bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct evidence for suppression of Auger recombination in GaInAsSbP/InAs mid-infrared light-emitting diodes
Authors: Cheetham K. J. , Krier A. , Marko I. P. , Aldukhayel A. , Sweeney S. J.
Published: October 2011

Mid-infrared light emitting diodes based on the pentanary alloy GaInAsSbP have been engineered to provide a favourable band structure for the suppression of non-radiative Auger recombination which is dominant in narrow band gap III-V materials. Hydrostatic pressure measurements at room temperature and at 100 K were used to tune the band gap towards resonance with the spin-orbit band gap. Analysis of the resulting electroluminescence confirms that the non-radiative Auger recombination process involving the spin-orbit-split-off-band is suppressed under ambient conditions.
A review of regulatory issues raised by genetically modified organisms in agriculture.
Authors: Ramjoué C.
Published: October 2011

The use of genetically modified organisms (GMOs) in agriculture has been controversial since the late 1990s, and the question of how to regulate the products of modern agricultural biotechnology is central to that debate. Aside from potential impacts on human health and the environment, regulators must consider and are influenced by a range of issues that go beyond scientific evidence. This paper reviews these regulatory issues, using the case studies of GMO regulation in the USA and the European Union for illustration. It first discusses approaches to technology and nature as fundamental choices associated with the use of GMOs in agriculture. It then moves on to socioeconomic issues, which form the context in which regulatory decisions are made. On the basis of these two first sections, the review turns to a discussion of ways in which regulators frame GM crop and food policies. Finally, it addresses possible challenges to regulation, in particular critical public opinion or trade clashes resulting from conflicting regulatory approaches. This paper concludes that, when there is perceived scientific uncertainty concerning the potential impacts of a new technology on the part of certain stakeholders and actors in the debate, non-scientific regulatory considerations, for example relating to ethical, social and economic issues, are of crucial importance in shaping regulation.
Optimizing biomedical and industrial products development based on flax.
Authors: Czemplik M. , Szopa J.
Published: October 2011

The principal goal of this review is to present the status of genetic modifications of flax (
Linum usitatissimum
) and its possible application in industry. Flax is a valuable source of oil and fibres, and development of genetic engineering allows the possibility of improving the quality of these products. There are different goals of flax modifications: improving the quality of flax fibres, improving oil properties, elevation of antioxidant level and creation of pathogen-resistant plants. These modifications made flax a more useful and precious source for a broad range of products applicable in industry. What makes flax valuable is the possibility of whole plant exploitation with almost no waste products.
Assessing impacts of organic production on pork and beef quality.
Authors: Sundrum A.
Published: October 2011

Organic livestock farming is based on a low-input production method, aiming to provide meat of a high product and process quality rather than maximizing production. Such high meat quality corresponds to the expectations of consumers, who are both seeking a premium product and who are willing to pay premium prices. This review focuses on the question of whether organic pork and beef production currently meet consumer demands, and it elaborates the potentials and limitations for producing high-quality meats under the current organic framework. Although defined by specific and basic guidelines, organic livestock production is characterized by largely heterogeneous farming conditions that allow for huge differences in the availability of nutrient resources, the implementation of feeding regimes, the use of genotypes, etc., all of which variously impact meat production. Correspondingly, there is substantial variation in the quality of organic meat entering the marketplace. According to the available literature, the quality of organic pork and beef was inconsistent and often fell short of expectations, as it is often similar to the quality of conventionally produced meat. Obviously, organic guidelines play a minor role with respect to meat quality. On the other hand, there is evidence that less intensified production systems may present suitable preconditions that would yield meats of high eating quality assumed that the relevant pre- and post-farmgate factors are considered and balanced within quality assurance systems. However, the trade value of carcasses is determined primarily by lean meat and cut composition while qualitative traits of meat are of no relevance. Neither does continuous recording of qualitative traits take place nor is an outstanding meat quality rewarded by higher prices. Of the various parameters, the intramuscular fat is highly related to palatability traits in both pork and beef and could be used to distinguish between different levels of eating quality. Despite the fact that many consumers express their wish for high-quality meats, the payment and marketing systems counteract all efforts to follow consumer demands and fail to communicate adequately differentiated meat palatability. It is concluded that only a direct assessment of qualitative traits and a payment system that honours meat quality grades that are above average can contribute so as to improve the currently unsatisfying situation. This, however, requires a shift in the paradigm from a guideline-oriented to an output-oriented approach, and the implementation of a systematic approach for an effective and efficient balancing of the multiple variables and complex interactions within each farming system.
Costs and benefits of induced resistance to herbivores and pathogens in plants.
Authors: Cipollini D. , Heil M.
Published: October 2011

