bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Heliothis subflexa herbivory on fruit abscission by Physalis species: the roles of mechanical damage and chemical factors
Authors: PETZOLD JENNIFER , BROWNIE CAVELL , GOULD FRED
Published: August 2009

1. Insect oral secretions are important for the induction of a number of plant responses, but the relative role of mechanical damage in the induction of these responses is often not well understood. Damage from the frugivore Heliothis subflexa, a specialist on Physalis species, causes herbivore‐induced fruit abscission. In this field study, we examined the separate and combined effects of mechanical damage and H. subflexa oral secretions on Physalis fruit abscission.

2. To determine the relative role of mechanical and chemical factors, the following treatments were administered to fruit: (1) three levels of mechanical damage, (2) natural herbivore damage by control larvae and by larvae surgically treated to inhibit saliva secretion, and (3) injection of H.subflexa oral secretions and a water control. Abscission of mechanically damaged fruit with and without the addition of oral secretions was also compared.

3. Mechanical damage was sufficient to cause fruit abscission, and the addition of oral secretions to mechanically damaged fruit did not cause an increase in fruit abscission. Normal caterpillars and those treated to inhibit saliva secretion caused similar abscission rates.

4. Though most studies examining the effects of insect oral secretions on induced plant responses find these chemical stimuli to be important or essential, the results of the present study showed that oral secretions are not necessary for fruit abscission. Future work is needed to determine the relative importance of mechanical damage in herbivore‐induced plant responses in other systems.
Adapted DAX‐8 fractionation method for dissolved organic matter (DOM) from soils: development, calibration with test components and application to contrasting soil solutions
Authors: Amery F. , Vanmoorleghem C. , Smolders E.
Published: August 2009

Most methods to fractionate natural dissolved organic matter (DOM) rely on sorption of acidified DOM samples onto XAD‐8 or DAX‐8 resin. Procedural differences among methods are large and their interpretation is limited because there is a lack of calibration with DOM model molecules. An automated column‐based DOM fractionation method was set up for 10‐ml DOM samples, dividing DOM into hydrophilic (HPI), hydrophobic acid (HPOA) and hydrophobic neutral (HPON) fractions. Fifteen DOM model components were tested in isolation and in combination. Three reference DOM samples of the International Humic Substances Society were included to facilitate comparison with other methods. Aliphatic low‐molecular‐weight acids (LMWAs) and carbohydrates were classified as HPI DOM, but some LMWAs showed also a partial HPO character. Aromatic LMWAs and polyphenols partitioned in the HPOA fraction, menadione (quinone) and geraniol (terpenoid) in HPON DOM. Molecules with log Kow > 0.5 had negligible HPI fractions. The HPO molecules except geraniol had specific UV absorbance (SUVA, measure for aromaticity) >3 litres g−1 cm−1 while HPI molecules had SUVA values <3 litres g−1 cm−1. Distributions of DOM from eight soils ranged from 31 to 72% HPI, 25 to 46% HPOA and 2 to 28% HPON of total dissolved organic carbon. The SUVA of the HPI DOM was consistently smaller compared with the HPOA DOM. The SUVA of the natural DOM samples was not explained statistically by fractionation and the variation coefficient of SUVA among samples was not reduced by fractionation. Hence, fractionation did not reduce the variability in this DOM property, which casts some doubts on the practical role of DOM fractionation in predicting DOM properties.
Diversity of total, nitrogen‐fixing and denitrifying bacteria in an acid forest soil
Authors: Rösch C. , Bothe H.
Published: August 2009

To assess the diversity of total, denitrifying and N2‐fixing bacteria in a nitrogen (N)‐limited, acid forest soil, isolated DNA was analysed for the genes 16S rRNA, nosZ and nifH. Sequence information for these genes was obtained from clone libraries and from our TReFID computer program, which employs terminal restriction patterns for bacteria using multiple restriction enzymes. Both approaches indicated that Proteobacteria (α‐ and γ‐groups) and Acidobacteria dominated. A comprehensive list of bacteria retrieved from this soil is provided and compared with literature data on the bacterial community compositions from other sites. The study indicated that the current PCR conditions with the primers employed allowed retrieval of only a portion of the bacteria occurring in soils. Massive treatment of a soil plot with NH4NO3 caused an increase in the N content, which was rapidly followed by an enhancement of carbon (C) content. Thus the C/N ratio stayed below 16.0 and the soil remained N‐limited. This may explain why the bacterial diversity did not undergo drastic shifts as was tentatively inferred from the available data sets.
Near infrared spectroscopy for soil bulk density assessment
Authors: Moreira C. S. , Brunet D. , Verneyre L. , Sá S. M. O. , Galdos M. V. , Cerri C. C. , Bernoux M.
Published: August 2009

