bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary interpretation and paleoecology of herbivores from Pikermi and Samos (late Miocene of Greece)
Authors: Solounias Nikos , Rivals Florent , Semprebon Gina M.
Published: January 2010

A large sample of the Pikermi and Samos ungulates was examined by microwear analysis using a light stereomicroscope (561 extinct and 809 extant comparative specimens). The results were used to infer the dietary adaptations of individual species and to evaluate the Pikermian Biome ungulate fauna. Many of the bovids have wear consistent with mixed feeding, although a few mesodont taxa apparently enjoyed an exclusive browsing and or grazing diet. The giraffids spanned the entire dietary spectrum of browsing, mixed feeding, and grazing, but most of the three-toed horses (Hippotherium) were hypsodont grazers. The colobine monkeyMesopithecus pentelicidisplays microwear consistent with a mixed fruit and leaf diet most likely including some hard objects. Similar results were obtained from prior scanning electron microscopy microwear studies at 500 times magnification and from the light microscope method at 35 times magnification for the same species. Results show that diet can differ between species that have very similar gross tooth morphology. Our results also suggest that the Pikermian Biome was most likely a woodland mosaic that provided a diversity of opportunities for species that depended on browsing as well as species that ate grass. The grasses were most likely C3grasses that would grow in shaded areas of the woodland, glades, and margins of water. The ungulate component of the Pikermi and Samos fauna was more species-rich and more diverse in diet than the ungulates observed in modern African forests, woodlands, or savannas, yet dietarily most similar to the ungulates found in woodland elements of India and to some extent of Africa. It is unlikely that the Pikermi and Samos ungulates inhabited dense forests because we find no evidence for heavy fruit browsing. Conversely, a pure savanna is unlikely because many mixed feeders are present as well as browsers. Extant woodland African species are morphologically and trophically very similar to the African savanna species. Therefore the evolution of grazing and of hypsodont morphology for Africa may have evolved within the Plio-Pleistocene woodlands of Africa. Our results show that major dietary and morphologic ungulate evolution may take place within woodlands rather than as a consequence of species moving into savannas both during the late Miocene of Pikermi and Samos and during the Pleistocene–Recent of Central Africa.
On raptors and rodents: testing the ecological fidelity and spatiotemporal resolution of cave death assemblages
Authors: Terry Rebecca C.
Published: January 2010

Natural accumulations of skeletal remains represent a valuable source of ecological data for paleontologists and neontologists alike. Use of these records requires a quantitative assessment of the degree to which potential biasing factors affect how accurately ecological information from the living community is recorded in the sedimentary record. This has been a major focus in recent years for taphonomists working with marine records, yet terrestrial systems have remained virtually unstudied—particularly communities of small-bodied taxa. Our ability to assess the potential origins and effects of postmortem bias in terrestrial skeletal assemblages (both modern and fossil) has therefore been limited. Predation is a common mechanism by which small-mammal skeletal remains are concentrated; raptors regurgitate the remains of their small-mammal prey in pellets rich in skeletal material, which accumulate below long-term roosting sites, especially in protected areas such as caves and rock shelters. Here I compare small-mammal death assemblages concentrated via owl predation at Two Ledges Chamber, a long-term owl cave roost in northwestern Nevada, with data from modern trapping surveys to evaluate (1) their ecological fidelity to the modern small-mammal community, (2) the effects of temporal variation and time-averaging (over months to centuries) on live-dead agreement, and (3) how spatial averaging affects the landscape-scale picture of the small-mammal community as reconstructed from dead remains. Despite potential obstacles to the recovery of ecological information from skeletal deposits generated via predation, I find high live-dead agreement across all ecological metrics and all temporal comparisons. I also find that the effects of time-averaging (specifically increased species richness of the death assemblage) become significant only at the century scale. Finally, I combine a mixing model approach with a principal coordinates analysis to show that the owls at Two Ledges Chamber sample from all habitats present in the immediate vicinity of the cave, producing a high-fidelity snapshot of the community that is spatially integrated at the local landscape scale.
The geological completeness of paleontological sampling in North America
Authors: Peters Shanan E. , Heim Noel A.
Published: January 2010

A growing body of work has quantitatively linked many macroevolutionary patterns, including short- and long-term changes in biodiversity, rates of taxonomic extinction and origination, and patterns of extinction selectivity, to temporal variability in the sedimentary rock record. Here we establish a new framework for more rigorously testing alternative hypotheses for these and many other results by documenting the large-scale spatiotemporal intersection of the North American sedimentary rock and fossil records. To do this, we combined 30,387 fossil collections in the spatially explicit Paleobiology Database with a comprehensive macrostratigraphic database consisting of 18,815 sedimentary lithostratigraphic units compiled from 814 geographic regions distributed across the United States and Canada. The geological completeness of paleontological sampling, here defined as the proportion of the available sedimentary rock record that has been documented to have at least one fossil occurrence, irrespective of taxonomy or environment, is measured at four different levels of stratigraphic resolution: (1) lithostratigraphic rock units, (2) hiatus-bound rock packages, (3) regional stratigraphic columns, and (4) sediment coverage area (km2). Mean completeness estimates for 86 Phanerozoic time intervals (approximately stages; median duration 5.3 Myr) range from 0.18 per interval in the case of lithostratigraphic rock units to 0.23 per interval for stratigraphic columns and sediment coverage area. Completeness estimates at all four levels of stratigraphic resolution exhibit similar temporal variation, including a significant long-term increase during the Phanerozoic that is accentuated by an abrupt Campanian–Maastrichtian peak. This Late Cretaceous peak in completeness is approximately five times greater than the least complete Phanerozoic time intervals (Early Cambrian, Early Devonian, late Permian, and Early Cretaceous). Geological completeness in the Cenozoic is, on average, approximately 40% greater than in the Paleozoic. Temporal patterns of geological completeness do not appear to be controlled exclusively by variation in the frequency of subsurface rock units or an increase over time in the proportion of terrestrial rock, but instead may be general features of both the marine and terrestrial fossil records.
First record ofOphthalmosaurus(Reptilia: Ichthyosauria) from the Tithonian (Upper Jurassic) of Mexico
Authors: Buchy Marie-Céline
Published: January 2010

