bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation between injected volume and optical parameters in refilled isolated porcine lenses
Authors: Koopmans Steven A. , Terwee Thom , Haitjema Henk J. , Deuring Henk , van Aarle Sonja , Kooijman Aart C. 
Published: October 2004

AbstractPurpose:  This study was performed to elucidate the correlation between added lens refill material and enhanced lens power as well as the correlation between lens refilling volume and accommodative amplitude as determined by equatorial stretching of ex vivo refilled pigs’ lenses.Methods:  Nine porcine lenses were refilled with increasing amounts of silicone oil. After each refill step, the lens power, the lens power change, and the lens thickness were measured both in the relaxed state and with a 3‐mm larger ciliary body diameter. In addition, the spherical aberration of the refilled lenses was also quantified.Results:  Injection of 0.04 mL silicone material into the relaxed lens enhanced the lens power by 1 D. A 0.54‐mm increase of the lens thickness in relaxed lenses added 1 D to the lens power. Increasing the lens refilling volume decreased the lens power changes measured at 3‐mm ciliary body stretch. Spherical aberration was positive in the refilled lenses and increased with increasing lens refilling volume.Conclusion:  The correlation found between the refilling volume and the lens power (0.04 mL D−1), as well as the correlation between the lens thickness and the lens power (0.54 mm D−1), might be important factors to be controlled in conjunction with surgery, as these also determine the lens power in the presence of this refill material. An increasing lens filling volume is associated with decreasing accommodative amplitude. The positive spherical aberration of refilled porcine lenses presents a sharp contrast to the negative aberration of natural pigs’ lenses. Different lens contours and the transition from a gradient to a homogeneous refractive index might be responsible for this change in spherical aberration.
School vision screening, ages 5–16 years: the evidence‐base for content, provision and efficacy
Authors: Logan Nicola S. , Gilmartin Bernard 
Published: October 2004

AbstractThe optometric profession in the UK has a major role in the detection, assessment and management of ocular anomalies in children between 5 and 16 years of age. The role complements a variety of associated screening services provided across several health care sectors. The review examines the evidence‐base for the content, provision and efficacy of these screening services in terms of the prevalence of anomalies such as refractive error, amblyopia, binocular vision and colour vision and considers the consequences of their curtailment. Vision screening must focus on pre‐school children if the aim of the screening is to detect and treat conditions that may lead to amblyopia, whereas if the aim is to detect and correct significant refractive errors (not likely to lead to amblyopia) then it would be expedient for the optometric profession to act as the major provider of refractive (and colour vision) screening at 5–6 years of age. Myopia is the refractive error most likely to develop during primary school presenting typically between 8 and 12 years of age, thus screening at entry to secondary school is warranted. Given the inevitable restriction on resources for health care, establishing screening at 5 and 11 years of age, with exclusion of any subsequent screening, is the preferred option.
PRICE AND QUANTITY QUOTES ON NASDAQ: A STUDY OF DEALER QUOTATION BEHAVIOR
Authors: Chung Kee H. , Zhao Xin 
Published: October 2004

AbstractWe show that the majority of quotes posted by NASDAQ dealers are noncompetitive and only 19.5% (18.4%) of bid (ask) quotes are at the inside. The percentage of dealer quotes that are at the inside is higher for stocks with wider spreads, fewer market makers, and more frequent trading, and lower for stocks with larger trade sizes and higher return volatility. These results support our conjecture that dealers have greater incentives to be at the inside for stocks with larger market‐making revenues and smaller costs. Dealers post large depths when their quotes are at the inside and frequently quote the minimum required depth when they are not at the inside. The latter quotation behavior leads to the negative intertemporal correlation between dealer spread and depth.
Setting Riparian/Aquatic Restoration Objectives within a Watershed Context
Authors: Kershner Jeffrey L. 
Published: October 2004