Soil bulk density values are needed to convert organic carbon content to mass of organic carbon per unit area. However, field sampling and measurement of soil bulk density are labour‐intensive, costly and tedious. Near‐infrared reflectance spectroscopy (NIRS) is a physically non‐destructive, rapid, reproducible and low‐cost method that characterizes materials according to their reflectance in the near‐infrared spectral region. The aim of this paper was to investigate the ability of NIRS to predict soil bulk density and to compare its performance with published pedotransfer functions. The study was carried out on a dataset of 1184 soil samples originating from a reforestation area in the Brazilian Amazon basin, and conventional soil bulk density values were obtained with metallic “core cylinders”. The results indicate that the modified partial least squares regression used on spectral data is an alternative method for soil bulk density predictions to the published pedotransfer functions tested in this study. The NIRS method presented the closest‐to‐zero accuracy error (−0.002 g cm−3) and the lowest prediction error (0.13 g cm−3) and the coefficient of variation of the validation sets ranged from 8.1 to 8.9% of the mean reference values. Nevertheless, further research is required to assess the limits and specificities of the NIRS method, but it may have advantages for soil bulk density predictions, especially in environments such as the Amazon forest.
Lipopolysaccharide binding of the mite allergen Der f 2
Authors: Ichikawa Saori , Takai Toshiro , Yashiki Tomoe , Takahashi Seizo , Okumura Ko , Ogawa Hideoki , Kohda Daisuke , Hatanaka Hideki
Published: August 2009

Lipid‐binding properties and/or involvement with host defense are often found in allergen proteins, implying that these intrinsic biological functions likely contribute to the allergenicity of allergens. The group 2 major mite allergens, Der f 2 and Der p 2, show structural homology with MD‐2, the lipopolysaccharide (LPS)‐binding component of the Toll‐like receptor (TLR) 4 signalling complex. Elucidation of the ligand‐binding properties of group 2 mite allergens and identification of interaction sites by structural studies are important to explore the relationship between allergenicity and biological function. Here, we report a ligand‐fishing approach in which His‐tagged Der f 2 was incubated with sonicated stable isotope‐labelledEscherichia colias a potential ligand source, followed by isolation of Der f 2‐bound material by a HisTrap column and NMR analysis. We found that Der f 2 binds to LPS with a nanomolar affinity and, using fluorescence and gel filtration assays that LPS binds to Der f 2 in a molar ratio of 1 : 1. We mapped the LPS‐binding interface of Der f 2 by NMR perturbation studies, which suggested that LPS binds Der f 2 between the two large β‐sheets, similar to its binding to MD‐2, the LPS‐binding component of the innate immunity receptor TLR4.
A temporal perspective of the computer game development process
Authors: Stacey Patrick , Nandhakumar Joe
Published: August 2009

Abstract.  This paper offers an insight into the games software development process from a time perspective by drawing on an in‐depth study in a games development organization. The wider market for computer games now exceeds the annual global revenues of cinema. We have, however, only a limited scholarly understanding of how games studios produce games. Games projects require particular attention because their context is unique. Drawing on a case study, the paper offers a theoretical conceptualization of the development process of creative software, such as games software. We found that the process, as constituted by the interactions of developers, oscillates between two modes of practice: routinized and improvised, which sediment and flux the working rhythms in the context. This paper argues that while we may predeterminately lay down the broad stages of creative software development, the activities that constitute each stage, and the transition criteria from one to the next, may be left to the actors in the moment, to the temporality of the situation as it emerges. If all development activities are predefined, as advocated in various process models, this may leave little room for opportunity and the creative fruits that flow from opportunity, such as enhanced features, aesthetics and learning.
Anticipatory anxiety in children visiting the dentist: lack of effect of preparatory information
Authors: OLUMIDE FUNMI , NEWTON J TIM , DUNNE STEPHEN , GILBERT DAVID B.
Published: August 2009

Aim.  This study sought to explore whether viewing a leaflet explaining the benefits of dental treatment would have a significant impact on children's anticipatory anxiety.

Method.  Fifty children aged 8–12, attending the paediatric dental clinic of King's College Hospital, London, took part in this triple‐masked, randomized control study. The participants were randomly allocated to one of two groups and either shown an intervention leaflet containing child‐friendly dental information (the experimental group) or a leaflet with child‐friendly information on the benefits of healthy eating (the control group). Using the Facial Image Scale, anxiety was measured when the children arrived for their dental appointment, once before reading the leaflet and again after reading the leaflet.

Results.  There was no statistically significant effect of the experimental leaflet on self‐reported anxiety levels in this study, although anxiety levels did drop slightly in both groups after reading a leaflet.

Conclusions.  Providing paediatric patients with preparatory information about what to expect from a visit to the dentist had no effect on anticipatory anxiety in comparison to reading a leaflet about healthy eating. We speculate that reading, or cognitive processing, may have some beneficial effect. Future work should investigate this possibility.
Winter warming events damage sub‐Arctic vegetation: consistent evidence from an experimental manipulation and a natural event
Authors: Bokhorst Stef F. , Bjerke Jarle W. , Tømmervik Hans , Callaghan Terry V. , Phoenix Gareth K.
Published: August 2009

1.  The Arctic is experiencing considerable change in climate, particularly in winter, and a greater frequency of extreme climatic events is expected. However, the impacts of winter climate change and extreme events have received far less attention than the impacts of season‐long summer warming. Here we report findings from observations following a natural event and from experimental studies to show that short (<10 days) extreme winter warming events can cause major damage to sub‐Arctic plant communities at landscape scales.

