cssi/SciSciGPT-SciSciNet huggingface dataset:
Radiation Induced Redox Reactions and Fragmentation of Constituent Ions in Ionic Liquids. 1. Anions

Room temperature ionic liquids (IL) find increasing use for the replacement of organic solvents in practical applications, including their use in solar cells and electrolytes for metal deposition, and as extraction solvents for the reprocessing of spent nuclear fuel. The radiation stability of ILs is an important concern for some of these applications, as previous studies suggested extensive fragmentation of the constituent ions upon irradiation. In the present study, electron paramagnetic resonance (EPR) spectroscopy has been used to identify fragmentation pathways for constituent anions in ammonium, phosphonium, and imidazolium ILs. Many of these detrimental reactions are initiated by radiation-induced redox processes involving these anions. Scission of the oxidized anions is the main fragmentation pathway for the majority of the practically important anions; (internal) proton transfer involving the aliphatic arms of these anions is a competing reaction. For perfluorinated anions, fluoride loss followin...
Dripping phenomena of water droplets impacted on horizontal wire screens

Abstract The dripping phenomena of water droplets impacted on horizontal wire screens at isothermal condition were studied. Uniform droplet streams of about 350 μm in diameters with a velocity of 2.8 m/s were produced using a piezo-electric droplet generator. The wire diameter of the screens ranged from a coarse screen of 1.6 mm with 2×2 meshes per linear inch to a fine screen of 0.14 mm with 100×100 meshes. For droplets impinging on the coarse wire screens, they wet the wires and form thin liquid clusters. As these clusters of water accumulate around the wires, dripping drops are produced on the bottom side of the wires as well as at the corners of the meshes. The phenomena are very similar to the dripping drops formed beneath single wires. For screens with medium size opening, the dripping drops are mostly formed at the mesh stitch apertures surrounded by the wires. For fine mesh screens, the liquid films on the top surface pass through the fine mesh openings and form liquid ligaments at the bottom side of the screen. This resembles the situation of drops dripping from a ceiling. In all cases, the drops gradually evolve into a pendent shape under the influence of surface tension and gravity. Eventually, the weight of the pendent drop exceeds the surface tension and the drop falls off from the bottom of the screen. Non-dimensional parameters have been used to identify the dripping characteristics and to quantify the size of the dripping drops.
Release of Copper from Mine Tailings on the Keweenaw Peninsula

Over 500 million tons of copper-rich mine tailings were dumped into lakes, rivers, wetlands, and along the shore of Lake Superior between 1850 and 1968. Metals leaching from mine residues have impacted ecosystems throughout the Keweenaw Peninsula as well as Lake Superior. The objective of this study was to elucidate the chemical processes that release Cu from mine tailings into the water. Copper in mining residues from three contrasting environments (lake sediments, wetland stamp stands, and exposed lakeshore tailings piles) was fractionated with a sequential extraction technique (SET) to identify and quantify the labile pools of copper. The SET revealed that the carbonate and oxide fractions were the largest pools of Cu (ca. 50 ∼ 80%) in lakeshore and wetland stamp sands whereas the organic matter fraction was the largest reservoir (ca. 32%) in the lake sediments. X-ray diffraction and SEM confirmed the presence of the copper-bearing minerals cuprite, tenorite, malachite, and elemental Cu. Size fractionation studies suggested that weathering of native (elemental) Cu results in enrichment of particle surfaces with Cu oxides and carbonates; fine particles also are enriched in these phases. Both laboratory titrations and computer modeling suggested that aqueous Cu concentrations are limited by mineral (malachite and copper(II) oxides) dissolution and precipitation reactions. Concentrations of DOC and pH depressions caused by microbial activity strongly affect the dissolved Cu concentrations. At some sites, aqueous concentrations of copper approach equilibrium with a Cu oxyhydroxide that has a solubility intermediate between that of cupric hydroxide (Cu(OH)2) and tenorite (CuO).
Consistency of time series and trends of stratospheric ozone as seen by ozonesonde, SAGE II, HALOE, and SBUV(/2)

[1] We examined the consistency of time series for stratospheric ozone obtained by ozonesondes, SAGE II, HALOE, and SBUV(/2) in the northern extratropics and find excellent agreement for interannual variability and trends of ozone for 50–12.5 hPa over Europe. Ozonesonde, SAGE, and HALOE data agree well for ∼200 hPa–12.5 hPa. Ozone in the past few years is ∼6% below values in the early 1980s for 80–20 hPa, while values for 200–125 hPa are similar to those in the early 1980s. Small differences in monthly mean ozone and trends between ozonesondes and SAGE are caused by spatial and temporal sampling differences. The quality of SBUV(/2) Version 8 ozone data was evaluated by comparison to the homogeneous SAGE data. Most biases between SBUV(/2) and SAGE data are within ±10% except for large negative biases of SBUV(/2) at 50 hPa in the tropics. There is less homogeneity in the SBUV(/2) time series for the upper stratosphere, with negative biases for NOAA-11 after 1997 at 3–5 hPa and positive biases for NOAA-9 and 16 at 2–5 hPa, compared to earlier SBUV data, implying that the later data may lead to errors in calculated ozone trends. SBUV(/2) ozone trends agree well with SAGE trends in the midlatitude lower stratosphere for 1984–2000, but SBUV(/2) trends are as much as 4%/decade more positive than SAGE trends in the upper stratosphere. We find that SAGE sampling does not influence zonal mean trends, implying that SAGE/SBUV(/2) trend differences are related to data quality and to the different coordinate systems in which ozone is measured.
Outcomes of extended donors in pancreatic transplantation with portal-enteric drainage.

