Search Results - (Author, Cooperation:P. M. Allen)

2014-02-11

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Antigens, CD/metabolism ; Cell Division ; Cross-Priming/*immunology ; Dendritic Cells/cytology/*immunology/*metabolism ; Female ; *Gene Expression Regulation ; Granulocyte-Macrophage Colony-Stimulating Factor/metabolism ; Inflammation/immunology/metabolism ; Integrin alpha Chains/metabolism ; Interferon Regulatory Factors/metabolism ; Listeria monocytogenes/immunology ; Liver/cytology/immunology ; Lung/cytology/immunology ; Male ; Mice ; Proto-Oncogene Proteins c-myc/deficiency/*metabolism ; T-Lymphocytes/*immunology ; Transcription, Genetic ; Vesiculovirus/immunology

2018-05-08

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2018-04-13

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Microbiology

1752-1688

Blackwell Publishing Journal Backfiles 1879-2005

Architecture, Civil Engineering, Surveying

Geography

Electronic Resource

1745-6584

Blackwell Publishing Journal Backfiles 1879-2005

Energy, Environment Protection, Nuclear Power Engineering

Geosciences

An automated base flow separation technique has been developed and tested. Base flow is considered to be the ground-water contribution to stream flow. Estimates of the amount of base flow can be derived from stream flow records. Such estimates are critical in the assessment of low flow characteristics of streams for use in water supply, water management, and pollution assessment. An automated base flow separation technique using a digital filter has been tested against three other automated techniques and manual separation methods. The filter appears to be comparable to other automated techniques in its ability to reproduce the results produced from graphical separation techiques. The filter technique is easy to use and has the added advantage in that it can be adjusted by the user to take into account personnel preferences in separation of stream flow into surface flow and base flow.The slope of the base flow recession has been used to estimate the volume of water in storage in the basin above the level of the stream channel, the amount of recharge to the shallow aquifer, and as an input into water budget models. A second automated technique was developed to calculate the slope of the base flow recession curve from stream flow record. This technique is an adaptation of the Master Recession Curve procedure. The results of this method were compared to manual estimates with an efficiency of 74 percent.

Electronic Resource

1752-1688

Blackwell Publishing Journal Backfiles 1879-2005

Architecture, Civil Engineering, Surveying

Geography

This paper describes the application of a continuous daily water balance model called SWAT (Soil and Water Assessment Tool) for the conterminous U.S. The local water balance is represented by four control volumes; (1) snow, (2) soil profile, (3) shallow aquifer, and (4) deep aquifer. The components of the water balance are simulated using “storage” models and readily available input parameters. All the required databases (soils, landuse, and topography) were assembled for the conterminous U.S. at 1:250,000 scale. A GIS interface was utilized to automate the assembly of the model input files from map layers and relational databases. The hydrologic balance for each soil association polygon (78,863 nationwide) was simulated without calibration for 20 years using dominant soil and land use properties. The model was validated by comparing simulated average annual runoff with long term average annual runoff from USGS stream gage records. Results indicate over 45 percent of the modeled U.S. are within 50 mm of measured, and 18 percent are within 10 mm without calibration. The model tended to under predict runoff in mountain areas due to lack of climate stations at high elevations. Given the limitations of the study, (i.e., spatial resolution of the data bases and model simplicity), the results show that the large scale hydrologic balance can be realistically simulated using a continuous water balance model.

Electronic Resource

1752-1688

Blackwell Publishing Journal Backfiles 1879-2005

Architecture, Civil Engineering, Surveying

Geography

: To quantify and model the natural ground water recharge process, six sites located in the midwest and eastern United States where previous water balance observations had been made were compared to computerized techniques to estimate: (1) base flow and (2) ground water recharge. Results from an existing automated digital filter technique for separating baseflow from daily streamflow records were compared to baseflow estimates made in the six water balance studies. Previous validation of automated baseflow separation techniques consisted only of comparisons with manual techniques. In this study, the automated digital filter technique was found to compare well with measured field estimates yielding a monthly coefficient of determination of 0.86. The recharge algorithm developed in this study is an automated derivation of the Rorabaugh hydrograph recession curve displacement method that utilizes daily streamflow. Comparison of annual recharge from field water balance measurements to those computed with the automated recession curve displacement method had coefficients of determination of 0.76 and predictive efficiencies of 71 percent. Monthly estimates showed more variation and are not advocated for use with this method. These techniques appear to be fast, reproducible methods for estimating baseflow and annual recharge and should be useful in regional modeling efforts and as a quick check on mass balance techniques for shallow water table aquifers.

