Is this the end of the Emergency Department theatre?

In the UK, many emergency departments (EDs) were built with dedicated theatres reflecting surgical origins. This study assessed the number and type of procedures performed in such a facility over a 16-year period. A retrospective cohort study of ED theatre usage was carried out in Aberdeen Royal Infirmary from 1995 to 2010. Cases were identified from theatre log books, and relevant demographics were extracted and analyzed. In total, 8785 procedures were performed, although this decreased from 1078 cases in 1995 to 214 cases in 2010. Common procedures included fracture manipulation, abscess drainage and foreign body removal. Use of ED theatre has reduced considerably. The reasons for this are complex, but may reflect a reduction in the surgical skill set of staff in the ED. Sound basic surgical skills are valuable to the emergency physician and further consideration should be given to how these are best acquired in the course of training.

Cryptic sociality in rattlesnakes (Crotalus horridus) detected by kinship analysis.

Research on social behaviour has largely concentrated on birds and mammals in visually active, cooperatively breeding groups (although such systems are relatively rare) and focused much less on species that rarely interact other than for mating and parental care. We used microsatellite markers to characterize relatedness among aggregations of timber rattlesnakes (Crotalus horridus), a putatively solitary reptile that relies heavily on chemical cues, and found that juveniles and pregnant females preferentially aggregate with kin under certain conditions. The ability to recognize kin and enhance indirect fitness thus might be far more widespread than implied by studies of animals whose behaviour is primarily visually and/or acoustically mediated, and we predict that molecular markers will reveal many additional examples of 'cryptic' sociality.

Roads, interrupted dispersal, and genetic diversity in timber rattlesnakes.

Anthropogenic habitat modification often creates barriers to animal movement, transforming formerly contiguous habitat into a patchwork of habitat islands with low connectivity. Roadways are a feature of most landscapes that can act as barriers or filters to migration among local populations. Even small and recently constructed roads can have a significant impact on population genetic structure of some species, but not others. We developed a research approach that combines fine-scale molecular genetics with behavioral and ecological data to understand the impacts of roads on population structure and connectivity. We used microsatellite markers to characterize genetic variation within and among populations of timber rattlesnakes (Crotalus horridus) occupying communal hibernacula (dens) in regions bisected by roadways. We examined the impact of roads on seasonal migration, genetic diversity, and gene flow among populations. Snakes in hibernacula isolated by roads had significantly lower genetic diversity and higher genetic differentiation than snakes in hibernacula in contiguous habitat. Genetic-assignment analyses revealed that interruption to seasonal migration was the mechanism underlying these patterns. Our results underscore the sizeable impact of roads on this species, despite their relatively recent construction at our study sites (7 to 10 generations of rattlesnakes), the utility of population genetics for studies of road ecology, and the need for mitigating effects of roads.

Noise and tremor in the perception of vocal aging in males.

OBJECTIVE/HYPOTHESIS: To specify a set of acoustic cues for vocal aging and to establish their perceptual relevance. STUDY DESIGN: Perceptual testing. METHODS: To identify the acoustic and perceptual correlates of the aging voice, voice quality [in conjunction with speaking rate and fundamental frequency (F(0))] was systematically manipulated using resynthesis to determine its effect on perceived age. Ten young male voices were resynthesized using two levels of noise (random modulation of F(0) contour) and two levels of tremor (constant modulation of F(0) contour with a low-amplitude wave) under a speaking-rate manipulation (an increase in speaking rate that is common to older male voices). These materials were submitted to 40 naive listeners in an age-estimation task. Two sets of comparison materials were also included for evaluation: unmanipulated samples from a 150 voice database of young, middle-aged, and older voices and disordered voice samples representing natural manifestations of the voice qualities of interest. RESULTS: Speaking rate, highest degree of tremor, and highest degree of noise all shifted, in an additive manner, the mean perceived age of the young male voices by a maximum of 12 years on average; individual voices were observed being shifted by a generation. Fundamental frequency manipulations had no significant effect on perceived age. CONCLUSIONS: Voice quality (both tremor and noise) and speaking rate are all perceptually relevant cues of age in male voices.

