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Level Differences (level + difference)
Selected AbstractsNeural correlates of binaural masking level difference in the inferior colliculus of the barn owl (Tyto alba)EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2010Ali Asadollahi Abstract Humans and animals are able to detect signals in noisy environments. Detection improves when the noise and the signal have different interaural phase relationships. The resulting improvement in detection threshold is called the binaural masking level difference. We investigated neural mechanisms underlying the release from masking in the inferior colliculus of barn owls in low-frequency and high-frequency neurons. A tone (signal) was presented either with the same interaural time difference as the noise (masker) or at a 180° phase shift as compared with the interaural time difference of the noise. The changes in firing rates induced by the addition of a signal of increasing level while masker level was kept constant was well predicted by the relative responses to the masker and signal alone. In many cases, the response at the highest signal levels was dominated by the response to the signal alone, in spite of a significant response to the masker at low signal levels, suggesting the presence of occlusion. Detection thresholds and binaural masking level differences were widely distributed. The amount of release from masking increased with increasing masker level. Narrowly tuned neurons in the central nucleus of the inferior colliculus had detection thresholds that were lower than or similar to those of broadly tuned neurons in the external nucleus of the inferior colliculus. Broadly tuned neurons exhibited higher masking level differences than narrowband neurons. These data suggest that detection has different spectral requirements from localization. [source] Bilateral Bone-Anchored Hearing Aids (BAHAs): An Audiometric Evaluation,THE LARYNGOSCOPE, Issue 1 2004Claudia Priwin MD Abstract Objectives Since the technique to implant bone-anchored hearing aids (BAHAs) with the use of osseointegrated implants was developed in 1977, more than 15,000 patients have been fitted with BAHAs worldwide. Although the majority have bilateral hearing loss, they are primarily fitted unilaterally. The main objective of this study was to reveal benefits and drawbacks of bilateral fitting of BAHAs in patients with symmetric or slight asymmetric bone-conduction thresholds. The possible effects were divided into three categories: hearing thresholds, directional hearing, and binaural hearing. Study Design Prospective study of 12 patients with bilateral BAHAs. Methods Baseline audiometry, directional hearing, speech reception thresholds in quiet and in noise, and binaural masking level difference were tested when BAHAs were fitted unilaterally and bilaterally. Results Eleven of the 12 patients used bilateral BAHAs on a daily basis. Tests performed in the study show a significant improvement in sound localization with bilateral BAHAs; the results with unilateral fitting were close to the chance level. Furthermore, with bilateral application, the improvement of the speech reception threshold in quiet was 5.4 dB. An improvement with bilateral fitting was also found for speech reception in noise. Conclusions Overall, the results with bilateral fitted BAHAs were better than with unilaterally fitted BAHA; the benefit is not only caused simply by bilateral stimulation but also, to some extent, by binaural hearing. Bilateral BAHAs should be considered for patients with bilateral hearing loss otherwise suitable for BAHAs. [source] Teil 2: Trittschalldämmung , Flankentrittschallpegel und TrittschallminderungBAUPHYSIK, Issue 2 2004Elmar Sälzer Dipl.-Ing. Im Teil 1 [1] der insgesamt dreiteiligen Darstellung des Schallschutzes von Hohlraumböden wurde über die geschichtliche Entwicklung der seit Anfang der 1980er Jahre auf den Markt gekommenen Hohlraumböden, die wesentlichen Konstruktionsprinzipien solcher Böden und über die Schallängsdämmung, dargestellt durch die bewertete Norm-Flankenpegeldifferenz, berichtet. Im vorliegenden zweiten Teil werden die beiden Aspekte der Trittschalldämmung, und zwar des Flankentrittschallpegels , der früher auch als horizontale Trittschalldämmung bezeichnet wurde , und der Trittschallminderung (früher Trittschallverbesserung) dargestellt. Der nachfolgenden Darstellung der beiden Parameter der Trittschalldämmung liegen ca. 150 Messungen im schalltechnischen Labor zu Grunde, die zum großen Teil noch nach DIN 52 210 [3], in jüngerer Zeit selbstverständlich nach DIN EN ISO 140-12 [4] durchgeführt wurden. Sound protection of cavity floors. Part 2: Impact sound insulation , namely impact sound flanking level and impact sound reduction In part 1 [1] of this three-part report on cavity floor sound protection, the history of the