Bimodal Group Research Articles

Quality of life in bimodal hearing users (unilateral cochlear implants and contralateral hearing aids).

The main objective was to evaluate the bimodal self-rated benefits on auditory performance under real conditions and the quality of life in two groups of cochlear-implanted adults, with or without a contralateral hearing aid. The secondary objective was to investigate correlations between the use of a hearing aid and residual hearing on the non-implanted ear. This retrospective study was realized between 2000 and 2010 in two referral centers. A population of 183 postlingually deaf adults, implanted with a cochlear experience superior to 6 months, was selected. The Speech, Spatial, and other Qualities of Hearing Scale were administered to evaluate the auditory performances, and the Nijmegen Cochlear Implant Questionnaire to evaluate the quality of life. The population was divided into two groups: a group with unilateral cochlear implants (Cochlear Implant-alone, n = 54), and a bimodal group with a cochlear implant and a contralateral hearing aid (n = 62). Both groups were similar in terms of auditory deprivation duration, duration of cochlear implant use, and pure-tone average on the implanted ear. There was a significant difference in terms of pure-tone average on low and low-to-mid frequencies on the non-implanted ear. The scores on both questionnaires showed an improvement in the basic sound perception and quality of social activities for the bimodal group. The results suggest that the bimodal stimulation (cochlear implant and contralateral hearing aid) improved auditory perception in quiet and the quality of life domain of social activities.

Fast phonetic learning in very young infants: what it shows, and what it doesn't show.

Fast phonetic learning in very young infants: what it shows, and what it doesn't show.

Thermodilution-Derived Coronary Blood Flow Pattern Immediately After Coronary Intervention as a Predictor of Microcirculatory Damage and Midterm Clinical Outcomes in Patients With ST-Segment–Elevation Myocardial Infarction

Despite a sufficient coronary blood flow after primary percutaneous coronary intervention for patients with ST-segment-elevation myocardial infarction; some patients have a poor outcome because of microcirculatory damage. This study evaluates whether the thermodilution-derived coronary blood flow parameters immediately after primary percutaneous coronary intervention predict early microvascular damage and midterm outcomes in patients with ST-segment-elevation myocardial infarction. Using a pressure sensor/thermistor-tipped guidewire, we measured the index of microcirculatory resistance at maximum hyperemia, and coronary blood flow pattern was assessed from the thermodilution curves after successful primary percutaneous coronary intervention in 88 patients with ST-segment-elevation myocardial infarction. Coronary blood flow pattern was classified into 3 groups according to the shape of thermodilution curve: a narrow unimodal (n=41), a wide unimodal (n=32), or bimodal (n=15). All patients had contrast-enhanced cardiac magnetic resonance scans within 2 weeks. The index of microcirculatory resistance values were significantly higher both in a wide unimodal and in a bimodal groups than in a narrow unimodal group (65±41 and 76±38 versus 20±9U; P<0.001). Bimodal group had higher prevalence of microvascular obstruction on contrast-enhanced cardiac magnetic resonance when compared with the other groups (100%, 78%, and 30%; P<0.001). Patients in bimodal group had a higher risk of death and heart failure rehospitalization at 6 months (73%, 6.3%, 7.3%; P<0.001). Multivariate analysis revealed that bimodal shape of the thermodilution curve was the only independent predictor of cardiac death at 6 months after ST-segment-elevation myocardial infarction (P<0.01). A bimodal shape of the thermodilution curve, which may indicate myocardial edema and consequent extrinsic compression of the capillary network, is associated with microcirculatory damage and poor midterm clinical outcomes rather than index of microcirculatory resistance value itself.

