bluuebunny/crossref_metadata_2025 huggingface dataset:
Conversion of Coastal Habitats in Singapore: Indications of Unsustainable Development
Authors: Hilton Michael J. , Manning Sarah S.
Published: August 2009

The Republic of Singapore, a small island state lying at the southern extremity of Peninsular Malaysia has, along with other ASEAN nations, stated its commitment to the principle of ‘sustainable development’ and ecological sustainability. This paper presents an assessment of the impact of post-World War II development on the extent and quality of intertidal coastal ecosystems and ecocomplexes in Singapore — specifically on coral reefs, mangroves, and intertidal sand- and mud-flats — and hence an evaluation of Singapore's commitment to maintaining coastal ecosystems and coastal biodiversity. The extent of these habitats was mapped from topographic and hydrographic maps, and estimates of their future area was derived from the Singapore Concept Plan for the year ‘x’ (AD c. 2030).
Mortality Factors of Dalmatian Pelicans (Pelecanus crispus) Wintering in Macedonia, Greece
Authors: Pyrovetsi Myrto , Papazahariadou Margarita
Published: August 2009

A survey of dead Dalmatian Pelicans (Pelecanus crispus) at Kerkini Lake, Greece, the major wintering site in Europe of this world-endangered species, was undertaken to investigate the causes of high mortality that occurred during 1991–93. In February 1991, 30% of the population wintering on the Lake (30 individuals) were found dead, the majority (85%) having died of natural causes. A loss of this magnitude does not reflect only locally or on the genetic stock of the species but is also a matter of grave concern relative to its conservation world-wide.

Most mortality of the Pelicans coincided with subzero temperatures and the Lake freezing over — conditions that direct fish to deep waters, and make them unavailable to the Pelicans. Necropsies were carried out on the carcasses of 13 Pelicans, including stomach and gizzard, etc., contents' analysis, and gross pathological, bacteriological, toxicological, and parasitological, examinations. All the carcasses found at Lake Kerkini were dehydrated and emaciated. No food was found in the digestive system of the Pelicans, but there was a heavy parasite burden. Species of seven helminth genera were detected in the carcasses, three of them (Bolbophorus, Contracaecum, and Synhimantus) being reported for the first time in Greece. Contracaecum spp. in large numbers (up to 875 worms per bird), were found in the digestive system of all the carcasses. Most parasites were observed to penetrate the wall of the gizzard, causing haemorrhages and ulcers. No evidence of chlorinated hydrocarbon contamination or bacterial infection was found. Mycotic lesions were detected in the air-sacs of one Dalmatian Pelican, which may have contributed to the death of that particular individual in connection with the parasite burden.
Measurements of Impact of Tourist Off-road Driving on Grasslands in Masai Mara National Reserve, Kenya: A Simulation Approach
Authors: Onyeanusi Augustine E.
Published: August 2009

A quantitative measurement of tourist off-road driving was conducted in Masai Mara National Reserve, Kenya. Off-road driving was simulated in a grassland area of the Reserve that was heavily used by tourists. A mathematical model was employed to estimate the overall impact of tourist off-road driving on the Reserve's grassland communities.

The results of off-road driving simulation experiments showed that damage increased with the number of vehicular passes. Off-road driving was more destructive to the vegetation at the loops than on the straight. The magnitude of the estimated loss due to extrapolation of the findings of the simulation experiments to the whole reserve was very small. The aesthetic quality of the reserve was, however, adversely affected by the off-road driving, as was, doubtless, the privacy of the animals.
An Experimental Approach to the Reclamation of a Limestone Quarry Floor: the Fourth to Seventh Years
Authors: Hambler David J. , Dixon Jean M.
Published: August 2009

An experiment to suggest a technique for rehabilitation of a hard-limestone quarry floor in northern England was carried into its seventh year (see also Dixon & Hambler, 1984). The stress-tolerant grass Festuca rubra var. fallax Hack, cultivar Cascade proved suitable as a primary colonist, especially when sown onto rubble treated with a powdery manure derived from sewage. The community so produced was composed mainly of F. rubra and mosses, their proportions varying reciprocally with time but remaining approximately stable in a series of summer estimates of percentage cover.

The dry-weight per unit area of this vegetation, and that of other experimental sets, did not increase between the third and sixth years of the experiment. The organic content of the developing soil, however, increased considerably. Trifolium repens, where sown with the grass, had no obvious ecological impact, although its improved performance on Rabbit ‘middens’ indicated the general nutrient deficiency of the site.

A net flow of immigrant flowering-plants into the experimental site slowed down by the seventh year. Limestone grassland species arrived but the most abundant species were ruderals. All of the potentially large ruderal species failed to attain their full competitive potential, as did F. rubra. The community dominated by F. rubra and mosses proved unfavourable for the establishment of both Poa annua and Epilobium angustifolium— the latter being regarded as a particularly undesirable weed in this context.

