Restoration of Old Forest Features in Coast Redwood Forests Using Early‐stage Variable‐density Thinning

To accelerate development of old forest features in coast redwood, two thinning treatments and an unthinned control were compared in three treatment areas in north coastal California. One thinning treatment was designed to restore old forest densities of 125 trees/ha and the other 250 trees/ha representing a one‐step and partial treatments to the desired stand density. Four years after treatment, numbers of trees had increased in the thinning treatments due to recruitment of new trees, but had decreased in the control due to self‐thinning. Residual trees increased in stem volume following thinning by 128% in low‐density thinning compared to 70% in the controls indicating thinning accelerated stand development. The thinning treatments also moved the species composition of these stands to a greater proportion of redwood. Considerable slash was produced by the thinning treatments but was decomposing rapidly. Black bears damaged approximately 15% of all trees and more than 38% of residual trees in the thinned treatments compared to less than 2% of all trees in the control. This damage included killing some trees and damaging other trees that survived. Decisions over restoration densities in these stands are complicated by prolonged stand development, and balancing risks and costs. In this case, the bears represent a stochastic factor that dramatically increases risk. Thinning appears to be an effective means of enhancing old forest development by accelerating tree growth, modifying species composition, and increasing stand‐level variability. Continued monitoring will be necessary to evaluate long‐term trends in density relative to effects of bear damage.     

O‐8FALSE NEGATIVE BRONCHIAL CYTOLOGY

Introduction: BK virus nephropathy is an emerging cause of renal transplant failure accounting for allograft loss in 45–50% of recipients between 2–60 months post‐transplantation. The Renal Transplant Unit in Royal Free Hospital has devised a local surveillance programme for screening renal transplant patients at weekly intervals by urinary cytology (UC) and electron microscopy (EM), and confirmation of positive results by plasma PCR and allograft biopsy. Objective: (i) To monitor the implementation of local guidelines; (ii) To compare UC with EM and (iii) To identify areas for improvement. Methods: Decoy cell and EM positive cases were retrieved from the WinPath database for new renal transplant recipients (n = 55) during 1^st November 2004 to 31^st October 2005 in Royal Free Hospital. Plasma PCR was retrieved for positive cases. Results: Up to eight samples were sent for UC at random intervals from 47 patients, and up to 7 were sent for EM from 42 patients. Eleven were UC‐positive and one was EM‐positive. PCR was not requested in UC‐positive cases and 3 out of 10 were positive retrospectively. The EM‐positive case was PCR‐positive but UC‐negative. Discussion: Urine Cytology is more appropriate and cost effective for screening than Electron Microscopy. During the period covered by this audit, samples were sent in an inconsistent fashion after allograft dysfunction rather than for screening. A screening protocol has been agreed and a re‐audit is planned.     

P‐1DIRECT‐TO‐VIAL USE OF THE LIQUI‐PREP™ CYTOLOGY SYSTEM

Introduction: The authors initiated the use of Liqui‐PREP? (LGM International Inc., Fort Lauderdale, FL, USA) in August, 2005. Cytotechnologists received extensive (one month) training by cytopathologists experienced in Liquid‐based cytology. The Liqui‐PREP? direct‐to‐vial procedure (LP) was compared to the conventional Pap smears in a routine screening population. Methods: Data derived from 26 178 LP cervical‐vaginal (CV) specimens were compared to data derived from 218 548 conventional Pap smears (CS). Both data sets reflect patient samples collected concurrently (August–December, 2005) by 117 participating outpatient medical practices from a well‐defined geographic area. There were no significant personnel changes during the study period. The diagnostic results, classified according to Bethesda criteria were calculated. Results:

Culture of a Gastric Non‐Helicobacter pylori Helicobacter from the Stomach of a 14‐Year‐Old Girl

Helicobacter felis belongs to the fastidious gastric non‐Helicobacter pylori helicobacter species that are typically found in the stomach of cats and dogs. These bacteria have the potential to colonize the human stomach and are then associated with gastritis, gastroduodenal ulcers, and MALT lymphoma. Strains cultured from the human stomach are rare. Here, we present the first isolation of H. felis from a gastric biopsy specimen of a 14‐year‐old girl who presented with persistent epigastric pain. The strain was cultured using our routine protocol for H. pylori and identified by phylogenetic analyses of partial urease AB and gyrB gene sequences.     

