bluuebunny/crossref_metadata_2025 huggingface dataset:
What can cities do to increase resilience?
Authors: Crichton David
Published: August 2007

This paper examines climate change mitigation and adaptation from an insurance industry perspective, with particular reference to London and the USA. It illustrates how British insurers are increasingly shaping public policy and using new technology to manage the risks from climate change impacts and makes a plea for society to make more use of insurance expertise in future decision making. In particular, more dialogue is needed between architects, planners and insurers to adapt our buildings and cities for climate change impacts. The paper is an abbreviated and updated version of the paper presented by the author in Houston, Texas, in 2005.
Heightened tropical cyclone activity in the North Atlantic: natural variability or climate trend?
Authors: Holland Greg J , Webster Peter J
Published: August 2007

We find that long-period variations in tropical cyclone and hurricane frequency over the past century in the North Atlantic Ocean have occurred as three relatively stable regimes separated by sharp transitions. Each regime has seen 50% more cyclones and hurricanes than the previous regime and is associated with a distinct range of sea surface temperatures (SSTs) in the eastern Atlantic Ocean. Overall, there appears to have been a substantial 100-year trend leading to related increases of over 0.7°C in SST and over 100% in tropical cyclone and hurricane numbers. It is concluded that the overall trend in SSTs, and tropical cyclone and hurricane numbers is substantially influenced by greenhouse warming. Superimposed on the evolving tropical cyclone and hurricane climatology is a completely independent oscillation manifested in the proportions of tropical cyclones that become major and minor hurricanes. This characteristic has no distinguishable net trend and appears to be associated with concomitant variations in the proportion of equatorial and higher latitude hurricane developments, perhaps arising from internal oscillations of the climate system. The period of enhanced major hurricane activity during 1945–1964 is consistent with a peak period in major hurricane proportions.
The Met Office Hadley Centre climate modelling capability: the competing requirements for improved resolution, complexity and dealing with uncertainty
Authors: Pope V , Brown S , Clark R , Collins M , Collins W , Dearden C , Gunson J , Harris G , Jones C , Keen A , Lowe J , Ringer M , Senior C , Sitch S , Webb M , Woodward S
Published: August 2007

Predictions of future climate change require complex computer models of the climate system to represent the full range of processes and interactions that influence climate. The Met Office Hadley Centre uses ‘families’ of models as part of the Met Office Unified Model Framework to address different classes of problems. The HadGEM family is a suite of state-of-the-art global environment models that are used to reduce uncertainty and represent and predict complex feedbacks. The HadCM3 family is a suite of well established but cheaper models that are used for multiple simulations, for example, to quantify uncertainty or to test the impact of multiple emissions scenarios.
Estimating the potential for twenty-first century sudden climate change
Authors: Shindell Drew
Published: August 2007

I investigate the potential for sudden climate change during the current century. This investigation takes into account evidence from the Earth's history, from climate models and our understanding of the physical processes governing climate shifts. Sudden alterations to climate forcing seem to be improbable, with sudden changes instead most likely to arise from climate feedbacks. Based on projections from models validated against historical events, dramatic changes in ocean circulation appear unlikely. Ecosystem–climate feedbacks clearly have the potential to induce sudden change, but are relatively poorly understood at present. More probable sudden changes are large increases in the frequency of summer heatwaves and changes resulting from feedbacks involving hydrology. These include ice sheet decay, which may be set in motion this century. The most devastating consequences are likely to occur further in the future, however. Reductions in subtropical precipitation are likely to be the most severe hydrologic effects this century, with rapid changes due to the feedbacks of relatively well-understood large-scale circulation patterns. Water stress may become particularly acute in the Southwest US and Mexico, and in the Mediterranean and Middle East, where rainfall decreases of 10–25% (regionally) and up to 40% (locally) are projected.
The criticality hypothesis: how local cortical networks might optimize information processing
Authors: Beggs John M
Published: August 2007

Early theoretical and simulation work independently undertaken by Packard, Langton and Kauffman suggested that adaptability and computational power would be optimized in systems at the ‘edge of chaos’, at a critical point in a phase transition between total randomness and boring order. This provocative hypothesis has received much attention, but biological experiments supporting it have been relatively few. Here, we review recent experiments on networks of cortical neurons, showing that they appear to be operating near the critical point. Simulation studies capture the main features of these data and suggest that criticality may allow cortical networks to optimize information processing. These simulations lead to predictions that could be tested in the near future, possibly providing further experimental evidence for the criticality hypothesis.
Coherence resonance in a chemical excitable system driven by coloured noise
Authors: Beato Valentina , Sendiña-Nadal Irene , Gerdes Ingeborg , Engel Harald
Published: August 2007

