2,636 research outputs found

    Seleucid frontier policy in the East: The nature and extent of imperial control

    Get PDF
    Modern views of Seleucid control of the Eastern territories (Iran and Central Asia) have shifted in the last two decades as a result of excavation, and a re-evaluation of the nature of the Seleucid state.1 In my thesis I will undertake a substantial and critical assessment of the primary sources and will also demonstrate recent divergent approaches to numismatics in the Hellenistic East (Holt, 1999a Bopearachchi, 1991 1994). Although there is a great variety of literary evidence provided by later authors, none of them provide a complete account of the Seleucid monarchy, as the majority are of a fragmentary nature. I will examine the reliability and usefulness of these literary sources as well as the aims of the respective authors and their style of composition. The nature and extent of imperial control of the Seleucids in the East is often agreed to contrast with that in the west. This historical background will be better understood by my outline of the known major events of their reigns. Also, I will emphasise the close trade links between the centre of the Seleucid Empire and the Eastern provinces by examining the evidence for merchandise unique to the East, appearing in the west, and vice versa.4 My research will pull together the primarily archaeological evidence now available not only from Ai Khanoum, but also Merv and Kandahar, with Lyonnet's (1997) study of Central Asian pottery forming a guide. The main aim will be to examine Seleucid frontier policy with regard to the Eastern part of the empire, indicating the regions under direct Seleucid control as well as explaining when, where and why frontier zones appear. Also, I will employ and illustrate the concept of frontiers, not as a line or simple zone, but as a series of overlapping zones in which the political, social, ethnic, religious, linguistic, economic and military boundaries all overlapped.5

    Quantifying interspecific variation in dispersal ability of noctuid moths using an advanced tethered flight technique

    Get PDF
    This is the final version. Available on open access from Wiley via the DOI in this recordDispersal plays a crucial role in many aspects of species' life histories, yet is often difficult to measure directly. This is particularly true for many insects, especially nocturnal species (e.g. moths) that cannot be easily observed under natural field conditions. Consequently, over the past five decades, laboratory tethered flight techniques have been developed as a means of measuring insect flight duration and speed. However, these previous designs have tended to focus on single species (typically migrant pests), and here we describe an improved apparatus that allows the study of flight ability in a wide range of insect body sizes and types. Obtaining dispersal information from a range of species is crucial for understanding insect population dynamics and range shifts. Our new laboratory tethered flight apparatus automatically records flight duration, speed, and distance of individual insects. The rotational tethered flight mill has very low friction and the arm to which flying insects are attached is extremely lightweight while remaining rigid and strong, permitting both small and large insects to be studied. The apparatus is compact and thus allows many individuals to be studied simultaneously under controlled laboratory conditions. We demonstrate the performance of the apparatus by using the mills to assess the flight capability of 24 species of British noctuid moths, ranging in size from 12-27 mm forewing length (~40-660 mg body mass). We validate the new technique by comparing our tethered flight data with existing information on dispersal ability of noctuids from the published literature and expert opinion. Values for tethered flight variables were in agreement with existing knowledge of dispersal ability in these species, supporting the use of this method to quantify dispersal in insects. Importantly, this new technology opens up the potential to investigate genetic and environmental factors affecting insect dispersal among a wide range of species.Rothamsted Research receives grant aided support from the Biotechnology and Biological Sciences Research Council. H.B.C.J. was funded by a BBSRC Quota studentship awarded to J.W.C. and J.K.H

    Exploring potential mechanisms involved in the relationship between eudaimonic wellbeing and nature connection

    Get PDF
    ArticleThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.A growing body of research demonstrates associations between nature connection and a wide variety of positive health and wellbeing outcomes. Yet, the interpretation of this research is restricted because underpinning mechanisms − particularly the psychological mechanisms of wellbeing enhancement as opposed to wellbeing restoration − remain largely unexplored. Understanding such mechanisms is important for theory development and for assisting policy-makers and urban planners to translate this theory into practice effectively. This essay examines the limitations in our current understanding of the psychological mechanisms involved in the relationship between nature connection and eudaimonic wellbeing. It also advances opportunities to move the field forward through exploring two potential mechanisms, namely satisfying the psychological need of relatedness and fostering intrinsic value orientation. These mechanisms may explain how an individual’s level of nature connection enhances their psychological wellbeing. Understanding such mechanisms could improve the implementation of targeted nature connection policies and interventions designed to enhance psychological wellbeing among complex urban populations with diverse needs

    Radiographic Image Enhancement by Wiener Decorrelation

    Get PDF
    The primary focus of the application of image processing to radiography is the problem of segmentation. The general segmentation problem has been attacked on a broad front [1, 2], and thresholding, in particular, is a popular method [1, 3-6]. Unfortunately, geometric unsharpness destroys the crisp edges needed for unambiguous decisions, and this difficulty can be considered a problem in filtering in which the object is to devise a high-pass (sharpening) filter. This approach has been studied for more than 20 years [7-13]

