bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal patterns of persistence and infectivity of Metarhizium anisopliae var. acridum in grasshopper cadavers in the Sahel
Authors: Arthurs S.P. , Thomas M.B. , Lawton J.L.
Published: October 2003

Field‐based experiments were conducted to evaluate the fate and infectivity of the entomopathogenic fungus Metarhizium anisopliae var. acridum (Deuteromycotina: Hyphomycetes) in grasshopper cadavers in the Sahel. Unlike uninfected cadavers, which were rapidly scavenged, those infected with the fungus persisted in the environment for a number of weeks. The environmental factor most associated with cadaver disappearance was rainfall. The high environmental humidity associated with rainfall was also required for sporulation of the fungus on host cadavers, although the likelihood of sporulation differed between microsites. Characteristics of the infection profile from infective cadavers were investigated by the sequential exposure of uninfected hosts to sporulating cadavers in field cages. This experiment revealed that cadavers remained infective for > 30 days, with the net infectivity changing through time. The most likely explanation for these changes is climatic influences on both the fungus and host. High humidity was not required for infection. A measurement of the transmission coefficient between healthy hosts and sporulating cadavers in the field was obtained at a realistic density of infectious cadavers. This revealed a figure of 0.45 m2 day−1. Overall, these experiments show that following host death, M. anisopliae var. acridum can be persistent in the environment, sporulate on host cadavers and reinfect new hosts at a realistically low field density, although at least in arid or semi‐arid areas, rainfall may be critical to the horizontal transmission of this pathogen.
Transgenic Bt potato and conventional insecticides for Colorado potato beetle management: comparative efficacy and non‐target impacts
Authors: Reed Gary L. , Jensen Andrew S. , Riebe Jennifer , Head Graham , Duan Jian J.
Published: October 2003

Field studies were conducted in 1992 and 1993 in Hermiston, Oregon, to evaluate the efficacy of transgenic Bt potato (Newleaf®, which expresses the insecticidal protein Cry3Aa) and conventional insecticide spray programs against the important potato pest, Leptinotarsa decemlineata (Say), Colorado potato beetle (CPB), and their relative impact on non‐target arthropods in potato ecosystems. Results from the two years of field trials demonstrated that Newleaf potato plants were highly effective in suppressing populations of CPB, and provided better CPB control than weekly sprays of a microbial Bt‐based formulation containing Cry3Aa, bi‐weekly applications of permethrin, or early‐ and mid‐season applications of systemic insecticides (phorate and disulfoton). When compared with conventional potato plants not treated with any insecticides, the effective control of CPB by Newleaf potato plants or weekly sprays of a Bt‐based formulation did not significantly impact the abundance of beneficial predators or secondary potato pests. In contrast to Newleaf potato plants or microbial Bt formulations, however, bi‐weekly applications of permethrin significantly reduced the abundance of several major generalist predators such as spiders (Araneae), big‐eyed bugs (Geocorus sp.), damsel bugs (Nabid sp.), and minute pirate bugs (Orius sp.), and resulted in significant increases in the abundance of green peach aphid (GPA), Myzus persicae (Sulzer) – vector of viral diseases, on the treated potato plots. While systemic insecticides appeared to have reduced the abundance of some plant sap‐feeding insects such as GPA, lygus bugs, and leafhoppers, early and mid‐season applications of these insecticides had no significant impact on populations of the major beneficial predators. Thus, transgenic Bt potato, Bt‐based microbial formulations and systemic insecticides appeared to be compatible with the development of integrated pest management (IPM) against other potato pests such as GPA because these CPB control measures have little impact on major natural enemies. In contrast, the broad‐spectrum pyrethroid insecticide (permethrin) is less compatible with IPM programs against GPA and the potato leafroll viral disease.
Larval interactions in aphidophagous predators: effectiveness of wax cover as defence shield of Scymnus larvae against predation from syrphids
Authors: Agarwala Basant K. , Yasuda Hironori
Published: October 2003

Small‐sized predators in the aphidophagous guild of Aphis gossypii Glover colonies on hibiscus trees in Japan exploit aphids at low prey abundance. Scymnus (Pullus) posticalis Sicard beetles were the first predatory species to attack aphids in the spring, and their larvae co‐occurred with larvae of Eupeodes freguens (Matsumura) syrphids in aphid‐infested leaves of hibiscus for 3 weeks in absence of large‐sized coccinellid predators. Larval interaction between Scymnus and syrphid predators was examined in relation to effectiveness of wax cover of Scymnus against predation from syrphids. Waxless first instar larvae were not protected but wax‐covered larvae of second, third and fourth instars were protected from predation by syrphid larvae. The protection was lower in the second instar which has a thin wax cover and significantly higher in the third and fourth instars having a thick wax cover. In addition, larvae from which the wax was removed were significantly more vulnerable to predation. Vulnerability of Scymnus larvae to predation from syrphids was directly related to the thickness of wax cover. Results suggest that the wax cover of Scymnus larvae act as an effective defence mechanism against predation from syrphid larvae.
Captures of the olive fruit fly Bactrocera oleae on spheres of different colours
Authors: Katsoyannos Byron I. , Kouloussis Nikos A.
Published: October 2003

