bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical, dielectric, and C band microwave scattering properties of first‐year sea ice during advanced melt
Authors: Scharien Randall K. , Geldsetzer Torsten , Barber David G. , Yackel John J. , Langlois A.
Published: December 2010

This paper investigates the influence of solar heating and intermittent cloud cover on the physical and dielectric properties of naturally snow‐free, warm (>−2°), first‐year sea ice (FYI) in the southeastern margin of the Beaufort Sea during advanced melt. A simple three‐layer physical model describing the surface is introduced and copolarized C band microwave signatures are simulated using a multilayer scattering model forced with four sets of measured surface parameters. Modeled backscatter signatures are compared to coincident surface‐based C band scatterometer signatures in order to elucidate the signature controlling properties of the ice. Results show that 50 MHz impedance probe dielectric measurements of desalinated upper ice layers exhibit statistically significant diurnal variations due to the link between solar forcing and the availability of free water in brine‐free upper ice layers. Enhanced downwelling longwave radiation to the surface from low‐level stratus clouds is positively linearly associated (r = 0.709) with volumetric moisture mv detected in upper ice layers. Model results show that desalinated upper ice layers contribute volume scattering from smooth, snow‐free FYI under the observed surface mv range. Sustained cloud‐free periods result in the formation of a 0.5–2.5 cm granular surface layer, composed of 5.2 mm ice grains, which enhances backscatter under relatively dry conditions. Sensitivity analyses show that layer thickness plays a significant role in scattering due to the increased number density of inclusions which act as discrete scatterers, and sufficient energy may penetrate to, and scatter from, the saline columnar ice layer under relatively dry conditions only (mv < 2%).
Living kidney donation: recovery and return to activities of daily living
Authors: Peters Thomas G , Repper Suzanne M , Jones Kenneth W , Walker George W , Vincent Mia , Hunter Richard D
Published: December 2010

To determine donor nephrectomy outcomes, a one page 20‐item survey of 42 cases was reviewed, including demographics, intervals to normal activities (e.g., driving a car, returning to work), and an open inquiry about the donation process. Hospital records were also reviewed. Nephrectomy under general anesthesia was through an anterior flank, extra‐retroperitoneal approach with postoperative epidural pain control. Early self‐care, progressive ambulation, and prescriptive pulmonary care were undertaken to facilitate recovery. Length of stay averaged 3.4 (range 2–8) d, and mean hospitalization charge was $15 169 (range $10 733–$29 579). Thirty‐four donors were employed outside the home; 18 (53%) returned to work within 4 wk, and the average duration away from work was 4.6 wk (range 6 d–10 wk). Within 2 wk, 25 (59%) were driving an automobile. Usual activities of daily living were fully performed by all donors at a mean of 4.8 wk (minimum 5 d). Forty respondents would donate again, and one might; one did not respond to this question. None reported intermediate or long‐term disabilities and all reported return to their pre‐donation level of activity. With the anterior extra‐retroperitoneal nephrectomy, most donors were out of the hospital within 4 d, were driving within 2 wk, and returned to gainful employment within 4 wk. Living kidney donation, as viewed by the donors, was a positive experience, which appeared to disrupt their lives minimally.
Hepatic and systemic haemodynamic changes after MARS in patients with acute on chronic liver failure
Authors: Catalina María‐Vega , Barrio José , Anaya Fernando , Salcedo Magdalena , Rincón Diego , Clemente Gerardo , Bañares Rafael
Published: December 2010

Abstract Hyperdynamic circulation and portal hypertension characterize acute on chronic liver failure (AoCLF), partially because of circulating mediators. Molecular Absorbents Recirculating System (MARS) may remove some of these substances. The objective of this study was to evaluate the effect of MARS on portal pressure, systemic haemodynamic and endogenous vasoactive systems. MARS treatment was performed in four patients with AoCLF (mean age 36.2 ± 3.1 years; Child–Pugh C 11 ± 1.8 points; three AAH and one NASH). Systemic and splanchnic haemodynamic measurements were performed before and after each session. Plasmatic renin activity (PRA) and NE were measured at baseline, at the end of the sessions and 10 days after MARS. All patients had severe portal hypertension (HVPG = 23 ± 7 mmHg) and pronounced hyperdynamic circulation (MAP 77.8 ± 11.7 mmHg; CO 11.2 ± 1.6 L/min; SVRI 478.5 ± 105 dyne s/cm5). HVPG decreased at the end of the first session in all patients (23 ± 7 mmHg vs 17.3 ± 9.9 mmHg; P = 0.05; mean decrease 32 ± 24%) because of a decrease in WHVP (40.7 ± 5.6 mmHg vs 34 ± 9.6 mmHg; P = 0.025; mean decrease 18 ± 19%). MARS significantly attenuated hyperdynamic circulation as shown by a decrease in CO (11.2 ± 1.6 L/min vs 9.4 ± 2.1 L/min; mean decrease 12.3%), with an increase in MAP (77.8 ± 11.7 mmHg vs 84.2 ± 8 mmHg; mean increase 9.2%) and in SVRI (478.5 ± 105 dyne s/cm5 vs 622 ± 198 dyne s/cm5; mean increase 41%). PRA and NE decreased significantly (14.2 ± 17.2 ng/mL/h vs 3.7 ± 3.4 ng/mL/h; 1319 ± 1002 pg/mL vs 617 ± 260 pg/mL, respectively). The NE decrease was correlated to HVPG decrease (r = 1, P = 0.01). MARS decreases portal hypertension and ameliorates hyperdynamic circulation in patients with AoCLF, probably mediated by clearance of vasoactive substances. Further studies are necessary to confirm these results.
MARS treatment in posthepatectomy liver failure
Authors: Van De Kerkhove Maarten‐Paul , De Jong Koert P. , Rijken Arjen M. , De Pont Anne‐Cornélie J. M. , Van Gulik Thomas M.
Published: December 2010

