Seasonal variation in dawn song characteristics in the common nightingale

Many male temperate zone passerines show a marked peak of singing activity before sunrise. The two main functions of this so-called dawn chorus are mate attraction and territory defence. We examined how seasonal patterns of different dawn song characteristics were related to mating status and to the breeding cycle of females in the common nightingale, Luscinia megarhynchos. We investigated two measures of song output: song rate and percentage performance time. We also calculated the proportion of 'whistle songs', a song category that is thought to be important in female choice. We predicted that if the main function of dawn singing in nightingales is to attract a social mate, then mated males should change their dawn singing behaviour after pair formation. In contrast, if dawn singing is mainly used in territory defence, we expected no difference in song traits between mated and unmated males throughout the season. We found that song rate and the proportion of whistle songs were low at the beginning of the season and did not predict future mating status. After arrival of females, all measures of dawn song performance remained largely constant throughout the breeding season, and we did not find significant differences in the seasonal variation between mated and unmated males. These findings are consistent with the hypothesis that song at dawn is important to defend a territory throughout the breeding season. (c) 2005 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Acoustic features of song categories and their possible implications for communication in the common nightingale (Luscinia megarhynchos)

In many passerine species, males sing more than one distinct song type. Commonly, songs are assigned to different song types or song categories based on phonological and syntactical dissimilarities. However, temporal aspects, such as song length and song rate, also need to be considered to understand the possible functions of different songs. Common nightingales (Luscinia megarhynchos) have large vocal repertoires of different song types but their songs additionally can be grouped into two distinct categories (particular groups of song types): whistle songs and nonwhistle songs. Whistle songs are hypothesised to be important to attract migrating females. We studied temporal properties of whistle songs and nonwhistle songs and examined the relationship between those song parameters and song output parameters, such as song rate and song length. To investigate how song parameters vary among males, we calculated the coefficients of variation for different song traits. We found that the variation in the proportion of whistle songs was significantly higher among males than variation in other song parameters. Furthermore, the proportion of whistle songs was negatively correlated with other sona output patterns. These findings suggest that the production of whistle songs might be constrained and/or that whistle songs and their succeeding pauses may act as a functional unit in communication.

Will attracting the creative class boost economic growth in old industrial regions? A case study of Scotland

Attracting in-migration of the creative class has been argued by Florida (2002) to be a route to higher economic growth in the era of the knowledge economy. This paper critically evaluates this proposition in relation to old industrial regions using the example of Scotland. The paper presents an assessment of, in the first instance, to what extent there is a shortage of skilled, talented and entrepreneurial individuals and, in the second instance, whether a talent attraction strategy alone can hope to attract such people to Scotland. It is proposed that for most migrants the availability of appropriate economic opportunities is a prerequisite for mobility. However, despite uncertain evidence that place attractiveness is a catalyst to mobility among the so-called creative class, this is not a reason for dismissing talent attraction programmes. Instead it is argued that talent attraction programmes have the potential to contribute to old industrial economies, but their success will be greatest when talent attraction is carefully targeted and based on economic realities rather than the marketing of ethereal conceptions of place attractiveness.

Does atypical work help the jobless? Evidence from a CAEAS/CPS cohort analysis

Atypical employment, such as temporary, on-call and contract work, has been found disproportionately to attract the jobless. But there is no consensus in the literature as to the labour market consequences of such job choice by unemployed individuals. Using data from the Current Population Survey, we investigate the implications of the initial job-finding strategies pursued by the jobless for their short- and medium-term employment stability. At first sight, it appears that taking an offer of regular employment provides the greatest degree of employment continuity for the jobless. However, closer inspection indicates that the jobless who take up atypical employment are not only more likely to be employed 1 month and 1 year later than those who continue to search, but also to enjoy employment continuity that is not less favourable than that offered by regular, open-ended employment.

International perspectives on the influence of structure and process of weaning from mechanical ventilation.

Background 
Recently, clinical and research attention has been focused on refining weaning processes to improve outcomes for critically ill patients who require mechanical ventilation. One such process, use of a weaning protocol, has yielded conflicting results, arguably because of the influence of existing context and processes.

Objective 
To compare international data to assess differences in context and processes in intensive care units that could influence weaning.  

Methods 
Review of existing national data on provision of care for critically ill patients, including structure, staffing, skill mix, education, roles, and responsibilities for weaning in intensive care units of selected countries.