Alighting and capture of wild olive fruit flies, Bactrocera oleae (Rossi) (Diptera, Tephritidae), on spheres of seven different colours was studied on Chios island, Greece. The 70‐mm‐diam plastic spheres, coated with adhesive, were suspended on olive trees. Yellow and orange spheres trapped the greatest number of males while red and black spheres trapped the greatest number of females. White and blue spheres were the least effective for both sexes. Peak captures occurred in the late afternoon and especially around sunset. Since mating takes place in the last hours of the photophase, the increased captures during that period may be related to the sexual behaviour of the fly. When red spheres were assessed against glass McPhail traps baited with 2% ammonium sulphate, which consist a standard tool for monitoring the olive fruit fly in Greece, there were no significant differences in male captures. However, spheres trapped almost three times as many females as McPhail traps. The possible mechanisms underlying colour discrimination, the motivation of alighting flies and the possible use of red spheres for monitoring and controlling B. oleae are discussed.
Unbiased estimation of greenhouse whitefly, Trialeurodes vaporariorum, mean density using yellow sticky trap in cherry tomato greenhouses
Authors: Kim Jong‐Kwan , Park Jung‐Joon , Park Heungsun , Cho Kijong
Published: October 2003

The spatial distribution of the count of adult greenhouse whiteflies, Trialeurodes vaporariorum (Westwood), on yellow sticky traps was analyzed using Taylor's power law and spatial autocorrelation statistics in the cherry tomato greenhouses from 1998–1999. Samples were collected weekly using a cylindrically shaped yellow sticky trap placed in a 5 by 8 grid covering 0.10–0.15 ha in each of five cherry tomato greenhouses. Taylor's (1961) power law indicated that counts of T. vaporariorum on traps were aggregated within greenhouses. Spatial autocorrelation analysis showed that trap catches were similar (positively autocorrelated) to a distance of 12.5 m, and then dissimilar (negatively autocorrelated) at >12.5 m. Autocorrelation‐lag plots showed a globally significant spatial relation in 34 of 57 sample‐weeks according to Bonferroni's approximation. The presence of this spatial relation was not related to the changes of mean density. Trap counts at the second lag distance (12.5–25 m) showed little spatial autocorrelation and tended to be the most spatially independent. A fixed‐precision‐level sequential sampling plan was developed using the parameters from Taylor's power law. The presence of spatial dependency in data sets degraded the sampling plan's precision relative to performance in data sets lacking significant spatial autocorrelation. Therefore, to obtain an unbiased mean density of T. vaporariorum per greenhouse, sticky traps should be placed at least >12.5 m apart to ensure that they are spatially independent.
Plant and host effects on the leafroller parasitoid Dolichogenidia tasmanica
Authors: Suckling D.M. , Burnip G.M. , Gibb A.R. , Daly J.M. , Armstrong K.F.
Published: October 2003

Parasitism by the braconid wasp Dolichogenidia tasmanica of first instar larvae of the lightbrown apple moth Epiphyas postvittana, established on four different species of potted host plants, was assessed after 2 weeks of field exposure in an apple orchard. Parasitism varied significantly between larval host plants (apple 58%, broom 59%, clover 30%, poplar 19% ). Parasitism on potted apple seedlings of the co‐evolutionary host, E. postvittana, was compared in a field trial with that of two native New Zealand leafroller species (to which D. tasmanica has had exposure for 5 decades only). Parasitism varied significantly with larval host (E. postvittana, 83%; Ctenopseustis herana, 58%;Planotortrix octo, 26% ). Larval collections were made from mature apple trees and identification of larvae was achieved by DNA analysis for the leafroller species using PCR‐RFLP of ITS1 + ITS2, and for the parasitoid by specific PCR of partial 18S. Parasitism under natural field conditions on mature apple trees was not different between larval hosts (mean 32.5% ). In laboratory studies, more P. octo larvae departed in response to parasitoid probing behaviour than E. postvittana, which is likely to contribute to the difference in parasitism rates. This study conclusively shows that D. tasmanica parasitises native New Zealand leafrollers, despite their different evolutionary origins.
Diversity of birch sawfly responses to seasonally atypical diets
Authors: Martel Jocelyn , Hanhimäki Sinikka , Kause Antti , Haukioja Erkki
Published: October 2003