While once considered noise in the background of constitutive resistance, the phenomenon of induced resistance to herbivores and pathogens is now firmly accepted as an integral component of plant defence. As for other forms of adaptive phenotypic plasticity, fitness costs and benefits of induced resistance are presumed to exist and may be realized in numerous ways; with their relative importance depending on when, where, and how induced resistance is deployed. Carefully controlled studies in which induced resistance has been manipulated in the absence of attack have provided some of the best evidence for direct costs of resistance in plants. Similar studies in the presence of attackers have provided evidence for fitness benefits, but fitness benefits of induced resistance have been rarely measured directly, especially in long-lived plants. The growing interest in placing induced resistance in a broader context has revealed many potential ecological costs and benefits that are dependent on the environment, but their fitness effects have been little examined. Induced indirect resistance (that is, resistance mediated by interactions with the third trophic level) has been an increasingly popular topic that comes with a unique set of potential costs and benefits. Further progress in our understanding of induced resistance will benefit from an increased synthesis of the literature from both agronomic and ecological perspectives, the former containing more pathogen-oriented studies in agricultural crops and the latter containing more examples of induced resistance to herbivores in wild plants. Such a melding of information will also better inform applications of induced resistance in agriculture.
Accelerated lambing: Part 1. Housing for sheep.
Authors: Hunter G. L.
Published: October 2011

This presentation has been written for those who may be considering practical intensification of sheep production and need information about its implications, potential and hazards, as well as for those with interests in this field of research. The limited literature on sheep housing and the management of a housed flock are considered, together with the importance of prolificacy and the suitability of a number of South African breeds to accelerated lambing. The productivity of a housed Ile de France flock in which three lambings a year was an objective, and difficulties met during 14 years of the flock's existence, are presented. 'Effective teaser rams' (ETRs) that both induce oestrus and increase lambing rate by as much as 20% have been noted and it is suggested that these as well as vasectomized goats (Effective teaser goats (ETGs)) may profitably be used for these purposes.
Expression QTL and their applications in genetic improvement of farm animals.
Authors: Wimmers K. , Murani E. , Ponsuksili S.
Published: October 2011

The integration of approaches based on genetic linkage maps and those based on function-driven holistic expression profiling, termed 'genetical genomics', has great potential for elucidating the expression and inheritance of complex traits. This review discusses the status and potential applications of 'genetical genomics' and how genomic/genetic, transcriptomic and phenotypic information can be used to promote the identification of functional positional candidate genes for traits important in farm animal breeding schemes. Linkage and/or genome-wide association analyses for traits that are relevant in animal breeding provide information about the positional candidacy of a particular gene. Analysing the relationship of the expression levels of genes and these traits adds information about the functional role of a gene and gives insight into functional pathways involved in the conversion of the traits. Mapping of expression quantitative trait loci (eQTL) enables the display of regulatory networks and localization of genomic variations affecting the mRNA expression of a gene either within the genes itself (
cis
) or distant from the gene (
trans
). The key advantage of eQTL mapping is that it connects variation at the level of RNA expression to variation at the level of DNA. Only the latter provides versatile tools for breeding, whereas the first reveals information on the biology of a trait and directs research to new candidate genes.
Are market-based instruments effective tools for environmental management?
Authors: Henderson B.
Published: October 2011

Over the past few decades market-based instruments have enjoyed increasing use in environmental management. To examine whether market-based instruments are effective tools for environmental management, a range of evaluations from the literature covering point- and non-point-source pollution control, along with biodiversity management, were reviewed. As found in other reviews, the environmental context of the particular issue being addressed is a key determinant of instrument performance. Market-based instruments have been applied most successfully to the management of industrial point-source pollution issues. In these cases, emissions have generally proven to be reasonably easy to measure and have had sufficiently direct relationships with their environmental impacts. In contrast, the diffuse-source environmental problems commonly encountered in rural contexts proved to be less amenable to market-based solutions. In these situations, difficulties in clearly linking management actions with environmental outcomes generally undermined their effectiveness and efficiency.
Whole genome marker-assisted selection.
Authors: Weller J. I.
Published: October 2011

