Search results for "physiologic"
showing 10 items of 2593 documents
Reintroducing photosynthesis.
2011
This article reports on conceptual difficulties related to photosynthesis and respiratory metabolism of a Plant Physiology course for undergraduate students that could hinder their better learning of metabolic processes. A survey of results obtained in this area during the last 10 academic years was performed, as well as a specific test, aimed to find out prior conceptual schemes in the students. The test included only basic, general questions on plant metabolism, and was passed on the first day of the course. Scores obtained by different groups of students were compared. Survey of students' performance in previous years shows that questions on plant metabolism result in significantly lower…
A failure of high level verbal response selection in progressive dynamic aphasia.
2005
Different theoretical interpretations have been offered in order to account for a specific language impairment termed dynamic aphasia. We report a patient (CH) who presented with a dynamic aphasia in the context of nonfluent progressive aphasia. CH had the hallmark of reduced spontaneous speech in the context of preserved naming, reading, and single word repetition and comprehension. Articulatory and grammatical difficulties were also present. CH had a very severe verbal generation impairment despite being able to describe pictorial scenes and action sequences well. In the experimental investigations CH was severely impaired in word, phrase, and sentence generation tasks when many competing…
Spatiotemporal Dynamics of the Processing of Spoken Inflected and Derived Words:A Combined EEG and MEG Study
2011
The spatiotemporal dynamics of the neural processing of spoken morphologically complex words are still an open issue. In the current study, we investigated the time course and neural sources of spoken inflected and derived words using simultaneously recorded electroencephalography (EEG) and magnetoencephalography (MEG) responses. Ten participants (native speakers) listened to inflected, derived, and monomorphemic Finnish words and judged their acceptability. EEG and MEG responses were time-locked to both the stimulus onset and the critical point (suffix onset for complex words, uniqueness point for monomorphemic words). The ERP results showed that inflected words elicited a larger left-late…
Do distractors interfere with memory for study pairs in associative recognition?
2006
In an associative recognition task, distractors generally consist of a rearrangement of the items composing the study pairs. This makes it possible that processing the distractors generates retroactive interference on memory for the study pairs. In Experiment 1, we explored this possibility in a yes/no recognition test concerning previously learned arbitrary associations between visual symbols and auditory syllables. Rearranged pairs had a deleterious impact on the accuracy and the speed of responses to related correct pairs. This effect did not vary as a function of the number of training blocks, and furthermore, in Experiment 2, the same effect was observed for overlearned small multiplic…
Coupling of Action-Perception Brain Networks during Musical Pulse Processing: Evidence from Region-of-Interest-Based Independent Component Analysis
2017
Our sense of rhythm relies on orchestrated activity of several cerebral and cerebellar structures. Although functional connectivity studies have advanced our understanding of rhythm perception, this phenomenon has not been sufficiently studied as a function of musical training and beyond the General Linear Model (GLM) approach. Here, we studied pulse clarity processing during naturalistic music listening using a data-driven approach (independent component analysis; ICA). Participants’ (18 musicians and 18 controls) functional magnetic resonance imaging (fMRI) responses were acquired while listening to music. A targeted region of interest (ROI) related to pulse clarity processing was defined…
Hunting for the beat in the body: on period and phase locking in music-induced movement.
2014
Music has the capacity to induce movement in humans. Such responses during music listening are usually spontaneous and range from tapping to full-body dancing. However, it is still unclear how humans embody musical structures to facilitate entrainment. This paper describes two experiments, one dealing with period locking to different metrical levels in full-body movement and its relationships to beat- and rhythm-related musical characteristics, and the other dealing with phase locking in the more constrained condition of sideways swaying motions. Expected in Experiment 1 was that music with clear and strong beat structures would facilitate more period-locked movement. Experiment 2 was assum…
Cellular, physiological, and molecular adaptive responses of Erwinia amylovora to starvation.
2013
Erwinia amylovora causes fire blight, a destructive disease of rosaceous plants distributed worldwide. This bacterium is a nonobligate pathogen able to survive outside the host under starvation conditions, allowing its spread by various means such as rainwater. We studied E. amylovora responses to starvation using water microcosms to mimic natural oligotrophy. Initially, survivability under optimal (28 °C) and suboptimal (20 °C) growth temperatures was compared. Starvation induced a loss of culturability much more pronounced at 28 °C than at 20 °C. Natural water microcosms at 20 °C were then used to characterize cellular, physiological, and molecular starvation responses of E. amylovora. Ch…
Estimating the decomposition of predictive information in multivariate systems
2015
In the study of complex systems from observed multivariate time series, insight into the evolution of one system may be under investigation, which can be explained by the information storage of the system and the information transfer from other interacting systems. We present a framework for the model-free estimation of information storage and information transfer computed as the terms composing the predictive information about the target of a multivariate dynamical process. The approach tackles the curse of dimensionality employing a nonuniform embedding scheme that selects progressively, among the past components of the multivariate process, only those that contribute most, in terms of co…
Splitting the dynamics of large biochemical interaction networks
2003
This article is inscribed in the general motivation of understanding the dynamics on biochemical networks including metabolic and genetic interactions. Our approach is continuous modeling by differential equations. We address the problem of the huge size of those systems. We present a mathematical tool for reducing the size of the model, master-slave synchronization, and fit it to the biochemical context.
Gold(I) Biscarbene Complexes Derived from Vascular-Disrupting Combretastatin A-4 Address Different Targets and Show Antimetastatic Potential
2014
Gold N-heterocyclic carbene (NHC) complexes are an emerging class of anticancer drugs. We present a series of gold(I) biscarbene complexes with NHC ligands derived from the plant metabolite combretastatin A-4 (CA-4) that retain its vascular-disrupting effect, yet address different cellular and protein targets. Unlike CA-4, these complexes did not interfere with tubulin, but with the actin cytoskeleton of endothelial and cancer cells. For the highly metastatic 518A2 melanoma cell line this effect was accompanied by a marked accumulation of cells in the G1 phase of the cell cycle and a suppression of active prometastatic matrix metalloproteinase-2. Despite these mechanistic differences the co…