Most insect herbivores are specialised on a particular plant taxon. To have a better understanding of host shift functions and consequences for insect herbivores, it is essential to gather more information on the effects of variation in host quality on specialists across species and environments. We examined the effects of seasonally atypical food on mortality, developmental time, and final body mass of six sawfly species (Hymenoptera: Symphyta) feeding on the foliage of mountain birch (Betula pubescens ssp. czerepanovii), whose pooled larval feeding periods form a gradient and cover the growing season. Insect phenology was manipulated so that the larvae of early‐season species would feed on atypically mature leaves and mid‐ or late‐season species would feed on atypically young leaves of their major host plant. Mortality increased dramatically for all species when the larval feeding schedule was advanced or delayed. This indicates a high degree of specialisation not only on a particular host but also to its phenological phases. The main cause of mortality on novel food was a rejection of the diet by the young larvae and their subsequent starvation. An interesting observation was that late‐season species showed this response on nutritious young foliage. The effects of seasonally atypical diets on larval development and growth were species‐specific and milder than the effects on mortality. Interestingly, for those individuals that accepted it, atypical food seemed to be most beneficial for species appearing at both ends of the seasonal gradient, which might be related to a wider exposure to variable food quality in natural conditions compared with other species. The diversity of responses to atypical food among closely related herbivore species with overlapping feeding periods on the same host plant is the most crucial finding of this study.
Sexual differences in life‐history traits in the butterfly Lycaena tityrus: a comparison between direct and diapause development
Authors: Fischer Klaus , Fiedler Konrad
Published: October 2003

During direct development the butterfly Lycaena tityrus was previously found to display sex‐related reaction norms in response to temperature. Based on selection for protandry in males and fecundity selection for larger females, males favoured early emergence over large size, leading to a dramatic weight loss at higher temperatures, whereas females maintained similar weights throughout. Because males were able to avoid a weight reduction relative to females in spite of their shorter development at lower temperatures, sexual size dimorphism existed at higher temperatures only. In the present paper we compare sexual differences in life‐history traits in L. tityrus between direct and diapause development at 25 °C. We demonstrate that, regardless of developmental pathway, protandry persisted and relative sexual size dimorphism, with females being larger, remained unchanged. Although diapausing individuals were less time‐constrained, allowing them to grow to considerably higher final weights in both sexes, males were not able to reduce their weight loss relative to females. This is explained by the pressure to gain a developmental advantage solely during post‐diapause development, whereas direct developing males may spread the burden over the whole larval period. Our results highlight the importance of considering sexual differences in selective pressures, which may influence central life‐history traits in manifold ways.
The lethal plant defense paradox remains: inducible host‐plant aristolochic acids and the growth and defense of the pipevine swallowtail
Authors: Fordyce James A.
Published: October 2003

Toxic plants with sequestering specialists are presented with a problem because plant derived toxins protect herbivores against natural enemies. It has been suggested that early induction of toxins and later relaxation of these defenses may help the plant resolve this problem because neonate caterpillars incur the physiological cost of dealing with toxins in early life, but are denied toxins when they are able to sequester them efficiently. In California, the pipevine swallowtail, Battus philenor L. (Lepidoptera: Papilionidae), feed exclusively on Aristolochia californica Torrey (Aristolochiaceae), an endemic vine that contains toxic alkaloids called aristolochic acids that caterpillars sequester to provide chemical defense in immature and adult stages. In a field experiment, the concentration of aristolochic acids doubled in the plant following leaf damage and returned to constitutive levels after six days. Neonate pipevine swallowtail caterpillars showed no aversion to high levels of aristolochic acid in a preference test. Caterpillars reared on leaves with supplemented aristolochic acid showed no physiological cost or increased mortality compared to caterpillars reared on un‐supplemented leaves. Searching efficiency and capture rate of lacewing larvae (Chrysoperla), a common predator of first instar caterpillars, was compromised significantly after feeding on caterpillars reared on leaves with supplemented concentrations of aristolochic acid compared to caterpillars feeding on control plants. Additionally, mortality of lacewings increased when they were provided with a diet of B. philenor caterpillars reared on supplemented leaves compared to caterpillars reared on control leaves. Thus, the induction of aristolochic acids in the plant following leaf damage does not resolve the problem confronted by the plant and may confer benefits to this sequestering specialist.
Mating disruption in Agrotis segetum monitored by harmonic radar
Authors: Svensson Glenn P. , Valeur Peter G. , Reynolds Donald R. , Smith Alan D. , Riley Joseph R. , Baker Thomas C. , Poppy Guy M. , Löfstedt Christer
Published: October 2003

The long‐range, pheromone‐mediated, flight behaviour of male moths under natural and mating disruption conditions was monitored by means of harmonic radar. Individual male turnip moths, Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), tagged with radar transponders, were released and tracked in plots with or without disruptive doses of sex pheromone. In addition, male attraction to pheromone‐baited traps and mating of calling females in treated and untreated plots was investigated. High doses of a four‐component pheromone blend reduced trap catch by 79% and mating of females by 62% when compared with control plots in pre‐radar experiments. Surprisingly, this effect was not associated with any pronounced differences in flight behaviour of males between a treatment and a control plot as revealed by harmonic radar recordings. In total, 20 flight tracks from a control plot and 22 flight tracks from a treatment plot were analysed. Moths could be followed for up to 77 min, corresponding to a track length of 7350 m. Mean ground speed ranged from 0.7 m s−1 to 5.4 m s−1. There was a strong trend (P = 0.06) for a greater number of male orientations to traps from downwind in the control field compared to the treatment field. Many flight tracks were fragmented due to radar shadow. Advantages and constraints using harmonic radar to study the pheromone‐mediated flight behaviour of nocturnal moths are discussed.
Influence of visual stimuli on host location in the butterfly, Eurema hecabe
Authors: Hirota Tadao , Kato Yoshiomi
Published: October 2003

