Compact Portion Research Articles

The risk factors affecting the persistence of corpus callosum splenium lesions.

The most compact portion of the corpus callosum (CC) is the corpus splenium (CS). To evaluate the connection between clinical and demographic features to determine whether neuroimaging findings will be permanent or temporary in CS patients. We enrolled 93 patients (age range = 18-86 years) with CS lesions. Demographic and clinical information were recorded. We examined the lesions depending on the location. Group 1 (n = 20) had lesions limited to the CS (egg-shaped or round); group 2 (n = 15) had "boomerang sign" lesions; and group 3 (n = 58) had splenium involvement in conditions affecting the whole brain (Boomerang sign+ plus). Group 1 had a lower mean age, shorter disease duration, and fewer persistent lesions than others (P < 0.01, P < 0.001, and P < 0.001, respectively). The mean disease onset age (in years) in group 1 was higher than that of the other groups (P < 0.045). Group 2 had lower potassium (K) (P < 0.003) and red cell distribution width levels (P < 0.029) than the other groups. Age <41.5 years (P < 0.001), age at illness initiation <48.5 years (P < 0.002), disease duration <5.5 months (P < 0.001), and eosinophil level <0.29 uL (P 0.014) all point to temporary lesions. Cases with limited CS lesions have younger onset ages, lower disease onset ages, and shorter disease durations. Age, age of disease onset, disease duration, and eosinophil level are risk variables that affect whether CS lesions are permanent or temporary.

3D structure of the H ii region Sh2-235 from tunable-filter optical observations

ABSTRACT We present observations of the H α, H β, [S ii] λλ6716, 6731 and [N ii] λ6583 emission lines in the galactic H ii region Sh2-235 with the Mapper of Narrow Galaxy Lines (MaNGaL), a tunable filter at the 1-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We show that the H ii region is obscured by neutral material with AV ≈ 2−4 mag. The area with the highest AV is situated to the south-west from the ionizing star and coincides with a maximum detected electron density of ≳300 cm−3. The combination of these results with archive AKARI far-infrared data allows us to estimate the contribution of the front and rear walls to the total column density of neutral material in S235 and explain the 3D structure of the region. The H ii region consist of a denser, more compact portion deeply embedded in the neutral medium and the less dense and obscured gas. The front and rear walls of the H ii region are inhomogeneous, with the material in the rear wall having a higher column density. We find a two-sided photodissociation region in the dense clump S235 East 1, illuminated by a UV field with G0 = 50−70 and 200 Habing units in the western and eastern parts, respectively.

Father Knows Best (TV Milestones Series) by Mary Desjardins (review)