Objective. Limited data are available on extended (EX) donor criteria in pancreatic transplantation (PTX). Methods. This retrospective study from February 2007 through April 2007 compared 2 cohorts of simultaneous kidney-pancreas transplantations (SKPT): the first from EX donors, which were defined as age <10 years or ≥45 years, or donation after cardiac death [DCD]), and the second from conventional (CONV) donors. Results. Among 79 SKPT, 19 (24%) were from EX donors (12 older than age 45 [mean age, 50.2 years], 3 pediatric donors <10, and 4 DCD donors) and the remaining 60 SKPT from CONV donors. The mean donor age was higher in EX than CONV donors (38 vs 25 years, P <.05). There were no other differences between the 2 cohorts. With a similar median follow-up of 29 months, patient, kidney and pancreatic graft survival rates were 89%, 89%, and 79%, for the EX, whereas corresponding outcomes for CONV donors were 93%, 87%, and 80%, respectively (all P = NS). The incidences were similar for delayed kidney graft function (5% in each group), early pancreatic graft loss due to thrombosis (5% EX vs 8% CONV donors), acute rejection (16% EX vs 18% CONV donors), surgical complications, and infections. There were no significant differences in 1-year mean serum creatinine (1.4 mg/dL in each group) or glycohemoglobin (5.2% vs 5.5%) levels between the EX and CONV donor groups, respectively. Conclusion. Short-term outcomes among SKPT from selected EX donors were comparable to CONV donors. Donors at the extremes of age and DCD donors may represent underused resources in SKPT.
Coke is It: How stories in childhood memories illuminate an icon

Abstract This paper builds on consumer storytelling theory and childhood memory research by proposing that earliest childhood memory stories are useful for developing brand myths and providing relevance to iconic brands. This article investigates consumers' childhood memories with Coca-Cola and finds that memories from early childhood are more predictive and insightful for understanding current brand attitudes than memories coming from adolescence. A focus group is unable to elicit memories from as early in life as the childhood memory session. In addition, the memories elicited by the group interviewer are not as relevant and meaningful to participants. When participants read experiences coming from the childhood memory session, those who connect with the earliest childhood memory stories have the strongest attitudes toward Coca-Cola. A discussion describes how this research method aids in generating insights about iconic brands and brands aspiring to become iconic.
Synthesis and solid state structure of tetra(2,6-di-isopropylphenoxy)-hexamethoxy-di-tantalum(V), Ta2(OC6H3Pri2)4(OCH3)6

Abstract The reaction of Ta(OAr-2,6-Pri2)2(CH3)3(OAr-2,6- pri2=2,6-di-isopropylphenoxide) with oxygen in hexane solvent has allowed the isolation of the mixed alkoxide, aryloxide Ta2(OAr-2,6-Pri2)4(OCH3)6 (1) as large white crystals which have been studied by X-ray diffraction methods. Crystal data for Ta2C54- H86O10, Mr=1257.16, monoclinic, P21/a, a= 22.137(7), b=10.494(3), c=12.452(4) A, β= 105.09(2)°, V=2792(2) ,A3, Z=2, Dx=1.495 g cm−3, Mα, λK=0.71069 A,μ=39.2 cm−1, F(000) =636, T=112 K,R=0.030 for 3212 unique observed reflections. The structure consists of an octahedral arrangement of oxygen donor atoms around two tantalum metal centers in an edge-shared bi-octahedron with two bridging methoxide ligands. The other four methoxide and four phenoxide ligands are terminal.
Numerical simulation of neutron diffraction from correlated/uncorrelated magnetic multilayers

Abstract We report stochastic diffraction simulations of magnetic multilayered systems. Results show that spectrum fringes from a system of many magnetic domains is a non-random effect - i.e., such fringes cannnot occur in the total absence of interlayer spin correlations. Simulation of diffraction spectra from superlattices with interlayer coupling probability 0
Does High-Stakes Testing Increase Cultural Capital among Low-Income and Racial Minority Students?.

This article draws on research from Texas and Chicago to examine whether high-stakes testing enables low-income and racial minority students to acquire cultural capital. While students' performance on state or district tests rose after the implementation of high-stakes testing and accountability policies in Texas and Chicago in the 1990s, several studies indicate that these policies seemed to have had deleterious effects on curriculum, instruction, the percentage of students excluded from the tests, and student dropout rates. As a result, the policies seemed to have had mixed effects on students' opportunities to acquire embodied and institutionalized cultural capital. These findings are consistent with the work of Shepard (2000), Darling-Hammond (2004a), and others who have written of the likely negative repercussions of high-stakes testing and accountability policies.
Osteocalcin, Skeletal Alkaline Phosphatase, and Bone Mineral Content in Very Low Birth Weight Infants: A Longitudinal Assessment

