Head Position Identification

1967 ◽  
Vol 10 (3) ◽  
pp. 438-448
Author(s):  
H. N. Wright
Keyword(s):  
Roc Curve ◽  
Head Position ◽  
Hearing Impaired ◽  
Type Ii ◽  
Experimental Conditions ◽  
Partial Explanation ◽  
Complex Sounds ◽  
Binaural Cues ◽  
Criterion Behavior ◽  
Stimulus Degradation

A binaural recording of traffic sounds that reached an artificial head oriented in five different positions was presented to five subjects, each of whom responded under four different criteria. The results showed that it is possible to examine the ability of listeners to localize sound while listening through earphones and that the criterion adopted by an individual listener is independent of his performance. For the experimental conditions used, the Type II ROC curve generated by manipulating criterion behavior was linear and consistent with a guessing model. Further experiments involving different degrees of stimulus degradation suggested a partial explanation for this finding and illustrated the various types of monaural and binaural cues used by normal and hearing-impaired listeners to localize complex sounds.

Identification and isolation of mouse type II cells on the basis of intrinsic expression of enhanced green fluorescent protein

2003 ◽  
Vol 285 (3) ◽  
pp. L691-L700 ◽  
Author(s):  
Jason M. Roper ◽  
Rhonda J. Staversky ◽  
Jacob N. Finkelstein ◽  
Peter C. Keng ◽  
Michael A. O'Reilly
Keyword(s):  
Epithelial Cells ◽  
Fluorescent Protein ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Green Fluorescence ◽  
Experimental Conditions ◽  
Green Fluorescent

The unique morphology and cell-specific expression of surfactant genes have been used to identify and isolate alveolar type II epithelial cells. Because these attributes can change during lung injury, a novel method was developed for detecting and isolating mouse type II cells on the basis of transgenic expression of enhanced green fluorescence protein (EGFP). A line of transgenic mice was created in which EGFP was targeted to type II cells under control of the human surfactant protein (SP)-C promoter. Green fluorescent cells that colocalized by immunostaining with endogenous pro-SP-C were scattered throughout the parenchyma. EGFP was not detected in Clara cell secretory protein-expressing airway epithelial cells or other nonlung tissues. Pro-SP-C immunostaining diminished in lungs exposed to hyperoxia, consistent with decreased expression and secretion of intracellular precursor protein. In contrast, type II cells could still be identified by their intrinsic green fluorescence, because EGFP is not secreted. Type II cells could also be purified from single-cell suspensions of lung homogenates using fluorescence-activated cell sorting. Less than 1% of presorted cells exhibited green fluorescence compared with >95% of the sorted population. As expected for type II cells, ultrastructural analysis revealed that the sorted cells contained numerous lamellar bodies. SP-A, SP-B, and SP-C mRNAs were detected in the sorted population, but T1α and CD31 (platelet endothelial cell adhesion molecule) were not, indicating enrichment of type II epithelial cells. This method will be invaluable for detecting and isolating mouse type II cells under a variety of experimental conditions.

Perception of Spectral Contrast by Hearing-Impaired Listeners

2005 ◽  
Vol 48 (4) ◽  
pp. 910-921 ◽  
Author(s):  
Laura E. Dreisbach ◽  
Marjorie R. Leek ◽  
Jennifer J. Lentz
Keyword(s):  
Hearing Loss ◽  
Internal Representation ◽  
Normal Hearing ◽  
Stimulus Level ◽  
Hearing Impaired ◽  
Frequency Resolution ◽  
Spectral Peak ◽  
Control Group ◽  
Complex Sounds ◽  
Spectral Contrast