Base and precious metal resources in seafloor massive sulfide deposits

Interest in seafloor massive sulfide deposits as a possible source of metals has been strong since the discovery of submarine hydrothermal vents in 1977. To aid decision-makers, an assessment of undiscovered seafloor massive sulfide deposits is made here. Estimates of number of undiscovered deposits and their metal contents are made and presented in probabilistic form to represent the inherent uncertainties in such estimates. The three-part form of assessment is used as a framework for this assessment because it can provide unbiased and reasonable estimates provided that consistent mineral deposit models are used. Four kilometer wide zones centered on a 256,000km2 tract associated with spreading centers and a tract of 100,000km2 associated with volcanic arcs and back-arc basins are delineated as permissive for undiscovered deposits. Well-explored volcanogenic massive sulfide deposits on land serve both as models of contained metals and as density models of deposit numbers. Density models provide probabilistic estimates of number of deposits in each tract. Frequency distributions of Zn, Cu, Pb, Ag, and Au contents in land deposits are used to represent metal contents in undiscovered seafloor deposits. Metal distributions were grouped into a mafic-related group to apply to the spreading center tract and a felsic and bimodal group to apply to the back-arc and volcanic arc tract. Tests of dependency of resource estimates demonstrate for the first time that independence can be assumed to combine such estimates using Monte Carlo simulation.Simulation is used to combine probabilistic number of deposits estimates for the two tracts and each of the five linked metal content distributions. Median estimates of undiscovered Zn, Cu, Pb, Ag, and Au are 6.4million, 4.6million, 1.2million, 10,000, and 390t respectively. Although there is considerable uncertainty in estimated amounts of Zn, Cu, Pb, Ag, and Au in undiscovered seafloor massive sulfide deposits located in the 4km wide zones, even the most optimistic estimates suggest that these deposits cannot make a substantial contribution to global metal production.

Sucking and swallowing rates after palatal anesthesia: an electromyographic study in infant pigs.

Infant mammalian feeding consists of rhythmic suck cycles and reflexive pharyngeal swallows. Although we know how oropharyngeal sensation influences the initiation and frequency of suck and swallow cycles, the role of palatal sensation is unknown. We implanted EMG electrodes into the mylohyoid muscle, a muscle active during suckling, and the thyrohyoid muscle, a muscle active during swallowing, in eight infant pigs. Pigs were then bottle-fed while lateral videofluoroscopy was simultaneously recorded from the electrodes. Two treatments were administered prior to feeding and compared with control feedings: 1) palatal anesthesia (0.5% bupivacaine hydrochloride), and 2) palatal saline. Using the timing of mylohyoid muscle and thyrohyoid muscle activity, we tested for differences between treatment and control feedings for swallowing frequency and suck cycle duration. Following palatal anesthesia, four pigs could not suck and exhibited excessive jaw movement. We categorized the four pigs that could suck after palatal anesthesia as group A, and those who could not as group B. Group A had no significant change in suck cycle duration and a higher swallowing frequency after palatal saline (P = 0.021). Group B had significantly longer suck cycles after palatal anesthesia (P < 0.001) and a slower swallowing frequency (P < 0.001). Swallowing frequency may be a way to predict group membership, since it was different in control feedings between groups (P < 0.001). The qualitative and bimodal group response to palatal anesthesia may reflect a developmental difference. This study demonstrates that palatal sensation is involved in the initiation and frequency of suck and swallow cycles in infant feeding.

Clinical Selection Criteria for a Second Cochlear Implant for Bimodal Listeners

To compare the speech perception benefit, provided by a contralateral hearing aid (HA) or a second cochlear implant (CI). Repeated measures. A total of 25 adult subjects participated in the study, including 12 bilateral (10 female and 2 male patients) and 13 bimodal (6 female and 7 male subjects) users. All bilateral users were sequentially implanted. The bimodal users were separated into a poor group (n = 5, aided pure-tone average (PTA) of 55 dB HL or greater at audiometric frequencies of 1 kHz or lesser) and a good group (n = 8, aided PTA < 55 dB HL). Consonant, vowel, and sentence recognition was measured in quiet and noise at +5 dB and +10 dB signal-to-noise ratios (SNRs). Speech recognition performance was evaluated under three listening conditions: CI alone, HA alone, and CI+HA for bimodal users; first CI alone, second CI alone, and first CI + second CI for bilateral users when speech and noise were presented from the front. There was no significant difference in the binaural benefit between the good bimodal and bilateral groups in vowel and sentence recognition. However, the binaural benefit is significantly better in the bilateral group than in the poor bimodal group for all 3 speech measures. These results suggest that the aided pure-tone average at audiometric frequencies of 1 kHz or lesser may serve as one of the clinical criteria for the recommendation of whether bimodal patients should consider a second cochlear implant to maximize their binaural listening ability.