We investigate how the temporal correlation in excitable systems driven by external noise affects the coherence of the system's response. The coupling to the fluctuating environment is introduced via fluctuations of a bifurcation parameter that controls the local dynamics of the light-sensitive Belousov–Zhabotinsky reaction and of its numerical description, the Oregonator model. Both systems are brought from a highly incoherent regime to a coherent one by an appropriate choice of the correlation time and keeping noise variance constant. This effect has been found both for an Ornstein–Uhlenbeck process and for a dichotomous telegraph signal. In the latter case, we are able to connect the optimal correlation time, for which the system behaviour is most coherent, with a characteristic time scale of the system.
Macro-instability: a chaotic flow component in stirred tanks
Authors: Hasal Pavel , Jahoda Milan , Fořt Ivan
Published: August 2007

Chaotic features of the macro-instability (MI) of flow patterns in stirred tanks are studied in this paper. Datasets obtained by measuring the axial component of the fluid velocity and the tangential force affecting the baffles are used. Two geometrically identical, flat-bottomed cylindrical mixing tanks (diameter of 0.3 m) stirred with either pitched blade turbine impellers or Rushton turbine impeller are used in the experiments, and water and aqueous glycerol solutions are used as the working liquids. First, the presence of the MI component in the data is examined by spectral analysis. Then, the MI components are identified in the data using the proper orthogonal decomposition (POD) technique. The attractors of the macro-instability are reconstructed using either the POD eigenmodes or a method of delays and finally the attractor invariants are evaluated. The dependence of the correlation dimension and maximum Lyapunov exponent on the vessel operational conditions is determined together with their distribution within the tank. No significant spatial variability of the correlation dimension value is observed. Its value is strongly influenced by impeller speed and by the vessel–impeller geometry. More profound spatial distribution is displayed by the maximum Lyapunov exponent taking distinctly positive values. These two invariants, therefore, can be used to locate distinctive regions with qualitatively different MI dynamics within the stirred tank.
Experimental evidence of phase coherence of magnetohydrodynamic turbulence in the solar wind: GEOTAIL satellite data
Authors: Koga D , Chian A.C.-L , Hada T , Rempel E.L
Published: August 2007

Magnetohydrodynamic (MHD) turbulence is commonly observed in the solar wind. Nonlinear interactions among MHD waves are likely to produce finite correlation of the wave phases. For discussions of various transport processes of energetic particles, it is fundamentally important to determine whether the wave phases are randomly distributed (as assumed in the quasi-linear theory) or have a finite coherence. Using a method based on the surrogate data technique, we analysed the GEOTAIL magnetic field data to evaluate the phase coherence in MHD turbulence in the Earth's foreshock region. The results demonstrate the existence of finite phase correlation, indicating that nonlinear wave–wave interactions are in progress.
Optimal moult strategies in migratory birds
Authors: Barta Zoltán , McNamara John M , Houston Alasdair I , Weber Thomas P , Hedenström Anders , Feró Orsolya
Published: August 2007

Avian migration, which involves billions of birds flying vast distances, is known to influence all aspects of avian life. Here we investigate how birds fit moult into an annual cycle determined by the need to migrate. Large variation exists in moulting patterns in relation to migration: for instance, moult can occur after breeding in the summer or after arrival in the wintering quarters. Here we use an optimal annual routine model to investigate why this variation exists. The modelled bird's decisions depend on the time of year, its energy reserves, breeding status, experience, flight feather quality and location. Our results suggest that the temporal and spatial variations in food are an important influence on a migratory bird's annual cycle. Summer moult occurs when food has a high peak on the breeding site in the summer, but it is less seasonal elsewhere. Winter moult occurs if there is a short period of high food availability in summer and a strong winter peak at different locations (i.e. the food is very seasonal but in opposite phase on these areas). This finding might explain why only long-distance migrants have a winter moult.
The physiological costs of reproduction in small mammals
Authors: Speakman John R
Published: August 2007

Life-history trade-offs between components of fitness arise because reproduction entails both gains and costs. Costs of reproduction can be divided into ecological and physiological costs. The latter have been rarely studied yet are probably a dominant component of the effect. A deeper understanding of life-history evolution will only come about once these physiological costs are better understood. Physiological costs may be direct or indirect. Direct costs include the energy and nutrient demands of the reproductive event, and the morphological changes that are necessary to facilitate achieving these demands. Indirect costs may be optional ‘compensatory costs’ whereby the animal chooses to reduce investment in some other aspect of its physiology to maximize the input of resource to reproduction. Such costs may be distinguished from consequential costs that are an inescapable consequence of the reproductive event. In small mammals, the direct costs of reproduction involve increased energy, protein and calcium demands during pregnancy, but most particularly during lactation. Organ remodelling is necessary to achieve the high demands of lactation and involves growth of the alimentary tract and associated organs such as the liver and pancreas. Compensatory indirect costs include reductions in thermogenesis, immune function and physical activity. Obligatory consequential costs include hyperthermia, bone loss, disruption of sleep patterns and oxidative stress. This is unlikely to be a complete list. Our knowledge of these physiological costs is currently at best described as rudimentary. For some, we do not even know whether they are compensatory or obligatory. For almost all of them, we have no idea of exact mechanisms or how these costs translate into fitness trade-offs.
The timing of birds' breeding seasons: a review of experiments that manipulated timing of breeding
Authors: Verhulst Simon , Nilsson Jan-Åke
Published: August 2007