The ability to discriminate the spectral shapes of complex sounds is critical to accurate speech perception. Part of the difficulty experienced by listeners with hearing loss in understanding speech sounds in noise may be related to a smearing of the internal representation of the spectral peaks and valleys because of the loss of sensitivity and an accompanying reduction in frequency resolution. This study examined the discrimination by hearing-impaired listeners of highly similar harmonic complexes with a single spectral peak located in 1 of 3 frequency regions. The minimum level difference between peak and background harmonics required to discriminate a small change in the spectral center of the peak was measured for peaks located near 2, 3, or 4 kHz. Component phases were selected according to an algorithm thought to produce either highly modulated (positive Schroeder) or very flat (negative Schroeder) internal waveform envelopes in the cochlea. The mean amplitude difference between a spectral peak and the background components required for discrimination of pairs of harmonic complexes (spectral contrast threshold) was from 4 to 19 dB greater for listeners with hearing impairment than for a control group of listeners with normal hearing. In normal-hearing listeners, improvements in threshold were seen with increasing stimulus level, and there was a strong effect of stimulus phase, as the positive Schroeder stimuli always produced lower thresholds than the negative Schroeder stimuli. The listeners with hearing loss showed no consistent spectral contrast effects due to stimulus phase and also showed little improvement with increasing stimulus level, once their sensitivity loss was overcome. The lack of phase and level effects may be a result of the more linear processing occurring in impaired ears, producing poorer-than-normal frequency resolution, a loss of gain for low amplitudes, and an altered cochlear phase characteristic in regions of damage.

Intracellular calcium and phospholipid turnover are not involved in the inhibition of iodothyronine 5'-deiodinase type II activity by T4

1991 ◽  
Vol 124 (1) ◽  
pp. 67-75
Author(s):  
Cristiana Juge-Aubry ◽  
Pierre Dôme ◽  
Catherine A. Siegrist-Kaiser ◽  
Alessandro M. Capponi ◽  
Albert G. Burger
Keyword(s):  
Intracellular Calcium ◽  
Calcium Concentration ◽  
Enzyme Inactivation ◽  
Free Calcium ◽  
Type Ii ◽  
Cytosolic Free Calcium ◽  
Experimental Conditions ◽  
Phospholipid Turnover ◽  
Free Calcium Concentration ◽  
Cytosolic Free Calcium Concentration

Abstract. In glial cell cultures, iodothyronine 5'-deiodinase type II is stimulated by dibutyryl cAMP. Serum-free medium increases enzyme activity and prolongs the half-life of the enzyme. T4 and rT3 specifically inhibit this activity. We tested whether enzyme inactivation by T4 was mediated by changes in cytosolic free calcium concentration and/or phospholipid turnover. Intracellular calcium concentration was decreased either by chelation of extracellular calcium or by chelation of extracellular and intracellular calcium. Neither basal hypothyroid 5'-deiodinase activity nor its inactivation by T4 were modified in such experimental conditions, compared with control cells incubated in normal calcium-containing medium. T4 by itself had no effect on the cytosolic free calcium concentration for up to 20 min. Studies on phospholipid turnover included norepinephrine in parallel to T4 as positive stimulation control. While norepinephrine clearly accelerated phosphoinositide turnover, there was no effect of T4 on any phospholipid turnover. These results suggest that neither cytosolic free calcium nor phospholipid turnover is involved in T4-dependent modulation of 5'-deiodinase type II activity in astrocytes in culture.

Cultured Lung Cells: Effects of Isotopic Dilution and Some Undefined Stimulation on the Incorporation of Radiolabeled Palmitate and Choline into Phosphatidyl Choline (Lecithin)

1979 ◽  
Vol 34 (1-2) ◽  
pp. 96-100 ◽  
Author(s):  
Giuseppe Colacicco ◽  
Mukul K. Basu ◽  
Apurba K. Ray ◽  
Murray Wittner ◽  
Robert M. Rosenbaum
Keyword(s):  
Phosphatidyl Choline ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Alveolar Epithelium ◽  
Isotopic Dilution ◽  
Lung Cells ◽  
Choline Uptake ◽  
Type Ii ◽  
Experimental Conditions ◽  
Choline Incorporation

Abstract Using radiolabels, we studied the effect of certain experimental conditions on the incorporation of choline and palmitate into phosphatidyl choline (lecithin) of cloned type II rat lung cells. When the label was changed from methyl-3H to 1,2-14C the incorporation of choline was reduced to 1/3; in contrast, when the label was moved from 1-14C to 9,10-3H, the incorporation of free palmitate was more than doubled. Removal of choline from the culture medium caused trebling of choline incorporation and appreciable decrease in palmitate uptake, indicating respectively an expected effect of increased choline label concentration in the absence of carrier, and a marked dependence of palmitate on choline incorporation. Removal of fetal calf serum produced more than 2/3 decrease in palmitate incorporation (instead of an expected increase because of palmitate isotope concentration), whereas choline uptake was not affected, meaning respectively that either serum hormones or serum lipids, or both simultaneously, are important for palmitate but not for choline incorporation. This is only the beginning of a host of studies required to clarify the role of fetal calf serum constituents onto lecithin biosynthesis in cultured lung cells and finally gain a full appreciation of the biosynthetic pathways of phosphatidyl choline (“surfactant”) in type II cells of alveolar epithelium.

