cssi/SciSciGPT-SciSciNet huggingface dataset:
Time-resolved fluorescence spectroscopy of crude oils and condensates

Abstract A pulsed laser fluorescence spectroscopy system, previously developed for coal characterization, was used to characterize thirteen crude oils and condensates. From time-resolved fluorescence spectra, three individual components (fluorophores) with decay times in the nanosecond and sub-nanosecond range were resolved. A good correlation was obtained between the fluorescence decay times of these components and API gravity. The fluorescence decay of normal crude oil was different from biodegraded crude oil. Two of the three resolved component spectra and decay times resembled those of anthracene and pyrene in solution.
Anti-TNF Antibody Modulates Cytokine and MHC Expression in Cardiac Allografts

Abstract Tumor necrosis factor-α (TNF) is a multifunctional cytokine evoked in response to alloantigen stimulation and may be involved in lymphocyte activation, adhesion molecule expression, and regulation of MHC class II antigens. Anti-TNF treatment prolongs cardiac allograft survival. We investigated the role of anti-TNF in the regulation of MHC class II antigens and cytokine mRNA expression of TNF, interferon-γ (IFN), IL-2, IL-4, and IL-10 in cardiac allografts to elucidate its immunological mechanism. Thesein vivostudies were conducted using a rat MHC mismatch Brown-Norway to Lewis (BN to LEW) heterotopic cardiac transplant model. In control untreated rats, allografts were rejected at 6.8 ± 0.6 days. Allograft survival was significantly prolonged to 12.7 ± 1.4 days with anti-TNF treatment. MHC class II expression, analyzed by indirect immunofluorescence cytometry, demonstrated that MHC class II-positive cells increased by 25% in spleens of untreated allografted rats compared to naive rats, while anti-TNF-treated allografted rats had a similar percentage of MHC II cells as naives. Further, naive, untransplanted rats and both anti-TNF and untreated, transplanted rats had heart and spleens harvested on Day 5 post-transplant. Cytokine mRNA expression was determined by semiquantitative RT-PCR. In heart and spleen cells from naives, TNF mRNA expression was undetectable or very weak. However, in rejecting allografts and spleen cells from untreated recipients, TNF expression was remarkably increased, while anti-TNF attenuated this TNF expression in both heart graft and spleen cells. Furthermore, IL-2, IL-10, and IFN expression were absent in naive hearts. However, in untreated allografts IL-2, IL-10, and IFN were strongly expressed, which was markedly decreased after anti-TNF treatment. Finally, IL-4 expression was found equally in naive hearts, untreated allografts, and anti-TNF-treated allografts. These results suggest that anti-TNF antibody treatment may not only neutralize TNF activity but also play a role in altering cytokine mRNA expression and MHC class II expression.
COMING FULL CIRCLE: PHYSICAL GEOGRAPHY IN THE TWENTIETH CENTURY

The role of physical geography (and its practitioners) in the affairs of the Association of American Geographers and in the development of American geography has been varied in both substance and influence during the past seventy-five years. Physical geography was at its strongest in the Association's first decade and has recently experienced a resurgence. American physical geographers have tended to be adherents of the so-called “man-land”tradition in geographical teaching and research, which position is supported herein: firstly, by a review and perspective of physical geography during this century; secondly, through an exposition of some geographical opportunities for the future; thirdly, by discussion of the breadth vs. depth question in geographic education; and, fourthly, by concluding comments on this century's closing circle of events past, present, and future in American geography.
Effects of interfacial diffusive transport on the dynamics of oscillating reactions

Abstract The interplay of mass transfer and reaction in two-phase systems exhibiting oscillatory behavior has been investigated. A distributed model, based on partial differential equations describing unsteady mass transfer and reaction at the interface and ordinary differential equations describing reaction in the bulk phases, has been developed. Two reaction systems—an abstract two-variable chemical mechanism and a three-variable kinetic model describing the oxidation of benzaldehyde—have been studied. Numerical simulation and stability analysis reveal that the simultaneous occurrence of mass transfer and reaction at the interface can affect the dynamic behavior. Oscillatory behavior, multiple steady states, and enhancement of the rate of diffusive transport across the interface are predicted by the distributed model; simulation with a simpler mass transfer model (which assumes no reaction near the interface) shows only a single, sometimes oscillatory, stable state.
Glucose-induced nitrate assimilation in prairie and cultivated soils

Native prairie and grassland soils are known to accumulate little inorganic N; however, N03 − is constantly being formed and re-immobilized. This suggests that microorganisms in prairie soils would be highly efficient in the assimilation of N03 − and would regularly have the assimilatory N03 − reductase (ANR) enzyme in an induced and active state. Aerated slurries and static systems prepared from prairie and cultivated soils amended with glucose and N03 − were observed for changes in N03 − concentration with time. Nitrate assimilation in the presence of glucose occurred more rapidly in cultivated than in prairie soils from the same soil map unit. Nitrate assimilation rates were not affected by inoculation of prairie soil with cultivated soil. It has been reported that the addition of glucose and NO3 − to soils results in increased peptidase activity and a release of free amino acids. Mixing, sieving, and slurrying of prairie soils followed by treatment with glucose and NO3 − may release free amino acids and other ANR inhibitors into the prairie soil slurries. Prairie soils had higher concentrations of soluble amino-N than cultivated soils with or without glucose and N03 − additions. Prairie soils also had greater concentrations of total Kjeldahl N and readily hydrolyzed amino acids than corresponding cultivated soils.
Silicon Oxidation Studies: The Role of H 2 O