From the Middle Jurassic on, the Tethys basin opened westward; the existence of a Carribean corridor linking the European and Pacific realms now appears well supported by comparison of marine reptile assemblages (e.g., Gasparini and Fernández, 1997, 2005; Gasparini et al., 2000; Fernández and Iturralde-Vinent, 2000; Gasparini and Iturralde-Vinent, 2001, 2006; Gasparini et al., 2002). Marine transgression in Mexico began during the Callovian, as evidenced by the evaporites of the Minas Viejas Fm. However, microfossils and invertebrate assemblages indicate that the Mexican Gulf remained isolated from both the European Archipelago and the Pacific, at least temporarily, until the middle Berriasian; the Florida uplift and southward movement of Yucatan were proposed as possibly forming a barrier (Salvador et al., 1993; Adatte et al., 1994, 1996; Goldhammer, 1999; Goldhammer and Johnston, 2001; Gasparini and Iturralde-Vinent, 2006). After almost a decade of field work and examination of collections, the Late Jurassic marine reptile assemblage of north-east Mexico confirms the conclusions drawn from microfossils and invertebrates. Poorly diagnostic ichthyosaur remains, with various thalattosuchians, numerically dominate the assemblage. Sauropterygians are rare, mainly represented by large pliosaurids of unclear affinities, a few vertebrae attributed to elasmosaurids, and a unique cryptoclidid. Turtles are yet to be reported (Frey et al., 2002; Buchy et al., 2003, 2005b, 2006a–d; Buchy, 2007, 2008a, b; material currently under study).
Blancan camelids from San Miguel de Allende, Guanajuato, central México
Authors: Jiménez-Hidalgo E. , Carranza-Castañeda O.
Published: January 2010

During the Pliocene, the diversification of the tribes Lamini and Camelini of the Family Camelidae took place in most of North America, but at present in Mexico the systematics of Pliocene Camelidae are poorly known. Fossil material described in this paper was recovered from Blancan I and Blancan III age floodplain and point bar deposits of the San Miguel de Allende basin, Guanajuato state, central Mexico, which approximately spans a time frame from 4.7 to 3.0 Ma. The identified taxa include the laminesHemiauchenia blancoensis(Meade) 1945,Hemiauchenia gracilisMeachen, 2005,Blancocamelus meadeiDalquest, 1975 andCamelopssp., while the camelines are represented byMegatylopussp. The records ofH. gracilisandB. meadeiin the Pliocene of central Mexico are the oldest in North America. Previous studies of the probable feeding strategies of these taxa indicate that they were browsers or browser-like intermediate feeders and just one was an intermediate feeder. The records of these species in the Early Blancan of Guanajuato extend their geographic distribution from the southern USA to central Mexico.
Three dimensional structure and fluid flow through the hydrospires of the blastoid echinoderm, Pentremites rusticus
Authors: Schmidtling Ronald C. , Marshall Charles R.
Published: January 2010

The fluid flow through the complex hydrospires of the spiraculate blastoid Pentremites rusticus was analyzed using the first high-resolution three-dimensional digital image (and animation) of the hydrospires taken from a serially sectioned specimen. Measurements of the cross-sectional areas within the hydrospires, in conjunction with the Principle of Continuity, were used to infer the relative water velocity throughout the structures. Even though the calyx narrows adorally, the hydrospires expand in size, keeping pace with the increasing volume of water that entered through the hydrospire pores. Thus, the water maintained a relatively constant velocity within the hydrospire canals, 3.4 to 4.5 times the incurrent velocity. The spiracular openings are sufficiently large that no substantial increase in the exit velocity of the seawater would have been achieved unless the spiracular cover plates were used to reduce the size of the spiracular openings, which we infer was probably the case. The three-dimensional images underscore the fact that the two hydrospires that lie under each ambulacrum do not share the same spiracle and are not connected. Thus, we here redefine the term “hydrospire set” to refer to the pair of hydrospires that are connected. A number of anomalous accessory pores and canals were identified in the digital images. This initial study is based on a single specimen, and thus we were unable to determine the full range of variation present in Pentremites rusticus. Nonetheless, the digital image and the application of the Principle of Continuity offer new insights into the form and function of these remarkable respiratory structures.
Giant short-faced bears (Arctodus simus) in Pleistocene Florida USA, a substantial range extension
Authors: Schubert Blaine W. , Hulbert Richard C. , Macfadden Bruce J. , Searle Michael , Searle Seina
Published: January 2010