    P-odd and CP-odd Four-Quark Contributions to Neutron EDM

    Full text link
    In a class of beyond-standard-model theories, CP-odd observables, such as the neutron electric dipole moment, receive significant contributions from flavor-neutral P-odd and CP-odd four-quark operators. However, considerable uncertainties exist in the hadronic matrix elements of these operators strongly affecting the experimental constraints on CP-violating parameters in the theories. Here we study their hadronic matrix elements in combined chiral perturbation theory and nucleon models. We first classify the operators in chiral representations and present the leading-order QCD evolutions. We then match the four-quark operators to the corresponding ones in chiral hadronic theory, finding symmetry relations among the matrix elements. Although this makes lattice QCD calculations feasible, we choose to estimate the non-perturbative matching coefficients in simple quark models. We finally compare the results for the neutron electric dipole moment and P-odd and CP-odd pion-nucleon couplings with the previous studies using naive factorization and QCD sum rules. Our study shall provide valuable insights on the present hadronic physics uncertainties in these observables.Comment: 40 pages, 7 figures. This is the final version. A discussion of the uncertainty of the calculation is adde

    Ferredoxin containing bacteriocins suggest a novel mechanism of iron uptake in <i>Pectobacterium spp</i>

    Get PDF
    In order to kill competing strains of the same or closely related bacterial species, many bacteria produce potent narrow-spectrum protein antibiotics known as bacteriocins. Two sequenced strains of the phytopathogenic bacterium &lt;i&gt;Pectobacterium carotovorum&lt;/i&gt; carry genes encoding putative bacteriocins which have seemingly evolved through a recombination event to encode proteins containing an N-terminal domain with extensive similarity to a [2Fe-2S] plant ferredoxin and a C-terminal colicin M-like catalytic domain. In this work, we show that these genes encode active bacteriocins, pectocin M1 and M2, which target strains of &lt;i&gt;Pectobacterium carotovorum&lt;/i&gt; and &lt;i&gt;Pectobacterium atrosepticum&lt;/i&gt; with increased potency under iron limiting conditions. The activity of pectocin M1 and M2 can be inhibited by the addition of spinach ferredoxin, indicating that the ferredoxin domain of these proteins acts as a receptor binding domain. This effect is not observed with the mammalian ferredoxin protein adrenodoxin, indicating that &lt;i&gt;Pectobacterium spp.&lt;/i&gt; carries a specific receptor for plant ferredoxins and that these plant pathogens may acquire iron from the host through the uptake of ferredoxin. In further support of this hypothesis we show that the growth of strains of &lt;i&gt;Pectobacterium carotovorum&lt;/i&gt; and &lt;i&gt;atrosepticum&lt;/i&gt; that are not sensitive to the cytotoxic effects of pectocin M1 is enhanced in the presence of pectocin M1 and M2 under iron limiting conditions. A similar growth enhancement under iron limiting conditions is observed with spinach ferrodoxin, but not with adrenodoxin. Our data indicate that pectocin M1 and M2 have evolved to parasitise an existing iron uptake pathway by using a ferredoxin-containing receptor binding domain as a Trojan horse to gain entry into susceptible cells

    Phosphorylation of Puma modulates its apoptotic function by regulating protein stability

    Get PDF
    Puma is a potent BH3-only protein that antagonises anti-apoptotic Bcl-2 proteins, promotes Bax/Bak activation and has an essential role in multiple apoptotic models. Puma expression is normally kept very low, but can be induced by several transcription factors including p53, p73, E2F1 and FOXO3a, whereby it can induce an apoptotic response. As Puma can to bind and inactivate all anti-apoptotic members of the Bcl-2 family, its activity must be tightly controlled. We report here, for the first time, evidence that Puma is subject to post-translational control through phosphorylation. We show that Puma is phosphorylated at multiple sites, with the major site of phosphorylation being serine 10. Replacing serine 10 with alanine causes reduced Puma turnover and enhanced cell death. Interestingly, Puma turnover occurs through the proteasome, and substitution of serine 10 causes elevated Puma levels independently of macroautophagy, Bcl-2 family member binding, caspase activity and apoptotic death. We conclude, therefore, that phosphorylation of Puma at serine 10 promotes Puma turnover, represses Puma's cell death potential and promotes cell survival. Owing to the highly pro-apoptotic nature of Puma, these studies highlight an important additional regulatory step in the determination of cellular life or death

    Loss of Kruppel-like factor 3 (KLF3/BKLF) leads to upregulation of the insulin-sensitizing factor adipolin (FAM132A/CTRP12/C1qdc2)

    Get PDF
    Krüppel-like factor 3 (KLF3) is a transcriptional regulator that we have shown to be involved in the regulation of adipogenesis in vitro. Here, we report that KLF3-null mice are lean and protected from diet-induced obesity and glucose intolerance. On a chow diet, plasma levels of leptin are decreased, and adiponectin is increased. Despite significant reductions in body weight and adiposity, wild-type and knockout animals show equivalent energy intake, expenditure, and excretion. To investigate the molecular events underlying these observations, we used microarray analysis to compare gene expression in Klf3(+/+) and Klf3(-/-) tissues. We found that mRNA expression of Fam132a, which encodes a newly identified insulin-sensitizing adipokine, adipolin, is significantly upregulated in the absence of KLF3. We confirmed that KLF3 binds the Fam132a promoter in vitro and in vivo and that this leads to repression of promoter activity. Further, plasma adipolin levels were significantly increased in Klf3(-/-) mice compared with wild-type littermates. Boosting levels of adipolin via targeting of KLF3 offers a novel potential therapeutic strategy for the treatment of insulin resistance

    Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study

    Get PDF
    A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected
    corecore