Incorporating movement into models of grey seal population dynamics

1. One of the most difficult problems in developing spatially explicit models of population dynamics is the validation and parameterization of the movement process. We show how movement models derived from capture-recapture analysis can be improved by incorporating them into a spatially explicit metapopulation model that is fitted to a time series of abundance data. 2. We applied multisite capture-recapture analysis techniques to photo-identification data collected from female grey seals at the four main breeding colonies in the North Sea between 1999 and 2001. The best-fitting movement models were then incorporated into state-space metapopulation models that explicitly accounted for demographic and observational stochasticity. 3. These metapopulation models were fitted to a 20-year time series of pup production data for each colony using a Bayesian approach. The best-fitting model, based on the Akaike Information Criterion (AIC), had only a single movement parameter, whose confidence interval was 82% less than that obtained from the capture-recapture study, but there was some support for a model that included an effect of distance between colonies. 4. The state-space modelling provided improved estimates of other demographic parameters. 5. The incorporation of movement, and the way in which it was modelled, affected both local and regional dynamics. These differences were most evident as colonies approached their carrying capacities, suggesting that our ability to discriminate between models should improve as the length of the grey seal time series increases.

Preferential π–π complexation between tamoxifen and borage oil/γ linolenic acid: Transcutaneous delivery and NMR spectral modulation

The effect of different proportions of borage oil on the in vitro transcutaneous delivery of tamoxifen were studied, with the aim of developing a gel capable of the simultaneous delivery of tamoxifen and gamma linolenic acid across (breast) skin. Supplementary work probed 1H NMR spectral data for tamoxifen in the presence of different proportions of polyunsaturated or unsaturated fatty acids. Typical, non-aqueous gels were modified to contain 1% tamoxifen and three levels of borage oil ( approximately 25% gamma linolenic acid) and the transcutaneous delivery of both tamoxifen and GLA across full thickness skin determined in vitro. Both tamoxifen and gamma linolenic acid permeated the skin with the ratio of moles being consistent at approximately 4:1. This was irrespective of time, amount of borage oil contained in the formulation (above a minimum) and the presence of other (unsaturated) excipients: mineral oil, Miglyiol 810N, white soft paraffin, PEG400 and Cabosil M5. Dose-dependent downfield shifts of tamoxifen aromatic protons were observed in the presence of borage oil and linolenic acid (gamma and alpha), but not saturated triacyl glycerol. The permeation data suggested vehicular complexation between tamoxifen and polyunsaturated constituents of borage oil and that such complexes permeated the skin intact. The 1H NMR data supported the hypothesis that such complexation was a consequence of preferential pi-pi orbital interactions between the phenyl groups of tamoxifen and the multiple double bonds of GLA. The mechanism for the permeation of intact complexes across skin remains to be elucidated.

Combining demographic, environmental and genetic data to test hypotheses about colonization events in metapopulations

We describe a method for making inferences about the factors that influence colonization processes in natural populations. We consider the general situation where we have genetic data from a newly colonized population and also from I source populations that may have contributed individuals to the founding group that established the new population. The model assumes that p (biotic/abiotic) factors, G(1), ... ,G(p) may have influenced some individuals in some of the source populations to find a new habitat patch where they could establish a new population. The aim of the method is to determine the composition of the founding group and to ascertain if the aforementioned factors have indeed played a role in the colonization event. We investigate the performance of our method using simulated data sets and illustrate its application with data from the grey seal Halichoerus grypus. These applications demonstrate that the method can identify accurately those factors that are most important for the founding of new populations. This is the case even when genetic differentiation among source populations is low. The estimates of the contribution that each source population makes to the founding groups is somewhat sensitive to the degree of genetic differentiation but it is still possible to identify the sources that are the main contributors to the founding group, even when genetic differentiation is low (F(ST) = 0.01).

Older adults' trait ratings of three age-groups around the Pacific rim

In this paper, we assess the traits that older adults associate with younger, middle-aged, and older adults in five Pacific Rim nations from Western and Eastern cultural traditions (Australia, People's Republic of China (PRC), Hong Kong, Philippines, Thailand). We find cross-cultural trends which replicate patterns found in the US context. In most cultures, attractiveness, strength, activity, liberalism, health, and flexibility are seen to decline with increasing age. Kindness assessments are positively associated with age across cultures. Mixed patterns are found with assessments of wisdom and generosity, with respondents from the PRC and Hong Kong being notably more negative about increasing age than other respondents. Implications for the aging process across cultures are discussed, and suggestions made for future research.

