Floodplain connectivity, disturbance and change: a palaeoentomological investigation of floodplain ecology from south-west England

1. Floodplain environments are increasingly subject to enhancement and restoration, with the purpose of increasing their biodiversity and returning them to a more 'natural' state. Defining such a state based solely upon neoecological data is problematic and has led several authors to suggest the use of a palaeoecological approach.2. Fossil Coleopteran assemblages recovered from multiple palaeochannel fills in south-west England were used to investigate past floodplain and channel characteristics during the mid- to late-Holocene. Ordination of coleopteran data was performed using Detrended Correspondence Analysis (DCA) and produced clear and discrete clustering. This clustering pattern is related to the nature of the environment in which assemblages were deposited and hence channel configuration and dynamics.3. The DCA clustering pattern is strongly related to measures of ecological evenness, and a strong relationship between these indices and the composition of the water beetle assemblage within samples was revealed. Repeating the ordination with presence–absence data results in a similar pattern of clustering, implying that assemblage composition is crucial in determining cluster placement.4. As assemblage composition is primarily a function of floodplain topography and hence disturbance regime, we attempt to relate these data to the Intermediate Disturbance Hypothesis (IDH). A significant positive correlation was found between ecological diversity (Shannon's H') and Axis 1 of all ordinations in predominantly aquatic assemblages

Sigma and omega meson propagation in a dense nuclear medium

The propagation of the scalar ($\sigma$) and vector ($\omega$) mesons in nuclear matter is studied in detail using the Walecka model over a wide range of densities and including the effects of a finite $\sigma$ width through the inclusion of a two-pion loop. We calculate the dispersion relation and spectral functions of the $\sigma$ and (transverse and longitudinal) $\omega$ mesons, including the effect of $\sigma$-$\omega$ mixing in matter. It is shown that the mixing effect is quite important in the propagation of the (longitudinal) $\omega$ and $\sigma$ mesons above normal nuclear matter density. We find that there is a two-peak structure in the spectral function of the $\sigma$ channel, caused by $\sigma$-$\omega$ mixing.Comment: 17 pages including 6 ps files, submitted to Phys. Lett. B. Acknowledgement is revise

Societal Stability and Environmental Change : Examining the Archaeology - Soil Erosion Paradox

This paper critically examines the soil-exhaustion and societal collapse hypothesis both theoretically and empirically. The persistence of civilisations, especially in theMediterranean, despite intensive and erosive arable farming, creates what is described here as the archaeology-soil erosion paradox. This paper examines the data used to estimate past erosion and weathering rates, before presenting three case studies which engage with the theoretical arguments. Study 1 shows 5000 years of high slope erosion rates with both soil use and agriculture continuously maintained in the catchment. Study 2 shows how ancient agricultural terraces were constructed as part of integrated agricultural systems which fed the ancient city of Stymphalos - now abandoned. Study 3 presents a recent example of how after the removal of terraces high soil erosion rates result during intense rainstorms but that arable agriculture can still be maintained whilst external costs are borne by other parties. What these case studies have in common is the creation of soil and increased weathering rates whilst productivity is maintained due to a combination of soft bedrocks and/or agricultural terraces. In societal terms this may not be sustainable but it does not necessarily lead to land abandonment or societal collapse – this is the paradox

Role of tumour necrosis factor gene polymorphisms (-308 and -238) in breast cancer susceptibility and severity

Introduction Genetic polymorphisms in the promoter region of the tumour necrosis factor (TNF) gene can regulate gene expression and have been associated with inflammatory and malignant conditions. We have investigated two polymorphisms in the promoter of the TNF gene (-308 G>A and -238 G>A) for their role in breast cancer susceptibility and severity by means of an allelic association study. Methods Using a case–control study design, breast cancer patients (n = 709) and appropriate age-matched and sex-matched controls obtained from the Breast Screening Unit (n = 498) were genotyped for these TNF polymorphisms, using a high-throughput allelic discrimination method. Results Allele frequencies for both polymorphisms were similar in both breast cancer cases and controls. However, the -308 polymorphism was found to be associated with vascular invasion in breast tumours (P = 0.024). Comparison with other standard prognostic indices did not show any association for either genotype. Conclusions We demonstrated no association between the -308G>A polymorphism and the -238G>A polymorphism in the promoter region of TNF and susceptibility to breast cancer, in a large North European population. However, the -308 G>A polymorphism was found to be associated with the presence of vascular invasion in breast tumours

Beyond Villages and Open Fields: The Origins and Development of a Historic Landscape Characterised by Dispersed Settlement in South-West England