Fossils of the giant short-faced bear,Arctodus simus(Cope, 1879), have been recovered from over 100 localities in North America, extending from Mexico to Alaska and California to Virginia. Despite this large range, the species has never been recorded from the southeastern United States. The lesser short-faced bear,Arctodus pristinusLeidy, 1854 is well represented from this region, particularly Florida, but all known occurrences are late Pliocene – middle Pleistocene in age (about 2.5 to 0.3 Ma). DifferentiatingA. simusfromA. pristinuscan be difficult because large individuals ofA. pristinusoverlap in size with small individuals ofA. simus, and there are few morphological differences. However, these two taxa can be clearly separated based on the relative proportions of their molars and premolars. Two Pleistocene records ofA. simusrepresenting a minimum of three individuals from the Withlacoochee River drainage of central Florida are reported here, substantially extending the distribution of this massive bear into southeastern North America. A late Pleistocene age for these occurrences is corroborated by an associated Rancholabrean fauna and rare earth elemental analyses. One of the reported individuals is quite large, supporting the hypothesis of extreme sexual dimorphism inA. simusand rejecting a hypothesis of two subspecies.
The ETS oncogene family transcription factor FEV identifies serotonin-producing cells in normal and neoplastic small intestine
Authors: Wang Yu-cheng , Zuraek Marlene B , Kosaka Yasuhiro , Ota Yasuharu , German Michael S , Deneris Evan S , Bergsland Emily K , Donner David B , Warren Robert S , Nakakura Eric K
Published: January 2010

Neuroendocrine (NE) or carcinoid tumors of the small intestine (SI) frequently metastasize and produce the hormone serotonin, causing significant morbidity and mortality. A member of the ETS oncogene family of transcription factors, Fev, acts with the homeodomain transcription factor Nkx2.2 in the development of serotonin neurons in mice. In this study, we investigated the role of Fev in normal and neoplastic SI. In NE tumors (NETs) of the SI, serotonin stimulates tumor growth and causes debilitating symptoms, such as diarrhea, flushing, wheezing, and right-sided valvular heart disease (i.e. carcinoid syndrome). Compared with those in the matched normal human SI, FEV expression levels were significantly elevated in primary NETs (20-fold, P<0.0001), lymph node metastases (35-fold, P=0.004), and NET liver metastases (22-fold, P<0.0001) resected from patients with serotonin excess. Fev is expressed in the wild type but not in Nkx2.2 (−/−) mouse SI, in which cells producing serotonin are absent. Using recombination-based cell lineage tracing, we found that FEV-positive cells give rise to serotonin-producing cells in the SI. In Fev (−/−) mouse SI, we observed no difference in the number of cells producing serotonin or other hormones. We conclude that FEV expression identifies serotonin-producing cells in normal and neoplastic SI and is a novel target for diagnosis of patients with NETs of the SI.
Methane Flux in Cropland and Adjacent Riparian Buffers with Different Vegetation Covers
Authors: Kim Dong‐Gill , Isenhart Thomas M. , Parkin Timothy B. , Schultz Richard C. , Loynachan Thomas E.
Published: January 2010

While water quality functions of conservation buffers established adjacent to cropped fields have been widely documented, the relative contribution of these re‐established perennial plant systems to greenhouse gases has not been completely documented. In the case of methane (CH4), these systems have the potential to serve as sinks of CH4or may provide favorable conditions for CH4production. This study quantifies CH4flux from soils of riparian buffer systems comprised of three vegetation types and compares these fluxes with those of adjacent crop fields. We measured soil properties and diel and seasonal variations of CH4flux in 7 to 17 yr‐old re‐established riparian forest buffers, warm‐season and cool‐season grass filters, and an adjacent crop field located in the Bear Creek watershed in central Iowa. Forest buffer and grass filter soils had significantly lower bulk density (P< 0.01); and higher pH (P< 0.01), total carbon (TC) (P< 0.01), and total nitrogen (TN) (P< 0.01) than crop field soils. There was no significant relationship between CH4flux and soil moisture or soil temperature among sites within the range of conditions observed. Cumulative CH4flux was −0.80 kg CH4–C ha−1yr−1in the cropped field, −0.46 kg CH4–C ha−1yr−1within the forest buffers, and 0.04 kg CH4–C ha−1yr−1within grass filters, but difference among vegetation covers was not significant. Results suggest that CH4flux was not changed after establishment of perennial vegetation on cropped soils, despite significant changes in soil properties.
Simulating Pesticide Transport from a Sloped Tropical Soil to an Adjacent Stream
Authors: Kahl G. , Ingwersen J. , Totrakool S. , Pansombat K. , Thavornyutikarn P. , Streck T.
Published: January 2010