Reviewed by: Father Knows Best (TV Milestones Series) by Mary Desjardins Jesse Schlotterbeck Mary Desjardins. Father Knows Best (TV Milestones Series). Detroit, MI: Wayne SU Press, 2015. This contribution to Wayne State University's TV Milestones Series (which covers programs from the 1950s through the 2000s) analyzes Father Knows Best, which ran on CBS and NBC from 1954 through 1960. Mary Desjardins accurately introduces her book as a remedy to the problem that this popular series "has received little in-depth or sustained critical attention from television scholars" (1). In a compact portion of the introduction worth quoting at length, Desjardins outlines numerous points of interest: "I will use textual and extra-textual evidence to analyze the stylistic, generic, and industrial practices exemplified by Father Knows Best in relation to the social and cultural contexts in which the program was first produced and in which it has been received by audiences and critics for sixty years" (1-2). The author delivers effectively on this promise of a broad-ranging critical analysis. Father Knows Best makes for an interesting series for analysis not because it is a self-evidently rich text, but because it is so apparently superficial. Desjardins, is well aware of the program's low default status in television history. She writes that Father Knows Best is often "remembered today via a cultural shorthand that views the 1950s as an era of massive conformity and authoritarianism, and this series, with its close-knit family looking to a wise 'everyman father' as emblematic of those repressive social mechanisms" (1). The standard reader, fittingly, is imagined as skeptical of the program's importance, but willing to be convinced otherwise. Desjardins makes a convincing case that Father Knows Best is, indeed, a series worthy of scholarly attention. The book contains four chapters which cover two related topics: chapters one ("Media Transitions, Media Legacies") and four ("Rerun and Rewritten") cover the show's place in media history, including the career trajectories of the major performers, its prior existence as a radio drama, and the after-life of Father Knows Best on cable television reruns and DVD sets. Chapters two ("Fathers and Sons") and three ("Women in the House") analyze the performance of gender. These two dominant points of interest give the book a needed focus. Should readers be more interested in one topic or the other, chapters one and four or two and three could effectively be read as stand-alone sections. Desjardins' historical research for this volume is admirably thorough. For example, she challenges claims about whether the radio version of Father Knows Best, which predated the television show, included a question mark in the title. While numerous scholarly sources indicate that it did, reviewing "contemporary newspaper and magazine sources" such as "profiles of Robert Young, radio schedule listings, [and] program reviews" on the radio show, Desjardins does not find a single instance of this different title (105). She draws a hesitant conclusion about the source of this misunderstanding (an interview in which the wrong sponsor was erroneously identified, leading scholars to believe Young was discussing the television show when he was, more likely, referring to the radio version) while setting the record straight that the radio program never appeared as Father Knows Best? in the 1950s (106). As Father Knows Best focuses on a family of five (Jim, Margaret, and their children Betty, Bud, and Kathy), episodes sustain their variety by rotating the emphasis on different characters. Desjardins strikes a nice balance by including careful analyses of episodes that star different cast members. For example, the following episodes analyzed in the text all emphasize a distinct cast [End Page 74] member: "Betty and the Jet Pilot," "Father is a Dope," "An Extraordinary Woman," featuring Margaret; "Kathy Becomes a Girl," and "The Gold Turnip," featuring Bud. As Desjardins delves into analysis of specific episodes she often focuses on "social themes" such as "change versus tradition, autonomy versus family togetherness, and self-fulfillment versus altruism" (2). Desjardins effectively makes the case that Father Knows Best is a more accomplished program in terms of technique and style than it is typically given credit for, especially compared to contemporary competitors such as The Stu Erwin...

Brain of the tree pangolin (Manis tricuspis). III. The unusual locus coeruleus complex.

Here, we used a range of immunohistochemical stains, focussing on tyrosine hydroxylase and dopamine-β-hydroxylase, to show that within the pons of tree pangolins clusters of noradrenergic neurons are present. No noradrenergic neurons were observed in the pontine periventricular gray matter (A6 and A4 groups missing), with all noradrenergic neurons being found within the pontine tegmentum (A7 and A5 groups). The tree pangolin is unique in lacking the locus coeruleus (A6) cell group observed in all vertebrates previously studied; however, noradrenergic axons and terminal networks were found throughout the cerebral cortex. We propose this is achieved through a unique structural reorganization of this system. First, the number of noradrenergic neurons in the compact portion of the subcoeruleus (A7sc) of the tree pangolin is increased, providing a total number of noradrenergic neurons in the pontine tegmentum (A7diffuse, A7sc, A5) that is equivalent to the entire locus coeruleus complex in related species of similar brain mass. Second, the most medially located noradrenergic neurons of the A7sc have dendrites that extend into the ventrolateral periventricular gray matter, in the location where the A6 neurons should have been located, forming a "pseudo A6" region. Third, the topological relationships of this "pseudo A6" region to other neurochemical systems that interact with the A6 neurons, such as the orexinergic, cholinergic, and serotonergic systems, appear to be maintained. Thus, a unique structural plasticity of this region appears to maintain the standard functions of the locus coeruleus complex in this unusual mammalian species.

Thalamic reticular nucleus in Caiman crocodilus: forebrain connections

Forebrain connections of the thalamic reticular nucleus associated with the lateral forebrain bundle were analyzed in Caiman crocodilus. Both the compact portion, the dorsal peduncular nucleus, and the diffuse part, the perireticular region, associated with the lateral forebrain bundle, were studied. A small tracer injection into the dorsal peduncular nucleus demonstrated reciprocal connections with a restricted portion of the dorsal thalamus. Tracer placements into this nucleus retrogradely labeled cells in a caudal portion of the ventrolateral area of the telencephalon. These results are compared with similar studies in other amniotes.

