Procedural understanding in biology: the ‘thinking behind the doing’

Several developments in science education aim to improve pupils' ability to ‘think scientifically’. This paper argues for the explicit teaching of the ideas that pupils need to ‘think about’ to do this; ideas related to the design of investigations and the collection, presentation, analysis, and evaluation of the resulting evidence — ideas which are important both for pupils who continue to study or work with biology and for all pupils to become biologically literate. This paper considers some of the concepts of evidence which are particularly important to biology, and discusses how and why the ideas could be taught.     

Weevil x Insecticide: Does ‘Personality’ Matter?

An insect’s behavior is the expression of its integrated physiology in response to external and internal stimuli, turning insect behavior into a potential determinant of insecticide exposure. Behavioral traits may therefore influence insecticide efficacy against insects, compromising the validity of standard bioassays of insecticide activity, which are fundamentally based on lethality alone. By extension, insect ‘personality’ (i.e., an individual’s integrated set of behavioral tendencies that is inferred from multiple empirical measures) may also be an important determinant of insecticide exposure and activity. This has yet to be considered because the behavioral studies involving insects and insecticides focus on populations rather than on individuals. Even among studies of animal ‘personality’, the relative contributions of individual and population variation are usually neglected. Here, we assessed behavioral traits (within the categories: activity, boldness/shyness, and exploration/avoidance) of individuals from 15 populations of the maize weevil (Sitophilus zeamais), an important stored-grain pest with serious problems of insecticide resistance, and correlated the behavioral responses with the activity of the insecticide deltamethrin. This analysis was performed at both the population and individual levels. There was significant variation in weevil ‘personality’ among individuals and populations, but variation among individuals within populations accounted for most of the observed variation (92.57%). This result emphasizes the importance of individual variation in behavioral and ‘personality’ studies. When the behavioral traits assessed were correlated with median lethal time (LT₅₀) at the population level and with the survival time under insecticide exposure, activity traits, particularly the distance walked, significantly increased survival time. Therefore, behavioral traits are important components of insecticide efficacy, and individual variation should be considered in such studies. This is so because population differences provided only crude approximation of the individual personality in a restrained experimental setting likely to restrict individual behavior favoring the transposition of the individual variation to the population.     

Does malaria epidemiology project Cameroon as ‘Africa in miniature’?

Cameroon, a west-central African country with a ~20 million population, is commonly regarded as ‘Africa in miniature’ due to the extensive biological and cultural diversities of whole Africa being present in a single-country setting. This country is inhabited by ancestral human lineages in unique eco-climatic conditions and diverse topography. Over 90% Cameroonians are at risk of malaria infection, and ~41% have at least one episode of malaria each year. Historically, the rate of malaria infection in Cameroon has fluctuated over the years; the number of cases was about 2 million in 2010 and 2011. The Cameroonian malaria control programme faces an uphill task due to high prevalence of multidrug-resistant parasites and insecticide-resistant malaria vectors. Above all, continued human migration from the rural to urban areas as well as population exchange with adjoining countries, high rate of ecological instabilities caused by deforestation, poor housing, lack of proper sanitation and drainage system might have resulted in the recent increase in incidences of malaria and other vector-borne diseases in Cameroon. The available data on eco-environmental variability and intricate malaria epidemiology in Cameroon reflect the situation in the whole of Africa, and warrant the need for in-depth study by using modern surveillance tools for meaningful basic understanding of the malaria triangle (host-parasite-vector-environment).     

Does screw–bone interface modelling matter in finite element analyses?