Serum osteocalcin (Gla) and skeletal alkaline phosphatase (SAP) concentration both reflect osteoblast activity in the dynamic process of bone formation. To assess the relation in premature infants between change in bone mineral content (BMC) and both Gla and SAP serum concentration, we longitudinally measured BMC via photon absorptiometry and serum Gla and SAP concentration from birth to 16 wk in 20 very low birth weight infants. Serum total calcium, phosphorus, parathyroid hormone, and vitamin D metabolite concentrations were also monitored. All serum values were measured in the 20 mothers at delivery. Cord blood Gla concentrations were significantly (p less than 0.03) greater than maternal levels, and by 1 wk had significantly (p less than 0.001) increased from birth values. Total calcium, parathyroid hormone, phosphorus, and vitamin D concentrations remained in the normal range throughout the study. The increase in serum Gla concentrations, birth to 1 wk, were significantly correlated with the simultaneous increase in 1,25-dihydroxyvitamin D concentrations. The correlation between the change in BMC, however, over the first 4 mo of life and both Gla and SAP serum concentrations failed to reach statistical significance. Finally, a significant (p less than 0.003) negative correlation was measured between serum Gla and SAP concentrations at wk 4, and, although not significant, a consistently negative correlation was measured from 1-16 wk of age.(ABSTRACT TRUNCATED AT 250 WORDS)
DISPERSAL LIMITATION AND ENVIRONMENTAL HETEROGENEITY SHAPE SCALE‐DEPENDENT DIVERSITY PATTERNS IN PLANT COMMUNITIES

Understanding the large-scale distribution of species diversity requires distinguishing two of the primary factors that cause compositional differences: dispersal limitation and environmental variation. In a community with a naturally discontinuous spatial structure, we asked (1) at what scale(s) nonrandom variation in species composition occurs and (2) at what scale(s) such variation is associated with spatial separation, indicative of dispersal limitation, and at what scale(s) variation is associated with environmental heterogeneity? We sampled 50 seeps (small wetlands) on five serpentine outcrops. Using a randomization model, we showed that additive beta diversity (a measure of community dissimilarity) was lower than random within seeps and higher than random among both seeps and outcrops. Using Mantel tests, we showed that plant community dissimilarity, in both the full seep assemblage as well as in a subset of seep endemics, at the two larger scales was associated with different forms of environmental heterogeneity and, at the largest scale, was also associated with geographic distance. We conclude that diversity in this system is shaped by multiple scales of heterogeneity and by dispersal limitation at the largest scale.
The writing on the wall : The messages in Hungarian graffiti

L'etude de graffiti sur les murs de Szeged en Hongrie met en evidence un mode d'expression politique et culturelle. Certains symboles ou slogans vont a l'encontre de l'influence capitaliste anglaise et revelent des ideologies extremistes. Ces expressions variees revelent les contradictions et les ambiguites a l'egard non seulement du pluralisme politique, de l'emergence de plusieurs groupes economiques mais aussi des valeurs de l'expression culturelle : alors que pour les uns la presence occidentale est une menace, pour les autres il s'agit de la liberte de s'approprier des symboles culturels
Recovery of point defects in cold worked Au, Ag and Cu

Abstract The recovery of the electrical resistivity of polycrystalline, 99.999% pure Au, Ag and Cu, after deformation at −195°C, has been studied throughout the range from −100 to +200°C. The recovery curves after large deformations agree with those in the literature, showing the rather continuous recovery of the stages II, III and IV. However, after strains of a few percent or less, the isochronal curves reveal 4 well-separated stages which we have called a, b, c and d. With increasing strain stages b and c merge, making up stage III of Ag and Cu. In Au this stage is composed of the overlapping stages b, c and d. The migration energy, E , determined by the slope intersection method, increases from 0.4 to 0.8 eV, as recovery proceeds in stage III of Au. For Ag and Cu, the first part of this stage shows increasing E -values (0.2 to 0.5 eV for Ag and 0.5 to 0.7 eV for Gu), whereas the second part reveals a constant energy (0.55 ± 0.03 eV for Ag and 0.72 ± 0.03 eV for Cu). The activation energy for stage IV of Ag is 0.89 ± 0.06 eV. In Cu this stage is too small to determine the energy for the defect migration involved. In addition, it is shown that in the alloys Au + 4.64 at.% Cu, Au + 3.6 at.% Ag, Ag + 15.4 at.% Au and Cu + 3.92 at.% Au, the migration of the defects in the stages and d influences the degree of short range order. The present results are compared with literature data and it is concluded that the c and d defects are di- and single vacancies respectively. The concept of a uniquely activated, second order process for stage III of the noble metals, is criticized.
Opposition to Human Rights Treaties in the United States Senate: The Legacy of the Bricker Amendment

As we consider the status of the human rights covenants today, it would appear that the ghost of Senator John Bricker must be smiling at the fulfillment of his wish. Thirty years after the defeat of the Bricker Amendment, the covenants and most other major human rights treaties have yet to receive Senate approval.2 During the same period, these covenants have been ratified by eighty-five other nations, including fifteen Western democracies.3 The question which deserves our attention is why the United States has not ratified these treaties as well. The United States has long considered itself the leading protector of human rights. Many Americans consider the Declaration of Independence and its references to "inalienable rights" to be the source of reintroduction of basic human rights into the modern political
Faster fractal image compression using quadtree recomposition

