cssi/SciSciGPT-SciSciNet huggingface dataset:
Investigating surface water well interaction using stable isotope ratios of water

Because surface water can be a source of undesirable water quality in a drinking water well, an understanding of the amount of surface water and its travel time to the well is needed to assess a well’s vulnerability. Stable isotope ratios of oxygen in river water at the City of La Crosse, Wisconsin, show peak-to-peak seasonal variation greater than 4‰ in 2001 and 2002. This seasonal signal was identified in 7 of 13 city municipal wells, indicating that these 7 wells have appreciable surface water contributions and are potentially vulnerable to contaminants in the surface water. When looking at wells with more than 6 sampling events, a larger variation in d 18 O compositions correlated with a larger fraction of surface water, suggesting that samples collected for oxygen isotopic composition over time may be useful for identifying the vulnerability to surface water influence even if a local meteoric water line is not available. At ime series ofd 18 O from one of the municipal wells and from a piezometer located between the river and the municipal well showed that the travel time of flood water to the municipal well was approximately 2 months; non-flood arrival times were on the order of 9 months. Four independent methods were also used to assess time of travel. Three methods (groundwater temperature arrival times at the intermediate piezometer, virus-culture results, and particle tracking using a numerical groundwater-flow model) yielded flood and non-flood travel times of less than 1 year for this site. Age dating of one groundwater sample using 3 H– 3 He methods estimated an age longer than 1 year, but was likely confounded by deviations from piston flow as noted by others. Chlorofluorocarbons and SF6 analyses were not useful at this site due to degradation and contamination, respectively. This work illustrates the utility of stable hydrogen and oxygen isotope ratios of water to determine the contribution and travel time of surface water in groundwater, and demonstrates the importance of using multiple methods to improve estimates for time of travel of 1 year or less. q 2004 Elsevier B.V. All rights reserved.
111Cd NMR studies of the domain specificity of Ag+ and Cu+ binding to metallothionein.

Metal displacement reactions of Cd7MT with Ag+ or Cu+ and interprotein metal exchange reactions between Cd7MT and Ag12MT or Cu12MT were studied by 111Cd NMR. Titration of 111Cd7MT with Ag+ indicates that Ag+ binds preferentially to the β-domain of the protein to form the metal hybrid species, (Cd4)α(Ag6)βMT. Once the β-domain is filled, additional Ag+ ions displace Cd2+ from the α-domain to form (Ag6)α(Ag6)βMT. The metal displacement reaction is cooperative and the two domains react independently of one another. The (Cd4)α(Ag6)βMT hybrid protein is also formed as the major product of direct interprotein metal exchange between Cd7MT and Ag12MT. Cu+ reacts with Cd7MT in a manner similar to Ag+, with addition of 6 equiv of Cu+ leading to preferential formation of (Cd4)α(Cu6)βMT, and 12 equiv of Cu+ to formation of (Cu6)α(Cu6)βMT. However, unlike Ag+, Cu+ appears to produce intermediate species that may contain mixed-metal clusters. Interprotein metal exchange between Cu12MT and Cd7MT leads to the net transfe...
Degumming of soybean oil: Quantitative analysis of phospholipids in crude and degummed oil1

Phospholipids of crude and degummed soybean oils were isolated and separated by column chromatography and thin layer chromatography. Standards and specific spray reagents were used to identify the phospholipids. Phospholipids identified in the crude and degummed oils were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid, lysophosphatidylcholine and lysophosphatidylethanolamine. Several unknown phosphorus-containing compounds were present. Samples of crude and degummed oil were collected from four soybean oil processors over four consecutive days. Total and individual phospholipids were quantitated by determining the phosphorus content. The total phosphorus content of crude oil varied among companies, with the average ranging from 453 to 676 ppm. The average total phosphorus content of the degummed oil of the four processors ranged from 12 to 84 ppm. Processors removed an average of 86-98% of the phosphorus present in the crude oil during the degumming process. There was also a daily variation in phosphorus removal within the individual companies. During the degumming process, the proportion of phosphatidylcholine decreased and the proportion of unknown, nonpolar phosphorus compounds increased in samples from all companies. Significantly higher proportions of phosphatidic acid and lyso compounds were found in the degummed oil of some but not all companies.
Retreat of the Laurentide ice sheet from 14,000 to 9000 years ago