Thalamic reticular nucleus in Caiman crocodilus: Relationship with the dorsal thalamus

The thalamic reticular nucleus was investigated in one group of crocodilians, Caiman crocodilus. This neuronal aggregate is composed of two parts: a compact portion and a diffuse region made up of scattered cells within the forebrain bundles. In Caiman, both the lateral and medial forebrain bundles project to the telencephalon and the thalamic reticular nucleus is associated with each fiber tract. In the lateral forebrain bundle, the compact area is termed the nucleus of the dorsal peduncle (dorsal peduncular nucleus) while the diffuse part is called the perireticular area. In the medial forebrain bundle, the interstitial nucleus comprises one part of the compact area while another region without a specific neuronal label is also present. Similar to the perireticular cells of the lateral forebrain bundle, scattered cells are also present in the medial forebrain bundle. Morphological features of the thalamic reticular nucleus are revealed with stains for the following: fibers; cells; succinic acid dehydrogenase; and acetylcholinesterase. Regardless of which dorsal thalamic nucleus was injected, a localized region of the thalamic reticular nucleus contained retrogradely labeled cells and anterogradely labeled axons and terminals. This grouping was termed clusters and was felt to represent the densest interconnection between the dorsal thalamus and the reticular nucleus. Using clusters as an index of interconnections, the reticular nucleus was divided into sectors, each of which was associated with a specific dorsal thalamic nucleus. An organization similar to that found in Caiman is present in other sauropsids as well as in mammals. These data suggest that a thalamic reticular nucleus is present in all amniotes and has morphological properties similar to those described in this analysis. Lastly, a hypothesis is presented to explain how the external shape of the reticular nucleus in Caiman might be transformed into the homologous area in a representative bird and mammal.

Nuclear organization of some immunohistochemically identifiable neural systems in two species of the Euarchontoglires: A Lagomorph, Lepus capensis, and a Scandentia, Tupaia belangeri

The present study describes the organization of the nuclei of the cholinergic, catecholaminergic, serotonergic and orexinergic systems in the brains of two members of Euarchontoglires, Lepus capensis and Tupaia belangeri. The aim of the present study was to investigate the nuclear complement of these neural systems in comparison to previous studies on Euarchontoglires and generally with other mammalian species. Brains were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei revealed in the current study were similar between the species investigated and to mammals generally, but certain differences in the nuclear complement highlight potential phylogenetic interrelationships within the Euarchontoglires and across mammals. In the northern tree shrew the nucleus of the trapezoid body contained neurons immunoreactive to the choline acetyltransferase antibody with some of these neurons extending into the lamellae within the superior olivary nuclear complex (SON). The cholinergic nature of the neurons of this nucleus, and the extension of cholinergic neurons into the SON, has not been noted in any mammal studied to date. In addition, cholinergic neurons forming the medullary tegmental field were also present in the northern tree shrew. Regarding the catecholaminergic system, the cape hare presented with the rodent specific rostral dorsal midline medullary nucleus (C3), and the northern tree shrew lacked both the ventral and dorsal divisions of the anterior hypothalamic group (A15v and A15d). Both species were lacking the primate/megachiropteran specific compact portion of the locus coeruleus complex (A6c). The nuclei of the serotonergic and orexinergic systems of both species were similar to those seen across most Eutherian mammals. Our results lend support to the monophyly of the Glires, and more broadly suggest that the megachiropterans are more closely related to the primates than are any other members of Euarchontoglires studied to date.

Mechanical Behavior of Sintered Nano-sized Ag Particles

In this study, time-dependent mechanical properties of the sintered nano-sized Ag particles were investigated. Stress relaxation was observed from the ambient temperature (0.24Tm), lower than 0.4Tm (493K), at which, as a rule of thumb, creep occurs in metal materials. The stress exponent and the activation energy of the compact portion of Ag are similar to those of dislocation creep. The results in this study, however, do not adapt to the high temperature creep theory from the viewpoint of diffusion. In addition, the elastic modulus of the compact portion of Ag is one fourth of the elastic modulus of bulk Ag. The crystallinity in the vicinity of grain boundaries is considered to be low in quality compared to bulk Ag. Thus, it can also be considered that the grain boundary of such poor quality is closely related to the low modulus of elasticity and the occurrence of low temperature creep.

