Using Rasch Analysis to Assess and Improve the Measurement Properties of a Questionnaire With Few Items: The York Binaural Hearing-Related Quality of Life (YBHRQL) Questionnaire.

OBJECTIVES: The York Binaural Hearing-Related Quality of Life questionnaire is a condition-specific preference-based instrument sensitive to advantages of binaural over monaural hearing. Respondents use 5-point scales to report the difficulty experienced with three dimensions of listening that are easier or more successful when hearing is binaural: understanding speech in spatially separated noise, localizing sources of sound in azimuth, and the associated effort and fatigue. Previously, a preference value was estimated for each combination of dimension and level so that a value of binaural utility could be assigned to a respondent to inform analyses of cost effectiveness. The present objective was to determine whether the questionnaire conforms with the Rasch model sufficiently well for estimates of the binaural abilities of respondents to be obtained on an interval scale to inform parametric analyses of clinical effectiveness. DESIGN: Data were obtained from unilateral cochlear implantees (N = 418; 209 ≤62 years; 209 ≥63 years) and members of the public (N = 325; 207 ≤62 years; 118 ≥63 years). A subset of implantees (N = 118) responded at test and retest. Responses were fitted to the partial credit model using the Extended Rasch Modeling package. Conformity with the model was evaluated in six ways: the ordering of response categories ( Monotonicity ) was assessed with plots of response probability against ability; differential item functioning ( DIF ) was assessed by analyses of variance of standardized response residuals; alignment of participants' abilities with item difficulties ( Targeting ) was assessed with person-item maps; fit to the model ( Fit ) was assessed by comparing the means and variabilities of observed and expected responses, and by comparing observed values with analyses of simulated datasets; the hypothesis that item difficulties and participants' abilities were measured on a single underlying scale ( Unidimensionality ) was assessed with principal components analyses of standardized response residuals. RESULTS: Values of fit statistics were toward the lower end of the acceptable range. Comparisons with analyses of simulated datasets showed that low values were primarily the result of the structural limitation of including only three items. Modal values of the probabilities of response categories were ordered monotonically, but some response thresholds were disordered because of under-use of one category. Pooling categories to correct disordered thresholds resulted in estimates of ability that were less discriminatory of differences within and between groups, and showed less reproducibility between test and retest, than did the original estimates. Neither source-related DIF nor gender-related DIF arose. Uniform age-related DIF arose for the speech-in-noise item and could be managed by resolving the item. The resulting estimates of ability and difficulty were well targeted and unidimensional. CONCLUSIONS: The York Binaural Hearing-Related Quality of Life questionnaire, with three items each with five response categories, conforms with the Rasch model sufficiently well to yield practically useful measures of the abilities of participants. The trait measured by the questionnaire aligns with the ability to benefit from binaural hearing. More discriminatory measurement of this ability would be achieved with more items. Nonetheless, the questionnaire possesses the virtue that responses to the same three questions can be scored in different ways to inform parametric analyses of both cost-effectiveness and clinical effectiveness.

Development and Critical Evaluation of a Condition-Specific Preference-Based Measure Sensitive to Binaural Hearing in Adults: The York Binaural Hearing-Related Quality-of-Life System.