The intricate pattern of moraines of the Laurentide ice sheet in the Great Lakes region reflects the marked lobation of the ice margin in late Wisconsin time, and this in turn reflects the distribution of steam-cut lowlands etched in preglacial times in the weak-rock belts of gentle Paleozoic fold structures. It is difficult to trace and correlate moraines from lobe to lobe and to evaluate the magnitude of recession before readvance, but three breaks stand out in the sequence, with readvances at about 14,500, 13,000, and 11,500 years ago. The first, corresponding to the Cary advance of the Lake Michigan lobe, is represented to the west by distant advance of the Des Moines lobe in Iowa, and to the east by the overriding of lake beds by the Erie lobe. The 13,000-year advance is best represented by the Port Huron moraine of the Lake Michigan and Huron lobes, but by relatively little action to west and east. The 11,500-year advance is based on the Valders till of the Lake Michigan lobe, but presumed correlations to east and west prove to be generally older, and the question is raised that these and some other ice advances in the Great Lakes region may represent surges of the ice rather than regional climatic change. Surging may involve the buildup of subglacial meltwater, which can provide the basal sliding necessary for rapid forward movement. It would be most favored by the conditions in the western Lake Superior basin, where the Superior lobe had a suitable form and thermal regime, as estimated from geomorphic and paleoclimatic criteria. The Valders advance of the Lake Michigan and Green Bay lobes may also have resulted from a surge: the eastern part of the Lake Superior basin, whence the ice advanced, has a pattern of deep gorges that resemble subglacial tunnel valleys, which imply great quantities of subglacial water that may have produced glacial surges before the water became channeled.
Critical analysis of the graphical determination of Hansen's solubility parameters for lightly crosslinked polymers

The most widely accepted method for determining Hansen's three-dimensional solubility parameters (3DSP) for crosslinked polymers entails graphically estimating the center of a spherical region in 3DSP-coordinate space whose boundaries are defined in terms of the extent of swelling by solvents whose 3DSP values are known. In this article, the results of immersion tests performed at 25°C with 53 solvents on each of four commercial polymeric glove materials are used to critically evaluate this method. Analyses reveal a number of serious shortcomings with respect to the reliability of 3DSP estimates obtained. In the context of modeling solubility or other measures of solvent–polymer compatability, it is recommended that alternative methods be sought for determining 3DSPs for crosslinked polymers. © 1996 John Wiley & Sons, Inc.
Compliant MEMS: design methods and applications (Abstract Only)

A systematic method of synthesis of monolithic mechanical structures called compliant mechanisms is presented. Sophisticated mechanical functions can be realized with these mechanisms and their unitized construction eliminates joint friction, clearances, and the need for assembly.
Albumin thiolate anion is an intermediate in the formation of albumin-S-S-homocysteine

Abstract An elevated concentration of plasma total homocysteine is an independent risk factor for cardiovascular disease. Greater than 80% of circulating homocysteine is covalently bound to plasma protein by disulfide bonds. It is known that albumin combines with cysteine in circulation to form albumin-Cys34-S–S-Cys. Studies are now presented to show that the formation of albumin-bound homocysteine proceeds through the generation of an albumin thiolate anion. Incubation of human plasma withl-35S-homocysteine results in the association of >90% of the protein-bound 35S-homocysteine with albumin as shown by nonreduced SDS-polyacrylamide gel electrophoresis. Treatment of the complex with β-mercaptoethanol results in near quantitative release of the boundl-35S-homocysteine, demonstrating that the binding of homocysteine to albumin is through a disulfide bond. Furthermore, using an in vitro model system to study the mechanisms of this disulfide bond formation, we show that homocysteine binds to albumin in two steps. In the first step homocysteine rapidly displaces cysteine from albumin-Cys34-S–S-Cys, forming albumin-Cys34 thiolate anion and homocysteine-cysteine mixed disulfide. In the second step, albumin thiolate anion attacks homocysteine-cysteine mixed disulfide to yield primarily albumin-Cys34-S–S-Hcy and to a much lesser extent albumin-Cys34-S–S-Cys. The results clearly suggest that when reduced homocysteine enters circulation, it attacks albumin-Cys34-S–S-Cys to form albumin-Cys34thiolate anion, which in turn, reacts with homocysteine-cysteine mixed disulfide or homocystine to form albumin-bound homocysteine.
Ethnicity is associated with alterations in oxytocin relationships to pain sensitivity in women

It is well established that African Americans (AA) experience greater pain associated with a variety of clinical conditions, and greater pain sensitivity to experimental pain tasks relative to non-Hispanic Whites (W). Notably, African Americans do not show the same relationships involving endogenous pain regulatory mechanisms and pain sensitivity documented in Caucasians, including positive associations between blood pressure, norepinephrine, cortisol and greater pain tolerance. Objectives. The purpose of this study was to examine the relationship between plasma oxytocin (OT) and pain sensitivity and to explore the relation of OT to other factors known to influence pain perception. Design. OT concentration and sensitivity to ischemic, cold pressor, and thermal pain tasks were assessed in African American (n=25) and non-Hispanic White (n=23) pre-menopausal women. Results. African American women demonstrated significantly lower pain tolerance across tasks compared with Whites (F 1,46=6.31, p=0.0156) and als...
Position along the nasal/temporal plane affects synaptic development by adult photoreceptors, revealed by micropatterning