The effect of screw-bone interface modelling strategies was evaluated in the setting of a tibial mid-shaft fracture stabilised using locking plates. Three interface models were examined: fully bonded interface; screw with sliding contact with bone; and screw with sliding contact with bone in an undersized pilot hole. For the simulation of the last interface condition we used a novel thermal expansion approach to generate the pre-stress that the bone would be exposed to during screw insertion. The study finds that the global load-deformation response is not influenced by the interface modelling approach employed; the deformation varied by less than 1% between different interaction models. However, interface modelling is found to have a considerable impact on the local stress-strain environment within the bone in the vicinity of the screws. Frictional and tied representations did not have significantly different peak strain values (<5% difference); the frictional interface had higher peak compressive strains while the tied interface had higher tensile strains. The undersized pilot hole simulation produced the largest strains. The peak minimum principal strains for the frictional interface were 26% of those for the undersized pilot hole simulation at a load of 770 N. It is concluded that the commonly used tie constraint can be used effectively when the only interest is the global load-deformation behaviour. Different contact interface models, however, alter the mechanical response around screw holes leading to different predictions for screw loosening, bone damage and stress shielding.     

Demographic Transition in India: An Evolutionary Interpretation of Population and Health Trends Using ‘Change-Point Analysis’

Background and Rationale

Lack of a robust analytical tool for trend analysis of population and health indicators is the basic rationale of this study. In an effort to fill this gap, this study advances ‘Change-Point analyzer’ as a new analytical tool for assessment of the progress and its pattern in population and health indicators.

Methodology/Principal Findings

The defining feature of ‘change-point analyzer’ is that, it detects subtle changes that are often missed in simple trend line plots and also quantified the volume of change that is not possible in simple trend line plots. A long-term assessment of ‘change-point analyses’ of trends in population and health indicators such as IMR, Population size, TFR, and LEB in India show multiple points of critical changes. Measured change points of demographic and health trends helps in understanding the demographic transitional shifts connecting it to contextual policy shifts. Critical change-points in population and health indicators in India are associated with the evolution of structural changes in population and health policy framework.

Conclusions

This study, therefore, adds significantly to the evolutionary interpretation of critical change-points in long-term trajectories of population and health indicators vis-a-vis population and health policy shifts in India. The results have not only helped in reassessing the historical past and the current demographic transition trajectory but also advanced a new method of assessing the population and health trends which are necessary for robust monitoring of the progress in population and health policies.     

Pigeon homing: Does initial orientation include a ‘preferred compass direction’?

Summary To find out whether the initial orientation of pigeons is affected by a spontaneous directional tendency, as postulated by Wallraff's (1974, 1978, 1982) hypothesis, experienced birds were released at test sites distributed symmetrically around their loft. — The length of the mean vectors of the single releases, the deviations from the home direction, the homeward components as well as the homing speed did not show a correlation with the geographic position of the home direction. Summarizing four sites each on 21 experimental circles, we frequently obtained significant compass vectors, but they varied in direction between 115° ESE and 351° N, depending on what sites had been used, and did not indicate a uniform trend.A preferred compass direction as an integrated part of pigeon navigation, being the reason for the frequently observed deviations from the home direction, could not be confirmed. — The problematic nature of simply pooling the data of several symmetrically distributed test sites and calling any resulting significant vector a preferred compass direction is discussed, together with other possible reasons for asymmetrical distributions of release site biases.Abbreviation PCD preferred compass direction     

Towards understanding: antisemitism and the contested uses and meanings of ‘Yid’ in English football

This article addresses an omission in the currently brief body of work on antisemitism in football and contributes to and advances wider sociological debates in the sub-disciplines of race and ethnicity, religion, linguistics and sport. The article examines antisemitic discourse in English football and in doing so, explains the different uses and meanings of ‘Yid’ in the vernacular culture of fans. While many conceive of ‘Yid’ as an ethnic epithet, fans of Tottenham Hotspur – Gentiles and Jews – have appropriated and embraced the term, using it to deflect the antisemitic abuse they are targeted with due to their ‘Jewish identity’. The study maps the contested uses of ‘Yid’ on a continuum to explain and demarcate between the nuanced forms of antisemitism in football. It makes central the cultural context in which ‘Yid’ is used, together with the intent underpinning its use, since epithets and slurs are not simply determined by their lexical form.     

Actinomycetes biosynthetic potential: how to bridge in silico and in vivo?

