cssi/SciSciGPT-SciSciNet huggingface dataset:
Chemical kinetics and mass transport effects in solution-based selective-area growth of ZnO nanorods

We present a combined experimental and modeling study of the dependence of solution-based zinc oxide (ZnO) selective-area growth rates on pattern dimension. Selective growth is achieved by patterning a portion of the substrate with an organic template that inhibits growth. The density of ZnO nanorods and the mass grown per unit area of exposed surface increases as the distance between the exposed growth regions is increased and as the width of the exposed lines is decreased. A 2-D model was developed to calculate selective growth at the exposed surface regions, the loss of reactant material due to a competing reaction in solution, liquid-phase and surface diffusive mass transport to (or on) the growth surface, and the ZnO growth reaction at the surface. To explain the experimental results, we found it necessary to include a reaction by-product in the chemistry model, the desorption of which is the rate limiting step. A relatively simple, three-step reaction mechanism, combined with the species mass transport model, provides a good, semi-quantitative description of the experimental observations in the selective-area growth of ZnO from supersaturated solutions.
Long-Term Corn Residue Effects

A better understanding of C turnover, with estimates of root-derived C, is needed to manage soil C sequestration. The objective was to evaluate the long-term treatment and environmental effects on unharvestable soil C components. Two N fertilizer treatments and a control were imposed during 29 yr of continuous corn (Zea mays L.) with stover removal as silage vs. stover return during grain harvest with moldboard plow (MB) tillage. Soil organic carbon (SOC) declined and natural 13 C abundance (δ 13 C) increased during the 29-yr period. Field averages of SOC and δ 13 C (0-30 cm) were 96.4 Mg ha -1 and -17.3‰ in 1965; respective values in 1995 were 78.9 Mg ha -1 and -16.6%o. Loss of SOC was greater with stover removed or no fertilization, but δ 13 C increased for all treatments. Stover yield (SY), SOC, and δ 13 C data were applied to a model to estimate unharvestable C and predict total source C (SC) input from corn. The SC for 29 yr totaled 172 to 189 Mg ha -1 when stover was harvested and 268 to 284 Mg ha -1 when stover was returned. The SC input from unharvestable sources was 1.8 times more than SC from aboveground stover when N was added and 1.7 when N was not added. The root-to-shoot ratio was 1.1 when N was added and 1.2 with no N. Only 5.3% of the SC was retained as SOC. Unharvestable C contributions to rhizodeposition are much larger than suggested from controlled studies including C-enriched CO 2 followed by soil respiration or CO 2 efflux measurements.
FMRFamide- and pancreatic polypeptidelike immunoreactivity of endocrine cells in the midgut of a mosquito

Immunocytochemical surveys of midguts from female mosquitoes, Aedes aegypti, reveal that half of the estimated 500 endocrine cells in a midgut contain a substance recognized by antisera to bovine pancreatic polypeptide and a molluscan peptide, FMRFamide (phenylalanine-methionine-arginine-phenylalanine-amide). With light microscopy the cells resemble an endocrine type because of their basal position in the epithelium, conical shape, and, in some instances, apical extensions to the lumen. At the ultrastructural level, the immunoreactive substance is contained specifically within the secretory granules of such cells. Immunoreactive cells are distributed exclusively in the midgut region where blood is stored, and ingestion of vertebrate blood reduces the number of such cells and the intensity of reaction in others. These two facts suggest that a blood meal stimulates release of the immunoreactive substance from the cells. Since the immunocytochemical localization is supplemented by a demonstrated secretory response, the cells are considered to be peptidergic endocrine cells.
Three-stage approaches for optimizing some variations of the resource constrained shortest-path sub-problem in a column generation context

This paper presents a unified three-stage approach (TSA), comprising preprocessing, setup, and iterative solution stages, for solving several variations of the resource constrained shortest-path problem (RCSP). TSA is designed specially for column-generation applications in which sub-problems must be solved repetitively. The first two stages are implemented one time and only the third stage need be applied repetitively. In a companion paper, the authors proposed a TSA for solving RCSP on an acyclic graph with upper bound resource-limitation constraints. This paper shows that a TSA can be designed to solve each of several related problems: shortest-path with equality resource-limitation constraints; shortest-path with resource windows; resource-constrained, k-shortest path; and multiple-resource, multiple-choice knapsack. A numerical example demonstrates application of a TSA to design an international assembly system and its supply chain using branch and price with multiple-choice knapsack sub-problems. Computational results show that our TSA can solve this sub-problem effectively in such a column-generation environment.
Comparison of cell-free protein synthesis by different regions of chicken brain