Comparison of Bimodal and Bilateral Cochlear Implant Users on Speech Recognition With Competing Talker, Music Perception, Affective Prosody Discrimination, and Talker Identification

Despite excellent performance in speech recognition in quiet, most cochlear implant users have great difficulty with speech recognition in noise, music perception, identifying tone of voice, and discriminating different talkers. This may be partly due to the pitch coding in cochlear implant speech processing. Most current speech processing strategies use only the envelope information; the temporal fine structure is discarded. One way to improve electric pitch perception is to use residual acoustic hearing via a hearing aid on the nonimplanted ear (bimodal hearing). This study aimed to test the hypothesis that bimodal users would perform better than bilateral cochlear implant users on tasks requiring good pitch perception. Four pitch-related tasks were used. 1. Hearing in Noise Test (HINT) sentences spoken by a male talker with a competing female, male, or child talker. 2. Montreal Battery of Evaluation of Amusia. This is a music test with six subtests examining pitch, rhythm and timing perception, and musical memory. 3. Aprosodia Battery. This has five subtests evaluating aspects of affective prosody and recognition of sarcasm. 4. Talker identification using vowels spoken by 10 different talkers (three men, three women, two boys, and two girls). Bilateral cochlear implant users were chosen as the comparison group. Thirteen bimodal and 13 bilateral adult cochlear implant users were recruited; all had good speech perception in quiet. There were no significant differences between the mean scores of the bimodal and bilateral groups on any of the tests, although the bimodal group did perform better than the bilateral group on almost all tests. Performance on the different pitch-related tasks was not correlated, meaning that if a subject performed one task well they would not necessarily perform well on another. The correlation between the bimodal users' hearing threshold levels in the aided ear and their performance on these tasks was weak. Although the bimodal cochlear implant group performed better than the bilateral group on most parts of the four pitch-related tests, the differences were not statistically significant. The lack of correlation between test results shows that the tasks used are not simply providing a measure of pitch ability. Even if the bimodal users have better pitch perception, the real-world tasks used are reflecting more diverse skills than pitch. This research adds to the existing speech perception, language, and localization studies that show no significant difference between bimodal and bilateral cochlear implant users.

Milk flow traits in Mediterranean Italian Buffaloes

The aim of this study was to analyze the milk flow pattern in Italian Mediterranean Buffaloes in relation to parity and oxytocin administration. A total of 330 milk flow recorders were collected during morning and evening milkings by using an electronic milk flow meters (Lactocorder®). Milk flow curves were examined and subject were divided according milk flow pattern in: normal pattern, bimodal pattern and “double pattern”. Data were analysed by using ANOVA and Chi square test. Total milk yield per milking was significantly higher (P<0.01) in pluriparous and consistent with the average DIM of 205 days. No differences in milk yield and maximum milk flow were found between the oxytocin groups while both parameters were higher in bimodal and double pattern groups compared to normal milk flow pattern. Lag time was higher (P<0.01) in oxytocin treated group and in normal vs the other two pattern groups. Length of main milking phase was higher in pluriparous, oxytocin treated group (P<0.01) and in bimodal vs the normal one (P<0.05) while double pattern showed the highest value (P<0.01). Percentage of bimodal milk flow was 13.7% while a double flow pattern was 12.4%. A higher percentage of double pattern was found in oxytocin treated buffaloes vs normal and bimodal ones (18.1% vs 8.1% and 7.5% respectively; P< 0.05) and in pluriparous vs primiparous (74.4% vs 25.6%; P< 0.05).

Speech Recognition in Noise in Children With Cochlear Implants While Listening in Bilateral, Bimodal, and FM-System Arrangements

Speech recognition performance in noise was examined in children with cochlear implants (CIs) when using (a) a second CI (bilateral group), (b) a hearing aid (HA) on the nonimplant ear (bimodal group), and (c) a frequency modulation (FM) system on 1 or both sides. While always maintaining use of the first CI, 2 groups participated in 6 conditions each using various listening arrangements with the second CI, HA, or FM system. Speech-in-noise thresholds were determined using simple phrases, classroom noise, and a method-of-limits approach. No group differences were detected across any conditions. In the no-FM-system conditions, no significant benefit of bilateral or bimodal input was found relative to a single CI. In the FM-system conditions, thresholds were significantly lower (up to 20 dB) relative to all other conditions when FM-system input was provided to the first-implanted side or to both sides simultaneously. Children's speech-in-noise thresholds did not improve when providing input to the second side with a CI or an HA relative to a single CI. However, children with CIs had better speech recognition in noise with the use of an FM system on one or both sides relative to the conditions with no FM system. Binaural conditions with a single FM receiver on the second CI or HA yielded significantly poorer performance than any other FM condition.

