Guanosine nucleotides regulate B2 kinin receptor affinity of agonists but not of antagonists: Discussion of a model proposing receptor precoupling to G protein

The effect of nucleotides on binding of the B2 kinin (BK) receptor agonist {[}H-3]BK and the antagonist {[}H-3]NPC17731 to particulate fractions of human foreskin fibroblasts was studied. At 0 degrees C, particulate fractions exhibited a single class of binding sites with a Kd of 2.3 nM for {[}H-3]BK and a K-d Of 3.8 nM for the antagonist {[}H-3]NPC17731. Incubation with radioligands at 37 degrees C for 5 min gave a reduction of agonist, as well as antagonist, binding that was between 0-40% depending on the preparation, even in the absence of guanosine nucleotides. As shown by Scatchard analysis, this reduction in specific binding was due to a shift in the affinity of at least a fraction of the receptors. The presence at 37 degrees C of the guanine nucleotides GTP, GDP and their poorly hydrolyzable analogs left {[}H-3]-NPC17731 binding unaffected, but reduced the receptor affinity for {[}H-3]BK to a K-d Of about 15 nM. The maximal number of receptors, however, was unchanged. This affinity change was strongly dependent on the presence of bivalent cations, in particular Mg2+. It was reversed by incubation at 0 degrees C, The rank order of the guanosine nucleotides for {[}H-3]BK binding reduction was GTP{[}gamma S] = Gpp{[}NH]p > GTP = GDP > GDP{[}beta S]. GMP, ATP, ADP and AMP showed no influence on agonist binding. A model for the interaction of the B2 kinin receptor with G proteins is discussed

Secure Cloud Controlled UAS Operations

Integrating a small unmanned aircraft system (sUAS) with cloud capabilities for military or enterprise use has not usually been feasible due to cybersecurity concerns. With recent advancements in blockchain networks the possibility of large cloud connected UAS networks has emerged. Our team investigates how to integrate data collected from a sUAS with a cloud-based service for data collection, storage, and processing implemented to ensure data privacy and data integrity. Our proposed network architecture implements a blockchain network to maintain decentralized security for the network. The research’s objectives include running security tests against a blockchain network & host/client networks and then comparing their performance and abilities to support the cloud based UAS. Specifically, we are using an open-source project called AirSim to support a virtual UAS that is connected to the UAS flight controller, the Pixhawk, to test a hardware-in the loop solution. This test is a preliminary proof of concept, and after it proves successful we are moving to a test involving a physical UAS. Data is transmitted from the UAS to a client server in Amazon Web Services (AWS) where it is placed into a blockchain and sent to the host server for processing. Overall, we believe a cloud supported communication network with a blockchain to secure data is an efficient and wise method of UAS control with information processing

Childhood Maltreatment and Early Alcohol Use Among High-Risk Adolescents

Objective: Child maltreatment (CM) is prevalent among U.S. youth and has been associated with subsequent maladaptive behaviors, including substance use. The current study examines the associations between early child maltreatment and (1) preteen alcohol-use initiation and (2) heavy episodic drinking among students in a large study of adolescents. Method: The Youth Violence Survey is a cross-sectional survey of public school students enrolled in Grades 7,9, 11, and 12 in a school district in a high-risk community. The analysis sample was limited to students who provided complete data on all relevant variables (N = 3,559). Fifty-two percent of the analysis sample was female. Early child maltreatment was defined as witnessing domestic violence and experiencing physical and/or sexual abuse before the age of 10 years. Outcome variables include ever drinking alcohol, preteen alcohol-use initiation, and heavy episodic drinking. Results: Witnessing domestic violence, experiencing physical abuse, and experiencing sexual abuse were significantly associated with preteen alcohol-use initiation (adjusted odds ratio [AOR] = 1.55, 95% confidence interval [CI]: 1.26-1.91; AOR = 2.10, 95% CI: 1.69-2.63; AOR = 1.57, 95% CI: 1.16-2.14, respectively). Students who experienced one or more types of maltreatment were 1.5-3 times more likely to report preteen alcohol-use initiation. Heavy episodic drinking was associated only with childhood sexual abuse in boys (AOR = 2.62, 95% CI: 1.52-4.50). Conclusions: Prevention and treatment of the negative impact of early child maltreatment may delay and reduce alcohol use

Ramsey's Method of Separated Oscillating Fields and its Application to Gravitationally Induced Quantum Phaseshifts

We propose to apply Ramsey's method of separated oscillating fields to the spectroscopy of the quantum states in the gravity potential above a vertical mirror. This method allows a precise measurement of quantum mechanical phaseshifts of a Schr\"odinger wave packet bouncing off a hard surface in the gravitational field of the earth. Measurements with ultra-cold neutrons will offer a sensitivity to Newton's law or hypothetical short-ranged interactions, which is about 21 orders of magnitude below the energy scale of electromagnetism.Comment: 7 pages, 6 figure

Complete determination of the reflection coefficient in neutron specular reflection by absorptive non-magnetic media

An experimental method is proposed which allows the complete determination of the complex reflection coefficient for absorptive media for positive and negative values of the momenta. It makes use of magnetic reference layers and is a modification of a recently proposed technique for phase determination based on polarization measurements. The complex reflection coefficient resulting from a simulated application of the method is used for a reconstruction of the scattering density profiles of absorptive non-magnetic media by inversion.Comment: 14 pages, 4 figures, reformulation of abstract, ref.12 added, typographical correction

A CVD diamond detector for (n,alpha) cross section measurements

Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike LicenceIn astrophysics, the determination of the optical alpha-nucleus potential for low alpha-particle energies, crucial in understanding the origin of the stable isotopes, has turned out to be a challenge. Theory still cannot predict the optical potentials required for the calculation of the astrophysical reaction rates in the Hauser-Feshbach statistical model and there is scant experimental information on reactions with alpha particles at the relevant astrophysical energies. Measurements of (n,alpha) cross-sections offer a good opportunity to study the alpha channel. At the n_TOF experiment at CERN, a prototype detector, based on the chemical vapor deposition (CVD) diamond technology, has been recently developed for (n,alpha) measurements. A reference measurement of the 10B(n,alpha)7Li reaction was performed in 2011 at n_TOF as a feasibility study for this detector type. The results of this measurement and an outline for future experiments are presented here