The cell-free protein synthesis by the postmitochondrial supernatant from chicken cerebrum was twofold greater than protein synthesis by the cerebellum or optic lobes. Ribosomal aggregation of mRNA and ribonuclease activity of the postmitochondrial supernatant from the three brain regions was not statistically different. The higher protein synthetic activity of the cerebral postmitochondrial supernatant was associated with both the postribosomal supernatant (cell sap) and microsomal fractions. Cerebral monomeric ribosomes were more active in polyuridylic acid directed polyphenylalanine synthesis than monomeric ribosomes from either the cerebellum or optic lobes. The ability of cerebral cell sap to support polyuridylic acid directed polyphenylalanine synthesis was 1.6 to 2 times greater than cell sap from the other two regions. Cell sap factors other than tRNAphe or phenylalanyl-tRNA synthetases appear to be responsible for the higher protein synthetic activity of the cbr cell sap.
Small angle X-ray scattering from block polymers. II. The bulk state

The basic theory of X-ray scattering is applied to various hypothetical models for the bulk state of block polymers in order to explain the angular dependent scattering. The intensity of scattering is calculated for a rnicellar model, a zone model, and a molecular dumbbell model. The molecular dumbbell model, in contrast to the micellar and zone models, assumes that a block copolymer containing domains may be treated as one giant molecule and that, therefore, the locations of the domains are not random but are governed by the statistics of the segments which interconnect them. Experimental and calculated scattering curves are compared for several different types of block polymers.
Arthropathy of Lowe's (Oculocerebrorenal) Syndrome

We describe 3 children with Lowe's syndrome who developed joint manifestations--a previously rarely recognized feature. Two children had swelling and contractures of large and small joints; the third child had a small joint effusion and hypermobile joints. None of them had antinuclear antibody or rheumatoid factor; synovial effusions and biopsies showed no evidence of inflammatory cell infiltration. By light microscopy, profuse fibrous tissue and sparse synovial lining cells were found. Electron microscopy of the synovium of 2 patients showed large amounts of normal appearing collagen, unidentified thin fibrils, and focal profuse granular and fibrillar basement membrane-like material around small vessels, similar to findings described in other tissues in this syndrome. Whether these clinical and pathologic findings are results of the still incompletely understood basic metabolic defect or not, they should be recognized as features that may be seen in patients with Lowe's syndrome.
Restoring abandoned pasture land with native tree species in Costa Rica: Effects of exotic grass competition and light

Abstract Understanding the early establishment requirements and performance of tropical tree seedlings is essential to ensuring the success of restoration plantings. This study was designed to characterize growth and light requirements of six common neotropical tree species Pseudosamanea guachapele (Fabaceae), Tabebuia impetiginosa (Bignoniaceae), Ceiba pentandra (Bombacaceae), Pachira quinata (Bombacaceae), Dalbergia retusa (Fabaceae), and Tabebuia rosea (Bignoniaceae) in an abandoned pasture under contrasting light environments and grass competition. Field studies were conducted in the pastures of the Santa Ana Conservation Center in Costa Rica. Two differing grass competition sites were selected, one dominated by a tall grass, Hyparrhenia rufa and another dominated by a short grass, Cynodon mlenfluensis . Three light treatments were created (2, 37 and 100% light) using either neutral shade cloth (2 and 37%) or no shade cloth (100%). Growth characteristics and biomass partitioning of the seedlings were measured. Species differed in their relative growth rates (RGRs). The light × species interaction was significant at both sites. While all species had similar performance under 100% light on both short grass and tall grass sites, species growth differences were evident under 37 and 2% light levels. For example, at the short grass site, T. rosea had higher RGR than D. retusa and P. quinata under 2% light whereas both Tabebuia species performed better than other species at the tall grass site. The general trend was to increase root mass ratio and decrease leaf mass ratio with increasing levels of light. As an initial step for restoring abandoned pasture lands we recommend using all these species in direct and moderate light conditions. Incorporating all species will create a more heterogeneous environment. Choosing light demanding species that can tolerate grass competition may help ensure success in the early stage of restoration.
A Single Mutation in the Non-Amyloidogenic Region of IAPP Greatly Reduces Toxicity

While the disruption of cellular membranes by prefibrillar states of amyloid proteins is a likely cause of cell-death during amyloid-related diseases, research has been hampered by the complex nature of the aggregation process. The 1-19 fragment of IAPP, a peptide implicated in beta-cell death during type 2 diabetes, is particularly informative for mechanistic studies on amyloid prefibrillar states as it forms toxic oligomers when bound to the membrane but does not progress further to form amyloid fibers. Human IAPP1-19 causes a rapid increase in beta-cell islet intracellular calcium levels indicative of a loss of beta-cell membrane integrity. The toxicity of IAPP may be linked to the induction of curvature in the membrane. Solid-state NMR and DSC show that toxic versions of IAPP stabilize negative curvature, while the non-toxic full-length rat IAPP peptide does not. Despite a difference of only one residue from hIAPP1-19 (H18R substitution), the rat version of the IAPP1-19 peptide is significantly less toxic both in vitro and in vivo. This difference is reduced at higher peptide to lipid ratios, suggesting that the self-association of rIAPP1-19 within the membrane is impaired. The toxicity difference can be traced to the difference in charge at residue 18. At pH 6.0, membrane disruption by hIAPP1-19 is significantly reduced and becomes equivalent to that of rIAPP1-19. DSC shows that while hIAPP1-19 has a minimal effect on the phase transition of lipid vesicles, rIAPP1-19 has a strong effect, indicating a surface-associated topology for rIAPP1-19 and a transmembrane topology for hIAPP1-19 ; a result in agreement with NMR quenching studies. Our results indicate that the modulation of the peptide orientation in the membrane by His18 plays a key role in the toxicity of hIAPP by altering the interaction with the membrane.
Collapse and recovery of green fluorescent protein chromophore emission through topological effects.