The concept of visual acceptability was applied as a measure of the success of each sowing/treatment combination; the most successful might be recommended for rehabilitation of a worked-out limestone quarry.
Impacts from Mosquito Control-induced Sulphur Mobilization in a Cape Cod Estuary
Authors: Soukup Michael A. , Portnoy John W.
Published: August 2009

Insect control programmes sometimes include environmental modification techniques such as diking and drainage. The impacts of such techniques are not often known or assessed. As a telling example having wide implications, we present an analysis of impacts in a small estuary which has been subjected to both diking and ditching—primarily for mosquito control.

The major impacts stem from katteklei formation. Desiccated salt-marsh sediments produce acidified leachates which result from oxidation of pyrites. Lowered pH and high (acid-mobilized) aluminium concentrations both surpass levels that are known to be toxic to aquatic fauna. Fish and invertebrate communities in the basin are impoverished, and important commercial species such as American Eels and Alewives are heavily decimated. The acid-tolerant mosquito Aedes cantator thrives, however. Thus a natural system of substantial economic and aesthetic value has been inadvertently devastated through application of unnecessarily harsh as well as, in this case, ineffective mosquito control methods. Their use should be re-evaluated for similar impacts wherever such application has been carried out or is being contemplated.
A World Ecoregions Map for Resource Reporting
Authors: Bailey Robert G. , Hogg Howard C.
Published: August 2009

An international project is proposed to create a map showing the world subdivided into macroecosystem regions within each of which ecological conditions are relatively uniform but which show certain natural potentials and limitations. The map should tend to supplement the Dasmann-Udvardy system of biogeographical provinces, being of higher resolution and greater ecological relevance. The primary purpose of the map will be to serve as a reporting structure for information about global resources and environment, though it will be based largely on published information.

Maps based on classification of climatic types, vegetation formations, and soil groups, will be synthesized and generalized to delineate the areas to be shown on the ecoregion map. Its delineations will be refined through consultations with local experts, and through the interpretation of low-resolution remote-sensing imagery. The usefulness of the map is considered favourably in relation to national-level policy analysis, environmental monitoring, transfer of agricultural technology, compatibility with remote-sensing systems for monitoring environmental conditions, and agricultural activities, biomass estimation, macroreserve selection, and land management.
Sensitivity of the Arctic Climate: A Factor in Developing Planning Strategies for Our Arctic Heritage
Authors: LeDrew Ellsworth F.
Published: August 2009

Studies have illustrated a sensitivity of the climate of the Arctic to natural and human-induced perturbations which greater than that in mid-latitudes or the tropics. This may be due, in part, to positive feedback linkages between the atmosphere and the cryosphere. We are only beginning understand the nature of the process linkages within the atmosphere-cryosphere-ocean-Biosphere system, however, and this is reflected in the discrepancies between various model simulations. This uncertainty increases our vulnerability to climatic change and variability. In the development of policy regarding management and development of our Arctic Heritage, we must attempt to reduce our vulnerability: we must be able to simulate the physical consequences of a perturbation with some veracity, and translate the results into the language of the policy analysts.

Three areas of research are highlighted as being important contributions towards this objective. The first is the derivation of climatically significant parameters from remotely-sensed data. Our climatologies and model validations are based upon spatially-biased data which include undetermined errors. With remotely-sensed imagery, we have access to previously inaccessible regions as well as spatial consistency in the data. The second area of research the detailed study of micro- and mesoscale processes at climatic ‘oases’. We must understand processes at these scales, and their linkage to the macroscale, if we are to design realistic General Circulation Models to simulate new climate states. The third area is effective communication of our knowledge in a form amenable to policy analysis. Current research is directed towards evaluating the impact of climatic variation in terms of risk assessment, and consideration of the policy implications of possible future climatic regimes through scenario analysis.
Successful Control of the Floating Weed Salvinia molesta in Papua New Guinea: A Useful Biological Invasion Neutralizes a Disastrous One
Authors: Thomas Phillip A. , Room Peter M.
Published: August 2009

Salvinia molesta, an aquatic weed native of Brazil, entered the floodplain of the Sepik River in Papua New Guinea in the early 1970s. It caused great distress to the local people by increasing exponentially to form thick mats covering many lakes and channels. A beetle from Brazil, Cyrtobagous salviniae, was established in one lagoon in 1982 and over the next 2 years 900,000 adults were redistributed manually among another 130 lagoons and lakes. Rates of beetle population increase (r) were close to 0.042 adult per adult per day in most lagoons. Local dispersal occurred when population densities reached 15 adults per kg of the Salvinia, damaging between 70% and 90% of Salvinia buds. Feeding by adults and larvae of the beetle caused entire mats of Salvinia to turn brown, die, and sink, but no deleterious changes in water quality were observed.

