Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 157
Filter
1.
Ear Hear ; 44(6): 1526-1539, 2023.
Article in English | MEDLINE | ID: mdl-37358331

ABSTRACT

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.


Subject(s)
Hearing , Quality of Life , Humans , Reproducibility of Results , Treatment Outcome , Surveys and Questionnaires , Psychometrics/methods
2.
Cell Mol Immunol ; 20(7): 835-849, 2023 07.
Article in English | MEDLINE | ID: mdl-37253946

ABSTRACT

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.


Subject(s)
COVID-19 , Interferon Type I , Humans , SARS-CoV-2/metabolism , Interleukin-6/metabolism , COVID-19/metabolism , Interferon-alpha/metabolism , Macrophages/metabolism , Cytokines/metabolism , Phagocytosis , Interferon Type I/metabolism , Dendritic Cells/metabolism
3.
Schweiz Arch Tierheilkd ; 164(6): 447-455, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35652255

ABSTRACT

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.


Subject(s)
Dog Diseases , Animals , Dog Diseases/drug therapy , Dog Diseases/surgery , Dogs , Hematoma/drug therapy , Hematoma/surgery , Hematoma/veterinary , Prednisolone/therapeutic use , Prospective Studies
4.
Ear Hear ; 43(2): 379-397, 2022.
Article in English | MEDLINE | ID: mdl-34432671

ABSTRACT

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.


Subject(s)
Cochlear Implantation , Cochlear Implants , Speech Perception , Adult , Cochlear Implantation/methods , Hearing , Humans , Quality of Life , Reproducibility of Results , Surveys and Questionnaires
5.
Vet Parasitol ; 283: 109165, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32535488

ABSTRACT

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.


Subject(s)
Cytokines/metabolism , Diptera/immunology , Gene Expression , Leukocytes, Mononuclear/metabolism , RNA, Messenger/genetics , Animals , Antigens , Cattle , Cells, Cultured , Diptera/genetics , RNA, Messenger/metabolism
6.
Nat Commun ; 10(1): 2639, 2019 06 14.
Article in English | MEDLINE | ID: mdl-31201328

ABSTRACT

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.

7.
Qual Life Res ; 28(5): 1145-1154, 2019 May.
Article in English | MEDLINE | ID: mdl-30484121

ABSTRACT

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.


Subject(s)
Cochlear Implantation/adverse effects , Quality of Life/psychology , Speech/physiology , Tinnitus/etiology , Adult , Cochlear Implantation/methods , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , Tinnitus/pathology
8.
Atten Percept Psychophys ; 80(6): 1520-1538, 2018 08.
Article in English | MEDLINE | ID: mdl-29696570

ABSTRACT

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.


Subject(s)
Attention/physiology , Auditory Perception , Cues , Time Factors , Female , Humans , Male , Speech Perception/physiology , Task Performance and Analysis , Young Adult
9.
Sci Rep ; 7(1): 6598, 2017 07 26.
Article in English | MEDLINE | ID: mdl-28747805

ABSTRACT

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.

10.
Hear Res ; 350: 160-172, 2017 07.
Article in English | MEDLINE | ID: mdl-28505526

ABSTRACT

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.


Subject(s)
Adolescent Behavior , Attention , Child Behavior , Disabled Children/psychology , Hearing Disorders/psychology , Perceptual Masking , Persons With Hearing Impairments/psychology , Sound Localization , Speech Perception , Acoustic Stimulation , Adolescent , Age Factors , Audiometry, Pure-Tone , Audiometry, Speech , Auditory Threshold , Brain Mapping/methods , Case-Control Studies , Child , Cues , Electroencephalography , England , Evoked Potentials, Auditory , Female , Hearing , Hearing Disorders/diagnosis , Hearing Disorders/physiopathology , Humans , Male , Psychoacoustics , Sex Factors
11.
J Assoc Res Otolaryngol ; 17(4): 331-40, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27164943

ABSTRACT

Studies with humans and other mammals have provided support for a two-channel representation of horizontal ("azimuthal") space in the auditory system. In this representation, location-sensitive neurons contribute activity to one of two broadly tuned channels whose responses are compared to derive an estimate of sound-source location. One channel is maximally responsive to sounds towards the left and the other to sounds towards the right. However, recent psychophysical studies of humans, and physiological studies of other mammals, point to the presence of an additional channel, maximally responsive to the midline. In this study, we used electroencephalography to seek physiological evidence for such a midline channel in humans. We measured neural responses to probe stimuli presented from straight ahead (0 °) or towards the right (+30 ° or +90 °). Probes were preceded by adapter stimuli to temporarily suppress channel activity. Adapters came from 0 ° or alternated between left and right (-30 ° and +30 ° or -90 ° and +90 °). For the +90 ° probe, to which the right-tuned channel would respond most strongly, both accounts predict greatest adaptation when the adapters are at ±90 °. For the 0 ° probe, the two-channel account predicts greatest adaptation from the ±90 ° adapters, while the three-channel account predicts greatest adaptation when the adapters are at 0 ° because these adapters stimulate the midline-tuned channel which responds most strongly to the 0 ° probe. The results were consistent with the three-channel account. In addition, a computational implementation of the three-channel account fitted the probe response sizes well, explaining 93 % of the variance about the mean, whereas a two-channel implementation produced a poor fit and explained only 61 % of the variance.