Benefits of bilateral cochlear implants and/or hearing aids in children

This study evaluated functional benefits from bilateral stimulation in 20 children ages 4–14, 10 use two CIs and 10 use one CI and one HA. Localization acuity was measured with the minimum audible angle (MAA). Speech intelligibility was measured in quiet, and in the presence of 2-talker competing speech using the CRISP forced-choice test. Results show that both groups perform similarly when speech reception thresholds are evaluated. However, there appears to be benefit (improved MAA and speech thresholds) from wearing two devices compared with a single device that is significantly greater in the group with two CI than in the bimodal group. Individual variability also suggests that some children perform similarly to normal-hearing children, while others clearly do not. Future advances in binaural fitting strategies and improved speech processing schemes that maximize binaural sensitivity will no doubt contribute to increasing the binaurally-driven advantages in persons with bilateral CIs.

Neural activity profiles of the neocortex and superior colliculus after bimodal sensory stimulation.

Current efforts at functional mapping of multisensory neurons are hampered by the need for both cellular-level resolution and the separate visualization of activity by different sensory cues. We have used a recently developed technique that exploits the differential time course of zif268 mRNA versus protein induction in neurons after sensory stimulation. Adult male rats were visually and acoustically deprived and then exposed to one of the following stimulation sequences: (i) no sensory stimulation; (ii) 2 h visual stimulation followed by 30 min auditory stimulation; (iii) 2 h auditory stimulation followed 30 min of visual stimulation; and (iv) 2 h compound visual and auditory stimulation. The neocortex and superior colliculus (SC) were then processed for fluorescent immunocytochemistry and in situ hybridization for staining of Zif268 protein and mRNA products. We have found that activity patterns in primary visual and auditory cortices were in accord with the sequence of the compound stimulus. We also show that SC superficial layers contained a pool of exclusively unimodal neurons, similar to that of visual cortex. Activity patterns of deep SC layers contained multimodal neurons with varying degrees of visual and auditory convergence. The deep SC layers also showed that auditory processing was largely carried out by a small, bimodal group of neurons whereas visual processing was coordinated by both a large unimodal and a small bimodal pool of neurons.

Changes of HDL Subfractions by Eicosapentaenoic Acid Intake and Physical Load in 20- to 25-Year-Old Men

The effects of daily eicosapentaenoic acid (EPA) intake and physical activity on high-density lipoprotein (HDL) subfraction, which may be an index of health status, were examined. The HDL subfraction, triglyceride and T-chol levels in the serum of 10 male volunteers aged 20–25 were examined before, immediately after and 1 h after being subjected to a physical load by bicycle ergometer at 90 W for 20 min. Subjects were then given 1.25 g EPA/day for 2 weeks, and the above test was repeated. By EPA intake, the distribution of HDL3b and 3c decreased significantly by 16.8 and 15.3%, respectively, and that of 2b increased significantly by 17.9%. The rate of change of subfraction of the 29th part (2b) of 30 parts in the total range of HDL increased by 67%, and decreased by 47% in 7th part (3c). By physical load, the distribution of HDL2a increased significantly by 15.4%, while 3b tended to decrease. By physical load after EPA intake, the distribution of 2a decreased significantly by 9.7%, and those of 3b and 3c increased significantly by 20.5 and 5.4%, respectively, and that of the 7th part (3c) increased by 37%. Thus, the physical load after EPA intake is effective to prevent arteriosclerosis as increasing the rate of change of HDL3c and as showing the longevity pattern of the HDL subfraction. Concentration of TG in a modal HDL pattern group increased by 95% after EPA intake, but that of a bimodal group did not show any change. HDL-cholesterol level in the bimodal group was higher than that in the modal group, especially after EPA intake. Two type III subjects changed to type IV by the load and the EPA intake, respectively. Thus, it seemed that the transformation from a modal pattern to a bimodal pattern by a certain lifestyle, especially regular physical activity and proper food intake, is a very important trial for the prevention of cerebrovascular diseases.

Interpersonal communication skills of deaf adolescents and their relationship to communication history

As part of a longitudinal study, the conversational skills of 67 deaf adolescents were assessed in spoken English, simultaneous communication (SimCom) and American Sign Language (ASL). Two groups of students were identified on the basis of the communication used in their current educational program: a small group of 16 students in programs using spoken English (oral) and a larger group of 51 students in programs using sign communication (bimodal). Students in spoken English programs had good spoken English skills and limited ASL skills, whereas the reverse was true for students in bimodal programs. Most students demonstrated sufficient skill in one or more systems to meet basic interpersonal communications needs, but not those required for advanced academic discourse. In neither group was spoken English related to ASL skill. SimCom skills were strongly related to spoken English in the oral program group and to ASL in the bimodal program group. Spoken English in adolescence was highly predictable from spoken English in early childhood. Within the bimodal program group, students with deaf parents had better SimCom and ASL skills than those with hearing parents. Among bimodal program students with hearing parents, better SimCom skills (but not ASL skills) were associated with earlier introduction to sign communication in school and to mothers' use of sign communication.

