723 research outputs found
Do British birds conform to Bergmann's and Allen's rules? An analysis of body size variation with latitude for four species
Capsule: An analysis of body mass and wing length for four bird species shows trends broadly in line with predictions from Bergmann's and Allen's rules but with species- and sex-specific trends in terms of body size variation with latitude in Britain. Aims: To analyse body size characteristics for bird species with latitude in Britain and to test Bergmann’s and Allen’s rules (over a range of c. 740 km). Methods Body mass and wing length for four bird species (Blackbird Turdus merula, House Sparrow Passer domesticus, Robin Erithacus rubecula, and Song Thrush Turdus philomelos) were analysed using principal components regression analysis to investigate trends with latitude, longitude, or by sex and Julian day. Results: Evidence was found for latitudinal gradients in body mass for male Blackbird, female House Sparrow (both increasing in size northwards), and female Robin (decreasing in size northwards) and in wing length for female Robin and male Song Thrush (decreasing and increasing northwards, respectively). Conclusion: Trends were broadly in line with predictions from Bergmann's and Allen's rules except for Robin which had trends opposite to those expected. Differences in trends between sexes suggest a role for an interplay between natural and sexual selection with latitude that deserves further consideration
Digging the optimum pit: Antlions, spirals and spontaneous stratification
Most animal traps are constructed from self-secreted silk, so antlions are rare among trap builders because they use only materials found in the environment. We show how antlions exploit the properties of the substrate to produce very effective structures in the minimum amount of time. Our modelling demonstrates how antlions: (i) exploit self-stratification in granular media differentially to expose deleterious large grains at the bottom of the construction trench where they can be ejected preferentially, and (ii) minimize completion time by spiral rather than central digging. Both phenomena are confirmed by our experiments. Spiral digging saves time because it enables the antlion to eject material initially from the periphery of the pit where it is less likely to topple back into the centre. As a result, antlions can produce their pits—lined almost exclusively with small slippery grains to maximize powerful avalanches and hence prey capture—much more quickly than if they simply dig at the pit’s centre. Our demonstration, for the first time to our knowledge, of an animal using self-stratification in granular media exemplifies the sophistication of extended phenotypes even if they are only formed from material found in the animal’s environment
Pitch Patterns in Vocal Expression of “Happiness” and “Sadness” in the Reading Aloud of Prose on the Basis of Selected Audiobooks
The primary focus of this paper is to examine the way the emotional categories of “happiness” and “sadness” are expressed vocally in the reading aloud of prose. In particular, the two semantic categories were analysed in terms of the pitch level and the pitch variability on a corpus based on 28 works written by Charles Dickens. passages with the intended emotional colouring were selected and the fragments found in the corresponding audiobooks. They were then analysed acoustically in terms of the mean F0 and the standard deviation of F0. The results for individual emotional passages were compared with a particular reader’s mean pitch and standard deviation of pitch. The differences obtained in this way supported the initial assumptions that the pitch level and its standard deviation would raise in “happy” extracts but lower in “sad” ones. Nevertheless, not all of these tendencies could be statistically validated and additional examples taken from a selection of random novels by other nineteenth century writers were added. The statistical analysis of the larger samples confirmed the assumed tendencies but also indicated that the two semantic domains may utilise the acoustic parameters under discussion to varying degrees. While “happiness” tends to be signalled primarily by raising F0, “sadness” is communicated mostly by lowering the variability of F0. Changes in the variability of F0 seem to be of less importance in the former case, and shifts in the F0 level less significant in the latter
Volumetric versus single slice measurements of core abdominal muscle for Sarcopenia
Objectives:
We investigated whether total psoas muscle area (TPMA) was representative of the total psoas muscle volume (TPMV). Secondly, we assessed whether there was a relationship between the two commonly used single slice measurements of sarcopenia, TPMA and total abdominal muscle area (TAMA).
Methods:
Pre-operative CT imaging of 110 patients undergoing elective endovascular aneurysm repair were analysed by two trained independent observers. TPMA was measured at individual vertebral levels between the second lumbar vertebrae and sacrum. TPMV was also estimated between the second lumbar vertebrae and sacrum. TAMA was measured at the third lumbar vertebrae (L3). Observer differences were assessed using Bland-Altman plots. Associations between the different measures were assessed using linear regression and Pearson's correlation.
Results:
We found single slice measurements of the TPMA to be representative of the TPMV at individual levels between L2 to the sacrum. The strongest association was seen at L3 (adjusted regression coefficient 16.7, 95% CI 12.1 to 21.4, p < 0.001). There was no association between TPMA and TAMA (adjusted regression coefficient - 0.7, 95% CI - 4.1 to 2.8, p = 0.710).
Conclusions:
We demonstrate that measurements of the TPMA between L2 to the sacrum are representative of the TPMV, with the greatest association at the third lumbar vertebrae. There was no association between the TPMA and TAMA.
