bluuebunny/crossref_metadata_2025 huggingface dataset:
The potential of reflective mulching in combination with insecticide sprays for control of aphid‐borne viruses of iris and tulip in Tasmania
Authors: WILSON C R
Published: February 2008

Silver coloured plastic mulches and weekly insecticide sprays were examined individually and in combination for efficacy in reducing spread of tulip breaking potyvirus (TBV) in tulip, and these plus mineral oil treatments, alone and in combination with insecticide and mulch, were evaluated for their effect on iris mild mosaic potyvirus (IMMV) spread in bulbous iris. In the iris trial, significant reductions in virus spread were noted for all treatments, with the combined treatment of mulch and insecticide giving the best virus control. However, with little virus spread there were no significant treatment effects on TBV spread in tulips. Reduced numbers of aphid vectors were trapped over unsprayed mulched than non‐mulched plots. Mulch treatments had no effect on stem length or harvested bulb weight while the insecticide treatment (tulips only) and treatments incorporating mineral oil significantly reduced both stem length and bulb weight. This work suggests that enhanced virus management in flowerbulb production may be achieved by incorporating reflective mulches in current virus control strategies.
Effects of plant extracts on the feeding behaviour of the slug Arion lusitanicus
Authors: BARONE M. , FRANK T.
Published: February 2008

Methanol extracts of the plants Geranium robertianum, Lepidium sativum, Origanum vulgare, Salvia officinalis, Salvia pratensis, Saponaha officinalis, Thymus vulgaris, Trifolium repens and Valerianella locusta were produced and applied to cotyledons of 6–8 days old rape seedlings to investigate whether they can influence the feeding of the slug Arion lusitanicus on young rape. All plant extracts appeared to reduce slug feeding on rape to some extent, but only the extracts of Saponaria officinalis and V. locusta significantly deterred A. lusitanicus from feeding. The small effects of some extracts may be due to a poor extraction efficiency or an insufficient feeding inhibition capacity of these extracts.
Spectral decomposition of starbursts and active galactic nuclei in 5-8 μm Spitzer-IRS spectra of local ultraluminous infrared galaxies
Authors: Nardini E. , Risaliti G. , Salvati M. , Sani E. , Imanishi M. , Marconi A. , Maiolino R.
Published: February 2008

We present an analysis of the 5–8 μm Spitzer-IRS spectra of a sample of 68 local ultraluminous infrared galaxies (ULIRGs). Our diagnostic technique allows a clear separation of the active galactic nucleus (AGN) and starburst (SB) components in the observed mid-infrared emission, and a simple analytic model provides a quantitative estimate of the AGN/SB contribution to the bolometric luminosity. We show that AGN are ∼30 times brighter at 6 μm than SBs with the same bolometric luminosity, so that even faint AGN can be detected. Star formation events are confirmed as the dominant power source for extreme IR activity, since ∼85 per cent of ULIRG luminosity arises from the SB component. None the less an AGN is present in the majority (46/68) of our sources.
Good food in family day care: Improving nutrition and food safety in family day care
Authors: BRAVO Andy , CASS Yona , TRANTER Dian
Published: February 2008

Aim:  To determine the effectiveness of a nutrition and food safety intervention in family day care schemes.

Methods:  Staff and carers from seven Sydney family day care schemes completed a nutrition and food safety knowledge questionnaire and diet history about food and drinks offered to children in care before and after attending workshops and receiving advice and resources. Participating schemes' nutrition and food safety policies were assessed before and after intervention. At baseline, 18 staff members and 104 carers were interviewed. Diet histories were collected for 20 infants and 103 one‐to‐five‐year olds. Post intervention, 21 staff and 102 carers were interviewed and diet histories collected for 22 infants and 102 one‐to‐five‐year olds. Baseline and post‐intervention data were compared using the χ2‐test for categorical data (or the Fisher's exact test when expected values were below five), and t‐tests for independent samples for normally distributed means.

Results:  Nutrition and food safety knowledge and the number (from one to seven) and quality of appropriate policies improved post intervention. Changes in mean per cent nutrition scores for infants (78.2% to 83.4%) and for one‐to‐five‐year olds (68.8% to 75.2%; P < 0.01) indicated improvements in nutritional quality of food and drinks offered during care.

Conclusion:  Health promotion strategies can improve food and drinks offered in family day care and make a sustainable contribution to children's access to safe and nutritious food.
Preliminary results of patient satisfaction with nutrition handouts versus dietetic consultation in oncology outpatients receiving chemotherapy
Authors: ISENRING Elisabeth , CROSS Giordana , KELLETT Elizabeth , KOCZWARA Bogda
Published: February 2008

Aim:  To determine patient satisfaction with nutrition interventions in outpatients receiving chemotherapy identified as at nutritional risk.