2.  In the landscape observations, impacts were assessed following an extreme winter warming event that occurred in December 2007 in northern Scandinavia. During this event, temperatures rose up to 7 °C resulting in loss of snow cover and exposure of vegetation to firstly warm and then returning cold temperatures.

3.
 In the following summer, extensive areas of damaged dwarf shrub vegetation could be observed. Ground observations showed damaged areas to have a 16 times greater frequency of dead shoots of the dominant shrub Empetrum hermaphroditum, resulting in 87% less summer growth compared to neighbouring undamaged areas. The landscape scale extent of this damage was confirmed by satellite‐derived Normalized Differential Vegetation Index values that showed a considerable 26% reduction (comparing July 2007 with July 2008 values) over an area of 1424 km2. This reduction indicates a significant decline in either leaf area or photosynthetic capacity or efficiency at the landscape scale.

4.
 Strikingly similar damage was also observed in a field manipulation experiment using heating lamps and soil warming cables to simulate such extreme events in sub‐Arctic heathland over two winters. Here, an up to 21 times greater frequency of dead shoots and 47% less shoot growth of E. hermaphroditum was observed in plots exposed to simulated winter warming events compared to unmanipulated controls.

5.
 Synthesis. These combined landscape observations and experimental findings provide compelling evidence that winter warming events can cause considerable damage to sub‐Arctic vegetation. With increasing winter temperatures predicted, any increase in such damage may have major consequences for productivity and diversity of these sub‐Arctic ecosystems, in contrast to the greening of parts of the Arctic currently attributed to summer warming.
Inclusion of biotic stress (consumer pressure) alters predictions from the stress gradient hypothesis
Authors: Smit Christian , Rietkerk Max , Wassen Martin J.
Published: August 2009

1.  The stress gradient hypothesis (SGH) predicts a shift from net negative interactions in benign environments towards net positive in harsh environments in ecological communities. While several studies found support for the SGH, others found evidence against it, leading to a debate on how nature and strength of species interactions change along stress gradients, and to calls for new empirical and theoretical work.

2.  In the latest attempt in this journal, it is successfully argued how the SGH should be expanded by considering different life strategies of species (stress tolerance versus competitive ability) and characteristics of abiotic stress (resource versus non‐resource based) over wider stress gradients (opposed to low–high contrasts), but the crucial role of biotic stress by consumers is largely ignored in this refinement.

3.  We point out that consumers strongly alter the outcome of species interactions in benign and harsh environments, and show how inclusion of consumer‐incurred biotic stress alters the predicted outcome of interactions along resource‐ and non‐resource‐based stress gradients for stress‐tolerant and competitive benefactors and beneficiaries.

4.
 Synthesis. New studies should include stress gradients consisting of both abiotic and biotic components to disentangle their impacts, and to improve our understanding of how species interactions change along environmental gradients.
A mutational wrench in the HAMP gearbox
Authors: Manson Michael D.
Published: August 2009

HAMP domains communicate between input and output signalling elements in bacterial proteins. In the Tsr chemoreceptor, they convert axial movement of transmembrane helix 2 into changes in packing of the cytoplasmic kinase‐control module (KCM). Zhou et al. suggest transmembrane helix 2 ‘tugs’ on HAMP to destabilize x‐da packing of the parallel four‐helix bundle of the HAMP homodimer. Attractants would inhibit tugging. HAMP stability may be inversely related to stability of the a‐d packing of the anti‐parallel four‐helix bundle of KCM, a relationship possibly facilitated by HAMP/KCM helical mismatch. The beauty of this idea lies in its simplicity and testability.
Comparison of three diagrammatic keys for the quantification of late blight in tomato leaves
Authors: Corrêa F. M. , Bueno Filho J. S. S. , Carmo M. G. F.
Published: August 2009

Three diagrammatic grading keys were designed for the assessment of the severity of late blight (caused by Phytophthora infestans) in tomato leaves. Simplified and broad keys considered, respectively, six (3, 12, 22, 40, 60 and 77%) and eight (3, 6, 12, 22, 40, 60, 77 and 90%) levels of disease severity, whilst a modified key based on a previous proposal for potato late blight considered six levels (1, 5, 10, 16, 32 and 50%). The keys were validated by 24 evaluators who assessed digital images of tomato leaves exhibiting different areas with lesions. Evaluator errors were compared using a mixed model in which evaluators were considered as random effects and the keys and evaluations as fixed effects. The accuracy and precision of the evaluators were compared by simple linear regression between the estimated and actual values of disease severity. The repeatability of evaluators was assessed using Pearson’s correlation coefficient. There was significant (P ≤ 0·001) variability amongst the errors made by evaluators, although the precision of each of the three keys was high with a coefficient of determination (R2) of 0·96, 0·93 and 0·83 for the simplified, broad and modified key, respectively. Repeatability of estimations amongst the evaluators was adequate (correlation coefficients of 0·91, 0·91 and 0·90 for the three keys, respectively). The simplified and broad keys resulted in higher precision and accuracy for the estimation of severity than did the modified key. Since the simplified key considers a smaller number of disease severity levels, its use is recommended in the assessment of late blight in tomato leaves.
Canopy‐microclimate effects on the antagonism between Trichoderma stromaticum and Moniliophthora perniciosa in shaded cacao
Authors: Loguercio L. L. , Santos L. S. , Niella G. R. , Miranda R. A. C. , De Souza J. T. , Collins R. T. , Pomella A.W.V.
Published: August 2009