The influence of visual stimuli on female host location was investigated in Eurema hecabe (Lepidoptera: Pieridae). Mated females with no oviposition experience were presented with artificial plant models treated with the methanol extract of the host plant, Lespedeza cuneata (Fabaceae). When models of different colours were presented to females, they landed and deposited eggs predominantly on the yellow‐green model. However, the size of the model was not important. When females were presented with simple square models and a model on which small squares were assembled, they predominantly chose the assembly model. This suggests that female discern the pattern which resembles the leaf of their main host plants, which consists of many small leaflets. However, the whole image of a leaf of the host plant was not an essential cue for host location, as females also chose the square with the central space more frequently than that without the space. We suggest that the long contour of a complicated form plays a role in female host location.
The fruit fly parasitoid Fopius arisanus: reproductive attributes of pre‐released females and the use of added sugar as a potential food supplement in the field
Authors: Bautista Renato C. , Harris Ernest J. , Vargas Roger I.
Published: October 2003

Fopius (= Biosteres) arisanus (Sonan) (=Opius oophilus Fullaway) (Hymenoptera: Braconidae) is an egg‐pupal parasitoid of tephritid fruit flies. Small scale releases of F. arisanus were undertaken in coffee, Coffea arabica L., on the island of Kauai, to evaluate its potential for suppression of fruit fly populations. In conjunction with field releases, assays were conducted to determine the quality of pre‐released parasitoids. In addition, the suitability of various sugars as potential food supplements in the field was evaluated. Spermathecal dissection showed that >70% of a total 1.7 million females released in 1998 and 1999 were successfully mated. Moreover, a sperm rating of 2.5–2.6 indicated that the spermathecae of inseminated females were 50% full. There were 85–137 matured eggs (mean = 101.7 ± 11.5) in the ovaries of mated or virgin females. When honey was replaced with ripe coffee and water, ripe coffee, or water alone, 10 days after emergence, females remained alive for another 5.5, 5.4, and 4.9 days, respectively. There was corresponding deterioration in the ovaries of gravid females. Mean eggs of honey‐deprived females declined from >100 to <70 shortly before their death. Suitability test of various sugars showed that females lived longer when fed with honey (26 days), maple syrup (25 days) or molasses (20 days). Moreover, females provided with these sugars produced mean cumulative progeny per female of 77.2 ± 19, 67 ± 7, and 81 ± 14, respectively, during a 2‐week egging period. Our findings provided a basis for development of field release strategy for F. arisanus.
Survival and fecundity of Bt‐susceptible Colorado potato beetle adults after consumption of transgenic potato containing Bacillus thuringiensis subsp. tenebrionis Cry3A toxin
Authors: Nault Brian A.
Published: October 2003

Survival and fecundity of Colorado potato beetle adults, Leptinotarsa decemlineata (Say), that had or had not fed previously on non‐transgenic potato before exposure to transgenic potato containing the Bacillus thuringiensis subsp. tenebrionis Cry3A toxin (Bt) was investigated. In the laboratory, < 5% of first‐generation adults survived after two weeks when restricted to Bt foliage since eclosion, but over 85% of adults that had fed initially on non‐Bt potato survived exposure to Bt potato for two weeks. In field experiments, less than 0.5% of adults that were exclusively provided Bt potato plants survived overwinter, whereas 44% to 57% survived overwinter when fed non‐Bt potato plants for two weeks before being provided Bt potato as a final pre‐overwintering host. Survival through the winter increased as the duration of initial feeding on non‐Bt potato increased and was similar for beetles provided either tubers or Bt potato plants as a final pre‐overwintering host. Only overwintered beetles that fed initially on non‐Bt potato before encountering either tubers or Bt potato as a final pre‐overwintering host laid eggs the following spring. Survival and reproduction of potato beetle adults after colonizing Bt potato fields should not be adversely affected as long as they have had sufficient time to feed initially on non‐Bt potato. Implications for how potato production practices in the Mid‐Atlantic US may affect the utility of general resistance management plans for Bt potato are discussed.
Scaling properties and symmetrical patterns in the epidemiology of rotavirus infection
Authors: José Marco V. , Bishop Ruth F.
Published: October 2003

The rich epidemiological database of the incidence of rotavirus, as a cause of severe diarrhoea in young children, coupled with knowledge of the natural history of the infection, can make this virus a paradigm for studies of epidemic dynamics. The cyclic recurrence of childhood rotavirus epidemics in unvaccinated populations provides one of the best documented phenomena in population dynamics.