AbstractDeclines in native plant and animal communities have prompted new interest in the restoration of aquatic and riparian ecosystems. Past restoration activities typically have been site specific, with little thought to processes operating at larger scales. A watershed analysis process developed in the Pacific Northwest identifies four operating scales useful in developing restoration priorities: region, basin, watershed, and specific site. Watershed analysis provides a template for restoration practitioners to use in prioritizing restoration activities. The template identifies seven key steps necessary to understand and develop restoration priorities: (1) characterization, (2) identification of key issues and questions, (3) documentation of current conditions, (4) description of reference conditions, (5) identification of objectives, (6) summary of conditions and determination of causes, and (7) recommendations. When a similar process was used in the Uinta Mountains, Utah, and in the Siuslaw National Forest, Oregon, specialists were able to identify key habitat conditions and habitat forming processes and then to establish restoration priorities and implement the appropriate activities. Watershed analysis provides a valuable set of tools for identifying restoration activities and is currently being used throughout the Pacific Northwest to develop management strategies and restoration priorities. Although the analysis requires significant time, money, and personnel, experience suggests that watershed analysis provides valuable direction for managing aquatic and riparian resources.
Applying a Two‐Stage System to Prioritize Riparian Restoration at the San Luis Rey River, San Diego County, California
Authors: Olson Craig , Harris Richard 
Published: October 2004

AbstractA two‐stage system for selecting stream reaches and riparian communities for restoration was applied to the 80‐km San Luis Rey River below the Lake Henshaw dam in southern California. In the first stage, data from topographic quadrangles and aerial photographs were analyzed to define and classify reaches. These analyses concluded that (1) 28 km of the river and adjacent floodplain were suitable for second‐stage evaluation of restoration needs and (2) 32 km met criteria for reference conditions at the stream reach scale and should be protected from further impacts. The remaining 20 km of the river and flood‐plain were considered unsuitable for restoration to reach‐scale reference conditions; individual sites may be restored under existing regulatory review. Second‐stage field sampling provided data on vegetation and floodplain landforms and substrate from more than 3000 plots within the 28 km of river and 1120 ha of floodplain selected for further study. Classification of floristic samples stratified by landform/substrate class indicated six primary riparian communities on the floodplain, some associated with particular flood‐plain landform/substrate classes and others ubiquitous. Reference conditions for these communities were interpreted from the data. There were two major departures from reference conditions: tree‐dominated communities were less extensive than historic levels and exotic plants had significantly invaded some landforms and communities, displacing natural communities. General goals would include restoration of tree communities and removal of exotics, with further consideration of site‐specific objectives. The results included estimates of the areas by community type requiring restoration. The approach was developed for streams in the semi‐arid western United States, but it may be adapted for use elsewhere.
The Role of GIS in Selecting Sites for Riparian Restoration Based on Hydrology and Land Use
Authors: Russell Gordon D. , Hawkins Charles P. , O'Neill Michael P. 
Published: October 2004

AbstractSuccessful long‐term wetland restoration efforts require consideration of hydrology and surrounding land use during the site selection process. This article describes an approach to initial site selection in the San Luis Rey River watershed in southern California that uses watershed‐level information on basin topography and land cover to rank the potential suitability of all sites within a watershed for either preservation or restoration. This approach requires the use of a geographic information system (GIS) to map relative wetness and land cover within a watershed. Relative potential wetness values were derived from U.S. Geological Survey (USGS) 30‐m digital elevation models by calculating the flow that would potentially accumulate at all 30‐m × 30‐m pixels within the water‐shed. Land cover was derived from a Landsat scene covering the 1500 km2 study area. We ranked sites (contiguous groups of pixels > 1 ha with similar land cover) in terms of their potential for restoration or preservation based on their wetness values (low, medium, and high), size, and proximity to existing riparian vegetation. Sites with medium or high wetness values and extant vegetation were identified as potential preservation sites. Agricultural or barren sites with medium to high wetness were identified as potential restoration sites. Approximately 5500 ha (3.67% of the total watershed) were prioritized for preservation or restoration.
A Comparison of Approaches to Prioritizing Sites for Riparian Restoration
Authors: Kentula Mary E. 
Published: October 2004

