Search results for "Transmitter"
showing 10 items of 348 documents
Classification of Solutions to the Minimum Energy Problem in One Dimensional Sensor Networks
2016
We classify of the minimum energy problem in one dimensional wireless sensor networks for the data transmission cost matrix which is a power function of the distance between transmitter and receiver with any real exponent. We show, how these solutions can be utilized to solve the minimum energy problem for the data transmission cost matrix which is a linear combination of two power functions. We define the minimum energy problem in terms of the sensors signal power, transmission time and capacities of transmission channels. We prove, that for the point-to-point data transmission method utilized by the sensors in the physical layer, when the transmitter adjust the power of its radio signal t…
Maximum Lifetime Problem in Sensor Networks with Limited Channel Capacity
2016
We analyze the maximum lifetime problem in sensor networks with limited channel capacity for multipoint-to-multipoint and broadcast data transmission services. For the transmission model in which the transmitter adjust the power of its radio signal to the distance to the receiver we propose a new Signal to Interference plus Noise Ratio function and use it to modify the Shannon-Hartley channel capacity formula. We show, that in order to achieve an optimal data transmission regarding considered the maximum lifetime problem we cannot allow for any interference of signals. For considered transmission model and the modified capacity formula we solve the maximum lifetime problem in one dimensiona…
GLP-2 receptor expression in excitatory and inhibitory enteric neurons and its role in mouse duodenum contractility.
2011
Background. Glucagon-like peptide 2 (GLP-2), a nutrient-responsive hormone, exerts various actions in the gastrointestinal tract that are mediated by a G-protein coupled receptor called GLP-2R. A little information is available on GLP-2R expression in enteric neurons and nothing on the interstitial cells of Cajal (ICC). Methods. We investigated presence and distribution of the GLP-2R in the mouse duodenum by immunohistochemistry and the potential motor effects of GLP-2 on the spontaneous and neurally evoked mechanical activity. Key Results. The GLP-2R was expressed by the myenteric and submucosal neurons. Labelling was also present in nerve varicosities within the circular muscular layer an…
Ar LoRaWAN raidītājiem aprīkotu objektu monitoringa sistēma
2022
Putnu migrācijas pētījumi palīdz uzzināt daudz jauna par putnu dzīvesveidu. Šiem pētījumiem bieži tiek izmantoti nelieli putni, jo tie ir vieglāk pieejami. Nelielu putnu migrācijas pētījumos šobrīd īsti nav iespēju noteikt putnu lokāciju migrācijas laikā. Izmantojot šā brīža modernākās ierīces, putnu migrācijā dati tiek iegūti, uzliekot vides uztveršanas ierīci putnam, noņemot to nākamajā ligzdošanas periodā (pēc gada). Migrācijas ceļi pēc šādas metodes tiek rēķināti no sensoru datiem pēc tam, kad putns ir atgriezies ligzdošanas vietā. Tā kā putna ķermenis ir viegls, tad arī ierīcei, kas lokācijas datus pārraidītu, ir jābūt nelielai, vieglai un ar zemu enerģijas patēriņu. Darbā apskatītais …
Structure-activity relationship of dopaminergic halogenated 1-benzyl-tetrahydroisoquinoline derivatives
2009
Two series of halogenated 1-benzyl-7-chloro-6-hydroxy-tetrahydroisoquinolines were prepared to explore the influence of each series on the affinity for dopamine receptors. All the compounds displayed a high affinity for D(1)-like and/or D(2)-like dopamine receptors in striatal membranes, although they were unable to inhibit [(3)H]-dopamine uptake in striatal synaptosomes. The halogen placed on the benzylic ring in 1-benzyl-THIQs, compounds of the series 1, 2'-bromobenzyl derivatives with K(i) values into the nanomolar range, and the series 2, 2',4'-dichlorobenzyl-THIQ homologues, proves to be an important factor to modulate affinity at dopamine receptor. (C) 2009 Elsevier Masson SAS. All ri…
Modulation of the Endocannabinoids N-Arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) on Executive Functions in Human.
2013
Animal studies point to an implication of the endocannabinoid system on executive functions. In humans, several studies have suggested an association between acute or chronic use of exogenous cannabinoids (Δ9-tetrahydrocannabinol) and executive impairments. However, to date, no published reports establish the relationship between endocannabinoids, as biomarkers of the cannabinoid neurotransmission system, and executive functioning in humans. The aim of the present study was to explore the association between circulating levels of plasma endocannabinoids N-arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) and executive functions (decision making, response inhibition and cognit…
Altered receptor binding densities in experimental antiphospholipid syndrome despite only moderately enhanced autoantibody levels and absence of beha…
2013
Abstract Experimental antiphospholipid syndrome (eAPS) in Balb/c mice causes neuropsychiatric abnormalities including hyperactivity, increased explorative behavior and cognitive deficits. Recently, we have demonstrated that these behavioral changes were linked to an upregulation of serotonergic 5-HT1A receptor binding densities in cortical and hippocampal regions while excitatory and inhibitory neurotransmitter receptors remain largely unchanged. To examine whether the observed behavioral features depend on a critical antibody concentration, mice with only moderately enhanced antiphospholipid antibodies (aPL), about 50–80% of high levels, were analyzed and compared to controls. The staircas…
Compensatory mechanisms enhance hippocampal acetylcholine release in transgenic mice expressing human acetylcholinesterase
2001
Central cholinergic neurotransmission was studied in learning-impaired transgenic mice expressing human acetylcholinesterase (hAChE-Tg). Total catalytic activity of AChE was approximately twofold higher in synaptosomes from hippocampus, striatum and cortex of hAChE-Tg mice as compared with controls (FVB/N mice). Extracellular acetylcholine (ACh) levels in the hippocampus, monitored by microdialysis in the absence or presence of 10(-8)-10(-3) M neostigmine in the perfusion fluid, were indistinguishable in freely moving control and hAChE-Tg mice. Muscarinic receptor functions were unchanged as indicated by similar effects of scopolamine on ACh release and of carbachol on inositol phosphate fo…
Expression of inhibitory glycine receptors in postnatal rat cerebral cortex.
1993
The developmental expression of inhibitory glycine receptors was analyzed in postnatal rat cerebral cortex using the specific monoclonal antibody, MAb 4a. This antibody defines an epitope common to all known glycine receptor alpha-subunits. At birth, high levels of immunoreactivity were found, which transiently increased during the second postnatal week, but subsequently declined to low adult levels. Biochemical analysis of the MAb 4a antigen from parietal areas indicates that cortical glycine receptors correspond to the neonatal receptor isoform previously identified in spinal cord of newborn animals. Immunocytochemistry showed that, within 2 weeks after birth, MAb 4a-reactive glycine rece…
The Role of Monoamines in the Development of Cold-Induced Edema
1976
Our results show that even the experimentally induced high concentrations of exogenous 5-HT in the brain tissue during the early phase of edema formation are not able to increase the amount of fluid accumulation in the normal and injured brain tissue. The changes of the endogenous 5-HT levels in the blood and the brain tissue result in similar hemispheric water and RISA differences between the injured and uninjured half of the brain. Moreover, 5-HT concentrations elevated by 100% failed to produce detectable edema in the normal brain tissue of the rat.