Housed within the 11-stranded β-barrel of the green fluorescent protein (GFP) is the arylideneimidazolidinone (AMI) chromophore, the component responsible for fluorescence. This class of small-molecule chromophore has drawn significant attention for its remarkable photophysical and photochemical properties, both within the intact protein and after its denaturation. All of the proteins so far isolated that have visible light fluorescence have been found to contain an AMI chromophore. These proteins comprise an extensive rainbow, ranging from GFP, which contains the simplest chromophore, p-hydroxybenzylideneimidazolidinone (p-HOBDI), to proteins having molecules with longer conjugation lengths and a variety of intraprotein interactions. The fluorescence invariably almost vanishes upon removal of the protective β-barrel. The role of the barrel in hindering internal conversion has been the subject of numerous studies, especially in our laboratories and those of our collaborators.A better understanding of thes...
Species-typical songs in white-crowned sparrows tutored with only phrase pairs

Modern theories of learned vocal behaviours, such as human speech and singing in songbirds1, posit that acoustic communication signals are reproduced from memory, using auditory feedback2. The nature of these memories, however, is unclear. Here we propose and test a model for how complex song structure can emerge from sparse sequence information acquired during tutoring. In this conceptual model, a population of combination-sensitive (phrase-pair) detectors is shaped by early exposure to song and serves as the minimal representation of the template necessary for generating complete song. As predicted by the model, birds that were tutored with only pairs of normally adjacent song phrases were able to assemble full songs in which phrases were placed in the correct order; birds that were tutored with reverse-ordered phrase pairs sang songs with reversed phrase order. Birds that were tutored with all song phrases, but presented singly, failed to produce normal, full songs. These findings provide the first evidence for a minimal requirement of sequence information in the acoustic model that can give rise to correct song structure.
The Comparative Effects of Compensatory and Noncompensatory Two-Dimensional Data on Unidimensional IRT Estimates

This study compared the effects of using a unidi mensional IRT model with two-dimensional data gener ated by noncompensatory and compensatory multidi mensional IRT models. Within each model, simulated datasets differed according to the degree of correlation between two vectors of θ parameters, ranging from 0 to .95. Results showed that the number-correct distri butions for each group of datasets were generally comparable, although factor analyses of tetrachoric correlations suggested that differences existed in the structure of the data from the two models. For the uni dimensional parameter estimates, it was found that the â values from the noncompensatory model appeared to be averages of the a1 and a2 values, while the â values from the compensatory model were best considered as an estimate of the sum of the a1 and a2 values. Con versely, the b values for the noncompensatory data were consistently greater than the b1 values, while the b values from the compensatory model were best con sidered as the aver...
Kinetics of A+B-->0 with driven diffusive motion.

We study the kinetics of two-species annihilation A+B\ensuremath{\rightarrow}0 when all particles undergo strictly biased motion in the same direction and with an excluded volume repulsion between same species particles. It was recently shown that the density in this system decays as ${\mathit{t}}^{\mathrm{\ensuremath{-}}1/3}$, compared to ${\mathit{t}}^{\mathrm{\ensuremath{-}}1/4}$ density decay in A+B-g0 with isotropic diffusion and either with or without the hard-core repulsion. We suggest a relatively simple explanation for this ${\mathit{t}}^{\mathrm{\ensuremath{-}}1/3}$ decay based on the Burgers equation. Related properties associated with the asymptotic distribution of reactants can also be acounted for within this Burgers equation description.
Bilinear Transformations Applied to the Tuning of the Output Network of a Transmitter

The literature on the proper tuning of the output network of a class-C power amplifier inductively coupled to a load is surprisingly meager and, in general, there seems to exist considerable confusion concerning the relation between the following three conditions: (a) Resonance of the secondary circuit (b) Maximum-minimum point of average plate current (c) Maximum coupled circuit efficiency. This state of affairs is probably due in large part to the complexity of mathematics involved in a straightforward analysis of the circuits involved. In this paper we have employed the powerful theory of bilinear transformations in a complex plane, for which circles are transformed into circles, to determine the actual value of the secondary capacitance for a maximum-minimum of average plate current and for maximum coupled circuit efficiency. The results of this investigation show that (b) and (c) differ widely from (a)-except for the case of a series load in the secondary circuit. Moreover, although (b) may differ considerably from (c), these two conditions are indistinguishable if the Q of the primary coil is large, and the coefficient of coupling is very small.
Identity, Institutions, and War: A New Look at South Asian Rivalry