Quinolinic acid lesions of the pedunculopontine nucleus impair sleep architecture, but not locomotion, exploration, emotionality or working memory in the rat

Anatomical and functional studies have shown that the NADPH-diaphorase-positive cholinergic neurons of the pedunculopontine nucleus (PPN) send projections to several areas in the brain. The purpose of this work was to investigate whether bilateral lesions with quinolinic acid, a neurotoxin with greater selectivity for NADPH-diaphorase-positive neurons, aimed at the compact portion of the PPN would affect the performance of adaptive behaviors, such as sleep, locomotion, and spontaneous alternation. Lesioned animals were divided in a low lesion group (LL, <50% neuron loss) and a high lesion group (HL, ≥50% neuron loss). The LL animals did not show any significant changes in sleep patterns, as compared to controls. In contrast, the HL group showed a significant increase in the number of REM sleep periods, and a reduction of REM sleep average duration, but did not differ in the total time spent in REM sleep. HL animals also showed an increase in the number of SWS periods, though wakefulness parameters did not show significant alterations. The duration and number of both REM and SWS sleep episodes were significantly correlated with the number of NADPH-diaphorase-positive neurons in the PPN. The short-term habituation pattern of locomotion, the vertical exploratory activity, as well as the thigmotaxis (an index of emotionality), displayed by LL and HL rats in a novel environment were similar to those of control animals. Likewise, there were no significant differences in spontaneous alternation among the groups. Our results indicate that quinolinic acid lesions of NADPH-diaphorase-positive cholinergic neurons localized in the posterior region of the PPN disrupt normal sleep structure, while motor activity and spontaneous alternation remain unaffected.

Multiple forebrain systems converge on motor neurons innervating the thyroarytenoid muscle

The present study investigated the central connections of motor neurons innervating the thyroarytenoid laryngeal muscle that is active in swallowing, respiration and vocalization. In both intact and sympathectomized rats, the pseudorabies virus (PRV) was inoculated into the muscle. After initial infection of laryngomotor neurons in the ipsilateral loose division of the nucleus ambiguus (NA) by 3 days post-inoculation, PRV spread to the ipsilateral compact portion of the NA, the central and intermediate divisions of the nucleus tractus solitarii, the Botzinger complex, and the parvicellular reticular formation by 4 days. Infection was subsequently expanded to include the ipsilateral granular and dysgranular parietal insular cortex, the ipsilateral medial division of the central nucleus of the amygdala, the lateral, paraventricular, ventrolateral and medial preoptic nuclei of the hypothalamus (generally bilaterally), the lateral periaqueductal gray, the A7 and oral and caudal pontine nuclei. At the latest time points sampled post-inoculation (5 days), infected neurons were identified in the ipsilateral agranular insular cortex, the caudal parietal insular cortex, the anterior cingulate cortex, and the contralateral motor cortex. In the amygdala, infection had spread to the lateral central nucleus and the parvicellular portion of the basolateral nucleus. Hypothalamic infection was largely characterized by an increase in the number of infected cells in earlier infected regions though the posterior, dorsomedial, tuberomammillary and mammillary nuclei contained infected cells. Comparison with previous connectional data suggests PRV followed three interconnected systems originating in the forebrain; a bilateral system including the ventral anterior cingulate cortex, periaqueductal gray and ventral respiratory group; an ipsilateral system involving the parietal insular cortex, central nucleus of the amygdala and parvicellular reticular formation, and a minor contralateral system originating in motor cortex. Hypothalamic innervation involved several functionally specific nuclei. Overall, the data imply complex CNS control over the multi-functional thyroarytenoid muscle.