The collective impact of several environmental factors on the biocontrol activity of Trichoderma stromaticum (Ts) against Moniliophthora perniciosa (Mp), the cause of cacao witches’ broom disease, was assessed under field conditions of shaded cacao (Theobroma cacao) in south‐eastern Bahia, Brazil. Biocontrol experiments were performed adjacent to an automated weather station, with sensors and Ts‐treated brooms placed at different canopy heights. Sporulation occurred at the same dates for all Ts isolates, but in different quantities. Broom moisture >30%, air temperature of approximately 23 ± 3°C, relative humidity >90%, solar radiation intensities <0·12 KW m−² and wind speed near zero were the key environmental parameters that preceded Ts sporulation events. A multiple logistic regression indicated that these weather variables combined were capable of distinguishing sporulation from non‐sporulation events, with a significant effect of wind speed. Analyses of environmental factors at ground level indicated similar pre‐sporulation conditions, with a soil moisture content above a threshold of 0·34 m3 m−3 preceding all sporulation events. The sporulation of five selected Ts isolates was compared at four different canopy heights. Isolates responded differently to weather variation in terms of sporulation and antagonism to Mp at different canopy levels, indicating that different microclimates are established along the vertical profile of a shaded cacao plantation. The potential of these findings for development of predictive mathematical models and disease‐management approaches is discussed.
Seed viability determination in parasitic broomrapes (Orobanche and Phelipanche) using fluorescein diacetate staining
Authors: THOROGOOD C J , RUMSEY F J , HISCOCK S J
Published: August 2009

Fluorescein diacetate (FDA) was investigated as a potential viability stain for seeds of holoparasitic broomrapes Orobanche and Phelipanche (Orobanchaceae), using four weedy and two non‐weedy taxa. FDA viabilities were compared with the currently used 2,3,5‐triphenyl tetrazolium chloride (TTC) test, and in vitro germination induced by the strigolactone analogue GR‐24. Viable FDA‐stained seeds were characterised by bright yellow–green fluorescence under 450–490 nm blue light. These viable seeds could be discriminated from non‐viable seeds, in which low levels of fluorescence, similar to non‐stained control seeds were observed. FDA viabilities were not significantly different from those obtained using the TTC stain; however, viability values for both stains were consistently higher than levels of artificially induced germination. Positive TTC‐staining showed continuous variation that was difficult to interpret. Nevertheless, the TTC test does not involve grinding seeds, and therefore probably remains a practical alternative to FDA for screening soil samples contaminated with Orobanche and Phelipanche seeds, which indicates different applications for the two viability tests. Interestingly, the strigolactone analogue GR‐24 only induced germination in O. crenata, P. ramosa and O. minor, suggesting a high specificity towards this germination inducer among the species investigated. We suggest that FDA‐staining provides a potential alternative to the currently used TTC test for seed viability assays for Orobanche and Phelipanche, and other parasitic weeds which are an obstacle to crop cultivation.
An amino acid substitution at position 205 of acetohydroxyacid synthase reduces fitness under optimal light in resistant populations of Solanum ptychanthum
Authors: ASHIGH J , TARDIF F J
Published: August 2009

The Ala205Val substitution in acetohydroxyacid synthase confers herbicide resistance in Solanum ptychanthum, but the effect on fitness is unknown. This study aimed to compare the germination, growth, seed production and competitiveness of resistant (R) and susceptible (S) populations under various light conditions in the field and in a controlled environment. Under optimal light conditions of high irradiance and high red/far‐red, the S populations produced more seeds compared with R populations, despite no difference in germination and above‐ground vegetative productivity. Any reduction in light intensity and red/far‐red diminished the reproductive ability of both R and S populations. This effect was more pronounced for S, so that, under sub‐optimal conditions, there were no differences between the two types. Replacement series with three ratios of R:S (16:0, 8:8 and 0:16) showed no competitive difference between the two types. Under optimal light conditions, the S populations always had a higher reproductive output and fitness than the R populations. This would likely cause S individuals to dominate in the absence of herbicide selection pressure, if light competition is reduced.
Weed suppression ability of three winter wheat varieties at different row spacing under organic farming conditions
Authors: DREWS S , NEUHOFF D , KÖPKE U
Published: August 2009