OBJECTIVES: The widely-used generic preference-based measures of health-related quality of life-the EuroQol Descriptive System (EQ-5D) and the Health Utilities Index (HUI3)-are limited in their response to technologies that improve hearing. The EQ-5D lacks construct validity for hearing, while the HUI3 is restricted by a ceiling effect and by using speech reception as the only evidence of the ability to hear. Consequently, neither measure consistently registers benefits from binaural hearing, such as those from bilateral versus unilateral cochlear implantation. The objectives were to test whether informants value binaural hearing, to develop a condition-specific preference-based measure sensitive to binaural hearing, to assess the psychometric properties of the new instrument, and to determine whether it meets requirements for informing judgments of cost-effectiveness: does it measure greater gains than do the generic preference-based measures, while avoiding exaggerating losses, and displaying sensitivity to side effects? DESIGN: Three levels of function, ranging from no difficulty to great difficulty, were defined on each of three dimensions where listening is easier or more successful when hearing is binaural rather than monaural: perception of speech in spatially separated noise, localization of sounds, and effort and fatigue. Informants (N = 203) valued the 27 combinations of levels and dimensions in a time trade-off task with a 10-year time frame to provide a value of binaural-related quality of life ("binaural utility") for each combination. A questionnaire was compiled to allow respondents to report their level of function on each dimension so that a value of binaural utility could be assigned to them. The questionnaire and the age-standardized valuations constitute The York Binaural Hearing-Related Quality-of-Life System (YBHRQL). Adult users of unilateral implants (N = 8), bilateral implants (N = 11), or bimodal aiding (N = 9) undertook performance tests of spatial listening and completed the HUI3, EQ-5D, and Speech, Spatial, and Qualities of Hearing (SSQ) questionnaires. They completed the YBHRQL questionnaire 24 and 38 mo later. RESULTS: Despite long intervals between measurements, the YBHRQL demonstrated desirable psychometric properties: good construct validity evidenced by significant correlations with performance measures and the SSQ index; a greater ability than the EQ-5D or HUI3 to distinguish unilateral, bimodal, and bilateral listening; and good reproducibility. The YBHRQL did not exaggerate losses of utility but was insensitive to a potential side effect of implantation (pain/discomfort). It measured a gain in utility from bilateral compared with unilateral implantation (median = 0.11, interquartile range, 0.03 to 0.16) that was greater than the gain measured by the EQ-5D (0.00, 0.00 to 0.00) but not the HUI3 (0.00, 0.00 to 0.17). CONCLUSIONS: The YBHRQL summarizes the contribution of binaural hearing to quality of life by combining the functional status of a listener with the preferences of independent informants. It would be an efficient clinical outcome measure. In addition, if used alongside the EQ-5D or HUI3, it would provide evidence which could beneficially modulate confidence in the cost-effectiveness of interventions. Further research on its sensitivity to side effects, and on the size of the gains in utility which it measures, is needed to determine whether it could stand alone to inform resource-allocation decisions.

Sensitivity of EQ-5D-3L, HUI2, HUI3, and SF-6D to changes in speech reception and tinnitus associated with cochlear implantation.

PURPOSE: There is concern that some generic preference-based measures (GPMs) of health-related quality of life may be insensitive to interventions that improve hearing. Establishing where sensitivity arises could contribute to the design of improved measures. Accordingly, we compared the sensitivity of four widely used GPMs to a clinically effective treatment-cochlear implantation-which restores material degrees of hearing to adults with little or no functional hearing. METHODS: Participants (N = 147) received implants in any of 13 hospitals in the UK. One month before implantation and 9 months after, they completed the HUI2, HUI3, EQ5D3L, and SF-6D questionnaires, together with the EuroQoL visual-analogue scale as a direct measure of health, a performance test of speech reception, and a self-report measure of annoyance due to tinnitus. RESULTS: Implantation was associated with a large improvement in speech reception and a small improvement in tinnitus. HUI2 and HUI3 were sensitive to the improvement in speech reception through their Sensation and Hearing dimensions; EQ5D3L was sensitive to the improvement in tinnitus through its Anxiety/Depression dimension; SF-6D was sensitive to neither. Participants reported no overall improvement in health. Variation in health was associated with variation in tinnitus, not variation in speech reception. CONCLUSIONS: None of the four GPMs was sensitive to the improvements in both speech reception and tinnitus that were associated with cochlear implantation. To capture fully the benefits of interventions for auditory disorders, developments of current GPMs would need to be sensitive to both the health-related and non-health-related aspects of auditory dysfunction.

Target identification using relative level in multi-talker listening.

