scholarly journals Chronic exposure to odors at naturally occurring concentrations triggers limited plasticity in early stages of Drosophila olfactory processing

2021 ◽  
Author(s):  
Zhannetta V. Gugel ◽  
Elizabeth Maurais ◽  
Elizabeth J. Hong
Keyword(s):  
Chronic Exposure ◽  
Dynamic Range ◽  
Olfactory Receptor Neuron ◽  
Projection Neurons ◽  
Single Class ◽  
Odor Coding ◽  
Early Stages ◽  
Olfactory Processing ◽  
High Concentrations ◽  
The Stability

ABSTRACTIn insects and mammals, chronic exposure to odors at high concentrations in early life alters olfactory function, but the role of odor experience-dependent plasticity in more naturalistic contexts is less clear. We investigated olfactory plasticity in the Drosophila antennal lobe by exposing flies to odors at concentrations that are typically encountered in natural odor sources. These stimuli also strongly and selectively activated only a single class of olfactory receptor neuron (ORN) input, facilitating the investigation of input-specific plasticity. Overall, chronic exposure to three such odors elicited limited plasticity in the odor responses of second-order projection neurons (PNs). Exposure to some odors elicited mild increases in PN responses to weak stimuli, extending the lower bound of the dynamic range of PN signaling. When present, plasticity was observed broadly in multiple PN types and thus was not selective for PNs receiving direct input from the chronically active ORNs. Chronic E2-hexenal exposure did not affect PN intrinsic properties, local inhibitory innervation, ORN responses, or ORN-PN synaptic strength, but modestly increased broad lateral excitation evoked by some odors. These results show that PN odor coding is only mildly affected by strong persistent activation of a single olfactory input and highlight the stability of early stages of insect olfactory processing to significant perturbations in the sensory environment.

scholarly journals Relative versus absolute RNA quantification: a comparative analysis based on the example of endothelial expression of vasoactive receptors

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Kevin Kuhlmann ◽  
Melanie Cieselski ◽  
Julia Schumann
Keyword(s):  
Dynamic Range ◽  
Genetic Material ◽  
Housekeeping Genes ◽  
Digital Pcr ◽  
Absolute Quantification ◽  
Test Procedures ◽  
Experimental Conditions ◽  
Rna Quantification ◽  
The Stability ◽  
Inflammatory Milieu

Abstract Background In the present study, two distinct PCR methods were used for the quantification of genetic material and their results were compared: real-time-PCR (qPCR; relative quantification) and droplet digital PCR (ddPCR; absolute quantification). The comparison of the qPCR and the ddPCR was based on a stimulation approach of microvascular endothelial cells in which the effect of a pro-inflammatory milieu on the expression of vasoactive receptors was investigated. Results There was consistency in directions of effects for the majority of genes tested. With regard to the indicated dimension of the effects, the overall picture was more differentiated. It was striking that deviations were more pronounced if the measured values were on the extreme edges of the dynamic range of the test procedures. Conclusions To obtain valid and reliable results, dilution series are recommended, which should be carried out initially. In case of ddPCR the number of copies per µl should be adjusted to the low three-digit range. With regard to qPCR it is essential that the stability and reliability of the reference genes used is guaranteed. Here, ddPCR offers the advantage that housekeeping genes are not required. Furthermore, an absolute quantification of the sample can be easily performed by means of ddPCR. Before using ddPCR, however, care should be taken to optimize the experimental conditions. Strict indications for this methodology should also be made with regard to economic and timing factors.

scholarly journals Performance of the 4Kscore Test in Plasma and Serum and Stability of the Component Analytes in Clinical Samples

2018 ◽  
Vol 3 (2) ◽  
pp. 185-199 ◽  
Author(s):  
Christina E Higgins ◽  
Patricia Neybold ◽  
Marcella B Holdridge ◽  
Catherine R Barnes ◽  
Yan Dong ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Specific Antigen ◽  
Clinical Information ◽  
Target Population ◽  
Clinical Samples ◽  
Free Psa ◽  
Total Prostate Specific Antigen ◽  
Edta Plasma ◽  
The Stability ◽  
Intact Psa