In retinal degeneration, death of photoreceptors causes blindness. Repair of the retina by transplanting photoreceptors has resulted in limited functional connectivity between transplanted and host neurons. We hypothesize that absence of appropriate biological cues, specifically positional (retinotopographic) cues, reduces synaptogenesis. Here we use micropatterning to test whether regional origin affects the early synaptic development of photoreceptors. Right and left retinas from salamanders were first labelled with dextran tetramethyl-rhodamine and fluorescein, respectively, bisected into nasal (N)/temporal (T) or dorsal (D)/ventral (V) halves, individually dissociated, mixed, and cultured for 1 week. Origin of cells was identified by the fluorescent label. Interactions between photoreceptors and neighboring (target) cells were assessed by the number of neuritic contacts with a presynaptic swelling (varicosity). Randomly-plated photoreceptors showed no preference for cellular origin, likely due to multiple potential interactions available to each cell. To reduce cell–cell interactions, culture substrate was patterned using a microfluidic device with 10 μm-wide channels separated by 200 μm, thus allowing only 1–2 targets per photoreceptor. In patterned cultures, 36.89% of N rod cells contacted T targets but only 27.42% of N rod cells contacted N targets; similarly 35.05% of T rod cells contacted N cells but only 17.08% contacted T cells. Thus, opposite regions were more permissive of contact. However, neither cone nor D/V rod cells showed preferences for positional origin of targets. In conclusion, micropatterning demonstrated that neuritic differentiation by rod cells depends on retinotopographic cues along the nasal/temporal plane, suggesting that transplanting rod cells of known positional origin will increase transplant success.
Application of Correlation Analysis Techniques to Mass Spectral Data

Abstract The power of mass spectrometry as an analytical technique lies in the ability of the analyst to deduce the molecular structure of the compound under study from the data collected. Correlation analysis techniques (from information theory) can be employed to enhance the quantitative information present in the spectrum, as well as aid the analyst in the interpretation of the mass spectral data.
High power ring laser with diffraction grating coupling and axial mode selection

The performance of a high power, diffraction grating coupled ring resonator laser is described. A cw output power of four kilowatts at 10.6 microns in a near diffraction limited beam was obtained. The active medium was generated by a gas dynamic laser. Axial mode selection in resonator was used in conjunction with the Doppler shifted gain of the flowing medium to control the direction of oscillation. It is deduced from the directional behavior of the laser and the mode selective properties of the resonator that single frequency operation was obtained.
The folate cycle and disease in humans

The folate cycle and disease in humans. The prevalence of hyperhomocysteinemia in renal disease patients, its treatment by folate administration, and its aggravation by the 677 C→T mutation of methylene-tetrahydrofolate (methylene-THF) reductase has established the folate cycle as an important factor in the pathogenesis and management of renal disease. Proper function of the folate cycle depends on normal function of involved enzymes adequate of the vitamin and its correct disposition within the body. Vital processes in folate disposition include conversion of dietary folylpolyglutamates to monoglutamates, intestinal absorption, receptor and carrier-mediated transport across cell membranes, and cellular export. Folate coenzymes are responsible for the one-carbon unit transfer in intermediary metabolism and are required for several reactions in key metabolic processes, for example of purine, pyrimidine and methionine synthesis, and glycine and serine metabolism. Methionine synthase and its recently discovered reducing protein as well as methylene tetrahydrofolate reductase are key folate enzymes in homocysteine metabolism. Deficiencies of these enzymes are important causes of severe disease in the rare remethylation defects causing homocystinuria. Knowledge of their catalytic and molecular properties is important in understanding possible causes of moderate hyperhomocysteinemia, as for example, the well-known 677 C→T transition of methylene tetrahydrofolate reductase.
A Scheme for Hardware Reduction in Wireless Retrodirective Transponders

Typical transponders operate with an omni-directional response to interrogation, with a single antenna element, resulting in inefficient use of available power. Conventional retrodirective array architectures require phase-conjugators at each element, placing a heavy burden on the amount of active circuitry required and limited real estate. In this paper a switching feed network is integrated into a retrodirective array architecture to offer an N to 1 reduction in the amount of required phase-conjugating hardware, and therefore cost, while offering the directivity of an array architecture and maintaining omni-directional receive and transmit coverage. A four-element retrodirective transponder array is realized under this switching configuration. The introduced switching network can also serve as a built-in modulator for simple data transfer tasks.
Volcanic Gases in the April 1979 Soufriere Eruption

Six gas samples from the 17 April 1979 Soufriere eruption plume were analyzed for carbonyl sulfide, carbon disulfide, carbon monoxide, carbon dioxide, methane, nitrous oxide, fluorocarbon-11, fluorocarbon-12, methyl chloroform, and carbon tetrachloride. Only carbon monoxide, carbon dioxide, carbonyl sulfide, and carbon disulfide were found to have increased mixing ratios as compared with those in clean tropospheric air, but the increases were not sufficient to contribute greatly to the global budgets of these four components.
Use of starch and potato peel waste for perchlorate bioreduction in water.

