Quantitative Investigation of Leaf Photosynthetic Pigments during Annual Biological Cycle of Vitis vinifera L. Table Grape Cultivars

Variations in chlorophyll a/b and chlorophyll/carotenoid ratios are indicators of senescence, stress ordamage to the photosynthetic apparatus and affect the normal course of plant biological processes. Theaim of this work was to investigate the chlorophyll (a and b) and carotenoid content and ratios in theleaves of four Vitis vinifera L. table grape cultivars in the main phenophases of the annual biologicalcycle. During the annual cycle, the moisture content of the leaves decreased significantly (up to 21%),along with a reduction in leaf area and perimeter. Chlorophyll a and b showed a continuous accumulationuntil grape véraison, with lower values of the Chl a/b ratio at the beginning of the vegetative period.Carotenoids continued their biosynthesis until grape ripening (for another 30 days), at which stage therewas a significant decrease in the chlorophyll/carotenoid ratio (2.62 ± 0.31). At véraison, peroxidase hadthe most intense activity (0.20 to 0.51 U/mg), possibly because of involvement in chlorophyll degradation,while total phenolic content started to decrease. Grape véraison could be regarded as the starting point offoliage senescence. Moreover, the relationship between total chlorophyll (by extraction) and chlorophyllcontent index (non-destructive method) was very significant (R2 = 0.92). These results contribute to a betterunderstanding of foliar pigment dynamics and the timing of their decline in order to define the behaviourof table grape cultivars during the annual biological cycle

Сравнительная оценка структуры заболеваемости студентов I курса Государственного Медицинского и Фармацевтического Университета им. Н. A. Тестемицану

Department of Family Medicine and Laboratory of Genetics, Nicolae Testemiţanu State Medical and Pharmaceutical University, Chisinau, Republic of Moldova, Congresul III al Medicilor de Familie din Republica Moldova, 17–18 mai, 2012, Chişinău, Republica Moldova, Conferinţa Naţională „Maladii bronhoobstructive la copii”, consacrată profesorului universitar, doctor habilitat Victor Gheţeul, 27 aprilie, Chişinău, Republica MoldovaThe purpose of this work was to comparatively evaluate the morbidity spectrum of the first year students of the SMPhU ”Nicolae Testemiţanu” enrolled in 2002-2004 and 2010-2011. Materials and methods: the data of medical examination performed at the University Clinic of Primary Care were analyzed in order to estimate the morbidity spectra. Results: the comparative analysis of the health status of students revealed an increase of students being “sick” from 24.0% in 2002-2004 to 35.0% in 2010-2011. The comparative analysis of morbidity spectra denotes a significant increase in proportions of eye pathology, pathologies of urinary and digestive tracts and endocrine system in the morbidity structure during 2002-2011 period. Conclusions: our data support the need of medical examination of first-year students in order to identify the existing chronic pathologies, proper treatment, and monitoring their diseases during the academic years.Целью настоящей работы была сравнительная оценка структуры заболеваемости студентов первого курса Государственного Медицинского и Фармацевтического Университета имени „Николая Тестемицану”, поступивших на учебу в 2002-2004 и 2010-2011 годы. Материал и методы: результаты медицинского осмотра студентов первого курса 2002-2004 и 2010-2011 годов поступления, для определения спектра заболеваемости. Результаты: сравнительный анализ состояния здоровья студентов показал увеличение группы студентов «больных» от 24,0% в 2002-2004 гг. до 35,0% в 2010-2011 гг. В структуре заболеваемости за период 2002-2011 годы произошло значительное увеличение доли глазной патологии, патологии мочеполового, пищеварительного трактов и эндокринной системы. Выводы: Для выявления существующих хронических заболеваний, своевременного их лечения и мониторинга динамики состояния здоровья студентов во время учебы, необходимо проведение медицинского осмотра студентов на первом курсе

Testing the potential of a virtual reality neurorehabilitation system during performance of observation, imagery and imitation of motor actions recorded by wireless functional near-infrared spectroscopy (fNIRS)

Background Several neurorehabilitation strategies have been introduced over the last decade based on the so-called simulation hypothesis. This hypothesis states that a neural network located in primary and secondary motor areas is activated not only during overt motor execution, but also during observation or imagery of the same motor action. Based on this hypothesis, we investigated the combination of a virtual reality (VR) based neurorehabilitation system together with a wireless functional near infrared spectroscopy (fNIRS) instrument. This combination is particularly appealing from a rehabilitation perspective as it may allow minimally constrained monitoring during neurorehabilitative training. Methods fNIRS was applied over F3 of healthy subjects during task performance in a virtual reality (VR) environment: 1) 'unilateral' group (N = 15), contralateral recording during observation, motor imagery, observation & motor imagery, and imitation of a grasping task performed by a virtual limb (first-person perspective view) using the right hand; 2) 'bilateral' group (N = 8), bilateral recording during observation and imitation of the same task using the right and left hand alternately. Results In the unilateral group, significant within-condition oxy-hemoglobin concentration Δ[O2Hb] changes (mean ± SD μmol/l) were found for motor imagery (0.0868 ± 0.5201 μmol/l) and imitation (0.1715 ± 0.4567 μmol/l). In addition, the bilateral group showed a significant within-condition Δ[O2Hb] change for observation (0.0924 ± 0.3369 μmol/l) as well as between-conditions with lower Δ[O2Hb] amplitudes during observation compared to imitation, especially in the ipsilateral hemisphere (p < 0.001). Further, in the bilateral group, imitation using the non-dominant (left) hand resulted in larger Δ[O2Hb] changes in both the ipsi- and contralateral hemispheres as compared to using the dominant (right) hand. Conclusions This study shows that our combined VR-fNIRS based neurorehabilitation system can activate the action-observation system as described by the simulation hypothesis during performance of observation, motor imagery and imitation of hand actions elicited by a VR environment. Further, in accordance with previous studies, the findings of this study revealed that both inter-subject variability and handedness need to be taken into account when recording in untrained subjects. These findings are of relevance for demonstrating the potential of the VR-fNIRS instrument in neurofeedback applications

