1,204 research outputs found
Can patterns of urban biodiversity be predicted using simple measures of green infrastructure?
Urban species and habitats provide important ecosystem services such as summertime cooling, recreation, and pollination at a variety of scales. Many studies have assessed how biodiversity responds to urbanization, but little work has been done to try and create recommendations that can be easily applied to urban planning, design and management practice. Urban planning often operates at broad spatial scales, typically using relatively simplistic targets for land cover mix to influence biodiversity and ecosystem service provision. Would more complicated, but still easily created, prescriptions for urban vegetation be beneficial? Here we assess the importance of vegetation measures (percentage vegetation cover, tree canopy cover and variation in canopy height) across four taxonomic groups (bats, bees, hoverflies and birds) at multiple spatial scales (100, 250, 500, 1000 m) within a major urban area (Birmingham, the United Kingdom). We found that small-scale (100–250-m radius) measures of vegetation were important predictors for hoverflies and bees, and that bats were sensitive to vegetation at a medium spatial-scale (250–500 m). In contrast, birds responded to vegetation characteristics at both small (100 m) and large (1000 m) scales. Vegetation cover, tree cover and variation in canopy height were expected to decrease with built surface cover; however, only vegetation height showed this expected trend. The results indicate the importance of relatively small patches of vegetation cover for supporting urban biodiversity, and show that relatively simple measures of vegetation characteristics can be useful predictors of species richness (or activity density, in the case of bats). They also highlight the danger of relying upon percentage built surface cover as an indicator of urban biodiversity potential
Migration of Apicomplexa Across Biological Barriers: The Toxoplasma and Plasmodium Rides
The invasive stages of Apicomplexa parasites, called zoites, have been largely studied in in vitro systems, with a special emphasis on their unique gliding and host cell invasive capacities. In contrast, the means by which these parasites reach their destination in their hosts are still poorly understood. We summarize here our current understanding of the cellular basis of in vivo parasitism by two well-studied Apicomplexa zoites, the Toxoplasma tachyzoite and the Plasmodium sporozoite. Despite being close relatives, these two zoites use different strategies to reach their goal and establish infection
Early anastomotic complications in colorectal surgery: a systematic review of techniques for endoscopic salvage
Angle-dependence of quantum oscillations in YBa2Cu3O6.59 shows free spin behaviour of quasiparticles
Measurements of quantum oscillations in the cuprate superconductors afford a
new opportunity to assess the extent to which the electronic properties of
these materials yield to a description rooted in Fermi liquid theory. However,
such an analysis is hampered by the small number of oscillatory periods
observed. Here we employ a genetic algorithm to globally model the field,
angular, and temperature dependence of the quantum oscillations observed in the
resistivity of YBa2Cu3O6.59. This approach successfully fits an entire data set
to a Fermi surface comprised of two small, quasi-2-dimensional cylinders. A key
feature of the data is the first identification of the effect of Zeeman
splitting, which separates spin-up and spin-down contributions, indicating that
the quasiparticles in the cuprates behave as nearly free spins, constraining
the source of the Fermi surface reconstruction to something other than a
conventional spin density wave with moments parallel to the CuO2 planes.Comment: 8 pages, 4 figure
The Activities of Current Antimalarial Drugs on the Life Cycle Stages of Plasmodium: A Comparative Study with Human and Rodent Parasites
Michael Delves and colleagues compare the activity of 50 current and experimental antimalarials against liver, sexual blood, and mosquito stages of selected human and nonhuman parasite species, including Plasmodium falciparum, Plasmodium berghei, and Plasmodium yoelii
Mycotic aneurysm of the femoral artery complicating Staphylococcus aureus bacteremia: a case report
INTRODUCTION: Staphylococcus aureus is the major cause of bacteremia, with the potential for some complications, namely mycotic aneurysms, defined as irreversible dilatation of an artery due to destruction of the vessel wall by infection.
CASE PRESENTATION: The authors present the case of a 52 year-old-Caucasian male, admitted with Staphylococcus aureus bacteremia and mycotic aneurysm of the right superficial femoral artery, associated with advanced atherosclerotic process.
CONCLUSION: Mycotic aneurysms are rare, and a high index of suspicion is needed, because appropriate treatment will certainly affect the outcome, as they are associated with high morbidity and mortality
Resource Sharing via Capability-Based Multiparty Session Types
Multiparty Session Types (MPST) are a type formalism used to model communication protocols among components in distributed systems, by specifying type and direction of data transmitted. It is standard for multiparty session type systems to use access control based on linear or affine types. While useful in offering strong guarantees of communication safety and session fidelity, linearity and affinity run into the well-known problem of inflexible programming, excluding scenarios that make use of shared channels or need to store channels in shared data structures.
In this paper, we develop capability-based resource sharing for multiparty session types. In this setting, channels are split into two entities, the channel itself and the capability of using it. This gives rise to a more flexible session type system, which allows channel references to be shared and stored in persistent data structures. We illustrate our type system through a producer-consumer case study. Finally, we prove that the resulting language satisfies type safety
Assessing architectural evolution: A case study
This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2011 SpringerThis paper proposes to use a historical perspective on generic laws, principles,
and guidelines, like Lehman’s software evolution laws and Martin’s design principles, in order to achieve a multi-faceted process and structural assessment of a system’s architectural evolution. We present a simple structural model with associated historical metrics and
visualizations that could form part of an architect’s dashboard. We perform such an assessment for the Eclipse SDK, as a case study of a large, complex, and long-lived system for which sustained effective architectural evolution is paramount. The twofold aim of checking generic principles on a well-know system is, on the one hand,
to see whether there are certain lessons that could be learned for best practice of architectural evolution, and on the other hand to get more insights about the applicability of such principles. We find that while the Eclipse SDK does follow several of the laws and principles, there are some deviations, and we discuss areas of architectural improvement and limitations of the assessment approach
How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?
This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1).For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace changes in gene expression during cold acclimation that lead to an increase in cold tolerance. We used an RNA-Seq approach to investigate this in two species of the Drosophila virilis group. We found that the majority of genes that are differentially expressed during cold acclimation differ between the two species. Despite this, the biological processes associated with the differentially expressed genes were broadly similar in the two species. These included: metabolism, cell membrane composition, and circadian rhythms, which are largely consistent with previous work on cold acclimation/cold tolerance. In addition, we also found evidence of the involvement of the rhodopsin pathway in cold acclimation, a pathway that has been recently linked to thermotaxis. Interestingly, we found no evidence of differential expression of stress genes implying that long-term cold acclimation and short-term stress response may have a different physiological basis.PostprintPeer reviewe
Quantitative conversations: the importance of developing rapport in standardised interviewing
© 2014, The Author(s). When developing household surveys, much emphasis is understandably placed on developing survey instruments that can elicit accurate and comparable responses. In order to ensure that carefully crafted questions are not undermined by ‘interviewer effects’, standardised interviewing tends to be utilised in preference to conversational techniques. However, by drawing on a behaviour coding analysis of survey paradata arising from the 2012 UK Poverty and Social Exclusion Survey we show that in practice standardised survey interviewing often involves extensive unscripted conversation between the interviewer and the respondent. Whilst these interactions can enhance response accuracy, cooperation and ethicality, unscripted conversations can also be problematic in terms of survey reliability and the ethical conduct of survey interviews, as well as raising more basic epistemological questions concerning the degree of standardisation typically assumed within survey research. We conclude that better training in conversational techniques is necessary, even when applying standardised interviewing methodologies. We also draw out some theoretical implications regarding the usefulness of the qualitative–quantitative dichotomy
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