Showing papers by "University of Exeter published in 2007"

When Species Meet

Abstract: "When Species Meet is a breathtaking meditation on the intersection between humankind and dog, philosophy and science, and macro and micro cultures."-Cameron Woo, Publisher of Bark magazine In 2006, about 69 million U.S. households had pets, giving homes to around 73.9 million dogs, 90.5 million cats, and 16.6 million birds, and spending over $38 billion dollars on companion animals. As never before in history, our pets are truly members of the family. But the notion of "companion species"d-knotted from human beings, animals and other organisms, landscapes, and technologies-includes much more than "companion animals."d In When Species Meet, Donna J. Haraway digs into this larger phenomenon to contemplate the interactions of humans with many kinds of critters, especially with those called domestic. At the heart of the book are her experiences in agility training with her dogs Cayenne and Roland, but Haraway's vision here also encompasses wolves, chickens, cats, baboons, sheep, microorganisms, and whales wearing video cameras. From designer pets to lab animals to trained therapy dogs, she deftly explores philosophical, cultural, and biological aspects of animal-human encounters. In this deeply personal yet intellectually groundbreaking work, Haraway develops the idea of companion species, those who meet and break bread together but not without some indigestion. "A great deal is at stake in such meetings,"she writes, "and outcomes are not guaranteed. There is no assured happy or unhappy ending-socially, ecologically, or scientifically. There is only the chance for getting on together with some grace."d Ultimately, she finds that respect, curiosity, and knowledge spring from animal-human associations and work powerfully against ideas about human exceptionalism. One of the founders of the posthumanities, Donna J. Haraway is professor in the History of Consciousness Department at the University of California, Santa Cruz. Author of many books and widely read essays, including The Companion Species Manifesto: Dogs, People, and Significant Otherness and the now-classic essay "The Cyborg Manifesto,"she received the J. D. Bernal Prize in 2000, a lifetime achievement award from the Society for Social Studies in Science.

Autobiographical memory specificity and emotional disorder.

Abstract: The authors review research showing that when recalling autobiographical events, many emotionally disturbed patients summarize categories of events rather than retrieving a single episode. The mechanisms underlying such overgeneral memory are examined, with a focus on M. A. Conway and C. W. Pleydell-Pearce's (2000) hierarchical search model of personal event retrieval. An elaboration of this model is proposed to account for overgeneral memory, focusing on how memory search can be affected by (a) capture and rumination processes, when mnemonic information used in retrieval activates ruminative thinking; (b) functional avoidance, when episodic material threatens to cause affective disturbance; and (c) impairment in executive capacity and control that limits an individual's ability to remain focused on retrieval in the face of distraction.

Why “what works” won’t work: evidence‐based practice and the democratic deficit in educational research

Abstract: Why ‘what works’ won’t work. Evidence-based practice and the democratic deficit of educational research

A niche for isotopic ecology

Abstract: Fifty years ago, GE Hutchinson defined the ecological niche as a hypervolume in n-dimensional space with environmental variables as axes. Ecologists have recently developed renewed interest in the concept, and technological advances now allow us to use stable isotope analyses to quantify these niche dimensions. Analogously, we define the isotopic niche as an area (in δ-space) with isotopic values (δ-values) as coordinates. To make isotopic measurements comparable to other niche formulations, we propose transforming δ-space to p-space, where axes represent relative proportions of isotopically distinct resources incorporated into an animal's tissues. We illustrate the isotopic niche with two examples: the application of historic ecology to conservation biology and ontogenetic niche shifts. Sustaining renewed interest in the niche requires novel methods to measure the variables that define it. Stable isotope analyses are a natural, perhaps crucial, tool in contemporary studies of the ecological niche.

Spinal cord stimulation versus conventional medical management for neuropathic pain: a multicentre randomised controlled trial in patients with failed back surgery syndrome.