Evaluation of Hearing-Impaired Listeners Using a Nonsense-Syllable Test I. Test Reliability

1982 ◽  
Vol 25 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Judy R. Dubno ◽  
Donald D. Dirks
Keyword(s):  
Nonsense Syllable ◽  
Covariance Structure ◽  
Hearing Impaired ◽  
Analysis Of Covariance ◽  
Test Reliability ◽  
Experimental Conditions ◽  
Individual Subject ◽  
Closed Set ◽  
Wide Range ◽  
Recognition Ability

The reliability of a closed-set Nonsense-Syllable Test was determined on a group of 38 listeners with mild-to-moderate sensorineural hearing loss. Eight randomizations of the 91-item test (four trials on each of two days) were presented monaurally, under earphones, at 90 dB SPL with a cafeteria background noise set at a +20-dB S/N ratio. Performance under these conditions ranged from 21.4 to 91.2%, reflecting the wide range of syllable-recognition ability of these subjects. Reliability of the eight measurements was determined by analysis of variance and analysis of covariance structure (parallel-test modelling) for the entire test and each of 11 subtests. Overall and individual subject results failed to show any systematic differences in scores over eight trials. Likewise, no significant differences were found in performance on individual syllables, nor were changes in the relative occurrence of specific syllable confusions noted. This test is highly reliable when evaluating hearing-impaired subjects, and thus is appropriate for use in investigations where identical items are administered under multiple experimental conditions.

scholarly journals Data paper: FoRAGE (Functional Responses from Around the Globe in all Ecosystems) database: a compilation of functional responses for consumers and parasitoids

2018 ◽  
Author(s):  
Stella F. Uiterwaal ◽  
Ian T. Lagerstrom ◽  
Shelby R. Lyon ◽  
John P. DeLong
Keyword(s):  
Prey Density ◽  
Type Ii ◽  
Functional Responses ◽  
Food Web Structure ◽  
Experimental Conditions ◽  
Data Set ◽  
Global Database ◽  
Web Structure ◽  
Resource Interactions ◽  
Consumer Resource

Functional responses - the relationships between consumer foraging rate and resource (prey) density - provide key insights into consumer-resource interactions and predation mechanics while also being a major contributor to population dynamics and food web structure. We present a global database of standardized functional response parameters extracted from the published literature. We refit the functional responses with a Type II model using standardized methods and report the fitted parameters along with data on experimental conditions, consumer and resource taxonomy and type, as well as the habitat and dimensionality of the foraging interaction. The consumer and resource species covered here are taxonomically diverse, from protozoans filtering algae to wasps parasitizing moth larvae to wolves hunting moose. The FoRAGE database (doi:10.5063/F17H1GTQ) is a living data set that will be updated periodically as new functional responses are published.

scholarly journals Biosensor Based Immunoassay: A New Approach for Serotyping of Toxoplasma gondii

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2065
Author(s):  
Susana Sousa ◽  
António Castro ◽  
José Manuel Correia da Costa ◽  
Eulália Pereira
Keyword(s):  
Gold Nanoparticles ◽  
Toxoplasma Gondii ◽  
Point Of Care ◽  
Colorimetric Method ◽  
Type Ii ◽  
Serum Samples ◽  
Experimental Conditions ◽  
New Approach ◽  
New Methodologies ◽  
Definition Of

Toxoplasmosis is the most reported parasitic zoonosis in Europe, with implications in human health and in the veterinary field. There is an increasing need to develop serotyping of Toxoplasma gondii (T. gondii) in view of greater sensitivity and efficiency, through the definition of new targets and new methodologies. Nanotechnology is a promising approach, with impact in the development of point-of-care devices. The aim of this work was to develop a simple but highly efficient method for Toxoplasma gondii serotyping based on gold nanoparticles. A simple colorimetric method was developed using gold nanoparticles modified with the synthetic polymorphic peptide derived from GRA6 antigen specific for type II T. gondii. The method of preparation of the gold nanoprobes and the experimental conditions for the detection were found to be critical for a sensitive discrimination between positive and negative sera. The optimized method was used to detect antibodies anti-GRA6II both in mice and human serum samples. These results clearly demonstrate that a biosensor-based immunoassay using AuNPs conjugated with polymorphic synthetic peptides can be developed and used as a serotyping device