Most applications of genomic selection (GS) have so far been in animals, especially dairy cattle, although theoretical studies have also been conducted for maize. For the last 50 years, commercial breeding programmes for dairy cattle have been based on the progeny test scheme, which results in an average generation interval of approximately 7 years for the sire to dam path. It should be possible to double rates of genetic gain by the application of GS, if generation intervals are reduced to close to the biological minimum. During the last decade, methods were developed for high-throughput genotyping of thousands of single nucleotide polymorphisms per individuals. The number of potential polymorphic markers per species was increased from about 1000 to tens of thousands, and costs per individual marker genotype were reduced from several dollars to less than one cent. The application of marker-assisted selection based on genome-wide association studies requires solutions to new statistical problems. Specifically how should information from pedigree, phenotypic records and genotypes be combined to optimally rank candidates for selection? Various linear and Bayesian methods have been proposed and tested to compute genomic estimated breeding values. Linear models require significantly less computing time, and perform nearly as well as Bayesian methodologies. Methods are generally evaluated by comparing genomic evaluations based only on pedigree and genotype to genetic evaluations based on daughter records of the same bulls. Genomic selection programmes for dairy cattle have been implemented in the USA, Canada, Australia, New Zealand and the Netherlands. With declining genotyping costs it becomes economically viable to genotype more individuals, including candidate bull dams. More emphasis can be placed on low heritability traits, such as fertility and disease traits, and it will be easier to control the increase in inbreeding in commercial animal populations.
Quantitative trait mutations in cattle, sheep and pigs: a review.
Authors: Stinckens A. , Schroyen M. , Peeters L. , Janssens S. , Buys N.
Published: October 2011

Most economically important traits in farm animals, such as daily gain, muscularity, meat quality, milk production, reproduction and others, are complex multifactorial traits that are controlled by an unknown number of genes combined with environmental factors. Since these traits show a continuous distribution rather than discrete values as monogenic or qualitative traits do, they are called quantitative traits and a polymorphism that affects such a quantitative trait is called a quantitative trait mutation (QTM). During the last few decades, several QTMs for different economically important quantitative traits in farm animals, such as muscularity, meat quality and milk production, were discovered. Also, for various congenital disorders, causal polymorphisms could be found or are under investigation. However, for other quantitative traits, no such QTMs have been revealed so far. An explanation for this discrepancy lies in the extent of the effect of the different polymorphisms that underlie a certain quantitative trait since this effect can vary from very small to quite large (up to 25-30% of the total phenotypic variance of a particular trait). Although new, emerging cost-effective genome-wide single-nucleotide polymorphism (SNP) genotyping techniques have become available, only QTMs that explain a large portion of the phenotypic variation are worth unravelling, especially in the light of genome-wide selection. In this review, the research for QTMs is positioned against these contemporary techniques. Moreover, an overview is given of, past and present, research efforts in identifying QTMs in farm animals and the incorporation of these polymorphisms in modern animal breeding.
Classical biological control of weeds with Curculionidae.
Authors: Herrick N. J. , Kok L. T.
Published: October 2011

The intentional use of insects to control weeds has been in practice for more than 150 years. Historically, species from the orders Lepidoptera and Coleoptera have shown the greatest success. Among the Coleoptera, the weevils (family Curculionidae) have played an integral role in the suppression of more than 50% of targeted weed programmes in various regions of the world. Notable successes using Curculionidae are in the control of waterhyacinth, Australian
Acacia
spp. and several thistle species. Published records indicate that of the 67 weed species targeted for control with Curculionidae worldwide, most are terrestrial-herbaceous weeds (65.7%). Curculionidae used for most of the targeted terrestrial-herbaceous (
n
=44) and aquatic/semi-aquatic weeds (
n
=6) are in North America, while the majority of the terrestrial-arborescent weeds (
n
=17) are in Africa. Of the 75 species of Curculionidae used to control these weeds worldwide, 34 are in North America. Success, as defined by the establishment of a biological control agent that has a detrimental impact on the target weed, is dependent on the number of programmes implemented and the resources for follow-through. This review provides insight into the successful establishment of some selected weevil species and their impact on their target weeds.
Poultry sector development, highly pathogenic avian influenza and the smallholder production systems.
Authors: Rushton J. , Viscarra R. E. , Taylor N. , Hoffmann I. , Schwabenbauer K.
Published: October 2011

Poultry sectors are the fastest-changing component of the general livestock sector. These changes are typified by tremendous growth in poultry populations in industrial production systems. These industrial systems generally separate feed mills, breeding, production and processing into different operations. In a competitive market environment, such operations may be physically separated, but are closely integrated by strong private regulations. In less competitive market environments, encouraged by protection policies, industrial poultry chains are loosely integrated and are weakly regulated by governments. Large breeding flocks continue to exist, but are very weakly linked to low investment fattening and layer production units. Investment in processing is low and live bird markets are commonly used to market products. Loosely integrated industrial chains create enormous risks for the spread of contagious diseases such as highly pathogenic avian influenza (HPAI), and affect the smallholder poultry producers who live and work alongside the industrial units and traditionally use live-bird markets for the sale of their own products and purchase of poultry. The review will discuss how changes in sector policy could improve industrial poultry sector performance and in turn reduce risks to the smallholder producers.
Can the rural economy deliver ecosystem services?
Authors: Speranza C. I. I. , Sand I. van de
Published: October 2011

