Predicting emotion perception abilities for cochlear implant users.

OBJECTIVE: In daily life, failure to perceive emotional expressions can result in maladjusted behaviour. For cochlear implant users, perceiving emotional cues in sounds remains challenging, and the factors explaining the variability in patients' sensitivity to emotions are currently poorly understood. Understanding how these factors relate to auditory proficiency is a major challenge of cochlear implant research and is critical in addressing patients' limitations. DESIGN: To fill this gap, we evaluated different auditory perception aspects in implant users (pitch discrimination, music processing and speech intelligibility) and correlated them to their performance in an emotion recognition task. STUDY SAMPLE: Eighty-four adults (18-76 years old) participated in our investigation; 42 cochlear implant users and 42 controls. Cochlear implant users performed worse than their controls on all tasks, and emotion perception abilities were correlated to their age and their clinical outcome as measured in the speech intelligibility task. RESULTS: As previously observed, emotion perception abilities declined with age (here by about 2-3% in a decade). Interestingly, even when emotional stimuli were musical, CI users' skills relied more on processes underlying speech intelligibility. CONCLUSIONS: These results suggest that speech processing remains a clinical priority even when one is interested in affective skills.

The Montreal Protocol for Identification of Amusia.

The Montreal Battery for the Evaluation of Amusia (MBEA; Peretz, Champod, & Hyde Annals of the New York Academy of Sciences, 999, 58-75, 2003) is an empirically grounded quantitative tool that is widely used to identify individuals with congenital amusia. The use of such a standardized measure ensures that the individuals tested will conform to a specific neuropsychological profile, allowing for comparisons across studies and research groups. Recently, a number of researchers have published credible critiques of the usefulness of the MBEA as a diagnostic tool for amusia. Here we argue that the MBEA and its online counterpart, the AMUSIA tests (Peretz et al. Music Perception, 25, 331-343, 2008), should be considered steps in a screening process for amusia, rather than standalone diagnostic tools. The goal of this article is to present, in detailed and easily replicable format, the full protocol through which congenital amusics should be identified. In providing information that has often gone unreported in published articles, we aim to clarify the strengths and limitations of the MBEA and to make recommendations for its continued use by the research community as part of the Montreal Protocol for Identification of Amusia.

The cerebellum's contribution to beat interval discrimination.

From expert percussionists to individuals who cannot dance, there are widespread differences in people's abilities to perceive and synchronize with a musical beat. The aim of our study was to identify candidate brain regions that might be associated with these abilities. For this purpose, we used Voxel-Based-Morphometry to correlate inter-individual differences in performance on the Harvard Beat Assessment Tests (H-BAT) with local inter-individual variations in gray matter volumes across the entire brain space in 60 individuals. Analysis revealed significant co-variations between performances on two perceptual tasks of the Harvard Beat Assessment Tests associated with beat interval change discrimination (faster, slower) and gray matter volume variations in the cerebellum. Participant discrimination thresholds for the Beat Finding Interval Test (quarter note beat) were positively associated with gray matter volume variation in cerebellum lobule IX in the left hemisphere and crus I bilaterally. Discrimination thresholds for the Beat Interval Test (simple series of tones) revealed the tendency for a positive association with gray matter volume variations in crus I/II of the left cerebellum. Our results demonstrate the importance of the cerebellum in beat interval discrimination skills, as measured by two perceptual tasks of the Harvard Beat Assessment Tests. Current findings, in combination with evidence from patients with cerebellar degeneration and expert dancers, suggest that cerebellar gray matter and overall cerebellar integrity are important for temporal discrimination abilities.

The differential effects of norepinephrine and dopamine on cerebrospinal fluid pressure and spinal cord perfusion pressure after acute human spinal cord injury.