Abstract: Patients with neuropathic pain secondary to failed back surgery syndrome (FBSS) typically experience persistent pain, disability, and reduced quality of life. We hypothesised that spinal cord stimulation (SCS) is an effective therapy in addition to conventional medical management (CMM) in this patient population. We randomised 100 FBSS patients with predominant leg pain of neuropathic radicular origin to receive spinal cord stimulation plus conventional medical management (SCS group) or conventional medical management alone (CMM group) for at least 6 months. The primary outcome was the proportion of patients achieving 50% or more pain relief in the legs. Secondary outcomes were improvement in back and leg pain, health-related quality of life, functional capacity, use of pain medication and non-drug pain treatment, level of patient satisfaction, and incidence of complications and adverse effects. Crossover after the 6-months visit was permitted, and all patients were followed up to 1 year. In the intention-to-treat analysis at 6 months, 24 SCS patients (48%) and 4 CMM patients (9%) (p<0.001) achieved the primary outcome. Compared with the CMM group, the SCS group experienced improved leg and back pain relief, quality of life, and functional capacity, as well as greater treatment satisfaction (p

Indirect radiative forcing of climate change through ozone effects on the land-carbon sink

Abstract: The evolution of the Earth's climate over the twenty-first century depends on the rate at which anthropogenic carbon dioxide emissions are removed from the atmosphere by the ocean and land carbon cycles. Coupled climate-carbon cycle models suggest that global warming will act to limit the land-carbon sink, but these first generation models neglected the impacts of changing atmospheric chemistry. Emissions associated with fossil fuel and biomass burning have acted to approximately double the global mean tropospheric ozone concentration, and further increases are expected over the twenty-first century. Tropospheric ozone is known to damage plants, reducing plant primary productivity and crop yields, yet increasing atmospheric carbon dioxide concentrations are thought to stimulate plant primary productivity. Increased carbon dioxide and ozone levels can both lead to stomatal closure, which reduces the uptake of either gas, and in turn limits the damaging effect of ozone and the carbon dioxide fertilization of photosynthesis. Here we estimate the impact of projected changes in ozone levels on the land-carbon sink, using a global land carbon cycle model modified to include the effect of ozone deposition on photosynthesis and to account for interactions between ozone and carbon dioxide through stomatal closure. For a range of sensitivity parameters based on manipulative field experiments, we find a significant suppression of the global land-carbon sink as increases in ozone concentrations affect plant productivity. In consequence, more carbon dioxide accumulates in the atmosphere. We suggest that the resulting indirect radiative forcing by ozone effects on plants could contribute more to global warming than the direct radiative forcing due to tropospheric ozone increases.

The impact of agricultural soil erosion on the global carbon cycle

Abstract: Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year(-1) to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, we estimated a global carbon sink of 0.12 (range 0.06 to 0.27) petagrams of carbon per year(-1) resulting from erosion in the world's agricultural landscapes. Our analysis directly challenges the view that agricultural erosion represents an important source or sink for atmospheric CO2.

Thresholds and the resilience of Caribbean coral reefs

Abstract: Many coral reefs in the Caribbean are in poor health, having suffered coral losses and increases in macroalgae. Using models, Mumby et al. show that since the mass mortality of a grazing urchin in 1983, Caribbean reefs have shown a general loss of resilience. The reefs are now expected to be highly sensitive to parrot fish exploitation, but this modelling may help identify areas most resilient to both grazing and hurricane damage, with important consequences for reef management. Use of a model has shown that the mass mortality of a grazing urchin in 1983 has made Caribbean reefs susceptible a general loss of resilience. The reefs are now highly sensitive to parrotfish exploitation, with important consequences for reef management. The deteriorating health of the world’s coral reefs threatens global biodiversity, ecosystem function, and the livelihoods of millions of people living in tropical coastal regions1. Reefs in the Caribbean are among the most heavily affected2,3, having experienced mass disease-induced mortality of the herbivorous urchin Diadema antillarum4 in 1983 and two framework-building species of coral5. Declining reef health is characterized by increases in macroalgae. A critical question is whether the observed macroalgal bloom on Caribbean reefs is easily reversible. To answer this question, we must resolve whether algal-dominated reefs are an alternative stable state of the ecosystem or simply the readily reversible result of a phase change along a gradient of some environmental or ecological parameter6. Here, using a fully parameterized simulation model in combination with a simple analytical model, we show that Caribbean reefs became susceptible to alternative stable states once the urchin mortality event of 1983 confined the majority of grazing to parrotfishes. We reveal dramatic hysteresis in a natural system7,8 and define critical thresholds of grazing and coral cover beyond which resilience is lost. Most grazing thresholds lie near the upper level observed for parrotfishes in nature, suggesting that reefs are highly sensitive to parrotfish exploitation. Ecosystem thresholds can be combined with stochastic models of disturbance to identify targets for the restoration of ecosystem processes. We illustrate this principle by estimating the relationship between current reef state (coral cover and grazing) and the probability that the reef will withstand moderate hurricane intensity for two decades without becoming entrained in a shift towards a stable macroalgal-dominated state. Such targets may help reef managers face the challenge of addressing global disturbance at local scales.

