Stomatal guard cells are totipotent

It has been successfully demonstrated, using epidermis explants of sugar beet (Beta vulgaris L.), that stomatal guard cells retain full totipotent capacity. Despite having one of the highest degrees of morphological adaptation and a unique physiological specialization, it is possible to induce a re-expression of full (embryogenic) genetic potential in these cells in situ by reversing their highly differentiated nature to produce regenerated plants via a callus stage. The importance of these findings both to stomatal research and to our understanding of cytodifferentiation in plants is discussed.

A high efficiency technique for the generation of transgenic sugar beets from stomatal guard cells

An optimized protocol has been developed for the efficient and rapid genetic modification of sugar beet (Beta vulgaris L.). A polyethylene glycol-mediated DNA transformation technique could be applied to protoplast populations enriched specifically for a single totipotent cell type derived from stomatal guard cells, to achieve high transformation frequencies. Bialaphos resistance, conferred by the pat gene, produced a highly efficient selection system. The majority of plants were obtained within 8 to 9 weeks and were appropriate for plant breeding purposes. All were resistant to glufosinate-ammonium-based herbicides. Detailed genomic characterization has verified transgene integration, and progeny analysis showed Mendelian inheritance.

A dual QPSK soft-demapper for ECMA-368 exploiting time-domain spreading and guard interval diversity

When considering the relative fast processing speed and low power requirements for Wireless Personal Area Networks (WPAN) and Wireless Universal Serial Bus (USB) consumer based products, then the efficiency and cost effectiveness of these products become paramount. This paper presents an improved soft-output QPSK demapper suitable for the products above that not only exploits time diversity and guard carrier diversity, but also merges the demapping and symbol combining functions together to minimize CPU cycles, or memory access dependant upon the chosen implementation architecture. The proposed demapper is presented in the context of Multiband OFDM version of UWB (ECMA-368) as the chosen physical implementation for high-rate Wireless USB.

A dual QPSK soft-demapper for multiband OFDM exploiting time-domain spreading and guard interval diversity

When considering the relative fast processing speeds and low power requirements for Wireless Personal Area Networks (WPAN) including Wireless Universal Serial Bus (WUSB) consumer based products, then the efficiency and cost effectiveness of these products become paramount. This paper presents an improved soft-output QPSK demapper suitable for the products above that not only exploits time diversity and guard carrier diversity, but also merges the demapping and symbol combining functions together to minimize CPU cycles, or memory access dependant upon the chosen implementation architecture. The proposed demapper is presented in the context of Multiband OFDM version of Ultra Wideband (UWB) (ECMA-368) as the chosen physical implementation for high-rate Wireless US8(1).

A novel method for assessing risks to pollinators from plant protection products using honeybees as a model species

Pollination is one of the most important ecosystem services in agroecosystems and supports food production. Pollinators are potentially at risk being exposed to pesticides and the main route of exposure is direct contact, in some cases ingestion, of contaminated materials such as pollen, nectar, flowers and foliage. To date there are no suitable methods for predicting pesticide exposure for pollinators, therefore official procedures to assess pesticide risk are based on a Hazard Quotient. Here we develop a procedure to assess exposure and risk for pollinators based on the foraging behaviour of honeybees (Apis mellifera) and using this species as indicator representative of pollinating insects. The method was applied in 13 European field sites with different climatic, landscape and land use characteristics. The level of risk during the crop growing season was evaluated as a function of the active ingredients used and application regime. Risk levels were primarily determined by the agronomic practices employed (i.e. crop type, pest control method, pesticide use), and there was a clear temporal partitioning of risks through time. Generally the risk was higher in sites cultivated with permanent crops, such as vineyard and olive, than in annual crops, such as cereals and oil seed rape. The greatest level of risk is generally found at the beginning of the growing season for annual crops and later in June–July for permanent crops.

Pollination services in the UK: how important are honeybees?