For three seasons, six field trials were conducted in winter wheat (Triticum aestivum) at different sites in North Rhine‐Westphalia, Germany. The aim was to evaluate the performance of three varieties, which differ in their shading behaviour, in suppressing weeds under organic farming (Ökologischer Landbau) conditions and grown at three row spacings. The experimental factors were cultivar, row width and row orientation. Key parameters of crop and weed development, including ground cover and biomass, were assessed at different growth stages and analysed with anova. Growth of the site‐specific weed vegetation was significantly affected in five of six trials. Weed growth was reduced by cvs Astron and Pegassos compared with cv. Greif, and was lower at 12 cm compared with 24 cm row spacing. No effect of row orientation (East‐West, North‐South) on weed growth was observed. The more competitive cultivars Astron and Pegassos were taller than the less competitive cv. Greif and had higher ground cover and light interception, presumably induced by planophile leaf inclination and partly, in the case of cv. Astron, because of higher leaf area index (LAI). Narrow row spacing (12 cm), resulting in a more even spatial plant distribution, increased crop ground cover, LAI, dry matter and light interception. In two trials, the variety with planophile leaf inclination performed better at wider row spacing, suggesting that planophile wheat cultivars may be advantageous in wider row stands.
The relative generality of plant invasion mechanisms and predicting future invasive plants
Authors: REN M‐X , ZHANG Q‐G
Published: August 2009

This study presents an updated analysis of the relative generality of invasion mechanisms in invasive plants. We categorised eight invasion mechanisms into three classes, according to the ecological processes behind the invasions: physical environment mechanisms (phenotypic plasticity in environmental tolerance and evolutionary adaptation to physical environment), resource use mechanisms (resource competition, resource utilisation and allelopathy) and enemy release mechanisms (high growth/reproduction rate, evolutionarily increased competitive ability and phenotypic plasticity in resource allocation). An analysis of 133 invasive plant species in the literature showed the enemy release mechanisms are equally general as resource use mechanisms, while the physical environment mechanisms are less general. Among the eight specific invasion mechanisms, phenotypic plasticity (either in resource allocation or in environmental tolerance), allelopathy, evolutionarily increased competitive ability and high resource‐use efficiency are fairly common. Furthermore, chemical defence behaviour is very common in plant invaders. Species invading through enemy release were more likely to originate from Europe and those invading through resource competition/utilisation were often native to tropical and North America and Asia. Invaders with allelopathy were more likely to be from tropical and North America and those showing evolutionarily increased competitive ability were often native to temperate regions such as Europe and North America. Collectively, phenotypic plasticity, defence strategy and native status can be used not only to predict a plant’s invasiveness, but also for identifying the potential invasion mechanisms.
Relative fitness of females and hermaphrodites in a natural gynodioecious population of wild radish,Raphanus sativusL. (Brassicaceae): comparison based on molecular genotyping
Authors: MIYAKE K. , MIYAKE T. , TERACHI T. , YAHARA T.
Published: August 2009

In many gynodioecious species, sex determination involves both cytoplasmic male‐sterility (CMS) genes and nuclear genes that restore male function. Differences in fitness among genotypes affect the dynamics of those genes, and thus that of gynodioecy. We used a molecular marker to discriminate between hermaphrodites with and without a CMS gene in gynodioeciousRaphanus sativus.We compared fitness through female function among the three genotypes: females, hermaphrodites with the CMS gene and those without it. Although there was no significant difference among the genotypes in seed size, hermaphrodites without the CMS gene produced significantly more seeds, and seeds with a higher germination rate than the other genotypes, suggesting no fitness advantage for females and no benefit to bearing the CMS gene. Despite the lack of fitness advantage for females in the parameter values we estimated, a theoretical model of gynodioecy shows it can be maintained if restorer genes impose a cost paid in pollen production. In addition, we found that females invest more resources into female reproduction than hermaphrodites when they become larger. If environmental conditions enable females to grow larger this would facilitate the dynamics of CMS genes.
Complete lack of mitochondrial divergence between two species of NE Atlantic marine intertidal gastropods
Authors: KEMPPAINEN P. , PANOVA M. , HOLLANDER J. , JOHANNESSON K.
Published: August 2009

Some mitochondrial introgression is common between closely related species, but distinct species rarely show substantial introgression in their entire distribution range. In this study, however, we report a complete lack of mitochondrial divergence between two sympatric species of flat periwinkles (Littorina fabalis and Littorina obtusata) which, based on previous allozyme studies, diverged approximately 1 Ma. We re‐examined their species status using both morphology (morphometric analysis) and neutral genetic markers (microsatellites) and our results confirmed that these species are well separated. Despite this, the two species shared all common cytochrome‐b haplotypes throughout their NE Atlantic distribution and no deep split between typical L. fabalis and L. obtusata haplotypes could be found. We suggest that incomplete lineage sorting explains most of the lack of mitochondrial divergence between these species. However, coalescent‐based analyses and the sympatric sharing of unique haplotypes suggest that introgressive hybridization also has occurred.
Selection of low investment in sex in a cyclically parthenogenetic rotifer
Authors: CARMONA M. J. , DIMAS‐FLORES N. , GARCÍA‐ROGER E. M. , SERRA M.
Published: August 2009

