Relative roles of dispersal dynamics and competition in determining the isotopic niche breadth of a wetland fish

1. The niche variation hypothesis predicts that among-individual variation in niche use will increase in the presence of intraspecific competition and decrease in the presence of interspecific competition. We sought to determine whether the local isotopic niche breadth of fish inhabiting a wetland was best explained by competition for resources and the niche variation hypothesis, by dispersal of individuals from locations with different prey resources or by a combination of the two. We analysed stable isotopes of carbon and nitrogen as indices of feeding niche and compared metrics of within-site spread to characterise site-level isotopic niche breadth. We then evaluated the explanatory power of competing models of the direct and indirect effects of several environmental variables spanning gradients of disturbance, competition strength and food availability on among-individual variation of the eastern mosquitofish (Gambusia holbrooki). 2. The Dispersal model posits that only the direct effect of disturbance (i.e. changes in water level known to induce fish movement) influences among-individual variation in isotopic niche. The Partitioning model allows for only direct effects of local food availability on among-individual variation. The Combined model allows for both hypotheses by including the direct effects of disturbance and food availability. 3. A linear regression of the Combined model described more variance than models limited to the variables of either the Dispersal or Partitioning models. Of the independent variables considered, the food availability variable (per cent edible periphyton) explained the most variation in isotopic niche breadth, followed closely by the disturbance variable (days since last drying event). 4. Structural equation modelling provided further evidence that the Combined model was best supported by the data, with the Partitioning and the Dispersal models only modestly less informative. Again, the per cent edible periphyton was the variable with the largest direct effect on niche variability, with other food availability variables and the disturbance variable only slightly less important. Indirect effects of heterospecific and conspecific competitor densities were also important, through their effects on prey density. 5. Our results support the Combined hypotheses, although partitioning mechanisms appear to explain the most diet variation among individuals in the eastern mosquitofish. The results also support some predictions of the niche variation hypothesis, although both conspecific and interspecific competition appeared to increase isotopic niche breadth in contrast to predictions that interspecific competition would decrease it. We think this resulted from high diet overlap of co-occurring species, most of which consume similar macroinvertebrates.

Crossover promotion and prevention

Peer reviewed

New cassettes for single-step drug-resistance and prototrophic marker switching in fission yeast

Copyright © 2015 John Wiley & Sons, Ltd. Funded by College of Life Science and Medicine, University of Aberdeen, UK This work was funded by a start-up grant from the College of Life Science and Medicine, University of Aberdeen, UK. I am grateful to J. Bähler, E. Hartsuiker, F. Klein, J. Kohli, K. Nasmyth, M. C. Whitby, the Leibniz Institute – German Collection of Microorganisms and Cell Cultures (DMSZ) and the National BioResource Project Japan (NBRP) for providing materials used in this study. I thank Alistair J. P. Brown and Takashi Kubota for critically reading this manuscript.

Crossover promotion and prevention

Peer reviewed

New cassettes for single-step drug-resistance and prototrophic marker switching in fission yeast

Copyright © 2015 John Wiley & Sons, Ltd. Funded by College of Life Science and Medicine, University of Aberdeen, UK This work was funded by a start-up grant from the College of Life Science and Medicine, University of Aberdeen, UK. I am grateful to J. Bähler, E. Hartsuiker, F. Klein, J. Kohli, K. Nasmyth, M. C. Whitby, the Leibniz Institute – German Collection of Microorganisms and Cell Cultures (DMSZ) and the National BioResource Project Japan (NBRP) for providing materials used in this study. I thank Alistair J. P. Brown and Takashi Kubota for critically reading this manuscript.

On the microstructure, growth pattern and original porosity of belemnite rostra: insights from calcitic Jurassic belemnites

Calcitic belemnite rostra are usually employed to perform paleoenvironmental studies based on geochemical data. However, several questions, such as their original porosity and microstructure, remain open, despite they are essential to make accurate interpretations based on geochemical analyses.This paper revisits and enlightens some of these questions. Petrographic data demonstrate that calcite crystals of the rostrum solidum of belemnites grow from spherulites that successively develop along the apical line, resulting in a “regular spherulithic prismatic” microstructure. Radially arranged calcite crystals emerge and diverge from the spherulites: towards the apex, crystals grow until a new spherulite is formed; towards the external walls of the rostrum, the crystals become progressively bigger and prismatic. Adjacent crystals slightly vary in their c-axis orientation, resulting in undulose extinction. Concentric growth layering develops at different scales and is superimposed and traversed by a radial pattern, which results in the micro-fibrous texture that is observed in the calcite crystals in the rostra.Petrographic data demonstrate that single calcite crystals in the rostra have a composite nature, which strongly suggests that the belemnite rostra were originally porous. Single crystals consistently comprise two distinct zones or sectors in optical continuity: 1) the inner zone is fluorescent, has relatively low optical relief under transmitted light (TL) microscopy, a dark-grey color under backscatter electron microscopy (BSEM), a commonly triangular shape, a “patchy” appearance and relatively high Mg and Na contents; 2) the outer sector is non-fluorescent, has relatively high optical relief under TL, a light-grey color under BSEM and low Mg and Na contents. The inner and fluorescent sectors are interpreted to have formed first as a product of biologically controlled mineralization during belemnite skeletal growth and the non-fluorescent outer sectors as overgrowths of the former, filling the intra- and inter-crystalline porosity. This question has important implications for making paleoenvironmental and/or paleoclimatic interpretations based on geochemical analyses of belemnite rostra.Finally, the petrographic features of composite calcite crystals in the rostra also suggest the non-classical crystallization of belemnite rostra, as previously suggested by other authors.