Pollination services are known to provide substantial benefits to human populations and agriculture in particular. Although many species are known to provide pollination services, honeybees (Apis mellifera) are often assumed to provide the majority of these services to agriculture. Using data from a range of secondary sources, this study assesses the importance of insect pollinated crops at regional and national scales and investigates the capacity of honeybees to provide optimal pollination services to UK agriculture. The findings indicate that insect pollinated crops have become increasingly important in UK crop agriculture and, as of 2007, accounted for 20% of UK cropland and 19% of total farmgate crop value. Analysis of honeybee hive numbers indicates that current UK populations are only capable of supplying 34% of pollination service demands even under favourable assumptions, falling from 70% in 1984. In spite of this decline, insect pollinated crop yields have risen by an average of 54% since 1984, casting doubt on long held beliefs that honeybees provide the majority of pollination services. Future land use and crop production patterns may further increase the role of pollination services to UK agriculture, highlighting the importance of measures aimed at maintaining both wild and managed species.

Diesel exhaust rapidly degrades floral odours used by honeybees

Honeybees utilise floral odours when foraging for flowers; we investigated whether diesel exhaust pollution could interrupt these floral odour stimuli. A synthetic blend of eight floral chemicals, identified from oilseed rape, was exposed to diesel exhaust pollution. Within one minute of exposure the abundances of four of the chemicals were significantly lowered, with two components rendered undetectable. Honeybees were trained to recognise the full synthetic odour mix; altering the blend, by removing the two chemicals rendered undetectable, significantly reduced the ability of the trained honeybees to recognize the altered odour. Furthermore, we found that at environmentally relevant levels the mono-nitrogen oxide (NOx) fraction of the exhaust gases was a key facilitator of this odour degradation. Such changes in recognition may impact upon a honeybee's foraging efficiency and therefore the pollination services that they provide.

Financial protection in the UK building industry: a guide for clients and the construction supply chain.

There is a clear need for financial protection in the construction industry, both to guarantee satisfactory completion of construction projects and to guard against non-payment. However, the cost of financial protection is often felt to be disproportionately high, with unnecessary overlap between different measures. The Reading Construction Forum has commissioned and steered research which is published in this report in an effort to bring the problem out into the open and to clarify the various options open to the various parties and stakeholders in the construction process. "Financial Protection in the UK Building Industry" is the first definitive report on the subject, offering an accurate and simple guide that all levels within the construction industry can understand. This accessible new guide considers the problem of financial protection and clearly lays out the alternative solutions.It looks by turn at the client, the main contractor, and the sub-contractor, discussing which financial protection options are available to each of them, and considers the pros and cons of each option. The cost of each type of financial protection is weighed against the amount of protection provided and the risks involved. The book concludes with guidance for consultants, emphasising relevant points to consider when advising clients and contractors about which type of financial protection to choose. "Financial Protection in the UK Building Industry" was researched by a literature search, collection of statistical data, and financial data, as well as discussions with clients, contractors, sub-contractors and consultants. This investigation has shown that the direct costs of implementing financial protection measures are marginal, and that wider adoption of payment protection would create a more equitable situation between contracting parties.This guide will enable anyone in the construction industry to consider all the options, and determine what is the best solution for them. "Reading Construction Forum Financial Protection for the UK Building Industry" was complied by the University of Reading, funded by the Reading Construction Forum. The Forum has recently commissioned and steered a number of high-profile reports covering important aspects of the construction industry. Members of the Forum include major companies which are concerned with achieving high quality in the design, construction and use of commercial, retail and industrial buildings. All are committed to change and innovation in the British and European construction industries.