development of cavity floors introduced on the market since the early 1980s, the main design principles of such floors, and the concepts of flanking level reduction and weighted standard flanking level difference were illustrated. This second part examines two aspects of impact sound insulation, namely impact sound flanking level , previously sometimes referred to as horizontal impact sound insulation , and impact sound reduction. The following discussion of these two impact sound insulation parameters is based on approximately 150 measurements in an acoustics laboratory. The bulk of the measurements was carried out according to DIN 52 210 [3], more recent measurements according to DIN EN ISO 140-12 [4]. [source] Neural correlates of binaural masking level difference in the inferior colliculus of the barn owl (Tyto alba)EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2010Ali Asadollahi Abstract Humans and animals are able to detect signals in noisy environments. Detection improves when the noise and the signal have different interaural phase relationships. The resulting improvement in detection threshold is called the binaural masking level difference. We investigated neural mechanisms underlying the release from masking in the inferior colliculus of barn owls in low-frequency and high-frequency neurons. A tone (signal) was presented either with the same interaural time difference as the noise (masker) or at a 180° phase shift as compared with the interaural time difference of the noise. The changes in firing rates induced by the addition of a signal of increasing level while masker level was kept constant was well predicted by the relative responses to the masker and signal alone. In many cases, the response at the highest signal levels was dominated by the response to the signal alone, in spite of a significant response to the masker at low signal levels, suggesting the presence of occlusion. Detection thresholds and binaural masking level differences were widely distributed. The amount of release from masking increased with increasing masker level. Narrowly tuned neurons in the central nucleus of the inferior colliculus had detection thresholds that were lower than or similar to those of broadly tuned neurons in the external nucleus of the inferior colliculus. Broadly tuned neurons exhibited higher masking level differences than narrowband neurons. These data suggest that detection has different spectral requirements from localization. [source] Is there a role of visual cortex in spatial hearing?EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2004Ulrike Zimmer Abstract The integration of auditory and visual spatial information is an important prerequisite for accurate orientation in the environment. However, while visual spatial information is based on retinal coordinates, the auditory system receives information on sound location in relation to the head. Thus, any deviation of the eyes from a central position results in a divergence between the retinal visual and the head-centred auditory coordinates. It has been suggested that this divergence is compensated for by a neural coordinate transformation, using a signal of eye-in-head position. Using functional magnetic resonance imaging, we investigated which cortical areas of the human brain participate in such auditory,visual coordinate transformations. Sounds were produced with different interaural level differences, leading to left, right or central intracranial percepts, while subjects directed their gaze to visual targets presented to the left, to the right or straight ahead. When gaze was to the left or right, we found the primary visual cortex (V1/V2) activated in both hemispheres. The occipital activation did not occur with sound lateralization per se, but was found exclusively in combination with eccentric eye positions. This result suggests a relation of neural processing in the visual cortex and the transformation of auditory spatial coordinates responsible for maintaining the perceptual alignment of audition and vision with changes in gaze direction. [source] Person-factors in the California Adult Q-Set: closing the door on personality trait types?,EUROPEAN JOURNAL OF PERSONALITY, Issue 1 2006Robert R. McCrae To investigate recent hypotheses of replicable personality types, we examined data from 1540 self-sorts on the California Adult Q-Set (CAQ). Conventional factor analysis of the items showed the expected Five-Factor Model (FFM). Inverse factor analysis across random subsamples showed that none of the previously reported person-factors were replicated. Only two factors were replicable, and, most importantly, these factors were contaminated by mean level differences in item endorsement. Results were not due to sample size or age heterogeneity. Subsequent inverse factor analysis of standardized items revealed at least three