Methods:  An observational, cross‐sectional study was conducted at an Australian public hospital in 61 oncology outpatients receiving chemotherapy. A simple malnutrition screening tool was used to identify nutritional risk. Patients identified as moderate risk were triaged to receive nutrition handouts on increasing energy and protein intake. Those at high risk received nutrition counselling and support by a dietitian. Patient satisfaction was assessed using a modification of a valid and reliable satisfaction with nutrition services questionnaire.

Results:  Sixty‐one patients entered the study and one‐third (20/61) were at nutritional risk. Seven patients were at high risk, and received dietetic review while 13 patients were at moderate risk and received nutrition handouts. Patients identified as at nutritional risk (n = 20) were approached to complete the satisfaction with nutrition services questionnaire. Eighteen patients completed the questionnaire (n = 7: dietetic review; and n = 11: nutrition handout). Nutrition information/advice was rated as helpful (n = 15), met patient expectations (n = 16) and overall patient satisfaction was rated highly. Patients who had received a dietitian review recorded a clinically but not statistically higher overall satisfaction with nutrition services than those patients receiving the nutrition handout.

Conclusion:  The high patient satisfaction helps support nutrition intervention at the chemotherapy unit. A prospective trial is required to determine the benefits of this triage and nutrition intervention on nutrition‐related outcomes.
Riverina men's study: An exploration of rural men's attitudes to health and body image
Authors: O'KANE Gabrielle , CRAIG Pippa , SUTHERLAND David
Published: February 2008

Aim:  To determine the attitudes of rural men to matters of health and body image.

Methods:  Focus group discussions were used to examine the attitudes of a sample of Australian rural men to matters of health and body image in the context of their eating and exercise behaviours. Forty‐two rural men, aged 25–64 years, took part in four focus groups, one exclusively for farmers, in south‐western New South Wales (NSW).

Results:  Results from these focus groups reveal that many of the masculine myths surrounding male behaviour in relation to health and ideas on body image persist among rural men in south‐western NSW. Talking about health is not considered a male past‐time; visiting health professionals is still seen as a last resort; being a ‘big bloke’ is perceived to be advantageous and heavy drinking is still considered an Australian male domain, especially among the younger men in the groups.

Conclusion:  The present study provides a deeper understanding of rural men's attitudes to body image issues and lifestyle behaviours, which is critical to helping change health outcomes for this hard‐to‐reach group.
Validation of the General Nutrition Knowledge Questionnaire in an Australian community sample
Authors: HENDRIE Gillian A. , COX David N. , COVENEY John
Published: February 2008

Aim:  To validate the General Nutrition Knowledge Questionnaire developed by Parmenter and Wardle (1999) in an Australian community sample. This questionnaire differs from previous assessments of knowledge because it incorporates a broad range of nutrition concepts, including knowledge of dietary recommendations, healthy food choices, nutrient sources and some diet–disease relationships.

Methods:  The original questionnaire was developed in the UK, and thus modified to suit the current Dietary Guidelines for Australians and current public health nutrition recommendations. A total of 156 people, of which 116 were community members, completed the questionnaire (113 items). As an indication of concurrent validity, a subsample of nutrition and dietetic students were included (n = 40). As a measure of test–retest reliability, a subsample (n = 57), including students and community members, answered the questionnaire on two occasions, two weeks apart.

Results:  Both overall internal reliability of the questionnaire items (Cronbach's alpha = 0.92) and test–retest reliability (r = 0.87) were high. The nutrition and dietetic students, hypothesised to have higher knowledge levels, scored consistently higher than the general community sample, indicating good concurrent validity.

Conclusion:  A test of a modified version of the General Nutrition Knowledge Questionnaire found it to be a valid and reliable measure of nutrition knowledge, appropriate for use in a section of the Australian community. The validated tool may be used in the future for the comprehensive assessment of general nutrition knowledge; however, further testing in differing sections of Australian society may be warranted.
Promoting the reuse of enteral feeding equipment in ambulatory patients: Where do we stand?
Authors: OSLAND Emma
Published: February 2008

Cleaning and reuse of single‐use and single‐patient‐use enteral feeding equipment is common in Australia, particularly in ambulatory patients. This practice may result in feed product contamination and adverse clinical outcomes for the patient, and exposes the health professional providing the advice to liability for harm caused. The present article reviews the literature addressing cleaning and reuse of enteral feeding equipment to provide guidance to health professionals managing and supporting patients receiving home enteral nutrition.
Development of an electromagnetic hydrocyclone separator for purification of wastewater
Authors: Ali‐Zade Parviz , Ustun Ozgur , Vardarli Feyzullah , Sobolev Konstantin
Published: February 2008

A number of various organic and inorganic contaminants are commonly present in the technological fluids hindering production quality. Importantly, waste influents must be purified to meet the appropriate environmental standards for their disposal. This paper deals with the development of a treatment technique for technological and wastewater streams allowing the separation of microscopic droplets of water, sand, oil and other organic and inorganic contaminants. Some existing approaches and processes for treatment of contaminated fluids are briefly reviewed and the design of an electromagnetic hydrocyclone separator is presented in this paper. The effect of the main forces on the separation of small‐sized impurities (<10 μm) is analysed. The experimental tests demonstrated the efficiency of the developed apparatus in purifying the industrial wastewaters of the textile dyeing industry.
Combined biological treatment of high‐sulphate wastewater from yeast production
Authors: Zub S. , Kurissoo T. , Menert A. , Blonskaja V.
Published: February 2008

