Patterns of painting in satin bowerbirds Ptilonorhynchus violaceus and males' responses to changes in their paint

Satin bowerbirds Ptilonorhynchus violaceus have an elaborate multi-component sexual display, some components of which have been extensively studied. We describe a relatively unstudied component of this display, bower painting, and birds' responses to manipulations of their paint. Males of this species focus their display around a stick bower constructed on the forest floor which they decorate with a variety of objects and paint. Painting involves a male masticating plant material and wiping the plant-saliva mixture onto the inside walls of the bower; during courtship visits to bowers, females nibble at this paint. We found that 93% of 53 males painted their bowers at our study site and the time males spent painting their bowers accounted for 24% of their time at the bower. We experimentally removed and added paint to bowers to test whether males respond to these changes in their paint. Males gave more advertisement calls and spent less time manipulating sticks at the bower when we added fresh wet paint to their bowers compared to older dried paint or a control treatment. They did not respond to the removal of paint from their bowers, perhaps because it was primarily older dried paint that was removed. We also found that males painted more frequently when there was measurable wind in their bowers, which could have degraded the quality of the signal. Our findings indicate that fresh wet paint is more important to males than older dried paint and, together with previous work at this site, suggest that paint may act as a signal to females. Given that females nibble bower sticks during courtship, we suggest that bower paint may function as a chemical sexual signal rather than a visual signal.

How lifetimes shape epigenotype within and across generations

Despite our detailed characterization of the human genome at the level of the primary DNA sequence, we are still far from understanding the molecular events underlying phenotypic variation. Epigenetic modifications to the DNA sequence and associated chromatin are known to regulate gene expression and, as such, are a significant contributor to phenotype. Studies of inbred mice and monozygotic twins show that variation in the epigenotype can be seen even between genetically identical individuals and that this, in some cases at least, is associated with phenotypic differences. Moreover, recent evidence suggests that the epigenome can be influenced by the environment and these changes can last a lifetime. However, we also know that epigenetic states in real-time are in continual flux and, as a result, the epigenome exhibits instability both within and across generations. We still do not understand the rules governing the establishment and maintenance of the epigenotype at any particular locus. The underlying DNA sequence itself and the sequence at unlinked loci (modifier loci) are certainly involved. Recent support for the existence of transgenerational epigenetic inheritance in mammals suggests that the epigenetic state of the locus in the previous generation may also play a role. Over the next decade, many of these processes will be better understood, heralding a greater capacity for us to correlate measurable molecular marks with phenotype and providing the opportunity for improved diagnosis and presymptomatic healthcare.

Assembly of Human Papillomavirus Type-16 Virus-Like Particles: Multifactorial Study of Assembly and Competing Aggregation

Pentameric capsomeres of human papillomavirus capsid protein L1 expressed in Escherichia coli self-assemble into virus-like particles (VLPs) in vitro. A multifactorial experimental design was used to explore a wide range of solution conditions to optimize the assembly process. The degree of assembly was measured using an enzyme-linked immunosorbent assay, and a high-throughput turbidity assay was developed to monitor competing aggregation. The presence of zinc ions in the assembly buffer greatly increased the incidence of aggregation and had to be excluded from the experiment for meaningful analysis. Assembly of VLPs was optimal at a pH of about 6.5, calcium and sodium ions had no measurable effect, and dithiothreitol and glutathione inhibited assembly. Tryptophan fluorescence spectroscopy demonstrated that an increase in urea concentration reduced the rate of VLP formation but had no effect on the final concentration of assembled VLPs. This study demonstrates the use of the hanging-drop vapor-diffusion crystallization method to screen for conditions that promote aggregation and the use of tryptophan fluorescence spectroscopy for real-time monitoring of the assembly process.

Combined acamprosate and naltrexone, with cognitive behavioural therapy is superior to either medication alone for alcohol abstinence: A single centres' experience with pharmacotherapy