Abstract The cost of carbon substrates for microbial reduction of perchlorate (ClO4−) is central to the success and competitiveness of a sustainable bioremediation strategy for ClO4−. This study explored the potential application of starch in combination with an amylolytic bacterial consortia and potato peel waste for ClO4− bioreduction. We obtained a potent amylolytic bacterial consortium that consisted of a Citrobacter sp. S4, Streptomyces sp. S2, Flavobacterium sp. S6, Pseudoxanthomonas sp. S5, Streptomyces sp. S7, and an Aeromonas sp. S8 identified by 16S rDNA sequencing. ClO4− concentration substantially decreased in purified starch medium inoculated with the amylolytic bacterial consortium and Dechlorosoma sp. perclace. Potato peel waste supported ClO4− reduction by perclace with the rate of ClO4− reduction being dependent on the amount of potato peels. Over 90% ClO4− removal was achieved in 4 days in a single time point experiment with 2% (w/v) potato peels waste. ClO4− reduction in a non-sterile 0.5% potato peel media inoculated with perclace occurred with an initial concentration of 10.14±0.04 mg L−1 to 2.87±0.4 mg L−1 (71.7% reduction) within 5 days. ClO4− was not detected in the cultures in 6 days. In a non-sterile 0.5% potato media without perclace, ClO4− depletion occurred slowly from an initial value of 9.99±0.15 mg L−1 to 6.33±0.43 mg L−1 (36.63% reduction) in 5 days. Thereafter, ClO4− was rapidly degraded achieving 77.1% reduction in 7 days and not detected in 9 days. No susbstantial reduction of ClO4− was observed in the sterile potato peel media without perclace in 7 days. Redox potential of the potato peel cultures was favorable for ClO4− reduction, decreasing to as low as −294 mV in 24 h. Sugar levels remained very low in cultures effectively reducing ClO4− and was substantially higher in sterilized controls. Our results indicate that potato peel waste in combination with amylolytic microorganisms and Dechlorosoma sp. perclace can be economically used to achieve complete ClO4− removal from water.
Induction of salicylic acid biosynthesis and systemic acquired resistance using the active oxygen species generator rose bengal

Summary Salicylic acid (SA) is an important signal molecule which plays a critical role in plant defense against pathogen invasion. Previous work has demonstrated that abiotic stresses such as ozone and ultraviolet-C radiation, which are potent active oxygen species (AOS) generators, increase endogenous SA levels and induce the accumulation of pathogenesis-related (PR) proteins in tobacco. Rose bengal (RB), a photodynamic AOS generator, was investigated for its ability to directly induce SA biosynthesis and activate molecular markers of systemic acquired resistance (SAR) using a pathogen-free system. Tobacco leaves were treated with RB solution and harvested at various time points. RB treatment led to a significant elevation in both free and total SA levels. The elevation of free SA levels was dose-dependent at RB concentrations above 20 mmol - L-1. RB treatment also induced the expression of PR-1 a gene transcripts and activated SAR throughout the plant. In additional experiments, the AOS scavengers N-acetyl-L-cysteine (NAC; 30 mmol - L-) and pyrrolidine dithiocarbamate (PDTC; 100 pmol - L-) were applied to tobacco leaves prior to RB application. Pre-treatment with NAC or PDTC prevented the accumulation of SA and diminished PR-la gene expression by RB. NAC or PDTC also prevented the acquisition of systemic resistance typically induced by RB.
Barriers to communication about end-of-life care in AIDS patients

Patients and physicians do not adequately discuss patients’ preferences for medical care at the end of life. Our objective was to perform a qualitative study using focus groups to identify barriers and facilitators to communication about end-of-life medical care for patients with AIDS and their physicians. Patients with AIDS and physicians with moderate or extensive HIV experience were recruited from clinics and community-based settings using network sampling. A total of 47 patients participated in six focus groups and 19 physicians participated in three groups. Patients or physicians identified 29 barriers and facilitators to communication about end-of-life care. Many patients and physicians expressed discomfort talking about death and dying, and some felt that discussing end-of-life care could cause harm or even hasten death. Several patients expressed the view that a living will obviated the need for discussion with their physician. Previous experience of discrimination from the health care system was a strong barrier to end-of-life communication for some patients with AIDS. Some patients hesitate to bring up end-of-life issues because they want to protect their physicians from uncomfortable discussions. Many patients identified the quality of communication as an important facilitator to these difficult discussions. Improving the quality of patient-physician communication about end-of-life care will require that physicians identify and overcome the barriers to this communication. To improve the quality of medical care at the end of life, we must address the quality of communication about end-of-life care.
Structure-Function Relations in the Inhibition of Murine Contact Hypersensitivity by Amiloride

Topical application of amiloride, a potent inhibitor of the Na + /H + antiport, inhibits cutaneous inflammation induced by ultraviolet radiation or contact hypersensitivity in mice. Amiloride analogues with greater and lesser inhibition of the Na + /H + exchange were tested to determine whether anti-inflammatory effects correlate with this activity. Structural analogues of amiloride without significant activity at the Na + /H + antiport (pyrazine, pyrazinamide, and chloropyrazine) failed to inhibit contact hypersensitivity. N-amidino-3-amino-5-dimethyl amino-6-chloropy-razinecarboxamide (DMA) has a 23-fold greater affinity for the Na + /H + antiport compared to amiloride, but failed to inhibit contact hypersensitivity in this assay. 3,5-diamino-6-chloropyrazine-amido-guanidine (DCG), which has only 7% of the affinity of amiloride for the antiport, suppressed contact hyper-sensitivity as well as amiloride. Experiments examining the ability of these agents to diffuse through mouse skin revealed amiloride to be superior to both DCG and DMA, which were approximately equal. DMA, with greater inhibition of the Na + /H + antiport but lesser ability to inhibit contact hypersensitivity, inhibited protein synthesis and induced cell death more than amiloride or DCG. Amiloride and DCG hold promise as topical anti-inflammatory agents. Their anti-inflammatory properties do not correlate with affinity for the Na + /H + antiport, ability to penetrate murine skin, or inhibition of protein synthesis.
Stand characteristics of sericea lespedeza on the Louisiana Coastal Plain