The Idea of Pakistan. By Stephen P. Cohen. Washington DC: Brookings Institution Press, 2004. 382 pages. Cloth, $32.95. Pakistan: Between Mosque and Military. By Husain Haqqani. Washington DC: Carne...
Deuterium in the early solar system

An attempt is made to construct a self-consistent picture of the deuterium abundance in the early solar system based on the assumption of chemical equilibrium in the solar nebula. A recent determination of the D/H ratio for the atmosphere of Jupiter is consistent with a previous estimate of the D/H ratio for the protosun. The high (greater than .00015) D/H ratios determined from analyses of carbonaceous meteorites imply an equilibrium temperature less than 270 K, in marked disagreement with the equilibrium temperature determined for the same material by oxygen isotope cosmothermometry.
Cytosolic free calcium in chick heart cells its role in cell injury

The role of cytosolic free Ca 2+ (Ca f ) in cell injury was investigated using two methods for measuring Ca f in freshly disaggregated embryonic chick heart cells. The null-point method, using arsenazo III, is based on determining the extracellular Ca 2+ concentration at which no net Ca 2+ movement occurs when plasma membrane permeability is increased. With this technique, the null point Ca f averaged 0.23±0.07 μ m ( n =6) in the basal state. Using quin2, an intracellular fluorescent dye, to measure Ca f a value of 0.05±0.01 μ m ( n =5) was obtained. Elevation of Ca f by various agents was associated with an increase in cell injury as measured by the release of the cytosolic enzyme, LDH. However, the relationship between Ca f and LDH release was not a direct one under all experimental conditions, indicating that the level of Ca f is not the sole determinant of cell injury.
Effects of hypoxic and aerobic incubation on lipogenesis from [U-14C]glucose in sections of normal and atherosclerotic aorta from the rabbit

Abstract Lipogenesis from [U-14C]glucose was measured during hypoxic and aerobic incubation of sections of rabbit aorta. The studies were designed to determine the in situ lipogenic capabilities of each portion of normal and atherosclerotic aorta to provide further insight into the source of the lipids that accumulate during atherosclerosis. Sections of atherosclerotic lesions (AL) incorporated more radiosubstrate into lipids than any other sections and this incorporation was increased under hypoxic conditions. AL had greater synthetic capacity than atherosclerotic adventitia (AA), and both were greater than the media (AM) between the lesion and adventitia. AM was not significantly different from the intima + media from normal rabbit aorta. It was concluded that AL has sufficient capabilities for lipogenesis to account for lipid accumulation exclusive of any AA contributions; accumulation in vivo would represent both this de novo synthesis in situ plus exogenous lipid available to the atherosclerotic intima from the blood supply. Within AL, the synthesized triglycerides had 55 to 60% of the radioactivity present in the phospholipids even though the absolute concentrations of triglycerides were only 5% that of the phospholipids. This indicates an active metabolic role for triglycerides without net accumulation and this metabolism is increased during hypoxic conditions.
Genetics of epithelial polarity and pattern in the Drosophila retina

This review is focused on recent advances in our understanding of the development of coordinated cell polarity, through experiments on the Drosophila compound eye. Each eye facet (or "ommatidium") contains a set of eight photoreceptor cells, placed so that their rhabdomeres form an asymmetric trapezoid. The array of ommatidia is organized so that these trapezoids are aligned in two mirror-image fields, dorsal and ventral to the eye midline (or "equator"). The development of this pattern depends on two systems of positional information that inform the cluster of cells that will form an ommatidium of anterior/posterior (a/p) and dorsal/ventral (d/v) direction. The former (a/p) is encoded by a progressive wave of development (the morphogenetic furrow). The latter (d/v) involves molecules known to act in tissue polarity in other organs and organisms. Our understanding of the function of these molecules rests not only on their mutant phenotypes, biochemistry, and expression patterns, but also on the spatial effects when mutant patches of cells are made (genetic mosaics).
Global solutions to problems in the classic theory of static dislocations

Abstract Problems in the classic theory of static dislocations are shown to be well posed and solvable whenever an associated elasticity problem is well posed and solvable. The presence of nonzero distributions of dislocation density show up in distributions of body forces for the associated elasticity problem. The body forces for the associated elasticity problem are explicitly computed in terms of the dislocation distributions. If the assigned distributions of dislocation density have compact support, the anelastic parts of the stress and strain tensors are shown to decay like r−1 in regions where the dislocation densities all vanish. The straight screw dislocation problem is solved explicitly. The solution agrees exactly with the classical solution outside the dislocation core. Since the total stress, strain, and elastic displacement fields are also explicitly determined inside the dislocation core in terms of the assigned distribution of dislocation densities, the solution is global. Although the total elastic displacements are shown to vanish everywhere, evaluation of the distortion outside the dislocation core leads to effective anelastic displacement functions that agree with the Volterra solution. All physically relevant quantities are determined globally (both inside and outside the dislocation cores), while the effective anelastic displacement functions only exist in regions where all of the dislocation densities vanish.
A map of the distal region of the long arm of human chromosome 21 constructed by radiation hybrid mapping and pulsed-field gel electrophoresis.