Aims: To compare treatment outcomes amongst patients offered pharmacotherapy with either naltrexone or acamprosate used singly or in combination, in a 12-week outpatient cognitive behavioural therapy (CBT) programme for alcohol dependence. Methods: We matched 236 patients across gender, age group, prior alcohol detoxification, and dependence severity and conducted a cohort comparison study of three medication groups (CBT+acamprosate, CBT+naltrexone, CBT+combined medication) which included 59 patients per group. Outcome measures included programme attendance, programme abstinence and for those who relapsed, cumulative abstinence duration (CAD) and days to first breach (DFB). Secondary analyses compared the remaining matched 59 subjects who declined medication with the pharmacotherapy groups. Results: Across medication groups, CBT+ combined medication produced the greatest improvement across all outcome measures. Although a trend favoured the CBT+ combined group, differences did not reach statistical significance. Programme attendance: CBT + Acamprosate group (66.1%), CBT + Naltrexone group (79.7%), and in the CBT + Combined group (83.1%). Abstinence rates were 50.8, 66.1, and 67.8%, respectively. For those that did not complete the programme abstinent, the average number of days abstinent (CAD) were 45.07, 49.95, and 53.58 days, respectively. The average numbers of days to first breach (DFB) was 26.79, 26.7, and 37.32 days. When the focal group (CBT + combined) was compared with patients who declined medication (CBT-alone), significant differences were observed across all outcome indices. Withdrawal due to adverse medication effects was minimal. Conclusions: The addition of both medications (naltrexone and acamprosate) resulted in measurable benefit and was well tolerated. In this patient population naltrexone with CBT is as effective as combined medication with CBT, but the trend favours combination medication.

Evaluation of different models to describe egg and pupal development of Xyleborus fornicatus Eichh. (Coleoptera: Scolytidae), the shot-hole borer of tea in Sri Lanka

Abstract Development data of eggs and pupae of Xyleborus fornicatus Eichh. (Coleoptera: Scolytidae), the shot-hole borer of tea in Sri Lanka, at constant temperatures were used to evaluate a linear and seven nonlinear models for insect development. Model evaluation was based on fit to data (residual sum of squares and coefficient of determination or coefficient of nonlinear regression), number of measurable parameters, the biological value of the fitted coefficients and accuracy in the estimation of thresholds. Of the nonlinear models, the Lactin model fitted experimental data well and along with the linear model, can be used to describe the temperature-dependent development of this species.

The UK productivity gap in the service sector: do management practices matter?

Purpose – This paper aims to contribute to the debate on the drivers of the productivity gap that exists between the UK and its major international competitors. Design/methodology/approach – From the macro perspective the paper explores the quantitative evidence on the productivity differentials and how they are measured. From the micro perspective, the article explores the quantitative evidence on the role of management practices claimed to be a key determinant in promoting firm competitiveness and in bridging the UK gap. Findings – This study suggests that management practices are an ambiguous driver of firm productivity and higher firm performance. On the methodological side, qualitative and subjective measures of either management practices or firm performance are often used. This makes the results not comparable across studies, across firms or even within firms over time. Productivity and profitability are often and erroneously interchangeably used while productivity is only one element of firm performance. On the other hand, management practices are multi-dimensional constructs that generally do not demonstrate a straightforward relationship with productivity variables. To assume that they are the only driver of higher productivity may be misleading. Moreover, there is evidence of an inverse causal relationship between management practices and firm performance. This calls into question most empirical results of the extant literature based on the unidirectional assumption of direct causality between management practices and firm performance. Research limitations/implications – These and other issues suggest that more research is needed to deepen the understanding of the UK productivity gap and more quantitative evidence should be provided on the way in which management practices contribute to the UK competitiveness. Their impact is not easily measurable due to their complexity and their complementary nature and this is a fertile ground for further research. Originality/value – This paper brings together the evidence on the UK productivity gap and its main drivers, provided by the economics, management and performance measurement literature. This issue scores very highly in the agenda of policy makers and academics and has important implications for practitioners interested in evaluating the impact of managerial best practices.

Reducing medicines waste in the community

There is increasing concern at the amount and cost of prescribed medicines that are unused or wasted and then have to be disposed of. Previous studies have used health promotion and Dispose Unwanted Medicines Properly campaigns targeted at the patient to describe and quantify the annual cost of waste. The reasons patients return unused drugs to pharmacies have also been explored. The paper focuses on patient explanations for not needing medication; categorized as: over-collection in the past, self-management strategies, changes in medical condition, other changes in patient circumstances, or the repeat medicines policy at the surgery. The aim of the original study was to make a measurable change in prescribed medicines with a reduction in medicines wastage, whilst at the same time achieving improved standards of pharmaceutical care. Information on patient needs and behaviour came from consultation in the pharmacy monitoring forms and interview. The study was based on two medical practices in the West Midlands, UK, comparing an outer city and an inner city population. The participants were general practitioners, pharmacists and 350 repeat prescription patients. Prescriptions were issued for two three-month periods. The outcome was that 23.8% of the prescribed items were not dispensed, at a value of £13.1K, 58% of the medications that would be expected to be regularly supplied were collected. The study suggests that closer professional management at the point of dispensing and an understanding of patient experiences can help reduce the amount of unwanted medication collected by patients.