In this paper, we present a fractal image compression algorithm employing a new quadtree recomposition (QR) approach. In this approach, quadtree subblocks of an image are iteratively recombined into larger blocks for fractal coding. For complex images, this approach exhibits superior runtime performance, when compared to a classical quadtree decomposition (QD) scheme, while maintaining high fidelity for reconstructed images. Quantitative results include an evaluation of attained compression ratios, runtime performance, and signal-to-noise ratios (SNR) for reconstructed images.
Evaluation of Ailanthus altissima as a Bioindicator to Detect Phytotoxic Levels of Ozone

Abstract Ozone is a common ground-level air pollutant that can be harmful to human health, vegetation, and ecosystems. Ailanthus altissima (Tree-of-Heaven) is an exotic, invasive tree species found across most of the US that has been suggested as a bioindicator to detect phytotoxic levels of ambient ozone. We conducted greenhouse exposures and field studies to evaluate the ozone-sensitivity of Tree-of-Heaven, including seedlings from several seed sources. Severity of ozone-induced foliar symptoms was directly related to ozone concentration and varied among seed sources. Tree-of-Heaven seedlings out-planted in the field developed foliar symptoms induced by ambient ozone levels at or near the national ambient air quality standard (NAAQS) for photochemical oxidants and ozone. Our results provide data that may be considered when setting new a NAAQS for photochemical oxidants and ozone.
Instability of the split-step method for a signal with nonzero central frequency

We obtain analytical conditions for the occurrence of numerical instability (NI) of a split-step method when the simulated solution of the nonlinear Schrodinger equation is close to a plane wave with nonzero carrier frequency. We also numerically study such an instability when the solution is a sequence of pulses rather than a plane wave. The plane-wave-based analysis gives reasonable predictions for the frequencies of the numerically unstable Fourier modes but overestimates the instability growth rate. The latter is found to be strongly influenced by the randomness of the signal’s profile: The more randomly it varies during the propagation, the weaker is the NI. Using an example of a realistic transmission system, we demonstrate that our single-channel results can be used to predict occurrences of NI in multichannel simulations. We also give an estimate for the integration step size for which NI, while present, will not affect simulation results for such systems. Using that estimate may lead to a significant saving of computational time.
Gustatory responses of priapulus caudatus de lamarck, 1816 (priapulida, priapulidae): Feeding behavior and chemoreception by a living fossil

Feeding behavior and chemoreception by the living fossil Priapulus caudatus is described and characterized by behavioral methods. Worms respond to chemical stimulation of the anterior circumoral field with a Stereotypic feeding reflex. This response is not elicited by tactile stimuli alone. Chemoreceptors appear to be restricted to the circumoral field since the feeding response is not evoked when other regions of the body are chemically stimulated. Priapulus caudatus fed only on tissues of macrobenthic species common to its habitat. Ingestion of both live and dead tissues, in addition to algae, indicates that P. caudatus is omnivorous in the Bay of Fundy region. This feeding strategy is adaptive for survival in the extreme environmental conditions characteristic of the niche occupied by P. caudatus.
Mental health treatment preferences of primary care patients.

Primary care patients were surveyed about emotional symptoms, treatment history, and treatment preferences. Four hundred and one patients completed questionnaires while waiting for appointments, and 271 (68%) mailed back additional materials. Many patients expressed a desire for help with the way they were feeling; understanding the cause of one's feelings was most commonly identified as likely to be helpful. Most preferred individual intervention. A range of attitudes and pragmatic concerns were barriers to seeking care. More patients said that they would likely to attend a fitness program than counseling, stress management, or healthy living classes. Distressed patients were more likely to say that they would seek medications and less likely to feel that they weren't the type to seek care or that they could work it out themselves. This work supports the need for continued patient education and for primary care-based mental health services that are responsive to patients’ preferences.
Neighborhood safety and social involvement: Associations with parenting behaviors and depressive symptoms among African-American and Euro-American mothers.

The relation between neighborhood characteristics and parenting and the mediating role of maternal depressive symptoms was examined among African American and Euro-American mothers of kindergarten children. Mothers' ratings of neighborhood safety were related to disciplinary strategies for both African American and Euro-American mothers but not to expressions of affection. Interviewers' ratings of safety were related to mothers' use of hostile socialization strategies. Both mothers' and interviewers' reports of safety were linked with maternal depressive symptoms. Depressive symptoms mediated the relation between neighborhood safety and inconsistent discipline, suggesting that the influence of safety on inconsistent discipline was due to its impact on maternal depression. Although there were similarities across ethnic groups, the relation between social involvement and mothers' withdrawal of interactions with their children differed across groups.
The descent of the antibody-based immune system by gradual evolution

