Search results for "Llum"
showing 10 items of 570 documents
Carbon stable isotope composition of charophyte organic matter in a small and shallow Spanish water body as a baseline for future trophic studies
2015
<p>Quantitative descriptions of foodweb structure based on isotope niche space require knowledge of producers’ isotopic signatures. In freshwater ecosystems charophytes are one of the main components of submerged vegetation and the feeding base for many herbivorous consumers, but knowledge about their organic carbon isotopic signatures is sparse. In this study, the δ<sup>13</sup>C organic values (and organic %C and %N) of the four species of submerged macrophytes (three charophytes - <em>Chara hispida</em>, <em>Nitella hyalina</em> and <em>Tolypella glomerata </em>- and one angiosperm, <em>Myriophyllum spicatum</em>) growing …
Digitiform Sensilla on the Maxillar Palp of Coleoptera
1981
The fine structure of the digitiform sensilla on the distal segment of the maxillar palps of Tenebrio and Dermestes is described. Each sensillum is associated with a single sensory cell and three enveloping cells, which enclose two receptor lymph cavities. The inner receptor lymph cavity of both species shows a different structural feature. Branches of the outer dendritic segments, which contain numerous microtubules, run to the tip of the hairshaft. A dendritic sheath extends to the apex of the peg. The hairshaft possesses a second canal, which is free of dendrites. The poreless hairshaft is inserted in a cuticular canal; the longer distal part of the shaft is positioned in a narrow superf…
Methods to Evaluate Lighting Quality in Educational Environments
2015
Abstract The current standard for lighting of indoor work places (EN 12464-1) essentially prescribes values of photometric quantities (illuminance, Unified Glare Index, etc.); therefore it does not allow a comprehensive analysis of the luminous environment. In Italy, educational buildings do not always comply with the standard requirements for lighting. Therefore an analysis of their current state is needed and this paper illustrates two methods, developed by the authors, to carry out this investigation: the former is based on the analysis of luminance maps obtained through the HDR imaging technique whereas the latter focuses on the evaluation of non-visual effects of light.
Inside the Thompson laboratory during the “cerebellar years” and the continuing cerebellar story
2011
This paper is based on the talk by one of the authors (DL) given at the symposium for the retirement of RF Thompson (RF Thompson: A bridge between 20th and 21st century neuroscience). We first make some informal observations of the historical times and research conditions in the Thompson laboratory when the cerebellum was found to play a critical role in eye lid classical conditioning, the "cerebellar years". These conditions influenced our collaborative international program on the phenomenon known as "transfer of training" or "savings". Our research shows that the appearance of "savings" is an artifact of the order of testing, and depends upon the functioning of the contralateral interpos…
Illumination Correction on MR Images
2006
Objective. An important artifact corrupting Magnetic Resonance Images is the rf inhomogeneity, also called bias artifact. This anomaly produces an abnormal illumination fluctuation on the image, due to variations of the device magnetic field. This artifact is particularly strong on images acquired with a device specialized on upper and lower limbs due to their coil configuration. A method based on homomorphic filtering aimed to suppress this artifact was proposed by Guillemaud. This filter has two faults: it doesnt provide an indication about the cutoff frequency (cf) and introduces another illumination artifact on the edges of the foreground. This work is an improvement to this method because i…
Study of ambient light influence for three-dimensional scanners based on structured light
2007
Ambient light in a scene can introduce errors into range data from most commercial three-dimensional range scanners, particularly scanners that are based on projected patterns and structured lighting. We study the effects of ambient light on a specific commercial scanner. We further present a method for characterizing the range accuracy as a function of ambient light distortions. After a brief review of related research, we first describe the capabilities of the scanner we used and define the experimental setup for our study. Then we present the results of the range characterization relative to ambient light. In these results, we note a systematic error source that appears to be an artifact…
Shaping pseudoneglect with transcranial cerebellar direct current stimulation and music listening
2015
Non-invasive brain stimulation modulates cortical excitability depending on the initial activation state of the structure being stimulated. Combination of cognitive with neurophysiological stimulations has been successfully employed to modulate responses of specific brain regions. The present research combined a neurophysiological pre-conditioning with a cognitive conditioning stimulation to modulate behavior. We applied this new state-dependency approach to investigate the cerebellar role in musical and spatial information processing, given that a link between musical perception and visuo-spatial abilities and a clear cerebellar involvement in music perception and visuo-spatial tasks have …
Septins 2, 7 and 9 and MAP4 colocalize along the axoneme in the primary cilium and control ciliary length
2013
International audience; Septins are a large, evolutionarily conserved family of GTPases that form hetero-oligomers and interact with the actin-based cytoskeleton and microtubules. They are involved in scaffolding functions, and form diffusion barriers in budding yeast, the sperm flagellum and the base of primary cilia of kidney epithelial cells. We investigated the role of septins in the primary cilium of retinal pigmented epithelial (RPE) cells, and found that SEPT2 forms a 1:1:1 complex with SEPT7 and SEPT9 and that the three members of this complex colocalize along the length of the axoneme. Similar to observations in kidney epithelial cells, depletion of cilium-localized septins by siRN…
Application of PGPB Combined with Variable N Doses Affects Growth, Yield-Related Traits, N-Fertilizer Efficiency and Nutritional Status of Lettuce Gr…
2022
Nitrogen (N) fertilization is a crucial agricultural practice for boosting production traits in vegetables. However, N synthetic fertilizers—commonly adopted by farmers—have several counterproductive effects on the environment and on humans. The research was performed to assess the combined influence of plant growth promoting bacteria (PGPB) (Azospirillum brasilense DSM 1690, A. brasilense DSM 2298 and Pseudomonas sp. DSM 25356) and various N fertilization doses (0, 30, 60 or 120 kg ha−1) on growth, yield, quality and nitrogen indices of lettuce in protected cultivation. Plant height, root collar diameter, number of leaves and fresh weight were enhanced by A. brasilense DS…
Properties and roles of BKCa channels in cultured cerebellar granule neuron: Experimental and simulation studies
2006
We studied the properties and roles of large-conductance calcium-sensitive potassium channels (BK"C"a) in cultured rat cerebellar granule neurons. In intact cells these channels had chord conductances of 130-200pS. The conductance, threshold for channel activation and the mean open time and open probability depend on the age of cells. In computer simulations the elimination of BK"C"a channel decreases the maximum and minimum peak values of an action potential, causes reduced hyperpolarization and increases firing frequency. The observed alterations may be linked to the complexity of granule neuron excitability during maturation and provide new insight into modeling the developmental changes…