the gray matter volume of patients with ulcerative colitis in remission: a voxel based morphometry study
No full textBackground: Recent neuroimaging studies have investigated the brain involvement in patients with Crohn's disease (CD) and Ulcerative Colitis (UC). Functional studies found abnormalities in cognitive and emotional functions in CD and UC, while a voxel based morphometry (VBM) study found morphological changes in CD. We conducted a VBM study to compare the gray matter (GM) volume of UC patients and controls. Methods: Eighteen UC patients in remission and eighteen healthy controls underwent structural MRI. VBM is a fully automated technique allowing identification of regional differences in the amount of GM, which enables an objective analysis of the whole brain. VBM was used for comparisons between patients and controls. Results: UC patients were all in remission and had a mild clinical course. There were no differences between patients and controls in GM volume. Conclusion: The brain morphology of patients with UC in remission is similar to controls. The lack of GM abnormalities in UC patients might reflect the mild clinical course of the inflammatory bowel disorder. Further research involving patients with different degrees of disease severity or during flares could shed more light on potential brain structural changes in UC
Ricerche bioagronomiche su specie erbcee biocide
No full textIn agricoltura si è sempre sentita la necessità di difendere le produzioni da insetti, crittogame e fitopatie in genere, sia in pieno campo che in magazzino. Già due millenni di anni fa, si usavano in agricoltura derivati da piante con caratteristiche insetticide. In Europa e nel Nord America furono usati per oltre 150 anni, fino a quando la scoperta degli insetticidi chimici di sintesi, fra la metà degli anni 30 e il 1950, decretò il loro declino.
Vari problemi connessi ad un uso spesso sconsiderato di prodotti di sintesi hanno portato alla necessità di sviluppare un modo alternativo per il controllo delle fitopatie utilizzando prodotti di origine vegetale.
Molti estratti vegetali ed oli essenziali possono rappresentare fonti alternative di controllo di insetti nocivi, anche nei prodotti conservati, in quanto costituiscono una ricca e potenziale fonte di principi bioattivi anche se non sempre privi di tossicità per l’ambiente e l’uomo.
La letteratura scientifica degli ultimi 25 anni descrive centinaia di metaboliti secondari delle piante, che manifestano effetti repellenti o tossici verso i naturali nemici delle piante coltivate, ma pochi sono ancora gli insetticidi di origine vegetale in commercio.
Grande è l’ interesse verso i principi attivi di origine botanica, quali mezzi di lotta validi, alternativi ai prodotti chimici di sintesi, a basso impatto sugli esseri viventi e sull’ambiente. Pur nella tutela delle biodiversità, la loro coltivazione in Italia potrebbe portare a vantaggi dal punto di vista economico, in modo che zone marginali non vengano completamente abbandonate, ma anzi, si salvaguardi il reddito degli addetti all’agricoltura. Inoltre, si potrebbe contare sull’origine certa della filiera e sulla qualità della produzione, inseribile in quella più ampia dei prodotti farmaceutici ed erboristici. La tossicità del prodotto di origine vegetale verso gli insetti è influenzata dalla composizione chimica, dalla provenienza dell’essenza vegetale, dalle condizioni ecologiche, dal metodo, dal tempo di estrazione e dalla parte della pianta utilizzata. Inoltre, la suscettibilità degli insetti ai composti vegetali è variabile, in funzione della specie, del particolare stadio vitale e delle caratteristiche dell’ambiente di impiego. Scopo del presente lavoro è stato quello di individuare le caratteristiche bio-agronomiche di alcune specie che in letteratura risultano efficaci sugli insetti. La coltivazione, sia in vaso che in pieno campo, ha voluto verificare il loro adattamento alle nostre condizioni agropedologiche, attraverso lo studio delle caratteristiche biologico-riproduttive e le loro produzioni quali-quantitative. E’ stata valutata la resa in biomassa totale ed utile, estraendo i p.a. contenuti nelle diverse parti. In alcuni casi sono stati fatti verificare gli effetti tossici e/o repellenti sugli insetti delle derrate alimentari. Sono state inoltre valutate le caratteristiche germinative dei semi riprodotti. Le specie oggetto della ricerca appartengono alle famiglie botaniche delle Leguminosae (Cassia sophera, Clitoria ternatea, Medicago truncatula, Tephrosia cinerea, Tephrosia purpurea): Asteraceae (Ageratum conyzoides, Artemisia judaica, A. tridentata, A. vulgaris, Inula conyza); Lamiaceae (Hyptis emoryi, H. lanceolata, H. spicigera, H. suaveolens, Plectranthus barbatus); Asclepiadaceae (Calotropis procera)