Abstract Background The 4Kscore Test determines a personalized risk score for aggressive prostate cancer by combining the blood sample measurements of total prostate-specific antigen (tPSA), free PSA (fPSA), intact PSA (iPSA), and human kallikrein-related peptidase 2 (hK2) with patient clinical information to generate the patient risk's score; thus, accuracy and precision of the 4Kscore depend on the reliability of these measurements. Although tPSA and fPSA are measured on a Food and Drug Administration (FDA)-approved platform, the performance of the iPSA and hK2 assays in the clinical setting has not previously been reported. Methods Analytical performance was determined for the iPSA and hK2 assays in both serum and EDTA plasma, according to Clinical and Laboratory Standards Institute guidelines. Equivalence of the 4Kscore in both sample matrices was demonstrated in a 353-patient clinical cohort, and the stability of endogenous iPSA and hK2 for at least 3 days was demonstrated in a smaller subset. Results Intralaboratory and interlaboratory precision of the iPSA and hK2 assays in both matrices was comparable with that of FDA-approved tPSA and fPSA assays (<18% for iPSA; <8% for hK2). The picogram per milliliter sensitivity and wide dynamic range of the iPSA and hK2 assays allowed for accurate measurements in the target population. The 4Kscore generated in either matrix up to 3 days after collection is equivalent to that measured within 24 h of collection (Passing–Bablok slope 95% CI: plasma, 0.999–1.034; serum, 0.997–1.040). Conclusions The robust performance of component assays and reliable stability of the endogenous analytes in clinical samples proven here ensures an accurate 4Kscore Test result.

scholarly journals The potentional of plants to cleanup metals from an old landfill site

2017 ◽  
Author(s):  
Yahya Jani ◽  
Charlotte Marchand ◽  
William Hogland
Keyword(s):  
Contaminated Soils ◽  
Hazardous Materials ◽  
Average Concentration ◽  
Soil Samples ◽  
Landfill Site ◽  
Group Company ◽  
Timothy Grass ◽  
Xrf Scanning ◽  
High Concentrations ◽  
The Stability

Old landfill sites contain different hazardous materials like heavy metals which have the ability to affects the entire environment. These places are sometimes covered by plants to increase the stability of the soil and to reduce the effects of erosion. 15 soil samples (3 samples from each place) and 5-7 timothy-grass (Phleum pretense) plants from 5 different places were taken from an old landfill place in an active landfill site in Högbytorp /Sweden owned by Ragn-sells Group Company. XRF scanning was used to analyze the metal content of soil samples and of plants. High concentrations of metals were detected in the soil samples like Fe with an average of about 25000 ppm, Mn about 250 ppm and 2800 ppm of Ti. The plants results showed an average concentration of Fe in the shoots about 730 ppm, Mn about 60 ppm and Ti about 1760 ppm. On the other hand, the roots results showed an average concentration of about 10 000 ppm of Fe, about 160 ppm of Mn and 2200 ppm of Ti. These results gave the indication that the Timothy-grass has the ability to extract metals from contaminated soils and can help to cleanup these soils.

Preparation and Immunological Traits of Monoclonal Antibody against Sarafloxacin

2012 ◽  
Vol 459 ◽  
pp. 54-57
Author(s):  
Guo Ying Fan ◽  
Jin Qing Jiang
Keyword(s):  
Monoclonal Antibody ◽  
Detection Limit ◽  
Cell Fusion ◽  
Light Chain ◽  
Dynamic Range ◽  
Fusion Technology ◽  
Alternative Method ◽  
Ic50 Values ◽  
The Stability ◽  
Igg1 Isotype

Through cell fusion technology, five hybridoma lines of sarafloxacin (SAR), named S1-B2, S2-C6, S2-E7, S3-C5, and S3-E5, were identified and their corresponding mAbs were of the IgG1 isotype with a k light chain. The Kaffs of all mAbs were between 2.8 and 4.6×109 L/mol. The titers and IC50 values of purified ascite fluids were in the range of 0.512–2.56×106 and 0.32–0.48 ng/mL, respectively. The performances of S1-B2 and S2-C6 were more consistent in the stability experiments. Based on the S1-B2 hybridoma, an icELISA method was developed. The dynamic range was from 0.004 to 18 ng/mL, with a detection limit for the assay and IC50 values of 0.002 and 0.32 ng/mL, respectively. Therefore, the establishment of these hybridomas may provide an alternative method for the detection of SAR residues in food-original animals.