The thermal oxidation of Si using and ambients has been studied with an automated ellipsometer which can observe the oxidationin situ. The oxidations were carried out in the temperature range of 780°–980°C on oriented single crystal Si. The resulting film growth data was analyzed according to a linear‐parabolic oxidation model. The parabolic rate constant was found to increase abruptly with small additions of to while the linear rate constant increased gradually over the range of added (0–2000 ppm). The over‐all increase in the rate of oxidation due to in was found to be greater than predicted based on the independent diffusion and reaction of and related oxidant species. These effects of were found to be reversible. Therefore, the kinetic role of on the oxidation of silicon is essentially twofold. The acts both as an additional source of oxidant and as an accelerator for the oxidation process involving. It is postulated that this latter effect occurs because the modifies the network thereby enhancing diffusion of the primary oxidant through the film.
Oil Application Reduces White Pine Blister Rust Severity in Black Currants

ABSTRACT White pine blister rust (Cronartium ribicola Fisch.), an economically important disease of five-needled white pines (Pinus L. section strobus), also infects leaves of black currants (Ribes nigrum L.) as an alternate host. Recommended rust control-procedures include eradication, prohibition, or restriction of planting or growing black currants in specific states. Chemical or cultural control techniques for cultivated Ribes have been neglected in rust management plans. The objective of this study was to examine the effect of mineral oil spray on rust infection in seven susceptible cultivated black currant cultivars. Mineral oil at 8 ml/l was sprayed until run-off at 0, 2-week, and 4-week intervals from August through October 2000, on these black currant cultivars growing in Corvallis, Oregon. Plants were visually rated for disease severity in mid-October. Mineral oil applications significantly reduced rust infection compared to the unsprayed control. The disease severity of three highly susceptible...
The use of quantitative polymerase chain reaction for the detection and enumeration of the harmful alga Aureococcus anophagefferens in environmental samples along the United States East Coast

Aureococcus anophagefferens is a small pelagophyte that has caused harmful brown tide blooms in New York, New Jersey, Rhode Island, and Maryland. It is visually indistinguishable from other small algae in environmental samples using standard light microscopy, and current species-specific immunofluorescent counting techniques are not sensitive enough to detect concentrations lower than approximately 5000 cells mL−1. A TaqMan molecular probe was developed that is specific for A. anophagefferens based on a unique 18S rDNA sequence to detect cells at low levels. Real-time quantitative PCR (qPCR) on an ABI Prism 7700 Sequence Detection System was used to generate a standard curve of cycle thresholds (Ct) with known concentrations of A. anophagefferens (R2 = 0.98). Cell concentrations of A. anophagefferens in environmental samples are determined by linear regression analysis, with a sensitivity of approximately 1 cell mL−1. Estuarine and coastal water samples were collected along the U.S. East Coast from Florida to Delaware, and during a transect from the Delaware River to offshore mid-Atlantic waters, then analyzed using qPCR. Aureococcus has a wide distribution at background concentrations as far south as Northern Florida, far outside the presently recognized range of the organism. It was also found in offshore Atlantic samples, suggesting a possible oceanic source for bloom inoculation. qPCR allows for detection of cells at prebloom levels, which is essential for effective management and prediction of brown tide blooms.
Unstable modes of a spherical stellar system

The radial orbit instability for a family of anisotropic isochrone spheres is studied by a numerical linear stability analysis, and the results are compared with N-body simulations. A new way of choosing basis functions for the modes is introduced that allows spatially infinite systems to be handled without truncation. Previous studies of the same models, by adiabatic deformation and N-body integrations, found instability for b = / ≥ 2; the present computation indicate that very slowly growing modes persist for anisotropies as small as b = 1.4.
Immunological characterization of catfish (Ictalurus punctatus) insulin and proinsulin

1. Insulin and insulin intermediates were isolated and characterized from catfish (Ictalurus punctatus) pancreatic islets. 2. An antibody developed to this catfish insulin allowed the identification of proinsulin, and insulin intermediates. 3. Amino acid composition of the isolated insulin intermediates was similar to the calculated amino acid composition of proinsulin, as determined from the analyses of the separate A, B and C chains.
Management of inpatient hyperglycemia: assessing perceptions and barriers to care among resident physicians.

