Multiple Operators
Multiple Operators - Related Videos
08:18
A Protocol for the Use of Remotely-Supervised Transcranial Direct Current Stimulation (tDCS) in Multiple Sclerosis (MS)
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Cited by 51 •
2015
The goal of this pilot study is to describe a protocol for the remotely-supervised delivery of transcranial direct current stimulation (tDCS) so that the procedure maintains standards of in-clinic practice, including safety, reproducibility, and tolerability. The feasibility of this protocol was tested in participants with multiple sclerosis (MS).
07:57
Operating the Glovebox
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2023
Robert M Rioux, Ajay Sathe, Zhifeng Chen, Pennsylvania State University, University Park, PA A glovebox is an isolated enclosure that is designed to maintain an inert atmosphere. The manipulation of chemicals or apparatus is done via the use of gloves, which allow operation while still maintaining an inert atmosphere. A positive pressure is utilized to compensate for any passive leaks. Objects can be transferred in and out of the box using an antechamber that acts as an airlock between the box...
08:39
Operant Sensation Seeking in the Mouse
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Cited by 27 •
2010
In this protocol we describe a method of operant learning using sensory stimuli as a reinforcer in the mouse. It requires no prior training or food restriction, and it allows the study of motivated behavior without the use of a pharmacological or natural reinforcer such as food.
12:54
Operation of a Benchtop Bioreactor
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Cited by 9 •
2013
Fermentors are used to increase culture yield and productivity of bioengineered cells. After screening multiple microbial or animal cell culture candidates in shake flasks, the next logical step is to increase the selected culture’s biomass with the fermentor. This video demonstrates the setup and operation of a typical benchtop bioreactor system.
11:35
The Multiple Sclerosis Performance Test (MSPT): An iPad-Based Disability Assessment Tool
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Cited by 106 •
2014
Precise measurement of neurological and neuropsychological impairment and disability in multiple sclerosis is challenging. We report methodologic details on a new test, the Multiple Sclerosis Performance Test (MSPT). This new approach to the objective of quantification of MS related disability provides a computer-based platform for precise, valid measurement of MS severity.
FAQs
Transcription depends on which operator sites are occupied and how that occupancy affects the promoter. A repressor bound at a relevant site can block RNA polymerase recruitment, whereas an activator can facilitate recruitment. With multiple sites, these opposing effects let the cell combine regulatory inputs rather than responding to only one controlling interaction, producing more condition-sensitive gene expression.
Ligand binding changes regulation by altering the behavior of a repressor or activator associated with an operator. The ligand therefore provides an environmental or metabolic signal that can change whether transcription is favored. When several operators respond to different regulatory inputs, ligand-dependent changes at those sites help connect external conditions with coordinated expression of genes.
Cooperative interactions allow regulatory proteins at separate operator sites to influence one another, so their combined effect can differ from the effect of either protein alone. DNA looping can bring distant regulatory sequences or bound proteins into functional proximity. Together, these mechanisms make the physical arrangement of operators important for the strength and integration of transcriptional regulation.
The placement of operators near a promoter can determine how bound repressors or activators affect RNA polymerase recruitment. Because an operon can coordinate transcription of multiple genes, this arrangement links their expression to shared regulatory signals. Such organization helps cells adjust groups of genes together when metabolic conditions or environmental inputs change.
Analysis should consider the number and position of operator sites, the regulatory proteins that bind them, and whether those proteins repress or activate transcription. Researchers can also examine ligand effects, cooperative interactions, and DNA looping. Relating these features to RNA polymerase recruitment helps reveal how regulatory DNA architecture produces integrated gene-expression responses.
In bacterial transcriptional systems, separate operator sites can receive different regulatory signals while influencing the same promoter or gene group. Repressors and activators then adjust RNA polymerase recruitment according to those inputs. This arrangement supports coordinated metabolic regulation, allowing expression patterns to change as environmental conditions alter the signals reaching the regulatory proteins.
Multiple operators provide a framework for combining regulatory inputs within a designed transcriptional system. By arranging sites for repressors or activators, a circuit can connect ligand-responsive behavior, cooperative interactions, or DNA looping to gene expression. Studying these natural arrangements therefore helps researchers understand how regulatory DNA architecture can be adapted to create coordinated expression responses.