Previous studies have suggested that listeners can identify words spoken by a target talker amidst competing talkers if they are distinguished by their spatial location or vocal characteristics. This "direct" identification of individual words is distinct from an "indirect" identification based on an association with other words (call-signs) that uniquely label the target. The present study assessed listeners' ability to use differences in presentation level between a target and overlapping maskers to identify target words. A new sentence was spoken every 800 ms by an unpredictable talker from an unpredictable location. Listeners reported color and number words in a target sentence distinguished by a unique call-sign. When masker levels were fixed, target words could be identified directly based on their relative level. Speech-reception thresholds (SRTs) were low (-12.9 dB) and were raised by 5 dB when direct identification was disrupted by randomizing masker levels. Thus, direct identification is possible using relative level. The underlying psychometric functions were monotonic even when relative level was a reliable cue. In a further experiment, indirect identification was prevented by removing the unique call-sign cue. SRTs did not change provided that other cues were available to identify target words directly. Thus, direct identification is possible without indirect identification.

Historic Variations in Winter Indoor Domestic Temperatures and Potential Implications for Body Weight Gain.

It has been argued that the amount of time spent by humans in thermoneutral environments has increased in recent decades. This paper examines evidence of historic changes in winter domestic temperatures in industrialised countries. Future trajectories for indoor thermal comfort are also explored. Whilst methodological differences across studies make it difficult to compare data and accurately estimate the absolute size of historic changes in indoor domestic temperatures, data analysis does suggest an upward trend, particularly in bedrooms. The variations in indoor winter residential temperatures might have been further exacerbated in some countries by a temporary drop in demand temperatures due to the 1970s energy crisis, as well as by recent changes in the building stock. In the United Kingdom, for example, spot measurement data indicate that an increase of up to 1.3°C per decade in mean dwelling winter indoor temperatures may have occurred from 1978 to 1996. The findings of this review paper are also discussed in the context of their significance for human health and well-being. In particular, historic indoor domestic temperature trends are discussed in conjunction with evidence on the links between low ambient temperatures, body energy expenditure and weight gain.

Macrophage phagocytosis of SARS-CoV-2-infected cells mediates potent plasmacytoid dendritic cell activation.

Early and strong interferon type I (IFN-I) responses are usually associated with mild COVID-19 disease, whereas persistent or unregulated proinflammatory cytokine responses are associated with severe disease outcomes. Previous work suggested that monocyte-derived macrophages (MDMs) are resistant and unresponsive to SARS-CoV-2 infection. Here, we demonstrate that upon phagocytosis of SARS-CoV-2-infected cells, MDMs are activated and secrete IL-6 and TNF. Importantly, activated MDMs in turn mediate strong activation of plasmacytoid dendritic cells (pDCs), leading to the secretion of high levels of IFN-α and TNF. Furthermore, pDC activation promoted IL-6 production by MDMs. This kind of pDC activation was dependent on direct integrin-mediated cell‒cell contacts and involved stimulation of the TLR7 and STING signaling pathways. Overall, the present study describes a novel and potent pathway of pDC activation that is linked to the macrophage-mediated clearance of infected cells. These findings suggest that a high infection rate by SARS-CoV-2 may lead to exaggerated cytokine responses, which may contribute to tissue damage and severe disease.

The use of adrenaline autoinjectors by children and teenagers.

BACKGROUND: Although adrenaline is recommended as first line treatment for anaphylaxis, it is often not utilized. There has been a debate about when adrenaline autoinjectors should be prescribed and how many should be dispensed. OBJECTIVES: To see how many adrenaline autoinjectors were used during anaphylactic reactions and to determine why they were not used in situations where they were clinically indicated. METHODS: Patients were recruited prospectively at 14 paediatric allergy clinics throughout UK. Participants completed a questionnaire covering demographic data, atopic status and details of allergic reactions in the previous year and reasons for using more than one device. RESULTS: A total of 969 patients were recruited of whom 466 (48.1%, 95% CI: 37.9-58.2) had had at least one reaction in the previous year; 245 (25.3%, 95% CI: 16.2-34.4) of these reactions were anaphylaxis. An adrenaline autoinjector was used by 41 (16.7%, 95% CI: 11.7-21.3) participants experiencing anaphylaxis. Thirteen participants received more than one dose of adrenaline, for nine of these a health professional gave at least one. The commonest reasons for using more than one were severe breathing difficulties (40%), lack of improvement with first dose (20%) and miss-firing (13.3%). The commonest reasons for not using adrenaline in anaphylaxis were 'thought adrenaline unnecessary' (54.4%) and 'unsure adrenaline necessary' (19.1%). Many with wheeze did not use their autoinjector. CONCLUSIONS AND CLINICAL RELEVANCE: Adrenaline is used by only a minority of patients experiencing anaphylaxis in the community. Thirteen of the 41 patients with anaphylaxis who used their autoinjector needed another dose of adrenaline. Further research is needed to consider how to best encourage the usage of adrenaline when clinically indicated in anaphylaxis.