Abstract We have used radiation hybrid (RH) mapping and pulsedfield gel electrophoresis (PFGE) to determine the order and positions of 28 DNA markers from the distal region of the long arm of human chromosome 21. The maps generated by these two methods are in good agreement. This study, combined with that of D. R. Cox et al. (1990, Science 250:245–250), results in an RH map that covers the long arm of chromosome 21 (21q). We have used a subtelomeric probe to show that our map includes the telomere and have identified single-copy genes and markers within 200 kbp of the telomere. Comparison of the physical and RH maps with genetic linkage maps shows “hot spots” of meiotic recombination in the distal region, one of which is close to the telomere, in agreement with previous cytogenetic observations of increased recombination frequency near telomeres.
AUTHENTIC OR NOT, IT'S ORIGINAL

I am a literary critic who grew up in a household almost empty of books but often filled with food. The formative years of my life were spent cooking with my mother in the kitchens of restaurants w...
The problem of reconstruction in potential persistent malignancy; a foresight saga.

Summary 1.A case is reported of basal-cell epithelioma of the nose and cheek, proven at 18 years, starting from a burn in infancy. Ineffectually treated for eight years with heavy irradiation elsewhere, the patient was under the writer's personal observation and care for nineteen years, with apparent elimination by excision on four occasions, and with three reconstructions of the nose and cheek, the last being eight and a half years ago with no signs of reappearance. Reappearance of tumour was believed to be a new malignant growth as a late effect of irradiation. 2.Irradiation may (a) cure the disease, (b) imprison tumour cells that may later become active, or (c) stimulate tissues to neoplastic growth. Tissue that has been irradiated is more difficult to cure and more difficult to repair. 3.In a large majority of instances adequate surgical excision followed by plastic surgical repair is preferable to treatment by irradiation, as the excised tissue can be examined for adequacy of margin, and there will be no sequel˦ of irradiation, such as discomfort to the patient, damage to the tissues, and stimulus of neoplastic activity. 4.If surgery is used in malignancy of the face the excision should be sufficiently wide at the first attack to remove all of the tumour. This should be checked by localised specimens and a competent pathologist. 5.Immediate reconstruction may be started at the operation of excision if the diseased area is small, does not involve structures that cannot be readily repaired, and has not been previously treated, particularly by irradiation. 6.Where the tumour is possibly scattered over a considerable area, has been previously unsuccessfully treated, particularly by irradiation, where skeletal structures and the nasal and oral cavities are involved, and where there is a question of adequacy of excision, coverage of the defect by thick tissues should be delayed until adequate time has elapsed to warrant a definitive reconstruction. Thin skin grafts may be applied to close over the defects in the interim so that these areas can be under observation for the appearance of any neoplastic growth. 7.The surgeon who makes the repair should be the surgeon who excises the diseased tissue, provided he has the training and ability to do both. He should be safer because he can afford to be adequately radical. With his choice of possible pre-excisional procedures, the immediate application of flaps and free skin grafts, he may speed repair, avoid discomfort for the patient, and facilitate later reconstruction. 8.It is not always possible to have the foresight to anticipate all eventualities in complicated cases.
Modeling culturally authentic style shifting with virtual peers

We report on a new kind of culturally-authentic embodied conversational agent more in line with the ways that culture and ethnicity function in the real world. On the basis of the careful analysis of a corpus of verbal and nonverbal behavior, we found that children shift dialects and ways of using their body depending on social context and task. Based on these results, we implemented a culturally authentic African American virtual peer capable of "code-switching" between African American English and Mainstream American English, and of using nonverbal behavior differently, depending on context. An evaluation of the agent revealed that the virtual peer elicited the same style changes in real children as real children did in one another.
The Practice of Educational Leadership in African American Communities of Learning: Context, Scope, and Meaning

This article provides a synthesis that delineates the scope and context that give meaning, purpose, and setting to the exercise of effective educational leadership and to the attainment of meaningful student achievement within schools that serve large numbers of African American students. Historical, theoretical, and empirical frames of inquiry provide the background for understanding good leadership and leadership practices that address the learning needs of African American students. Understanding the interconnectedness of good leadership and cultural practices that support and sustain African American student achievement are to be found through an awareness of the unique framework of cultural uplift and interpersonal and institutional caring, hallmarks that have characterized effective school leadership and student achievement in African American learning communities.
Preparing for digital curation governance: educating stewards of public information