This review explores how rural economies in developing countries can provide or enhance the provision of ecosystem services (ES). It does so by analysing two categories of ES that agricultural landscapes provide, namely carbon sequestration and hydrological services. One of the major constraints that rural economies face in providing ES lies in the public-good nature of many ES, which results in their underprovision. External factors, policies, processes and institutions, and the characteristics and perceptions of ES providers are important factors that influence ES provision (ESP). Payment for ecosystem services (PES) has emerged as a promising market-based instrument to incentivise the provision of ES. This review shows that despite its theoretical appeal, there are a number of practical challenges that hamper its wider application in developing countries. Scientific uncertainty about the relations between some management practices and the generation of ES persists. This uncertainty and other challenges such as the high transaction costs, insecure land tenure, limited demand and awareness, and the lack of capacity regarding the implementation of PES need to be addressed in order to increase ESP. The main drivers for PES schemes are external to the rural economy and come from both the international and the national level. In addition, perverse incentives and weak enforcement of environmental laws need to be addressed to foster the provision of ES and PES. In order to ensure and enhance the provision of ES in rural economies, it is important to continue to apply and revisit other instruments that address the public-good problem in addition to further improving and refining PES.
Microgoats in India and their role in future animal production in an era of climatic change.
Authors: Rout P. K. , Sharma M. C.
Published: October 2011

The major objective of this review is to analyse how microlivestock can help us to reduce poverty through sustainable development and enhance food production to meet the demands of the growing population. The role of microgoats has been examined on the basis of sustainability indicators in relation to climatic variation. The sustainability of microgoats has been analyzed on the basis of ecological adaptability, economically viability and energy efficiency in particular production environments and their suitability in diverse environmental conditions. The present review also highlights the importance of microgoats for future agriculture. Microgoats play multifaceted roles such as providing nutrition, fulfilling family needs, maintaining soil fertility and playing a vital role during disasters in disadvantaged areas. Microgoats are distributed in areas that show extreme climatic variation and seem to be efficient in food production under particular situations. Livestock production is increasingly going to face challenges of heat stress, water scarcity, coastal flooding, disease onset and food security. Therefore it is necessary to evaluate the different genotypes present in specific locations to establish which of them will be suitable in future for national and global applications. It is necessary to analyse suitable livestock components for sustainable agriculture and analyse closely the consequence of climate change as it will cause problems for the environment and subsequently disturb the peace, harmony and security of the whole world.
Molecular targets of quercetin in cancer chemoprevention.
Authors: Granado-Serrano A. B. , Ramos S.
Published: October 2011

Prevention of cancer through dietary intervention has received increasing interest recently, and dietary polyphenols have become important potential chemopreventive natural agents. Quercetin, among polyphenols, has been reported to interfere with the initiation, promotion and progression of cancer. It might lead to the modulation of proteins in diverse pathways and require the integration of different signals for the final chemopreventive effect. Quercetin has been demonstrated to act on multiple key elements in signal transduction pathways related to cellular proliferation, differentiation, apoptosis and inflammation; however, these molecular mechanisms of action are not completely characterized and many features remain to be elucidated. The aim of this review is to provide insights into the molecular basis of the potential chemopreventive activity of quercetin with an emphasis on its ability to control intracellular signalling cascades considered as relevant targets in a cancer-preventive approach.
Bt
plants and effects on soil micro-organisms.
Authors: Mocali S.
Published: October 2011

The continued and increasing adoption of genetically modified plants (GMPs) in agriculture has raised both perspectives on increasing the productivity and some concern over their potential effects on the environment, especially on soil. These effects include unintentional changes in the chemical compositions of root exudates, and the direct or indirect effects of transgenic plants on non-target species of soil micro-organisms that have a key role in the maintenance of soil quality and environmental sustainability. Therefore any change to the quality of crop residues and rhizosphere inputs could modify the dynamics of the composition and activity of organisms in soil. One of the most common transgenic traits in commercial GMPs is insect resistance based on the expression of Cry toxin derived from
Bacillus thuringiensis
(
Bt
), and it is crucial that risk assessment studies on the use of
Bt
crops consider the impacts on micro-organisms in soil. This review summarizes the results of most of the studies that have been conducted to specifically test the effects of
Bt
plants on soil microbial communities, and examines the role of soil properties as one of the most important factors to be considered to study the interactions between micro-organisms and
Bt
plants. Most studies suggest that the
Bt
plants that have been released for commercial purposes could cause small changes in microbial communities and these are often transient in duration. However, experimental results are often contrasting and, given our limited knowledge of the soil system and the linkage with the soil microbial community's diversity and function, more work needs to be done on a case-by-case basis to further evaluate the effects of
Bt
plants on soil micro-organisms and soil ecosystem functions.
An introduction to association mapping in plants.
Authors: Stich B. , Melchinger A. E.
Published: October 2011