Objective: To develop insight into resident physician attitudes about inpatient hyperglycemia and determine perceived barriers to optimal management.Methods: As part of a planned educational program, a questionnaire was designed and administered to determine the opinions of residents about the importance of inpatient glucose control, their perceptions about what glucose ranges were desirable, and the problems they encountered when trying to manage hyperglycemia in hospitalized patients.Results: Of 70 resident physicians from various services, 52 completed the survey (mean age, 31 years; 48% men; 37% in first year of residency training). Most respondents indicated that glucose control was "very important" in critically ill and perioperative patients but only "somewhat important" in non-critically ill patients. Most residents indicated that they would target a therapeutic glucose range within the recommended levels in published guidelines. Most residents also said they felt "somewhat comfortable" managing h...
A Linear Relationship between Fitness and the Logarithm of the Critical Bottleneck Size in Vesicular Stomatitis Virus Populations

We explored the relationship between fitness change and population size during transmission in vesicular stomatitis populations of very high fitness. The results show a linear correlation between the logarithm of the critical bottleneck size (population size at which there are no significant fitness changes after 20 passages) and the initial fitness of the population. In addition, limits to fitness increases during large-population passages of very-high-fitness strains were abolished by increasing the population size during transmission, indicating that beneficial variation is still available in these populations.
Initial conditions at Emancipation: The long-run effect on black–white wealth and earnings inequality

Abstract Black–white wealth inequality is much greater than black–white earnings inequality in the United States. The existing empirical literature has not been able to fully explain the wealth gap. This paper investigates how much of current black–white income and wealth inequality can be explained by initial conditions at Emancipation and nearly 100 years of segregated schools. A two-sector model with group-specific human capital accumulation and school expenditure differences can explain the path of black–white convergence in earnings over the past 130 years. The model also reproduces the fact that black–white wealth ratios remain much lower than black–white earnings ratios.
Optical arithmetic unit using bit-WDM

A novel arithmetic unit is proposed consisting of a pipelined optical ripple carry adder that adds two words with bits multiplexed by different wavelengths on a single fiber. The addition result is returned to a fiber bus in the same format as the incoming words. The corresponding operand bit pairs are split off the fiber using wavelength division demultiplexers. Full adders compute the sum for each bit pair and the carry from the next lower significant bit pair. The full adder uses couplers and NOT, NOR and novel XOR logic gates constructed using semiconductor optical amplifiers for gain and wavelength shifting.
THE MULTIPLE DIMENSIONS OF DYSPNEA: REVIEW AND HYPOTHESES

Although dyspnea is a common and troubling symptom, our understanding of the neurophysiology of dyspnea is woefully incomplete. Most measurements of dyspnea treat it as a single entity. Although the multidimensional dyspnea concept has been mentioned for many decades, only recently has the concept been the subject of experimental tests. Emerging evidence has begun to favor the hypothesis that dyspnea comprises multiple dimensions or components that can be measured as different entities. Most recently, studies have begun to show that there is a separable 'affective dimension' (i.e. unpleasantness and emotional impact). Understanding of the multidimensional measurement of pain is far in advance of dyspnea, and has enabled progress in the neurophysiology of pain, including identification of separate neural structures subserving various elements of pain perception. We propose here a multidimensional model of dyspnea based on a state-of-the-art pain model, and review existing evidence in the light of this model.
Family Medicine and Geriatric Medicine: Economic and Ideological Conflict.

As the needs for geriatric medical care increase, it becomes important to identify sources of care for this expanding population. This paper focuses on the supports and impediments inherent in the provision of geriatric medical care by family physicians. Supports include a community and family oriented approach, a generalist perspective, experience in coordination of inpatient and outpatient services, and an educational commitment to geriatric training. Impediments include an excessive and inaccessible knowledge base, the conflict between biomedical and psychosocial approaches to care, inadequate reimbursement for comprehensive care, and difficulties in educating family practice residents. As family physicians have traditionally provided the majority of geriatric health care, particularly in the rural United States, these issues are important to address.
The role of juvenile hormone and brain factor(s) in the regulation of plasma juvenile hormone esterase activity during the last larval stadium of the tobacco hornworm, Manduca sexta

