bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of GABA in the fetal, postnatal, and adult human retinas: An immunohistochemical study
Authors: Nag T. C. , Wadhwa S. 
Published: June 2009

AbstractThe expression of GABA in the human fetal (12–25 weeks of gestation), postnatal (five-month-old), and adult (35-year-old) retinas was investigated by immunohistochemistry. GABA expression was seen as early as 12 weeks in the undifferentiated cells of the inner neuroblast zone; a few optic nerve fiber layer axons were clearly labeled, suggesting that some of the stained cell bodies were prospective ganglion cells, others could be displaced amacrine cells. From 16–17 to 24–25 weeks, intense labeling was found in the amacrine, displaced amacrine, and some ganglion cells. During this time period, horizontal cells (identified by calbindin immunohistochemistry), undergoing migration (periphery) and differentiation (center), expressed GABA prominently. In the postnatal retina, some horizontal cells were moderately labeled, but very weakly in a few cells, in the adult. The Müller cells developed immunoreactivity first weakly at 12 weeks and then moderately from 16–17 weeks onward. The staining was also evident in the postnatal and adult retinas, showing labeled processes of these glial cells. Virtually no axons in the adult optic nerve and nerve fiber layer were stained; the staining was restricted to a few, large ganglion cells and displaced amacrine cells. Some amacrines were also labeled. The possibility that GABA might play a role in horizontal cell differentiation and maturation is highlighted. Other evidences suggest that GABA might play a role in metabolism during retinal development.
Immunocytochemical localization of dopamine D1 receptors in the retina of mammals
Authors: Nguyen-Legros J. , Simon A. , Caillé I. , Bloch B. 
Published: June 2009

AbstractDopamine is one of the major neurotransmitters in the retina. It is released from amacrine and interplexiform cells into both inner (IPL) and outer (OPL) plexiform layers. Several dopaminergic actions are known to occur through D1 receptors (D1R) but the precise location of these receptors has not been established. An antibody that recognizes the intracytoplasmic C-terminal of the rat D1R was used to detect D1R, immunohistochemically, in rats (Wistar and RCS), mouse, hamster, and macaque monkey retinas. The OPL was heavily stained in each species, consistent with the known actions of dopamine on horizontal cells. Three to five bands were observed in the IPL, depending on species. Three were in the a sublayer, the outermost of which was close to the amacrine cell layer, and may represent the massive dopamine input to the AII rod-amacrine cells. As observed in mice, where bipolar cells are D1-immunoreactive, the band located in sublayer 3 of the IPL may contain cone-bipolar cell terminals. A band of D1R-immunoreactivity in the b sublayer of the IPL contains ON-bipolar cell terminals and a second site of interaction between dopaminergic cells and the AII amacrine cells. This sublayer was absent from the RCS rat retina, suggesting a severe impairment of the rod-driven pathway following rod degeneration in these mutant rats. Cells in the ganglion cell layer exhibited relatively heavy staining, and may be ganglion cells or displaced amacrine cells. Some extrasynaptic localizations of D1R in the retina are suggested.
The appearance and distribution of microglia in the developing retina of the rat
Authors: Ashwell K. W. S. , Holländer H. , Streit W. , Stone J. 
Published: June 2009