New perspectives for the use of Ampelomyces-based biofungicides for effective control of powdery mildew on grapevine
No full textPowdery mildew (PM) is one of the most widespread diseases of grapevine across Europe, and its control requires intensive fungicide sprays. During a 3-year study (2007-09) carried out in Northern Italy, the efficacy of late-season applications of the hyperparasitic fungus Ampelomyces quisqualis isolate M-10 (formulated product: AQ10® WG), a sustainable alternative to chemical fungicides, in reducing PM inoculum and thus disease pressure the following season was evaluated. AQ10 proved to be effective in stopping the production of new chasmothecia and reducing the number of mature ascocarps in potted grapevine plants, leading to reducing the PM severity on both leaves and bunches in the vineyard the following season. Late-season applications of AQ10 showed a mean efficacy of 40% (1 application) to 64% (2 applications) in reducing disease severity on bunches the following sprin
BIOCONTROL OF FUSARIUM HEAD BLIGHT: MOLECULAR INTERACTION BETWEEN TRICHODERMA AND MYCOTOXIGENIC FUSARIUM
No full textFusarium Head Blight (FHB) is a re-emerging disease of wheat that causes extensive agricultural damage through direct losses in yield and quality due to the presence of Fusarium damaged kernels and their associated mycotoxins such as the trichothecene deoxynivalenol (DON). Biological control, including the treatment of crop residues with antagonists such as mycoparasitic Trichoderma species to reduce pathogen inoculum of FHB, holds considerable promise. The main purpose of this PhD thesis is to select fungal antagonists able to compete with FHB causal agents, particularly Fusarium graminearum and Fusarium culmorum, in order to prevent the presence of DON on wheat.
Potential antagonists were screened on the basis of their growth in presence of DON in liquid cultures in multi-wells microplates. For each isolate, growth curves in presence/absence of DON were submitted to linear regression and statistically compared. 10 out of 100 Trichoderma spp., 56 out of 93 F. oxysporum and 2 out of 40 Pythium spp. isolates showed a statistically comparable growth rate in presence/absence of DON. At the end of growth period, cultural filtrates were submitted to HPLC analysis in order to investigate the fate of the mycotoxin. No one of cultural substrates showed a DON content lower than the initial one, enabling us to reject the hypothesis of mycotoxin degradation.
The ten Trichoderma isolates and two Pythium spp., selected for their ability to grow in presence of DON, were investigated as potential antagonists against Fusarium culmorum and F. graminearum mycotoxigenic isolates in plate confrontation assays. The results showed that three Trichoderma isolates were successful antagonists and exhibited antibiosis and mycoparasitism.
In addition, we assessed the transcription of some chitinase-encoding genes, known for their involvement during mycoparasitic growth conditions, in various stages of plate confrontation assays with F. culmorum and F. graminearum by RT-PCR. The results showed that almost all investigated genes encoding chitinases from subgroups A, B and C responded to mycoparasitic conditions and were up-regulated before contact or/and at contact with the host.
In order to evaluate the ability to prevent DON production by F. graminearum, competition tests on natural substrates of these three Trichoderma isolates against mycotoxigenic F. graminearum confirmed the positive results achieved on agar plates. Among these 3 isolates, one showed the best capacity of inhibiting DON production and was chosen for the following analysis.
An in vitro competition test on natural substrates (wheat straw and rice) was performed using qPCR as a tool to estimate the effect of the selected T. gamsii isolate on pathogen’s growth and DON accumulation. Results achieved on rice, confirmed the ability of T. gamsii 6085 to antagonize F. graminearum and F. culmorum isolates whose biomass, in presence of Trichoderma, was lower then the control. On wheat straw, a substrate very poor in nutrients, T. gamsii 6085 seemed to develop very badly and growth of both Fusarium was unaffected by the presence of the antagonist.
In the last part of the work we investigated a possible mechanism possibly involved in DON resistance in Trichoderma. We evaluated the gene expression of some PDR-ABC transporters in confrontation plate assay and in the above mentioned competition test on rice
The visual system in eyelid myoclonia with absences
No full textOBJECTIVE:
To investigate the functional and structural brain correlates of eyelid myoclonus and absence seizures triggered by eye closure (eye closure sensitivity [ECS]).