Abstract During the last (fifth) larval stadium of gate-1 Manduca sexta there were two peaks of juvenile hormone esterase activity in the plasma. The first peak occurred on day 3 preceding wandering and the second of a similar size on day 8 preceding pupation. The topical application of juvenoids (juvenile hormone I, epofenonane, and ( RS )-methoprene) to the abdomens of prewandering (day 0 to 3) and postwandering (day 5 and 7) larvae increased the plasma juvenile hormone esterase activity. Head ligation and starvation of prewandering larvae blocked the first peak and ligation of postwandering larvae blocked the second peak. Application of juvenoids could not rescue the effects of ligation and starvation in prewandering day 0 to 2 larvae, but ligation of day 1 and 2 larvae for 24 h followed by juvenoid treatment restored normal juvenile hormone esterase activity levels in ligated but not starved larvae. Juvenile hormone acted directly on the abdomen presumably on the fat body to increase juvenile hormone esterase activity throughout the last stadium but day-3 and -7 larvae were most responsive. Injection of head extracts of day-1, -2 and -3 fifth-instar larvae into the abdomens of head-ligated day-1 larvae did not increase the plasma juvenile hormone esterase activity, whereas it increased the α-naphthyl acetate esterase activity. Day-1 head extract decreased the plasma juvenile hormone esterase activity in unligated day-0, -1 and -6 larvae and in 24 h head-ligated, day-2 larvae that were treated with epofenonane. In day-1 unligated larvae treated with epofenonane one head equivalent reduced the juvenile hormone esterase activity by 48%. Injection of 4 head equivalents from day-1 larvae into larvae of the same age not treated with juvenoids completely inhibited the normal increase in juvenile hormone esterase activity seen between day 1 and 2. The inhibitory factor was specific in action not affecting the α-naphthyl acetate esterase activity, was dose-dependent, and found both in head and brain but not in whole body extracts. The inhibitory effect was present in head extracts prepared from day-1, -2 and -3 larvae. Head extracts also significantly decreased the juvenile hormone esterase activity in the whole body of normal as well as epofenonane-treated larvae without affecting the α-naphthyl acetate esterase activity.
Processing of English inflectional morphology

The present paper explores the representation of inflectional morphology in the English lexicon. There has been a long-standing debate about how these inflectional relationships might be involved during on-line processing. Inflected forms may be derived from an uninflected base form by rule application; by contrast, both regular and irregular inflection may be treated in the same way, with morphological patterns emerging from mappings between base and inflected forms. The present series of experiments investigated these issues using a lexical decision task. The first experiment showed that response latencies to nouns were significantly shorter than those to verbs. A possible explanation for these results can be found in differences in inflectional structure between English nouns and verbs. Namely, the relative frequency of uninflected compared with inflected forms is greater for nouns than for verbs. Two additional experiments compared noun stimuli with different inflectional structures. In all cases, differences in response latencies were predicted by the frequency of the surface form, whether uninflected or inflected. The pattern of results lends support for a unitary associative system for processing regular inflection of nouns in English and argues against the view that regular inflected plurals are derived by rule from a single, uninflected lexical entry.
Evaluation of hydrogen bonding ability of liquids and solids by C-13 NMR. Silica gel as a strong hydrogen bond donor

The chemical shift difference between signals of C(β) and C(α) of unsaturated ketones, Δδ, which we used before to measure acid strengths, has now been used to evaluate the hydrogen bond donor ability of solvents which are not acidic enough to hydronate the indicator. For such solvents there is no general correlation between H-bond donor ability and acid strength: hexa-fluoroisopropanol is a much weaker acid than acetic acid, but it is a stronger H-bond donor. The method can be applied to evaluate the H-bonding properties of solid surfaces, and it was thus found that silica gel has a much stronger H-bond donor ability than methanol or acetic acid.
Isolation of Campylobacter jejuni in Hunan, the People's Republic of China: Epidemiology and comparison of Chinese and American methodology

Abstract The incidence of infection with Campylobacter jejuni was determined in individuals with and without diarrheal disease seen at a hospital in Changsha, China. Stool specimens were cultured by two methods: one developed by the Chinese and a second control method used commonly in the United States. Among people with diarrhea, 18.7% of the 48 children and 8.7% of 104 adults were infected with Campylobacter jejuni . In the group without diarrhea, 8.6% of 105 children but none of 76 adults tested had the organism in their stool. Of the 27 total positive cultures, the Chinese method was positive in 26, compared with 21 for the control method. The Chinese culture method was at least as sensitive and specific as the American method. The biochemical characteristics and antibiotic sensitivities of Chinese isolates were similar to organisms isolated in other parts of the world. This study shows that Campylobacter jejuni is a common enteric pathogen in China and that the asymptomatic carrier state of this organism is significant in children.
1349 CONGENITAL ABSENCE OF DUCTUS ARTERIOSUS (ADA)

Newborn infants (NB) with cyanotic heart disease and reduced pulmonary flow are often ductus-dependent and improve with prostaglandin (PGE) infusion. However, PGE may fail if the ductus arteriosus is absent. The angiograms of 19 cyanotic NB (mean age 2.7 d) were analyzed. Group A consisted of 5 with ADA, and group B of 14 with patent ductus (PDA). All had pulmonary atresia complex with or without VSD. The diameters of aorta (ascending [AA], descending [DA], at diaphragm level [DDA]), right pulmonary artery (RPA), and left pulmonary artery (LPA) were obtained. Aortic size in A did not differ from those in B at all 3 levels. However, RPA and LPA were smaller in A than in B shown by mean pulmonary/aortic ratios: RPA/AA = 0.21 vs 0.389, RPA/DA = 0.38 vs 0.628, RPA/DDA = 0.41 v 0.64, LPA/AA = 0.20 vs 0.36, LPA/DA = 0.36 vs 0.60, LPA/DDA = 0.39 vs 0.605 (p value in all < 0.005), indicating impaired pulmonary artery growth in utero in pulmonary atresia or severe pulmonary stenosis with ADA. The angiograms in B showed PDA in all, and no increase of bronchial collaterals. In contrast, bronchial flow was abundant in A. Aortic valve stenosis was present in 3/5 in A but in 0/14 in B. ADA may be suspected clinically in cyanotic NB with reduced pulmonary flow if there is no response to PGE infusion and/or if aortic valve stenosis is also present. The diagnosis may be established angiographically based on non-visualization of the ductus, diminutive pulmonary arteries and abundant bronchial flow.
Episodic stridor with latex nipple use in a 2-month-old infant