AbstractWe have examined the development of microglia in the rat retina, using a peroxidase-conjugated lectin derived fromGriffonia simplicifolia. Retinas were studied from animals aged from E(embryonic day)12, just after the invagination of the optic cup and prior to the closure of the optic fissure, to adulthood. The lectin also proved a sensitive label for the endothelial cells of the developing retina. Our results provide some support for the view that microglia are derived from the monocyte-macrophage series of blood cells. At E12, most labeled cells were found at the vitreal surface, suggesting that they had come from the hyaloid circulation, while some had entered the retina and appeared to be migrating towards its ventricular surface. From E14 to early postnatal ages, most labeled cells had processes and resembled the amoeboid microglial cells described in silver carbonate staining studies (Ling, 1982). The number of labeled cells rose from about 700 to E14 to a peak of about 27,000 at P(postnatal day)7, and fell to about 19,600 by P12. As early as E16, a regularity was apparent in the distribution of microglial cells over the surface of the retina, the cells tending to avoid each other. Microglial cells are found throughout the thickness of the very young retina, but as the layers of the retina differentiate, they are increasingly restricted to the inner half of the retina. Our findings indicate that microglia enter the retina well before the period of neuronal death, making it unlikely that they invade the retina solely in response to cell death. Our results confirm however that, once in the retina, microglia become associated with, and appear to phagocytose, the pyknotic debris which appears during the period of neuronal death. They also become closely associated with the retinal vasculature. In the adult, the intensity of the labeling of microglia was much reduced. Those cells which were labeled appeared more differentiated, resembling the “resting microglia” described in earlier studies.
Dopamine synthesis and metabolism in rhesus monkey retina: Development, aging, and the effects of monocular visual deprivation
Authors: Iuvone P. Michael , Tigges Margarete , Fernandes Alcides , Tigges Johannes 
Published: June 2009

AbstractThe normal postnatal development, the influence of age, and the effects of visual deprivation on the dopamine system in the retina of rhesus monkeys were examined. The lowest level of retinal dopamine was found at birth. By 3–4 weeks of age, the dopamine concentration had more than doubled. This level remained relatively constant in the retinas of older infants and of adult monkeys up to 34 yr of age. The level of the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) and the activity of tyrosine hydroxylase did not significantly change as a function of age during the postnatal life span.Monocular occlusion of newborn or infant monkeys for 1–15 months with opaque contact lenses resulted in decreases in the retinal concentrations of dopamine and DOPAC relative to the concentrations in the same animals' unoccluded eyes. Occlusion also resulted in a lower level of tyrosine hydroxylase activity in the retina. Monocular eyelid suture from birth to 15 months of age resulted in less consistent alterations of retinal dopamine and DOPAC levels; tyrosine hydroxylase activity, however, was consistently reduced by lid suture. Thus, dopamine synthesis and metabolism, and the ontogenetic increase of the retinal dopamine level of rhesus monkey are reduced by light deprivation.
Identification and localization of 5-hydroxytryptamine receptor sites in macaque visual cortex
Authors: Parkinson David , Coscia Elizabeth C. , Daw Nigel W. 
Published: June 2009

AbstractThe two main receptor subtypes for 5-hydroxytryptamine (5HT) were measured and localized in visual cortical areas of macaque monkey. [3H]5HT was used to label all 5HT-1 receptor subtypes and [3H]ketanserin was used to label 5HT-2 receptors. Both receptor types could be demonstrated in membranes prepared from macaque primary visual cortex. The specificity of these ligands for 5HT-1 or 5HT-2 receptors was demonstrated by the pharmacological profile of inhibitors of the specific binding. 5HT-1A receptor sites were detected by displacement experiments and by direct labeling with [3H]8-hydroxy-2(di-n-propylamino) tetralin 8OH-DPAT. Receptor autoradiography showed that the distribution of these receptor subtypes varied from one part of visual cortex to another. 5HT-1 receptors, labeled with [3H]5HT were present in several bands through layer IV of primary visual cortex with the densest band seen in and above layer IVA: another band was in lower layer VI. The band in layer VI was predominantly 5HT-1A sites. There were two main bands of 5HT-2 receptor sites, the most prominent around the IV/V boundary, and the other extending from layer IVA upwards. Adjacent areas showed 5HT receptors in a broad band corresponding to layer IV. 5HT-1A sites were found in superficial layers of adjacent areas, except V2. These layering patterns did not correspond precisely with cytoarchitectonic layering, nor with the pattern of 5HT-containing presynaptic fibres in published reports. It is important, therefore, in considering the role of the 5HT-containing neurons in cortical function to take account not only of the anatomy of the presynaptic terminals, but also of the postsynaptic receptors upon which the released transmitter will act, and their location within the cortex.
Quantitative aspects of synaptic ribbon formation in the outer plexiform layer of the developing cat retina
Authors: Rapaport David H. 
Published: June 2009