Cyclical parthenogens, which combine asexual and sexual reproduction, are good models for research into the ecological and population processes affecting the evolutionary maintenance of sex. Sex in cyclically parthenogenetic rotifers is necessary for diapausing egg production, which is essential to survive adverse conditions between planktonic growing seasons. However, within a planktonic season sexual reproduction prevents clonal proliferation. Hence, clones with a low propensity for sex should be selected, becoming dominant in the population as the growing season progresses. In this context, we studied the dynamics of the heritable variation in propensity for sexual reproduction among clones of aBrachionus plicatilisrotifer population in a temporary Mediterranean pond during the period the species occurred in plankton. Clonal isolates displayed high heritable variation in their propensity for sex. Moreover, the frequency of clones with low propensity for sex increased during the growing season, which supports the hypothesized short‐term selection for low investment in sex within a growing season. These results demonstrate (1) the inherent instability of the cyclical parthenogenetic life cycle, (2) the cost of sexual reproduction in cyclical parthenogens where sex produces diapausing eggs and (3) the role of the association between sexual reproduction and diapause in maintaining sex in these cyclical parthenogens.
Extra‐pair fertilizations contribute to selection on secondary male ornamentation in a socially monogamous passerine
Authors: ALBRECHT T. , VINKLER M. , SCHNITZER J. , POLÁKOVÁ R. , MUNCLINGER P. , BRYJA J.
Published: August 2009

Despite considerable research effort, it remains unclear whether extra‐pair fertilizations (EPF) drive the evolution of male secondary ornamentation in socially monogamous systems. In this study, we test the hypothesis that EPF contribute to the evolution or maintenance of male feather ornamentation in a sexually dichromatic passerine, the Scarlet Rosefinch, Carpodacus erythrinus. We show that the colouration of ornamental breast feathers is a good predictor of basic sources of variation in male annual reproductive output in rosefinches and that the annual realized reproductive success of males is positively associated with measures of ornamental colouration only when gains and losses because of EPF are considered. The results indicate that EPF in rosefinches may rely on absolute (good genes) rather than self referential (genetic complementarity) criteria of mate choice. Our study corroborates the potentially important role of EPF in the evolution and/or maintenance of elaborate male ornaments in socially monogamous taxa.
Nursing and the reality of politics
Authors: Betts Clinton E
Published: August 2009

Notwithstanding the remarkable achievements made by medical science over the last half of the twentieth century, there is a palpable sense that a strictly medical view of human health, that is one founded on modernist assumptions, has become problematic, if not counterproductive. In this study, I argue that as nursing continues to eagerly welcome and indeed champion medical epistemology in the form of knowledge transfer, evidence‐based practice, research utilization, outcomes‐based practice, quantifiable efficiency and effectiveness, it risks becoming little more than a medical science addendum and indeed one that inherits the problems now facing contemporary medicine. The purpose of this study then is to attempt to resituate nursing as a discipline at work within an ontopolitical matrix of radical democratic pluralism. I begin by tracing a philosophical line from Kuhn’s paradigms to Bloor’s strong programme of Sociology of Scientific Knowledge. Following this, I attempt to explicate the thought of Bruno Latour as a philosophical alternative to Sociology of Scientific Knowledge. Next, I outline the radical pluralism of William Connolly in an effort to demonstrate its similarity to Latour’s philosophy and finally how such a position is germane to contemporary nursing and the reality of politics. I do this with reference to the controversial issue of illicit drug use and harm reduction. In effect, I argue that such an issue cannot be dealt with using scientific evidence alone, but rather requires a philosophy of advocacy, what I term democratic advocacy, that is capable of responding to the politics of suffering, which is to say suffering that results from identity/difference.
Complexity and contradiction: home care in a multicultural area
Authors: Skott Carola , Lundgren Solveig M
Published: August 2009

The aim of this study was to explore the meaning of experience for home‐care nurses in a multicultural area of Sweden. Interviews and group discussions with a team of five home‐care nurses were interpreted in accordance with a hermeneutical perspective. The meaning was expressed in connection with the complexities of place, and space for care. Contradictions developed from diversities of perspectives incorporated in this particular multicultural area. Nurses saw themselves as mediators and allowed complexity to be considered in order to manage care. They took on responsibility of creating a ‘space of care’, while the organizational structures of home care were perceived as something outside the care praxis. Making contradictions evident renders an intermediary caring strategy feasible.
The replacement of the replacement in menopause: hormone therapy, controversies, truth and risk
Authors: Burrell Beverley A.
Published: August 2009