Latex allergy in the pediatric population is most commonly identified in patients who have undergone multiple operations for neural tube defects or exstrophic genitourinary anomalies. However, there are a significant number of children who, without the usual risk factors, clinically and/or serologically appear to be latex allergic. There is sporadic information in the medical literature regarding reactions to latex allergens in household items, especially in patients younger than 1 year old. Several recent reports even support the existence of reactions to latex pacifiers. We report a case of an atopic 2-month-old infant who experienced the previously unreported reaction of repeated stridor on exposure to a latex nipple while feeding. It is important that clinicians recognize stridor as a potential reaction to latex in infants.
Quinone‐amine polymers. XV. Syntheses and characterization of high‐temperature resistant poly(arylamino‐quinone)s

Several poly(arylamino-quinone)s (PAAQs) were prepared by the conventional solution polymerization of p-benzoquinone with various aromatic diamines in tetrahydrofuran. Polymers prepared by this method were found to be more soluble in many organic solvents compared to the PAAQs prepared by other reported methods. The poly(arylamino-quinone)s were obtained in 82.3–94.5% yield and had inherent viscosities in the range of 0.073–0.251 dL/g. Among the PAAQs, the polymer prepared from p-benzoquinone and 1,3-bis(3-aminophenoxy)benzene (APB) had demonstrated exceptionally good solubility and thermal stability. © 1994 John Wiley & Sons, Inc.
Quantifying Microstegium vimineum seed movement by non-riparian water dispersal using an ultraviolet-marking based recapture method.

Microstegium vimineum is a shade tolerant annual C4 invasive grass in the Eastern US, which has been shown to negatively impact species diversity and succession in hardwood forests. To date, empirical studies have shown that population expansion is limited to <1 m yr−1, which is largely driven by gravity dispersal. However, this likely does not fully account for all mechanisms of population-scale dispersal as we observe greater rates of population expansion. Though water, both riparian and non-riparian water (i.e., ephemeral overland flow), have been speculated mechanisms for M. vimineum dispersal, few studies have empirically tested this hypothesis. We designed an experiment along the slopes of a Southwest Virginia hardwood forest to test the role of non-riparian water on local seed dispersal. We developed a seed marking technique by coating each seed with an ultraviolet (UV) powder that did not affect buoyancy to aid in situ seed recapture. Additionally, a new image analysis protocol was developed to automate seed identification from UV photos. Total seed mobility (summation of individual seed movement within each transect) was positively correlated with precipitation. Over a period of one month with 52.32 mm of precipitation, the maximum dispersal distance of any single recaptured seed was 2.4 m, and the average distance of dispersed seed was 0.21±0.04 m. This is the first quantitative evidence of non-riparian water dispersal in a forest understory, which accounts for an additional pathway of population expansion.
Matching horizon features using a Messy Genetic Algorithm

Three line segment matching techniques are compared on horizon line matching problems. The application is to reduce camera angle uncertainty for outdoor robots. Each of the three algorithms seeks an optimal many-to-many match between a subset of 2D line segments extracted from a rendered terrain map and segments extracted from an image. Two algorithms are non-deterministic, with one performing Random Starts Local Search and the other using a Messy Genetic Algorithm. The third algorithm searches a list of ranked key feature matches using a limited deterministic local search. The Random Starts Local Search Algorithm is the slowest of the three algorithms and fails to find the best match on 9 out of 54 problems. In contrast, the Messy Genetic Algorithm correctly solves all 54 test problems. The Key Feature Algorithm is the fastest, but it fails to find the optimal match in three cases. The results suggest the Messy Genetic Algorithm is superior to the other two algorithms on problems of this type. The test imagery was collected on one of the Unmanned Ground Vehicle Program's vehicles operating at the Lockheed Martin Demo C test site. Using the optimal matches it is shown that uncertainty in camera pointing angle is reduced from several degrees to less than a degree.
Modeling player preferences in avatar customization using social network data: A case-study using virtual items in Team Fortress 2

