Search results for "Pyramid"

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…

A multi-process system for HEp-2 cells classification based on SVM

2016

An automatic system for pre-segmented IIF images analysis was developed.A non-standard pipeline for supervised image classification was adopted.The system uses a two-level pyramid to retain some spatial information.From each cell image 216 features are extracted.15 SVM classifiers one-against-one have been implemented. This study addresses the classification problem of the HEp-2 cells using indirect immunofluorescence (IIF) image analysis, which can indicate the presence of autoimmune diseases by finding antibodies in the patient serum. Recently, studies have shown that it is possible to identify the cell patterns using IIF image analysis and machine learning techniques. In this paper we de…

Copper(II) complexes of 1,4,5,8,9,12-hexaazatriphenylene with oxalate, squarate, perchlorate as auxiliary ligands or counter ion

2002

Abstract The crystal structures of [Cu(hat)(H2O)(ox)]·H2O (I), [Cu(hat)(H2O)3(sq)]·3H2O (II) and [Cu(hat)(H2O)2](ClO4)2·4H2O (III) have been determined from X-ray single crystal diffraction data (hat=1,4,5,8,9,12-hexaazatriphenylene, ox=oxalate, sq=squarate=dianion of 3,4-dihydroxy-cyclobut-3-ene-1,2-dione). Compound I crystallises in the triclinic system, space group P 1 with a=6.6626(10), b=9.2001(14), c=12.9954(19) A , α=103.301(15), β=91.414(21), γ=105.523(13)°, Z=2; compound II in the orthorhombic system, space group P212121 with a=6.9274(2), b=8.4327(3), c=34.0577(14) A , Z=4; and compound III in the monoclinic system, space group C2/c with a=22.6652(10), b=9.2220(10), c=16.1400(10) A…

Oxidovanadium(V) Complexes with Aminoethanol Bis(phenolate) [O,N,O,O] Ligands: Preparations, Structures, N-Dealkylation and Condensation Reactions

2011

The reactions between [VO(acac)2] (acac– = acetylacetonate ion) or [VO(OPr)3] and trianionic tetradentate N,N-bis(2-methylene-4,6-alkylphenolate)aminoethanolate ligands, [L13– (4,6-dimethyl), L23– (4-methyl, 6-tert-butyl), L33– (4-tert-butyl, 6-methyl), L43– (4,6-di-tert-butyl)], afford mononuclear complexes [VO(L1)] (1) and [VO(L2)] (2) with a trigonal bipyramidal coordination sphere around the VV ion, or dinuclear octahedral complexes [V2O2(L3)2] (3) and [V2O2(L4)2] (4). In methanol an adduct with the formula [VO(L1)(MeOH)]·1/2MeOH (5) is obtained. According to multinuclear NMR spectroscopy all those complexes have a mononuclear structure in CDCl3 solutions. In wet polar solvents complex …

Self-assembled hydrogen-bonded coordination networks in two copper(II) carboxylates with 4-pyridylmethanol

2011

AbstractThe crystal and molecular structure of [Cu(nif)2(4-PM)2]·CH3OH (1) and [Cu(2-Clbz)2(4-PM)2(H2O)] (2), (where nif = niflumate anion, 2-Clbz = 2-chlorobenzoate anion and 4-PM is the 4-pyridylmethanol), have been determinated by X-ray crystallography. The Cu2+ cation in (1), is coordinated by two pairs of oxygen atoms from asymmetric bidentate niflumate anions and by a pair of pyridine nitrogen atoms from monodentate 4-pyridylmethanol ligands in trans position forming an extremely elongated bipyramid. The Cu2+ cation in (2), is coordinated by a pair of oxygen atoms from monodentate 2-chlorobenzoate anions, further by a pair of pyridine nitrogen atoms from monodentate 4-pyridylmethanol …

Syntheses, crystal structures and magnetic properties of di- and trinuclear croconato-bridged copper(ii) complexes

2002

The new croconato-bridged copper(II) compounds [Cu2(terpy)2(H2O)2(C5O5)](NO3)2·H2O (1) and [Cu3(phen)5(C5O5)2](CF3SO3)2 (2) (C5O52− = croconate, dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione; terpy = 2,2′:6′,2″-terpyridine; phen = 1,10-phenanthroline) have been prepared, and their crystal structures and variable temperature magnetic susceptibilities determined. The structure of complex 1 consists of croconato-bridged dinuclear [Cu2(terpy)2(H2O)2(C5O5)]2+ complex ions, nitrate counter ions and water of hydration. The croconato ligand exhibits an asymmetrical bis-bidentate coordination mode through four of its five oxygen atoms. The two crystallographically independent copper atoms hav…

Syntheses, crystal structures and magnetic properties of dinuclear copper(II) complexes with pyrazino[2,3-f  ][4,7]phenanthroline (pap) as bridging l…

2000

Three dinuclear copper(II) complexes with pyrazino[2,3-f][4,7]phenanthroline (pap) as bridging ligand have been prepared; [Cu2(pap)(C2O4)2]·5H2O 1, [Cu2(pap)(H2O)7(SO4)]SO4·3H2O 2 and [Cu2(pap)(H2O)3(NO3)3]NO33. These are the first metal complexes of pap which have been characterized by X-ray crystallography and magnetic susceptibility measurements. In 1 the dinuclear complex is intercepted by a mirror plane; the bridging pap and the terminal oxalate ligands are bidentate in the equatorial plane of copper. In addition copper has weak axial interactions to oxygen atoms of oxalate in two neighbouring molecules. In 2 the two crystallograpically independent copper atoms are both six-co-ordinate…

A trigonal-bipyramidal cyanide cluster with single-molecule-magnet behavior: synthesis, structure, and magnetic properties of ([MnII(tmphen)2]3[MnIII…

2003

An update to Hippocampome.org by integrating single-cell phenotypes with circuit function in vivo.

2021

Understanding brain operation demands linking basic behavioral traits to cell-type specific dynamics of different brain-wide subcircuits. This requires a system to classify the basic operational modes of neurons and circuits. Single-cell phenotyping of firing behavior during ongoing oscillations in vivo has provided a large body of evidence on entorhinal–hippocampal function, but data are dispersed and diverse. Here, we mined literature to search for information regarding the phase-timing dynamics of over 100 hippocampal/entorhinal neuron types defined in Hippocampome.org. We identified missing and unresolved pieces of knowledge (e.g., the preferred theta phase for a specific neuron type) a…