Radial growth of Rhizocarpon section Rhizocarpon lichen thalli over six years at snoqualmie pass in the Cascade Range, Washington State

This article describes a 6-yr study of the radial growth rates (RGR, mm yr-1) of Rhizocarpon section Rhizocarpon thalli on a talus slope at Snoqualmie Pass in the Cascade Range, Washington State, United States (47°27'N; 121°26'W). At the end of the growth period, 32 of a total of 39 thalli had exhibited a positive RGR, and 7 of a total of 39 thalli showed no measurable growth. Mean RGR of all thalli was 0.07 mm yr-1 (range, 0-0.19 mm, SD = 0.06). Analysis of variance suggested no significant variation in RGR in successive growth periods, but significant differences were present both within and between thalli. The slope of a boulder facet did not influence RGR, but growth was affected by aspect, the least growth being observed on north-northwest facets. A plot of RGR against thallus diameter revealed a wide scatter of data points with little evidence for a significant change in growth with thallus size. Hence, the study showed that the RGR of Rhizocarpon thalli at Snoqualmie is extremely slow and highly variable and significantly less than estimates based on lichenometry. To determine the growth curve of a yellow-green Rhizocarpon by direct measurement at such a site would require a large sample of thalli and careful standardization of the species studied, the aspect conditions under which the thalli were measured, and the initial hypothallus width of the thalli. © 2005 Regents of the University of Colorado.

Development and growth of the lichen Rhizocarpon geographicum

The development of new areolae on the marginal hypothallus of the lichen Rhizocarpon geographicum (L.) DC was studied after complete or partial removal of the central areolae. New areolae developed slowly on the isolated hypothalli over two years. Development was similar when the areolae were completely removed and when the central areolae were separated from the marginal hypothallus by ‘moats’ 2 to 5 mm in width. However, in intact thalli, the marginal areolae developed rapidly during Jan. – June 1986 but showed periods of retreat from the margin during Oct. - Dec. 1985 and July – Sept. 1986. These results suggested that primary areolae may develop from free-living algal cells trapped by the hypothallus while secondary areolae may develop from zoospores produced by the thallus. Complete removal of the areolae resulted in no measurable radial growth of the marginal hypothallus over 18 months. Removal of the central areolae to within 1 and 2 mm of the hypothallus significantly reduced growth. These results suggest that the areolae may supply the hypothallus with carbon for growth. When the marginal hypothallus was experimentally removed a new hypothallus developed within one year. Regeneration occurred initially by retreat of the marginal areolae and later by new hyphal growth. The concentration of ribitol, arabitol and mannitol was measured in the areolae and marginal hypothallus on four occasions in 1985/6 in a population growing on a steep south facing rock surface. The three carbohydrates were present in significantly higher concentration in the areolae than in the hypothallus. Hence, the slow growth of this species may result from inhibited transport of carbohydrate from areolae to hypothallus.

Technology flows, outsourcing and productivity:an analysis of UK trade and FDI

By engaging in trade and foreign direct investment (FDI) with foreign partners, a country can access the R&D and related knowledge stocks of other countries (by accident or by design) and so benefit from those stocks of knowledge at a cost lower than that which would be incurred by developing the knowledge internally. This should lead to beneficial ‘spillover’ effects on the productivity of domestic firms. However, the literature on technology spillovers from trade and FDI is ambiguous in its findings. This may in part be because of the assumption in much of the work that trade and FDI flows are homogeneous in their determinants and thus in their effects. We develop a taxonomy of trade and FDI determinants based on R&D intensity and unit labour cost differentials, and test for the presence of spillovers from inward investment and imports on an extensive sample of UK manufacturing plants. We find that both trade and FDI have measurable spillover effects, but the size of these effects varies depending on the technological and labour cost differentials between the UK and its trading partners. There is therefore an identifiable link between the determinants and effects of trade and FDI which the previous literature has not explored. We also find that absorptive capacity matters for spillovers from FDI, but not from trade. Overall, these findings suggest that the productivity effects of FDI are largely restricted to plants with high absorptive capacity, while the productivity effects of imports occur largely among higher-technology plants regardless of their absorptive capacity.