Game players express their values related to self-expression through various means such as avatar customization, gameplay styles, and interactions with other players. Multiplayer online games, now often integrated with social networks, provide social contexts in which player-to-player interactions take place, for example, through the trading of virtual items between players. Building upon a theoretical framework based in computer science and cognitive science, we present results from a novel approach to modeling and analyzing player values in terms of both preferences made in avatar customization, and patterns in social networking use. Our approach resulted in the development of the Steam-Player-Preference Analyzer (Steam-PPA) system, which (1) performs advanced data collection on publicly available social networking profile information and (2) the AIR Toolkit Status Performance Classifier (AIR-SPC), which uses machine learning techniques including clustering, natural language processing, and support vector machines (SVM) to perform inference on the data. As an initial case-study, we apply both systems to the popular, and commercially successful, multi-player first-person-shooter game Team Fortress 2 by analyzing information from player accounts on the social network Steam, together with avatar customization information generated by the player within the game. Our model uses social networking information to predict the likelihood of players customizing their profile in several ways associated with the monetary values of the players' avatar.
Stable isotope compositions of quartz pebbles and their fluid inclusions as tracers of sediment provenance: Implications for gold- and uranium-bearing quartz pebble conglomerates

Oxygen isotope compositions of pebbles from late Archean to paleo-Proterozoic gold- and/or uranium-bearing oligomictic quartz pebble conglomerates of the Witwatersrand district, South Africa, and Huronian Supergroup, Canada, were determined in an attempt to define the nature of the source terrain. The [delta][sup 18]O values of quartz pebbles within any one sample typically vary by [approximately] 4[per thousand] or more, but occasionally by as much as 8[per thousand], even for adjacent pebbles within the same hand specimen. In addition, adjacent quartz pebbles of widely contrasting [delta][sup 18]O values also preserve distinct isotopic signatures of their fluid inclusions. This overall heterogeneity suggests that the pebbles did not undergo significant oxygen isotope exchange after incorporation in the conglomerates. Therefore, oxygen isotope analyses of such quartz pebbles, in combination with a detailed investigation of their mineral and fluid inclusions, can provide a useful method for characterizing pebble populations and hence dominant sediment source modes. Comparison of values found in this study with [delta][sup 18]O values of quartz from Archean granites, pegmatites, and mesothermal greenstone gold veins, i.e., [delta][sup 18]O values of sources commonly proposed for the conglomerate ores, suggests that uranium is derived from a granitic source, whereas gold has a mesothermal greenstone goldmore » source. Low [delta][sup 18]O values of chert pebbles (9[per thousand] to 11.5[per thousand]) relative to those expected for Archean and Proterozoic marine cherts (commonly [ge] 17[per thousand]) effectively exclude marine cherts, and therefore, auriferous iron formations and exhalatives, as likely sources of gold.« less
Geysers and geothermal power production

Both in the United States and other countries, development of geothermal energy resources is being pushed [17](Fig. 9). A geothermal area is a complicated mechanical and thermal system (Fig. 6). It is important that efforts be made to better understand the gross heat and mass transfer in static geothermal basins; to describe flow patterns, discharge rates, and surface heat transfer in well defined thermal hot spots; and to appreciate the effect of mechanical forces on geothermal phenomena arising from alterations in porosity and permeability distributions due to deformation of the basin. Incisive studies of geysers are contributing significantly to the development of a more complete understanding of these matters.
Cpc1, a Chlamydomonas central pair protein with an adenylate kinase domain

Mutations at CPC1 disrupt assembly of a central pair microtubule-associated complex and alter flagellar beat frequency in Chlamydomonas. Sequences of wild-type genomic clones that complement cpc1, and of corresponding cDNAs, reveal the gene product to be a 205 kDa protein with two predicted functional domains, a single EF hand motif near the C-terminus and an unusual centrally located adenylate kinase domain. Homologs are expressed in mammals (testis and tracheal cilia) as well as ciliated lower eukaryotes. Western blots confirm that Cpc1 is one of six subunits in a 16S central pair-associated complex. Motility defects associated with cpc1 alleles in vivo are partially rescued in vitro by reactivation of axonemes or cell models in saturating concentrations of ATP; thus the Cpc1 complex is essential for maintaining normal ATP concentrations in the flagellum.
Application of Uniaxial Confining-core Clamp with Hydrous Pyrolysis in Petrophysical and Geochemical Studies of Source Rocks at Various Thermal Maturities

Understanding changes in petrophysical and geochemical parameters during source rock thermal maturation is a critical component in evaluating source-rock petroleum accumulations. Natural core data are preferred, but obtaining cores that represent the same facies of a source rock at different thermal maturities is seldom possible. An alternative approach is to induce thermal maturity changes by laboratory pyrolysis on aliquots of a source-rock sample of a given facies of interest. Hydrous pyrolysis is an effective way to induce thermal maturity on source-rock cores and provide expelled oils that are similar in composition to natural crude oils. However, net-volume increases during bitumen and oil generation result in expanded cores due to opening of bedding-plane partings. Although meaningful geochemical measurements on expanded, recovered cores are possible, the utility of the core for measuring petrophysical properties relevant to natural subsurface cores is not suitable. This problem created during hydrous pyrolysis is alleviated by using a stainless steel uniaxial confinement clamp on rock cores cut perpendicular to bedding fabric. The clamp prevents expansion just as overburden does during natural petroleum formation in the subsurface. As a result, intact cores can be recovered at various thermal maturities for the measurement of petrophysical properties as well as for geochemical analyses. This approach has been applied to 1.7-inch diameter cores taken perpendicular to the bedding fabric of a 2.3to 2.4-inch thick slab of Mahogany oil shale from the Eocene Green River Formation. Cores were subjected to hydrous pyrolysis at 360 °C for 72 h, which represents near maximum oil generation. One core was heated unconfined and the other was heated in the uniaxial confinement clamp. The unconfined core developed open tensile fractures parallel to the bedding fabric that result in a 38 % vertical expansion of the core. These open fractures did not occur in the confined core, but short, discontinuous vertical fractures on the core periphery occurred as a result of lateral expansion.
Carbon monoxide consumption and production by wetland peats