Abstract Posthepatectomy liver failure (PHLF) is a dramatic complication following extensive liver resection or liver resection in a compromised liver, leading to death in 80% of cases. Molecular Adsorbent Recirculating System (MARS) is able to extract water and protein bound toxins out of the blood in liver failure patients. This paper describes the initial experience in the Netherlands using the MARS liver assist device in five patients with PHLF. In all patients, improvement of biochemical parameters was observed during MARS treatment along with clinical improvement in three patients. One patient survived. No clear guidelines for MARS treatment and prognostic factors for outcome after MARS treatment with regard to this patient group are available. In this paper, a MARS treatment regimen for PHLF is suggested based on literature and our own experience.
Economic evaluation and 1‐year survival analysis of MARS in patients with alcoholic liver disease
Authors: Hessel Franz P. , Mitzner Steffen R. , Rief Jana , Guellstorff Britta , Steiner Susanne , Wasem Jürgen
Published: December 2010

AbstractObjective of this study was to determine 1‐year survival, costs and cost‐effectiveness of the artificial liver support system Molecular Adsorbent Recirculating System (MARS) in patients with acute‐on‐chronic liver failure (ACLF) and an underlying alcoholic liver disease. In a case–control study, 13 patients treated with MARS were compared to 23 controls of similar age, sex and severity of disease. Inpatient hospital costs data were extracted from patients' files and hospital's internal costing. Patients and treating GPs were contacted, thus determining resource use and survival 1‐year after treatment. Mean 1‐year survival time in MARS group was 261 days and 148 days in controls. Kaplan–Meier analysis shows advantages of MARS patients (Logrank:P = 0.057). Direct medical costs per patient for initial hospital stay and 1‐year follow‐up from a payer's perspective were €18 792 for MARS patients and €9638 for controls. The costs per life‐year gained are €29 719 (time horizon 1 year). From a societal perspective, the numbers are higher (costs per life‐year gained: €79 075), mainly because of the fact that there is no regular reimbursement of MARS and therefore intervention costs were not calculated from payer's perspective. A trade‐off between medical benefit and higher costs has to be made, but 1‐year results suggest an acceptable cost‐effectiveness of MARS. Prolonging the time horizon and including indirect costs, which will be done in future research, would probably improve cost‐effectiveness.
Application of Molecular Adsorbents Recirculating System to remove NO and cytokines in severe liver failure patients with multiple organ dysfunction syndrome
Authors: Guo Li‐Min , Liu Jing‐Yuan , Xu Dao‐Zhen , Li Bao‐Shun , Han Hao , Wang Ling‐Hang , Zhang Wei‐Yan , Lu Lian‐He , Guo Xia , Sun Feng‐Xia , Zhang Hong‐Yu , Liu Xiao‐Dong , Zhang Jian‐Ping , Yao Yun , He Zhong‐Ping , Wang Min‐Min
Published: December 2010

Background: Molecular Adsorbents Recirculating System (MARS) is a new promising artificial liver support therapy, the aim of this study was to assess the effectiveness of MARS to remove nitrous oxide (NO) and cytokines in severe liver failure patients with multiple organ dysfunction syndrome (MODS).

Methods: Sixty single MARS treatments were performed with length of 6–24 h on 24 severe liver failure patients (18 males/6 females) with MODS.

Results: The MARS therapy was associated with a significant removal of NO and certain cytokines such as TNF‐α, IL‐6, IL‐8, and INF‐γ, together with marked reduction of other non‐water‐soluble albumin bound toxins and water‐soluble toxins, these were associated with a improvement of the patients' clinical conditions including hepatic encephalopathy, deranged hemodynamic situation and as well as renal and respiratory function, thus resulted into marked decrease of Sequential Organ Failure Assessment (SOFA) score and improved outcome: nine patients were able to be discharged from the hospital or bridged to successful liver transplantation, the overall survival of 24 patients was 37.5%.