Histological examination of the chaetognathan morphological structure in the region of a supposed trunk-tail septum

A histological examination was conducted based on sections done in series in transverse and longitudinal directions of Aidanosagitta macilenta (Sagittidae, Chaetognatha) in a region which includes the anterior parts of the testes and the posterior part of the ovaries. We found that, in mature individuals (the 4th stage of maturation), the anterior parts of the testes are located in front of the posterior part of the ovaries. The anterior parts of the testes have a ventral position adjoining the ventral muscular bands. The ovaries are located more dorsally than the testes at the level of lateral fi elds. A transverse trunk-tail septum between testes and ovaries was not revealed. These data support an idea that a structure which was earlier treated as a tail-trunk septum is actually the anterior edges of the testes. Both longitudinal coelomic cavities continue into the tail region without any transverse septa. The paired tail cavities as can be seen from their composition and functions represent the testes consisting of a peripheral compact portion with undifferentiated germ cells and a space where the maturation of cells occurs. The tail is distinguished anatomically as a post-anal portion of the body but it is not a true segment as it is not separated from a trunk part of the body by the trunk-tail septum. The body of Chaetognatha consists of two true parts (segments). A mesenterial septum divides the body longitudinally-symmetrically from a trunk-head septum down only to the caudal end of the gut. In the tail region there is a medial septum formed by the medial walls of testes. Gonads in both females and males do not have any duct connecting them with a gut cavity. The ovaries and the testes are covered by a coelomic lining and a duct between the ovaries and the testes is absent.

Stereologic analysis of cell number and size during postnatal development in the rat substantia nigra

Parkinson's disease is characterized by age-related atrophy and loss of dopaminergic neurons within the compact portion of the substantia nigra (SNpc) projecting to neostriatum. Despite numerous studies using rodent models to examine mechanisms underlying this disorder, the fundamental question of whether development- or age-related changes occur in the rodent SNpc remains unanswered. The present study used a three-level, optical fractionator approach to estimate the number and size of SNpc neurons immunoreactive for tyrosine hydroxylase (TH) in eight young (2-month) and eight older (7-month) Sprague–Dawley rats. Following standard protocols for animal care and tissue harvesting, every eighth 60-μm section from a gapless coronal series was treated immunohistochemically for TH along with a thionin counterstain. Neither the ventral tegmental area nor the lateral part of the SN was included in the analysis. The total bilateral number of SNpc TH+ neurons (∼8000) was equivalent between groups, whereas mean TH+ neuronal volume decreased significantly in the older group (∼18%). In contrast, volume of the SNpc increased with age by 17%, as did volume of the entire brain (24%). TH+ cells in the SNpc were also significantly larger on the left versus right side of the brain. These data are consistent with the hypothesis that age-related volumetric expansion of the SNpc is accounted for by an increase in the ratio between neuropil and average neuron somal size during intermediate postnatal development.

The airway‐related parasympathetic motoneurones in the ventrolateral medulla of newborn rats were dissociated anatomically and in functional control

The respiratory-related synaptic control of the airway-related preganglionic parasympathetic motoneurones (APPMs) has not been investigated, and whether differently targeted APPMs receive differential respiratory-related synaptic modulation is unknown. In this study, putative APPMs in the ventrolateral medulla of newborn rats were retrogradely traced with fluorescent tracer and were examined using the patch-clamp method in brainstem slices with respiratory rhythm. The results indicate that tracer application directly to the recurrent laryngeal nerve only labelled the putative APPMs within the compact portion of nucleus ambiguus (cNA), while tracer injection into the trachea wall labelled the putative APPMs both in cNA and in the area ventral/ventrolateral to cNA (vNA). The putative APPMs within cNA received mainly inhibitory inputs, which in some (9 of 20) neurones showed an inspiratory-related attenuation and in others (7 of 20) showed an inspiratory-related augmentation. At least some putative APPMs within cNA, of which the inhibitory synaptic inputs showed inspiratory-related changes, might be related to the control of laryngeal muscles. The putative APPMs in vNA receive both excitatory and inhibitory inputs, and central inspiratory activity excited some (11 of 19) neurones via augmentation of their excitatory inputs and inhibited others (8 of 19) via augmentation of their inhibitory inputs. At least some putative APPMs in vNA might be trachea-related motoneurones. These results provide evidence that APPMs controlling different segments of the airway might be dissociated in the ventrolateral medulla both anatomically and in functional control.