The wastewater from baker's yeast production contains above‐average concentrations of organic pollutants (25 000 mg/L total chemical oxygen demand, TCOD), nutrients (1500 mg/L Ntot, 100 mg/L Ptot) and sulphate (2900 mg/L SO42−). Baker's yeast wastewater with a flow rate of 190 m3/day was treated in a mesophilic anaerobic/anoxic continuous stirred tank reactor (CSTR) system. At the expense of the reduction of trimethylglycine (or betaine‐component of sugar‐beet molasses) to other nitrogen‐containing compounds, it was possible to re‐oxidize the sulphides to elemental sulphur, remove them from the wastewater and increase biogas production. Therefore, the average removal efficiency in the anaerobic/anoxic system was 79% by TCOD, 100% by SO42− in which the concentration of sulphides in the effluent did not exceed 50 mg/L. The application of this combined anaerobic/anoxic system to a full‐scale treatment plant supported biogas production up to 1300 m3/day, and the purification of wastewater was feasible without the use of granular sludge.
Experiences of algae in UK waters: a treatment perspective
Authors: Henderson Rita , Chips Michael , Cornwell Neill , Hitchins Philip , Holden Barrie , Hurley Steve , Parsons Simon A. , Wetherill Andrew , Jefferson Bruce
Published: February 2008

Algae blooms are a seasonal problem in UK waters and during these periods interferences with treatment plants are reported. This paper presents an analysis of data from 2000 to 2005 demonstrating UK experiences of algae at water treatment works. Cell populations are lower than those reported in the 1970s and 1980s, but reach levels that adversely affect treatment processes. Diatoms and cyanobacteria dominate in spring and autumn respectively. A treatment works including pre‐oxidation, coagulation, flotation and filtration removes on average 96% of influent cells, while rapid gravity filters alone remove 63–75%. Cells present in the filtrate are typically either unicellular, micro‐algae, or flagellated algae. filter blockages in the spring and autumn are caused by large cells of complex morphology, including the diatoms Melosira and Asterionella. Overall, since the 1980s the key issue with respect to algae treatment has changed from one of treatability to that of process optimisation and economics.
How groundwater seepage and transport modelling software can be useful for studying gaseous transport in an unsaturated soil
Authors: Chesnaux R.
Published: February 2008

The aim of this paper is to show how standard hydrogeologic software, usually used to model contaminant transport in groundwater under unsaturated conditions, can also be used to model gas transport in unsaturated porous media. Physical processes involved in the interaction between the atmosphere and the unsaturated soils are considered: transport by diffusion through the air and the groundwater, exchange between the liquid and gas phases and consumption. These physical processes are incorporated into the governing equations of a groundwater numerical code; by considering air, contained in the unsaturated soil, as water in the seepage numerical model, the air effectively becomes fluid within the numerical code. Then, the investigated gas is defined as the contaminant in the transport model, which is transported by ‐the air for the modeller‐, and ‐water for the numerical code‐. The over‐riding assumption is that the air profiles and, therefore, water profiles of volume contents remain constant. The approach is illustrated using two examples, which consider the transport of oxygen. The first deals with oxygen distribution through a laboratory‐cell diffusion containing reactive mining tailings. The second deals with the oxygen fluxes through the vadose zone, between the atmosphere and an unconfined aquifer's water table. Both examples consider different cases of oxygen consumption.
Shallow aquifer resources in the federal capital territory of Nigeria
Authors: Jimoh O. D. , Wojuola O. A.
Published: February 2008

Public water supply to the Federal Capital Territory (FCT) of Nigeria is inadequate and an alternative source of water includes streams, hand‐dug wells and boreholes. A survey showed that 41% of the territory uses hand‐dug wells, while 23% depends on boreholes and 16% depends on streams. Measurements were taken from 84 wells in 2002 and 2003 to assess the contribution of hand‐dug wells. The parameters considered include ground surface elevation, water level, permeability and well yield. The well diameter ranged between 0.7 and 1.2 m, while the depth ranged between 4.5 and 16 m. The permeability ranged between 0.000518 and 0.002541 cm/s. The source of recharge to the aquifer is rain, and well productivity ranged between 211 and 1806 L/day. Wells located in seven out of nine groups considered cannot meet the water demand of an average household (20 people) in the territory.
Meeting the phosphorus consent with biological nutrient removal under UK winter conditions
Authors: Manyumba Future , Wood Elizabeth , Horan Nigel
Published: February 2008