Most traits that are related to fitness and agricultural value of plants are quantitatively inherited. Currently, there is tremendous interest in using association mapping approaches to dissect such traits. This is enabled by advances in genomic technology as well as the development of statistical models for association mapping that take into account population structure and familial relatedness. In this introductory review, we describe the relation of linkage disequilibrium to association mapping, give an overview of the steps required for association mapping as well as point out the possible limitations of such approaches.
Metabolic surgery: nutritional outcomes and health benefits.
Authors: Roux C. W. le , Pournaras D. J.
Published: October 2011

Metabolic surgery is not only the most effective treatment for morbid obesity, but also leads to the improvement or remission of a number of comorbidities. In this review, we present the available evidence for the effect of these surgical procedures on different systems using the King's College criteria. Some of these outcomes can be attributed to weight loss; however, there is increasing evidence for weight-loss-independent effects of metabolic surgery.
Risk assessment of toxic contaminants in animal feed.
Authors: Mantovani A. , Frazzoli C.
Published: October 2011

Feed contaminants are a broad issue ranging from undesirable or unauthorized feed components or additives through to environmental pollutants and to contaminants related to specific steps of food production, such as storage or cross-contamination. In many cases, e.g. most mycotoxins and plant-derived compounds, feed contaminants may pose a risk mostly for farm animal welfare; however, feeds can also be a major vehicle for the presence of bioaccumulating pollutants in human diet, especially for vulnerable farm animal productions, such as aquaculture or grazing ruminants. Critical risk assessment issues include the characterization of toxicological hazards, the possible pathways of feed contamination and the carry-over of parent compound or metabolites to foods of animal origin as well as the pinpointing of situations that may require risk management measures. Some examples are considered in detail, taking into account the assessments performed by the European Food Safety Authority: cross-contamination by coccidiostats, the endocrine-disrupting mycotoxin zearalenone, the trace element Cr(III) and the persistent organic pollutant hexaclorobenzene. Emerging issues, such as the widespread, bioaccumulating brominated flame retardants and the potentially undesirable high levels of phytooestrogens, are also discussed. Diagnostic health risk assessment, considered as a tool for decision-making in field situations, is also reviewed with regard to unavoidable, long-standing (e.g. methylmercury) and short-term contamination instances. Management of feed contaminants relies primarily on the implementation of good practice in feed production; specific research needs may target feed sources less prone to contamination as well as safe and effective detoxifying agents. Overall, the risk assessment of feed contaminants has a critical role in veterinary public health both as a basis to define the reference thresholds for prevention, as well as guidance for risk diagnosis and field intervention in contamination events.
Plants as reservoirs for human enteric pathogens.
Authors: Holden N. J.
Published: October 2011

Outbreaks of enteric pathogens associated with fresh produce, in the form of raw or minimally processed fruit and vegetables, have increased over recent times. The pathogens may be bacterial, viral or protoctist parasites and many are considered to be zoonotic. Contamination of fresh produce occurs by a number of routes, in particular from irrigation water or manure. While some pathogens are vectored into the food chain by plants, others are able to colonize plants and use them as alternative hosts. Enteric bacteria normally associated with animal hosts can colonize and proliferate on or within plants, in particular in the rhizosphere. Some have the ability to internalize into plant tissue, from where they can be detected in edible foliage. Specific interactions have been demonstrated that are dependent on both the microbe and plant host. Colonization of non-animal hosts by enteric pathogens has, until recently, been largely neglected. However, alternative environmental reservoirs such as plants need to be considered in the context of transmission of enteric pathogens through the food chain.
The role of zinc in the treatment and prevention of diarrhoea.
Authors: Salvatore S. , Wagner P. , Nespoli L. , Vandenplas Y.
Published: October 2011

Zinc is an essential micronutrient involved in many metabolic processes, cell growth, neurological, intestinal and immune functions. Zinc deficiency is common in developing countries because of inadequate intake or reduced absorption, and may also be a result of excessive intestinal losses of zinc caused by diarrhoea. Several hospital- and community-based randomized trials, all performed in developing countries, consistently showed that zinc is an effective treatment for acute or persistent diarrhoea in children younger than 5 years. The mechanism of action of zinc in acute diarrhoea is not completely known. Plausible mechanisms include improved absorption of water and electrolytes by the intestine, faster regeneration of gut epithelium, increased levels of enterocyte brush-border enzymes and an enhanced immune response. In developing countries, zinc also showed a significant effect in the prevention of diarrhoea. Dispersible tablet formulation (20 mg/day) has demonstrated to be a cheap, stable, easy-to-prepare and acceptable alternative. Populations that would benefit from zinc treatment, other than those with zinc-deficient diets, are still to be defined.
Palatability: principles, methodology and practice for farm animals.
Authors: Forbes J. M.
Published: October 2011