The time taken for beetles to spread throughout a lagoon and for the weed to be controlled was generally 12–18 months, depending on the area of the Salvinia mat, its thickness, and its mobility when blown by the wind. Herbicide was used to aid establishment of the beetle at one site by thinning a thick mat which had been colonized by sudd vegetation. An equilibrium appeared to be reached with the Salvinia present at < 1% of its former populationdensity.
A Tale of Two Islands: Some Lessons for Marine Resource Management
Authors: Savina Gail C. , White Alan T.
Published: August 2009

A comparison of two island fishing communities in the Visayas, Philippines, shows significant differences in coral-reef habitat and in diversity of selected reef-fishes, as well as important differences in fishing customs and catch composition. During the sampling months of April–May 1985, fishermen on the 72-ha Apo Island, Negros, caught more than two-thirds of their total fish-catch on the reef, whereas fishermen on the 200-ha Pamilacan Island, Bohol, caught less than 20% of their total catch on the reef during the same period. This discrepancy may be attributable to reef quality or fishing customs, or to both these factors.
The Selection of Conservation Areas in Antarctica: An Example Using the Arthropod Fauna of Antarctic Islands
Authors: Usher Michael B. , Edwards Marion
Published: August 2009

Four conservation areas in the maritime Antarctic (three Specially Protected Areas and a Site of Special Scientific Interest) are compared with neighbouring islands which have not been awarded similar conservation status. Comparisons are carried out by using the terrestrial arthropod fauna, as opposed to the plant communities. Results indicate that arthropod diversity can vary significantly between localities for samples collected from the same vegetation types, but that within a limited geographical area the diversity of such faunas is similar.
The Effect of Human Activity on Shorebirds in Two Coastal Bays in Northeastern United States
Authors: Burger Joanna
Published: August 2009

The effects of human activities on shorebirds migrating through Raritan and Delaware Bays (New Jersey, USA) were examined from late April to late October 1982. Less than 5% of the 471,055 shorebirds counted in the censuses were in Raritan Bay, and only eight species accounted for 95% of the total. Bird populations peaked during late May to early June, and had a secondary peak in early August. People walking accounted for 43% (Raritan Bay) and 50% (Delaware Bay) of the disturbances. Other disturbances, in descending order of abundance, were of fishermen, airplanes, dogs, clam-diggers, off-road vehicles, boats, children, and joggers.
Incentives for Private Forestry: The Case of the Republic of Ireland
Authors: Gairdner Gillian
Published: August 2009

Forest decline in the tropical zone of the world has provoked an enormous amount of concern but, so far, few if any panaceas. Leaving aside the pervasive impact of clearance for agriculture to focus for the time being exclusively on the role of timber extraction in the moist tropics, it appears that, in present circumstances at least, commercial logging is effectively incompatible with sustainable forest use. For this reason there is a developing interest in the potential which private-sector plantation forestry may have, in these areas, for significantly contributing to both local and export timber needs and so relieving pressure on the remaining area of natural forest. The peculiarly long-term character of investment in trees, and the capital-poor nature of the countries concerned mean, however, that financial incentives will almost certainly be necessary if plantations are to have real consequence.

It is in this context that the recent history of the forest programme in Ireland, the country with the lowest overall proportion of forest cover and the highest percentage of state (as opposed to private) forestry in the EC, may be relevant. Forestry incentives introduced in 1980, and aimed at landowners in the agriculturally disadvantaged western region, were initially ineffective, despite the region's comparative advantages for timber-growing. However, major additions to the level and range of support in the second half of the 1980s, led to an exponential increase in grant-uptake.

The very success of the above scheme in recent years has caused it to be critized for the loss of large areas of bogland which have considerable environmental value but low potential for timber production in any normal investment sense. In addition, plantations in all parts of the region are overwhelmingly coniferous. More generous, country-wide incentives for environmentally desirable broadleafed planting are too new for it to be known what effect they will have on the afforestation of the better land. It seems almost certain, however, that attempts to reconcile productive and environmental aims in private forestryprogrammes inevitably increase their complexity and cost: this has undesirable implications for the possible transfer of such schemes to developing countries in the tropics.
Wildlife and Reclamation Ecology: Rabbit Middens on Seeded Limestone Quarry-spoil
Authors: Dixon Jean M. , Hambler David J.
Published: August 2009

Middens (i.e. persistent ‘dung-heaps’) produced by Rabbits (Oryctolagus cuniculus) on a limestone quarry-spoil bank in the process of reclamation were small areas of enhanced biological activity, initiated and maintained by Rabbits, that were probably beneficial, through recycling of nutrients, to those same Rabbits.

The soil of the middens, at a depth of 0–5 cm, was moister, richer in nutrients, of lower pH, and more humic, than elsewhere on the spoil. It probably owed these characteristics to the Rabbits' urine as well as dung.

Middens were ‘beneficial’ to the pioneer vegetation through the resultant of increased fertility and grazing; sown grasses were stimulated to produce local patches of sward on the spoil. The plants themselves were more intensely green, and richer in nitrogen, phosphorus, and potassium, than those in the surrounding area.