A Foucauldian discourse analysis is employed to identify how our current understandings of menopause are culturally and historically determined by medical discourse. The polarity of the normal and the abnormal (pathological) became the crux of medical deliberation, where deviation from norms becomes the reason for intervention. Through manifold relations of power and the ‘struggle of knowledges’ medicine derives social authority, influencing social orthodoxies thus normalising menopausal women via discursive constructs. The course of nature in ageing women has been re‐categorised as unnatural. In using the case of hormone therapy (HT) and the emergence of bio‐identical or natural hormones, while deconstructing the premises used in marketing both types of hormone therapy, the tenuousness of scientific claims about these hormones is revealed. Discourses on bio‐identical hormones (BHT) display a reliance on seemingly opposing naturalist and scientific arguments. Menopause, having been constructed as a deficiency disease, required initially chemical hormone replacement and now bio‐identical hormones replacing the mainstream medical solution. The idea of the postmenopausal state as diseased is perpetuated as the basis to suggest therapies to women. This paper suggests that although therapeutic in a few cases, hormone preparations are in fact potentially dangerous lifestyle drugs.
Comparative effects of different smoke treatments on germination of Australian native plants
Authors: LLOYD MICHAEL V. , DIXON KINGSLEY W. , SIVASITHAMPARAM K.
Published: August 2009

Abstract
This study consists of a series of investigations designed to determine the potential of concentrated smoke products to stimulate seed germination and assist in the rehabilitation of degraded landscapes. Aerosol smoke and conventional smoke water products are not practical for use in broad‐scale seed bank regeneration programmes due to infrastructure limitations and the high rate of application required for their use. Concentrated smoke products have been found to be effective in stimulating soil seed banks and are suitable for broad‐scale use due to the lower rate of application required to elicit germination within smoke‐responsive species. The use of concentrated smoke products on undisturbed soil seed banks at 50 and 100 mL m‐2 increased total seedling numbers 10‐fold, while species richness more than doubled over untreated controls. Although aerosol smoke applied directly to soil promoted 10 times more seedlings compared to concentrated smoke products, species richness levels in each treatment were similar. Concentrated smoke products cause leaf scorch when applied directly over plants in active growth, with limited to nil damage when plants are not actively growing. The affected plants generally recovered following application of concentrated smoke products as a foliar spray.
Fire regimes of World Heritage Kakadu National Park., Australia
Authors: GILL A. M. , RYAN P. G. , MOORE P. H. R. , GIBSON M.
Published: August 2009

Abstract
LANDSAT Multi‐Spectral Scanner imagery was used to determine aspects of the fire regimes of Kakadu National Park (in the wet‐dry tropics of Australia) for the period 1980–1995. Three landscape types recognized in this Park were Plateau, Lowlands and Floodplain. Areas burned in early and late dry seasons each year were documented using a Geographical Information System. Regression analyses were used to examine time trends in the areas burned each year and the interrelationships between early and late dry season burning. The proportions of landscapes having different stand ages (years since fire), and the proportions having had different fire intervals, were compared with results expected from the simplest random model (i.e. one in which the probability of ignition at a point [PIP] burning annually was constant). Using overlays of successive stand‐age maps, PIP could be calculated as a function of stand age. The Lowlands burned extensively each year; the areas burned by late dry season fires adding to those burned in the early dry season such that around 50–60% of the total area burned annually. Early dry season fires have lower intensities than late dry season fires, on average. Using a theoretically constant PIP and the mean proportion burned per year as the only input, predictions of areas burned as a function of stand age and fire interval were reasonable when compared with the empirical data, but best for the Lowlands landscape. PIP functions for Lowlands and Floodplains had negative slopes, an unexpected result. The nature of these PIP functions may reflect heterogeneity in fire proneness of the various vegetation types within landscapes. The scale of measurement, the scale of variation in vegetation types within a landscape, and the accuracy of the determination of burned areas, are constraints on the accuracy of fire‐interval and seasonally determination perceived from an analysis of satellite data.
Is there a representative wavelength for photosynthetically active radiation in the terrestrial environment?
Authors: OLESEN T.
Published: August 2009

Abstract
The spectral quality of photosynthetically active radiation (PAR; 400–700 nm) incident at an open site and on a forest floor was analysed to determine whether narrowband (1 nm) wavelengths could be used to estimate total incident PAR. The narrowband estimates were not as good as the broadband estimates based on silicon photovoltaic sensors, but the variance at 530 nm was sufficiently small for narrowband sensors to be considered as low‐cost and light‐weight alternatives to broadband sensors.
Reproductive ecology of the jacky dragon (Amphibolurus muricatus): an agamid lizard with temperature‐dependent sex determination
Authors: HARLOW PETER S. , TAYLOR JENNIFER E.
Published: August 2009