Motion of Non-Spherical Microparticles with Center of Gravity Offset in a Circulating Flow.

The motion and structure of non-spherical particles with center of gravity offset in a circulating flow are analyzed numerically using a dumbbell model. The calculation is performed by the Stokesian dynamics which accounts for multiple-body hydrodynamic interparticle interactions based on the Stokes equation. A dumbbell is found to rotate or orient, depending on the center of gravity offset and the strength of the circulating vortex. The cluster deforms and rotates, and its formation shows a sequence of modes such as rupture, isolation, and aggregation. Three types of particle systems are used : (a) rotating particle groups, (b) orienting particle groups, (c) bimodal groups of rotating and orienting particles. In particle system (b), each particle forms face-to-face aggregations and the size of clusters becomes large compared with those of particle system (a). In particle system (c), the particles of each species, i. e., rotating particles and orienting particles, gather together and form clusters which consist of the same kind of particles. It appears that the local separation of two particle species results from the motion of particle pairs of two species, where the rotating particle rolls over the orienting particle.

Phenological Behavior of Habit and Habitat Classes on Barro Colorado Island (Panama Canal Zone)

Phenological patterns of flowering and fruiting are presented for species of phanerogams on Barro Colorado Island. The phenological patterns represent overall averages rather than for any single year or for any individual. Flowering and fruiting graphs were prepared by calculating the total number of species which might be in flower or fruit for any month. Species were divided according to both habit and habitat. Aquatic and suffruticose herbs were found to be aseasonal as were the arborescent plants of clearings. Clearing herbs, herbaceous vines, epiphytic herbs, as well as lianas and trees, are seasonal with a peak of activity in the dry season. Forest herbs including herbs of forest trails, lightgaps and edges, as well as shrubs, have a peak of activity in the rainy season. In contrast to the clearing herbs, these groups appear to be relatively unaffected by conditions of drought, and flowering is probably cued by the onset of the rainy season. The average length of flowering time is least for those groups which were markedly seasonal such as lianas and larger trees. Species studied were divided into 20 seasonal groups, 6 nonseasonal groups, and 1 bimodal group. A total of 295 species flower and fruit all year. The largest seasonal categories include those species which flower and fruit in the wet season (171 spp.) and those which flower and fruit in the dry season (132 spp.). More species flower and fruit in the rainy season than in the dry season, despite the fact that the overall flowering and fruiting curves peak in the dry season. THE DATA PRESENTED HERE are the result of field observations and herbarium studies made between 1967 and 1974, and include observations made during more than three years in Panama and a survey of more than 50,000 herbarium specimens from Barro Colorado Island and adjacent areas. The study has been an integral part of the new Barro Colorado Island Flora which is now being completed and which attempts to determine the phenological behavior of flowering and fruiting for all species of flowering plants that occur on the Island. In these data no attempt has been made to outline the phenology of individual plants, though numerous individuals were repeatedly observed. Instead the data represent what are thought to be the normal phenological variation for each species. This might be termed its historical pattern of flowering. No attempt has been made to include the broad outlier especially when the phenology of the species involved is well-known. In the well-known species an estimated 95 percent or more of the flowering or fruiting probably falls within the time span indicated in the studies. The flowering or fruiting period given for most species is broader than that for any single year. However, since weather patterns are in general consistent and since plants have probably evolved a phenology which is compatible with a particular climatic condition, I have chosen to look at overall phenological patterns rather than what might happen in any one year. Variation in phenological patterns from year to year for any species is considerable and can also be great between individuals in a given year both in terms of timing and duration. Although other phenological studies have been made (Rovirosa 1892; Fournier and Salas 1966; Janzen 1967; Smythe 1970; Foster, unpublished; Frankie, Baker, and Opler 1974), this is the only known attempt to define an entire flora in a phenological

CHEMICAL DISCRIMINATION OF TERRA ROSSAS AND RENDZINAS

SummaryOne of the discriminant functions of mathematical statistics is used in a re‐examination of the chemical features of some terra rossas and rendzinas from South Australia. The results indicate that these soils constitute a bimodal group chemically. Dichotomy is therefore justifiable on chemical as well as on mor‐phological grounds.The use of a discriminant function in taxonomic work is illustrated by an application to some extra‐Australian terra rossas and rendzinas. The result suggests that soils with similar morphological features usually have similar chemical features.