Electronic Resource

1522-9602

Springer Online Journal Archives 1860-2000

Biology

Mathematics

Abstract In order to represent the biological evolution of a predator-prey ecology it is necessary to add to the equations of population dynamics terms corresponding to spontaneous mutation. Using a Volterra-Lotka ecology as an example, a model is developed for this. It is based on the assumption of two levels of description; a local one containing mutation probabilities, and the other the macroscopic average equations for the whole system. Diffusion processes link the two. The “evolutionary state” of a species is interpreted as an average effectiveness in terms of a genetic parameter space and it is shown that as a result of random mutations the ecosystem drifts irreversibly through this space.

Electronic Resource

1433-3023

Modified Kelly Air cystoscope ; Polymerase chain reaction studies ; Urethral biopsy ; Urethral colposcopy ; Urethral condyloma acuminata ; Urethral vascular ectasia

Springer Online Journal Archives 1860-2000

Medicine

Abstract In a 24-month prospective study, 22 patients with documented papillomavirus lesions elsewhere in the lower genital tract underwent biopsy of the urothelium of the urethra. These patients met the accepted criteria for urethral syndrome. The specimens were obtained under colposcopic control with small tissue biopsy forceps inserted through a modified Kelly air cystoscope. Polymerase chain reaction amplification and subsequent DNA primer evaluation failed to reveal the presence of papillomavirus infection in 20 of the 22 patients. Differentiated squamous mucosa was found on morphologic studies from these biopsies in 18 instances (82%). This multicenter study was unable to document the presence of human papillomavirus infection of the proximal urethral vesical neck or bladder trigone.

Electronic Resource

1433-3023

Intraurethral steroid injection ; Modified Kelly air cystoscope ; Urethral colposcopy ; Urethral condylomata ; Urethral syndrome

Springer Online Journal Archives 1860-2000

Medicine

Abstract While fiber-optic instruments are commonly utilized to diagnose urethral mucosal abnormalities, their usefulness in therapy is limited. In 1893 Howard Kelly described an instrument which allowed direct visualization of the urethra and bladder mucosa. In this study the classic Kelly air cystoscope was modified and used to diagnose and treat patients with inflammatory and neoplastic lesions of the urethral musoca, using direct visualization techniques with and without colposcopy. The urethral mucosa was subjected to biopsy and carbon dioxide laser ablation. Steroid infiltration of the submocosal tissue was also performed. The authors' study group consisted of 49 patients with inflammatory (20), condylomatous (22), cystic (2) and undiagnosed (5) conditions of the proximal and midurethral mucosa. This simple, inexpensive instrument allowed direct access to the urethral mucosa for diagnostic and therapeutic intervention. Patients suffered no significant morbidity from the use of this instrument.

Electronic Resource

1432-0495

Key words Reservoir sediments ; Sediment type ; Sediment source

Springer Online Journal Archives 1860-2000

Geosciences

Abstract  Bottom sediments were collected from seven Texas reservoirs to assess the spatial distribution of sediment types in reservoirs. The sediment samples were analyzed for water content, organic content, and grain-size distributions. The reservoirs are characterized by distinct water content patterns (referred to in this paper as Types I, II, and III) that reflect the lithologic units comprising their drainage area. The water content, organic content, and percent mud decreases from Type I (shale, marl) through Type II (limestone-marl-sandstone) to Type III (granite-gneiss-schist-sandstone) reservoirs. Reported elemental concentrations in the reservoir sediments are consistent with concentrations in the dominant rocks within their drainage area. While water depth accounts for part of the spatial distribution, sediment source explains the overall distribution of sediment types. Coarse-grained source rocks, multiple source rocks, and multiple tributaries which input sediment at different points contribute to an inconsistent sediment type distribution. Depending on the sediment source, sand and gravel-size sediments are present in the deeper regions of some reservoirs. This disrupts the classical morphometry (water depth, slope) controlled sediment distribution pattern (coarser sediments in shallower regions and finer sediments in deeper regions) of natural lakes. Thus, the location of tributaries and the type of sediments they carry are the dominant factors that control the sediment type distribution in reservoirs.

