Search results for "structures"

Adaptive Whisking in Mice

2021

Rodents generate rhythmic whisking movements to explore their environment. Whisking trajectories, for one, appear as a fixed pattern of whisk cycles at 5-10 Hz driven by a brain stem central pattern generator. In contrast, whisking behavior is thought to be versatile and adaptable to behavioral goals. To begin to systematically investigate such behavioral adaptation, we established a whisking task, in which mice altered the trajectories of whisking in a goal-oriented fashion to gain rewards. Mice were trained to set the whisker to a defined starting position and generate a protraction movement across a virtual target (no touch-related tactile feedback). By ramping up target distance based o…

Gender-related variations in hemolymph parameters of Carabus lefebvrei (Coleoptera: Carabidae): HPLC analysis and phenoloxidase activity

2017

We characterized the enzymatic activity of basal and total phenoloxidase and HLPC and SDS- PAGE profiles in hemolymph of Carabus lefebvrei males and females at different reproductive status. The phenoloxidase activity was activated by trypsin and inhibited by phenoloxidase activity specific inhibitor phenylthiourea. Our results demonstrated that both in males and females, there were no significant differences in the basal phenoloxidase activity between reproductive and virgin beetles, while the total phenoloxidase activity increased significantly in virgin specimens. Thus, resources seem to be invested to increase the humoral response in pre-reproductive phase forming a barrier against path…

Efficiency of acetic acid and formic acid as a catalyst in catalytical and mechanocatalytical pretreatment of barley straw

2016

In this study, the potential of organic acids (formic acid, acetic acid) in a catalytical and mechanocatalytic conversion of lignocellulosic barley straw to valuable sugars is explored using sulfuric acid as a reference. Acid-catalyzed hydrolysis has been carried out with acid-impregnated samples as well as unmodified barley straw. In the mechanocatalytical approach, pretreatment consists of impregnation with the acid catalyst and mechanical treatment by ball milling following chemical hydrolysis. Straw samples and residues were analyzed by Fourier transform infrared spectrometry (FT-IR) whereas hydrolysate analysis was based on total reducing sugar (TRS) determination following the DNS met…

Maternal n-3 long chain polyunsaturated fatty acids increase n-3 fatty acids in brain glial cells and retina in the rat and improve rod sensitivity

2007

International audience; Purpose: To evaluate the efficacy of long chain n-3 polyunsaturated fatty acids (LC-PUFA) given to female rats during gestation and lactation on the incorporation of n-3 PUFA in the retina and brain glial cells of the newborn rat, and to evaluate the consequences on the electroretinographic (ERG) response. Methods: Sprague Dawley rats were fed during gestation and lactation with a 20%-lipid rich diet containing 0.75% of EPA and 0.55% of DHA. The fatty acid profile was analyzed in the eyeball and in brain glial cells of the litters sacrificed at birth. The retina and brain glial cell phospholipids were similarly analyzed in 14 day-old rats and in the mothers. Standard…

RPE/Choroid and Neuroretina Differences in Lipid Profile in Humans, and Possible Correlations to Dietary Lipid Intake

2008

International audience; Purpose: : To provide data on the differences in the lipid profile of the neural retina and RPE/choroid in healthy human eyes, and to establish plausible relationships with dietary fat intake, by comparing the lipid profile of the extra orbital fat. Methods: : Human eyes were collected from 28 human donors. The neural retina was dissected from the RPE/choroid. In 6 donors, the lacrimal gland and a piece of the extra orbital fat were collected. The lipid profile of the human samples was analyzed into classes. Phospholipids and cholesteryl esters were purified from RPE/choroid. The fatty acid composition of the retina, lipid fractions of RPE/choroid, and lacrimal gland…

Vendace (Coregonus albula) Disperse Their Eggs Widely during Spawning

2021

Depending on their reproductive strategy, different fish species either aggregate or disperse eggs and larvae in their reproductive habitat. Because yolk-sac larvae of vendace (Coregonus albula) disperse widely across the littoral and pelagic zones of boreal lakes, it is unclear where the exact spawning and egg incubation locations are. Vendace egg and larvae densities were studied in Lake Southern Konnevesi to clarify its spawning strategy. In autumn 2019, 1–2 weeks prior to spawning, 500 egg samplers were installed in five depth zones in 20 sampling plots. Fertilized eggs were found in 18 plots. The mean density of eggs was 74 eggs m–2 and the mean fertilization rate 85%. During spawning,…

Sn-Co Nanowires: High-Performing Electrodes as Anodes for Lithium-ion Batteries

2012

Retinal Straylight Before and After Penetrating Keratoplasty in an Eye with a Post-Herpetic Corneal Scar

2008

Objetivo: Estudio in vivo de la luz dispersa que alcanza la retina en un paciente antes y despues de someterse a una queratoplastia penetrante (o sus siglas en ingles, PKP). Metodos: En un paciente varon de 65 anos con una ulcera corneal herpetica se midio la proporcion de luz dispersa que alcanza la retina tanto antes como despues de una PKP, utilizando para ello un metodo psicometrico denominado "de comparacion por compensacion" («Compensation comparison method», C-Quant straylightmeter, Oculus GmbH, Alemania). Resultados: La cantidad de luz dispersa que alcanza la retina medida antes de la cirugia fue elevada en comparacion con los valores obtenidos en estudios previos en sujetos normale…

Geographical Variation in Egg Mass and Egg Content in a Passerine Bird

2011

Reproductive, phenotypic and life-history traits in many animal and plant taxa show geographic variation, indicating spatial variation in selection regimes. Maternal deposition to avian eggs, such as hormones, antibodies and antioxidants, critically affect development of the offspring, with long-lasting effects on the phenotype and fitness. Little is however known about large-scale geographical patterns of variation in maternal deposition to eggs. We studied geographical variation in egg components of a passerine bird, the pied flycatcher (Ficedula hypoleuca), by collecting samples from 16 populations and measuring egg and yolk mass, albumen lysozyme activity, yolk immunoglobulins, yolk and…

Ligand mediated evolution of size dependent magnetism in cobalt nanoclusters.

2018

We use density functional theory to model the impact of a ligand shell on the magnetic properties of CoN (15 ≤ N ≤ 55) nanoclusters. We study three different ligand shells on each nanocluster core size, each known to have different electronic interactions with the surface: pure Cl ligand shells (X-type), pure PH3 ligand shells (L-type), and two component ligand shells with mixtures of Cl and PH3 ligands. The simulations show that the identity, arrangement, and total coverage of the ligand shell controls the distribution of local magnetic moments across the CoN core. On the surface of an unpassivated CoN nanocluster, the Co-Co coordination number (CN) is known to determine the local magnetic…