Reproductive success usually declines in the course of the season, which may be a direct effect of breeding time, an effect of quality (individuals with high phenotypic or environmental quality breeding early), or a combination of the two. Being able to distinguish between these possibilities is crucial when trying to understand individual variation in annual routines, for instance when to breed, moult and migrate. We review experiments with free-living birds performed to distinguish between the ‘timing’ and ‘quality’ hypothesis. ‘Clean’ manipulation of breeding time seems impossible, and we therefore discuss strong and weak points of different manipulation techniques. We find that the qualitative results were independent of manipulation technique (inducing replacement clutches versus cross-fostering early and late clutches). Given that the two techniques differ strongly in demands made on the birds, this suggests that potential experimental biases are limited. Overall, the evidence indicated that date and quality are both important, depending on fitness component and species, although evidence for the date hypothesis was found more frequently. We expected both effects to be prevalent, since only if date
per se
is important, does an incentive exist for high-quality birds to breed early. We discuss mechanisms mediating the seasonal decline in reproductive success, and distinguish between effects of absolute date and relative date, for instance timing relative to seasonal environmental fluctuations or conspecifics. The latter is important at least in some cases, suggesting that the optimal breeding time may be frequency dependent, but this has been little studied. A recurring pattern among cross-fostering studies was that delay experiments provided evidence for the quality hypothesis, while advance experiments provided evidence for the date hypothesis. This indicates that late pairs are constrained from producing a clutch earlier in the season, presumably by the fitness costs this would entail. This provides us with a paradox: evidence for the date hypothesis leads us to conclude that quality is important for the ability to breed early.
Shrink and share: humanity's present and future Ecological Footprint
Authors: Kitzes Justin , Wackernagel Mathis , Loh Jonathan , Peller Audrey , Goldfinger Steven , Cheng Deborah , Tea Kallin
Published: August 2007

Sustainability is the possibility of all people living rewarding lives within the means of nature. Despite ample recognition of the importance of achieving sustainable development, exemplified by the Rio Declaration of 1992 and the United Nations Millennium Development Goals, the global economy fails to meet the most fundamental minimum condition for sustainability—that human demand for ecosystem goods and services remains within the biosphere's total capacity. In 2002, humanity operated in a state of overshoot, demanding over 20% more biological capacity than the Earth's ecosystems could regenerate in that year. Using the Ecological Footprint as an accounting tool, we propose and discuss three possible global scenarios for the future of human demand and ecosystem supply. Bringing humanity out of overshoot and onto a potentially sustainable path will require managing the consumption of food, fibre and energy, and maintaining or increasing the productivity of natural and agricultural ecosystems.
Drivers of change in global agriculture
Authors: Hazell Peter , Wood Stanley
Published: August 2007

As a result of agricultural intensification, more food is produced today than needed to feed the entire world population and at prices that have never been so low. Yet despite this success and the impact of globalization and increasing world trade in agriculture, there remain large, persistent and, in some cases, worsening spatial differences in the ability of societies to both feed themselves and protect the long-term productive capacity of their natural resources. This paper explores these differences and develops a country×farming systems typology for exploring the linkages between human needs, agriculture and the environment, and for assessing options for addressing future food security, land use and ecosystem service challenges facing different societies around the world.
An engineering approach to modelling, decision support and control for sustainable systems
Authors: Day W , Audsley E , Frost A.R
Published: August 2007

Engineering research and development contributes to the advance of sustainable agriculture both through innovative methods to manage and control processes, and through quantitative understanding of the operation of practical agricultural systems using decision models. This paper describes how an engineering approach, drawing on mathematical models of systems and processes, contributes new methods that support decision making at all levels from strategy and planning to tactics and real-time control. The ability to describe the system or process by a simple and robust mathematical model is critical, and the outputs range from guidance to policy makers on strategic decisions relating to land use, through intelligent decision support to farmers and on to real-time engineering control of specific processes. Precision in decision making leads to decreased use of inputs, less environmental emissions and enhanced profitability—all essential to sustainable systems.
Precision animal breeding
Authors: Flint A.P.F , Woolliams J.A
Published: August 2007

We accept that we are responsible for the quality of life of animals in our care. We accept that the activities of man affect all the living things with which we share this planet. But we are slow to realize that as a result we have a duty of care for all living things. That duty extends to the breeding of animals for which we are responsible. When animals are bred by man for a purpose, the aim should be to meet certain goals: to improve the precision with which breeding outcomes can be predicted; to avoid the introduction and advance of characteristics deleterious to well-being; and to manage genetic resources and diversity between and within populations as set out in the Convention on Biological Diversity. These goals are summed up in the phrase precision animal breeding. They should apply whether animals are bred as sources of usable products or services for medical or scientific research, for aesthetic or cultural considerations, or as pets. Modern molecular and quantitative genetics and advances in reproductive physiology provide the tools with which these goals can be met.
Integrated pest management: the push–pull approach for controlling insect pests and weeds of cereals, and its potential for other agricultural systems including animal husbandry
Authors: Hassanali Ahmed , Herren Hans , Khan Zeyaur R , Pickett John A , Woodcock Christine M
Published: August 2007