STUDY DESIGN: Prospective vasopressor cross-over interventional studyObjectives:To examine how two vasopressors used in acute traumatic spinal cord injury (SCI) affect intrathecal cerebrospinal fluid pressure and the corresponding spinal cord perfusion pressure (SCPP). SETTING: Vancouver, British Columbia, Canada. METHODS: Acute SCI patients over the age of 17 with cervical or thoracic ASIA Impairment Scale (AIS). A, B or C injuries were enrolled in this study. Two vasopressors, norepinephrine and dopamine, were evaluated in a 'crossover procedure' to directly compare their effect on the intrathecal pressure (ITP). The vasopressor cross-over procedures were performed in the intensive care unit where ITP, mean arterial pressure (MAP) and heart rate were being continuously measured. The SCPP was calculated as the difference between MAP and ITP. RESULTS: A total of 11 patients were enrolled and included in our analysis. There were 6 patients with AIS A, 3 with AIS B and 2 with AIS C injuries at baseline. We performed 24 cross-over interventions in these 11 patients. There was no difference in MAP with the use of norepinephrine versus dopamine (84±1 mm Hg for both; P=0.33). Conversely, ITP was significantly lower with the use of norepinephrine than with dopamine (17±1 mm Hg vs 20±1 mm Hg, respectively, P<0.001). This decrease in ITP with norepinephrine resulted in an increased SCPP during the norepinephrine infusion when compared with dopamine (67±1 mm Hg vs 65±1 mm Hg respectively, P=0.0049). CONCLUSION: Norepinephrine was able to maintain MAP with a lower ITP and a correspondingly higher SCPP as compared with dopamine in this study. These results suggest that norepinephrine may be preferable to dopamine if vasopressor support is required post SCI to maintain elevated MAPs in accordance with published guidelines.

Structural biomarkers in the cerebrospinal fluid within 24 h after a traumatic spinal cord injury: a descriptive analysis of 16 subjects.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To characterize the cerebrospinal fluid (CSF) concentrations of glial fibrillary acidic protein, neuron specific enolase (NSE), S-100ß, tau and neurofilament heavy chain (NFH) within 24 h of an acute traumatic spinal cord injury (SCI), and to correlate these concentrations with the baseline severity of neurologic impairment as graded by the American Spinal Injury Association impairment scale (AIS). METHODS: A lumbar puncture was performed to obtain CSF from 16 acute traumatic SCI patients within 24 h post injury. Neurological examinations were performed within 24 h of injury and again at 6 or 12 months post injury. The correlations between the CSF concentrations and initial AIS were calculated by using Pearson correlation coefficients. In addition, an independent Student's t-test was used to test for differences in CSF concentrations between patients of different AIS grades. RESULTS: The CSF NSE concentrations were significantly correlated with the baseline neurologic impairment being either 'motor complete' (AIS A, B) or 'motor incomplete' (AIS C, D) (r=0.520, P<0.05). The mean S-100ß concentration in motor complete patients was significantly higher compared with motor incomplete patients; 377.2 µg l(-1) (s.d.±523 µg l(-1)) vs 57.1 µg l(-1) (s.d.±56 µg l(-1)) (P<0.05), respectively. Lastly, the mean NFH concentration in motor complete patients was significantly higher compared with motor incomplete patient, 11 813 ng l(-1) (s.d.±16 195 ng l(-1)) vs 1446.8 ng l(-1) (s.d.±1533 ng l(-1)), (P<0.05), respectively. CONCLUSION: In this study we identified differences in the structural CSF biomarkers NSE, S-100ß and NFH between motor complete and motor incomplete SCI patients. Our data showed no clear differences in any of the protein concentrations between the different AIS grades.

A prospective evaluation of hemodynamic management in acute spinal cord injury patients.

STUDY DESIGN: Prospective observational study of acute spinal cord-injured (SCI) patients. OBJECTIVES: To determine how effectively mean arterial blood pressure (MAP) and spinal cord perfusion pressure (SCPP) are maintained at target levels in acute SCI patients. SETTING: Single-institution study at a Canadian level-one trauma center. METHODS: Twenty-one individuals with cervical or thoracic SCI were enrolled within 48 h of injury. A lumbar intrathecal drain was inserted for monitoring intrathecal cerebrospinal fluid pressure (ITP). The MAP was monitored concurrently with ITP, and the SCPP was calculated. Data was recorded hourly from the time of first assessment until at least the end of the 5th day post injury. RESULTS: All subjects had at least one recorded episode with a MAP below 80 mm Hg, and 81% had at least one episode with a MAP below 70 mm Hg. On average, subjects with cervical injuries had 18.4% of their pressure recordings below 80 mm Hg. Subjects with thoracic cord injuries had on average 35.9% of their MAP recordings <80 mm Hg. CONCLUSION: It is common practice to establish MAP targets for optimizing cord perfusion in acute SCI. This study suggests that even in an acute SCI referral center, when prospectively scrutinized, the actual MAP may frequently fall below the intended targets. Such results raise awareness of the vigilance that must be kept in the hemodynamic management of these patients, and the potential discrepancy between routinely setting target MAP according to 'practice guidelines' and actually achieving them.

Accuracy of hospital-based surveillance systems for surgical site infection after adult spine surgery: a Bayesian latent class analysis.