METHODS:
Fifteen patients with eyelid myoclonus with absences (EMA, Jeavons syndrome), 14 patients with idiopathic generalized epilepsies (IGE) without ECS, and 16 healthy controls (HC) underwent an electroencephalography (EEG)-correlated functional magnetic resonance imaging (fMRI) and voxel brain morphometry (VBM) protocol. The functional study consisted of 30-second epochs of eyes-open and eyes-closed conditions. The following EEG events were marked and the relative fMRI maps obtained: (1) eye closure times, (2) spontaneous blinking, and (3) spontaneous and eye closure-triggered spike and wave discharges (SWD; for EMA and IGE). Within-group and between-groups comparisons were performed for fMRI and VBM data as appropriate.
RESULTS:
In EMA compared to HC and IGE we found: (1) higher blood oxygenation level-dependent (BOLD) signal related to the eye closure over the visual cortex, the posterior thalamus, and the network implicated in the motor control of eye closure, saccades, and eye pursuit movements; and (2) increments in the gray matter concentration at the visual cortex and thalamic pulvinar, whereas decrements were observed at the bilateral frontal eye field area. No BOLD differences were detected when comparing SWD in EMA and IGE.
INTERPRETATION:
Results demonstrated altered anatomo-functional properties of the visual system in EMA. These abnormalities involve a circuit encompassing the occipital cortex and the cortical/subcortical systems physiologically involved in the motor control of eye closure and eye movements. Our work supports EMA as an epileptic condition with distinctive features and provides a contribution to its classification among epileptic syndromes
Functional magnetic resonance imaging study reveals differences in the habituation to psychological stress in patients with Crohn's disease versus healthy controls
No full textIn patients with Crohn's disease (CD) stress is believed to increase the incidence of disease relapse. The brain processes stressful stimuli and triggers the stress-evoked responses. Habituation to stress is an adaptive process that allows minimizing these responses. We hypothesized inadequate habituation to stress in CD patients. The aim of this study was to compare the neural habituation between CD patients and controls. Twenty CD patients and eighteen controls underwent a functional magnetic resonance imaging while performing two repeated runs of a stress-evoking task. The task elicited different neural activity between the groups across runs in (1) amygdala, hippocampus, (2) insula, putamen (3) cerebellar regions, suggesting altered habituation to stress in patients. These structures regulate the neuroendocrine and autonomic stress-evoked responses that control the proinflammatory responses. The inadequate habituation to stress that we found in patients could play a role in the relationship between stress and inflammatory exacerbations in C
Epilepsy-related brain networks in ring chromosome 20 syndrome: An EEG-fMRI study
No full textTo identify the brain networks that are involved in the different electroencephalography (EEG) abnormalities in patients with ring chromosome 20 [r(20)] syndrome. We hypothesize the existence of both distinctive and common brain circuits for the paroxysmal high voltage sharp waves (hSWs), the seizures, and the slow-wave 3-7 Hz rhythm that characterize this condition.
METHODS:
Thirteen patients with [r(20)] syndrome were studied by means of EEG simultaneously recorded with functional magnetic resonance imaging (EEG-fMRI). EEG traces were reviewed in order to detect the pathologic interictal (hSWs) and ictal activities; the 3-7 Hz theta-delta power was derived using a fast Fourier transform. A group-level analysis was performed for each type of EEG abnormality separately using a fixed-effect model and a conjunction analysis. Finally, a second-level random-effect model was applied considering together the different EEG abnormalities, without distinction between hSW, seizures, or theta-delta rhythms.
RESULTS:
Subcontinuous theta-delta rhythm was recorded in seven patients, seizures in two, and hSWs in three patients. The main results are the following: (1) the slow-wave rhythm was related to blood oxygen level-dependent (BOLD) increases in the premotor, sensory-motor, and temporoparietal cortex, and to BOLD decrements involving the default mode (DMN) and the dorsal attention networks (DANs); (2) the ictal-related BOLD changes showed an early involvement of the prefrontal lobe; (3) increases in BOLD signal over the basal ganglia, either for interictal and ictal activities, were observed; (4) a common pattern of positive BOLD changes in the bilateral perisylvian regions was found across the different EEG abnormalities.
SIGNIFICANCE:
The BOLD increment in the perisylvian network and the decrease of the DMN and DAN could be the expression of the [r(20)] syndrome-related cognitive and behavioral deficits. The observed BOLD patterns are similar to the ones detected in other epileptic encephalopathies, suggesting that different epileptic disorders characterized by neurobehavioral regression are associated with dysfunction in similar brain networks. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here