Sericea lespedeza has been an important forage legume in portions of the USA for decades but has recently been recognized as invasive in some ecosystems. Stand characteristics potentially affecting usefulness and invasiveness were assessed on forested and open sites of a Louisiana Coastal Plain landscape. Typical heavy weed competition, which was not overcome by increased seeding rate or extent of seedbed preparation, occurred in full sunlight. An open longleaf pine canopy suppressed competitive herbaceous species and enhanced establishment compared to that in full sunlight. Shade of either longleaf pines or dense overstory of tall weeds reduced productivity but not stands. Sericea lespedeza spread was limited to a few meters during 7 years, apparently due to lack of an effective dispersal mechanism. Long stand life under mature longleaf pines and in the open field along with ability to re-colonize from soil seed reserves contribute to both usefulness of sericea lespedeza for conservation, forage, and wildlife habitat in agricultural landscapes and potential undesired persistence, especially with land-use changes to less intensive management, on Louisiana Coastal Plain landscapes.
Estrogen- and antiestrogen-induced ornithine decarboxylase activity and uterine growth in the rat

The estrogen antagonists tamoxifen and monohydroxytamoxifen are also classified as partial estrogen agonists. In infantile rats, estradiol induced a single peak of uterine ODC activity at 6h following injection regardless of the extent of induction by various estradiol doses. By contrast, the timing of the ODC activity peak induced by tamoxifen and monohydroxytamoxifen was highly dependent upon the dosing conditions and was delayed to 18 h at lower tamoxifen doses. In immature rats, tamoxifen and monohydroxytamoxifen induced two peaks of uterine ODC activity resembling those induced by estradiol. Both ODC activity peaks were delayed by 9 h, without decreases in peak heights, by a 50-fold tamoxifen dose reduction. In all experiments the initial appearance of antiestrogen- and estradiol-induced ODC activity corresponded to initial uterine wet weight gain regardless of dosing condition. Thus, when dose-related temporal shifts are taken into account, tamoxifen and monohydroxytamoxifen are complete agonists with respect to induction of uterine weight gain and ODC activity.
Multicore OSes: looking forward from 1991, er, 2011

Upcoming multicore processors, with hundreds of cores or more in a single chip, require a degree of parallel scalability that is not currently available in today's system software. Based on prior experience in the supercomputing sector, the likely trend for multicore processors is away from shared memory and toward shared-nothing architectures based on message passing. In light of this, the lightweight messages and channels programming model, found among other places in Erlang, is likely the best way forward. This paper discusses what adopting this model entails, describes the architecture of an OS based on this model, and outlines a few likely implementation challenges.
Impacts of climate change on natural forest productivity – evidence since the middle of the 20th century

Changes to forest production drivers (light, water, temperature, and site nutrient) over the last 55 years have been documented in peer-reviewed literature. The main objective of this paper is to review documented evidence of the impacts of climate change trends on forest productivity since the middle of the 20th century. We first present a concise overview of the climate controls of forest production, provide evidence of how the main controls have changed in the last 55 years, followed by a core section outlining our findings of observed and documented impacts on forest productivity and a brief discussion of the complications of interpreting trends in net primary production (NPP). At finer spatial scales, a trend is difficult to decipher, but globally, based on both satellite and ground-based data, climatic changes seemed to have a generally positive impact on forest productivity when water was not limiting. Of the 49 papers reporting forest production levels we reviewed, 37 showed a positive growth trend, five a negative trend, three reported both a positive and a negative trend for different time periods, one reported a positive and no trend for different geographic areas, and two reported no trend. Forests occupy 52% of the Earth’s land surface and tend to occupy more temperature and radiation-limited environments. Less than 7% of forests are in strongly water-limited systems. The combined and interacting effects of temperature, radiation, and precipitation changes with the positive effect of CO2, the negative effects of O3 and other pollutants, and the presently positive effects of N will not be elucidated with experimental manipulation of one or a few factors at a time. Assessments of the greening of the biosphere depend on both accurate measurements of rates (net ecosystem exchange, NPP), how much is stored at the ecosystem level (net ecosystem production) and quantification of disturbances rates on final net biome production.
An Evaluation of Competitive Industrial Structure and Regional Manufacturing Employment Change