The antibody-based immune system (AIS) is one of many means by which organisms protect themselves against pathogens and parasites. The AIS is present in jawed vertebrates (gnathostomes) but absent in all other taxa, including jawless vertebrates (agnathans). We argue that the AIS has been assembled from elements that have primarily evolved to serve other functions and incorporated existing molecular cascades, resulting in the appearance of new organs and new types of cells. Some molecules serving other functions have been appropriated by the AIS, whereas others have been modified to serve new functions, either after the duplication of their encoding genes or through the acquisition of an additional function without gene duplication. A few molecules may have been created de novo. The deployment and integration of the ready-made elements gives the impression of a sudden origin of the AIS. In reality, however, the AIS is an example of an organ system that has evolved gradually through a series of small steps over an extended period.
Effect of iron oxide removal on heavy metal sorption by acid subsoils

The adsorption of Cd, Cu, Pb, and Zn from 0.025 M NaClO4 solutions by two ferruginous subsoils, Christiana silty clay loam and Dothan sandy clay, was investigated. Under acidic conditions, selective dissolution and removal of the Fe oxide soil component by dithionite-citrate-bicarbonate (DCB) generally increased heavy metal adsorption by the soils. This effect was attributed to increased electrostatic attraction of cations to the DCB-washed soils as evidenced by substantial reduction in the zero point of charge (ZPC) for the Dothan soil following DCB extraction. Alternately, the DCB extraction stripped Fe and Al species bound to structural exchange sites or eliminated coatings which reduce cation accessibility to such sites. Addition of low levels (10−6 M) of ferric iron suppressed heavy metal adsorption capacity of the DCB-extracted Christiana soil to values comparable to the unmodified whole soil system. While hydrous oxide surfaces represent highly reactive sites for cation binding, Fe oxides can modify both the pH-dependent and structural exchange sites in a manner which hinders heavy metal adsorption. Thus, a soil's Fe-oxide content is unlikely to be a reliable guide to heavy metal adsorption capacity.
The Enzymes Of Glycogen Metabolism in the Various Cell Fractions from the Normal Human Epidermis

In the normal human epidermis, glycogen synthetase is sedimented with glycogen as is the glycogen synthetase D phosphatase which converts the D to the I form. Glycogen synthetase I kinase is not associated with glycogen. Phosphorylase is associated (sedimentable) with glycogen to a lesser extent and exists mainly in the b form. Phosphorylase b kinase is present in the normal human epidermis and it is not associated with glycogen under our experimental conditions.
Mie scattering of growing molecular contaminants

Molecular contamination of optical surfaces from outgassed material has been shown in many cases to proceed from acclimation centers and to produce many roughly hemispherical "islands" of contamination on the surface. The mathematics of the hemispherical scattering is simplified by introducing a Virtual source below the plane of the optic, in this case a mirror, allowing the use of Mie theory to produce a solution for the resulting sphere .in transmission. Experimentally, a fixed wavelength in the vacuum ultraviolet was used as the illumination source and scattered light from the polished and coated glass mirrors was detected at a fixed angle as the contamination islands grew in time.
Prognostic significance of human papillomavirus in oropharyngeal squamous cell carcinomas.

Objectives/Hypothesis: The human papillomavirus (HPV) has been identified as a causative factor in 20% to 25% of all head and neck squamous cell carcinomas (HNSCC). Ongoing research suggests that the presence of HPV DNA in HNSCC predicts a positive prognosis with respect to disease-free and overall survival. However, most studies have been limited by the heterogeneity in treatment regimens and/or anatomic subsites of tumor origin. In this study, we correlate clinical outcomes with HPV status for patients with oropharyngeal carcinomas who were uniformly treated with a concurrent chemoradiation treatment protocol. Study Design: Retrospective study. Methods: Demographic and clinicopathologic parameters, including age at diagnosis, gender, race, smoking and alcohol history, tumor stage and grade, locoregional recurrence, metastatic spread, recurrence-free survival, overall survival and disease-specific death, were obtained from medical charts and established databases. These parameters were correlated with HPV status of the tumors established by in situ hybridization analysis. Results: HPV positivity correlated with improved clinical outcomes regarding locoregional control (P = .042), recurrence-free survival (P = .009), overall survival (P = .017), and disease-specific death (P = .09). Advanced T stage was a significant risk factor for recurrence and death independent of HPV status. Conclusions: In patients with oropharyngeal carcinoma uniformly treated with chemoradiation, the presence of HPV is a favorable prognostic indicator with respect to recurrence and overall survival. However, advanced T stage was an independent risk factor for recurrence and death that can to some degree offset this benefit.
A zeta-potential model for ionic surfactant adsorption on an ionogenic hydrophobic surface