replicable factors; when five person-factors were extracted, they could be aligned precisely with the dimensions of the FFM. The major factors of person similarity can be accounted for entirely in terms of the FFM, consistent with the hypothesis that there are no replicable personality types in the CAQ. Published in 2006 John Wiley & Sons, Ltd. [source] Confinement of Charge Carriers and Excitons in Electrophosphorescent Devices: Mechanism of Light Emission and Degradation,ADVANCED MATERIALS, Issue 16 2007D. Chin Charge-carrier and exciton confinement is essential for efficiency and stability enhancment of electrophosphorescent devices. Emission-layer lifetimes of a 4,4,- N,N,-dicarbazole-biphenyl host doped with either a red- or green- emitting dye (upper and lower figures) show a strong dependence and near independence, respectively, on the type of exciton blocking layer used (four are shown). This is explained using energy- level differences and corresponding charge-trapping behavior. [source] Only Male Mice Show Sensitization of Handling-Induced Convulsions Across Repeated Ethanol Withdrawal CyclesALCOHOLISM, Issue 3 2007L.M. Veatch Background: Alcohol abuse, especially when experienced in multiple cycles of chronic abuse and withdrawal, leads to a sensitization of central nervous system hyperexcitability that may culminate in overt expression of seizures. In spite of the growing prevalence of alcohol abuse and dependence in females shown in recent epidemiologic studies, evidence of sexual dimorphism in the expression of alcohol withdrawal-induced seizures and the development of seizure sensitization following multiple cycles of ethanol (EtOH) exposure and withdrawal has not been examined in either animal models or in clinical reports. Methods: Subjects in these experiments were male and female C3H/Hecr mice. The female mice were intact or ovariectomized, with ovariectomized mice receiving 17- , -estradiol or placebo pellets. All mice were exposed to 4 cycles of exposure to 16-hour EtOH vapor, separated by 8-hour withdrawal periods. During each 8-hour withdrawal, hourly assessment of seizure propensity was assessed as handling-induced convulsions. Additional assessments were taken up to 72 hours after the final EtOH withdrawal cycle. Results: Male and female mice showed similar seizure propensity during an initial withdrawal from chronic EtOH. Across subsequent withdrawal cycles, however, male mice exhibited a robust increase in seizure severity beginning with the third withdrawal cycle. In marked contrast, female mice failed to demonstrate sensitization of seizure severity. The lack of seizure sensitization following up to 4 cycles of alcohol exposure and withdrawal could not be explained by hormonal status (presence or absence of estrogen) or by sex differences in blood alcohol levels. Conclusions: Male and female mice exposed to the same number of cycles of EtOH withdrawal demonstrate differences in expression of seizures. Males show the typical sensitization of seizures, or kindling response, which has been reported clinically as well as in animal models, but females do not. The reason for the lack of seizure sensitization in female mice remains to be elucidated, but may be related to sex differences in alcohol effects on excitatory/inhibitory neurotransmission, rather than to hormonal or blood alcohol level differences. [source] The Effect of Irradiance on Carboxylating/Decarboxylating Enzymes and Fumarase Activities in Mesembryanthemum crystallinum L. Exposed to Salinity StressPLANT BIOLOGY, Issue 1 2001Z. Miszalski Abstract: In Mesembryanthemum crystallinum plants, treated for 9 days with 0.4 M NaCl at low light intensities (80 - 90 or 95 - 100 ,E m -2 s -1; , = 400 - 700 nm), no day/night malate level differences (,malate) were detected. At high light (385 - 400 ,E m -2 s -1) strong stimulation of PEPC activity, accompanied by a ,malate of 11.3 mM, demonstrated the presence of CAM metabolism. This indicates that, to evolve day/night differences in malate concentration, high light is required. Salt treatment at low light induces and increases the activity of NAD- and NADP-malic enzymes by as much as 3.7- and 3.9-fold, while at high light these values reach 6.4- and 17.7-fold, respectively. The induction of activity of both malic enzymes and PEPC (phospoenolpyruvate carboxylase) take place before ,malate is detectable. An increase in SOD (superoxide dismutase) was observed in plants cultivated at high light in both control and salt-treated plants. However, in salt-treated plants this effect was more pronounced. Carboxylating and decarboxylating enzymes seem to be induced by a combination of different signals, i.e., salt and light intensity. Plants performing CAM, after the decrease of activity of both the decarboxylating enzymes at the beginning of the light period, showed an increase in these enzymes