Non-blinded treatment of aural -hematoma with oral prednisolone as a monotherapy in privately-owned dogs.

INTRODUCTION: Aural hematoma is the most common injury of the pinna in dogs. Treatment options are various. More recently, medical therapy has been more commonly pursued than surgical options. Therefore, our hypothesis was that monotherapy with oral prednisolone for one month is sufficient to successfully treat dogs diagnosed with aural hematoma. In this open prospective experimental study without control group, clinicians treated 24 privately-owned dogs suffering from aural hematoma with oral prednisolone at 1 mg / kg / day for 14 days, followed by 0,5 mg / kg / day for another 14 days. In case of strong side effects, the dose reduction was already initiated after 7 days of treatment. The success was assessed subjectively after 14 days by the owner and after 28 days by a clinician or specialist. In addition, before and after treatment the thickness of the swelling was measured. In 21 of 24 dogs, oral prednisolone treatment for 28 days lead to a subjective clinical improvement of at least 80 %. The ear thickness was reduced by at least 50 %. This study showed that treating dogs suffering from aural hematoma for four weeks with oral prednisolone used as a monotherapy leads to promising results and could be considered as an economical, non-invasive and safe treatment alternative for aural hematoma in dogs.

INTRODUCTION: L'hématome auriculaire est la lésion la plus fréquente du pavillon de l'oreille chez le chien. Les options de traitement sont diverses. Depuis un certain temps, la thérapie médicale a été plus souvent proposée que les options chirurgicales. Par conséquent, notre hypothèse était qu'une monothérapie avec de la prednisolone orale pendant un mois est suffisante pour traiter avec succès les chiens souffrant d'un hématome auriculaire. Dans cette étude expérimentale prospective ouverte sans groupe de contrôle, les cliniciens ont traité 24 chiens privés souffrant d'un hématome auriculaire avec de la prednisolone orale à raison de 1 mg / kg / jour pendant 14 jours, suivie de 0,5 mg / kg / jour pendant 14 autres jours. En cas de forts effets secondaires, la réduction de la dose était déjà amorcée après 7 jours de traitement. Le succès du traitement a été évalué subjectivement après 14 jours par le propriétaire et après 28 jours par un clinicien ou un spécialiste. En outre, l'épaisseur de l'enflure a été mesurée avant et après le traitement. Chez 21 des 24 chiens, le traitement oral à la prednisolone pendant 28 jours a entraîné une amélioration clinique subjective d'au moins 80 %. L'épaisseur de l'oreille a été réduite d'au moins 50 %. Cette étude a montré que le traitement des chiens souffrant d'un hématome auriculaire pendant quatre semaines avec de la prednisolone orale utilisée en monothérapie conduit à des résultats prometteurs et pourrait être considéré comme une alternative de traitement économique, non invasive et sûre pour l'hématome auriculaire chez les chiens.

Benefit of temporal fine structure to speech perception in noise measured with controlled temporal envelopes.

Previous studies have assessed the importance of temporal fine structure (TFS) for speech perception in noise by comparing the performance of normal-hearing listeners in two conditions. In one condition, the stimuli have useful information in both their temporal envelopes and their TFS. In the other condition, stimuli are vocoded and contain useful information only in their temporal envelopes. However, these studies have confounded differences in TFS with differences in the temporal envelope. The present study manipulated the analytic signal of stimuli to preserve the temporal envelope between conditions with different TFS. The inclusion of informative TFS improved speech-reception thresholds for sentences presented in steady and modulated noise, demonstrating that there are significant benefits of including informative TFS even when the temporal envelope is controlled. It is likely that the results of previous studies largely reflect the benefits of TFS, rather than uncontrolled effects of changes in the temporal envelope.