Abstract
The jacky dragon, Amphibolurus muricatus (White, ex Shaw 1790) is a medium sized agamid lizard from the southeast of Australia. Laboratory incubation trials show that this species possesses temperature‐dependent sex determination. Both high and low incubation temperatures produced all female offspring, while varying proportions of males hatched at intermediate temperatures. Females may lay several clutches containing from three to nine eggs during the spring and summer. We report the first field nest temperature recordings for a squamate reptile with temperature‐dependent sex determination. Hatchling sex is determined by nest temperatures that are due to the combination of daily and seasonal weather conditions, together with maternal nest site selection. Over the prolonged egg‐laying season, mean nest temperatures steadily increase. This suggests that hatchling sex is best predicted by the date of egg laying, and that sex ratios from field nests will vary over the course of the breeding season. Lizards hatching from eggs laid in the spring (October) experience a longer growing season and should reach a larger body size by the beginning of their first reproductive season, compared to lizards from eggs laid in late summer (February). Adult male A. muricatus attain a greater maximum body size and have relatively larger heads than females, possibly as a consequence of sexual selection due to male‐male competition for territories and mates. If reproductive success in males increases with larger body size, then early hatching males may obtain a greater fitness benefit as adults, compared to males that hatch in late summer. We hypothesize that early season nests should produce male‐biased sex ratios, and that this provides an adaptive explanation for temperature‐dependent sex determination in A. muricatus.
Responses of ant communities to dry sulfur deposition from mining emissions in semi‐arid tropical Australia, with implications for the use of functional groups
Authors: HOFFMANN BENJAMIN D. , GRIFFITHS ANTHONY D. , ANDERSEN ALAN N.
Published: August 2009

AbstractThe impact of dry deposition of SO2emissions on ant abundance, diversity and composition was investigated at Mount Isa in the semiarid tropics of northern Australia. Forty plots were sampled, stratified at two levels: sulfur deposition zones (high, medium, low, and two control zones) and habitat (Ridge and Plain). The two habitats supported distinctly different ant communities. Ants had clear responses to SO2emissions. Ant abundance was lowest in the high and medium sulfur zones in both habitats. Species richness in high SO2plots (up to 5 km from the source) was approximately half that of control plots in Ridge habitat, and was substantially less than controls in the Plain habitat. Ant community composition in the high sulfur zone was clearly separated from those of other zones in ordinations. Vector fitting showed soil SO4concentration as a primary correlative factor in this separation. Ant abundance and richness were both negatively correlated with soil SO4concentration, and positively correlated with plant species richness and distance away from the smelters. The abundance of 10 of the 21 most common species showed significant responses to emissions. Five species showed positive responses, and all belong to species‐groups known to be abundant at disturbed sites throughout northern Australia. Relative abundance and richness of Eyrean (arid adapted) taxa collectively responded positively to sulfur, and Torresian (tropical) and Widespread species responded negatively. Despite large changes in species composition and abundances, there was relatively little change in the abundance of functional groups that have been widely used in studies of Australian ant communities. Ants are sensitive to SO2emissions and appear to be good candidates as an indicator group in this context. However, an alternative functional group framework is required for the identification of recurrent responses of arid zone ant communities to disturbance.
Influence of multiple fire‐related germination cues on three Sydney Grevillea (Proteaceae) species
Authors: KENNY BELINDA J.
Published: August 2009

Abstract
Many species found in fire‐prone habitats that possess a soil‐stored seedbank only recruit seedlings in large numbers following a fire. Fire‐related germination cues are presumably used by these seeds as signals that a fire has occurred, and would include the heating that occurs in the soil and the combustion products of burning vegetation, smoke and charcoal. Three Sydney species, Grevillea buxifolia (Sm.) R. Br., Grevillea sericea (Sm.) R. Br. and Grevillea speciosa (Knight) McGillivray, were studied for the interactive effects of these cues on their germination. The germination of all species was found to increase with both smoke and heat treatments. While smoke always had a greater influence than heat, the relationship between the two treatments varied with species. The presence of two fire‐related germination cues should allow these species to take better advantage of the recruitment opportunities of the post‐fire environment.
Factors influencing the distribution of medium‐sized ground‐dwelling mammals in southeastern mainland Australia
Authors: CLARIDGE ANDREW W. , BARRY SIMON C.
Published: August 2009

Abstract
The forage diggings of medium‐sized ground‐dwelling mammals (bandicoots and potoroos) were recorded over two seasons across 136 forested study sites, representing a stratified sample of the climatic, geological and topographic features of far south‐eastern mainland Australia. Diggings, presumably left by bandicoots, were recorded at a total of 42 sites, and those of potoroos at 27 sites. Statistical models were developed for the occurrence of these diggings, based on environmental attributes measured for each site. At a landscape scale, mean minimum temperature of the coldest month was an important explanatory variable for both groups of animals, with likelihood of their occurrence increasing with increasing temperature during that period. More locally, soil fertility and time since last fire also influenced the occurrence of bandicoot and potoroo diggings, while density of ground cover was additionally important in explaining the occurrence of bandicoot diggings. Bandicoot and potoroo diggings were more likely to occur with decreasing soil fertility and increasing time since fire, while occurrence of bandicoot diggings also increased with increasing density of ground cover. The possible management implications of our findings for conservation of medium‐sized ground‐dwelling mammals in multiple‐use forests are discussed.