This paper makes use of epidemiological data on rotavirus infection in young children admitted to hospital in Melbourne, Australia from 1977 to 2000. Several mathematical methods were used to characterize the overall dynamics of rotavirus infections as a whole and individually as serotypes G1, G2, G3, G4 and G9. These mathematical methods are as follows: seasonal autoregressive integrated moving-average (SARIMA) models, power spectral density (PSD), higher-order spectral analysis (HOSA) (bispectrum estimation and quadratic phase coupling (QPC)), detrended fluctuation analysis (DFA), wavelet analysis (WA) and a surrogate data analysis technique. Each of these techniques revealed different dynamic aspects of rotavirus epidemiology. In particular, we confirm the existence of an annual, biannual and a quinquennial period but additionally we found other embedded cycles (e.g.
ca
. 3 years). There seems to be an overall unique geometric and dynamic structure of the data despite the apparent changes in the dynamics of the last years. The inherent dynamics seems to be conserved regardless of the emergence of new serotypes, the re-emergence of old serotypes or the transient disappearance of a particular serotype. More importantly, the dynamics of all serotypes is multiple synchronized so that they behave as a single entity at the epidemic level.

Overall, the whole dynamics follow a scale-free power-law fractal scaling behaviour. We found that there are three different scaling regions in the time-series, suggesting that processes influencing the epidemic dynamics of rotavirus over less than 12 months differ from those that operate between 1 and
ca
. 3 years, as well as those between 3 and
ca
. 5 years. To discard the possibility that the observed patterns could be due to artefacts, we applied a surrogate data analysis technique which enabled us to discern if only random components or linear features of the incidence of rotavirus contribute to its dynamics. The global dynamics of the epidemic is portrayed by wavelet-based incidence analysis. The resulting wavelet transform of the incidence of rotavirus crisply reveals a repeating pattern over time that looks similar on many scales (a property called self-similarity). Both the self-similar behaviour and the absence of a single characteristic scale of the power-law fractal-like scaling of the incidence of rotavirus infection imply that there is not a universal inherently more virulent serotype to which severe gastroenteritis can uniquely be ascribed.
Inflammation in central nervous system injury
Authors: Allan Stuart M. , Rothwell Nancy J.
Published: October 2003

Inflammation is a key component of host defence responses to peripheral inflammation and injury, but it is now also recognized as a major contributor to diverse, acute and chronic central nervous system (CNS) disorders. Expression of inflammatory mediators including complement, adhesion molecules, cyclooxygenase enzymes and their products and cytokines is increased in experimental and clinical neurodegenerative disease, and intervention studies in experimental animals suggest that several of these factors contribute directly to neuronal injury. Most notably, specific cytokines, such as interleukin–1 (IL–1), have been implicated heavily in acute neurodegeneration, such as stroke and head injury.

In spite of their diverse presentation, common inflammatory mechanisms may contribute to many neurodegenerative disorders and in some (e.g. multiple sclerosis) inflammatory modulators are in clinical use. Inflammation may have beneficial as well as detrimental actions in the CNS, particularly in repair and recovery. Nevertheless, several anti–inflammatory targets have been identified as putative treatments for CNS disorders, initially in acute conditions, but which may also be appropriate to chronic neurodegenerative conditions.
Mammal population regulation, keystone processes and ecosystem dynamics
Authors: Sinclair A. R. E.
Published: October 2003

The theory of regulation in animal populations is fundamental to understanding the dynamics of populations, the causes of mortality and how natural selection shapes the life history of species. In mammals, the great range in body size allows us to see how allometric relationships affect the mode of regulation. Resource limitation is the fundamental cause of regulation. Top–down limitation through predators is determined by four factors: (i) body size; (ii) the diversity of predators and prey in the system; (iii) whether prey are resident or migratory; and (iv) the presence of alternative prey for predators. Body size in mammals has two important consequences. First, mammals, particularly large species, can act as keystones that determine the diversity of an ecosystem. I show how keystone processes can, in principle, be measured using the example of the wildebeest in the Serengeti ecosystem. Second, mammals act as ecological landscapers by altering vegetation succession. Mammals alter physical structure, ecological function and species diversity in most terrestrial biomes. In general, there is a close interaction between allometry, population regulation, life history and ecosystem dynamics. These relationships are relevant to applied aspects of conservation and pest management.
Human nutrition and food research: opportunities and challenges in the post-genomic era
Authors: Fairweather-Tait Susan J.
Published: October 2003