Benefits of knowing who, where, and when in multi-talker listening.

The benefits of prior information about who would speak, where they would be located, and when they would speak were measured in a multi-talker spatial-listening task. On each trial, a target phrase and several masker phrases were allocated to 13 loudspeakers in a 180 degrees arc, and to 13 overlapping time slots, which started every 800 ms. Speech-reception thresholds (SRTs) were measured as the level of target relative to masker phrases at which listeners reported key words at 71% correct. When phases started in pairs all three cues were beneficial ("who" 3.2 dB, "where" 5.1 dB, and "when" 0.3 dB). Over a range of onset asynchronies, SRTs corresponded consistently to a signal-to-noise ratio (SNR) of -2 dB at the start of the target phrase. When phrases started one at a time, SRTs fell to a SNR of -8 dB and were improved significantly, but only marginally, by constraining "who" (1.9 dB), and not by constraining "where" (1.0 dB) or "when" (0.01 dB). Thus, prior information about "who," "where," and "when" was beneficial, but only when talkers started speaking in pairs. Low SRTs may arise when talkers start speaking one at a time because of automatic orienting to phrase onsets and/or the use of loudness differences to distinguish target from masker phrases.

Effectiveness of computer-based auditory training for adult users of cochlear implants.

Cochlear implantation is effective at restoring partial hearing to profoundly deaf adults, but not all patients receive equal benefit. The present study evaluated the effectiveness of a computer-based self-administered training package that was designed to improve speech perception among adults who had used cochlear implants for more than three years. Eleven adults were asked to complete an hour of auditory training each day, five days a week, for a period of three weeks. Two training tasks were included, one based around discriminating isolated words, and the other around discriminating words in sentences. Compliance with the protocol was good, with eight out of eleven participants completing approximately 15 hours of training, as instructed. A significant improvement of eight percentage points was found on a test of consonant discrimination, but there were no significant improvements on sentence tests or on a test of vowel discrimination. Self-reported benefits were variable and generally small. Further research is needed to establish whether auditory training is particularly effective for identifiable sub-groups of cochlear-implant users.

Cytokine expression in bovine PBMC cultures stimulated with Hypoderma lineatum antigens.

Hypoderma antigens are involved in host inflammation and immune response, conditioning larvae survival. In this study, peripheral blood mononuclear cell (PBMC) cultures from Hypoderma sensitized and unsensitized cattle were performed to determine the effect of H. lineatum antigens and incubation time (18, 24, 48 h) on IFN-γ, TNF-α, IL-10 and IL-4 mRNA gene expression determined by RT-qPCR. TNF-α and IL-4 gene expression were higher in Hypoderma previously sensitized PBMCs, suggesting that a mixed Th1/Th2 response may play a significant role in host defence reactions against Hypoderma exhibited by previously infested cattle. Incubation time had a significant effect on IL-10 and TNF-α gene expression, which decreased over time. Regarding to H. lineatum antigens, the crude larval extract and the purified fraction hypodermin B (HB) produced a significant reduction of the mRNA expression levels of the proinflammatory cytokine, IFN-γ; moreover, the HB had a stimulating effect on the mRNA gene expression of the anti-inflammatory cytokine IL-10, demonstrating that the parasite would modulate the host defence mechanisms by avoiding harmful immune responses that would limit its survival into the host tissues.

Covert auditory spatial orienting: an evaluation of the spatial relevance hypothesis.