This paper describes the ‘push–pull’ or ‘stimulo-deterrent diversionary’ strategy in relation to current and potential examples from our own experiences. The push–pull effect is established by exploiting semiochemicals to repel insect pests from the crop (‘push’) and to attract them into trap crops (‘pull’). The systems exemplified here have been developed for subsistence farming in Africa and delivery of the semiochemicals is entirely by companion cropping, i.e. intercropping for the push and trap cropping for the pull. The main target was a series of lepidopterous pests attacking maize and other cereals. Although the area given to the cereal crop itself is reduced under the push–pull system, higher yields are produced per unit area. An important spin-off from the project is that the companion crops are valuable forage for farm animals. Leguminous intercrops also provide advantages with regard to plant nutrition and some of the trap crops help with water retention and in reducing land erosion. A major benefit is that certain intercrop plants provide dramatic control of the African witchweed (striga). Animal husbandry forms an essential part of intensive subsistence agriculture in Africa and developments using analogous push–pull control strategies for insect pests of cattle are exemplified.
Improving water use in crop production
Authors: Morison J.I.L , Baker N.R , Mullineaux P.M , Davies W.J
Published: August 2007

Globally, agriculture accounts for 80–90% of all freshwater used by humans, and most of that is in crop production. In many areas, this water use is unsustainable; water supplies are also under pressure from other users and are being affected by climate change. Much effort is being made to reduce water use by crops and produce ‘more crop per drop’. This paper examines water use by crops, taking particularly a physiological viewpoint, examining the underlying relationships between carbon uptake, growth and water loss. Key examples of recent progress in both assessing and improving crop water productivity are described. It is clear that improvements in both agronomic and physiological understanding have led to recent increases in water productivity in some crops. We believe that there is substantial potential for further improvements owing to the progress in understanding the physiological responses of plants to water supply, and there is considerable promise within the latest molecular genetic approaches, if linked to the appropriate environmental physiology. We conclude that the interactions between plant and environment require a team approach looking across the disciplines from genes to plants to crops in their particular environments to deliver improved water productivity and contribute to sustainability.
Water pollution by agriculture
Authors: Moss Brian
Published: August 2007

Agriculture disrupts all freshwater systems hugely from their pristine states. The former reductionist concept of pollution was of examining individual effects of particular substances on individual taxa or sub-communities in freshwater systems, an essentially ecotoxicological concept. It is now less useful than a more holistic approach that treats the impacts on the system as a whole and includes physical impacts such as drainage and physical modification of river channels and modification of the catchment as well as nutrient, particulate and biocide pollution. The European Water Framework Directive implicitly recognizes this in requiring restoration of water bodies to ‘good ecological quality’, which is defined as only slightly different from pristine state. The implications for the management of agriculture are far more profound than is currently widely realized.
Homology as a parsimony problem: a dynamic homology approach for morphological data
Authors: Ramírez Martín J.
Published: August 2007

The primary data used to reconstruct phylogenies comes organized in the conceptual grid of homology correspondences, and the construction of this theory‐rich grid depends in part on knowledge of relationships. This situation is not satisfactory as a conceptual system, because the evidence is not clearly delimited from the results. I explore the testing of alternative hypotheses of morphological correspondences in a quantitative cladistic context. The varying homology assessments implied by classical criteria of homology (topological equivalence, or position and connections; composition of structures, or commonality in details of construction) can be expressed as regular characters in a cladistic analysis. Doing so provides adequate transformation costs for changes in schemas of correspondences. Correspondences imply evolutionary transformations, and multiple schemas of correspondences can be compared according to the evolutionary transformations that they imply. The method is used to test the correspondences in sclerites of the male copulatory organs of spiders of the subfamily Amaurobioidinae (Arachnida, Araneae, Anyphaenidae). The correspondences of three sclerites are tested, in a data set of 93 species having one, two or three sclerites, using a simultaneous analysis of all the morphological characters. Most parsimonious trees are identified together with the correspondences they imply. Once the correspondences are integrated in the phylogenetic analysis, it is easy to evaluate the robustness of trees or decay in optimality after changes in anatomical interpretations. A Bremer support for anatomical interpretations is proposed, calculated as the increase in tree length when the specific interpretation is not used.