The in vitro delivery of NSAIDs across skin was in proportion to the delivery of essential fatty acids in the vehicle--evidence that solutes permeate skin associated with their solvation cages?

As part of our investigations into novel dual action topical anti-arthritis systems, the permeation of ibuprofen or ketoprofen plus eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were determined from a fish oil vehicle across pig ear skin in vitro. The steady state fluxes of ibuprofen and ketoprofen were 9.17+/-1.98 microgram cm(-2)h(-1) and 6.12+/-2.39 microgram cm(-2)h(-1), respectively. At 24h, 5.7 microgram cm(-2) EPA and 3.1 microgram cm(-2) DHA permeated when the solute was ibuprofen; 1.4 microgram cm(-2) EPA and 1.0 microgram cm(-2) DHA when ketoprofen was the solute. At 12h, the ketoprofen/ibuprofen ratio of the moles permeated was 0.27, the ratio of EPA permeated simultaneously with ketoprofen and ibuprofen was 0.22 and the ratio of DHA permeated simultaneously with ketoprofen and ibuprofen was 0.24. We believe this is the first time that simultaneous permeation across skin of a solute and its vehicle has been determined purposefully. The data successfully demonstrated that simultaneous permeation of NSAIDs and essential fatty acids, EPA and DHA from a formulation containing fish oil is feasible. In addition, for both NSAIDs, the relative rates of permeation of EPA and DHA, were in proportion to their levels in the fish oil and the permeation rate of either fatty acid was higher when the permeation rate of the solute was greater. This suggested that the greater the rate of permeation of the NSAID, the greater the rate of permeation of the vehicle, and that a solute permeates skin complete with its vehicular solvation cage. This apparent relationship between solute and vehicle fluxes may be of more widespread significance to skin permeation experimentation.

Comparing grandchildren's and grandparents' stake in their relationship

This paper examines the intergenerational stake hypothesis in the grandparent-grandchild relationship. The hypothesis predicts that older generations will perceive more closeness in a relationship than younger generations. Grandparent-grandchild dyads are surveyed concerning various aspects of their relationship. Using measures of closeness and an established typology of grandparent-grandchild relationship style (Cherlin & Furstenberg, 1985), the study finds that grandparents perceive their relationship with their grandchildren to be considerably closer than their grandchildren perceive the relationship. However, their grandchildren perceive the relationship to be more active than their grandparents do. Explanations of these findings consistent with the intergenerational stake hypothesis are advanced. It is found that the two parties often disagree as to the nature of their relationship on the Cherlin and Furstenberg typology. Details of these disagreements are examined in detail, and implications for the grandparent-grandchild relationship are discussed.

Patterns of colonization in a metapopulation of grey seals

The colonization of a new habitat is a fundamental process in metapopulation biology, but it is difficult to study. The emigration of colonists from established populations might be induced by resource competition owing to high local population density. Migration distances are also important because they determine the frequency and scale of recolonization and hence the spatial scale of the metapopulation. Traditionally, these factors have been investigated with demographic approaches that are labour-intensive and are only possible in amenable species. In many cases, genetic differentiation is minimal, preventing traditional genetic approaches from identifying the source of colonists unambiguously. Here we present a bayesian approach that integrates genetic, demographic and geographic distance data. We apply the method to study the British metapopulation of grey seals, which has been growing at 6% per year over the last few decades. Our method reveals differential recruitment to three newly founded colonies and implicates density-dependent dispersal in metapopulation dynamics by using genetic data.

Data quality probes--a synergistic method for quality monitoring of electronic medical record data accuracy and healthcare provision

Increasing reliance is being placed on electronic medical records to support clinical care and achieve improved quality standards. In order for clinical information systems (CIS) to deliver, the data within needs to be complete, consistent and accurate. This data of course only forms part of the process in delivering quality health care during the clinician-patient encounter. This paper outlines a method of assessing the quality of the processes involved in healthcare provision and data quality within a CIS. It proposes a principle of Data Quality Probes (DQP) that can be used to assess the performance of the whole encounter system. The main feature of this is the generation of a query which clinical knowledge predicts should not retrieve any cases in a system performing flawlessly. This approach is applied practically within the paradigm of a UK family practice testing the DQP that only patients who have had a hysterectomy should be prescribed unopposed oestrogen hormone replacement therapy.