Results 
Australia, New Zealand, Denmark, Norway, Sweden, and the United Kingdom showed similarities in critical care provision, structure, skill mix, and staffing ratios in intensive care units. Weaning in these countries is generally a collaborative process between nurses and physicians. Notable differences in intensive care units in the United States were the frequent use of an open structure and inclusion of respiratory therapists on the intensive care unit’s health care team. Nurses may be excluded from direct management of ventilator weaning in some institutions, as this role is primarily assumed by respiratory therapists guided by medical directives. Availability of critical care beds was highest in the United States and lowest in the United Kingdom.

Conclusion 
Context and processes of care that could influence ventilator weaning outcomes varied considerably across countries. Further quantification of these contextual influences should be considered when translating research findings into local clinical practice and when designing randomized, controlled trials.

The impact of a PCR assay for candidemia on antifungal drug prescribing in critical care: an interrupted time series pilot study.

Objective To evaluate the feasibility of conducting a definitive study to assess the impact of introducing a rapid PCR-based test for candidemia on antifungal drug prescribing. Method Prospective, single centre, interrupted time series study consisting of three periods of six months' duration. The assay was available during the second period, during which the PCR assay was available for routine use by physicians Monday–Friday with guaranteed 24-h turnaround time. For each period total antifungal drug use, expressed as treatment-days, was recorded and an adjustment was made to exclude estimated use for proven candidemia. Also, during the intervention period, antifungal prescribing decisions for up to 72 h after each PCR result became available were recorded as either concordant or discordant with that result. Results While overall antifungal use remained relatively stable throughout, after adjustment for candidemia, there was a 38% reduction in use following introduction of the PCR test; however, this was nonsignificant at the 95% level. During the intervention period overall concordance between the PCR result and prescribing decisions was 84%. Conclusions The PCR assay for candidemia was requested, prescribing decisions were generally concordant with the results produced and there was an apparent decrease in antifungal prescription, although this was sustained even after withdrawal of the intervention; these findings should be more thoroughly evaluated in a larger trial.

Ownership structure, organisational flexibility and store performance in retail chains.

Drawing on agency and flexible capability perspectives, the authors develop a theoretical framework explaining the impact of ownership structure on organisational flexibility and store performance in retail chains. The researchers argue that franchised stores attract more entrepreneurial managers with more flexible capabilities and they have a stronger incentive to align their flexible capabilities with the demands of the business environment. A sample of 105 franchised and company-owned stores of an optical retail chain is used to test the hypotheses. Furthermore, the study found strong support for the hypotheses that 'Franchised stores have a higher structural flexibility than company-owned stores', but only weak support for operational and strategic flexible capabilities. Furthermore, in line with the study's theoretical framework, it has been found that in a highly turbulent business environment, franchised stores perform better than company-owned stores. The paper concludes with a discussion of the implications for theory development and management of ownership structures in retail chains.

Flow-mediated dilatation of the brachial artery is a poorly reproducible indicator of microvascular function in Type I diabetes mellitus

Aim: Two Type I diabetes and control group comparator studies were conducted to assess the reproducibility of FMD and to analyse blood flow data normally discarded during FMD measurement.

Design: The studies were sequential and differed only with regard to operator and ultrasound machine. Seventy-two subjects with diabetes and 71 controls were studied in total.

Methods: Subjects had FMD measured conventionally. Blood velocity waveforms were averaged over 10 pulses post forearm ischaemia and their component frequencies analysed using the wavelet transform, a mathematical tool for waveform analysis. The component frequencies were grouped into 11 bands to facilitate analysis.

Results: Subjects were well-matched between studies. In Study 1, FMD was significantly impaired in subjects with Type I diabetes vs. controls (median 4.35%, interquartile range 3.10-4.80 vs. 6.50, 4.79-9.42, P < 0.001). No differences were detected between groups in Study 2, however. However, analysis of blood velocity waveforms yielded significant differences between groups in two frequency bands in each study.

Conclusions: This report highlights concerns over the reproducibility of FMD measures. Further work is required to fully elucidate the role of analysing velocity waveforms after forearm ischaemia.

Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis

Background: Age-related macular degeneration (AMD) is the leading cause of blindness in Western countries. Numerous risk factors have been reported but the evidence and strength of association is variable. We aimed to identify those risk factors with strong levels of evidence which could be easily assessed by physicians or ophthalmologists to implement preventive interventions or address current behaviours.