© The Willi Hennig Society 2007.
Population genetic structure of Plasmopara viticola in the Western Cape Province of South Africa
Authors: KOOPMAN TREVOR , LINDE CELESTE C. , FOURIE PAUL H. , MCLEOD ADÉLE
Published: August 2007

Plasmopara viticola populations in South Africa were studied for two consecutive grape growing seasons, in an organically managed and a conventional fungicide‐sprayed vineyard. Three to four samplings in each season were genotyped with four microsatellite markers (GOB, CES, ISA and BER). Population differentiation (Fst) between the conventional fungicide‐sprayed vineyard and organically managed vineyard was low (0.004 and 0.016) in both growing seasons, suggesting one metapopulation. However, differences in the relative contribution of the predominant and new genotypes to epidemics in the two vineyards suggested that fungicide applications may have selected for reduced pathogen diversity. In both years and vineyards, sexual (oosporic) reproduction and/or migration occurred throughout the year and contributed between 12 and 74% to the epidemic. Hardy–Weinberg analyses suggest that South African P. viticola populations are randomly mating. Epidemics in both years and vineyards were dominated by one or two genotypes that each contributed between 14 and 67% to the epidemic through asexual reproduction. The remaining genotypes showed low levels of asexual reproduction, with most genotypes never being able to reproduce asexually. However, for some genotypes asexual reproduction was important, as it enabled survival of the genotypes from one season to the next. In total, ten genotypes were able to survive asexually or vegetatively from one season to the next. The populations were further characterized by the presence of a high frequency of isolates that most likely have elevated ploidy levels.
T‐helper type 2‐dependent early recruitment of antigen non‐specific CD4+ T cells in experimental asthma
Authors: Kinyanjui M. W. , Tamaoka M. , Fixman E. D.
Published: August 2007

Background
Following antigen challenge, adoptively transferred antigen‐specific CD4+ T cells induce allergic airway inflammation, comprised primarily of an increase in lymphocytes and eosinophils.

Objective
Our goal was to better understand the contribution of the GATA‐3 transcription factor to the ability of adoptively transferred T cells to induce airway inflammation in the Brown Norway rat model of adoptively transferred asthma.

Methods
We transduced antigen‐stimulated CD4+ T cells with recombinant retroviruses encoding enhanced green fluorescent protein (EGFP) only or EGFP and the GATA‐3 transcription factor. Each population of transduced cells was adoptively transferred to naïve recipients that were then challenged with antigen. Airway inflammatory responses were then quantified.

Results
Our data indicate that T cells transduced with retroviruses encoding GATA‐3 expressed high levels of GATA‐3 protein as well as T‐helper type 2 cytokines. Following adoptive transfer and airway antigen challenge, these gene‐modified T cells induced robust inflammatory responses in the lungs and draining lymph nodes. Increased numbers of total inflammatory cells and eosinophils were recovered in the bronchoalveolar lavage fluid (BALF). In addition, the number of antigen non‐specific CD4+ T cells recovered in the BALF as well as the lung and draining lymph nodes was enhanced in recipients of GATA‐3 overexpressing T cells following antigen challenge. Nevertheless, the transduced CD4+ T cells comprised only a small percentage of the population of CD4+ T cells infiltrating the lung and were not detectable at all in the draining lymph nodes.

Conclusion
These data provide evidence that GATA‐3 plays a significant role in the ability of antigen‐specific T cells to amplify allergic inflammatory responses in vivo by promoting the recruitment of endogenous antigen non‐specific T cells to the lung.
Anti‐androgens increase N‐terminal pro‐BNP levels in men with prostate cancer
Authors: Dockery Frances , Bulpitt Christopher J. , Agarwal Sanjiv , Vernon Clare , Nihoyannopoulos Petros , Kemp Martin , Hooper James , Rajkumar Chakravarthi
Published: August 2007

Objective  The aim of this study was to determine the effects of anti‐androgens on left ventricular (LV) function and levels of N‐terminal proB‐type natriuretic peptide (NT‐proBNP), a sensitive cardiac risk marker, in men with prostate cancer as these are widely used drugs in this condition, and evidence suggests that endogenous androgens are cardioprotective in men.

Design and patients  Forty‐three men (mean age 70·7 ± 6·2 years) with prostate cancer were randomized to goserelin (an LH‐releasing hormone analogue) or bicalutamide (an androgen‐receptor blocker) for 6 months; 20 men with a history of prostate cancer on no treatment were studied in parallel.

Results  Mean changes in testosterone and oestradiol, respectively, from baseline to 6 months were –88% and –46% with goserelin, +50% and +44% with bicalutamide, and –1% and –9% for the ‘no‐treatment’ group. Bicalutamide significantly increased NT‐proBNP from baseline to 3 and 6 months (median value at baseline, 3 and 6 months: 55, 101 and 118 ng/l, respectively). Goserelin caused a significant increase from baseline to 3 months but not to 6 months (median value at baseline, 3 and 6 months: 66, 87 and 72 ng/l, respectively). No significant changes occurred in the ‘no‐treatment’ cohort (median value at baseline 3 and 6 months: 60, 53 and 60 ng/l, respectively). No significant changes in LV function, blood pressure (BP), body mass index or waist–hip ratio occurred to account for the changes in NT‐proBNP.