AbstractThis study compares the results of Olson and Harris (1997) and Russell et al. (1997) in their work to prioritize sites for riparian restoration in the San Luis Rey River watershed. Olson and Harris defined reaches of the mainstem and evaluated the relative potential for restoration and protection based on cover of natural vegetation, land use, and connectivity. Then they used data on geomorphic conditions, plant species composition, and community structure to prescribe strategies for restoration. Russell et al. used a modeling approach within a geographic information system to combine data on wetness and land use/land cover to identify areas with potential for protection and restoration. They prioritized the areas based on patch size and proximity to extant riparian habitat. The mainstem and associated floodplain defined by Olson and Harris was more than twice the size of the area defined by Russell et al., because Olson and Harris considered the entire valley floor, whereas Russell et al. used a wetness index to identify saturated zones within the floodplain. For seven of the twelve management units delineated along the mainstem, the two studies agreed on a strategy of restoration or protection. They differed on two. No comparison could be made of the three units for which Olson and Harris used project review, a unique category. Agreement of the results is due to the similarity of criteria used to identify and rank sites for protection and restoration; disagreement is due primarily to the level of resolution of the data. Both approaches have potential for use in watershed‐level planning. The predictive power of the two approaches may be maximized when they are used in a complementary fashion.
Identifying Sites for Riparian Wetland Restoration: Application of a Model to the Upper Arkansas River Basin
Authors: O'Neill Michael P. , Schmidt John C. , Dobrowolski James P. , Hawkins Charles P. , Neale Christopher M. U. 
Published: October 2004

AbstractWe present a conceptual model for identifying restoration sites for riparian wetlands and discuss its application to reaches within the Upper Arkansas River basin in Colorado. The model utilizes a Geographic Information System (GIS) to analyze a variety of spatial data useful in characterizing geomorphology, hydrology, and vegetation of riparian wetland sites. The model focuses on three basic properties of riparian wetland sites: relative soil moisture, disturbance regime, and vegetative characteristics. A relative wetness index is used to define nominal soil moisture classes within the watershed. These classes generally coincide with uplands (low), channel margins (moderate), and channels or open water (high). Vegetative conditions are characterized using color infrared aerial photographs. Land cover types are grouped into five major land cover classes: riparian, moist herbaceous, bare ground, upland, and open water. Disturbance regime is characterized by a reach‐based index of specific power (ω). Preliminary results indicate that reaches within the Upper Arkansas River basin can be classified as high energy (ω≥ 8 W/m2) or low energy (ω≤ 3W/m2), using discharge estimates that reflect the 10‐year flood event. Field surveys of channel and floodplain conditions show that high‐energy reaches (ω≥ 8W/m2) are characterized by sites where the channel occupies a large proportion of the valley bottom. By contrast, low‐energy reaches (ω, ≤ 3 W/m2) are characterized by meandering channels with wide alluvial valleys. Restoration potential is evaluated as a combination of nominal scores from wetness, land cover, and disturbance indices. Application of these methods to field sites within the Upper Arkansas River basin identifies a wide range of riparian wetland sites for preservation or restoration. Potential sites within identified reaches are prioritized using size and proximity criteria.
Classification and Mapping of Riparian Systems Using Airborne Multispectral Videography
Authors: Neale Christopher M. U. 
Published: October 2004

AbstractAirborne multispectral videography has become a useful tool for classifying and mapping riparian vegetation because its spectral and digital format has high spatial resolution. This paper explains the processing steps and procedures required to use this type of spectral imagery for riparian vegetation classification and mapping. A description of the Utah State University airborne system is given, along with the image processing steps used for developing finalized products, because these are used in other articles in this volume. Examples of riparian applications using high‐resolution imagery are included.
Riparian Restoration: Current Status and the Reach to the Future
Authors: Landers Dixon H. 
Published: October 2004