Actinomycetes genome sequencing and bioinformatic analyses revealed a large number of “cryptic” gene clusters coding for secondary metabolism. These gene clusters have the potential to increase the chemical diversity of natural products. Indeed, reexamination of well-characterized actinomycetes strains revealed a variety of hidden treasures. Growing information about this metabolic diversity has promoted further development of strategies to discover novel biologically active compounds produced by actinomycetes. This new task for actinomycetes genetics requires the development and use of new approaches and tools. Application of synthetic biology approaches led to the development of a set of strategies and tools to satisfy these new requirements. In this review, we discuss strategies and methods to discover small molecules produced by these fascinating bacteria and also discuss a variety of genetic instruments and regulatory elements used to activate secondary metabolism cryptic genes for the overproduction of these metabolites.     

Can habitat modelling for the octopus Eledone cirrhosa help identify key areas for Risso’s dolphin in Scottish waters?

Marine protected areas (MPAs) are becoming increasingly important tools in the conservation of cetaceans. This has led to an interest in the use of species distribution models to predict where cetacean species are likely to occur based on the distribution of environmental variables. However, relationships between cetacean distribution and environmental variables are generally assumed to reflect the environmental preferences of their prey. Thus, understanding the distribution of prey may increase our ability to identify important areas for cetaceans. Here, we describe the diet of Risso’s dolphin (Grampus griseus) by analysing stomach contents of individuals stranded in Scotland over the last twenty years. Next, we use habitat modelling to test whether Rissos’s dolphin distribution in Scottish waters, as inferred from sightings, is related to the distribution of its main prey, the octopus Eledone cirrhosa. While good models of the relationship between the distribution of E. cirrhosa and environmental variables were obtained, there was no evidence of a relationship between modelled octopus distribution and the occurrence of Risso’s dolphins. These results suggest that identifying key areas for its main prey species is unlikely to help identify potential MPAs for Risso’s dolphin, at least at the spatial resolution used in this study.     

Fractal Dimension in Butterflies’ Wings: a novel approach to understanding wing patterns ?

The geometrical complexity in the wings of several, taxonomically different butterflies, is analyzed in terms of their fractal dimension. Preliminary results provide some evidence on important questions about the (dis)similarity of the wing patterns in terms of their fractal dimension. The analysis is restricted to two groups which are widely used in the literature as typical examples of mimicry, and a small number of unrelated species, thus implying the consideration of only a fraction of the wing pattern diversity. The members of the first mimicry ring, composed by the species Danaus plexippus (better known as the monarch butterfly), and the two subspecies Basilarchia archippus obsoleta (or northern viceroy) and Basilarchia archippus hoffmanni (or tropical viceroy), are found to have a very similar value for the fractal dimension of their wing patterns, even though they do not look very similar at first sight. It is also found that the female of another species (Neophasia terlootii), which looks similar to the members of the previous group, does not share the same feature, while the Lycorea ilione albescens does share it. For the members of the second group of mimicry related butterflies, the Greta nero nero and the Hypoleria cassotis, it is shown that they also have very close values for the fractal dimension of their wing patterns. Finally, it is shown that other species, which apparently have very similar wing patterns, do not have the same fractal dimension. A possible, not completely tested hypothesis is then conjectured: the formation of groups by individuals whose wing patterns have an almost equal fractal dimension may be due to the fact that they do share the same developmental raw material, and that this common feature is posteriorly modified by natural selection, possibly through predation.We sincerely acknowledge the invaluable help of Adolfo Ibarra Vázquez, senior curator of the Lepidopterous collection at the Instituto de Biología, Universidad Nacional Autónoma de México, and the comments made by two anonymous referees     

Does Erythropoietin Cause Hemoglobin Variability- Is It ‘Normal’?