Subject(s)
Auditory Cortex/physiology , Models, Biological , Adult , Electroencephalography , Female , Humans , Male , Young Adult
12.
Hear Res ; 336: 83-100, 2016 06.
Article in English | MEDLINE | ID: mdl-27178442

ABSTRACT

Selective attention is critical for successful speech perception because speech is often encountered in the presence of other sounds, including the voices of competing talkers. Faced with the need to attend selectively, listeners perceive speech more accurately when they know characteristics of upcoming talkers before they begin to speak. However, the neural processes that underlie the preparation of selective attention for voices are not fully understood. The current experiments used electroencephalography (EEG) to investigate the time course of brain activity during preparation for an upcoming talker in young adults aged 18-27 years with normal hearing (Experiments 1 and 2) and in typically-developing children aged 7-13 years (Experiment 3). Participants reported key words spoken by a target talker when an opposite-gender distractor talker spoke simultaneously. The two talkers were presented from different spatial locations (±30° azimuth). Before the talkers began to speak, a visual cue indicated either the location (left/right) or the gender (male/female) of the target talker. Adults evoked preparatory EEG activity that started shortly after (<50 ms) the visual cue was presented and was sustained until the talkers began to speak. The location cue evoked similar preparatory activity in Experiments 1 and 2 with different samples of participants. The gender cue did not evoke preparatory activity when it predicted gender only (Experiment 1) but did evoke preparatory activity when it predicted the identity of a specific talker with greater certainty (Experiment 2). Location cues evoked significant preparatory EEG activity in children but gender cues did not. The results provide converging evidence that listeners evoke consistent preparatory brain activity for selecting a talker by their location (regardless of their gender or identity), but not by their gender alone.


Subject(s)
Attention/physiology , Auditory Perception/physiology , Electroencephalography , Speech Perception/physiology , Voice , Acoustics , Adolescent , Adult , Child , Cues , Evoked Potentials , Female , Humans , Male , Young Adult
13.
Neuroreport ; 27(4): 242-6, 2016 Mar 02.
Article in English | MEDLINE | ID: mdl-26730514

ABSTRACT

Studies on humans and other mammals have provided evidence for a two-channel or three-channel representation of horizontal space in the auditory system, with one channel maximally responsive to each of the left hemispace, the right hemispace and, possibly, the midline. Mammalian studies have suggested that the contralateral channel is larger in both cortices, but human studies have found this contralateral preference in only one of the cortices. However, human studies are in conflict as to whether the contralateral preference is in the left or the right auditory cortex, and there are a number of methodological differences that this conflict could be attributed to. A key difference between studies is the duration of the silent interval preceding each stimulus and any perception of sound-source movement that the absence of a silent interval creates. We presented auditory noises that alternated between -90° (left) and +90° (right) and recorded neural responses (event-related potentials) using electroencephalography. We randomly varied the duration of the silent interval preceding each stimulus to create a condition with an immediate (local) stimulus context similar to that used in a study reporting contralateral preference in the left auditory cortex, a condition with a local context similar to that in a study reporting contralateral preference in the right auditory cortex, and an intermediate condition. Surprisingly, we found that both auditory cortices exhibited a similarly strong contralateral preference under all conditions, with responses 27% greater, on average, to the contralateral than the ipsilateral space. This suggests that both the cortices can exhibit a contralateral preference, but whether these preferences manifest depends on the global, rather than the local, stimulus context.


Subject(s)
Auditory Cortex/physiology , Sound Localization/physiology , Acoustic Stimulation , Electroencephalography , Evoked Potentials, Auditory , Female , Functional Laterality , Humans , Male , Neuropsychological Tests , Young Adult
14.
Dev Comp Immunol ; 45(2): 321-43, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24709051

ABSTRACT

Over the last few years, we have seen an increasing interest and demand for pigs in biomedical research. Domestic pigs (Sus scrofa domesticus) are closely related to humans in terms of their anatomy, genetics, and physiology, and often are the model of choice for the assessment of novel vaccines and therapeutics in a preclinical stage. However, the pig as a model has much more to offer, and can serve as a model for many biomedical applications including aging research, medical imaging, and pharmaceutical studies to name a few. In this review, we will provide an overview of the innate immune system in pigs, describe its anatomical and physiological key features, and discuss the key players involved. In particular, we compare the porcine innate immune system to that of humans, and emphasize on the importance of the pig as model for human disease.