Conclusion: We can confirm the positive therapeutic impact and safety to use MARS on liver failure patients with MODS associated with elevated levels of NO and cytokines.
A survey of the dental needs of hospital inpatients in Scotland
Authors: Wilson Nairn H. F.
Published: December 2010

Abstract Eight hundred and ninety‐four inpatients in four hospitals in Edinburgh were assessed for oral care maintenance and dental needs during their hospitalization. The data were used to estimate future inpatients' dental requirements and the hospital dental services which would be necessary to meet these needs. Seventeen percent of the sample was found to be suffering from pain or discomfort of dental origin and over 30 % were considered to require some form of dental treatment before their expected date of inpatient discharge.
Yeast evolution and ecology meet genomics
Authors: Dunham Maitreya J , Louis Edward J
Published: December 2010

The EMBO Conference on Experimental Approaches to Evolution and Ecology in Yeast covered a broad range of interests. The applications of genomic methods to ecological and evolutionary questions emphasize that the yeasts are poised to make significant contributions to these fields.
Culturing Non-hematopoietic Mesenchymal Stromal Cells and Requirements of GMP in Stem Cell-based Therapies
Authors: Bieback Karen , Karagianni Marianna , Schmidtke-Schrezenmeier Gerlinde , Fekete Natalie , Schrezenmeier Hubert
Published: December 2010

In the recent years MSC have merged as a clinically critical cell population for cellular therapy of a variety of indications raising a lot of expectations and hope. Whereas clinical trials have been initiated worldwide, standardized protocols for isolation, expansion and characterisation seem to lag behind. Furthermore, there is growing evidence, that “MSC” despite sharing a common name, are a heterogeneous cell population with different efficacy in different therapeutic settings. Whether they are primary heterogeneous, or whether they develop it by external stimuli or senescence is still open. Therefore one must avoid generalizing specific findings in one indication with one specific MSC preparation to other therapeutic settings. Otherwise lack of efficacy or adverse events seen with one specific preparation in a specific indication may jeopardize the whole field. For the success of cell-based therapies, we regard it as major critical issue to standardise and harmonise translational protocols to develop these processes along-side with developing therapies and not thereafter. The development of a pre-clinical efficacy test for a specific indication is therefore highly desirable but admittedly also highly challenging. Moreover, test systems with regard to potential adverse events, e.g. immunosuppression or tumorigenicity, need to be established. Contact and exchange with the regulatory authorities has to be established to agree on an appropriate test panel.
Regeneration of the Vascular System
Authors: Schleicher M. , Huber A. J. , Wendel H. P. , Stock U. A.
Published: December 2010

Tissue engineering of blood vessels is an evolving research field. Driven by the shortcomings of the currently available blood vessel substitutes such as need for anticoagulation, susceptibility to infections, inability to grow and autorepair a multidisciplinary approach to design and grow viable blood vessels, identical to the native arteries or veins has started.

The following chapters will give an update of the recent developments, potential future applications and current limitations of tissue engineered blood vessels.
Homing of Mesenchymal Stromal Cells
Authors: Henschler Reinhard , Deak Erika , Schäfer Richard
Published: December 2010

Over the last years, Mesenchymal Stromal Cells (MSCs), also termed Mesenchymal Stem Cells have been studied in a still increasing number of tissue regenerative processes and as potential new treatment options for a substantial number of medical indications. In addition to the local application of MSCs which has been primarily studied e.g. in bone regeneration, cartilage replacement, as well as soft tissue and ligament repair, MSCs have been proposed in several further diseases as systemic or local intravascular applied cellular therapeutic, e.g. in a stress condition, to suppress or modulate immune reactions or to spur blood cells regeneration after hematopoietic stem cell transplantation.

This has created new interest and research activities on how MSCs, which grow in tissue culture as adherent fibroblasts, will behave when injected into the blood stream. Specific questions which have been raised include (a) the adhesion molecules which MSCs may use to co-ordinately interact with the vessel wall, (b) whether MSCs can follow tissue specific homing stimuli in a similar or analogous way as leukocytes, or (c) whether the intravenously (i.v.) transplanted MSCs will rather be eliminated e.g. by phagocytosis before or instead of entering into tissues. This chapter therefore wishes to highlight important fact of the current status on knowledge in this area.
Breeding skylarks Alauda arvensis on Environmentally Sensitive Area arable reversion grass in southern England: survey‐based and experimental determination of density
Authors: Wakeham‐Dawson Andrew , Szoszkiewicz Krzysztof , Stern Karen , Aebischer Nicholas J.
Published: December 2010

1. In the South Downs and South Wessex Downs (southern England), designated an Environmentally Sensitive Area (ESA) in 1987 and 1993, respectively, farmers may undertake to conserve existing areas of downland turf (chalk grassland rich in plants and invertebrates) and to create new areas of grassland out of previously cultivated land (arable reversion), in exchange for annual payments. These areas are subject to strict management prescriptions.

2. Singing skylarks were surveyed on 40 km2 of downland turf, arable reversion, non‐ESA grass and arable land between 1994 and 1996 (April–July) in the two ESAs. The emphasis was on two types of arable reversion: permanent grassland sown with agricultural grass species, and chalk downland sown with traditional chalk grass species.

3. The surveys showed that singing skylark density was greater on chalk downland arable reversion than on permanent grassland reversion, in swards above 15 cm in height and in fields without boundary scrub. In general, permanent grassland reversion did not support more skylarks than winter wheat or grass not entered in the ESA schemes; highest densities were in undersown spring barley. Singing skylark density decreased after mowing in May–June in the South Wessex Downs ESA.