It is estimated that up to 342 wastewater treatment plants (Wwtps) in England and Wales will require a phosphorus (P) consent by 2010. Although biological P removal is considered to be the most sustainable option for P removal, it has always been problematic for plants that remove both nitrogen and P due to the inadequate concentration of organic material during wet periods. Two biological nutrient removal (BNR) configurations, the Johannesburg (JHB) process and a combined JHB and five‐stage Bardenpho process, were evaluated over a period of 2 years to assess the impact of sewage strength on bio‐P removal. The JHB achieved an average effluent total phosphorus (TP) of 2.4 mg/L and the combined JHB and five‐stage process averaged 1.4 mg/L effluent TP. The major problems affecting the performance of both configurations were: dissolved oxygen (DO) in the recycled mixed liquor, nitrate in the return activated sludge (RAS) and low influent biological oxygen demand (BOD) concentrations. Acetate dosing proved successful as a source of volatile fatty acids (VFAs) in the anaerobic zone during periods of low‐strength sewage. An acetate dosing strategy based on the influent flow rate to the plant was found to be a simple and effective technique that ensured that a consent of <1 mg TP/L could be met.
The method of application and short term results of tympanostomy tubes for the treatment of primary secretory otitis media in three Cavalier King Charles Spaniel dogs
Authors: Corfield GS , Burrows AK , Imani P , Bryden SL
Published: February 2008

Primary secretory otitis media is an uncommon disease affecting predominantly Cavalier King Charles Spaniel dogs. Current treatment recommendations include repeated manual removal of the mucoid effusion from the tympanic cavity through a myringotomy incision and topical or systemic corticosteroids. The aim of this study was to assess the efficacy of tympanostomy tubes to provide continual tympanic cavity ventilation and drainage for the treatment of primary secretory otitis media in three dogs. Tympanostomy tubes were placed within a myringotomy incision in the pars tensa with the aid of an operating microscope. Clinical signs resolved rapidly in all cases following the procedure and all cases were asymptomatic at the time of follow‐up, 8, 6 and 4 months later. Results of this study indicate that tympanostomy tubes provide continual tympanic cavity ventilation and drainage and may be an acceptable alternative to repeated myringotomy for the treatment of primary secretory otitis media.
The effect of a single intravenous fluid bolus on packed cell volume and plasma total solids concentration in Red‐collared Lorikeets (Trichoglossus haematodus rubritorquis)
Authors: WICKS RM , SCHULTZ DJ
Published: February 2008

Objective  To determine the effect of a single intravenous (IV) fluid bolus on the hydration of an avian patient, using packed cell volume (PCV) and plasma total solids (TS) to estimate hydration.

Procedure   Ten birds were allocated randomly to one of three groups, and administered 30 mL/kg or 50 mL/kg intravenous fluid, or were part of a control group and did not receive IV fluid. Blood was collected before the IV fluid bolus was administered, and at 1 minute, 3 hours and 6 hours after administration of the fluid. Samples were used to determine PCV and TS and results were compared between groups and between the different time points.

Results   Administration of 30 mL/kg or 50 mL/kg compound sodium lactate solution caused a statistically significant decrease in PCV. Within 3 hours, the PCV was not significantly different to the initial value or to the PCV of control birds. Administration of 30 mL/kg compound sodium lactate solution did not result in a significant decrease in TS. However, administration of 50 mL/kg produced a significant decrease in TS, which was still significantly less than controls 6 hours after the fluid was administered.

Conclusion   These findings suggest that an intravenous bolus of fluid may be safely administered to an anaemic bird, since PCV is significantly decreased for less than 3 hours. Up to 50 mL/kg of fluid may be administered as an intravenous bolus to a bird, to produce significant haemodilution that persists for up to 6 hours.
Rural veterinary services in Western Australia: Part B. Rural practice
Authors: MAXWELL JAL , COSTA ND , LAYMAN LL , ROBERTSON ID
Published: February 2008

Objective   To determine the current status of rural veterinary services in Western Australia.

Procedure   A questionnaire was sent to all eligible rural practitioners registered in 2006 and the replies were transferred to Microsoft Excel for analysis.

Results   Of the rural practitioners invited to participate in the survey replies were received from 67%. There were equal numbers of females and males. Their mean age was 44 years. Ninety per cent of respondents considered knowledge gained as an undergraduate was sufficient to equip them for practice, but only 60% considered their practical skills adequate. Thirteen per cent of those in rural practices in 2005 had left by 2006. Eighty‐nine per cent of respondents were in mixed practice, the balance in specific species practice, such as equine, large animal and production animal consultancy. The majority of rural practitioners relied on servicing companion animals for their viability; 7% earned their income from servicing production animals only. Seventy per cent utilised merchandising and the sale of pet foods to supplement the income received from the traditional veterinary services and 34% found it necessary to earn an independent income. A quarter considered that rural practice did not have a future.

