975 research outputs found

    Conservation assessment of the Drakaea livida (Orchidaceae) ecotypes and an evaluation of methods for their identification

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    Morphologically cryptic taxa must be accounted for when quantifying biodiversity and implementing effective conservation measures. Some orchids pollinated by sexual deception of male insects contain morphologically cryptic ecotypes, such as the warty hammer orchid Drakaea livida (Orchidaceae). This species is comprised of three cryptic pollination ecotypes, which can be distinguished based on differences in pollinator species and floral volatiles. The present study aims were: (a) to investigate the geographic range of the three D. livida ecotypes, enabling assessment of their conservation status; and (b) to test the efficacy of different methods of identifying the D. livida ecotypes. Three methods of ecotype identification were assessed: morphometric analysis, genome size comparison, and analysis of chemical volatile composition of labellum extracts from pollinated flowers. MaxEnt species distribution models revealed that each ecotype has a different predicted geographic range, with small areas of overlap at the range margins. One ecotype is known from just ten populations over a limited geographic area, the majority of which has been cleared for agriculture, and urban development. While there was broad overlap between the ecotypes in individual morphological traits, multivariate analysis of morphological traits provided correct assignment to ecotype in 87% of individuals. Using the labellum of pollinated flowers, screening for volatile chemical compounds associated with particular ecotypes returned an even higher correct assignment rate, of 96.5%. As such, we advocate that the use of volatiles from the labellum of recently pollinated flowers is an effective way to determine the ecotype of unknown individuals of D. livida, with minimal impact on the flowering plant

    Growth and patterning of laser ablated superconducting YBa2Cu3O7 films on LaAlO3 substrates

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    A high quality superconducting film on a substrate with a low dielectric constant is desired for passive microwave circuit applications. In addition, it is essential that the patterning process does not effect the superconducting properties of the thin films to achieve the highest circuit operating temperatures. YBa2Cu3O7 superconducting films were grown on lanthanum aluminate substrates using laser ablation with resulting maximum transition temperature (T sub c) of 90 K. The films were grown on a LaAlO3 which was at 775 C and in 170 mtorr of oxygen and slowly cooled to room temperature in 1 atm of oxygen. These films were then processed using photolithography and a negative photoresist with an etch solution of bromine and ethanol. Results are presented on the effect of the processing on T(sub c) of the film and the microwave properties of the patterned films

    Matchings on infinite graphs

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    Elek and Lippner (2010) showed that the convergence of a sequence of bounded-degree graphs implies the existence of a limit for the proportion of vertices covered by a maximum matching. We provide a characterization of the limiting parameter via a local recursion defined directly on the limit of the graph sequence. Interestingly, the recursion may admit multiple solutions, implying non-trivial long-range dependencies between the covered vertices. We overcome this lack of correlation decay by introducing a perturbative parameter (temperature), which we let progressively go to zero. This allows us to uniquely identify the correct solution. In the important case where the graph limit is a unimodular Galton-Watson tree, the recursion simplifies into a distributional equation that can be solved explicitly, leading to a new asymptotic formula that considerably extends the well-known one by Karp and Sipser for Erd\"os-R\'enyi random graphs.Comment: 23 page

    Non-host volatile blend optimization for forest protection against the European Spruce Bark Beetle, Ips typographus

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    Conifer feeding bark beetles (Coleoptera, Curculionidae, Scolytinae) pose a serious economic threat to forest production. Volatiles released by non-host angiosperm plants (so called non-host volatiles, NHV) have been shown to reduce the risk of attack by many bark beetle species, including the European spruce bark beetle, Ips typographus. However, the most active blend for I. typographus, containing three green leaf volatiles (GLVs) in addition to the key compounds trans-conophthorin (tC) and verbenone, has been considered too expensive for use in large-scale management. To lower the cost and improve the applicability of NHV, we aim to simplify the blend without compromising its anti-attractant potency. Since the key compound tC is expensive in pure form, we also tested a crude version: technical grade trans-conophthorin (T-tC). In another attempt to find a more cost effective substitute for tC, we evaluated a more readily synthesized analog: dehydroconophthorin (DHC). Our results showed that 1-hexanol alone could replace the three-component GLV blend containing 1- hexanol, (3Z)-hexen-1-ol, and (2E)-hexen-1-ol. Furthermore, the release rate of tC could be reduced from 5 mg/day to 0.5 mg/day in a blend with 1-hexanol and (–)-verbenone without compromising the anti-attractant activity. We further show that T-tC was comparable with tC, whereas DHC was a less effective anti-attractant. DHC also elicited weaker physiological responses in the tC-responding olfactory receptor neuron class, providing a likely mechanistic explanation for its weaker anti-attractive effect. Our results suggest a blend consisting of (–)-verbenone, 1-hexanol and technical transconophthorin as a cost-efficient anti-attractant for forest protection against I. typographus