HCO3− and CO2 leakage from Synechococcus UTEX 625

The leakage of various inorganic carbon species from air-grown cells of Synechococcus UTEX 625 was investigated after a light to dark transition or during a light period using a mass spectrometer under a wide variety of experimental conditions. Total inorganic carbon efflux and CO₂ efflux during the initial period of darkness were measured with or without carbonic anhydrase in the reaction medium respectively. The HCO₃^? efflux after a light to dark transition was estimated by difference. Carbon dioxide efflux in the light was measured by inhibiting CO₂ transport with either Na₂S or COS₃ or quenching the ¹³C inorganic carbon transport by the addition of ¹²C inorganic carbon in excess. In cells in which CO₂ fixation was inhibited, when only the HCO₃^? transport system was fully operative, CO₂ effluxed continuously during the light period at a rate equal to about 25% of that in darkness. When only the CO₂ transport system was operative, HCO₃^? effluxed during the light period. The difference between the light and dark efflux rates was consistent with a 0.6 unit decrease in the intracellular pH upon darkening the cells. The permeabilities of the cell for CO₂ (2.94 ± 0.14 ± 10^?8ms^?1; mean ± SE, n=137) and HCO₃^? (1.4–1.7 ± 10^?9 ms^?1) were calculated.     

P‐15COMPARISON OF RESULTS FOR A NON‐GYNAECOLOGICAL CYTOLOGY EQA SCHEME

The problems encountered with a glass slide circulation are legion but timely circulation is a major problem and is an inherent deficiency of our Non‐gynaecological EQA scheme. This applies not only to consultants but also to specialist registrars (SpRs) and technical staff that are not formally included in the circulation list. In 2005 only 7 technical staff and 4 out of 47 SpRs took part on a formal basis, their participation being dependant on access to slides during their cytology attachment. The results for the 2005 circulation have been analysed and despite the small numbers of participating technical staff and SpRs their answers concur with the consultant body. To address the issues of timeliness and circulation problems a pilot teaching set has been developed by SlidePath into a virtual microscope web based circulation and sent to all SpRs in our region. They have recorded their answers and been given immediate access to the consensus consultant opinion with illustrations of follow up histology. A questionnaire was completed to evaluate the scheme. The facility of immediate feedback of consultant consensus is particularly pertinent to the educational element of the scheme and use of virtual microscopy addresses the issue of timely circulation. If further funding was made available technical staff could also be given the opportunity to try this web‐based circulation.     

O‐4CHARACTERISTICS OF FALSE NEGATIVE LBC SAMPLES

Background: Liquid based cytology (LBC) is the method of choice for the processing of samples in the cervical screening programme in England and Wales. Two LBC systems are in use; ThinPrep® and SurePath®. The manufacturers of SurePath® recommend that slides are screened in two separate directions perpendicular to each other (bidirectional screening) during the initial learning period. There is currently no evidence to evaluate whether this method is superior to screening in one direction only (unidirectional). Objectives: To compare the detection rate of high‐grade dyskaryosis in SurePath® preparations between screeners who used a unidirectional method and screeners who used a bidirectional method, to see if the screening method influenced detection rate. Methods: A questionnaire was sent to 23 screening staff at our Cytology Centre in October 2005, enquiring as to the method they used to screen SurePath® slides, as well as the grade of staff and the number of years experience they had screening cervical cytology slides. The staff were divided into two groups based on whether they screened unidirectionally or bidirectionally. A retrospective computerised search of all the slides screened by the staff for the period September 2004 to August 2005 was carried out, and the high‐grade detection rate at primary screening for the groups were calculated. Further analysis was carried out to determine the statistical significance of any difference between the two groups, as well as to account for potential confounding factors. Results: Initial results suggesting a statistically significant difference between the screening methods were later shown to be confounded by experience. Critical analysis of the data and study design reveal that no firm conclusions can be made on the basis of this work. Conclusion: No firm conclusions on screening method can be drawn due to fundamental limitations and confounding factors in this retrospective work‐based study. Recommendations for further studies are made, controlling for confounding factors.     