Crónicas, reliquias, piedras legendarias y coronaciones en la Edad Media

Este artículo es un estudio histórico de la leyenda de la «Piedra del Destino», que fue parte del asiento del trono de coronación de los reyes de Escocia y que fue trasladada a la abadía de Westminster por el rey Eduardo de Inglaterra, que la situó bajo el trono de la coronación de los reyes de Inglaterra. La «Piedra del Destino», como muchas reliquias y antigüedades de la Edad Media, tuvo una larga historia, escrita por cronistas e historiadores. Una historia muy semejante a otras translationes de reliquias. La historia de la «Piedra del Destino» contiene ricos aspectos jurídicos, políticos y sacrales. Para comprenderlos es necesario analizar las crónicas, entendidas como textos históricos, que dan sentido a los rituales jurídicos y políticos de la Edad Media.

Doing Relationships and Sexuality Education with Young People in State Care

Background: Existing literature indicates that young people in state carehave particular sexual health needs that include addressing their social andemotional well-being, yet little has been published as to how thesecomponents of sex education are actually delivered by service-providers.Objective: To analyse the processes involved in delivering relationship andsexuality education to young people in state care from the perspectives ofa sample of service-providers with a role in sexual health care delivery.Design: Qualitative methodological strategy.Setting: Service-delivery sites at urban and rural locations in Ireland.Method: Twenty-two service-providers were interviewed in depth, and datawere analysed using a qualitative analytical strategy resembling modifiedanalytical induction.Findings: Participants proffered their perceptions and examples of theirpractices of sex education in relation to the following themes: (1)acknowledging the multi-dimensional nature of sexual health in the case ofyoung people in care; (2) personal and emotional development educationto address poor self-esteem, emotional disconnectedness and an inabilityto recognise and express emotions; (3) social skills’ education as part of arepertoire of competencies needed to negotiate relationships and safer sex;(4) the application of positive social skills embedded in everyday socialsituations; and (5) factual sexuality education.Conclusion: Insights into service providers’ perceptions of the multidimensionalnature of the sexual health needs of young people in statecare, and the ways in which these service-providers justified their practicemake visible the complex character of sex education and the degree of skillrequired to deliver it to those in state care.

La imagen de Barbación en las "Res Gestae" de Amiano Marcelino1

Este artículo analiza uno de los personajes secundarios más relevantes de las Res Gestae (RG) de Amiano Marcelino, el magister peditum Barbación. El historiador presenta a Barbación como un ser infame: colaborador en la muerte de Galo, cobarde, arrogante y desleal con Juliano durante la campaña militar del 357, delator de falsedades ante Constancio, merecedor de una muerte indigna. Sin embargo, un estudio de conjunto de los pasajes de Res Gestae, tomando como apoyo metodológico las técnicas de argumentación aplicadas al retrato y el concepto de ‘argumentación implícita’ de Sabbah 1978 y los métodos de caracterización de personajes de Pauw 1977, corrige esta visión comúnmente aceptada y demuestra la parcialidad del historiador. Así mismo se pone de manifiesto que el personaje, como otros actantes secundarios en las RG, es una réplica del carácter de Constancio II.

La inevitable inconsistencia del Zeus/Júpiter épico

Durante años la investigación literaria ha encontrado fruición en buscar y encontrar inconsistencias narrativas en la Tebaida de Estacio. Concretamente, hay cierto grado de consenso respecto a que las incongruencias en que incurre Júpiter son debidas a negligencia o incuria por parte del poeta. De hecho, no se puede negar que el soberano del cielo se contradice en las ocasiones en que alude a su relación con el Destino. No obstante, no será únicamente el poeta flavio el objeto de mi atención en este artículo. Hoy día se continúa acudiendo a la autoridad filosófica de Séneca (fundamentalmente a Dial. 1.5.8) siempre que el Zeus/Júpiter poshomérico (también el virgiliano) incurre en lo que hemos dado en considerar «incoherencias». Sin embargo, excepción hecha de las composiciones hesiódicas, el estatuto teológico de Zeus/Júpiter es altamente inestable en toda la tradición literaria griega y romana. Quizá deberíamos aceptar, entonces, que durante siglos los que estudiamos literatura antigua hemos tendido a prescindir de la voz autorial y de su autoridad omnímoda para manipular el material literario preexistente con el objeto de generar nuevos significados y nuevas cosmovisiones. En definitiva, nos hemos mostrado proclives a calificar de inconsistencias todo aquello que no se adecua a nuestras expectativas o prejuicios.

Pain assessment in surgical patients with impaired cognition

Pain is considered the 5th vital sign and its measurement/assessment and records are required and must be systematic. Ineffective pain management involves complications in clinical status of patients, longer hospitalization times and higher costs with health. In the surgical patient with impaired cognition, hetero measurements should be made, based on behavioural and physiological indicators. We used to determine the efficacy and efficiency of the Observer Scale, the Abbey Pain Scale and Pain Assessment in Advanced Dementia (PAINAD). Our study is an applied, non-experimental, quantitative, descriptive and analytical research. The data collection instrument consisted of patients’ sociodemographic and clinical data, the Observer Scale, the Abbey Pain Scale (Rodrigues, 2013) and PAINAD (Batalha et al., 2012). We assessed pain at an early phase and 45 minutes after an intervention for its relief. The sample is non-probabilistic for convenience, consisting of 76 surgical patients with impaired cognition, admitted to the surgery services of a central hospital, aged between 38 and 96 years. There was a positive correlation between the results of the three scales, most evident in the initial evaluation. Pain intensity in the same patient is higher when assessed with PAINAD (OM = 2.16) and lower when assessed with the Observer Scale (OM = 1.78). The most effective and efficient scale is PAINAD. Due to the small sample size, we suggest confirmatory studies so that the results can be generalized.