Conclusion   The majority of rural practitioners in Western Australia depend on companion animals, not production animals, to remain viable, with very few operating production animal services. Poor remuneration is a major reason why veterinarians leave rural practice, and many find it necessary to supplement their income or develop an independent income.
Are the speeds of species invasions regulated? The importance of null models
Authors: Starrfelt Jostein , Kokko Hanna
Published: February 2008

Understanding the mechanisms and patterns that govern the invasion of species is essential for coping with global change of the biological world. A recent study highlights the possibility, based on data from a wide range of different taxa, that the invasion speed of species could be governed by a regulatory process. In principle, it is possible that mechanisms such as Allee effects could cause the invasion fronts to be regulated, such that the change in the rate of spread is negatively related to the current rate. This is very similar to how some populations are regulated around an equilibrium size, and finding the regulation structure if true, is of both pure and applied interest. However, here we will argue that the methods used so far are incomplete, thus even though there is a theoretical possibility that the speed of species invasions are regulated, more scrutiny is needed for its detection. Analysing changes of the ratio of current and past rate of spread against current ratios may give the impression of regulation in null models that are in fact unregulated. In addition we show that the apparent pattern is highly influenced by the spatial scale of investigation. Our results show that detecting regulatory patterns in species invasions is similarly non‐trivial as is detecting density‐dependence per se, but necessary, given the importance of this problem.
First insights into specificity of belowground tritrophic interactions
Authors: Rasmann Sergio , Turlings Ted C. J.
Published: February 2008

Tritrophic interactions involving plants, herbivores and parasites have been only recently documented for belowground systems, where entomopathogenic nematodes can exploit root herbivore induced volatile compounds to locate their hosts. Little is known, however, about whether the specificity of such interactions rivals that of the remarkable interactions found in aboveground studies. Using a belowground six‐arm olfactometer that allows recording of nematode attraction, specificity of nine economically important species of different trophic levels, including plants, root feeders and entomopathogenic nematodes, was tested. We found that belowground tritrophic interactions are variable at the level of plant volatiles that are induced, elicitation by herbivores, as well as behavior of nematodes. We argue that studies on specificity and variability of belowground responses should be included in plant defense theories and in efforts to exploit tritrophic interactions to improve biological control practices.
Mechanisms of succession along the emersion gradient in intertidal rocky shore assemblages
Authors: Viejo Rosa M. , Arenas Francisco , Fernández Consolación , Gómez María
Published: February 2008

Theoretical models predict that the relative importance of competition and facilitation vary inversely along gradients of abiotic stress, with facilitation dominating under harsh conditions (the so called “stress‐gradient hypothesis”). To date, very few studies have tested this hypothesis in the framework of succession. Moreover, the generality of the hypothesis is currently under debate and the necessity to examine responses at the community level and using different stress levels has been emphasized. We evaluate the mechanisms of succession across the emersion gradient in a rocky shore system. After complete clearing of experimental plots at four shore heights, we removed two separate components of the assemblage: ephemeral green algae, early colonists and canopy‐forming species, main space holders in undisturbed assemblages. We aimed to test two hypotheses: (a) the net effect of ephemeral algae on canopy‐forming species shift along the emersion gradient according to the predictions of the stress‐gradient hypothesis and (b) the net effect of the canopy‐forming group on associate species change, from neutral/negative to positive, as succession progresses and plants grow, especially at the highest shore heights. Our results did not support the predictions of the stress gradient hypothesis in the framework of succession. We did detect changes through time in the effect of canopy‐forming species, from negative to positive, but this was not dependent on the shore height. The outcome of interactions depended on the identity and life‐stage of the species. Moreover, indirect interactions among species could also create a less predictable relationship between successional mechanisms and the environmental gradient.
The influence of competition from herbaceous vegetation and shade on simulated browsing tolerance of coniferous and deciduous saplings
Authors: Vandenberghe Charlotte , Freléchoux François , Buttler Alexandre
Published: February 2008

The ability of saplings to tolerate browsing (i.e. the ability to persist with reduced biomass and to compensate for biomass loss) is influenced by the level of stress and their growth strategies. Ultimately, insight into species‐specific responses of saplings to browsing, shade and competition from neighbours will help explain diversity, structure and function of grazed ecosystems such as the endangered wood‐pasture systems. We measured the survival, whole‐sapling biomass and compensatory growth responses of two coniferous (Picea abies and Abies alba) and two deciduous (Acer pseudoplatanus and Fagus sylvatica) tree species to simulated summer browsing (one single clipping event), shade (installation of a shade cloth) and neighbour removal (mowing surrounding vegetation to ground level) treatments and the interactions between them after two‐growing seasons. For all species, there were interacting effects on growth of browsing and environmental condition (shade and neighbours). Simulated browsing resulted in relatively smaller growth losses when plants were growing slowly due to competitive conditions related to herbaceous neighbours. Although none of the clipped saplings could fully compensate for their biomass losses, the saplings were closer to compensation under high competitive conditions than under low competitive conditions. Survival of the clipped saplings remained relatively high and was only significantly reduced for Picea and Acer. Picea was least tolerant of competition and was the only species for which growth was not negatively affected by strong irradiance of a mountain pasture. Surprisingly, the tolerance of saplings to herbivory as browsing tolerance was enhanced under conditions that negatively affected sapling performance (i.e. survival and growth). Apparently, the relative impact of browsing at the early sapling stage is linked to tree life history characteristics such as competition and shade tolerance and will be lower in situations with intense competitive interactions and/or strong irradiance.
Belowground and aboveground consequences of interactions between live plant species mixtures and dead organic substrate mixtures
Authors: Nilsson Marie‐Charlotte , Wardle David A. , DeLuca Thomas H.
Published: February 2008