Wetland peats were analyzed for their potential to consume and produce carbon monoxide (CO) under aerobic and anaerobic conditions. Kinetic and functional characteristics of anaerobic CO consumption were compared with those of methanogenesis. Inhibitors of methanogenesis and sulfate reduction decreased the rate of CO consumption by 30 and 20%, respectively, suggesting that methanogens and sulfate reducers played secondary roles in CO uptake. Low concentrations of nitrate (0.2 mM) stimulated CO uptake, while high concentrations (20 mM) were partially inhibitory. Sulfate (20 mM), ferric iron (60 μmol cm−3), and acetate (10 mM) had no effect on CO consumption. Formate and glucose (10 mM) temporarily stimulated net CO and H2 production. Aerobic incubations of previously anaerobic peat stimulated transient CO production. Kinetic analysis of anaerobic CO consumption by two sediment types (organic peat and mineral silt) showed that maximum potential uptake velocities (Vmaxp) in each sediment were similar, 1–2 nmol CO cm−3 sediment h−1, with apparent half saturation constants (Kapp) ranging from 5 to 37 nM CO. Anaerobic CO consumption may limit CO accumulation in wetland peats and sediments, thereby affecting CO emissions. Understanding the role and characteristics of wetland CO consumption may help explain current and future patterns in wetland CO dynamics.
Renal effects in the delayed toxicity of O,S,S-trimethyl phosphorodithioate

Abstract A single oral dose (20–40 mg/kg) of O,S,S-trimethyl phosphorodithioate (OSS-Me), a malathion impurity with delayed toxic properties, administered to rats resulted in hyperamino aciduria, oliguria, polyuria, and in some cases anuria. The major uinary amino acids observed by TLC were alanine, glycine, glutamic acid, cysteine, methionine, and trytophan. Blood urea nitrogen/creatinine ratios of less than 15 1 were also observed. Polyacrylamide gel electrophoresis of urinary proteins from treated animals gave patterns indicating the presence of large amounts of low-molecular-weight proteins in the 10,000–25,000 range. The results provide evidence for OSS-ME-induced kidney tubular damage in rats.
Declining death rates reflect progress against cancer.

Background The success of the “war on cancer” initiated in 1971 continues to be debated, with trends in cancer mortality variably presented as evidence of progress or failure. We examined temporal trends in death rates from all-cancer and the 19 most common cancers in the United States from 1970–2006.
A Critique of “Democratic Administration” and Its Supporting Ideation*

This paper analyzes Vincent Ostrom's major work, The Intellectual Crisis in American Public Administration, which he offers as providing paradigmatic direction for public administration and political science. The analysis urges caution as to that theory's status, especially from five analytic perspectives. Basically, attention is directed at the methodology or mode of inquiry associated with Ostrom's grounding of his argument in public choice theory, with special attention to the role of values. The adequacy of major assumptions of Ostrom's argument as descriptions of reality also is evaluated. Moreover, the critical lack of content in several key concepts is established. In addition, the analysis shows how opposite and simultaneous courses of action are implied by the argument. Finally, attention is directed at how Ostrom's argument can lead to unexpected consequences, even some that are opposite those effects Ostrom intends.
Anthracene cycloadducts as highly selective chiral auxiliaries.

A new chiral auxiliary was designed and easily prepared from a Diels−Alder cycloadduct of an enantiomerically pure anthracene with maleimide. Excellent diastereoselectivities in Diels−Alder reactions, conjugate additions, and aldol reactions employing these auxiliaries are now reported.
Catabolism of arginine by the mixed bacteria in human salivary sediment under conditions of low and high glucose concentration

The catabolism of glucose by the oral mixed bacteria results in a lowering of the pH whereas arginine degradation favours a rise. In the mouth, low and high levels of glucose cause different plaque pH conditions which, in turn, might affect the rate and mode of degradation of arginine. This possibility was examined in the suspended salivary-sediment system where these pH conditions can be simulated. With the pH, the metabolic parameters examined were arginine utilization, ammonia, carbon dioxide and putrescine formation, utilization of glucose and changes in levels of L(+)- and D(-)-lactic acid. At the lower glucose concentration, the pH rapidly fell and then slowly rose whereas, with the higher glucose level, the pH showed a greater fall and no subsequent rise. The more acidic pH conditions favoured by the higher glucose level inhibited arginine degradation and the appearance of its various end-products and intermediates. Arginine degradation with arginine-[U-14C] and paper chromatography-autoradiography showed successive appearance of citrulline, ornithine and putrescine and, depending upon the pH, some succinate. When the pH was held constant at several different values, arginine degradation was optimal when the pH was near neutrality. In supplementary experiments, arginine had little effect on the ability of the oral mixed bacteria to utilize glucose and produce and utilize lactic acid, whereas the arginine peptide, arginylisoleucine and saliva supernatant stimulated these processes. Thus glycolysis enhancement and a more rapid clearance of fermentable carbohydrate by the oral bacteria would accompany pH-rise activity with arginine peptide and saliva but would not accompany pH-rise activity with arginine.
"Half" membrane enrichment: verification by electron microscopy.