Abstract Adsorption of ionic surfactants on a hydrophobic surface (i.e., Nuclepore track-etched polycarbonate membranes, Nuclepore Corp., Pleasanton, CA 94566) is investigated using electrokinetics. Zeta potentials computed from streaming-potential measurements are used in conjunction with an ionogenic surface charge model to characterize, for the first time, the electrical nature of these membranes. The polycarbonate surface exhibits a low, negative surface charge density (ca. a maximum magnitude of 0.2 μC/cm 2 ) and is ionogenic in nature in that the charge develops by the hydrolysis of discrete carboxylic surface groups with an average p K s of 3.92. Electron spectroscopy for chemical analysis (ESCA) confirms the presence of carboxylic groups on the surface. Streaming-potential measurements are also made for the adsorption of cationic surfactants (alkyltrimethylammonium bromides) and an anionic surfactant (sodium dodecyl sulfate) as a function of solution pH, ionic strength, and surfactant concentration. The ionogenic model for the membrane surface is extended to include Langmuir specific adsorption of the surfactants in the submonolayer region. Agreement between the proposed surfactant adsorption model and the new zeta-potential data is excellent over the range of pH and surfactant concentration studied. The standard free energy of adsorption for dodecyltrimethylammonium bromide is found to be −7.9 RT with a maximum adsorption site density of 4.9 × 10 16 sites/m 2 . Likewise, the standard free energy for adsorption for sodium dodecyl sulfate is −8.6 RT with a maximum adsorption density of 1.3 × 10 16 sites/m 2 . These results, derived from electrokinetic measurements, are in good accord with accepted values (1–4).
Performance of three new-generation pulse oximeters during motion and low perfusion in volunteers

Abstract Study Objective To evaluate pulse oximeter performance during motion and induced low perfusion in volunteers. Design Prospective volunteer study. Setting Direct Observation unit. Subjects 10 healthy adult volunteers. Interventions Ten volunteers were monitored with three different pulse oximeters while they underwent desaturation to about 75% oxygen saturation (SpO 2 ) and performed machine-generated (MG) and volunteer-generated (VG) hand movements with the test hand, keeping the control hand stationary. Measurements SpO 2 and pulse rate readings from the motion (test) and stationary (control) hands were recorded as well as the number of times and the duration that the oximeters connected to the test hands did not report a reading. Sensitivity, specificity, performance index for SpO 2 , and pulse rate (PR) were calculated for each pulse oximeter by comparing performance of the test hand with the control hand. Main Results During both MG and VG motion, the Masimo Radical had higher SpO 2 specificity (93% and 97%) than the Nellcor N-600 (67% and 77%) or the Datex-Ohmeda TruSat (83% and 82%). The Masimo Radical also had higher SpO 2 sensitivity (100% and 95%) than the Nellcor N-600 (65% and 50%) or the Datex-Ohmeda TruSat (20% and 15%) during both MG and VG motion. During MG motion, the Masimo Radical had the lowest PR failure rate (0%) compared with the Nellcor N-600 (22.2%) and Datex-Ohmeda TruSat (1.3%). However, during VG motion, the Masimo Radical had the lowest SpO 2 failure rate (0%) of the three devices (Nellcor N-600 16.4% and Datex-Ohmeda TruSat 1.7%). Both the Masimo Radical and the Datex-Ohmeda TruSat had lower PR failure rates (0% and 4.4%) than the Nellcor N-600 (33.9%). There were no significant differences in SpO 2 or PR performance index between the three devices. Conclusions The Masimo Radical had higher SpO 2 sensitivity and specificity than the Nellcor N-600 and Datex-Ohmeda TruSat during conditions of motion and induced low perfusion in this volunteer study.
Concept learning in mentally retarded Ss using three types of verbal labels

Three groups of mentally retarded Ss learned a concept using verbal labels from different linguistic form classes. The group using verb labels required more trials to criterion than the noun-label or adjective-label groups. These findings were similar to those reported previously for three groups of normal children equal in mental age to the present Ss. Questions were raised concerning the relationship between learning and transfer in normal and mentally retarded Ss on tasks requiring different form-class labels.
Aortic dissection with aortopulmonary artery fistula.

A case of aortic dissection complicated by aortopulmonary artery fistula is reported. Aggressive diagnostic and surgical management was associated with a favorable, longterm outcome. © 1993 Wiley-Liss, Inc.
Computer mediated communications and developing countries

Abstract This article reviews Computer Mediated Communications (CMC), encompassing the technology and its evaluation, with emphasis on factors crucial to the introduction of this technology in developing countries. The discussion of some promising application areas for developing countries includes education, networks of specialists, international committees and trade groups, and crisis detection and management. Also included is a summary of factors important to fostering and evolving the utilization of CMC technology.
Engineering a new core

A diverse and technically literate core of graduates from engineering programs is needed now more than ever before to help serve, lead, and transform a troubled world. In order to prepare our engineering students to be effective and ethical professionals, citizens, and individuals, we have restructured our curriculum through a new core that offers a more effective and coherent experience, providing more opportunities for interdisciplinary, experiential, and civic education. This paper presents our approach to preparing engineering students to not only be proficient in engineering and science principles but to be aware of the interplay among science, technology, and society. We describe the core requirements and how we adapted our program to incorporate their learning objectives through a combination of exercises required in the Introduction to Engineering course they take in their freshman year in conjunction with their senior capstone design project.
Pulmonary Dirofilariasis: The Largest Single-Hospital Experience

Pulmonary dirofilariasis caused by Dirofilaria immitis, the dog heartworm, is a rarely reported pulmonary lesion. It most often appears as a solitary pulmonary nodule, often mistaken for a primary or metastatic lung tumor, and the diagnosis is not often established until thoracotomy with excisional lung biopsy is performed. Sporadic reports of pulmonary dirofilariasis in the United States total only 87 cases. The ten resections of pulmonary dirofilariasis at the Methodist Hospital in Houston, Tex, represent the largest reported series of cases originating at a single hospital. We present an overview of the pathogenesis of this disease, its clinical manifestations and epidemiologic features. The prevalence of pulmonary dirofilariasis appears to be increasing. Thus, surgeons and pathologists need to be aware of this etiology of granulomatous pulmonary lesions.
Character tables of p-groups with derived subgroup of prime order III