In all terrestrial ecosystems, plant‐derived resources mainly enter the belowground subsystem in two ways – as dead plant parts (i.e. organic substrates) and as resources released from the rhizosphere of live plants. While the effects of identity of live plants or dead plant parts on aboveground and belowground properties have been well studied, much remains unknown about the effects of combinations of live plant species and dead plant‐derived substrates. In particular, no study to date has experimentally investigated the effects of simultaneously varying the composition or diversity of both live plants and dead plant parts. We performed a pot experiment consisting of a full factorial of 12 organic substrate addition treatments by eight live plant treatments, in which the composition and diversity of both substrates and live plants were varied. The 12 substrate treatments consisted of no substrates added, each of the four substrates represented singly (four treatments), each of the possible pairwise combinations of the four substrates (six treatments), and all four substrates added together. As expected, substrate and live plant identity both had important effects both above‐ and belowground. Mixtures of plant species always had effects that could be explained by the effects of the component plant species grown singly. Usually mixtures of substrates also had effects that could be predicted by the effects of component substrates added singly, but there were instances in which mixtures of certain substrates (notably mixtures containing Populus tremula leaf litter) had synergistic effects both belowground and aboveground, with especially strong effects on the growth of Pinus sylvestris seedlings. However, there was never any evidence of interactive effects between live plant species diversity or composition and added substrate diversity or composition, either aboveground or belowground. This means that whatever effects added substrates have on ecological properties operates independently of the influence of live plants, and vice versa. In total, this study shows that most resources entering the belowground subsystem have effects that are independent of the effects of other resources, though there are isolated instances in which strong (and potentially ecologically meaningful) synergistic interactions may occur for specific combinations of dead organic substrates.
An analysis of hatching success in the great reed warbler Acrocephalus arundinaceus
Authors: Knape Jonas , Sköld Martin , Jonzén Niclas , Åkesson Mikael , Bensch Staffan , Hansson Bengt , Hasselquist Dennis
Published: February 2008

Hatching success is a potentially important fitness component for avian species. Previous studies of hatching success in natural populations have primarily focused on effects of inbreeding but a general understanding of variation in hatching success is lacking. We analyse data on hatching success in a population of great reed warblers Acrocephalus arundinaceus in Lake Kvismaren in south central Sweden. The effects of a range of covariates, including three measures of inbreeding as well as effects of classifications in the data (such as identities of individuals), on hatching success are analysed simultaneously. This is done by means of fitting Bayesian binomial mixed models using Markov chain Monte Carlo methods. Using random effects for each individual parent we check for unexplained variation in hatching success among male and female individuals and compare it to effects of covariates such as degree of inbreeding. Model selection showed that there was a significant amount of unexplained variation in hatching probability between females. This was manifested by a few females laying eggs with a substantially lower hatching success than the majority of the females. The deviations were of the same order of magnitude as the significant effect of parent relatedness on hatching success. Whereas the negative effect of parent relatedness on hatchability is an expression of inbreeding, the female individual effect is not due to inbreeding and could reflect maternal effects, that females differ in fertilisation and/or incubation ability, or an over representation of genetic components from the female acting on the early developing embryo.
Partitioning average competition and extreme‐genotype effects in genetically diverse infections
Authors: Rauch Gisep , Kalbe Martin , B.H. Reusch Thorsten
Published: February 2008

Competition between parasite genotypes in genetically diverse infections is widespread. However, experimental evidence on how genetic diversity influences total parasite load is variable. Here we use an additive partition equation to quantify the negative effect of inter‐genotypic competition on total parasite load in diverse infections. Our approach controls for extreme‐genotype effects, a process that can potentially neutralise, or even reverse, the negative effect of competition on total parasite load. A single extreme‐genotype can have a disproportionate effect on total parasite load if it causes the highest parasite load in its single‐infection, while increasing its performance in diverse relative to single infections. We show that in theory such disproportionate effects of extreme‐genotypes can lead to a higher total parasite load in diverse infections than expected, even if competition reduces individual parasite performance on average. Controlling for the extreme‐genotype effect is only possible if the competition effect on total parasite load is measured appropriately as the average difference between the realised number of each parasite genotype in mixed infections and the expected number based on single infection parasite loads. We apply this approach to sticklebacks that were experimentally infected with different trematode genotypes. On average, genetically diverse infections had lower parasite loads than expected from single‐infection results. For the first time we demonstrate that competition between co‐infecting genotypes per se caused the parasite load reduction, while extreme‐genotype effects were not significant. We thus suggest that to correctly quantify the effect of competition alone on total parasite load in genetically diverse infections, the extreme‐genotype effect has to be controlled for.
Providing water for goats in arid landscapes: effects on feeding effort with regard to time period, herd size and secondary compounds
Authors: M. Shrader Adrian , P. Kotler Burt , S. Brown Joel , I. H. Kerley Graham
Published: February 2008