AbstractThe development of synaptic ribbons in rod and cone photoreceptor terminals of the cat retina was studied using quantitative electron microscopy. At the region of the area centralis, synaptic ribbon profiles are initially recognized at PCD (postconception day) 59. Synaptic ribbon density increases rapidly, reaching a peak of 0.55 ribbons/μm3 at PCD 68 (postnatal day 3) and maintains approximately that value for an additional 8 d. Following PCD 76, ribbon density begins to decrease, to 0.37 ribbons/μm3 at PCD 82 and 0.25 ribbons/μm3 at PCD 102. Although ribbon density drops by approximately 50% during this 39-d period, the outer plexiform layer (OPL) volume at the area centralis increases by about 20%. Ribbon density continues to decrease gradually over a protracted period to reach a final adult value of 0.11–0.14 ribbons/μm3. During the period of high ribbon density, rod spherules with two, or even three ribbon profiles, were routinely observed. In contrast, in the adult, spherules with more than one ribbon profile are only rarely encountered. During development, the length of synaptic ribbon profiles increases from a mean of 0.22 μm at PCD 62 to the 0.47 μm mean length found in the adult.
Effects of dark maintenance on retinal biochemistry and function during taurine depletion in the adult rat
Authors: Cocker Susan E. , Lake Norma 
Published: June 2009

AbstractLight dependence of the effects of taurine depletion on retinal function and biochemistry was examined in albino rats housed either in cyclic lighting or in continuous darkness. Measurements of retinal taurine, DNA, and rhodopsin contents, and electroretinogram amplitudes were made at weekly intervals. Naka-Rushton parameters were estimated for thebwave amplitude-intensity function. No significant effects of lighting regime were observed on retinal taurine levels in untreated rats, or on the time course or extent of taurine depletion in animals treated with guanidinoethyl sulfonate, an antagonist of taurine transport. In both lighting schemes, treatment led to a linear reduction of retinal taurine content which plateaued after 5–6 weeks at 50% of control despite continued treatment. DNA values did not differ among groups, whereas rhodopsin levels doubled in both groups of dark-maintained rats. For treated rats housed in cyclic lighting, the onset of electroretinogram deficits paralleled the loss of retinal taurine in the absence of changes in rhodopsin levels or cell death.Vmaxwas significantly reduced after 4 weeks of treatment. In contrast, for rats housed in continuous darkness, there were no significant differences in electroretinogram parameters between control and taurine-depleted rats until after 10–14 weeks of treatment. This implies that light exposure accelerates the appearance of functional changes associated with retinal taurine deficiency. The basis of the light dependence and the interpretation of related studies is discussed.
Sur la relation d'Élaboration: des approches intuitives aux approches formelles
Authors: KLEIBER GEORGES , VASSILIADOU HÉLÈNE 
Published: June 2009

ABSTRACTLe but de notre article est d'entreprendre une réflexion générale sur une des relations de discours parmi les plus importantes, la relation dite d’Élaboration. Il s'agit d'un terme technique pour désigner une relation sémantique ou conceptuelle entre des phrases ou propositions. Toutefois, le sens mondain (non technique) qu'elle a a des répercussions sur l'emploi technique. On constate alors que c'est bien souvent ce sens mondain ou courant, à savoir qu'élaborer c'est préparer, réaliser quelque chose, qui intervient dans la reconnaissance ou dans l'analyse des exemples. Notre propos se limitera ainsi à examiner les définitions du type intuitif qu'on a pu donner de la relation d’Élaboration. Chemin faisant, nous aborderons également la définition donnée dans le cadre de la RST de W. C. Mann et S. Thompson pour en arriver à des caractérisations plus formelles. Nous ouvrirons, enfin, des pistes qui donneront lieu ultérieurement à une analyse plus poussée qui nous aidera à comparer la relation d'Élaborationavec d'autres relations discursives.
h-COBORDISMS AND MAPPING CYLINDER OBSTRUCTIONS
Authors: VAJIAC BOGDAN 
Published: June 2009