4. In 1995 and 1996, a fully randomized experiment was carried out on 12 fields (each c. 5 ha) at Plumpton, Sussex, to verify the survey findings. Six fields were grazed to maintain a sward below 10 cm in height (short‐grazed), and the others grazed to maintain a sward between 15 and 25 cm (long‐grazed) during the skylark breeding season (April–July).

5. On average, singing skylarks were six times as abundant, and non‐singing ones twice as abundant, in experimental long‐grazed fields as in short‐grazed fields. The total number and number of taxa of chick‐food invertebrates were about twice as large on average, and the number of grass seed heads recorded in July was two to 15 times as great, in long‐grazed as in short‐grazed fields.

6. Grazing‐exclusion cages within a randomized block experiment at New Erringham, Sussex, were sampled for invertebrates in mid‐May 1995 & 1996. Ungrazed cages (sward up to 40 cm tall) supported over five times as many invertebrates and over three times as many invertebrate taxa as grazed areas (sward <2 cm tall).

7. These results contributed to revised management prescriptions for the South Downs (1997) and South Wessex Downs (1998) ESAs. Prescriptions to encourage taller swards and to prevent mowing during the nesting season in the South Wessex Downs, and removal of the 10‐cm limit on sward height, allowance of fertilizer on some arable reversion grassland, and an arable tier encouraging undersown spring cereals and overwinter stubbles in the South Downs, will benefit grassland birds.
Acidifying peat as an aid to the reconstruction of lowland heath on arable soil: lysimeter experiments
Authors: Davy A. J. , Dunsford S. J. , Free A. J.
Published: December 2010

1. Soil acidification is prerequisite for the reconstruction of lowland heath communities dominated by Calluna vulgaris on land that has been cultivated intensively. Naturally occurring sulphidic peat from a coastal basin deposit was investigated as a potential soil modifier. Its total S and Fe contents confirmed the presence of pyrite (FeS2).

2. In a lysimeter experiment, the surface pH of peat dropped rapidly from 6·5 to 2·5 as pyrite oxidized to produce sulphuric acid. It increased only slightly in the following 5 years. The pH of leachate from the lysimeters dropped to c. 2·0, rising to c. 3·0 over 5 years. Large pulses of soluble iron and sulphate were released from the lysimeters, peaking in the first winter; the Fe discharge fell to background levels after 2 years but SO42− concentrations were still elevated after 5 years. Calluna vulgaris seeds were not able to germinate and survive on the raw peat, even with irrigation. Some seedlings became established on the control agricultural soil but succumbed rapidly to competition from arable weeds.

3. In a second experiment, we amended the surface 15 cm of agricultural soil with peat and compared its properties with bracken litter. The peat sample acidified less, but both peat and bracken incorporation resulted in surface acidification. Neither acidity nor Fe was released in leachates, although the expected pulse of SO42− was discharged from treatments involving peat. Calluna vulgaris seedlings established well on peat mixtures and responded to initial weed control and irrigation treatments. However, after 1 year, competition from Trifolium repens, Agrostis gigantea and Agrostis capillaris had extinguished the C. vulgaris populations, except on the bracken litter mixture where some seedlings persisted for a further 2 years. Weed roots had grown through all the surface layers and exploited the underlying arable soil.

4. The weed seed bank is a major obstacle to heathland reconstruction on arable soil. Pyritic peat has potential as a soil amendment to lower pH and fertility and improve water retention, but it would be needed in greater proportions and to greater depths than used here in order to reduce weed competitiveness. Its use would release large amounts of mobile sulphate into the soil, potentially an issue for groundwater protection; the evidence suggests that the soluble iron and acidity released would not penetrate to a great depth in the profile.
Modelling the incidence of virus yellows in sugar beet in the UK in relation to numbers of migrating Myzus persicae
Authors: Werker A. R. , Dewar A. M. , Harrington R.
Published: December 2010

1. The incidence of virus yellows diseases in sugar beet crops in eastern England during 1965–96 was analysed in relation to numbers of migrating Myzus persicae, the principal vector.

2. A non‐linear model was fitted to the data incorporating dual routes of infection: primary infection, arising from winged immigrant aphids carrying the virus, and secondary infection, arising from local dispersion of their wingless offspring transferring the virus from infected to uninfected plants.

3. The model was fitted to the data assuming that (i) the epidemic commenced when the first migrating aphid was recorded, (ii) the rate of primary infection was dependent on the total number of aphids migrating up to the end of June, and (iii) the rate of secondary infection was dependent on the proportion of diseased plants in the crop.

4. A good description of virus yellows incidence in August depended on allowing the rate parameters for primary and secondary infection to decrease sigmoidally over the years during 1965–96. The shape of this function depicted a major change in the epidemiology of virus yellows since 1974–76. Amongst several contributory factors, this change coincided with the introduction and subsequent wide use of systemic granular pesticides.