Hemoglobin variability (Hb-var) in patients with chronic kidney disease has been stipulated to be a result of exogenous treatment with erythropoiesis stimulating agents (ESA) and has been related to mortality in dialysis patients. We hypothesized the existence of Hb-var independent of ESA administration and compared it to that in healthy adults using data from the Scripps-Kaiser and NHANES III databases. We studied the Hb-var in 1571 peritoneal dialysis patients which included 116 patients not requiring treatment with erythropoietin. We systematically studied the differences between the groups that needed ESA therapy and those who did not. White race and male sex were significant predictors of need for erythropoietin therapy. We found peritoneal dialysis patients to exhibit significantly increased Hb-var independent of treatment with exogenous erythropoietin (0.99 gm/dL vs. 1.17 gm/dL, p-value<0.001). We found age to be a significant determinant of Hb-var in the ESA treated group. Hb-var in younger patients (<30 years) was increased by 50% compared to young healthy adults. The Hb-var in elderly (>60 years) peritoneal dialysis patients was similar to that seen in healthy elders, suggesting similarity with anemia of aging. We conclude that exogenous ESA administration does not explain Hb-var entirely but may enhance it. Intrinsic factors affecting erythropoiesis including age may be the major determinants of Hb-var.     

Individual-based modelling in ecology: what makes the difference?

Is individual-based modelling really a new approach in ecology? A large part of the uncertainty surrounding this question is a consequence of imprecisely delimited boundaries between classical and individual-based modelling. Genuine 'individual-based' models describe a population made up of individuals that may differ from one another; they also describe changes in numbers of individuals rather than in the population density, and take resource dynamics explicitly into account. Individual-based models that fulfil these criteria will not characterize ecological systems as 'stable' systems in their ideal form, with equilibrium states represented by points in the phase space.     

Sexual Selection: Does Condition Dependence Fail to Resolve the ‘Lek Paradox’?

The 'lek paradox'--the hypothesis that females do not gain substantial genetic benefits from mate choice--could be resolved by sexually selected traits being indicative of male condition. A recent paper, however, suggests that this may not be the case in Drosophila bunnanda.     

In What Sense Does ‘Nothing Make Sense Except in the Light of Evolution’?

Dobzhansky argued that biology only makes sense if life on earth has a shared history. But his dictum is often reinterpreted to mean that biology only makes sense in the light of adaptation. Some philosophers of science have argued in this spirit that all work in 'proximal' biosciences such as anatomy, physiology and molecular biology must be framed, at least implicitly, by the selection histories of the organisms under study. Others have denied this and have proposed non-evolutionary ways in which biologists can frame these investigations. This paper argues that an evolutionary perspective is indeed necessary, but that it must be a forward-looking perspective informed by a general understanding of the evolutionary process, not a backward-looking perspective informed by the specific evolutionary history of the species being studied. Interestingly, it turns out that there are aspects of proximal biology that even a creationist cannot study except in the light of a theory of their effect on future evolution.     

We-intentionality: an essential element in understanding human culture?

Culture is a powerful cause of human behavior, yet there have been few attempts to synthesize the biological and social sciences in order to provide an explanation of culture and hence to lay the foundations for a comprehensive human science. This essay explores one possible way of doing this by outlining the likely psychological mechanisms that give rise to the unique human capacity for creating social reality. The core assumption is that "we-intentionality," which is key to understanding social constructions, can and must be linked to specific evolved psychological traits, and hence placed within a neuroscience perspective.     

‘I need help’: caregivers' experiences of caring for their relatives with mental illness in Jamaica

The findings reported here form part of a larger research project that examined non-compliance with medication among the mentally ill patients attending public clinics in a specific parish in Jamaica. The aim of the research was to explore the perceptions of caregivers about caring for the mentally ill at two outpatient psychiatric clinics. Caregivers involved in looking after their relatives with mental illness played a vital role in mental health promotion. This study sought to examine the caregivers'' perception of mental illness, including how they thought the illness was best controlled, the reasons why their relatives found it difficult to take their medication as instructed, and the coping skills that they employed when caring for their relatives. There were two focus groups, consisting of four individuals each, at two psychiatric clinics.The results revealed the following about the majority of the caregivers. First, it was recognised that caregivers have a good knowledge (and awareness) of medication usage inferred by either the absence or the presence of their relatives'' symptoms. Secondly, they sometimes felt sad and hopeless as a result of being the victims of violent attacks by those for whom they provided care. Thirdly, they highlighted issues of cost, accessibility and availability of medications as being problematic. Fourthly, in some cases they received little or no assistance from other family members.