in darkness when the malate pool reaches higher levels. In CAM plants the activity of fumarase (Krebs cycle) is much lower than that in C3 plants. The role of mitochondria in CAM plants is discussed. [source] Latino worker perceptions of construction risks,AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2010Nancy Nivison Menzel PhD Abstract Background Construction is a hazardous occupation, with Latino (Hispanic) workers at a greater risk for death than other ethnicities/races. Latinos accounted for over half of construction injuries involving days away from work in Nevada in 2006. Methods This study recruited 30 Latino construction workers from three Southern Nevada trade unions to participate in four focus groups conducted in Spanish to determine their perceived risks for injury. Audiotapes were transcribed into English transcripts, which were analyzed for themes. Results Themes included language/communication difficulties, traditional Latino values, construction trade skill level differences, and health literacy. Participants were unfamiliar with the workers' compensation system. Conclusions Small contractors in particular should provide more effective safety training in Spanish and appropriate safety equipment. Unions should offer English language training using simulation and more information about workers' compensation rights. Occupational health providers should consider Latino beliefs and communication needs when assessing health status or providing care. Am. J. Ind. Med. 53:179,187 2010. © 2009 Wiley-Liss, Inc. [source] Sources of variance in curriculum-based measures of silent readingPSYCHOLOGY IN THE SCHOOLS, Issue 4 2003Rachel Brown-Chidsey Curriculum-Based Measurement silent reading (CBM-SR) items have been found to be reliable and valid for measuring reading comprehension skills This generalizability study reports the findings from administration of three CBM-SR passages to fifth through eighth grade students in one school district. Using Repeated Measures Analyses of Variance (RMANOVA) procedures, the statistical probability of performance on the CBM-SR task as a differential indicator of reading comprehension skill was found to be significant among students in different grade levels and between students who did and did not receive special education services. Follow-up analyses were conducted using generalizability theory to estimate the amount of variance in CBM-SR scores from individual score differences, grade levels, and special education status. The results indicated that on two of the passages, variability in CBM-SR scores came primarily from grade level differences in scores on the tasks, while on the third passage, the differences were most attributable to individual differences in scores, regardless of grade level or special education services. Implications for the use of CBM-SR items for routine assessment of students' reading skills are discussed. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 363,377, 2003. [source] Transcriptome response of the Pacific oyster (Crassostrea gigas) to infection with Vibrio tubiashii using cDNA AFLP differential displayANIMAL GENETICS, Issue 5 2009N. Taris Summary We used qualitative complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) differential display analysis and real-time, quantitative PCR (RT-qPCR) to identify genes in the Pacific oyster Crassostrea gigas, whose transcription either changes in response to exposure to a pathogenic bacterium (Vibrio tubiashii) or varies between families known to differ in sensitivity to heat stress, before and at 12 and 36 h after bacterial exposure at a temperature of 25 °C. These conditions simulate those associated with summer mortality syndrome, a poorly understood cause of massive mortalities in cultured Pacific oysters in North America, Asia and Europe. Using 32 AFLP primer pairs, we identified 92 transcript-derived fragments that are qualitatively differentially expressed. We then cloned and sequenced 14 of these fragments, designed fragment-specific primers and quantified their transcription patterns using RT-qPCR. Most of the differences in transcription patterns between stress-tolerant and stress-sensitive families were evident before bacterial exposure, and genes that responded to bacterial exposure did so in parallel between stress-sensitive and stress-tolerant families. blast searches of sequence databases revealed that these fragments represent genes involved in immune response as well as genes related to metabolic processes. Our data support the hypothesis that family level differences in resistance to stress in Pacific oysters are largely attributable to constitutive differences in gene transcription or ,general vigour' that are detectable before and maintained after infection, rather than being due to induced responses at the transcriptome level. [source] | |||||||||||||