Drucker J. An evaluation of competitive industrial structure and regional manufacturing employment change, Regional Studies. This paper examines the relationship between regional industrial structure and employment change in the manufacturing sector and nineteen subsectors in the United States from 1987 to 1997. The relative associations of economic diversity, industrial specialization and competitive structure with economic performance are assessed using a non-causal regression framework. Multiple facets of industrial structure at the regional scale, including competitive structure, are considered together by exploiting confidential microdata to construct and evaluate detailed metrics across broad geographic and industrial ranges. The findings suggest the importance of industrial competitive structure for understanding regional employment change, economic performance and industrial development.
Principles and Applications of the Photochemical Control of Cellular Processes

Biological processes, particularly gene function, are naturally regulated with high spatiotemporal resolution in single cells and multicellular organisms. The activity of genes, proteins, and other biological molecules is precisely controlled in timing and location. This is especially evident during the complex biological processes observed in the development of an organism. In order to understand and to study these processes and their misregulation in human disease, it is imperative to control them with the same level of spatiotemporal resolution found in nature. Here, light irradiation represents a unique tool, because it can be easily and precisely controlled in timing, location, and amplitude; thus, light enables the precise activation and deactivation of biological function. Rather than providing a comprehensive literature review, this article focuses on the basic concepts and requirements of controlling biological (especially cellular) function with light. Recent examples are used to illustrate these concepts. The interested reader can find additional excellent and comprehensive reviews regarding the photochemical regulation of biologically active molecules in the literature.[1]
New Pairs of Inks and Papers for Photolithography, Microcontact Printing, and Scanning Probe Nanolithography

Currently, there is considerable interest in producing patterned metallic structures with reduced dimensions for use in technologies such as ultra large scale integration (ULSI) device fabrication, nanoelectromechanical systems (NEMS), and arrayed nanosensors, without sacrificing throughput or cost effectiveness. Research in our laboratory has focused on the preparation of precious metal thin films on semiconductor substrates via electroless deposition. This method provides for the facile interfacing of metal nanoparticles with a group (IV) and III-IV compound semiconductor surfaces. Morphologically complex films composed of gold, platinum, and palladium nanoparticles have been prepared as a result of the immersion of germanium and gallium arsenide substrates into dilute, aqueous solutions of tetrachloraurate (III), tetrachloroplatinate (II), and tetrachloropalladate (II), respectively. Continuous metallic films form spontaneously under ambient conditions, in the absence of a fluoride source or an externally applied current. This facile electroless deposition methodology provides an alternative to complex and expensive vacuum methods of metallization, yet allows for the preparation of both thin and thick nanostructured films with control over surface morphology and deposition rate. Furthermore, precious metal films prepared in this way exhibit excellent adhesion to the underlying semiconductor substrate. The resultant films were characterized utilizing scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and scanning probe microscopy (SPM). In order to apply this novel metallization method toward the development of useful technologies, patterning utilizing photolithography, microcontact printing (μCP), and scanning probe nanolithography (SPN) has been demonstrated.
How varying pest and trap densities affect Tribolium castaneum capture in pheromone traps

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is an important insect pest in food processing facilities. Pheromone trapping is frequently used to monitor red flour beetle populations in structures; however, the optimal trap density and the relationship between trap captures and beetle density is not known. Two experiments were performed concurrently in environmentally controlled 30-m2 walk-in chambers to determine the relationship between aggregation pheromone trap captures of red flour beetles and beetle and trap number. In one experiment, beetle density was kept constant at 200 individuals per chamber while trap number was varied from 1 to 8, and in the other experiment trap number remained constant at one per chamber while beetle density varied from 20 to 800 individuals. Results indicated that approximately one out of 23 red flour beetles were captured in a trap. Number of beetles captured in traps increased significantly as beetle density increased; however, the proportion of beetles captured remained consistent across beetle densities with a mean of 4.7 ± 0.6% of individuals captured. Trap captures varied significantly with trap placement within experimental chambers, indicating that subtle differences in the trapping environment can influence trap captures. Data suggested that trap densities of 0.07–0.10 m−2 (2–3 traps per chamber) would maximize trap capture, whereas a trap density of 0.13 m−2 (four traps per chamber) would maximize the predictive ability of a trapping equation estimating beetle density from trap captures. Results provide information needed to more thoroughly explore how environmental factors might influence red flour beetle trap capture in the absence of changes in beetle density. Further understanding of these relationships will allow for more accurate assessments of absolute beetle density from pheromone trap capture data.
Analysis of N*N passive optical star coupler based on the normal modes of N input waveguides

An integrated passive N*N optical star coupler on silicon wafer is described. Antiresonant reflecting optical waveguides (ARROWs) are analyzed and utilized as the input and output waveguides of the N*N coupler. Combining the exact solutions of the slab ARROW waveguide with the effective index method, a 5*5 coupler is analyzed. In the slab waveguide analysis, the input waveguides are coupled to their neighbors. The interaction of the waveguides is described in terms of the normal modes of propagation. The resultant field distribution is then diffracted into the free space region which separates the input and output sections. The radiation illuminates the receiving aperture from which the receiving N waveguides branch out, each output element obtaining equal power levels. Different types of loss such as spillover loss and mismatch loss were analyzed and estimated for N=5. A 5*5 star coupler with a transmission efficiency of 56% at a wavelength of 1.3 mu m is achievable. >
Development and assessment of strategies to ensure economic sustainability of the U.S. automotive recovery infrastructure