Palatability is a complex concept, not amenable to concise definition because it depends not only on the organoleptic properties of the food but also on the experience and genetic background of the animal in question and its physiological state, as well as environmental conditions and social context. The learning of the association between the appearance, flavour or texture of a food and the metabolic consequences of eating that food provides the animal with a conditioned response to that food, either preference or aversion, irrespective of the nature of the sensory cue. Some flavours are innately preferred, others aversive, but conditioning can change these preferences. Critical to the understanding of palatability is an appreciation of the methods used to measure it. These range from the initial rate of eating of a food, through choices expressed between two (or more) foods offered simultaneously, to more sophisticated methods involving direct or operant conditioning. Many factors influence the outcome of palatability tests, including the length of the test, time of the day, sensory characteristics of foods, environmental factors, physiological state of the animal and opportunity to learn from conspecifics. Whether or not long-term intake can be predicted from short-term preference depends on how the latter is measured and whether the animals have innate or conditioned preferences for a food; thus, detailed knowledge of the animals' history and the conditions under which a test has been carried out is necessary in order to interpret and make use of palatability measurements.
Market-based payments for ecosystem services: current status, challenges and the way forward.
Authors: Yamasaki S. H. , Guillon B. M. C. , Brand D. , Patil A. M.
Published: October 2011

Human society relies on a vast array of services provided by ecosystems, such as climate stabilization (i.e. carbon sequestration), the benefits of biological diversity (e.g. pollination, waste and nutrient cycling, soil formation and chemical discoveries including pharmaceuticals) and the provision of safe drinking water. Payments for ecosystem services (PES) are schemes through which land managers are rewarded for conserving or enhancing the level of ecosystem services (ES) for the benefit of users of these ES. Markets for ES, which facilitate transactions between producers and buyers of ES, have been steadily developing for a range of ES. In this review, we seek to establish the case that market-based PES will slow the rate of ecosystem degradation and loss. We present various market mechanisms for PES, describe alternatives to market-based PES and suggest ways to identify the most appropriate approach within a given context. We then present what we currently perceive as the greatest challenges to the implementation of PES, and conclude, with suggestions, on ways to move forward with the development of market-based PES.
Plants and oomycetes, an intimate relationship: co-evolutionary principles and impact on agricultural practice.
Authors: Rietman H. , Champouret N. , Hein I. , Niks R. E. , Vleeshouwers V. G. A. A.
Published: October 2011

Plants face continuous attacks from a broad range of pathogens and have evolved effective defence mechanisms that are initiated upon pathogen attack. Invading oomycete pathogens secrete effectors, molecules that manipulate host cell defence and thereby enable colonization. However, plant species evolved resistance (R) genes to most specialized pathogen species. The R proteins can detect effectors, termed avirulence (AVR) proteins, and thus confer immunity to pathogens. Effectors and their interacting genes in the plant play a central role in the co-evolution of pathogens with their hosts. In this review, we discuss the role that effectors play in the pathogenesis and lifestyles of oomycetes. Particularly intriguing features emerge for (hemi-)biotrophic oomycetes, which establish an intimate contact with the host by forming haustoria. At this interface, effectors with an RXLR motif are translocated into the cytoplasm, where they reprogramme the host towards susceptibility. Such interactions between effectors and host targets are highly specific and are considered a result of tight co-evolution. In addition, we elaborate on the
Phytophthora infestans-Solanum
pathosystem, from which various
R
and
Avr
genes were cloned recently. We discuss a rationale for exploiting molecular insights into
R-Avr
interactions for developing more durable resistance strategies to control late blight in agriculture.
The specificity of temporal expectancy: Evidence from a variable foreperiod paradigm
Authors: Thomaschke Roland , Wagener Annika , Kiesel Andrea , Hoffmann Joachim
Published: October 2011

In speeded choice tasks with variable foreperiods (FPs), individuals behaviourally adapt to various frequency manipulations. Adaptations have been shown to frequencies of different stimulus–response events, to frequencies of different foreperiods, and to frequencies of different event–foreperiod combinations. We have investigated how participants adapt to a situation where all three frequency manipulations are done simultaneously. Three variable foreperiod experiments are reported. In Experiment 1, one target (the peak distributed target) appeared particularly frequently after one particular FP (the peak foreperiod), while another target was less frequent and equally distributed over all foreperiods. In Experiment 2, the equally distributed target was overall more frequent than the peak distributed one. In both experiments, performance advantages for the peak distributed target were specific to the peak foreperiod, and performance advantages at the peak foreperiod were specific to the peak distributed targets. A third experiment showed that, when two differently frequent target are both equally distributed over FPs, the performance distribution over FPs is not significantly different between both targets. Together, the results suggest that participants were able to simultaneously and specifically adapt to frequency manipulations in events, foreperiods, and event–foreperiod combinations.
Mental representations of arithmetic facts: Evidence from eye movement recordings supports the preferred operand-order-specific representation hypothesis
Authors: Zhou Fan , Zhao Qian , Chen Chuansheng , Zhou Xinlin
Published: October 2011