Associated with the soil surface of the middens was a rich invertebrate fauna, some members of which must be directly and entirely dependent on the dung. Overall the Rabbits were judged beneficial to the reclamation.
A Strategy for Conserving the Biodiversity of the Uttara Kannada District in South India
Authors: Daniels R. J. Ranjit , Chandran M. D. Subash , Gadgil Madhav
Published: August 2009

Taking the various values ascribed to biodiversity as its point of departure rather many years ago, the present study aims at deriving a conservation strategy for Uttara Kannada. This hilly district, with the highest proportion of its area under forests in South India, is divided into five ecological zones: coastal, northern evergreen, southern evergreen, moist deciduous, and dry deciduous. The heavily-populated coastal zone includes mangrove forests and estuarine wetlands. The evergreen forests are particularly rich in the diversity of plant species which they support — including wild relatives of a number of cultivated plants. They also serve a vital function in watershed conservation. The moist deciduous forests are rich in bird species; both moist and dry deciduous forests include a number of freshwater ponds and lakes that support a high diversity of aquatic birds.

Reviewing the overall distribution of biodiversity, we identify specific localities — including estuaries, evergreen forests, and moist deciduous forests — which should be set aside as Nature reserves. These larger reserves must be complemented by a network of traditionally-protected sacred groves and sacred trees that are distributed throughout the district and that protect today, for instance, the finest surviving stand of dipterocarp trees.

We also spell out the necessary policy-changes in overall development strategy that should stem the ongoing decimation of biodiversity. These include (1) revitalizing community-based systems of sustainable management of village forests and protection of sacred groves and trees; (2) reorienting the usage-pattern of reserve forests from production of a limited variety of timber and softwood species for industrial consumers, to production of a larger diversity of non-wood forest produce of commercial value to support the rural economy; (3) utilizing marginal lands under private ownership for generating industrial wood supplies; and (4) provision of incentives for in situ maintenance of land-races of cultivated plants — especially evergreen, fruit-yielding trees — by the local people.

It is proposed that this broad framework be now taken to the local communities, and that an action-plan be developed on the basis of inputs provided — and initiatives taken — by them.
Recreational Use, Valuation, and Management, of Killer Whales (Orcinus orca) on Canada's Pacific Coast
Authors: Duffus David A. , Dearden Philip
Published: August 2009

The management of many ocean wildlife species is left in an institutional void, yet certain species command considerable public attention and have burgeoning management problems. In this paper the non-consumptive recreational use of Killer Whales (Orcinus orca) on Canada's Pacific Ocean coast is used as an example of management difficulties that are associated with oceanic species. Problems associated with jurisdiction and institutional arrangements are coupled to significant levels of biological uncertainty and restricted management options, as well as to management concerns associated with the human domain. The case is conceptualized as an interaction between the human and more general ecological spheres, mediated by the history of the relationship between humans and the species in question. Two routes to regulation are presented, dealing respectively with the human and ecological aspects. Of particular significance is the idea that both types of information are necessary to maximize utility to both the human user and the Whales.

Results from an ongoing study of recreational use are presented to indicate some of the variables that have emerged. These are to be interpreted within current resource management infrastructure to create a tenuous situation. The unfortunate logic that results from this study is that if Killer Whales (a high-profile species) in Canada (a well-endowed nation) have not warranted more substantial protection, then the outlook for less well-known marine species in areas of the world where resource management priorities involve more direct survival concerns, is not optimistic.
Struggling to Save Malaysia's Endau–Rompin Rain Forest, 1972–92
Authors: Aiken S. Robert
Published: August 2009

The protracted dispute over the fate of the Endau-Rompin rain-forest in southern Peninsular Malaysia is outlined. Attention is focused on why a proposal to create an Endau-Rompin national park was eventually abandoned, on what has been done of late to protect the wilderness region, and on what has been learned from the dispute. The main points are as follows:

1. Endau-Rompin is one of the last-remaining extensive tracts of largely undisturbed rain-forest in southern Peninsular Malaysia.

2. TheThird Malaysia Plan 1976–1980incorporated an earlier proposal to create a national park in the Endau-Rompin region.

3. A controversy erupted in 1977 when the state govern ment of Pahang approved a logging concession in the core area of the proposed park.

4. Logging ceased in 1978, but in spite of the preparation of a preliminary management plan and the passage of theNational Parks Act(both in 1980), a national park was not created.

5. The 1985–6 ‘Malaysian Heritage and Scientific Expedition’ to Endau—Rompin focused a great deal of public attention on the wilderness region, but still a national park was not created.

6. In mid-1987 it was announced that there would be two adjoining state parks, not a national park, in the Endau-Rompin region.

7. The proposal to create a national park came to nothing because Pahang and Johor were unwilling to surrender their jurisdiction over their respective components of the required land to the Federal Government, and because the latter made no attempt to acquire the land in the national interest.

8. A state park has been established in the Johor part of the wilderness region, but the promised adjoining state park in Pahang has yet to be established. It would appear that the two parts of the protected area will be managed separately, with eco-tourism as an important focus.

9. For more than fifteen years the Malayan Nature Society has played a key role in the struggle to save the wilderness region.