Currently, 95% of all the vehicles discarded in the U.S. enter the recovery infrastructure. The material recovery efficiency of the infrastructure is approximately 80% by weight. Significant changes are being pursued by automotive manufacturers to reduce the environmental impact of vehicles during the use phase. However, the effect of these changes on the automotive recovery infrastructure is uncertain. In addition to vehicle changes, calls for higher material recovery efficiencies from the government and society also add to the uncertainty. In order to characterize the effects of these uncertainties, a Material Flow and Economic Exchange (MFEE) model has been established. The model-predicted results showed that higher material recovery rates can only be achieved if the business entities within the recovery infrastructure employ new technological strategies such as increased plastic recovery rates. However, the economic sustainability or profitability of the business entities was found to be jeopardized. This paper will focus on certain profit-enhancement strategies that may be employed to ensure the economic sustainability. The MFEE model is used to assess the adequacy of these strategies to improve the profitability of the business entities within the recovery infrastructure. Based on the analysis of these strategies it is shown that the economic burden of achieving higher material recovery rates will have to be shared by all the stakeholders within the recovery infrastructure. A discussion on the potential government policies that may be enacted to implement the technological and profit-enhancement strategies is presented.
Hyperbolic geometry from a local viewpoint

Introduction 1. Elementary transformations 2 Hyperbolic metric in the unit disk 3. Holomorphic functions 4. Topology and uniformization 5. Discontinuous groups 6 Fuchsian groups 7. General hyperbolic metric 8. The Kobayashi metric 9. The Caratheodory pseudo metric 10. Contraction properties 11. Applications 12 Applications II 13. Applications III 14. Estimating hyperbolic densities 15. Uniformly perfect domains 16 Appendix: Elliptic functions Bibliography.
Abundance and diversity of tidal marsh plants along the salinity gradient of the San Francisco Estuary: implications for global change ecology

From 2003 through 2005, tidal marsh plant species diversity and abundance on historically surveyed vegetation transects along the salinity gradient of the San Francisco Estuary were investigated to establish empirical relationships between plant distributions and environmental conditions, and furthermore to examine and predict past and future plant distribution changes. This study suggests that for most species, salinity is the primary control on plant distribution. Thus, ongoing changes in estuarine conditions (increasing sea level and salinity) are resulting in a complex mix of plant distribution changes. On the low marsh, where sediment salinity is similar to that of ambient water, halophytic species are replacing salt-intolerant taxa. However, on marsh plains, where increased tidal flooding is moderating high salinity (concentrated by evaporation), halophytic “high marsh” species are being replaced by salt-intolerant “low marsh” taxa. Thus, future changes in plant distributions will hinge on whether marsh sediment accumulation keeps pace with sea level rise.
Tactical ballistic missiles trajectory state and error covariance propagation

This paper addresses tracking tactical ballistic missiles (TBMs) from space and ships. Modeling errors in the tracking system produce an uncertainty covariance matrix. Determining the critical error sources and identifying the needed elements of the covariance matrix is one analysis objective. Given the shooter ship has received the TBM's state via a cue link, then a trajectory propagation model is needed to predict impact parameters and uncertainty error ellipses. Determining trajectory fidelity and quantifying the resulting errors is the second object of this paper. >
The stress tensor for simple shear flows of a granular material

The complete stress tensor has been measured using a computer simulation of an assemblage of rough, inelastic spheres in an imposed simple shear flow. Only five components of the stress tensor were found to be significantly different from zero. These represent the disperssive normal stresses τxx, τyy and τzz and the in-the-shear-plane shear stresses τxy and τyx; furthermore, the two off-diagonal stresses, τxy and τyx, were found to be equal so that the resultant stress tensor is symmetric. Two modes of microscopic momentum transport produce the final macroscopic stress tensor: the streaming or kinetic mode by which particles carry the momentum of their motion as they move through the bulk material, and the collisional mode by which momentum is transported by interparticle collisions. The contribution of each to the final result is examined separately. The friction coefficient, the ratio of shear to normal force, is shown to decrease at dense packings for both the collisional and streaming modes. Also observed were normal stress differences, both in and out of the shear plane, reflecting anisotropies in the granular temperature.
Barrier synchronization in distributed-memory multiprocessors using rendezvous primitives

This paper deals with barrier synchronization in wormhole routed distributed-memory multiprocessors. New rendezvous and multirendezvous synchronization primitives are proposed to implement a barrier between two and multiple processors, respectively. These primitives reduce the number of communication steps required to implement a barrier; thus, significantly reducing the synchronization overhead for networks with high communication start-up cost. Two algorithms for barrier synchronization on k-ary n-cube networks are presented. The rendezvous primitive allows one to synchronize all processors in nlog/sub 2/(k) steps. The multirendezvous primitive allows one to synchronize an arbitrary subset of processors in optimal number of communication steps depending on the ratio of the communication start-up (t/sub s/) to the link-propagation (t/sub p/) cost. >
Effect of engaging abutment position in implant-borne, screw-retained three-unit fixed cantilevered prostheses.