5. Good fits also depended on allowing the rates of disease progress to decay with time to accommodate effects of increasing host resistance with plant age to feeding aphids. This meant that early epidemics rose faster than late epidemics, which is consistent with general observations.

6. Given that the changes in the epidemiology of virus yellows over the years are associated with improvements in pest management practices, the model presents a useful extension to disease forecasting by providing predictions of disease risk in the absence of pesticides. Such predictions indicate that during the last decade up to five severe epidemics would have been likely.
Spatial and temporal patterns of heather use by sheep and red deer within natural heather/grass mosaics
Authors: Hester A. J. , Baillie G. J.
Published: December 2010

1. Fragmentation of heather and conversion to grass under heavy grazing is a widespread phenomenon. In the British uplands it is attributed in particular to the effects of sheep and red deer, but little is known about the processes by which fragmentation occurs under grazing by these different herbivores. This has hindered the prediction of herbivore impacts and thus the design of appropriate management schemes for the protection of heather‐dominated vegetation. In this paper we report the results of an experiment examining the patterns of impact by sheep and red deer grazing separately or together within an area of fragmenting heather in north‐east Scotland during 1991–95.

2. Heather utilization by both species declined rapidly with distance from grass, with both herbivores grazing similar amounts of heather, except in autumn where heather utilization by deer was greater than that by sheep.

3. Differential patterns of grass patch use by sheep and red deer resulted in greater heather utilization around larger grass patches by red deer, but no consistent differences in edge‐heather utilization by sheep. Both species grazed less edge‐heather downhill of grass patches than uphill or across the slope. Thus, we hypothesize that on sloping ground grazing impacts will be greatest uphill from grass for both herbivores, but their patterns of impact around different grass patches will diverge when a range of grass patch sizes is present.

4. Patterns of impact as a result of trampling damage differed from those due to grazing, with damage concentrated at downhill edges of patches and paths, with corresponding increases in cover of species such as Vaccinium myrtillus where the heather had declined.

5. We suggest that on sloping ground at lower herbivore densities, trampling may have more important impacts on the heather than grazing, but as herbivore densities increase the relative importance of grazing will increase, thus changing the patterns of impact on the vegetation.

6. The implications of these differences in herbivore impacts are discussed in relation to the management of heather‐dominated vegetation under grazing by sheep or red deer and the limitations of approaches based on stocking rates alone.
Management of permanent set‐aside on arable land in Sweden
Authors: Hansson Margareta , Fogelfors Håkan
Published: December 2010

1. Set‐aside fields have been an important element of the European agricultural landscape since the introduction of the set‐aside scheme by the European Community. However, countries in the European Community differ in their rules for managing set‐aside owing to different priorities.

2. In Sweden, a major goal is to reduce the total use of agricultural pesticides, consequently their use is prohibited in set‐aside. The options for weed control are therefore cutting and/or the use of a cover crop.

3. In this study, we describe the course of succession following the abandonment of farmland managed in different ways. The floristic composition was followed over a 10‐year period. Temporal trends in community development are described.

4. The experiment began in 1975 on farmland at six localities, distributed from southern to northern Sweden. The management treatments involving the application of fertilizers and cutting were applied to plots sown with a cover crop and to plots in which the succession started from bare ground.

5. We found that competitive interactions between species largely determined the successional course in our study. The competitive success of species was related to the management practices applied but there were also interactions between management and site conditions.

6. We propose that natural succession can be recommended on poor sites in combination with cutting, mainly to prevent the invasion of woody species. On fertile sites a cover crop should be used to suppress perennial weeds, and cutting is recommended mainly to increase species diversity.
Development of Sphagnum fallax diaspores on bare peat with implications for the restoration of cut‐over bogs
Authors: Buttler A. , Grosvernier P. , Matthey Y.
Published: December 2010

1. The growth of Sphagnum fallax was studied in a glasshouse experiment. Capitulum diaspores of S. fallax were cultivated on five different types of bare peat core, representing a gradient of increasing disturbance. Increases in length and weight were measured. Three microclimates were simulated by protecting the bare peat with a shading mesh and a plastic cover in combination with two water levels.

2. Significant differences in the growth of S. fallax were observed in relation to microclimate changes. Protection techniques such as shading mesh and perforated plastic film allowed a better development of the diaspores compared to bare peat. A plastic cover caused the best growth and compensated for a low water table level.

3. Peat properties are critical when diaspores grow in direct contact with decomposed peat. The porosity, and especially its vertical pattern in the peat profile, proved to be an important factor. A particular combination of microclimate conditions at the surface of the bare peat, and physical properties of the upper peat layers, may favour the growth of S. fallax diaspores even where there is a low water

Table 4
. Restoration of Sphagnum species on cut‐over bogs needs to consider both the microclimate conditions at the surface of the bare peat and the peat properties themselves. These factors are important for the diaspores, particularly in periods of climatic and hydrological stress. In such situations, commensalism with some vascular plants may be a useful trigger for Sphagnum growth.
Satellite imagery as a tool for monitoring species diversity: an assessment
Authors: Nagendra Harini , Gadgil Madhav
Published: December 2010

1. A landscape of 5 × 5·5 km in the Karnataka region of the Western Ghats of India was mapped into seven landscape element types, using field identification of types as well as supervised and unsupervised classification of satellite imagery.