10. The Endau-Rompin dispute revealed that NGOs such as the Malayan Nature Society can play a key role in the environmental arena, that ever-increasing competition for scarce natural resources makes it increasingly unlikely that new protected areas will be established, and that the protection and management of Malaysia's natural heritage is greatly confounded by the constitutional division of powers between the Federal and state governments.
Risk factors for sanitary condemnation in broiler chickens and their relative impact: application of an original multiblock approach
Authors: LUPO C. , BOUGEARD S. , BALAINE L. , MICHEL V. , PETETIN I. , COLIN P. , LeBOUQUIN S. , CHAUVIN C.
Published: August 2009

An innovative and well-adapted statistical method, called multiblock redundancy analysis, is proposed for a complex health-event analysis to account for the thematic block organization of variables. The outcome block contained the condemnation rates of 404 broiler chicken flocks, distinguishing infectious and traumatic condemnation categories. Explanatory variables were organized in blocks related to the different production stages (farm structure and routine husbandry practices; on-farm flock history and characteristics; catching, transport and lairage conditions; slaughterhouse and inspection features). The aim was to determine risk factors for both condemnation categories, and the relative impact of the different production stages on the whole condemnation rate. Results showed that significant factors were either specific to one condemnation category or related to both categories, and each of the explanatory blocks was involved in the explanation of infectious and traumatic condemnation rates. On-farm flock information explained 40% of the overall condemnation process whereas the other explanatory blocks had similar relative impacts.
Seroepidemiology of human herpesvirus 8 (HHV-8) infection in injecting drug users
Authors: ZAVITSANOU A. , MALLIORI M. , SYPSA V. , PETRODASKALAKI M. , PSICHOGIOU M. , ROKKA C. , GIANNOPOULOS A. , KALAPOTHAKI V. , WHITBY D. , HATZAKIS A.
Published: August 2009

A cross-sectional study was carried out in injecting drug users (IDUs) from Greece to assess the seroprevalence of human herpesvirus 8 (HHV-8) and to identify potentially associated risk factors. A total of 288 IDUs were tested for K8.1 antibodies to HHV-8 lytic antigen. Associations between HHV-8 serostatus and potential risk factors were examined using univariate and multivariate logistic regression analysis. Seroprevalence of HHV-8 was 24·3% (95% CI 19·5–29·7), increasing with age from 19·4% in those aged <30 years to 52·9% in those aged ⩾40 years (Pfor trend=0·003). No statistically significant associations between HHV-8-positive status and gender, educational level, age at first drug injection, needle sharing, number of imprisonments, complications from drug overdose, HIV and HCV were observed. In the multivariate logistic regression analysis, older age (⩾40vs. <40 years, OR 3·30, 95% CI 1·14–9·56) and report of septicaemia/abscess (yesvs. no, OR 1·80, 95% CI 1·01–3·18) were each independently associated with higher HHV-8 seroprevalence. HHV-8 is highly prevalent in the IDU population in Greece. The independent association between HHV-8 and reported abscess or septicaemia supports the hypothesis that poor hygiene conditions in the setting of drug injection may contribute to HHV-8 transmission.
Influenza epidemiology and characterization of influenza viruses in patients seeking treatment for acute fever in Cambodia
Authors: BLAIR P. J. , WIERZBA T. F. , TOUCH S. , VONTHANAK S. , XU X. , GARTEN R. J. , OKOMO-ADHIAMBO M. A. , KLIMOV A. I. , KASPER M. R. , PUTNAM S. D.
Published: August 2009

The epidemiology, symptomology, and viral aetiology of endemic influenza remain largely uncharacterized in Cambodia. In December 2006, we established passive hospital-based surveillance to identify the causes of acute undifferentiated fever in patients seeking healthcare. Fever was defined as tympanic membrane temperature >38°C. From December 2006 to December 2008, 4233 patients were screened for influenza virus by real-time reverse-transcriptase polymerase chain reaction (rRT–PCR). Of these patients, 1151 (27·2%) were positive for influenza. Cough (68·8%vs. 50·5%,P<0·0001) and sore throat (55·0%vs. 41·9%,P<0·0001) were more often associated with laboratory-confirmed influenza-infected patients compared to influenza-negative enrollees. A clear influenza season was evident between July and December with a peak during the rainy season. Influenza A and B viruses were identified in 768 (66·3%) and 388 (33·7%) of the influenza-positive population (n=1153), respectively. In December 2008, passive surveillance identified infection of the avian influenza virus H5N1 in a 19-year-old farmer from Kandal province who subsequently recovered. From a subset of diagnostic samples submitted in 2007, 15 A(H1N1), seven A(H3N2) and seven B viruses were isolated. The predominant subtype tested was influenza A(H1N1), with the majority antigenically related to the A/Solomon Island/03/2006 vaccine strain. The influenza A(H3N2) isolates and influenza B viruses analysed were closely related to A/Brisbane/10/2007 or B/Ohio/01/2005 (B/Victoria/2/87-lineage) vaccine strains, respectively. Phylogenetic analysis of the HA1 region of the HA gene of influenza A(H1N1) viruses demonstrated that the Cambodian isolates belonged to clade 2C along with representative H1N1 viruses circulating in SE Asia at the time. These viruses remained sensitive to oseltamivir. In total, our data suggest that viral influenza infections contribute to nearly one-fifth of acute febrile illnesses and demonstrate the importance of influenza surveillance in Cambodia.
The composition of the inner nuclear layer of the cat retina
Authors: MacNEIL MARGARET A. , PURRIER SHERYL , RUSHMORE R. JARRETT
Published: August 2009