Sequencing of the human genome has opened the door to the most exciting new era for nutritional science. It is now possible to study the underlying mechanisms for diet–health relationships, and in the near future dietary advice (and possibly tailored food products) for promoting optimal health could be provided on an individual basis, in relation to genotype and lifestyle. The role of food in human evolution is briefly reviewed, from palaeolithic times to modern–day hunter–gatherer societies. The aetiology of ‘diseases of modern civilization’, such as diabetes, heart disease and cancer, and the effect of changes in dietary patterns are discussed. The risk of disease is often associated with common single nucleotide polymorphisms, but the effect is dependent on dietary intake and nutritional status, and is often more apparent in intervention studies employing a metabolic challenge. To understand the link between diet and health, nutritional research must cover a broad range of areas, from molecular to whole body studies, and is an excellent example of integrative biology, requiring a systems biology approach. The annual cost to the National Health Service of diet–related diseases is estimated to be in excess of £15 billion, and although diet is a key component of any preventative strategy, it is not given the prominence it deserves. For example, less than 1% of the £1.6 billion budget for coronary heart disease is spent on prevention. The polygenic and multifactorial nature of chronic diseases requires substantial resources but the potential rewards, in terms of quality of life and economics, are enormous. It is timely therefore to consider investing in a long–term coordinated national programme for nutrition research, combining nutritional genomics with established approaches, to improve the health of individuals and of the nation.
On the rationale and interpretation of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops
Authors:   The American Association for Research into Nervous and Mental Diseases, Squire G. R. , Brooks D. R. , Bohan D. A. , Champion G. T. , Daniels R. E. , Haughton A. J. , Hawes C. , Heard M. S. , Hill M. O. , May M. J. , Osborne J. L. , Perry J. N. , Roy D. B. , Woiwod I. P. , Firbank L. G.
Published: October 2003

Farmland biodiversity and food webs were compared in conventional and genetically modified herbicide–tolerant (GMHT) crops of beet (Beta vulgarisL.), maize (Zea maysL.) and both spring and winter oilseed rape (Brassica napusL.). GMHT and conventional varieties were sown in a split–field experimental design, at 60–70 sites for each crop, spread over three starting years beginning in 2000. This paper provides a background to the study and the rationale for its design and interpretation. It shows how data on environment, field management and the biota are used to assess the current state of the ecosystem, to define the typical arable field and to devise criteria for selecting, sampling and auditing experimental sites in the Farm Scale Evaluations. The main functional and taxonomic groups in the habitat are ranked according to their likely sensitivity to GMHT cropping, and the most responsive target organisms are defined. The value of the seedbank as a baseline and as an indicator of historical trends is proposed. Evidence from experiments during the twentieth century is analysed to show that large changes in field management have affected sensitive groups in the biota byca. 50% during a year or short run of years — a figure against which to assess any positive or negative effects of GMHT cropping. The analysis leads to a summary of factors that were, and were not, examined in the first 3 years of the study and points to where modelling can be used to extrapolate the effects to the landscape and the agricultural region.
Invertebrates and vegetation of field margins adjacent to crops subject to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide–tolerant crops
Authors:   The American Association for Research into Nervous and Mental Diseases, Roy D. B. , Bohan D. A. , Haughton A. J. , Hill M. O. , Osborne J. L. , Clark S. J. , Perry J. N. , Rothery P. , Scott R. J. , Brooks D. R. , Champion G. T. , Hawes C. , Heard M. S. , Firbank L. G.
Published: October 2003

The effects of management of genetically modified herbicide–tolerant (GMHT) crops on adjacent field margins were assessed for 59 maize, 66 beet and 67 spring oilseed rape sites. Fields were split into halves, one being sown with a GMHT crop and the other with the equivalent conventional non–GMHT crop. Margin vegetation was recorded in three components of the field margins. Most differences were in the tilled area, with fewer smaller effects mirroring them in the verge and boundary. In spring oilseed rape fields, the cover, flowering and seeding of plants were 25%, 44% and 39% lower, respectively, in the GMHT uncropped tilled margins. Similarly, for beet, flowering and seeding were 34% and 39% lower, respectively, in the GMHT margins. For maize, the effect was reversed, with plant cover and flowering 28% and 67% greater, respectively, in the GMHT half. Effects on butterflies mirrored these vegetation effects, with 24% fewer butterflies in margins of GMHT spring oilseed rape. The likely cause is the lower nectar supply in GMHT tilled margins and crop edges. Few large treatment differences were found for bees, gastropods or other invertebrates. Scorching of vegetation by herbicide–spray drift was on average 1.6% on verges beside conventional crops and 3.7% beside GMHT crops, the difference being significant for all three crops.
Responses of plants and invertebrate trophic groups to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide–tolerant crops
Authors:   The American Association for Research into Nervous and Mental Diseases, Hawes C. , Haughton A. J. , Osborne J. L. , Roy D. B. , Clark S. J. , Perry J. N. , Rothery P. , Bohan D. A. , Brooks D. R. , Champion G. T. , Dewar A. M. , Heard M. S. , Woiwod I. P. , Daniels R. E. , Young M. W. , Parish A. M. , Scott R. J. , Firbank L. G. , Squire G. R.
Published: October 2003