Subject(s)
Immunity, Innate , Sus scrofa/immunology , Animals , Inflammation/immunology , Receptors, Cytoplasmic and Nuclear/metabolism , Receptors, Pattern Recognition/immunology , Swine/immunology , Swine Diseases/immunology
15.
Neurobiol Aging ; 35(3): 633-44, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24094582

ABSTRACT

One of the principal auditory disabilities associated with older age is difficulty in locating and tracking sources of sound. This study investigated whether these difficulties are associated with deterioration in the representation of space in the auditory cortex. In psychophysical tests, half of a group of older (>60 years) adults displayed spatial acuity similar to that of young adults throughout the frontal horizontal plane. The remaining half had considerably poorer spatial acuity at the more peripheral regions of frontal space. Computational modeling of electroencephalographic responses to abrupt location shifts demonstrated marked differences in the spatial tuning of populations of cortical neurons between the older adults with poor spatial acuity on the one hand, and those with good spatial acuity, as well as young adults, on the other hand. In those with poor spatial acuity, cortical responses contained little information with which to distinguish peripheral locations. We demonstrate a clear link between neural responses and spatial acuity measured behaviorally, and provide evidence for age-related changes in the coding of horizontal space.


Subject(s)
Aging/physiology , Aging/psychology , Auditory Cortex/physiopathology , Auditory Diseases, Central/etiology , Space Perception/physiology , Acoustic Stimulation , Adult , Aged , Auditory Diseases, Central/physiopathology , Auditory Diseases, Central/psychology , Electroencephalography , Female , Hearing/physiology , Humans , Male , Middle Aged , Sound Localization/physiology , Young Adult
16.
J Acoust Soc Am ; 133(5): 2899-909, 2013 May.
Article in English | MEDLINE | ID: mdl-23654395

ABSTRACT

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.


Subject(s)
Cues , Noise/adverse effects , Perceptual Masking , Signal Detection, Psychological , Speech Perception , Acoustic Stimulation , Adult , Auditory Threshold , Humans , Sound Localization , Space Perception , Speech Acoustics , Speech Reception Threshold Test , Time Factors , Voice Quality , Young Adult
17.
J Assoc Res Otolaryngol ; 14(1): 83-101, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23090057

ABSTRACT

Research with barn owls suggested that sound source location is represented topographically in the brain by an array of neurons each tuned to a narrow range of locations. However, research with small-headed mammals has offered an alternative view in which location is represented by the balance of activity in two opponent channels broadly tuned to the left and right auditory space. Both channels may be present in each auditory cortex, although the channel representing contralateral space may be dominant. Recent studies have suggested that opponent channel coding of space may also apply in humans, although these studies have used a restricted set of spatial cues or probed a restricted set of spatial locations, and there have been contradictory reports as to the relative dominance of the ipsilateral and contralateral channels in each cortex. The current study used electroencephalography (EEG) in conjunction with sound field stimulus presentation to address these issues and to inform the development of an explicit computational model of human sound source localization. Neural responses were compatible with the opponent channel account of sound source localization and with contralateral channel dominance in the left, but not the right, auditory cortex. A computational opponent channel model reproduced every important aspect of the EEG data and allowed inferences about the width of tuning in the spatial channels. Moreover, the model predicted the oft-reported decrease in spatial acuity measured psychophysically with increasing reference azimuth. Predictions of spatial acuity closely matched those measured psychophysically by previous authors.


Subject(s)
Auditory Cortex/physiology , Models, Biological , Sound Localization/physiology , Acoustic Stimulation , Adult , Electroencephalography , Female , Humans , Male , Spatial Behavior/physiology
18.
Indoor Built Environ ; 22(2): 360-375, 2013 Apr.
Article in English | MEDLINE | ID: mdl-26321874

ABSTRACT

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.

19.
Clin Exp Allergy ; 42(2): 284-92, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22181034

ABSTRACT

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.


Subject(s)
Adrenergic alpha-Agonists/administration & dosage , Anaphylaxis/prevention & control , Epinephrine/administration & dosage , Adolescent , Child , Child, Preschool , Female , Humans , Injections, Subcutaneous/instrumentation , Injections, Subcutaneous/methods , Male , Prospective Studies , United Kingdom
20.
Cochlear Implants Int ; 12(3): 164-9, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21917204

ABSTRACT

Modern health services need efficient tools for measuring outcomes from interventions, that is, tools of proven efficacy which make minimal demands on the time of clinicians in learning to administer tests and in interpreting results. This paper describes an apparatus designed to meet those requirements. The apparatus administers performance tests of spatial listening for children and adults with unilateral and bilateral cochlear implants. The apparatus was designed with guidance from clinicians. It possesses three key attributes: it is simple to use; the results of tests are scored automatically and are compared with reference data; the apparatus generates comprehensive personalized reports for individual participants that can be included in clinical notes. This paper describes the apparatus and reports results of a test measuring spatial release from masking of speech which illustrates the compatibility between the new apparatus and an older apparatus with which the reference data were gathered.


Subject(s)
Acoustic Stimulation/instrumentation , Cochlear Implantation/rehabilitation , Deafness/rehabilitation , Perceptual Masking/physiology , Sound Localization/physiology , Speech Perception/physiology , Acoustic Stimulation/methods , Adolescent , Adult , Child , Deafness/diagnosis , Eye Movements/physiology , Head Movements/physiology , Hearing Tests/instrumentation , Hearing Tests/methods , Humans , Noise , Photic Stimulation/instrumentation , Photic Stimulation/methods , Psychomotor Performance , Software , User-Computer Interface , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL
...