We report results of research into curriculum development for dual degree programs and the development of a dual degree curriculum jointly undertaken by the University of North Carolina's School of Information and Library Science (SILS) and School of Government (SOG). This IMLS-funded program provides training in public information stewardship to four cohorts of eighteen masters' level students. The curriculum development rests upon previous curriculum development projects, examination of masters' programs throughout the world, semi-structured interviews of public sector information experts, recommendations from an expert Advisory Board, and focus group responses from current and alumni project Fellows.
Spectroscopy of some infrared-transmitting waveguides for sensor and laser applications

Spectral attenuation measurements were obtained on some JR transmitting waveguides to evaluate their applicability for remote sensing and laser power delivery. Since there is such a wide variety of applications for fiber optics in these areas, it is important to evaluate materials with various physical and optical properties. Three categories of waveguides where analyzed: glass, crystalline, and hollow tubes. A fluoroaluminate glass optical fiber was fabricated and the attenuation was considerably higher (102103 times higher) than the more common ZBLAN fluoride optical fibers. A Te-Se-Br glass optical fiber was evaluated and it exhibited an extended JR edge to approximately 14 rim. Attenuation measurements were conducted on single crystal sapphire, silicon, KRS-13, and KBr core/KC1 clad optical fibers. The spectral characteristics of alumina, silica glass, and mullite hollow waveguides were also determined, and all measurements were obtained using a Fourier Transform Infrared Spectrometer.
Magnesium isotope fractionation in silicate melts by chemical and thermal diffusion

Abstract Two types of laboratory experiments were used to quantify magnesium isotopic fractionations associated with chemical and thermal (Soret) diffusion in silicate liquids. Chemical diffusion couples juxtaposing a molten natural basalt (SUNY MORB) and a molten natural rhyolite (Lake County Obsidian) were run in a piston cylinder apparatus and used to determine the isotopic fractionation of magnesium as it diffused from molten basalt to molten rhyolite. The thermal diffusion experiments were also run in a piston cylinder apparatus but with a sample made entirely of molten SUNY MORB displaced from the hotspot of the assembly furnace so that the sample would have a temperature difference of about 100–200 °C from one end to the other. The chemical diffusion experiments showed fractionations of 26Mg/24Mg by as much as 7‰, which resulted in an estimate for the mass dependence of the self-diffusion coefficients of the magnesium isotopes corresponding to D 26 Mg / D 24 Mg = ( 24 / 26 ) β with β = 0.05. The thermal diffusion experiments showed that a temperature difference of about 100 °C resulted in the MgO, CaO, and FeO components of the basalt becoming slightly enriched by about 1 wt% in the colder end while SiO2 was enriched by several wt% in the hotter end. The temperature gradient also fractionated the magnesium isotopes. A temperature difference of about 150 °C produced an 8‰ enrichment of 26Mg/24Mg at the colder end relative to the hotter end. The magnesium isotopic fractionation as a function of temperature in molten basalt corresponds to 3.6 × 10−2‰/°C/amu.
Marked radiographic response of a HER-2-overexpressing biliary cancer to trastuzumab

Trastuzumab is a monoclonal antibody targeting HER-2. HER-2 overexpression has been described in gallbladder cancer and in cholangiocarcinoma. This report describes the first case of a patient with HER-2 overexpressing metastatic gallbladder adenocarcinoma and responding radiographically and biochemically to trastuzumab alone.
Can Interest-Bearing Money Circulate? A Small-Denomination Arkansan Experiment, 1861-63

Legal restrictions theory suggests that dominance of non-interest-bearing currency is possible only because legal impediments prevent financial institutions from offering interest-bearing alternatives. A viable interest-bearing medium must be issued in denominations low enough for day-to-day use, however, and without historical examples of small-denomination interest-bearing issues we cannot properly test whether interest-bearing currency will circulate as legal restrictions theory predicts. Civil War Arkansas offers a rare instance where large quantities of small-denomination interest-bearing money were actually issued, mostly below $5. The results of this Arkansan experiment show that small-denomination interest-bearing issues can indeed function as the primary medium of exchange.
Spectral analysis and harmonizable processes

Spectral estimation for nonstationary harmonizable processes making use of a single realisation of the process as a function of time is considered. Consistent estimators based on smoothed versions of periodogram like forms are effective when the spectral support of the process consists of lines and the spectra are sufficiently smooth on the lines.
Genetic Diversity and Population Structure of Fusicladium effusum on Pecan in the United States

