1,721,010 research outputs found
Model of <i>hug</i> as Modulator of Feeding Behavior
No full text<p>The <i>hug</i> neurons, which express the neuropeptide gene <i>hug</i> and which interconnect gustatory sensillae via the SOG to the pharyngeal muscles, the protocerebrum, and the neuroendocrine organ, modulate chemosensory dependent feeding behavior. Increased <i>hug</i> signaling correlates with decreased feeding, whereas decreased <i>hug</i> signaling correlates with increased feeding (see Discussion section for details).</p
Subpopulations of <i>hug</i> Neurons Innervate Distinct Targets
No full text<div><p>(A and B) Enhancer trap line Okt30 (shown in green) labels SOG neurons projecting to ring gland. Okt30 expression pattern colocalizes with <i>hug</i> expression (shown in red in [B]). There are four double positive cells in (B). <i>dilp3</i> staining (blue) serves as morphological landmark.</p>
<p>(C) Direct detection and false colorization of GFP expressed in Okt30 positive cells (green) and YFP expressed under <i>hug</i> promoter (red) reveals only the axons to ring gland as double positive.</p>
<p>(D) TH promoter construct labels dopaminergic CNS neurons (shown in green). Four TH-positive SOG neurons also express <i>hug</i> (shown in red). <i>capa</i> staining (blue) serves as morphological landmark.</p>
<p>(E) Combination of projection patterns of TH positive cells (green) with <i>hug</i> cells (red) reveals the axons innervating the pharyngeal muscles as the only double positive ones.</p>
<p>(F) Schematic summary of (A–E) showing distinct subpopulations of <i>hug</i> neurons projecting to the ring gland only (green), pharynx only (blue), and the remaining targets (red).</p>
<p>(G–I) Projection pattern of <i>hug</i> is unaffected in <i>klu</i> mutants. Direct detection and false coloring of <i>hug</i> promoter-YFP (shown in green) in the <i>klu</i> background reveals the pharyngeal muscles (PM), the ring gland (RG), and the VNC as being targeted in feeding mutants. Trachea are false-colored (red) in composite figure (I).</p></div
Neuroanatomical Analysis of <i>hug</i> Interneurons in Adults
No full text<div><p>(A) Relative positions of adult CNS composed of brain hemispheres (BH) and VNC, as well as esophagus passing the brain through the foramen (F), proventriculus (P), crop (C), and gut (G) are depicted schematically. The neuroendocrine CC/CA complex is located on top of the proventriculus (arrow).</p>
<p>(B) Localization of <i>hug</i> neurons and projections in adult CNS relative to nuclear marker. Note projections to the protocerebrum (top of the head), VNC, and CC/CA (arrow).</p>
<p>(C) <i>hug</i> neuronal projections relative to general neuropil marker (22c10, shown in red).</p>
<p>(D–F) Close-ups of different optical sections (composed of confocal 1- to 2.5-μm sections) show spherical <i>hug</i> arborizations in median SOG region (green in [D]), arborizations in lateral SOG region (green in [E], arrow) and in protocerebrum (green in [F]).</p>
<p>(G) Transmission light image of CC/CA complex (arrow) on top of proventriculus (P).</p>
<p>(H) Immunofluorescent close-up of the area boxed in (G). Nuclei of elav positive CC cells (blue) and of CA (green, see arrow), <i>hug</i> axon terminals (green, see arrowhead).</p>
<p>(I) TH positive SOG neurons (green) co-express <i>hug</i> (red); <i>capa</i> staining serves as morphological landmark.</p>
<p>(J and K) Different optical sections (composed of confocal 1- to 2.5-mm sections) show <i>hug</i> (green) projections above the mushroom bodies and adjacent to the median neurosecretory cells marked by OK107 (mushroom body and median neurosecretory cell marker, red); <i>elav</i> marker, blue. (K) Close-up of the region in (J), showing the medial neurosecretory cells. Scale bars equal 20 μ.</p>
<p>(L and M) Different optical sections (composed of confocal 1-to 2.5-mm sections) showing OK107 (green) and <i>hug</i> (red) in larva. (M) Close-up of the median neurosecretory cell region. Scale bars equal 20 μ.</p></div
Overexpression of <i>hug</i> and Blocking <i>hug</i> Synaptic Transmission Causes Feeding Phenotypes
No full text<div><p>(A) Overexpression of <i>hug</i> neuropeptide gene under ubiquitous promoter leads to reduced feeding and growth (compare size of UAS-<i>hug</i> larvae and controls of same age) as well as to larval lethality. Note the individual phenocopying the <i>klu</i> feeding phenotype (arrow).</p>