Conclusion  Androgen receptor blockade and, to a lesser extent, androgen suppression cause an increase in NT‐pro‐BNP in men with prostate cancer. The significance is not clear but could imply an adverse effect on cardiovascular risk following hormonal manipulation.
Louis Agassiz (1807–1873): a passion for fishes
Authors: Duffin Christopher J.
Published: August 2007

This year marks the bicentenary of the birth of Louis Agassiz, a Swiss whose aim was to be the premier naturalist of his time. His father's assessment of him was that he had ‘a mania for rushing full gallop into the future’. His life was marked by the production of grandiose schemes, many of which he had the drive to complete. In addition to his massive ambition, he had a brilliant intellect, charming manner and boundless energy. These qualities often lead to his schemes coming to fruition, occasionally against tremendous odds, although sometimes with great cost to his health and personal relationships.
Chalk and landscape of the South Downs, England
Authors: Nowell David
Published: August 2007

The Upper Cretaceous Chalk hills of the South Downs form the southern flank of the Wealden anticline in south‐east England, with older Wealden and Purbeck sediments exposed at its core. With prominent chalk escarpments on each side of it, this major structure is up to 70 km wide, and extends eastwards for over 200 km from eastern Hampshire to the area around Boulogne‐sur‐Mer in Northern France, dissected by the English Channel.
Influences of species, latitudes and methodologies on estimates of phenological response to global warming
Authors: PARMESAN CAMILLE
Published: August 2007

New analyses are presented addressing the global impacts of recent climate change on phenology of plant and animal species. A meta‐analysis spanning 203 species was conducted on published datasets from the northern hemisphere. Phenological response was examined with respect to two factors: distribution of species across latitudes and taxonomic affiliation or functional grouping of target species. Amphibians had a significantly stronger shift toward earlier breeding than all other taxonomic/functional groups, advancing more than twice as fast as trees, birds and butterflies. In turn, butterfly emergence or migratory arrival showed three times stronger advancement than the first flowering of herbs, perhaps portending increasing asynchrony in insect–plant interactions. Response was significantly stronger at higher latitudes where warming has been stronger, but latitude explained < 4% of the variation. Despite expectation, latitude was not yet an important predictor of climate change impacts on phenology. The only two previously published estimates of the magnitude of global response are quite different: 2.3 and 5.1 days decade−1 advancement. The scientific community has assumed this difference to be real and has attempted to explain it in terms of biologically relevant phenomena: specifically, differences in distribution of data across latitudes, taxa or time periods. Here, these and other possibilities are explored. All analyses indicate that the difference in estimated response is primarily due to differences between the studies in criteria for incorporating data. It is a clear and automatic consequence of the exclusion by one study of data on ‘stable’ (nonresponsive) species. Once this is accounted for, the two studies support each other, generating similar conclusions despite analyzing substantially nonoverlapping datasets. Analyses here on a new expanded dataset estimate an overall spring advancement across the northern hemisphere of 2.8 days decade−1. This is the first quantitative analysis showing that data‐sampling methodologies significantly impact global (synthetic) estimates of magnitude of global warming response.
Can warm climate‐related structure of littoral predator assemblies weaken the clear water state in shallow lakes?
Authors: MEERHOFF MARIANA , CLEMENTE JUAN M. , De MELLO FRANCO TEIXEIRA , IGLESIAS CARLOS , PEDERSEN ASGER R. , JEPPESEN ERIK
Published: August 2007

Shallow lakes, the most abundant lake type in the world, are very sensitive to climatic changes. The structure and functioning of shallow lakes are greatly impacted by submerged plants, and these may be affected by climate warming in various, contrasting, ways.

Following a space‐for‐time substitution approach, we aimed to analyse the role of aquatic (submerged and free‐floating) plants in shallow lakes under warm climates. We introduced artificial submerged and free‐floating plant beds in five comparable lakes located in the temperate zone (Denmark, 55–57 °N) and in the subtropical zone (Uruguay, 30–35 °S), with the aim to study the structure and dynamics of the main associated communities.

Regardless of differences in environmental variables, such as area, water transparency and nutrient status, we found consistent patterns in littoral community dynamics and structure (i.e. densities and composition of fish, zooplankton, macroinvertebrates, and periphyton) within, but substantial differences between, the two regions. Subtropical fish communities within the macrophyte beds exhibited higher diversity, higher density, smaller size, lower relative abundance of potentially piscivores, and a preference for submerged plants, compared with otherwise similar temperate lakes. By contrast, macroinvertebrates and cladocerans had higher taxon richness and densities, and periphyton higher biomass, in the temperate lakes. Several indicators suggest that the fish predation pressure was much stronger among the plants in the subtropical lakes. The antipredator behaviour of cladocerans also differed significantly between climate zones. Submerged and free‐floating plants exerted different effects on the spatial distribution of the main communities, the effects differing between the climate zones. In the temperate lakes, submerged plants promoted trophic interactions with potentially positive cascading effects on water transparency, in contrast to the free‐floating plants, and in strong contrast to the findings in the subtropical lakes.