Financial protection in the UK building industry: bonds, retentions and guarantees

Financial Protection in the UK Building Industry provides comprehensive treatment of a complex aspect of construction management which is increasingly important in modern construction contracts. The term 'Financial Protection' refers to refers to the various mechanisms by which funds are made available to ensure the due performance of a partys contractual obligations. This book is based on material written for a research project funded by the Reading Construction Forum. Financial Protection in the UK Building Industry looks at the legal and economic background to the problem of providing financial protection to clients to guard against poor performance and or the insolvency of contractors, consultants and sub-contractors. The inclusion of practical guidance notes and summaries makes this a valuable guide for the construction professional as well as for the researcher. * provides in-depth analysis of financial protection measures * explores the ways in which financial protection can increase efficiency in the industry * financial protection in construction is beset with problems - this book points toward practical solutions

Inference on microsatellite mutation processes in the invasive mite, Varroa destructor, using reversible jump Markov chain Monte Carlo

Varroa destructor is a parasitic mite of the Eastern honeybee Apis cerana. Fifty years ago, two distinct evolutionary lineages (Korean and Japanese) invaded the Western honeybee Apis mellifera. This haplo-diploid parasite species reproduces mainly through brother sister matings, a system which largely favors the fixation of new mutations. In a worldwide sample of 225 individuals from 21 locations collected on Western honeybees and analyzed at 19 microsatellite loci, a series of de novo mutations was observed. Using historical data concerning the invasion, this original biological system has been exploited to compare three mutation models with allele size constraints for microsatellite markers: stepwise (SMM) and generalized (GSM) mutation models, and a model with mutation rate increasing exponentially with microsatellite length (ESM). Posterior probabilities of the three models have been estimated for each locus individually using reversible jump Markov Chain Monte Carlo. The relative support of each model varies widely among loci, but the GSM is the only model that always receives at least 9% support, whatever the locus. The analysis also provides robust estimates of mutation parameters for each locus and of the divergence time of the two invasive lineages (67,000 generations with a 90% credibility interval of 35,000-174,000). With an average of 10 generations per year, this divergence time fits with the last post-glacial Korea Japan land separation. (c) 2005 Elsevier Inc. All rights reserved.

Multiband OFDM modulation and demodulation for ultra wideband communications

This chapter considers the Multiband Orthogonal Frequency Division Multiplexing (MB- OFDM) modulation and demodulation with the intention to optimize the Ultra-Wideband (UWB) system performance. OFDM is a type of multicarrier modulation and becomes the most important aspect for the MB-OFDM system performance. It is also a low cost digital signal component efficiently using Fast Fourier Transform (FFT) algorithm to implement the multicarrier orthogonality. Within the MB-OFDM approach, the OFDM modulation is employed in each 528 MHz wide band to transmit the data across the different bands while also using the frequency hopping technique across different bands. Each parallel bit stream can be mapped onto one of the OFDM subcarriers. Quadrature Phase Shift Keying (QPSK) and Dual Carrier Modulation (DCM) are currently used as the modulation schemes for MB-OFDM in the ECMA-368 defined UWB radio platform. A dual QPSK soft-demapper is suitable for ECMA-368 that exploits the inherent Time-Domain Spreading (TDS) and guard symbol subcarrier diversity to improve the receiver performance, yet merges decoding operations together to minimize hardware and power requirements. There are several methods to demap the DCM, which are soft bit demapping, Maximum Likelihood (ML) soft bit demapping, and Log Likelihood Ratio (LLR) demapping. The Channel State Information (CSI) aided scheme coupled with the band hopping information is used as a further technique to improve the DCM demapping performance. ECMA-368 offers up to 480 Mb/s instantaneous bit rate to the Medium Access Control (MAC) layer, but depending on radio channel conditions dropped packets unfortunately result in a lower throughput. An alternative high data rate modulation scheme termed Dual Circular 32-QAM that fits within the configuration of the current standard increasing system throughput thus maintaining the high rate throughput even with a moderate level of dropped packets.

Working-class household consumption smoothing in interwar Britain

We examine the strategies interwar working-class British households used to “smooth” consumption over time and guard against negative contingencies such as illness, unemployment, and death. Newly discovered returns from the U.K. Ministry of Labour's 1937/38 Household Expenditure Survey are used to fully categorize expenditure smoothing via nineteen credit/savings vehicles. We find that households made extensive use of expenditure-smoothing devices. Families' reliance on expenditure-smoothing is shown to be inversely related to household income, while households also used these mechanisms more intensively during expenditure crisis phases of the family life cycle, especially the years immediately after new household formation.

