20 research outputs found
The first call note of the Anhui tree frog (<i>Rhacophorus zhoukaiya</i>) is acoustically suited for enabling individual recognition
<p>The effective production of acoustic signals is critically important for intraspecific communication in vocal animals; however, it is also highly time-consuming, energetically demanding and likely to increase predation risks. Thus, we hypothesized that the biological significance of each component of complex acoustic signals would differ serving specific functions and that the first component of such signals would be most important for social signalling and exhibit unique acoustic characteristics because of the precedence effect. To test this hypothesis, we measured temporal and spectral acoustic parameters for each note in the advertisement calls of the Anhui tree frog (<i>Rhacophorus zhoukaiya</i>), a species in which males build mud burrows and call from within these nests. Multivariate analyses including hierarchical cluster analysis and multidimensional scaling were used, based on temporal and spectral acoustic parameters for each of 10 notes/call. These results show that the first call notes form one cluster while the other notes form a second cluster in multidimensional space when the parameters measured were normalized. Furthermore, the temporal and spectral sound attributes of the first call note provide sufficient information for discrimination between different individuals. Moreover, discriminant analysis showed that the fundamental frequency of the first note is sufficient to identify individuals when the data are not normalized. Taken together, these results indicate that the first call note is poised to play an important role in Anhui tree frog vocal communication insofar as the temporal and spectral features provide sufficient information for individual recognition.</p
Presentation_1_Grade-control outdoor turning flight of robo-pigeon with quantitative stimulus parameters.pdf
IntroductionThe robo-pigeon using homing pigeons as a motion carrier has great potential in search and rescue operations due to its superior weight-bearing capacity and sustained flight capabilities. However, before deploying such robo-pigeons, it is necessary to establish a safe, stable, and long-term effective neuro-electrical stimulation interface and quantify the motion responses to various stimuli.MethodsIn this study, we investigated the effects of stimulation variables such as stimulation frequency (SF), stimulation duration (SD), and inter-stimulus interval (ISI) on the turning flight control of robo-pigeons outdoors, and evaluated the efficiency and accuracy of turning flight behavior accordingly.ResultsThe results showed that the turning angle can be significantly controlled by appropriately increasing SF and SD. Increasing ISI can significantly control the turning radius of robotic pigeons. The success rate of turning flight control decreases significantly when the stimulation parameters exceed SF > 100 Hz or SD > 5 s. Thus, the robo-pigeon's turning angle from 15 to 55° and turning radius from 25 to 135 m could be controlled in a graded manner by selecting varying stimulus variables.DiscussionThese findings can be used to optimize the stimulation strategy of robo-pigeons to achieve precise control of their turning flight behavior outdoors. The results also suggest that robo-pigeons have potential for use in search and rescue operations where precise control of flight behavior is required.</p
Super-resolution Imaging of Individual Human Subchromosomal Regions <i>in Situ</i> Reveals Nanoscopic Building Blocks of Higher-Order Structure
It is widely recognized
that the higher-order spatial organization
of the genome, beyond the nucleosome, plays an important role in many
biological processes. However, to date, direct information on even
such fundamental structural details as the typical sizes and DNA content
of these higher-order structures <i>in situ</i> is poorly
characterized. Here, we examine the nanoscopic DNA organization within
human nuclei using super-resolution direct stochastic optical reconstruction
microscopy (dSTORM) imaging and 5-ethynyl-2′-deoxyuridine click
chemistry, studying single fully labeled chromosomes within an otherwise
unlabeled nuclei to improve the attainable resolution. We find that,
regardless of nuclear position, individual subchromosomal regions
consist of three different levels of DNA compaction: (i) dispersed
chromatin; (ii) nanodomains of sizes ranging tens of nanometers containing
a few kilobases (kb) of DNA; and (iii) clusters of nanodomains. Interestingly,
the sizes and DNA content of the nanodomains are approximately the
same at the nuclear periphery, nucleolar proximity, and nuclear interior,
suggesting that these nanodomains share a roughly common higher-order
architecture. Overall, these results suggest that DNA compaction within
the eukaryote nucleus occurs <i>via</i> the condensation
of DNA into few-kb nanodomains of approximately similar structure,
with further compaction occurring <i>via</i> the clustering
of nanodomains
SW promotes cell adhesion.
<p>Left panels: HepG2 (A), MDA-MB-231 (B) and T24 cells (C) were pretreated with indicated doses of SW for 15 or 30 min before seeding into the matrigel-coated wells, and 2 h later, adhered cells were counted after removing the floating cells by PBS. Representative images were displayed. Scale bar, 200 μm. Right panels: quantification of the data in the left panel, shown were composite results of three independently experiments with triplicate. Columns, mean; bars, SD.</p
SW increases size and fluorescence intensity of focal adhesion.
