Search results for "Rites"

The angiopoietin-Tie2 pathway regulates Purkinje cell dendritic morphogenesis in a cell-autonomous manner.

2021

Neuro-vascular communication is essential to synchronize central nervous system development. Here, we identify angiopoietin/Tie2 as a neuro-vascular signaling axis involved in regulating dendritic morphogenesis of Purkinje cells (PCs). We show that in the developing cerebellum Tie2 expression is not restricted to blood vessels, but it is also present in PCs. Its ligands angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) are expressed in neural cells and endothelial cells (ECs), respectively. PC-specific deletion of Tie2 results in reduced dendritic arborization, which is recapitulated in neural-specific Ang1-knockout and Ang2 full-knockout mice. Mechanistically, RNA sequencing reveals that Tie…

Long-spined polymorphic neurons of the medial cortex of lizards: a Golgi, Timm, and electron-microscopic study.

1988

The morphology, ultrastructure, and principal synaptic input of longspined neurons located in the inner plexiform layer of the medial cortex in three related species of lizards is described. Golgi impregnations have been used to define the external morphology of these neurons and their axonal trajectories. Their most striking characteristic is the presence of very long spines or “microdendrites” especially abundant on the distal dendritic segments. Axons have ascendent trajectories, pass through the cell layer, and ramify in the outer plexiform layer. Combined Golgi-electron microscopy as well as standard electron microscopy permitted the definition of the ultrastructure of these neurons. T…

Assessing and modeling nitrite inhibition in microalgae-bacteria consortia for wastewater treatment by means of photo-respirometric and chlorophyll f…

2022

Abstract Total nitrite (TNO2 = HNO2 + NO−2) accumulation due to the activity of ammonia-oxidizing bacteria (AOB) was monitored in microalgae-bacteria consortia, and the inhibitory effect of nitrite/free nitrous acid (NO2-N/FNA) on microalgae photosynthesis and inhibition mechanism was studied. A culture of Scenedesmus was used to run two sets of batch reactors at different pH and TNO2 concentrations to evaluate the toxic potential of NO2-N and FNA. Photo-respirometric tests showed that NO2-N accumulation has a negative impact on net oxygen production rate (OPRNET). Chlorophyll a fluorescence analysis was used to examine the biochemical effects of NO2-N stress and the mechanism of NO2-N inhi…

Cloning and expression of the sponge longevity gene SDLAGL.

2000

Porifera show a characteristic Bauplan in spite of the fact that (almost) all cells are telomerase-positive and presumably provided with an unlimited potency for cell proliferation. One gene, SDLAGL, was identified in the marine sponge Suberites domuncula whose deduced polypeptide showed high sequence similarity to the longevity assurance genes from other Metazoa. While in single cells no transcripts of SDLAGL could be identified, high expression was seen after re-aggregation of single cells and in proliferating cells of primmorphs.

Cloning of sponge heat shock proteins: evolutionary relationships between the major kingdoms

2009

In the present study we have cloned from sponges (Porifera) those molecules which are involved in the protection of organisms against physiological and stress conditions; the inducible heat shock protein Mr 70,000, hsp70, from the marine sponge Geodia cydonium, its interacting hsp40, a DnaJ-like protein (from G. cydonium) and the constitutively expressed counterpart the glucose-regulated protein Mr 78,000, GRP78 from Suberites domuncula. Alignments of the sequences revealed that the deduced aa sequences of all sponge hsp's share high homology to other metazoan sequences, and are separated from related sequences from plants and fungi (hsp70, GRP78, DnaJ) as well as Bacteria (DnaK, the hsp70 …

Assessment of the Current for a Non-Linear Power Inductor Including Temperature in DC-DC Converters

2023

A method for estimating the current flowing through a non-linear power inductor operating in a DC/DC converter is proposed. The knowledge of such current, that cannot be calculated in closed form as for the linear inductor, is crucial for the design of the converter. The proposed method is based on a third-order polynomial model of the inductor, already developed by the authors; it is exploited to solve the differential equation of the inductor and to implement a flux model in a circuit simulator. The method allows the estimation of the current up to saturation, intended as the point at which the differential inductance is reduced to half of its maximum value. The current profile depends al…

Single neuron binding properties and the magical number 7

2008

When we observe a scene, we can almost instantly recognize a familiar object or can quickly distinguish among objects differing by apparently minor details. Individual neurons in the medial temporal lobe of humans have been shown to be crucial for the recognition process, and they are selectively activated by different views of known individuals or objects. However, how single neurons could implement such a sparse and explicit code is unknown and almost impossible to investigate experimentally. Hippocampal CA1 pyramidal neurons could be instrumental in this process. Here, in an extensive series of simulations with realistic morphologies and active properties, we demonstrate how n radial (ob…

A modeling study suggesting how a reduction in the context-dependent input on CA1 pyramidal neurons could generate schizophrenic behavior.

2011

The neural mechanisms underlying schizophrenic behavior are unknown and very difficult to investigate experimentally, although a few experimental and modeling studies suggested possible causes for some of the typical psychotic symptoms related to this disease. The brain region most involved in these processes seems to be the hippocampus, because of its critical role in establishing memories for objects or events in the context in which they occur. In particular, a hypofunction of the N-methyl-D-aspartate (NMDA) component of the synaptic input on the distal dendrites of CA1 pyramidal neurons has been suggested to play an important role for the emergence of schizophrenic behavior. Modeling st…

New foundings of contourite deposits in an active continental margin (Southern Tyrrhenian Sea)

2014

Application of Cell Culture for the Production of Bioactive Compounds from Sponges:  Synthesis of Avarol by Primmorphs from Dysidea avara

2000

Among all metazoan phyla, sponges are known to produce the largest number of bioactive compounds. However, until now, only one compound, arabinofuranosyladenine, has been approved for application in humans. One major obstacle is the limited availability of larger quantities of defined sponge starting material. Recently, we introduced the in vitro culture of primmorphs from Suberites domuncula, which contain proliferating cells. Now we have established the primmorph culture also from the marine sponge Dysidea avara and demonstrate that this special form of sponge cell aggregates produces avarol, a sesquiterpenoid hydroquinone, known to display strong cytostatic activity especially against ma…