Classical Analytical Description of Negative Hydrogen Ions

Studies of negative hydrogen ions (hereafter, NHI), such as, H– and D–, are important from both practical and fundamental points of view. One of the reasons for practical importance has to do with heating tokamak plasmas by external beams of NHI. Another practical use is the injection of NHI in high power proton accelerator facilities – for enhancing their performance. In addition, NHI are also important for studies of opacities of the atmospheres of the Sun and of the A-type stars. We present a classical analytical description of NHI in the situation where the underlying hydrogen (or deuterium) atom constitutes a rapid subsystem while the outer electron represents a slow subsystem. We focus at the case where the inner electron is in a circular state, so that the subsystem “nucleus plus inner electron” does not have the average electric dipole moment – in distinction to previous studies where the presence of the average dipole moment was the crucial requirement. By using the separation of rapid and slow subsystems, we show analytically that there is a classical bound state in such system and studied its parameters. In particular, we calculate analytically the primary frequency of the radiation of such system. This could be used for its experimental detection. The states that we found for the above systems could be considered as classical counterparts of the double-excited states of NHI previously studied in the literature in frames of quantum mechanics. The existence of classical counterparts of the double-excited states of NHI is a counterintuitive result.

Pathological Fracture of Femoral Neck Associated to Femoral Head Osteonecrosis: Case Report

Introduction: The osteonecrosis of femoral head is a progressive and devastating condition for the prognosis of the coxofemoral joint, with an increase in its prevalence and an etiology of multifactorial nature, and with compromise specially in young or middle age (20 to 40 years of age) patients [1-3]. The fractures associated to femoral head osteonecrosis are very rare, being the subchondral portion the site with a higher compromise, and the junction between the necrotic bone and the bone under remodeling process another site of potential fracture [4-7]. The management of this condition can vary from a conservative management to a surgical management with total hip arthroplasty, depending on patient’s clinic and the extension of his necrotic lesion. Discussion: This patient presents a sub-capital fracture of his femoral neck, associated to osteonecrosis of the femoral head. This patient was managed with decompression of the osteonecrosis nucleus plus bone graft and osteosynthesis with cannulate screws, in order to decrease bone hypertension and avoid femoral collapse. Conclusion: Although femoral neck fractures, as a complication from femoral head osteonecrosis are rare, in our patient such association can be found due to the worsening of his painful clinical features and the absence of a previous traumatic event, which allows discarding femoral osteonecrosis as a fracture complication.

Yokomichi : Une collection du Paléolithique supérieur du Japon abordée selon un œil technologique français