AbstractIn this paper we prove a realizability theorem for Quinn’s mapping cylinder obstructions for stratified spaces. We prove a continuously controlled version of the s-cobordism theorem which we further use to prove the relation between the torsion of an h-cobordism and the mapping cylinder obstructions. This states that the image of the torsion of an h-cobordism is the mapping cylinder obstruction of the lower stratum of one end of the h-cobordism in the top filtration. These results are further used to prove a theorem about the realizability of end obstructions.
Obama Indicates Strong Support for Science
Authors: Showstack Randy 
Published: June 2009

In remarks delivered at the U.S. National Academy of Sciences (NAS) annual meeting on 27 April, U.S. President Barack Obama indicated his administration's strong support for science and for pursuing a clean energy economy. He also announced a goal that the United States “will devote more than 3% of our [gross domestic product] to research and development.”“This represents the largest commitment to scientific research and innovation in American history,” Obama said, noting that the American Recovery and Reinvestment Act already is providing the nation with its largest single boost to investment in basic research.
Perspectives on AAC Intervention in School Settings
Authors: Warren Lori , Warren Faye 
Published: June 2009

Abstract
This article presents the perspective of a parent and an AAC device user on the importance of focused intervention on language development with individuals with complex communication needs who use AAC devices. The parent perspective outlines the speech-language pathology treatment story of her child. Using that lessons of that story, the parent challenges readers to advocate for the development of long-range language development planning and implementation of an AAC language development curriculum. In addition, the parent emphasizes the need for strong collaborative team building in order to support effective language intervention programs. The user perspective highlights the issue of core vocabulary, advanced vocabulary building, and traditional intervention on syntax, morphology, and discourse development. The reader is strongly urged to maintain focus on language development, rather than technology or device operation, as the essential element of life-long success for individuals using AAC devices.
AAC and the IEP
Authors: Hurd Robin 
Published: June 2009

Abstract
The team in IEP team is a necessity for students with complex communication needs. These students need the expertise of each team member to design a custom education that allows them to make progress towards state educational standards and build communication competence across curriculum areas. This article covers the strengths each team member brings to the IEP team. Parents bring a long-term perspective of the student; general education teachers bring their knowledge of what curriculum will be covered in the inclusion classroom; and special education teachers bring their training in working with and making adaptations for students with special needs. The article also focuses specifically on ways the speech-language pathologist contributes information on how language is used across the curriculum. A vital part of the role of the SLP on the IEP team is to pinpoint specific areas of language need and to provide teachers with ways to address those areas of need within their curriculum.
Monitoring the Effectiveness of Hospital Cleaning Practices by Use of an Adenosine Triphosphate Bioluminescence Assay
Authors: Boyce John M. , Havill Nancy L. , Dumigan Diane G. , Golebiewski Michael , Balogun Ola , Rizvani Ramo 
Published: June 2009

Objective.To evaluate the usefulness of an adenosine triphosphate (ATP) bioluminescence assay for assessing the efficacy of daily hospital cleaning practices.Design.A 2-phase prospective intervention study.Setting.A university-affiliated community teaching hospital.Methods.During phase I of our study, 5 high-touch surfaces in 20 patient rooms were sampled before and after daily cleaning. Moistened swabs were used to sample these surfaces and were then plated onto routine and selective media, and aerobic colony counts were determined after 48 hours of incubation. Specialized ATP swabs were used to sample the same high-touch surfaces in the 20 patient rooms and were then placed in luminometers, and the amount of ATP present was expressed as relative light units. During phase II of our study, after in-service housekeeper educational sessions were given, the housekeepers were told in advance when ATP readings would be taken before and after cleaning.Results.During phase I, the colony counts revealed that the 5 high-touch surfaces were often not cleaned adequately. After cleaning, 24 (24%) of the 100 surface samples were still contaminated with methicillin-resistantStaphylococcus aureus, and 16 (16%) of the 100 surface samples still yielded vancomycin-resistant enterococci. ATP readings (expressed as relative light units) revealed that only bathroom grab bars and toilet seats were significantly cleaner after daily cleaning than before. During phase II, a total of 1,013 ATP readings were obtained before and after daily cleaning in 105 rooms. The median relative light unit was significantly lower (ie, surfaces were cleaner) after cleaning than before cleaning for all 5 high-touch surfaces.Conclusions.Suboptimal cleaning practices were documented by determining aerobic colony counts and by use of an ATP bioluminescence assay. ATP readings provided quantitative evidence of improved cleanliness of high-touch surfaces after the implementation of an intervention program.
Volatile Sampling from Biological Sources by the Closed-Loop-Stripping Technique
Authors: Kunert Maritta , David Anja , Becher Jana , Boland Wilhelm 
Published: June 2009