2. Plant communities distributed in these landscape element types were surveyed in the field using 246 quadrats of 10 × 10 m, in order to assess whether these types could be distinguished in terms of species composition. All angiosperms excluding grasses, which could not be identified accurately in the field, were recorded for this purpose.

3. Landscape element types identified in the field harboured significantly distinctive sets of species of flowering plants, and were also by and large distinctive in terms of their species richness.

4. Landscape element types could be identified accurately on the basis of supervised classification: the types thus demarcated harboured distinctive sets of flowering plants.

5. Landscape element types coupled to satellite imagery could then be used to organize a programme of monitoring biodiversity.

6. Unsupervised classification of satellite imagery did not permit classification of landscape element types with a high enough level of accuracy. In consequence, the demarcated landscape element types did not harbour significantly distinctive sets of species of flowering plants. Unsupervised classification is therefore not appropriate in a programme of monitoring biodiversity.
Moisture controls on Sphagnum growth and CO2 exchange on a cutover bog
Authors: McNeil P. , Waddington J. M.
Published: December 2010

1. Abandoned cutover peatlands are persistent sources of atmospheric CO2. Net ecosystem CO2 exchange and Sphagnum net primary production of an abandoned block‐cut bog were measured in the field and in the laboratory using gas exchange techniques to determine the processes controlling CO2 exchange in these ecosystems.

2. Sphagnum net primary production was offset by peat respiration, resulting in the peatland becoming a net source of CO2 during the summer months.

3. Sphagnum photosynthesis was greatest at wet sites. In addition, sites with vascular plant cover photosynthesized at approximately twice the rate of sites where vascular plants were removed.

4. Laboratory results indicate that drying and wetting cycles negatively affect Sphagnum net primary production and net ecosystem CO2 exchange. Sphagnum and peat respiration increased 4–14‐fold upon rewetting, whereas Sphagnum photosynthesis did not recover until 20 days of saturation.

5. Synthesis and applications. This research emphasizes the importance of stable moisture availability for the growth of Sphagnum and the eventual development of a new acrotelm on the cutover bog surface. Restoration techniques must therefore include companion species and a constant moisture supply above the minimum threshold for Sphagnum mosses.
Stochastic models of foot and mouth disease in feral pigs in the Australian semi‐arid rangelands
Authors: Dexter N.
Published: December 2010

Foot and mouth disease (FMD) is one of the world's most important livestock diseases and pigsSus scrofaare highly susceptible. In countries with significant feral pig populations, such as Australia, the possibility that FMD may become established in these populations is a cause of considerable concern.

Current models of FMD in feral pigs in Australia are based on deterministic population and behavioural parameters. However, the population dynamics of feral pigs in the semi‐arid regions of Australia vary stochastically, in concert with the biomass of rainfall‐driven pasture.

This study explored how stochastic variation in the population dynamics of feral pigs in semi‐arid rangelands affected the probability of persistence of an FMD epizootic, and its impact on the density of feral pigs. A stochastic model of feral pig population dynamics, with death rate linked to vegetation and rainfall, was linked to a deterministic model of FMD in feral pigs.

Unlike the fully deterministic model, the stochastic model predicted inevitable extinction of the disease. When the transmission coefficient for FMD (β) was set at the mean value of 9 km2pig−1 day−1, the mean persistence time of the epizootic (in 1000 simulations) was 3338 days, with a maximum persistence time of 8439 days.

On average the FMD epizootic reduced the population density of feral pigs, compared with the density of uninfected pig populations, by between 54% and 43% for transmission coefficients (β) equal to the estimated likely mean and minimum values (9·0 km2pig−1 day−1and 2·5 km2pig−1 day−1), respectively. This compares with a suppression of 27% in density for the equivalent deterministic model.

Further stochasticity was introduced to the linked population and disease model by making the transmission coefficient β stochastic with values based on radio‐telemetry of a population of feral pigs in the semi‐arid rangelands over an 18‐month period.

The addition of a stochastically varying β lowered the mean persistence time of the simulated epizootic to 1037 days in 1000 simulations and reduced the maximum persistence time to 3907 days. Pig density was reduced by 45% compared with uninfected populations.

Synthesis and applications.These simulations suggest that any control programme to suppress a FMD outbreak in feral pigs in the semi‐arid rangelands of Australia should take account of prevailing environmental conditions when aiming to reduce feral pig populations beneath a threshold density (NT) below which the disease cannot persist. As theNTis higher than for the equivalent deterministic model, the disease may be easier to control than such models suggest.
Long‐term dynamics of Chernobyl 137Cs in freshwater fish: quantifying the effect of body size and trophic level
Authors: Sundbom Marcus , Meili Markus , Andersson Evert , Östlund Mikael , Broberg Anders
Published: December 2010

1. Freshwater fish are a potentially important link in the transfer of radionuclides from polluted ecosystems to people. A pulsed contamination event such as the Chernobyl fallout in 1986 is a challenge to the prediction of radioactivity in biota, because activity concentrations of radionuclides can change dynamically among populations during an initial equilibration phase. This was demonstrated from time‐series of 137caesium (Cs) in fish from three Swedish lakes (1986–2000, eight species, > 7600 individuals). In addition, we used these data to test hypotheses about the influence of fish size and trophic level on the temporal patterns of 137Cs.