Purpose: To investigate the effects of internally connected engaging component position in screw-retained fixed cantilevered prostheses. Materials and Methods: Twenty-one three-unit fixed dental prostheses (FDPs) were cast in high-palladium alloy in three groups. In group A, engaging components were incorporated into the units away from the cantilevered segment; proximal units received nonengaging components. In group B, these positions were reversed. Control specimens were fabricated using all nonengaging components. Specimens were attached to internally connected 3.5 (diameter) × 13 mm (length) implants, torqued to 32 Ncm, and embedded into epoxy resin. Specimens were tested in cyclic fatigue with a 2 Hz sine wave and 0.1 min/max load ratio. Load amplitude started at 1.8 N and increased by 1.8 N every 60 cycles until fracture. Log-rank statistic, ANOVA, Spearman's correlation, and LIFETEST procedures were used to evaluate level of statistical significance within the results. Results: In the control group, the mean number of cycles to fracture was 31,205 ± 2639. Mean axial force at fracture was 932 ± 78 N. In group A, these numbers were 38,160 ± 4292 and 1138 ± 128 N, and in group B, 31,810 ± 3408 and 949 ± 101 N. Statistical significance levels for number of cycles to fracture were: Control versus group A, p= 0.0117, and groups A versus B, p= 0.0156 (statistically significant). Control versus group B, p= 0.357 (not statistically significant). Log-rank statistic for the survival curves is greater than would be expected by chance; there was a statistically significant difference between survival curves (p= 0.012). The location and mode of failure were noteworthy (always in the abutment screw). Conclusions: The position of the engaging component had significant effects on the results. Within the limitations of this investigation, it can be concluded that using an engaging abutment in a screw-retained fixed cantilevered FDP provides a mechanical advantage, and engaging the implant furthest from the cantilever when designing a screw-retained cantilever FDP increased resistance to fracture of the distal abutment screw.
Nowhere-zero 3-flows in locally connected graphs

Let G be a graph. For each vertex v ∈V(G), Nv denotes the subgraph induces by the vertices adjacent to v in G. The graph G is locally k-edge-connected if for each vertex v ∈V(G), Nv is k-edge-connected. In this paper we study the existence of nowhere-zero 3-flows in locally k-edge-connected graphs. In particular, we show that every 2-edge-connected, locally 3-edge-connected graph admits a nowhere-zero 3-flow. This result is best possible in the sense that there exists an infinite family of 2-edge-connected, locally 2-edge-connected graphs each of which does not have a 3-NZF. © 2003 Wiley Periodicals, Inc. J Graph Theory 42: 211–219, 2003
Antagonistic effects of simultaneous exposure of ergot alkaloids on kidney adenosine triphosphatase system.

Abstract Much of the research on fescue toxicosis has concentrated on evaluating animal response to grazing endophyte-infected (E+) versus endophyte-free tall fescue or the effects of single toxins such as ergonovine (EN), ergovaline (EV), or ergotamine (ET) on animal performance. Such approaches have eliminated the opportunity to test the possible additive, synergistic, or antagonistic interactions of one or more ergot alkaloids with the other ergot alkaloids found in E+ tall fescue. This study was conducted to determine the effects of simultaneous exposure of pairs of EN, EV, and ET on the kidney adenosine triphosphatase (ATPase) system in vitro. Tests were performed using three separate rat kidney homogenates and were repeated four times at concentrations of 0, 75, and 200 μM. Individually, EN, EV, and ET induced dose-dependent inhibitions of kidney Na+/K+ ATPase, with EN being most potent, followed by purified EV, and then by ET. The ergot alkaloids inhibited Mg2+ ATPase to a lesser degree than Na+/K+...
Spatial Research—Measurement for What?

PREPARING for this paper led to discovery of the following: "This type model lacks some of the refinements of other types-notably it is necessary to assume away the problems raised by the interrelation of import and export markets, and the problems of the effects of the balance of trade on the levels of activity, as well as the effects of the terms of trade on real incomes, and thus on savings and so on the rate of growth of the economy" [1]. I expect to show that spatial research need not assume away all the important issues in the measurement of economic variables. In doing this I shall use international and interregional trade theory quite synonymously for most of the tools of international trade and methods of analysis can be applied to trading and welfare changes of regional groups within a country.' Even the mobility assumptions are interchangeable for factors within countries are to a degree immobile and between countries mobile.
Radiology Resident Remediation: Five Important Questions to Ask

OBJECTIVE. Residents needing remediation are difficult to recognize, assess, and address. The purposes of this article are to review common signs that a resident needs remediation and the causes of the deficiencies and to detail a checklist for preparing to approach the resident. CONCLUSION. Radiology residents who need remediation generally have either academic or professionalism deficits, and their remediation programs should be tailored to the deficit. Having a clear definition of the problem while eliciting the resident's thoughts on the nature of and solution to the problem are instrumental in the solution.