The higher impact of fish may result in higher sensitivity of warm lakes to external changes (e.g. increase in nutrient loading or water level changes). The current process of warming, particularly in temperate lakes, may entail an increased sensitivity to eutrophication, and a threat to the high diversity, clear water state.
Parallel post‐space preparation in different tooth types ex vivo: deviation from the canal centre and remaining dentine thickness
Authors: Huysmans M. C. D. N. J. M. , Klein M. H. J. , Kok G. F. , Whitworth J. M.
Published: August 2007

Aim  To determine the deviation of parallel‐sided twist‐drills during post‐channel preparation and relate this to tooth type and position.

Methodology  Human teeth with single root canals were selected: maxillary second premolars (group i); maxillary lateral incisors (group ii); mandibular canines (group iii); mandibular first premolars (group iv; all groups n = 16). The teeth were reduced to 17 mm length by sectioning the crown, and the root canals prepared and filled. Microradiographs were made in two directions. The teeth were individually embedded in a gypsum jaw and placed in a phantom head. Two operators performed parallel post‐space preparation (12 mm length, 1.25 mm diameter) to the following protocol: gutta‐percha removal with Gates Glidden drills numbers 2 and 3 and post‐space enlargement with parallel drills numbers 3, 4 and 5, consecutively. Subsequently, microradiographs were re‐exposed. The original and post‐operative microradiographs were digitized and superimposed, and deviation of the post‐space from the filled canal and remaining dentine thickness measured.

Results  Overall, the mean deviation was 0.07 mm to the mesial (95% CI: 0.01–0.12), and 0.27 mm to the buccal (95% CI: 0.18–0.35). Group ii had significantly more buccal deviation than other groups (P = 0.004–0.008). A remaining dentine thickness of <0.5 mm occurred 16 times in 14 teeth, and of <1 mm occurred 97 times in 52 teeth.

Conclusions  Deviation during parallel post‐preparation was common, predominantly in mesial and buccal directions, especially in maxillary incisors. This deviation increased the risk of perforation considerably.
Variation in assessing the need for change of snacking habits in schoolchildren's oral health counselling
Authors: KASILA KIRSTI , POSKIPARTA MARITA , KETTUNEN TARJA , PIETILÄ ILPO
Published: August 2007

Objectives.  This study examined counselling communication activities that were used for assessing schoolchildren's need for change of snacking habits. In addition, the schoolchildren's assessment of their need for change was explored after a follow‐up year (2002–2003).

Material and methods.  The follow‐up research data included 66 counselling sessions in 2002 and 31 counselling sessions in 2003, with 31 schoolchildren. The sessions were conducted by four dental hygienists. The audio‐taped data were analysed qualitatively by using content analysis.

Results.  In 2002, the needs assessment was realized in three ways. Infrequently, the schoolchildren either disclosed their need for change or the counsellor explicitly determined the schoolchildren's need for change. Usually, however, the schoolchildren's needs assessment for change occurred through the counsellors’ communication activities of assessment, advice, and change‐inducing questions. In one‐third of the cases, the schoolchildren's need for change remained ambiguous during the sessions in 2002. With respect to positive changes in 2003, the schoolchildren themselves were aware of the need for change. Alternatively, the sessions included change discussion that addressed readiness for change and making changes during the counselling in 2002.

Conclusion.  Our results revealed that a thorough needs assessment of schoolchildren's snacking habits provides a foundation for behaviourally focused counselling.
Stream flow, salmon and beaver dams: roles in the structuring of stream fish communities within an anadromous salmon dominated stream
Authors: MITCHELL SEAN C. , CUNJAK RICHARD A.
Published: August 2007

The current paradigm of fish community distribution is one of a downstream increase in species richness by addition, but this concept is based on a small number of streams from the mid‐west and southern United States, which are dominated by cyprinids. Further, the measure of species richness traditionally used, without including evenness, may not be providing an accurate reflection of the fish community. We hypothesize that in streams dominated by anadromous salmonids, fish community diversity will be affected by the presence of the anadromous species, and therefore be influenced by those factors affecting the salmonid population.

Catamaran Brook, New Brunswick, Canada, provides a long‐term data set to evaluate fish community diversity upstream and downstream of an obstruction (North American beaver Castor canadensis dam complex), which affects distribution of Atlantic salmon Salmo salar.

The Shannon Weiner diversity index and community evenness were calculated for sample sites distributed throughout the brook and over 15 years. Fish community diversity was greatest upstream of the beaver dams and in the absence of Atlantic salmon. The salmon appear to depress the evenness of the community but do not affect species richness. The community upstream of the beaver dams changes due to replacement of slimy sculpin Cottus cognatus by salmon, rather than addition, when access is provided.