BACKGROUND: Surgical site infections (SSIs) of the spine are morbid and costly complications. An accurate surveillance system is required to properly describe the disease burden and the impact of interventions that mitigate SSI risk. Unfortunately, uniform approaches to conducting SSI surveillance are lacking because of varying SSI case definitions, the lack of a perfect reference case definition and heterogeneous data sources. AIM: To assess the accuracy of four independent data sources that capture SSIs after spine surgery, with estimation of a measurement-error-adjusted SSI incidence. METHODS: A Bayesian latent class model assessed the sensitivity/specificity of each data source to identify SSI and to estimate a measurement-error-adjusted incidence. The four data sources used were: the discharge abstract database (DAD), the National Surgical Quality Improvement Program (NSQIP) database, the Infection Prevention and Control Canada (IPAC) database, and the Spine Adverse Events Severity database. FINDINGS: A total of 904 patients underwent spine surgery in 2017. The most sensitive data source was DAD (0.799; 95% credible interval (CrI): 0.597-0.943); the least sensitive was NSQIP (0.497; 95% CrI: 0.308-0.694). The most specific data source was IPAC (0.997; 95% CrI: 0.993-1.000) and the least specific was DAD (0.969; 95% CrI: 0.956-0.981). The measurement-error-adjusted SSI incidence was 0.030 (95% CrI: 0.019-0.045). The crude incidence using the DAD overestimated the incidence, and the three other data sources underestimated it. CONCLUSION: SSI surveillance in the spine surgery population is feasible using several data sources, provided that measurement error is considered.

Temporal decoding of vocal and musical emotions: Same code, different timecourse?

From a baby's cry to a piece of music, we perceive emotions from our auditory environment every day. Many theories bring forward the concept of common neural substrates for the perception of vocal and musical emotions. It has been proposed that, for us to perceive emotions, music recruits emotional circuits that evolved for the processing of biologically relevant vocalizations (e.g., screams, laughs). Although some studies have found similarities between voice and instrumental music in terms of acoustic cues and neural correlates, little is known about their processing timecourse. To further understand how vocal and instrumental emotional sounds are perceived, we used EEG to compare the neural processing timecourse of both stimuli type expressed with a varying degree of complexity (vocal/musical affect bursts and emotion-embedded speech/music). Vocal stimuli in general, as well as musical/vocal bursts, were associated with a more concise sensory trace at initial stages of analysis (smaller N1), although vocal bursts had shorter latencies than the musical ones. As for the P2 - vocal affect bursts and Emotion-Embedded Musical stimuli were associated with earlier P2s. These results support the idea that emotional vocal stimuli are differentiated early from other sources and provide insight into the common neurobiological underpinnings of auditory emotions.

Musical and vocal emotion perception for cochlear implants users.

Cochlear implants can successfully restore hearing in profoundly deaf individuals and enable speech comprehension. However, the acoustic signal provided is severely degraded and, as a result, many important acoustic cues for perceiving emotion in voices and music are unavailable. The deficit of cochlear implant users in auditory emotion processing has been clearly established. Yet, the extent to which this deficit and the specific cues that remain available to cochlear implant users are unknown due to several confounding factors. Here we assessed the recognition of the most basic forms of auditory emotion and aimed to identify which acoustic cues are most relevant to recognize emotions through cochlear implants. To do so, we used stimuli that allowed vocal and musical auditory emotions to be comparatively assessed while controlling for confounding factors. These stimuli were used to evaluate emotion perception in cochlear implant users (Experiment 1) and to investigate emotion perception in natural versus cochlear implant hearing in the same participants with a validated cochlear implant simulation approach (Experiment 2). Our results showed that vocal and musical fear was not accurately recognized by cochlear implant users. Interestingly, both experiments found that timbral acoustic cues (energy and roughness) correlate with participant ratings for both vocal and musical emotion bursts in the cochlear implant simulation condition. This suggests that specific attention should be given to these cues in the design of cochlear implant processors and rehabilitation protocols (especially energy, and roughness). For instance, music-based interventions focused on timbre could improve emotion perception and regulation, and thus improve social functioning, in children with cochlear implants during development.

Microarray-based analysis of gene expression in very large gene families: the cytochrome P450 gene superfamily of Arabidopsis thaliana.

