scholarly journals Controlling and measuring dynamic odorant stimuli in the laboratory

2019 ◽  
Author(s):  
Srinivas Gorur-Shandilya ◽  
Carlotta Martelli ◽  
Mahmut Demir ◽  
Thierry Emonet
Keyword(s):  
Delivery System ◽  
Real World ◽  
Ionization Detector ◽  
Olfactory Neurons ◽  
Molecular Identity ◽  
Temporal Properties ◽  
Photo Ionization ◽  
Odor Signals

Animals experience complex odorant stimuli that vary widely in composition, intensity and temporal properties. However, stimuli used to study olfaction in the laboratory are much simpler. This mismatch arises from the challenges in measuring and controlling them precisely and accurately. Even simple pulses can have diverse kinetics that depend on their molecular identity. Here, we introduce a model to describe how stimulus kinetics depend on the molecular identity of the odorant and the geometry of the delivery system. We describe methods to deliver dynamic odorant stimuli of several types, including broadly distributed stimuli that reproduce some of the statistics of naturalistic plumes, in a reproducible and precise manner. Finally, we introduce a method to calibrate a Photo-Ionization Detector to any odorant it can detect, using no additional components. Our approaches are affordable and flexible and can be used to advance our understanding of how olfactory neurons encode real-world odor signals.

scholarly journals Photon Detection as a Process of Information Gain

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 392 ◽  
Author(s):  
J Gerhard Müller
Keyword(s):  
Information Gain ◽  
Signal To Noise Ratio ◽  
Second Law Of Thermodynamics ◽  
Ionization Detector ◽  
Photon Detectors ◽  
Photon Detection ◽  
Operation Conditions ◽  
Energy Bounds ◽  
Photo Ionization ◽  
Information Erasure

Making use of the equivalence between information and entropy, we have shown in a recent paper that particles moving with a kinetic energy ε carry potential information i p o t ( ε , T ) = 1 ln ( 2 ) ε k B T relative to a heat reservoir of temperature T . In this paper we build on this result and consider in more detail the process of information gain in photon detection. Considering photons of energy E p h and a photo-ionization detector operated at a temperature T D , we evaluate the signal-to-noise ratio S N ( E p h , T D ) for different detector designs and detector operation conditions and show that the information gain realized upon detection, i r e a l ( E p h , T D ) , always remains smaller than the potential information i p o t ( E p h , T D ) carried with the photons themselves, i.e.,: i r e a l ( E p h , T D ) = 1 ln ( 2 ) ln ( S N ( E p h , T D ) ) ≤ i p o t ( E p h , T D ) = 1 ln ( 2 ) E p h k B T D . This result is shown to be generally valid for all kinds of technical photon detectors, which shows that i p o t ( E p h , T D ) can indeed be regarded as an intrinsic information content that is carried with the photons themselves. Overall, our results suggest that photon detectors perform as thermodynamic engines that incompletely convert potential information into realized information with an efficiency that is limited by the second law of thermodynamics and the Landauer energy bounds on information gain and information erasure.

scholarly journals REAL-WORLD IMPLICATIONS OF HYBRID CLOSE LOOP (HCL) INSULIN DELIVERY SYSTEM

2019 ◽  
Vol 25 (5) ◽  
pp. 477-484 ◽  
Author(s):  
Eileen R. Faulds ◽  
Janet Zappe ◽  
Kathleen M. Dungan
Keyword(s):  
Delivery System ◽  
Real World ◽  
Insulin Delivery ◽  
Insulin Delivery System

976-P: Evaluation of Hybrid Closed-Loop Insulin Delivery System for Patients with Type 1 Diabetes in Real-World Clinical Practice: A One-Year Qualitative Observational Study

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 976-P
Author(s):  
AHMED H. ELDIB ◽  
SHAHEEN TOMAH ◽  
SHILTON E. DHAVER ◽  
HANNAH GARDNER ◽  
MHD WAEL TASABEHJI ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Clinical Practice ◽  
Observational Study ◽  
Delivery System ◽  
Real World ◽  
Closed Loop ◽  
Insulin Delivery ◽  
Insulin Delivery System ◽  
One Year

scholarly journals A peptide delivery system sneaks CRISPR into cells

2018 ◽  
Vol 293 (44) ◽  
pp. 17306-17307 ◽  
Author(s):  
Xingang Guan ◽  
Zhimin Luo ◽  
Wujin Sun
Keyword(s):  
Genome Editing ◽  
Delivery System ◽  
Real World ◽  
Peptide Delivery ◽  
Amphipathic Peptide ◽  
Single Nucleotide ◽  
Ribonucleoprotein Complexes ◽  
Delivery Options ◽  
Diabetes And Obesity ◽  
In Cells

The CRISPR-Cas9 system has developed into a powerful platform for genome editing in various types of cells and tissues with single-nucleotide precision, but limited delivery options hamper its application in real-world settings. A new study by Shen et al. describes the use of an amphipathic peptide to deliver Cas9/sgRNA ribonucleoprotein complexes, leading to the disruption of GFP genes in cells and mice. Disruption of the Nrip1 gene in isolated pre-adipocytes led to a “browning” phenotype, pointing to new options in the fight against diabetes and obesity.

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