Advances in Knowledge:
We demonstrate that a single slice measurement of TPMA at L3 is representative of the muscle volume, contrary to previous criticism. Future sarcopenia studies can continue to measure TPMA which is representative of the TPMV
Quantitative analysis of antibiotic usage in British sheep flocks
The aim of this study was to examine the variation in antibiotic usage between 207 commercial sheep flocks using their veterinary practice prescribing records. Mean and median prescribed mass per population corrected unit (mg/PCU) was 11.38 and 5.95, respectively and closely correlated with animal defined daily dose (ADDD) 1.47 (mean), 0.74 (median) (R2=0.84, P<0.001). This is low in comparison with the suggested target (an average across all the UK livestock sectors) of 50 mg/PCU. In total, 80 per cent of all antibiotic usage occurred in the 39 per cent of flocks where per animal usage was greater than 9.0 mg/PCU. Parenteral antibiotics, principally oxytetracycline, represented 82 per cent of the total prescribed mass, 65.5 per cent of antibiotics (mg/PCU) were prescribed for the treatment of lameness. Oral antibiotics were prescribed to 49 per cent of flocks, 64 per cent of predicted lamb crop/farm. Lowland flocks were prescribed significantly more antibiotics than hill flocks. Variance partitioning apportioned 79 per cent of variation in total antibiotic usage (mg/PCU) to the farm level and 21 per cent to the veterinary practice indicating that veterinary practices have a substantial impact on overall antimicrobial usage. Reducing antibiotic usage in the sheep sector should be possible with better understanding of the drivers of high usage in individual flocks and of veterinary prescribing practices
Patterns and frequency of anxiety in women undergoing gynaecological surgery
Patterns and frequency of anxiety in women undergoing gynaecological surgery
Aims. Within a gynaecological surgical setting to identify the patterns and frequency
of anxiety pre- and postoperatively; to identify any correlation between raised
anxiety levels and postoperative pain; to identify events, from the patients’ perspective,
that may increase or decrease anxiety in the pre- and postoperative periods.
Background. It is well documented that surgery is associated with increased anxiety,
which has an adverse impact on patient outcomes. Few studies have been conducted
to obtain the patient’s perspective on the experience of anxiety and the events and
situations that aggravate and ameliorate it.
Method. The study used a mixed method approach. The sample consisted of women
undergoing planned gynaecological surgery. Anxiety was assessed using the State
Trait Anxiety Inventory. Trait anxiety was measured at the time of recruitment.
State anxiety was then assessed at six time points during the pre- and postoperative
periods. Postoperative pain was also measured using a 10 cm visual analogue scale.
Taped semi-structured telephone interviews were conducted approximately a week
after discharge.
Results. State anxiety rose steadily from the night before surgery to the point of
leaving the ward to go to theatre. Anxiety then increased sharply prior to the
anaesthetic decreasing sharply afterwards. Patients with higher levels of trait anxiety
were more likely to experience higher levels of anxiety throughout their admission.
Elevated levels of pre- and postoperative anxiety were associated with increased
levels of postoperative pain. Telephone interviews revealed a range of events/situations
that patients recalled distressing them and many were related to inadequate
information.
Conclusion. This study found higher rates of anxiety than previously reported and
anxiety levels appeared raised before admission to hospital. This has important
clinical and research implications.Relevance to clinical practice. Patients with high levels of anxiety may be identified
preoperatively and interventions designed to reduce anxiety could be targeted to this
vulnerable group. Patient experiences can inform the delivery of services to meet
their health needs better
Using ground granulated blast-furnace slag and mineral wastes to reduce cement in paving block
Is popular radio a source of exposure to alcohol references in mid to later life?:A content analysis
Background
There is concern around alcohol consumption in mid to later life yet little understanding about what influences this behaviour. No previous research has explored the extent to which adults in mid to later life may be exposed to alcohol references in the media. This project aimed to determine the frequency of alcohol references on radio stations with a high proportion of listeners in mid to later life.
Methods
Content analysis of alcohol references on four popular UK music-based radio stations with a high proportion of listeners aged 55–64 years over three time points.
Results
Alcohol references occur frequently, but vary by time of year and type of radio station. When alcohol is mentioned its consumption is portrayed as the norm, without negative consequences. On three commercial stations, the majority of mentions came from advertising, whereas on BBC Radio 2 nearly all references were talk-based. All adverts for direct promotion of alcohol were by supermarkets. Alcohol was frequently associated with celebrations, socializing or something to consume for its own sake.
Conclusions
Adults in the age group 55–64 may be exposed to references to alcohol that could serve to reinforce norms of consumption of alcohol and promote purchases of cheap alcohol
Application of the Proportion of Sediment-sensitive Invertebrates (PSI) biomonitoring index
Sedimentation of river beds is a key pressure impacting riverine ecological communities. Research has identified the need for new approaches to help demonstrate and quantify the impacts of excessive fine-sediment deposition on benthic macroinvertebrate populations. To help meet this requirement, the Proportion of Sediment-sensitive Invertebrates (PSI) methodology was developed and has been in operational use in the United Kingdom for several years. This paper presents a number of case studies, at both national and local scales, showing how the method can be used to identify point and nonpoint fine-sediment pollution, as well as demonstrating the analysis of a national dataset to describe the relationship between PSI and a channel substrate index. A novel approach to displaying PSI data alongside local ecological and hydrological information is also presented and interpreted, to illustrate how improved understanding of biotic and abiotic relationships and interactions can be readily accomplished. Excessive fine-sediment accumulation on river beds results in impaired ecosystem health globally. The case studies and examples presented here will provide confidence that the PSI method can form the basis for evidence gathering and analysis, both within and beyond the United Kingdom. The paper concludes with an overview of the use of PSI in catchment research and management, a consideration of the relationship of the metric with other macroinvertebrate indices, and a summary of refinements recently applied to the index
A preliminary survey of epiphytes in some tree canopies in Zambia and the Democratic Republic of Congo
- …