Integrating individual behaviour and landscape genetics: the population structure of timber rattlesnake hibernacula.

Individuals of many species show high levels of fidelity to natal populations, often due to reliance on patchily distributed habitat features. In many of these species, the negative impacts of inbreeding are mitigated through specialized behaviours such as seasonal mating dispersal. Quantifying population structure for species with these characteristics can potentially elucidate social and environmental factors that interact to affect mating behaviour and population connectivity. In the northern part of their range, timber rattlesnakes are communal hibernators with high natal philopatry. Individuals generally recruit to the same hibernaculum as their mother and remain faithful to that hibernaculum throughout their lives. We examined the genetic structure of Crotalus horridus hibernacula in the northeastern USA using microsatellite loci. Sampled hibernacula exhibited only modest levels of differentiation, indicating a significant level of gene flow among them. We found no significant correlation between genetic differentiation and geographical distance, but did find significant positive correlation between genetic differentiation and a cost-based distance metric adjusted to include the amount of potential basking habitat between hibernacula. Therefore, thermoregulation sites may increase gene flow by increasing the potential for contact among individuals from different populations. Parentage analyses confirmed high levels of philopatry of both sexes to their maternal hibernaculum; however, approximately one-third of paternity assignments involved individuals between hibernacula, confirming that gene flow among hibernacula occurs largely through seasonal male mating dispersal. Our results underscore the importance of integrating individual-level behaviours and landscape features with studies of fine-scale population genetics in species with high fidelity to patchily distributed habitats.

Treatment outcomes for professional voice users.

Professional voice users comprise 25% to 35% of the U.S. working population. Their voice problems may interfere with job performance and impact costs for both employers and employees. The purpose of this study was to examine treatment outcomes of two specific rehabilitation programs for a group of professional voice users. Eighteen professional voice users participated in this study; half had complaints of throat pain or vocal fatigue (Dysphonia Group), and half were found to have benign vocal fold lesions (Lesion Group). One group received 5 weeks of expiratory muscle strength training followed by six sessions of traditional voice therapy. Treatment order was reversed for the second group. The study was designed as a repeated measures study with independent variables of treatment order, laryngeal diagnosis (lesion vs non-lesion), gender, and time. Dependent variables included maximum expiratory pressure (MEP), Voice Handicap Index (VHI) score, Vocal Rating Scale (VRS) score, Voice Effort Scale score, phonetogram measures, subglottal pressures, and acoustic and perceptual measures. Results showed significant improvements in MEP, VHI scores, and VRS scores, subglottal pressure for loud intensity, phonetogram area, and dynamic range. No significant difference was found between laryngeal diagnosis groups. A significant difference was not observed for treatment order. It was concluded that the combined treatment was responsible for the improvements observed. The results indicate that a combined modality treatment may be successful in the remediation of vocal problems for professional voice users.

Intraoral air pressure discrimination under conditions of experimental velopharyngeal insufficiency.

OBJECTIVE: This study assessed a single subject's ability to detect the difference limen (DLs) for his self-generated intraoral air pressure while his oral and nasal cavities were experimentally coupled. METHOD: The subject, a 46-year-old man, uses a speech bulb prosthesis to cover an unrepaired cleft of his hard and soft palates. The subject's oral and nasal cavities were experimentally coupled by drilling different size holes through the speech-bulb component of the prosthesis to approximate conditions of velopharyngeal insufficiency. There were four hole-size conditions (10, 15, 20, and 30 mm(2)), a no-prosthesis condition, and pre- and postbaseline conditions with the prosthesis intact. The subject blew into a tube connected to a pressure transducer and was presented with a series of paired pressure loads. The first pressure load of each pair was the referent (1, 3, or 5 cm H(2)O), and the second was a preselected comparator load of a different amount. The subject blew into the tube with sufficient force to center the voltage meter's needle at the zero mark. The subject then reported whether the second pressure load required more, less, or equal breath pressure, compared with the referent pressure load of that pair. RESULTS: Size of the hole coupling the oral/nasal cavities did not significantly affect the subject's difference limen. CONCLUSION: Experimental coupling of the oral/nasal cavities did not affect this subject's ability to detect differences in his self-generated intraoral air pressure.