Preferential flow from stream banks is an important component of pesticide transport in the mountainous areas of northern Thailand. Models can help evaluate and interpret field data and help identify the most important transport processes. We developed a simple model to simulate the loss of pesticides from a sloped litchi (Litchi chinensis Sonn.) orchard to an adjacent stream. The water regime was modeled with a two‐domain reservoir model, which accounts for rapid preferential flow simultaneously with slow flow processes in the soil matrix. Preferential flow is triggered when the topsoil matrix is saturated or the infiltration capacity exceeded. In addition, close to matrix saturation, rainfall events induce water release to the fractures and lead to desorption of pesticides from fracture walls and outflow to the stream. Pesticides undergo first order degradation and equilibrium sorption to soil matrix and fracture walls. The model was able to reproduce the dynamics of the discharge reasonably well (model efficiency [EF] = 0.56). The cumulative pesticide mass (EF = 0.91) and the pesticide concentration in the stream were slightly underestimated, but the deviation from measurement data is acceptable. Shape and timing of the simulated concentration peaks occurred in the same pattern as observed data. While the effect of surface runoff and preferential interflow on pesticide mass transport could not be absolutely clarified, according to our simulations, most concentration peaks in the stream are caused by preferential interflow pointing to the important role of this flow path in the hilly areas of northern Thailand.
A Review of Vegetated Buffers and a Meta‐analysis of Their Mitigation Efficacy in Reducing Nonpoint Source Pollution
Authors: Zhang Xuyang , Liu Xingmei , Zhang Minghua , Dahlgren Randy A. , Eitzel Melissa
Published: January 2010

Vegetated buffers are a well‐studied and widely used agricultural management practice for reducing nonpoint‐source pollution. A wealth of literature provides experimental data on their mitigation efficacy. This paper aggregated many of these results and performed a meta‐analysis to quantify the relationships between pollutant removal efficacy and buffer width, buffer slope, soil type, and vegetation type. Theoretical models for removal efficacy (Y) vs. buffer width (w) were derived and tested against data from the surveyed literature using statistical analyses. A model of the form Y = K × (1‐e−b×w), (0 < K ≤ 100) successfully captured the relationship between buffer width and pollutant removal, where K reflects the maximum removal efficacy of the buffer and b reflects its probability to remove any single particle of pollutant in a unit distance. Buffer width alone explains 37, 60, 44, and 35% of the total variance in removal efficacy for sediment, pesticides, N, and P, respectively. Buffer slope was linearly associated with sediment removal efficacy either positively (when slope ≤ 10%) or negatively (when slope > 10%). Buffers composed of trees have higher N and P removal efficacy than buffers composed of grasses or mixtures of grasses and trees. Soil drainage type did not show a significant effect on pollutant removal efficacy. Based on our analysis, a 30‐m buffer under favorable slope conditions (≈ 10%) removes more than 85% of all the studied pollutants. These models predicting optimal buffer width/slope can be instrumental in the design, implementation, and modeling of vegetated buffers for treating agricultural runoff.
Leaching of Three Sulfonylurea Herbicides during Sprinkler Irrigation
Authors: Cessna Allan J. , Elliott Jane A. , Bailey Jonathan
Published: January 2010

Sulfonylurea herbicides are widely applied on the Canadian prairies to control weeds in a variety of crops. Several sulfonylurea herbicides are mobile in soil, and there is concern about their possible movement to ground water. This study was performed to assess the susceptibility of three sulfonylurea herbicides commonly used in prairie crop production to leach under a worst‐case scenario. Thifensulfuron‐methyl, tribenuron‐methyl, and rimsulfuron were applied to a 9‐ha tile‐drained field, and then approximately 300 mm of irrigation water were applied over a 2‐wk period using a center pivot. The commencement of tile‐drain flow corresponded to the rise of the water table above tile‐drain depth, and peak flow rates corresponded to the greatest depths of ground water above the tile drains. The volume of irrigation water intercepted by the tile drains in each quadrant was determined by site hydrology and represented <10% of the irrigation water applied. Concentrations of thifensulfuron‐methyl, tribenuron‐methyl, and rimsulfuron in the tile‐drain effluent ranged (analysis by liquid chromatography/tandem mass spectrometry) from 2.0 to 248 ng L−1, not detected (nd) to 55 ng L−1, and nd to 497 ng L−1, respectively. Total herbicide transport from the root zone in each quadrant was estimated at <0.5% of the amount of each sulfonylurea herbicide applied. Thifensulfuron‐methyl was the only herbicide detected in ground water, with concentrations ranging from 1.2 to 2.5 ng L−1 With the frequency and amount of rainfall typically encountered in the prairie region of Canada, detectable concentrations (>1 ng L−1) of these sulfonylurea herbicides in ground water would be unlikely.
Impacts of Fertilization on Water Quality of a Drained Pine Plantation: A Worst Case Scenario
Authors: Beltran Bray J. , Amatya Devendra M. , Youssef Mohamed , Jones Martin , Callahan Timothy J. , Skaggs R. Wayne , Nettles Jami E.
Published: January 2010

Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North Carolina using a paired watershed approach. The plantation consists of three watersheds, two mature (31‐yr) and one young (8‐yr) (age at treatment). One of the mature watersheds was commercially thinned in 2002. The mature unthinned watershed was designated as the control. The young and mature‐thinned watersheds were fertilized at different rates with Arborite (Encee Chemical Sales, Inc., Bridgeton, NC), and boron. The outflow rates and nutrient concentrations in water drained from each of the watersheds were measured. Nutrient concentrations and loadings were analyzed using general linear models (GLM). Three large storm events occurred within 47 d of fertilization, which provided a worst case scenario for nutrient export from these watersheds to the receiving surface waters. Results showed that average nutrient concentrations soon after fertilization were significantly (α = 0.05) higher on both treatment watersheds than during any other period during the study. This increase in nutrient export was short lived and nutrient concentrations and loadings were back to prefertilization levels as soon as 3 mo after fertilization. Additionally, the mature‐thinned watershed presented higher average nutrient concentrations and loadings when compared to the young watershed, which received a reduced fertilizer rate than the mature‐thinned watershed.
Determining Phosphorus and Sediment Release Rates from Five Irish Tillage Soils
Authors: Regan J.T. , Rodgers M. , Healy M.G. , Kirwan L. , Fenton O.
Published: January 2010

The aim of this study was to compare the nutrient and sediment releases from five Irish tillage soils, inclined at 10‐ and 15‐degree slopes, under a simulated rainfall intensity of 30mmh−1 in a controlled laboratory study. Using the relationship between soil test phosphorus (STP) in the five soils and the dissolved reactive phosphorus (DRP) released in surface runoff, a runoff dissolved phosphorus risk indicator (RDPRI) was developed to identify the STP level for Irish tillage soils above which there may be a potential threat to surface water quality. The results of this study indicated that tillage soils may produce surface runoff P concentrations in excess of 30 μgL−1 (the value above which eutrophication of rivers is likely to occur and the maximum allowable concentration of DRP in rivers under the EU Water Framework Directive, WFD) if their Morgan's phosphorus (Pm), Mehlich 3 phosphorus (M3‐P), and water extractable phosphorus (WEP) concentrations exceed 9.5 mg L−1, 67.2 mg kg−1, and 4.4 mg kg−1, respectively. This work reinforces the statutory agronomic based requirements of the European Communities (Good Agricultural Practice for Protection of Waters) Regulations 2009 (S.I. no. 101 of 2009). A statistical analysis showed that WEP gave the best prediction for runoff DRP.
Nitrogen Source Tracking with δ15N Content of Coastal Wetland Plants in Hawaii
Authors: Bruland Gregory L. , MacKenzie Richard A.
Published: January 2010

Inter‐ and intra‐site comparisons of the nitrogen (N) stable isotope composition of wetland plant species have been used to identify sources of N in coastal areas. In this study, we compared δ15N values from different herbaceous wetland plants across 34 different coastal wetlands from the five main Hawaiian Islands and investigated relationships of δ15N with land use, human population density, and surface water quality parameters (i.e., nitrate, ammonium, and total dissolved N). The highest δ15N values were observed in plants from wetlands on the islands of Oahu (8.7–14.6‰) and Maui (8.9–9.2‰), whereas plants from wetlands on the islands of Kauai, Hawaii, and Molokai had δ15N values usually <4‰. The enrichment in δ15N values in plant tissues from wetlands on Oahu and Maui was most likely a result of the more developed and densely populated watersheds on these two islands. Urban development within a 1000‐m radius and population density were positively correlated to average δ15N vegetation values from each wetland site (r = 0.56 and 0.51, respectively; p < 0.001). This suggested that site mean δ15N values from mixed stands of wetland plants have potential as indices of N sources in coastal lowland wetlands in Hawaii and that certain sites on Oahu and Maui have experienced significant anthropogenic N loading. This information can be used to monitor future changes in N inputs to coastal wetlands throughout Hawaii and the Pacific.
Greenhouse Gas, Animal Performance, and Bacterial Population Structure Responses to Dietary Monensin Fed to Dairy Cows
Authors: Hamilton Scott W. , DePeters Edward J. , McGarvey Jeffery A. , Lathrop Jeremy , Mitloehner Frank M.
Published: January 2010

The present study investigated the effects of a feed additive and rumen microbial modifier, monensin sodium (monensin), on selected variables in lactating dairy cows. Monensin fed cows (MON, 600 mg d−1) were compared with untreated control cows (CON, 0 mg d−1) with respect to the effects of monensin on the production of three greenhouse gases (GHG), methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2), along with animal performance (dry matter intake; DMI), milk production, milk components, plasma urea nitrogen (PUN), milk urea nitrogen (MUN), and the microbial population structure of fresh feces. Measurements of GHG were collected at Days 14 and 60 in an environmental chamber simulating commercial dairy freestall housing conditions. Milk production and DMI measurements were collected twice daily over the 60‐d experimental period; milk components, PUN, and MUN were measured on Days 14 and 60. The microbial population structure of feces from 6 MON and 6 CON cows was examined on three different occasions (Days 14, 30, and 60). Monensin did not affect emissions of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). Over a 24‐h period, emissions of CH4, N2O, and CO2 decreased in both MON and CON groups. Animal performance and the microbial population structure of the animal fresh waste were also unaffected for MON vs. CON cows
Salinity Monitoring in Western Australia using Remotely Sensed and Other Spatial Data
Authors: Furby Suzanne , Caccetta Peter , Wallace Jeremy
Published: January 2010