Factors Influencing Environmental Attitudes and Behaviors: A U.K. Case Study of Household Waste Management

Abstract: Three waste management behaviors (waste reduction, reuse, and recycling) were examined with the use of a conceptual framework developed by the author. It was posited that environmental values, situational characteristics, and psychological factors all play a significant role in the prediction of waste management behavior, within the context of a core intention-behavior relationship. The framework was tested in a self-report questionnaire of 673 residents of Exeter, UK. It was found that the predictors of reduction, reuse, and recycling behavior differed significantly, with reduction and reuse being predicted by underlying environmental values, knowledge, and concern-based variables. Recycling behavior was, in contrast, characterized as highly normative behavior. The use of the approach taken for investigating other environmental behaviors is examined.

SPLASH: An interactive visualisation tool for smoothed particle hydrodynamics simulations

Abstract: This paper presents splash, a publicly available interactive visualisation tool for Smoothed Particle Hydrodynamics (SPH) simulations. Visualisation of SPH data is more complicated than for grid-based codes because the data are defined on a set of irregular points and therefore requires a mapping procedure to a two dimensional pixel array. This means that, in practise, many authors simply produce particle plots which offer a rather crude representation of the simulation output. Here we describe the techniques and algorithms which are utilised in splash in order to provide the user with a fast, interactive and meaningful visualisation of one, two and three dimensional SPH results.

Agency and learning in the lifecourse: Towards an ecological perspective

Abstract: This paper is a contribution to understanding the relationship between agency and learning in the lifecourse. The contribution is mainly of a theoretical and a conceptual nature in that a particular notion of agency is used that enables agency to be conceived as something that is achieved, rather than possessed, through the active engagement of individuals with aspects of their contexts-for-action. We refer to this as an ecological understanding of agency. On the part of the actor, such engagements are characterised by particular configurations of routine, purpose and judgement. The argument is made that learning about the particular composition of one's agentic orientations and how they play out in one's life can play an important role in the achievement of agency, and that life-narratives, stories about one's life, can be an important vehicle for such learning. We explore the potential of this approach through a discussion of aspects of the learning (auto-) biographies of two participants in the...

The Glass Cliff: Exploring the Dynamics Surrounding the Appointment of Women to Precarious Leadership Positions

Abstract: In this paper we explore the “glass cliff” form of discrimination. We review archival and experimental evidence of the glass cliff and identify multiple processes as having the potential to contribute to the phenomenon. We also outline a range of potential reactions to the phenomenon, and we elaborate strategies for eliminating glass cliffs, but, as with other forms of (gender) discrimination, we argue that these depend on the capacity for disadvantaged groups to overcome resistance on the part of those who are motivated to maintain the status quo.

The Other-Race Effect Develops During Infancy Evidence of Perceptual Narrowing

Abstract: Experience plays a crucial role in the development of face processing In the study reported here, we investigated how faces observed within the visual environment affect the development of the face-processing system during the 1st year of life We assessed 3-, 6-, and 9-month-old Caucasian infants' ability to discriminate faces within their own racial group and within three other-race groups (African, Middle Eastern, and Chinese) The 3-month-old infants demonstrated recognition in all conditions, the 6-month-old infants were able to recognize Caucasian and Chinese faces only, and the 9-month-old infants' recognition was restricted to own-race faces The pattern of preferences indicates that the other-race effect is emerging by 6 months of age and is present at 9 months of age The findings suggest that facial input from the infant's visual environment is crucial for shaping the face-processing system early in infancy, resulting in differential recognition accuracy for faces of different races in adulthood

Genome–wide association studies provide new insights into type 2 diabetes aetiology

Abstract: Human geneticists are currently in the middle of a race. Thanks to a new technology in the form of 'genome-wide chips', investigators can potentially find many novel disease genes in one large experiment. Type 2 diabetes has been hot out of the blocks with six recent publications that together provide convincing evidence for six new gene regions involved in the condition. Together with candidate approaches, these studies have identified 11 confirmed genomic regions that alter the risk of type 2 diabetes in the European population. One of these regions, the fat mass and obesity associated gene (FTO), represents by far the best example of an association between common variation and fat mass in the general population.

