JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Electrical signaling along the phloem and its physiological responses in the maize leaf.
Front Plant Sci
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
To elucidate the role of electrical signaling in the phloem of maize the tips of attached leaves were stimulated by chilling and wounding. Two different signals were detected in the phloem at the middle of the leaf using the aphid stylet technique: (1) action potentials (AP) arose in the phloem after chilling; and (2) variation potentials (VPs) were evoked after wounding the leaf tip. Combined electric potential and gas exchange measurements showed that while the wound-induced VP moved rapidly towards the middle of the leaf to induce a reduction in both the net-CO2 uptake rate and the stomatal conductance, there was no response in the gas exchange to the cold-induced AP. To determine if electrical signaling had any impact on assimilate transport the middle of the leaf was exposed to (14)CO2. Autoradiography of labeled assimilates provided evidence that phloem and intercellular transport of assimilates from mesophyll to bundle sheath cells was strongly reduced while the cold-induced AP moved through. In contrast, wound-induced VP did not inhibit assimilate translocation but did reduce the amount of the labeled assimilate in phloem and bundle sheath cells. Biochemical analysis revealed that callose content increased significantly in chilled leaves while starch increased in chilled but decreased in wounded leaves. The results led to the conclusion that different stimulation types incite characteristic phloem-transmitted electrical signals, each with a specific influence on gas exchange and assimilate transport.
Related JoVE Video
An unusual form of reaction wood in Koromiko [Hebe salicifolia G. Forst. (Pennell)], a southern hemisphere angiosperm.
Planta
PUBLISHED: 04-27-2011
Show Abstract
Hide Abstract
Koromiko [Hebe salicifolia G. Forst. (Pennell)] is a woody angiosperm native to New Zealand and Chile. Hebe spp. belong to the otherwise herbaceous family Plantaginaceae in the order Lamiales. Reaction wood exerting expansional forces was found on the lower side of leaning H. salicifolia stems. Such reaction wood is atypical for angiosperms, which commonly form contracting reaction wood on the upper side of leaning stems. Reaction wood typical for angiosperms is formed by species in other families in the order Lamiales. This suggests that the form of reaction wood is specific to the family level. Functionally the reaction wood of H. salicifolia is similar to that found in gymnosperms, which both act by pushing. However, their chemical, anatomical and physical characteristics are different. Typical features of reaction wood present in gymnosperms such as high density, thick-walled rounded cells and the presence of (1 ? 4)-?-galactan in the secondary cell wall layer are absent in H. salicifolia reaction wood. Reaction wood of H. salicifolia varies from normal wood in having a higher microfibril angle, which is likely to determine the direction of generated maturation stresses.
Related JoVE Video
Prognostic significance of erythropoietin in pancreatic adenocarcinoma.
PLoS ONE
PUBLISHED: 04-27-2011
Show Abstract
Hide Abstract
Erythropoietin (Epo) administration has been reported to have tumor-promoting effects in anemic cancer patients. We investigated the prognostic impact of endogenous Epo in patients with pancreatic ductal adenocarcinoma (PDAC).
Related JoVE Video
Covering a broad dynamic range: information processing at the erythropoietin receptor.
Science
PUBLISHED: 05-20-2010
Show Abstract
Hide Abstract
Cell surface receptors convert extracellular cues into receptor activation, thereby triggering intracellular signaling networks and controlling cellular decisions. A major unresolved issue is the identification of receptor properties that critically determine processing of ligand-encoded information. We show by mathematical modeling of quantitative data and experimental validation that rapid ligand depletion and replenishment of the cell surface receptor are characteristic features of the erythropoietin (Epo) receptor (EpoR). The amount of Epo-EpoR complexes and EpoR activation integrated over time corresponds linearly to ligand input; this process is carried out over a broad range of ligand concentrations. This relation depends solely on EpoR turnover independent of ligand binding, which suggests an essential role of large intracellular receptor pools. These receptor properties enable the system to cope with basal and acute demand in the hematopoietic system.
Related JoVE Video
Feasibility of fecal microRNAs as novel biomarkers for pancreatic cancer.
PLoS ONE
Show Abstract
Hide Abstract
Pancreatic cancer (PCA) is an aggressive tumor that associates with high mortality rates. Majority of PCA patients are diagnosed usually at late tumor stages when the therapeutic options are limited. MicroRNAs (miRNA) are involved in tumor development and are commonly dysregulated in PCA. As a proof-of-principle study, we aimed to evaluate the potential of fecal miRNAs as biomarkers for pancreatic cancer.
Related JoVE Video
In silico labeling reveals the time-dependent label half-life and transit-time in dynamical systems.
BMC Syst Biol
Show Abstract
Hide Abstract
Mathematical models of dynamical systems facilitate the computation of characteristic properties that are not accessible experimentally. In cell biology, two main properties of interest are (1) the time-period a protein is accessible to other molecules in a certain state - its half-life - and (2) the time it spends when passing through a subsystem - its transit-time. We discuss two approaches to quantify the half-life, present the novel method of in silico labeling, and introduce the label half-life and label transit-time. The developed method has been motivated by laboratory tracer experiments. To investigate the kinetic properties and behavior of a substance of interest, we computationally label this species in order to track it throughout its life cycle. The corresponding mathematical model is extended by an additional set of reactions for the labeled species, avoiding any double-counting within closed circuits, correcting for the influences of upstream fluxes, and taking into account combinatorial multiplicity for complexes or reactions with several reactants or products. A profile likelihood approach is used to estimate confidence intervals on the label half-life and transit-time.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.