The southwest of Western Australia is affected by dryland salinity that results in the loss of previously productive agricultural land, damage to buildings, roads, and other infrastructure, decline in pockets of remnant vegetation and biodiversity, and reduction in water quality. Accurate information on the location and rate of change of the extent of saline land over the region is required by resource managers. For the first time, comprehensive, spatially explicit maps of dryland salinity and its change over approximately 10 yr for the southwest agricultural region of Western Australia have been produced operationally in the ‘Land Monitor’ project. The methods rely on an integrated analysis of long‐term sequences of Landsat TM satellite image data together with variables derived from digital elevation models (DEMs). Understanding of the physical process and surface expression of salinity provided by experts was used to guide the analyses. Ground data—the delineation of salt‐affected land by field experts—was collected for training and validation. The results indicate that the land area currently affected by salinity in Western Australia's southwest is about 1 million hectares (in 1996) and the annual rate of increase is about 14,000 ha. This is a lesser extent than many previous estimates and lower rate of change than generally predicted from limited hydrological data. The results are widely distributed and publicly available. The key to providing accurate mapping and monitoring information was the incorporation of time series classification of a sequence of images over several years combined with landform information.
A Methodology to Estimate the Future Extent of Dryland Salinity in the Southwest of Western Australia
Authors: Caccetta Peter , Dunne Robert , George Richard , McFarlane Don
Published: January 2010

In the southwestern agricultural region of Western Australia, the clearing of the original perennial vegetation for annual vegetation‐based dryland agriculture has lead to rising saline groundwater levels. This has had effects such as reduced productivity of agricultural land, death of native vegetation, reduced stream water quality and infrastructure damage. These effects have been observed at many locations within the 18 million ha of cleared land. This has lead to efforts to quantify, in a spatially explicit way, the historical and likely future extent of the area affected, with the view to informing management decisions. This study was conducted to determine whether the likely future extent of the area affected by dryland salinity could be estimated by means of developing spatially explicit maps for use in management and planning. We derived catchment‐related variables from digital elevation models and perennial vegetation presence/absence maps. We then used these variables to predict the salinity hazard extent by applying a combination of decision tree classification and morphological image processing algorithms. Sufficient objective data such as groundwater depth, its rate of rise, and its concentration of dissolved salts were generally not available, so we used regional expert opinion (derived from the limited existing studies on salinity hazard extent) as training and validation data. We obtained an 87% agreement in the salinity hazard extent estimated by this method compared with the validation data, and conclude that the maps are sufficient for planning. We estimate that the salinity hazard extent is 29.7% of the agricultural land.
Use of Insoluble Polyacrylate Polymers to Aid Phytostabilization of Mine Soils: Effects on Plant Growth and Soil Characteristics
Authors: Qu G. , de Varennes A. , Cunha‐Queda C.
Published: January 2010

We evaluated the use of polyacrylate polymers to aid phytostabilization of mine soils. In a pot experiment, perennial ryegrass was grown in a mine soil and in uncontaminated soil. Growth was stimulated in the polymer‐amended mine soil compared with an unamended control, and water‐extractable levels of soil Cu and Zn decreased after polymer application. In an experiment performed in six 60‐cm‐diameter cylinders filled with fertilized mine soil, polymers were applied to three cylinders, with the remainder used as unamended control. Total biomass produced by indigenous plant species sown in polymer‐amended soil was 1.8 (Spring‐Summer) or 2.4 times (Fall‐Winter) greater than that of plants from unamended soil. The application of polymers to the mine soil led to the greatest activity of soil enzymes. Soil pH, biomass of Spergularia purpurea and Chaetopogon fasciculatus, and activities of protease and cellulase had large loadings on principal component (PC)1, whereas growth of Briza maxima and the activities of urease, acid phosphatase, and β‐glucosidase had large loadings on PC2. The treatments corresponding to controls were located on the negative side of PC1 and PC2. Amended treatments were on the positive side of PC2 (Spring‐Summer) or on the positive side of PC1 (Fall‐Winter), demonstrating differential responses of plants and soil parameters in the two growth cycles.
Combining LiDAR and IKONOS Data for Eco‐Hydrological Classification of an Ombrotrophic Peatland
Authors: Anderson K. , Bennie J. J. , Milton E. J. , Hughes P. D. M. , Lindsay R. , Meade R.
Published: January 2010

Remote sensing techniques have potential for peatland monitoring, but most previous work has focused on spectral approaches that often result in poor discrimination of cover types and neglect structural information. Peatlands contain structural “microtopes” (e.g., hummocks and hollows) which are linked to hydrology, biodiversity and carbon sequestration, and information on surface structure is thus a useful proxy for peatland condition. The objective of this work was to develop and test a new eco‐hydrological mapping technique for ombrotrophic (rain‐fed) peatlands using a combined spectral‐structural remote sensing approach. The study site was Wedholme Flow, Cumbria, UK. Airborne light dectection and ranging (LiDAR) data were used with IKONOS data in a combined multispectral‐structural approach for mapping peatland condition classes. LiDAR data were preprocessed so that spatial estimates of minimum and maximum land surface height, variance and semi‐variance (from semi‐variogram analysis) were extracted. These were assimilated alongside IKONOS data into a maximum likelihood classification procedure, and thematic outputs were compared. Ecological survey data were used to validate the results. Considerable improvements in thematic separation of peatland classes were achieved when spatially‐distributed measurements of LiDAR variance or semi‐variance were included. Specifically, the classification accuracy improved from 71.8% (IKONOS data only) to 88.0% when a LiDAR semi‐variance product was used. Of note was the improved delineation of management classes (includingEriophorumbog, active raised bog and degraded raised bog). The application of a combined textural‐optical approach can improve land cover mapping in areas where reliance on purely spectral discrimination approaches would otherwise result in considerable thematic uncertainty.
Trends and Transformation of Nutrients and Pesticides in a Coastal Plain Aquifer System, United States
Authors: Denver Judith M. , Tesoriero Anthony J. , Barbaro Jeffrey R.
Published: January 2010