Cytochrome P450 (P450s) are heme-thiolate protein products of a very large gene superfamily, present in all kingdoms and involved in a variety of metabolic reactions. P450s are classified according to the degree of amino acid sequence identity, with P450s of the same family defined as having >40% identity, and P450s of the same subfamily having >55% identity. Currently, 273 P450 genes distributed over 45 families have been identified in Arabidopsis, and its genome is estimated to contain as many as 286. Genome-wide DNA microarrays make it possible to broadly correlate P450 gene activity with alterations in physiological or developmental states. A potential problem with microarray research is that sequence similarity between and within these families of closely related genes may lead to cross-hybridization. We designed experiments to systematically evaluate the specificity of P450 microarrays, and showed that conditions could be optimized to provide a very high degree of hybridization specificity. Under these conditions, and employing a 20% intensity value of maximum hybridization intensity as a cut-off, labeled P450 genes exhibited essentially no cross-hybridization between families and within subfamilies. We also compared the gene transcription levels of microarray probes derived from EST clones and from genomic DNA sequences for which ESTs were not available, using cDNA produced from RNA from various Arabidopsis tissue as the target. Many of the P450 genes displayed tissue-specific expression, leading to hypotheses as to the function of individual genes and their regulation. We also observed that several of the genomic sequences reported high levels of expression, highlighting the limitations of expression analysis based on ESTs alone.

Intron-exon organization and phylogeny in a large superfamily, the paralogous cytochrome P450 genes of Arabidopsis thaliana.

The cytochrome P450 gene superfamily is represented by 80 genes in animal genomes and perhaps more than 300 genes in plant genomes. We analyzed about half of all Arabidopsis P450 genes, a very large dataset of truly paralogous genes. Sequence alignments were used to draw phylogenetic trees, and this information was compared with the intron-exon organization of each P450 gene. We found 60 unique intron positions, of which 37 were phase 0 introns. Our results confirm the polyphyletic origin of plant P450 genes. One group of these genes, the A-type P450s, are plant specific and characterized by a simple organization, with one highly conserved intron. Closely related A-type P450 genes are often clustered in the genome with as many as a dozen genes (e.g., of the CYP71 subfamily) on a short stretch of chromosome. The other P450 genes (non-A-type) form several distinct clades and are characterized by numerous introns. One such clade contains the two CYP51 genes, which are thought to encode obtusifoliol 14a demethylase. The two CYP51 genes have a single intron that is not shared with CYP51 genes from vertebrates or fungi, or with any other Arabidopsis P450 gene. Only a few of the Arabidopsis P450 genes are intronless (e.g., the CYP710A and CYP96A subfamilies). There was a relatively good correlation between intron conservation and phylogenetic relationships between members of the P450 subfamilies. Gene organization appears to be a useful tool in establishing the evolutionary relatedness of P450 genes, which may help in predictions of P450 function.

Lumbar radiculopathy secondary to gouty tophi in the filum terminale in a patient without systemic gout: case report.

OBJECTIVE AND IMPORTANCE: Gouty arthritis and gouty tophi of the spine are very rare. We present a patient with the clinical manifestations of an intradural tumor and histologically proven gouty deposits in the filum terminale. CLINICAL PRESENTATION: The patient presented with typical symptoms of lumbar radiculopathy and neurogenic claudication. There was no evidence of peripheral gout. INTERVENTION: Imaging studies, including computed tomography and magnetic resonance imaging, demonstrated a 1-cm, round, intradural, calcified lesion at the L3 vertebral level, causing moderate spinal stenosis. The patient underwent a two-level laminectomy and removal of the mass. A pathological examination of the specimen revealed gouty deposits in the region of the filum terminale. CONCLUSION: Spinal involvement in gout is very rare, and intradural gouty deposits have not been previously described. Intradural gout should be considered in the differential diagnosis of intradural masses.

Ballistic helmets and aspects of their design.

The head represents approximately 9% of the body area exposed in combat yet receives approximately 20% of all "hits." The desirability of protecting this vital structure would appear self-evident. Helmet design is a complex issue. Factors that designers of United States Army helmets thoughtfully consider include weight, ballistic qualities of the construction material, balance, helmet-to-person interface (comfort), maintenance of vision and hearing, equipment and weapon compatibility, ease of modification, available materials and manufacturing techniques, durability, ease of decontamination, disposability, and cost. The envisioned future role of the infantryman will make the interplay among these factors even more daunting.

[Health professionals in part-time employment: the challenge of balancing work and family]. / Professionnelles de la santé en précarité d'emploi: le défi de la conciliation travail-famille.

Looking at the case of occasional part-time nurses, this study highlights the difficulties in balancing work and family that are inherent in nonstandard jobs. Eight focus groups were held, involving 48 nurses in 4 regions of Quebec. Analysis of the data collected reveals that nurses "on call" are particularly affected by overwork and experience great difficulty in balancing their work and family obligations. The participants proposed a variety of solutions, such as establishing day care centres adapted to the needs of nurses on call and instituting a timetable grid for occasional part-time nurses so that they can plan their work hours.