Depuis les années 1970, l’étude des collections lithiques préhistoriques a vécu en France une profonde modernisation. André Leroi-Gourhan, d’abord intéressé par les techniques traditionnelles, prit pour objectif d’appréhender les activités techniques menées dans un site par un groupe préhistorique, dans une perspective ainsi dénommée « palethnologique ». Il a aussi promu la notion de chaîne opératoire introduite auparavant par Marcel Mauss. Mais ce sont les expérimentateurs de la taille des roches dures, F. Bordes et J. Tixier, qui vont permettre d’enrichir cette notion de ses applications concrètes. J. Tixier, surtout, stabilise la terminologie de la pierre taillée, et systématise la « lecture technologique » qui permet de reconstituer mentalement le déroulement du façonnage d’un outil ou du débitage d’un nucléus. Il introduit aussi une distinction fondamentale entre « méthode » (la démarche -l’agencement des enlèvements successifs- suivie pour atteindre le but de la chaîne opératoire : un type ou une classe de produits) et « technique(s) » (qui réfère aux modalités pratiques d’exécution des enlèvements). Sur cette base, dès 1980, Tixier et collègues introduisent les notions d’économie des matières premières, du débitage et de l’outillage, corollaires de la notion de règles de gestion. La notion d’intention -entre débitage, supports et (certains) outils- apparaît également, fondant le postulat selon lequel les modalités de la taille sont cohérentes avec la morphologie des produits recherchés. C’est ce postulat que suit la démarche française en technologie lithique : percevoir -comprendre- les intentions de la production lithique, avant de classer et de mesurer. Cette démarche est ensuite appliquée à la collection lithique de Yokomichi (Dept de Yamagata, NE de Honshu), à débitage laminaire mais antérieure à la production de lamelles, ainsi datable d’environ 18 000 BP. On perçoit d’abord qu’y coexistent deux débitages laminaires : l’un de lames légères et rectilignes à petit talon, tirées de nucléus étroits, et l’autre de fortes lames à talons épais débitées de nucléus plus larges. Parmi les outils retouchés, ce sont les quelques « couteaux de Sugikubo » (des pointes à dos élancées de profil rectiligne) dont les supports correspondent à l’intention première du débitage étroit, quelques autres outils étant réalisés sur des supports de second choix. Un tel couteau de Sugikubo, dans une collection similaire, présente une fracture à longue languette inverse qui suggère fortement qu’il s’agit en fait, au moins pour partie, de pointes de projectile. Le débitage large, lui, avait pour intention première l’obtention de grandes lames pointues, très difficiles à réaliser, tandis que ses nombreux produits de second choix et d’aménagement restent bruts (utilisables comme couteaux) ou se retrouvent dans les « burins de Kamiyama » (en fait, de très probables couteaux ravivés comme les couteaux de Kostienki). Une expérimentation montre que les deux débitages sont réalisés par percussion directe à la pierre tendre, mais selon des modalités distinctes : par percussion tangentielle pour les lames légères à petit talon, par percussion en retrait pour les lames plus fortes à gros talon.

Implementation of RLC Layer in the Terminal Side of TD-LTE

This paper focuses on the overall implementation process of RLC Layer in the Terminal Side of TD-LTE, which is based on the Nucleus Plus operating system. It contains primitive processing procedure and the realization of RLC layer entry function, which contains multi-instance module and state machine processing module. This helps to learn RLC layer and grasp the overall protocol stack.

Differential drives from rostral ventrolateral medullary neurons to three identified sympathetic outflows

Simultaneous recordings were made in chloralose-anesthetized cats from muscle vasoconstrictor (MVC), visceral vasoconstrictor (VVC), and renal (RSN) sympathetic fibers. Their barosensitivity was demonstrated, after which all baroreceptor nerves were cut. Multiple microinjections of sodium glutamate (5 nl, 0.1 M) were made in a grid pattern covering the rostral ventrolateral medulla (RVLM) pressor area on seven sides of four animals. Injections increased blood pressure by up to 87 +/- 22 mmHg and MVC, VVC, and RSN activities by up to 169 +/- 55, 62 +/- 23, and 67 +/- 36%, respectively. The relative responses between nerves (taken in pairs) showed significant inhomogeneity across injections into 5/7, 6/7, and 1/7 RVLMs for MVC vs. VVC, MVC vs. RSN, and VVC vs. RSN, respectively. Calculation showed that overall, less than half the response spikes due to RVLM glutamate injections could be accounted for by a hypothetical population of neurons that excited MVC, VVC, and RSN outflows in fixed proportion. Sites that exclusively drove MVC, VVC, or RSN outflows were found in 7/7, 3/7, and 5/7 RVLMs, respectively. Sites that selectively drove either nerve of a given pair were ubiquitous. The RVLM territories from which the three outflows could be activated overlapped but showed clear differences. Their shapes and sizes differed between animals and even between sides. They covered the subretrofacial (SRF) nucleus plus a variable rostromedial extension. The data support the view that the RVLM neurons driving these three sympathetic outflows are largely, perhaps entirely, separate populations.