Projected increase in continental runoff due to plant responses to increasing carbon dioxide

Abstract: An assessment of the contribution of plant physiological effects to future changes in continental water runoff suggests that flooding risk under future global warming scenarios may be greater than was assumed. The stomatal pores that allow CO2 to enter plants and water to escape open less widely when CO2 concentrations are high, reducing water loss from the plant and thus leaving more water at the land surface. This effect may have contributed to the increase in continental runoff observed during the twentieth century, but most predictions of future changes in runoff don't account for it. The concept of 'CO2 equivalent', widely used to compare the effects of greenhouse gases on climate, does not account for this effect, so it may need to be revisited in light of these findings. An ensemble of experiments is used with a global climate model to assess the contribution of plant 'physiological forcing' to future changes in continental runoff. It is found that the effect increases simulated global mean runoff by 6 per cent when the concentration of carbon dioxide is doubled relative to pre-industrial levels; an increase that is comparable to that simulated in response to climate change caused by radiative forcing. This finding suggests that the risk of flooding may be greater than previously assumed under future global warming scenarios. In addition to influencing climatic conditions directly through radiative forcing, increasing carbon dioxide concentration influences the climate system through its effects on plant physiology1. Plant stomata generally open less widely under increased carbon dioxide concentration2, which reduces transpiration1,3,4,5,6 and thus leaves more water at the land surface7. This driver of change in the climate system, which we term ‘physiological forcing’, has been detected in observational records of increasing average continental runoff over the twentieth century8. Here we use an ensemble of experiments with a global climate model that includes a vegetation component to assess the contribution of physiological forcing to future changes in continental runoff, in the context of uncertainties in future precipitation. We find that the physiological effect of doubled carbon dioxide concentrations on plant transpiration increases simulated global mean runoff by 6 per cent relative to pre-industrial levels; an increase that is comparable to that simulated in response to radiatively forced climate change (11 ± 6 per cent). Assessments of the effect of increasing carbon dioxide concentrations on the hydrological cycle that only consider radiative forcing9,10,11 will therefore tend to underestimate future increases in runoff and overestimate decreases. This suggests that freshwater resources may be less limited than previously assumed under scenarios of future global warming, although there is still an increased risk of drought. Moreover, our results highlight that the practice of assessing the climate-forcing potential of all greenhouse gases in terms of their radiative forcing potential relative to carbon dioxide does not accurately reflect the relative effects of different greenhouse gases on freshwater resources.

Projected increase in continental runoff due to plant responses to increasing carbon dioxide

Abstract: An assessment of the contribution of plant physiological effects to future changes in continental water runoff suggests that flooding risk under future global warming scenarios may be greater than was assumed. The stomatal pores that allow CO2 to enter plants and water to escape open less widely when CO2 concentrations are high, reducing water loss from the plant and thus leaving more water at the land surface. This effect may have contributed to the increase in continental runoff observed during the twentieth century, but most predictions of future changes in runoff don't account for it. The concept of 'CO2 equivalent', widely used to compare the effects of greenhouse gases on climate, does not account for this effect, so it may need to be revisited in light of these findings. An ensemble of experiments is used with a global climate model to assess the contribution of plant 'physiological forcing' to future changes in continental runoff. It is found that the effect increases simulated global mean runoff by 6 per cent when the concentration of carbon dioxide is doubled relative to pre-industrial levels; an increase that is comparable to that simulated in response to climate change caused by radiative forcing. This finding suggests that the risk of flooding may be greater than previously assumed under future global warming scenarios. In addition to influencing climatic conditions directly through radiative forcing, increasing carbon dioxide concentration influences the climate system through its effects on plant physiology1. Plant stomata generally open less widely under increased carbon dioxide concentration2, which reduces transpiration1,3,4,5,6 and thus leaves more water at the land surface7. This driver of change in the climate system, which we term ‘physiological forcing’, has been detected in observational records of increasing average continental runoff over the twentieth century8. Here we use an ensemble of experiments with a global climate model that includes a vegetation component to assess the contribution of physiological forcing to future changes in continental runoff, in the context of uncertainties in future precipitation. We find that the physiological effect of doubled carbon dioxide concentrations on plant transpiration increases simulated global mean runoff by 6 per cent relative to pre-industrial levels; an increase that is comparable to that simulated in response to radiatively forced climate change (11 ± 6 per cent). Assessments of the effect of increasing carbon dioxide concentrations on the hydrological cycle that only consider radiative forcing9,10,11 will therefore tend to underestimate future increases in runoff and overestimate decreases. This suggests that freshwater resources may be less limited than previously assumed under scenarios of future global warming, although there is still an increased risk of drought. Moreover, our results highlight that the practice of assessing the climate-forcing potential of all greenhouse gases in terms of their radiative forcing potential relative to carbon dioxide does not accurately reflect the relative effects of different greenhouse gases on freshwater resources.