Abstract Fusicladium effusum causes pecan scab, which is the most destructive disease of pecan orchards in the United States. Conidia of the pathogen are spread by rain splash and wind. The fungus is pathogenically diverse; yet there is no information on its genetic diversity or population genetics. Universally primed polymerase chain reaction (UP-PCR) was used to investigate the genetic diversity and population structure on a hierarchical sample of 194 isolates collected from 11 orchard locations from Florida to Texas, consisting of three to four isolates from each of five to six trees at each location. Genetic variation was high throughout the region, with all but nine of the multilocus haplotypes being unique. Nei's average gene diversity ranged from 0.083 for a population from Mississippi to 0.160 for a population from Kansas. An analysis of molecular variance of the hierarchically sampled populations found that the majority of the genetic variability (82.6%) occurred at the scale of the individual tr...
Modeling of building evacuation problems by network flows with side constraints

Abstract In this paper we model building evacuations by network flows with side constraints. Side constraints come from variable arc capacities on some arcs which are functions of flows in incident arcs. In this context we study maximum flow, minimum cost, and minimax objectives. For some special structured networks we propose ‘greedy’ algorithms for solving these problems. For more general network structures, solution procedures are recommended which take advantage of the network structures of the problems.
Multiple-Scattering Phenomena in the Scattering of Light from Randomly Rough Surfaces

The earliest theories of the scattering of electromagnetic waves from randomly rough surfaces were single-scattering theories, such as small-amplitude perturbation theory and the Kirchhoff approximation. The incorporation of multiple scattering into theories of rough surface scattering has led to the prediction of several new effects, which have now been verified experimentally. The new multiple-scattering effects to be discussed in this paper include enhanced backscattering, which is the presence of a well-defined peak in the retroreflection, direction in the angular dependence of the intensity of the diffuse component of the light scattered from a random surface; enhanced transmission, which is the presence of a peak in the antispecular direction in the angular dependence of the intensity of the diffuse component of the light transmitted through a thin metal film with a random surface; satellite peaks that accompany the enhanced backscattering and transmission peaks when light is scattered from, and transmitted through, roug h dielectric or metallic films that support two or more surface or guided waves; changes in the spectrum of light scattered from random surfaces (the Wolf shift); and the scattering of light uniformly within a specified angular range and the absence of scattering outside this range. This paper concludes with some suggestions for directions that research in the area of rough surface scattering could take in the next few years.
The measurement of the intensity ratios of spectral lines with electron multiplier photo-tubes.

Some properties of electron multiplier photo-tubes are investigated. The use of these tubes in quantitative spectrographic analysis is discussed, and a scheme for reducing the effect of the dark current is described. A sharply tuned electronic filter passing only the 120-cycle component of the signal is used to increase the signal to noise ratio. An amplifier circuit for measuring the intensity ratios of spectral lines is shown, and results from the application of this circuit to the analysis of chromium in steel are tabulated.
Spontaneous and Inducible Epidermal Hyperplasia in Transgenic Mice Expressing HIV-1 Nef

The pathophysiological consequence of HIV-1 nef gene expression was investigated in transgenic mice carrying a cDNA for Nef linked to either the HIV-1 LTR or the MMTV LTR. In HIV/Nef transgenic mouse lines, nef expression was detected exclusively in the skin and a significant fraction of HIV/Nef transgenic animals (30-75%, depending on the line) spontaneously developed discrete proliferative skin lesions resembling papillomas that were often accompanied by a progressive ulceration of the epidermal cell layer. Nef protein was detected in the basal cell layer of the epidermis and was elevated in the proliferating epidermis. Epidermal cell proliferation could be induced by UV-C irradiation of HIV/Nef transgenic animals but not control mice. An increase in nef expression in the skin accompanied this proliferation. MMTV/Nef mouse lines expressed Nef RNA and protein in organs typically permissive for MMTV LTR-directed transcription but with no obvious pathological consequence.
Small bowel obstruction: a population-based appraisal.

Background Small bowel obstruction (SBO) is a common reason for surgical consultation, but little is known about the natural history of SBO. We performed a population-based analysis to evaluate SBO frequency, type of operation, and longterm outcomes. Study design Using the California Inpatient File, we identified all patients admitted in 1997 with a diagnosis of SBO. Patients were excluded if they had a diagnosis of bowel obstruction in the previous 6 years (1991 to 1996). Of the remaining cohort, the natural history of SBO over the subsequent 5 years (1998 to 2002) was analyzed. Index hospitalization outcomes (eg, surgical versus nonsurgical management, length of stay, in-hospital mortality), and longterm outcomes, including SBO readmissions and 1-year mortality, were evaluated. Results We identified 32,583 patients with an index admission for SBO in 1997; 24% had surgery during the index admission. The distribution of surgical procedures was: 38% lysis of adhesions, 38% hernia repair, 18% small bowel resection with lysis of adhesions, and 6% small bowel resection with hernia repair. Patients who underwent operations during index admission had longer lengths of stay, lower mortality, fewer SBO readmissions, and longer time to readmission than patients treated nonsurgically. Regardless of treatment during the index admission, 81% of surviving patients had no additional SBO readmissions over the subsequent 5 years. Conclusions Most of the 32,583 patients requiring admission for index SBO in 1997 were treated nonsurgically, and few of these patients were readmitted. This is the first longitudinal population-based analysis of SBO evaluating surgical versus nonsurgical management and outcomes, including mortality and readmissions.
Considerations on the present state of lüders band studies