Selection for soyabeans with high and environmentally stable lutein concentrations

2014 ◽  
Vol 12 (S1) ◽  
pp. S12-S16 ◽  
Author(s):  
Krishna Hari Dhakal ◽  
Myoung-Gun Choung ◽  
Young-Sun Hwang ◽  
Felix B. Fritschi ◽  
J. Grover Shannon ◽  
...  
Keyword(s):  
Human Health ◽  
High Stability ◽  
Planting Dates ◽  
Early Maturity ◽  
Breeding Objective ◽  
Late Maturity ◽  
Selection For ◽  
High Concentrations ◽  
The Stability ◽  
Nutritional Benefits

Lutein has significant nutritional benefits for human health. Therefore, enhancing soybean lutein concentrations is an important breeding objective. However, selection for soybeans with high and environmentally stable lutein concentrations has been limited. The objectives of this study were to select soybeans with high seed lutein concentrations and to determine the stability of lutein concentrations across environments. A total of 314 genotypes were screened and 18 genotypes with high lutein concentrations and five genotypes with low lutein concentrations were selected for further examination. These 23 genotypes and two check varieties were evaluated under six environments (two planting dates for 2 years at one location and two planting dates for 1 year at another location). Lutein concentrations were influenced by genotype, environment and genotype × environment interactions. Genotypes with late maturity and low lutein concentrations were more stable than those with early maturity and high concentrations. Early (May) planting resulted in greater lutein concentrations than late (June) planting. Among the genotypes evaluated, PI603423B (7.7 μg/g) and PI89772 (5.8 μg/g) had the greatest mean lutein concentrations and exhibited medium and high stability across the six environments, respectively. Thus, these genotypes may be useful for breeding soybeans with high and stable seed lutein concentrations.

The chemical stability of mendipite, diaboleïte, chloroxiphite, and cumengéite, and their relationships to other secondary lead(II) minerals

1980 ◽  
Vol 43 (331) ◽  
pp. 901-904 ◽  
Author(s):  
D. Alun Humphreys ◽  
John H. Thomas ◽  
Peter A. Williams ◽  
Robert F. Symes
Keyword(s):  
Chloride Ion ◽  
Stability Diagram ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Stability Field ◽  
Cupric Ion ◽  
Free Energy Of Formation ◽  
High Concentrations ◽  
The Stability ◽  
Ph Range

SummaryThe chemical stabilities of mendipite, Pb3O2Cl2, diaboleïte, Pb2CuCl2(OH)4, chloroxiphite, Pb3CuCl2O2(OH)2, and cumengéite, Pb19Cu24Cl42 (OH)44, have been determined in aqueous solution at 298.2 K. Values of standard Gibbs free energy of formation, ΔGf°, for the four minerals are −740, −1160, −1129, and −15163±20 kJ mol−1 respectively. These values have been used to construct the stability diagram shown in fig. I which illustrates their relationships to each other and to the minerals cotunnite, PbCl2, paralaurionite, PbOHCl, and litharge, PbO. This diagram shows that mendipite occupies a large stability field and should readily form from cold, aqueous, mineralizing solutions containing variable amounts of lead and chloride ions, and over a broad pH range. The formation of paralaurionite and of cotunnite requires a considerable increase in chloride ion concentration, although paralaurionite can crystallize under much less extreme conditions than cotunnite. The encroachment of the copper minerals on to the stability fields of those mineral phases containing lead(II) only is significant even at very low relative activities of cupric ion. Chloroxiphite has a large stability field, and at given concentrations of cupric ion, diaboleïte is stable at relatively high aCl−. Cumengéite will only form at high concentrations of chloride ion.

Design optimization and stability enhancement of modified inter-digital capacitive humidity transducer with cobalt ferrite nanoparticles as dielectric

2019 ◽  
Vol 42 (4) ◽  
pp. 917-923
Author(s):  
Jiss Paul ◽  
Jacob Philip
Keyword(s):  
Recovery Time ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Dynamic Range ◽  
Ferrite Nanoparticles ◽  
Sensitive Layer ◽  
Humidity Transducer ◽  
The Stability ◽  
Stability Enhancement ◽  
Sensing Characteristics