The spatial relevance hypothesis (J. J. McDonald & L. M. Ward, 1999) proposes that covert auditory spatial orienting can only be beneficial to auditory processing when task stimuli are encoded spatially. We present a series of experiments that evaluate 2 key aspects of the hypothesis: (a) that "reflexive activation of location-sensitive neurons is not sufficient to produce attentional facilitation" and (b) that "any task constraint that makes space important for the listener will produce auditory spatial cue effects" (p. 1236). Experiment 1 showed significant reflexive-orienting benefits on a nonspatial task, refuting the first claim. However, Experiments 2 to 4 reveal that informative spatial cues can improve performance on a nonspatial task, consistent with the second claim. Auditory spatial-cue benefits found with nonspatial tasks appear smaller and less reliable than those found in visual spatial-orienting studies, possibly due to differences in the coding of spatial information in vision and audition. The final experiments consider the mechanisms by which auditory spatial orienting might facilitate auditory processing and provide tentative evidence that attention enhances processing at one ear rather than influencing neurons tuned to the attended location.

Direct band-gap crossover in epitaxial monolayer boron nitride.

Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unexplored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not confirmed experimentally. Here, in contrast to the technique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reflectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1 eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit.

Comparison of word-, sentence-, and phoneme-based training strategies in improving the perception of spectrally distorted speech.

PURPOSE: To compare the effectiveness of 3 self-administered strategies for auditory training that might improve speech perception by adult users of cochlear implants. The strategies are based, respectively, on discriminating isolated words, words in sentences, and phonemes in nonsense syllables. METHOD: Participants were 18 normal-hearing adults who listened to speech processed by a noise-excited vocoder to simulate the information provided by a cochlear implant. They were assigned randomly to word-, sentence-, or phoneme-based training and underwent 9 training sessions (20 min each) on separate days over a 2- to 3-week period. The effectiveness of training was assessed as the improvement in accuracy of discriminating vowels and consonants, as well as identifying words in sentences, relative to participants' best performance in repeated tests prior to training. RESULTS: Word- and sentence-based training led to significant improvements in the ability to identify words in sentences that were significantly larger than the improvements produced by phoneme-based training. There were no significant differences between the effectiveness of word- and sentence-based training. No significant improvements in consonant or vowel discrimination were found for the sentence- or phoneme-based training groups, but some improvements were found for the word-based training group. CONCLUSION: The word- and sentence-based training strategies were more effective than the phoneme-based strategy at improving the perception of spectrally distorted speech.

Cueing listeners to attend to a target talker progressively improves word report as the duration of the cue-target interval lengthens to 2,000 ms.

Endogenous attention is typically studied by presenting instructive cues in advance of a target stimulus array. For endogenous visual attention, task performance improves as the duration of the cue-target interval increases up to 800 ms. Less is known about how endogenous auditory attention unfolds over time or the mechanisms by which an instructive cue presented in advance of an auditory array improves performance. The current experiment used five cue-target intervals (0, 250, 500, 1,000, and 2,000 ms) to compare four hypotheses for how preparatory attention develops over time in a multi-talker listening task. Young adults were cued to attend to a target talker who spoke in a mixture of three talkers. Visual cues indicated the target talker's spatial location or their gender. Participants directed attention to location and gender simultaneously ("objects") at all cue-target intervals. Participants were consistently faster and more accurate at reporting words spoken by the target talker when the cue-target interval was 2,000 ms than 0 ms. In addition, the latency of correct responses progressively shortened as the duration of the cue-target interval increased from 0 to 2,000 ms. These findings suggest that the mechanisms involved in preparatory auditory attention develop gradually over time, taking at least 2,000 ms to reach optimal configuration, yet providing cumulative improvements in speech intelligibility as the duration of the cue-target interval increases from 0 to 2,000 ms. These results demonstrate an improvement in performance for cue-target intervals longer than those that have been reported previously in the visual or auditory modalities.