Pseudomonas syringae pv. tomato hijacks the Arabidopsis abscisic acid signalling pathway to cause disease

Abstract: We have found that a major target for effectors secreted by Pseudomonas syringae is the abscisic acid (ABA) signalling pathway. Microarray data identified a prominent group of effector-induced genes that were associated with ABA biosynthesis and also responses to this plant hormone. Genes upregulated by effector delivery share a 42% overlap with ABA-responsive genes and are also components of networks induced by osmotic stress and drought. Strongly induced were NCED3, encoding a key enzyme of ABA biosynthesis, and the abscisic acid insensitive 1 (ABI1) clade of genes encoding protein phosphatases type 2C (PP2Cs) involved in the regulation of ABA signalling. Modification of PP2C expression resulting in ABA insensitivity or hypersensitivity led to restriction or enhanced multiplication of bacteria, respectively. Levels of ABA increased rapidly during bacterial colonisation. Exogenous ABA application enhanced susceptibility, whereas colonisation was reduced in an ABA biosynthetic mutant. Expression of the bacterial effector AvrPtoB in planta modified host ABA signalling. Our data suggest that a major virulence strategy is effector-mediated manipulation of plant hormone homeostasis, which leads to the suppression of defence responses.

Social Identity, Organizational Identity and Corporate Identity: Towards an Integrated Understanding of Processes, Patternings and Products

Abstract: This paper provides an overview of previous work that has explored issues of social, organizational and corporate identity. Differences in the form and focus of research into these three topics are noted. Social identity work generally examines issues of cognitive process and structure; organizational identity research tends to address the patterning of shared meanings; studies of corporate identity tend to focus on products that communicate a specific image. Nonetheless, across these areas there is general consensus that collective identities are (a) made viable by their positivity and distinctiveness, (b) fluid, (c) a basis for shared perceptions and action, (d) strategically created and managed, (e) qualitatively different from individual identities and (f) the basis for material outcomes and products. This paper calls for greater cross-fertilization of the three identity literatures and discusses requirements for the integration of micro- and macro-level analyses.

The ingestible telemetric body core temperature sensor: a review of validity and exercise applications

Abstract: An ingestible telemetric temperature sensor for measuring body core temperature (Tc) was first described 45 years ago, although the method has only recently gained widespread use for exercise applications. This review aims to (1) use Bland and Altman's limits of agreement (LoA) method as a basis for quantitatively reviewing the agreement between intestinal sensor temperature (Tintestinal), oesophageal temperature (Toesophageal) and rectal temperature (Trectal) across numerous previously published validation studies; (2) review factors that may affect agreement; and (3) review the application of this technology in field-based exercise studies. The agreement between Tintestinal and Toesophageal is suggested to meet our delimitation for an acceptable level of agreement (ie, systematic bias 0.1 degrees C, although the 95% LoA is acceptable. Tintestinal responds less rapidly than Toesophageal at the start or cessation of exercise or to a change in exercise intensity, but more rapidly than Trectal. When using this technology, care should be taken to ensure adequate control over sensor calibration and data correction, timing of ingestion and electromagnetic interference. The ingestible sensor has been applied successfully in numerous sport and occupational applications such as the continuous measurement of Tc in deep sea saturation divers, distance runners and soldiers undertaking sustained military training exercises. It is concluded that the ingestible telemetric temperature sensor represents a valid index of Tc and shows excellent utility for ambulatory field-based applications.

Analysing the determinants of narrative risk information in UK FTSE 100 annual reports

Abstract: We investigate the relationship between the quantity of narrative risk information in corporate annual reports and ownership, governance, and US listing characteristics. We find that corporate risk reporting is negatively related to share ownership by long-term institutions, and thus the results of this study put forth that this important class of institutional investor has investment preferences for firms with a lower level of risk disclosure. Concerning governance, we find that different types of board director fulfil different functions, with both the number of executive and the number of independent directors positively related to the level of corporate risk reporting, but not the number of dependent non-executive directors. This supports a recent emphasis in the UK on the independent aspects of non-executive directors for good corporate governance. Separate investigation of business, financial, and internal control aspects of risk reporting that correspond to the three classes of risk-reporting guidance in the UK reveals that the pattern of risk information in the annual report may be dependent upon the form that reporting regulation takes.