Neural correlates of evidence accumulation during value-based decisions revealed via simultaneous EEG-fMRI

Current computational accounts posit that, in simple binary choices, humans accumulate evidence in favour of the different alternatives before committing to a decision. Neural correlates of this accumulating activity have been found during perceptual decisions in parietal and prefrontal cortex; however the source of such activity in value-based choices remains unknown. Here we use simultaneous EEG–fMRI and computational modelling to identify EEG signals reflecting an accumulation process and demonstrate that the within- and across-trial variability in these signals explains fMRI responses in posterior-medial frontal cortex. Consistent with its role in integrating the evidence prior to reaching a decision, this region also exhibits task-dependent coupling with the ventromedial prefrontal cortex and the striatum, brain areas known to encode the subjective value of the decision alternatives. These results further endorse the proposition of an evidence accumulation process during value-based decisions in humans and implicate the posterior-medial frontal cortex in this process

Visual attention and action: How cueing, direct mapping, and social interactions drive orienting

Despite considerable interest in both action perception and social attention over the last 2 decades, there has been surprisingly little investigation concerning how the manual actions of other humans orient visual attention. The present review draws together studies that have measured the orienting of attention, following observation of another’s goal-directed action. Our review proposes that, in line with the literature on eye gaze, action is a particularly strong orienting cue for the visual system. However, we additionally suggest that action may orient visual attention using mechanisms, which gaze direction does not (i.e., neural direct mapping and corepresentation). Finally, we review the implications of these gaze-independent mechanisms for the study of attention to action. We suggest that our understanding of attention to action may benefit from being studied in the context of joint action paradigms, where the role of higher level action goals and social factors can be investigated

Motor imagery during action observation: A brief review of evidence, theory and future research opportunities

Motor imagery (MI) and action observation (AO) have traditionally been viewed as two separate techniques, which can both be used alongside physical practice to enhance motor learning and rehabilitation. Their independent use has been shown to be effective, and there is clear evidence that the two processes can elicit similar activity in the motor system. Building on these well-established findings, research has now turned to investigate the effects of their combined use. In this article, we first review the available neurophysiological and behavioral evidence for the effects of combined action observation and motor imagery (‘AO+MI’) on motor processes. We next describe a conceptual framework for their combined use, and then discuss several areas for future research into AO+MI processes. In this review, we advocate a more integrated approach to AO+MI techniques than has previously been adopted by movement scientists and practitioners alike. We hope this early review of an emergent body of research, along with a related set of research questions, can inspire new work in this area. We are optimistic that future research will further confirm if, how, and when this combined approach to AO+MI can be more effective in motor learning and rehabilitation settings, relative to the more traditional application of AO or MI independently

Excitability of the Primary Motor Cortex Increases More Strongly with Slow- than with Normal-Speed Presentation of Actions

Introduction: The aim of the present study was to investigate how the speed of observed action affects the excitability of the primary motor cortex (M1), as assessed by the size of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS). Copyright:Methods: Eighteen healthy subjects watched a video clip of a person catching a ball, played at three different speeds (normal-, half-, and quarter-speed). MEPs were induced by TMS when the model\u27s hand had opened to the widest extent just before catching the ball ("open") and when the model had just caught the ball ("catch"). These two events were locked to specific frames of the video clip ("phases"), rather than occurring at specific absolute times, so that they could easily be compared across different speeds. MEPs were recorded from the thenar (TH) and abductor digiti minimi (ADM) muscles of the right hand.Results: The MEP amplitudes were higher when the subjects watched the video clip at low speed than when they watched the clip at normal speed. A repeated-measures ANOVA, with the factor VIDEO-SPEED, showed significant main effects. Bonferroni\u27s post hoc test showed that the following MEP amplitude differences were significant: TH, normal vs. quarter; ADM, normal vs. half; and ADM, normal vs. quarter. Paired t-tests showed that the significant MEP amplitude differences between TMS phases under each speed condition were TH, "catch" higher than "open" at quarter speed; ADM, "catch" higher than "open" at half speed.Conclusions: These results indicate that the excitability of M1 was higher when the observed action was played at low speed. Our findings suggest that the action observation system became more active when the subjects observed the video clip at low speed, because the subjects could then recognize the elements of action and intention in others