AbstractNine articles in the special issue of Restoration Ecology addressing the subject of site selection for riparian restoration activities were critically examined for this review. The approaches described make significant and original contributions to the field of riparian restoration. All are interdisciplinary to some extent, often combining the fields of hydrology, geomorphology, and biology in the design of restorations. A common component among the articles is that they take a broad view, if not a watershed view, of restoration site selection. The approaches can be generally described as top‐down strategic approaches to siting restorations, as opposed to the more methods‐ and site‐driven bottom‐up, or tactical, approach. All the articles recognize the importance of developing endpoints related to the ecological function of riparian ecosystems. They succeed in their quest for these indicators of ecological function to varying degrees. The most common indicator used in these papers is riparian vegetation. Several additional elements of scientific investigation, if successfully pursued, could provide vital information and advance our understanding of riparian restoration: developing interdisciplinary approaches more fully; defining endpoints and reference conditions; implementing multiple scale approaches; viewing restorations as experimental ecosystem manipulations; developing a philosophy regarding exotic species; incorporating geographic information systems more often; and integrating science, society, and politics. The foundation provided by the contributions in this issue should provide a strong basis for the rapid advancement of future research in the area of riparian restoration.
Inhibition of human embryonic palatal mesenchymal cell cycle by secalonic acid D: a probable mechanism of its cleft palate induction
Authors: Dhulipala VC , Welshons WV , Reddy CS 
Published: October 2004

Structured AbstractAuthors – Dhulipala VC, Welshons WV, Reddy CSObjective – To assess the mechanism(s) of cleft palate induction by secalonic acid D (SAD) in human embryonic palatal mesenchymal (HEPM) cells and compare them with those evaluated in the murine embryonic palate.Design – Effect of SAD on HEPM cell proliferation was studied by obtaining dose response curves for cell numbers, uptake of 3H‐thymidine and the expression of proliferating cell nuclear antigen (PCNA). Effects of SAD on cell cycle were assessed by flowcytometry. Cell‐labeling with 3H‐glucosamine and immunoblot analysis were conducted to study SAD effects on the synthesis of glycosaminogycans (GAG) and the expression of fibronectin and tenascin, respectively.Results – SAD induced a concentration‐dependent decrease in HEPM cell number and 3H‐thymidine uptake beginning at 0.1 μg of SAD/ml. Expression of PCNA and progression of cell cycle from G1 to S phase were inhibited following SAD exposure. Cell viability was significantly reduced only at7.5 μg/ml of SAD or higher indicating that the reduction in cell numbers by SAD at lower concentrations is likely due to reduced proliferation and at higher concentrations due to both reduced proliferation and cell death. Synthesis of extra cellular matrix components (GAGs, fibronectin or tenascin) by HEPM cells, however, was not inhibited by SAD.Conclusion – The results of these studies confirmed those of our previous studies with mice and the MEPM cells that SAD may induce cleft palate by reducing numbers of palatal mesenchymal cells by inhibition of their proliferation thereby leading to a reduction in the size of the developing palate shelves.
SPACETIME SYMMETRIES IN NONCOMMUTATIVE GAUGE THEORY: A HAMILTONIAN ANALYSIS
Authors: GHOSH SUBIR 
Published: October 2004