In arid regions, herbivores contend with a wide range of variables that influence their foraging ability. These may include plant secondary compounds (e.g. tannins and oxalates), water availability, time of day, and herd size. To determine the relative importance of these variables for goats living in a semi‐desert, we measured the remaining food resources after foraging events (giving up densities‐GUDs) as an index of foraging effort in artificial food patches. Time of day and the availability of drinking water had the greatest effect on GUDs. Goats achieved lower GUDs (i.e. ate more) in the afternoon than they did during the morning. We suggest this was due to missed opportunity costs of future foraging opportunities being lower in the afternoon. Ultimately, this implies that goats made short‐term foraging decisions based on estimates of future feeding opportunities. When water was available, feeding effort increased and GUDs dropped almost 50%. For goats living in an arid environment, food and water are strong complementary resources. The presence of low to moderate levels of tannic or oxalic acid in food was a slight deterrent, raising the GUDs similarly. Larger herds ate more and thus obtained lower GUDs. In addition, there was an interaction of herd size and water, suggesting that in arid environments, the effect of water intensifies with population density. Our approach allowed us to quantify and rank the effects that disparate environmental factors had on the goats’ foraging costs: water>time of day>herd size>plant secondary compounds. These findings ultimately demonstrate how the provision of water may increase grazing impacts by herbivores in arid landscapes.
An Uncertainty Analysis Method for Coordinate Referencing in Manufacturing Systems
Authors: Shen Y. , Duffie N. A.
Published: February 2008

Accurate and consistent transformations between design and manufacturing coordinate systems are essential for high quality part production. Fixturing and coordinate measurement are common coordinate referencing techniques which are used to locate points or measurement points on workpiece reference surfaces to establish these coordinate transformations. However, uncertainty sources such as geometric form deviations in workpiece surfaces, tolerances on fixture locators, and errors in coordinate measurements exist. A result is that coordinate transformations established using the locating and measurement points are in herently uncertain. An uncertainty analysis method for coordinate referencing is presented in this paper. The uncertainty interval concept is used to describe essential characteristics of uncertainty sources in coordinate referencing and coordinate transformation relationships. The method is applied to estimating uncertainties in simple and compound coordinate transformation obtained using coordinate referencing in an experimental mold manufacturing system. Results of Monte Carlo simulations are used to show that the uncertainty analysis method gives a consistent and high percentage of coverage in evaluating coordinate referencing in the examples studied.
Engineering Risk Assessment in Manufacturing Products with Short Time-to-Market Windows
Authors: Martinez-Heath M. R. , Deacon A. G.
Published: February 2008

This paper establishes the concept of manufacturing risk assessment based on design features. It also presents a methodology for assessing risks associated with producing feature-rich products with short time-to-market windows. Product design features are classified as inherent and value-added. Inherent features are functionalities of a product that provide a core benefit to the user. Without inherent features, a product cannot exist in the marketplace. Value-added design features augment the customer-perceived value of a product. A product with value-added features provides the manufacturer with a competitive and lucrative edge in the market place. To quantify risks associated with making a product, manufacturing is divided into three subprocesses: reliability, inherent feature augmentation, and value-added tolerance capabilities. Reliability estimates the availability to manufacture the selected product consistently; feature augmentation quantifies risks associated with incorporating inherent design features; and value-added tolerance capabilities measures the consistency in manufacturing value-added design. An example of a leading-edge technology product with a short life cycle is provided. Because of a short time-to-market window coupled with constraints in environmental variables, the bootstrap method is used to estimate key statistical parameters. Once manufacturing risks have been identified and evaluated, the next logical step for future work will be to couple these estimates with uncertainties involved in financing and marketing the product in question.
A Study on Mathematical Modeling of Parameter Optimization in Gas Tungsten Arc (GTA) Welding of Thin Pipes
Authors: Lho T.-J. , Na S.-J.
Published: February 2008

In order to estimate the optimal process parameter in circumferential GTA welding of thin pipes, the objective was chosen to maintain a uniform bead width over the full circumferential joint, while the constraints consist of the capacity limit of power source and related equipments. The analytical solution of heat conduction equation with a Gaussian heat source was adopted for calculating the temperature field in circumferential welding of the pipe workpiece. The linear complementary problem (LCP) with Lemke’s pivoting algorithm and Powell’s unconstrained search method with the sequential unconstrained minimization technique (SUMT) have been applied to evaluate the optimal welding current and welding velocity for a required bead width, respectively. The experimental results of the bead formation showed that the developed mathematical model can be effectively applied for obtaining the optimal welding condition in circumferential welding of thin pipes with a small diameter.
A Split Image Vision Sensor
Authors: Bassett J. , Walker G.
Published: February 2008