Effects of genetically modified herbicide–tolerant (GMHT) and conventional crop management on invertebrate trophic groups (herbivores, detritivores, pollinators, predators and parasitoids) were compared in beet, maize and spring oilseed rape sites throughout the UK. These trophic groups were influenced by season, crop species and GMHT management. Many groups increased twofold to fivefold in abundance between early and late summer, and differed up to 10–fold between crop species. GMHT management superimposed relatively small (less than twofold), but consistent, shifts in plant and insect abundance, the extent and direction of these effects being dependent on the relative efficacies of comparable conventional herbicide regimes. In general, the biomass of weeds was reduced under GMHT management in beet and spring oilseed rape and increased in maize compared with conventional treatments. This change in resource availability had knock–on effects on higher trophic levels except in spring oilseed rape where herbivore resource was greatest. Herbivores, pollinators and natural enemies changed in abundance in the same directions as their resources, and detritivores increased in abundance under GMHT management across all crops. The result of the later herbicide application in GMHT treatments was a shift in resource from the herbivore food web to the detritivore food web. The Farm Scale Evaluations have demonstrated over 3 years and throughout the UK that herbivores, detritivores and many of their predators and parasitoids in arable systems are sensitive to the changes in weed communities that result from the introduction of new herbicide regimes.
The spindle checkpoint requires cyclin-dependent kinase activity
Authors: D'Angiolella Vincenzo , Mari Cecilia , Nocera Donatella , Rametti Linda , Grieco Domenico
Published: October 2003

The spindle checkpoint prevents anaphase onset until completion of mitotic spindle assembly by restraining activation of the ubiquitin ligase anaphase-promoting complex/cyclosome–Cdc20 (APC/CCdc20). We show that the spindle checkpoint requires mitotic cyclin-dependent kinase (cdk) activity. Inhibiting cdk activity overrides checkpoint-dependent arrest in Xenopus egg extracts and human cells. Following inhibition, the interaction between APC/C and Cdc20 transiently increases while the inhibitory checkpoint protein Mad2 dissociates from Cdc20. Cdk inhibition also overcomes Mad2-induced mitotic arrest. In addition, in vitro cdk1-phosphorylated Cdc20 interacts with Mad2 rather than APC/ C. Thus, cdk activity is required to restrain APC/CCdc20 activation until completion of spindle assembly.
Quality labels as a marketing advantage
Authors: Fotopoulos Christos , Krystallis Athanasios
Published: October 2003

The adoption of different quality assurance schemes, such as the Protected Denomination of Origin/Geographical Indication (PDO/PGI) by the European Union, has been a response to the growing demand for certified quality food products among consumers. Tries to offer some more insights into the effectiveness of the PDO scheme and its acceptance by the consumer. The use of conjoint analysis in exploring Greek consumers’ willingness to pay (WTP) for PDO apples from the area of Zagora, Central Greece, has been selected as one of the most appropriate approaches to that target. Opens with a brief theoretical background presentation on the concepts of food quality and labelling. Proceeds with a detailed description of the research methodology, focusing on the WTP measurement method through the use of conjoint analysis, the identification of segments based on the importance consumers attach to the PDO label and the development of their profiles. Finally, concludes with some thoughts regarding the managerial implications of the findings, the limitations of the survey and the suggested research extensions.
The political cybernetics of organisations
Authors: Yolles Maurice
Published: October 2003

Viable systems theory is a development of managerial cybernetics within a critical systems theory context. The theory not only addresses cybernetics, it also shows how politics is fundamental to it. Politics used power and power processes to shape structures, manipulate information, and influence the way that people behave. The concept of centripetal politics used by Ionescu in his discussion of the changes over the last century to society is applied to organisations and their political processes. The outcome suggests the possibility of a political map that has the potential to explain organisational behaviour.
Emotion: the missing part of systems methodologies
Authors: Wang Catherine L. , Ahmed Pervaiz K.
Published: October 2003

This conceptual paper first examines the critical evolutionary stage of systems methodologies – from hard systems to soft systems, and elaborates their different focuses. This paper further explores the granularity of the “softness” of systems methodologies, and identifies a missing part: emotion. The emotional aspect of systems is associated to various soft elements of systems methodologies, such as value, perception, human well‐being, creativity and learning. Unfortunately, existing literature does not demonstrate a sufficient consideration of the role of emotion in systems methodologies. This paper incorporates the emotional aspect and discusses the role of emotion in effective systems methodologies.
Using raster quasi‐topology as a tool to study spatial entities
Authors: Li Yongli , Li Zhilin , Chen Yong‐qi , Li Xiaoxia
Published: October 2003

The study of spatial entities needs a model that is not only fully observable and controllable, but also computable. Euclidean topology on R2 is a usually used tool for this study, but it has the following two weaknesses. First, there exists some phenomenon of human perception of the spatial entity that cannot be simulated by it. Second, its observation of the basic geometric properties (interior, exterior, boundary) of the spatial entity lacks computability so that the model based on it lacks computability and cannot be directly used to practical systems. Consequently, in this paper, we present another tool for studying spatial entities – raster quasi‐topology on R2 and then compare the two tools.
Choosing leisure services: the effects of consumer timestyle
Authors: Cotte June , Ratneshwar S.
Published: October 2003

As the leisure industry matures, it is important for marketers to have a clear understanding of why people choose to consume specific leisure services. The paper proposes that “timestyle”, or how a person customarily perceives and uses time, influences the choice of leisure goals and resultant leisure services. Individuals’ timestyles can be characterized in terms of social, temporal, planning, and polychronic orientations. Data from qualitative research suggest that all four dimensions of timestyle can have systematic effects on leisure choices. Knowledge of the timestyle concept and its antecedent influences should allow leisure marketers to better understand and target the motivations that underlie consumer decisions on leisure services.
Antecedents to consumers’ disclosing intimacy with service employees
Authors: Hansen Håvard
Published: October 2003