Dynamic steady-state crack propagation in a transversely isotropic viscoelastic body

The problem considered herein is the dynamic, subsonic, steady-state propagation of a semi-infinite, generalized plane strain crack in an infinite, transversely isotropic, linear viscoelastic body. The corresponding boundary value problem is considered initially for a general anisotropic, linear viscoelastic body and reduced via transform methods to a matrix Riemann–Hilbert problem. The general problem does not readily yield explicit closed form solutions, so attention is addressed to the special case of a transversely isotropic viscoelastic body whose principal axis of material symmetry is parallel to the crack edge. For this special case, the out-of-plane shear (Mode III), in-plane shear (Mode II) and in-plane opening (Mode I) modes uncouple. Explicit expressions are then constructed for all three Stress Intensity Factors (SIF). The analysis is valid for quite general forms for the relevant viscoelastic relaxation functions subject only to the thermodynamic restriction that work done in closed cycles be non-negative. As a special case, an analytical solution of the Mode I problem for a general isotropic linear viscoelastic material is obtained without the usual assumption of a constant Poisson’s ratio or exponential decay of the bulk and shear relaxation functions. The Mode I SIF is then calculated for a generalized standard linear solid with unequal mean relaxation times in bulk and shear leading to a non-constant Poisson’s ratio. Numerical simulations are performed for both point loading on the crack faces and for a uniform traction applied to a compact portion of the crack faces. In both cases, it is observed that the SIF can vanish for crack speeds well below the glassy Rayleigh wave speed. This phenomenon is not seen for Mode I cracks in elastic material or for Mode III cracks in viscoelastic material.

Molecular mechanisms of initiation of fibrinolysis by fibrin

Fibrinogen is rather inert in the circulation, however, after conversion into fibrin it participates in various physiological processes including fibrinolysis. Initiation of fibrinolysis occurs through a number of orchestrated interactions between fibrin, plasminogen and its activator tPA which result in generation of plasmin. Numerous studies localized a set of specific low affinity tPA- and plasminogen-binding sites in each D region of fibrin(ogen). The tPA-binding site includes residues gamma312-324 and the plasminogen-binding site includes residues Aalpha148-160; they bind tPA and plasminogen with a K(d) of about 1 micro M. Another set of high affinity tPA- and plasminogen-binding sites (K(d)s = 16-33 nM) was identified in the compact portion of each fibrin(ogen) alphaC-domain within residues Aalpha392-610. All these sites are cryptic in fibrinogen and become exposed in fibrin. Recent studies with recombinant and proteolytic fibrin(ogen) fragments clarified the molecular mechanisms by which these sites become exposed. Namely, upon fibrin assembly, the interaction between the D and E regions causes conformational changes in the former that expose the low affinity binding sites. The exposure of the high affinity binding sites in the alphaC-domains is connected most probably with their switch from an intramolecular interaction in fibrinogen to an intermolecular one in fibrin. These mechanisms serve to minimize degradation of circulating fibrinogen and confine fibrinolysis to places of fibrin deposition.

Capillary coatings. Choices for capillary electrophoresis of DNA.