Sodium intake following destruction of the anterior hypothalamus in the rat.

Sodium intake and sodium output were measured in rats before and after lesioning of the anterior hypothalamus. Both parameters were lower than control rats following the lesioning procedure. When an amount of sodium was given orally to these lesioned rats to make up the deficit in sodium intake, no difference was found in sodium intake or output between the rats with lesions and normal rats. Rats with anterior hypothalamic lesions were able to increase their sodium intake following a period of sodium deprivation or adrenalectomy. When presented with concentrations of sodium chloride ranging between 0.9 and 2.5% rats with lesions decreased their intake of sodium in a manner similar to control rats except that the level of intake in the lesioned rats was lower for all concentrations. Control rats and those with lesions were not different in their intakes of KC1 solutions. These findings suggest that the anterior hypothalamus is important in setting the absolute intakes of sodium but does not interfere with the control mechanisms regulating the sodium intake.

The effect of water on the rate of conformational change in protein allostery.

The influence of solvation on the rate of quaternary structural change is investigated in human hemoglobin, an allosteric protein in which reduced water activity destabilizes the R state relative to T. Nanosecond absorption spectroscopy of the heme Soret band was used to monitor protein relaxation after photodissociation of aqueous HbCO complex under osmotic stress induced by the nonbinding cosolute poly(ethylene glycol) (PEG). Photolysis data were analyzed globally for six exponential time constants and amplitudes as a function of osmotic stress and viscosity. Increases in time constants associated with geminate rebinding, tertiary relaxation, and quaternary relaxation were observed in the presence of PEG, along with a decrease in the fraction of hemes rebinding CO with the slow rate constant characteristic of the T state. An analysis of these results along with those obtained by others for small cosolutes showed that both osmotic stress and solvent viscosity are important determinants of the microscopic R --> T rate constant. The size and direction of the osmotic stress effect suggests that at least nine additional water molecules are required to solvate the allosteric transition state relative to the R-state hydration, implying that the transition state has a greater solvent-exposed area than either end state.

Allosteric intermediates in hemoglobin. 2. Kinetic modeling of HbCO photolysis.

Nanosecond absorption spectra are measured in the Soret and near-UV spectral regions of human hemoglobin (Hb) after laser photolysis of the carbonyl adduct in order to study the dynamics of globin tertiary and quaternary conformational changes. Spectra and concentrations of physical intermediates, distinguished by extent of heme ligation and intraprotein relaxation, are obtained from a global analysis using a microscopic kinetic model that explicitly accounts for six observed relaxation and recombination processes. Three observed rate constants for CO rebinding and two intraprotein relaxation constants obtained are similar to constants determined by Hofrichter et al. [(1983) Proc. Natl. Acad. Sci. U.S.A. 80, 2235], the latter two comprising the 20-30-microseconds R --> T quaternary transition and a previously unassigned 1-microseconds intraprotein relaxation. On the basis of the modeled intermediate spectra, as well as UV circular dichroism results observed on this time scale [Björling, S.C., Goldbeck, R.A., Paquette, S.J., Milder, S.J., & Kliger, D.S. (1996) Biochemistry 35, 8619-8627], the 1-microsecond relaxation is assigned to heme conformational changes concomitant with a relaxation of protein conformation at the alpha 1 beta 2 interface corresponding to an initial step in a compound R --> T reaction path.

Nanosecond optical rotatory dispersion spectroscopy: application to photolyzed hemoglobin-CO kinetics.

A standard technique for static optical rotatory dispersion (ORD) measurements is adapted to the measurement of ORD changes on a nanosecond (ns) time scale, giving approximately a million-fold improvement in time-resolution over conventional instrumentation. The technique described here is similar in principle to a technique recently developed for ns time-resolved circular dichroism (TRCD) spectroscopy, although the time-resolved optical rotatory dispersion (TRORD) technique requires fewer optical components. As with static ORD, TRORD measurements may be interpreted by empirical comparisons or may be transformed, via the Kramers-Kronig relations, to more easily interpreted TRCD spectra. TRORD can offer experimental advantages over TRCD in studying kinetic processes effecting changes in the chiral structures of biological molecules. In particular, the wider dispersion of ORD bands compared with the corresponding CD bands means that ORD information may often be obtained outside of absorption bands, a signal-to-noise advantage for multichannel measurements. Demonstration of the technique by its application to ns TRORD and the transform-calculated TRCD of carboxy-hemoglobin (Hb-CO) after laser photolysis is presented.