A vision sensor has been developed that uses only two lenses, a split prism, and a detector to acquire an image. This system uses the split prism to create a split image such that the displacement of the image is proportional to its range from the sensor. Prototype sensors have been examined both theoretically and experimentally, and have been found to measure object ranges with less than ±2 percent error. Acquisition of a single-point depth measurement is sufficiently fast for real-time use, and the optical components needed to build the sensor are inexpensive. The effect that each optical component has on the performance of the sensor is also discussed, and an optimal system design procedure is developed.
Automated Monitoring of Manufacturing Processes, Part 1: Monitoring Methods
Authors: Du R. , Elbestawi M. A. , Wu S. M.
Published: February 2008

This paper presents a systematic study of various monitoring methods suitable for automated monitoring of manufacturing processes. In general, monitoring is composed of two phases: learning and classification. In the learning phase, the key issue is to establish the relationship between monitoring indices (selected signature features) and the process conditions. Based on this relationship and the current sensor signals, the process condition is then estimated in the classification phase. The monitoring methods discussed in this paper include pattern recognition, fuzzy systems, decision trees, expert systems and neural networks. A brief review of signal processing techniques commonly used in monitoring, such as statistical analysis, spectral analysis, system modeling, bi-spectral analysis and time-frequency distribution, is also included.
Automated Monitoring of Manufacturing Processes, Part 2: Applications
Authors: Du R. , Elbestawi M. A. , Wu S. M.
Published: February 2008

In Part 2 of this paper, three applications of automated monitoring of manufacturing processes are presented to demonstrate the use of monitoring methods discussed in Part 1 of the paper. These applications are: (1) tool condition monitoring in turning, (2) machining condition monitoring in tapping, and (3) metallographic condition monitoring in arc welding. For each application, a background review, monitoring index selection and experimental setup are first presented. Then, monitoring methods discussed in Part 1 of the paper were applied and the test results are investigated. Discussions of the monitoring success rate, sensitivity, robustness, monitoring index selection, and decision under uncertainty are also included.
Design and Algorithmic Implementation of a Part Loading Regulator for a Manufacturing Cell
Authors: Saleh A. , Odrey N. G. , Wilson G. R.
Published: February 2008

The focus of this paper is to present a control methodology for the regulation of loading and processing of parts in a manufacturing cell in the presence of minor disturbances. The control methodology addresses three states in the planning horizon of a manufacturing cell: steady state, transient state, and a match-up state when the system is transitioning from transient to steady state operation. The part loading regulation of the cell is accomplished via optimization of appropriate cost functions associated with each state. The proposed control architecture for the cell part regulator utilizes these cost functions to enforce the desired regulatory properties. Theoretical developments and detailed examples can be found in Saleh et al., 1990; Saleh, 1988.
Evolution of Generic Mathematical Models and Algorithms for the Surface Development and Manufacture of Complex Ducts
Authors: Sundar Varada Raj P.
Published: February 2008

Complex ducts bound by developable surfaces can be obtained by cutting out the required developed shape on plane sheets and then wedge-bending or folding along certain lines called generators or rulings. The problem then reduces to the theoretical determination of the 2-D shape to be cut so that on folding along the rulings, the required 3-D surface is accurately obtained. The first step in the surface unfolding process is the determination of the parametric β-θ relationship between two adjacent cross-sections of the duct. The cross-sections of the duct can be planar or nonplanar and composed of conic or spline curve segments, placed anywhere in space. In this paper the requisite β-θ relationships of the most generic form have been derived and can be directly applied to any complex duct. Based on these relationships, an efficient and compact algorithm for surface-unfolding has also been derived. The application of this algorithm to numerous prototype cases has been shown. The theory has been verified by physical modelling of various ducts occurring in the field of hydroturbines, and now forms the basis of an Integrated CAD-CAM System.
A Realistic Friction Model for Computer Simulation of Sheet Metal Forming Processes
Authors: Wilson W. R. D. , Hsu T-C. , Huang X-B.
Published: February 2008

A realistic model for friction in lubricated sheet-metal forming which takes account of the different lubrication regimes which may occur at the sheet/tooling interface is developed. Friction is expressed in terms of internal interface variables (mean lubricant film thickness, sheet roughness and tooling roughness) in addition to the more traditional external variables (interface pressure, sliding speed and strain rate). The new model has been coupled to an existing finite element membrane analysis of axisymmetric stretch forming. Numerical results using the coupled codes showed excellent agreement with measured strain distributions over a range of operating conditions. Computational times with the refined friction model were typically increased by about 10 percent compared to those with a simple Amontons-Coulomb constant friction coefficient model.