New investigations into macular pigment optical density

Macular pigment (MP) is the collective name for three carotenoids, lutein, zeaxanthin and meso-zeaxanthin, which are found at high concentrations in the central macula. The macular carotenoids, like all carotenoids, are entirely of dietary origin. The term ‘macular pigment optical density’ (MPOD) refers to the peak concentration of MP in the retina, which varies from one individual to the next and is measurable in vivo. On account of its blue-light-filtering and antioxidant properties, MP has become a subject of interest with respect to age-related macular degeneration (AMD), the hypothesis being that MP helps to protect against AMD; the higher the MPOD, the lower the risk for AMD. Recently, a new MPOD-measuring device, the MPS 9000 (MPS), entered the ophthalmic market. Using this device, the research described here aimed to contribute new information to the MP literature. A second MPOD instrument, the Macular Pigment Reflectometer, was also used at times, but a reliability study (included in the thesis) demonstrated that it was unsuitable for use on its own. First, a series of exploratory investigations were undertaken to maximize the accuracy and consistency of MPOD measurements taken with the MPS; a protocol was established that substantially improved repeatability. Subsequently, a series of MPOD-based studies were conducted on anisometropia, South Asian race, blue-light-filtering contact lenses, and dietary modification with kale. The principle findings were as follows: interocular MPOD differences were not attributable to interocular refractive error differences; young adults of South Asian origin had significant gender-related MPOD differences (males>females, p<0.01), and they also had significantly higher MPOD than Caucasians (p<0.0005); wearing blue-light-filtering contact lenses for eight months did not affect MPOD; and dietary modification with kale for 16 weeks did not increase MPOD. This body of research adds new insights to MP knowledge, which in turn may contribute to MP knowledge in the context of AMD.

Experimental studies of hypothallus growth in the lichen Rhizocarpon geographicum

Removal of the areolae of the crustose lichen Rhizocarpon geographicum (L.)DC. resulted in either low or no measurable radial growth of the marginal hypothallus. Radial growth of the hypothallus was also significantly reduced compared with intact thalli when (1) areolae were removed to within 1 and 2 mm of the hypothallus and (2) a 5 mm wide ‘moat’ was created between the areolae and the hypothallus. Adding ribitol (0.01 M) to isolated hypothalli at 3-month intervals over 15 months results in total radial growth c. 60% that of intact thalli. Adding an arabitol/mannitol mixture (0.05 M arabitol, 0.03 M mannitol) increased radial growth compared with deionized water and ribitol treatments. Adding ribitol (0.7 M), arabitol (0.2 M) and mannitol (0.08 M) to the areolae of intact thalli had no significant effects on radial growth of the hypothallus. On a south-facing rock surface, isolated hypothalli grew at a similar rate to intact thalli for 2 months. Growth then declined and the hypothalli disappeared from the rock surface within 6 months. The effects of addition of carbohydrate suggest that the marginal hypothallus has the capacity to utilize exogeneous materials. However, in intact thalli in the field, the radial growth of the hypothallus is likely to be a result of transfer of materials from the areolae through hyphal connections.

Novel hydrogel polymers

Hydrogels may be conveniently described as hydrophilic polymers that are swollen by, but do not dissolve in water. In this work a series of copolymer hydrogels and semi-interpenetrating polymer networks based on the monomers 2-hydroxyethyl methacrylate, N-vinyl pyrrolidone and N'N' dimethyl acrylamide, together with some less hydrophilic hydroxyalkyl acrylates and methacrylates have been synthesised. Variations in structure and composition have been correlated both with the total equilibrium water content of the resultant hydrogel and with the more detailed water binding behaviour, as revealed by differential scanning calorimetry studies. The water binding characteristics of the hydrogels were found to be primarily a function of the water structuring groups present in gel. The water binding abilities of these groups were, however, modified by steric effects. The mechanical properties of the hydrogels were also investigated. These were found to be dependent on both the polymer composition and the amount and nature of the water present in the gels. In biological systems, composite formation provides a means of producing strong, high water content materials. As an analogy with these systems hydrogel composites were prepared. In an initial study of these materials the water binding and mechanical properties of semi-interpenetrating polymer networks of N'N'dimethyl acrylamide with cellulosic type materials, with polyurethanes and with ester containing polymers were examined. A preliminary investigation of surface properties of both the copolymers and semi-interpenetrating polymer networks has been completed, using both contact angle measurements and anchorage dependent fibroblast cells. Measurable differences in surface properties attributable to structural variations in the polymers were detected by droplet techniques in the dehydrated state. However, in the hydrated state these differences were masked by the water in the gels. The use of cells enabled the underlying differences to be probed and the nature of the water structuring group was again found to be the dominant factor.