Pollinator community responses to the spatial population structure of wild plants: A pan-European approach

Land-use changes can alter the spatial population structure of plant species, which may in turn affect the attractiveness of flower aggregations to different groups of pollinators at different spatial scales. To assess how pollinators respond to spatial heterogeneity of plant distributions and whether honeybees affect visitation by other pollinators we used an extensive data set comprising ten plant species and their flower visitors from five European countries. In particular we tested the hypothesis that the composition of the flower visitor community in terms of visitation frequencies by different pollinator groups were affected by the spatial plant population structure, viz. area and density measures, at a within-population (‘patch’) and among-population (‘population’) scale. We found that patch area and population density were the spatial variables that best explained the variation in visitation frequencies within the pollinator community. Honeybees had higher visitation frequencies in larger patches, while bumblebees and hoverflies had higher visitation frequencies in sparser populations. Solitary bees had higher visitation frequencies in sparser populations and smaller patches. We also tested the hypothesis that honeybees affect the composition of the pollinator community by altering the visitation frequencies of other groups of pollinators. There was a positive relationship between visitation frequencies of honeybees and bumblebees, while the relationship with hoverflies and solitary bees varied (positive, negative and no relationship) depending on the plant species under study. The overall conclusion is that the spatial structure of plant populations affects different groups of pollinators in contrasting ways at both the local (‘patch’) and the larger (‘population’) scales and, that honeybees affect the flower visitation by other pollinator groups in various ways, depending on the plant species under study. These contrasting responses emphasize the need to investigate the entire pollinator community when the effects of landscape change on plant–pollinator interactions are studied.

Enhancement of buffer strips can improve provision of multiple ecosystem services

Farmland invertebrates play a pivotal role in the provision of ecosystem services, i.e. services that benefit humans. For example, bumblebees, solitary bees and honeybees, are crucial to the pollination of many of the world's crops and wildflowers, with over 70% of the world's major food crops dependent on the pollination services provided by these insects. The larvae of some butterfly species are considered to be pests; however, together with moth and sawfly larvae, they represent a key dietary component for many farmland birds. Spiders and ground beetles predate on crop pests including aphids, whilst soil macrofauna such as earthworms are vital for soil fertility services and nutrient recycling. Despite their importance, population declines of invertebrates have been observed during the last sixty years in the UK and NW Europe. For example, seven UK bumblebee species are in decline, and in the last 20 years, the species Bombus subterraneus (short-haired bumblebee) has become extinct, whilst there was a 54% decline in honeybee colony numbers in England from 1985 to 2005. Comparable trends have been documented for butterflies with a 23% decline in UK farmland species such as Anthocharis cardamines (orange tip) between 1990 and 2007. These declines have been widely attributed to the modern intensive arable management practices that have been developed to maximise crop yield. For example, loss and fragmentation of foraging and nesting habitats, including species-rich meadows and hedgerows, have been implicated in the decline of bees and butterflies. Increased use of herbicides and fertilisers has caused detrimental effects on many plant species with negative consequences for predatory invertebrates such as spiders and beetles which rely on plants for food and shelter.

High density lipoprotein: guardian of the vascular system?

The role of low-density lipoprotein in the development of coronary heart disease (CHD) is well recognised. There is also growing evidence that high-density lipoprotein cholesterol (HDL-C) is a powerful inverse predictor for premature CHD and that maintaining a high HDL-C level may guard against atherosclerosis. Patients with low HDL-C levels often also have central obesity, insulin resistance and other features of the metabolic syndrome. This syndrome is both increasingly common and strongly implicated in the growing worldwide epidemic of type 2 diabetes. HDL-C may be increased by lifestyle changes, e.g. weight loss, physical activity and smoking cessation. Pharmacological agents such as fibrates, niacin and statins have also been shown significantly to elevate HDL-C. Although current guidelines are beginning to recognise the protective role of HDL-C level in preventing coronary events, HDL-C should be adopted soon as a target for intervention in its own right.