There are three main hypotheses about mental representations of arithmetic facts: the independent representation hypothesis, the operand-order-free single-representation hypothesis, and the operand-order-specific single-representation hypothesis. The current study used electrical recordings of eye movements to examine the organization of arithmetic facts in long-term memory. Subjects were presented single-digit addition and multiplication problems and were asked to report the solutions. Analyses of the horizontal electrooculograph (HEOG) showed an operand order effect for multiplication in the time windows 150–300 ms (larger negative potentials for smaller operand first problems than for larger operand first ones). The operand order effect was reversed in the time windows from 400 to 1,000 ms (i.e., larger operand first problems had larger negative potentials than smaller operand first problems). For addition, larger operand first problems had larger negative potentials than smaller operand first in the series of time windows from 300 to 1,000 ms, but the effect was smaller than that for multiplication. These results confirmed the dissociated representation of addition and multiplication facts and were consistent with the prediction of the preferred operand-order-specific representation hypothesis.
Chaotic solution for the Black-Scholes equation
Authors: Emamirad Hassan , Goldstein Gisèle , Goldstein Jerome
Published: October 2011

The Black-Scholes semigroup is studied on spaces of continuous functions on

(
0
,
∞
)

(0,\infty )

which may grow at both 0 and at

∞
,

\infty ,

which is important since the standard initial value is an unbounded function. We prove that in the Banach spaces
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper Y Superscript s comma tau Baseline colon equals left-brace u element-of upper C left-parenthesis left-parenthesis 0 comma normal infinity right-parenthesis right-parenthesis colon limit Underscript x right-arrow normal infinity Endscripts StartFraction u left-parenthesis x right-parenthesis Over 1 plus x Superscript s Baseline EndFraction equals 0 comma limit Underscript x right-arrow 0 Endscripts StartFraction u left-parenthesis x right-parenthesis Over 1 plus x Superscript negative tau Baseline EndFraction equals 0 right-brace">

Y

s
,
τ

:=
{
u
∈
C
(
(
0
,
∞
)
)
:

lim

x
→
∞

u
(
x
)

1
+

x

s

=
0
,

lim

x
→
0

u
(
x
)

1
+

x

−
τ

=
0
}

Y^{s,\tau }:=\{u\in C((0,\infty )):\;\lim _{x\rightarrow \infty } \frac {u(x)}{1+x^{s}} =0, \; \lim _{x\rightarrow 0}\frac {u(x)}{1+x^{-\tau }} =0\}

\]
with norm
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-vertical-bar u double-vertical-bar Subscript upper Y Sub Superscript s comma tau Subscript Baseline equals sup Underscript x greater-than 0 Endscripts StartAbsoluteValue StartFraction u left-parenthesis x right-parenthesis Over left-parenthesis 1 plus x Superscript s Baseline right-parenthesis left-parenthesis 1 plus x Superscript negative tau Baseline right-parenthesis EndFraction EndAbsoluteValue greater-than normal infinity comma">

‖
u
‖

Y

s
,
τ

=

sup

x
>
0

|

u
(
x
)

(
1
+

x

s

)
(
1
+

x

−
τ

)

|

>
∞
,

\left \Vert u\right \Vert _{Y^{s,\tau }}=\underset {x>0}{\sup }\left \vert \frac {u(x)}{(1+x^{s})(1+x^{-\tau })}\right \vert >\infty ,

the Black-Scholes semigroup is strongly continuous and chaotic for

s
>
1

s>1

,

τ
≥
0

\tau \geq 0

with

s
ν
>
1

s\nu >1

, where

2

ν

\sqrt 2\nu

is the volatility. The proof relies on the Godefroy-Shapiro hypercyclicity criterion.
Quasi sure local convergence rate of a Brownian motion in the Hölder norm
Authors: Liu Yonghong , Li Yuhui
Published: October 2011

We estimate the local convergence rate of Strassen type for a Brownian motion in the Hölder norm with respect to

C

r
,
p

C_{r,p}

-capacity on an abstract Wiener space. The local convergence rate for increments of a Brownian motion in the Hölder norm with respect to

C

r
,
p

C_{r,p}

-capacity is also derived.
Interactive Effects of Temperature and Leaf Wetness Duration on Sporangia Germination and Infection of Cucurbit Hosts by Pseudoperonospora cubensis
Authors: Neufeld K. N. , Ojiambo P. S.
Published: October 2011