AbstractOne of the most distinguishing features of capillary electrophoresis (CE) is the electroosmotic flow (EOF). This electrokinetic phenomenon originates from the presence on the capillary surface of weakly acid hydroxyl groups attached to the silicon atoms. Different authors have reported an overall pKa value of 5.3 (1) or 6.3 (2) for surface silanols. In practice, when the capillary surface is bathed in any buffer solution with a pK higher than 2, immobilized negative charges are formed on the wall. The presence of this layer of immobilized charges causes adsorption of positive counter ions from the buffer solution. As a result, an electric double layer is generated at the silica-buffer solution interface consisting of an immobile layer of cationic species, tightly held to the ionized silanols, and a diffuse layer of hydrated ions loosely bound to the surface. Figure 1 shows a schematic representation of the electrical double layer structure at the surface-solution interface. Two planes can be envisioned in the double layer: the so-called (inner) Helmholtz plane (IHP) located in the center of the compact layer, and the outer Helmholtz plane (OHP) that delimits the compact portion of the double layer. In the diffuse part of the double layer, the ion concentration diminishes until it reaches that of the bulk solution. When an electric field is tangentially applied to the surface, the diffuse ions of the double layer migrate towards the cathode with their surrounding water molecules generating a flow of liquid in the capillary. This overall solution transport phenomenon is called EOF and has dramatic influences on the time the analytes reside inside the capillary (3). As a consequence of the forces exerted by the electric field on the ions of the diffuse layer, a plane of shear is formed between the diffuse and the mobile layer regions and the potential generated at this shear plane is termed zeta potential (ζ). In a typical buffer for DNA electrophoresis, the double layer is about 3 nm thick. A velocity gradient develops owing to the differences in the magnitude of frictional and electric forces within the double layer. The flow velocity that is zero across the wall increases in the region of the double layer reaching a maximum value at a very small distance from the charged surface. The bulk of the solution migrates with this maximum velocity. This means that the flow stream that originates at the wall of the capillary has an almost flat velocity distribution across the capillary diameter, deviating only within a few nanometers from the capillary surface. Unlike the parabolic hydrodynamic flow, EOF is almost plug-like and does not necessarily cause a deterioration of the separation. Schematic representation of the electric double layer that occurs on the interface of a silica capillary filled with buffer. KeywordsCapillary ElectrophoresisElectroosmotic FlowThionyl ChlorideNitrogen PressureNeutral MarkerThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Lectin binding in the ovary of the chick embryo and newborn.

The content, distribution and changes of the glycoconjugates sugar residues in the ovaries of chick embryos, from the 8th day of incubation to hatching and in 1-day old chick, were investigated. For this purpose, a battery of seven HRP-conjugated lectins was used (DBA, SBA, PNA, ConA, WGA, LTA and UEA I). Our data showed that SBA was a marker of the most immature oogonia in the ovarian cortex and medulla. The reactivity with ConA appeared to characterize the cells immediately prior to as well as during the meiotic division, as demonstrated by the presence of alpha-D-mannose at the "Balbiani bodies" in the oogonia of the ovarian cortex. The detection of Con A and SBA reactivity corresponded to maturative stages of the early oogonia in different cortical zones of the chick ovary. Our data also revealed that PNA seemed to be a marker of the degenerating oogonia located in the ovarian medulla. Moreover, PNA binding was a characteristic finding in the endothelial cells of the vessels located in the compact portion of the medulla in the left ovary, from the 8th to the 21st day of incubation and after hatching; PNA reactivity was only seen from the 16th day onwards in the endothelial cells of the cortex. During the whole considered period of incubation and after hatching, reactivity with UEAI, LTA and DBA was never detected.

Thyrotropin-like Immunoreactivity in the Developing Chicken Retina

The content, distribution and changes of the glycoconjugates sugar residues in the ovaries of chick embryos, from the 8th day of incubation to hatching and in 1-day old chick, were investigated. For this purpose, a battery of seven HRP-conjugated lectins was used (DBA, SBA, PNA, ConA, WGA, LTA and UEA I). Our data showed that SBA was a marker of the most immature oogonia in the ovarian cortex and medulla. The reactivity with ConA appeared to characterize the cells immediately prior to as well as during the meiotic division, as demonstrated by the presence of alpha-D-mannose at the "Balbiani bodies" in the oogonia of the ovarian cortex. The detection of Con A and SBA reactivity corresponded to maturative stages of the early oogonia in different cortical zones of the chick ovary. Our data also revealed that PNA seemed to be a marker of the degenerating oogonia located in the ovarian medulla. Moreover, PNA binding was a characteristic finding in the endothelial cells of the vessels located in the compact portion of the medulla in the left ovary, from the 8th to the 21st day of incubation and after hatching; PNA reactivity was only seen from the 16th day onwards in the endothelial cells of the cortex. During the whole considered period of incubation and after hatching, reactivity with UEAI, LTA and DBA was never detected.