© 2006 Society for Medieval Archaeology. Reproduced with the permission of the publisher. Journal home page http://www.maney.co.uk/journals/ma ; complete issue available at http://www.ingentaconnect.com/content/maney/medPollen evidence has, to date, made little contribution to our understanding of the origins and development of the medieval landscape. Compared to the prehistoric period, relatively few long palaeoenvironmental sequences provide a continuous record for the past two millennia, and those that have been analysed are mostly located in upland locations that lay beyond areas settled during this period. The nine sequences reported here from central Devon and the edges of Exmoor start to redress that imbalance. They suggest substantial clearance of woodland in lowland areas and the upland fringe by the Late Iron Age, and that the incorporation of this region into the Roman world had little impact on patterns of landscape exploitation. In a region that lay beyond the main area of Romanisation, it is not surprising that the 5th century saw little discernible change in management of the landscape. These palaeoenvironmental sequences suggest that around the 7th–8th centuries, however, there was a significant change in the patterns of land-use, which it is suggested relates to the introduction of a regionally distinctive system of agriculture known as ‘convertible husbandry’. This may also have been the context for the creation of today’s historic landscape of small hamlets and isolated farmsteads set within a near continuous fieldscape, replacing the late prehistoric/ Romano-British/post-Roman landscape of small, enclosed settlements with only very localised evidence for field systems. This transformation appears to be roughly contemporary with, or even earlier than, the creation of nucleated villages in the ‘Central Province’ of England, suggesting that the ‘great replanning’ was just one of several regionally distinctive trajectories of landscape change in the later 1st millennium A.D

Novel pharmacological actions of Trequinsin Hydrochloride improve human sperm cell motility and function

Background and purposeAsthenozoospermia is a leading cause of male infertility, but the development of pharmaceuticals to improve sperm motility has been hindered by the lack of effective screening platforms and knowledge of suitable molecular targets. We have demonstrated that a high throughput screening (HTS) strategy in conjunction with established in vitro tests can identify and characterise the action of compounds that improve sperm motility. The study aimed to apply HTS to identify new compounds from a novel small molecule library that increase intracellular calcium, [Ca2+]I, promote human sperm cell motility and systemically determine the mechanism of action. Experimental approach A validated HTS fluorometric [Ca2+]i assay was used to screen an in-house library of compounds. Trequinsin hydrochloride (a phosphodiesterase 3 inhibitor) was selected for detailed molecular (plate reader assays, electrophysiology and cyclic nucleotide measurement) and functional (motility and acrosome reaction) testing in sperm from healthy volunteer donors and, where possible, patients.   Key resultsThe fluorometric analysis identified Trequinsin as an efficacious agonist of [Ca2+]i, although less potent than progesterone (P4). Functionally, Trequinsin significantly increased cell hyperactivation and penetration into viscous medium in all donor sperm samples and cell hyperactivation in 22/25 (88%) patient sperm samples. The Trequinsin-induced [Ca2+]i response was cross-desensitised consistently by prostaglandin E1 but not with P4. Whole-cell patch clamp electrophysiology confirmed that Trequinsin activates CatSper and partially inhibits potassium channel activity. Trequinsin also increases intracellular cGMP.   Conclusion and Implications Trequinsin exhibits a novel pharmacological profile in human sperm and may be a suitable lead compound for the development of new pharmaceuticals to improve patient sperm function and fertilisation potential

High-Energy Aspects of Solar Flares: Overview of the Volume

In this introductory chapter, we provide a brief summary of the successes and remaining challenges in understanding the solar flare phenomenon and its attendant implications for particle acceleration mechanisms in astrophysical plasmas. We also provide a brief overview of the contents of the other chapters in this volume, with particular reference to the well-observed flare of 2002 July 23Comment: This is the introductory article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Delayed development of extrathoracic lung herniation after blunt thoracic trauma

A 51-year-old African American male with history of Chronic Obstructive Pulmonary Disease (COPD) and asthma was transferred to our institution after sustaining blunt thoracic trauma as a result of a truck falling off its jack onto his chest. According to EMS report, the patient was apneic and pulseless after the truck was removed and bystanders initiated CPR on the scene

Manitoba field survey of herbicide-resistant weeds

Non-Peer ReviewedIn 2002, 150 fields were randomly selected throughout the ecoregions of Manitoba and surveyed for grass and broadleaf weeds resistant to Group 1 (ACCase inhibitor) or Group 2 (ALS inhibitor) herbicides. One-third of surveyed fields had a herbicide-resistant weed biotype. Two biotypes new to western Canada are Group 2-resistant green foxtail and redroot pigweed. Of producers with resistant biotypes, 10% or fewer were aware of their occurrence