Abstract Two character tables of finite groups are isomorphic if there exist a bijection for the irreducible characters and a bijection for the conjugacy classes that preserve all the character values. We give necessary and sufficient conditions for two finite groups to have isomorphic character tables. In the case of finite p-groups with derived subgroup of order p, we show that the character tables can be classified by equivalence classes of certain homomorphisms of abelian p-groups.
Protein kinase C phosphorylates the synthetic peptide Arg-Arg-Lys-Ala-Ser-Gly-Pro-Pro-Val in the presence of phospholipid plus either Ca2+ or a phorbol ester tumor promoter.

Abstract The synthetic nonapeptide Arg-Arg-Lys-Ala-Ser-Gly-Pro-Pro-Val is a substrate for in vitro phosphorylation by a partially purified preparation of rat brain protein kinase C, with a Kmapp of about 130μM. The closely related peptide kemptide was a much weaker substrate, bovine serum albumin was not a substrate and the peptide Arg-Arg-Lys-Ala-Ala-Gly-Pro-Pro-Val was a weak inhibitor of the enzyme. Protein kinase C-catalyzed phosphorylation of histone III-S and the nonapeptide are regulated by identical mechanisms since with both substrates the reaction required added phospholipid and either Ca2+ (1mM) or TPA (200 nM TPA). Our findings show that polypeptides containing multiple basic residues followed by the sequence Ala-Ser can be substrates for TPA-stimulated phosphorylation by protein kinase C.
Resonant sum-frequency generation in chiral liquids

Sum-frequency generation in chiral liquids is conclusively demonstrated. Enhancement through both electronic and vibrational resonances is observed, providing a novel spectroscopic method for probing molecular chirality. Although the process is electric-dipole allowed, the signal strength is rather weak. This can be understood from the physical mechanism that leads to the chiral nonlinearity.
Influence of ammonia fertilization on cotton production in conservation tillage systems

Abstract Field studies were conducted to determine the influence of ammonia fertilization on cotton grown in conservation tillage systems. The studies were located on a Decatur silt loam (Rhodic Paleudult) in the Limestone Valley and a Norfolk sandy loam (Typic Paleudult) in the Coastal Plain of Alabama. Winter annual legumes, crimson clover (Trifolium incarnatum L. at the Norfolk site) and hairy vetch (Vicia villosa Roth at the Decatur site) were established as whole plots along with a winter fallow area. Sources of fertilizer differing widely in their NH4+‐N contents were used for split plot treatments applied at time of cotton (Gossypium hirsutum L.) planting. Fertilizer treatments included calcium nitrate, ammonium nitrate, urea, urea with dicyandiamide, and a no N check. The cotton was planted with a strip‐till conservation planter. Nitrogen production by winter legumes was adequate to meet N requirements for cotton on the Decatur silt loam (67 kg N/ha) but not at the Norfolk sandy loam site (101 kg ...
Social systems analysis II

Abstract We argue that there are 4 basic solution concepts for 2 × 2 symmetric games and corresponding to these, 4 basic human interactions and 4 types of societies. We propose a model in which the type of interaction is predicted by independence, inequality of power, communication, and mutuality of interests. We prove theorems classifying Moulin's inessential games in the case of an interior Nash equilibrium and argue that this explains coalition formation. We discuss classification of socially significant ideologies.
"Internet in a Box": Augmenting Bandwidth with the eGranary Digital Library

In terms of information access, the internet and the World Wide Web hold forth a historically unique chance for African universities to gain a more equal footing with their sister institutions in the West, yet most African universities are many years, possibly decades, away from reliable, robust ICT and adequate bandwidth. This paper will examine the ways in which the dearth and expense of bandwidth in Africa, in spite of heavy donor investment, pose a structural disincentive for the digitization of local content. It highlights the human and technical hurdles that face librarians. Finally, it reviews the potential role that bandwidth augmentation schemes, like the WiderNet Project's eGranary Digital Library, have to play in the sustainability of digital library development on campuses around Africa and in the rest of the developing world.
Harmonic imaging with gas‐filled microspheres: Initial experiences

The introduction of safe and efficacious ultrasound contrast agents, which significantly enhance the backscattered signals, has allowed previously inaccessible areas of slow flow to be imaged. However, imaging organ perfusion or small deep-lying vessels remains difficult. The ability of harmonic imaging to resolve these problems has been investigated. Harmonic imaging uses the nonlinear properties of microbubble-based agents by transmitting at the fundamental frequency but receiving at the second harmonic. In vitro measurements revealed a harmonic response 15 dB below the fundamental for a driving frequency of 2.5 MHz at an acoustic pressure of 50 kPa for one particular contrast medium. In vivo, two different gas-filled microbubble agents were administrated to 10 dogs and three rabbits. Three different scanners were used to obtain images of kidneys, liver, heart, and vessels in harmonic and conventional gray-scale, pulsed Doppler, and color Doppler modes. Enhancement lasted significantly longer in harmonic than in conventional modes (94 s; P = 0.00003). Harmonic images were less susceptible to artifacts, such as acoustic shadowing, and a wider range of dosages could therefore be used. A clear increase in the (flow) signal-to-clutter ratio was observed. Harmonic images were, however, very dependent on focal zone settings. These preliminary results demonstrate the potential of contrast-enhanced harmonic imaging, but further studies are required to establish clinical efficacy. © 1997 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 8, 69–81, 1997
Comparison of the masses of he and h1 on a mass-spectrograph☆