The cellular composition of the inner nuclear layer (INL) is largely conserved among mammals. Studies of rabbit, monkey, and mouse retinas have shown that bipolar, amacrine, Müller, and horizontal cells make up constant fractions of the INL (42, 35, 20, and 3%, respectively); these proportions remain relatively constant at all retinal eccentricities. The purpose of our study was to test whether the organization of cat retina is similar to that of other mammalian retinas. Fixed retinas were embedded in plastic, serially sectioned at a thickness of 1 μm, stained, and imaged at high power in the light microscope. Bipolar, amacrine, Müller, and horizontal cells were classified and counted according to established morphological criteria. Additional sets of sections were processed for protein kinase C and calretinin immunoreactivity to determine the relative fraction of rod bipolar and AII amacrine cells. Our results show that the organization of INL in the cat retina contains species-specific alterations in the composition of the INL tied to the large fraction of rod photoreceptors. Compared with other mammalian retinas, cat retinas show an expansion of the rod pathway with rod bipolar cells accounting for about 70% of all bipolar cells and AII cells accounting for nearly a quarter of all amacrine cells. Our results suggest that evolutionary pressures in cats over time have refined their retinal organization to suit its ecological niche.
Sorghum sudangrass as a summer cover and hay crop for organic fall cabbage production
Authors: Finney Denise M. , Creamer Nancy G. , Schultheis Jonathan R. , Wagger Michael G. , Brownie Cavell
Published: August 2009

No-tillage (NT) organic vegetable production presents several economic opportunities for growers in the southeastern United States while promoting natural resource conservation. This study was conducted to determine if removal of sorghum sudangrass (SS) cover crop biomass as hay, frequency at which the cover crop is mowed, and tillage affect weed suppression and head weight of transplanted organic cabbage. Sorghum sudangrass [Sorghum bicolor(L.) Moench×Sorgum sudanense(Piper) Staph.] was planted in May 2004 at Reidsville and Goldsboro, NC, preceding the planting of organic ‘Bravo’ cabbage (Brassica oleraceaL. Capitata group) in August and September 2004, respectively. SS management systems included: low-frequency mowing with hay removed following the first mowing operation (LFM-H), low-frequency mowing with hay not removed (LFM), high-frequency mowing with hay not removed (HFM) and a no cover crop control. Two tillage treatments were applied within each management system: conventional tillage (CT) and NT. Under NT conditions, SS mulch generated by LFM offered broadleaf weed control in cabbage similar to that achieved under CT, regardless of whether cover crop biomass was removed as hay. Mowing with higher frequency reduced SS cover crop biomass by 18–33% and reduced weed suppression in NT cabbage. Mowing frequency did not influence the quantity of SS that re-grew in the cabbage crop. SS re-growth contributed to lower head weight in NT compared to CT cabbage in Goldsboro, and crop failure of NT cabbage in Reidsville. Cabbage head weight was highest when the crop was not preceded by SS in both CT and NT systems (1.6 as opposed to 1.3–1.4 kg head−1). Our findings suggest that the potential for growers to manage a cover crop also as a hay crop does exist; however, SS may not be a compatible cover crop species for organic fall cabbage production due to high amounts of re-growth.
Neutral wind control of the Jovian magnetosphere‐ionosphere current system
Authors: Tao Chihiro , Fujiwara Hitoshi , Kasaba Yasumasa
Published: August 2009

In order to clarify the role of neutral dynamics in the Jovian magnetosphere‐ionosphere‐thermosphere coupling system, we have developed a new numerical model that includes the effect of neutral dynamics on the coupling current. The model calculates axisymmetric thermospheric dynamics and ion composition by considering fundamental physical and chemical processes. The ionospheric Pedersen current is obtained from the thermospheric and ionospheric parameters. The model simultaneously solves the torque equations of the magnetospheric plasma due to radial currents flowing at the magnetospheric equator, which enables us to update the electric field projected onto the ionosphere and the field‐aligned currents (FACs) depending upon the thermospheric dynamics. The self‐consistently calculated temperature and ion velocity are consistent with observations. The estimated neutral wind field captures the zonally averaged characteristics in previous three‐dimensional models. The energy extracted from the planetary rotation is mainly used for magnetospheric plasma acceleration below 73.5° latitude while consumed in the upper atmosphere, mainly by Joule heating at above 73.5° latitude. The neutral wind dynamics contributes to a reduction in the electric field of 22% compared with the case of neutral rigid corotation. About 90% of this reduction is attributable to neutral winds below the 550‐km altitude in the auroral region. The calculated radial current in the equatorial magnetosphere is smaller than observations. This indicates that the enhancement of the background conductance and/or the additional radial current at the outer boundary would be expected to reproduce the observed current.
Izmit earthquake postseismic deformation and dynamics of the North Anatolian Fault Zone
Authors: Hearn E. H. , McClusky S. , Ergintav S. , Reilinger R. E.
Published: August 2009