Electronic Resource

1432-1866

Springer Online Journal Archives 1860-2000

Geosciences

Abstract A regional fluid inclusion study of Cu-Au (+Zn-Pb) mineralisation in the Harlech Dome area, North Wales, gives support to the concept of two distinct metallogenic episodes. The inclusion assemblages associated with the porphyry copper mineralisation at Coed-y-Brenin are consistent with a genetic model of early potassic-propylitic alteration overprinted by later phyllic alteration. High salinity fluids, normally characteristic of potassic alteration, are confined to the host rock quartz. The meteoric/hydrothermal system is closely linked to the emplacement of late-Cambrian diorites. Integrated fluid inclusion and mineralogical studies of the Gold-belt veins suggest that the mineralising fluids were probably dehydration waters released from weakly metamorphosed Cambrian and perhaps Precambrian sediments during hydraulic fracturing in a tensional zone at the close of the Caledonian orogeny. Localisation of economic concentrations of gold in veins at the level of the Clogau Formation is ascribed to a destabilisation of metal complexes caused by a change in fluid buffering from a pyrite-magnetite assemblage in the Lower Cambrian sediments to a pyrite-pyrrhotite-graphite assemblage in the Upper Cambrian sediments. Veining associated with the Coed-y-Brenin porphyry copper deposit and related breccia pipes can be distinguished from the copper-gold veins of the coextensive Dolgellau Gold-belt by the presence in the former of inclusions notably richer in CO2. Furthermore the Gold-belt fluids have a distinctive low CO2/CH4+N2+H2 ratio.

Electronic Resource

1572-9516

Springer Online Journal Archives 1860-2000

Physics

Abstract In order to model any macroscopic system, it is necessary to aggregate both spatially and taxonomically. If average processes are assumed, then kinetic equations of “population dynamics” can be derived. Much effort has gone into showing the important effects introduced by non-average effects (fluctuations) in generating symmetry-breaking transitions and creating structure and form. However, the effects of microscopic diversity have been largely neglected. We show that evolution will select for populations which retain “variability,” even though this is, at any given time, loss-making, predicting that we shall not observe populations with “optimal behavior,” but populations which can “learn.” This lesser short-term efficiency may be why natural diversity is so great. Evolution is seen to be “driven” by the noise to which it leads.

Electronic Resource

1573-2932

atmospheric acid deposition ; chemical time bombs ; complex systems modelling ; eutrophication ; phosphate adsorption

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Abstract This work recognises the widespread deterioration of the natural environment, and the continual emergence of sudden environmental changes resulting from complex non-linear interactions of apparently disparate phenomena. Incorporating contemporary views of complexity and evolution, this paper presents a dynamic complex systems model which displays the discontinuous and non-linear characteristics which emerge from the inter-relationships of two such phenomena – acid rain and eutrophication – within the soil domain. A description is given of the chemical and hydrological sub-modules which provide the basis of this spatio-temporal model, and the inter-relationships between the buffering of acid and the adsorption of phosphates by the soil. Various representations of soil acidification, phosphate adsorption and hydrology drawn from existing models and literature are used to address both the chemical interactions and the spatial hydrological flows within the context of a river catchment. The resulting model can be easily applied to any chosen catchment due to the minimal data requirements and its generic representation. It may be utilised to describe non-point sources of phosphates as part of assessments of potential eutrophication, overcoming some of the limitations found in existing models, and provides the basis for the examination of Chemical Time Bomb (CTB) phenomena whereby the soil changes from being a phosphate sink to being a phosphate source.

Electronic Resource