PERIODIC AIR-BREATHING BEHAVIOUR IN A PRIMITIVE FISH REVEALED BY SPECTRAL ANALYSIS

1994 ◽  
Vol 197 (1) ◽  
pp. 429-436
Author(s):  
M Hedrick ◽  
S Katz ◽  
D Jones
Keyword(s):  
Lung Ventilation ◽  
Phylogenetic Position ◽  
Breath Holding ◽  
Type I ◽  
Type Ii ◽  
Experimental Conditions ◽  
Air Breathing ◽  
Ventilatory Pattern ◽  
Gas Bladder ◽  
Amia Calva

The ventilatory patterns of air-breathing fish are commonly described as 'arrhythmic' or 'irregular' because the variable periods of breath-holding are punctuated by seemingly unpredictable air-breathing events (see Shelton et al. 1986). This apparent arrhythmicity contrasts with the perceived periodism or regularity in the gill ventilation patterns of some fish and with lung ventilation in birds and mammals. In this sense, periodism refers to behaviour that occurs with a definite, recurring interval (Bendat and Piersol, 1986). The characterisation of aerial ventilation patterns in fish as 'aperiodic' has been generally accepted on the basis of qualitative examination and it remains to be validated with rigorous testing. The bowfin, Amia calva (L.), is a primitive air-breathing fish that makes intermittent excursions to the air­water interface to gulp air, which is transferred to its well-vascularized gas bladder. Its phylogenetic position as the only extant member of the sister lineage of modern teleosts affords a unique opportunity to examine the evolution of aerial ventilation and provides a model for the examination of ventilatory patterns in primitive fishes. To establish whether Amia calva exhibit a particular pattern of air-breathing, we examined time series records of aerial ventilations from undisturbed fish over long periods (8 h). These records were the same as those used to calculate average ventilation intervals under a variety of experimental conditions (Hedrick and Jones, 1993). Their study also reported the occurrence of two distinct breath types. Type I breaths were characterised by an exhalation followed by an inhalation, whereas type II breaths were characterised by inhalation only. It was also hypothesized that the type I breaths were employed to meet oxygen demands, whereas the type II breaths were used to regulate gas bladder volume. However, they did not investigate the potential presence of a periodic ventilatory pattern. We now report the results of just such an analysis of ventilatory pattern that demonstrates a clear periodism to air-breathing in a primitive fish.

Hypoxia promotes nucleus pulposus phenotype in 3D scaffolds in vitro and in vivo

2014 ◽  
Vol 21 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Ganjun Feng ◽  
Li Li ◽  
Ying Hong ◽  
Hao Liu ◽  
Yueming Song ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Collagen Type ◽  
Type Ii ◽  
Collagen Type Ii ◽  
Low Oxygen ◽  
Nucleus Pulposus Cells ◽  
Experimental Conditions ◽  
3D Scaffolds

Object The role of oxygen in disc metabolism remains a matter of debate. Whether the effect of hypoxic priming on the nucleus pulposus phenotype can be maintained in vivo is not clear. The goal of the present study was to test the hypothesis that priming in a low oxygen tension in vitro could promote a nucleus pulposus phenotype in vivo. Methods Bovine nucleus pulposus cells were seeded in 3D scaffolds and subjected to varying oxygen tensions (2% and 20%) for 3 weeks. The constructs were then implanted subcutaneously for 8 weeks. Changes in the extracellular matrix were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction, glycosaminoglycan (GAG) assay, DNA assay, collagen quantification, and histological and immunohistological analyses. Results Hypoxia resulted in greater production of sulfated glycosaminoglycan and higher levels of gene expression for collagen Type II, aggrecan, and SOX-9. Furthermore, after hypoxic priming, the subcutaneously implanted constructs maintained the nucleus pulposus phenotype, which was indicated by a significantly higher amount of glycosaminoglycan and collagen Type II. Conclusions Hypoxia enhanced the nucleus pulposus phenotype under experimental conditions both in vitro and in vivo. When used in combination with appropriate scaffold material, nucleus pulposus cells could be regenerated for tissue-engineering applications.

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