Semiclassical limit for the Binegar–Zierau quantization of the minimal nilpotent orbits of SOo(2p,2)

Let n be an odd integer greater than 3 and X be the (n+1)-dimensional anti-de Sitter space–time. Binegar and Zierau have constructed in Commun. Math. Phys. 138, 245–258 (1991) a unitary representation H=H+⊕H− of the conformal group SOo(n+1,2) of X. They have shown that this particular representation is, in a certain algebraic sense, a quantization of the union, On+1min=On+1min+∪On+1min−, of the two minimal nilpotent orbits in so(n+1,2) [Commun. Math. Phys. 138, 245–258 (1991)]. (This work is part of the author’s Ph.D. thesis.) In spite of this, it is known how to obtain ℋ from On+1min using a known quantization procedure. One reason for this interest in ℋ is that, in the case n=3, H+ is the representation carried by the one-particle sector of the massless scalar field on the anti-de Sitter space–time X. In this paper, we strengthen this link between the coadjoint orbits On+1min± and H±, by studying the semiclassical limit of the latter. In this way, we clarify their appearance in the massless theory and corroborate the existing evidence that H± is the “correct” quantization of On+1min±. As a preliminary, we show that the projection onto so(n,2)* of On+1min± is the union of the two coadjoint orbits Ono± and Onmin± (Proposition IV.1); one of those is the phase space of the classical massless particle on X. We then show (Theorem VI.1 and Corollary VI.3) that the semiclassical limit of the spectral counting function of the generator of the SO(2) subgroup of SOo(n,2) in the representation H± is dominated by a Weyl term, expressed naturally in terms of the symplectic volume of a compact portion of the classical phase space Ono±. Furthermore, we show (Theorem VI.4) that the highest weight vectors of the representation coincide in the semiclassical limit with the BKW functions constructed starting from Ono±. We show in addition that, even though the orbit method applied to On+1min± does not yield H±, it nevertheless establishes a natural relation between them. Namely, the simple SO(n+1)×S0(2)-modules appearing in H+ are those we obtain if we apply the orbit method to integral SO(n+1)×S0(2)-orbits contained in the projection on (so(n+1)⊕so(2))* of On+1min± (Sec. VII). As a by-product of our analysis, we study the restriction to SOo(n,2) of ℋ (Proposition VIII.1) and we show that the unitary structure on ℋ is exactly a Klein–Gordon scalar product on X (Proposition IX.2).

The peripheral myelin protein 22 and epithelial membrane protein family

The peripheral myelin protein 22 (PMP22) and the epithelial membrane proteins (EMP-1, -2, and -3) comprise a subfamily of small hydrophobic membrane proteins. The putative four-transmembrane domain structure as well as the genomic structure are highly conserved among family members. PMP22 and EMPs are expressed in many tissues, and functions in cell growth, differentiation, and apoptosis have been reported. EMP-1 is highly up-regulated during squamous differentiation and in certain tumors, and a role in tumorigenesis has been proposed. PMP22 is most highly expressed in peripheral nerves, where it is localized in the compact portion of myelin. It plays a crucial role in normal physiological and pathological processes in the peripheral nervous system. Progress in molecular genetics has revealed that genetic alterations in the PMP22 gene, including duplications, deletions, and point mutations, are responsible for several forms of hereditary peripheral neuropathies, including Charcot-Marie-Tooth disease type 1A (CMT1A), Dejerine-Sottas syndrome (DDS), and hereditary neuropathy with liability to pressure palsies (HNPP). The natural mouse mutants Trembler and Trembler-J contain a missense mutation in different hydrophobic domains of PMP22, resulting in demyelination and Schwann cell proliferation. Transgenic mice carrying many copies of the PMP22 gene and PMP22-null mice display a variety of defects in the initial steps of myelination and/or maintenance of myelination, whereas no pathological alterations are detected in other tissues normally expressing PMP22. Further characterization of the interactions of PMP22 and EMPs with other proteins as well as their regulation will provide additional insight into their normal physiological function and their roles in disease and possibly will result in the development of therapeutic tools.