Chemical modification of smectite clays

Today, speciality use organoclays are being developed for an increasingly large number of specific applications. Many of these, including use in cosmetics, polishes, greases and paints, require that the material be free from abrasive impurities so that the product retains a smooth `feel'. The traditional `wet' method preparation of organoclays inherently removes abrasives naturally present in the parent mineral clay, but it is time-consuming and expensive. The primary objective of this thesis was to explore the alternative `dry' method (which is both quicker and cheaper but which provides no refining of the parent clay) as a process, and to examine the nature of the organoclays produced, for the production of a wide range of commercially usable organophilic clays in a facile way. Natural Wyoming bentonite contains two quite different types of silicate surface (that of the clay mineral montmorillonite and that of a quartz impurity) that may interact with the cationic surfactant added in the `dry' process production of organoclays. However, it is oil shale, and not the quartz, that is chiefly responsible for the abrasive nature of the material, although air refinement in combination with the controlled milling of the bentonite as a pretreatment may offer a route to its removal. Ion exchange of Wyoming bentonite with a long chain quaternary ammonium salt using the `dry' process affords a partially exchanged, 69-78%, organoclay, with a monolayer formation of ammonium ions in the interlayer. Excess ion pairs are sorbed on the silicate surfaces of both the clay mineral and the quartz impurity phases. Such surface sorption is enhanced by the presence of very finely divided, super paramagnetic, Fe2O3 or Fe(O)(OH) contaminating the surfaces of the major mineral components. The sorbed material is labile to washing, and induces a measurable shielding of the 29Si nuclei in both clay and quartz phases in the MAS NMR experiment, due to an anisotropic magnetic susceptibility effect. XRD data for humidified samples reveal the interlamellar regions to be strongly hydrophobic, with the by-product sodium chloride being expelled to the external surfaces. Many organic cations will exchange onto a clay. The tetracationic cyclophane, and multipurpose receptor, cyclobis(paraquat-p-phenylene) undergoes ion exchange onto Wyoming bentonite to form a pillared clay with a very regular gallery height. The major plane of the cyclophane is normal to the silicate surfaces, thus allowing the cavity to remain available for complexation. A series of group VI substituted o-dimethoxybenzenes were introduced, and shown to participate in host/guest interactions with the cyclophane. Evidence is given which suggests that the binding of the host structure to a clay substrate offers advantages, not only of transportability and usability but of stability, to the charge-transfer complex which may prove useful in a variety of commercial applications. The fundamental relationship between particle size, cation exchange capacity and chemical composition of clays was also examined. For Wyoming bentonite the extent of isomorphous substitution increases with decreasing particle size, causing the CEC to similarly increase, although the isomorphous substitution site: edge site ratio remains invarient throughout the particle size range studied.

Development of a novel in vitro system for nasal drug delivery development

There is currently, no ideal system for studying nasal drug delivery in vitro. The existing techniques such as the Ussing chamber and cell culture all have major disadvantages. Most importantly, none of the existing techniques accurately represent the interior of the nasal cavity, with its airflow and humidity; neither do they allow the investigation of solid dosage forms.The work in this thesis represents the development of an in vitro model system in which the interior characteristics of the nasal cavity are closely represented, and solid or minimal volume dosage forms can be investigated. The complete nasal chamber consists of two sections: a lower tissue, viability chamber and an upper nasal chamber. The lower tissue viability chamber has been shown, using existing tissue viability monitoring techniques, to maintain the viability of a number of epithelial tissues, including porcine and rabbit nasal tissue, and rat ileal and Payers' patch tissue. The complete chamber including the upper nasal chamber has been shown to provide tissue viability for porcine and rabbit nasal tissue above that available using the existing Ussing chamber techniques. Adaptation of the complete system, and the development of the necessary experimental protocols that allow aerosol particle-sizing, together with videography, has shown that the new factors investigated, humidity and airflow, have a measurable effect on the delivered dose from a typical nasal pump. Similarly, adaptation of the chamber to fit under a confocal microscope, and the development of the necessary protocols has shown the effect of surface and size on the penetration of microparticulate materials into nasal epithelial tissues. The system developed in this thesis has been shown to be flexible, in allowing the development of the confocal and particle-sizing systems. For future nasal drug delivery studies, the ability to measure such factors as the size of the delivered system in the nasal cavity, the depth of penetration of the formulation into the tissue are essential. Additionally, to have access to other data such as that obtained from drug transport in the same system, and to have the tissue available for histological examination represents a significant advance in the usefulness of such an in vitro technique for nasal delivery.