Neurology Update: “Recent Developments in the Understanding of the Nervous System”

Neural Mechanisms of Sensori-Motor Integration New methods of investigation have enlarged understanding of the mechanisms underlying activity in the nervous system. Excitable cells transmit impulses by means of their special membrane properties and excitation is transmitted from cell to cell across specialized sites called synapses. In the nuclei of the central nervous system there are many small neurons that have no axon or only very short axons and dendrites. These are referred to as interneurons and the chemical transmitters they release may be excitatory or inhibitory to the cells with which they synapse. Cells with axons ending in a nucleus and cells with dendrites in the nucleus plus the interneurons which may intervene between the input of the message by an axon reaching the nucleus and its transmission onwards, form networks of cells that act as micro-circuits, affecting the nature of the neural signal. Control of transmission by these networks is the means by which sensory and motor impulses may be modified, enhanced, suppressed or facilitated. The integration of many sensory inputs, and the feedback during movement modulate and shape the motor response. An understanding of the mechanisms of inhibition and facilitation becomes increasingly important for therapists who use techniques based on “sensori-motor integration“.

A ONE-WAVELENGTH, TWO-AREA METHOD IN MICROSPECTROPHOTOMETRY FOR PURE AMPLITUDE OBJECTS

A one-wavelength method for nuclei in smears is tested and discussed. It eliminates need for visual estimates of areas and measurements to check for possible slight variations in absorption spectrum which would vitiate applicability of the two-wavelength method. Extinction ( E1) is obtained from an intranuclear plug measurement; area of absorbing material is computed as a function of ratios between "one minus transmittances", one intranuclear, the second including in addition "free" or "non-absorbing" areas around it. If T1 represents intranuclear transmittance, T2 total transmittance (nucleus plus free area), A1 the area of the nucleus and A2 the area from which T2 was obtained (absorbing plus nonabsorbing media), total extinction times area is computed as [See equation in the PDF file]

FINE STRUCTURE AND MORPHOGENIC MOVEMENTS IN THE GASTRULA OF THE TREEFROG, HYLA REGILLA

The blastoporal groove of the early gastrula of the treefrog, Hyla regilla, was examined with the electron microscope. The innermost extension of the groove is lined with invaginating flask- and wedge-shaped cells of entoderm and mesoderm. The distal surfaces of these cells bear microvilli which are underlain with an electron-opaque layer composed of fine granular material and fibrils. The dense layer and masses of vesicles proximal to it fill the necks of the cells. In flask cells bordering the forming archenteron the vesicles are replaced by large vacuoles surrounded by layers of membranes. The cells lining the groove are tightly joined at their distal ends in the region of the dense layer. Proximally, the cell bodies are separated by wide intercellular spaces. The cell body, which is migrating toward the interior of the gastrula, contains the nucleus plus other organalles and inclusions common to amphibian gastrular cells. A dense layer of granular material, vesicles, and membranes lies beneath the surface of the cell body and extends into pseudopodium-like processes and surface undulations which cross the intercellular spaces. A special mesodermal cell observed in the dorsal lining of the groove is smaller and denser than the surrounding presumptive chordamesodermal cells. A long finger of cytoplasm, filled with a dense layer, vesicles and membranes, extends from its distal surface along the edge of the groove, ending in a tight interlocking with another mesodermal cell. Some correlations between fine structure and the mechanics of gastrulation are discussed, and a theory of invagination is proposed, based on contraction and expansion of the dense layer and the tight junctions at distal cell surfaces.

Comments on the paper by A. D. Walsh

I agree very much with Dr Walsh that a satisfactory knowledge of effective atomic electronegativities is very important and that we should concentrate on obtaining such knowledge. The effective electronegativity of an atom varies, of course, in different circumstances. This appears to be the explanation of the difference in strength (length and force constant) of the C—H bonds in methane and acetylene. The effective attraction of the carbon atom for the electrons in a C—H bond in methane is a resultant of the attraction of the carbon nucleus plus Is core and the repulsion of the electrons associated with the other three C—H bonds. In acetylene the effective attraction of the carbon atom for the electrons in the C—H bond is the resultant of the attraction of the nucleus plus core and the repulsion of the electrons in the triple bond. Because these last six electrons are drawn away into the triple bond on the far side of the carbon atom from the C—H bond it seems that their repulsion on the electrons in the C—H bond is less than that of the six electrons in the three other C—H bonds in methane which are relatively nearer.