Microalgal Biomass and Lipid Production on Dairy Effluent Using a Novel Microalga, <Emphasis Type="Italic">Chlorella</Emphasis> sp. Isolated from Dairy Wastewater

The present study focused on cost-effective production of microalgal biomass and lipid production on dairy effluent. The novel microalga, Chlorella sp. isolated from the dairy effluent showed high growth and lipid production on the undiluted and two-fold diluted dairy effluent which were four to five times higher than those of Chlorella vulgaris (control). The high growth of Chlorella sp. was thought to be possibly due to its heterotrophic growth capacity, high turbidity, COD, nutrients and trace elements. In contrast, C. vulgaris showed poor heterotrophic and photoautotrophic growth under the highly turbid conditions of dairy effluent. Both Chlorella sp. and C. vulgaris showed similar total FAME (mg FAME/g algal cells). The fatty acid composition analysis revealed that both Chlorella sp. and C. vulgaris possessed major C18 and C20 fatty acids which will be used for biodiesel production. Overall, the novel microalga, Chlorella sp. isolated from the dairy effluent showed high potential for cost-effective algal cultivation and lipid production on dairy effluent without any modification of process.     

Using species‐environmental amplitudes to predict pH values from vegetation

Question: Species optima or indicator values are frequently used to predict environmental variables from species composition. The present study focuses on the question whether predictions can be improved by using species environmental amplitudes instead of single values representing species optima. Location: Semi‐natural, deciduous hardwood forests of northwestern Germany. Methods: Based on a data set of 558 relevés, species responses (presence/absence) to pH were modelled with Huisman‐Olff‐Fresco (HOF) regression models. Species amplitudes were derived from response curves using three different methods. To predict the pH from vegetation, a maximum amplitude overlap method was applied. For comparison, predictions resulting from several established methods, i. e. maximum likelihood/present and absent species, maximum likelihood/present species only, mean weighted averages and mean Ellenberg indicator values were calculated. The predictive success (squared Pearson's r and root mean square error of prediction) was evaluated using an independent data set of 151 relevés. Results: Predictions based upon amplitudes defined by maximum Cohen's x probability threshold yield the best results of all amplitude definitions (R²= 0.75, RMSEP = 0.52). Provided there is an even distribution of the environmental variable, amplitudes defined by predicted probability exceeding prevalence are also suitable (R²= 0.76, RMSEP = 0.55). The prediction success is comparable to maximum likelihood (present species only) and – after rescaling – to mean weighted averages. Predicted values show a good linearity to observed pH values as opposed to a curvilinear relationship of mean Ellenberg indicator values. Transformation or rescaling of the predicted values is not required. Conclusions: Species amplitudes given by a minimum and maximum boundary for each species can be used to efficiently predict environmental variables from species composition. The predictive success is superior to mean Ellenberg indicator values and comparable to mean indicator values based on species weighted averages.     

183 The Environmental Impacts of Harvesting Beach‐Cast Seaweeds

Until recently the commercial collection of beach‐cast seaweeds in New Zealand was prohibited but the legislation has recently been amended to allow permitting of this activity. This review collates existing information on the role of beach‐cast seaweed in coastal ecosystems to describe the nature and extent of the effects that commercial removals of beach cast seaweed may have on the marine environment. It outlines the amount of beach‐cast seaweed available for harvest in New Zealand and the fate of seaweed when not collected; reviewing current information on the importance of beach‐cast seaweeds and its inhabitants on: feeding and nesting shorebirds, and nutritional contribution of seaweed inhabitants to nearshore coastal ecosystems when seaweed is washed back into the sea It also identifies key research gaps related to any environmental impacts that the removal of beach cast seaweed might have.     

152 Non‐Indigenous and Invasive Marine Algae in Hawaii

The introduction of non‐indigenous species is currently viewed as one of the largest threats to global biodiversity. Non‐indigenous marine algae (NIMA) in temperate seas around the world have caused significant losses to ecosystem structure and function. However, the introduction of invasive species in tropical marine ecosystems has not typically been viewed as a significant threat despite the number of species that have been transported to reef regions around the world for open‐reef aquaculture. The research presented here represents some of the first quantified evidence of significant negative impacts of NIMA in tropical waters. This study characterized several ecological and physiological aspects of one the most successful and potentially threatening NIMA on Hawaii's coral reefs, K. alvarezii. Results of large‐scale surveys and a number of permanently established invader removal plots suggest that K. alvarezii is having negative impacts on native species diversity. Interactions between K. alvarezii and coral abundance were examined using photoquadrats and results indicate that the invader is causing coral death as a result of overgrowth and shading. Possible mechanisms influencing invader success including responses to nutrient enrichment, grazer consumption rates and reproductive characteristics were examined. Results from a number of experiments suggest that without mitigation K. alvarezii will continue to spread. In an effort to minimize negative impacts and prevent spread several management strategies were examined including manual removal, use of chemical and temperature treatments and enhancement of native sea urchins. While some of these tools are promising control options, rapid implementation is needed to prevent further damage.