2. In order to facilitate comparisons, a pulse‐response model was developed to extract key parameters from field data: the timing (tmax) and level (Csmax) of the peak concentrations, the near steady‐state level (Csbase) and the long‐term decline rate (λ).

3. Peak concentrations in different fish were attained 56–806 days after the fallout. This delay (tmax) increased with body size and trophic level. Csmax increased with fish size but was highest at intermediate trophic levels. Csbase increased by a factor of 1·8 per trophic level, but was not influenced by size across species. The 137Cs‐size relationship within species, however, shifted from negative to positive during the first 2 years.

4. The apparent ecological half‐life (T1/2) for 137Cs increased after tmax and initially differed among fish and lakes. About 10 years after the fallout T1/2 was no longer significantly different among fish or lakes, suggesting that steady‐state among 137Cs levels in fish had been reached. The mean T1/2 during 1996–2000 was 46 years, implying that the future recovery from present 137Cs levels (more than 10‐fold higher than pre‐Chernobyl levels) will be dominated by the physical decay of 137Cs (30 years).

5. The influence of fish size and trophic level on 137Cs dynamics has been consistent among the three lakes. The duration of the 137Cs pulse in fish appeared to be regulated by fish ecophysiology, whereas the amplitude also appeared to be regulated by lake characteristics.

6. Synthesis and applications. These data have implications for the predictive modelling of pulsed contaminants in lake ecosystems and show that (i) complex temporal concentration trends in fish can be adequately modelled by a combination of simple first‐order equations; (ii) a one‐component decline function is insufficient to describe the observed increase in ecological half‐life over time; (iii) fish weight and trophic level can and should be treated as independent variables because their influence differs and changes over time. For management purposes, a pulse‐response model for fish can be scaled to different systems by using established relationships to account for differences in fallout and catchment biogeochemistry.
Teretrius nigrescens against larger grain borer Prostephanus truncatus in African maize stores: biological control at work?
Authors: Holst Niels , Meikle William G.
Published: December 2010

Following the accidental introduction of the bostrichid beetle Prostephanus truncatus into East and West Africa around 1980, a classical biological control campaign was launched in 1991; the histerid beetle Teretrius nigrescens was released as a biocontrol agent to prevent the destructive outbreak of the pest in small‐farm maize stores. However, while the campaign has been ongoing, so has discussion in the scientific community about the merits of this campaign and its chances of success.

From published and unpublished data from experimental maize stores in Benin, West Africa, we derived statistical models describing the in‐store insect population dynamics, and were thus able to point out significant biological interactions and to explain the observed lack of biological control.

We found that (i) T. nigrescens reduced significantly the population growth rate of both P. truncatus and the non‐target pest, the weevil Sitophilus zeamais; (ii) T. nigrescens displayed a positive numerical response to both prey species, P. truncatus and S. zeamais; (iii) asymmetric competition existed between the two prey species, S. zeamais was negatively affected by P. truncatus but not vice versa; (iv) T. nigrescens and S. zeamais displayed negative intraspecific density‐dependence whereas P. truncatus was resource‐limited.

We conclude that classical biological control with T. nigrescens is not likely to become successful, mainly due to the predator's intraspecific density‐dependence and its low population growth rate compared with its prey. We recommend that further research on P. truncatus integrated pest management takes into account the farmer as an active agent managing the store.

Synthesis and applications. When biocontrol does not result in satisfactory pest control, as in the case of P. truncatus, farmers should learn how to scout for the pest and take action when a need is detected. In areas where the pest is usually only a minor problem, the agricultural extension service should consider setting up a simple early warning system for their region. When attempts at classical biological control remain unsuccessful, as in the case of P. truncatus now for 10 years, policy‐makers should prioritize training of extension service and farmers in integrated pest management techniques (e.g. need‐based use of insecticides) as a necessary supplement to biocontrol.
Modelling the daily food requirements of wintering great cormorants: a bioenergetics tool for wildlife management
Authors: Gremillet David , Wright Gordon , Lauder ALAN. , Carss David N. , Wanless Sarah
Published: December 2010

Great cormorants Phalacrocorax carbo, Linnaeus are large piscivorous birds which occur in Asia, Australia, Africa, Europe and North America. Their European breeding population has increased by at least 15% per annum over the last 15 years, reaching a total of c. 200 000 pairs in the late 1990s. There are concerns that this increase is adversely affecting freshwater fish populations throughout Europe, but real assessment requires a detailed knowledge of cormorant food requirements.

The daily food intake (DFI) of great cormorants has been measured during the breeding season, but little is known about DFI in winter when these poorly insulated birds experience consistently low temperatures. DFI is likely to vary widely according to abiotic and biotic conditions, making predictions about impact particularly difficult.