Abstract The principal features of plastic deformation in materials which form Luders bands are reviewed in terms of dislocation mobility and are related to the static (or near static) stress-strain curve. Delay-time for yielding individual grains or grain orientation is suggested as the principal cause for uneven Luders band fronts. Some details regarding the propagating band front are discussed. The conflicting results in the literature are reviewed and form the basis for suggested additional study. Some examples are the influence of the ratio of specimen size to grain size on the type of band front and its orientation, the strain profile for a propagating front, the stress dependence of the propagation velocity, and the stress dependence of individual dislocations and their effect on the Luders band. Consideration of large numbers of moving dislocations and concentration on their average properties and characteristics have been shown to lead to agreement with experimental work. This approach is believed to be a sound beginning for a better understanding of the Luders band mechanism.
Evidence for neuronal interactions by electrical field effects in the CA3 and dentate regions of rat hippocampal slices

During population spikes in slices of rat hippocampus, transmembrane differential recordings (intracellular minus extracellular) revealed electrical field-effect depolarizations in CA3 pyramidal and dentate granule neurons. The field-effect depolarizations were not seen in single-ended recordings, and were consistently shown to increase neuronal excitability. Therefore, as previously shown for the CA1 area, large population spikes from CA3 pyramidal and dentate granule cells are associated with transmembrane depolarizations that increase neuronal excitability.
Long-term culture and passage of human fetal liver cells that synthesize albumin

Long-term cultures of hepatocytes were established from livers of human fetuses obtained by abortion at 18 to 23 wk of gestation. Cells obtained by collagenase dissociation of liver were maintained in defined serum-free medium on a substratum of positively charged plastic. Under these conditions, the cells divide and form a confluent monolayer. After multiple passages over a period of 3 mo., the cells retained an epithelioid morphology and continued to synthesize and secrete albumin.
Blood pressure aberrations associated with carotid endarterectomy.

This report examines and reviews the frequency, potential causes and management of blood pressure aberrations in 100 consecutive carotid thromboendarterectomies. Reasons for operation and postoperative sequelae included: asymptomatic stenosis, transient ischemic attacks, non-hemispheric symptoms, amaurosis fugax, previous stroke, and evolving stroke. Hypertension (greater than or equal to 100 mmHg diastolic) occurred within 24 hours of operation in 37 instances (37%). Recognized causes included: manifestation of preoperative hypertension (19); carotid sinus denervation or transient mild cerebral edema (16); and massive cerebral edema in the two postoperative strokes of the series. Control of hypertension was most commonly managed by intravenous administration of nitroprusside. Profound immediate hypotension and bradycardia occurred in association with six procedures (6%). Accelerated carotid sinus nerve activity after removal of the noncompliant plaque was the probable cause of this reflex. Management included intravenous administration of parasympatholytic (atropine), and sympathomimetic (epinephrine) drugs. Aberrations of blood pressure, after carotid TEA are common but with proper management do not represent a risk factor for perioperative stroke.
First Records of Merope tuber Newman (Mecoptera: Meropeidae) from Mississippi

ABSTRACT: Merope tuber Newman is reported from Mississippi for the first time, and its known distribution in the state is mapped. The Mississippi localities for M. tuber are among the southernmost for the species, with all of them lying in the southeastern Coastal Plain physiogeographic province where few previous records have been reported.
Toward an inductive understanding of membrane fouling

Abstract A retrospective overview of how module design, hydrodynamics and membrane modification have been used to control concentration polarization is presented. Membrane fouling is arbitrarily divided into transport and solute association. Recent developments of each are discussed. Finally, a prospective view of the research needed to eventually formulate a unified fouling theory is offered.
The contribution of systems science to information systems research

Systems science has been considered the basis for information systems. A wealth of research in information systems in the framework of systems science has produced an astonishing array of theoretical results and empirical insights, and a large suite of tools and methods. This paper aims at reviewing the contribution of systems science to information systems research and tracing how concepts and findings in systems science have been applied, extended and refined in information systems research. As we approach the end of twentieth century, this paper points out that systems science is a necessity to deal with the overwhelming systems complexity in the information era of the next century. Copyright © 2000 John Wiley & Sons, Ltd.
Facing Structural Inequality: Students' Orientation to Oppression and Practice with Oppressed Groups

This study investigated the relationship between social work students' views on oppression and their willingness to serve and advocate for oppressed populations. The sample included students from 3 accredited programs in a southeastern state in the United States, 1 large urban-based public university with BSW and MSW programs, and 2 small, rural, faith-based institutions with BSW programs. A typology of 4 categories was used for the study. Findings have pertinence for the social work profession as it continues to explicate its moral obligation as a service provider and for social work education as it suggests the further development of a curriculum model that relates to the principles of structural justice.