<p>(A) HepG2 and T24 cells were treated with SW (3.5 μg/μl) for indicated times and then immuno-stained with F-actin (FITC-phalloidin) and vinculin (red). Nuclei were counterstained by DAPI (blue). Representative images were displayed. Scale bar, 100 μm. (B) The area of adhesion sites per cell (where F-actin and vinculin merged). Shown were composite results of two independently experiments (n = 50 cells). Columns, mean; bars, SD. (C) The fluorescence intensity of vinculin in the adhesion patches per cell. Shown were composite results of two independently experiments (n = 50 cells). Columns, mean; bars, SD.</p
Sarsaparilla (<i>Smilax Glabra</i> Rhizome) Extract Inhibits Migration and Invasion of Cancer Cells by Suppressing TGF-β1 Pathway
<div><p>Sarsaparilla, also known as <i>Smilax Glabra</i> Rhizome (SGR), was shown to modulate immunity, protect against liver injury, lower blood glucose and suppress cancer. However, its effects on cancer cell adhesion, migration and invasion were unclear. In the present study, we found that the supernatant of water-soluble extract from SGR (SW) could promote adhesion, inhibit migration and invasion of HepG2, MDA-MB-231 and T24 cells <i>in vitro</i>, as well as suppress metastasis of MDA-MB-231 cells <i>in vivo</i>. Results of F-actin and vinculin dual staining showed the enhanced focal adhesion in SW-treated cells. Microarray analysis indicated a repression of TGF-β1 signaling by SW treatment, which was verified by real-time RT-PCR of TGF-β1-related genes and immunoblotting of TGFBR1 protein. SW was also shown to antagonize TGF-β1-promoted cell migration. Collectively, our study revealed a new antitumor function of Sarsaparilla in counteracting invasiveness of a subset of cancer cells by inhibiting TGF-β1 signaling.</p></div
SW inhibits cell scratch wound healing.
<p><i>In vitro</i> scratch assay was used to evaluate the effect of SW on the migration of HepG2 (A), MDA-MB-231 (B) and T24 cells (C). Representative images were displayed in left panel; quantification of the data in left panel was shown in right panel, shown were composite results of three independently experiments with triplicate parallel samples. The migration index represents migration speed in relative to control group. Columns, mean; bars, SD.</p
SW inhibits cell migration.
<p>HepG2 (A), T24 (B) and MDA-MB-231 (C) cells were seeded into the transwell insert in the presence of indicated doses of SW for 12 h. Cells reaching the bottom side of the transwell membrane were stained and representative images were displayed in the upper panel. Scale bar, 200 μm. The data in left panel were quantified and shown in the middle panel, and the cell viability was reflected by cell confluence rate in the right panel. Shown were composite results of two independently experiments. Columns, mean; bars, SD; NS, not statistically significant.</p
SW inhibits cell invasion <i>in vitro</i> and metastasis <i>in vivo</i>.
<p>(A) The transwell chambers were pre-coated with 60 μl matrigel dilution (1:4 in serum-free medium) before seeding cells. Cells were incubated with indicated doses of SW for 36 h before staining. Representative images were displayed in the upper panel. Scale bar, 200 μm. The data of migration and cell viability were quantified and shown respectively in lower panel, shown were composite results of two independently experiments with triplicate. Columns, mean; bars, SD; NS, not statistically significant. (B) Left panel: representative pictures of H&E stained lung tissues in PBS- and SW-treated group. Paraffin-embedded lungs were sectioned at 30-μm intervals and > 10 MDA-MB-231 cancer cells were identified as metastatic foci. Magnification, 4× (upper) and 20× (lower). Right panel: quantification of lung metastatic foci in PBS- and SW-treated mice group (n = 8 for each group). Columns, mean; bars, SD.</p
SW abrogates TGF-β1-induced boost in migration.
<p>HepG2 (A), MDA-MB-231 (B) and T24 (C) cells were seeded into the transwell inserts in the presence of TGF-β1 plus SW. 12 h later, Cells were stained and pictured. Representative images were displayed in the left panel. Scale bar, 100 μm. The data of migration were quantified and shown in the middle panel. The cell viability was reflected by cell confluence rate in the right panel. Shown was composite results of two independently experiments with triplicate. Columns, mean; bars, SD; NS, not statistically significant.</p