We modelled DFI for great cormorants wintering at Loch Leven, Scotland, using behavioural data recorded via radio‐tracking of free‐ranging individuals, metabolic measurements obtained from captive birds, and published data. DFI was estimated to be 672 g day−1 (predicted maximum range 441–1095 g day−1), values similar to DFI of great cormorants breeding under temperate conditions and of other aquatic bird species.

During winter great cormorants at Loch Leven decreased their average dive time and increased dive efficiency (higher proportion of time spent underwater). They nonetheless spent 130 min day−1 in the water and allocated more than a third of their daily energy budget to diving.

Synthesis and applications: In view of the need for the sound management of cormorant populations, we present a general bioenergetics model, based on simple behavioural and dietary inputs, that computes an estimate of DFI outside the breeding season for a range environmental conditions and habitats. An interactive computer programme for this model is available (http://www.cepe.c‐strasbourg.fr) to help scientists and managers estimate local values for average, minimum and maximum DFI.
Influence of mechanical cutting and pathogen application on the performance and nutrient storage of Cirsium arvense
Authors: Kluth Stephanie , Kruess Andreas , Tscharntke Teja
Published: December 2010

1. In order to develop an effective biological control technique, the influence of mechanical and pathogen treatments on performance and nutrient storage of the weed creeping thistle Cirsium arvense was studied over a 2‐year period. To our knowledge, this is the first study to evaluate the effect of a combination of cutting and application of the rust Puccinia punctiformis as a possible biocontrol organism on thistles.

2. We conducted a complete two‐factorial design using potted plants, with the application of the rust and cutting of thistles as the treatment factors. Treatments were applied once every year in June.

3. Inoculation reduced above‐ground biomass in the first year. First year cutting reduced the number of thistle shoots, but stimulated compensatory growth with an increased growth rate and biomass. Only a second year cutting treatment significantly reduced above‐ and below‐ground biomass, despite an increased growth rate.

4. The number of flower heads was strongly reduced by both cutting and combined treatments. The proportion of fertile flower heads was increased by cutting, whereas the combination treatment strongly reduced it.

5. Analysing storage nutrients, starch concentrations did not differ among treatments. Cutting reduced sugar concentrations, but pathogen infection tended to increase concentrations, resulting in significant interaction effects. Cutting also reduced below‐ground carbon concentrations, but the carbon : nitrogen ratio was not influenced.

6. Synthesis and applications. The traditional mechanical technique of cutting was shown to be effective in reducing plant reproductive success and concentration of storage nutrients. Additional infection with a plant pathogen further restricted sexual reproduction, indicating that combined treatments may be more effective for biological control of perennial weed species. Whilst further studies are needed to establish P. punctiformis as a mycoherbicide, some synergism between repeated cutting and rust inoculation indicates that there is potential for a biological approach to the control of creeping thistle.
North Atlantic summers have warmed more than winters since 1353, and the response of marine zooplankton
Authors: Kamenos Nicholas A.
Published: December 2010

Modeling and measurements show that Atlantic marine temperatures are rising; however, the low temporal resolution of models and restricted spatial resolution of measurements (
i
) mask regional details critical for determining the rate and extent of climate variability, and (
ii
) prevent robust determination of climatic impacts on marine ecosystems. To address both issues for the North East Atlantic, a fortnightly resolution marine climate record from 1353–2006 was constructed for shallow inshore waters and compared to changes in marine zooplankton abundance. For the first time summer marine temperatures are shown to have increased nearly twice as much as winter temperatures since 1353. Additional climatic instability began in 1700 characterized by ∼5–65 year climate oscillations that appear to be a recent phenomenon. Enhanced summer-specific warming reduced the abundance of the copepod
Calanus finmarchicus
, a key food item of cod, and led to significantly lower projected abundances by 2040 than at present. The faster increase of summer marine temperatures has implications for climate projections and affects abundance, and thus biomass, near the base of the marine food web with potentially significant feedback effects for marine food security.
Structure of RavA MoxR AAA+ protein reveals the design principles of a molecular cage modulating the inducible lysine decarboxylase activity
Authors: El Bakkouri Majida , Gutsche Irina , Kanjee Usheer , Zhao Boyu , Yu Miao , Goret Gael , Schoehn Guy , Burmeister Wim P. , Houry Walid A.
Published: December 2010

The MoxR family of AAA+ ATPases is widespread throughout bacteria and archaea but remains poorly characterized. We recently found that the
Escherichia coli
MoxR protein, RavA (
R
egulatory
A
TPase
v
ariant
A
), tightly interacts with the inducible lysine decarboxylase, LdcI/CadA, to form a unique cage-like structure. Here, we present the X-ray structure of RavA and show that the
αβα
and all-
α
subdomains in the RavA AAA+ module are arranged as in magnesium chelatases rather than as in classical AAA+ proteins. RavA structure also contains a discontinuous triple-helical domain as well as a
β
-barrel-like domain forming a unique fold, which we termed the LARA domain. The LARA domain was found to mediate the interaction between RavA and LdcI. The RavA structure provides insights into how five RavA hexamers interact with two LdcI decamers to form the RavA-LdcI cage-like structure.