Arabidopsis systemic immunity uses conserved defense signaling pathways and is mediated by jasmonates

Abstract: In the absence of adaptive immunity displayed by animals, plants respond locally to biotic challenge via inducible basal defense networks activated through recognition and response to conserved pathogen-associated molecular patterns. In addition, immunity can be induced in tissues remote from infection sites by systemic acquired resistance (SAR), initiated after gene-for-gene recognition between plant resistance proteins and microbial effectors. The nature of the mobile signal and remotely activated networks responsible for establishing SAR remain unclear. Salicylic acid (SA) participates in the local and systemic response, but SAR does not require long-distance translocation of SA. Here, we show that, despite the absence of pathogen-associated molecular pattern contact, systemically responding leaves rapidly activate a SAR transcriptional signature with strong similarity to local basal defense. We present several lines of evidence that suggest jasmonates are central to systemic defense, possibly acting as the initiating signal for classic SAR. Jasmonic acid (JA), but not SA, rapidly accumulates in phloem exudates of leaves challenged with an avirulent strain of Pseudomonas syringae. In systemically responding leaves, transcripts associated with jasmonate biosynthesis are up-regulated within 4 h, and JA increases transiently. SAR can be mimicked by foliar JA application and is abrogated in mutants impaired in jasmonate synthesis or response. We conclude that jasmonate signaling appears to mediate long-distance information transmission. Moreover, the systemic transcriptional response shares extraordinary overlap with local herbivory and wounding responses, indicating that jasmonates may be pivotal to an evolutionarily conserved signaling network that decodes multiple abiotic and biotic stress signals.

Reduced specificity of autobiographical memory and depression: the role of executive control.

Abstract: It has been widely established that depressed mood states and clinical depression, as well as a range of other psychiatric disorders, are associated with a relative difficulty in accessing specific autobiographical information in response to emotion-related cue words on an Autobiographical Memory Test (AMT; J. M. G. Williams & K. Broadbent, 1986). In 8 studies the authors examined the extent to which this relationship is a function of impaired executive control associated with these mood states and clinical disorders. Studies 1–4 demonstrated that performance on the AMT is associated with performance on measures of executive control, independent of depressed mood. Furthermore, Study 1 showed that executive control (as measured by verbal fluency) mediated the relationship between both depressed mood and a clinical diagnosis of eating disorder and AMT performance. Using a stratified sample in Study 5, the authors confirmed the positive association between depressed mood and impaired performance on the AMT. Studies 6–8 involved experimental manipulations of the parameters of the AMT designed to further indicate that reduced executive control is to a significant extent driving the relationship between depressed mood and AMT performance. The potential role of executive control in accounting for other aspects of the AMT literature is discussed.

Electrochromism and Electrochromic Devices

Abstract: Electrochromic materials, both organic and inorganic, have widespread applications in light-attenuation, displays and analysis. Written in an accessible manner, this book provides a comprehensive treatment of all types of electrochromic systems and their many applications. Coverage develops from electrochromic scope and history to new searching presentations of optical quantification and theoretical mechanistic models. Non-electrode electrochromism and photo-electrochromism are summarised, with updated comprehensive reviews of electrochromic oxides (tungsten-trioxide particularly), metal co-ordination complexes and metal-cyanometallates, viologens and other organics; and more recent exotics such as fullerenes, hydrides, and conjugated electroactive polymers are also covered. The book concludes by examining device construction and durability. With an extensive bibliography, recent advances in the field, modern applications and a step-by-step development from simple examples to sophisticated theories, this book is ideal for researchers in materials science, polymer science, electrical engineering, physics, chemistry, bioscience and (applied) optoelectronics.

