Search results for "Animal Structures"
showing 10 items of 876 documents
Neuroblast formation and patterning during early brain development in Drosophila.
2004
The Drosophila embryo provides a useful model system to study the mechanisms that lead to pattern and cell diversity in the central nervous system (CNS). The Drosophila CNS, which encompasses the brain and the ventral nerve cord, develops from a bilaterally symmetrical neuroectoderm, which gives rise to neural stem cells, called neuroblasts. The structure of the embryonic ventral nerve cord is relatively simple, consisting of a sequence of repeated segmental units (neuromeres), and the mechanisms controlling the formation and specification of the neuroblasts that form these neuromeres are quite well understood. Owing to the much higher complexity and hidden segmental organization of the bra…
Time spent on the smartphone does not relate to manual dexterity in young adults.
2021
Abstract Background The Grooved Pegboard Test (GPT) is widely adopted to evaluate manual dexterity, it presents normative data but the test is influenced by different factors. The influence of time spent on smartphones has not been considered before, for this reason, the objective of this study was to evaluate if smartphone use influences the time to complete the GPT. A total of 38 (21 women; 17 men) young adults 20.7 (1.5) years participated in the study. The time spent on the smartphones during the last seven days was recorded through the device itself and the GPT performance was measured. A correlation analysis between the time spent on the smartphone and GPT was performed while the t-te…
Neuronal receptors display cytoskeleton-independent directed motion on the plasma membrane
2018
Summary Directed transport of transmembrane proteins is generally believed to occur via intracellular transport vesicles. However, using single-particle tracking in rat hippocampal neurons with a pH-sensitive quantum dot probe that specifically reports surface movement of receptors, we have identified a subpopulation of neuronal EphB2 receptors that exhibit directed motion between synapses within the plasma membrane itself. This receptor movement occurs independently of the cytoskeleton but is dependent on cholesterol and is regulated by neuronal activity.
Comparison of testing acute toxicity on embryo of zebrafish, Brachydanio rerio and RTG-2 cytotoxicity as possible alternatives to the acute fish test
1995
Abstract The present study compares two possible alternative methods to replace the acute fish test. Fertilized eggs of zebrafish, Brachydanio rerio were used to investigate the acute toxicity of chemicals. Different toxicological endpoints such as coagulation of the eggs, development of gastrulation, number of somites, development of organs, circulation, heartbeat, otolithanlage and pigmentation have been examined during the embryonic development of zebrafish within the first 48 h. Differences to the normal development were measured by these endpoints. Chemicals have been examined in a preliminary approach with respect to their cytotoxicity on the RTG-2 cells (Rainbow Trout Gonad). The vit…
Tritium retention measurements by accelerator mass spectrometry and full combustion of W-coated and uncoated CFC tiles from the JET divertor
2016
Abstract Accelerator mass spectrometry (AMS) and the full combustion method (FCM) followed by liquid scintillation counting were applied to quantitatively determine the tritium retention in the tungsten-coated carbon fibre composites (CFC), in comparison to uncoated CFC tiles from the JET divertor. The tiles were adjacent and exposed to plasma operations between 2007 and 2009. The tritium depth profiles are showing that the tritium retention on the W-coated tile was reduced by a factor of 13.5 in comparison to the uncoated tile whereas the bulk tritium concentration is approximately the same for both tiles.
CHEMICAL AND PHYSICAL SIGNALS MEDIATING CONSPECIFIC AND HETEROSPECIFIC AGGREGATION BEHAVIOR OF FIRST INSTAR STINK BUGS
2004
We investigated cues that mediate the aggregation behavior of immature pentatomid bugs by using nymphs of six different pentatomid bug species (Nezara viridula, Acrosternum hilare, Chlorochroa ligata, Chlorochroa sayi, Thyanta pallidovirens, and Euschistus conspersus). When first instars of any two species were put together in a Petri dish, they readily formed heterospecific aggregations similar to their natural conspecific aggregations. The chemical profiles of first and second instar nymphs of each species were determined by solvent extraction with pentane, followed by GC-MS analysis. Immature bugs of the different species had some compounds in common, and some that were more species spec…
Fine Structure of Antennal Sensilla of Paysandisia archon and Electrophysiological Responses to Volatile Compounds Associated with Host Palms
2014
Paysandisia archon (Lepidoptera: Castniidae) is a serious pest of palm trees. A comprehensive knowledge of the insect olfactory system is essential for the development of efficient semiochemical-based control methods. The olfactory sensilla are located particularly on the antennae, and these can detect plant volatiles that provide important cues for the insects in the search for their host plants. To date, the fine structure of P. archon antennal sensilla studies and their role in host-plant perception have not been investigated in great detail. Using light microscopy and scanning and transmission electron microscopy, the antennae of both sexes of P. archon are described here in detail, acc…
Clinical application of adult olfactory bulb ensheathing glia for nervous system repair
2011
Abstract The ability of adult olfactory bulb ensheathing glia (OB-OEG) to promote histological and functional neural repair has been broadly documented. Pre-clinical studies show that beneficial effects of adult OB-OEG are repeatable in the same type of spinal cord injury initially tested, in other spinal cord and CNS injury models, in different species and after the administration of these cells in different forms (either alone or in combination with other cells, drugs, products or devices). These studies demonstrate the reproducibility, robustness, fundamental nature and relevance of the findings. Therefore, the use of adult OB-OEG for spinal cord injury repair meets the scientific criter…
Risk assessment of second primary cancer according to histological subtype of non-Hodgkin lymphoma.
2015
Non-Hodgkin lymphoma (NHL) represents a heterogeneous group of diseases that are known to carry a considerable risk of second primary cancer (SPC). However, little attention has been paid to SPC risk assessment according to NHL subtypes. Data from 10 French population-based cancer registries were used to establish a cohort of 7546 patients with a first diagnosis of NHL (eight subtypes) between 1989 and 2004. Standardized incidence ratios (SIRs) of metachronous SPC were estimated. Among the 7546 patients diagnosed with a NHL, the overall SPC risk was 25% higher than that in the reference population (SIR = 1.25, 95% confidence interval 1.15–1.36). In univariate analysis, the SPC risk differed…
Hepatic arterial infusion of gemcitabine-oxaliplatin in a large metastasis from colon cancer
2010
International audience; Hepatic arterial infusion (HAI) of chemotherapy can be performed in cases of liver-confined metastatic disease, resulting in increased local drug concentrations. Here we report the case of a 61-year-old man who presented with an isolated large unresectable liver metastasis of colon cancer after failure of surgery and multiple administration of systemic chemotherapy. The patient was treated with a combination of gemcitabine and oxaliplatin using HAI. The tolerance was excellent and a radiological complete response was obtained after 8 cycles of HAI. The rationale for the use of gemcitabine and oxaliplatin as well as that for the combination of the 2 drugs is discussed…