We have modeled postseismic deformation from 1999 to 2003 in the region surrounding the 1999 Izmit and Düzce earthquake ruptures, using a three‐dimensional viscoelastic finite element method. Our models confirm earlier findings that surface deformation within the first few months of the Izmit earthquake is principally due to stable frictional afterslip on and below the Izmit earthquake rupture. A second deformation process is required, however, to fit the surface deformation after several months. Viscoelastic relaxation of lower crust and/or upper mantle with a viscosity of the order of 2 to 5 × 1019 Pa s improves the models' fit to later GPS site velocities. However, for a linear viscous rheology, this range of values is inconsistent with highly localized interseismic deformation around the North Anatolian Fault Zone (NAFZ) that was well observed prior to the earthquake sequence. The simplest solution to this problem is to assume that the effective viscosity of the relaxing material increases with time after large earthquakes, that is, that it has a power law or Burger's body (transient) rheology. A Burger's body rheology with two characteristic viscosities (2 to 5 × 1019 Pa s and at least 2 × 1020 Pa s) in the mantle is consistent with deformation around the NAFZ throughout the earthquake cycle.
Freshwater transport at Fimbulisen, Antarctica
Authors: Walkden Graham J. , Heywood Karen J. , Nicholls Keith W. , Abrahamsen Povl
Published: August 2009

The intricate near‐circumpolar system of fronts and currents surrounding Antarctica isolates much of Earth's freshwater from the saline oceans immediately north. The Antarctic Slope Front sustains bathymetrically steered flow at the shelf break, whereas the shallow Coastal Current travels rapidly alongside the ice front. A hydrographic survey of the southeastern Weddell Sea finds these two features to have merged near the narrow (<40 km wide) continental shelf at Fimbulisen. On the prime meridian, its Trolltunga ice tongue overshoots the shelf break northward into this slope current. Observations on either side of the ice tongue demonstrate its retarding effect on the westward‐flowing waters it overhangs and its contribution to the poorly understood freshwater budget. From oxygen isotope ratio measurements and referenced geostrophic shears, we find the combined glacial meltwater and sea ice melt transport upstream of Trolltunga at 0.6°E to account for 18.0 ± 5.8 mSv of the total 1.6 ± 0.2 Sv westward transport (Sv = 106 m3 s−1). In Trolltunga's lee and downstream at 2.8°W, we find this figure to ultimately increase to 23.8 ± 15.5 mSv of a total 2.8 ± 0.4 Sv transport. Each of these sections was impeded by sea ice cover, so these estimates of westward transport are probably lower limits. The westward glacial ice meltwater transport of 10 ± 3 mSv at 2.8°W highlights the role that Fimbulisen plays in preconditioning shelf waters before they reach broad continental shelves in the southwestern Weddell Sea where they transform to bottom waters.
Characteristics of gaseous pollutants at Gucheng, a rural site southwest of Beijing
Authors: Lin Weili , Xu Xiaobin , Ge Baozhu , Zhang Xiaochun
Published: August 2009

During the Campaigns of Air Quality Research in Beijing and Surrounding Region 2006, ambient O3, NOx, SO2, and CO are observed for the first time at Gucheng site southwest of Beijing. This paper characterizes these pollutants, analyzes their sources, and studies their pollution levels. From July 2006 to September 2007 the average concentrations of NOx, CO, SO2, O3, and Ox(= O3 + NO2) are 29.0 ± 19.4 ppb, 1.52 ± 0.73 ppm, 17.1 ± 12.8 ppb, 28.5 ± 13.8 ppb, and 47.1 ± 8.5 ppb, respectively. The levels of these gases varied greatly from season to season, with the levels of NOx, CO, and SO2 being higher and the level of O3 being lower in winter and the levels of NOx, CO, and SO2 being lower and the level of O3 being higher in summer. Levels of O3 and SO2 often exceed Grades I or II of the Chinese Ambient Air Quality Standards. According to estimation of source contributions, biomass burning seems to be one of the major sources for the air pollutants, particularly CO and NOx. The ground measurements of NO2 and O3 at Gucheng correlate well with the satellite measurements of tropospheric columns NO2 and O3, respectively, which suggests that the site has good regional representativeness. Therefore the site is well situated for monitoring regional background concentrations of air pollutants in the North China Plain and an ideal upwind site for studying air quality in Beijing. In August, over 80% of trajectories of more polluted air masses moved northward from Gucheng and passed over Beijing.
Albedo effect on radiative errors in air temperature measurements
Authors: Huwald Hendrik , Higgins Chad W. , Boldi Marc‐Olivier , Bou‐Zeid Elie , Lehning Michael , Parlange Marc B.
Published: August 2009