Four local‐scale sites in areas with similar corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] agriculture were studied to determine the effects of different hydrogeologic settings of the Northern Atlantic Coastal Plain (NACP) on the transport of nutrients and pesticides in groundwater. Settings ranged from predominantly well‐drained soils overlying thick, sandy surficial aquifers to predominantly poorly drained soils with complex aquifer stratigraphy and high organic matter content. Apparent age of groundwater, dissolved gases, N isotopes, major ions, selected pesticides and degradates, and geochemical environments in groundwater were studied. Agricultural chemicals were the source of most dissolved ions in groundwater. Specific conductance was strongly correlated with reconstructed nitrate (the sum of N in nitrate and N gas) (R2 = 0.81, p < 0.0001), and is indicative of the relative degree of agricultural effects on groundwater. Trends in nitrate were primarily related to changes in manure and fertilizer use at the well‐drained sites where aquifer conditions were consistently oxic. Nitrate was present in young groundwater but completely removed over time through denitrification at the poorly drained sites where there were variations in chemical input and in geochemical environment. Median concentrations of atrazine (6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine), metolachlor (2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl)acetamide), and some of their common degradates were higher at well‐drained sites than at poorly drained sites, with concentrations of degradates generally higher than those of the parent compounds at all sites. An increase in the percentage of deethylatrazine to total atrazine over time at one well‐drained site may be related to changes in manure application.
Modifying Broiler Diets with Phytase and Vitamin D Metabolite (25‐OH D3): Impact on Phosphorus in Litter, Amended Soils, and Runoff
Authors: McGrath Joshua M. , Sims J. Thomas , Maguire Rory O. , Saylor William W. , Angel Roselina
Published: January 2010

Adding phytase and 25‐ hydroxycholecalciferol (25‐OH D3) to broiler diets has been shown effective at reducing total P concentrations in broiler litter. This study was conducted to determine the impact of field application of broiler litter from modified diets on P solubility in litter‐amended soils and P losses in runoff. Five broiler diets and their resulting litters were evaluated: a high P diet, a low P diet, each of those basal diets with phytase added, and a low P diet with phytase and 25‐OH D3 added. A field study was initiated at two sites with each of the five broiler litters and a commercial P fertilizer (triple superphosphate [TSP]) applied at the same total P rate (150 kg P ha−1) and a control where no P was applied. Soil P was monitored over time at two depths (0–5 cm and 0–15 cm) soils were collected in the spring and fall to perform rainfall simulation studies. Broiler litter or TSP application increased soil water‐soluble P and Mehlich 3‐P concentrations relative to the control, however there were no consistent differences detected between litter treatments. Results from the rainfall simulation experiments indicate that diet modification with phytase or 25‐OH D3 does not increase the potential for P losses in runoff from amended soils relative to traditional diets. Moreover, broiler diet modification to reduce excreted P could be a potentially effective method for reducing watershed scale P surpluses in areas of intensive broiler production, without raising concerns over soluble P losses from litter‐amended soils.
A Watershed‐scale Assessment of Cost‐Effectiveness of Sediment Abatement with Flow Diversion Terraces
Authors: Yang Qi , Zhao Zhengyong , Benoy Glenn , Chow Thien Lien , Rees Herb W. , Bourque Charles P.‐A. , Meng Fan‐Rui
Published: January 2010

Soil conservation beneficial management practices (BMPs) are effective at controlling soil loss from farmlands and minimizing water pollution in agricultural watersheds. However, costs associated with implementing and maintaining these practices are high and often deter farmers from using them. Consequently, it is necessary to conduct cost‐benefit analysis of BMP implementation to assist decision‐makers with planning to provide the greatest level of environmental protection with limited resources and funding. The Soil and Water Assessment Tool (SWAT) was used to evaluate the efficacy of flow diversion terraces (FDT) in abating sediment yield at the outlet of Black Brook Watershed (BBW), northwestern New Brunswick. Different FDT‐implementation scenarios were expressed as the ratio of land area protected by FDT to the total cultivated area. From this analysis, we found that average annual sediment yield decreased exponentially with increased FDT protection. When the proportion of FDT‐protected areas was low, sediment reductions caused by FDT increased sharply with increasing use of FDT. Similarly, marginal sediment yield abatement costs (dollar per tonne of sediment reduction) increased exponentially with increasing proportion of FDT‐protected area. The results indicated that increasing land protection with FDT from 6 to 50% would result in a reduction of about 2.1 tonne ha−1 yr−1 and costs of sediment reduction increased from $7 to $12 per tonne. Increasing FDT‐protected cropland from 50 to 100%, a reduction of about 0.9 tonne of sediment ha−1 yr−1 would occur and the costs would increase from $12 to $53 per tonne of sediment yield reduction.
Simplified Method for Quantifying Theoretical Underestimation of Chamber‐Based Trace Gas Fluxes
Authors: Venterea Rodney T.
Published: January 2010