Desiccation-tolerance in bryophytes: a review

Abstract: Desiccation-tolerance (DT), the ability to lose virtually all free intracellular water and then recover normal function upon rehydration, is one of the most remarkable features of bryophytes. The physiology of bryophytes differs in major respects from that of vascular plants by virtue of their smaller size; unlike vascular plants, the leafy shoots of bryophytes equilibrate rapidly with the water potential in their surroundings and tend to be either fully hydrated or desiccated and metabolically inactive. The time required to recover from desiccation increases and degree of recovery decreases with length of desiccation; both also depend upon temperature and intensity of desiccation. Tolerance in at least some species shows phenotypic plasticity. Recovery of respiration, photosynthesis and protein synthesis takes place within minutes or an hour or two; recovery of the cell cycle, food transport and the cytoskeleton may take 24 hours or more. Positive carbon balance is essential to survival of repea...

Trophic cascade facilitates coral recruitment in a marine reserve

Abstract: Reduced fishing pressure and weak predator–prey interactions within marine reserves can create trophic cascades that increase the number of grazing fishes and reduce the coverage of macroalgae on coral reefs. Here, we show that the impacts of reserves extend beyond trophic cascades and enhance the process of coral recruitment. Increased fish grazing, primarily driven by reduced fishing, was strongly negatively correlated with macroalgal cover and resulted in a 2-fold increase in the density of coral recruits within a Bahamian reef system. Our conclusions are robust because four alternative hypotheses that may generate a spurious correlation between grazing and coral recruitment were tested and rejected. Grazing appears to influence the density and community structure of coral recruits, but no detectable influence was found on the overall size-frequency distribution, community structure, or cover of corals. We interpret this absence of pattern in the adult coral community as symptomatic of the impact of a recent disturbance event that masks the recovery trajectories of individual reefs. Marine reserves are not a panacea for conservation but can facilitate the recovery of corals from disturbance and may help sustain the biodiversity of organisms that depend on a complex three-dimensional coral habitat.

Two genes in Arabidopsis thaliana encoding GDP-L-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability.

Abstract: Summary Plants synthesize ascorbate from guanosine diphosphate (GDP)-mannose via l-galactose/l-gulose, although uronic acids have also been proposed as precursors. Genes encoding all the enzymes of the GDP-mannose pathway have previously been identified, with the exception of the step that converts GDP-l-galactose to l-galactose 1-P. We show that a GDP-l-galactose phosphorylase, encoded by the Arabidopsis thaliana VTC2 gene, catalyses this step in the ascorbate biosynthetic pathway. Furthermore, a homologue of VTC2, At5g55120, encodes a second GDP-l-galactose phosphorylase with similar properties to VTC2. Two At5g55120 T-DNA insertion mutants (vtc5-1 and vtc5-2) have 80% of the wild-type ascorbate level. Double mutants were produced by crossing the loss-of-function vtc2-1 mutant with each of the two vtc5 alleles. These show growth arrest immediately upon germination and the cotyledons subsequently bleach. Normal growth was restored by supplementation with ascorbate or l-galactose, indicating that both enzymes are necessary for ascorbate generation. vtc2-1 leaves contain more mannose 6-P than wild-type. We conclude that the GDP-mannose pathway is the only significant source of ascorbate in A. thaliana seedlings, and that ascorbate is essential for seedling growth. A. thaliana leaves accumulate more ascorbate after acclimatization to high light intensity. VTC2 expression and GDP-l-galactose phosphorylase activity rapidly increase on transfer to high light, but the activity of other enzymes in the GDP-mannose pathway is little affected. VTC2 and At5g55120 (VTC5) expression also peak in at the beginning of the light cycle and are controlled by the circadian clock. The GDP-l-galactose phosphorylase step may therefore play an important role in controlling ascorbate biosynthesis.

Retinotopic mapping of adult human visual cortex with high-density diffuse optical tomography

Abstract: Functional neuroimaging is a vital element of neuroscience and cognitive research and, increasingly, is an important clinical tool. Diffuse optical imaging is an emerging, noninvasive technique with unique portability and hemodynamic contrast capabilities for mapping brain function in young subjects and subjects in enriched or clinical environments. We have developed a high-performance, high-density diffuse optical tomography (DOT) system that overcomes previous limitations and enables superior image quality. We show herein the utility of the DOT system by presenting functional hemodynamic maps of the adult human visual cortex. The functional brain images have a high contrast-to-noise ratio, allowing visualization of individual activations and highly repeatable mapping within and across subjects. With the improved spatial resolution and localization, we were able to image functional responses of 1.7 cm in extent and shifts of <1 cm. Cortical maps of angle and eccentricity in the visual field are consistent with retinotopic studies using functional MRI and positron-emission tomography. These results demonstrate that high-density DOT is a practical and powerful tool for mapping function in the human cortex.