<p>(B) Partial rescue of <i>klu</i> feeding defect by blocking <i>hug</i> neuronal activity. <i>n</i>= 5; error bars represent standard deviation; see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030305#s4" target="_blank">Materials and Methods</a> for details.</p>
<p>(C) Schematic of adult internal morphology with proventriculus, crop, and gut. Crop is depicted in full and empty state.</p>
<p>(D) Feeding behavior of adult flies monitored by the presence of red food in the midgut and crop (marked by arrows). Starting from the same feeding status (empty crop at time point 0 min), experimental flies expressing TeTxLC under hugS3 construct initiate uptake of red food immediately (notice large amount of red food in crop and gut after 5 min) when confronted with red yeast paste after feeding on standard fly food overnight (overnight normal). In contrast, control flies (hugS3 flies and TeTxLC flies crossed with wild-type) initiate food uptake after 15–35 min (notice traces of red food in midgut) when confronted with red yeast paste. The same feeding status is detected in experimental as well as in control flies after long feeding period on red yeast (overnight normal, 180 min). Overnight starvation equalizes feeding behavior when flies are confronted with red yeast paste for 15 min (notice same amount of red food in all cases at overnight starvation 15 min). Two representative samples of each time point and genotype are displayed. Two independent experiments were carried out, and for each experimental set ten individuals were taken out randomly and dissected. From 20 total flies, 16 ± 2 showed the phenotype displayed here o/n, overnight.</p></div
Neuroanatomical Analysis of <i>hug</i> Expression and Neuronal Projection Patterns in Larvae
No full text<div><p>(A) A schematic drawing of the <i>Drosophila</i> larval CNS, showing the relative positions of the two brain hemispheres (BH) and the VNC, with the neuroendocrine ring gland (RG) located dorsoanterior to the CNS. The esophagus goes through the brain, and we have termed the hole through which the esophagus passes as the foramen (F). Positions of the SOG, the larval antennal lobes (AL), the mushroom bodies (MB), and the median neurosecretory cells (mNSC) are depicted.</p>
<p>(B) <i>hug</i> expression (shown in green) is restricted to the SOG. <i>adipokinetic hormone</i> (<i>akh</i>, shown in red) serves as a ring gland marker; the CNS is false-colored in blue.</p>
<p>(C) Detection of marker gene expression under <i>hug</i> promoter-Gal4 (hugS3) construct (shown in green) labels <i>hug</i> cell bodies and neuronal projections relative to the neuropil (22C10, shown in red) and nuclei of post-mitotic neurons (elav, shown in blue).</p>
<p>(D–F) The endogenous <i>hug</i> expression pattern (shown in red in [D]) is reproduced by the hugS3 expression pattern (shown in [E]). Note double-positive cell bodies in (F). <i>akh</i> serves as ring gland marker; CNS, ring gland, and foramen are outlined.</p>
<p>(G and H) Immunofluorescent (G) as well as direct (H) detection of GFP expressed under the <i>hug</i> promoter-Ga14 construct reveals putative <i>hug</i> dendrites dorsoanterior of the <i>hug</i> cell bodies, where spherical structures are innervated. The <i>hug</i> cell bodies in the depicted blow-up of SOG region are out of focus in (H).</p>
<p>(I) <i>hug</i> axons innervating the protocerebrum cross the midline, showing ipsilateral and contralateral innervation of mushroom body region.</p>
<p>(J–L) Expression of eGFP under hugS3 shows <i>hug</i> axons leaving the SOG laterally (see arrows). These can be followed to the cephalopharyngeal complex of the larvae (K and L) onto the pharyngeal muscles (axons shown in green overlayed with transmission light picture; note the mouth hook apparatus in black). Dorsal (K) and lateral views (L) are shown, anterior points to upper left corner.</p>
<p>All fluorescence images in this and subsequent figures are Z-stack projections, and all scales bars are 50 μm, unless otherwise noted.</p></div
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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