The rediscovery of Mendelism in agricultural context: Erich von Tschermak as plant-breeder

Why was Mendelism rediscovered? One way in which historians have addressed this issue is to look at wider trends in research during the 1890s of which the rediscoverers were part. Quite a lot is known about one such research tradition, namely the attempts to resolve the question of evolutionary mechanism through the use of varietal crosses. But another relevant research tradition is still largely unknown: the work of commercial breeders, several of whom were using hybridisation by the 1890s. In this paper I begin by looking at Tschermak's initial career, the sequence of events by which he came upon Mendel's work, and why he was excited by what he read. Then I place Tschermak's early work in the context of commercial plant-breeding in German-speaking Europe toward the end of the 19th century. Finally I look again at the question of Tschermak's somewhat ambivalent relationship to Mendelism after 1900. I argue that his initial misunderstanding of the concept of segregation was due to the fact that he approached Mendel's work with the perspective of a breeder rather than that of a geneticist.

Expectations for communication with positive and negative subtypes of older adults

The study uses a recently-developed scale for eliciting perceptions, expectations, and evaluations of intergenerational communication. As predicted, it is found that younger adults expect to experience more anxiety, receive more complaining, and receive lower levels of attunement from an older adult who is portrayed as "despondent" than one who is portrayed as a "perfect grandparent." In addition, younger adults with more negative attitudes toward older adults expect to experience more negative effect, anxiety, and communication apprehension, to feel more compassion for the older adult, and to receive lower levels of attunement and more complaining from the older adult than those with more positive attitudes. Surprisingly, younger adults with higher levels of young age identification expect to experience lower levels of apprehension, more attunement from the older adult, and to feel more compassion for the older adult than those with lower levels of age identity. These findings are discussed in terms of theoretical models of intergenerational communication, in particular the communication predicament model. In addition, younger people's feelings of having "helped" an older person are discussed in the context of intergroup theory.

Oxygen induces fatty acid (n-6)-desaturation independently of temperature in Acanthamoeba castellanii

Induction of a microsomal oleate delta12 (n-6) desaturase which is mainly responsible for an increase in membrane lipid unsaturation at low temperature has been observed in the free-living amoeba Acanthamoeba castellanii. In this study we show that the enzyme can also be regulated by oxygen independently of temperature in batch cultures grown to O2-limitation. Raising the oxygen concentration from below the lower limit of detection (< 0.1 microM) to approximately air-saturation (230 microM), whilst maintaining the growth temperature constant (30 degrees C), increased lipid unsaturation and elevated n-6-desaturase activity 2.3-fold. Addition of the protein synthesis inhibitor, anisomycin, showed that increased desaturase activity was due to new protein synthesis rather than activation of pre-existing enzyme. These observations are important for future studies of the mechanism of temperature adaptation in poikilotherms.

Factors affecting levels of genetic diversity in natural populations

Genetic variability is the clay of evolution, providing the base material on which adaptation and speciation depend. It is often assumed that most interspecific differences in variability are due primarily to population size effects, with bottlenecked populations carrying less variability than those of stable size. However, we show that population bottlenecks are unlikely to be the only factor, even in classic case studies such as the northern elephant seal and the cheetah, where genetic polymorphism is virtually absent. Instead, we suggest that the low levels of variability observed in endangered populations are more likely to result from a combination of publication biases, which tend to inflate the level of variability which is considered 'normal', and inbreeding effects, which may hasten loss of variability due to drift. To account for species with large population sizes but low variability we advance three hypotheses. First, it is known that certain metapopulation structures can result in effective population sizes far below the census size. Second, there is increasing evidence that heterozygous sites mutate more frequently than equivalent homozygous sites, plausibly because mismatch repair between homologous chromosomes during meiosis provides extra opportunities to mutate. Such a mechanism would undermine the simple relationship between heterozygosity and effective population size. Third, the fact that related species that differ greatly in variability implies that large amounts of variability can be gained or lost rapidly. We argue that such cases are best explained by rapid loss through a genome-wide selective sweep, and suggest a mechanism by which this could come about, based on forced changes to a control gene inducing coevolution in the genes it controls. Our model, based on meiotic drive in mammals, but easily extended to other systems, would tend to facilitate population isolation by generating molecular incompatabilities. Circumstances can even be envisioned in which the process could provide intrinsic impetus to speciation.