    Conceptualizing throughput legitimacy: procedural mechanisms of accountability, transparency, inclusiveness and openness in EU governance

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    This symposium demonstrates the potential for throughput legitimacy as a concept for shedding empirical light on the strengths and weaknesses of multi-level governance, as well as challenging the concept theoretically. This article introduces the symposium by conceptualizing throughput legitimacy as an ‘umbrella concept’, encompassing a constellation of normative criteria not necessarily empirically interrelated. It argues that in order to interrogate multi-level governance processes in all their complexity, it makes sense for us to develop normative standards that are not naïve about the empirical realities of how power is exercised within multilevel governance, or how it may interact with legitimacy. We argue that while throughput legitimacy has its normative limits, it can be substantively useful for these purposes. While being no replacement for input and output legitimacy, throughput legitimacy offers distinctive normative criteria— accountability, transparency, inclusiveness and openness— and points towards substantive institutional reforms.Published versio

    Existing and evolving in two minds : beliefs in relation to health and illness expressed by older South Africans

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    The aim of the study was to illuminate beliefs in relation to health and illness expressed by older Africans within the context of a society in transition, namely South Africa. An ethnographic research approach influenced by the interpretive phenomenological tradition was selected to gain an understanding of the participants’ experiences. A focused ethnographic design was employed, using group and individual in-depth interviews and participant observations. Sixteen elderly persons (ten females and six males) from Hammanskraal, a rural area north of Pretoria, were involved in the research. The findings illuminate a world understanding where body and mind are inseparable and relationships provide the foundation for improving and maintaining health and being cured from illness. The ongoing transition that the elderly in South Africa experience influences health and illness beliefs, with a need to adapt to existing parallel health care systems, Western biomedicine and African traditional medicine. As the study draws attention to the importance of caring for the elderly to be contextualised, it is recommended that the care of the elderly be applied to the unique needs of the individual involved. Failure to do so may otherwise have severe consequences such as an apparent high risk of developing stereotypes, which can lead to cultural misunderstandings, prejudice and discrimination.The research was funded by grants from the Nordic Africa Institute, Uppsala, Sweden and Blekinge Institute of Technology, Sweden.http://www.unisa.ac.za/Default.asp?Cmd=ViewContent&ContentID=24782http://reference.sabinet.co.za/sa_epublication/ajnmam201

    The politics of impunity: a study of journalists’ experiential accounts of impunity in Bulgaria, Democratic Republic of Congo, India, Mexico and Pakistan

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    Definitions of impunity regarding crimes against journalists have thus far been too narrow. Therefore we propose a new approach to understanding impunity as also being grounded in journalists’ lived reality and perceptions to better understand the complexity and breadth of impunity. It is based on the findings obtained through a set of semi-structured interviews with 40 editors and senior journalists in five countries and expressed in a new typology of impunity. We argue that what we call the ‘Politics of Impunity’ is a policy of governance whereby impunity is used as a political tool by the state and state-sponsored actors to achieve journalistic self-censorship. This is done through the deliberate deprivation of private autonomy brought about by the enforced exile of journalists into a ‘space of exception’ where they are both within and beyond the law. The exercise of the ‘Politics of Impunity’ in an increasing number of states creates an environment that only allows for politically compliant journalism

    Subcutaneous Tissue: To Suture or Not to Suture at Cesarean Section

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    Objective: The null hypothesis for this investigation was that there was no difference in the frequency of wound disruption between women who had their subcutaneous tissues approximated with suture and those who did not during cesarean section

    A multidimensional account of democratic legitimacy: how to make robust decisions in a non-idealized deliberative context

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    This paper analyses the possibility of granting legitimacy to democratic decisionmaking procedures in a context of deep pluralism. We defend a multidimensional account according to which a legitimate system needs to grant, on the one hand, that citizens should be included on an equal footing and acknowledged as reflexive political agents rather than mere beneficiaries of policies, and, on the other hand, that their decisions have an epistemic quality. While Estlund\u2019s account of imperfect epistemic proceduralism might seem to embody a dualistic conception of democratic legitimacy, we point out that it is not able to recognize citizens as reflexive political agents and is grounded in an idealized model of the circumstances of deliberation. To overcome these ambiguities, we develop an account of democratic legitimacy according to which disagreement is the proper expression of citizens\u2019 reflexive agency and the attribution of epistemic authority does not stem from a major expertise or specific ability, but it comes through the public confrontation among disagreeing agents. Consequently, the epistemic value of deliberation should be derived from the reasons-giving process rather than from the reference to the alleged quality of its outcomes. In this way, we demonstrate the validity of the multidimensional perspective of legitimacy, yet abstain from introducing any outcome-oriented criterion. Finally, we argue that this account of legitimacy is well suited for modeling deliberative democracy as a decision-making procedure that respects the agency of every citizen and grants her opportunity to influence public choices
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