We study spacetime symmetries in noncommutative (NC) gauge theory in the (constrained) Hamiltonian framework. The specific example of NC CP(1) model, posited in Ref. 9, has been considered. Subtle features of Lorentz invariance violation in NC field theory were pointed out in Ref. 13. Out of the two — observer and particle — distinct types of Lorentz transformations, symmetry under the former, (due to the translation invariance), is reflected in the conservation of energy and momentum in NC theory. The constant tensor θμν (the noncommutativity parameter) destroys invariance under the latter. In this paper we have constructed the Hamiltonian and momentum operators which are the generators of time and space translations respectively. This is related to the observer Lorentz invariance. We have also shown that the Schwinger condition and subsequently the Poincaré algebra is not obeyed and that one cannot derive a Lorentz covariant dynamical field equation. These features signal a loss of the Particle Lorentz symmetry. The basic observations in the present work will be relevant in the Hamiltonian study of a generic noncommutative field theory.
BRANE UNIVERSES TESTED AGAINST ASTRONOMICAL DATA
Authors: DABROWSKI MARIUSZ P. , GODŁOWSKI WŁODZIMIERZ , SZYDŁOWSKI MAREK 
Published: October 2004

We discuss observational constrains coming from supernovae imposed on the behaviour of the Randall–Sundrum models. We test the models using the Perlmutter SNIa data as well as the new Knop and Tonry/Barris samples. The data indicates that, under the assumption that we admit zero pressure dust matter on the brane, the cosmological constant is still needed to explain current observations. We estimate the model parameters using the best-fitting procedure and the likelihood method. The observations from supernovae give a large value of the density parameter for brane matter Ωλ,0≃0.01 as the best fit. For high redshifts z>1.2, the difference between the brane model and the ΛCDM (Perlmutter) model becomes detectable observationally. From the maximum likelihood method we obtained the favored value of Ωλ,0=0.004±0.016 for Ωk,0=0 and Ω m ,0=0.3. This gives the limit Ωλ,0<0.02 at 1σ level. While the model with brane effects is preferred by the supernovae type Ia data, the model without brane fluid is still statistically admissible. We also discuss how fit depends on restrictions of the sample, especially with respect to redshift criteria. We also pointed out the property of sensitive dependence of results with respect to the choice of ℳ parameter. For comparison the limit on brane effects which comes from CMB anisotropies and BBN is also obtained. The uncertainty in the location of the first peak gives a stronger limit Ωλ,0<1.0×10-12, whereas from BBN we obtain that Ωλ,0<1.0×10-27. However, both very strict limits are obtained with the assumption that brane effects do not change the physics in the pre-recombination era, while the SNIa limit is model independent. We demonstrate that the fit to supernovae data can also be obtained if we admit the phantom matter p=-(4/3)ϱ on the brane, where this matter mimics the influence of the cosmological constant. We show that phantom matter enlarges the age of the universe on the brane which is demanded in cosmology. Finally, we propose to check for dark radiation and brane tension by the application of the angular diameter of galaxies minimum value test.
Effects of Composition Levels on the Cellular Structure and the Thermal Properties of Biodegradable Cushioning Extrudates
Authors: Lui Wai-Bun , Peng Jinchyau 
Published: October 2004

Response surface methodology (RSM) was used to analyze the effect of polyvinyl alcohol (PVA) and calcium carbonate (CaCO3) on the cellular structure and the thermal properties of a biodegradable cushioning extrudate. A central-composite design (CCD) was used to develop models for the objective responses. The experiments were run at 105 C with a feed rate of 27.8 L/h, a screw speed of 500 rpm and a die diameter of 3.92 mm. The responses were most affected by changes in polyvinyl alcohol (PVA) levels and to a lesser extent by calcium carbonate (CaCO3) levels. The objective of this study is to focus on the composition levels affecting the cellular structure (average pore size) and the thermal properties (specific heat capacity and thermal conductivity) of extruded foams and to evaluate the possibility of using corn/PVA extrudates as packaging and insulating materials. The experimental results indicated that: 1. The cell sizes become smaller and more uniform and the cell walls become thinner with the increase in the PVA ratio. Moreover, using the CaCO3 also made the cell sizes become smaller and more uniform. 2. For all the treatments, the specific heat increased linearly as the temperature increased. 3. Several treatments have potential applications for thermal insulation because of their relatively high specific heat values and low thermal conductivity values.