Abstract The ratio of the masses of He : Ht was measured by comparison of He++ with H21+ on fourteen spectra, and the measurements give He : H1 = 3.971283 ± 0.000042. If He = 4.00216 ± 0.00013 on the O16 scale as given by Aston, then H1 = 1.007775 ± 0.000035 in excellent agreement with the value 1.00778 reported by Aston. A method is suggested for the determination of the mass of H2 in terms of He and C.
Influence of Natural Dissolved Organic Matter, Temperature, and Mixing on the Abiotic Hydrolysis of Triazine and Organophosphate Pesticides

Abiotic hydrolysis of simazine, atrazine, diazinon, methylparathion, and chlorpyrifos was studied in three different natural waters and buffered Milli-Q water. The triazines showed no detectable decrease in concentration in any of the waters over 43 days at pH 8.0 and 40 °C. The rates of hydrolysis for diazinon and methylparathion were statistically similar in all waters tested. Chlorpyrifos exhibited a ∼32% decrease in hydrolysis rate in the presence of a high concentration of dissolved organic matter (DOM) (34.5 mg/L dissolved organic carbon). The activation energies are larger, and thus the predicted hydrolysis rates are significantly slower than those previously reported. The effect of continuous vigorous mixing on hydrolysis rates was investigated and found to have only a minor effect. The results suggest that uncatalyzed abiotic hydrolysis is very slow for these compounds at the temperatures and pH's typical of most natural waters and affirm the need for a greater understanding of the relative influence of DOM, catalysis, and biodegradation on the fate of organophosphate and triazine pesticides.
Nonprofit Organizations as Inter‐regional Actors: Lessons from Southern Growth

Nonprofit organizations involved in improving a region's economic, political, and social situations must deal with a unique set of circumstances. The “collective good” aspect of regional economic development necessitates that nonprofit organizations such as the Southern Growth Policies Board include actors from the public, private, and nonprofit sectors. Regional actors from these three sectors occupy important positions in the Southern Growth Policies Board's organizational structure and play important roles in guiding and supporting the organization's regional development initiatives. While the actions of individual states and political actors sometime undermine the collective development of the South, the Southern Growth Policies Board serves as a nexus that facilitates a regional discourse on economic development.
DRUG PARTITIONING. II. IN VITRO MODEL FOR DRUG ABSORPTION.

An in vitro model to simulate some factors involved in the absorption process is described. It consists of a tube containing two aqueous phases separated by an immiscible phase. A rocking apparatus agitates the fluids while causing the liquid interfaces to expand and contract. Rates of drug transfer and equilibrium drug distribution were determined under conditions where one aqueous phase was maintained at pH 7.4 and the other buffered at various pH values. Salicylic acid, barbital, antipyrine, aminopyrine, and tetracycline were studied in this manner. The initial drug transfer simulated a first-order rate process. Results of the equilibrium studies are in general agreement with predictions of the pH-partition theory. Tetracycline did not undergo transfer from one aqueous phase to the other at any pH condition of the study.
Social sciences research: ethical and policy implications.

Ethical issues are raised about the conduct of social research in the dental field particularly with respect to the use of survey methodology and aggregated data. Problems associated with respondent identifiers, open-ended and probing questioning, privacy of subject-matter, community contamination and burden, group stereotyping, knowledge of law violations, mis-use of data banks, re-use of data, effects of disclosure, and referral for treatment are discussed. The natural and the contrived social experiments are reviewed as well as the issue of needed research on the effects of regulation on science and on the protection of privacy. Language: en
Seroprevalence of pathogens in domestic carnivores on the border of Madidi National Park, Bolivia

The importance of diseases of domestic animals in the conservation of wildlife is increasingly being recognised. Wild carnivores are susceptible to many of the pathogens carried by domestic dogs and cats and some of these pathogens have caused disease outbreaks and severe population declines in threatened species. The risk of disease spillover from domestic to wild carnivores in South America has not been extensively investigated. This study examined the disease exposure of domestic carnivores living near a protected area in Bolivia. Forty dogs and 14 cats living in three towns on the eastern border of Madidi National Park were sampled. High levels of exposure to canine distemper virus, canine parvovirus, Sarcoptes scabiei and Toxoplasma gondii were found among domestic dogs, with similarly high levels of exposure to feline parvovirus, feline calicivirus and T. gondii being found among domestic cats. If contact occurs between domestic and wild carnivores, disease spillover may represent an important risk for the persistence of wild carnivores in the region. Additional research is therefore necessary to determine if wild carnivores living in proximity to these domestic carnivore populations are being exposed to these pathogens.