Within Catamaran Brook, location of beaver dams and autumn streamflow interact to govern adult Atlantic salmon spawner distribution, which then dictates juvenile production and effects on fish community. These communities in an anadromous Atlantic salmon dominated stream do not follow the species richness gradient pattern shown in cyprinid‐dominated streams and an alternative model for stream fish community distribution in streams dominated by anadromous salmonids is presented. This alternative model suggests that community distribution may be a function of semipermeable obstructions, streamflow and the distribution of the anadromous species affecting resident stream fish species richness, evenness, biomass and production.
E‐learning in a low‐status female profession: the role of motivation, anxiety and social support in the learning divide
Authors: Vandenbroeck M. , Verschelden G. , Boonaert T.
Published: August 2007

Abstract  The literature seems to suggest that women may be at risk from being excluded from adult education programmes, which use e‐learning, especially when they have low economic status. Based on a survey of 551 women, family day care providers, we conclude that there is a persistent divide in PC access and use, as well as in perceived PC skills according to age. Yet, this divide seems to run less along traditional lines, suggesting that personal factors play a more important role. Motivation and anxiety are two related but distinct personal factors that influence computer use and skills in this population. We also found that these factors are mediated by the family context: motivation is higher when (young) children are present in the family. Moreover, children may represent an important form of social support for women not yet using computers. This study concludes that the concerns about the gender gap in computer use may benefit from taking the scaffolding possibilities of the family into consideration and that there may be a case for growing optimism in the use of information and communication technology for adult learning in specific, gender‐segregated professions with low status.
Does operational diagnosis of schizophrenia significantly impact intellectual deficits in psychotic disorders?
Authors: Kitamura H. , Shioiri T. , Itoh M. , Sato Y. , Shichiri K. , Someya T.
Published: August 2007

Background  Evidence suggests that, as a group, patients with schizophrenia have intellectual deficits that may precede the manifestation of psychotic symptoms; however, how successfully intelligence tests are able to discriminate schizophrenia from other psychotic disorders has yet to be investigated in detail.

Methods  Using Wechsler Adult Intelligence Scale – Revised (WAIS‐R) data for 55 inpatients with schizophrenia and 28 inpatients with non‐schizophrenic psychotic disorders (NSPD) (schizophreniform disorder, brief psychotic disorder, delusional disorder, psychotic disorder due to a general medical condition, and psychotic disorders not otherwise specified), intelligence performance was compared between schizophrenia and NSPD and among different subtypes of schizophrenia.

Results  There were no significant differences in intelligence quotient (IQ), verbal IQ (VIQ) and performance IQ (PIQ) discrepancy, and subtest scores of WAIS‐R between the patients with schizophrenia and those with NSPD. These diagnostic groups were not discriminated well by any WAIS‐R variables. Schizophrenia patients with prominent negative symptoms, on the other hand, had a significantly larger IQ discrepancy (VIQ > PIQ) than those without prominent negative symptoms and NSPD patients. Intelligence performance in schizophrenia did not differ with respect to diagnostic subtypes and longitudinal courses.

Conclusions  The current study failed to show diagnostic usefulness of WAIS‐R in discriminating schizophrenia and other psychoses. A diagnosis of schizophrenia does not significantly impact intellectual deficits in psychotic disorders.
The prevalence and incidence of mental ill‐health in adults with Down syndrome
Authors: Mantry D. , Cooper S.‐A. , Smiley E. , Morrison J. , Allan L. , Williamson A. , Finlayson J. , Jackson A.
Published: August 2007

Background  While there is considerable literature on adults with Down syndrome who have dementia, there is little published on the epidemiology of other types of mental ill‐health in this population.

Method  Longitudinal cohort study of adults with Down syndrome who received detailed psychiatric assessment (n = 186 at the first time point; n = 134 at the second time point, 2 years later).

Results  The prevalence of Down syndrome for the 16 years and over population was 5.9 per 10 000 general population. Point prevalence of mental ill‐health of any type, excluding specific phobias, was 23.7% by clinical, 19.9% by Diagnostic Criteria for Psychiatric Disorders for use with Adults with Learning Disabilities/Mental Retardation (DC‐LD), 11.3% by ICD‐10 Classification of Mental and Behavioural Disorders: Diagnostic Criteria for Research (DCR‐ICD‐10) and 10.8% by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Revised (DSM‐IV‐TR) criteria. Two‐year incidence of mental ill‐health of any type was 14.9% by clinical and DC‐LD, 9.0% by DCR‐ICD‐10 and 3.7% by DSM‐IV‐TR criteria. The highest incidence was for depressive episode (5.2%) and dementia/delirium (5.2%). Compared with persons with intellectual disabilities (ID) of all causes, the standardized rate for prevalence of mental ill‐health was 0.6 (0.4–0.8), or 0.4 (0.3–0.6) if organic disorders are excluded, and the standardized incidence ratio for mental ill‐health was 0.9 (0.6–1.4), or 0.7 (0.4–1.2) if organic disorders are excluded. Urinary incontinence was independently associated with mental ill‐health, whereas other personal factors, lifestyle and supports, and other types of health needs and disabilities were not.

Conclusions  Mental ill‐health is less prevalent in adults with Down syndrome than for other adults with ID. The pattern of associated factors differs from that is found for other adults with ID, with few associations found. This suggests that the protection against mental ill‐health is biologically determined in this population, or that there are other factors protective for mental ill‐health yet to be identified for the population with Down syndrome.