Outbreaks of cucurbit downy mildew caused by Pseudoperonospora cubensis are dependent on the weather but effects of temperature and leaf wetness duration on infection have not been studied for different cucurbits. To determine the effects of these two weather variables on sporangia germination and infection of cucurbit host types by P. cubensis, three host types; cucumber (‘Straight 8’), cantaloupe (‘Kermit’), and acorn squash (‘Table Queen’), were inoculated and exposed to leaf wetness durations of 2 to 24 h at six constant temperatures ranging from 5 to 30°C in growth-chamber experiments. Sporangia germination was assessed after each wetness period, and leaf area infected was assessed 5 and 7 days after inoculation. Germination of sporangia was highest on cantaloupe (16.5 to 85.7%) and lowest on squash (10.7 to 68.9%), while disease severity was highest and lowest on cucumber and cantaloupe, respectively. Host type, temperature, wetness duration and their interactions significantly (P < 0.0001) affected germination and disease severity. Germination and disease data for each host type were separately fitted to a modified form of a Weibull function that characterizes a unimodal response and monotonic increase of germination or infection with temperature and wetness duration, respectively. The effect of host type on germination and infection was characterized primarily by differences in the upper limit parameter in response to temperature. Differences among host types based on other parameters were either small or inconsistent. Temperature and wetness duration that supported a given level of germination or infection varied among host types. At 20°C, 15% leaf area infected was expected following 2, 4, and 8 h of wetness for cucumber, squash, and cantaloupe, respectively. When temperature was increased to 25°C, 15% disease severity was expected following 3, 7, and 15 h of wetness for cucumber, squash, and cantaloupe, respectively. Risk charts were constructed to estimate the potential risk of infection of cucurbit host types by P. cubensis based on prevailing or forecasted temperature and leaf wetness duration. These results will improve the timing and application of the initial fungicide spray for the control of cucurbit downy mildew.
A Decade of Hospital Discharges Related to Eosinophilic Esophagitis
Authors: Erwin Elizabeth A. , Asti Lindsey , Hemming Traci , Kelleher Kelly J.
Published: October 2011

Eosinophilic esophagitis (EoE) is a recently characterized chronic, allergic, gastrointestinal disorder. Using the Pediatric Health Information System, we report trends in diagnostic codes related to EoE in inpatients from 1999 through 2010. Esophagitis not elsewhere classifiable, EoE, and dysphagia have increased over time. Similar to other allergic disorders, EoE appears to be increasing across the United States.
A unified approach to rigid body rotational dynamics and control
Authors: Udwadia Firdaus E. , Schutte Aaron D.
Published: October 2011

This paper develops a unified methodology for obtaining both the general equations of motion describing the rotational dynamics of a rigid body using quaternions as well as its control. This is achieved in a simple systematic manner using the so-called fundamental equation of constrained motion that permits both the dynamics and the control to be placed within a common framework. It is shown that a first application of this equation yields, in closed form, the equations of rotational dynamics, whereas a second application of the self-same equation yields two new methods for explicitly determining, in closed form, the nonlinear control torque needed to change the orientation of a rigid body. The stability of the controllers developed is analysed, and numerical examples showing the ease and efficacy of the unified methodology are provided.
Comments on ‘An improved free surface capturing method based on Cartesian cut cell mesh for water-entry and -exit problems’
Authors: Qian Ling , Causon Derek , Mingham Clive
Published: October 2011

In the paper entitled ‘An improved free surface capturing method based on Cartesian cut cell mesh for water-entry and -exit problems’ (
Wang & Wang 2009
Proc. R. Soc. A
465
, 1843–1868 (
doi:10.1098/rspa.2008.0410
)), the present authors' earlier work (

Qian
et al
. 2006

,
Proc. R. Soc. A
462
, 21–42 (
doi:10.1098/rspa.2005.1528
)) has been specifically applied to the study of water-entry and -exit of solid objects. An extended boundary condition, retaining the term owing to acceleration of moving boundaries in the momentum equation, has been implemented for calculating the pressure gradient at solid surfaces and, based on their numerical experiments, it was concluded by Wang and Wang that without this term the calculation will substantially under-predict the impact forces and may even break down. Therefore, a more complex procedure based on the exact solution of a Riemann problem for moving boundaries was implemented. In this short comment, by applying the authors' free surface capturing code to the same flow problem of water-entry of a wedge, it can, however, be demonstrated that the results from implementing the new pressure boundary condition are nearly identical to that of employing the original boundary condition without the acceleration term, indicating that its effects on the simulation results are minimal. A further examination of the implementation details on the pressure boundary condition also supports this conclusion.