INTRODUCTIONThe closed-loop-stripping technique with absorber traps (e.g., charcoal, porous polymers) can be used to collect volatiles from different biological sources, for example, plants and insects. One notable advantage of the method is the high signal-to-noise ratio that can be achieved by continuous sampling of the volatiles from a producing source within a closed environment. The equipment required for the technique is inexpensive and can be easily adapted to the demands of the analyzed subject. Moreover, the system can be operated in the field since only air and a battery are needed. The volatiles can be recovered from the trap by thermodesorption or by elution with solvents. Solvent elution has the advantage that unknown compounds can be subjected to chemical transformations facilitating structure elucidation. Only very low amounts of solvents (20-40 μL) are needed to elute the microcarbon traps (1.5-5 mg). Single traps efficiently absorb volatiles up to the lower microgram range. Higher concentrations may result in insufficient trapping. In this protocol, we describe the collection of volatiles released from lima bean leaves (Phaseolus lunatus) after damage by feeding larvae of Spodoptera littoralis. The enclosed volume of air containing the emitted volatiles is circulated through miniature charcoal traps for 4 h or more. For analysis, the traps are eluted with dichloromethane.
RNA Immunoprecipitation to Determine RNA-Protein Associations In Vivo
Authors: Selth Luke A. , Gilbert Chris , Svejstrup Jesper Q. 
Published: June 2009

INTRODUCTIONThe crucial roles of RNA-binding proteins in all aspects of RNA metabolism, particularly in the regulation of mRNAs and subsequent control of gene expression patterns, have become increasingly evident. RNA immunoprecipitation (RIP) is a powerful technique used to detect the association of individual proteins with specific RNA molecules in vivo. Live cells are treated with formaldehyde to generate protein-RNA cross-links between proximal molecules. Following immunoprecipitation of a protein of interest and cross-link reversal, associated RNAs can be recovered, characterized, and quantitated by reverse transcriptase polymerase chain reaction (RT-PCR). Protein association with specific RNA regions can be performed under a variety of conditions (e.g., different environmental and cell-cycle states) and/or in mutant strains. Furthermore, because formaldehyde inactivates cellular enzymes essentially immediately upon addition to cells, RIP provides snapshots of protein-RNA interactions at specific time points and hence is useful for kinetic analyses of events occurring on RNA in vivo. The basics of RIP are very similar to chromatin immunoprecipitation (ChIP), but with some caveats that are important to appreciate to take full advantage of the possibilities afforded by RIP.
The impact and implications of virtual character expressiveness on learning and agent–learner interactions
Authors: Veletsianos G. 
Published: June 2009

AbstractThe possible benefits of agent expressiveness have been highlighted in previous literature; yet, the issue of verbal expressiveness has been left unexplored. I hypothesize that agent verbal expressiveness may improve the interaction between pedagogical agents and learners, ultimately enhancing learning outcomes. Evidence from a quasi‐experimental investigation, indicates that learners who interacted with an expressive agent 1) scored higher on a post‐task exam; and 2) rated the agent's ability to interact higher, than learners who interacted with a nonexpressive agent. Qualitative results provided insight into this finding, while indicating the complexity of deploying pedagogical agents in educational settings.