Most standard air temperature measurements are subject to significant errors mainly due to sensor heating by solar radiation, even when the measurement principle is accurate and precise. We present various air temperature measurements together with other measurements of meteorological parameters using different sensor systems at a snow‐covered and a vegetated site. Measurements from naturally ventilated air temperature sensors in multiplate shields are compared to temperatures measured using sonic anemometers which are unaffected by solar radiation. Over snow, 30 min mean temperature differences can be as large as 10°C. Unshielded thermocouples were also tested and are generally less affected by shortwave radiation. Temperature errors decrease with decreasing solar radiation and increasing wind speed but do not completely disappear at a given solar radiation even in the presence of effective ventilation. We show that temperature errors grow faster for reflected than for incident solar radiation, demonstrating the influence of the surface properties on radiative errors, and we detect the albedo as a variable with major influence on the magnitude of the error as well as a key quantity in possible error correction schemes. An extension is proposed for an existing similarity regression model to correct for radiative errors; thus, surface‐reflected shortwave radiation is identified as a principal source of error and the key variable for obtaining a unique nondimensional scaling of radiative errors.
From flumes to rivers: Can sediment transport in natural alluvial channels be predicted from observations at the laboratory scale?
Authors: Dogan Emrah , Tripathi Shivam , Lyn Dennis A. , Govindaraju Rao S.
Published: August 2009

Doubt regarding the applicability of laboratory results to alluvial streams has led some to develop sediment transport predictors based solely on field data, and most current sediment transport formulae have typically been calibrated at least partially on field data. This paper examines the transferability of flume results to the field by exploring the extent to which a unified approach to the prediction of (1) flow regime, (2) depth, and (3) total sediment transport can be developed entirely with laboratory data. Relevance vector machine (RVM)‐based probabilistic models were constructed with only laboratory data, and their performances were tested against field data and found to be comparable with or better than currently available methods. Comparison of a laboratory‐trained RVM with a field‐trained RVM suggests that the prediction performances of the two models for unseen field data are not statistically different given the prediction uncertainty. For transferability, the choice of predictor variables is important with successful predictors being characterized by similar probability distribution in the laboratory and field data, e.g., as quantified by the Kullback‐Leibler divergence.
Seasonality of polar surface warming amplification in climate simulations
Authors: Lu Jianhua , Cai Ming
Published: August 2009

The IPCC AR4 global warming climate simulations reveal a pronounced seasonality of polar warming amplification with maximum warming amplification in winter and minimum in summer. In this paper, we study the relative importance of surface albedo feedback (SAF), changes in cloud radiative forcing (CRF), changes in surface sensible and latent heat fluxes, changes in heat storage, and changes in the clear‐sky downward infrared radiation in causing the strong seasonality of polar warming amplification by calculating partial temperature changes due to each of these processes using the surface energy budget equation. The main thermodynamic factor for a small polar warming amplification in summer is that the positive SAF is largely cancelled out by the negative surface CRF feedback in summer. The positive SAF is relatively much weaker in winter compared to its amplitude in summer, therefore does not contribute to the pronounced polar warming amplification in winter. The seasonal cycle of polar surface warming amplification, in terms of both spatial patterns and temporal amplitude, closely follows the seasonal cycle of the warming due to changes in clear‐sky downward longwave radiation alone, indicating the importance of the atmospheric processes, such as water vapor feedback and dynamical feedbacks associated with the enhancement of poleward moist static energy transport, in causing the pronounced seasonality of polar warming amplification.
Impacts of reduced sea ice on winter Arctic atmospheric circulation, precipitation, and temperature
Authors: Higgins Matthew E. , Cassano John J.
Published: August 2009

Changes predicted by the Community Atmospheric Model version 3 (CAM3) in winter Arctic atmospheric circulation, precipitation, and temperature due to projected reductions in sea ice are investigated from a synoptic climatology perspective using the self‐organizing map (SOM) technique. A decrease in 1000 hPa geopotential height (Z1000) over Alaska and northern North America is found to be a result of an increase in frequency of patterns with low pressure over much of the Arctic basin. Over Alaska in particular, a deepening of Aleutian lows is also found to contribute to lower Z1000 in this region. With reduced sea ice, Z1000 increases over Siberia and is found to be the result of increases in the frequency of strong high‐pressure ridges. Increases over the Greenland and Norwegian Seas are found to be the result of decreases in frequency of strong Icelandic low cyclones. Large increases in precipitation across the Arctic are found to be primarily due to thermodynamic changes, such as increased moisture in the atmosphere, rather than changes in the frequency of cyclones. Temperature changes for the winter season are found to be due almost equally to diabatic heating and changes in temperature advection.
GillespieSSA: A user-friendly stochastic simulation package for R
Authors: Pineda-Krch Mario
Published: August 2009

GillespieSSA is a package for the statistical computing and graphics language and environment R. GillespieSSA provides a simple to use and extensible interface to several stochastic simulation algorithms for generating simulated trajectories of finite population continuous-time model. Currently it implements Gillespie’s exact stochastic simulation algorithm (Direct method) and several approximate methods (Explicit tau-leap, Binomial tau-leap, and Optimized tau-leap). The package also contains a library of template models that can be run as demo models and can easily be customized and extended. Currently the following models are included, decaying-dimerization reaction set, linear chain system, logistic growth model, Lotka predator-prey model, Rosenzweig-MacArthur predator-prey model, Kermack-McKendrick SIR model, and a metapopulation SIRS model.