The paper presents a model that suggests that four relationship variables traditionally found to affect behavior beneficial to the firm also increase consumers’ disclosing intimacy. Employee benevolence, credibility, image, and consumers’ satisfaction with the relationship to the employee are all proposed to increase intimate disclosures by the consumer. The model is tested in a sample of retail bank customers using structural equation modeling. The findings support the important role of benevolence and image, but do not confirm the hypothesized effects of credibility and satisfaction. The results and managerial implications are discussed and limitations and suggestions for future research presented.
Managerial implications of predicting purchase behavior from purchase intentions: a retail patronage case study
Authors: Newberry C. Robert , Klemz Bruce R. , Boshoff Christo
Published: October 2003

Services managers are dependent on forecasting purchase behavior when making resource allocation decisions. Purchase intentions are commonly used as a basis to forecast purchase behavior. This practice is, however, not without its critics. In a study of restaurant patrons, it was found that the patrons who expressed strong purchase intent and made a subsequent purchase demonstrated distinct attitudes differences when compared to those patrons who also expressed strong purchase intent but failed to make a subsequent purchase. The results suggest that the service manager could be misled, and therefore could make costly service mix mistakes, if purchase intent is used solely to model purchase behavior. Specific strategy implications are discussed.
Queer Patriarchies, Queer Racisms, International
Authors: Nast Heidi J
Published: October 2003

This paper explores the potential for certain gay white men to benefit from postindustrial sectors that depend structurally and implicitly upon white supremacy and heteropatriarchy. The paper maps out how gay white patriarchies coexist with, and in some cases displace, heteronormative patriarchies, shoring up pre–existing racialized and politically and economically conservative processes of profit–accumulation. Former cultural investments in a fatherhood defined by biological procreation are accordingly dislodged by investments in fatherhoods abstracted from procreation, which circulate in a variety of commodity forms. Motherhood is geographically and socially sidelined, procreation becoming a service and commodity form purchasable from impoverished places within or outside nations. The white oedipal Family romance is geopolitically reconstituted, with the proprietary reach of patriarchy irrupting out of the confines of the biologically homebound and racist triad of mother–father–son and into extrafamilial, and often transnationalized, domains of racialized and class–transected procreational purchase.
Language and Other Abstract Objects [1981]: The Metaphysics Of Linguistics
Authors: McEvoy Mark
Published: October 2003

Book reviewed:

Jerrold J. Katz, Language and Other Abstract Objects
The Metaphysics of Meaning [1990]
Authors: Meehan Douglas B.
Published: October 2003

Book reviewed:

Jerrold J. Katz, The Metaphysics of Meaning
Sense, Reference, and Philosophy [2003]: The Epimenidean Dilemma and the Definition of Truth
Authors: McDonald Fritz
Published: October 2003

Book reviewed:

Jerrold J. Katz, Sense, Reference, and Philosophy
Horror Angelorum: Terroristic Structures in the Eyes of Walter Benjamin, Hans Urs Von Balthasar's Rilke and Slavoj Žižek
Authors: Maeseneer Yves de
Published: October 2003

In search for a European theological contribution to the debate on the new global context, this essay undertakes a theological‐aesthetic exploration of theological motifs in the current political imagination, in particular: the theme of the angel. After a problematisation of the theological reception of Benjamin's Messianic‐apocalyptic angel figure, I develop a critical position in the wake of von Balthasar. Von Balthasar's interpretations of Rilke and Bonaventure lead to two angelological paradigms, the monad and the crucified seraph, which occur in current political debates, as exemplified in recent essays of Zizek.
Voluntary Environmental Agreements: Taking Up Positions And Meeting Pressure
Authors: Grepperud Sverre , Pedersen Pål Andreas
Published: October 2003

This paper portrays voluntary agreements as a Nash‐bargaining game between the authorities and the polluting industry. Before bargaining starts, the authorities threaten to introduce emission licences if the negotiations come to nothing, while industry, by the use of lobbying campaigns, can make it politically costly to regulate by law. The most likely game of the ones considered is characterized by the authorities first announcing a level of licensing, whereupon industry will adjust its lobbying activity. This game results in a relatively defensive industry and authorities than other games under consideration.
Encouraging School Attendance in Mozambique by Granting a Minimum Income to Parents
Authors: Lavinas Lena
Published: October 2003

This article explains the reasons behind the introduction of Minimum Income for School Attendance (MISA) programmes in sub‐Saharan Africa. Following a brief description of the ideas behind these programmes and their advantages over the traditional social security safety nets and guaranteed‐income programmes, we describe the pilot scheme which the government of Mozambique is intending to introduce in 2003 and evaluate its prospects for success and the trade‐offs which will have to be made. We then explore the contribution which such a plan can make to the creation of a social protection system, which still does not exist in Mozambique.