Characterisation of porcine bone marrow progenitor cells identified by the anti-c-kit (CD117) monoclonal antibody 2B8/BM.

c-kit (CD117) plays an important role in the early stages of haematopoiesis. Previous studies of porcine haematopoietic stem cells have relied for their identification on the use of the c-kit ligand stem cell factor. Here, we describe a new mAb, 2B8/BM, that recognizes a 155-kDa protein expressed on a small subset (2-8%) of bone marrow haematopoietic cells. 2B8/BM(+) cells have a blast appearance, and are mostly negative for lineage-specific markers or express low levels of CD172a or SLA-II. In in vitro colony-forming unit assays these cells were able to give rise to erythroid and myeloid colonies. Altogether these data suggested that the 2B8/BM antigen might be the porcine orthologue of the human c-kit. This specificity was confirmed by the binding of mAb 2B8/BM to CHO cells transfected with a plasmid encoding the porcine c-kit ectodomain. This antibody can facilitate the isolation and enrichment of porcine stem cells to be used in procedures aimed to induce xenograft tolerance or to test their potential to repair damaged tissues and organs.

Peripheral hearing loss reduces the ability of children to direct selective attention during multi-talker listening.

Restoring normal hearing requires knowledge of how peripheral and central auditory processes are affected by hearing loss. Previous research has focussed primarily on peripheral changes following sensorineural hearing loss, whereas consequences for central auditory processing have received less attention. We examined the ability of hearing-impaired children to direct auditory attention to a voice of interest (based on the talker's spatial location or gender) in the presence of a common form of background noise: the voices of competing talkers (i.e. during multi-talker, or "Cocktail Party" listening). We measured brain activity using electro-encephalography (EEG) when children prepared to direct attention to the spatial location or gender of an upcoming target talker who spoke in a mixture of three talkers. Compared to normally-hearing children, hearing-impaired children showed significantly less evidence of preparatory brain activity when required to direct spatial attention. This finding is consistent with the idea that hearing-impaired children have a reduced ability to prepare spatial attention for an upcoming talker. Moreover, preparatory brain activity was not restored when hearing-impaired children listened with their acoustic hearing aids. An implication of these findings is that steps to improve auditory attention alongside acoustic hearing aids may be required to improve the ability of hearing-impaired children to understand speech in the presence of competing talkers.

An atomic carbon source for high temperature molecular beam epitaxy of graphene.

We report the use of a novel atomic carbon source for the molecular beam epitaxy (MBE) of graphene layers on hBN flakes and on sapphire wafers at substrate growth temperatures of ~1400 °C. The source produces a flux of predominantly atomic carbon, which diffuses through the walls of a Joule-heated tantalum tube filled with graphite powder. We demonstrate deposition of carbon on sapphire with carbon deposition rates up to 12 nm/h. Atomic force microscopy measurements reveal the formation of hexagonal moiré patterns when graphene monolayers are grown on hBN flakes. The Raman spectra of the graphene layers grown on hBN and sapphire with the sublimation carbon source and the atomic carbon source are similar, whilst the nature of the carbon aggregates is different - graphitic with the sublimation carbon source and amorphous with the atomic carbon source. At MBE growth temperatures we observe etching of the sapphire wafer surface by the flux from the atomic carbon source, which we have not observed in the MBE growth of graphene with the sublimation carbon source.

High IFN-alpha responses associated with depletion of lymphocytes and natural IFN-producing cells during classical swine fever.

During the acute phase of the viral hemorrhagic disease, classical swine fever (CSF), a severe hematologic depletion in primary lymphoid organs and depletion of peripheral blood T and B lymphocytes are observed. The onset of these pathologic events is before viremia and independent of leukocyte infection, indicating a host-mediated effect possibly through a cytokine storm. Here, we show that high serum levels of interferon- alpha (IFN-alpha) were found during this phase of CSF, detectable as early as 2 days postinfection and reaching maximum levels 3-5 days postinfection (250-1300 U/mL). This IFN-alpha response was related to the virulence of the viral strain used, with avirulent virus not inducing any detectable serum IFN-alpha. A progressive depletion of natural IFN-producing cells/plasmacytoid dendritic cells (pDC), the likely in vivo source of IFN-alpha, was also induced by the viral infection. An important finding was that the onset of severe lymphopenia was concomitant with the IFN-alpha responses, and all animals with serum IFN-alpha had depleted B and T lymphocytes. A statistically significant correlation between lymphocyte depletion and serum IFN-alpha indicates a relationship between the two events, which is supported by the known hematologic effects of high IFN-alpha doses in vivo.