Membranes of intact erythrocytes bound to polylysine-treated glass fracture nonrandomly when covered with thin copper and frozen. Electron microscopic examination of the glass side reveals extensive areas of outer "half" membrane (B face) and of the copper side, inner "half" membrane (A face). This technique allows the ultrastructural examination of square-centimeter areas of fractured membrane and the chemical analysis of these membrane "halves".
Method development and validation for optimized separation of benzo[a]pyrene–quinone isomers using liquid chromatography–mass spectrometry and chemometric response surface methodology

The successful separation of three benzo[a]pyrene-quinone isomers, two of which were previously unresolved, using liquid chromatography-mass spectrometry (LC-MS) and response surface methodology is presented. Initial efforts centered on chromatographic separation of benzo[a]pyrene-1,6/3,6-quinone peaks evaluated for both resolution and retention time. The mergence of the two parameters was accomplished using the Derringer's desirability function with subsequent optimization by a Box-Behnken response surface design. By implementing the optimal flow rate, column temperature and eluent composition predicted by the validated model, enhanced resolution of the two isomers was achieved in less than 20 min. Calibrations were performed to quantify these isomers and the limits of detection were determined. Optimal model conditions were then used to identify three independent benzo[a]pyrene-quinone isomers produced in the irradiation of a benzo[a]pyrene standard solvated in oxygen-saturated methanol/methylene chloride. This work is not only highly significant to the field of environmental chemistry, but instructive for investigators struggling with the co-elusion of isomeric compounds in their work.
In situ microscopic observation of the formation process of pinning centers in Nd-Ba-Cu-O superconductor

Abstract Novel method of investigation the development of nanolevel microstructure to introduce effective pinning centers in Nd-123 superconductor was attempted. Compositional deviation in nanometer scale of Ba and Nd developed during post heat treatment of Nd-123 crystal grain was observed by means of in situ high temperature microscopic observation, suggested as the origin of improved pinning force. Crystal growth condition of Y-123 superconductor in polycrystalline bodies under applied stress was studied for the microstructure control to improve transport current properties. Behavior of crystal growth front of superconducting grains through the solid state diffusion or the existence of small amount of liquid phase was examined in various conditions of temperature and applied stress. Interfacial reaction of introduced pinning centers and growing surface of superconducting matrix grains was investigated to promote the uniform dispersion of nanoparticles in matrix for increasing J c .
Electronic structure of calcium hexaboride within the weighted density approximation

We report calculations of the electronic structure of CaB 6 using the weighted density approximation ~WDA! to density-functional theory. We find a semiconducting band structure with a sizable gap, in contrast to local-density approximation ~LDA! results, but in accord with recent experimental data. In particular, we find an X-point band gap of 0.8 eV. The WDA correction of the LDA error in describing the electronic structure of CaB6 is discussed in terms of the orbital character of the bands and the better cancellation of self-interactions within the WDA. The discovery of ferromagnetism in the lightly doped CaB6 and SrB6 resulted in considerable experimental and theoretical work aimed at understanding this unexpected phenomenon. The reported ferromagnetism is particularly remarkable considering that the material, Ca12xLaxB6, contains no elements with partially filled d or f orbitals, and even more strangely, the ferromagnetism is associated with very low doping levels (,1%), andtherefore low carrier concentrations, has a very low moment (;0.07 m B /La for x 50.005), but a very high Curie temperature, TC as high as 600 K ~Ref. 1!. Further, a semiconducting material, with ferromagnetism of this type, could potentially be of importance in producing room-temperature spintronic devices. 2,3
The role of temperature in forming sol–gel biocomposites containing polydopamine

To further improve the physical strength and biomedical applicability of bioceramics built on hydroxyapatite–gelatin (HAp–Gel) and siloxane sol–gel reactions, we incorporated mussel adhesive inspired polydopamine (PD) into our original composite based on HAp–Gel cross-linked with siloxane. Surprisingly, with the addition of PD, we observed that the processing conditions and temperatures play important roles in the structure and performance of these materials. A systematic study to investigate this temperature dependence behavior discloses that the rate of crosslinking of silane during the sol–gel process is significantly influenced by the temperature, whereas the polymerization of the dopamine only shows minor temperature dependence. With this discovery, we report an innovative thermal process for the design and application of these biocomposites.