A modified inter-digital capacitive (IDC) transducer for relative humidity (RH) measurement is fabricated by coating a thick film of polyvinyl alcohol (PVA) on the structure. The effective capacitance of the sensor, measured at 1MHz, increases with RH at room temperature. The RH sensing characteristics of PVA coated IDC transducer are analysed in terms of its sensitivity, dynamic range, frequency response, repeatability and recovery time. It is found that the stability of such a PVA based RH transducer improves remarkably by diffusing nanoparticles of CoFe2O4 in the PVA layer. A standard deviation of ± 0.05 and ± 0.01 for a sensitive layer with pure PVA and PVA-CoFe2O4 combination respectively results in a measurement error of ± 0.005 and ± 0.003.

scholarly journals Effect of Deformation Structure and Annealing Temperature on Corrosion of Ultrafine-Grain Fe-Cr Alloy Prepared by Equal Channel Angular Pressing

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Muhammad Rifai ◽  
Motohiro Yuasa ◽  
Hiroyuki Miyamoto
Keyword(s):  
Grain Boundaries ◽  
Equal Channel Angular Pressing ◽  
Annealing Temperature ◽  
Surface Region ◽  
Passivation Layer ◽  
Ultrafine Grain ◽  
Deformation Structure ◽  
Early Stages ◽  
Angular Pressing ◽  
The Stability

The effect of the deformation structure and annealing temperature on the corrosion of ultrafine-grain (UFG) Fe-Cr alloys with 8 to 12% Cr prepared by equal channel angular pressing (ECAP) was investigated with particular emphasis on the stability of the passivation layer. Fe-Cr alloys were processed by ECAP using up to eight passes at 423 K by the Bc route, followed by annealing at temperatures of 473 to 1173 K for 1 h. Passivity appeared in all alloys as a result of ECAP, and the stability of the passivation layer was evaluated by anodic polarization measurements in a 1000 mol·m−3 NaCl solution. The stability of the passivation layer increased as the degree of deformation became more extensive with successive ECAP passes, and distinct escalation occurred with the formation of a UFG microstructure. In the early stages of annealing at moderate temperatures, the stability of the passivation layer deteriorated, although no visible grain growth occurred, and this effect increased monotonically with increasing annealing temperature. The high degree of stability of the passivation layer on UFG alloys following ECAP can be attributed to the large number of high-angle nonequilibrium grain boundaries, which may lead to Cr enrichment of the surface region. The deterioration of the passivation layer in the early stages of annealing may be attributed to a change in the grain boundaries to an equilibrium state. The present results show that the superiority of as-ECAPed materials of the Fe-Cr alloy to recovered ones by heat treatment can be achieved with 8–10% Cr as observed in 20% Cr.

Speciation of cadmium in soil solutions of saline/sodic soils and relationship with cadmium concentrations in potato tubers (Solanum tuberosum L.)

Soil Research ◽  
1997 ◽  
Vol 35 (1) ◽  
pp. 183 ◽  
Author(s):  
M. J. McLaughlin ◽  
K. G. Tiller ◽  
M. K. Smart
Keyword(s):  
Soil Solution ◽  
Soil Ph ◽  
Solanum Tuberosum L ◽  
Alkaline Soil ◽  
Sodic Soils ◽  
Chloro Complexes ◽  
Soil Solutions ◽  
High Concentrations ◽  
The Stability ◽  
Saline Solutions

Fifty commercial potato crops and associated soils were sampled. Soil solutions were extracted from rewetted soils by centrifugation, and solution composition was related to Cd concentrations in tubers. Soils were also extracted with 0·01 M Ca(NO3)2 and 0·01 M CaCl2 solutions, and Cd2+ activities in the extracts were calculated by difference using the stability constants for formation of CdCl2-nn species. The soils had saline solutions (>4 dS/m), and Cl- and SO2-4 in solution markedly affected the speciation of Cd in soil solution, with chloro-complexes, in particular, dominating. While low soil pH was associated with high (>25 nM) concentrations of Cd in soil solution, chloro-complexation also led to high concentrations of Cd in solution, even at neutral to alkaline soil pH values. Tuber Cd concentrations were not related to activities of Cd2+ in soil solution or to activities in dilute salt extracts of soil. Tuber Cd concentrations were related to the degree of chloro-complexation of Cd in solution. The relationship of tuber Cd concentrations to chloro-complexation in soil solution suggests that Cd species other than the free Cd2+ ion are involved in the transport through soil and uptake of Cd by plants.

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