Closed chambers used to measure soil‐atmosphere exchange of trace gases including nitrous oxide (N2O) and carbon dioxide (CO2) generate errors due to suppression of the gas concentration gradient at the soil‐atmosphere interface. A method is described here for estimating the magnitude of flux underestimation arising from chamber deployment. The technique is based on previously established gas transport theory and has been simplified to facilitate application while preserving the fundamental physical relationships. The method avoids the use of nonlinear regression but requires knowledge of soil properties including texture, bulk density, water content, temperature, and pH. Two options are presented: a numerical technique which is easily adapted to spreadsheet application, and a graphical method requiring minimal calculation. In both cases, the magnitude of theoretical flux underestimation (TFU) is determined, taking into account effects of chamber geometry and deployment time, the flux‐calculation scheme, and properties of the soil and gas under consideration. Application to actual data and recent studies confirmed that TFU can vary widely within and across sites. The analysis also revealed a highly linear correlation between soil water content and TFU, suggesting that previously observed relationships between water content and trace gas flux may in part reflect artifacts of chamber methodology. The method described here provides a practical means of improving the absolute accuracy of flux estimates and normalizing data obtained using different chamber designs in different soils.
Enhanced Interferon-α2b Production in Periplasmic Space of Escherichia coli through Medium Optimization using Response Surface Method
Authors: Tan Joo Shun , Ramanan Ramakrishnan Nagasundara , Azaman Siti Nor Ani , Ling Tau Chuan , Shuhaimi Mustapha , Ariff Arbakariya B.
Published: January 2010

The influence of different carbon and nitrogen sources on growth of recombinant Escherichia coli and human
interferon-α2b (IFN-α2b) production in periplasmic space was studied in shake flask culture. A statistical method based
on Plackett-Burman design was used to screen the main medium components that greatly influenced the performance of
the fermentation process. The optimization of medium was performed using response surface methodology (RSM) where
three critical factors (glucose, yeast extract and peptone) were optimized using central composite design. The highest yield
of periplasmic recombinant human interferon-α2b (PrIFN-α2b) (335.8 μg/L) was predicted to be obtained in optimized
medium containing 5.47 g/L glucose, 55.24 g/L yeast extract and 42.27 g/L peptone.. The production of IFN-α2b in periplasmic
space in optimized medium was about 2.5, 11.7 and 124.4 times higher than Terrific broth (TB), Luria-Bertani
(LB), and minimal medium (M9), respectively.
Need of Assistance with Daily Oral Hygiene Measures Among Nursing Home Resident Elderly Versus the Actual Assistance Received from the Staff
Authors: Forsell Marianne , Sjögren Petteri , Johansson Olle
Published: January 2010

The aim was to evaluate the need of assistance with daily oral hygiene measures among nursing home resident elderly versus the actual assistance received from the staff. The need of daily oral hygiene assistance was assessed descriptively for nursing home resident elderly who participated in an annual oral health screening in three geographical regions in Sweden, in the year 2008. All individuals of age ≥ 65 years were included (n = 22,453; 6,327 men; 16,126 women). The proportion of individuals in need of assistance with daily oral hygiene measures was 77.5 % (n=22,453), whereas the proportion of individuals receiving assistance with daily oral hygiene measures was 6.9 % in total (n=22,453). The proportions were largely similar in all geographical regions. There seems to be a large discrepancy between the need of assistance with daily oral hygiene measures, and the oral hygiene assistance received, among nursing home resident elderly.
Influence of Prosthetic Screw Material on Joint Stability in Passive and Non-Passive Implant-Supported Dentures
Authors: Spazzin Aloísio Oro , Henriques Guilherme Elias Pessanha , Nóbilo Mauro Antônio de Arruda , Consani Rafael Leonardo Xediek , Correr-Sobrinho Lourenço , Mesquita Marcelo Ferraz
Published: January 2010

Objectives:

This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit.

Methods:

Ten mandibular implant-supported dentures were fabricated. Twenty cast models were fabricated using these dentures. Four groups (n=10) were tested, according to the vertical fit of the dentures [passive and non-passive] and prosthetic screw materials [titanium (Ti) or gold (Au) alloy]. The one-screw test was performed to quantify the vertical misfits using an optic microscope. The loosening torque for the prosthetic screws was measured 24 hours after the tightening torque (10 Ncm) using a digital torque meter. Data were analyzed by two-way ANOVA and Tukey’s test (α=0.05).

Results:

Overall, dentures with passive fit and Ti screws resulted in significantly higher loosening torque of the prosthetic screws (p<0.05). No significant interaction was found between fit level and screw material (p=0.199). The prosthetic screw material and fit of implant-supported dentures have an influence on screw joint stability. Ti screws presented higher joint stability than Au screws and minimum of misfit should be found clinically to improve the mechanical behavior of the screw joint.